JP7067586B2 - Anisotropic conductive film - Google Patents

Anisotropic conductive film Download PDF

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JP7067586B2
JP7067586B2 JP2020088028A JP2020088028A JP7067586B2 JP 7067586 B2 JP7067586 B2 JP 7067586B2 JP 2020088028 A JP2020088028 A JP 2020088028A JP 2020088028 A JP2020088028 A JP 2020088028A JP 7067586 B2 JP7067586 B2 JP 7067586B2
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anisotropic conductive
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朋之 石松
怜司 塚尾
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Dexerials Corp
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Description

本発明は、異方性導電フィルムに関する。 The present invention relates to an anisotropic conductive film.

絶縁性樹脂バインダに導電粒子を分散させた異方性導電フィルムが、ICチップ等の電子部品を配線基板等に実装する際に広く使用されているが、このような異方性導電フィルムにおいては、導電粒子同士が連結もしくは凝集した状態で存在していることが知られている。このため、異方性導電フィルムを、電子機器の軽量小型化に伴い狭ピッチ化しているICチップの端子と配線基板の端子との接続に適用した場合、異方性導電フィルム中に連結もしくは凝集した状態で存在している導電粒子により、隣接する端子間で短絡が生ずる場合があった。 An anisotropic conductive film in which conductive particles are dispersed in an insulating resin binder is widely used when mounting electronic components such as IC chips on a wiring board or the like. In such an anisotropic conductive film, , It is known that conductive particles exist in a state of being connected or aggregated. Therefore, when the anisotropic conductive film is applied to the connection between the terminal of the IC chip and the terminal of the wiring board, which have become narrower due to the weight reduction and miniaturization of the electronic device, they are connected or aggregated in the anisotropic conductive film. Due to the conductive particles existing in this state, a short circuit may occur between adjacent terminals.

従来、このような狭ピッチ化に対応した異方性導電フィルムとして、フィルム中に導電粒子を規則配列させたものが提案されている。例えば、延伸可能なフィルムに粘着層を形成し、その粘着層表面に導電粒子を単層で密集充填した後、このフィルムを導電粒子間距離が所期の距離になるまで2軸延伸処理して導電粒子を規則配列させ、その後、導電粒子に対し異方性導電フィルムの構成要素となる絶縁性接着ベース層を押し当て、導電粒子を絶縁性接着ベース層に転写させて得た異方性導電フィルムが提案されている(特許文献1)。また、凹部を表面に有する転写型の凹部形成面に導電粒子を散布し、凹部形成面をスキージして凹部に導電粒子を保持させ、その上から転写用の粘着層が形成された粘着フィルムを押し当て、粘着層に導電粒子を一次転写させ、次に、粘着層に付着した導電粒子に対し、異方性導電フィルムの構成要素となる絶縁性接着ベース層を押し当て、導電粒子を絶縁性接着ベース層に転写させて得た異方性導電フィルムも提案されている(特許文献2)。これらの異方性導電フィルムについては、一般に、導電粒子側表面に、導電粒子を覆うように絶縁性接着カバー層が積層されている。 Conventionally, as an anisotropic conductive film corresponding to such a narrowing of pitch, a film in which conductive particles are regularly arranged in a film has been proposed. For example, an adhesive layer is formed on a stretchable film, conductive particles are densely filled on the surface of the adhesive layer with a single layer, and then this film is biaxially stretched until the distance between the conductive particles reaches the desired distance. The conductive particles are regularly arranged, and then the insulating adhesive base layer, which is a component of the anisotropic conductive film, is pressed against the conductive particles, and the conductive particles are transferred to the insulating adhesive base layer to obtain anisotropic conductivity. A film has been proposed (Patent Document 1). Further, the conductive particles are sprayed on the transfer type recess forming surface having the recesses on the surface, the recess forming surface is squeezed to hold the conductive particles in the recesses, and the adhesive film on which the adhesive layer for transfer is formed is formed. The conductive particles are first transferred to the pressure-sensitive adhesive layer, and then the insulating adhesive base layer, which is a component of the anisotropic conductive film, is pressed against the conductive particles adhering to the pressure-sensitive adhesive layer to insulate the conductive particles. An anisotropic conductive film obtained by transferring it to an adhesive base layer has also been proposed (Patent Document 2). In these anisotropic conductive films, an insulating adhesive cover layer is generally laminated on the surface on the conductive particle side so as to cover the conductive particles.

WO2005/054388号WO2005 / 054388 特開2010-33793号公報Japanese Unexamined Patent Publication No. 2010-33793

しかしながら、導電粒子は静電気等により凝集して二次粒子化し易いため、導電粒子を一次粒子として常時単独で存在させることは困難である。このため、特許文献1や特許文献2の技術には以下のような問題が生ずる。即ち、特許文献1の場合には、延伸可能フィルムの全面に導電粒子を欠陥なく単層で密集充填することが難しく、導電粒子が凝集状態で延伸可能フィルムに充填され、ショートの原因となったり、充填されない領域(いわゆる「抜け」)が生じ、導通不良の原因になったりするという問題があった。また、特許文献2の場合、転写型の凹部が粒子径の大きな導電粒子で覆われると、その後のスキージにより取り除かれて、導電粒子を保持していない凹部が生じ、異方性導電フィルムに導電粒子の「抜け」が生じて導通不良の原因になったり、反対に凹部に多数の小さな導電粒子が押し込まれると、絶縁性接着ベース層に転写させた際、導電粒子の凝集が生じたり、また、凹部の底部側に位置している導電粒子が、絶縁性接着ベース層と接触していないため、絶縁性接着ベース層の表面に散らばり、規則配列が損なわれ、ショートや導通不良の原因になったりするという問題があった。 However, since the conductive particles are easily aggregated by static electricity or the like to become secondary particles, it is difficult for the conductive particles to always exist alone as primary particles. Therefore, the techniques of Patent Document 1 and Patent Document 2 have the following problems. That is, in the case of Patent Document 1, it is difficult to densely fill the entire surface of the stretchable film with conductive particles in a single layer without defects, and the conductive particles are filled in the stretchable film in an aggregated state, which may cause a short circuit. There is a problem that an unfilled region (so-called “missing”) is generated, which causes poor continuity. Further, in the case of Patent Document 2, when the transfer type concave portion is covered with the conductive particles having a large particle diameter, the concave portion is removed by the subsequent squeegee to generate a concave portion that does not hold the conductive particles, and the anisotropic conductive film is conductive. If the particles are "lost" and cause poor continuity, or if a large number of small conductive particles are pushed into the recesses, the conductive particles will aggregate when transferred to the insulating adhesive base layer. Since the conductive particles located on the bottom side of the recess are not in contact with the insulating adhesive base layer, they are scattered on the surface of the insulating adhesive base layer, which impairs the regular arrangement and causes a short circuit or poor continuity. There was a problem of particles.

このように、特許文献1や2では、異方性導電フィルムに規則的パターンで配列されるべき導電粒子の「抜け」と「凝集」とをどのように制御すべきか、ということについては、十分に考慮されていないというのが実情である。 As described above, in Patent Documents 1 and 2, how to control the "missing" and "aggregation" of the conductive particles that should be arranged in a regular pattern on the anisotropic conductive film is sufficient. The fact is that it is not taken into consideration.

本発明の目的は、以上の従来の技術の問題点を解決することであり、規則的パターンで配列されるべき導電粒子の「抜け」と「凝集」の観点から、ショートや導通不良の発生が大きく抑制された異方性導電フィルムを提供することである。 An object of the present invention is to solve the above-mentioned problems of the prior art, and from the viewpoint of "missing" and "aggregation" of conductive particles that should be arranged in a regular pattern, short circuits and poor continuity may occur. It is to provide a greatly suppressed anisotropic conductive film.

本発明者は、平面格子の格子点に導電粒子を配置する際に、異方性導電フィルムの基準領域に想定される平面格子パターンの全格子点に対する、「導電粒子が配置されていない格子点の割合」と「導電粒子が凝集して配置されている格子点の割合」とを制御することにより、上述の目的を達成できることを見出し、本発明を完成させるに至った。また、そのような異方性導電フィルムが、転写体の凹部に導電粒子を配置するのではなく、表面に柱状の凸部が形成された転写体の当該凸部の先端に導電粒子を付着させて転写を行うことにより製造できることを見出し、本発明の製造方法を完成させた。 The present inventor of the present invention, when arranging conductive particles at the lattice points of a planar lattice, "lattice points where conductive particles are not arranged" with respect to all the lattice points of the planar lattice pattern assumed in the reference region of the anisotropic conductive film. It was found that the above-mentioned object can be achieved by controlling "the ratio of the lattice points in which the conductive particles are aggregated and arranged", and the present invention has been completed. Further, such an anisotropic conductive film does not arrange the conductive particles in the concave portions of the transfer body, but causes the conductive particles to adhere to the tips of the convex portions of the transfer body having columnar convex portions formed on the surface. We found that it can be produced by performing transfer, and completed the production method of the present invention.

即ち、本発明は、絶縁性接着ベース層に導電粒子が平面格子パターンの格子点に配置された構造の異方性導電フィルムであって、
異方性導電フィルムの基準領域に想定される平面格子パターンの全格子点に対する導電粒子が配置されていない格子点の割合が、20%未満であり、
該平面格子パターンの全格子点に対する複数の導電粒子が凝集して配置されている格子点の割合が、15%以下であり、抜けと凝集の合計が25%未満である異方性導電フィルムを提供する。
That is, the present invention is an anisotropic conductive film having a structure in which conductive particles are arranged at lattice points of a planar lattice pattern on an insulating adhesive base layer.
The ratio of the lattice points where the conductive particles are not arranged to all the lattice points of the planar lattice pattern assumed in the reference region of the anisotropic conductive film is less than 20%.
An anisotropic conductive film in which the ratio of the lattice points in which a plurality of conductive particles are aggregated and arranged to all the lattice points of the plane lattice pattern is 15% or less, and the total of omission and aggregation is less than 25%. offer.

また、本発明は、絶縁性接着ベース層と絶縁性接着カバー層とが積層され、それらの界面近傍に導電粒子が平面格子パターンの格子点に配置された構造の異方性導電フィルムであって、
異方性導電フィルムの基準領域に想定される平面格子パターンの全格子点に対する導電粒子が配置されていない格子点の割合が、20%未満であり、
該平面格子パターンの全格子点に対する複数の導電粒子が凝集して配置されている格子点の割合が、5%以下である異方性導電フィルムを提供する。この場合も、抜けと凝集の合計は好ましくは25%未満である。
Further, the present invention is an anisotropic conductive film having a structure in which an insulating adhesive base layer and an insulating adhesive cover layer are laminated and conductive particles are arranged at lattice points of a planar lattice pattern in the vicinity of their interfaces. ,
The ratio of the lattice points where the conductive particles are not arranged to all the lattice points of the planar lattice pattern assumed in the reference region of the anisotropic conductive film is less than 20%.
Provided is an anisotropic conductive film in which the ratio of the lattice points in which a plurality of conductive particles are aggregated and arranged to all the lattice points of the plane lattice pattern is 5% or less. Again, the total loss and agglomeration is preferably less than 25%.

また、本発明は、絶縁性接着ベース層と絶縁性接着カバー層とが積層され、それらの界面近傍に導電粒子が平面格子パターンの格子点に配置された構造の異方性導電フィルムの製造方法であって、以下の工程(イ)~(ホ):
<工程(イ)>
平面格子パターンの格子点に相当する柱状の凸部が表面に形成された転写体を用意する工程;
<工程(ロ)>
該転写体の凸部の少なくとも天面を微粘着層とする工程;
<工程(ハ)>
該転写体の凸部の微粘着層に導電粒子を付着させる工程;
<工程(ニ)>
該転写体の導電粒子が付着した側の表面に絶縁性接着ベース層を重ねて押圧することにより、絶縁性接着ベース層に導電粒子を転着させる工程;及び
<工程(ホ)>
導電粒子が転着した絶縁性接着ベース層に対し、導電粒子転着面側から絶縁性接着カバー層を積層する工程
を有する製造方法を提供する。
Further, the present invention is a method for manufacturing an anisotropic conductive film having a structure in which an insulating adhesive base layer and an insulating adhesive cover layer are laminated and conductive particles are arranged at lattice points of a plane lattice pattern in the vicinity of their interfaces. The following steps (a) to (e):
<Process (a)>
A step of preparing a transfer body in which a columnar convex portion corresponding to a lattice point of a planar lattice pattern is formed on the surface;
<Process (b)>
A step of forming at least the top surface of the convex portion of the transfer body as a slightly adhesive layer;
<Process (c)>
A step of adhering conductive particles to the slightly adhesive layer of the convex portion of the transfer body;
<Process (d)>
A step of transferring the conductive particles to the insulating adhesive base layer by superimposing and pressing the insulating adhesive base layer on the surface of the transfer body on the side to which the conductive particles are attached; and <Step (e)>.
Provided is a manufacturing method including a step of laminating an insulating adhesive cover layer from a conductive particle transfer surface side on an insulating adhesive base layer on which conductive particles are transferred.

更に、本発明は、第1の電子部品の端子と、第2の電子部品の端子とが、本発明の異方性導電フィルムにより異方性導電接続された接続構造体を提供する。 Further, the present invention provides a connection structure in which the terminals of the first electronic component and the terminals of the second electronic component are anisotropically conductively connected by the anisotropic conductive film of the present invention.

本発明の異方性導電フィルムにおいては、基準領域に想定される平面格子パターンの全格子点に対する「導電粒子が配置されていない格子点」の割合が20%未満に設定され、「複数の導電粒子が凝集して配置されている格子点」の割合が15%以下に設定され、しかも抜けと凝集の合計が25%未満に設定されている。このため、本発明の異方性導電フィルムを異方性導電接続に適用した場合、良好な初期導通抵抗値とエージング後の良好な導通信頼性とを実現でき、ショートの発生も抑制できる。また、COGのみならず、バンプ面積や距離が十分に大きい電子部品、例えばFOG等に対して、経済性に優れる。 In the anisotropic conductive film of the present invention, the ratio of "lattice points where conductive particles are not arranged" to all the lattice points of the planar lattice pattern assumed in the reference region is set to less than 20%, and "a plurality of conductivity". The ratio of "lattice points where particles are aggregated and arranged" is set to 15% or less, and the total of omission and aggregation is set to less than 25%. Therefore, when the anisotropic conductive film of the present invention is applied to the anisotropic conductive connection, a good initial conduction resistance value and good conduction reliability after aging can be realized, and the occurrence of a short circuit can be suppressed. Further, it is excellent in economy not only for COG but also for electronic parts having a sufficiently large bump area and distance, such as FOG.

本発明の好ましい異方性導電フィルムにおいては、基準領域に想定される平面格子パターンの全格子点に対する「導電粒子が配置されていない格子点」の割合が20%未満に設定され、しかも「複数の導電粒子が凝集して配置されている格子点」の割合が5%以下である。このため、本発明の異方性導電フィルムを異方性導電接続に適用した場合、良好な初期導通抵抗値とエージング後の良好な導通信頼性とを実現でき、ショートの発生も抑制できる。 In the preferred anisotropic conductive film of the present invention, the ratio of "lattice points where conductive particles are not arranged" to all the lattice points of the planar lattice pattern assumed in the reference region is set to less than 20%, and moreover, "plurality". The ratio of "lattice points in which the conductive particles of the above are aggregated and arranged" is 5% or less. Therefore, when the anisotropic conductive film of the present invention is applied to the anisotropic conductive connection, a good initial conduction resistance value and good conduction reliability after aging can be realized, and the occurrence of a short circuit can be suppressed.

また、本発明の異方性導電フィルムの製造方法においては、平面格子パターンの格子点に相当する柱状の凸部が表面に形成された転写体を使用し、その凸部の天面に形成した微粘着層に導電粒子を付着させた後に、その導電粒子を絶縁性接着ベース層に転写する。このため、異方性導電フィルムの基準領域に想定される平面格子パターンの全格子点に対する「導電粒子が配置されていない格子点」の割合を20%未満とし且つ平面格子パターンの全格子点に対する「複数の導電粒子が凝集して配置されている格子点」の割合を5%以下にすることができる。よって、本発明の製造方法は、経済的に有利に異方性導電フィルムを製造することができ、この異方性導電フィルムを用いれば、狭ピッチ化したICチップと配線基板とを、ショートや導通不良の発生を大きく抑制しつつ、異方性導電接続が可能となる。 Further, in the method for producing an anisotropic conductive film of the present invention, a transfer body in which a columnar convex portion corresponding to a lattice point of a planar lattice pattern is formed on the surface is used and formed on the top surface of the convex portion. After the conductive particles are attached to the slightly adhesive layer, the conductive particles are transferred to the insulating adhesive base layer. Therefore, the ratio of "lattice points on which conductive particles are not arranged" to all the lattice points of the planar lattice pattern assumed in the reference region of the anisotropic conductive film is set to less than 20%, and the ratio to all the lattice points of the planar lattice pattern is set to less than 20%. The ratio of "lattice points in which a plurality of conductive particles are aggregated and arranged" can be set to 5% or less. Therefore, the manufacturing method of the present invention can economically and economically produce an anisotropic conductive film, and if this anisotropic conductive film is used, the IC chip having a narrow pitch and the wiring board can be short-circuited. Anisotropic conductive connection is possible while greatly suppressing the occurrence of conduction failure.

図1は、本発明の異方性導電フィルムの断面図である。FIG. 1 is a cross-sectional view of the anisotropic conductive film of the present invention. 図2は、本発明の異方性導電フィルムの平面透視図である。FIG. 2 is a perspective perspective view of the anisotropic conductive film of the present invention. 図3Aは、本発明の製造方法の工程説明図である。FIG. 3A is a process explanatory view of the manufacturing method of the present invention. 図3Bは、本発明の製造方法の工程説明図である。FIG. 3B is a process explanatory view of the manufacturing method of the present invention. 図3Cは、本発明の製造方法の工程説明図である。FIG. 3C is a process explanatory view of the manufacturing method of the present invention. 図3Dは、本発明の製造方法の工程説明図である。FIG. 3D is a process explanatory view of the manufacturing method of the present invention. 図3Eは、本発明の製造方法の工程説明図である。FIG. 3E is a process explanatory view of the manufacturing method of the present invention. 図3Fは、本発明の製造方法の工程説明図であると同時に、本発明の異方性導電フィルムの概略断面図である。FIG. 3F is a process explanatory view of the manufacturing method of the present invention, and at the same time, is a schematic cross-sectional view of the anisotropic conductive film of the present invention.

本発明の異方性導電フィルムは、絶縁性接着ベース層と絶縁性接着カバー層とが積層され、それらの界面近傍に導電粒子が平面格子パターンの格子点に配置された構造を有する。この異方性導電フィルムの基準領域に想定される平面格子パターンの全格子点に対する導電粒子が配置されていない格子点の割合は、20%未満であり、該平面格子パターンの全格子点に対する複数の導電粒子が凝集して配置されている格子点の割合は、15%以下であり、抜けと凝集の合計が25%未満である。以下、本発明の異方性導電フィルムを図面を参照しながら詳細に説明する。 The anisotropic conductive film of the present invention has a structure in which an insulating adhesive base layer and an insulating adhesive cover layer are laminated, and conductive particles are arranged at lattice points of a planar lattice pattern in the vicinity of their interfaces. The ratio of the lattice points where the conductive particles are not arranged to all the lattice points of the plane lattice pattern assumed in the reference region of the anisotropic conductive film is less than 20%, and a plurality of lattice points to all the lattice points of the plane lattice pattern. The ratio of the lattice points where the conductive particles of the above are aggregated and arranged is 15% or less, and the total of omission and aggregation is less than 25%. Hereinafter, the anisotropic conductive film of the present invention will be described in detail with reference to the drawings.

<異方性導電フィルム>
図1(断面図)と図2(平面透視図)に示すように、本発明の異方性導電フィルム10は、絶縁性接着ベース層11と絶縁性接着カバー層12とが積層され、それらの界面近傍に導電粒子13が平面格子パターン(図2の点線)の格子点に配置された構造を有する。図1及び図2では、平面格子パターンは、異方性導電フィルム10の長手方向とそれに直交する方向(短手方向)に沿って想定されているが、長手方向と短手方向とに対し全体が傾斜して想定されてもよい。ここで、矢印Aは、平面格子の格子点に導電粒子が配置されていない位置、いわゆる導電粒子が「抜け」ている位置を示している。なお、矢印Bは、導電粒子同士が接触して凝集している位置を示しており、矢印Cは、導電粒子同士が非接触で凝集している位置を示している。ここで、「非接触で凝集」するとは、導電粒子同士が導電粒子の平均粒子径の25%を超えない範囲で近接していることを意味する。
<Animate conductive film>
As shown in FIGS. 1 (cross-sectional view) and 2 (planar perspective view), in the anisotropic conductive film 10 of the present invention, the insulating adhesive base layer 11 and the insulating adhesive cover layer 12 are laminated, and they are laminated. It has a structure in which the conductive particles 13 are arranged at the grid points of the plane grid pattern (dotted line in FIG. 2) in the vicinity of the interface. In FIGS. 1 and 2, the planar lattice pattern is assumed along the longitudinal direction of the anisotropic conductive film 10 and the direction orthogonal to the longitudinal direction (short direction), but is assumed as a whole with respect to the longitudinal direction and the lateral direction. May be assumed to be tilted. Here, the arrow A indicates a position where the conductive particles are not arranged at the lattice points of the plane lattice, that is, a position where the so-called conductive particles are “missing”. The arrow B indicates the position where the conductive particles are in contact with each other and aggregate, and the arrow C indicates the position where the conductive particles are in contact with each other and aggregate. Here, "non-contact aggregation" means that the conductive particles are close to each other within a range not exceeding 25% of the average particle diameter of the conductive particles.

(導電粒子の「抜け」)
本発明の異方性導電フィルムにおいては、異方性導電フィルムの基準領域に想定される平面格子パターンの全格子点に対する「導電粒子が配置されていない格子点」(図2のA)の割合(導電粒子が抜けている格子の割合)を20%未満、好ましくは18%以下、より好ましくは10~18%に設定する。これにより、本発明の異方性導電フィルムを異方性導電接続に適用した場合に、良好な初期導通性とエージング後の良好な導通信頼性とを実現でき、ショートの発生も抑制できる。
("Missing" of conductive particles)
In the anisotropic conductive film of the present invention, the ratio of "lattice points where conductive particles are not arranged" (A in FIG. 2) to all the lattice points of the planar lattice pattern assumed in the reference region of the anisotropic conductive film. (Ratio of lattices from which conductive particles are missing) is set to less than 20%, preferably 18% or less, and more preferably 10 to 18%. Thereby, when the anisotropic conductive film of the present invention is applied to the anisotropic conductive connection, good initial conductivity and good conduction reliability after aging can be realized, and the occurrence of short circuit can be suppressed.

(平面格子パターン)
平面格子パターンとしては、斜方格子、六方格子、正方格子、矩形格子、平行体格子が挙げられる。中でも、最密充填可能な六方格子が好ましい。
(Plane grid pattern)
Examples of the plane lattice pattern include an oblique lattice, a hexagonal lattice, a square lattice, a rectangular lattice, and a parallelepiped lattice. Of these, a hexagonal grid that can be packed most densely is preferable.

ここで、異方性導電フィルムの基準領域として、異方性導電フィルム全面を選択することも可能であるが、通常、異方性導電フィルムの平面中央部の以下の関係式(A)、好ましくは関係式(1)と、関係式(2)及び(3)とを満たす辺X及び辺Yからなる略方形の領域を基準領域として選択することが好ましい。 Here, it is possible to select the entire surface of the anisotropic conductive film as the reference region of the anisotropic conductive film, but usually, the following relational expression (A) at the center of the plane of the anisotropic conductive film is preferable. Is preferably selected as a reference region in a substantially square region consisting of sides X and sides Y satisfying the relational expression (1) and the relational expressions (2) and (3).

Figure 0007067586000001
Figure 0007067586000001

なお、接続面積を比較的大きく取れるFOG接続に適用する場合には、フィルム中の導電粒子の存在量を少なくすることが可能であり、そのような場合には、以下に示すように、XとYとの値をそれぞれ大きくすること、好ましくは20D以上とすることが好ましく、「X+Y」の数値も100Dから400D近傍の数値、最終的には400Dとすることが好ましい。 When applied to a FOG connection in which a relatively large connection area can be obtained, it is possible to reduce the abundance of conductive particles in the film. In such a case, as shown below, X and It is preferable that the value with Y is increased, preferably 20D or more, and the numerical value of "X + Y" is also a numerical value in the vicinity of 100D to 400D, and finally 400D.

Figure 0007067586000002
Figure 0007067586000002

式(A)及び(1)~(3)、上記式において、Dは、導電粒子の平均粒子径である。導電粒子の平均粒子径は、画像型の粒度分布計により測定することができる。面観察から計測してもよい。また、辺Yは異方性導電フィルムの長手方向(図2参照)に対し±45°未満の範囲の直線であり、辺Xは辺Yに垂直な直線である。 In the formulas (A) and (1) to (3), D is the average particle diameter of the conductive particles. The average particle size of the conductive particles can be measured by an image-type particle size distribution meter. It may be measured from the surface observation. Further, the side Y is a straight line in a range of less than ± 45 ° with respect to the longitudinal direction of the anisotropic conductive film (see FIG. 2), and the side X is a straight line perpendicular to the side Y.

このように基準領域を規定することにより、基準領域を導電粒子が押圧されるバンプの形状に相似ないしは近似させることができ、結果的に、導電粒子の平面格子パターンからのズレの許容範囲を大きくすることができ、異方性導電接続を経済的に且つ安定して行えるようになる。換言すれば、この基準領域の最小の辺を導電粒子径の5倍以上とすることにより、この範囲内で想定される範囲内で導電粒子の位置ズレや抜け、近接があっても、いずれかのバンプで捕捉され、且つバンプ間スペースで過度に凝集することがないため、異方性導電接続を確実に行うことができる。 By defining the reference region in this way, the reference region can be made similar to or approximate to the shape of the bump on which the conductive particles are pressed, and as a result, the allowable range of deviation of the conductive particles from the planar lattice pattern is increased. This makes it possible to economically and stably perform anisotropic conductive connection. In other words, by making the smallest side of this reference region 5 times or more the diameter of the conductive particles, even if the conductive particles are misaligned, missing, or close to each other within the range assumed within this range, any one of them. Since it is captured by the bumps of the above and does not excessively aggregate in the space between the bumps, the anisotropic conductive connection can be reliably performed.

なお、最小の辺を導電粒子径の5倍以上とする理由は、一般的に、異方性導電接続されるバンプの少なくとも1辺において捕捉を確実にするため導電粒子の平均粒子径よりも大きくする必要があり、しかもバンプ間スペースについてもショート防止の理由から、導電粒子の平均粒子径の望ましくは2倍以上の大きさを設ける必要があるからである。換言すれば、一つの基準となる円形の導電粒子に着目したときに、この導電粒子の平均粒子径Dにその径の4倍の長さ(4D)を足した長さ(即ち5D)を直径とする同心円内で想定外の不良が生じなければ、上記の要件を満たすことができると考えられるからである。また、ファインピッチとする場合のバンプ間の最小距離が、一例として、導電粒子径の4倍未満となるからでもある。 The reason why the smallest side is 5 times or more the diameter of the conductive particles is generally larger than the average particle diameter of the conductive particles in order to ensure capture on at least one side of the bump to be anisotropically conductively connected. This is because it is necessary to provide a space between bumps that is preferably at least twice the average particle diameter of the conductive particles for the reason of preventing short circuit. In other words, when focusing on the circular conductive particles that serve as a reference, the diameter (that is, 5D) is the average particle diameter D of the conductive particles plus four times the diameter (4D). This is because it is considered that the above requirements can be satisfied if unexpected defects do not occur within the concentric circles. Further, it is also because the minimum distance between the bumps in the case of fine pitch is, for example, less than four times the diameter of the conductive particles.

(導電粒子の凝集)
また、本発明の異方性導電フィルムにおいては、平面格子パターンの全格子点に対する複数の導電粒子が凝集して配置されている格子点(図2のB及びC)の割合は、好ましくは15%以下、より好ましくは5%以下である。0%になることが理論上最も好ましいことから、0.1%未満でもよい。凝集配置格子点の割合が5%以下であれば、本発明の異方性導電フィルムを異方性導電接続に適用した場合にも、より良好な初期導通性とエージング後の導通信頼性とを実現でき、ショートの発生もいっそう抑制できる。ここで、一つの格子点に対する導電粒子の凝集の程度は、ショート抑制の観点から小さい方が好ましく、2個を超えないことが好ましい。なお、図2のCのように、凝集している導電粒子同士が互いに接触していない場合には、その間隔は導電粒子の平均粒子径の25%以内が好ましく、より好ましくは15%以内である。
(Aggregation of conductive particles)
Further, in the anisotropic conductive film of the present invention, the ratio of the lattice points (B and C in FIG. 2) in which a plurality of conductive particles are aggregated and arranged with respect to all the lattice points of the planar lattice pattern is preferably 15. % Or less, more preferably 5% or less. Since it is theoretically most preferable to be 0%, it may be less than 0.1%. When the ratio of the cohesive arrangement lattice points is 5% or less, even when the anisotropic conductive film of the present invention is applied to the anisotropic conductive connection, better initial conductivity and conduction reliability after aging can be obtained. This can be achieved, and the occurrence of short circuits can be further suppressed. Here, the degree of aggregation of the conductive particles with respect to one lattice point is preferably small from the viewpoint of suppressing short circuit, and preferably does not exceed two. When the aggregated conductive particles are not in contact with each other as shown in C of FIG. 2, the interval is preferably 25% or less, more preferably 15% or less of the average particle diameter of the conductive particles. be.

(導電粒子の配置)
導電粒子は、フィルムの長手方向と垂直な方向に、11個以上連続で配置されていることが好ましく、13個以上連続で配置されていることがより好ましい。これは、バンプの長手方向に対して導電粒子の欠落が生じると、異方性導電接続に支障をきたすおそれが生じるためである。この場合、フィルムの長手方向に沿って連続した3列全てで上の条件を満たすことが好ましく、5列全てで上の条件を満たすことがより好ましい。これにより、バンプに捕捉される導電粒子数を一定以上にすることができ、安定な異方性導電接続を行うことができる。
(Arrangement of conductive particles)
It is preferable that 11 or more conductive particles are continuously arranged in a direction perpendicular to the longitudinal direction of the film, and more preferably 13 or more are continuously arranged. This is because if the conductive particles are missing in the longitudinal direction of the bump, the anisotropic conductive connection may be hindered. In this case, it is preferable that the above conditions are satisfied in all three rows continuous along the longitudinal direction of the film, and it is more preferable that the above conditions are satisfied in all five rows. As a result, the number of conductive particles captured by the bump can be increased to a certain level or more, and stable anisotropic conductive connection can be performed.

導電粒子が凝集している場合、2個凝集した導電粒子の周囲には、2個連結した導電粒子の組みが3つ以下であることが好ましく、より好ましくは2つ以下、更により好ましくは1つ以下である。2個凝集した導電粒子が密集して存在すると、ショート発生の要因になるからである。 When the conductive particles are aggregated, it is preferable that the number of pairs of the two connected conductive particles is three or less, more preferably two or less, and even more preferably 1 around the two aggregated conductive particles. Less than one. This is because the dense presence of two aggregated conductive particles causes a short circuit.

また、導電粒子の欠落は、フィルムの長手方向に4個以上連続するものと、フィルムの長手方向と垂直な方向に4個以上連続するものが交わっていないことが好ましく、4個以上連続する何れかの欠落が、一つ以上の格子点になる導電粒子を介して隣接していないことがより好ましく、4個以上連続する何れかの欠落が、二つ以上の格子点になる導電粒子を介して隣接していないことが更により好ましい。このような欠落の交わりは、一つの方向の欠落に対して3列まで同時に交わっても問題はない。欠落がこれ以上に連続していなければ、その近傍の導電粒子によってバンプに捕捉されるからである。 Further, it is preferable that four or more conductive particles are not continuously missing in the longitudinal direction of the film and four or more consecutive particles are not intersected in the direction perpendicular to the longitudinal direction of the film. It is more preferable that the missing pieces are not adjacent to each other via the conductive particles that become one or more lattice points, and it is preferable that any of four or more consecutive missing pieces are transmitted through the conductive particles that become two or more lattice points. It is even more preferable that they are not adjacent to each other. There is no problem in the intersection of such defects even if up to three rows are simultaneously intersected for the defects in one direction. This is because if the defects are not continuous any more, they will be captured by the bumps by the conductive particles in the vicinity.

なお、このように連続する欠落が交わった領域が近傍に複数あることは、一般に好ましくないが、欠落した領域と同数以上の導電粒子の配列を介していれば異方性導電接続の安定性には問題はない。 It is generally unfavorable that there are a plurality of regions where continuous defects intersect in the vicinity, but the stability of the anisotropic conductive connection is improved if the array of conductive particles is equal to or larger than the number of the missing regions. Is no problem.

(粒子面積占有率)
更に、異方性導電フィルムの基準領域の面積に対する、その面積中に存在する全導電粒子の粒子面積占有率は、FOG接続のように、バンプサイズやバンプ間距離が比較的大きいものに対しては、通常0.15%以上、好ましくは0.35%以上、より好ましくは1.4%以上が有効である。この場合の上限は35%以下が好ましく、32%以下がより好ましい。また、バンプサイズやバンプ間距離が比較的小さくなる場合(例えばCOG接続)には、更に好ましくは15~35%、特に好ましくは16~20%である。この範囲であれば、本発明の異方性導電フィルムを異方性導電接続に適用した場合にも、より良好な初期導通性とエージング後の導通信頼性とを実現でき、ショートの発生もいっそう抑制できる。ここで、粒子面積占有率は、基準領域の面積Sに対する、その基準領域内に存在する全導電粒子が占有する面積の割合である。全導電粒子が占有する面積とは、導電粒子の平均粒子径をRとし、導電粒子の数をnとした時に(R/2)×π×nで表される。従って、粒子面積占有率(%)=[{(R/2)×π×n}/S]×100で表される。
(Particle area occupancy)
Further, the particle area occupancy of all the conductive particles existing in the reference area of the anisotropic conductive film with respect to the area of the reference region is such that the bump size and the distance between bumps are relatively large, such as FOG connection. Is usually 0.15% or more, preferably 0.35% or more, and more preferably 1.4% or more. In this case, the upper limit is preferably 35% or less, more preferably 32% or less. Further, when the bump size and the distance between bumps are relatively small (for example, COG connection), it is more preferably 15 to 35%, and particularly preferably 16 to 20%. Within this range, even when the anisotropic conductive film of the present invention is applied to the anisotropic conductive connection, better initial conductivity and conduction reliability after aging can be realized, and short circuits are further generated. Can be suppressed. Here, the particle area occupancy rate is the ratio of the area occupied by all the conductive particles existing in the reference region to the area S of the reference region. The area occupied by all the conductive particles is expressed as (R / 2) 2 × π × n when the average particle diameter of the conductive particles is R and the number of conductive particles is n. Therefore, the particle area occupancy rate (%) = [{(R / 2) 2 × π × n} / S] × 100.

ちなみに、導電粒子の平均粒子径が2μm、個数密度500個/mm(0.0005個/μm)、X=Y=200D、X+Y=400Dとした場合の計算上の粒子面積占有率は、0.157%となる。導電粒子の平均粒子径が3μm、個数密度500個/mm(0.0005個/μm)、X=Y=200D、X+Y=400Dとした場合の計算上の粒子面積占有率は、0.35325%となる。導電粒子の平均粒子径が3μm、個数密度2000個/mm(0.002個/μm)、X=Y=200D、X+Y=400Dとした場合の計算上の粒子面積占有率は、1.413%となる。また、導電粒子の平均粒子径が30μm、個数密度500個/mm(0.0005個/μm)、X=Y=200D、X+Y=400Dとした場合の計算上の粒子面積占有率は、35.325%となる。 By the way, when the average particle diameter of the conductive particles is 2 μm, the number density is 500 pieces / mm 2 (0.0005 pieces / μm 2 ), X = Y = 200D, and X + Y = 400D, the calculated particle area occupancy rate is It will be 0.157%. When the average particle diameter of the conductive particles is 3 μm, the number density is 500 / mm 2 (0.0005 / μm 2 ), X = Y = 200D, and X + Y = 400D, the calculated particle area occupancy is 0. It will be 35325%. When the average particle size of the conductive particles is 3 μm, the number density is 2000 pieces / mm 2 (0.002 pieces / μm 2 ), X = Y = 200D, and X + Y = 400D, the calculated particle area occupancy rate is 1. It will be 413%. Further, when the average particle diameter of the conductive particles is 30 μm, the number density is 500 particles / mm 2 (0.0005 particles / μm 2 ), X = Y = 200D, and X + Y = 400D, the calculated particle area occupancy rate is It will be 35.325%.

(導電粒子)
導電粒子としては、公知の異方性導電フィルムにおいて使用されているものを適宜選択して使用することができる。例えば、ニッケル、銅、銀、金、パラジウムなどの金属粒子、ポリアミド、ポリベンゾグアナミン等の樹脂粒子の表面をニッケルなどの金属で被覆した金属被覆樹脂粒子等を挙げることができる。また、導電粒子の平均粒子径は、製造時の取り扱い性の観点から、好ましくは1~30μm、より好ましくは1~10μm、特に好ましくは2~6μmである。平均粒子径は、前述したように、画像型粒度分布計により測定することができる。面観察から計測してもよい。
(Conductive particles)
As the conductive particles, those used in known anisotropic conductive films can be appropriately selected and used. For example, metal particles such as nickel, copper, silver, gold, and palladium, and metal-coated resin particles in which the surface of resin particles such as polyamide and polybenzoguanamine are coated with a metal such as nickel can be mentioned. The average particle size of the conductive particles is preferably 1 to 30 μm, more preferably 1 to 10 μm, and particularly preferably 2 to 6 μm from the viewpoint of handleability at the time of manufacture. As described above, the average particle size can be measured by an image-type particle size distribution meter. It may be measured from the surface observation.

異方性導電フィルム中の導電粒子の存在量は、平面格子パターンの格子ピッチ並びに導電粒子の平均粒子径に依存しており、通常は、300~40000個/mmである。 The abundance of conductive particles in the anisotropic conductive film depends on the lattice pitch of the planar lattice pattern and the average particle diameter of the conductive particles, and is usually 300 to 40,000 particles / mm 2 .

(隣接格子点間距離)
また、異方性導電フィルムに想定される平面格子パターンにおける隣接格子点間距離は、導電粒子の平均粒子径の好ましくは0.5倍より大きく、より好ましくは1倍以上、更に好ましくは1~20倍である。この範囲であれば、本発明の異方性導電フィルムを異方性導電接続に適用した場合にも、より良好な初期導通性とエージング後の導通信頼性とを実現でき、ショートの発生もいっそう抑制できる。
(Distance between adjacent grid points)
Further, the distance between adjacent lattice points in the planar lattice pattern assumed for the anisotropic conductive film is preferably larger than 0.5 times, more preferably 1 time or more, still more preferably 1 to 1 to the average particle diameter of the conductive particles. It is 20 times. Within this range, even when the anisotropic conductive film of the present invention is applied to the anisotropic conductive connection, better initial conductivity and conduction reliability after aging can be realized, and short circuits are further generated. Can be suppressed.

(絶縁性接着ベース層)
絶縁性接着ベース層11としては、公知の異方性導電フィルムにおいて絶縁性接着ベース層として使用されているものを適宜選択して使用することができる。例えば、アクリレート化合物と光ラジカル重合開始剤とを含む光ラジカル重合性樹脂層、アクリレート化合物と熱ラジカル重合開始剤とを含む熱ラジカル重合性樹脂層、エポキシ化合物と熱カチオン重合開始剤とを含む熱カチオン重合性樹脂層、エポキシ化合物と熱アニオン重合開始剤とを含む熱アニオン重合性樹脂層等、又はそれらの硬化樹脂層を使用することができる。また、これらの樹脂層には、必要に応じてシランカップリング剤、顔料、酸化防止剤、紫外線吸収剤等を適宜選択して含有させることができる。
(Insulating adhesive base layer)
As the insulating adhesive base layer 11, those used as the insulating adhesive base layer in a known anisotropic conductive film can be appropriately selected and used. For example, a photoradical polymerizable resin layer containing an acrylate compound and a photoradical polymerization initiator, a thermal radical polymerizable resin layer containing an acrylate compound and a thermal radical polymerization initiator, and heat containing an epoxy compound and a thermal cationic polymerization initiator. A cationically polymerizable resin layer, a thermal anion polymerizable resin layer containing an epoxy compound and a thermal anion polymerization initiator, or a cured resin layer thereof can be used. Further, these resin layers can appropriately select and contain a silane coupling agent, a pigment, an antioxidant, an ultraviolet absorber and the like, if necessary.

なお、絶縁性接着ベース層11は、上述したような樹脂を含むコーティング組成物を塗布法により成膜し乾燥させることや、更に硬化させることにより、あるいは予め公知の手法によりフィルム化することにより形成することができる。 The insulating adhesive base layer 11 is formed by forming a coating composition containing a resin as described above into a film by a coating method and drying it, further curing it, or forming a film by a method known in advance. can do.

このような絶縁性接着ベース層11の厚みは、好ましくは1~30μm、より好ましくは2~15μmである。 The thickness of such an insulating adhesive base layer 11 is preferably 1 to 30 μm, more preferably 2 to 15 μm.

(絶縁性接着カバー層)
絶縁性接着カバー層12としては、公知の異方性導電フィルムにおいて絶縁性接着カバー層として使用されているものを適宜選択して使用することができる。また、先に説明した絶縁性接着ベース層11と同じ材料から形成したものも使用することができる。
(Insulating adhesive cover layer)
As the insulating adhesive cover layer 12, a known anisotropic conductive film used as the insulating adhesive cover layer can be appropriately selected and used. Further, those formed from the same material as the insulating adhesive base layer 11 described above can also be used.

なお、絶縁性接着カバー層12は、上述したような樹脂を含むコーティング組成物を塗布法により成膜し乾燥させることや、更に硬化させることにより、あるいは予め公知の手法によりフィルム化することにより形成することができる。 The insulating adhesive cover layer 12 is formed by forming a coating composition containing a resin as described above into a film by a coating method and drying it, further curing it, or forming a film by a method known in advance. can do.

このような絶縁性接着カバー層12の厚みは、好ましくは1~30μm、より好ましくは2~15μmである。 The thickness of such an insulating adhesive cover layer 12 is preferably 1 to 30 μm, more preferably 2 to 15 μm.

更に、絶縁性接着ベース層11や絶縁性接着カバー層12には、必要に応じてシリカ微粒子、アルミナ、水酸化アルミニウム等の絶縁性フィラーを加えてもよい。絶縁性フィラーの配合量は、それらの層を構成する樹脂100質量部に対して3~40質量部とすることが好ましい。これにより、異方性導電接続の際に絶縁接着剤層10が溶融しても、溶融した樹脂で導電粒子2が不要に移動することを抑制することができる。 Further, an insulating filler such as silica fine particles, alumina, or aluminum hydroxide may be added to the insulating adhesive base layer 11 and the insulating adhesive cover layer 12, if necessary. The blending amount of the insulating filler is preferably 3 to 40 parts by mass with respect to 100 parts by mass of the resin constituting the layer. As a result, even if the insulating adhesive layer 10 is melted during the anisotropic conductive connection, it is possible to prevent the conductive particles 2 from moving unnecessarily due to the melted resin.

(絶縁性接着ベース層と絶縁性接着カバー層との積層、導電粒子の埋め込み)
なお、導電粒子13を挟んで絶縁性接着ベース層11と絶縁性カバー層12とを積層する場合、公知の手法により行うことができる。この場合、導電粒子13は、これらの層の界面近傍に存在する。ここで、「界面近傍に存在」とは、導電粒子の一部が一方の層に食い込み、残部が他方の層に食い込んでいることを示している。また、導電粒子を絶縁性接着ベース層に埋め込んでもよい。この場合、絶縁性接着カバー層を積層しなくとも形成することができる。
(Lamination of insulating adhesive base layer and insulating adhesive cover layer, embedding of conductive particles)
When the insulating adhesive base layer 11 and the insulating cover layer 12 are laminated with the conductive particles 13 interposed therebetween, a known method can be used. In this case, the conductive particles 13 are present in the vicinity of the interface between these layers. Here, "presence near the interface" means that a part of the conductive particles bites into one layer and the rest bites into the other layer. Further, the conductive particles may be embedded in the insulating adhesive base layer. In this case, it can be formed without laminating the insulating adhesive cover layer.

<異方性導電フィルムの製造>
次に、絶縁性接着ベース層と絶縁性接着カバー層とが積層され、それらの界面近傍に導電粒子が平面格子パターンの格子点に配置された構造の本発明の異方性導電フィルムの製造方法を説明する。この製造方法は、以下の工程(イ)~(ホ)を有する。図面を参照しながら、工程毎に詳細に説明する。なお、本発明は特にこの製造方法に限定されるものではない。
<Manufacturing of anisotropic conductive film>
Next, the method for producing an anisotropic conductive film of the present invention having a structure in which an insulating adhesive base layer and an insulating adhesive cover layer are laminated and conductive particles are arranged at lattice points of a planar lattice pattern in the vicinity of their interfaces. To explain. This manufacturing method has the following steps (a) to (e). Each process will be described in detail with reference to the drawings. The present invention is not particularly limited to this manufacturing method.

(工程(イ))
まず、図3Aに示すように、平面格子パターンの格子点に相当する柱状の凸部101が表面に形成されている転写体100を用意する。ここで、柱状とは、円柱状もしくは角柱状(三角柱、四角柱、六角柱等)である。この柱状は錐体を含む。好ましくは円柱状である。凸部101の高さは、異方性導電接続すべき端子ピッチ、端子巾、スペース巾、導電粒子の平均粒子径等に応じて決定することができるが、使用する導電粒子の平均粒子径の好ましくは1.2倍以上2倍未満である。また、凸部101の巾(半分の高さでの巾)は、導電粒子の平均粒子径の好ましくは0.7倍以上1.3倍以下である。この高さと巾がこれらの範囲であれば、脱落と抜けが連続的に発生することが避けられるという効果が得られる。
(Process (a))
First, as shown in FIG. 3A, a transfer body 100 having a columnar convex portion 101 corresponding to a lattice point of a planar lattice pattern formed on the surface thereof is prepared. Here, the columnar column is a columnar prism or a prismatic column (triangular prism, square prism, hexagonal prism, etc.). This column contains a cone. It is preferably cylindrical. The height of the convex portion 101 can be determined according to the terminal pitch to be anisotropically conductively connected, the terminal width, the space width, the average particle diameter of the conductive particles, etc. It is preferably 1.2 times or more and less than 2 times. The width of the convex portion 101 (width at half height) is preferably 0.7 times or more and 1.3 times or less the average particle diameter of the conductive particles. If this height and width are within these ranges, it is possible to obtain the effect of avoiding continuous dropout and omission.

更に、凸部101は、導電粒子が安定的に付着していられるようなレベルの平坦な天面を有する。 Further, the convex portion 101 has a flat top surface at a level at which conductive particles can be stably attached.

*転写体の具体例
この工程(イ)で用意すべき転写体は、公知の手法を利用して作成することができ、例えば、金属プレートを加工して原盤を作成し、それに硬化性樹脂を塗布し、硬化させて作成することができる。具体的には、平坦な金属板を切削加工して、凸部に対応した凹部を形成した転写体原盤も作成し、この原盤の凹部形成面に転写体を構成する樹脂組成物を塗布し、硬化させた後、原盤から引き離すことにより転写体が得られる。
* Specific example of transfer material The transfer material to be prepared in this step (a) can be prepared by using a known method. For example, a metal plate is processed to prepare a master, and a curable resin is applied to it. It can be applied and cured. Specifically, a flat metal plate is machined to create a transfer master master in which recesses corresponding to the convex portions are formed, and a resin composition constituting the transfer body is applied to the recess-forming surface of the master. After curing, the transcript is obtained by pulling it away from the master.

(工程(ロ))
次に、図3Bに示すように、表面に複数の凸部101が平面格子パターンで形成された転写体100の凸部101の少なくとも天面を微粘着層102とする。
(Process (b))
Next, as shown in FIG. 3B, at least the top surface of the convex portion 101 of the transfer body 100 in which a plurality of convex portions 101 are formed in a plane lattice pattern on the surface is designated as a microadhesive layer 102.

*転写体の微粘着層
微粘着層102は、異方性導電フィルムを構成する絶縁性接着ベース層に導電粒子が転着されるまで、導電粒子を一時的に保持できる粘着力を示す層であり、凸部101の少なくとも天面に形成される。従って、凸部101全体が微粘着性であってもよい。微粘着層102の厚みは、微粘着層102の材質、導電粒子の粒子径等に応じて適宜決定することができる。また、“微粘着”とは、絶縁性接着ベース層に導電粒子を転着する際に、絶縁性接着ベース層よりも粘着力が弱いという意味である。
* Slightly adhesive layer of transfer material The slightly adhesive layer 102 is a layer that exhibits adhesive strength that can temporarily hold conductive particles until the conductive particles are transferred to the insulating adhesive base layer constituting the anisotropic conductive film. Yes, it is formed on at least the top surface of the convex portion 101. Therefore, the entire convex portion 101 may be slightly adhesive. The thickness of the fine adhesive layer 102 can be appropriately determined according to the material of the fine adhesive layer 102, the particle diameter of the conductive particles, and the like. Further, "slightly adhesive" means that the adhesive force is weaker than that of the insulating adhesive base layer when the conductive particles are transferred to the insulating adhesive base layer.

このような微粘着層102は、公知の異方性導電フィルムに使用されている微粘着層を適用することができる。例えば、シリコーン系の粘着剤組成物や絶縁性接着ベース層や絶縁性接着カバー層と同材質の粘着層を、凸部101の天面に塗布することにより形成することができる。 As such a slightly adhesive layer 102, the slightly adhesive layer used in a known anisotropic conductive film can be applied. For example, it can be formed by applying an adhesive layer made of the same material as the silicone-based adhesive composition, the insulating adhesive base layer, or the insulating adhesive cover layer to the top surface of the convex portion 101.

(工程(ハ))
次に、図3Cに示すように、転写体100の凸部101の微粘着層102に導電粒子103を付着させる。具体的には、転写体100の凸部101の上方から導電粒子103を散布し、微粘着層102に付着しなかった導電粒子103をブロアを用いて吹き飛ばせばよい。もしくは図3Cから面の方向を逆転させ、導電粒子を一面に敷き詰めた面に突起の天面を付着させてもよい。導電粒子に不要な応力を加えないためである。このように配置に必要な導電粒子のみを突起天面に付着させることで導電粒子を回収し再利用しやすくなり、開口部に導電粒子を充填し取り出す方法に比べ、経済性にも優れることになる。なお、開口部に導電粒子を充填し取り出す方法の場合、充填されなかった導電粒子には不要な応力がかかりやすくなることが懸念される。
(Process (c))
Next, as shown in FIG. 3C, the conductive particles 103 are attached to the slightly adhesive layer 102 of the convex portion 101 of the transfer body 100. Specifically, the conductive particles 103 may be sprayed from above the convex portion 101 of the transfer body 100, and the conductive particles 103 that did not adhere to the fine adhesive layer 102 may be blown off using a blower. Alternatively, the direction of the surface may be reversed from FIG. 3C, and the top surface of the protrusion may be attached to the surface on which the conductive particles are spread all over. This is because unnecessary stress is not applied to the conductive particles. By adhering only the conductive particles necessary for placement to the top surface of the protrusion in this way, the conductive particles can be easily collected and reused, which is more economical than the method of filling the openings with the conductive particles and taking them out. Become. In the case of the method of filling the opening with conductive particles and taking them out, there is a concern that unnecessary stress is likely to be applied to the unfilled conductive particles.

なお、図3Cでは、左半分の凸部101の巾を、右半分の凸部101よりも狭く調整している。この結果、左半分と右半分では、図3Cに示すように、導電粒子103の凝集の態様に相違点が生ずることがある。 In FIG. 3C, the width of the convex portion 101 on the left half is adjusted to be narrower than that on the convex portion 101 on the right half. As a result, as shown in FIG. 3C, there may be a difference in the mode of aggregation of the conductive particles 103 between the left half and the right half.

(工程(ニ))
次に、図3Dに示すように、転写体100の導電粒子103が付着した側の表面を、異方性導電フィルムを構成すべき絶縁性接着ベース層104を重ねて押圧することにより、絶縁性接着ベース層104の片面に導電粒子103を転着させる(図3E)。この場合、転写体100を、その凸部101が下向きになるように絶縁性接着ベース層104に重ねて押圧することが好ましい。下向きにしてブロアすることで、凸部の天面に貼着されていない導電粒子を除去し易くさせるためである。
(Process (d))
Next, as shown in FIG. 3D, the surface of the transfer body 100 on the side to which the conductive particles 103 are attached is pressed with the insulating adhesive base layer 104 that should form the anisotropic conductive film in an overlapping manner to have insulating properties. Conductive particles 103 are transferred to one side of the adhesive base layer 104 (FIG. 3E). In this case, it is preferable to press the transfer body 100 on the insulating adhesive base layer 104 so that the convex portion 101 faces downward. This is because the blower is directed downward to facilitate the removal of conductive particles that are not attached to the top surface of the convex portion.

(工程(ホ))
図3Fに示すように、導電粒子103が転着した絶縁性接着ベース層104に対し、導電粒子転着面側から絶縁性接着カバー層105を積層する。これにより本発明の異方性導電フィルム200が得られる。
(Process (e))
As shown in FIG. 3F, the insulating adhesive cover layer 105 is laminated on the insulating adhesive base layer 104 to which the conductive particles 103 are transferred from the conductive particle transfer surface side. As a result, the anisotropic conductive film 200 of the present invention can be obtained.

なお、この異方性導電フィルム200においては、平面格子パターンの一つの格子点に複数の導電粒子同士が水平方向に接触してあるいは近接して凝集配置される場合がある。これは、導電粒子を転写体の凸部の微粘着層に付着させる際に、凸部の幅(微粘着層の幅)と導電粒子の平均粒子径とが略同等の大きさのため、一つの凸部上に導電粒子が複数存在すること考え難いものの、余分な導電粒子が微粘着層の端部に付着したり、凸部から脱落しブロアーしきれなかったものが転写体の凸部間隙に残存する場合があり得るからである。 In the anisotropic conductive film 200, a plurality of conductive particles may be aggregated and arranged in horizontal contact with each other or in close proximity to one lattice point of the planar lattice pattern. This is because the width of the convex portion (width of the microadhesive layer) and the average particle diameter of the conductive particles are approximately the same size when the conductive particles are attached to the fine adhesive layer of the convex portion of the transfer body. Although it is unlikely that there are multiple conductive particles on one convex part, the extra conductive particles that adhere to the end of the microadhesive layer or fall off from the convex part and cannot be blown out are the convex gaps of the transfer body. This is because it may remain in.

<接続構造体>
本発明の異方性導電フィルムは、第1の電子部品(例えば、ICチップ)の端子(例えばバンプ)と、第2の電子部品(例えば配線基板)の端子(例えばバンプ、パッド)との間に配置し、第1又は第2の電子部品側から熱圧着により本硬化させて異方性導電接続することにより、ショートや導通不良が抑制された、いわゆるCOG(chip on glass)やFOG(film on glass)等の接続構造体を与えることができる。
<Connection structure>
The anisotropic conductive film of the present invention is formed between a terminal (for example, a bump) of a first electronic component (for example, an IC chip) and a terminal (for example, a bump, a pad) of a second electronic component (for example, a wiring board). So-called COG (chip on glass) and FOG (film) in which short circuits and poor continuity are suppressed by being placed in the first or second electronic component side and being main-cured by thermocompression bonding to form an anisotropic conductive connection. A connection structure such as on glass) can be provided.

以下、本発明を具体的に説明する。 Hereinafter, the present invention will be specifically described.

実施例1
厚さ2mmのニッケルプレートを用意し、四方格子パターンで円柱状の凹部(内径5μm、深さ6μm)を形成し、転写体原盤とした。隣接凹部中心間距離は8μmであった。従って、凹部の密度は16000個/mm2であった。
Example 1
A nickel plate having a thickness of 2 mm was prepared, and a columnar recess (inner diameter 5 μm, depth 6 μm) was formed in a four-sided lattice pattern to form a transfer master. The distance between the centers of the adjacent recesses was 8 μm. Therefore, the density of the recesses was 16000 pieces / mm2.

得られた転写体原盤に、フェノキシ樹脂(YP-50、新日鉄住金化学(株))60質量部、アクリレート樹脂(M208、東亞合成(株))29質量部、光重合開始剤(IRGCUR184、BASFジャパン(株))2質量部を含有する光重合性樹脂組成物を、乾燥厚みが30μmとなるようにPET(ポリエチレンテレフタレート)フィルム上に塗布し、80℃で5分間乾燥後、高圧水銀ランプにて1000mJ光照射することにより転写体を作成した。 60 parts by mass of phenoxy resin (YP-50, Nippon Steel & Sumikin Chemical Co., Ltd.), 29 parts by mass of acrylate resin (M208, Toa Synthetic Co., Ltd.), photopolymerization initiator (IRGCUR184, BASF Japan) on the obtained transfer master. Co., Ltd. A photopolymerizable resin composition containing 2 parts by mass is applied onto a PET (polyethylene terephthalate) film so that the drying thickness is 30 μm, dried at 80 ° C. for 5 minutes, and then used with a high-pressure mercury lamp. A transcript was prepared by irradiating with 1000 mJ light.

転写体を原盤から引き剥がし、凸部が外側になるように直径20cmのステンレス製のロールに巻き付け、このロールを、回転させながらエポキシ樹脂(jER828、三菱化学(株))70質量部とフェノキシ樹脂(YP-50、新日鉄住金化学(株))30質量部とを含有する微粘着剤組成物を、不織布に含浸させた粘着シートに接触させ、凸部の天面に微粘着剤組成物を付着させ、厚さ1μmの微粘着層を形成して転写体を得た。 The transfer body is peeled off from the master, wrapped around a stainless steel roll with a diameter of 20 cm so that the convex part is on the outside, and while rotating this roll, 70 parts by mass of epoxy resin (jER828, Mitsubishi Chemical Corporation) and phenoxy resin. (YP-50, Nippon Steel & Sumikin Chemical Co., Ltd.) A fine pressure-sensitive adhesive composition containing 30 parts by mass is brought into contact with a pressure-sensitive adhesive sheet impregnated in a non-woven fabric, and the fine pressure-sensitive adhesive composition is adhered to the top surface of the convex portion. Then, a slightly adhesive layer having a thickness of 1 μm was formed to obtain a transferred product.

この転写体の表面に、平均粒子径4μmの導電粒子(ニッケルメッキ樹脂粒子(AUL704、積水化学工業(株)))を散布した後、ブロアすることにより微粘着層に付着していないで導電粒子を除去した。 Conductive particles having an average particle diameter of 4 μm (nickel-plated resin particles (AUL704, Sekisui Chemical Co., Ltd.)) are sprayed on the surface of this transfer body, and then blown to prevent the conductive particles from adhering to the fine adhesive layer. Was removed.

導電粒子が付着した転写体を、その導電粒子付着面から、絶縁性接着ベース層である厚さ5μmのシート状の熱硬化型の絶縁性接着フィルム(フェノキシ樹脂(YP-50、新日鉄住金化学(株))60質量部、エポキシ樹脂(jER828、三菱化学(株))40質量部、カチオン系硬化剤(SI-60L、三新化学工業(株))2質量部、及びシリカ微粒子(アエロジルRY200、日本アエロジル(株))20質量部を含有する絶縁性接着組成物から形成したフィルム)に対し、温度50℃、圧力0.5MPaで押圧することにより、絶縁性接着ベース層に導電粒子を転写させた。 A sheet-like heat-curable insulating adhesive film (phenoxy resin (YP-50, Nippon Steel & Sumitomo Metal Chemical Co., Ltd.) with a thickness of 5 μm, which is an insulating adhesive base layer, is attached to the transfer material to which the conductive particles are attached. Co., Ltd.) 60 parts by mass, epoxy resin (jER828, Mitsubishi Chemical Corporation) 40 parts by mass, cationic curing agent (SI-60L, Sanshin Chemical Industry Co., Ltd.) 2 parts by mass, and silica fine particles (Aerodil RY200, A film formed from an insulating adhesive composition containing 20 parts by mass of Nippon Aerodil Co., Ltd.) is pressed at a temperature of 50 ° C. and a pressure of 0.5 MPa to transfer conductive particles to an insulating adhesive base layer. rice field.

得られた絶縁性接着ベース層の導電粒子転着面に、透明な絶縁性接着カバー層として厚さ15μmのシート状の別の絶縁性接着フィルム(フェノキシ樹脂(YP-50、新日鉄住金化学(株))60質量部、エポキシ樹脂(jER828、三菱化学(株))40質量部、及びカチオン系硬化剤(SI-60L、三新化学工業(株))2質量部を含有する絶縁性接着組成物から形成されたフィルム)を重ね、温度60℃、圧力2MPaで積層した。これにより異方性導電フィルムが得られた。 Another sheet-like insulating adhesive film (phenoxy resin (YP-50, Nippon Steel & Sumitomo Metal Corporation)) with a thickness of 15 μm as a transparent insulating adhesive cover layer on the conductive particle transfer surface of the obtained insulating adhesive base layer. )) Insulating adhesive composition containing 60 parts by mass of epoxy resin (jER828, Mitsubishi Chemical Corporation) and 2 parts by mass of cationic curing agent (SI-60L, Sanshin Chemical Industry Co., Ltd.) The film formed from the above was laminated, and laminated at a temperature of 60 ° C. and a pressure of 2 MPa. As a result, an anisotropic conductive film was obtained.

実施例2
導電粒子の散布量とブロア回数とを実施例1の場合に比べてそれぞれ2倍とすること以外、実施例1を繰り返すことにより異方性導電フィルムを得た。
Example 2
An anisotropic conductive film was obtained by repeating Example 1 except that the spraying amount of the conductive particles and the number of blowers were doubled as compared with the case of Example 1.

実施例3
転写体原盤の凹部の内径を3.6μm、隣接凹部中心間距離を6μmとして凹部の密度を28000個/mm2とし、且つ平均粒子径4μmの導電粒子に代えて平均粒子径3μmの導電粒子(AUL703、積水化学工業(株)))を使用すること以外、実施例1を繰り返すことにより異方性導電フィルムを得た。
Example 3
The inner diameter of the recesses of the transfer master is 3.6 μm, the distance between the centers of the adjacent recesses is 6 μm, the density of the recesses is 28,000 / mm2, and the conductive particles having an average particle diameter of 3 μm (AUL703) are replaced with the conductive particles having an average particle diameter of 4 μm. , Sekisui Chemical Co., Ltd.)), an anisotropic conductive film was obtained by repeating Example 1.

実施例4
導電粒子の散布量とブロア回数とを実施例3の場合に比べてそれぞれ2倍とすること以外、実施例3を繰り返すことにより異方性導電フィルムを得た。
Example 4
An anisotropic conductive film was obtained by repeating Example 3 except that the spraying amount of the conductive particles and the number of blowers were doubled as compared with the case of Example 3.

比較例1
転写体原盤の凹部の深さを4.4μm、凹部の内径を4.8μm、隣接凹部中心間距離を5.6μmとして凹部の密度を32000個/mmとすること以外、実施例1を繰り返すことにより異方性導電フィルムを得た。
Comparative Example 1
Example 1 is repeated except that the depth of the recesses of the transfer master is 4.4 μm, the inner diameter of the recesses is 4.8 μm, the distance between the centers of the adjacent recesses is 5.6 μm, and the density of the recesses is 32000 pieces / mm 2 . As a result, an anisotropic conductive film was obtained.

比較例2
転写体原盤の凹部の深さを3.3μm、凹部の内径を3.6μm、隣接凹部中心間距離を4.2μmとして凹部の密度を57000個/mmとし、且つ平均粒子径4μmの導電粒子に代えて平均粒子径3μmの導電粒子(AUL703、積水化学工業(株))を使用すること以外、実施例1を繰り返すことにより異方性導電フィルムを得た。
Comparative Example 2
Conductive particles with a recess depth of 3.3 μm, an inner diameter of the recess 3.6 μm, a distance between adjacent recess centers 4.2 μm, a recess density of 57,000 / mm 2 , and an average particle diameter of 4 μm. An anisotropic conductive film was obtained by repeating Example 1 except that conductive particles having an average particle diameter of 3 μm (AUL703, Sekisui Chemical Co., Ltd.) were used instead.

<評価>
(導電粒子の「抜け」と「凝集」)
実施例1~4及び比較例1~2の異方性導電フィルムについて、その透明な絶縁性接着カバー層側から光学顕微鏡(MX50、オリンパス(株))で1cm四方の領域を観察し、想定される平面格子パターンにおいて導電粒子が付着していない格子点の全格子点に対する割合(抜け[%])と、2個以上の導電粒子が凝集している格子点の全格子点に対する割合とを調べた。得られた結果を表1に示す。
<Evaluation>
("Distraction" and "aggregation" of conductive particles)
With respect to the anisotropic conductive films of Examples 1 to 4 and Comparative Examples 1 and 2, a 1 cm square area was observed with an optical microscope (MX50, Olympus Corporation) from the transparent insulating adhesive cover layer side, and it was assumed. Investigate the ratio of lattice points to which no conductive particles are attached to all lattice points (missing [%]) and the ratio of lattice points to which two or more conductive particles are aggregated to all lattice points. rice field. The results obtained are shown in Table 1.

また、凝集した導電粒子同士の最大距離(凝集距離)を測定し、併せて表1に示した。なお、「凝集」方向は、いずれも異方性導電フィルムの水平方向であった。 In addition, the maximum distance (aggregation distance) between the aggregated conductive particles was measured and also shown in Table 1. The "aggregation" direction was the horizontal direction of the anisotropic conductive film.

(粒子面積占有率)
導電粒子の平均粒子径と、転写体原盤の凹部密度(=転写体の凸部密度)とから、導電粒子の「抜け」と「凝集」とを考慮した上で、粒子面積占有率を計算した。得られた結果を表1に示す。
(Particle area occupancy)
The particle area occupancy was calculated from the average particle size of the conductive particles and the concave density of the transfer master (= convex density of the transfer), taking into consideration the "missing" and "aggregation" of the conductive particles. .. The results obtained are shown in Table 1.

(初期導通抵抗)
実施例及び比較例の異方性導電フィルムを用いて、バンプ間スペースが12μmで、高さ15μm、30×50μmの金バンプを有するICチップと、12μmスペースの配線が設けられたガラス基板とを180℃、60MPa、5秒という条件で異方性導電接続し、接続構造体を得た。得られた接続構造体について、抵抗測定器(デジタルマルチメーター7565、横河電気(株))を用いて初期導通抵抗値を測定した。得られた結果を表1に示す。0.5Ω以下であることが望まれる。
(Initial conduction resistance)
Using the anisotropic conductive films of Examples and Comparative Examples, an IC chip having a gap between bumps of 12 μm, a height of 15 μm, and a gold bump of 30 × 50 μm, and a glass substrate provided with wiring of 12 μm space were obtained. An anisotropic conductive connection was made under the conditions of 180 ° C., 60 MPa, and 5 seconds to obtain a connection structure. The initial conduction resistance value of the obtained connection structure was measured using a resistance measuring device (digital multimeter 7565, Yokogawa Electric Co., Ltd.). The results obtained are shown in Table 1. It is desired that it is 0.5Ω or less.

(導通信頼性)
初期導通抵抗値の測定に使用した接続構造体を、温度85℃、湿度85%に設定されたエージング試験器中に投入し、500時間放置した後の導通抵抗値を、初期導通抵抗と同様に測定した。得られた結果を表1に示す。5Ω以下であることが望まれる。
(Conduction reliability)
The connection structure used for measuring the initial conduction resistance value was put into an aging tester set at a temperature of 85 ° C. and a humidity of 85%, and the conduction resistance value after being left for 500 hours was set to the same as the initial conduction resistance value. It was measured. The results obtained are shown in Table 1. It is desired that it is 5Ω or less.

(ショート発生率)
初期導通抵抗で使用したものと同じ接続構造体を作成し、隣接する配線間のショートの発生の有無を調べた。得られた結果を表1に示す。ショート発生率が50ppm以下であることが望まれる。
(Short occurrence rate)
The same connection structure used for the initial conduction resistance was created, and the presence or absence of a short circuit between adjacent wirings was investigated. The results obtained are shown in Table 1. It is desirable that the short circuit occurrence rate is 50 ppm or less.

Figure 0007067586000003
Figure 0007067586000003

表1の結果から、実施例1~4の異方性導電フィルムを使用した接続構造体は、初期導通抵抗、導通信頼性、ショート発生率の各評価項目について、良好な結果を示したことがわかる。 From the results in Table 1, it can be seen that the connection structure using the anisotropic conductive film of Examples 1 to 4 showed good results for each evaluation item of initial conduction resistance, conduction reliability, and short circuit occurrence rate. Understand.

他方、比較例1、2の異方性導電フィルムの場合、導電粒子の「抜け」の割合は少ないものの「凝集」の割合が高すぎるため、ショートの発生率の評価が低いものであった。 On the other hand, in the case of the anisotropic conductive films of Comparative Examples 1 and 2, although the ratio of "missing" of the conductive particles was small, the ratio of "aggregation" was too high, so that the evaluation of the short circuit occurrence rate was low.

実施例5
凹部密度が500個/mmである転写原盤を使用するために隣接凹部中心間距離を調整すること以外、実施例2と同様にして転写体を作成し、更に異方性導電フィルムを作成した。得られた異方性導電フィルムについて、実施例2と同様に導電粒子の「抜け」と「凝集」とを測定し、更に粒子面積占有率を算出した。その結果、導電粒子の「抜け」と「凝集」とは実施例2と同等であった。また、粒子面積占有率は0.6%であった。
Example 5
A transfer body was prepared in the same manner as in Example 2 except that the distance between the centers of adjacent recesses was adjusted in order to use a transfer master having a recess density of 500 pieces / mm 2 , and an anisotropic conductive film was further prepared. .. With respect to the obtained anisotropic conductive film, “missing” and “aggregation” of the conductive particles were measured in the same manner as in Example 2, and the particle area occupancy was further calculated. As a result, the “missing” and “aggregation” of the conductive particles were equivalent to those in Example 2. The particle area occupancy was 0.6%.

また、得られた異方性導電フィルムを、ガラス基板(ITOベタ電極)とフレキシブル配線基板(バンプ幅:200μm、L(ライン)/S(スペース)=1、配線高さ10μm)との間に挟み、接続バンプ長さが1mmとなるように、180℃、80MPa、5秒という条件で異方性導電し、評価用の接続構造体を得た。得られた接続構造体について、その「初期導通抵抗値」と、温度85℃で湿度85%RHの恒温槽に500時間投入した後の「導通信頼性」とを、デジタルマルチメータ(34401A、アジレント・テクノロジー株式会社製)を使用して電流1Aで4端子法にて導通抵抗を測定し、「初期導通抵抗値」の場合には、測定値が2Ω以下の場合を良好、2Ωを超えるものを不良と評価し、「導通信頼性」の場合には、測定値が5Ω以下の場合を良好、5Ω以上の場合を不良と評価した。その結果、実施例5の接続構造体は、いずれも「良好」と評価された。また、実施例2と同様に「ショート発生率」を測定したところ、実施例2と同様に良好な結果が得られた。 Further, the obtained anisotropic conductive film is placed between the glass substrate (ITO solid electrode) and the flexible wiring board (bump width: 200 μm, L (line) / S (space) = 1, wiring height 10 μm). Anisically conducted under the conditions of 180 ° C., 80 MPa, and 5 seconds so that the length of the connection bump was 1 mm, and a connection structure for evaluation was obtained. For the obtained connection structure, the "initial conduction resistance value" and the "conduction reliability" after being placed in a constant temperature bath at a temperature of 85 ° C. and a humidity of 85% RH for 500 hours are measured by a digital multimeter (34401A, Agilent). -Measure the conduction resistance by the 4-terminal method with a current of 1A using (Technology Co., Ltd.), and in the case of "initial conduction resistance value", it is good if the measured value is 2Ω or less, and if it exceeds 2Ω. It was evaluated as defective, and in the case of "conductivity reliability", the case where the measured value was 5Ω or less was evaluated as good, and the case where the measured value was 5Ω or more was evaluated as defective. As a result, all of the connection structures of Example 5 were evaluated as "good". Moreover, when the "short-circuit occurrence rate" was measured in the same manner as in Example 2, good results were obtained as in Example 2.

実施例6
凹部密度が2000個/mmである転写原盤を使用するために隣接凹部中心間距離を調整すること以外、実施例2と同様にして転写体を作成し、更に異方性導電フィルムを作成した。得られた異方性導電フィルムについて、実施例2と同様に導電粒子の「抜け」と「凝集」とを測定し、更に粒子面積占有率を算出した。その結果、導電粒子の「抜け」と「凝集」とは実施例2と同等であった。また、粒子面積占有率は2.4%であった。
Example 6
A transfer body was prepared in the same manner as in Example 2 except that the distance between the centers of adjacent recesses was adjusted in order to use a transfer master having a recess density of 2000 pieces / mm 2 , and an anisotropic conductive film was further prepared. .. With respect to the obtained anisotropic conductive film, “missing” and “aggregation” of the conductive particles were measured in the same manner as in Example 2, and the particle area occupancy was further calculated. As a result, the “missing” and “aggregation” of the conductive particles were equivalent to those in Example 2. The particle area occupancy was 2.4%.

また、得られた異方性導電フィルムを、実施例5と同様にガラス基板とフレキシブル配線基板との間に挟み異方性導電接続することにより評価用の接続構造体を得た。得られた接続構造体について、実施例5と同様に、「初期導通抵抗値」、「導通信頼性」、「ショート発生率」とを評価したところ、いずれも良好な結果が得られた。 Further, the obtained anisotropic conductive film was sandwiched between the glass substrate and the flexible wiring board in the same manner as in Example 5, and the anisotropic conductive connection was obtained to obtain a connection structure for evaluation. As for the obtained connection structure, the "initial conduction resistance value", "conduction reliability", and "short-circuit occurrence rate" were evaluated in the same manner as in Example 5, and good results were obtained in all of them.

本発明の好ましい異方性導電フィルムにおいては、基準領域に想定される平面格子パターンの全格子点に対する「導電粒子が配置されていない格子点」の割合が20%未満に設定され、しかも平面格子パターンの全格子点に対する「複数の導電粒子が凝集して配置されている格子点」の割合が5%以下である。このため、本発明の異方性導電フィルムを異方性導電接続に適用した場合、良好な初期導通性とエージング後の良好な導通信頼性とを実現でき、ショートの発生も抑制できるので、狭ピッチ化したICチップと配線基板とを、異方性導電接続する場合に有用である。 In the preferred anisotropic conductive film of the present invention, the ratio of "lattice points on which conductive particles are not arranged" to all the lattice points of the planar lattice pattern assumed in the reference region is set to less than 20%, and the planar lattice is set. The ratio of "lattice points in which a plurality of conductive particles are aggregated and arranged" to all the lattice points of the pattern is 5% or less. Therefore, when the anisotropic conductive film of the present invention is applied to an anisotropic conductive connection, good initial conductivity and good conduction reliability after aging can be realized, and the occurrence of short circuit can be suppressed, so that the narrowness is narrowed. This is useful when the pitched IC chip and the wiring board are anisotropically conductively connected.

10、200 異方性導電フィルム
11、104 絶縁性接着ベース層
12、105 絶縁性接着カバー層
13、103 導電粒子
100 転写体
101 凸部
102 微粘着層
A 導電粒子が抜けている格子点
B 導電粒子が互いに接して凝集している格子点
C 導電粒子が互いに離間して凝集している格子点
10,200 Anisotropic conductive film 11,104 Insulating adhesive base layer 12,105 Insulating adhesive cover layer 13,103 Conductive particles 100 Transfer piece 101 Convex part 102 Fine adhesive layer A Lattice point where conductive particles are missing B Conductive Lattice points where particles are in contact with each other and aggregated C Lattice points where conductive particles are separated from each other and aggregated

Claims (19)

絶縁性接着ベース層に導電粒子が平面格子パターンの格子点に配置された構造の異方性導電フィルムであって、
導電粒子が配置されていない格子点を抜けとし、複数の導電粒子が凝集して配置されている格子点を凝集としたときに、
異方性導電フィルムの基準領域に想定される平面格子パターンの全格子点に対する抜けの割合が、20%未満であり、
異方性導電フィルムの基準領域に想定される平面格子パターンの全格子点に対する凝集の割合が、15%以下であり、抜けと凝集の合計が25%未満であり、
基準領域が、異方性導電フィルムの平面中央部の以下の関係式(A)、(2)及び(3):
Figure 0007067586000004
を満たす辺X及び辺Yからなる略方形の領域であり、ここで、Dは導電粒子の平均粒子径であり、辺Yは異方性導電フィルムの長手方向に対し±45°未満の範囲の直線であり、辺Xは辺Yに垂直な直線である異方性導電フィルム。
An anisotropic conductive film having a structure in which conductive particles are arranged at lattice points of a planar lattice pattern on an insulating adhesive base layer.
When the lattice points where the conductive particles are not arranged are passed through and the lattice points where a plurality of conductive particles are aggregated and arranged are aggregated.
The ratio of omission to all grid points of the planar grid pattern assumed in the reference region of the anisotropic conductive film is less than 20%.
The ratio of agglomeration to all the lattice points of the planar lattice pattern assumed in the reference region of the anisotropic conductive film is 15% or less, and the total of omission and agglomeration is less than 25% .
The reference region is the following relational expression (A), (2) and (3): in the center of the plane of the anisotropic conductive film.
Figure 0007067586000004
It is a substantially rectangular region consisting of sides X and sides Y that satisfy the conditions, where D is the average particle diameter of the conductive particles, and side Y is in the range of less than ± 45 ° with respect to the longitudinal direction of the anisotropic conductive film. An anisotropic conductive film that is a straight line and the side X is a straight line perpendicular to the side Y.
更に、絶縁性接着カバー層が絶縁性接着ベース層に積層されている請求項1記載の異方性導電フィルム。The anisotropic conductive film according to claim 1, wherein the insulating adhesive cover layer is laminated on the insulating adhesive base layer. 更に、絶縁性接着カバー層が絶縁性接着ベース層積層され、それらの界面近傍に導電粒子が平面格子パターンの格子点に配置された構造を有し
異方性導電フィルムの基準領域に想定される平面格子パターンの全格子点に対する凝集の割合が、5%以下である請求項1記載の異方性導電フィルム。
Further, the insulating adhesive cover layer is laminated on the insulating adhesive base layer , and the conductive particles are arranged at the lattice points of the planar lattice pattern in the vicinity of their interfaces.
The anisotropic conductive film according to claim 1, wherein the ratio of aggregation of the planar lattice pattern assumed in the reference region of the anisotropic conductive film to all the lattice points is 5% or less.
基準領域が、異方性導電フィルムの平面中央部の以下の関係式(1)~(3):
Figure 0007067586000005
を満たす辺X及び辺Yからなる略方形の領域であり、ここで、Dは導電粒子の平均粒子径であり、辺Yは異方性導電フィルムの長手方向に対し±45°未満の範囲の直線であり、辺Xは辺Yに垂直な直線である請求項1~3のいずれかに記載の異方性導電フィルム。
The reference region is the following relational expression (1) to (3) in the center of the plane of the anisotropic conductive film.
Figure 0007067586000005
It is a substantially rectangular region consisting of sides X and sides Y that satisfy the conditions, where D is the average particle diameter of the conductive particles, and side Y is in the range of less than ± 45 ° with respect to the longitudinal direction of the anisotropic conductive film. The anisotropic conductive film according to any one of claims 1 to 3 , wherein the side X is a straight line and the side X is a straight line perpendicular to the side Y.
異方性導電フィルムの基準領域の面積に対する、その面積中に存在する全導電粒子の粒子面積占有率が15~35%である請求項1~4のいずれかに記載の異方性導電フィルム。 The anisotropic conductive film according to any one of claims 1 to 4, wherein the particle area occupancy of all the conductive particles existing in the reference region of the anisotropic conductive film is 15 to 35%. 導電粒子の平均粒子径が1~10μmであり、平面格子パターンの隣接格子点間距離が導電粒子の平均粒子径の0.5倍より大きい請求項1~5のいずれかに記載の異方性導電フィルム。 The anisotropic substance according to any one of claims 1 to 5, wherein the average particle size of the conductive particles is 1 to 10 μm, and the distance between adjacent lattice points of the planar lattice pattern is larger than 0.5 times the average particle size of the conductive particles. Conductive film. 基準領域が、異方性導電フィルムの平面中央部の以下の関係式:
Figure 0007067586000006
を満たす辺X及び辺Yからなる略方形の領域であり、ここで、Dは導電粒子の平均粒子径であり、辺Yは異方性導電フィルムの長手方向に対し±45°未満の範囲の直線であり、辺Xは辺Yに垂直な直線である請求項1~3のいずれかに記載の異方性導電フィルム。
The reference region is the following relational expression in the center of the plane of the anisotropic conductive film:
Figure 0007067586000006
It is a substantially rectangular region consisting of sides X and sides Y that satisfy the conditions, where D is the average particle diameter of the conductive particles, and side Y is in the range of less than ± 45 ° with respect to the longitudinal direction of the anisotropic conductive film. The anisotropic conductive film according to any one of claims 1 to 3 , wherein the side X is a straight line and the side X is a straight line perpendicular to the side Y.
異方性導電フィルムの任意の基準領域の面積に対する、その面積中に存在する全導電粒子の粒子面積占有率が0.15%以上である請求項7記載の異方性導電フィルム。 The anisotropic conductive film according to claim 7, wherein the particle area occupancy of all the conductive particles existing in the area of the arbitrary reference region of the anisotropic conductive film is 0.15% or more. 導電粒子の平均粒子径が1~30μmであり、平面格子パターンの隣接格子点間距離が導電粒子の平均粒子径の0.5倍以上である請求項7または8記載の異方性導電フィルム。 The anisotropic conductive film according to claim 7 or 8, wherein the average particle diameter of the conductive particles is 1 to 30 μm, and the distance between adjacent lattice points of the planar lattice pattern is 0.5 times or more the average particle diameter of the conductive particles. 絶縁性接着ベース層に導電粒子が平面格子パターンの格子点に配置された構造の異方性導電フィルムであって、
導電粒子が配置されていない格子点を抜けとし、複数の導電粒子が凝集して配置されている格子点を凝集としたときに、
異方性導電フィルムの基準領域に想定される平面格子パターンの全格子点に対する抜けの割合が、20%未満であり、
異方性導電フィルムの基準領域に想定される平面格子パターンの全格子点に対する凝集の割合が、15%以下であり、抜けと凝集の合計が25%未満であり、
異方性導電フィルムの基準領域の面積に対する、その面積中に存在する全導電粒子の粒子面積占有率が15~35%である異方性導電フィルム。
An anisotropic conductive film having a structure in which conductive particles are arranged at lattice points of a planar lattice pattern on an insulating adhesive base layer.
When the lattice points where the conductive particles are not arranged are passed through and the lattice points where a plurality of conductive particles are aggregated and arranged are aggregated.
The ratio of omission to all grid points of the planar grid pattern assumed in the reference region of the anisotropic conductive film is less than 20%.
The ratio of agglomeration to all the lattice points of the planar lattice pattern assumed in the reference region of the anisotropic conductive film is 15% or less, and the total of omission and agglomeration is less than 25%.
An anisotropic conductive film in which the particle area occupancy of all the conductive particles existing in the reference region of the anisotropic conductive film is 15 to 35% .
更に、絶縁性接着カバー層が絶縁性接着ベース層に積層されている請求項10記載の異方性導電フィルム。The anisotropic conductive film according to claim 10, wherein the insulating adhesive cover layer is laminated on the insulating adhesive base layer. 更に、絶縁性接着カバー層が絶縁性接着ベース層に積層され、それらの界面近傍に導電粒子が平面格子パターンの格子点に配置された構造を有し、Further, the insulating adhesive cover layer is laminated on the insulating adhesive base layer, and the conductive particles are arranged at the lattice points of the planar lattice pattern in the vicinity of their interfaces.
異方性導電フィルムの基準領域に想定される平面格子パターンの全格子点に対する凝集の割合が、5%以下である請求項10記載の異方性導電フィルム。 The anisotropic conductive film according to claim 10, wherein the ratio of aggregation of the planar lattice pattern assumed in the reference region of the anisotropic conductive film to all the lattice points is 5% or less.
基準領域が、異方性導電フィルムの平面中央部の以下の関係式(1)~(3):The reference region is the following relational expression (1) to (3) in the center of the plane of the anisotropic conductive film.
Figure 0007067586000007
Figure 0007067586000007
を満たす辺X及び辺Yからなる略方形の領域であり、ここで、Dは導電粒子の平均粒子径であり、辺Yは異方性導電フィルムの長手方向に対し±45°未満の範囲の直線であり、辺Xは辺Yに垂直な直線である請求項10~12のいずれかに記載の異方性導電フィルム。It is a substantially rectangular region consisting of sides X and sides Y that satisfy the conditions, where D is the average particle diameter of the conductive particles, and side Y is in the range of less than ± 45 ° with respect to the longitudinal direction of the anisotropic conductive film. The anisotropic conductive film according to any one of claims 10 to 12, wherein the side X is a straight line and the side X is a straight line perpendicular to the side Y.
導電粒子の平均粒子径が1~10μmであり、平面格子パターンの隣接格子点間距離が導電粒子の平均粒子径の0.5倍より大きい請求項10~13のいずれかに記載の異方性導電フィルム。The anisotropic substance according to any one of claims 10 to 13, wherein the average particle size of the conductive particles is 1 to 10 μm, and the distance between adjacent lattice points of the planar lattice pattern is larger than 0.5 times the average particle size of the conductive particles. Conductive film. 基準領域が、異方性導電フィルムの平面中央部の以下の関係式:The reference region is the following relational expression in the center of the plane of the anisotropic conductive film:
Figure 0007067586000008
Figure 0007067586000008
を満たす辺X及び辺Yからなる略方形の領域であり、ここで、Dは導電粒子の平均粒子径であり、辺Yは異方性導電フィルムの長手方向に対し±45°未満の範囲の直線であり、辺Xは辺Yに垂直な直線である請求項10~12のいずれかに記載の異方性導電フィルム。It is a substantially rectangular region consisting of sides X and sides Y that satisfy the conditions, where D is the average particle diameter of the conductive particles, and side Y is in the range of less than ± 45 ° with respect to the longitudinal direction of the anisotropic conductive film. The anisotropic conductive film according to any one of claims 10 to 12, wherein the side X is a straight line and the side X is a straight line perpendicular to the side Y.
異方性導電フィルムの任意の基準領域の面積に対する、その面積中に存在する全導電粒子の粒子面積占有率が0.15%以上である請求項15記載の異方性導電フィルム。The anisotropic conductive film according to claim 15, wherein the particle area occupancy of all the conductive particles existing in the area with respect to the area of an arbitrary reference region of the anisotropic conductive film is 0.15% or more. 導電粒子の平均粒子径が1~30μmであり、平面格子パターンの隣接格子点間距離が導電粒子の平均粒子径の0.5倍以上である請求項15または16記載の異方性導電フィルム。The anisotropic conductive film according to claim 15 or 16, wherein the average particle size of the conductive particles is 1 to 30 μm, and the distance between adjacent lattice points of the planar lattice pattern is 0.5 times or more the average particle size of the conductive particles. 第1の電子部品の端子と、第2の電子部品の端子とが、請求項1~17のいずれかに記載の異方性導電フィルムにより異方性導電接続された接続構造体。 A connection structure in which a terminal of a first electronic component and a terminal of a second electronic component are anisotropically conductively connected by the anisotropic conductive film according to any one of claims 1 to 17 . 第1の電子部品の端子と、第2の電子部品の端子とを、請求項1~17のいずれかに記載の異方性導電フィルムにより異方性導電接続する、接続構造体の製造方法。 A method for manufacturing a connection structure, wherein a terminal of a first electronic component and a terminal of a second electronic component are anisotropically conductively connected by the anisotropic conductive film according to any one of claims 1 to 17 .
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