Photoresist Hole Blast Device
Original Publication Date: 1988-Sep-01
Included in the Prior Art Database: 2005-Feb-15
Certain products require the etching of thin internal circuit cores. Copper around the tooling holes of these cores must be protected from etching off to ensure the integrity of the holes for accuracy in subsequent registration steps. To prevent the copper from being etched off, a photoresist film must be placed over the tooling hole. Prior to exposing the photoresist, the photoresist must be removed from those places where it covers the holes in order to allow the photo tool pins to penetrate the hole for registration. A protective MYLAR* film and the photoresist are usually removed from the tooling hole using a heated tip and brush assembly. Certain photoresists require the removal of the MYLAR cover sheet prior to the exposure operation. It is on these types of dry film resists that the subject device is utilized.