Insulation sheet, multi-layer wiring substrate and production processes thereof
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsShingo Komatsu, Seiichi Nakatani, Yasuhiro Sugaya, Toshiyuki Asahi, Yoshiyuki Yamamoto
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Abstract
An insulation sheet for use in producing a wiring substrate comprises, as via bole conductors, conductive paste filled in via holes formed through the insulation sheet, and a curing-starting temperature of the conductive paste is lower than a melting-starting temperature of the insulation sheet. A wiring substrate is produced by laminating such insulation sheets, that have conductive paste in via holes, and subjecting this laminate to thermo-compression bonding, wherein deformation of via holes and dislocation of the via holes, because of a molten insulation sheet, does not occur.
Claims44
A multi-layer wiring substrate comprising:
- at least one insulating layer;
- wiring layers disposed on both sides of said at least one insulating layer;
- and
- via hole conductors located in via holes penetrating said at least one insulating layer so as to be electrically connected to said wiring layers,
- wherein said via hole conductors are formed of a conductive paste having a curing-starting temperature lower than a melting-starting temperature of an insulation sheet which is to form said at least one insulating layer.
An insulation sheet for use in production of a wiring substrate, said insulation sheet comprising:
- insulating material;
- and
- conductive paste filled into via holes formed through said insulating material so as to define via hole conductors,
- wherein said conductive paste has a curing-starting temperature lower than a melting-starting temperature of said insulating material.
A process for preparing an insulation sheet, comprising:
- forming via holes through an insulation sheet, and
- filling said via holes with conductive paste which has a curing-starting temperature lower than a melting-starting temperature of said insulation sheet.
A process for producing a wiring substrate, comprising:
- preparing an insulation sheet including
- (i) insulating material, and
- (ii) conductive paste filled into via holes formed through said insulating material so as to define via hole conductors,
- wherein said conductive paste has a curing-starting temperature lower than a melting-starting temperature of said insulating material, and
- disposing a wiring layer onto at least one of main surfaces of said insulation sheet to thereby electrically connect said via hole conductors to said wiring layer.
Dependencies are inferred from the claim text.