Metal clad laminate, preparation method thereof, and method for preparing flexible circuit board by using the same

Patent metadata

Field	Value
Publication number	US-2016374208-A1
Application number	US-201615185946-A
Country	US
Kind code	A1
Filing date	Jun 17, 2016
Priority date	Jun 17, 2015
Publication date	Dec 22, 2016
Grant date	—

Abstract

The present disclosure provides a metal clad laminate, a preparation method thereof, and a method for preparing a flexible circuit board by using the same. The metal clad laminate of the present disclosure includes a first metal foil, a first polyimide layer directly disposed on the first metal foil, a second metal foil, and a second polyimide layer directly disposed on the second metal foil, the first polyimide layer being in contact with the second polyimide layer. The metal clad laminate of the present disclosure is equivalent to a double-sided flexible copper clad laminate (FCCL) in structure, is superior to a single-sided FCCL in terms of mechanical performance in reducing warpage, and has the advantage of being useful for circuit fabrication simultaneously on both sides thereof.

First claim

What is claimed is:

1 . A metal clad laminate, comprising:
a first metal foil; a first polyimide layer directly disposed on the first metal foil; a second metal foil; and a second polyimide layer directly disposed on the second metal foil; wherein the first polyimide layer is in contact with the second polyimide layer.

2 . The metal clad laminate according to claim 1 , wherein at least one of the first polyimide layer and the second polyimide layer comprises in its composition a polymeric unit derived from a diaminosiloxane monomer, an alkylene diamine monomer or a combination thereof.

3 . The metal clad laminate according to claim 2 , wherein the diaminosiloxane monomer has a general formula (□) below:

wherein each R9 is independently H, a linear or branched C1-C4 alkyl, or phenyl; a may be the same or different and is an integer ranging from 1 to 6; and m is an integer ranging from 1 to 15.

4 . The metal clad laminate according to claim 3 , wherein in formula (□), a is an integer ranging from 2 to 5.

5 . The metal clad laminate according to claim 3 , wherein in formula (□), m is an integer ranging from 1 to 5.

6 . The metal clad laminate according to claim 3 , wherein the diaminosiloxane monomer is selected from:

and a combination thereof,
wherein m is an integer ranging from 1 to 5.

7 . The metal clad laminate according to claim 2 , wherein the alkylene diamine monomer has a general formula (IV) below:
H 2 N—R 2 —NH 2   (IV)
wherein each R 2 is C 2 -C 14 alkylene.

8 . The metal clad laminate according to claim 7 , wherein the alkylene diamine monomer is selected from:

and a combination thereof.

9 . The metal clad laminate according to claim 1 , wherein the first polyimide layer and the second polyimide layer each have a glass transition temperature in the range of 260 to 340° C.

10 . The metal clad laminate according to claim 1 , wherein the first polyimide layer and the first metal foil, and the second polyimide layer and the second metal foil have a close or substantially the same coefficient of thermal expansion.

11 . The metal clad laminate according to claim 1 , wherein the first polyimide layer and the second polyimide layer each have a coefficient of thermal expansion ranging from 15 to 25 ppm/° C.

12 . The metal clad laminate according to claim 2 , wherein the first and second polyimide layer are formed by imidizing a precursor produced through condensation of a dianhydride monomer and a diamine monomer, and wherein the diamine monomer comprises a diaminosiloxane monomer, an alkylene diamine monomer, or a combination thereof and the total amount of the diaminosiloxane monomer and the alkylene diamine monomer is in the range from 0.1 to <10 mol %, based on the total moles of the diamine monomers.

13 . The metal clad laminate according to claim 12 , wherein the total amount of the diaminosiloxane monomer and the alkylene diamine monomer is in the range from 0.5 to 7.5 mol %, based on the total moles of the diamine monomers.

14 . The metal clad laminate according to claim 12 , wherein the total amount of the diaminosiloxane monomer and the alkylene diamine is in the range from 1 to <5 mol %, based on the total moles of the diamine monomers.

15 . The metal clad laminate according to claim 12 , wherein the dianhydride monomer is an aromatic dianhydride monomer.

16 . The metal clad laminate according to claim 12 , wherein the diamine monomer further comprises an aromatic diamine.

17 . The metal clad laminate according to claim 1 , wherein the metal clad laminate is a quasi double-sided two-layer metal clad laminate or a double-sided two-layer metal clad laminate.

18 . The metal clad laminate according to claim 15 , wherein the metal clad laminate is a quasi double-sided two-layer metal clad laminate, wherein the peeling strength between the first polyimide layer and the second polyimide layer is 1 to 500 gf/cm.

19 . The metal clad laminate according to claim 16 , wherein the peeling strength between the first polyimide layer and the second polyimide layer is 3 to 100 gf/cm.

20 . The metal clad laminate according to claim 16 , wherein the peeling strength between the first polyimide layer and the second polyimide layer is 5 to 50 gf/cm.

21 . The metal clad laminate according to claim 15 , wherein the metal clad laminate is a double-sided two-layer metal clad laminate, wherein the peeling strength between the first polyimide layer and the second polyimide layer is greater than 500 gf/cm.

22 . The metal clad laminate according to claim 1 , wherein the first metal foil and the second metal foil are each independently selected from a copper foil, an aluminium foil or a copper-aluminium alloy foil.

23 . A method for preparing the metal clad laminate according to claim 1 , comprising:
(a) providing a first metal film comprising a first metal foil and a first polyimide layer directly disposed on the first metal foil; (b) providing a second metal film comprising a second metal foil and a second polyimide layer directly disposed on the second metal foil; and (c) superposing the first polyimide layer of the first metal film onto the second polyimide layer of the second metal film and laminating.

24 . The method for preparing the metal clad laminate according to claim 21 , wherein the lamination temperature in step (c) is controlled at 300 to 390° C., and the lamination line pressure is controlled at 1 to 60 kgf/cm, such that the peeling strength between the first polyimide layer and the second polyimide layer is 1 to 500 gf/cm.

25 . The method for preparing the metal clad laminate according to claim 21 , wherein the lamination temperature in step (c) is controlled at 350 to 400° C., and the lamination line pressure is controlled at 100 to 200 kgf/cm, such that the peeling strength between the first polyimide layer and the second polyimide layer is greater than 500 gf/cm.

26 . A method for preparing a flexible circuit board by using the metal clad laminate according to claim 16 , further comprising:
forming at least one circuit unit respectively on the surface of the first metal foil and the second metal foil of the metal clad laminate; and separating the first polyimide layer from the second polyimide layer, to form two single-sided flexible circuit boards.

27 . A method for preparing a flexible circuit board by using the metal clad laminate according to claim 19 , further comprising:
forming at least one circuit unit respectively on the surface of the first metal foil and the surface of the second metal foil to prepare a double-sided flexible circuit board.

Assignees

• Eternal Mat Co Ltd

Inventors

• Chiang Shun-Jen
• Wu Chung-Jen
• Chou Meng-Yen

Classifications

• H05K3/0097 Primary

  Processing two or more printed circuits simultaneously, e.g. made from a common substrate, or temporarily stacked circuit boards (H05K3/0052 takes precedence) · CPC title

• C09D179/08

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

• H05K3/10 Primary

  in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern · CPC title

• H05K1/11

  Printed elements for providing electric connections to or between printed circuits · CPC title

• H05K2203/1545

  Continuous processing, i.e. involving rolls moving a band-like or solid carrier along a continuous production path · CPC title