Laser Selective Stripping Case Studies

Laser Selective Stripping Case Studies

INNO Laser* has collaborated with numerous customers in applications such as flexible printing, silicon photovoltaics (Si-PV), interventional catheters, and fine copper wire stripping. This chapter highlights real-world case studies of laser stripping applications, providing insights into INNO Laser's stripping capabilities and work quality. In this article, we will showcase several successful laser stripping projects completed in partnership with industrial clients.

Stripping the transparent oxide coating on Si-PV.

The purpose of this process is to remove the oxide anti-reflection (AR) coating to open up an electronic connection window. The quality requirements are narrow channels, sharp edges, and no melting on the crystalline silicon surface. Inno Laser's patented picosecond ps-1064nm laser stripping technology successfully achieves the non-destructive removal of the AR coating. The mechanism of the process involves interference between the incident light beam and the reflected beam from the silicon surface, thereby removing the oxide layer without damaging the silicon surface.

Stripping the polyimide coating on flexible stainless steel mesh masks

This process plays an important role in selective micro-screen printing for large-scale applications. It is essential to ensure that there are no residual polymers left after stripping the polyimide coating, and that the surrounding polyimide (PI) and the underlying metal woven mesh are not damaged. Failure to meet these standards may lead to serious printing quality issues. Inno Laser has worked closely with industry clients, conducting extensive testing with ns-355nm, ps-355nm, and fs-515nm lasers. After customer evaluation, it was determined that the ps-355nm and fs-515nm stripping methods meet the required quality standards.

The image below shows the clean stripping process, with no debris or melting observed at the edges of the SUS woven mesh and the PI layer.

Stripping the black ink coating from the glass plate

Black ink can be applied to various uses on glass displays, such as frames, labels, and decorative elements. Laser stripping of black ink from glass displays is a precise and efficient method, particularly suitable for complex or intricate designs. The process is simple: the laser heats and vaporizes the ink, breaking it down into gas while keeping the glass surface clean. Due to black's high absorption rate across almost all wavelengths, using ns-1064nm and ns-532nm lasers is more cost-effective and efficient.

Peeling off the polymer coating layer from the metal wire

For fine wires with diameters in the millimeter range or smaller, laser cable stripping is more efficient compared to mechanical methods. Unlike planar stripping, cable stripping may involve multiple laser beams directed from two or three different angles at a static cable, or the cable may be rotated to expose it to a focused, static laser beam. When peeling off the polymer coating on fine metal wires, using ns-UV lasers or ps/fs-GR/UV lasers can minimize thermal effects, depending on the quality requirements and budget.

Peeling off the polymer coating from SUS woven wire

The following image shows examples of peeling the polymer coating from SUS woven wire using ns-355nm and fs-515nm lasers, demonstrating the clean and damage-free peeling process achieved with fs-515nm laser.

Peeling the Polymer Coating from Copper Wires.

The following image shows another example of using ns-355nm and fs-515nm lasers to peel the polymer coating from copper wires. The image demonstrates the smooth surface of the copper wire after ablation, with the fs-515nm laser achieving a particularly clean peeling effect at the edges.

From a technical perspective, the fs-515nm laser demonstrates higher superiority in wire stripping compared to the ns-355nm laser and is capable of handling certain specific applications. However, in terms of overall cost-effectiveness, the ns-355nm laser offers better value for money and is more commonly used.

*INNO Laser is a highly trusted and closely partnered laser supplier for ARGUS laser marking equipment.