Function of a nebulizer in medical technology

The functional principle of a nebulizer is based on a membrane with micrometer-scale holes. The membrane atomizes medicine by turning them from a liquid into an aerosol. To ensure the resulting aerosol is homogeneous, nebulizers require a continuous actuation. Specially formed piezo discs function as ultrasonic transducers which excite the membrane to perform ultrasonic oscillations in the order of 100 kHz.

Current research shows that smaller sized boreholes lead to the creation of smaller particles of the active agent which can travel further into the lungs achieving higher effectiveness. Thus, the goal should be to miniaturize screen holes as far as possible.

Conventional manufacturing processes reach their limits in this pursuit, as the further reduction of holes becomes either not physically possible or leads to excessively high tool wear. An innovative approach is the use of laser systems with ultrashort pulses, because the shorter the pulses are, the smaller the size of bore hole is which it is able to create. Using the appropriate focusing lens and wavelength of laser radiation, bore hole sizes can be reduced down to a diameter of just five micrometers (5 µm).

Software solutions make adjusting the distribution and shape of bore holes simple, which means one laser processing unit can be used to manufacture an entire range of different products.

The laser drilling process and its influencing factors

Laser drilling describes a targeted removal of material in a predefined workpiece. In classical high-precision laser drilling an ultrashort pulse laser source is utilized in combination with a beam guidance (and shaping) module, a galvanometer scanner with two scanning mirrors and a focusing module in order to create and control the laser beam. Each individual laser pulse is focused onto the workpiece and absorbed by the material. The absorption leads to a high local heating, and this effect is what removes material from the workpiece. The resulting holes are conical in shape, with the entrance showing a larger diameter than the exit, as seen in the diagram below. The aspect ratio – the ratio between the exit diameter and the hole depth – usually peaks at 1:5.

Several parameters can influence the quality and the cycle time of the process. Lasers with short pulse durations in the order of pico- and femtoseconds do not create melt ejections and bulging and have very small heat-affected zones. This enables a more precise and small-scale processing than is possible with other laser systems with longer pulses.

However, the lower heat input typically means many successive pulses are required to create a hole which usually increases processing time.

To nonetheless enable efficient processing, repetition rates of ultrashort pulse laser systems are typically very high. Percussion drilling, the process whereby material is removed by multiple pulses onto the same area, can reach pulse frequencies of up to 500 MHz – 500 million repetitions per second! But even with this technology, repetition rates can not be scaled without restrictions, as the material vapor created during the process itself absorbs laser radiation which takes energy away from the ablation of underlying material.

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The various laser drilling processes explained:

Laser drilling

The specifics of laser drilling nebulizer screens

There are several approaches to laser drilling of nebulizers. Which one is most suitable depends on the customers individual requirements. Besides the desired hole diameter, the material thickness, the type of substrate and the specific shape of the borehole are highly influential factors.

As is the case with many products in the field of medical technology, nebulizers are typically made from a stainless steel. These are processable with ultrashort pulse lasers in the infrared, green and ultraviolet spectra. The choice of wavelength is determined by weighing the respective advantages and drawbacks.

While many longer wavelengths such as those in the infrared spectrum generate a larger spot size, they have the advantage of also having a longer Rayleigh length. This metric refers to the length of the waist in the laser beams cross section around its focal distance and indicates the range of focus deviation which has no effect on the quality of the processing result. Even though a smaller laser focus as those of green and ultraviolet wavelengths delivers an even more precise and small-scale processing, its disadvantages, mainly the reduced ablation volume per time, must be taken into account. The fitting wavelength is therefore not only chosen based on the required quality of the end result but must also correspond to the homogeneity of the workpiece material and the required throughput rates.

Often the desired bore hole diameter is below 3 µm because the aforementioned effect of lower droplet sizes is well-known. The thickness of the foil material usually lies around a few tenths of a micrometer, which means that with an aspect ratio of 1:5 the diameter can only be achieved either at the entry or at the exit. All three wavelengths are suitable for the creation of an exit diameter of this size. Because the entrance hole diameter must be significantly higher due to the conicity of the drill hole, a larger amount of material has to be removed which requires a longer processing time.

To counteract this and achieve a further increase in processing rate it is not sufficient to increase the mean laser power of the system. The increased energy density would surpass the ideal point of the material, which would cause it to overheat and deform. To avoid this effect, a so-called burst mode can be utilized. This method divides the laser power into grouped pulses which are individually modulated to control the emitted energy. The mean power remains the same. The burst method allows an increased processing rate and therefore a reduced cycle time.

After an initial parameter study and cycle time optimization, the team in the Pulsar Photonics laser application center was able to use the aforementioned burst method to create 4,000 conical bores with a diameter of 3.5 µm each in a total laser time of 25 seconds. With the resulting membrane, droplet sizes between 4 and 10 µm could be achieved in a nebulizer application.

The result can be seen below: the complete screen is shown on the left, the center is a microscope image of a grid section showing the high uniformity of the result and the picture on the right shows the diameter of an individual bore.

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Why Laser machinges are especially suited for the processing of medical parts

Laser machine for medical technology

About the author:
Louisa Draack, m. Sc.

Louisa Draack is responsible for technical sales at Pulsar Photonics. She has a masters degree in Industrial Engineering from the FH Aachen and nearly six years of experience in the field of laser processing with short and ultrashort pulse lasers.

Contact Louisa directly

Der Beitrag How ultrashort pulse laser systems innovate and improve the manufacturing of nebulizers in medical technology erschien zuerst auf Pulsar Photonics.

How are requirements for a laser machine written?

Product Requirements Document for a laser machine: a comprehensive guide on the most important contents

Louisa Draack | 6th of February 2024 ᛫ 15 Min.

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The efficient planning and execution of machine purchasing projects in the field of laser technology begin with a clear and detailed set of requirements. Customers often face the challenge of precisely expressing their specific requirements while not yet having a clear idea what the laser process will look like and which machine technology is required. It is possible that there are already very concrete ideas regarding the implementation and application but the specific process sequence and laser technologies are not determined yet.

In this case, the creation of a product requirements document (PRD), which details the application, the desired sequence and the target, is helpful. With this article we aim to provide a comprehensive guide on how to put together such a document which clearly lists what it is you require and which provides sufficient scope for the supplier to find the best solution for your requirements. We will touch on the following aspects:

1. What is a product requirements document and what is it used for?
2. Difference to functional specifications
3. When do such documents have to be created?
4. What belongs in a requirements document?
5. Our most important advice
6. Template for a product requirement document

What is a Product requirements document and what is it used for?

According to DIN 69901-5, the definition of a product requirements document (German: “Lastenheft”) is defined as follows:

„Vom Auftraggeber festgelegte Gesamtheit der Forderungen an die Lieferung und Leistung eines Auftragnehmers innerhalb eines Auftrages“

Translation: “The totality of requirements set by the customer for the delivery and services provided by the contractor within an order”.

Just like the initial feasability tests in the laser application center, the PRD serves to establish early on, which requirements are present and how they can be fulfilled.

Important functions of the PRD therefore are to indicate technical details, targets, the desired timeline and potentially the financial expectations.

Which differences exist between PRD and Technical Specifications?

With the term “technical specifications” we are referring to the German term of “Pflichtenheft”. While the PRD is written by the customer or client, the technical specifications are the contractors or manufacturers answer to these requirements. The contents of the specifications therefore describe, how the desired requirements can be realized and clearly outlines, which points cannot be fulfilled for example due to physical limitations of laser technology.

When does a Product requirements document (for a laser machine project) need to be created?

Ideally, the PRD should be created in the initial phase of a project. The success and lead time of a laser machine project are heavily dependent on how early and accurately the requirements are described. Ideally, the first version should be created before contacting potential suppliers. A requirements analysis should be done in advance in order to determine which wishes and prerequisites are posed to the laser macine by the various stakeholders.

After discussing the desired application with the various laser machine manufacturers, the product requirements document can be adjusted and further specified based on their experience.

It is advantageous for the PRD to be finalized shortly before the assignment because its contents are subject to the negotiations and subsequently form a core component of the contract. Should changes later be desired which carry an impact on pricing, this often entails a follow-up order and an extension of the delivery timeline.

What should the Product requirements document (for a laser machine project) contain?

As always, “as little as possible, as much as necessary” applies. In this context it is important that contents are communicated openly and as accurately as possible to avoid any open questions or misunderstandings on the recipient’s side. For this, the contractor needs to know which targets and results the customer is looking to achieve and which purpose the laser machine is to be purchased. Nonetheless, there has to be sufficient scope for the supplier to implement solutions based on their point of view and prior experience and if possible founded on their existing machine portfolio.

Project overview and definition of targets for a laser machine project

In the introduction, the customer explains, which purpose the project is to serve, what motivation and targets are present and in which context the project is planned.

Requirements for the laser process are briefly summarized to provide an overview for the potential contractor so they may determine, whether or not their existing machine lineup matches the requirements and if the inquiry is relevant to them.

This is also an opportunity to communicate the desired delivery time so the supplier can check, whether or not it is achievable based on their projected capacity utilization.

Project participants and their contact information should also be mentioned at this stage.

In addition, a display of the change history can serve to make the document’s versions traceable.

1. Description of the products to be machined

This chapter will go into greater detail concerning the planned application. It is important to closely and accurately describe the product to be machined and the planned application. Important information for the laser machine manufacturer includes:

• Number of planned products
• Dimensions of the workpieces (width x depth x height) and their shape
• Detailed description of the material with category and number
• Material thickness
• Coatings, platings or other surface treatments
• Machining task (drilling, welding, soldering, cutting etc.)
• Detailed description of the application e.g. by entry and exit diameter, borehole pattern, desired surface finish, machining depth
• Definition of the exact surface at which the machining is to be done
• Required accuracy of the machining
• Reference to technical drawings which are either directly introduced or added as an appendix

Description of the process sequence

Besides the product itself, the process sequence for the machine is also relevant to the first chapter. Most laser machines are manually loaded in their base configuration. Some manufacturers such as Pulsar Photonics provide the possibility of implementing an automated loading and unloading or a robot-based parts handling system within the laser machining enclosure. The customer’s process chain influences how these can be implemented.

Through a description of the machine’s sequence the supplier can understand, which orientation the workpiece has inside the machine, in which position it leaves the machine and if auxiliary components such as trays are available for the transport of the components. Additionally, the supplier learns whether the products are created in lots or as singles.

Detailed description of interfaces and requirements for software and hardware

Interfaces of the machine for the connection to a production data acquisition system or other databases in the customer’s environment should also be mentioned at this stage. This makes sure the contractor has the possibility to design such interfaces and potentially required sensors accordingly.

Many enterprises have precise requirements for the software. As these are highly relevant to the development of the machine’s software, it is essential for the interfaces to be specified in the requirements document. Should internal documents already exist for this purpose, they may be mentioned in the applicable documents and added as an appendix to the PRD. Required user interfaces are also to be mentioned in this section.

What software does a laser machine need?

Frequently the rules apply not just to the software but also to specific hardware componentry or manufacturers thereof. The correspondent information is also relevant for the machine manufacturer in order to verify if and at what cost such provisions are realizable.

There are other factors which can also make specific components necessary. For example, previous testing with other laser manufacturers may have shown that a specific laser model is suitable. The precise designation of this laser source should in this case also be mentioned in the PRD. Further relevant requirements are the planned duration of use, the machine availability and the required cycle time.

In addition to the technically relevant information concerning the project, the planned project plan is decisive for the feasability of a project. This plan should include not only the desired date of delivery but also important milestones such as the date of order, the desired date of the FAT at the contractor’s production site as well as the SAT at the customer’s site where the machine is to be utilized.

Creating a product requirements document for your laser machine: what you shouldn’t forget

A project requirements document (PRD) for a laser machine project serves as the foundation for a successfull collaboration between client and contractor by defining clear and precise requirements. The consideration of all relevant technical, temporal and commercial aspects in the PRD ensures that both parties are operating on a shared basis of understanding. In this regard it is important to strike a balance between a detailed description and sufficient flexibility for the supplier to enable innovative and tailor-made solutions. Finally, a well-designed PRD is not only conducive to an optimization of the project duration and costs but also ensures that the end result fully meets the customer’s expectations. Hence, the creation of this document should be considered an investment into the quality and efficiency of the entire project. By following the recommendations given in this article, it is possible to ensure that the PRD serves as a powerful tool for the achievement of the project’s success.

The points which were not mentioned in this context can not be incorporated into the supplier’s offer and may lead to additional costs and a delay of the delivery.

More on the Author:

Louisa Draack, m. Sc.

Louisa Draack is responsible for the technical sales of laser micromachining units at Pulsar Photonics. She has a master’s degree in Industral Engineering from the FH Aachen and at the time of writing nearly six years of work experience in the area of laser machining with short and ultrashort pulse lasers.

Contact Louisa Draack directly

translated by Joël Hafner

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What are ultrashort pulse lasers?

How ultrashort pulse lasers work, which applications they are found in and which advantages and disadvantages they have

Patrick Gretzki | 27th of May 2024 ᛫ 10 min.

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Ultrashort pulse laser – the scalpel of laser technology

The invention of lasers revolutionized many applications and even made entirely new ones possible. Thanks to their high intensity and power density, lasers can be used to cut, texture, modify, weld and ablate many materials. For melting processes such as laser soldering, laser welding and laser cutting, the laser is focussed to a tiny spot and locally melts the material.

Besides the continuosly operating cw-lasers there is another important category: pulsed laser beam sources. These emit their laser energy in small pulses, the duration of which varies between milliseconds and femtoseconds (0.000 000 000 000 001s) depending on the type of laser utilized. Such laser sources are called short pulse (SP) and ultrashort pulse lasers (USP) respectively. They allow the laser to reach a very high power and intensity at its peak while maintaining a relatively low mean power. A femtosecond laser can reach a momentary output power equivalent to that of a small powerplant (>100 MW) while only drawing a mean power of 10 W, which roughly compares to a small lightbulb.

The physical absorption processes associated with such high intensity radiation can differ greatly compared to longer laser pulses. This means glass, ceramics and polymers can be processed with infrared-USP lasers because they undergo nonlinear absorption processes during the laser-material-interaction.

The following article will show how ultrashort pulse lasers work, which applications they can be found in and which advantages and disadvantages they have.

Material processing with ultrashort pulse lasers

The physical processes involved in the use of USP lasers are fundamentally different from those associated with continuous wave (cw) processing. The radiation of a cw laser is absorbed by the material and converted into heat. The material (most often metals) melts and the surrounding area conducts part of the heat into the rest of the material. This results in a large area being heated and can cause a change in the material’s structure. The affected area is called heat-affected zone (HAZ).

The shorter the pulses become, the higher the resulting local intensity is. The material is heated up faster, which means there is less time for heat to be conducted away. As a result, shorter pulses cause higher maximum temperatures in the material and lead to local vaporization.

If pulse duration is decreased even further, nonlinear effects can start to be seen. Classical absorption effects are no longer applicable. For example: glass is nearly 100 % transparent for green light. A continuous laser beam with a low intensity would barely be absorbed and ultimately have no effect. However, if a critical intensity is exceeded, multi-photon absorption occurs. This means glass is no longer transparent for green light with picosecond-length pulses and can be processed with a USP laser in this range.

In metals, the laser energy is absorbed in a very shallow layer near the surface. USP lasers, due to their high intensity, immediately cause high temperatures far above the evaporation point. The material is not able to transport heat to other areas in such a short time. This leads to a highly localized energy input and causes the evaporated material to be shot out of the ablation zone akin to an explosion. Because the surrounding area doesn’t heat up, the term cold ablation is commonly used to describe this process.

Examples for the use of usp lasers

Thanks to their unique optical properties and interactions with material, USP lasers have a wide range of applications. Their high precision and special abilities have made them an important tool in many industries.

The applications can roughly be categorized as follows:

1. Material processing: USP lasers are utilized for precise material processing applications such as micro processing, fine drilling, engraving, cutting and surface texturing.

2. Medical applications: USP lasers are useful in medical applications such as corrective eye surgery and dermatological therapies.

3. Research and science: USP lasers are deployed in numerous scientific research applications including spectroscopy, microscopy and material characterization.

4. Optical coherence tomography (OCT): USP lasers are used in OCT imaging to create high resolution cross-section images of biological tissue and other materials, which makes them indispensable for medical diagnosis applications.

5. Photovoltaics: USP lasers are used in the solar industry for the precise machining of solar cells and other components to increase their efficiency. Thanks to their high material and depth selectivity they are also useful for the processing of thin films.

6. Nanotechnology: USP lasers are utilized in nanotechnology applications for the manufacturing and characterization of nanostructures, nanoparticles and nanoscale-materials. The particular physical interaction of lasers enables the creation of nanoparticles without the use of any solvents or stabilizers.

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An Overview of various application areas of usp lasers at pulsar photonics:

Application Areas

Summary

Laser processing is revolutionizing the way in which we manufacture products and will have a major impact on the future of manufacturing and machining. Companies which invest in these technologies will be able to raise their competitiveness and keep ahead in a constantly changing global economic environment. Ultrashort pulse (USP) lasers, with their ability to create extremely short laser pulses in the femto- and picosecond range, represent the pinnacle of laser technology. With innovative scaling methods they are able to process surface areas up to the square meter range.

USP lasers can raise the precision of laser processing even further and enable the processing of challenging materials. These properties make them an indispensable tool in many high-tech industries and research areas. With new processes and machines, part costs can be lowered to a competitive level, helping the technology to further penetrate the market.

on the author:
Patrick Gretzki

Patrick Gretzki is head of system technology at Pulsar Photonics. After studying physics at the RWTH, he worked in USP laser material processing for 8 years at Fraunhofer ILT where he, among other things, lead the team for thin film processing.

More information about system technology at Pulsar Photonics can be found here.

Der Beitrag What are ultrashort pulse lasers? erschien zuerst auf Pulsar Photonics.

What determines the cost of a laser machine?

Like in almost all areas of life, when it comes to the cost of laser machines the old adage of “it depends” very much applies.

Simple laser marking machines with a nanosecond laser (power < 30 W, wavelength in the infrared range) are available for less than 100.000 €. This includes for example a laser scanner, a z-axis, a rotational axis and an enclosure with laser protection class 1.

Things are different when looking at the field of high-precision laser micromachining with ultrashort pulse laser beam sources. USP-machines enable the precise machining of workpieces to the nearest micrometer with nearly no thermal influence. Besides a costly femtosecond beam source, these require a precision axis system and a 3D-scanner. These components are complemented by a machine enclosure with laser protection class 1, X-ray protection and auxiliary assemblies. Even a compact – but fully-featured – USP laser machine like the RDX500 by Pulsar Photonics has a starting price of around 475.000 €.

When an even higher level of performance and flexibility are needed, Pulsar USP-machines with an extended configuration are available. For example, some machines enable the use of two working stations per enclosure which can be supplied by one or more high powered USP laser beam sources. In many cases, such high-end machines also integrate measurement technology for the observation and control of process and products. Solutions for automatic loading and unloading are available. One machine suited very well for these extended capabilities is the Pulsar Photonics RDX800.

If a truly fully automated USP production solution is needed, a specially constructed machine is usually necessary. These may come with automatic handling systems and measurement tools for a 100 % verification of products. Such a system also requires a software solution which is individually tailored to the customers use case. Pulsar Photonics serves this market with its fully automated laser machine P1000, which can be freely configured starting from around 1.000.000€.

How can a better understanding for these prices be achieved? The following section should help interested parties to obtain an understanding for the costs and to explain, what the main cost factors are for the individual assemblies of a laser machine.

The most important component assemblies of a laser machine and the most important development aspects for a machine project are:

• Machine technology
• Laser technology
• Measurement technology
• Engineering und other services
• Auxiliary units and automation solutions

The following section provides a rough estimate for each individual aspect using estimates for the categories and wholesale prices of selected components.

Machine Technology

This category includes all the base components without which an operation of the machine – independent of the specific machining job – would not be possible.

1. Machine enclosure with load-bearing machine frame and bed made of granite for high precision and stability
2. Electronic and electrical equipment including control cabinet and emergency stop system
3. XY cross tables or portal systems for workpiece handling and positioning: small format cross tables for positioning in the single-digit micrometer range are available for as little as 30.000 €. However, in large format special machines these solutions can cost several hundred thousand Euros.

Total cost for machine technology: 100.000 €

Laser Technology

The laser technology is in many ways the heart of a laser processing machine. Consequently, the associated components consitute a large part of the total cost of the machine.

1. Laser beam source:
   The choice of laser beam source is central to the manufacturing processes the machine is capable of. Selecting a laser for ablating processes usually involves a trade-off between the required precision (dependent on pulse duration, advantage USP lasers) and productivity (dependent on power, advantage longer pulse lasers). Typical prices for these categories are:
   • Compact fiber lasers for marking systems suitable for production are available starting from 20.000 €, high-powered cw lasers are significantly more expensive at >100.000 €.
   • Compact, open beam USP lasers suitable for production are available starting from 100.000 €. For higher powered units of 100 W and above, shorter pulse durations in the fs range, second wavelengths in the VIS or UV range, costs rise into the range of >200.000€. High powered USP laser beam sources cost several hundred thousand Euros.
2. Processing head:
   The processing optics turn the laser beam into a highly capable machining tool. They determine, which size and shape the beam cross section has in the processing plane and which structure dimensions and depths can be manufactured. Different optics can be utilized depending on the machining process. There are many options for fixed and drilling optics, 2D- and 3D-scanning systems, which are able to move the beam within the scanfield at speed of up to 30 m/s. Even simple marking systems are fitted with galvanometer scanners and focusing optics. Finally, there are significant differences in the price depending on the selected quality of such optics.
3. Beam control and shaping:
   This is necessary to enable the laser beam to travel from its source to the processing head. It includes: fiber guided systems and open beam systems, switching devices, polarizers, expanders and collimators.

Total cost for laser technology: 150.000-200.000 €

Measurement technology

Laser machines utilize various measurement systems both in the preparation of processes (calibration), process and product monitoring as well as machine calibration and diagnosis. Common components and assemblies are:

1. Camera-based measuring technology such as image processing for registration mark recognition or beam diagnosis
2. Condition monitoring systems
3. Powermeter
4. Laser or confocal measuring technology
5. Spectrometer for online process monitoring
6. Inspection systems for 100 % control

The cost for individual sensors typically lies between a few hundred Euros up to the five digit range. The cost for integration, programming and testing usually exceeds the purchase price for the sensors. Pulsar Photonics laser machines for micromachining are developed with a base configuration of measurement technology. This includes camera systems for the precise positioning of workpieces, measurement and remote servicing, condition monitoring systems with a set of sensors, spacing systems and software-based solutions.

Total cost for measurement technology: 50.000-150.000 €

Pulsar Photonics Optical Modules – Overview

Engineering and ancillary services

Simply acquiring subsystems and component parts is not sufficient for the construction of a laser system. It is a complex project which requires clear planning and is realized in many subprojects. These include:

1. Project management and work preparation
2. Mechanical and electrical installation
3. Calibration and parameterization
4. Commissioning of technical processes
5. Design and software development including a wide range of CAD-/CAM-processing and assistance solutions
6. Technical documentation
7. Financing, inventory management
8. Entrepreneurial risk and revenue

Software development may be necessary depending on the complexity of the machine, solutions fit for production are not realistically achievable below 15.000 €. On the other hand, simple marking software solutions are available starting from a few thousand Euros. Customer-specific variants, licenses, CAD-CAM interfaces, ERP or PLS integrations can in some cases require a large subproject in the magnitude of >100.000 €.

Total cost for engineering und ancillary services: >150.000 €

Blog: development of a software solution

Auxiliary units and automation solutions

Laser-based manufacturing processes often require additional systems. The same is true for automatic loading and unloading as well as the handling of workpieces within the machine.

Such systems can include:

1. Handling systems, linear conveyors, sorting switches
2. Roll-to-roll or conveyor systems
3. Robots with effectors
4. Vacuum/negative pressure units, filter systems, air compressors, flushing systems, climatization technology and cooling units

The exact configuration required can differ greatly depending on both product and process. A solid base equipment level of machines for laser micromachining without automation includes filtering and extraction systems, compressed air systems e.g. for the supply of process gas as well as units for cooling of laser beam source, optics, control cabinet and potentially the machine. This hardware is available starting from 50.000 €. If specialized systems are needed, costs can rise significantly.

Total cost for auxiliary units and automation solutions: starting from 50.000 € and as high as >500.000 €

More on the author:

Dr. Marius Gipperich

Dr. Marius Gipperich is key account manager at Pulsar Photonics. After studying materials science and engineering he earned a doctorate at the RWTH Aachen University, researching manufacturing technology and laser material processing. He has collected more than five years of practical experience in the area of laser technology.

Contact Dr. Marius Gipperich directly

Der Beitrag What Does a Laser Machine for Micromachining Cost? erschien zuerst auf Pulsar Photonics.

Basics of Laser Drilling

The principle of laser drilling is based on the targeted removal of material from a workpiece with a defined thickness through the use of laser radiation. Typically, a cylindrical or conical volume is removed from the workpiece, creating a borehole with an entry and an exit. The removal of material is achieved through the exposure to laser radiation. The laser radiation is focused on the workpiece and absorbed therein. Through the absorption and a high local heating, a phase change is created in the material, leading to the creation of a melt and a material vapor. The material vapor creates high pressure, thereby transporting the molten material out of the borehole. Thus, with increasing irradiation time, a borehole is created within the workpiece.

How is the quality of a laser borehole specified?

A laser drilled borehole comprises a number of attributes, which can be characterized by geometrically measurable metrics:

1. Borehole diameter and circularity
   A borehole consists of an entry and an exit, the terminology is analogous to the entry and exit sides of the laser beam. For the typically circular boreholes, these diameters can easily be determined. Because the diameters D between laser entry and exit can differ, entry and exit diameters D_in und D_out are defined.
   The shape of circular boreholes may deviate from the perfect circular shape, for example due to differences in the beam profile from the ideal form or due to the occurence of polarization effects. Thus, a borehole circularity is defined as a measure of form tolerance: circularity = (D_max-D_min) / 2, wherein D_max is the maximum diameter and D_min is the minimum diameter of the borehole.
2. Taper α
   Depending on the drilling method, the walls of the borehole may not be perfectly perpendicular to the entry plane. They may have a slight taper, typically in the range of 80-90°. Due to the deviance of the wall angle from the vertical, the exit diameter is smaller than the entrance diameter.
3. Aspecr ratio A=D_in:t
   The aspect ratio of a borehole is defined by the ratio of its entry diameter D_in and the material thickness t (depth of the borehole). The various laser drilling methods mainly differ in this metric. The aspect ratio of each drilling method is limited by the taper that occurs during drilling. For tapers α < 90°, the sidewalls of the borehole meet at a certain depth. This geometrical effect leads to an aborted drilling process and thus to a limitation in the achievable aspect ratio using percussion drilling. The typical aspect ratios of 1:3-1:5 for percussion drilling correspond to sidewall angles of α = 80-85°.
   
   Synchroton capture of USP percussion drilling in metal (video still, borehole entry on the right, cross section). The maximum aspect ratio is limited to ca. 1:5 by the sidewall angle. (Source: Fraunhofer ILT, Aachen)
4. Tolerances
   When producing a large number of holes, the average hole diameter and the variance of the hole diameters are particularly relevant. The drilling tolerances specify the achievable deviances from a target diameter.
5. Bulges
   Due to the molten materical exiting from the borehole during the laser process, adhesions may occur on either side of the borehole. After the drilling process, these adhesions are visible as bulges. Typically a maximum bulging height is defined, which is determined by the distance between the unprocessed workpiece surface and the highest bulge around the borehole.
6. Heat-affected zone (HAZ)
   Due to the heat input into the workpiece during laser drilling, a change in the structural conditions of the workpiece can occur in the region of the borehole walls. In metals, the heat-affected zone often shows itself through a discoloration around the borehole geometry (tempering color).

The achievable borehole qualities and drilling rates depend chiefly on the drilling method and laser beam source which are utilized. Hence, these are explained further in the following chapters.

Which Laser Drilling Methods Exist?

Single pulse drilling

Single pulse drilling applies a single long duration laser pulse to drill through the material.
The extraction of the melt is usually achieved with the support of a process gas nozzle. Workpieces with a material thickness of up to several millimeters can be drilled with high pulse energies and longer pulse durations (ms to µs range). The drilling time in relation to the material thickness is minimal but the achievable quality is limited due to the melt within the ablation.

Typically achievable quality:

• Borehole diameter: 50-400 µm
• Diameter tolerances: ~5-15 µm
• Achievable aspect ratio: 1:3-1:5
• Bulging: Melt bulges at the entry and exit
• Heat-affected zone: pronounced zone due to the long duration laser pulses utilized in single pulse drilling
• Drilling rates: 20-200 Hz
• Typical application areas: Microsieves, engine blades

Percussion Drilling

During percussion drilling, material is removed step-by-step by repeated irradiation with multiple pulses onto the same area. Depending on the pulse length utilized, borehole depths of up to 10 mm are possible. For both single pulse and percussion drilling, the laser beam is stationary during processing. The borehole diameter correlates with the focus diameter on the workpiece and the pulse energy applied. The drilling time is low and the achievable quality is dependant on the pulse duration. The shorter the pulses, the higher the quality. Especially in the case of short pulse durations (ns-ps-fs), the entry diameter of the borehole is always larger than the exit.

Typically achievable quality:

• Borehole diameter: 1-400 µm
• Diameter tolerances: <1-15 µm
• Achievable aspect ratio: 1:3-1:5
• Bulging: Melt bulges dependant on pulse duration
• Heat-affected zone: dependant on pulse duration
• Drilling rates: 20-3.000 Hz
• Typical application areas: Microsieves, microscopic boreholes in polymers, ultra-small drills

Trepanning

Trepanning utilizes a beam that is guided around a center point (typically the borehole axis) to drill a larger hole. This allows the creation of boreholes much larger than the focus diameter. The enlarged borehole is created through a cutting process.

Typically achievable quality:

• Borehole diameter: 0.1-x mm (limited by processing area)
• Diameter tolerances: <3-10 µm
• Achievable aspect ratio: 1:x-1:2
• Bulging: Melt bulges dependant on pulse duration
• Heat-affected zone: dependant on pulse duration
• Drilling rates: 1-50 Hz
• Typical application areas: Precise cutting of apertures

Helical Drilling

To overcome the issue of non-vertical borehole walls and the limitation this creates in terms of achievable depth, another process called helical drilling has established itself as a solution, especially when using short pulse durations.

In helical drilling, the laser beam is guided onto the workpiece in a circular motion using a motorized helical drilling optic. With multiple passes, the circular material ablation creates a borehole. A slight angle of the laser beam relative to the vertical axis allows the creation of a borehole with α=90° and makes high aspect ratios of up to 1:20 achievable . These high aspect ratios are in part possible thanks to reflections of the laser radiation at the bore walls, which enable a propagation of the laser beam through to the exit diameter.

USP helical drilling thus enables a laser drilling process with vertical bore walls, low ellipticity and smooth walls. The method allows boreholes with extremely high quality, drilling times range from 100 ms up to a few seconds.

Typically achievable quality:

• Borehole diameter: 30-300 µm
• Diameter tolerances: 1-3 µm
• Achievable aspect ratio: 1:20
• Bulging: no bulging when utilizing USP-lasers
• Heat-affected zone: very low
• Drilling rates: 0.1-5 Hz
• Typical application areas: Injection nozzles, other nozzles

Deep hole drilling with Waterjet-guided laser Cutting

The waterjet-guided method allows for the creation of deep boreholes with extreme aspect ratios (structure width/material thickness), both with short and long pulse laser radiation. The laser beam is optically coupled to a thin coaxial waterjet inside a specialized nozzle. The water acts as a light conductor and guides the laserbeam through the workpiece, maintaining its focus. This process enables the creation of shaped holes and cuts with aspect ratios of up to 1:400.

Typically achievable quality:

• Borehole diameter: 100-1000 µm
• Diameter tolerances: 10-20 µm
• Achievable aspect ratio: 1:400
• Bulging: low melt bulging
• Heat-affected zone: minimal heat-affected zone thanks to water cooling
• Drilling rates: 0.01-1 Hz
• Typical application areas: engine blades, deep boreholes

On the author:

Dr. sTEPHAN eIFEL

Dr. Stephan Eifel is one of the three managing partners of Pulsar Photonics and a laser enthusiast! In the year 2013, during his scholarly work at the Fraunhofer Institut for Laser Technology, he founded Pulsar Photonics together with his fellow researchers Dr. Jens Holtkamp and Dr. Joachim Ryll.

Der Beitrag What is Laser Drilling? erschien zuerst auf Pulsar Photonics.

Laser drilling redefined: Pulsar Photonics’ RDX2Drill works in single-pulse mode

Drilling thick metal sheets precisely and efficiently

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Pulsar Photonics uses the single-pulse drilling process in the new RDX2Drill series to precisely and efficiently “shoot” holes in thick metal sheets. The plus: Sieves or filters made of high-strength materials and thick sheets can now also be micro-drilled with the laser. Such filters can therefore withstand high pressures or the strongest mechanical stresses.

Pulsar Photonics GmbH from Aachen deliberately uses single-pulse drilling for its RDX2Drill machine series. “These are high-energy pulses that do not work in an ultrashort pulse cycle, as is usually the case, but last microseconds or even milliseconds,” explains Dr. Marius Gipperich, Manager Key Account & Business Development. “They therefore have so much energy that each pulse basically shoots a hole in the material.”

RDX2Drill – Laser Lasermachine

If the laser “shoots” 50 holes per second …

Although the process does not have as many pulses per time as the ultrashort pulse laser, the speed is still impressive. For example, one user is currently running a process with 1.5 millimeter thick stainless steel sheet metal in which the RDX2Drill is laser drilling 50 holes per second. In his opinion, this value can be increased even further. The new system can therefore drill up to hundreds of thousands of holes with diameters of 100 to 400 micrometers in metallic materials with a material thickness of 0.5 to 1.5 mm with the utmost precision. Gipperich: “The efficiency and costs, primarily in the production of holes with diameters of around 200 micrometers, clearly speak for our laser drilling.”

A QCW (Quasi Continuous Wave) fiber laser with an output of several kilowatts perforates workpieces with a wavelength of 1060 to 1080 nm (infrared). One of the strengths is the combination of flexible system technology from the modular system with individual software. Gipperich: “One of our unique selling points is the Photonic Elements machine control system, which we have developed, designed and perfected exclusively for laser processing.”

Special software only for laser processing

Photonic Elements enables precise control and optimized process management, increasing the precision and efficiency of laser drilling. The digital control also allows you to switch quickly and easily between different component variants. This is a particular advantage for sieves and filters with high material thicknesses, which are subject to high pressure loads and require precise, customer-specific drilling patterns. Introducing this process was a challenge, emphasizes Gipperich: “With this melt-based process, we have to remove several hundred grams of melt per component. For this reason, the systems are equipped with an enclosure that surrounds the process area. The majority of the melt is extracted, collected and disposed of safely.

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Automatic focus tracking instead of component distortion

The process generates a lot of heat in the component, which leads to distortion. Automatic focus tracking, which compensates for component deformations caused by thermal stress, for example, has proven itself as a countermeasure. With the purchase, the user is entering a complex technology that requires special training from the Aachen-based company: Nevertheless, it is worth getting started because the new RDX2Drill series is suitable for many applications: for example, sieves and filters for waste water filtration, hydrogen production, recycling and energy generation.

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Pulsar Photonics

Pulsar Photonics GmbH is an innovative high-tech company in the field of laser technology. The company’s range of services includes the laser application center, system engineering with software development and the laser system technology division.

Since its foundation, the company has been working intensively on scaling approaches for production. For customers, it offers exclusive services ranging from professional application development and ramp-up to the construction of automated production machines with service and know-how transfer. Pulsar Photonics continuously invests in its own production capacities for single part and series production with (ultra) short pulse lasers. The core processes are structuring, drilling and precision cutting.

The company was founded in 2013 as a spin-off of the Fraunhofer ILT in Aachen, has its headquarters in Aachen and operates three production plants. Pulsar has been part of the Schunk Group since 2021 and currently has around 100 employees.

Press Contact

Sonja Wichert
E-Mail: wichert@pulsar-photonics.de
Pulsar Photonics GmbH
Alte Würselener Str. 13, 52080 Aachen
Website: www.pulsar-photonics.de

Der Beitrag Laser drilling redefined: Pulsar Photonics’ RDX2Drill works in single-pulse mode erschien zuerst auf Pulsar Photonics.

Cool Cut: Laser and water for precise ceramic processing

Pulsar Photonics RDX1000 LWJ: Brittle-hard materials under control with the laser-water process

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With the RDX1000 LWJ, Pulsar Photonics is launching a new generation of systems for precision machining. The combination of classic laser processing and laser waterjet technology from Synova enables high-precision cuts in ceramics, silicon carbide and hard metals – without thermal damage or mechanical wear.

“As part of the Schunk Group, we are pursuing the goal of further developing innovative manufacturing technologies for brittle-hard materials,” explains Dr. Stephan Eifel, Managing Director of Pulsar Photonics GmbH, Aachen. “With the RDX1000 LWJ, we are now enabling processing that was previously only possible with elaborate mechanical processes or complex post-processing steps.”

The RDX1000 LWJ is based on Synova’s patented Laser MicroJet process, which guides a laser beam over several millimetres in a fine water jet. As a result, the beam guidance remains stable while the material is cooled at the same time. “This combination gives us processing depths and precision that would not be achievable with conventional laser processes,” summarizes Eifel.

RDX1000 LWJ – Laser Machine

Deep cuts in thick materials

In addition, typical laser ablation processes for cutting often only achieve an aspect ratio of 1:3 to 1:5. This means that a kerf one hundred micrometers wide only reaches up to 500 micrometers deep into the material. Wider kerfs must be selected for deeper cuts, which leads to longer process times. With the RDX1000 LWJ, however, aspect ratios of up to 1:100 can be achieved – a dimension that was previously only possible with complex mechanical processes. “For example, we can drill or cut a structure just 100 micrometres wide into a 10 millimetre thick ceramic – this opens up completely new possibilities in production,” emphasizes the expert.

Another unique selling point is the combination of two processing stations: In addition to water-guided laser processing, a separate dry processing station is also available. “This gives our customers maximum flexibility,” says Dr. Eifel. “They can use both classic laser processes and the laser waterjet for particularly demanding machining tasks.”

This versatility makes it possible to implement hybrid processing strategies. For example, materials can first be structured and then precisely drilled through with the laser waterjet – an advantage in the production of complex functional components.

Testing in the Schunk MACHLab

The MACHLab, the Schunk’s group-wide application center, tests the technology under real production conditions. “Here we create a development environment in which new applications can be transferred directly to production,” emphasizes Dr. Eifel. Schunk sees great potential in the processing of 3D-printed silicon carbide in particular, as well as in the production of high-precision components for microelectronics.

The machining of technical ceramics, for example, repeatedly presents manufacturers with challenges when it comes to delicate structures. Due to their high hardness and brittleness, these materials tend to form microcracks or burrs when machined using conventional methods. “The RDX1000 LWJ enables extremely precise cutting and drilling without thermal damage or mechanical abrasion,” explains Dr. Eifel.

Precise cooling channels and fine micro-holes

The aerospace industry is also increasingly using brittle-hard high-performance materials, for example for engine blades or heat protection tiles. The RDX1000 LWJ enables deeper and more precise cooling channels in heat-resistant materials without compromising their structure. “This reduces component weights and increases efficiency – a real game changer for this industry,” explains Eifel. “We are only at the beginning of a paradigm shift in the laser material processing of ceramic components,” Dr. Eifel is convinced. “By working with Synova and using it in the Schunk Group’s MACHLab, we are consistently driving forward the industrial application of laser waterjet technology.”

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Pulsar Photonics

Pulsar Photonics GmbH is an innovative high-tech company in the field of laser technology. The company’s range of services includes laser process technology, machine manufacturing with software development and the laser systems technology division.

Since its foundation, the company has been working intensively on scaling approaches for production. For customers, the company offers exclusive services ranging from professional application development and ramp-up to the construction of automated production machines with service and know-how transfer. Pulsar Photonics is continuously investing in its own production capacities for single part and series production with (ultra) short pulse lasers. The core processes are structuring, drilling and precision cutting.

Pulsar Photonics GmbH is headquartered in Aachen and operates two production plants there. The company was founded in 2013 as a spin-off of the Fraunhofer ILT in Aachen and was financed in its growth phase by the Hightech Gründerfonds HTGF, Bonn. Pulsar Photonics has been part of the Schunk Group since 2021.

With more than 100 employees today, the fast-growing and profitable company is a German SME and part of the LaserRegionAachen structural change initiative.

Synova S.A.

Synova S.A., headquartered in Duillier, Switzerland, has been a pioneer in advanced laser cutting systems for over 25 years. The integration of our innovative Laser MicroJet technology, which combines a laser in a hair-thin water jet, into a robust industrial CNC platform, offers great results for the machining of a wide range of materials. Our unique technology provides customers significant efficiency improvements, unparalleled cutting quality, and enhanced precision across various applications. Visit our website to learn more www.synova.ch.

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Press Contact
Sonja Wichert
Phone: +49 (0) 2405 49 504 – 36
E-Mail: info@pulsar-photonics.de
Pulsar Photonics GmbH
Alte Würselener Str. 13, 52080 Aachen
Website: www.pulsar-photonics.de/en

Der Beitrag Cool Cut: Laser and water for precise ceramic processing erschien zuerst auf Pulsar Photonics.

1000 laser beams in parallel swing

Aachen, June 19, 2024

Pulsar Photonics GmbH from Aachen is continuing to develop laser micromachining: a system with an ultrashort pulse laser is currently being built that structures surfaces of more than ten square meters precisely and sustainably. In future, the scaling concept will even allow surfaces ten times larger to be processed using thousands of laser beams. “We’re not the only ones doing large-area laser micromachining,” explains Dr. Joachim Ryll, Managing Director of Pulsar Photonics. “But our approach is unique. Our aim is to structure surfaces in parallel and individually on a single large system.”

This is particularly relevant as the demand for surface structuring without chemical substances is increasing. This is due to increasing environmental restrictions and regulations that limit the use of chemicals. The ultrashort pulse laser (USP laser) offers a sustainable alternative for this. Until now, USP lasers have mainly been used for small-area applications, but there are already solutions that can effectively process surfaces in the square meter range for flat glass, film substrates and embossing rollers.

Up to five workstations in parallel use

The Aachen-based company relies on a special kind of bridge technology for its RDX2800 gantry system: its machine modules are based on a modular system. Each module can precisely process flat components of up to 2.5 x 1.5 meters with USP lasers. Pulsar lines up several modules in a row and can therefore process larger components that are well over 10 m². Within a machine module, several work stations enable both individualized single-beam and multi-beam processing. A total of more than a thousand laser beams can be used simultaneously. In the EU infrastructure project NextGenBat, the Aachen-based company has already shown how the productivity of laser micromachining can be significantly increased. They developed a roll-to-roll system that dries and structures electrodes for lithium-ion cells. The “MultiBeamMultiScanner” optics split the laser power into several partial beams in order to work more efficiently. The company is now taking the first step towards a modular system with a pilot customer. “The industrial implementation on a large scale is the special attraction,” explains Dr. Ryll. A system is planned for the pilot customer in which several interlinked workstations will precisely roughen and structure the surface of flat components measuring over ten square meters using USP lasers and multi-beam technology with several partial beams.

Extremely careful calibration of the free jet process

Laser micromachining stands and falls with the beam guidance from the laser to the workpiece. Dr. Ryll: “As we are dealing with high-energy radiation, guidance through fibres is currently out of the question due to the associated losses. That’s why we use the free beam to overcome this challenge.” However, because even minor angular errors in laser processing can lead to significant structural deviations, extremely precise adjustment and calibration of the scanning and coordinate devices is required. The precision of laser micromachining also depends largely on well thought-out data and heat management. It is crucial that the workstations are correctly supplied with data in real time: Real-time online monitoring is therefore central to the operation of the system. “This monitoring enables us to continuously track how and when the machine is working with certain files,” explains Dr. Ryll.

Demonstrator plate (1000 mm x 1000 mm) for large-area USP laser processing with sample structures for functional surfaces and deep engravings. © Pulsar Photonics GmbH.

Wide range of applications in XXL format

Building on this advanced development, the Fraunhofer ILT spin-off is already working in dimensions that significantly exceed ten square meters. According to the Managing Director, the aim is to develop technologies that can be used to process areas of 100 square meters or more. The demand for potential applications for laser micromachining in XXL format is high: according to Dr. Ryll, it ranges from the preparation of surfaces for bonding and coating processes to large-area tool processing and micro- and nanostructuring through to the production of large-format screens.

Dr. Joachim Ryll, Managing Director of Pulsar Photonics GmbH, is focusing on a completely new approach to large-area laser micromachining: “The aim is to develop technologies that can be used to process areas of 100 square meters or even more.”

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Examples of applications are:

• Large-scale roughening and modification of surfaces in preparation for bonding and coating processes
• Large-area tool processing, e.g. for forming and shaping tools, also for the paper, film or plastics processing industry
• Large-scale micro- and nanostructuring for the production of functional surfaces
• Production of large-format screens for process engineering applications
  

More info RDX2800

Pulsar Photonics

Pulsar Photonics GmbH is an innovative high-tech company in the field of laser technology. The company’s range of services includes laser process technology, plant engineering with software development and the laser systems technology division.

Since its foundation, the company has been working intensively on scaling approaches for production. For customers, the company offers exclusive services ranging from professional application development and ramp-up to the construction of automatic production machines with service and know-how transfer. Pulsar Photonics is continuously investing in its own production capacities for single part and series production with (ultra) short pulse lasers. Core processes are structuring, drilling and precision cutting.

Pulsar Photonics GmbH has its headquarters in Aachen. The company was founded in 2013 as a spin-off of the Fraunhofer ILT in Aachen and was financed in its growth phase by the Hightech Gründerfonds HTGF, Bonn. Pulsar Photonics has been part of the Schunk Group since 2021.

With more than 90 employees today, the fast-growing and profitable company is a German SME and part of the LaserRegionAachen structural change initiative.

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Pictures of the Press Release (Download)

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How do you process technical ceramics with lasers?

The various processing methods for technical ceramics and their challenges

Philip Oster | 08. January 2024 ᛫ 10 Min.

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What is technical ceramics?

Technical ceramics, also known as industrial ceramics, are worlds away from classic utility ceramics with their cups, bowls and vases. This starts with the manufacturing process: the greater purity of the raw materials and the narrower tolerance in terms of grain size allow ceramic materials to be created during sintering that have very special properties and can be used in a wide range of applications.

This article provides a brief introduction to the properties and areas of application of technical ceramics, outlines the challenges and methods of processing and highlights the possibilities of laser processing, in particular USP laser processing.

Properties and applications of technical ceramics

The properties of technical ceramics are inextricably linked to their production: The type and preparation of the starting powder, the shaping and the firing process ultimately determine the specific characteristics of the resulting material.

One example of a technical ceramic material is reaction-bonded, silicon-infiltrated silicon carbide, SiSiC: it is manufactured from silicon powder and carbon powder by reaction firing under inert gas. In comparison to the usual shrinkage during sintering, large complex structures are created. Like silicon carbide (SiC), these structures are characterized by high hardness, thermal conductivity, chemical resistance and corrosion resistance. In addition, the silicon embedded in the pores improves the oxidation capacity. SiSiC materials are therefore particularly suitable as heating elements or construction parts in furnaces.

These are some of the properties that are generally found in ceramic materials: They have great hardness and heat resistance and have low thermal expansion. They can conduct heat and are resistant to corrosion in chemical applications. They are also biocompatible, meaning they have no negative impact on living organisms in their environment. Ceramics that are not electrically conductive are ideal as insulating materials.

With these properties, industrial ceramics can be used in a wide range of applications. They can be found in a wide range of applications across all industries, from semiconductor production and automotive applications to high-frequency circuits. The high hardness combined with biocompatibility is a great advantage in medical technology and the heat resistance of hard ceramics makes them suitable for use in high-temperature applications as well as bearing and sealing technology.

Processing technical ceramics and its challenges

The manufacturing processes of technical ceramics only allow for rough shaping. Small cavities, micrometer-sized structures or drill holes can hardly be realized. Technical ceramics must therefore be processed before they can be used in a wide variety of applications. One of the material’s outstanding properties poses a challenge here: its great hardness. Technical ceramics are hard and brittle, which means they tend to break and have a low fracture toughness. Various methods and tools are used in an attempt to meet this challenge when machining technical ceramics.

Processing methods – overview

MECHANICAL PROCESSING

Diamond tools are used for the mechanical processing of ceramics. Only they are hard enough to cut, drill or structure the ceramic material using a milling cutter. However, there is still a risk of the material breaking or requiring additional reworking due to mechanical stress during processing. And although diamond is very wear-resistant, diamond tools also need to be replaced regularly, which is an additional cost factor.

ALTERNATIVE PROCESSING METHODS

Neben den rein mechanischen Methoden finden sich einige Alternativen zur Bearbeitung der technischen Keramik:

• Abrasive water jetting (AWJ) cuts the ceramic material with a jet of water to which a hard powdery material – the abrasive – is added.
• Electrical discharge machining (EDM) generates heat through an electric current and thus removes material. This method can only be used with conductive ceramics.
• Laser-assisted machining (LAM) supports conventional mechanical processes such as milling, grinding or lapping with targeted laser radiation. The ceramic material is heated locally, which makes machining easier.

LASER PROCESSING

Laser technology is playing an increasingly important role in the drilling, cutting and structuring of technical ceramics. The hardness of the material poses no problem for the laser. In addition, the actual tool – the laser beam – is wear-free, which minimizes or completely eliminates costs for downtimes and tool changes. Laser processing thus opens up numerous possibilities for product refinement, improves the technical usability of the ceramic material and opens up new applications. Which processing is possible depends on the type of laser. Here is an overview:

• CW (continuous wave) lasers are characterized by continuous, constant laser radiation over time, which causes a lot of heat to hit the material.
  Too much heat can cause the material to explode. For this reason, delicate, small-scale processing is not possible and CW lasers are not generally used for drilling.
• Short-pulse lasers (KP) emit laser pulses at nanosecond intervals and, like QCW lasers, KP lasers can also make straight cuts through technical ceramics. They are also suitable for laser drill holes from a diameter of 1 mm and for coarse structuring of the material.
• Ultra-short pulse lasers (USP) emit laser pulses at picosecond and femtosecond intervals. With this combination of high heat exposure and short duration, the USP laser enables delicate processing of ceramic materials and opens up new ways of drilling, cutting and structuring technical ceramics.

USP laser processing – methods, possibilities and costs

Processing with the USP laser is characterized by a very high light intensity in the laser focus. This causes the ceramic material to vaporize without the typical melting phase. As a result, there is no melt or processing residue on the material, it remains clean and does not need to be reworked. At the same time, this type of processing places a low thermal load on surrounding areas, with the result that the ceramic material does not break.

Compared to a mechanical milling machine, for example, the USP laser loses out in terms of speed: the USP laser processes the material more slowly. However, it can be operated at a very high average power due to its high thermal resistance. This increases the ablation volume, which in turn partially compensates for the lack of speed of the USP laser.

The costs of USP laser processing are generally dependent on the duration of the laser processing. This can be broken down as follows for the individual processing types: Drilling costs increase with increasing material thickness and number of holes. Cutting becomes more expensive with increasing material thickness and cutting length. For structuring, the higher the material volume, the higher the costs. The special properties of USP laser processing come into their own when creating small and extremely small structures and when processing ceramic materials with micrometer precision – the USP laser works its way forward micrometer by micrometer, so to speak, until the target depth is reached. Only with the USP laser is it possible to create free contours and round cutting and drilling.

• Micro-drilling is only possible with a USP laser. Nanosecond lasers can only be used from a diameter of 1 mm, drilling with CW lasers is very unusual.

• Helical drilling with special optics is possible from a diameter of 70 micrometers and can be infinitely enlarged. This processing creates a cylindrical hole and thus differs from the conical paths of all other drilling methods. The aspect ratio is typically AV 1:15.

• Cutting with QCW and KP lasers is only possible for straight cuts. Round and free shapes require a UKP laser. The aspect ratio is 1:3.

• Microstructures and their micrometer precision are only possible with a USP laser. The precision is found both in the plane and in the z-depth, the aspect ratio is 1:3.

Find out more about laser processing of technical ceramics

More info about the author:

Philip Oster, M. Sc.

Philip Oster is Head of the Laser Application Center at Pulsar Photonics. He has a degree in Applied Physics with a focus on laser technology and over 10 years of practical and managerial project experience.

Der Beitrag How do you process technical ceramics with lasers? erschien zuerst auf Pulsar Photonics.

Pulsar Photonics, machine builder and contract manufacturer in the field of laser technology, is taking a significant step in its corporate development next year. With the infrastructure partner Walbert-Schmitz GmbH & Co. KG and a seven-figure investment, the ground-breaking ceremony for the new headquarters in Aachen has now taken place. This decision not only reflects practical growth, but will also further improve the company’s visibility.

From Fraunhofer ILT to future location: development since 2013

Pulsar’s history began in 2013 on the premises of the Fraunhofer Institute for Laser Technology ILT. In 2015, the company moved to the Technologiepark Herzogenrath (TPH), which became the headquarters from then on. As the number of employees grew, new premises were needed – initially in the TPH. Then from 2022 with another manufacturing hall in Aachen: Ideal conditions for the laser machine construction team.

Manufacturing hall 3 for system technology followed a year later. “With Hall 4, which we will be moving into this year, our workspace now extends to more than 4,500 impressive square meters,” summarizes Dr. Joachim Ryll, one of the three Managing Directors.

10 years after the company was founded, the next major milestone is now set to follow: the business divisions will be brought together at one location one after the other and the headquarters will also be relocated from Herzogenrath to Aachen. The ground-breaking ceremony for this final step took place a few weeks ago.

Creating an attractive workspace

The new location at the Verlautenheide highway exit not only offers the urgently needed reserves for future growth, but also makes it possible for the first time to create space before acute demand arises.

Another decisive aspect, however, is the consolidation of the business divisions at a joint location. No longer separated locally, the interaction between the various divisions will be strengthened. “This spatial proximity should not only shorten transport routes again, but above all intensify cooperation and the exchange of information between the teams,” the management agrees.

“We not only want to be attractive for staff due to the convenient connections, but also take into account all aspects of a workspace in a modern and pleasant atmosphere,” says Ryll. “From home office to office home” is how Burkhardt Mohns, Managing Partner at W-S, likes to describe this development.

Space for sustainable growth prospects

Pulsar Photonics wants to grow spatially, but also create the basis for a modern and future-oriented working environment. The focus on modern working methods and technologies should make it possible to operate more flexibly and efficiently. This includes not only the design of the workspaces, but also the technological and digital infrastructure such as the expansion of fiber optic networks, the networking between the teams or the implementation of modern in-house IT.

At the same time, measures are planned to pave the way for a sustainable and energy-efficient orientation of the company. This includes the availability of space for the use of renewable energy sources such as solar or the provision of larger parking spaces for bicycles and electric cars. The planned building is a so-called KfW building and therefore meets certain energy standards. These include the use of CO2-reduced building components, a green roof, heating by heat pump and photovoltaic systems to secure the power supply. Prospects that are due in particular to the infrastructure partner. However, the current operation is also ensured by the real availability of larger electrical connection cross-sections for machine operation.

Improved visibility in a favorable position

The excellent highway connection at Aachener Kreuz not only makes mobility easier for employees, it also offers an important logistical advantage for customers, suppliers and service providers. “Our aim is to become even more visible as a laser company in the region,” says Ryll. “To this end, the new headquarters will be designed to be representative.”

Contribution to positive structural change

“We are delighted to be able to make a contribution to positive structural change with this location decision. Not least by creating jobs, the alliance partners in the laser region are helping to shape the future prospects in Aachen and the surrounding area in a sustainable way,” explains Ryll.

A seven-figure investment is being made to construct the new building, which will later be used primarily for assembly and production. With a work and manufacturing area of around 1,600 square meters, the first construction phase of the new building should be completed and ready to move into by the end of 2024. The three-member management team is looking positively to the next 10 years. “With the additional building, we want to create a platform that takes our corporate culture, creativity and regional collaboration to a new level. Healthy, profitable and sustainable growth is important to us – both in the past and today,” says Joachim Ryll.

Pulsar Photonics

Pulsar Photonics GmbH is an innovative high-tech company in the field of laser technology. The company’s range of services includes laser process technology, machine manufacturing with software development and the laser systems technology division.

Since its foundation, the company has been working intensively on scaling approaches for production. For customers, the company offers exclusive services ranging from professional application development and ramp-up to the construction of automatic production machines with service and know-how transfer. Pulsar Photonics is continuously investing in its own production capacities for single part and series production with (ultra) short pulse lasers. The core processes are structuring, drilling and precision cutting.

Pulsar Photonics GmbH has its headquarters in Aachen-Herzogenrath and operates two further manufacturing halls in Aachen-Verlautenheide. The company was founded in 2013 as a spin-off of the Fraunhofer ILT in Aachen and was financed in its growth phase by the Hightech Gründerfonds HTGF, Bonn. Pulsar Photonics has been part of the Schunk Group since 2021.

With more than 90 employees today, the fast-growing and profitable company is a German SME and part of the LaserRegionAachen structural change initiative.

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Der Beitrag New chapter at Pulsar Photonics: ground-breaking ceremony for the new headquarters in Aachen erschien zuerst auf Pulsar Photonics.