JP2003246032A - Mold releasing multi-layer film and cover lay molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold releasing multi-layer film which is improved in plating properties in the post-process of a flexible wiring board. <P>SOLUTION: In the mold releasing multi-layer film having a mold release side layer, an intermediate layer, and a mold release opposite side layer, the resin of the mold release side layer is poly(methyl pentene) or a methyl pentene-α-olefin copolymer; the resin of the intermediate layer is a copolymer of an α-olefin selected from ethylene, propylene, butene, pentene, hexene, and methyl pentene, a multi-component copolymer, an ethylene-(meth)acrylate copolymer, or an ethylene-vinyl acetate-(meth)acrylic acid copolymer; and the resin of the mold release opposite side layer is polypropylene. The resin of the intermediate layer has a melt flow rate of 0.3-10.0 g/10 min and a melting point of 50-150°C, the resin of the mold release side layer has Rockwell's hardness of 65-88 and a thickness of 10-100 μm, and an adhesive resin layer is arranged between the mold rease side layer and the intermediate layer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a release multilayer film used in the manufacturing process of flexible printed wiring boards.

[0002]

2. Description of the Related Art Flexible printed wiring boards (hereinafter referred to as F
In the manufacturing process of (PC), a coverlay (hereinafter, referred to as a heat-resistant resin film with an adhesive for the purpose of insulation and circuit protection) on an insulating substrate, for example, a flexible circuit board having a predetermined circuit on the surface of a polyimide resin film. C
(Hereinafter referred to as L), and press-laminating is usually performed using a release film. In this manufacturing process, releasability between the FPC and the contact plate, suppression of adhesive flow from the CL end surface by sufficiently following the unevenness of the FPC, prevention of conductor contamination, and even pressure distribution by wrapping the entire FPC That is, releasability, conformability to shape, FPC
There is a demand for a release film that is excellent in void-free property (hereinafter referred to as moldability) due to uniform pressure on the whole, as well as in plating property on a circuit in a later step.

[0003]

DISCLOSURE OF THE INVENTION The present invention maintains the characteristics of excellent mold releasability, conformability to shape, and uniform moldability, while being unsatisfactory with conventional mold release multilayer films.
It is intended to provide a release multilayer film having improved plating properties in the subsequent step and a coverlay molding method using the same.

[0004]

The present invention relates to [1] a release multi-layer film comprising three layers of a release side layer, an intermediate layer and a release side layer, wherein the resin of the release side layer is polymethylpentene. Or a copolymer of polymethylpentene and α-olefin,
The resin for the intermediate layer is an α-olefin copolymer or multi-component copolymer selected from ethylene, propylene, butene, pentene, hexene and methylpentene, a copolymer of ethylene and an acrylic ester or a methacrylic ester, ethylene and vinyl acetate. , A copolymer with acrylic acid or methacrylic acid and a copolymer thereof selected from partially ionically crosslinked products, or a mixture thereof, the resin of the layer on the opposite side of the mold release is polypropylene, and the resin of the intermediate layer is a melt. With a flow rate of 0.3 to 10.0 g / 10 minutes and a melting point of 50 to 150 ° C,
The resin of the release side layer has a Rockwell hardness of 65 to 88, a thickness of 10 to 100 μm, and includes an adhesive resin layer between the release side layer and the intermediate layer, a release multilayer film,
[2] The release multilayer film according to the item [1], wherein the resin of the intermediate layer has a thickness of 20 to 290 μm, [3] In the manufacturing process of the flexible printed wiring board, the item [1] or the item [2]. A cover lay molding method, characterized in that the release multilayer film described above is used for press lamination of a cover lay.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The resin used in the release side layer of the present invention is polymethylpentene or a copolymer of polymethylpentene and α-olefin. Polymethylpentene is represented by the following formula (1).

The copolymerization ratio of the copolymer of polymethylpentene and α-olefin and the type of α-olefin are not particularly limited. The Rockwell hardness of polymethylpentene or a copolymer of polymethylpentene and α-olefin is from 65 to 88, preferably from 75 to 85. When it is less than 65, the conformability to shape with FPC, particularly the plating property, is poor, and when it exceeds 88, the releasability deteriorates and the film is broken. In order to adjust the Rockwell hardness to 65 to 88, polymethylpentene or a copolymer of polymethylpentene and α-olefin may be used alone or as a mixture of two or more kinds. The Rockwell hardness in the present invention is ASTM
It is measured according to the R scale of D785.

The thickness of polymethylpentene or a copolymer of polymethylpentene and α-olefin is 10 to 100.
μm. It is preferably 15 to 50 μm. 1
If it is less than 0 μm, the polymethylpentene or the copolymer of polymethylpentene and α-olefin will be broken after press lamination, and when separating the FPC and the release multilayer film, F
Polymethylpentene or a copolymer of polymethylpentene and α-olefin remains on the PC side. 100 μm
When it exceeds, the conformability to the shape is deteriorated and the flow amount of the adhesive adhering to the CL is increased.

The resin used in the intermediate layer of the present invention is an α-olefin copolymer or multi-component copolymer selected from ethylene, propylene, butene, pentene, hexene and methylpentene, and ethylene and an acrylic ester or a methacrylic ester. It is a copolymer, a copolymer selected from ethylene and vinyl acetate, a copolymer of acrylic acid or methacrylic acid, and a partially ionically crosslinked product thereof, or a mixture thereof. The melt flow rate of the resin of this intermediate layer is 0.3.
~ 10.0 g / 10 minutes. If it is less than 0.3 g / 10 minutes, the moldability such as conformability to shape is poor, and if it exceeds 10.0 g / 10 minutes, the exudation of the resin from the end surface of the release multilayer film is increased and the workability is deteriorated. The melt flow rate in the present invention is measured according to ASTM D1238.

The melting point of the resin of the intermediate layer is 50 to 150 ° C. If it is less than 50 ° C, the workability during the disassembling work is poor, and 1
If it exceeds 50 ° C, the CL adhesive flow amount increases. The resin thickness of the intermediate layer is preferably 20 to 290 μm, and 20 μm
If it is less than m, the moldability is poor, and if it exceeds 290 μm, the exudation from the end face of the release multilayer film is increased and the workability is deteriorated, which is not preferable. The melting point in the present invention is measured with a differential scanning calorimeter (heating rate 10 ° C./min).

The resin used in the layer opposite to the mold release layer of the present invention is polypropylene. This depends on the balance of heat resistance, cost, extrudability and the like. Examples of polypropylene include homopolymers, random copolymers, and block copolymers. The thickness of polypropylene is not particularly limited. By using a three-layer structure in which polypropylene is used for the layer on the side opposite to the mold release, it is not necessary to insert a cushion material in the press laminate molding method,
The complicated laminating process can be simplified.

The release multilayer film of the present invention comprises a release side layer,
It is indispensable to include an intermediate layer and a layer opposite to the release layer, and to include an adhesive resin layer between the release layer and the intermediate layer. The total thickness of the release multilayer film is preferably from 50 to 300 μm, and when it is less than 50 μm, the moldability is poor, and when it exceeds 300 μm, the exudation on the end face of the release multilayer film is increased and the workability is deteriorated, which is not preferable. Adhesive types include maleic anhydride modified polyolefin, nitrile rubber,
Examples include styrene-butadiene rubber, ethylene-propylene rubber, natural rubber and butyl rubber. The release side layer of the release multilayer film in the present invention refers to a layer in contact with the FPC surface.

The release multilayer film of the present invention may be produced by any of a coextrusion laminating method, an extrusion laminating method and a dry laminating method. In the case of the co-extrusion laminating method, the resin is laminated and adhered in the die in the case of the co-extrusion laminating method, and in the case of the extrusion laminating method, the adhesive is applied to the base film side with a roll (plate) to form the base material. The film and the extruded resin are laminated, and in the same way, the dry laminating method applies the adhesive to the base film side with a roll (plate) to laminate the films. In the FPC manufacturing process, the release multilayer film of the present invention is
As a molding method for pressure laminating, which is used for L press lamination, for example, a releasing multilayer film, FP
About 10 to 30 objects to be pressed having a structure in which C and a release multilayer film are stacked in this order are placed, and after heating and pressurizing under predetermined conditions, post-curing may be performed.

[0013]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. The characteristics of the raw materials used in the examples and comparative examples shown below are as follows. Copolymer of polymethylpentene and α-olefin (TP
X): Part number MX002 [Rockwell hardness 62], Part number MX004 [Rockwell hardness 80], Part number RT18
[Rockwell hardness 89] (manufactured by Mitsui Chemicals, Inc.) Ethylene-vinyl acetate copolymer (EVA): prototype [vinyl acetate content (VAC) 10% by weight, melting point 93 ° C, melt flow rate (MFR) = 0 .1 g / 10 minutes], product number Evaflex V-5716RC [vinyl acetate content (V
AC) 10% by weight, melting point 93 ° C., melt flow rate (MFR) = 2.5 g / 10 minutes], prototype [vinyl acetate content (VAC) 10% by weight, melting point 93 ° C., melt flow rate (MFR) = 15 g / 10 min] (Mitsui DuPont Polychemical Co., Ltd.) Polyethylene (PE): Part number Sumikasen L211 [melt flow rate (MFR) = 2.0 g / 10 min, melting point 1]
12 ° C. (Sumitomo Chemical Co., Ltd.) Ethylene-methyl acrylate copolymer (EMMA):
Product number Acryft WD203-1 [melt flow rate (MFR) = 2.0 g / 10 minutes, melting point 90 ° C.] (Sumitomo Chemical Co., Ltd.) Polypropylene 1 (PP1): Product number FS2011DG
[Homopolypropylene, melting point 160 ° C.] (Sumitomo Chemical Co., Ltd.) Polypropylene 2 (PP2): Part number FS2011DG
[Homopolypropylene, melting point 160 ° C] (Sumitomo Chemical Co., Ltd.) Adhesive: Admer QB550 (Mitsui Chemicals, Inc.)

Example 1 A release multilayer film was prepared by using four extruders in each of three extruders in which TPX was used as a release layer, Admer QB550 was used as an adhesive layer, EVA was used as an intermediate layer, and PP was used as a layer opposite to the release layer in a three-layer die. By supplying, it was extruded and laminated to be integrated.
In Examples 2 to 6 and Comparative Examples 1 to 7, the resins having the characteristics shown in Tables 1 and 2 were used in the same manner. Using a multi-stage press machine, the release multi-layer film, the FPC, and the release multi-layer film were stacked in this order, and the temperature was 60 ° C. at 150 ° C. and 30 kg / cm ² .
After pressurizing for a minute and then cooling under pressure to 50 ° C., the following evaluation items were evaluated. The evaluation results are shown in Tables 1 and 2.

Moldability ○: Void generation rate less than 2.0% ×: Void generation rate 2.0% or more CL adhesive flow amount (adhesive seepage length from CL end face) ○: Flow amount less than 150 μm × : Flow amount 150 μm or more Bleed amount on film end surface ○: Bleed amount less than 5 mm ×: Bleed amount 5 mm or more TPX (release side layer) breakage ○: Breakage occurrence rate less than 2.0% ×: Breakage occurrence rate 2 Plating property of 0.0% or more (a product with 90% or more of the required plating area being plated is a good product) ○: 98% or more of a good product ×: Less than 98% of a good product

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

INDUSTRIAL APPLICABILITY The present invention maintains the characteristics of excellent mold releasability, conformability to shape, and uniform moldability, and has a plating property in the post-process of FPC which cannot be achieved by the conventional mold release multilayer film. And a cushioning material need not be inserted, and the release process can simplify the lamination process.

Continued front page    F term (reference) 4F100 AK04B AK04J AK07B AK07C                       AK07J AK08A AK08B AK08J                       AK09B AK09J AK25B AK25J                       AK68B AK70B AL01A AL01B                       BA04 BA07 BA10A BA10C                       CB00D GB43 JA04B JA06B                       JK12A JL00 YY00A YY00B                 5E314 AA24 BB02 CC15 FF06 GG11                       GG24

Claims (3)

[Claims] 1. In a release multi-layer film having three layers of a release side layer, an intermediate layer and a release opposite side layer, the resin of the release side layer is polymethylpentene or a copolymer of polymethylpentene and α-olefin. Combined, the resin of the intermediate layer is ethylene, propylene, butene, pentene, hexene, α-olefin copolymer or multicomponent copolymer selected from methylpentene, a copolymer of ethylene and an acrylic ester or a methacrylic ester, ethylene and A copolymer selected from a copolymer with vinyl acetate, acrylic acid or methacrylic acid and a partial ionic cross-linked product thereof, or a mixture thereof, the resin on the side opposite to the mold release is polypropylene, and the resin on the intermediate layer is , Melt flow rate 0.3 to 10.0 g / 10 minutes, melting point 5
At 0 to 150 ° C., the resin of the release side layer has a Rockwell hardness of 65 to 88, a thickness of 10 to 100 μm, and includes an adhesive resin layer between the release side layer and the intermediate layer. Multilayer film. 2. The resin of the intermediate layer has a thickness of 20 to 290 μm.
The release multilayer film according to claim 1, which is m. 3. A coverlay molding method, wherein the release multilayer film according to claim 1 or 2 is used for press lamination of a coverlay in a process of manufacturing a flexible printed wiring board.