JP2001339131A - Flexible printed-wiring board, metal clad laminated sheet therefor, resin composition used therefor and for coverlay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide excellently useful technique that shows a superior fire retardant property despite a non-halogen, and can achieve characteristics required as the adhesive or the like of a flexible printed-wiring board in balance. SOLUTION: The resin composition of a non-halogen is used for a metal-clad laminated sheet for a flexible printed-wiring board where a film and metal foil are laminated, the flexible printed-wiring board, and coverlay. NBR rubber with as little epoxy resin, a phosphor compound, a curing agent, and ionizable impurities as possible is used as main constituents.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, a coverlay, and a flexible printed wiring board which are halogen-free and excellent in flame retardancy. It is.

[0002]

2. Description of the Related Art In a flexible printed wiring board (hereinafter, referred to as "FPC") in which copper foil is laminated and adhered to one or both surfaces of a film of polyester or polyimide, the film and the copper foil are used. The resin composition used for sticking the resin or the resin composition used for the coverlay or cover coat attached to the FPC includes F
In order to enhance the functionality of PCs, it is required to have excellent properties such as mechanical properties, electrical properties (copper migration properties), thermal properties, chemical resistance, and adhesion. May require flame retardancy.

[0003] A coverlay is a laminate of a resin composition as an adhesive on a polyimide film or polyethylene terephthalate film. The coverlay has a strong adhesiveness between the film and the copper foil to prevent repeated bending and displacement. It is used to prevent the disconnection of the circuit when it is received, to maintain the insulation of the circuit, and to prevent moisture from entering from outside and rust.

[0004] Incidentally, those resin compositions containing an epoxy resin as a main component are generally used.
Flame retardant standard (for example, UL standard 94V-0 grade)
Method for mixing a bromine-based halogen compound into the adhesive composition in order to achieve (for example, Japanese Patent Publication No. Hei 7-33501).
However, this method has a problem that hydrogen bromide, which is a toxic gas, is generated during combustion.
A resin composition that meets the flame retardancy standards without using a halogen compound and achieves a good balance of the properties required for the resin composition for the purpose of enhancing the functionality of FPC (non-halogen resin composition). Is required.

The present invention solves the above problems,
An object of the present invention is to provide a technique excellent in practicality capable of exhibiting excellent flame retardancy while being non-halogen and achieving a well-balanced property required as an adhesive of a flexible printed wiring board.

[0006]

The gist of the present invention will be described.

A non-halogen resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay in which a film and a metal foil are laminated, comprising an epoxy resin, a phosphorus compound, a curing agent And NBR with as little ionic impurities as possible
The present invention relates to a resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a cover lay, which is mainly composed of rubber.

In the resin composition used for the metal-clad laminate for a flexible printed wiring board, the flexible printed wiring board and the coverlay according to the first aspect, the mixing ratio of the phosphorus compound is such that phosphorus is contained in all organic components. 2 to 5
% (Weight). The present invention relates to a resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a cover lay, which is set so as to be% (weight).

Further, in the resin composition used for the metal-clad laminate for a flexible printed wiring board, the flexible printed wiring board and the coverlay according to any one of claims 1 and 2, an aromatic phosphoric acid is used as a phosphorus compound. The present invention relates to a resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a cover lay, wherein an epoxy resin containing an ester or phosphorus is employed.

[0010] In the resin composition used for the metal-clad laminate for flexible printed wiring boards, flexible printed wiring boards and coverlays according to any one of claims 1 to 3, diaminodiphenyl sulfone is used as a curing agent. The present invention relates to a resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a cover lay, which is employed.

In the resin composition used for the metal-clad laminate for a flexible printed wiring board, the flexible printed wiring board and the coverlay according to any one of claims 1 to 4, a metal hydrate is mixed. The present invention relates to a resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay.

Further, in the resin composition used for the metal-clad laminate for a flexible printed wiring board, the flexible printed wiring board, and the coverlay according to claim 5, aluminum hydroxide is employed as a metal hydrate. The present invention relates to a resin composition used for a metal-clad laminate for flexible printed wiring boards, flexible printed wiring boards and coverlays.

Further, in the resin composition used for the metal-clad laminate for a flexible printed wiring board, the flexible printed wiring board and the coverlay according to any one of claims 5 and 6, the mixing ratio of the metal hydrate is as follows. A resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay, wherein the content is set to 60% (weight) or less with respect to all organic components. is there.

Further, the resin composition used for the metal-clad laminate for a flexible printed wiring board, the flexible printed wiring board, and the cover lay according to any one of claims 1 to 7 is obtained by adhering a film and a metal foil. The present invention relates to a flexible printed wiring board characterized by being used as an adhesive to be applied.

A coverlay is formed from a resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay according to any one of claims 1 to 7, and Are provided on a metal foil.

[0016]

The present invention exhibits excellent flame retardancy due to a phosphorus compound having high flame retardancy.

Further, the phosphorus compound generally has high hygroscopicity. If water is present in the resin composition, the ionic impurities originally present in the resin composition and the above-mentioned water cause the electric characteristics to be increased. In particular, although the copper migration property is deteriorated, in the present invention, since the NBR rubber containing as little ionic impurities as possible in the resin composition contains almost no ionic impurities, the entire resin composition Has a low ionic impurity, and therefore has no adverse effect due to the presence of the phosphorus compound, and exhibits high copper migration.

Further, N containing as little ionic impurities as possible
Due to the high flexibility of the BR rubber, high flexibility is exhibited even after curing, and it can withstand repeated use in a bent state.

Since the present invention is constituted as described above, it is practically capable of exhibiting excellent flame retardancy despite being non-halogen and exhibiting the characteristics required for a resin composition of a flexible printed wiring board. It will be a technology with excellent sex.

[0020]

Embodiments of the present invention will be described below.

The present embodiment relates to a non-halogen resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a cover lay, in which a film and a metal foil are laminated. It is mainly composed of NBR rubber containing as little phosphorus compound, hardener and ionic impurities as possible.

The metal-clad laminate for a flexible printed wiring board is a laminate of a film and a metal foil, the flexible printed wiring board is a metal-clad laminate for a flexible printed wiring board provided with a circuit, The coverlay is provided on a flexible printed wiring board to protect the circuit.

As the film, a polyimide film or a polyester film is employed. In addition, you may employ | adopt the film of another material.

As the epoxy resin, an epoxy resin having at least two epoxy groups in one molecule and containing no halogen is employed. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin,
Phenol novolak type epoxy resin, cresol novolak type epoxy resin, biphenyl type epoxy resin, naphthalene ring-containing epoxy resin, alicyclic epoxy and the like are used.

As the phosphorus compound, a phosphate ester is employed. Specifically, an aromatic phosphate ester is employed as this phosphorus compound. Note that a phosphorus-containing epoxy resin may be used instead of the phosphate ester.

The mixing ratio of the phosphorus compound is set so that the phosphorus content is 2 to 5% (by weight) with respect to all the organic components.

This mixing ratio has been confirmed by experiments. When the mixing ratio is less than 2% (weight), for example, when the film is used for attaching a film to a copper foil, the copper foil is provided only on one side of the film. FPC can achieve UL 94V-0 grade flame retardancy, but FPC with copper foil on both sides of the film cannot achieve UL 94V-0 grade flame retardancy, If it is more than 5% (weight), the adhesive strength will be reduced.

As the curing agent, diaminodiphenyl sulfone is employed. Also, boron trifluoride monoethylamine is employed as an accelerator for this curing agent. In addition, you may employ | adopt another hardening | curing agent and a hardening accelerator.

The NBR rubber containing as little ionic impurities as possible is a nitrile rubber containing a high-purity carboxyl group having a sodium ion of 20 ppm or less, a potassium ion of 6 ppm or less, and a chloride ion of 5 ppm or less (for example, PNR-1H manufactured by Nippon Synthetic Rubber Co., Ltd.). T4633 or Zeon F
N3703). It is desirable that the amount of sodium ions, potassium ions and chlorine ions be as small as possible.

Further, a metal hydrate is mixed with the resin composition in order to enhance the flame retardancy. As the metal hydrate, aluminum hydroxide or magnesium hydroxide is employed.

The mixing ratio of the metal hydrate is set at 60% (weight) or less with respect to all organic components.

This mixing ratio has been confirmed by experiments. If the mixing ratio is more than 60% (weight), problems such as a decrease in adhesive strength and a problem that filling between the circuits when used in a coverlay occur. I do.

The mixing ratio of the metal hydrate is desirably set to 10% (by weight) or more with respect to all organic components in order to exhibit high flame retardancy.

Hereinafter, experimental results confirming the effect of the present embodiment will be described in detail.

In this example, the composition was as follows (hereinafter referred to as Experimental Example 1).

Novolak type epoxy resin (Epicoat 152 manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts Bisphenol A type epoxy resin (AER6121A75 manufactured by Asahi Ciba Co., Ltd.) 93 parts Aromatic phosphoric acid ester (Daichi Chemical Industry Co., Ltd.) PX200) 120 parts NBR rubber with as little ionic impurities as possible (PNR-1H manufactured by Nippon Synthetic Rubber Co., Ltd.) 40 parts Aluminum hydroxide (Al2 (OH) 3) 180 parts Diaminodiphenylsulfone 8.3 parts Three Boron fluoride monoethylamine 0.5 part For comparison with Experimental example 1, Comparative example 1
In the above, an ordinary NBR rubber (Nippon 107 manufactured by Nippon Zeon Co., Ltd.) is used in place of the NBR rubber containing no aromatic phosphate and containing as little ionic impurities as possible.
The one that adopted 2) was prepared.

Similarly, as Comparative Example 2, Experimental Example 1
In the above, there was prepared one in which ordinary NBR rubber (Nippol 1072 manufactured by Zeon Corporation) was used instead of the NBR rubber containing as little ionic impurities as possible.

The flame retardancy was evaluated based on whether or not the UL standard 94V-0 grade could be achieved.

The migration properties are as follows:
Was evaluated experimentally.

A) Each of the resin compositions (adhesive) was applied to a polyimide film (Apical 25NP manufactured by Kaneka Chemical Industry Co., Ltd.).
I) was applied using a bar coater to a thickness of 10 μm after drying, and dried by heating at 150 ° C. for 5 minutes.
Electrolytic copper foil (Mitsui Metal Industry Co., Ltd. 3EC-3)
18 μm) is bonded together using a laminator to obtain a single-sided plate.

B. Further, the adhesive after drying with a bar coater was applied to the polyimide film surface of the single-sided plate with a thickness of 1%.
0 μm (the same adhesive is applied to both surfaces of the polyimide film), and after heating and drying at 150 ° C. for 5 minutes, electrolytic copper foil (Mitsui Metal Industry Co., Ltd.) is applied to the adhesive surface.
3EC-3 18 μm) is bonded using a laminator to obtain a double-sided board.

C) This double-sided board was cured by heating at 160 ° C. for 5 hours. Subsequently, a comb pattern of L / S = 200/100 was formed on one side, and a coverlay (each adhesive on a polyimide film) was formed thereon. That have been applied and dried so that the thickness after drying is 25 μm) at 180 ° C. × 2.9.
The test pieces are bonded by hot pressing under the conditions of 4 MPa × 30 minutes.

D Apply 50 V DC to the test piece in an atmosphere of 85 ° C. and 85% (Rh) and hold for 240 hours. Thereafter, the presence or absence of a tree in the test piece is checked using a microscope.

The migration is a phenomenon in which when a voltage is applied between copper foil circuits, copper ions are eluted from the anode using ionic impurities in the adhesive as a medium, and copper is deposited on the cathode side. When the precipitation of copper becomes severe, the copper deposited between the circuits grows like a tree branch. This is called a tree. When a tree occurs, insulation between circuits cannot be maintained.

An experiment was conducted, and it was confirmed that Experimental Example 1 was an adhesive satisfying the UL standard 94V-0 grade, free from tree generation, and excellent in flame retardancy and migration.

In Comparative Example 1, although no tree was generated, it was not possible to satisfy the UL standard 94V-0 grade, and it was confirmed that the adhesive was low in flame retardancy.

Further, in Comparative Example 2, it was confirmed that, although satisfying the UL standard 94V-0 grade, a tree was formed and the adhesive had low migration property.

According to the above experimental results, this embodiment shows that FP
It was confirmed that the resin composition was excellent in flame retardancy and migration required for the adhesive used in C.

In this embodiment, other characteristics required for the adhesive of the FPC, that is, mechanical characteristics (flexibility to withstand repeated bending), thermal characteristics, chemical resistance, and adhesiveness It has been confirmed that they are also fully equipped.

Since the present embodiment is configured as described above, it exhibits excellent flame retardancy while being non-halogen.
A highly practical resin composition that exhibits excellent copper migration properties despite the use of phosphate esters, and can successfully exhibit the properties required as adhesives for flexible printed wiring boards. Things.

A flexible printed wiring board in which a film and a copper foil are adhered with the resin composition, and a flexible printed wiring board in which the resin composition is used as a coverlay have excellent flame retardancy. In addition, the electrical characteristics are excellent.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C08L 9/02 C08L 9/02 63/00 63/00 A H05K 3/38 H05K 3/38 E (72) Inventor Shuichi Fujita 1-5-5 Minamihonmachi, Joetsu City, Niigata Prefecture Inside Arisawa Works, Ltd. (72) Inventor Takahiro Horie 1-5-5 Minamihonmachi, Joetsu City, Niigata Prefecture Inside Arisawa Works, Ltd. (72) Inventor Aiko Nakazawa 1-5-5 Minamihonmachi, Joetsu-shi, Niigata F-term in Arisawa Seisakusho Co., Ltd. (Reference) 4F100 AA00B AA04B AA04H AA18B AA18H AA19B AA19H AB01A AB17A AB33A AH02B AH02H AH03B AH04 AKH29B AH04AH29A AN02B BA03 BA05 BA06 BA07 BA10A BA10C CA02B GB43 JJ07 JK17B 4J002 AC072 CD021 CD031 CD051 CD061 DE079 DE149 EV217 EW046 EY018 FD136 FD139 FD147 FD 158 GF00 GQ01 5E343 AA02 AA12 AA18 AA33 AA38 BB05 BB21 BB67 CC02 CC03 CC06 CC07 EE21 GG20

Claims (9)

[Claims] 1. A non-halogen resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a cover lay in which a film and a metal foil are laminated, comprising an epoxy resin, a phosphorus compound, NBR with as little curing agent and ionic impurities as possible
A resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a cover lay, comprising a rubber as a main component. 2. The resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board and a coverlay according to claim 1, wherein the mixing ratio of the phosphorus compound is such that phosphorus is based on all organic components. 2-5%
A resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay, which is set to be (weight). 3. The resin composition for use in a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay according to claim 1, wherein the phosphorus compound is an aromatic phosphoric acid. A resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay, wherein an epoxy resin containing an ester or phosphorus is employed. 4. The resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board and a coverlay according to claim 1, wherein diaminodiphenyl sulfone is used as a curing agent. A resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay, which is employed. 5. A resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board and a coverlay according to claim 1, wherein a metal hydrate is mixed. A resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay. 6. The resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay according to claim 5, wherein aluminum hydroxide is used as a metal hydrate. A resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a cover lay, characterized by the following. 7. The resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board and a coverlay according to claim 5, wherein a mixing ratio of a metal hydrate is: And a resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a cover lay, which is set to 60% (weight) or less based on all organic components. 8. The resin composition used for a metal-clad laminate for flexible printed wiring boards, a flexible printed wiring board, and a coverlay according to claim 1, wherein a film and a metal foil are adhered to each other. A flexible printed wiring board characterized by being used as an adhesive. 9. A coverlay is formed from a resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay according to claim 1. Is provided on a metal foil.