Maskless Circuit Board Patterning Using Scanning Lasers
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01
There is a pressing desire to do away with standard lithography-mask technology for making circuitization patterns on boards. The cost of masks and photoresist together with alignment problems associated with masks makes it important to find suitable alternatives. The following techniques will permit rapid patterning of epoxy boards, fully covered with 1.25 mil copper, to become circuitized by subtractive etching using coating schemes. The coating is selectively removed via a scanning laser which can be programmed via a computer and microprocessor in conjunction with a similarly controlled automated table. Patterning occurs by local removal of the coating via heat with the laser providing the energy to boil, sublimate or decompose the coating. Photothermal decomposition is also a viable process.