Laser Micromachining Services Utilizing Infrared and UV Lasers

Developments in pulsed laser technology have made it possible to use micromachining on tiny devices, such as medical devices, with minimal damage to the surrounding material. With the rapid scientific advances in the laser field, A-Laser’s micromachining expertise is essential.

A-Laser specializes in the complex process of utilizing both infrared and UV lasers. Infrared lasers focus a beam on the surface of a material, which then converts to heat and melts the material.  Ultra-violet lasers operate using ablation, which instantly removes materials by breaking the bonds directly. This process evaporates the material instantly with minimal heat effects.  High-precision micromachining requires exact harmonization. Both the laser pulse train and a linear stage must be synchronized to ensure a precise control that is on target.

Laser Micromachining Services:

Laser depaneling

rigid and flex boards

Laser cutting

using customer provided designs

Laser drilling

Microvias and micro holes

Laser processing

Tubes, reels, and flat material stocks

Laser micromachining is the use of lasers for cutting, drilling, welding, or to make other material modifications to achieve features on the single or double-digit micrometer level. Laser machining can be done in three ways: direct writing, mask projection, and interference.

Direct writing is done by focusing the laser beam on the substrate. The desired pattern is then produced either by translating the laser beam or the substrate. Important considerations are working distance, the size of the focal point, and the depth of focus.

Mass projection involves the use of a laser to illuminate and then project a feature on the substrate in a much smaller size. This technique allows fabrication of large patterns on the substrate using a low number of laser pulses.

Interference is achieved by splitting the primary laser beam into two beams, then superimposing them to create an interference pattern.

Pulsed vs Continuous Wave Mode

laser waves

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A vital part of laser micromachining is minimizing heat transfer to the area of the substrate that is adjacent to the micromachining material. Lasers can function in either the pulsed mode or continuous wave mode.

In the continuous wave mode, laser output is essentially constant with time.

In the pulsed mode, the laser output is concentrated in small pulses. Pulsed mode laser devices provide pulses with sufficient energy for micromachining a given material and small pulse durations. The small pulse duration minimizes heat flow to surrounding material.The length of the laser pulse can vary from milliseconds to femtoseconds.

The peak power is correlated to the duration of the laser pulse, so pulsed lasers can attain much higher peak values than continuous wave.

Laser machining primarily involves interaction that leads to ablation of the substrate material. The energy transfer that occurs is dependent on both material and laser properties. The laser properties that are factors include peak power, pulse width, and emission wavelength. Material considerations are whether or not it can absorb laser energy either by thermal and/or photochemical processes.

Why do pulse widths matter?

A-Laser cuts are clean and precise.  The demand to make smaller, faster, lighter and lower-cost devices requires lasers that meet the challenge.  Pulsed lasers are used for precision micromachining of various materials. The ability to produce varied pulse widths is key to precision, throughput, quality, and cost-effectiveness.

Nanosecond lasers use the same average power with a higher rate of material removal and therefore higher throughput than picosecond and femtosecond lasers.  

Picosecond and femtosecond lasers melt material in order to remove it, through the processes of evaporation and molten material expulsion.  This melting effects the precision and quality of machining since the material removed clings to the edges and re-solidifies.

micromachining pulse widths

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Nanosecond vs. Picosecond Machining:

Power vs. Precision

Reduced melting of steel occurs when processed using picosecond laser pulses as opposed to nanosecond.  Also, the material removal threshold, which is energy per area, is much lower for material removal with a picosecond laser pulse than a nanosecond pulse.

Clearly, it is beneficial to have the higher peak power achieved with the shorter picosecond pulse because that initiates material removal at a much lower energy per pulse.  However, a majority of cutting and drilling processes are performed at a higher energy level than the material threshold. This, then, allows for a higher throughput with the nanosecond laser at the same average power level.  When higher quality is the most important requirement of the project, a picosecond laser would be the choice.

Picosecond vs. Femtosecond:

Power vs. Price

When an even shorter width is needed, considerations such as material used, quality requirements and pricing become determinates.  A femtosecond laser may provide unsurpassed quality, but the higher cost is a serious factor.

Both picosecond and femtosecond lasers provide high power and similar low material removal thresholds, with femtoseconds having the lowest removal threshold for many materials.  However, at the most common levels higher than the threshold, the material removal rate is material dependent.

Laser Ablation

Laser machining primarily involves interaction that leads to ablation of the substrate material. The energy transfer that occurs is dependent on both material and laser properties. The laser properties that are factors include peak power, pulse width, and emission wavelength. Material considerations are whether or not it can absorb laser energy either by thermal and/or photochemical processes.

In thermal ablation, absorption of laser energy causes rapid heating. This increase in temperature results in melting and/or vaporization of the material. Thermal ablation may cause a large heat-affected zone, and is commonly observed with long wavelength and continuous wave lasers.

When the laser photon energy is greater than the bond energy of the substrate material, photochemical processes are observed. This occurs as the substrate material is vaporized because of bond disassociation that is induced by photon absorption.

If the substrate material is able to absorb higher amounts of laser energy, the laser ablation process is more efficient. Materials that are micromachined using shorter (femtosecond) laser pulses exhibit fewer thermal effects than those processed with longer pulse lasers.

How Will Laser Micromachining Services Advance in the Future?

2.5D Surface Shaping

Thin-film Patterning & De-coating

High-Density Drilling

Scribing, Grooving, and Dicing

Lasers are effective in that they are extremely versatile and accurate, which allows our laser systems to reach a level of precision with the cleanliness of cuts like never before. Pulse width is also important to note as they can affect throughput and quality. Our lasers are equipped to deliver speeds of up to several hundred features per second. Before designing a tool, we conduct studies to ensure the best laser fluence. We are able to determine the ideal speed for each material and design, with minimal carbon redeposit. Our individual laser tool designs are unique for each material to assure the cleanliness and accuracy of each cut.

With the ever-changing and high-speed scientific developments in the laser field, A-Laser’s micromachining is crucial. Micromachining pulse laser technology protects the integrity of the substrate material while producing the desired results.

Why A-Laser?

Today’s world is driven by high-tech advancements with tolerances that are rigorous, meticulous, and austere which leaves no room for error. This is why we are proud our expertise continues to serve those in the aerospace, automotive, electronic, or medical industries.

We offer QC reports that include all features outlined on your prints including special application call outs like true position and concentricity, with an AQL sampling rate that is best suited for your needs. Whether you need a single panel for a medical device, or a full-scale production for industrial cutting, our world-class operations, and engineering staff are able to effectively tailor each solution unique to your needs, regardless of where you are on your manufacturing supply chain.

Our newest laser system was revealed in January 2018 which focuses on depaneling. Mechanical depaneling comes at a risk, as it can heavily damage materials. However, our newest machine has a quick turn time, thus helping streamline the process for the removal of individual boards while providing you with the maximum yield for your entire production. It is also capable of processing thicker boards (80 to 100 mil thick) at much higher speeds, resulting in an easy and fast process of microvia drilling for through cut and blind vias.

Our advanced precision lasers can help you achieve optimal results in the shortest time possible and in the most economical way. Coupled with our ESD safe production environment and expertise with handling loaded and unloaded panels, we are the number one destination for all work involving electronic boards and panels.