JP4092790B2 - Circuit board - Google Patents

Description

（ここでＲ_１は水素原子または炭素数１〜２のアルキル基、好ましくは炭素数１〜４の直鎖または分岐したアルキル基であり、Ｒ_２は炭素数２〜１３の直鎖状または分岐したアルキル基であり、ｎは１０〜２５０の整数である）
【０００６】
三次元架橋性樹脂は、少なくともエポキシ系樹脂と潜在性硬化剤を含有しているものが好ましい。接着剤樹脂組成物はフィルム状であることが好ましい。接着剤樹脂組成物には、導電粒子が０．１〜２０体積％含有されていてもよい。
【０００７】
【発明の実施の形態】
本発明に用いられる回路部材として半導体チップ等の能動素子、抵抗体、コンデンサ等の受動素子、プリント基板、ポリイミドやポリエステルを基材としたフレキシブル配線等が挙げられる。半導体チップや基板の電極パッド上には、めっきで形成されるバンプや金ワイヤの先端をトーチ等により溶融させ、金ボールを形成し、このボールを電極パッド上に圧着した後、ワイヤを切断して得られるワイヤバンプ等の突起電極を設け、接続端子として用いることができる。
本発明に用いられる接着剤の吸水率０．０１〜０．３重量％かつガラス転移温度８０℃〜１５０℃の熱可塑性樹脂としては一般式（１）で示され、芳香族炭化水素系溶媒に可溶であるポリアリレート樹脂が使用される。
前記ポリアリレート樹脂は、ビスフェノール化合物又はそのエステル化誘導体と芳香族ジカルボン酸又はその酸塩化物から合成される。
【０００８】
前記ポリアリレート樹脂を合成するためのビスフェノール化合物としては、１，１（４，４’−ジヒドロキシジフェニル）３−メチルブタン（Ｒ１は水素原子、Ｒ２は炭素数４の分岐したアルキル基）、２，２（４，４’−ジヒドロキシジフェニル）４−メチルペンタン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数４の分岐したアルキル基）、１，１（４，４’−ジヒドロキシジフェニル）３ーエチルヘキサン（Ｒ１は水素原子、Ｒ２は炭素数７の分岐したアルキル基）３，３（４，４’−ジヒドロキシジフェニル）ペンタン（Ｒ１は炭素数２のアルキル基、Ｒ２は炭素数２のアルキル基）、２，２（４，４’−ジヒドロキシジフェニル）ヘプタン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数５の直鎖状アルキル基）、１，１（４，４’−ジヒドロキシジフェニル）ヘプタン（Ｒ１は水素原子、Ｒ２は炭素数６の直鎖状アルキル基）、２，２（４，４’−ジヒドロキシジフェニル）オクタン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数６の直鎖状アルキル基）、１，１（４，４’−ジヒドロキシジフェニル）オクタン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数７の直鎖状アルキル基）、２，２（４，４’−ジヒドロキシジフェニル）ノナン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数７の直鎖状アルキル基）、１，１（４，４’−ジヒドロキシジフェニル）ノナン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数８の直鎖状アルキル基）、２，２（４，４’−ジヒドロキシジフェニル）デカン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数８の直鎖状アルキル基）、１，１（４，４’−ジヒドロキシジフェニル）デカン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数９の直鎖状アルキル基）、２，２（４，４’−ジヒドロキシジフェニル）ウンデカン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数９の直鎖状アルキル基）、１，１（４，４’−ジヒドロキシジフェニル）ウンデカン（Ｒ１は水素原子、Ｒ２は炭素数１０の直鎖状アルキル基）、２，２（４，４’−ジヒドロキシジフェニル）ドデカン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数１０の直鎖状アルキル基）、１，１（４，４’−ジヒドロキシジフェニル）ドデカン（Ｒ１は水素原子、Ｒ２は炭素数１１の直鎖状アルキル基）、２，２（４，４’−ジヒドロキシジフェニル）トリデカン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数１１の直鎖状アルキル基）、１，１（４，４’−ジヒドロキシジフェニル）トリデカン（Ｒ１は水素原子、Ｒ２は炭素数１２の直鎖状アルキル基）、２，２（４，４’−ジヒドロキシジフェニル）テトラデカン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数１２の直鎖状アルキル基）、１，１（４，４’−ジヒドロキシジフェニル）テトラデカン（Ｒ１は水素原子、Ｒ２は炭素数１３の直鎖状アルキル基）、及び２，２（４，４’−ジヒドロキシジフェニル）ペンタデカン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数１３の直鎖状アルキル基）が挙げられ、これらは２種以上が混合されていてもよい。好ましくは２，２（４，４’−ジヒドロキシジフェニル）オクタン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数６の直鎖状アルキル基）、１，１（４，４’−ジヒドロキシジフェニル）デカン（Ｒ１は炭素数１のアルキル基、Ｒ２は炭素数９の直鎖状アルキル基）が使用される。
【０００９】
また、前記ポリアリレート樹脂を合成するための芳香族ジカルボン酸としては、フタル酸、イソフタル酸、テレフタル酸、４ーメチルフタル酸、５ーｔｅｒｔーブチルーイソフタル酸及び２，５ージメチルフタル酸が挙げられる。これらは単独もしくは２種以上が混合されてもよく、好ましくは（Ａ）イソフタル酸または５ーｔｅｒｔーブチルーイソフタル酸及び（Ｂ）テレフタル酸が（Ａ）：（Ｂ）＝１：９９〜９９：１の混合比であることが好ましく、さらに好ましくは（Ａ）：（Ｂ）＝５０：５０であることが好ましい。
【００１０】
前記ポリアリレート樹脂は界面重合法、溶液重合法又は溶融重合法等の通常の方法で合成することができる。例えば、界面重合法の場合、ビスフェノール化合物をベンジルトリエチルアンモニウムクロリド等の触媒と共に水酸化ナトリウム水溶液に溶解し、芳香族ジカルボン酸塩化物を水に溶解せず、生成したポリアリレート樹脂が溶解する溶媒、例えば、トルエンに溶解し、これらの溶液を混合して１０〜５０℃で３０分〜３時間反応させて目的のポリアリレート樹脂を合成する。
また、溶液重合法の場合、生成するポリアリレート樹脂が溶解するような溶媒、例えば、トルエン、クロロホルム、テトラヒドロフラン、１、４−ジオキサン、シクロヘキサノン、ピリジン等にビスフェノール化合物及び芳香族ジカルボン酸塩化物を溶解し、トリエチルアミン等の塩基存在下に１０℃〜５０℃で３０分〜３時間反応させて目的のポリアリレート樹脂を合成する。
さらに、溶融重合法の場合、ビスフェノール化合物のエステル化誘導体例えばビスフェノールジアセテートと芳香族ジカルボン酸を２００〜３５０℃の高温でエステル交換反応を行うことによって、目的のポリアリレート化合物を合成する。
【００１１】
本発明のポリアリレート樹脂は、接着剤に強靭性を付与する目的で、テトラヒドロフランを溶媒としたゲルパーミテーションクロマトグラフィーで測定した際の分子量が、ポリスチレン換算で２万以上３０万以下が好ましい。２万以下では硬化物が脆くなくおそれがあり、３０万以上では樹脂組成物の流動性が低下するため、電子部品と回路基板の接続行った際、電子部品と回路基板間の接着剤樹脂による充填が困難になる。
【００１２】
本発明に用いられる三次元架橋性樹脂は、接着時の高信頼性を得られる樹脂として、エポキシ系樹脂とイミダゾール系、ヒドラジド系、三フッ化ホウ素−アミン錯体、スルホニウム塩、アミンイミド、ポリアミンの塩、ジシアンジアミド等の潜在性硬化剤の混合物が用いられる。
【００１３】
本発明の接着剤樹脂組成物は、前記ポリアリレート樹脂と前記三次元架橋性樹脂の配合比が重量部で１：９９〜９９：１で使用することができ、好ましくは１０：９０〜９０：１０である。
本発明の接着剤樹脂組成物には、硬化物の弾性率を低減する目的でアクリルゴム等のゴム成分を配合することもできる。
本発明の接着剤樹脂組成物には、フィルム形成性をより容易にするために、フェノキシ樹脂等の熱可塑性樹脂を配合することもできる。特に、フェノキシ樹脂は、エポキシ系樹脂をベース樹脂とした場合、エポキシ樹脂と構造が類似しているため、エポキシ樹脂との相溶性、接着性に優れる等の特徴を有するので好ましい。フィルム形成は、これら少なくともポリアリレート樹脂、エポキシ樹脂、潜在性硬化剤からなる接着組成物を有機溶剤に溶解あるいは分散により、液状化して、剥離性基材上に塗布し、硬化剤の活性温度以下で溶剤を除去することにより行われる。この時用いる溶剤は、芳香族炭化水素系と含酸素系の混合溶剤が材料の溶解性を向上させるため好ましい。
【００１４】
本発明の接着剤には、チップのバンプや基板電極の高さばらつきを吸収するために、異方導電性を積極的に付与する目的で導電粒子を分散することもできる。本発明において導電粒子は、例えばＡｕ、Ｎｉ、Ａｇ、Ｃｕやはんだ等の金属の粒子またはこれらの金属表面に、金やパラジウムなどの薄膜をめっきや蒸着によって形成した金属粒子であり、また、ポリスチレン等の高分子の球状の核材にＮｉ、Ｃｕ、Ａｕ、はんだ等の導電層を設けた導電粒子を用いることができる。粒径は、基板の電極の最小の間隔よりも小さいことが必要で、電極の高さばらつきがある場合、高さばらつきよりも大きいことが好ましく、かつ無機充填材の平均粒径より大きいことが好ましく、１〜１０μｍが好ましい。また、接着剤に分散される導電粒子量は、０．１〜３０体積％であり、好ましくは０．２〜１５体積％である。
【００１５】
本発明の回路部材接続用接着剤は、各成分を有機溶剤に溶解あるいは分散させ、任意の方法で攪拌、混合することによって容易に製造することができ、さらに、剥離性基材上に塗布し、硬化剤の活性温度以下で溶剤を除去することによってフィルム形成を行うことができる。その際に、上記の配合組成物以外にも、通常のエポキシ樹脂系組成物の調整で用いられる添加剤を加えて差し支えない。
本発明のフィルム状接着剤の膜厚は、特に限定するものではないが、第一および第２の回路部材間のギャップに比べ、厚いほうが好ましく、一般にはギャップに対して５μｍ以上厚い膜厚が望ましい。
【００１６】
【実施例】
以下に、本発明を実施例に基づいて詳細に説明する。
実施例１
２，２（４，４’−ジヒドロキシジフェニル）オクタン２．９８ｇとトリエチルアミン２．６３ｇをＴＨＦ５０ｍｌ中で窒素雰囲気下１０℃で攪拌した。この混合物に、イソフタル酸クロリド１．０１ｇとテレフタルサンクロリド１．０１ｇを加え、ゆっくりと攪拌した。２時間攪拌した後、アセトン３００ｍｌ中に滴下し、生成した沈殿物をろ取した。沈殿物をＴＨＦに溶解し、不溶物をろ別した後、ろ液をメタノール３００ｍｌに滴下した。生成した沈殿物をろ取してポリアリレート樹脂１．３ｇを得た。
ＧＰＣ測定の結果、ポリスチレン換算でＭｎ＝１７４００、Ｍｗ＝３２０００、Ｍｗ／Ｍｎ＝１．８３であった。
生成物のＦＴ−ＩＲ分析を行い、原料のジフェノール由来のＯＨ伸縮振動（３２００〜３４００ｃｍ^-1）の消失とエステル結合に由来するＣ−ＣＯ−Ｏ伸縮振動（１２６０〜１１７０ｃｍ^-1）の存在を確認した。
生成したポリアリレート樹脂をＴＨＦに溶解させ、シャーレに塗布し、溶媒を気散させることによってキャストフィルムを作製した。キャストフィルムを２ｃｍ角に切断し、減圧下に１００℃で乾燥させた後、重量を測定し、さらに、純水に２４時間浸漬後、重量を測定して重量増加を算出することによって、ポリアリレート樹脂の吸水率を測定した。吸水率測定の結果、生成したポリアリレート樹脂の吸水率は０．０５であった。また、キャストフィルムを動的粘弾性測定装置を用いて弾性率を測定し、ｔａｎδのピーク値によってＴｇを測定した結果、Ｔｇ１４５℃であった。
生成したポリアリレート樹脂１．０ｇをトルエン５ｇに溶解し、２０％溶液を得た。次いで、マイクロカプセル型潜在性硬化剤を含有する液状エポキシ（エポキシ当量１８５）１．８５ｇをこの溶液に加え、攪拌し、さらにポリスチレン系核体（直径：５μｍ）の表面にＡｕ層を形成した導電粒子を５容量％分散してフィルム塗工用溶液を得た。この溶液をセパレータ（シリコーン処理したポリエチレンテレフタレートフィルム、厚み４０μｍ）にロールコータで塗布し、１００℃、１０分乾燥し厚み４０μｍの接着フィルムを作製した。接着フィルムを１５０℃で３時間硬化させ、硬化フィルムを動的粘弾性測定装置を用いて弾性率を測定し、ｔａｎδのピーク値によってＴｇを測定した結果、Ｔｇ１５０℃であった。
次に、作製した接着フィルムを用いて、金バンプ（面積：８０×８０μｍ、スペース３０μｍ、高さ：１５μｍ、バンプ数２８８）付きチップ（１０×１０ｍｍ、厚み：０．５ｍｍ）とＮｉ／ＡｕめっきＣｕ回路プリント基板（電極高さ：２０μｍ、厚み：０．８ｍｍ）の接続を以下に示すように行った。接着フィルム３（１２×１２ｍｍ）をＮｉ／ＡｕめっきＣｕ回路プリント基板に６０℃、０．５ＭＰａで仮接続工程を行った。仮接続工程後、セパレータを剥離した。チップのバンプとＮｉ／ＡｕめっきＣｕ回路プリント基板の位置合わせを行った後、１７０℃、３０ｇ／バンプ、２０秒の条件でチップ上方から加熱、加圧を行い、本接続を行った。
本接続後の接続抵抗は、１バンプあたり最高で５ｍΩ、平均で１．５ｍΩ、絶縁抵抗は１０８Ω以上であり、これらの値は−５５〜１２５℃の熱衝撃試験１０００サイクル処理、ＰＣＴ試験（１２１℃、２気圧）２００時間、２６０℃のはんだバス浸漬１０秒後においても変化がなく、良好な接続信頼性を示した。
【００１７】
【発明の効果】
本発明の回路板は、接着剤として、接着樹脂組成物が少なくとも三次元架橋性樹脂及び吸水率０．０１〜０．２重量％かつガラス転移温度８０℃〜１５０℃の熱可塑性樹脂を含むことによって、耐湿特性及び耐熱性の良好な硬化物を得ることができ、結果として、接続信頼性を大幅に向上させることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit board in which a semiconductor chip is bonded and fixed to a substrate with an adhesive by, for example, a flip chip mounting method, and the electrodes of both are electrically connected.
[0002]
[Prior art]
In the semiconductor mounting field, flip chip mounting, in which an IC chip is directly mounted on a printed circuit board or a flexible wiring board, has attracted attention as a new mounting form corresponding to cost reduction and high definition. As the flip chip mounting method, there are known a method in which solder bumps are provided on the terminals of the chip and solder connection is made, and a method in which electrical connection is made through a conductive adhesive. In these methods, there is a problem that when the stress based on the difference in thermal expansion coefficient between the chip to be connected and the substrate is exposed to various environments, the stress is generated at the connection interface and the connection reliability is lowered. For this reason, a method of injecting an epoxy resin-based underfill material into the gap between the chip and the substrate is generally studied for the purpose of alleviating the stress at the connection interface. However, this underfill injection process has a problem that the process becomes complicated and disadvantageous in terms of productivity and cost. Recently, flip-chip mounting using an anisotropic conductive adhesive having anisotropic conductivity and a sealing function has attracted attention from the viewpoint of process simplicity in order to solve such problems.
[0003]
[Problems to be solved by the invention]
When the chip is mounted on the substrate via an anisotropic conductive material, the adhesive strength between the adhesive and the chip or the adhesive and the substrate interface decreases under moisture absorption conditions, and the thermal expansion coefficient between the chip and the substrate under temperature cycling conditions. When stress based on the difference is generated in the connection portion, there is a problem that when reliability tests such as a thermal shock test, a PCT test, and a high temperature and high humidity test are performed, the connection resistance increases and the adhesive peels off. In addition, since the semiconductor package performs a solder reflow temperature test after absorbing moisture in a high-temperature and high-humidity test, the moisture absorbed in the adhesive expands rapidly, resulting in increased connection resistance and peeling of the adhesive. There's a problem. In general, a technique of dispersing liquid rubber, cross-linked rubber, and core-shell type rubber particles is known for the purpose of relaxing internal stress of the epoxy resin and strengthening it. However, it is known that a cured product in which rubber is dispersed in an epoxy resin has a lower softening point temperature (or glass transition temperature, hereinafter referred to as Tg) than a cured product of an epoxy resin alone, and has high heat resistance. This is a cause of lowering reliability in the field where the demand is required. On the other hand, increasing the crosslinking density of the epoxy resin to improve Tg in the rubber dispersion system decreases the rubber dispersion effect, increases the brittleness of the cured product, increases the water absorption rate, and decreases the reliability. Cause it. In addition, as a method for toughening an epoxy resin without lowering Tg, blending with a high heat-resistant thermoplastic resin known as engineering plastic is known. Generally, these engineering plastics are soluble in solvents. Therefore, the compounding with the epoxy resin is due to the kneading of the powder, and the development to the adhesive use is inappropriate.
The present invention provides a circuit board that does not increase connection resistance at the connection portion and does not peel off the adhesive, and greatly improves connection reliability.
[0004]
[Means for Solving the Problems]
The circuit board of the present invention includes a first circuit member having a first connection terminal and a second circuit member having a larger thermal expansion coefficient than the first circuit member having a second connection terminal. The connection terminal and the second connection terminal are arranged to face each other , an adhesive is interposed between the first connection terminal and the second connection terminal arranged to face each other, and the first and the second arrangement terminals are arranged to face each other by heating and pressing. A circuit board in which a connection terminal and a second connection terminal are electrically connected, wherein the adhesive comprises at least a three-dimensional crosslinkable resin and a water absorption of 0.01 to 0.2% by weight and a glass transition temperature of 80 ° C. A circuit board, which is an adhesive containing a thermoplastic resin at ˜150 ° C. Interposed between opposing circuit electrodes, a circuit member connecting adhesive for electrically connecting the circuit electrodes pressurize the pressure direction of the electrode facing each other, the adhesive resin composition is at least three-dimensional cross-linking And a thermoplastic resin having a water absorption of 0.01 to 0.2% by weight and a glass transition temperature of 80 ° C to 150 ° C. Water absorption 0.01 to 0.3 wt% and the glass transition temperature of 80 ° C. to 150 DEG ° C. for the thermoplastic resin is represented by the following general formula (1), polyarylate resins used can be dissolved in an aromatic hydrocarbon solvent Is done.
[0005]
[Formula 4]

(Wherein R ₁ is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and R ₂ is a linear or branched group having ₂ to 13 carbon atoms. And n is an integer of 10 to 250)
[0006]
The three-dimensional crosslinkable resin preferably contains at least an epoxy resin and a latent curing agent. The adhesive resin composition is preferably in the form of a film. The adhesive resin composition may contain 0.1 to 20% by volume of conductive particles.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Examples of circuit members used in the present invention include active elements such as semiconductor chips, passive elements such as resistors and capacitors, printed boards, flexible wiring based on polyimide or polyester, and the like. On the electrode pad of the semiconductor chip or substrate, the bump formed by plating or the tip of the gold wire is melted with a torch or the like to form a gold ball, and after the ball is pressed onto the electrode pad, the wire is cut. Protruding electrodes such as wire bumps obtained in this way can be provided and used as connection terminals.
The thermoplastic resin having a water absorption of 0.01 to 0.3% by weight and a glass transition temperature of 80 to 150 ° C. used in the present invention is represented by the general formula (1), and is used as an aromatic hydrocarbon solvent. Polyarylate resins that are soluble are used.
The polyarylate resin is synthesized from a bisphenol compound or an esterified derivative thereof and an aromatic dicarboxylic acid or an acid chloride thereof.
[0008]
Examples of the bisphenol compound for synthesizing the polyarylate resin include 1,1 (4,4′-dihydroxydiphenyl) 3-methylbutane (R1 is a hydrogen atom, R2 is a branched alkyl group having 4 carbon atoms), 2,2 (4,4′-dihydroxydiphenyl) 4-methylpentane (R1 is an alkyl group having 1 carbon atom, R2 is a branched alkyl group having 4 carbon atoms), 1,1 (4,4′-dihydroxydiphenyl) 3-ethylhexane ( R1 is a hydrogen atom, R2 is a branched alkyl group having 7 carbon atoms, 3,3 (4,4′-dihydroxydiphenyl) pentane (R1 is an alkyl group having 2 carbon atoms, R2 is an alkyl group having 2 carbon atoms), 2 , 2 (4,4′-dihydroxydiphenyl) heptane (R1 is an alkyl group having 1 carbon atom, R2 is a linear alkyl group having 5 carbon atoms), 1,1 (4,4′-dihydride) Xidiphenyl) heptane (R1 is a hydrogen atom, R2 is a linear alkyl group having 6 carbon atoms), 2,2 (4,4'-dihydroxydiphenyl) octane (R1 is an alkyl group having 1 carbon atom, R2 is a carbon number) 6 linear alkyl group), 1,1 (4,4'-dihydroxydiphenyl) octane (R1 is an alkyl group having 1 carbon atom, R2 is a linear alkyl group having 7 carbon atoms), 2,2 (4 , 4′-dihydroxydiphenyl) nonane (R1 is an alkyl group having 1 carbon atom, R2 is a linear alkyl group having 7 carbon atoms), 1,1 (4,4′-dihydroxydiphenyl) nonane (R1 is 1 carbon atom) R2 is a linear alkyl group having 8 carbon atoms), 2,2 (4,4′-dihydroxydiphenyl) decane (R1 is an alkyl group having 1 carbon atom, R2 is a linear alkyl group having 8 carbon atoms) Group), 1,1 (4,4'-di) Droxydiphenyl) decane (R1 is an alkyl group having 1 carbon atom, R2 is a linear alkyl group having 9 carbon atoms), 2,2 (4,4′-dihydroxydiphenyl) undecane (R1 is an alkyl group having 1 carbon atom) , R2 is a linear alkyl group having 9 carbon atoms), 1,1 (4,4′-dihydroxydiphenyl) undecane (R1 is a hydrogen atom, R2 is a linear alkyl group having 10 carbon atoms), 2,2 ( 4,4′-dihydroxydiphenyl) dodecane (R1 is an alkyl group having 1 carbon atom, R2 is a linear alkyl group having 10 carbon atoms), 1,1 (4,4′-dihydroxydiphenyl) dodecane (R1 is a hydrogen atom) , R2 is a linear alkyl group having 11 carbon atoms), 2,2 (4,4'-dihydroxydiphenyl) tridecane (R1 is an alkyl group having 1 carbon atom, R2 is a linear alkyl group having 11 carbon atoms), 1,1 (4 4′-dihydroxydiphenyl) tridecane (R1 is a hydrogen atom, R2 is a linear alkyl group having 12 carbon atoms), 2,2 (4,4′-dihydroxydiphenyl) tetradecane (R1 is an alkyl group having 1 carbon atom, R2 Is a linear alkyl group having 12 carbon atoms), 1,1 (4,4′-dihydroxydiphenyl) tetradecane (R1 is a hydrogen atom, R2 is a linear alkyl group having 13 carbon atoms), and 2,2 (4 , 4′-dihydroxydiphenyl) pentadecane (R1 is an alkyl group having 1 carbon atom, R2 is a linear alkyl group having 13 carbon atoms), and two or more of these may be mixed. Preferably, 2,2 (4,4′-dihydroxydiphenyl) octane (R1 is an alkyl group having 1 carbon atom, R2 is a linear alkyl group having 6 carbon atoms), 1,1 (4,4′-dihydroxydiphenyl) Decane (R1 is an alkyl group having 1 carbon atom and R2 is a linear alkyl group having 9 carbon atoms) is used.
[0009]
Examples of the aromatic dicarboxylic acid for synthesizing the polyarylate resin include phthalic acid, isophthalic acid, terephthalic acid, 4-methylphthalic acid, 5-tert-butyl-isophthalic acid, and 2,5-dimethylphthalic acid. These may be used alone or in admixture of two or more. Preferably, (A) isophthalic acid or 5-tert-butyl-isophthalic acid and (B) terephthalic acid are (A) :( B) = 1: 99 to 99. The mixing ratio is preferably 1: 1, more preferably (A) :( B) = 50: 50.
[0010]
The polyarylate resin can be synthesized by an ordinary method such as an interfacial polymerization method, a solution polymerization method or a melt polymerization method. For example, in the case of the interfacial polymerization method, a solvent in which a bisphenol compound is dissolved in an aqueous sodium hydroxide solution together with a catalyst such as benzyltriethylammonium chloride, an aromatic dicarboxylic acid chloride is not dissolved in water, and the produced polyarylate resin is dissolved, For example, it melt | dissolves in toluene, these solutions are mixed, and it is made to react for 30 minutes-3 hours at 10-50 degreeC, and synthesize | combines the target polyarylate resin.
In the case of a solution polymerization method, a bisphenol compound and an aromatic dicarboxylic acid chloride are dissolved in a solvent in which the resulting polyarylate resin is dissolved, for example, toluene, chloroform, tetrahydrofuran, 1,4-dioxane, cyclohexanone, pyridine and the like. Then, the reaction is carried out at 10 ° C. to 50 ° C. for 30 minutes to 3 hours in the presence of a base such as triethylamine to synthesize the desired polyarylate resin.
Furthermore, in the case of the melt polymerization method, an esterified derivative of a bisphenol compound, for example, bisphenol diacetate and an aromatic dicarboxylic acid is subjected to a transesterification reaction at a high temperature of 200 to 350 ° C., thereby synthesizing a target polyarylate compound.
[0011]
The polyarylate resin of the present invention preferably has a molecular weight of 20,000 or more and 300,000 or less in terms of polystyrene as measured by gel permeation chromatography using tetrahydrofuran as a solvent for the purpose of imparting toughness to the adhesive. If it is 20,000 or less, the cured product may not be brittle, and if it is 300,000 or more, the fluidity of the resin composition decreases. Therefore, when the electronic component and the circuit board are connected, the adhesive resin between the electronic component and the circuit board is used. Filling becomes difficult.
[0012]
The three-dimensional crosslinkable resin used in the present invention is an epoxy resin and an imidazole, hydrazide, boron trifluoride-amine complex, sulfonium salt, amine imide, polyamine salt as a resin that can obtain high reliability at the time of adhesion. A mixture of latent curing agents such as dicyandiamide is used.
[0013]
The adhesive resin composition of the present invention can be used at a blending ratio of the polyarylate resin and the three-dimensional crosslinkable resin of 1:99 to 99: 1 by weight, preferably 10:90 to 90: 10.
In the adhesive resin composition of the present invention, a rubber component such as acrylic rubber can be blended for the purpose of reducing the elastic modulus of the cured product.
In the adhesive resin composition of the present invention, a thermoplastic resin such as a phenoxy resin can also be blended in order to make film forming easier. In particular, a phenoxy resin is preferable when an epoxy resin is used as a base resin, since the structure is similar to that of an epoxy resin, and thus has characteristics such as excellent compatibility with an epoxy resin and adhesiveness. For film formation, an adhesive composition comprising at least a polyarylate resin, an epoxy resin, and a latent curing agent is liquefied by dissolving or dispersing in an organic solvent, and applied onto a peelable substrate, and the temperature is below the activation temperature of the curing agent. By removing the solvent. The solvent used at this time is preferably an aromatic hydrocarbon-based and oxygen-containing mixed solvent because the solubility of the material is improved.
[0014]
In the adhesive of the present invention, conductive particles can be dispersed for the purpose of positively imparting anisotropic conductivity in order to absorb variations in the height of the bumps of the chip and the substrate electrodes. In the present invention, the conductive particles are, for example, metal particles such as Au, Ni, Ag, Cu, and solder, or metal particles formed by plating or vapor deposition of a thin film such as gold or palladium on the metal surface, and polystyrene. Conductive particles in which a conductive spherical layer such as Ni, Cu, Au, or solder is provided on a high-molecular spherical core material such as the above can be used. The particle size needs to be smaller than the minimum distance between the electrodes of the substrate, and when there is a variation in the height of the electrodes, it is preferably larger than the variation in height and larger than the average particle size of the inorganic filler. 1 to 10 μm is preferable. The amount of conductive particles dispersed in the adhesive is 0.1 to 30% by volume, preferably 0.2 to 15% by volume.
[0015]
The adhesive for connecting a circuit member of the present invention can be easily produced by dissolving or dispersing each component in an organic solvent, stirring and mixing by an arbitrary method, and applying the adhesive on a peelable substrate. Film formation can be performed by removing the solvent below the activation temperature of the curing agent. In that case, the additive used by adjustment of a normal epoxy resin type composition other than said compounding composition may be added.
The film thickness of the film adhesive of the present invention is not particularly limited, but is preferably thicker than the gap between the first and second circuit members, and generally has a thickness of 5 μm or more with respect to the gap. desirable.
[0016]
【Example】
Hereinafter, the present invention will be described in detail based on examples.
Example 1
2.98 g of 2,2 (4,4′-dihydroxydiphenyl) octane and 2.63 g of triethylamine were stirred in 50 ml of THF at 10 ° C. in a nitrogen atmosphere. To this mixture, 1.01 g of isophthalic acid chloride and 1.01 g of terephthalic acid chloride were added and stirred slowly. After stirring for 2 hours, it was dropped into 300 ml of acetone, and the produced precipitate was collected by filtration. The precipitate was dissolved in THF and insoluble matter was filtered off, and the filtrate was added dropwise to 300 ml of methanol. The produced precipitate was collected by filtration to obtain 1.3 g of a polyarylate resin.
As a result of GPC measurement, it was Mn = 17400, Mw = 32000, and Mw / Mn = 1.83 in terms of polystyrene.
The product was subjected to FT-IR analysis, and disappearance of OH stretching vibration (3200 to 3400 cm ⁻¹ ) derived from the raw material diphenol and presence of C—CO—O stretching vibration (1260 to 1170 cm ⁻¹ ) derived from the ester bond. It was confirmed.
The produced polyarylate resin was dissolved in THF, applied to a petri dish, and the solvent was diffused to prepare a cast film. The cast film was cut into 2 cm squares, dried at 100 ° C. under reduced pressure, measured for weight, further immersed in pure water for 24 hours, and then measured for weight increase to calculate weight increase. The water absorption of the resin was measured. As a result of the water absorption measurement, the water absorption of the produced polyarylate resin was 0.05. Moreover, the elastic modulus of the cast film was measured using a dynamic viscoelasticity measuring apparatus, and the Tg was measured by the peak value of tan δ.
1.0 g of the produced polyarylate resin was dissolved in 5 g of toluene to obtain a 20% solution. Next, 1.85 g of a liquid epoxy (epoxy equivalent 185) containing a microcapsule-type latent curing agent was added to this solution, stirred, and a conductive layer having an Au layer formed on the surface of a polystyrene core (diameter: 5 μm). The particles were dispersed by 5% by volume to obtain a film coating solution. This solution was applied to a separator (silicone-treated polyethylene terephthalate film, thickness 40 μm) with a roll coater and dried at 100 ° C. for 10 minutes to produce an adhesive film having a thickness of 40 μm. The adhesive film was cured at 150 ° C. for 3 hours, the elastic modulus of the cured film was measured using a dynamic viscoelasticity measuring apparatus, and Tg was measured according to the peak value of tan δ. As a result, Tg was 150 ° C.
Next, using the produced adhesive film, a chip (10 × 10 mm, thickness: 0.5 mm) with gold bumps (area: 80 × 80 μm, space 30 μm, height: 15 μm, number of bumps 288) and Ni / Au plating A Cu circuit printed board (electrode height: 20 μm, thickness: 0.8 mm) was connected as shown below. The adhesive film 3 (12 × 12 mm) was temporarily connected to a Ni / Au plated Cu circuit printed board at 60 ° C. and 0.5 MPa. After the temporary connection step, the separator was peeled off. After alignment of the bumps of the chip and the Ni / Au plated Cu circuit printed circuit board, heating and pressurization were performed from above the chip under the conditions of 170 ° C., 30 g / bumps for 20 seconds to perform the main connection.
The connection resistance after this connection is 5 mΩ maximum per bump, 1.5 mΩ on average, and the insulation resistance is 108 Ω or more. These values are the thermal shock test 1000 cycle treatment at −55 to 125 ° C., PCT test (121 No change even after 10 seconds of immersion in a solder bath at 260 ° C. for 200 hours at 2 ° C., and good connection reliability was exhibited.
[0017]
【The invention's effect】
In the circuit board of the present invention, the adhesive resin composition contains at least a three-dimensional crosslinkable resin and a thermoplastic resin having a water absorption of 0.01 to 0.2% by weight and a glass transition temperature of 80 to 150 ° C. as an adhesive. Thus, a cured product having good moisture resistance and heat resistance can be obtained, and as a result, connection reliability can be greatly improved.

Claims (8)

A first circuit member having a first connection terminal and a second circuit member having a larger coefficient of thermal expansion than the first circuit member having a second connection terminal; and arranged to face the terminal, the opposed to the adhesive is interposed between the first connecting terminal and second connecting terminal, by heating and pressing the first connecting terminal and a second connection to the facing A circuit board with electrically connected terminals,
Wherein the adhesive is an adhesive containing at least three-dimensionally crosslinked resin and water absorption of 0.01 to 0.2 wt% and the glass transition temperature of 80 ° C. to 150 DEG ° C. for the thermoplastic resin,
A circuit board in which the thermoplastic resin of the adhesive resin composition is a polyarylate resin represented by the following general formula (1).

(Here, R ₁ is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, R ₂ is a linear or branched alkyl group having ₂ to 13 carbon atoms, and n is an integer of 10 to 250) The circuit board according to claim 1 , wherein the three-dimensional crosslinkable resin of the adhesive resin composition contains an epoxy resin and a latent curing agent. A first circuit member having a first connection terminal and a second circuit member having a larger coefficient of thermal expansion than the first circuit member having a second connection terminal; Terminals are arranged opposite to each other, an adhesive is interposed between the first and second connection terminals arranged opposite to each other, and the first connection terminal and the second connection arranged opposite to each other by heating and pressing. A circuit board with electrically connected terminals,
An adhesive resin composition contains at least an epoxy resin, the circuit board containing the polyarylate resin and latent curing agent which is soluble in an aromatic hydrocarbon solvent. The circuit board according to claim 3, wherein the polyarylate resin is a polyarylate resin represented by the following general formula (1).

(Where R ₁ Is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, R ₂ Is a linear or branched alkyl group having 2 to 13 carbon atoms, and n is an integer of 10 to 250)   The circuit board according to claim 1, wherein the adhesive is in a film form.   6. The circuit board according to claim 1, wherein 0.2 to 20% by volume of conductive particles are dispersed in the adhesive. An adhesive resin composition containing an epoxy resin, a polyarylate resin dissolved in an aromatic hydrocarbon solvent, and a latent curing agent. The adhesive resin composition according to claim 7, wherein the polyarylate resin is a polyarylate resin represented by the following general formula (1).

(Where R ₁ Is a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, R ₂ Is a linear or branched alkyl group having 2 to 13 carbon atoms, and n is an integer of 10 to 250)