Systems and methods for drilling holes in printed circuit boards

Abstract

An entry sheet comprising polymer material for drilling printed circuit boards is provided. The entry sheet is suitable for use with a broad range of diameters, including commonly available drill diameters. The entry sheet comprises an adhesive epoxy configured to, among others, resist drill deflection, resist mechanical damage, and reduce to dust such that the entry sheet may increase drilling accuracy, protect printed circuit board from damage, minimize entry burrs, and may addresses other issues such as fliers, bird nesting, and the like.

What is claimed is: 
     
         1 . An entry sheet for drilling circuit boards, the entry sheet comprising:
 a substrate layer having a thickness of about 6 mils or less; and   an entry sheet component provided over the substrate layer, wherein the entry sheet component has a thickness of about 6 mils or less.   
     
     
         2 . The entry sheet of  claim 1 , wherein the entry sheet has a thickness in the range of about 4-12 mils. 
     
     
         3 . The entry sheet of  claim 1 , wherein the substrate layer has a thickness in the range of about 1-6 mils. 
     
     
         4 . The entry sheet of  claim 1 , wherein the entry sheet component has a thickness in the range of about 3-6 mils. 
     
     
         5 . The entry sheet of  claim 1 , wherein the entry sheet is configured to be used with drill diameters in the range of about 0.10-6.7 mm. 
     
     
         6 . The entry sheet of  claim 1 , wherein the entry sheet component comprises an adhesive. 
     
     
         7 . The entry sheet of  claim 1 , wherein the entry sheet component comprises an epoxy. 
     
     
         8 . The entry sheet of  claim 7 , wherein the epoxy is of the type bisphenol a/epichlorohydrin. 
     
     
         9 . The entry sheet of  claim 1 , wherein the substrate layer comprises high-density fiberboard, medium density fiberboard, metal, metal alloys, paper, melamine, random fiber mats, plastic, chip board, particle board, phenolic, phenolic supported with paper, cloth, or glass fiber, solid phenolic sheets, or laminated phenolic sheets. 
     
     
         10 . An entry sheet for drilling circuit boards, the entry sheet comprising:
 an entry sheet component configured to be used with drill diameters in the range of about 6.7 mm or less, wherein the entry sheet component comprises an adhesive.   
     
     
         11 . The entry sheet of  claim 10 , wherein the entry sheet has a thickness in the range of about 3-6 mils. 
     
     
         12 . The entry sheet of  claim 10 , wherein the entry sheet further comprises a substrate layer having a thickness of about 6 mils or less. 
     
     
         13 . The entry sheet of  claim 12 , wherein the substrate layer comprise high-density fiberboard, medium density fiberboard, metal, metal alloys, paper, melamine, random fiber mats, plastic, chip board, particle board, phenolic, phenolic supported with paper, cloth, or glass fiber, solid phenolic sheets, or laminated phenolic sheets. 
     
     
         14 . The entry sheet of  claim 10 , wherein the adhesive is an epoxy. 
     
     
         15 . The entry sheet of  claim 14 , wherein the epoxy is of the type bisphenol a/epichlorohydrin. 
     
     
         16 . The entry sheet of  claim 10 , wherein the entry sheet is configured to degrade to dust. 
     
     
         17 . The entry sheet of  claim 10 , wherein the entry sheet component is configured to resist mechanical damage. 
     
     
         18 . The entry sheet of  claim 10 , wherein the entry sheet component is configured to restrain lateral deflection of drill spindles used to drill holes in the circuit boards.