JP3564718B2 - Adhesive materials for heat spreaders - Google Patents

Abstract

PURPOSE:To provide a heat-resistant adhesive material having good puntchability and excellent heat-resistance and electrical characteristics, enabling the bonding at a low temperature and effective for remarkably simplifying the production process of a package for semiconductor mounting use by laminating a heat-resistant adhesive to a metallic foil. CONSTITUTION:This heat-resistant adhesive material is a laminate having a heat-resistant adhesive layer on at least one surface of a metallic foil (preferably copper-based metallic foil, etc.). The heat-resistant adhesive is preferably a polyimide resin thin film produced by reacting an aromatic tetracarboxylic acid such as 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride with a diamine component containing >=70mol% of a siloxane-based diamine consisting of 1,1,3,3-tetramethyl-1,3-bis(4-aminopropyl)disiloxane and imidating the obtained polyamic acid. The material can be produced e.g. by extruding a solvent solution containing the varnish of the above polyamic acid through a film-forming slit, uniformly applying the solution to a surface of a metallic foil, removing the solvent with heat and heat-treating the product for imidation.

Description

（ただし、式中ｎは１以上の整数を示す。またＲ_１ およびＲ_２ は、それぞれ同一または異なって、低級アルキレン基またはフェニレン基を示し、Ｒ_３ 、Ｒ_４ 、Ｒ_５ およびＲ_６ は、それぞれ同一または異なって、低級アルキル基、フェニル基またはフェノキシ基を示す。）
一般式［Ｉ］で表されるシロキサン系ジアミンの具体例としては、１，１，３，３−テトラメチル−１，３−ビス（４−アミノフェニル）ジシロキサン、１，１，３，３−テトラフェノキシ−１，３−ビス（４−アミノエチル）ジシロキサン、１，１，３，３，５，５−ヘキサメチル−１，５−ビス（４−アミノフェニル）トリシロキサン、１，１，３，３−テトラフェニル−１，３−ビス（２−アミノエチル）ジシロキサン、１，１，３，３−テトラフェニル−１，３−ビス（３−アミノプロピル）ジシロキサン、１，１，５，５−テトラフェニル−３，３−ジメチル−１，５−ビス（３−アミノプロピル）トリシロキサン、１，１，５，５−テトラフェニル−３，３−ジメトキシ−１，５−ビス（４−アミノブチル）トリシロキサン、１，１，５，５−テトラフェニル−３，３−ジメトキシ−１，５−ビス（５−アミノペンチル）トリシロキサン、１，１，３，３−テトラメチル−１，３−ビス（２−アミノエチル）ジシロキサン、１，１，３，３−テトラメチル−１，３−ビス（３−アミノプロピル）ジシロキサン、１，１，３，３−テトラメチル−１，３−ビス（４−アミノブチル）ジシロキサン、１，３−ジメチル−１，３−ジメトキシ−１，３−ビス（４−アミノブチル）ジシロキサン、１，１，５，５−テトラメチル−３，３−ジメトキシ−１，５−ビス（２−アミノエチル）トリシロキサン、１，１，５，５−テトラメチル−３，３−ジメトキシ−１，５−ビス（４−アミノブチル）トリシロキサン、１，１，５，５−テトラメチル−３，３−ジメトキシ−１，５−ビス（５−アミノペンチル）トリシロキサン、１，１，３，３，５，５−ヘキサメチル−１，５−ビス（３−アミノプロピル）トリシロキサン、１，１，３，３，５，５−ヘキサエチル−１，５−ビス（３−アミノプロピル）トリシロキサン、１，１，３，３，５，５−ヘキサプロピル−１，５−ビス（３−アミノプロピル）トリシロキサン、などが挙げられるが好ましくは、１，１，３，３−テトラメチル−１，３−ビス（３−アミノプロピル）ジシロキサンである。上記シロキサン系ジアミンは、単独あるいは二種以上混合して用いられる。
【００１７】
シロキサン系ジアミン以外のジアミン成分としては、４，４´−ジアミノジフェニルエーテル、４，４´−ジアミノジフェニルメタン、４，４´−ジアミノジフェニルスルホン、パラフェニレンジアミン等の公知のものを使用しうる。
【００１８】
上記芳香族テトラカルボン酸とジアミンとの反応は、従来公知の方法に準じて行うことができる。例えば、略化学量論量の酸成分とジアミン成分とを、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ，Ｎ−ジメチルアセトアミド、Ｎ−メチル−２ピロリドン等の有機溶媒中で、０〜８０℃の温度で反応させれば良い。これらの溶媒は、単独あるいは２種以上混合して用いられ、ポリアミック酸が折出しない程度であれば、ベンゼン、トルエン、ヘキサン、シクロヘキサン、テトラヒドロフラン、メチルエチルケトン等を加えても良い。
【００１９】
ポリアミック酸ワニス濃度は、特に限定されないが、通常５〜６０重量％が好ましく１０〜４０重量％がとくに好ましい。
【００２０】
本発明の耐熱性接着材料は、加熱温度１００〜３００℃において発生するガス量が１０００ｐｐｍ以下の条件を満足することが重要である。発生ガス量が１０００ｐｐｍ以下であれば金属箔、耐熱樹脂、リードフレームなどと接着した場合の発泡は無いが、好ましくは２００ｐｐｍ以下さらに好ましくは１００ｐｐｍ以下が良い。
【００２１】
ここで、耐熱接着材料の加熱温度１００〜３００℃において発生するガス量とは該耐熱接着材料のサンプルについて後述するＴＧ・ＤＴＧ−ＭＳ法
「ＴＧ ：Ｔｈｅｒｍｏｇｒａｖｉｍｅｔｒｉｃ Ａｎａｌｙｓｉｓ （熱重量分析）
ＤＴＧ：Ｄｅｒｉｖａｔｉｖｅ ＴｈｅｒｍｏｇｒａｖｉｍｅｔｒｉｃＡｎａｌｙｓｉｓ （微分熱重量分析）
ＭＳ ：Ｍａｓｓ Ｓｐｅｃｔｏｒｍｅｔｒｙ （質量分析） 」
により測定して求めたものである。
【００２２】
このような諸特性を満足する本発明の耐熱性接着材料を得る方法としては、例えば、次の方法があげられる。
【００２３】
すなわち金属箔上に、上記ポリアミック酸ワニスを１０〜４０重量％含む溶媒溶液を製膜用スリットから吐出させて均一に塗工する。この塗工方法としてはロールコータ、ナイフコータ、密封コータ、コンマコータ、ドクターブレードフロートコータなどによるものが挙げられる。次に上記のように耐熱性樹脂フィルムに塗工した溶液の溶媒を、通常６０℃以上１９０℃程度の温度で連続的または断続的に１０〜６０分間で加熱除去した後、さらにイミド化するための加熱処理を行なう。イミド化するための加熱処理としては２００〜３５０℃の範囲で１〜１５分程度の加熱処理を行なうことが好ましい。
【００２４】
このようにして金属箔上に３〜３０μｍのポリアミック酸のイミド化した薄膜を形成する。その後、汚染防止、キズ防止などの必要に応じ厚み１５〜６０μｍのポリエステルフィルム、ポリプロピレンなどの保護フィルムをイミド化せしめた薄膜上に張り合わせておくことが好ましい。
【００２５】
本発明品の使用例の一部として、金属との積層、例えば耐熱樹脂フィルムとの積層するフレキシプリント基板用途、ＴＡＢ用キャリアテープおよびリードフレーム固定用接着テープ、ヒートスプレッダー用接着テープ、ＬＯＣ用接着テープなどのリードフレーム周辺材料など種々あげられる。
【００２６】
具体例としてＬＯＣ用接着テープに使用する場合には、本発明品を使用目的の幅にスリットしたあと、吸着水分を除去後リードフレームと重ね合わせ１５０℃以上３００℃で加熱圧着し、さらにＩＣチップを接着固定すれば良い。接着力向上のためにはさらに加熱キュアを施したほうが好ましい。圧着の温度、圧力および加熱キュアの条件は樹脂の組成、膜厚、などによって適宜選定すればよい。また、加熱圧着の方法は、ヒートプレス、加熱ロールなど製造工程によって好ましく選定すれば良い。
【００２７】
【実施例】
以下、本発明を実施例に基づいて詳細に説明するが、本発明はこれらに限定されるものではない。なお、以下の説明で発泡、加熱時の発生ガス量および接着力はそれぞれ次の方法で評価および測定したものである。
【００２８】
［発泡］
銅箔をエッチング除去後、接着剤表面を光学顕微鏡によって観察した。
［発生ガス量］
イミド化した薄膜を有する試料約１００ｍｇを精密科学天秤で秤量後、ＤＴ・ＤＴＧ−ＭＳ法によって測定した。
【００２９】
ＤＴ・ＤＴＧ−ＭＳ法とは、ＴＧ装置にＭＳ装置を直結して、重量変化と同時に、加熱時に試料から発生するガスの濃度変化を温度の関数として追跡する手法である。測定機および測定条件はつぎのとおりである。
【００３０】
測定機 ；島津制作所（株）製ＴＧ（マクロ天秤）−ＭＳ同時測定装置
データ処理；東レリサーチセンター製データ処理システム“ＴＨＡＤＡＰ−ＴＧＭＳ”
測定精度 ；１０ｐｐｍ
測定モード；試料を白金製容器に入れてあらかじめ５０℃で６時間真空乾燥した後、ＴＧ装置にセット後、乾燥ヘリウムを５０ｍｌ／分で１２時以上流してから、１０℃／分で昇温を開始し、４００℃までのＴＧ−ＭＳ曲線を測定し、１５０℃から３００℃の発生ガスの総量を求めた。
【００３１】
［接着力］
＊ＬＯＣ用およびヒートスプレッダー用接着テープ
接着剤つき金属箔を、幅１０ｍｍ、長さ１００ｍｍに切断したあと、同じサイズの厚み０．２ｍｍの銅箔を、図１に示すように接着面積が１ｃｍ^２ になるように重ね合わせた後、熱圧着し、雰囲気温度１９０℃に２分おいたあと、剪断応力をテンシロンにて、引張り速度５０ｍｍ／分で測定した。実用的は、１．０ｋｇ／ｃｍ^２ 以上の接着力が必要とされる。
【００３２】
［パンチング性］
金型で接着剤つき金属箔を、図２に示す形状にパンチングしたあと、エッジを実態顕微鏡（ＮＩＫＯＮ （株）ＮＳＭＺ−１０；倍率１３．２〜８０倍）で観察し「バリ」などの異物の有無をみた。
【００３３】
実施例１
温度計、攪拌装置、還流コンデンサおよび乾燥Ｎ_２ 吹込口を供えた３００ｍｌの４口フラスコにＮ，Ｎ−ジメチルアセトアミド１７５ｇ入れ窒素気流下でビス（３−アミノプロピル）テトラメチルジシロキサン１４．１１ｇ（９２ｍｏｌ％）および４、４´−ジアミノジフェニルエーテル０．９９ｇ（８ｍｏｌ％）を溶解したあと、３，３´，４，４´−ベンゾフェノンテトラカルボン酸二無水物１９．８９ｇ（１００ｍｏｌ％）を加え、１０℃で１時間攪拌を続けた。その後５０℃で３時間攪拌して反応させポリアミック酸ワニスを得た。
【００３４】
該ワニスを、厚み０．２０ｍｍの銅箔上に乾燥後の厚みが１０μｍになるように塗工し、窒素雰囲気中で１３０℃で１０分乾燥し、さらに、２００℃で２分乾燥し、さらに、２４０℃で５分加熱処理し、１００℃以下になってから取り出した。該塗工品の発生ガス量を測定したところ、５０ｐｐｍ以下であった。
【００３５】
上記作製接着剤つき金属箔を図１に示すヒートスプレッダー用の形状にパンチングしたところ、「バリ」および「屑」の発生はなかった。さらに、該塗工品と，厚み０．２００ｍｍの銅箔とを重ね合わせ、表面温度１９０℃に加熱したロールラミネータで線圧７ｋｇ／ｃｍ、速度０．５ｍ／分で張り合わせた。発泡は認められず、接着力（剪断応力）を測定したところ、１０ｋｇ／ｃｍ^２ であり、ＬＯＣ用およびヒートスプレッダー用接着テープとして、実用レベルを満足する値であった。
【００３６】
実施例２
実施例１と同様の反応装置にＮ，Ｎ−ジメチルアセトアミド１４６ｇ入れ窒素気流下でビス（３−アミノプロピル）テトラメチルジシロキサン１４．３３ｇ（９０ｍｏｌ％）およびパラフェニレンジアミン０．６９ｇ（１０ｍｏｌ％）を溶解したあと、３，３´，４，４´−ベンゾフェノンテトラカルボン酸二無水物１８．５８ｇ（９０ｍｏｌ％）およびピロメリット酸二無水物１．４０ｇ（１０ｍｏｌ％）を加え、１０℃で１時間攪拌を続けた。その後５０℃で３時間攪拌して反応させポリアミック酸ワニスを得た。
【００３７】
該ワニスを実施例１と同じ金属箔上に、乾燥後の厚みが７μｍになるように塗工し、実施例１と同じ条件で窒素雰囲気中で乾燥、熱処理し、試料を作製した。
該塗工品の発生ガス量を測定したところ、５０ｐｐｍ以下であった。
【００３８】
上記作製接着剤つき金属箔を、図１に示すヒートスプレッダー用の形状にパンチングしたところ、「バリ」および「屑」の発生はなかった。さらに、該塗工品と銅箔とを重ね合わせ、表面温度１９０℃に加熱したロールラミネータで線圧７ｋｇ／ｃｍ、速度０．５ｍ／分で張り合わせた。発泡は認められず、接着力（剪断応力）を測定したところ、１０ｋｇ／ｃｍ^２ であり、ＬＯＣ用およびヒートスプレッダー用接着テープとして、実用レベルを満足する値であった。
【００３９】
実施例３
実施例２と同じ条件で作製した、接着剤つき銅箔と銅箔を張り合わせた試料を、イナート（窒素ガス雰囲気）オーブン中で加熱処理し、接着力を測定した結果、実施例２よりも接着力がさらに向上し、１５ｋｇ／ｃｍ^２ であり、ＬＯＣ用およびヒートスプレッダー用接着テープとして、実用レベルを十分満足する値であった。
【００４０】
実施例４
実施例２で得たポリアミック酸ワニスを、両面を低温プラズマ処理した６μｍのポリフェニレンスルファイド樹脂フィルム（“トレリナ”（東レ（株）製））に乾燥後の膜厚が、それぞれ６μｍになるように塗工し、８０℃で１０分乾燥し、さらに、１２０℃で１０分乾燥、さらに、１５０℃で１５分乾燥した。該塗工品をイミド化のため、２３０℃で５分加熱処理を施した。該フィルムの発生ガス量を測定したところ６０ｐｐｍ以下であった。
【００４１】
上記作製フィルムの接着剤樹脂塗工面と、０．２ｍｍの銅箔とを重ね合わせ表面温度２２０℃に加熱したロールラミネータで線圧７ｋｇ／ｃｍ、速度１ｍ／分で張り合わせ、積層体を得た。該積層体を厚み０．２ｍｍの銅フレーム材と重ね合わせ、表面温度１９０℃に加熱したロールラミネータで線圧７ｋｇ／ｃｍ、速度０．５ｍ／分で張り合わせた。発泡は認められず、接着力（剪断応力）を測定したところ、１０ｋｇ／ｃｍ^２ であり、ＬＯＣ用およびヒートスプレッダー用接着テープとして、実用レベルを満足する値であった。
【００４２】
【発明の効果】
本発明は上述のごとく構成したので、金属、耐熱性樹脂などと接着が容易に可能なうえ、パンチング時に「屑」の発生がなく、さらに張り合わせ後の発泡がなく、接着性、耐熱性、および電気特性が優れる耐熱性接着材料を確実に得ることができる。また、半導体実装用パッケージを製造するに際し、工程を大幅に簡略化でき、短時間かつ経済的に製造が可能になる。
【図面の簡単な説明】
【図１】本発明の耐熱性接着材料の剪段応力（接着力）を測定するための試料を表す図である。
【図２】本発明の耐熱性接着材料のパンチング形状の一例を表す図である。[0001]
[Industrial applications]
The present invention relates to a heat-resistant adhesive material, and more particularly, to a high-quality heat-resistant adhesive material having high adhesive strength.
[0002]
[Prior art]
As electronic devices have become smaller and higher in performance, small, thin, lightweight, and high-density packages have also been required in the field of semiconductor mounting.
[0003]
In this semiconductor mounting technology, the development of a high-performance heat-resistant adhesive tape for joining components has been required.
[0004]
For example, a LOC (lead on chip) adhesive tape for fixing an IC chip on a lead frame with a double-sided adhesive tape, and a heat spreader adhesive tape for bonding an IC chip and a metal heat radiating plate for heat dissipation of the IC chip. .
[0005]
At present, this adhesive tape uses a polyimide film coated on both sides with an epoxy thermosetting adhesive.
[0006]
For example, an example of a process for manufacturing a heat spreader package using this tape is as follows (1) to (12). That is,
(1) Punch a metal plate to the size of a heat spreader (2) Punch an adhesive tape according to the size of a metal plate for a heat spreader (3) Remove "punching debris" at the time of punching (4) Adhere to the punched metal plate Laminating the tape (5) Bonding by heating (6) Bonding the bonded product obtained in (5) with a predetermined lead frame (7) Curing under predetermined conditions (8) Bonding and fixing the IC on a heat spreader (9) If necessary, cure under predetermined conditions (10) Wire-bond the IC and the lead frame (11) Seal with resin (12) Cure
Here, an adhesive that does not generate “punching debris” on the metal plate without using an adhesive tape, that is, a material that has a good “cut” and a heat-resistant adhesive that does not require curing, that is, a metal foil material with a heat-resistant adhesive is used. The present inventors have found that if used, the four steps (2), (3), (4) and (5) of the above steps can be omitted, and the production can be performed in a short time and economically. We studied diligently to make this technology practical.
[0008]
[Problems to be solved by the invention]
That is, an object of the present invention is to provide a heat-resistant adhesive material which can greatly simplify the steps in manufacturing a package for semiconductor mounting and can be manufactured in a short time and economically.
[0009]
[Means for Solving the Problems]
That is, the present invention is a polyimide resin heat resistant adhesive of the laminate having at least one surface heat-resistant adhesive of the metal foil, the polyimide resin is 70 an aromatic tetracarboxylic acid, a siloxane diamine Ri Do polyamic acid obtained by reacting a diamine component containing mol% or more from the imidized film is achieved by the production method of the heat spreader, wherein the punching combined laminate to the shape of the heat spreader .
[0010]
The metal foil in the present invention may be any material that is generally used as a semiconductor mounting material. For example, copper-based alloys and 42 alloys are preferable, but aluminum, stainless steel and the like may be used.
[0011]
The heat-resistant adhesive of the present invention is preferably a polyimide resin having a Tg of 150 ° C. or lower. Further, the present adhesive may be laminated on a heat-resistant resin film such as a polyimide film and a polyphenylene sulfide film. When Tg exceeds 150 ° C., the bondable temperature is unlikely to fall below 200 ° C. If the temperature at which the bonding is possible exceeds 200 ° C., the surface oxidation of the copper foil becomes unfavorable when a copper foil is used as the metal foil.
[0012]
The bondable temperature in the present invention is as follows: a metal foil with an adhesive is cut into a width of 10 mm and a length of 100 mm, and a copper foil of the same size having a thickness of 0.2 mm is laminated, and then thermocompression-bonded to obtain a width of 5 mm. The temperature at which the 90-degree peel strength at a tensile speed of 50 mm / min is 0.5 kg / cm or more at a tensile rate of 10 kg after cutting into pieces.
[0013]
The polyimide resin preferably used in the present invention is a thin film obtained by imidizing a polyamic acid obtained by reacting an aromatic tetracarboxylic acid with a diamine component containing at least 70 mol% of a siloxane-based diamine. When the diamine component is other than the siloxane-based diamine, "punching debris" is liable to be generated at the time of punching, and when the siloxane-based diamine is at most 70 mol%, the bondable temperature will not easily become 200 ° C. or less. 80 mol% or more is preferable from an adhesive point.
[0014]
The aromatic tetracarboxylic acid used in the present invention includes 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenonetetracarboxylic dianhydride, , 2 ', 3,3'-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3 '-Biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, bis ( 3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3 Dicarboxyphenyl) methane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalene Tetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic Acid dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, and the like are used. These may be used alone or in combination of two or more.
[0015]
Examples of the siloxane-based diamine used in the present invention include those represented by the following general formula [I].
[0016]
Embedded image

(Wherein, n represents an integer of 1 or more. R ₁ and R ₂ are the same or different and each represents a lower alkylene group or a phenylene group; and R ₃ , R ₄ , R _5, and R ₆ represent The same or different, each represents a lower alkyl group, a phenyl group or a phenoxy group.)
Specific examples of the siloxane-based diamine represented by the general formula [I] include 1,1,3,3-tetramethyl-1,3-bis (4-aminophenyl) disiloxane, 1,1,3,3 -Tetraphenoxy-1,3-bis (4-aminoethyl) disiloxane, 1,1,3,3,5,5-hexamethyl-1,5-bis (4-aminophenyl) trisiloxane, 1,1, 3,3-tetraphenyl-1,3-bis (2-aminoethyl) disiloxane, 1,1,3,3-tetraphenyl-1,3-bis (3-aminopropyl) disiloxane, 1,1, 5,5-tetraphenyl-3,3-dimethyl-1,5-bis (3-aminopropyl) trisiloxane, 1,1,5,5-tetraphenyl-3,3-dimethoxy-1,5-bis ( 4-aminobutyl) trisiloxane, 1 1,5,5-tetraphenyl-3,3-dimethoxy-1,5-bis (5-aminopentyl) trisiloxane, 1,1,3,3-tetramethyl-1,3-bis (2-aminoethyl ) Disiloxane, 1,1,3,3-tetramethyl-1,3-bis (3-aminopropyl) disiloxane, 1,1,3,3-tetramethyl-1,3-bis (4-aminobutyl ) Disiloxane, 1,3-dimethyl-1,3-dimethoxy-1,3-bis (4-aminobutyl) disiloxane, 1,1,5,5-tetramethyl-3,3-dimethoxy-1,5 -Bis (2-aminoethyl) trisiloxane, 1,1,5,5-tetramethyl-3,3-dimethoxy-1,5-bis (4-aminobutyl) trisiloxane, 1,1,5,5- Tetramethyl-3,3-dimethoxy-1,5 Bis (5-aminopentyl) trisiloxane, 1,1,3,3,5,5-hexamethyl-1,5-bis (3-aminopropyl) trisiloxane, 1,1,3,3,5,5- Hexaethyl-1,5-bis (3-aminopropyl) trisiloxane, 1,1,3,3,5,5-hexapropyl-1,5-bis (3-aminopropyl) trisiloxane, and the like. Preferably, it is 1,1,3,3-tetramethyl-1,3-bis (3-aminopropyl) disiloxane. The siloxane-based diamines are used alone or in combination of two or more.
[0017]
As the diamine component other than the siloxane-based diamine, known diamine components such as 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, and paraphenylenediamine can be used.
[0018]
The reaction between the aromatic tetracarboxylic acid and the diamine can be performed according to a conventionally known method. For example, a substantially stoichiometric amount of an acid component and a diamine component can be prepared at a temperature of 0 to 80 ° C. in an organic solvent such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone. You only have to react. These solvents may be used alone or as a mixture of two or more kinds, and benzene, toluene, hexane, cyclohexane, tetrahydrofuran, methyl ethyl ketone and the like may be added as long as the polyamic acid is not separated out.
[0019]
The concentration of the polyamic acid varnish is not particularly limited, but is usually preferably 5 to 60% by weight, and particularly preferably 10 to 40% by weight.
[0020]
It is important that the heat-resistant adhesive material of the present invention satisfies the condition that the amount of gas generated at a heating temperature of 100 to 300 ° C. is 1000 ppm or less. When the amount of generated gas is 1000 ppm or less, there is no foaming when bonded to a metal foil, a heat-resistant resin, a lead frame, or the like, but preferably 200 ppm or less, more preferably 100 ppm or less.
[0021]
Here, the amount of gas generated at a heating temperature of the heat-resistant adhesive material of 100 to 300 ° C. refers to a TG / DTG-MS method “TG: Thermogravimetric Analysis (thermogravimetric analysis)” for a sample of the heat-resistant adhesive material.
DTG: Derivative Thermogravimetric Analysis (Differential Thermogravimetric Analysis)
MS: Mass Spectrometry (Mass Spectrometry) "
It is obtained by measuring according to
[0022]
As a method for obtaining the heat-resistant adhesive material of the present invention satisfying such various properties, for example, the following methods can be mentioned.
[0023]
That is, a solvent solution containing 10 to 40% by weight of the above polyamic acid varnish is discharged from the slit for film formation onto the metal foil to be uniformly applied. Examples of the coating method include a roll coater, a knife coater, a sealing coater, a comma coater, and a doctor blade float coater. Next, the solvent of the solution applied to the heat-resistant resin film as described above is usually continuously or intermittently heated at a temperature of about 60 ° C. or more and about 190 ° C. for 10 to 60 minutes, and then further imidized. Is performed. As the heat treatment for imidization, it is preferable to carry out a heat treatment in the range of 200 to 350 ° C. for about 1 to 15 minutes.
[0024]
Thus, an imidized thin film of polyamic acid having a thickness of 3 to 30 μm is formed on the metal foil. After that, it is preferable that a protective film such as a polyester film or polypropylene having a thickness of 15 to 60 μm is adhered to the imidized thin film as required for preventing contamination and preventing scratches.
[0025]
Examples of the use of the product of the present invention include lamination with a metal, for example, a flexible printed circuit board laminated with a heat-resistant resin film, a carrier tape for TAB and an adhesive tape for fixing a lead frame, an adhesive tape for a heat spreader, and an adhesive for LOC. There are various types of peripheral materials for lead frames such as tapes.
[0026]
As a specific example, when used for an adhesive tape for LOC, after slitting the product of the present invention to the intended width, removing the adsorbed moisture, superimposing it on a lead frame, and heat-pressing at 150 ° C or more and 300 ° C, and furthermore, IC chip May be bonded and fixed. In order to improve the adhesive strength, it is preferable to further perform heat curing. The pressure, the pressure, and the conditions for the heat curing may be appropriately selected depending on the composition, the film thickness, and the like of the resin. In addition, the method of thermocompression bonding may be preferably selected depending on the manufacturing process such as a heat press or a heating roll.
[0027]
【Example】
Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto. In the following description, the amount of gas generated during foaming and heating and the adhesive force were evaluated and measured by the following methods, respectively.
[0028]
[Foaming]
After the copper foil was removed by etching, the surface of the adhesive was observed with an optical microscope.
[Amount of generated gas]
About 100 mg of a sample having an imidized thin film was weighed with a precision scientific balance, and then measured by the DT / DTG-MS method.
[0029]
The DT / DTG-MS method is a technique in which an MS device is directly connected to a TG device, and a change in the concentration of gas generated from the sample at the time of heating is tracked as a function of a temperature simultaneously with a change in weight. The measuring machine and the measuring conditions are as follows.
[0030]
Measuring machine; TG (macro balance) -MS simultaneous measurement device manufactured by Shimadzu Corporation Data processing; Data processing system "THADAP-TGMS" manufactured by Toray Research Center
Measurement accuracy: 10 ppm
Measurement mode: After placing the sample in a platinum container and vacuum-drying it at 50 ° C. for 6 hours in advance, setting it on a TG device, flowing dry helium at 50 ml / min for at least 12 hours, and then raising the temperature at 10 ° C./min. Starting, the TG-MS curve up to 400 ° C. was measured, and the total amount of generated gas at 150 ° C. to 300 ° C. was determined.
[0031]
[Adhesive strength]
* Adhesive tape for LOC and heat spreader After cutting the metal foil with adhesive into a 10 mm width and 100 mm length, a copper foil of the same size and a thickness of 0.2 mm is bonded to a copper foil having a bonding area of 1 cm ^{2 as} shown in FIG. Then, after thermocompression bonding and 2 minutes at an ambient temperature of 190 ° C., the shear stress was measured with Tensilon at a pulling speed of 50 mm / min. Practically, an adhesive force of 1.0 kg / cm ² or more is required.
[0032]
[Punching property]
After punching a metal foil with an adhesive into a shape shown in FIG. 2 using a mold, observe the edge with a stereoscopic microscope (NISMON Co., Ltd., NSMZ-10; magnification 13.2 to 80 times), and check for foreign matter such as "burr". I looked for it.
[0033]
Example 1
Thermometer, stirrer, reflux condenser and dry _{N 2} four-necked flask blow port the offerings were 300 ml N, N-dimethylacetamide 175g insertion under a nitrogen stream bis (3-aminopropyl) tetramethyl disiloxane 14.11 g ( After dissolving 0.99 g (8 mol%) of 4,4′-diaminodiphenyl ether and 19.89 g (100 mol%) of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, Stirring was continued at 10 ° C. for 1 hour. Thereafter, the mixture was stirred and reacted at 50 ° C. for 3 hours to obtain a polyamic acid varnish.
[0034]
The varnish is coated on a copper foil having a thickness of 0.20 mm so that the thickness after drying becomes 10 μm, dried at 130 ° C. for 10 minutes in a nitrogen atmosphere, further dried at 200 ° C. for 2 minutes, And heat-treated at 240 ° C. for 5 minutes. The amount of gas generated from the coated product was measured and found to be 50 ppm or less.
[0035]
When the above-prepared metal foil with an adhesive was punched into a shape for a heat spreader shown in FIG. 1, "burrs" and "dust" were not generated. Further, the coated product was superimposed on a copper foil having a thickness of 0.200 mm, and bonded with a roll laminator heated to a surface temperature of 190 ° C. at a linear pressure of 7 kg / cm and a speed of 0.5 m / min. Foaming was not observed, and the adhesive strength (shear stress) was measured. As a result, it was 10 kg / cm ² , which was a value satisfying a practical level as an adhesive tape for LOC and heat spreader.
[0036]
Example 2
146 g of N, N-dimethylacetamide was placed in the same reactor as in Example 1, and 14.33 g (90 mol%) of bis (3-aminopropyl) tetramethyldisiloxane and 0.69 g (10 mol%) of paraphenylenediamine were placed under a nitrogen stream. Is dissolved, and 18.58 g (90 mol%) of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and 1.40 g (10 mol%) of pyromellitic dianhydride are added thereto. Stirring was continued for hours. Thereafter, the mixture was stirred and reacted at 50 ° C. for 3 hours to obtain a polyamic acid varnish.
[0037]
The varnish was applied on the same metal foil as in Example 1 so that the thickness after drying became 7 μm, and dried and heat-treated in a nitrogen atmosphere under the same conditions as in Example 1 to prepare a sample.
The amount of gas generated from the coated product was measured and found to be 50 ppm or less.
[0038]
When the above-prepared metal foil with an adhesive was punched into a shape for a heat spreader shown in FIG. 1, "burrs" and "dust" were not generated. Further, the coated product and the copper foil were overlaid, and bonded together with a roll laminator heated to a surface temperature of 190 ° C. at a linear pressure of 7 kg / cm and a speed of 0.5 m / min. Foaming was not observed, and the adhesive force (shear stress) was measured. As a result, it was 10 kg / cm ² , which was a value satisfying a practical level as an adhesive tape for LOC and a heat spreader.
[0039]
Example 3
A sample prepared by bonding the copper foil with adhesive and the copper foil prepared under the same conditions as in Example 2 was heated in an inert (nitrogen gas atmosphere) oven, and the adhesive strength was measured. The force was further improved and was 15 kg / cm ² , which was a value sufficiently satisfying a practical level as an adhesive tape for LOC and heat spreader.
[0040]
Example 4
The polyamic acid varnish obtained in Example 2 was dried on a 6 μm polyphenylene sulfide resin film (“TORELINA” (manufactured by Toray Industries, Inc.)) whose both surfaces were subjected to low-temperature plasma treatment so that the film thickness after drying was 6 μm. It was applied, dried at 80 ° C. for 10 minutes, further dried at 120 ° C. for 10 minutes, and further dried at 150 ° C. for 15 minutes. The coated product was subjected to a heat treatment at 230 ° C. for 5 minutes for imidization. The amount of gas generated from the film was measured and found to be 60 ppm or less.
[0041]
The adhesive resin coated surface of the produced film and a copper foil of 0.2 mm were overlapped and bonded with a roll laminator heated to a surface temperature of 220 ° C. at a linear pressure of 7 kg / cm and a speed of 1 m / min to obtain a laminate. The laminate was superimposed on a copper frame material having a thickness of 0.2 mm, and was laminated with a roll laminator heated to a surface temperature of 190 ° C. at a linear pressure of 7 kg / cm and a speed of 0.5 m / min. Foaming was not observed, and the adhesive force (shear stress) was measured. As a result, it was 10 kg / cm ² , which was a value satisfying a practical level as an adhesive tape for LOC and a heat spreader.
[0042]
【The invention's effect】
Since the present invention is configured as described above, it can be easily bonded to a metal, a heat-resistant resin, and the like, and there is no generation of "dust" at the time of punching, and further, there is no foaming after lamination, adhesion, heat resistance, and A heat-resistant adhesive material having excellent electrical properties can be reliably obtained. Further, in manufacturing a semiconductor mounting package, the steps can be greatly simplified, and the manufacturing can be performed in a short time and economically.
[Brief description of the drawings]
FIG. 1 is a diagram showing a sample for measuring a shear stress (adhesive force) of a heat-resistant adhesive material of the present invention.
FIG. 2 is a diagram illustrating an example of a punched shape of the heat-resistant adhesive material of the present invention.

Claims (6)

A heat resistant adhesive polyimide resin laminate having at least one surface heat-resistant adhesive of the metal foil, the polyimide resin is an aromatic tetracarboxylic acid, a diamine containing a siloxane diamine 70 mole% or more Ri Do polyamic acid obtained by reacting a component from imidized film, method of manufacturing a heat spreader, wherein the punching combined laminate to the shape of the heat spreader. The method for producing a heat spreader according to claim 1, wherein the glass transition point of the polyimide resin is 150C or lower. Method for producing a heat spreader according to claim 1, wherein the siloxane diamine is represented by the following general formula [I].

(In the formula, n represents an integer of 1 or more. R ₁ and R ₂ may be the same or different, each represents a lower alkylene group or a phenylene group, and R ₃ , R ₄ , R ₅ and R ₆ may be the same or different and each represents a lower alkyl group, a phenyl group or a phenoxy group.) The method for manufacturing a heat spreader according to claim 1, wherein the heat-resistant adhesive has a bondable temperature of 200C or less. The method for producing a heat spreader according to claim 1, wherein the amount of generated gas at a heating temperature of the laminate of 100C or more and 300C or less is 1000ppm or less. On at least one side of the metal foil, a heat-resistant adhesive composition having a polyamic acid obtained by reacting an aromatic tetracarboxylic acid with a diamine component containing at least 70 mol% of a siloxane-based diamine is applied, dried, and dried. A method for producing a material for a heat spreader, wherein the heat treatment is performed at -270 ° C.

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