Use of Sacrificial Copper Allowing Removal by Mechanical Methods
Original Publication Date: 1987-Aug-01
Included in the Prior Art Database: 2005-Feb-01
Copper foil used in the production of multilayered printed circuit boards, or the like, normally has a smooth or bright side and a rough or oxide side. The rough or oxide side is oriented next to the prepreg in order to achieve the optimum adhesion between the prepreg and the copper foil during lamination. This copper foil must occasionally be removed, which is conventionally done by chemical etching using either cupric chloride or ferric chloride etchants. The chemical etching process introduces a waste by-product which must be disposed, and the etchants themselves are hazardous at the higher temperatures required for their use. A described process eliminates the need for etching by using mechanical means. In producing the board there are two lamination steps required.