Metallization removal is commonly used to produce isolated circuit traces for applications such as medical biosensors, solar panels, RFIDs and flexible displays. Three techniques are generally used for metallization patterning today: etching, printed metallization (screen and ink jet) and patterned laser ablation. The first two options have the disadvantages of hazardous byproducts and demanding process controls.  

Patterned laser removal is an ideal production solution for the ablation of metalized layers (conductive inks, sputtered films, and thin foils) because of its dry, non-contact, digital, single step process. Fiber and Ultraviolet (UV) lasers are particularly ideal for ablation because metalized materials can effectively be removed with minimal damage to the carrier substrate. The process can be completed on either side of a material.

The laser source and wavelength used is dependent upon the material to be processed, including the type of coating to be removed and the type of substrate below the coating. Proper choice of laser wavelength also depends on the required ablation width and quality. For example:

• Very thin (< 1 μm) conductive coatings are easily removed with YAG, UV, and Green wavelengths.
• Very thin, nonconductive coatings tend to be transparent to YAG laser wavelengths but ablate very well with UV laser wavelengths.
• Thick conductive coatings may take a good deal of energy to ablate, slowing UV laser processing to the point where it may not be a viable solution. Instead, a fiber or YAG laser is a good choice.

CO₂ lasers typically are not used to remove conductive coatings from polymers. This is because generally polymers absorb CO₂ laser wavelengths, causing damage to the substrate layer under the conductive coating. The polymer underneath can also be damaged just from the amount of heat generated during the conductive coating’s vaporization.

However, CO₂ lasers can be used in conjunction with Fiber, YAG, and UV lasers to cut or score a material to create registration marks, eliminating the need for pre-processing the material. Laser ablation is the most efficient method for developing prototypes and shortening a product's time to market as a result of fast and easy changeover from development stage to full-scale production.

Using LasX's steered beam technology, a high rate of short laser pulses and controlled field of view patterning is achieved with precision. Line widths range between 25 and 200µm and tolerances of under +/- 50µm are obtainable. When utilizing camera vision systems, these patterns may be matched to other components all while continuously moving through the process area. LasX manufactures a range of LaserSharp® ablation modules suited for electronic and medical device applications. MicroFlow Medical Services also offers contract services for metalized ablation.