Stacked Drilling of Copper-Bondable Surface Signal Cores
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
Signal cores that have their copper surfaces etched off prior to drilling normally encounter drilling problems associated with the copper etch. Because the cores are thin, they tend to lift during drilling, thereby causing both drill breakage and poor X-Y location. The drilling of the core also raises debris around the hole rim. These problems are addressed and protection for the signal core's surface is provided in a drilling procedure that uses a stackable vacuum chuck and a thin sheet of drilling entry material in conjunction with a clearance template. The signal cores 1 are stacked in a stackable vacuum chuck 2 with either an aluminum or copper entry sheet 3. A clearance template 4 is placed on the top of entry sheet 3.