Multilayer circuit board
First Claim
Patent Images
1. A multilayer circuit board having a multilayer structure, comprising:
- a plurality of printed wiring hoards including at least a first printed wiring board and a second printed wiring board, wherein each of said first and second printed wiring boards includes a metal core substrate having a first major surface and a second major surface which are opposite and parallel to each other;
an electrically insulating layer at least partially covering each of the major surfaces;
a conductive printed wiring layer formed on the surface of said electrically insulating layer and including a plurality of wiring lines;
a solder resist layer partially covering the surface of said conductive printed wiring layer; and
wherein each metal substrate comprises a plurality of integral metal projections made of the same metal material in a single continuous piece as that of the metal core substrate, said projections being of a predetermined height on at least one of said first major surface or said second major surface so as to provide an air gap between the adjacent printed wiring boards in said multilayer structure, wherein the metal core substrate of said first printed wiring board and the metal core substrate of said second printed wiring board are made of the same metal material with each other; and
wherein said solder resist layer comprises at least one local opening for exposing metal surface at a region corresponding to at least one of said metal projections.
1 Assignment
0 Petitions
Accused Products
Abstract
A multilayer circuit board formed by integrally laminating a plurality of printed wiring boards in a multilayer structure so as to provide air gaps therebetween. An insulating layer is formed on each of both surfaces of a metal core substrate having through-hole forming apertures and a printed wiring layer is formed on the each insulating layer. Metal projections integrally formed on the metal core substrate serve as bonding electrodes between the adjacent wiring boards in the multilayer structure. The width of the air gap provided between the adjacent wiring boards is determined by the height of the metal projections.
-
Citations
10 Claims
-
1. A multilayer circuit board having a multilayer structure, comprising:
-
a plurality of printed wiring hoards including at least a first printed wiring board and a second printed wiring board, wherein each of said first and second printed wiring boards includes a metal core substrate having a first major surface and a second major surface which are opposite and parallel to each other;
an electrically insulating layer at least partially covering each of the major surfaces;
a conductive printed wiring layer formed on the surface of said electrically insulating layer and including a plurality of wiring lines;
a solder resist layer partially covering the surface of said conductive printed wiring layer; and
wherein each metal substrate comprises a plurality of integral metal projections made of the same metal material in a single continuous piece as that of the metal core substrate, said projections being of a predetermined height on at least one of said first major surface or said second major surface so as to provide an air gap between the adjacent printed wiring boards in said multilayer structure, wherein the metal core substrate of said first printed wiring board and the metal core substrate of said second printed wiring board are made of the same metal material with each other; and
wherein said solder resist layer comprises at least one local opening for exposing metal surface at a region corresponding to at least one of said metal projections. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
Specification