The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 31, 2000
Filed:
May. 04, 1999
Kazunori Omoya, Osaka, JP;
Takeshi Suzuki, Osaka, JP;
Tatsuo Ogawa, Osaka, JP;
Takashi Oobayashi, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A paste for via-hole filling is provided, and the paste comprises at least (a) 30-70 volume % of conductive particles whose average diameter ranges from 0.5 to 20 .mu.m and whose specific surface area ranges from 0.05 to 1.5 m.sup.2 /g, and (b) 70-30 volume % of resin comprising at least 10 weight % of epoxy resin comprising at least one epoxy group per molecule, in which the total amount of a hydroxyl group, an amino group and a carboxyl group is not more than 5 mol % of the epoxy group, and the epoxy equivalent ranges from 100 to 350 g/eq. The conductive paste for filling via-holes and a printed circuit board comprising thereof can be used to provide an inner-via-hole connection between electrode layers without using a through-hole plating technique. The conductive paste comprises a metallic particle such as copper, an epoxy resin, a hardener and a dispersant if necessary. The paste having low viscosity and low volatility is used to fill holes disposed in a laminated substrate. Then, this substrate is heated and pressurized together with copper foils on both sides to attain a printed circuit board where both sides are electrically connected by inner-via-hole.