Abstract: Apparatus and method for protecting intermediate layers of a multi-layer printed circuit board from chemical or other damage from processing of a layer or layers to which previously fabricated layers of the printed circuit board are attached prior to such additional processing. A thin layer of protective material is selectively attached to intermediate or inner layers of a multi-layer printed circuit board after fabrication of such layers, when the outer or subsequent layers are attached. Inner or intermediate layer(s) of a multi-layer printed circuit board are fabricated. When outer layer(s) of the resulting printed circuit board are attached to the inner or intermediate layer(s), a layer of protective material such as a thin sheet of chemical-resistive plastic is disposed between the inner or intermediate layer(s) and the outer layer(s) and is selectively or completely attached or bonded thereto such as with a layer of acrylic adhesive.

Abstract: Method for protecting intermediate layers of a multi-layer printed circuit board from chemical or other damage from processing of a layer or layers to which previously fabricated layers of the printed circuit board are attached prior to such additional processing. A thin layer of protective material is selectively attached to intermediate or inner layers of a multi-layer printed circuit board after fabrication of such layers, when the outer or subsequent layers are attached. Inner or intermediate layer(s) of a multi-layer printed circuit board are fabricated. When outer layer(s) of the resulting printed circuit board are attached to the inner or intermediate layer(s), a layer of protective material such as a thin sheet of chemical-resistive plastic is disposed between the inner or intermediate layer(s) and the outer layer(s) and is selectively or completely attached or bonded thereto such as with a layer of acrylic adhesive.