October 3, 2008--Tamarack Scientific Company (Corona, CA) has developed a laser ablation system that directly patterns biochip sensors in a thin layer of metal on polyimide. The video shows a 40 mm x 10 mm part being ablated in a thin layer of copper on polyimide, showing a slow ramp-up in speed to a rate of over 150 parts per second.
Theoretically, this system could ablate nearly 300 parts per second. At such high speeds, you will have to look closely at the video to see how fast it is moving as it looks like a still picture. Watch the video with the volume up so you can hear the laser pulsing to understand how fast it really is going.
The advantage of an excimer-based ablation technique over conventional photolithography is its ability to dramatically reduce production costs. Using conventional photolithography, the substrate layer is typically patterned as per the following procedure: resist coating, soft bake, exposure, development, post-development hard bake, etching, and resist stripping. On the other hand, using excimer ablation, the substrate can be patterned directly in one step, reducing the overall manufacturing cost and improving yield.
Excimer ablation is a non-thermal laser ablation process that does not heat the surrounding area, thus minimizing potential damage to the material around the ablation (see www.laserfocusworld.com/articles/332968). A high-power excimer laser and projection lenses provide the ability to generate features or holes as small as a couple of microns. A mask, similar to a semiconductor reticle, determines the pattern to be produced, allowing generation of complex shapes and providing the ability to change patterns by simply replacing the mask.
For more information, visit www.tamsci.com.