| 摘要 |
Synthetic resin coating material for permanent or removable masking of printed circuit boards, contg. a thermosetting resin which is solid at =60 degrees C., contains >=3 functional gps. and is initially a high viscosity liquid or gel which changes to the final solid state without liquefaction during hardening. The material can be applied by screen printing with high resolution, allowing circuits with high conductor density and spacing of 0.25-0.1 mm. max. to be made. No flow into holes, etc. occurs during hardening, and sharp edges and contours are maintained. Adhesion to copper is good and the coating is resistant to chemicals used in metal deposition, thermal shock in the solder bath and chemicals used to remove solider. |
