Laser Recording of Circuit Structures from Conducting Polymers in Insulating Polymer Layers

The paper is a report on a newly developed material and on technological studies which open up new methods for the combined application of laser and computer technology for advanced industrial applications, e.g., for the laser direct imaging of conducting paths, circuit structures in printed circuit boards and probably also in moulded interconnection devices. The process uses — instead of copper and photoresists — layers of a special polymer poly(bis‐alkylthio‐acetylene), PATAC, in which leads or conducting organic structures will be written by laser‐induced local conversion of PATAC into conductive polymer tracks. The organic leads obtained can be reinforced by electroplating if necessary. It is a purely additive process, which works without etching, thus avoiding environmental problems. The new material and technology also allow the direct imaging of resistors, capacitors and inductors on to printed circuit boards and make it possible to make chips and other electronic components conductive. It enables the production of leads in the 10 μm scale and for this reason is suitable for hybrid technology. The new technology is not restricted to one plane and can, therefore, also be used for 3‐D boards or MIDs.