JP2004135191A - Surface-mounted surface acoustic wave device and manufacturing method therefor - Google Patents

Surface-mounted surface acoustic wave device and manufacturing method therefor Download PDF

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Publication number
JP2004135191A
JP2004135191A JP2002299636A JP2002299636A JP2004135191A JP 2004135191 A JP2004135191 A JP 2004135191A JP 2002299636 A JP2002299636 A JP 2002299636A JP 2002299636 A JP2002299636 A JP 2002299636A JP 2004135191 A JP2004135191 A JP 2004135191A
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Prior art keywords
saw
chip
resin film
adhesive resin
substrate
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Japanese (ja)
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Yuji Ogawa
小川　祐史
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Toyo Communication Equipment Co Ltd
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Toyo Communication Equipment Co Ltd
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Priority to JP2002299636A priority Critical patent/JP2004135191A/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/93—Batch processes
    • H01L24/95—Batch processes at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips
    • H01L24/97—Batch processes at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/10—Bump connectors; Manufacturing methods related thereto
    • H01L2224/15—Structure, shape, material or disposition of the bump connectors after the connecting process
    • H01L2224/16—Structure, shape, material or disposition of the bump connectors after the connecting process of an individual bump connector
    • H01L2224/161—Disposition
    • H01L2224/16151—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/16221—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/16225—Disposition the bump connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
    • H01L2924/151—Die mounting substrate
    • H01L2924/1517—Multilayer substrate
    • H01L2924/15172—Fan-out arrangement of the internal vias
    • H01L2924/15174—Fan-out arrangement of the internal vias in different layers of the multilayer substrate

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  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a SAW device of a structure, wherein a SAW (surface acoustic wave) chip is mounted on a wiring substrate via conductor bumps disposed therebetween, which can ensure a coupling strength between the substrate and the chip, while avoiding infiltration of air into a surface which an adhesive resin film comes into contact and eliminating the need for a large-scale facility such as a vacuum tank, when application of an adhesive resin film to the outer surface of the chip and formation of an airtight space between the bottom of the chip and the upper surface of the substrate are carried out. <P>SOLUTION: The SAW device includes the board 2, the SAW chip 15, and the film 20 provided between the lower surface of the chip and the upper surface of the substrate to define an airtight space S for combining the substrate and the chip into a single unit. The film adheres tightly to the entire outer surface of the chip, other than its lower surface and covers this surface. The outer peripheral edge of the film has a plate shape having a surface area as to reach the upper surface of the substrate. The film is heated and softened to adhere tightly to the entire outer surface of the chip other than the lower surface of the chip and on the upper surface of the substrate, to thereby define the airtight space between the lower surface of the chip and the upper surface of the substrate. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、弾性表面波チップを配線基板上にバンプを用いて搭載してから弾性表面波チップを樹脂にて封止した構造の弾性表面波デバイスを製造する工程において発生する種々の不具合を解決した表面実装型弾性表面波デバイス、及びその製造方法に関するものである。
【０００２】
【従来の技術】
弾性表面波デバイス（ＳＡＷデバイス）は、水晶等の圧電基板上に櫛歯状の電極指（ＩＤＴ）を配置した構成を備え、例えばＩＤＴに高周波電界を印加することによって弾性表面波を励起し、弾性表面波を圧電作用によって高周波電界に変換することによってフィルタ特性を得るものである。
ところで、ＳＡＷデバイスの占有面積の小型化を図るために、特開平２−１８６６６２号公報、ＷＯ９７／０２５９６等には、図７に示すように、ＳＡＷチップ１１０を構成する圧電基板１１１とほぼ同等の面積を備えた表面実装用の配線基板１０１の上面に、ＩＤＴ１１２を形成した面を下向きにした状態のＳＡＷチップ１１０を導体バンプ１１３によってフリップチップ実装し、更にＳＡＷチップの下面と配線基板上面との間にＳＡＷ伝搬用の気密空間Ｓを確保しつつＳＡＷチップ外面から配線基板上面にかけて液状の封止樹脂１１５を被覆してから硬化させた樹脂封止型ＳＡＷデバイス１００が提案されている。
しかし、樹脂封止型ＳＡＷデバイス１００にあっては、配線基板１０１上のＳＡＷチップ１１０を樹脂被覆する際に、液状の封止樹脂１１５の一部がＳＡＷチップ１１０の裾部と配線基板１０１との間の間隙から気密空間Ｓ内に浸透してＳＡＷチップ下面のＩＤＴ１１２に付着し易くなり、その結果挿入損失を劣化させ、フィルタとして十分に機能し得なくする虞がある。特に、大面積の配線基板母材上に所定のピッチにてＳＡＷチップを搭載した状態で、全てのＳＡＷチップに対する樹脂被覆を行うためにはスクリーン印刷による一括処理が効率的ではあるが、この場合には比較的粘度の低い液状樹脂を使用する必要があるため、液状樹脂が気密空間内へ浸入する可能性が増大する。
このような不具合を解消するためには、例えば粘度の高い液状樹脂によってＳＡＷチップの裾部全周にダムを形成して気密空間を確保してから、粘性の低い液状樹脂をＳＡＷチップ外面に被覆する対策が考えられるが、この方法は工程数が増大するばかりでなく、微量の樹脂を特定部位に精度よく塗布する作業はきわめて煩雑であり、生産性低下、コストアップをもたらす原因となる。
【０００３】
これに対して、特開２００１−１７６９９５には、図８（ａ）に示すように、液状樹脂をＳＡＷチップ外面に被覆するのではなく、配線基板母材上１０１Ａにフェイスダウンで搭載した複数のＳＡＷチップ１１０の上面に対して、一枚の大面積の変形プラスチックフィルム等の接着性樹脂フィルム１２０を接着してから加熱することにより、接着性樹脂フィルム１２０を溶融軟化させてＳＡＷチップ外面（上面、及び側面）に密着させると共に、ＳＡＷチップの裾部全周と配線基板上面との間隙に充填させて前記気密空間Ｓを形成する方法が開示されている（図８（ａ）の点線部）。この方法によれば、液状樹脂が気密空間内に浸入してＩＤＴ１１２に付着する虞はなくなる。
しかし、この方法によった場合、各ＳＡＷチップ上に接着された接着性樹脂フィルム部分は隣接する他のＳＡＷチップ上に接着された他の接着性樹脂フィルム部分と連続一体化しているため、ＳＡＷチップ間に張り出した樹脂フィルム部分が溶融軟化してＳＡＷチップ間に垂れ下がった時に、垂れ下がり部分が変形してその形状にばらつきが発生したり、また硬化収縮時に互いに引っ張り合いが発生して変形し易くなる（図８（ａ）の点線部）。このため、接着性樹脂フィルム１２０とＳＡＷチップ外面及び配線基板上面との接触面に空気、又は空気が置換された不活性ガスが介在し易くなり、これらの気体が浸入しないように接着性フィルムを被覆することが容易でなくなる。即ち、接着性樹脂フィルムによる密着性を高めるためには、接触面に気体が介在することを厳に回避する必要があるが、気体の浸入を防ぐためには被覆工程を真空、或いは真空に近い雰囲気中で実施するか、或いは図８（ｂ）のように配線基板母材１０１Ａの適所に吸引孔１０５を形成しておき、吸引孔１０５から負圧を導入して、接着性樹脂フィルム１２０と配線基板との間の空間を負圧に保つ必要がある。いずれの場合も、真空ポンプ、真空槽が必要となり、設備の大型化、高コスト化、工程の複雑化による生産性の低下といった問題が発生する。
【特許文献１】特開平２−１８６６６２号公報
【特許文献２】ＷＯ９７／０２５９６
【特許文献３】特開２００１−１７６９９５公報
【０００４】
【発明が解決しようとする課題】
本発明は上記に鑑みてなされたものであり、表面実装用の配線基板上の配線パターン上に導体バンプを介してＳＡＷチップを搭載した構造のＳＡＷデバイスにおいて、接着性樹脂フィルムによってＳＡＷチップ外面の被覆と、ＳＡＷチップ裾部と配線基板上面との間での気密空間形成を行う場合に、真空ポンプ等の設備を用いずに接着性樹脂フィルムが接触する面に気体が浸入することを確実に防止することができる表面実装型ＳＡＷデバイス、及びその製造方法を提供することを課題とする。
【０００５】
【課題を解決するための手段】
上記課題を解決するため、本発明は次の如き手段を備える。
即ち、請求項１の表面実装型ＳＡＷデバイスは、絶縁基板、該絶縁基板の底部に設けた表面実装用の外部電極、及び該絶縁基板の上面に設けられ且つ該外部電極と導通した配線パターン、を備えた配線基板と、圧電基板、該圧電基板下面に形成されたＩＤＴ、及び前記配線パターン上に導体バンプを介してフリップチップ実装される接続パッド、を備えたＳＡＷチップと、前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成するように配線基板とＳＡＷチップとを一体化する接着性樹脂フィルムと、を備えた表面実装型ＳＡＷデバイスにおいて、前記接着性樹脂フィルムは、前記ＳＡＷチップの下面を除いた外面全体に密着してこれを覆うと共に、その外周縁が配線基板上面に達する面積を有した平板状であり、加熱により溶融軟化してＳＡＷチップ下面を除いた外面全体及び配線基板上面に密着固定して前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成することを特徴とする。
配線基板上にＳＡＷチップをフェイスダウン状態でフリップチップ実装した場合、熱可塑性樹脂等から成る極薄シート状の接着性樹脂フィルムを用いて、ＳＡＷチップ上面及び側面に密着させると共にＳＡＷチップ下面と配線基板上面との間に気密空間を形成するように樹脂フィルムの外周縁を配線基板上面に固着することにより、ＳＡＷチップと配線基板との結合強度を高めながらも、気密空間内に樹脂が浸入してＩＤＴに付着する不具合を防止できる。しかし、従来のように大面積の接着性樹脂フィルムを複数のＳＡＷチップ上に跨って添設して溶融加熱すると、ＳＡＷチップ間の間隙に相当する位置にある樹脂フィルム部分が溶融軟化して自重によって垂れ下がった時に、垂れ下がり形状にばらつきが発生し、硬化収縮時に互いに引っ張り合いが発生して変形し易くなる。このため、接着性樹脂フィルムとＳＡＷチップ外面及び配線基板上面との接触面に空気等の気体が介在し易くなる。また、接着面に介在する気体の量が多い場合には、配線基板とＳＡＷチップとの結合強度の低下をもたらす原因ともなる。
本発明では、使用する接着性樹脂フィルムの形状を、ＳＡＷチップ個片単位で被覆可能な小面積としたので、ＳＡＷチップ間に位置する張り出し部分が溶融軟化時に同一形状で垂れ下がることが可能となり、しかも隣接する樹脂フィルムとは干渉し合わないで垂れ下がり、且つ硬化するので、互いに影響を及ぼすことがなくなり、空気等の気体を巻き込むことが無くなる。
【０００６】
請求項２の発明に係る表面実装型ＳＡＷデバイスは、請求項１において、前記接着性樹脂フィルムの外面を、さらに樹脂層にて被覆したことを特徴とする。
接着性樹脂フィルムによる気密接合、及び結合強度を高めるために、更に樹脂被覆することも有効な手段である。
請求項３の発明に係る製造方法は、絶縁基板、該絶縁基板の底部に設けた表面実装用の外部電極、及び該絶縁基板の上面に設けられ且つ該外部電極と導通した配線パターン、を備えた配線基板と、圧電基板、該圧電基板下面に形成されたＩＤＴ、及び前記配線パターン上に導体バンプを介してフリップチップ実装される接続パッド、を備えたＳＡＷチップと、前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成するように配線基板とＳＡＷチップとを一体化する接着性樹脂フィルムと、を備えた表面実装型ＳＡＷデバイスの製造方法において、前記配線基板上面の配線パターン上に前記ＳＡＷチップの接続パッドを導体バンプを介して実装するフリップチップ実装工程と、前記ＳＡＷチップの下面を除いた外面全体に密着してこれを覆うと共に、外周縁が配線基板上面に達する面積を有した平板状の接着性樹脂フィルムを、ＳＡＷチップ上面に添設する添設工程と、前記接着性樹脂フィルムを加熱することにより溶融軟化させて、ＳＡＷチップ下面を除いた外面全体及び配線基板上面に密着固定させて前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成する加熱工程と、から成ることを特徴とする。
配線基板上にＳＡＷチップをフリップチップ実装したＳＡＷデバイスにおいて、ＳＡＷチップの下面に位置するＩＤＴと配線基板との間に気密空間を確保しながらＳＡＷチップを配線基板に強固に固定する手段として接着性樹脂フィルムを用いることは有効であるが、大面積の樹脂フィルムを複数のＳＡＷチップに跨って添設した上で、加熱工程を実施すると、ＳＡＷチップ間の間隙内に垂れ下がる樹脂フィルム部分の形状ばらつきを回避することができない。そこで、本発明では、ＳＡＷチップ毎に被覆するに足る面積を有した接着性樹脂フィルムを用いて個片単位で添設、加熱工程を実施するようにした。この結果、溶融軟化後の樹脂フィルムの被覆形状が均一化し、気体の巻き込み、接着不良を回避することが可能となる。
【０００７】
請求項４の製造方法は、絶縁基板、該絶縁基板の底部に設けた表面実装用の外部電極、及び該絶縁基板の上面に設けられ且つ該外部電極と導通した配線パターンを備えた配線基板を、複数個シート状に連結した大面積の配線基板母材を用いた、表面実装型ＳＡＷデバイスの製造方法において、下面に接続パッドとＩＤＴを備えたＳＡＷチップの該接続パッドを、前記配線基板上の配線パターン上に導体バンプを介して接続するフリップチップ実装工程と、前記ＳＡＷチップの下面を除いた外面全体に密着してこれを覆うと共に、外周縁が配線基板上面に達する面積を有した平板状の接着性樹脂フィルムを、各ＳＡＷチップ上面に添設する添設工程と、前記接着性樹脂フィルムを加熱することにより溶融軟化させて、ＳＡＷチップ下面を除いた外面全体及び配線基板上面に密着固定して前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成する加熱工程と、前記配線基板母材を、配線基板個片毎に切断する切断工程と、から成ることを特徴とする。請求項３に示した接着性樹脂フィルムによるＳＡＷチップの被覆作業は、大面積の配線基板母材上に所定の間隔でフリップチップ実装したＳＡＷチップに対して行ってもよい。これによれば、溶融軟化によりＳＡＷチップ外面に被覆した樹脂フィルムの形状を均一化しながら量産することが可能となる。
請求項５の発明は、請求項３に記載の前記添設工程において、保持面に前記接着性樹脂フィルムの非接着面側を添設保持したキャリアテープを用い、該キャリアテープにより保持された接着性樹脂フィルムの接着面の中央部を前記ＳＡＷチップ上面に接着してから前記キャリアテープを接着性樹脂フィルムから剥離することを特徴とする。
接着性樹脂フィルムをＳＡＷデバイス個片毎に被覆する場合、薄肉であるために変形、撓み易い樹脂フィルムの取り扱いは極めて煩雑である。そこで、十分な保形性を有したキャリアテープに樹脂フィルムを保持させておくことにより、樹脂フィルムをＳＡＷチップ上に添設する作業が容易化し、添設位置不良等が発生することが無くなる。
【０００８】
請求項６の発明は、請求項４に記載の前記添設工程において、保持面に複数の前記接着性樹脂フィルムの非接着面側を添設保持したキャリアテープを用い、該キャリアテープにより保持された各接着性樹脂フィルムの接着面の中央部を前記各ＳＡＷチップ上面に接着してから前記キャリアテープを各接着性樹脂フィルムから一括剥離することを特徴とする。
配線基板母材上に実装された複数のＳＡＷチップに対して小面積の樹脂フィルムを添設する作業を個片単位で行うとした場合には生産性が悪化する虞がある。そこで、大面積のキャリアテープに予め所定の配置で樹脂フィルムを保持しておき、このキャリアテープを用いて複数のＳＡＷチップ上に各樹脂フィルムを一括して添設することにより、添設工程を簡略化、正確化することが可能となる。
請求項７の発明は、絶縁基板、該絶縁基板の底部に設けた表面実装用の外部電極、及び該絶縁基板の上面に設けられ且つ該外部電極と導通した配線パターンを備えた配線基板を、複数個シート状に連結した大面積の配線基板母材を用いた、表面実装型ＳＡＷデバイスの製造方法において、下面に接続パッドとＩＤＴを備えたＳＡＷチップの該接続パッドを、前記各配線基板上の配線パターン上に導体バンプを介して接続するフリップチップ実装工程と、前記複数のＳＡＷチップに跨ってそれらの上面を覆うと共に、全てのＳＡＷチップの側面から配線基板上面に達する面積を有し、且つ複数の通気穴を備えた平板状の接着性樹脂フィルムを、各ＳＡＷチップ上面に添設する添設工程と、前記接着性樹脂フィルムを加熱することにより溶融軟化させる過程で前記通気穴から気体を排気すると共に全ての通気穴を閉止し、且つＳＡＷチップ下面を除いた外面全体及び配線基板上面に密着固定して前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成する加熱工程と、前記配線基板母材を、配線基板個片毎に切断する切断工程と、から成ることを特徴とする。
複数のＳＡＷチップを一括して被覆する従来タイプの大面積の接着性樹脂フィルムを用いてＳＡＷチップへの添設、加熱工程を実施した場合には、隣接するＳＡＷチップ間の間隙に垂れ下がる樹脂フィルム部分の形状にばらつきが発生したり、樹脂フィルム間での引張りによって、気体の巻き込み、固着不良等が発生する余地があったが、樹脂フィルムを変形させやすくするための通気穴を多数貫通形成しておくことにより、垂れ下がり部の形状が安定化し、しかも通気穴からの排気作用によって気体の巻き込みを解消できる。更に、加熱後の硬化時には、通気穴は閉止状態となる。
【０００９】
請求項８の発明は、請求項７において、前記通気穴の直径は、１ｍｍ以下であることを特徴とする。
通気穴の最大直径を１ｍｍ程度とすることにより、排気機能と加熱後の通気穴閉止機能を併有させることが可能となる。
請求項９の発明は、請求項７又は８において、前記接着性樹脂フィルムの単位面積内に含まれる前記通気穴の合計開口面積Ａと、単位面積内における非通気穴部分の面積Ｂとの比（Ｂ／（Ａ＋Ｂ））を、Ｂ／（Ａ＋Ｂ）≧０．５としたことを特徴とする。
このように合計開口面積と非通気穴部分の面積比を設定することにより、排気機能と加熱後の通気穴閉止機能を両立させることが更に確実となる。
請求項１０の発明は、請求項３、４、５、６、７、又は８に記載の前記加熱工程によって前記ＳＡＷチップ下面を除いた外面全体及び配線基板上面に密着固定された前記接着性樹脂フィルムの外面を、さらに樹脂層にて被覆する樹脂被覆工程を備えたことを特徴とする表面実装型ＳＡＷデバイスの製造方法。
接着性樹脂フィルムによる気密接合、及び結合強度を高めるために、更に樹脂被覆することは有効な手段である。
【００１０】
【発明の実施の形態】
以下、本発明を図面に示した実施の形態により詳細に説明する。
図１（ａ）及び（ｂ）は本発明の一実施形態に係る表面実装型弾性表面波デバイス（以下、ＳＡＷデバイス、という）の外観斜視図、及びその縦断面図である。
このＳＡＷデバイス１は、絶縁基板３、絶縁基板３の底部に設けた表面実装用の外部電極４、及び、絶縁基板３の上面に設けられ且つ内部導体６を介して外部電極４と導通した配線パターン５、から成る配線基板２と、配線パターン５と導体バンプ１０を介して電気的機械的に接続される接続パッド１６、及びＩＤＴ１７を夫々圧電基板１８の下面に備えたＳＡＷチップ１５と、ＳＡＷチップ１５の下面を除いた外面（上面、及び側面）に内面側の接着面にて密着すると共に、その外周縁部２０ｂを配線基板１上に密着固定させた接着性樹脂フィルム２０と、を備えている。
ＳＡＷチップを構成するＩＤＴ１７は、図示しない給電側のリード端子から高周波電界を印加されることによって弾性表面波を励起し、弾性表面波を圧電作用によって高周波電界に変換することによってフィルタ特性を得ることができる。接着性樹脂フィルム２０は、例えば約１００μｍ程度の厚さの変形プラスチックフィルム（例えば、エポキシ系フィルム）等の熱可塑性絶縁樹脂フィルムであり、片面にのみ接着剤が塗布されている。この接着性樹脂フィルム２０は、ＳＡＷチップ１５の下面と配線基板２の上面との間に、樹脂が充填されていないＳＡＷ伝搬用の気密空間Ｓが確保されるように、その外周縁２０ｂを配線基板２の上面に密着固定される。この例では、ＳＡＷチップの平面形状が矩形であるため、それに対応して接着性樹脂フィルム２０の形状も矩形となっている。
この実施形態に係るＳＡＷデバイス１によれば、一つのＳＡＷデバイスに対して一枚の接着性樹脂フィルム２０を用い、しかもこの接着性樹脂フィルム２０は、ＳＡＷチップ１５の下面１８ｃを除いた外面全体（上面１８ａ、側面１８ｂ）に密着してこれを覆うと共に、その外周縁２０ｂが配線基板２の上面に達する面積を有した平板状である。更に、この接着性樹脂フィルム２０は、加熱により溶融軟化してＳＡＷチップ下面を除いた外面全体及び配線基板上面に密着固定してＳＡＷチップ下面と配線基板上面との間に気密空間Ｓを形成すると同時に、配線基板上とＳＡＷチップ１５との固定を強固にする補強機能を発揮する。
このため、従来のように大面積の配線基板母材上に隣接配置した複数のＳＡＷチップ全体を覆う大面積の接着性樹脂フィルムを用いて加熱を行い、溶融軟化した接着性樹脂フィルムによって個々のＳＡＷチップ外面を一括被覆させる場合に発生しやすかったＳＡＷチップ間に位置する樹脂フィルム形状のばらつきと、それに起因した接着面への気体の浸入という不具合を解決することができる。
【００１１】
次に、図２は本発明のＳＡＷデバイスの変形例の断面図であり、このＳＡＷデバイス１は、接着性樹脂フィルム２０の外表面に更に絶縁樹脂膜２１を被覆形成した構成を備えている。絶縁樹脂膜２１は、スクリーン印刷、ディスペンサを用いた充填等によって形成され、気密性、及び配線基板に対するＳＡＷチップの固定力を補強する上で有効である。
【００１２】
次に、図３は本発明のＳＡＷデバイスの製造手順を示す図である。
尚、この例では複数の配線基板個片２をシート状に連結一体化した配線基板母材２５を用いたバッチ処理によるＳＡＷデバイスの生産方法を例示するが、この製造工程は独立した配線基板個片に対して個別に加工を加えてＳＡＷデバイスを単品生産する方法にも適用できる。
まず、図３（ａ）に示した如く、絶縁基板３の下面に外部電極４を有すると共に上面に配線パターン５を備えた配線基板個片２を複数個、シート状に連結した大面積の配線基板母材２５を用意し、各個片領域に対して、下面１８ｃに接続パッド１６とＩＤＴ１７を備えたＳＡＷチップ１５の接続パッド１６を、配線パターン５上に導体バンプ１０を介して電気的機械的に接続する（フリップチップボンディング）。導体バンプ１０は、予め接続パッド１６側に形成しておいてもよいし、配線パターン５上に形成してもよい。導体バンプ１０は、例えば金属ボール、或いはボール状の樹脂の外面に導体を被覆したものを使用する。
次いで、図３（ｂ）の添設工程では、各ＳＡＷチップ１５の下面１８ｃを除いた外面全体に密着してこれを覆うと共に、外周縁２０ｂが配線基板２上面に達する面積を有した平板状の接着性樹脂フィルム２０の接着面を、各ＳＡＷチップ上面１８ａに個別に添設（接着）する。なお、添設時に、接着性樹脂フィルム２０の接着面がＳＡＷチップ１５の上面１８ａに確実に接着するように図４（ａ）（ｂ）に示した如き加圧手段２２によって加圧するようにしてもよい。或いは、図４（ｂ）のように、ＳＡＷチップ１５の上面のみならず、樹脂フィルムの張り出し部分２０ａがチップの側面１８ｂ側に確実に垂れ下がるように押さえ込む突起２２ａを加圧手段２２に設けるようにしてもよい。
また、ＳＡＷチップ１５間の間隔は、隣接し合うＳＡＷチップ上に添設された接着性樹脂フィルム２０の外周縁２０ｂ同士が干渉し合わない程度の近接した間隔に設定することができ、図８（ａ）に示した従来例におけるＳＡＷチップ間隔と同等に設定することができる。
【００１３】
次いで、図３（ｃ）の加熱工程では、接着性樹脂フィルム２０を図示しない加熱手段によって溶融温度以上に加熱することにより溶融軟化させて、ＳＡＷチップ上面１８ａと接する部分を除いた張り出し部分２０ａを自重によって垂れ下げ変形させ、ＳＡＷチップ下面１８ｃを除いた外面全体及び配線基板上面に密着固定させてＳＡＷチップ下面と配線基板上面との間に気密空間Ｓを形成する。即ち、接着性樹脂フィルム２０の接着面のうちＳＡＷチップ上面１８ａと接している部分を除き、ＳＡＷチップ１５上面から側方に張り出している部分２０ａは加熱によって垂れ下がり、ＳＡＷチップ側面１８ｂに密着すると同時に、外周縁部２０ｂは配線基板上面に密着し、硬化時に固定された状態となる。
各接着性樹脂フィルム２０は隣接する他の樹脂フィルムから独立しており、各樹脂フィルムは均一に加熱することによって同一の挙動により（ｃ）の状態となる。この際、隣接する樹脂フィルムからの応力の影響を受けて引っ張られることがないため、空気、ガス等が接着面に入り込む余地が無くなり、密着面を得ることができる。
なお、加熱工程においても、図４（ａ）（ｂ）に示すごとき加圧手段（加圧用型）２２によって、各接着性樹脂フィルム２０を各ＳＡＷチップ外面（上面、及び側面）に加圧しながら加熱することにより、密着性を高めるようにしてもよい。
気密空間Ｓを真空化したい場合には、真空槽内にて上記加熱工程を実施するが、この場合の加熱方法はホットプレート等による配線基板側からの加熱、或いは輻射熱を利用した加熱による。
最後に、ダイシング等にて配線基板個片間の境界線に沿って切断することにより、ＳＡＷデバイス個片１を得ることとなる。
【００１４】
この製造方法によれば、接着性樹脂フィルム２０の張り出し部２０ａの突出長が配線基板上面に達する程度の長さであるため、接着性樹脂フィルム２０の全体面積を必要最小限に極限することができ、樹脂フィルムの軟化時に気体を巻き込むことなく、ＳＡＷチップ側面及び配線基板上面に接着することが可能となる。また、封止時に気密空間内を真空置換する場合には、配線基板等に貫通孔を形成することなく、簡単な真空槽内に配置して置換作業を行えばよく、設備費を低く抑えることができる。即ち、前述の如く、真空槽内において加熱工程を実施する際に、配線基板側からのホットプレート等による加熱、或いは輻射熱を利用した加熱によって接着性樹脂フィルムを加熱して軟化させることにより、気密空間を形成すると同時に、気密空間を真空にすることができる。
【００１５】
次に、上記添設工程において、各ＳＡＷチップ１５上に接着性樹脂フィルムを添設する作業を効率化するためには、複数のＳＡＷチップ上に一括して接着性樹脂フィルムを添設することが有効である。
即ち、図５は、添設工程を効率化するために使用するキャリアテープの構成及び添設手順を示す図である。
このキャリアテープ３０は、接着性樹脂フィルムを支持するに足る十分な強度を備えた樹脂等から成る大面積のテープであり、その一面（保持面）には、接着性樹脂フィルム２０の非接着面を接着面の接着力よりも弱い接着力にて保持し得る接着剤が塗布されている。この保持面上に複数の接着性樹脂フィルム２０を予め所定の配置（配線基板母材２５上のＳＡＷチップ１５と同配置）にて保持しておき、添設時には、キャリアテープ３０により保持された接着性樹脂フィルム２０の接着面の中央部をＳＡＷチップ上面１８ａに接着してからキャリアテープを各接着性樹脂フィルムから一括剥離する。これにより、キャリアテープ３０により保持された複数の接着性樹脂フィルムが一括して対応する全てのＳＡＷチップ上面に転写され、個片ごとに接着性樹脂フィルム２０を接着する手間が省ける。なお、ＳＡＷチップ個片毎に接着性樹脂フィルム２０を添設する場合にも、一枚ずつ接着性樹脂フィルム２０を保持した所要の小面積のキャリアテープを使用すれば、添設作業が効率化する。
次に、図２に示したごとき絶縁樹脂膜２１を、接着性樹脂フィルム２０の外面に被覆形成する場合には、図３（ｃ）に示した加熱工程の後に、接着性樹脂フィルム２０の外面をさらに樹脂層２１にて被覆する樹脂被覆工程を追加すればよい。
【００１６】
次に、図６（ａ）（ｂ）及び（ｃ）は本発明の他の実施形態に係る接着性樹脂フィルムの平面図、及びＳＡＷデバイスのバッチ処理による製造工程を示す図である。
本実施形態に係る接着性樹脂フィルムを用いて製造されるＳＡＷデバイスの構造は、図１に示したものと同等である。
本発明による製造方法の特徴的な構成は、大面積の配線基板母材２５を用いた表面実装型ＳＡＷデバイスの製造方法において、複数のＳＡＷチップ１５に跨って被覆される大面積の接着性樹脂フィルム２０を用いると共に、接着性樹脂フィルム２０に多数の円形の通気穴２３を等間隔、或いはランダムな配置にて貫通形成した点にある。
即ち、本製造方法は、下面に接続パッド１６とＩＤＴ１７を備えたＳＡＷチップ１５の該接続パッド１６を、各配線基板２上の配線パターン５上に導体バンプ１０を介して接続するフリップチップ実装工程と、複数のＳＡＷチップ１５に跨ってそれらの上面を覆うと共に、全てのＳＡＷチップの側面から配線基板上面に達する面積を有し、且つ複数の通気穴２３を備えた平板状の接着性樹脂フィルム２０を、各ＳＡＷチップ上面に添設する添設工程と、接着性樹脂フィルム２０を加熱することにより溶融軟化させる過程で通気穴２３から気体を排気すると共に全ての通気穴２３を閉止し、且つＳＡＷチップ１５下面を除いた外面全体及び配線基板上面に密着固定してＳＡＷチップ下面と配線基板上面との間に気密空間Ｓを形成する加熱工程と、前記各工程を経た配線基板母材２５を配線基板個片毎に切断する切断工程と、から成る。
【００１７】
加熱工程において、接着性樹脂フィルム２０の内側に位置する気体を円形の通気穴２３から排気させる機能と、排気完了後に全ての通気穴２３を閉止する機能の良否は、加熱温度、樹脂フィルムの肉厚、通気穴の開口面積比、及び個々の通気穴の開口面積等によって決定される。
例えば、円形の通気穴２３の直径は、例えば１ｍｍ以下とすることにより、樹脂フィルムが溶融して冷却するまでの間に通気穴２３が確実に埋められて閉止された状態となる。しかも、通気穴２３の直径を１ｍｍの範囲で適切に調整することにより、加熱によって通気穴２３が塞がれる前に、内部の気体を確実に外部へ押し出すことが可能となる。
また、接着性樹脂フィルム２０の単位面積内に含まれる通気穴２３の合計開口面積をＡとし、単位面積内における非通気穴部分の面積をＢとした場合の両者の比（Ｂ／（Ａ＋Ｂ））を、Ｂ／（Ａ＋Ｂ）≧０．５とすることにより、加熱によって通気穴が塞がれる前における気体の排出と、気体排出完了後の通気穴の閉止を安定して行うことが可能となる。例えば、非通気穴部分の面積Ｂが過小であって通気穴３２の合計開口面積Ａが過大な場合には、通気穴の閉止が確実に行われないか、或いは通気穴を閉止した後の当該部分の肉厚が薄くなって十分な被覆を実現できなくなる一方で、非通気穴部分の面積Ｂが過大な場合には排気が十分に行われないうちに通気穴の閉止が行われるため、通気穴の合計開口面積Ａと非通気穴部分の面積Ｂとの比を上記の範囲内となるように設定することが好ましい。更に、通気穴２３と非通気穴部分との面積に関する上記比率は、同時に、ＳＡＷチップ間に位置する樹脂フィルムの張り出し部分２０Ｂが加熱工程中に溶融軟化することにより自重によって確実にＳＡＷチップ間の間隙内に垂れ下がって落ち込み、ＳＡＷチップ間に露出した配線基板上面部分に接触することを保証する比率であることが必要である。つまり、通気穴２３を形成することによって、加熱による軟化時に樹脂フィルムの張り出し部分２０Ｂの変形が容易化するため、ＳＡＷチップ間の間隙内への落ち込みが確実となり、張り出し部分２０Ｂを均一形状にＳＡＷチップの側面と配線基板上面に夫々密着させることが可能となる。
【００１８】
なお、通気穴２３の形状は、円形である必要はなく、楕円形、長円形、小判形、多角形、長方形等、スリット形状、排気機能と、加熱冷却後の閉止機能を有した形状であれば円形に限定されない。また、上記機能を実現できるのであれば、単なる切り込みであってもよい。
また、ＳＡＷチップの上面１８ａと接する樹脂フィルム部分の通気穴と、ＳＡＷチップ間に位置する樹脂フィルム部分の通気穴の開口径、合計開口面積を異ならせるようにしてもよい。
【００１９】
【発明の効果】
以上のように本発明によれば、表面実装用の配線基板上の配線パターン上に導体バンプを介してＳＡＷチップを搭載した構造のＳＡＷデバイスにおいて、接着性樹脂フィルムによってＳＡＷチップ外面の被覆と、ＳＡＷチップ裾部と配線基板上面との間での気密空間形成を行う場合に、大がかりな真空槽等の設備を用いることなく、接着性樹脂フィルムが接触する面に気体が浸入することを防止しながらも、配線基板ＳＡＷチップとの結合強度を確実にすることができる。
即ち、請求項１の表面実装型ＳＡＷデバイスにおいては、接着性樹脂フィルムは、ＳＡＷチップの下面を除いた外面全体に密着してこれを覆うと共に、その外周縁が配線基板上面に達する面積を有した平板状であり、加熱により溶融軟化してＳＡＷチップ下面を除いた外面全体及び配線基板上面に密着固定して前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成する。つまり、本発明では、使用する接着性樹脂フィルムの形状を、ＳＡＷチップ個片単位で被覆可能な小面積としたので、ＳＡＷチップ間に位置する張り出し部分が溶融軟化時に同一形状で垂れ下がることが可能となり、しかも隣接する樹脂フィルムとは干渉し合わないで垂れ下がり、且つ硬化するので、互いに影響を及ぼすことがなくなり、空気等の気体を巻き込むことが無くなる。
請求項２の発明に係る表面実装型ＳＡＷデバイスは、接着性樹脂フィルムの外面を、さらに樹脂層にて被覆したので、接着性樹脂フィルムによる気密接合、及び結合強度を高めることができる。
【００２０】
請求項３の発明に係る製造方法では、ＳＡＷチップ毎に被覆するに足る面積を有した接着性樹脂フィルムを用いて個片単位で添設、加熱工程を実施するようにした。この結果、溶融軟化後の樹脂フィルムの被覆形状が均一化し、気体の巻き込み、接着不良を回避することが可能となる。
請求項４の製造方法では、接着性樹脂フィルムによるＳＡＷチップの被覆作業を、大面積の配線基板母材上に所定の間隔でフリップチップ実装したＳＡＷチップに対して行うので、溶融軟化によりＳＡＷチップ外面に被覆した樹脂フィルムの形状を均一化しながら量産することが可能となる。
請求項５の発明では、十分な保形性を有したキャリアテープに樹脂フィルムを保持させておくことにより、樹脂フィルムをＳＡＷチップ上に添設する作業が容易化し、添設位置不良等が発生することが無くなる。
請求項６の発明では、大面積のキャリアテープに予め所定の配置で樹脂フィルムを保持しておき、このキャリアテープを用いて複数のＳＡＷチップ上に各樹脂フィルムを一括して添設することにより、添設工程を簡略化、正確化することが可能となる。
請求項７の発明では、樹脂フィルムを変形させやすくするための通気穴を多数貫通形成しておくことにより、垂れ下がり部の形状が安定化し、しかも通気穴からの排気作用によって気体の巻き込みを解消できる。更に、加熱後の硬化時には、通気穴は閉止状態となる。
請求項８の発明では、通気穴の最大直径を１ｍｍ程度とすることにより、排気機能と加熱後の通気穴閉止機能を併有させることが可能となる。
請求項９の発明では、合計開口面積と非通気穴部分の面積比を所定に設定することにより、排気機能と加熱後の通気穴閉止機能を両立させることが更に確実となる。
請求項１０の発明では、樹脂被覆することにより、更に接着性樹脂フィルムによる気密接合、及び結合強度を高めることができる。
【図面の簡単な説明】
【図１】（ａ）及び（ｂ）は本発明の一実施形態に係る表面実装型弾性表面波デバイスの外観斜視図、及びその縦断面図。
【図２】本発明のＳＡＷデバイスの変形例の構成を示す断面図。
【図３】（ａ）（ｂ）及び（ｃ）は本発明のＳＡＷデバイスの製造手順を示す図。
【図４】（ａ）及び（ｂ）は加圧手段の構成例を示す図。
【図５】本発明の他の実施形態に係る製造手順を示す図。
【図６】（ａ）（ｂ）及び（ｃ）は本発明の他の実施形態に係る接着性樹脂フィルムの平面図、及び製造手順の説明図。
【図７】従来例のＳＡＷデバイスの構成図。
【図８】（ａ）及び（ｂ）は従来例のＳＡＷデバイスの製造手順を説明する図。
【符号の説明】
１　ＳＡＷデバイス、２　配線基板、３　絶縁基板、４　外部電極、５　配線パターン、６　内部導体、１０　導体バンプ、１５　ＳＡＷチップ、１６　接続パッド、１７　ＩＤＴ、１８　圧電基板、１８ａ　上面、１８ｂ　側面、１８ｃ下面、２０　接着性樹脂フィルム、２０ａ　張り出し部分、２０ｂ　外周縁部、２２　加圧手段、２３　通気穴、Ｓ　気密空間、３０　キャリアテープ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention solves various problems that occur in a process of manufacturing a surface acoustic wave device having a structure in which a surface acoustic wave chip is mounted on a wiring board using bumps and then the surface acoustic wave chip is sealed with a resin. And a method of manufacturing the same.
[0002]
[Prior art]
A surface acoustic wave device (SAW device) has a configuration in which a comb-shaped electrode finger (IDT) is arranged on a piezoelectric substrate such as quartz, and excites a surface acoustic wave by applying a high-frequency electric field to the IDT, for example. A filter characteristic is obtained by converting a surface acoustic wave into a high-frequency electric field by a piezoelectric action.
Incidentally, in order to reduce the occupied area of the SAW device, Japanese Patent Application Laid-Open No. 2-186662, WO97 / 02596, and the like show, as illustrated in FIG. On the upper surface of the surface-mounting wiring board 101 having an area, the SAW chip 110 with the surface on which the IDT 112 is formed is flip-chip mounted with the conductive bumps 113, and the lower surface of the SAW chip and the upper surface of the wiring board are further connected. A resin-sealed SAW device 100 has been proposed in which a liquid sealing resin 115 is coated from the outer surface of the SAW chip to the upper surface of the wiring board and then cured while securing an airtight space S for SAW propagation therebetween.
However, in the resin-sealed SAW device 100, when the SAW chip 110 on the wiring board 101 is covered with the resin, a part of the liquid sealing resin 115 is formed between the bottom of the SAW chip 110 and the wiring board 101. From the gap between them, it easily penetrates into the airtight space S and adheres to the IDT 112 on the lower surface of the SAW chip. As a result, the insertion loss may be deteriorated and the filter may not function sufficiently. In particular, in a state where SAW chips are mounted at a predetermined pitch on a large-area wiring board base material, batch processing by screen printing is efficient in order to perform resin coating on all SAW chips. Since it is necessary to use a liquid resin having a relatively low viscosity, the possibility of the liquid resin entering the airtight space increases.
In order to solve such a problem, for example, a dam is formed around the skirt of the SAW chip with a liquid resin having a high viscosity to secure an airtight space, and then the liquid resin having a low viscosity is coated on the outer surface of the SAW chip. However, this method not only increases the number of steps but also requires a very small amount of resin to be applied to a specific site with high accuracy, which leads to a decrease in productivity and an increase in cost.
[0003]
On the other hand, Japanese Patent Application Laid-Open No. 2001-176995 discloses that a plurality of liquid-state resins are mounted face-down on a wiring substrate base material 101A instead of coating the liquid resin on the outer surface of the SAW chip as shown in FIG. The adhesive resin film 120 such as a large-area deformable plastic film is adhered to the upper surface of the SAW chip 110 and then heated, thereby melting and softening the adhesive resin film 120 to form an outer surface of the SAW chip (upper surface). And the side surface) and filling the gap between the entire circumference of the skirt of the SAW chip and the upper surface of the wiring board to form the hermetic space S (a dotted line portion in FIG. 8A). . According to this method, there is no possibility that the liquid resin enters the airtight space and adheres to the IDT 112.
However, according to this method, the adhesive resin film portion bonded on each SAW chip is continuously integrated with another adhesive resin film portion bonded on another adjacent SAW chip. When the resin film portion that protrudes between the chips melts and softens and hangs between the SAW chips, the sagging portion deforms, causing variations in its shape. (Dotted line in FIG. 8A). For this reason, air or an inert gas in which air is replaced easily intervenes on the contact surface between the adhesive resin film 120 and the outer surface of the SAW chip and the upper surface of the wiring board, and the adhesive film is formed so that these gases do not enter. It is not easy to coat. That is, in order to enhance the adhesiveness of the adhesive resin film, it is necessary to strictly prevent gas from intervening in the contact surface. However, in order to prevent gas from entering, the coating process must be performed in a vacuum or an atmosphere close to vacuum. 8A. Alternatively, as shown in FIG. 8B, a suction hole 105 is formed at an appropriate position of the wiring board base material 101A, and a negative pressure is introduced from the suction hole 105 to connect the adhesive resin film 120 to the wiring. It is necessary to keep the space between the substrate and the substrate at a negative pressure. In any case, a vacuum pump and a vacuum tank are required, and problems such as an increase in size of the equipment, an increase in cost, and a decrease in productivity due to complicated processes occur.
[Patent Document 1] Japanese Patent Application Laid-Open No. 2-186662
[Patent Document 2] WO97 / 02596
[Patent Document 3] JP-A-2001-176995
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above, and in a SAW device having a structure in which a SAW chip is mounted via a conductive bump on a wiring pattern on a wiring board for surface mounting, an outer surface of the SAW chip is formed by an adhesive resin film. When forming an airtight space between the coating and the bottom of the SAW chip and the upper surface of the wiring board, make sure that gas enters the surface where the adhesive resin film comes into contact without using equipment such as a vacuum pump. It is an object of the present invention to provide a surface-mounted SAW device that can be prevented and a method for manufacturing the same.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention includes the following means.
That is, the surface-mount SAW device according to claim 1 includes an insulating substrate, an external electrode for surface mounting provided on the bottom of the insulating substrate, and a wiring pattern provided on the upper surface of the insulating substrate and electrically connected to the external electrode; A SAW chip comprising: a wiring substrate having: a piezoelectric substrate; an IDT formed on the lower surface of the piezoelectric substrate; and a connection pad flip-chip mounted on the wiring pattern via a conductor bump; and a lower surface of the SAW chip. And an adhesive resin film that integrates the wiring board and the SAW chip so as to form an airtight space between the wiring board and the upper surface of the wiring board, wherein the adhesive resin film comprises: The SAW chip is in a flat plate shape having an area that reaches the upper surface of the wiring board while being in close contact with and covering the entire outer surface except for the lower surface of the SAW chip. Softened and closely fixed to the entire and the wiring board top outer surface except for the SAW chip lower surface and forming an airtight space between the wiring board top surface and the SAW chip underside.
When a SAW chip is flip-chip mounted on a wiring board in a face-down state, an ultra-thin sheet-like adhesive resin film made of a thermoplastic resin or the like is used to adhere the SAW chip to the upper surface and side surfaces and to connect the SAW chip to the lower surface. By fixing the outer edge of the resin film to the upper surface of the wiring board so as to form an airtight space between the upper surface of the substrate and the upper surface of the wiring board, the resin penetrates into the airtight space while increasing the bonding strength between the SAW chip and the wiring substrate. As a result, the problem of adhering to the IDT can be prevented. However, when a large-area adhesive resin film is attached over a plurality of SAW chips and melt-heated as in the prior art, the resin film portion located at a position corresponding to the gap between the SAW chips melts and softens and its own weight is reduced. When it sags, the sagging shape varies, and it tends to be deformed due to mutual pulling during curing shrinkage. For this reason, gas such as air is likely to intervene on the contact surface between the adhesive resin film and the outer surface of the SAW chip and the upper surface of the wiring board. Also, when the amount of gas interposed on the bonding surface is large, it may cause a decrease in the bonding strength between the wiring board and the SAW chip.
In the present invention, since the shape of the adhesive resin film to be used is a small area that can be covered in SAW chip pieces, the overhanging portion located between the SAW chips can hang down in the same shape during melt softening, In addition, since it hangs down and hardens without interfering with the adjacent resin film, it does not affect each other and does not involve gas such as air.
[0006]
According to a second aspect of the present invention, in the surface mount SAW device according to the first aspect, the outer surface of the adhesive resin film is further covered with a resin layer.
It is also an effective means to further coat with resin in order to increase the hermetic joining and bonding strength with the adhesive resin film.
A manufacturing method according to a third aspect of the present invention includes an insulating substrate, an external electrode for surface mounting provided on a bottom portion of the insulating substrate, and a wiring pattern provided on an upper surface of the insulating substrate and electrically connected to the external electrode. A SAW chip including a wiring substrate, a piezoelectric substrate, an IDT formed on the lower surface of the piezoelectric substrate, and a connection pad that is flip-chip mounted on the wiring pattern via a conductive bump. A method of manufacturing a surface-mounted SAW device, comprising: an adhesive resin film that integrates a wiring board and a SAW chip so as to form an airtight space between the wiring board and an upper surface of the wiring board; A flip-chip mounting step of mounting the connection pads of the SAW chip on top of the conductive bumps via conductive bumps, and contacting the entire outer surface of the SAW chip except for the lower surface thereof; An additional step of attaching a flat adhesive resin film having an area whose outer peripheral edge reaches the upper surface of the wiring board to the upper surface of the wiring board, and melting and softening the adhesive resin film by heating the adhesive resin film. And a heating step of forming an airtight space between the lower surface of the SAW chip and the upper surface of the wiring substrate by being tightly fixed to the entire outer surface except the lower surface of the SAW chip and the upper surface of the wiring substrate.
In a SAW device in which a SAW chip is flip-chip mounted on a wiring board, adhesiveness is used as a means for firmly fixing the SAW chip to the wiring board while securing an airtight space between the IDT located on the lower surface of the SAW chip and the wiring board. It is effective to use a resin film. However, when a heating process is performed after a large-area resin film is attached across a plurality of SAW chips, the shape variation of the resin film portion hanging down in the gap between the SAW chips is reduced. Can not be avoided. Therefore, in the present invention, the heating step is carried out in units of individual pieces using an adhesive resin film having an area sufficient to cover each SAW chip. As a result, the coating shape of the resin film after the melt softening becomes uniform, and it becomes possible to avoid entrainment of gas and poor adhesion.
[0007]
A manufacturing method according to claim 4, wherein the insulating substrate, an external electrode for surface mounting provided on the bottom of the insulating substrate, and a wiring substrate provided on the upper surface of the insulating substrate and provided with a wiring pattern electrically connected to the external electrode. In a method of manufacturing a surface-mount SAW device using a large-area wiring board base material connected in a plurality of sheets, a connection pad of a SAW chip having a connection pad and an IDT on a lower surface is placed on the wiring board. A flip-chip mounting step of connecting via a conductive bump on the wiring pattern of the above, and a flat plate having an area whose outer peripheral edge reaches the upper surface of the wiring board while being in close contact with and covering the entire outer surface except the lower surface of the SAW chip. An adhesive resin film in the form of an adhesive is attached to the upper surface of each SAW chip, and the adhesive resin film is melted and softened by heating to remove the lower surface of the SAW chip. A heating step of forming an air-tight space between the lower surface of the SAW chip and the upper surface of the wiring substrate by tightly fixing the entire surface and the upper surface of the wiring substrate; and a cutting step of cutting the wiring substrate base material into individual wiring substrate pieces And characterized in that: The covering operation of the SAW chip with the adhesive resin film according to the third aspect may be performed on the SAW chip which is flip-chip mounted at a predetermined interval on a large-area wiring board base material. According to this, it becomes possible to mass-produce the resin film coated on the outer surface of the SAW chip by melt softening while making the shape uniform.
According to a fifth aspect of the present invention, in the attaching step according to the third aspect, a carrier tape having a non-adhesive surface side of the adhesive resin film attached and held on a holding surface is used, and the adhesive held by the carrier tape is used. The carrier tape is peeled off from the adhesive resin film after the center of the adhesive surface of the adhesive resin film is adhered to the upper surface of the SAW chip.
When the adhesive resin film is coated for each SAW device piece, handling of the resin film which is easily deformed and bent due to its thinness is extremely complicated. Therefore, by holding the resin film on a carrier tape having a sufficient shape-retaining property, the work of attaching the resin film on the SAW chip is facilitated, and the attachment position defect and the like do not occur.
[0008]
According to a sixth aspect of the present invention, in the attaching step of the fourth aspect, a carrier tape having a non-adhesive surface side of the plurality of adhesive resin films attached to a holding surface is held by the carrier tape. The center portion of the adhesive surface of each adhesive resin film is adhered to the upper surface of each SAW chip, and then the carrier tape is peeled off from each adhesive resin film at a time.
If the work of attaching a small-area resin film to a plurality of SAW chips mounted on a wiring board base material is performed in individual pieces, productivity may be deteriorated. Therefore, a resin film is held in a predetermined arrangement on a large-area carrier tape in advance, and each resin film is collectively attached on a plurality of SAW chips using the carrier tape, so that the attaching step is performed. Simplification and accuracy can be achieved.
The invention according to claim 7 includes an insulating substrate, a surface mounting external electrode provided on the bottom of the insulating substrate, and a wiring substrate provided on the upper surface of the insulating substrate and having a wiring pattern electrically connected to the external electrode, In a method of manufacturing a surface-mounted SAW device using a large-area wiring board base material connected in a plurality of sheets, a connection pad of a SAW chip having a connection pad and an IDT on a lower surface is placed on each of the wiring boards. A flip-chip mounting step of connecting via conductive bumps on the wiring pattern, and covering the upper surfaces of the plurality of SAW chips, and having an area reaching the upper surface of the wiring substrate from the side surfaces of all the SAW chips, And an attaching step of attaching a flat adhesive resin film having a plurality of ventilation holes to the upper surface of each SAW chip, and melting and softening the adhesive resin film by heating the adhesive resin film. In the process of exhausting the gas from the vent hole, all the vent holes are closed, and the entire outer surface except the lower surface of the SAW chip and the upper surface of the wiring substrate are fixed in close contact with the lower surface of the SAW chip and the upper surface of the wiring substrate. And a cutting step of cutting the wiring board base material into individual wiring board pieces.
If a conventional large-area adhesive resin film that covers a plurality of SAW chips collectively is used to attach and heat the SAW chips, a resin film that hangs down in the gap between adjacent SAW chips There was room for variations in the shape of the parts and for entrainment of gas and poor adhesion due to tension between the resin films.However, a large number of ventilation holes were formed to facilitate deformation of the resin films. By doing so, the shape of the hanging portion is stabilized, and the entrainment of gas can be eliminated by the exhaust action from the ventilation hole. Further, at the time of curing after heating, the ventilation holes are closed.
[0009]
The invention according to claim 8 is characterized in that, in claim 7, the diameter of the ventilation hole is 1 mm or less.
By setting the maximum diameter of the ventilation hole to about 1 mm, it is possible to have both the exhaust function and the ventilation hole closing function after heating.
According to a ninth aspect of the present invention, in the seventh or eighth aspect, a ratio of a total opening area A of the ventilation holes included in a unit area of the adhesive resin film to an area B of a non-venting hole portion in the unit area is provided. (B / (A + B)) is set so that B / (A + B) ≧ 0.5.
By setting the ratio of the total opening area to the area ratio of the non-venting hole portion in this way, it is further ensured that both the exhaust function and the closing function of the vent hole after heating are achieved.
According to a tenth aspect of the present invention, the adhesive resin is adhered and fixed to the entire outer surface excluding the lower surface of the SAW chip and the upper surface of the wiring board by the heating step according to the third, fourth, fifth, sixth, seventh, or eighth aspect. A method for manufacturing a surface-mounted SAW device, further comprising a resin coating step of coating an outer surface of a film with a resin layer.
In order to increase the hermetic bonding and bonding strength with the adhesive resin film, further resin coating is an effective means.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
1A and 1B are an external perspective view and a longitudinal sectional view of a surface-mount type surface acoustic wave device (hereinafter, referred to as a SAW device) according to an embodiment of the present invention.
The SAW device 1 includes an insulating substrate 3, an external electrode 4 for surface mounting provided on the bottom of the insulating substrate 3, and a wiring provided on the upper surface of the insulating substrate 3 and electrically connected to the external electrode 4 via an internal conductor 6. A wiring board 2 comprising a pattern 5, a connection pad 16 electrically and mechanically connected to the wiring pattern 5 via a conductor bump 10, and a SAW chip 15 having an IDT 17 on the lower surface of a piezoelectric substrate 18; An adhesive resin film that is adhered to an outer surface (upper surface and side surface) excluding a lower surface of the chip by an inner adhesive surface, and that an outer peripheral edge portion is tightly fixed on the wiring substrate; ing.
The IDT 17 constituting the SAW chip excites a surface acoustic wave by applying a high-frequency electric field from a lead terminal (not shown) on the power supply side, and obtains a filter characteristic by converting the surface acoustic wave into a high-frequency electric field by a piezoelectric action. Can be. The adhesive resin film 20 is, for example, a thermoplastic insulating resin film such as a deformable plastic film (for example, an epoxy-based film) having a thickness of about 100 μm, and an adhesive is applied to only one surface. The adhesive resin film 20 has its outer peripheral edge 20b wired between the lower surface of the SAW chip 15 and the upper surface of the wiring board 2 so as to secure an airtight space S for SAW propagation that is not filled with resin. It is closely fixed to the upper surface of the substrate 2. In this example, since the planar shape of the SAW chip is rectangular, the shape of the adhesive resin film 20 is correspondingly rectangular.
According to the SAW device 1 according to this embodiment, one adhesive resin film 20 is used for one SAW device, and the adhesive resin film 20 covers the entire outer surface of the SAW chip 15 except for the lower surface 18c. (Upper surface 18a, side surface 18b), and is a flat plate having an area whose outer peripheral edge 20b reaches the upper surface of the wiring board 2 while covering the same. Further, the adhesive resin film 20 is melted and softened by heating to be tightly fixed to the entire outer surface except for the lower surface of the SAW chip and the upper surface of the wiring substrate to form an airtight space S between the lower surface of the SAW chip and the upper surface of the wiring substrate. At the same time, it exerts a reinforcing function for firmly fixing the SAW chip 15 on the wiring board.
For this reason, heating is performed using a large-area adhesive resin film that covers the entirety of a plurality of SAW chips arranged adjacently on a large-area wiring board base material as in the related art, and each individual resin is melted and softened by the adhesive resin film. It is possible to solve the problem that the resin film located between the SAW chips, which is likely to be generated when the outer surface of the SAW chip is collectively covered, and the intrusion of gas into the bonding surface caused by the variation.
[0011]
Next, FIG. 2 is a cross-sectional view of a modified example of the SAW device of the present invention. The SAW device 1 has a configuration in which an outer surface of an adhesive resin film 20 is further coated with an insulating resin film 21. The insulating resin film 21 is formed by screen printing, filling using a dispenser, or the like, and is effective in reinforcing airtightness and fixing force of the SAW chip to the wiring board.
[0012]
Next, FIG. 3 is a view showing a manufacturing procedure of the SAW device of the present invention.
In this example, a method of producing a SAW device by batch processing using a wiring board base material 25 in which a plurality of wiring board pieces 2 are connected and integrated in a sheet shape is illustrated. The present invention is also applicable to a method of individually manufacturing a SAW device by individually processing pieces.
First, as shown in FIG. 3A, a large-area wiring in which a plurality of wiring board pieces 2 each having an external electrode 4 on the lower surface of the insulating substrate 3 and having a wiring pattern 5 on the upper surface are connected in a sheet shape. A substrate base material 25 is prepared, and the connection pads 16 of the SAW chip 15 having the connection pads 16 and the IDTs 17 on the lower surface 18c are provided for each individual region. (Flip chip bonding). The conductor bump 10 may be formed in advance on the connection pad 16 side, or may be formed on the wiring pattern 5. The conductor bump 10 is, for example, a metal ball or a ball-shaped resin whose outer surface is covered with a conductor.
Next, in the additional step of FIG. 3B, the SAW chip 15 is in close contact with and covers the entire outer surface except for the lower surface 18 c, and the outer peripheral edge 20 b has an area reaching the upper surface of the wiring board 2. The adhesive surface of the adhesive resin film 20 is individually attached (adhered) to the upper surface 18a of each SAW chip. At the time of attachment, pressure is applied by pressing means 22 as shown in FIGS. 4A and 4B so that the bonding surface of the adhesive resin film 20 is securely bonded to the upper surface 18a of the SAW chip 15. Is also good. Alternatively, as shown in FIG. 4B, the pressing means 22 is provided with not only the upper surface of the SAW chip 15 but also a projection 22a that presses down so that the projecting portion 20a of the resin film hangs down to the side surface 18b side of the chip. May be.
Further, the interval between the SAW chips 15 can be set to a close interval such that the outer peripheral edges 20b of the adhesive resin film 20 provided on the adjacent SAW chips do not interfere with each other. It can be set to be equal to the SAW chip interval in the conventional example shown in FIG.
[0013]
Next, in the heating step of FIG. 3 (c), the adhesive resin film 20 is melted and softened by being heated to a melting temperature or higher by a heating means (not shown), so that the overhang portion 20a excluding the portion in contact with the SAW chip upper surface 18a is removed. The airtight space S is formed between the lower surface of the SAW chip and the upper surface of the wiring substrate by being hung and deformed by its own weight and closely adhered to the entire outer surface except the lower surface 18c of the SAW chip and the upper surface of the wiring substrate. That is, except for the portion of the adhesive surface of the adhesive resin film 20 that is in contact with the SAW chip upper surface 18a, the portion 20a that protrudes laterally from the upper surface of the SAW chip 15 hangs down by heating and adheres to the SAW chip side surface 18b. The outer peripheral edge portion 20b is in close contact with the upper surface of the wiring board and is fixed during curing.
Each adhesive resin film 20 is independent of the other adjacent resin films, and each resin film is brought into the state (c) by the same behavior by uniformly heating. At this time, there is no room for air, gas or the like to enter the bonding surface because the resin film is not pulled by the influence of the stress from the adjacent resin film, and a close contact surface can be obtained.
In the heating step, each adhesive resin film 20 is pressed against the outer surface (upper surface and side surface) of each SAW chip by pressing means (pressing die) 22 as shown in FIGS. The adhesion may be increased by heating.
When it is desired to evacuate the hermetic space S, the above-described heating step is performed in a vacuum chamber. In this case, the heating method is heating from the wiring board side using a hot plate or the like or heating using radiant heat.
Finally, the SAW device piece 1 is obtained by cutting along the boundary between the wiring board pieces by dicing or the like.
[0014]
According to this manufacturing method, since the protruding length of the protruding portion 20a of the adhesive resin film 20 is a length that reaches the upper surface of the wiring board, it is possible to minimize the entire area of the adhesive resin film 20 to a necessary minimum. Thus, the resin film can be bonded to the side surface of the SAW chip and the upper surface of the wiring board without involving gas when the resin film is softened. In addition, when performing vacuum replacement in the hermetic space at the time of sealing, the replacement work may be performed by disposing in a simple vacuum tank without forming a through-hole in a wiring board or the like, and equipment cost may be reduced. Can be. That is, as described above, when the heating step is performed in the vacuum chamber, the adhesive resin film is heated and softened by heating from a wiring board side using a hot plate or the like, or heating using radiant heat, thereby providing airtightness. At the same time as forming the space, the airtight space can be evacuated.
[0015]
Next, in the above attaching step, in order to increase the efficiency of attaching the adhesive resin film on each SAW chip 15, it is necessary to attach the adhesive resin film on a plurality of SAW chips at once. Is valid.
That is, FIG. 5 is a diagram showing a configuration of a carrier tape used for improving the efficiency of the attaching process and an attaching procedure.
The carrier tape 30 is a large-area tape made of a resin or the like having sufficient strength to support the adhesive resin film, and one surface (holding surface) of the carrier tape 30 has a non-adhesive surface of the adhesive resin film 20. Is applied so that the adhesive can be held with an adhesive strength weaker than the adhesive strength of the adhesive surface. A plurality of adhesive resin films 20 were previously held on the holding surface in a predetermined arrangement (the same arrangement as the SAW chip 15 on the wiring board base material 25). After bonding the central part of the adhesive surface of the adhesive resin film 20 to the SAW chip upper surface 18a, the carrier tape is collectively peeled off from each adhesive resin film. Thereby, the plurality of adhesive resin films held by the carrier tape 30 are collectively transferred onto the upper surfaces of all the corresponding SAW chips, and the labor of bonding the adhesive resin film 20 for each individual piece can be omitted. In addition, even when the adhesive resin film 20 is attached to each SAW chip piece, using a carrier tape of a required small area holding the adhesive resin film 20 one by one can increase the attachment efficiency. I do.
Next, when the insulating resin film 21 as shown in FIG. 2 is formed on the outer surface of the adhesive resin film 20, the outer surface of the adhesive resin film 20 is formed after the heating step shown in FIG. May be further added with a resin coating step of coating with a resin layer 21.
[0016]
Next, FIGS. 6A, 6B and 6C are a plan view of an adhesive resin film according to another embodiment of the present invention and a view showing a manufacturing process of a SAW device by batch processing.
The structure of a SAW device manufactured using the adhesive resin film according to the present embodiment is the same as that shown in FIG.
A characteristic configuration of the manufacturing method according to the present invention is that a large-area adhesive resin covered over a plurality of SAW chips 15 is used in a method of manufacturing a surface-mount SAW device using a large-area wiring board base material 25. The point is that a large number of circular ventilation holes 23 are formed through the adhesive resin film 20 at equal intervals or at random at the same time as using the film 20.
That is, the present manufacturing method is a flip-chip mounting step of connecting the connection pads 16 of the SAW chip 15 having the connection pads 16 and the IDTs 17 on the lower surface to the wiring patterns 5 on each wiring board 2 via the conductive bumps 10. And a flat adhesive resin film having an area extending from the side surfaces of all the SAW chips to the upper surface of the wiring board and having a plurality of ventilation holes 23 while covering the upper surfaces thereof over the plurality of SAW chips 15. 20 is attached to the upper surface of each SAW chip, and gas is exhausted from the ventilation holes 23 in the process of heating and melting and softening the adhesive resin film 20, and all the ventilation holes 23 are closed; and A heating step of forming an airtight space S between the lower surface of the SAW chip and the upper surface of the wiring board by tightly fixing the entire outer surface except the lower surface of the SAW chip 15 and the upper surface of the wiring substrate; A cutting step of cutting the wiring board base material 25 that has undergone the respective processes in the wiring board individual pieces, made of.
[0017]
In the heating step, the function of exhausting the gas located inside the adhesive resin film 20 from the circular ventilation holes 23 and the function of closing all the ventilation holes 23 after the exhaust is completed depends on the heating temperature, the thickness of the resin film, and the like. It is determined by the thickness, the opening area ratio of the ventilation holes, the opening area of each ventilation hole, and the like.
For example, when the diameter of the circular ventilation hole 23 is, for example, 1 mm or less, the ventilation hole 23 is securely filled and closed before the resin film is melted and cooled. In addition, by appropriately adjusting the diameter of the ventilation hole 23 within a range of 1 mm, it is possible to reliably push out the gas inside to the outside before the ventilation hole 23 is closed by heating.
Further, when the total opening area of the ventilation holes 23 included in the unit area of the adhesive resin film 20 is defined as A, and the area of the non-venting hole portion in the unit area is defined as B, the ratio between the two (B / (A + B) ) Is set to B / (A + B) ≧ 0.5, thereby stably discharging the gas before the air hole is closed by heating and closing the air hole after the gas discharge is completed. Become. For example, when the area B of the non-venting hole portion is too small and the total opening area A of the venting hole 32 is too large, the closing of the venting hole is not surely performed, or the closing after the closing of the venting hole is performed. When the area B of the non-venting hole portion is too large, the venting hole is closed before the exhaust is sufficiently performed. It is preferable to set the ratio of the total opening area A of the holes to the area B of the non-venting hole portion to be within the above range. Furthermore, the above-mentioned ratio with respect to the area of the vent hole 23 and the area of the non-vent hole portion is such that the projecting portion 20B of the resin film located between the SAW chips is melted and softened during the heating step, so that the weight between the SAW chips is surely reduced. It is necessary that the ratio is such that it hangs down in the gap and contacts the upper surface portion of the wiring board exposed between the SAW chips. In other words, the formation of the ventilation holes 23 facilitates the deformation of the overhanging portion 20B of the resin film during softening by heating, so that it is ensured that the overhanging portion 20B falls into the gap between the SAW chips, and that the overhanging portion 20B is formed into a uniform shape. This makes it possible to closely contact the side surface of the chip and the upper surface of the wiring substrate.
[0018]
The shape of the ventilation hole 23 does not need to be circular, but may be elliptical, oval, oval, polygonal, rectangular, etc., a slit shape, a shape having an exhaust function, and a function of closing after heating and cooling. The shape is not limited to a circle. In addition, a simple cut may be used as long as the above function can be realized.
Further, the opening diameter and the total opening area of the ventilation holes of the resin film portion in contact with the upper surface 18a of the SAW chip and the ventilation holes of the resin film portion located between the SAW chips may be made different.
[0019]
【The invention's effect】
As described above, according to the present invention, in a SAW device having a structure in which a SAW chip is mounted via a conductive bump on a wiring pattern on a wiring board for surface mounting, covering the outer surface of the SAW chip with an adhesive resin film; When forming an airtight space between the bottom of the SAW chip and the upper surface of the wiring board, it is possible to prevent gas from entering the surface where the adhesive resin film comes into contact without using large-scale equipment such as a vacuum chamber. However, the bonding strength with the wiring board SAW chip can be ensured.
That is, in the surface-mount type SAW device of the first aspect, the adhesive resin film is in close contact with and covers the entire outer surface except for the lower surface of the SAW chip, and has an area whose outer peripheral edge reaches the upper surface of the wiring board. It is melt-softened by heating and is tightly fixed to the entire outer surface except for the lower surface of the SAW chip and the upper surface of the wiring substrate to form an airtight space between the lower surface of the SAW chip and the upper surface of the wiring substrate. In other words, in the present invention, the shape of the adhesive resin film used is a small area that can be covered in individual SAW chip units, so that the overhanging portion located between the SAW chips can hang down in the same shape during melt softening. In addition, the resin film hangs down and hardens without interfering with the adjacent resin film, so that it does not affect each other and no gas such as air is involved.
In the surface-mount SAW device according to the second aspect of the present invention, since the outer surface of the adhesive resin film is further covered with the resin layer, the hermetic bonding and the bonding strength by the adhesive resin film can be increased.
[0020]
In the manufacturing method according to the third aspect of the present invention, the heating step is performed in units of individual pieces using an adhesive resin film having an area sufficient to cover each SAW chip. As a result, the coating shape of the resin film after the melt softening becomes uniform, and it becomes possible to avoid entrainment of gas and poor adhesion.
In the manufacturing method according to the fourth aspect, since the SAW chip is coated with the adhesive resin film on the SAW chip which is flip-chip mounted at a predetermined interval on a large-area wiring board base material, the SAW chip is melt-softened. It becomes possible to mass-produce the resin film coated on the outer surface while making the shape uniform.
According to the fifth aspect of the present invention, the work of attaching the resin film to the SAW chip is facilitated by holding the resin film on the carrier tape having sufficient shape-retaining property. Will be eliminated.
According to the sixth aspect of the present invention, a resin film is held in a predetermined arrangement on a large-area carrier tape in advance, and each resin film is collectively attached on a plurality of SAW chips using the carrier tape. In addition, it is possible to simplify and correct the attachment process.
In the invention of claim 7, by forming a large number of ventilation holes for facilitating deformation of the resin film, the shape of the hanging portion is stabilized, and gas entrapment can be eliminated by the exhaust action from the ventilation hole. . Further, at the time of curing after heating, the ventilation holes are closed.
In the invention of claim 8, by setting the maximum diameter of the ventilation hole to about 1 mm, it becomes possible to have both the exhaust function and the ventilation hole closing function after heating.
According to the ninth aspect of the invention, by setting the ratio of the total opening area and the area ratio of the non-venting hole portion to a predetermined value, it is further ensured that both the exhaust function and the function of closing the vent hole after heating are achieved.
According to the tenth aspect of the present invention, the resin coating can further enhance the hermetic bonding and the bonding strength with the adhesive resin film.
[Brief description of the drawings]
FIGS. 1A and 1B are an external perspective view and a longitudinal sectional view of a surface-mount type surface acoustic wave device according to an embodiment of the present invention.
FIG. 2 is a sectional view showing a configuration of a modified example of the SAW device of the present invention.
FIGS. 3A, 3B and 3C are diagrams showing a procedure for manufacturing a SAW device according to the present invention.
FIGS. 4A and 4B are diagrams illustrating a configuration example of a pressing unit.
FIG. 5 is a diagram showing a manufacturing procedure according to another embodiment of the present invention.
6 (a), (b) and (c) are a plan view of an adhesive resin film according to another embodiment of the present invention and an explanatory view of a manufacturing procedure.
FIG. 7 is a configuration diagram of a conventional SAW device.
FIGS. 8A and 8B are diagrams for explaining a manufacturing procedure of a conventional SAW device.
[Explanation of symbols]
Reference Signs List 1 SAW device, 2 wiring board, 3 insulating board, 4 external electrodes, 5 wiring patterns, 6 internal conductor, 10 conductor bump, 15 SAW chip, 16 connection pad, 17 IDT, 18 piezoelectric substrate, 18a top surface, 18b side surface, 18c Lower surface, 20 adhesive resin film, 20a overhang, 20b outer peripheral edge, 22 pressing means, 23 ventilation hole, S airtight space, 30 carrier tape

Claims (10)

絶縁基板、該絶縁基板の底部に設けた表面実装用の外部電極、及び該絶縁基板の上面に設けられ且つ該外部電極と導通した配線パターン、を備えた配線基板と、
圧電基板、該圧電基板下面に形成されたＩＤＴ、及び前記配線パターン上に導体バンプを介してフリップチップ実装される接続パッド、を備えたＳＡＷチップと、
前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成するように配線基板とＳＡＷチップとを一体化する接着性樹脂フィルムと、
を備えた表面実装型ＳＡＷデバイスにおいて、
前記接着性樹脂フィルムは、前記ＳＡＷチップの下面を除いた外面全体に密着してこれを覆うと共に、その外周縁が配線基板上面に達する面積を有した平板状であり、加熱により溶融軟化してＳＡＷチップ下面を除いた外面全体及び配線基板上面に密着固定して前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成することを特徴とする表面実装型ＳＡＷデバイス。An insulating substrate, an external electrode for surface mounting provided on the bottom of the insulating substrate, and a wiring pattern provided on the upper surface of the insulating substrate and electrically connected to the external electrode;
A SAW chip including a piezoelectric substrate, an IDT formed on the lower surface of the piezoelectric substrate, and a connection pad flip-chip mounted on the wiring pattern via a conductive bump;
An adhesive resin film for integrating the wiring substrate and the SAW chip so as to form an airtight space between the lower surface of the SAW chip and the upper surface of the wiring substrate;
In a surface mount type SAW device provided with
The adhesive resin film is in close contact with and covers the entire outer surface except for the lower surface of the SAW chip, and has a flat plate shape having an area whose outer peripheral edge reaches the upper surface of the wiring board. A surface-mounted SAW device, wherein an airtight space is formed between the lower surface of the SAW chip and the upper surface of the wiring substrate by tightly fixing the entire outer surface except the lower surface of the SAW chip and the upper surface of the wiring substrate. 前記接着性樹脂フィルムの外面を、さらに樹脂層にて被覆したことを特徴とする請求項１に記載の表面実装型ＳＡＷデバイス。The surface mount SAW device according to claim 1, wherein an outer surface of the adhesive resin film is further covered with a resin layer. 絶縁基板、該絶縁基板の底部に設けた表面実装用の外部電極、及び該絶縁基板の上面に設けられ且つ該外部電極と導通した配線パターン、を備えた配線基板と、
圧電基板、該圧電基板下面に形成されたＩＤＴ、及び前記配線パターン上に導体バンプを介してフリップチップ実装される接続パッド、を備えたＳＡＷチップと、
前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成するように配線基板とＳＡＷチップとを一体化する接着性樹脂フィルムと、
を備えた表面実装型ＳＡＷデバイスの製造方法において、
前記配線基板上面の配線パターン上に前記ＳＡＷチップの接続パッドを導体バンプを介して実装するフリップチップ実装工程と、
前記ＳＡＷチップの下面を除いた外面全体に密着してこれを覆うと共に、外周縁が配線基板上面に達する面積を有した平板状の接着性樹脂フィルムを、ＳＡＷチップ上面に添設する添設工程と、
前記接着性樹脂フィルムを加熱することにより溶融軟化させて、ＳＡＷチップ下面を除いた外面全体及び配線基板上面に密着固定させて前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成する加熱工程と、
から成ることを特徴とする表面実装型ＳＡＷデバイスの製造方法。An insulating substrate, an external electrode for surface mounting provided on the bottom of the insulating substrate, and a wiring pattern provided on the upper surface of the insulating substrate and electrically connected to the external electrode;
A SAW chip including a piezoelectric substrate, an IDT formed on the lower surface of the piezoelectric substrate, and a connection pad flip-chip mounted on the wiring pattern via a conductive bump;
An adhesive resin film for integrating the wiring substrate and the SAW chip so as to form an airtight space between the lower surface of the SAW chip and the upper surface of the wiring substrate;
In a method of manufacturing a surface-mounted SAW device having
A flip-chip mounting step of mounting the connection pads of the SAW chip on the wiring pattern on the upper surface of the wiring board via conductive bumps;
An attaching step of attaching a flat adhesive resin film having an area whose outer peripheral edge reaches the upper surface of the wiring board while adhering to and covering the entire outer surface except the lower surface of the SAW chip; When,
The adhesive resin film is melted and softened by heating, and is tightly fixed to the entire outer surface except for the lower surface of the SAW chip and to the upper surface of the wiring substrate to form an airtight space between the lower surface of the SAW chip and the upper surface of the wiring substrate. Heating step;
A method for manufacturing a surface-mount SAW device, comprising: 絶縁基板、該絶縁基板の底部に設けた表面実装用の外部電極、及び該絶縁基板の上面に設けられ且つ該外部電極と導通した配線パターンを備えた配線基板を、複数個シート状に連結した大面積の配線基板母材を用いた、表面実装型ＳＡＷデバイスの製造方法において、
下面に接続パッドとＩＤＴを備えたＳＡＷチップの該接続パッドを、前記配線基板上の配線パターン上に導体バンプを介して接続するフリップチップ実装工程と、
前記ＳＡＷチップの下面を除いた外面全体に密着してこれを覆うと共に、外周縁が配線基板上面に達する面積を有した平板状の接着性樹脂フィルムを、各ＳＡＷチップ上面に添設する添設工程と、
前記接着性樹脂フィルムを加熱することにより溶融軟化させて、ＳＡＷチップ下面を除いた外面全体及び配線基板上面に密着固定して前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成する加熱工程と、
前記配線基板母材を、配線基板個片毎に切断する切断工程と、
から成ることを特徴とする表面実装型ＳＡＷデバイスの製造方法。An insulating substrate, an external electrode for surface mounting provided on the bottom of the insulating substrate, and a wiring substrate provided on the upper surface of the insulating substrate and having a wiring pattern electrically connected to the external electrode were connected in a plurality of sheets. In a method for manufacturing a surface-mounted SAW device using a large-area wiring board base material,
A flip-chip mounting step of connecting the connection pad of the SAW chip having a connection pad and an IDT on the lower surface to a wiring pattern on the wiring board via a conductive bump;
A flat plate-like adhesive resin film having an area whose outer peripheral edge reaches the upper surface of the wiring board while being in close contact with and covering the entire outer surface except the lower surface of the SAW chip is additionally provided on the upper surface of each SAW chip. Process and
The adhesive resin film is melted and softened by heating to form an airtight space between the lower surface of the SAW chip and the upper surface of the wiring substrate by tightly fixing the entire outer surface except the lower surface of the SAW chip and the upper surface of the wiring substrate. Heating step;
A cutting step of cutting the wiring board base material into individual wiring board pieces;
A method for manufacturing a surface-mount SAW device, comprising: 請求項３に記載の前記添設工程においては、保持面に前記接着性樹脂フィルムの非接着面側を添設保持したキャリアテープを用い、該キャリアテープにより保持された接着性樹脂フィルムの接着面の中央部を前記ＳＡＷチップ上面に接着してから前記キャリアテープを接着性樹脂フィルムから剥離することを特徴とする表面実装型ＳＡＷデバイスの製造方法。4. The attaching step according to claim 3, wherein a carrier tape having a non-adhesive surface side of the adhesive resin film attached and held on a holding surface is used, and an adhesive surface of the adhesive resin film held by the carrier tape is used. A method of manufacturing a surface-mounted SAW device, wherein the carrier tape is peeled off from the adhesive resin film after the center of the SAW chip is adhered to the upper surface of the SAW chip. 請求項４に記載の前記添設工程においては、保持面に複数の前記接着性樹脂フィルムの非接着面側を添設保持したキャリアテープを用い、該キャリアテープにより保持された各接着性樹脂フィルムの接着面の中央部を前記各ＳＡＷチップ上面に接着してから前記キャリアテープを各接着性樹脂フィルムから一括剥離することを特徴とする表面実装型ＳＡＷデバイスの製造方法。5. In the attaching step according to claim 4, a carrier tape having a non-adhesive surface side of the plurality of adhesive resin films attached and held on a holding surface, and each of the adhesive resin films held by the carrier tape is used. A method for manufacturing a surface-mounted SAW device, comprising: bonding a central portion of the bonding surface of (1) to the upper surface of each of the SAW chips, and then peeling off the carrier tape from each of the adhesive resin films. 絶縁基板、該絶縁基板の底部に設けた表面実装用の外部電極、及び該絶縁基板の上面に設けられ且つ該外部電極と導通した配線パターンを備えた配線基板を、複数個シート状に連結した大面積の配線基板母材を用いた、表面実装型ＳＡＷデバイスの製造方法において、
下面に接続パッドとＩＤＴを備えたＳＡＷチップの該接続パッドを、前記各配線基板上の配線パターン上に導体バンプを介して接続するフリップチップ実装工程と、
前記複数のＳＡＷチップに跨ってそれらの上面を覆うと共に、全てのＳＡＷチップの側面から配線基板上面に達する面積を有し、且つ複数の通気穴を備えた平板状の接着性樹脂フィルムを、各ＳＡＷチップ上面に添設する添設工程と、
前記接着性樹脂フィルムを加熱することにより溶融軟化させる過程で前記通気穴から気体を排気すると共に全ての通気穴を閉止し、且つＳＡＷチップ下面を除いた外面全体及び配線基板上面に密着固定して前記ＳＡＷチップ下面と前記配線基板上面との間に気密空間を形成する加熱工程と、
前記配線基板母材を、配線基板個片毎に切断する切断工程と、
から成ることを特徴とする表面実装型ＳＡＷデバイスの製造方法。An insulating substrate, an external electrode for surface mounting provided on the bottom of the insulating substrate, and a wiring substrate provided on the upper surface of the insulating substrate and having a wiring pattern electrically connected to the external electrode were connected in a plurality of sheets. In a method for manufacturing a surface-mounted SAW device using a large-area wiring board base material,
A flip chip mounting step of connecting the connection pads of a SAW chip having connection pads and IDTs on the lower surface to wiring patterns on the wiring boards via conductive bumps;
A flat adhesive resin film having an area extending from the side surfaces of all the SAW chips to the upper surface of the wiring board and covering a plurality of air holes, while covering the upper surfaces of the plurality of SAW chips, An attaching step of attaching to the upper surface of the SAW chip;
In the process of melting and softening the adhesive resin film by heating, the gas is exhausted from the ventilation holes and all the ventilation holes are closed, and the entire outer surface except the lower surface of the SAW chip and the upper surface of the wiring board are firmly fixed. A heating step of forming an airtight space between the lower surface of the SAW chip and the upper surface of the wiring board;
A cutting step of cutting the wiring board base material into individual wiring board pieces;
A method for manufacturing a surface-mount SAW device, comprising: 前記通気穴の直径は、１ｍｍ以下であることを特徴とする請求項７に記載の表面実装型ＳＡＷデバイスの製造方法。8. The method according to claim 7, wherein the diameter of the ventilation hole is 1 mm or less. 前記接着性樹脂フィルムの単位面積内に含まれる前記通気穴の合計開口面積Ａと、単位面積内における非通気穴部分の面積Ｂとの比（Ｂ／（Ａ＋Ｂ））を、
Ｂ／（Ａ＋Ｂ）≧０．５
としたことを特徴とする請求項７又は８に記載の表面実装型ＳＡＷデバイスの製造方法。The ratio (B / (A + B)) between the total opening area A of the ventilation holes included in the unit area of the adhesive resin film and the area B of the non-venting hole portion in the unit area is as follows:
B / (A + B) ≧ 0.5
The method for manufacturing a surface-mounted SAW device according to claim 7, wherein: 請求項３、４、５、６、７、又は８に記載の前記加熱工程によって前記ＳＡＷチップ下面を除いた外面全体及び配線基板上面に密着固定された前記接着性樹脂フィルムの外面を、さらに樹脂層にて被覆する樹脂被覆工程を備えたことを特徴とする表面実装型ＳＡＷデバイスの製造方法。9. The method according to claim 3, 4, 5, 6, 7, or 8, wherein the entire outer surface except the lower surface of the SAW chip and the outer surface of the adhesive resin film adhered and fixed to the upper surface of the wiring board are further resin-coated. A method for manufacturing a surface mount SAW device, comprising a resin coating step of coating with a layer.
JP2002299636A 2002-10-11 2002-10-11 Surface-mounted surface acoustic wave device and manufacturing method therefor Pending JP2004135191A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006032478A (en) * 2004-07-13 2006-02-02 Nippon Steel Chem Co Ltd Process for manufacturing semiconductor device
JP2008108782A (en) * 2006-10-23 2008-05-08 Nec Electronics Corp Electronic equipment and manufacturing method thereof
JP2012138430A (en) * 2010-12-25 2012-07-19 Kyocera Corp Electronic device

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006032478A (en) * 2004-07-13 2006-02-02 Nippon Steel Chem Co Ltd Process for manufacturing semiconductor device
JP4593187B2 (en) * 2004-07-13 2010-12-08 新日鐵化学株式会社 Manufacturing method of semiconductor device
JP2008108782A (en) * 2006-10-23 2008-05-08 Nec Electronics Corp Electronic equipment and manufacturing method thereof
JP2012138430A (en) * 2010-12-25 2012-07-19 Kyocera Corp Electronic device

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