JP2004345159A - Release multilayered film and coverlay molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a release multilayered film constituted so as to reduce the leaching amount of a film end surface incapable of being achieved in a conventional release multilayered film while keeping characteristics excellent in releasability, shape followability, uniform moldability, plating properties and appearance finish wrinkles of FPC. <P>SOLUTION: In the release multilayered film having at least three layers, that is, a release side layer, an intermediate layer and a release opposite side layer, the resin of the release side layer and release opposite side layer comprises a polymethylpentene or a polymethylpentene/α-olefin copolymer and the resin of the intermediate layer has a melt flow rate of 0.2-3.0 g/10 min. A coverlay molding method using it is also disclosed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００７】
ポリメチルペンテン又はポリメチルペンテンとαオレフィンとの共重合体の厚みは、１０〜１００μｍである。好ましくは１５〜５０μｍが望ましい。１０μｍ未満だとプレスラミネート後にポリメチルペンテン又はポリメチルペンテンとαオレフィンとの共重合体が破れ、ＦＰＣと離型多層フィルムを分離する際に、ＦＰＣ側にポリメチルペンテン又はポリメチルペンテンとαオレフィンとの共重合体が残ってしまう。１００μｍを越えると対形状追従性が悪くなりＣＬに付着している接着剤のフロー量が多くなる。
【０００８】
本発明の中間層に用いる樹脂は、メルトフローレートが０．２〜３．０ｇ／１０分間である。０．２ｇ／１０分間未満だと成形性が悪く、３．０ｇ／１０分間を超えるとプレス時に離型多層フィルムの端面より樹脂がシミ出してきて、プレス熱盤等に付着して、次工程への２次汚染の懸念がある。中間層厚みは特に規定はしない。
【０００９】
離型側層と離型反対側層を挟む中間層の間に接着樹脂を介しても差し支えはないが、接着樹脂を介さないほうがフィルム端面シミ出しは少なく好ましい。
【００１０】
本発明に用いる離型多層フィルムの製法は、共押出ラミネート工法、押出ラミネート工法、ドライラミネート工法等のいずれの工法でもよい。
【００１１】
本発明の離型多層フィルムをＦＰＣの製造工程において、カバーレイのプレスラミネートに用い、加圧積層する成形方法としては、例えば、熱盤の間に、離型多層フィルム、片面ＦＰＣの順に重ねた構成物を置き、所定の条件で加熱加圧後、後硬化をすればよい。本発明に用いる離型多層フィルムは、特に短時間成形方法（一般的にはＨｏｔ−Ｈｏｔ用プレスと称されるプレス方法）に有効的である。
【００１２】
【実施例】
以下に本発明を実施例によって、更に詳細に説明するが、本発明はこれらの実施例に限定されるものではない。以下に示す実施例及び比較例において使用した原材料の特性は、以下の通りである。
・ポリメチルペンテンとαオレフィンとの共重合体（ＴＰＸ）：品番ＭＸ００４（三井化学（株）製）
・エチレン−メチルアクリレート共重合体（ＥＭＭＡ）：品番アクリフトＷＤ１０５−１［メルトフローレート（ＭＦＲ）＝０．５ｇ／１０分、融点１０５℃］（住友化学工業（株）製）
・エチレン−メチルアクリレート共重合体（ＥＭＭＡ）：品番アクリフトＷＤ２０３−１［メルトフローレート（ＭＦＲ）＝２．０ｇ／１０分、融点１０６℃］（住友化学工業（株）製）
・エチレン−メチルアクリレート共重合体（ＥＭＭＡ）：品番アクリフトＷＤ３０１［メルトフローレート（ＭＦＲ）＝７．０ｇ／１０分、融点１００℃］（住友化学工業（株）製）
・ポリプロピレン：ノーブレンＦＨ１０１６［メルトフローレート（ＭＦＲ）＝０．５ｇ／１０分、融点１６４℃］（住友化学工業（株）製）
・ポリプロピレン：ノーブレンＦＬＸ８０Ｅ４［メルトフローレート（ＭＦＲ）＝８．０ｇ／１０分、融点１５８℃］（住友化学工業（株）製）
【００１３】
＜実施例１〜４＞
３台の押出機にそれぞれ離型側層としてＴＰＸ、中間層としてＥＭＭＡ単体、ＰＰ単体、ＥＭＭＡとＰＰのブレンド系、離型反対側層にＴＰＸを三層ダイスに供給することにより共押出し、表１に示した構成内容の離型多層フィルムを作成した。
その離型多層フィルムとＦＰＣとを１段型プレス機を用い、１８５℃、５ＭＰａで２分加熱・加圧後、取り出して、以下の評価項目で評価した。評価結果を表１に示した。
＜比較例１〜３＞
３台の押出機にそれぞれ離型側層としてＴＰＸ、中間層としてＥＭＭＡ単体、ＰＰ単体、離型反対側層にＴＰＸを三層ダイスに供給することにより共押出し、表２に示した構成内容の離型多層フィルムを作成した。
その離型多層フィルムとＦＰＣとを１段型プレス機を用い、１８５℃、５ＭＰａで２分加熱・加圧後、取り出して、以下の評価項目で評価した。評価結果を表２に示した。
尚、評価はＪＰＣＡ規格（デザインガイドマニュアル・片面及び両面フレキシブルプリント配線板・ＪＰＣＡ―ＤＧ０２）に準拠し、以下のような項目と基準で行った。
【００１４】
成形性（７．５．３．３項の気泡による）
○：ボイド発生率 ２．０％未満
×：ボイド発生率 ２．０％以上
ＣＬ接着剤のフロー量（７．５．３．６項のカバーレイの接着剤の流れ及びカバーコートのにじみによる）
○：フロー量 １５０μｍ未満
×：フロー量 １５０μｍ以上
仕上がり外観シワ（７．５．７．２項しわによる）
○：シワ発生率 ２．０％未満
×：シワ発生率 ２．０％以上
ＴＰＸ（離型側層）の破れ（７．５．７．１項表面の付着物による）
○：破れ発生率 ２．０％未満
×：破れ発生率 ２．０％以上
メッキ付き性（必要メッキ面積の９０％以上にメッキが付いているものを良品：７．５．４項めっきの外観による）
○：良品が９８％以上
×：良品が９８％未満
フィルム端面シミ出し長さ（フィルム４方向端面からの樹脂がシミ出した長さを測定）
◎：０．８ｍｍ未満
○：０．８〜１．２ｍｍ
×：１．２ｍｍ以上
【００１５】
【表１】

【００１６】
【表２】

【００１７】
【発明の効果】
本発明は、離型性、対形状追従性、均一な成形性、メッキ付き性、ＦＰＣの外観仕上がりシワに優れた特性を維持しながら、従来の離型多層フィルムでは達成できなかったフィルム端面シミ出し量を軽減させた離型多層フィルムである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a release multilayer film used in a manufacturing process of a flexible printed wiring board.
[0002]
[Prior art]
In the manufacturing process of a flexible printed wiring board (hereinafter referred to as FPC), an insulating base material, for example, a flexible circuit board having a predetermined circuit on the surface of a polyimide resin film is coated with a heat-resistant resin with an adhesive for the purpose of insulation and circuit protection. It is common practice to cover with a coverlay (hereinafter referred to as CL) which is a film and press-laminate using a release film. In this manufacturing process, the releasability of the FPC and the plate, the flow of the adhesive from the CL end face by sufficiently following the unevenness of the FPC and the prevention of contamination of the conductor, and the uniformization of the pressure applied to the entire FPC, that is, In addition to releasing property, conformability to shape, devoiding property by uniform pressure to the whole FPC (hereinafter referred to as moldability), finished appearance wrinkle of FPC, small amount of film end face stain when pressing, and post-process There is a demand for a release film which is excellent in, for example, plating on circuits.
[0003]
[Problems to be solved by the invention]
The present invention provides a film at the time of pressing which is not satisfactory with the conventional multilayer film while maintaining excellent properties such as mold release property, conformability to shape, uniform moldability, plating property, and FPC finished appearance wrinkle. An object of the present invention is to provide a release multilayer film having a reduced amount of end face spots and a coverlay molding method using the same.
[0004]
[Means for Solving the Problems]
The present invention
(1) In a release multilayer film having at least three layers of a release side layer, an intermediate layer and a release opposite side layer, the resin of the release side layer and the release opposite side layer is polymethylpentene or polymethylpentene and α-olefin. A release multilayer film, wherein the resin of the intermediate layer has a melt flow rate of 0.2 to 3.0 g / 10 minutes.
(2) A coverlay molding method, wherein the release multilayer film according to (1) is used for press lamination of a coverlay in a manufacturing process of the flexible printed wiring board;
It is.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
The resin used for 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.
[0006]
Embedded image

[0007]
The thickness of polymethylpentene or a copolymer of polymethylpentene and α-olefin is 10 to 100 μm. Preferably, it is 15 to 50 μm. If it is less than 10 μm, the polymethylpentene or the copolymer of polymethylpentene and α-olefin is broken after press lamination, and when separating the FPC from the release multilayer film, the polymethylpentene or polymethylpentene and α-olefin are added to the FPC side. Copolymer remains. If it exceeds 100 μm, the ability to follow the shape is deteriorated, and the flow amount of the adhesive adhering to the CL increases.
[0008]
The resin used for the intermediate layer of the present invention has a melt flow rate of 0.2 to 3.0 g / 10 minutes. If it is less than 0.2 g / 10 minutes, the moldability is poor, and if it exceeds 3.0 g / 10 minutes, the resin comes out of the end surface of the release multilayer film at the time of pressing and adheres to a hot platen for press, etc. There are concerns about secondary pollution to the country. The thickness of the intermediate layer is not particularly specified.
[0009]
An adhesive resin may be interposed between the release side layer and the intermediate layer sandwiching the release opposite side layer, but it is preferable that no adhesive resin is interposed between the release side layer and the intermediate layer.
[0010]
The method for producing the release multilayer film used in the present invention may be any method such as a co-extrusion lamination method, an extrusion lamination method, and a dry lamination method.
[0011]
In the manufacturing process of the FPC, the release multilayer film of the present invention is used for press lamination of a cover lay, and as a forming method of press-laminating, for example, a release multilayer film and a single-sided FPC are stacked in this order between hot plates. The component may be placed, heated and pressed under predetermined conditions, and then post-cured. The release multilayer film used in the present invention is particularly effective for a short-time molding method (a press method generally called a hot-hot press).
[0012]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. The characteristics of the raw materials used in the following Examples and Comparative Examples are as follows.
-Copolymer of polymethylpentene and α-olefin (TPX): Part number MX004 (manufactured by Mitsui Chemicals, Inc.)
Ethylene-methyl acrylate copolymer (EMMA): Part number Acryft WD105-1 [melt flow rate (MFR) = 0.5 g / 10 min, melting point 105 ° C] (Sumitomo Chemical Industries, Ltd.)
-Ethylene-methyl acrylate copolymer (EMMA): Part number Acryft WD203-1 [melt flow rate (MFR) = 2.0 g / 10 min, melting point 106 ° C] (manufactured by Sumitomo Chemical Co., Ltd.)
Ethylene-methyl acrylate copolymer (EMMA): Part number Acryft WD301 [melt flow rate (MFR) = 7.0 g / 10 min, melting point 100 ° C] (Sumitomo Chemical Industries, Ltd.)
-Polypropylene: Noblen FH1016 [melt flow rate (MFR) = 0.5 g / 10 min, melting point 164 ° C] (Sumitomo Chemical Co., Ltd.)
-Polypropylene: Noblen FLX80E4 [melt flow rate (MFR) = 8.0 g / 10 min, melting point 158 ° C] (Sumitomo Chemical Co., Ltd.)
[0013]
<Examples 1 to 4>
Each of the three extruders is coextruded by supplying TPX as a release side layer, EMMA alone, PP alone, a blend system of EMMA and PP as an intermediate layer, and TPX to a three-layer die for a release opposite side layer. A release multilayer film having the constitution shown in No. 1 was prepared.
The release multilayer film and the FPC were heated and pressed at 185 ° C. and 5 MPa for 2 minutes using a one-stage press, taken out, and evaluated by the following evaluation items. Table 1 shows the evaluation results.
<Comparative Examples 1 to 3>
Coextruding by supplying TPX as a release side layer to three extruders, EMMA alone, PP alone as an intermediate layer, and TPX to a release opposite side layer to a three-layer die. A release multilayer film was prepared.
The release multilayer film and the FPC were heated and pressed at 185 ° C. and 5 MPa for 2 minutes using a one-stage press, taken out, and evaluated by the following evaluation items. The evaluation results are shown in Table 2.
The evaluation was based on the JPCA standard (design guide manual, single-sided and double-sided flexible printed wiring boards, JPCA-DG02), and was performed according to the following items and criteria.
[0014]
Moldability (by bubbles in 7.5.3.3)
：: Void generation rate less than 2.0% ×: Void generation rate 2.0% or more Flow amount of CL adhesive (depending on the flow of the adhesive of the cover lay and the bleeding of the cover coat described in 7.5.3.6)
：: Flow amount less than 150 μm ×: Flow amount 150 μm or more Finished appearance wrinkle (due to wrinkles described in 7.5.7.2)
：: Wrinkle generation rate of less than 2.0% X: Wrinkle generation rate of 2.0% or more TPX (release side layer) tearing (depending on adherence to surface of 7.5.7.1)
：: tear occurrence rate of less than 2.0% x: tear occurrence rate of 2.0% or more Plating property (a good product having plating on 90% or more of the required plating area: good appearance of 7.5.4 plating) by)
Good: 98% or more of non-defective products X: Less than 98% of non-defective products Stained length of film end face (measured length of resin spotted from end face of film 4 direction)
◎: less than 0.8 mm ○: 0.8 to 1.2 mm
×: 1.2 mm or more
[Table 1]

[0016]
[Table 2]

[0017]
【The invention's effect】
The present invention provides a film end face stain that cannot be achieved with a conventional release multilayer film while maintaining excellent properties such as mold release property, conformability to shape, uniform moldability, plating property, and appearance finish wrinkle of FPC. It is a release multilayer film with a reduced amount of dispensing.

Claims (2)

In a release multilayer film having at least three layers of a release side layer, an intermediate layer and a release opposite side layer, the resin of the release side layer and the release opposite side layer is made of polymethylpentene or a mixture of polymethylpentene and α-olefin. A release multilayer film comprising a copolymer, wherein the resin of the intermediate layer has a melt flow rate of 0.2 to 3.0 g / 10 minutes. A coverlay molding method, wherein the release multilayer film according to claim 1 is used for press-lamination of a coverlay in a process of manufacturing a flexible printed wiring board.