Browse Prior Art Database

Manufacturing of Drilled and Copper-Plated Inner Layers Having Thin Copper Layers on One Side

IP.com Disclosure Number: IPCOM000118965D
Original Publication Date: 1997-Oct-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Pohl, G: AUTHOR [+3]

Abstract

Disclosed is a method to reduce the copper layers on the surface of the inner layers of a printed circuit board from three to two layers.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 97% of the total text.

Manufacturing of Drilled and Copper-Plated Inner Layers Having Thin
Copper Layers on One Side

      Disclosed is a method to reduce the copper layers on the
surface of the inner layers of a printed circuit board from three to
two layers.

      By the method described, a reduced overall layer thickness is
achieved.  Thus, the geometries of the conductive pattern can be met
according to today's requests.

The steps of the proposed method are as follows:
  o  Use of base material that is laminated with copper on both
      sides
  o  Drilling of holes
  o  Partially chemically copper plating the surfaces of the
      inner layers and holes
  o  Applying a positive photoresist on only the side that later
      on forms the outer side of the multilayer
  o  Radiating the laminate with Ultraviolet (UV) light of
      desired wavelength without using a mask
  o  Developing the holes
  o  Unilaterally adding copper on the inner layers and the holes
  o  Removing the resist
  o  Unilaterally photo-structuring the inner layers
  o  Pressing the inner layers to form multilayers whereby the
      surfaces carrying no copper form the outer layers of the
      multilayer
  o  Drilling and copper plating the multilayer
  o  Photo-structuring the outer layers of the multilayers

      When using this method, the outer layers of the multilayer are
formed only of two copper layers, i.e., the copper plated base
material and th...