【０００１】[0001]
【産業上の利用分野】本発明は優れた耐湿性、機械加工
性を有し、離型剤を必要としない等の特性を有するフレ
キシブルプリント回路保護用カバーレイフィルムに関す
るものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cover lay film for protecting a flexible printed circuit, which has excellent moisture resistance, machinability and does not require a release agent.
【０００２】[0002]
【従来の技術】近年エレクトロニクス製品の軽薄短小、
高性能化に伴いプリント基板の需要が高まり、なかでも
フレキシブルプリント基板は、その使用範囲が広がり需
要が伸びてきている。それにつれてフレキシブルプリン
ト回路の保護用カバーレイフィルムの使用が多くなり、
その性能向上が望まれている。一般に、カバーレイフィ
ルムは、Ｂステージ（以下半硬化状態の接着剤をいう）
の耐熱性接着剤付き耐熱性絶縁フィルムと離型紙とから
なり、この離型紙には原紙の片面または両面にポリエチ
レン（以下PEとする）、ポリ−４−メチルペンテン−１
（以下 TPXとする）またはポリプロピレン（以下PPとす
る）フィルムを貼り合わせたもの、原紙の両面にポリ塩
化ビニリデン（以下PVdCとする）をコートしたもの、原
紙の片面にPE或はPPフィルムを貼り合わせ反対面にPVdC
をコートしたもの等がある。さらにこれら離型紙の片面
或は両面にシリコーン離型剤等により、離型処理が施さ
れているものが知られている。2. Description of the Related Art In recent years, electronic products are light, thin, short, and small.
Demand for printed circuit boards has increased along with higher performance, and in particular, flexible printed circuit boards have expanded their use range and demand. As a result, the use of protective coverlay films for flexible printed circuits has increased,
It is desired to improve its performance. In general, a coverlay film has a B stage (hereinafter referred to as a semi-cured adhesive).
It consists of a heat-resistant insulating film with heat-resistant adhesive and a release paper. This release paper has polyethylene (hereinafter PE), poly-4-methylpentene-1 on one or both sides of the base paper.
(Hereinafter referred to as TPX) or polypropylene (hereinafter referred to as PP) film laminated, both sides of the base paper coated with polyvinylidene chloride (hereinafter referred to as PVdC), PE or PP film attached to one side of the base paper PVdC on the opposite side
There are those coated with. Further, it is known that one or both of these release papers are subjected to a release treatment with a silicone release agent or the like.
【０００３】[0003]
【発明が解決しようとする課題】前記、離型紙の片面の
みにPE或はPPフィルムを貼り合わせたものやPVdCをコー
トしたものは、吸放湿防止性が与えられていないため、
接着剤付き耐熱性絶縁フィルムと離型紙の湿度変化によ
る寸法変化率の違いから、湿度の低い冬季、湿度の高い
梅雨時に、カバーレイフィルムにカールが発生する欠点
がある。また、両面にPE、PPフィルムを貼り合わせたも
の、PVdCを原紙の両面にコートしたもの、原紙の片面に
PE或はPPを貼り合わせ反対面にPVdCをコートしたもの
は、カールの発生は予防できるが、カバーレイフィルム
の打ち抜き性、接着剤面との離型性が劣るという欠陥を
持っている。この接着剤面との離型性を改良するため
に、シリコーン系離型剤等により離型処理を施すと、こ
の離型剤がＢステージの耐熱性接着剤面に転写し、接着
剤の持つ基材との接着力を低下させる。このことは前記
片面のみのポリマーコート紙も同様である。また、PE、
PPフィルムを貼り合わせたものは、カバーレイフィルム
の孔加工時にPE、PPフィルムがクッション的な作用を及
ぼし型通りの孔加工が困難で、特に両面に貼り合わせた
ものについては著しい。両面に TPXフィルムを貼り合わ
せたものは、打ち抜き性、フラット性は良いが、接着剤
との密着性が悪く、耐熱性接着剤付き絶縁フィルムと離
型紙が剥れ易いという問題があった。本発明はこれらの
問題点、特には TPXフィルムを貼り合わせた離型紙と接
着剤との密着性を改善したものを提供しようとするもの
である。The above-mentioned release paper, which has a PE or PP film bonded to only one side thereof, or a PVdC-coated product, is not provided with a moisture absorption / release prevention property.
Due to the difference in the dimensional change rate due to the humidity change between the heat-resistant insulating film with adhesive and the release paper, there is a drawback that the coverlay film is curled during low humidity in the winter and high humidity in the rainy season. Also, PE and PP films are attached on both sides, PVdC is coated on both sides of the base paper, and one side of the base paper is
The one in which PE or PP is adhered and PVdC is coated on the opposite surface can prevent the occurrence of curl, but has a defect that the cover lay film is inferior in punching property and releasing property from the adhesive surface. In order to improve the releasability with this adhesive surface, a releasing treatment is performed with a silicone-based releasing agent or the like, and this releasing agent is transferred to the heat-resistant adhesive surface of the B stage, and the adhesive has Decreases the adhesive strength with the substrate. The same applies to the polymer-coated paper having only one side. Also PE,
In the case where the PP film is pasted, the PE and PP films have a cushioning effect at the time of punching the cover lay film, and it is difficult to punch the holes as usual. Especially, those stuck to both sides are remarkable. The TPX film laminated on both sides had good punchability and flatness, but had poor adhesion with the adhesive, and there was a problem that the heat-resistant adhesive insulating film and the release paper were easily peeled off. The present invention intends to provide these problems, particularly those having improved adhesion between a release paper having a TPX film bonded thereto and an adhesive.
【０００４】[0004]
【課題を解決するための手段】本発明者等は、前記課題
を解決すべく、接着剤の表面処理について種々検討を重
ねた結果、本発明に到達したもので、その要旨とすると
ころは、 １）耐熱性絶縁プラスチックフィルムの片面に接着剤を
塗布して半硬化状態とし、この接着剤面をコロナ放電に
より表面処理したものと２）原紙の両面にポリ−４−メ
チルペンテン−１フィルムを貼り合せた離型紙とを積層
してなるカバーレイフィルムにある。The present inventors have reached the present invention as a result of various studies on the surface treatment of the adhesive in order to solve the above-mentioned problems, and have reached the present invention. 1) An adhesive is applied to one side of a heat-resistant insulating plastic film to make it a semi-cured state, and this adhesive side is surface-treated by corona discharge. 2) Poly-4-methylpentene-1 film is applied to both sides of the base paper. It is a coverlay film formed by laminating release paper that has been stuck together.
【０００５】以下、本発明について詳細に説明する。先
ず、本発明で使用する耐熱性絶縁プラスチックフィルム
としては、ポリイミド、ポリエチレンテレフタレート、
ポリフェニレンスルフィドポリパラバン酸、ポリエーテ
ル・エーテルケトン等の各フィルムが挙げられるが、中
でもポリイミドフィルムが好適に用いられる。The present invention will be described in detail below. First, as the heat-resistant insulating plastic film used in the present invention, polyimide, polyethylene terephthalate,
Examples of the film include polyphenylene sulfide polyparabanic acid and polyether / etherketone. Among them, a polyimide film is preferably used.
【０００６】耐熱性接着剤としては、エポキシ・フェノ
ール／ポリエステル、 NBR／フェノール、エポキシ・フ
ェノール／ NBR、 NBR／エポキシ、エポキシ／ポリエス
テル、エポキシ／アクリル、アクリル等の各合成樹脂系
接着剤が挙げられ、これらの内１種または２種以上混合
して使用しても良い。中でもエポキシ・フェノール／ポ
リエステル、 NBR／エポキシ、エポキシ／ポリエステル
等難燃剤やフィラー等の添加によりタック性の小さいも
のが好適である。Examples of heat-resistant adhesives include synthetic resin adhesives such as epoxy / phenol / polyester, NBR / phenol, epoxy / phenol / NBR, NBR / epoxy, epoxy / polyester, epoxy / acrylic and acrylic. Of these, one kind or a mixture of two or more kinds may be used. Among them, epoxy / phenol / polyester, NBR / epoxy, epoxy / polyester, etc. having low tackiness by adding flame retardants or fillers are preferable.
【０００７】本発明の最も特徴とするところは、耐熱性
絶縁フィルムに塗布し、半硬化状態とした耐熱性接着剤
面をコロナ放電により表面処理することにある。即ち、
コロナ放電処理により表面処理した接着剤面と TPXフィ
ルムとの密着性が向上する。コロナ放電処理は、フィル
ム基材（以下半硬化状態の耐熱性接着剤付き耐熱性絶縁
フィルムをいう）を支持するローラーとこれに対向して
設置した電極との間に高電圧をかけてコロナ放電を発生
させ、その間をフィルム基材を順次移動させてフィルム
表面を処理する方法が好ましい。具体的な装置として
は、高周波発信器、高圧トランス、放電電極からなり、
高周波発信器は、周波数１〜110KHz、最大出力 0.3〜40
KWのものが好ましい。処理スピードは、１〜 200ｍ/mi
n、好ましくは10〜 100ｍ/minである。１ｍ/min未満で
は接着剤と TPXフィルム貼り離型紙との密着性が強過ぎ
るため、フィルムと離型紙の剥離が困難となり、200 ｍ
/minを越えると逆に接着剤と TPXフィルム貼り離型紙と
の密着性が弱くなる。The most characteristic feature of the present invention resides in that the heat-resistant adhesive surface, which is applied to a heat-resistant insulating film and is in a semi-cured state, is surface-treated by corona discharge. That is,
The adhesion between the adhesive surface treated by corona discharge treatment and the TPX film is improved. Corona discharge treatment is performed by applying a high voltage between a roller supporting a film base material (hereinafter referred to as a heat-resistant insulating film with a heat-resistant adhesive in a semi-cured state) and an electrode placed opposite to the corona discharge treatment. Is generated and the film substrate is sequentially moved between them to treat the film surface. As a concrete device, it consists of a high frequency oscillator, a high voltage transformer, a discharge electrode,
The high frequency oscillator has a frequency of 1 to 110 KHz and a maximum output of 0.3 to 40
KW's are preferred. Processing speed is 1 ~ 200m / mi
n, preferably 10 to 100 m / min. If it is less than 1 m / min, the adhesion between the adhesive and the release paper on which the TPX film is attached is too strong, making it difficult to peel the film from the release paper.
If it exceeds / min, the adhesiveness between the adhesive and the release paper with TPX film weakens.
【０００８】本発明で使用する離型紙は、原紙の両面に
TPXフィルムを貼り合せたものである。ここに用いる T
PXフィルムはその厚さが５〜50μｍの範囲が好ましく、
５μｍ未満では、 TPXフィルムの硬さ特性が離型紙に反
映されず、孔加工時に離型紙がクッション的な作用を及
ぼし、加工性に劣る。また、50μｍを越えると離型紙が
硬くなり過ぎて、孔加工時の金型の摩耗を促進し、打ち
抜き回数が低下する。また、片面にのみ TPXフィルムを
貼り合わせた離型紙では吸放湿防止性が与えられていな
いため接着剤付き耐熱性絶縁フィルムと離型紙の湿度変
化による寸法変化率の違いから湿度の低い冬期、湿度の
高い梅雨時に、カバーレイフィルムにカールが発生する
欠点を持ち使用に堪えない。The release paper used in the present invention is provided on both sides of the base paper.
It is a combination of TPX films. T used here
The thickness of the PX film is preferably in the range of 5 to 50 μm,
When the thickness is less than 5 μm, the hardness characteristics of the TPX film are not reflected in the release paper, and the release paper exerts a cushioning effect during perforation, resulting in poor processability. On the other hand, if the thickness exceeds 50 μm, the release paper becomes too hard, which accelerates the wear of the mold during drilling and reduces the number of punches. In addition, since the release paper with the TPX film bonded to only one side does not have moisture absorption and desorption prevention properties, the heat-resistant insulating film with adhesive and the release paper have different dimensional change rates due to humidity changes. The cover lay film has the drawback of curling during the rainy season, which makes it unusable.
【０００９】次に本発明のカバーレイフィルムの製造方
法を述べる。先ず前記耐熱性接着剤の有機溶剤溶液を耐
熱性絶縁フィルムに乾燥状態で10〜60μｍになるように
塗布し、溶剤を除去して接着剤を半硬化状態とする。こ
の場合必要に応じて 100℃程度に短時間加熱することも
ある。次にこの半硬化状態の耐熱性接着剤付き耐熱性絶
縁フィルムの接着剤面をコロナ放電により表面処理し、
前記離型紙と重ね合わせ、ロールラミネーター等により
圧着積層し、ロール状に巻き取って製造される。Next, a method for producing the coverlay film of the present invention will be described. First, an organic solvent solution of the heat-resistant adhesive is applied to the heat-resistant insulating film so as to have a thickness of 10 to 60 μm, and the solvent is removed to bring the adhesive into a semi-cured state. In this case, it may be heated to about 100 ° C for a short time if necessary. Next, the adhesive surface of the heat-resistant insulating film with heat-resistant adhesive in this semi-cured state is surface-treated by corona discharge,
It is manufactured by stacking it on the release paper, pressing and laminating it with a roll laminator, etc., and winding it into a roll.
【００１０】以下、発明の実施態様を実施例を挙げて具
体的に説明するが、本発明はこれらに限定されるもので
はない。なお、具体例中の部数および％は全て固形分の
重量による。The embodiments of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. All parts and percentages in the specific examples are based on the weight of the solid content.
（接着剤の調整）エピコート5050（臭素化ビスフェノー
ルＡ型エポキシ樹脂、油化シェルエポキシ社製商品名）
40部、エピコート5049（エポキシ樹脂、油化シェルエポ
キシ社製商品名）60部、ニポール1072（カルボキシル基
含有ニトリルゴム、日本ゼオン社製商品名）35部、硬化
剤・ 4,4−ジアミノジフェニルスルホン15部、充填剤・
水酸化アルミニウム40部を MEKに溶解し、ボールミルに
より均一に分散させ、固形分30％の MEK溶液とする。 （実施例１〜４、比較例１、２）厚さ25μｍのポリイミ
ドフィルムに前記接着剤溶液を乾燥後の塗布厚さが30μ
ｍになるように塗布し、80℃×２分、 120℃×５分加熱
乾燥し溶剤を除去し、接着剤を半硬化状態にした。次
に、この半硬化状態の接着剤面を表１に示した条件でコ
ロナ放電により表面処理した接着剤付き耐熱性絶縁フィ
ルムと離型紙とをロールラミネーターにより温度40℃、
ロール圧着の線圧５kg/cm で圧着積層してカバーレイフ
ィルムを作製した。カバーレイフィルムの性能評価はそ
の離型性と打ち抜き性を測定して表１に併記した。(Adhesive preparation) Epicoat 5050 (Brominated bisphenol A type epoxy resin, trade name of Yuka Shell Epoxy Co., Ltd.)
40 parts, Epicoat 5049 (epoxy resin, trade name manufactured by Yuka Shell Epoxy Co., Ltd.) 60 parts, Nipol 1072 (carboxyl group-containing nitrile rubber, manufactured by Nippon Zeon Co., Ltd.) 35 parts, curing agent, 4,4-diaminodiphenyl sulfone 15 parts, filler
Dissolve 40 parts of aluminum hydroxide in MEK and uniformly disperse with a ball mill to obtain a MEK solution with a solid content of 30%. (Examples 1 to 4, Comparative Examples 1 and 2) A coating thickness after drying the adhesive solution on a polyimide film having a thickness of 25 μm is 30 μm.
It was applied so as to have a thickness of m, and heated and dried at 80 ° C. for 2 minutes and 120 ° C. for 5 minutes to remove the solvent, and the adhesive was semi-cured. Then, the semi-cured adhesive surface was subjected to surface treatment by corona discharge under the conditions shown in Table 1 with a heat-resistant insulating film with adhesive and release paper at a temperature of 40 ° C. with a roll laminator.
A coverlay film was produced by laminating under pressure at a roll pressure of 5 kg / cm. For the evaluation of the performance of the coverlay film, its releasability and punching property were measured and shown in Table 1.
【００１１】表１に示したカバーレイフィルムの物性測
定法は以下のとおりである。 １）離型性：幅50mmのサンプルを 180°方向に100mm/mi
n.の速度で接着剤付きポリイミドフィルムを引き剥す。 ２）打ち抜き性：24cm×30cmサイズのカバーレイフィル
ムを２枚積み重ね、３mmφの穴を 500穴パンチングし、
各パンチング穴の外観を検査する。 評価：○ 完全にパンチングされ、外観良好。 △ 若干パンチング穴の抜けが悪い。 × ５％以上のパンチング穴の抜け残りがある。The methods of measuring the physical properties of the coverlay film shown in Table 1 are as follows. 1) Releasability: A sample with a width of 50 mm is 100 mm / mi in the 180 ° direction.
Peel the polyimide film with adhesive at a speed of n. 2) Punching performance: Stack two cover lay films of 24cm x 30cm size, punch 500 holes of 3mmφ,
Inspect the appearance of each punched hole. Evaluation: ○ Completely punched and good appearance. △ The punching holes are slightly missing. × 5% or more of the punching holes are left over.
【００１２】[0012]
【表１】[Table 1]
【００１３】[0013]
【発明の効果】本発明のカバーレイフィルムは、湿度変
化によるカールの発生がなく、耐熱性接着剤と両面 TPX
フィルム貼り離型紙との密着性に優れ、孔加工、切断等
の機械的連続加工性が改善された。さらに、シリコーン
系離型剤等による離型処理が不要であるため、Ｂステー
ジの耐熱性接着剤面への転写もなく、接着剤の持つ基材
との接着性を維持することができる等の特徴を有してい
る。本発明により優れたフレキシブルプリント回路用の
保護カバーレイフィルムを提供することが可能となり、
実用上その利用価値は極めて高い。EFFECTS OF THE INVENTION The coverlay film of the present invention does not cause curling due to humidity change, and has a heat-resistant adhesive and double-sided TPX.
It has excellent adhesion to film-release paper and has improved mechanical continuous processability such as hole making and cutting. Furthermore, since the release treatment with a silicone-based release agent is unnecessary, there is no transfer to the heat-resistant adhesive surface of the B stage, and the adhesiveness with the base material of the adhesive can be maintained. It has features. The present invention makes it possible to provide an excellent protective coverlay film for a flexible printed circuit,
Its practical utility is extremely high.
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2720992AJPH05193065A (en) | 1992-01-17 | 1992-01-17 | Overlay film |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2720992AJPH05193065A (en) | 1992-01-17 | 1992-01-17 | Overlay film |
| Publication Number | Publication Date |
|---|---|
| JPH05193065Atrue JPH05193065A (en) | 1993-08-03 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2720992APendingJPH05193065A (en) | 1992-01-17 | 1992-01-17 | Overlay film |
| Country | Link |
|---|---|
| JP (1) | JPH05193065A (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120231263A1 (en)* | 2009-11-20 | 2012-09-13 | E.I. Du Pont De Nemours And Company | Coverlay compositions and methods relating thereto |
| CN108586847A (en)* | 2018-05-21 | 2018-09-28 | 南昌正业科技有限公司 | A kind of low halogen cover film |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120231263A1 (en)* | 2009-11-20 | 2012-09-13 | E.I. Du Pont De Nemours And Company | Coverlay compositions and methods relating thereto |
| CN108586847A (en)* | 2018-05-21 | 2018-09-28 | 南昌正业科技有限公司 | A kind of low halogen cover film |
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