JP2012186210A

JP2012186210A - Conductive connection structure

Info

Publication number: JP2012186210A
Application number: JP2011046520A
Authority: JP
Inventors: Kenichiro Fujii; 健一郎藤井
Original assignee: NEC Casio Mobile Communications Ltd
Current assignee: NEC Casio Mobile Communications Ltd
Priority date: 2011-03-03
Filing date: 2011-03-03
Publication date: 2012-09-27

Abstract

PROBLEM TO BE SOLVED: To provide a conductive connection structure of a first wiring board mounting at least one chip component on one substrate surface and a second wiring board, in which the mounting surface can be narrowed, excellent conductive connection is possible even if the height of the chip components varies, high temperature heating at 200°C or higher is not required during conductive connection, sufficient conductive connection strength is ensured, and high degree of freedom is ensured in wiring connection design.SOLUTION: In a conductive connection structure 1, an external electrode 11E exposed to the upper end of a chip component 11 on a first wiring board 10 and a terminal of a second wiring board 30 are connected conductively via an anisotropic conductive adhesive mounted on the external electrode 11E.

Description

本発明は、一方の基板面に少なくとも１つのチップ部品が実装された第１の配線基板と第２の配線基板との導電接続構造に関するものである。 The present invention relates to a conductive connection structure between a first wiring board and a second wiring board in which at least one chip component is mounted on one board surface.

携帯電話等の通信端末は益々高機能化しており、それに伴ってそれに搭載される配線基板（ＰＣＢ：printed circuit board）の実装面積が不足傾向にある。この不足を補うために、回路ブロックごとのモジュール化等が進められている。
携帯電話等の通信端末においては、それに搭載される配線基板とフレキシブル配線基板（ＦＰＣ：Flexible Printed Board）とを接続することがなされる場合があるが、この接続部の狭小化が難しい。これは、通信端末の品質確保のために、配線間から発生する電波の感度抑圧などを考慮しなければならないからである。
具体的には、携帯電話等の通信端末に搭載された配線基板とＦＰＣとの接続には信号線から発生する電波の感度抑圧が必要であり、接続信号線間に電気的なグランドと繋がる機能部品として通常チップコンデンサを配置する必要がある。 Communication terminals such as mobile phones are becoming more and more sophisticated, and accordingly, the mounting area of a printed circuit board (PCB) mounted thereon tends to be insufficient. In order to make up for this shortage, modularization of each circuit block has been promoted.
In a communication terminal such as a mobile phone, there are cases where a wiring board mounted on the communication terminal and a flexible printed board (FPC) are connected, but it is difficult to narrow the connecting portion. This is because in order to ensure the quality of the communication terminal, it is necessary to consider sensitivity suppression of radio waves generated between the wires.
Specifically, it is necessary to suppress the sensitivity of radio waves generated from signal lines for the connection between a wiring board mounted on a communication terminal such as a mobile phone and an FPC, and the function of connecting an electrical ground between the connection signal lines Usually, a chip capacitor needs to be arranged as a component.

通信端末の配線基板とＦＰＣとの接続構造としては、表面実装（ＳＭＤ：Surface Mount Device）コネクタを用いた接続構造、あるいは異方性導電フィルム（ＡＣＦ：anisotropic conductive film）を用いた接続構造などがある。 The connection structure between the wiring board of the communication terminal and the FPC includes a connection structure using a surface mount (SMD) connector or a connection structure using an anisotropic conductive film (ACF). is there.

従来のＳＭＤコネクタを用いた接続構造では、ＳＭＤコネクタの実装面積とチップコンデンサの実装面積とが必要である。チップコンデンサは機能部品であるため、接続部の狭小化にはＳＭＤコネクタを小さくする必要がある。しかしながら、ＳＭＤコネクタの端子接続を人手で行うこと、及び端子の充分な嵌合力の確保を考慮すれば、端子ピッチを現状以上に小さくすることは難しい。 In the connection structure using the conventional SMD connector, the mounting area of the SMD connector and the mounting area of the chip capacitor are required. Since the chip capacitor is a functional component, it is necessary to make the SMD connector small in order to narrow the connection portion. However, considering the terminal connection of the SMD connector manually and securing sufficient fitting force of the terminals, it is difficult to reduce the terminal pitch beyond the current level.

従来のＡＣＦを用いた接続構造では、ＡＣＦの加熱加圧を行う接続ツールの位置合わせを考慮して、チップ部品を含めた各種部品を避けてＡＣＦを配置している。そのため、ＡＣＦの実装面積とチップコンデンサの実装面積がそれぞれ必要である。チップコンデンサは機能部品であるため、接続構造の狭小化にはＡＣＦの実装面積を小さくする必要があるが、ＡＣＦの加熱加圧を行う接続ツールの位置合わせを考慮してチップ部品を含めた各種部品を避けてＡＣＦを配置しなくてはならない、あるいは、加熱圧着時のＡＣＦのはみ出しを考慮しつつ狭ピッチで他の部品を配置しなければいけないなどの制限がある。 In the connection structure using the conventional ACF, the ACF is arranged avoiding various parts including chip parts in consideration of the alignment of the connection tool for heating and pressing the ACF. Therefore, an ACF mounting area and a chip capacitor mounting area are required. Since the chip capacitor is a functional component, it is necessary to reduce the mounting area of the ACF in order to narrow the connection structure. However, various types of chip capacitors including the chip component are considered in consideration of the alignment of the connection tool for heating and pressing the ACF. There is a limitation that the ACF must be arranged avoiding the parts, or other parts must be arranged at a narrow pitch in consideration of the protrusion of the ACF at the time of thermocompression bonding.

特許文献１には、ＬＳＩ等を搭載したマルチチップモジュール（１）上に実装された抵抗あるいはコンデンサ等のチップ部品（３）と実装基板（２）とを直接接続する接続構造が記載されている（請求項１、図１及び図２）。
特許文献１には、上記接続構造では、マルチチップモジュールと実装基板とを、厚みを一定としたチップ部品を用いて接続することができること（段落００１５）、そして、このように、マルチチップモジュールと実装基板の距離を一定に保つことで、接続面でのＢＧＡの存在しない領域に部品を実装することが可能となり、基板面積を小さくすることができること（段落００１６）が記載されている。 Patent Document 1 describes a connection structure for directly connecting a chip component (3) such as a resistor or a capacitor mounted on a multichip module (1) mounted with an LSI or the like and a mounting substrate (2). (Claim 1, FIG. 1 and FIG. 2).
In Patent Document 1, in the connection structure described above, the multichip module and the mounting substrate can be connected using a chip component having a constant thickness (paragraph 0015). It is described that by keeping the distance of the mounting board constant, it is possible to mount a component in a region where no BGA exists on the connection surface, and the board area can be reduced (paragraph 0016).

特許文献２には、液晶表示装置において、ＬＳＩなどの半導体チップ（７）の下面両側に多数のバンプ電極（７ａ）が設けられ、これらバンプ電極（７ａ）が異方導電性接着材（１３）を介して透明基板（５）に接合され、半導体チップ（７）が接合された透明基板（５）上の電極端子部（１０）に、フィルム基板（１）に設けられた接続端子部（１２）の基端部（１２ｂ）側が異方導電性接着材（１３）を介して接合されると共に、この接続端子部（１２）の先端部（１２ｃ）側が半導体チップ（７）の上面に接着剤（１４）を介して接合された接続構造が記載されている（請求項１−６、段落００２１−００２３、及び図２）。 In Patent Document 2, in a liquid crystal display device, a large number of bump electrodes (7a) are provided on both sides of the lower surface of a semiconductor chip (7) such as an LSI, and these bump electrodes (7a) are made of anisotropic conductive adhesive (13). The connection terminal portion (12) provided on the film substrate (1) is joined to the electrode terminal portion (10) on the transparent substrate (5) joined to the transparent substrate (5) through the semiconductor chip (7). ) Is joined via an anisotropic conductive adhesive (13), and the tip (12c) side of the connecting terminal (12) is bonded to the upper surface of the semiconductor chip (7). A connection structure joined via (14) is described (claims 1-6, paragraphs 0021-0023 and FIG. 2).

特許文献３には、液晶表示装置において、フレキシブル基板（ＦＰＣ２）と上側フレーム（ＳＨＤ）の導電接続にチップ部品（ＣＨＸ）と金属テープ（ＭＴＰ）を用い、上側ケース（ＳＨＤ）との間に導電接続用の部品を要しない接続構造が記載されている（請求項１、段落００３６−００３８、図１、及び要約書）。 In Patent Document 3, in a liquid crystal display device, a chip component (CHX) and a metal tape (MTP) are used for conductive connection between a flexible substrate (FPC2) and an upper frame (SHD), and the conductive material is connected between the upper case (SHD). A connection structure is described that does not require connecting parts (claim 1, paragraphs 0036-0038, FIG. 1, and abstract).

特開2004-356146号公報JP 2004-356146 A 特開2005-252134号公報JP 2005-252134 A 特開平11-305205号公報JP 11-305205 A

特許文献１に記載の接続構造では、複数のチップ部品の高さを揃えないと接続ができず、複数のチップ部品の高さにばらつきがあれば接続不良が生じてしまう。また、特許文献１では、接続時の加熱はチップ部品に使われる電極のはんだ組成に合わせて、一般的に２００℃以上の高温が必要である。そのため、マルチチップモジュール及び実装基板に実装された部品が高温加熱によって劣化する恐れがある。 In the connection structure described in Patent Document 1, connections cannot be made unless the heights of the plurality of chip components are equal, and if the heights of the plurality of chip components vary, a connection failure occurs. In Patent Document 1, heating at the time of connection generally requires a high temperature of 200 ° C. or higher in accordance with the solder composition of the electrode used for the chip component. Therefore, the components mounted on the multichip module and the mounting substrate may be deteriorated by high temperature heating.

特許文献２では、上記接続構造を採用することで、半導体チップとフィルム基板との接続強度を高めている。しかしながら、特許文献２に記載の接続構造では、基板面に対して平行方向には接続強度が高いが、基板面に対して交差する方向（例えば垂直方向）に引き剥がす力に対しては接続強度が充分ではない。 In Patent Document 2, the connection strength between the semiconductor chip and the film substrate is increased by adopting the connection structure. However, in the connection structure described in Patent Document 2, the connection strength is high in the direction parallel to the substrate surface, but the connection strength is against the force of peeling in the direction intersecting the substrate surface (for example, the vertical direction). Is not enough.

特許文献３で使用されている金属テープは、電気的に抵抗値が高く、振動あるいは衝撃等で剥がれやすいため、携帯電話等のモバイル機器のように省電力、耐振動性及び耐衝撃性が必要な機器に適応することが難しい。
特許文献３ではまた、すべての電極に共通した電気的なＧＮＤ（グランド）との接続はできるが、個々の電極に対してＧＮＤと平行して信号線として任意の配線を接続することができない。携帯電話等のモバイル機器の基板間接続では、送信側からの感度抑圧のためＧＮＤと平行して信号線同士を接続する構造が必要であるが、特許文献３の接続構造ではこれができない。 Since the metal tape used in Patent Document 3 has a high electrical resistance value and is easily peeled off by vibration or impact, power saving, vibration resistance and impact resistance are required like mobile devices such as mobile phones. Difficult to adapt to various devices.
In Patent Document 3, an electrical GND (ground) common to all electrodes can be connected, but an arbitrary wiring cannot be connected to each electrode as a signal line in parallel with the GND. In connection between substrates of mobile devices such as mobile phones, a structure in which signal lines are connected in parallel to GND is necessary for sensitivity reduction from the transmission side, but this cannot be achieved with the connection structure in Patent Document 3.

本発明は上記事情に鑑みてなされたものであり、
一方の基板面に少なくとも１つのチップ部品が実装された第１の配線基板と第２の配線基板との導電接続構造であって、
実装面積の狭小化を図ることができ、
チップ部品の高さにばらつきがあっても良好に導電接続が可能であり、
導電接続時に２００℃以上の高温加熱が不要であり、
基板面方向及び基板面に対して交差する方向（例えば垂直方向）に対しても充分な導電接続強度を確保でき、
配線接続設計の自由度が高い導電接続構造を提供することを目的とするものである。 The present invention has been made in view of the above circumstances,
A conductive connection structure between a first wiring board and a second wiring board in which at least one chip component is mounted on one board surface,
The mounting area can be reduced,
Even if there is variation in the height of the chip parts, it is possible to make a good conductive connection,
High-temperature heating of 200 ° C or higher is not necessary during conductive connection,
Sufficient conductive connection strength can be secured even in the substrate surface direction and the direction intersecting the substrate surface (for example, the vertical direction),
An object of the present invention is to provide a conductive connection structure having a high degree of freedom in wiring connection design.

本発明の導電接続構造は、一方の基板面上に、少なくとも上端に外部電極が露出した少なくとも１つのチップ部品が実装された第１の配線基板と、当該第１の配線基板の前記外部電極が導電接続される少なくとも１つの端子を有する第２の配線基板との導電接続構造であって、
前記第１の配線基板の前記チップ部品の前記上端に露出した前記外部電極と前記第２の配線基板の前記端子とが、前記外部電極上に載置された異方性導電性接着材を介して導電接続されたものである。 The conductive connection structure of the present invention includes a first wiring board on which at least one chip component having an external electrode exposed at least at the upper end is mounted on one board surface, and the external electrode of the first wiring board includes A conductive connection structure with a second wiring board having at least one terminal to be conductively connected,
The external electrode exposed at the upper end of the chip component of the first wiring board and the terminal of the second wiring board are connected via an anisotropic conductive adhesive placed on the external electrode. Are electrically connected.

本発明において、チップ部品の「上端」とは、第１の配線基板の基板面と反対側の端を意味している。 In the present invention, the “upper end” of the chip component means the end opposite to the substrate surface of the first wiring board.

本発明によれば、
一方の基板面に少なくとも１つのチップ部品が実装された第１の配線基板と第２の配線基板との導電接続構造であって、
実装面積の狭小化を図ることができ、
チップ部品の高さにばらつきがあっても良好に導電接続が可能であり、
導電接続時に２００℃以上の高温加熱が不要であり、
基板面方向及び基板面に対して交差する方向（例えば垂直方向）に対しても充分な導電接続強度を確保でき、
配線接続設計の自由度が高い導電接続構造を提供することができる。 According to the present invention,
A conductive connection structure between a first wiring board and a second wiring board in which at least one chip component is mounted on one board surface,
The mounting area can be reduced,
Even if there is variation in the height of the chip parts, it is possible to make a good conductive connection,
High-temperature heating of 200 ° C or higher is not necessary during conductive connection,
Sufficient conductive connection strength can be secured even in the substrate surface direction and the direction intersecting the substrate surface (for example, the vertical direction),
A conductive connection structure with a high degree of freedom in wiring connection design can be provided.

本発明に係る一実施形態の導電接続方法の工程を示す斜視図である。It is a perspective view which shows the process of the conductive connection method of one Embodiment which concerns on this invention. 本発明に係る一実施形態の導電接続方法の工程を示す斜視図である。It is a perspective view which shows the process of the conductive connection method of one Embodiment which concerns on this invention. 本発明に係る一実施形態の導電接続方法の工程を示す斜視図である。It is a perspective view which shows the process of the conductive connection method of one Embodiment which concerns on this invention. 従来の導電接続構造と本発明に係る一実施形態の導電接続構造の接続回路図である。It is a connection circuit diagram of the conventional conductive connection structure and the conductive connection structure of one Embodiment concerning this invention. 設計変更例を示す図である。It is a figure which shows the example of a design change. 他の設計変更例を示す図である。It is a figure which shows the example of another design change.

図面を参照して、本発明に係る一実施形態の導電接続構造について説明する。
図１〜図３は、導電接続方法の各工程を示す斜視図である。視認しやすくするため、図面上は各構成要素の図示を実際のものとは適宜異ならせて、簡略化してある。 A conductive connection structure according to an embodiment of the present invention will be described with reference to the drawings.
1 to 3 are perspective views showing respective steps of the conductive connection method. In order to facilitate visual recognition, the illustration of each component in the drawing is simplified by making it appropriately different from the actual one.

図３に示す本実施形態の導電接続構造１は、図１に示す第１の配線基板１０と図３に示す第２の配線基板３０との導電接続構造である。本実施形態では、第１の配線基板１０と第２の配線基板３０とが、図２に示す異方性導電フィルム（ＡＣＦ：anisotropic conductive film）等の異方性導電性接着材２０を介して導電接続されている。
本実施形態は、携帯電話等の通信端末に搭載された配線基板とＦＰＣとの導電接続構造等に好ましく適用できる。 The conductive connection structure 1 of the present embodiment shown in FIG. 3 is a conductive connection structure between the first wiring board 10 shown in FIG. 1 and the second wiring board 30 shown in FIG. In the present embodiment, the first wiring board 10 and the second wiring board 30 are connected via an anisotropic conductive adhesive 20 such as an anisotropic conductive film (ACF) shown in FIG. Conductive connection.
This embodiment can be preferably applied to a conductive connection structure between a wiring board mounted on a communication terminal such as a mobile phone and an FPC.

本実施形態において、配線基板１０、３０の種類は特に制限されず、リジッド基板、フレキシブル基板、リジッドフレックス基板、セラミック基板、あるいはガラス基板など、任意である。配線基板１０、３０の種類は同一でも非同一でもよい。
本実施形態では、第１の配線基板１０は非フレキシブル基板であり、第２の配線基板３０はフレキシブル基板である。 In the present embodiment, the types of the wiring substrates 10 and 30 are not particularly limited, and are arbitrary such as a rigid substrate, a flexible substrate, a rigid flex substrate, a ceramic substrate, or a glass substrate. The types of the wiring boards 10 and 30 may be the same or non-identical.
In the present embodiment, the first wiring board 10 is a non-flexible board, and the second wiring board 30 is a flexible board.

図１に示すように、第１の配線基板１０の一方の基板面１０Ｓ上には、少なくとも上端に外部電極１１Ｅが露出した少なくとも１つのチップ部品１１が実装されている。
本実施形態において、チップ部品１１は、互いに対向する一対の端面に各々、基板面１０Ｓに対して交差する方向（本実施形態では垂直方向）に広がった外部電極１１Ｅを有するものである。本実施形態において、チップ部品１１は、信号線から発生する電波の感度抑圧のために設けられ、接続信号線の間に電気的なグランドと繋がるチップコンデンサである。チップ部品１１の組成は特に制限されず、主材質がセラミックであり、一対の側面に外部電極１１ＥとしてＳｎメッキが施された一般的なものを利用できる。 As shown in FIG. 1, on one substrate surface 10S of the first wiring substrate 10, at least one chip component 11 having an external electrode 11E exposed at least at the upper end is mounted.
In the present embodiment, the chip component 11 has external electrodes 11E that spread in a direction intersecting the substrate surface 10S (vertical direction in the present embodiment) on a pair of end faces facing each other. In the present embodiment, the chip component 11 is a chip capacitor that is provided for suppressing sensitivity of radio waves generated from a signal line and is connected to an electrical ground between connection signal lines. The composition of the chip component 11 is not particularly limited, and a general material in which the main material is ceramic and Sn plating is applied to the pair of side surfaces as the external electrode 11E can be used.

本実施形態では、第１の配線基板１０において、複数のチップ部品１１が千鳥状に実装されている。図示例では計１２個のチップ部品１１が、６個ずつ２列に千鳥配置されている。複数のチップ部品１１の配列パターンは特に制限されないが、図示のように千鳥配置することで、高密度実装が可能であり、好ましい。
複数のチップ部品１１の実装方法は特に制限されず、本実施形態ではＳＭＴ（Surface Maunt Technology）によるはんだ付けである。
複数のチップ部品１１の配置パターンは、単列配置、（楕）円状配置、円弧状配置、Ｌ字状配置、及び十字状配置等でも構わない。
複数のチップ部品１１は、穴あるいは部品等を跨いで複数箇所に分けて実装しても構わない。 In the present embodiment, a plurality of chip components 11 are mounted in a staggered pattern on the first wiring board 10. In the illustrated example, a total of twelve chip components 11 are arranged in two rows in a row of six. The arrangement pattern of the plurality of chip parts 11 is not particularly limited, but high-density mounting is possible by arranging them in a staggered manner as shown in the drawing, which is preferable.
The mounting method of the plurality of chip components 11 is not particularly limited, and in this embodiment, soldering by SMT (Surface Maunt Technology) is performed.
The arrangement pattern of the plurality of chip parts 11 may be a single-row arrangement, an (elliptical) circular arrangement, an arc arrangement, an L-shaped arrangement, a cross-shaped arrangement, or the like.
The plurality of chip components 11 may be mounted in a plurality of locations across holes or components.

個々のチップ部品１１において、一方の電極１１Ｅは第１の配線基板１０の電気的なＧＮＤ（グランド）と接続され、他方の電極１１Ｅが第２の配線基板３０と接続され、基板間で必要な信号線をなしている。
本実施形態では、２列に配列した複数のチップ部品１１において、他列のチップ部品１１に遠い側（外側）の外部電極１１Ｅが第１の配線基板１０の電気的なＧＮＤ（グランド）と接続され、他列のチップ部品１１に近い側（中央側）の外部電極１１Ｅが第２の配線基板３０と接続され、基板間で必要な信号線をなしている。 In each chip component 11, one electrode 11E is connected to the electrical GND (ground) of the first wiring board 10, and the other electrode 11E is connected to the second wiring board 30, which is necessary between the boards. There is a signal line.
In the present embodiment, in the plurality of chip components 11 arranged in two rows, the external electrode 11E on the side (outside) far from the chip components 11 in the other rows is connected to the electrical GND (ground) of the first wiring board 10. The external electrode 11E on the side close to the chip component 11 in the other row (center side) is connected to the second wiring board 30 to form a necessary signal line between the boards.

第２の配線基板３０には、第１の配線基板１０の外部電極１１Ｅが導電接続される複数の端子（図示略）が設けられている。
第１の配線基板１０のチップ部品１１と第２の配線基板３０の端子の数を同数とすることが好ましい。この際、必要に応じて、複数のチップ部品１１には、数合わせのために、実際にはチップ部品として機能しないダミーチップ部品を含めることができる。かかる構成によって、第１の配線基板１０及び第２の配線基板３０間を安定した間隙で導電接続することができる。 The second wiring board 30 is provided with a plurality of terminals (not shown) to which the external electrodes 11E of the first wiring board 10 are conductively connected.
It is preferable that the number of the chip components 11 of the first wiring board 10 and the number of terminals of the second wiring board 30 be the same. At this time, if necessary, the plurality of chip parts 11 can include dummy chip parts that do not actually function as chip parts for the purpose of number matching. With this configuration, the first wiring board 10 and the second wiring board 30 can be conductively connected with a stable gap.

第２の配線基板３０の組成は特に制限されず、ポイリミドなどの柔軟で薄い樹脂フィルムを基材とし、端子及び配線をなす導電材として銅等を薄膜ラミネートした一般的なものを利用することができる。第２の配線基板３０の複数の端子配置は、第１の配線基板１０の複数のチップ部品１１の外部電極１１Ｅの配列パターンに合わせて設計される。 The composition of the second wiring board 30 is not particularly limited, and it is possible to use a general one in which a flexible and thin resin film such as polyimide is used as a base material and copper or the like is laminated as a conductive material for forming terminals and wirings. it can. The plurality of terminal arrangements of the second wiring board 30 are designed according to the arrangement pattern of the external electrodes 11E of the plurality of chip components 11 of the first wiring board 10.

異方性導電性接着材２０に関しては、配線間ショート防止のために、第１の配線基板１０上のチップ部品１１と第２の配線基板３０上の端子の接続ピッチ等に応じて、導電粒子の組成、粒径及び配合量等が選択される。
導電粒子としては、金属粒子、あるいは樹脂コア粒子を金属メッキしたものを使用できる。
導電粒子の代わりに、はんだ等の導電材を用いてもよい。
異方性導電性接着材２０の絶縁樹脂は特に制限されず、熱硬化性樹脂、熱可塑性樹脂、あるいは光硬化性樹脂を使用できる。異方性導電性接着材２０の絶縁樹脂としては、熱硬化性樹脂が好ましい。以下、異方性導電性接着材２０が熱硬化性である場合を例として、本実施形態を説明する。
異方性導電性接着材２０の形態は特に制限されず、シート状が好ましい。異方性導電性接着材２０としては、ペースト状のものを使用することもできる。 Regarding the anisotropic conductive adhesive 20, in order to prevent a short circuit between the wirings, the conductive particles are selected according to the connection pitch of the chip component 11 on the first wiring board 10 and the terminals on the second wiring board 30. The composition, particle size, blending amount, etc. are selected.
As the conductive particles, metal particles or those obtained by metal plating resin core particles can be used.
A conductive material such as solder may be used instead of the conductive particles.
The insulating resin of the anisotropic conductive adhesive 20 is not particularly limited, and a thermosetting resin, a thermoplastic resin, or a photocurable resin can be used. A thermosetting resin is preferable as the insulating resin of the anisotropic conductive adhesive 20. Hereinafter, the present embodiment will be described by taking as an example the case where the anisotropic conductive adhesive 20 is thermosetting.
The form in particular of the anisotropic conductive adhesive 20 is not restrict | limited, A sheet form is preferable. As the anisotropic conductive adhesive 20, a paste-like material can also be used.

導電接続を行うにあたっては、図２に示すように、図１に示した第１の配線基板１０の複数のチップ部品１１の基板間で必要な信号線をなす一方の外部電極１１Ｅ上に異方性導電性接着材２０を載置し、仮貼りする。この際、チップ部品１１よりも少ない数の異方性導電性接着材２０を用いることが好ましい。異方性導電性接着材２０は、あらかじめ複数のチップ部品１１上に取り付けておいても構わない。 In conducting the conductive connection, as shown in FIG. 2, anisotropy is formed on one external electrode 11E forming a necessary signal line between the substrates of the plurality of chip components 11 of the first wiring substrate 10 shown in FIG. The conductive conductive adhesive 20 is placed and temporarily attached. At this time, it is preferable to use a smaller number of anisotropic conductive adhesives 20 than the chip component 11. The anisotropic conductive adhesive 20 may be attached on the plurality of chip components 11 in advance.

本実施形態では、２列に配置した複数のチップ部品１１の他列のチップ部品１１に近い側（中央側）の外部電極１１Ｅに跨るように、チップ部品１１の数より少ない数である１個の異方性導電性接着材２０を載置している。
異方性導電性接着材２０の幅及び長さ、及び数は、複数のチップ部品１１の配列パターンに応じて設計され、複数のチップ部品１１の基板間で必要な信号線をなす側のすべての外部電極１１Ｅ上に異方性導電性接着材２０が載り、ＧＮＤに接続される側の外部電極１１Ｅ上には異方性導電性接着材２０が載らないように設計される。
異方性導電性接着材２０の厚みは、加熱圧着後に、複数のチップ部品１１と第２の配線基板３０とが良好に接続されるように設計される。 In this embodiment, the number of chip components 11 arranged in two rows is smaller than the number of chip components 11 so as to straddle the external electrodes 11E on the side (center side) close to the chip components 11 in the other row. The anisotropic conductive adhesive 20 is placed.
The width, length, and number of the anisotropic conductive adhesive material 20 are designed in accordance with the arrangement pattern of the plurality of chip components 11, and all of the sides that form necessary signal lines between the substrates of the plurality of chip components 11. The anisotropic conductive adhesive 20 is placed on the external electrode 11E, and the anisotropic conductive adhesive 20 is not placed on the external electrode 11E on the side connected to the GND.
The thickness of the anisotropic conductive adhesive 20 is designed so that the plurality of chip components 11 and the second wiring board 30 are well connected after thermocompression bonding.

次に図３に示すように、複数のチップ部品１１及び異方性導電性接着材２０上に第２の配線基板３０を載置し、チップ部品１１の信号線をなす外部電極１１Ｅと第２の配線基板３０の端子とを光学観察等により位置合わせする。最後に、第２の配線基板３０側から加熱加圧ツールを用いて、熱硬化型の異方性導電性接着材２０のある導電接続箇所を加熱加圧する。
第２の配線基板３０側から加熱圧着を行うと、第１の配線基板１０と第２の配線基板３０の信号線同士が異方性導電性接着材２０を介して結線される。また、第１の配線基板１０と第２の配線基板３０の信号線は同時にチップ部品１１を介して回路的には並列してＧＮＤと結線される。
異方性導電性接着材２０が熱可塑型あるいは光硬化型の場合には、異方性導電性接着材２０の物理特性に応じて、接着条件を調整する。 Next, as shown in FIG. 3, the second wiring board 30 is placed on the plurality of chip components 11 and the anisotropic conductive adhesive 20, and the external electrodes 11 E forming the signal lines of the chip components 11 and the second The terminal of the wiring board 30 is aligned by optical observation or the like. Finally, using a heating and pressing tool from the second wiring board 30 side, the conductive connection portion having the thermosetting anisotropic conductive adhesive 20 is heated and pressed.
When thermocompression bonding is performed from the second wiring board 30 side, the signal lines of the first wiring board 10 and the second wiring board 30 are connected through the anisotropic conductive adhesive 20. Further, the signal lines of the first wiring board 10 and the second wiring board 30 are simultaneously connected in parallel to the GND via the chip component 11 in terms of the circuit.
When the anisotropic conductive adhesive 20 is a thermoplastic type or a photocurable type, the bonding conditions are adjusted according to the physical characteristics of the anisotropic conductive adhesive 20.

以上のようにして、第１の配線基板１０に実装された必要に応じてダミーチップ部品１１を含む複数のチップ部品１１と第２の配線基板３０の複数の端子とが異方性導電性接着材２０を介して導電接続された導電接続構造１が得られる。 As described above, the plurality of chip parts 11 including the dummy chip parts 11 and the plurality of terminals of the second wiring board 30 mounted on the first wiring board 10 as necessary are anisotropically conductively bonded. A conductive connection structure 1 that is conductively connected through the material 20 is obtained.

本実施形態では、導電接続のためにＳＭＤコネクタ等のコネクタを必要としない。また、異方性導電性接着材２０を複数のチップ部品１１上に載置しており、異方性導電性接着材２０の実装領域は、ほぼ、複数のチップ部品１１の実装領域と同じである。したがって、本実施形態では、別途、ＳＭＤコネクタ等のコネクタ及び異方性導電性接着材２０の実装領域を必要としない。また、複数のチップ部品１１は、コネクタよりも狭ピッチに配置でき、千鳥配置等により高密度実装が可能である。本実施形態では、異方性導電性接着材２０のはみ出し領域を考慮しなくてよい。
以上の理由から、本実施形態では、実装面積の狭小化を図ることができる。本実施形態ではまた、高価なＳＭＤコネクタ等のコネクタを必要としないので、低コスト化が可能である。 In this embodiment, a connector such as an SMD connector is not required for conductive connection. Further, the anisotropic conductive adhesive 20 is placed on the plurality of chip parts 11, and the mounting area of the anisotropic conductive adhesive 20 is substantially the same as the mounting area of the plurality of chip parts 11. is there. Therefore, in this embodiment, a separate mounting area for the connector such as the SMD connector and the anisotropic conductive adhesive 20 is not required. Further, the plurality of chip parts 11 can be arranged at a narrower pitch than the connector, and high-density mounting is possible by staggered arrangement or the like. In this embodiment, the protruding region of the anisotropic conductive adhesive 20 need not be considered.
For the above reasons, in this embodiment, the mounting area can be reduced. In this embodiment, since an expensive SMD connector or the like is not required, the cost can be reduced.

図４は、従来の導電接続構造と本実施形態の導電接続構造の接続回路図である。図４の左図は、ＳＭＤコネクタを用いた従来構造の接続回路図を示し、図４の右図は本実施形態の接続回路図を示している。図中、Ｃはチップ部品１１（チップコンデンサ）、ＡＣＦは異方性導電性接着材２０を示している。
図４の左図に示す従来の導電接続構造では、第１の配線基板上のＩＣと第２の配線基板であるＦＰＣとがコネクタを介して導電接続されている。図４の右図に示す本実施形態の導電接続構造では、コネクタを介さずにＡＣＦを介してチップ部品ＣとＦＰＣとが接続されている。
携帯電話等のモバイル機器の基板間接続では、送信側からの感度抑圧のためＧＮＤと平行して信号線同士を接続する構造が必要であり、本実施形態ではかかる接続構造が可能である。したがって、本実施形態では、配線間から発生する電波の感度抑圧を良好に実施できる。 FIG. 4 is a connection circuit diagram of a conventional conductive connection structure and the conductive connection structure of the present embodiment. The left diagram of FIG. 4 shows a connection circuit diagram of a conventional structure using an SMD connector, and the right diagram of FIG. 4 shows a connection circuit diagram of this embodiment. In the figure, C indicates a chip component 11 (chip capacitor), and ACF indicates an anisotropic conductive adhesive 20.
In the conventional conductive connection structure shown in the left diagram of FIG. 4, the IC on the first wiring board and the FPC as the second wiring board are conductively connected via a connector. In the conductive connection structure of the present embodiment shown in the right diagram of FIG. 4, the chip component C and the FPC are connected via the ACF without using the connector.
In connection between substrates of a mobile device such as a mobile phone, a structure in which signal lines are connected in parallel to GND is necessary in order to suppress sensitivity from the transmission side. In this embodiment, such a connection structure is possible. Therefore, in this embodiment, it is possible to satisfactorily suppress the sensitivity of radio waves generated between the wirings.

本実施形態では、チップ部品１１の高さにばらつきがあっても良好に導電接続が可能である。これは、加熱圧着時に異方性導電性接着材２０の樹脂が軟化して広がり、チップ部品１１の高さにばらつきを吸収できるためである。また、異方性導電性接着材２０内の導電粒子の径を部分的に変えることで、異方性導電性接着材２０の厚みを部分的に調整し、チップ部品１１の高さのばらつきを吸収することも可能である。 In the present embodiment, the conductive connection can be satisfactorily performed even when the height of the chip component 11 varies. This is because the resin of the anisotropic conductive adhesive 20 is softened and spreads at the time of thermocompression bonding, and variations in the height of the chip component 11 can be absorbed. Further, by partially changing the diameter of the conductive particles in the anisotropic conductive adhesive 20, the thickness of the anisotropic conductive adhesive 20 is partially adjusted, and the variation in the height of the chip component 11 is reduced. Absorption is also possible.

本実施形態の導電接続温度は、異方性導電性接着材２０の樹脂が軟化する温度であればよく、はんだ接続のような高温を要しない。異方性導電性接着材２０の樹脂組成にもよるが、一般的なＡＣＦの場合、例えば１３０℃程度で導電接続を実施できる。したがって、本実施形態では、第１の配線基板１０及び第２の配線基板３０に実装された各種部品の熱による劣化を抑制できる。 The conductive connection temperature of the present embodiment may be a temperature at which the resin of the anisotropic conductive adhesive 20 is softened, and does not require a high temperature such as solder connection. Depending on the resin composition of the anisotropic conductive adhesive 20, in the case of a general ACF, conductive connection can be performed at about 130 ° C., for example. Therefore, in the present embodiment, deterioration due to heat of various components mounted on the first wiring board 10 and the second wiring board 30 can be suppressed.

本実施形態では、複数のチップ部品１１と第２の配線基板３０とを異方性導電性接着材２０を介して導電接続しており、異方性導電性接着材２０は、「背景技術」の項で挙げた特許文献３で使用されている金属テープよりも、抵抗値が低く、振動及び衝撃に強い。また、複数のチップ部品１１間に異方性導電性接着材２０の樹脂が充填され、基板面方向及び基板面に対して交差する方向（例えば垂直方向）に対しても充分な導電接続強度を確保できる。 In the present embodiment, the plurality of chip components 11 and the second wiring substrate 30 are conductively connected via the anisotropic conductive adhesive 20, and the anisotropic conductive adhesive 20 is “background art”. The resistance value is lower than that of the metal tape used in Patent Document 3 mentioned in the section, and it is strong against vibration and impact. In addition, the resin of the anisotropic conductive adhesive 20 is filled between the plurality of chip components 11, and sufficient conductive connection strength is obtained in the substrate surface direction and the direction intersecting the substrate surface (for example, the vertical direction). It can be secured.

以上説明したように、本実施形態によれば、
一方の基板面１０Ｓに少なくとも１つのチップ部品１１が実装された第１の配線基板１０と第２の配線基板３０との導電接続構造であって、
実装面積の狭小化を図ることができ、
チップ部品１１の高さにばらつきがあっても良好に導電接続が可能であり、
導電接続時に２００℃以上の高温加熱が不要であり、
基板面方向及び基板面に対して交差する方向（例えば垂直方向）に対しても充分な導電接続強度を確保でき、
配線接続設計の自由度が高い導電接続構造１を提供することができる。 As described above, according to the present embodiment,
A conductive connection structure between the first wiring board 10 and the second wiring board 30 in which at least one chip component 11 is mounted on one board surface 10S,
The mounting area can be reduced,
Even if there is a variation in the height of the chip component 11, good conductive connection is possible,
High-temperature heating of 200 ° C or higher is not necessary during conductive connection,
Sufficient conductive connection strength can be secured even in the substrate surface direction and the direction intersecting the substrate surface (for example, the vertical direction),
The conductive connection structure 1 having a high degree of freedom in wiring connection design can be provided.

本実施形態の導電接続構造は例えば、携帯電話内部の電子部品である主基板と副基板との接続、携帯電話内部の電子部品であるカメラと主基板との接続、携帯電話内部の電子部品である主基板とキーＦＰＣの接続、あるいは携帯電話内部の電子部品である主基板とタッチパネルＦＰＣの接続など、任意の導電接続に適用できる。 The conductive connection structure of the present embodiment is, for example, a connection between a main board and a sub board, which are electronic parts inside a mobile phone, a connection between a camera and a main board, which are electronic parts inside the mobile phone, and an electronic part inside the mobile phone. The present invention can be applied to any conductive connection such as a connection between a main board and a key FPC, or a connection between a main board that is an electronic component inside a mobile phone and a touch panel FPC.

（設計変更）
本発明は上記実施形態に限らず、本発明の趣旨を逸脱しない範囲内において適宜設計変更が可能である。 (Design changes)
The present invention is not limited to the above-described embodiment, and design changes can be made as appropriate without departing from the spirit of the present invention.

チップ部品１１としては、少なくとも上端（第１の配線基板１０の基板面１０Ｓとの反対側の端）に外部電極１１Ｅが露出したものであればよく、チップコンデンサの他、ＬＳＩ等のチップ部品等であっても、本発明を適用可能である。 The chip component 11 only needs to have the external electrode 11E exposed at least at the upper end (the end opposite to the substrate surface 10S of the first wiring substrate 10). Even so, the present invention is applicable.

チップ部品１１の高さのばらつきが異方性導電性接着材２０の厚みよりも大きく、異方性導電性接着材２０だけではチップ部品１１の高さのばらつきを吸収できないような場合、第２の配線基板３０の導電接続箇所及びその近傍を部分的にフライングリード構造あるいは切欠構造とすることで、個々のチップ部品１１に対して、その高さに合わせて第２の配線基板３０の端子を導電接続することができる。 When the variation in the height of the chip component 11 is larger than the thickness of the anisotropic conductive adhesive 20, and the variation in the height of the chip component 11 cannot be absorbed by the anisotropic conductive adhesive 20 alone, the second By making the conductive connection portion of the wiring board 30 and the vicinity thereof partially have a flying lead structure or a notch structure, the terminals of the second wiring board 30 can be arranged in accordance with the height of each chip component 11. Conductive connection can be made.

図５は第２の配線基板３０にフライングリード構造を設けた例を示しており、左上図は上面図、右図は上面図を図示右方から見た側面図、左下図は上面図を図示下方から見た側面図である。 FIG. 5 shows an example in which a flying lead structure is provided on the second wiring board 30. An upper left view shows a top view, a right view shows a top view, a side view seen from the right side, and a lower left view shows a top view. It is the side view seen from the bottom.

図５に示す例では、第１の配線基板１０に、相対的に背の高い高チップ部品１１Ｈと相対的に背の低い低チップ部品１１Ｌとが実装されている。
また、第２の配線基板３０が、ポリイミド等の絶縁樹脂からなる基材フィルム３１とその一方の面に形成され、端子及び配線をなす銅等の導電材からなる複数のリード３２とからなるフレキシブル配線基板からなり、第１の配線基板１０との導電接続箇所及びその近傍の基材フィルム３１がリード３２の直交方向に部分的に除去された中空部３３を有している。
図５に示す例においても、第１の配線基板１０のチップ部品１１と第２の配線基板３０の端子とは、異方性導電性接着材２０を介して接続されているが、ここでは異方性導電性接着材２０の図示を省略してある。 In the example shown in FIG. 5, a relatively tall high-chip component 11 H and a relatively short low-chip component 11 L are mounted on the first wiring board 10.
Further, the second wiring board 30 is formed of a base film 31 made of an insulating resin such as polyimide, and a flexible film formed of a plurality of leads 32 made of a conductive material such as copper, which is formed on one surface thereof and forms terminals and wiring. It has a hollow portion 33 that is made of a wiring board and in which a conductive film connected to the first wiring board 10 and a base film 31 in the vicinity thereof are partially removed in the direction orthogonal to the leads 32.
In the example shown in FIG. 5 as well, the chip component 11 of the first wiring board 10 and the terminals of the second wiring board 30 are connected via the anisotropic conductive adhesive 20, but here they are different. The illustration of the anisotropic conductive adhesive 20 is omitted.

第２の配線基板３０において、基材フィルム３１が部分的に除去された中空部３３はリード３２のみが存在し、屈曲性に優れ、リード３２ごとに形状を変えられる。
図示するように、高チップ部品１１Ｈと低チップ部品１１Ｌに対して、それぞれの高さに合うよう、中空部３３のリード３２を屈曲させて、高チップ部品１１Ｈと低チップ部品１１Ｌのそれぞれの一方の外部電極１１Ｅと第２の配線基板３０のリード３２とを異方性導電性接着材２０を介して接続することができる。 In the second wiring substrate 30, the hollow portion 33 from which the base film 31 has been partially removed has only the leads 32, is excellent in flexibility, and can be changed in shape for each lead 32.
As shown in the drawing, the lead 32 of the hollow portion 33 is bent so as to match the height of each of the high chip component 11H and the low chip component 11L, and one of the high chip component 11H and the low chip component 11L. The external electrode 11 E and the lead 32 of the second wiring substrate 30 can be connected via the anisotropic conductive adhesive 20.

図６は切欠構造を設けた例を示しており、左上図は上面図、右図は上面図を図示右方から見た側面図、左下図は上面図を図示上方から見た側面図である。 FIG. 6 shows an example in which a notch structure is provided. The upper left figure is a top view, the right figure is a side view when the top view is viewed from the right side, and the lower left figure is a side view when the top view is viewed from above. .

図６に示す例においても、第１の配線基板１０に、相対的に背の高い高チップ部品１１Ｈと相対的に背の低い低チップ部品１１Ｌとが実装されている。
この例では、第２の配線基板３０が、ポリイミド等の絶縁樹脂からなる基材フィルム３１とその一方の面に形成され、端子及び配線をなす銅等の導電材からなる複数のリード３２とからなるフレキシブル配線基板からなり、第１の配線基板１０との導電接続箇所及びその近傍の互いに隣接するリード３２間が部分的に除去された切欠部３４を有している。
図６に示す例においても、第１の配線基板１０のチップ部品１１と第２の配線基板３０の端子とは、異方性導電性接着材２０を介して接続されているが、ここでは異方性導電性接着材２０の図示を省略してある。 Also in the example shown in FIG. 6, a relatively tall high-chip component 11 H and a relatively short low-chip component 11 L are mounted on the first wiring board 10.
In this example, the second wiring board 30 includes a base film 31 made of an insulating resin such as polyimide and a plurality of leads 32 formed on one surface thereof and made of a conductive material such as copper and forming terminals and wiring. It has a cutout portion 34 in which a conductive connection portion with the first wiring substrate 10 and a portion between adjacent leads 32 in the vicinity thereof are partially removed.
In the example shown in FIG. 6 as well, the chip component 11 of the first wiring board 10 and the terminals of the second wiring board 30 are connected via the anisotropic conductive adhesive 20, but here they are different. The illustration of the anisotropic conductive adhesive 20 is omitted.

第２の配線基板３０においては、互いに隣接するリード３２間に切欠部３４が設けられているので、各リード３２の第１の配線基板１０との導電接続箇所及びその近傍は屈曲性に優れ、導電接続箇所ごとに形状を変えられる。
高チップ部品１１Ｈと低チップ部品１１Ｌに対して、それぞれの高さに合うよう、第２の配線基板３０の第１の配線基板１０との導電接続箇所及びその近傍を屈曲させて、高チップ部品１１Ｈと低チップ部品１１Ｌのそれぞれの一方の外部電極１１Ｅと第２の配線基板３０のリード３２とを異方性導電性接着材２０を介して接続することができる。 In the second wiring board 30, since the notches 34 are provided between the leads 32 adjacent to each other, the conductive connection portions of the leads 32 with the first wiring board 10 and the vicinity thereof are excellent in flexibility, The shape can be changed for each conductive connection point.
For the high chip component 11H and the low chip component 11L, the conductive connection portion of the second wiring board 30 and the vicinity of the first wiring board 10 and the vicinity thereof are bent so as to match the respective heights. One external electrode 11E of each of 11H and the low chip component 11L and the lead 32 of the second wiring board 30 can be connected via the anisotropic conductive adhesive 20.

１導電接続構造
１０第１の配線基板
１０Ｓ基板面
１１チップ部品
１１Ｅ外部電極
１１Ｈ高チップ部品
１１Ｌ低チップ部品
２０異方性導電性接着材
３０第２の配線基板
３１基材フィルム
３２端子及び配線をなすリード
３３中空部
３４切欠部 DESCRIPTION OF SYMBOLS 1 Conductive connection structure 10 1st wiring board 10S Substrate surface 11 Chip component 11E External electrode 11H High chip component 11L Low chip component 20 Anisotropic conductive adhesive 30 2nd wiring substrate 31 Base film 32 A terminal and wiring Eggplant lead 33 hollow 34 notch

Claims

A first wiring board on which at least one chip component having an external electrode exposed at least at its upper end is mounted on one board surface, and at least one terminal to which the external electrode of the first wiring board is conductively connected A conductive connection structure with a second wiring board having:
The external electrode exposed at the upper end of the chip component of the first wiring board and the terminal of the second wiring board are connected via an anisotropic conductive adhesive placed on the external electrode. Conductive connection structure with conductive connection.

The chip component has external electrodes spread in a direction intersecting the substrate surface on a pair of end surfaces facing each other,
The conductive connection structure according to claim 1, wherein the one external electrode of the chip component and the terminal of the second wiring board are conductively connected via the anisotropic conductive adhesive.

The conductive connection structure according to claim 2, wherein the chip component is a chip capacitor.

The conductive connection structure according to claim 1, wherein the number of the terminals of the chip component and the second wiring board is the same.

A plurality of the chip components are mounted on the first wiring board, and a plurality of the terminals are mounted on the second wiring board,
The external electrodes of the plurality of chip components and the terminals of the second wiring board are conductively connected via a smaller number of the anisotropic conductive adhesives than the chip components. The electrically conductive connection structure in any one of 1-4.

A plurality of the chip components having different heights are mounted on the first wiring board, and a plurality of the terminals are mounted on the second wiring board,
The second wiring board is formed of a flexible wiring board formed of an insulating base film and a conductive material which is formed on one surface of the base film and forms the terminal, and the first wiring The base film of the conductive connection portion with the substrate has a hollow part partially removed,
The conductive material in the hollow portion of the second wiring board is bent in accordance with the height of each of the plurality of chip components on the first wiring board, and the chip of the first wiring board is bent. The conductive connection structure according to claim 1, wherein the component and the conductive material of the second wiring board are conductively connected via the anisotropic conductive adhesive.

A plurality of the chip components having different heights are mounted on the first wiring board, and a plurality of the terminals are mounted on the second wiring board,
The second wiring board is composed of a flexible wiring board formed of an insulating base film and a conductive material which is formed on one surface of the base film and forms the terminal, and the second wiring A notch portion in which a portion between the conductive connection portions of the substrate adjacent to each other of the first wiring substrate is partially removed;
In accordance with the height of each of the plurality of chip components on the first wiring board, a conductive connection portion of the second wiring board with the first wiring board is bent, and the first wiring The conductive connection structure according to claim 1, wherein the chip component of the substrate and the conductive material of the second wiring substrate are conductively connected via the anisotropic conductive adhesive.