JP2001339132A - 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, and uses an epoxy resin, a phosphor compound, a curing agent, and NBR rubber as main constituents, and adopts a phenol-family curing agent as the curing agent.

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, and a coverlay which are halogen-free and excellent in flame retardancy.

[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] By the way, these resin compositions generally use an epoxy resin as a main component.
Flame retardant standard (for example, UL standard 94V-0 grade)
In order to achieve, a method of mixing a bromine-based halogen compound as a flame retardant in the adhesive composition, a method of using a halogen compound and a metal hydrate such as aluminum hydroxide as a flame retardant, and an antimony compound. Methods have been proposed for use as an adjuvant to the flame retardant, but these methods have the problem that toxic gases such as hydrogen bromide and antimony gas are generated during combustion, and no toxic gas is generated during combustion. In addition, there is a demand for a resin composition (non-halogen resin composition) which has achieved the flame retardancy standard.

In order to satisfy this requirement, for example, a method of using a large amount of a metal hydrate alone as a flame retardant or a method of using a phosphorus compound having excellent flame retardancy as a flame retardant are conceivable. Both have the drawback that the adhesive strength and the migration property are reduced, and the FPC is not practical as a resin composition.

[0006] Accordingly, there is a need for a resin composition that achieves flame retardancy specifications without using a halogen compound and that achieves a good balance of various properties required for an adhesive for enhancing the functionality of FPC. ing.

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

[0008]

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 a resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay, wherein a phenol-based curing agent is employed as the curing agent. It is related to.

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 1, a novolak type phenol resin is used as a phenolic curing agent.
Flexible print characterized by adopting resol type phenol resin, phenol aralkyl resin, triphenol alkane resin and its polymer, naphthalene ring-containing phenol resin, pentadiene modified phenol resin or higher condensed polycyclic aromatic modified phenol resin The present invention relates to a resin composition used for a metal-clad laminate for a wiring board, a flexible printed wiring board, and a coverlay.

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, together with a phenolic curing agent, promotes curing. 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, wherein an imidazole compound, a phosphine compound, a cycloamidine derivative or a urea compound is used as an agent. Things.

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 to 3, the phenolic curing agent is an epoxy resin. A metal-clad laminate for a flexible printed circuit board, wherein a molar ratio of a phenolic hydroxyl group in the phenolic resin to an epoxy group in the mixture is 0.5 to 1.8. The present invention relates to a resin composition used for a wiring board and a coverlay.

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, wherein the phosphorus compound is an aromatic condensed phosphorus. 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 acid ester is employed.

Further, in 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 5, the mixing ratio of the phosphorus compound is all. A resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay, wherein phosphorus is set to be 1 to 4% (weight) with respect to an organic component. It is related to.

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 6, wherein 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 7, aluminum hydroxide or magnesium hydroxide is used as the metal hydrate. 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.

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 7 and 8, 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.

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 9 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 the resin composition used for the metal-clad laminate for flexible printed wiring boards, the flexible printed wiring board, and the coverlay according to any one of claims 1 to 9, and the coverlay is provided. Are provided on a metal foil.

[0020]

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

Further, since the phenolic curing agent employed as the curing agent also has flame retardancy, even if the amount of the phosphorus compound used is small, the flame retardancy standard can be achieved.

Since the present invention is constructed as described above, it exhibits excellent flame retardancy despite being halogen-free, and also exhibits excellent migration property and adhesive strength required as an adhesive for flexible printed wiring boards. It is a technology with excellent practicality that can be done.

[0023]

Embodiments of the present invention will be described below.

This embodiment is 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. Mainly composed of a phosphorus compound, a curing agent and NBR rubber,
As the curing agent, a phenolic curing agent is employed.

Note that a metal-clad laminate for a flexible printed wiring board is a laminate of a film and a metal foil, a 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,
A phenol novolak type epoxy resin, a cresol novolak type epoxy resin, a biphenyl type epoxy resin, a naphthalene ring-containing epoxy resin, an alicyclic epoxy resin and the like are employed.

As the phosphorus compound, a phosphate ester is employed. As the phosphorus compound, specifically, an aromatic condensed phosphoric acid ester is employed.

The mixing ratio of the phosphorus compound is set so that the phosphorus content is 1 to 4% (by weight) with respect to all the organic components.

This mixing ratio has been confirmed by experiments. When the mixing ratio is less than 1% (weight), when used for bonding a film to a copper foil, in an FPC having a copper foil provided only on one side of the film, , UL standard 94V-0 grade can be achieved, but FPC with copper foil on both sides of the film cannot achieve UL standard 94V-0 grade flame retardancy, and 4% If it is larger than (weight), the adhesive strength will be reduced.

As the NBR rubber, an NBR rubber containing as little ionic impurities as possible is employed. Specifically, commercial names FN3703 (manufactured by Zeon Corporation), PNR-1H, T4
633 (manufactured by Nippon Synthetic Rubber Co., Ltd.), that 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 is used. It is desirable that the amount of sodium ions, potassium ions and chlorine ions be as small as possible.

The phenolic curing agent is a novolak type phenol resin, a resol type phenol resin, a phenol aralkyl resin, a triphenol alkane resin and a polymer thereof, a naphthalene ring-containing phenol resin, a pentadiene modified phenol resin or a higher condensed polycyclic aromatic modified. Phenolic resin is employed.

In order to accelerate the curing of the phenolic curing agent, a curing accelerator is used together with the phenolic curing agent. As the curing accelerator, specifically,
An imidazole compound, a phosphine compound, a cycloamidine derivative or a urea compound is employed. The curing accelerator is preferably mixed with the phenolic curing agent in an amount of 0.1 to 3% (by weight). If the amount of the curing accelerator is too large, the preservability of the prepreg state of the resin composition is deteriorated, and further, the heat resistance and the adhesiveness are reduced. When the amount of the curing accelerator is too small, the curing of the resin composition does not proceed sufficiently.

The phenolic curing agent is mixed such that the molar ratio of the phenolic hydroxyl group in the phenolic resin to the epoxy group in the epoxy resin is 0.5 to 1.8. When the molar ratio is less than 0.5, the curing of the resin composition does not proceed sufficiently. When the molar ratio is more than 1.8, unreacted phenolic curing agent remains in the resin composition, and heat resistance and adhesion Performance is reduced.

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 to 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.

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

Incidentally, other synthetic resins and additives (for example, polyester resin, antioxidant, surfactant, coupling agent, etc.) may be added as long as the various properties are not reduced.

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

The compositions of this example (Example 1) and the comparative example were as shown in Table 1 below.

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 was applied to a polyimide film (Apical 25NPI manufactured by Kanegafuchi Chemical Industry Co., Ltd.) using a bar coater to a thickness of 10 μm.
After heating and drying at 50 ° C. for 5 minutes, a roughened surface of electrolytic copper foil (3EC-318, manufactured by Mitsui Kinzoku Kogyo Co., Ltd., 18 μm) is bonded to the resin composition surface using a laminator to obtain a single-sided plate.

B. Further, each of the resin compositions was applied to the polyimide film surface of the single-sided plate using a bar coater to a thickness of 10 μm.
(The same resin composition is applied to both sides of the polyimide film.) After heating and drying at 150 ° C. for 5 minutes, electrolytic copper foil (Mitsui Metal Industry Co., Ltd.) is applied to the resin composition side.
A roughened surface of 3EC-3 (18 μm, manufactured by Co., Ltd.) is bonded using a laminator to obtain a double-sided plate.

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 resin was placed on a polyimide film). The composition (adhesive) is applied and dried so that the thickness after drying is 25 μm)) and hot-pressed under the condition of 180 ° C. × 2.94 MPa × 30 minutes to be bonded to the test piece. I do.

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 the 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.

The adhesive strength was evaluated by the peel strength (10 N / cm or more passed). The measurement of this peel force
A double-sided board prepared in the same manner as the test piece used in the evaluation of the migration property was cut to a width of 10 mm,
The force was measured using an autograph (manufactured by Shimadzu Corporation) when peeling the copper foil of the double-sided board in the 180 ° direction.

The results of this experiment are also shown in Table 1 below.

[0051]

[Table 1]

The CL peel force indicates the adhesive force between the FPC and the cover lay, and the CCL indicates the adhesive force between the film and the copper foil.

From the above experimental results, Example 1 is a non-halogen resin composition, but has the same flame retardancy, copper migration, and the like as the conventional halogen-containing resin composition.
It was confirmed that it had adhesive strength.

In Comparative Example 3, which contains a larger amount of the phosphorus compound than in Example 1, the adhesive force between the FPC and the cover lay and the adhesive force between the film and the copper foil are the same as those in Comparative Example 1 (conventional example). ), But this was not the case in Example 1, and it was confirmed that it had the same adhesive strength as Comparative Example 1. This is because, in Example 1, a phenol-based curing agent (one in which imidazole is used as a curing accelerator in a phenolic resin) is used as a curing agent, whereby the mixing amount of a phosphorus compound is reduced. It is thought that there is.

According to the experimental results, it was confirmed that simply changing the flame retardant from a halogen (brominated epoxy resin) to a phosphorus compound resulted in insufficient copper migration (see Comparative Example 2). It was confirmed that the method using rubber in order to solve the problem of copper migration property was insufficient in adhesive strength (see Comparative Example 3).

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

In this example, the other properties required for the resin composition for FPC, namely, the mechanical properties (flexibility to withstand repeated bending), the thermal properties, and the chemical resistance are also considered. It has been confirmed that they are well prepared.

Since the present embodiment is constructed as described above, it exhibits excellent flame retardancy while being non-halogen.
Despite the use of metal hydrates and phosphorus compounds, excellent properties required as adhesives for flexible printed wiring boards exhibiting excellent copper migration properties and sufficient adhesiveness can be exhibited. It becomes a resin composition excellent in practicality.

Further, 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 are excellent in flame retardancy. In addition, the electrical characteristics are excellent.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08K 3/22 C08K 3/22 5/521 5/521 C08L 9/02 C08L 9/02 63/00 63/00 Z H05K 3/38 H05K 3/38 E (72) Inventor Toru Ueki 1-5-5 Minamihonmachi, Joetsu-shi, Niigata Inside Arisawa Works Co., Ltd. (72) Inventor Shuichi Fujita 1-5-1-5 Minamihonmachi, Joetsu-shi, Niigata No. Inside Arisawa Manufacturing Co., Ltd. (72) Inventor Takahiro Horie 1-5-5 Minamihonmachi, Joetsu-shi, Niigata Prefecture F-term inside Arisawa Manufacturing Co., Ltd. 4F100 AK49B AK53C AL01C AL05C AN02C AR00C BA03 BA07 BA10A BA10B BA13 CA02C GB43 JB01 JJ07 JK06 JL11C YY00C 4J002 AC07Y CC03X CC04X CC06X CC07X CD04W CD05W CD06W CE00X DE078 DE148 AD03 ET016 EU006 EU116 EF016 EU006 EU116 AF116 EU006 EU116 006 FA12 FB05 FB07 JA08 5E343 AA02 AA18 AA33 AA38 BB04 BB21 BB67 CC02 CC03 CC06 CC07 DD80 EE21 GG13 GG20

Claims (11)

[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, A resin used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a cover lay, comprising a curing agent and an NBR rubber as main components, wherein a phenolic curing agent is employed as the curing agent. Composition. 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 phenolic curing agent is a novolak phenol resin or a resol phenol resin. Metal for flexible printed circuit boards, characterized by employing phenol aralkyl resins, triphenol alkane resins and polymers thereof, naphthalene ring-containing phenol resins, pentadiene modified phenol resins or higher condensed polycyclic aromatic modified phenol resins. Resin composition used for laminated laminates, flexible printed wiring boards and coverlays. 3. The resin composition used for the metal-clad laminate for flexible printed wiring boards, flexible printed wiring boards and coverlays according to claim 1 or 2, together with a phenolic curing agent to promote curing. 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 imidazole compound, a phosphine compound, a cycloamidine derivative or a urea compound is used as the agent. 4. 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 the phenolic curing agent is an epoxy resin. A metal-clad laminate for a flexible printed circuit board, wherein a molar ratio of a phenolic hydroxyl group in the phenolic resin to an epoxy group in the mixture is 0.5 to 1.8. A resin composition used for wiring boards and coverlays. 5. 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 phosphorus compound is an aromatic condensed phosphorus. 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 acid ester is employed. 6. The resin composition used in the metal-clad laminate for flexible printed wiring boards, flexible printed wiring boards and coverlays according to claim 1, wherein the mixing ratio of the phosphorus compound is all. A resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a coverlay, wherein phosphorus is set to be 1 to 4% (weight) with respect to an organic component. . 7. A 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 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. 8. 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 7, wherein aluminum hydroxide or magnesium hydroxide is used as the 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, wherein 9. 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 7, 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. 10. The resin composition used for a metal-clad laminate for a flexible printed wiring board, a flexible printed wiring board, and a cover lay according to claim 1, wherein a film and a metal foil are adhered. A flexible printed wiring board characterized by being used as an adhesive. 11. 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.