Adhesive composition for printed wiring boards, bonding film, coverlay, copper-clad laminate and printed wiring board

Patent metadata

Field	Value
Publication number	US-2016198570-A1
Application number	US-201414916191-A
Country	US
Kind code	A1
Filing date	Sep 8, 2014
Priority date	Sep 12, 2013
Publication date	Jul 7, 2016
Grant date	—

Abstract

An object of the present invention is to provide an adhesive composition for a printed wiring board, the adhesive composition having a good heat resistance. Another object of the present invention is to provide a coverlay for a printed wiring board, a copper-clad laminate, and a printed wiring board, all of which use the adhesive composition for a printed wiring board. The present invention provides an adhesive composition for a printed wiring board, the adhesive composition containing a siloxane-modified polyimide that includes structural units represented by formulae (1) and (2) below, an epoxy resin, and an inorganic filler. The siloxane-modified polyimide has a weight-average molecular weight (Mw) of 25,000 or more and 150,000 or less. A content of the inorganic filler is 10 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of the siloxane-modified polyimide. In formulae (1) and (2), Ar represents a tetravalent aromatic tetracarboxylic acid residue, m is 0.35 or more and 0.75 or less, and n is 0.25 or more and 0.65 or less. R 1 in formula (1) represents a divalent diamine siloxane residue, and R 2 in formula (2) represents a divalent aromatic diamine residue.

First claim

1 . An adhesive composition for a printed wiring board, the adhesive composition comprising:
a siloxane-modified polyimide that includes a first structural unit represented by formula (1) below and a second structural unit represented by formula (2) below; an epoxy resin; and an inorganic filler, wherein the siloxane-modified polyimide has a weight-average molecular weight (Mw) of 25,000 or more and 150,000 or less, and a content of the inorganic filler is 10 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of the siloxane-modified polyimide.

(In formulae (1) and (2), Ar represents a tetravalent aromatic tetracarboxylic acid residue.
In formula (1), R 1 represents a divalent diamine siloxane residue.
In formula (2), R 2 represents a divalent aromatic diamine residue.
In formula (1) above, m represents a molar ratio of the first structural unit to the total structural units of the siloxane-modified polyimide and is 0.35 or more and 0.75 or less.
In formula (2) above, n represents a molar ratio of the second structural unit to the total structural units of the siloxane-modified polyimide and is 0.25 or more and 0.65 or less.
However, there is no case where a total of m and n exceeds 1.)

2 . The adhesive composition for a printed wiring board according to claim 1 , wherein m is 0.35 or more and 0.65 or less, and n is 0.35 or more and 0.65 or less.

3 . The adhesive composition for a printed wiring board according to claim 1 , wherein the inorganic filler has an average particle size of 2 μm or more and 20 μm or less.

4 . The adhesive composition for a printed wiring board according to claim 1 , wherein the inorganic filler has a plate-like shape, and
the inorganic filler has an aspect ratio of 5 or more and 100 or less.

5 . The adhesive composition for a printed wiring board according to claim 1 , wherein a content of the epoxy resin is 50 parts by mass or less relative to 100 parts by mass of the siloxane-modified polyimide.

6 . The adhesive composition for a printed wiring board according to claim 1 , further comprising a phenolic resin.

7 . A bonding film for a printed wiring board, the bonding film being formed from the adhesive composition for a printed wiring board according to claim 1 .

8 . A coverlay for a printed wiring board, the coverlay comprising a cover film; and an adhesive layer stacked on one surface of the cover film and formed from the adhesive composition for a printed wiring board according to claim 1 .

9 . A copper-clad laminate comprising a base film; an adhesive layer stacked on one or both surfaces of the base film and formed from the adhesive composition for a printed wiring board according to claim 1 ; and a copper foil stacked on the adhesive layer.

10 . A printed wiring board comprising a base film; a conductive pattern stacked on the base film either directly or with another layer therebetween; and a coverlay stacked on the base film and the conductive pattern,
wherein the coverlay is the coverlay for a printed wiring board according to claim 8 .

11 . The printed wiring board according to claim 10 , wherein the conductive pattern includes a base conductor, and a surface treatment layer formed on at least a part of an outer surface of the base conductor, and
the surface treatment layer contains nickel (Ni), tin (Sn), or aluminum (Al) as a main component.

12 . The printed wiring board according to claim 10 , wherein a peel strength between the cover film and the conductive pattern after the printed wiring board is allowed to stand in air at 150° C. for 1,000 hours is 5 N/cm or more.

13 . The printed wiring board according to claim 10 , wherein a peel strength between the cover film and the conductive pattern after the printed wiring board is immersed in an ATF oil at 150° C. for 1,000 hours is 2 N/cm or more.

14 . The printed wiring board according to claim 10 , wherein a peel strength between the cover film and the conductive pattern after the printed wiring board is allowed to stand in air at 85° C. and 85% for 1,000 hours is 4 N/cm or more.

15 . The printed wiring board according to claim 10 , having a solder heat resistance at 340° C. for 60 seconds.

Assignees

• Sumitomo Electric Industries
• Sumitomo Elec Printed Circuits
• Sumitomo Electroc Ind Ltd

Inventors

• Yonezawa Takayuki
• Kaimori Shingo
• Sugawara Jun
• Asai Shogo
• Uchita Yoshifumi
• Kakimoto Masaya

Classifications

• H05K1/056 Primary

  the metal substrate being covered by an organic insulating layer · CPC title

• C09J179/08

  Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors · CPC title

• C09J7/10 Primary

  without carriers · CPC title

• B32B15/20

  comprising aluminium or copper {(B32B15/016 and B32B15/017 take precedence)} · CPC title

• B32B2264/10

  Inorganic particles · CPC title