JP2004053329A

JP2004053329A - Semiconductor sensor assembly and tire monitor sensor

Info

Publication number: JP2004053329A
Application number: JP2002209028A
Authority: JP
Inventors: Satoshi Shimada; 嶋田　　智
Original assignee: Hitachi Ltd; Hitachi Car Engineering Co Ltd
Current assignee: Hitachi Ltd; Hitachi Astemo Ltd
Priority date: 2002-07-18
Filing date: 2002-07-18
Publication date: 2004-02-19

Abstract

【課題】省エネルギー化をはかり電池の寿命を長くする。またゲル流れ防止し、さらに大量生産に適したプロセスにより安価に製造できる構造を提供すること。
【解決手段】圧力，温度，振動などを検出するセンサと信号処理回路を１チップに集積し、これらを保護するため可撓部（ダイヤフラム）を有する蓋基板をウエファ状態で接合する。
ダイヤフラム部以外をセンサチップをペレタイズした後に樹脂モールドし、ゲルによる保護で問題となるゲル流れを防止して信頼性を高め、大量生産に適したプロセスを提案する。
【選択図】　図１An object of the present invention is to save energy and extend the life of a battery. Another object of the present invention is to provide a structure that can prevent gel flow and can be manufactured at low cost by a process suitable for mass production.
A sensor for detecting pressure, temperature, vibration, and the like and a signal processing circuit are integrated on a single chip, and a lid substrate having a flexible portion (diaphragm) is bonded in a wafer state to protect them.
We propose a process suitable for mass production, in which the sensor chip is resin-molded after the sensor chip has been pelletized except for the diaphragm part, and gel flow, which is a problem in gel protection, is prevented to increase the reliability and improve mass production.
[Selection diagram] Fig. 1

Description

【０００１】
【発明の属する技術分野】
本発明は圧力，温度，振動などを検出するセンサの組み立て体に関する。また、本発明を応用する分野としてタイヤの圧力，温度，振動を検出するタイヤモニタセンサに関する。
【０００２】
【従来の技術】
従来のこの種のタイヤモニタセンサとしては、例えば、特開平２０００−
３５５２０３号公報，特開平２００１−１７４３５７号などに記載のセンサが知られている。特開平２０００−３５５２０３号公報に記載の圧力センサは、タイヤの微小振動を検出した際に制御回路を動作させることで電力消費量を必要最小限にする方法が提案されている。また特開平２００１−１７４３５７号公報には小型軽量構造の実現によりタイヤの着脱性改善とバランス補正量を低減することが提案されている。
【０００３】
【発明が解決しようとする課題】
このようなタイヤモニタセンサは省電力と小型化という要求に対する提案がなされているが、次のような課題が残されている。振動センサで走行検知して消費電力を節約し電池の寿命を長くするため、圧力センサと振動センサの２つのセンサが必要であったためモジュールが大型となり上記の着脱性やバランス補正の課題と、結線数が多くなりこのために自動車の使用環境での耐信頼性確保が難しく、またコストアップの要因であった。
【０００４】
一方、半導体集積技術で一つの基板上に圧力，温度センサを集積したセンサは既に実現しているが、タイヤモニタセンサに適用する場合、これとは別に振動を検知するためのセンサが必要なため上記と同じ課題が残されている。
【０００５】
また、水分や汚れなどからセンサや信号処理ＬＳＩを保護するため通常は表面にシリコーンゲルを塗布するが、タイヤ内部に取り付けられ長期間振動を蒙るためシリコーンゲルが流動する問題があり、これに耐える実装構造が上記課題に加えて残っている。
【０００６】
【課題を解決するための手段】
本発明はこの点に鑑みてなされたものであり、振動センサと圧力センサを集積化して小型化と組み立て工数を削減し、かつシリコーンゲル不要の樹脂パッケージにより信頼性向上を達成し、タイヤモニタセンサとしての実装に適したセンサ構造組み立て体を提案するものである。
【０００７】
本発明の特徴は、図１のように振動センサと圧力センサ及びその信号処理回路を形成した半導体単結晶シリコン製の回路基板と、周辺部に囲いを持つダイヤフラムを形成した単結晶シリコン製の蓋基板ウエファとを気密に接合し、個別チップにダイシング後に樹脂モールドしてパッケージする。これにより小型化と大量生産を実現する。
【０００８】
また図１，図２に示すように蓋基板上のダイヤフラムの周辺部には囲いを形成しているので樹脂がダイヤフラムに流れ込まないため、センサ組み立て体をリードフレーム上に載置し、ワイヤボンディングし該リードフレームの端部とダイヤフラム周辺部に設けた囲いの内側つまりダイヤフラムを除いて樹脂でモールドできる。または図３に示すようにダイヤフラムが形成される上面を除いてモールドする。このため小型の面付けパッケージが実現でき、ゲルによる保護が不要となり、ゲル流動などの問題が回避でき信頼性の高い実装が可能である。
【０００９】
本発明のセンサは、図１のような半導体回路基板上に図８のブロック構成のような振動，圧力、および温度センサと信号調整回路，電源回路，センサの出力側に設けたハイパスフィルター（微分回路）とローパスフィルター，通信回路及び制御回路からなる信号処理回路を集積し、蓋基板を気密に接合し、蓋基板の一部に圧力を受けて撓むダイヤフラムを形成し前記半導体基板上に形成した固定電極との間に形成した約１μｍの微小ギャップで静電容量を形成し、中央部に設けた質量部の変位で圧力と振動の両方を高感度で検知可能としている。
【００１０】
図６，図７のようにウェハプロセスにより、半導体回路基板に蓋基板を気密に接合し、各チップにペレタイズ後に樹脂モールドする。蓋基板の一部に形成したダイヤフラムで圧力を受けて、その変位を静電容量変化として変換し検知するので、半導体基板上に形成した検知用センサと信号調整回路には測定圧力が直接接触しないためガソリン蒸気や水分を含んだ気体の測定にも長期間使用できる。
【００１１】
本発明のセンサは、図８の構成により図９のように働く。振動センサが発した信号をトリガーとして、ウエイクアップモードとし、短期の時間周期でタイヤ内部の圧力と温度を伝送通信し、振動センサの信号が無い時は長期の時間周期で伝送通信するように制御できるため使用電力を必要最小限にすることができ電池の長寿命化が達成できる。
【００１２】
図２に示す本発明の１チップセンサは、半導体基板上に圧力，温度及び振動センサをそれぞれ独立に設けた実施例を示す。センサの信号調整回路，電源回路，センサの出力側に設けたハイパスフィルター（微分回路）とローパスフィルター，通信回路及び制御回路からなる信号処理回路を集積し、蓋基板を気密に接合し、蓋基板の一部に圧力を受けて撓む極薄のシールダイヤフラムを形成し前記半導体基板上に形成した静電容量式圧力センサの可動電極に当接させ圧力を伝達検知する。上記と同様に半導体基板上に形成したセンサと信号調整回路には測定圧力が直接接触しないためガソリン蒸気や水分を含んだ気体の測定にも長期間使用できる。
【００１３】
図１２に示すタイヤモニタセンサは、図１に示したセンサを用いてダイヤフラムの平面方向を車輪の回転軸の長手方向に平行に取り付けるためセンサが最上位置と最下位置の時にダイヤフラムの質量部がタイヤの上下振動を高感度で検知する。圧力センサは図１１のように振動と圧力を同時に検出するが、振動の変化は図１０▲１▼〜▲４▼に示すようにタイヤとサスペンションの達成振動数１０Ｈｚ〜１００Ｈｚと圧力空気圧の変動周期数ｍｉｎ　〜１ｈｒに比べて２桁の周期差があるため図８に示す回路構成によりフィルターを用いて両者を弁別検知できる。ゆえに１個の圧力センサで回転振動と圧力両方の物理量を検知することが可能である。また、停止時の圧力センサ出力を基準値としてＭＰＵのメモリに記憶しておき、走行時の出力と比較することによりタイヤ回転時に生じる遠心加速度による影響を差し引くことができるので圧力だけを正確に検知することができる。
【００１４】
また、図１３に示すタイヤモニタセンサは、図２に示した１チップセンサを用いて振動センサの受感方向を車輪の回転軸の長手方向に直角に取り付けるためタイヤの振動を高感度で検知でき、圧力センサの受感方向は回転軸と平行になっているため回転振動を検知せず、圧力だけを正確に検知することができる。
【００１５】
また、温度検知用として、前記信号処理回路と同じプロセスにより半導体基板上に抵抗体が形成されているので、この抵抗変化を電圧に変換して温度を検知することが可能である。
【００１６】
【発明の実施の形態】
図１に本発明の第１実施例の縦断面を示す。蓋基板２にダイヤフラム２１を形成し圧力と振動センサを兼ねた構造で、サーフェースマウントの樹脂パッケージ実装品を示す。半導体単結晶シリコン製の蓋基板２に形成したダイヤフラム２１で振動センサと圧力センサ用の可動電極を構成し、半導体単結晶シリコン製の半導体回路基板１上に設けた固定電極１２とで静電容量を形成する。
【００１７】
シリコン単結晶製の蓋基板２にはその一部を約１０μｍと薄く加工してダイヤフラム２１を形成する。ダイヤフラム２１が圧力に応動し半導体回路基板１の上面に形成した固定電極１２との間にもうけた微小空隙２５が変化し、これを静電容量変化に変換し、信号処理回路１１で所定の電気信号に処理し出力する。数気圧を測定するのに適した設計寸法は、前記ダイヤフラム２１の直径は例えば０．５ｍｍ　〜２ｍｍ、厚みが５〜１０μｍ、空隙が０．２μｍ　〜１μｍである。
【００１８】
またダイヤフラム２１の中央部に設けた質量体２２で振動を検知する。ダイヤフラム２１の寸法と質量体２２の重量で決まる固有振動数は、望ましくは図１０に示すタイヤの固有振動に近く設計し、その振動を効率良く検知する。
【００１９】
製造プロセスは、図６，図７のように上記半導体回路基板１と、蓋基板２はウエファ状態で気密に接合し、個別チップにダイシングしこのセンサ組み立て体をリードフレーム上に接着し、ワイヤボンディングした後に樹脂モールドしてパッケージする。樹脂モールド時にダイヤフラム２１の薄肉部に樹脂が流れ込まないようにその周辺部に囲いを設け、この部分とリードフレーム４の端子部４１を除いて全体をモールドする。このため小型の面付けパッケージが実現でき、ゲルによる保護が不要となり、ゲル流動などの問題が回避でき信頼性の高い実装が可能である。また、小型化と大量生産を実現する。
【００２０】
図２は本発明の第２実施例の縦断面を示し、回路基板に圧力，振動及び温度センサと信号処理回路を形成した１チップセンサの構造図。振動センサと圧力センサ及び温度センサ（図示しない）が前記半導体回路基板１側にすべて形成される。本例では、蓋基板２に形成したダイヤフラム２１は圧力センサの可動電極１５上の突起を加圧し、前記半導体回路基板１に形成した固定電極１２との間で構成した静電容量を変化させ圧力を検知する。振動センサは別に形成した梁状の可動電極１５と固定電極１４とで形成する静電容量により構成する。このセンサの振動感知方向は圧力センサとは直交しており、後述するタイヤ圧センサの装着に都合がよいように配慮されている。
【００２１】
圧力センサの可動電極１３は導電性ポリシリコンで構成され、前記半導体回路基板１上に形成した固定電極１２との間には微小空隙が形成されている。固定電極１２はＳｉＯ_２　などの誘電体膜を介して半導体回路基板１上に形成されて、前記半導体回路基板１から絶縁されており、前記可動電極１３との間に形成される空隙により静電容量を形成する。前記蓋基板２に形成したダイヤフラム２１が可動電極１５上の突起を加圧し静電容量が変化しこれから圧力変化を検知する。数気圧を測定するのに適した設計寸法は、前記可動電極１３の直径は例えば１００μｍ〜５００μｍ、厚みが０．５　〜２μｍ、空隙が０．２μｍ〜０．５μｍである。
【００２２】
別に形成した振動センサは、紙面に垂直方向に伸びる梁状の可動電極１５と前記半導体回路基板１上に一端が固定され前記固定電極１４との間に形成した複数の約１μｍの空隙で静電容量を構成する。梁状の可動電極１５は前記半導体回路基板１の平面方向の振動の変化に応動して静電容量が変化し振動を検知する。
【００２３】
本発明の特徴は、半導体回路基板１上に独立して振動，圧力センサを形成するため微小な振動検知が可能であり、特にタイヤ圧センサに応用する場合には、図１３に後述するように圧力センサの感知方向と振動センサの感知方向を直交させているため互いに独立に圧力，振動を検出できる。互いに最適寸法に設計できるため感度と精度がよいセンサを搭載できる。
【００２４】
また全体の製造プロセスは、図１の説明で述べた図６，図７のように実施され同じような特徴と効果を有する。
【００２５】
前記静電容量は、詳細に記載しないが、通常用いられるように周囲圧力に応じて変化するアクティブ容量と、周囲圧力に対し実質的に変化しない基準容量とが形成されており、両者の差ないし比を検出する。すなわち前記信号処理回路１１では静電容量変化を積分するＣＶ変換器で出力信号として定められた信号に調整し電圧または周波数として出力する。
【００２６】
また静電容量の設計は、つぎのように電気的，機械的及び製造プロセス要因の面から寸法が設計される。印加圧力による静電容量変化とダイアフラム膜の強度を勘案して圧力センサの寸法が設計される。周囲圧力をＰとしたとき、前記ダイアフラムの厚みｈの上限値を次式（１）で求まる変位ｗ（ｐ）に基づき、前記ダイアフラムの直径２ａに応じて設定する。
【００２７】
ｗ（ｐ）＝ＫＰ・ａ^４／ｈ^３
Ｋ＝３（１−ν^２）／（１６Ｅ）　　　　　　　　　　　　　　　　　…（１）
但し、νはポアソン比、Ｅはヤング率
前記ダイアフラムの厚みｈの下限値を、次式（２）に基づき、前記ダイアフラムの直径２ａに応じて設定する。
【００２８】
ｈ＝αａ　　　　　　　　　　　　　　　　　　　　　　　　　　…（２）
数気圧の測定であれば、α＝０．１〜０．５である。
【００２９】
温度センサ自身はすでに公知の手法で実施されているため図示しないが、半導体基板上に形成され、前記可動電極１３と同じプロセスにより形成した導電性ポリシリコンの抵抗を用い、この抵抗変化から温度を検知する。
【００３０】
半導体回路基板１上に形成した導電性ポリシリコンの抵抗と該導電性ポリシリコン抵抗とは温度係数の異なる信号処理回路の１１中に形成する拡散抵抗とで構成したホイートストンブリッジ回路の出力電圧を処理し所定の信号レベルに調整して出力する。
【００３１】
図３は本発明の第３実施例の縦断面を示し、例えば配線基板４１の材料としてセラミック基板を用いる場合の実装構造例を示す。この例では図２に説明したセンサチップを、サーフェースマウントのパッケージ実装時に配線基板にＣＣＢで結線する例を示す。このため回路基板１側に貫通電極５を形成する。
【００３２】
半導体回路基板１の一部に形成した下面まで貫通拡散の位置にセットした半田ボール４１を用いて配線基板４１うえの電極膜に接続する。本実施例の特徴は、図２に前述したセンサの機能，特徴を維持しながら、ＭＰＵなど別のＬＳＩチップと電子部品とベアチップの状態で配線基板４１上に実装できるため、本複合センサの機能を自動車のパワートレイン制御にとどまらずＦＡ，ＰＡ分野のモニタなどさまざまなシステムに応用展開が可能である。
【００３３】
図４は本発明の第４実施例の縦断面を示し、樹脂パッケージの形態として必要最小限の形体を示しており、ダイヤフラムを形成する上面を除いて半導体回路基板１と蓋基板２の接合界面の絶縁膜を側面全周に亘って囲み樹脂パッケージした実装品を示す。本実施例の特徴は、これによりパッケージ用樹脂の量を節約することができる。
【００３４】
図５は本発明の第５実施例の縦断面を示し、半導体回路基板１にダイヤフラム２１を形成し、半導体回路基板１の製造プロセス時に形成する拡散抵抗をピエゾ抵抗として用いる。ダイヤフラム２１の中央に質量部を持ち圧力と振動センサを兼ねた構造で、ＣＣＢで結線するサーフェースマウントの樹脂パッケージ実装品を示す。本実施例の特徴は、前述の静電容量式のセンサに比べて、微小空間を形成する必要がないため製造プロセスが容易である。
【００３５】
図６，図７によりウエファ状態で回路基板と蓋基板を接合した後チップ周辺の溝部をダイシングし、ペレタイズする製造プロセスを説明する。
【００３６】
概要は、上記半導体回路基板１と、蓋基板２はウエファ状態で気密に接合し、個別チップにダイシングしこのセンサ組み立て体をリードフレーム上に接着し、ワイヤボンディングした後に樹脂モールドしてパッケージするものである。
【００３７】
ウエファ同士を気密に接合する技術は、種々検討されており、最も簡単な方法が蓋基板２をガラスとする構造である。ガラス中のＮａイオンの移動を利用した静電接合技術を利用する。この方法は図１〜図４の実施例に適用するためにはガラス板の微細加工に高い精度が必要である。一方、蓋基板２にシリコン基板を用いればエッチングによる微細な高精度加工が容易なため極薄のダイヤフラム微小空隙を形成できるが、シリコン−シリコンのウエファ接合技術を用いる必要がある。互いを直接接合させる場合は６００℃〜１０００℃の高温での作業となる。ＡｕやＡＬ膜などを挟むことにより作業温度の低い接合の利用も可能である。これらの制約を勘案して最適な接合技術を採用しウエファ状態で回路基板と蓋基板を合わせ気密接合を行い、拡大図に示すようなチップ周辺の溝部をダイシングしてペレタイズする。この後は図１，図２に示したリードフレーム４かまたは図３，図４，図５に示したセラミック基板４１０の上に接着し、配線した後に樹脂モールドする。樹脂モールド時にダイヤフラム２１の薄肉部に樹脂が流れ込まないようにその周辺部に囲い１００を設け、この部分とリードフレーム４の端子部４１を除いて全体をモールドする。本プロセスの採用によって小型の面付けパッケージが実現でき、ゲルによる保護が不要となり、ゲル流動などの問題が回避でき信頼性の高い実装が可能である。また、小型化と大量生産を実現できる特徴を有する。
【００３８】
図８は本発明をタイヤ圧センサに適用したときの構成ブロック図を示す。
【００３９】
ブロック図の構成要素は、圧力センサ１３，振動センサ１４と温度センサ１２３が構成されており、センサの出力側には該センサ信号のレベル調整を行う容量・電圧変換１１０と抵抗・電圧変換回路１１３、及びハイパスフィルター（微分回路）１１１とローパスフィルター１１２が形成される。これらの信号を切りかえるマルチプレクサーＭＰＸ１１５，デジタル値に変換するＡＤ変換器Ａ／Ｄ１１６，特性補正などの演算処理をするマイクロプロセッサユニットＭＰＵ１１７，センサの出力部には通信Ｉ／Ｏ回路１１８及び発信器ＯＳＣ１１９、そして電源回路１２０からなる。
【００４０】
図９は本発明のタイヤ圧センサの検知アルゴリズムの要点説明図である。図８を参照して以下の動作を説明する。
【００４１】
ダイヤフラムセンサ１３，１４は圧力と振動を検知可能とし、信号処理回路
１１０〜１２０は、振動センサが外部から印加される振動に応動して発した信号をハイパスフィルター（微分回路）１１１を通してトリガー信号として、マイクロプロセッサユニットＭＰＵ１１７に送り、ウエイクアップモードとする。マイクロプロセッサユニットＭＰＵ１１７により、ダイヤフラムセンサ１３，１４と温度センサ１２３は、圧力，温度信号を測定し、特性補正処理した値を前記ローパスフィルター１１１及び抵抗・電圧変換回路１１３，マルチプレクサーＭＰＸ１１５を通して第１の時間周期３０秒に一回送信する。また、マイクロプロセッサユニットＭＰＵ１１７は、振動センサの信号が無い時はスリープモードとし第２の時間周期１時間に一回送信するように制御し通信する。本実施例の特徴は、振動センサを同一チップ上に設けて圧力と振動及び温度を検知可能としたため、振動センサが外部から印加される振動を検知し走行時／停止時の通信時間を的確に制御でき走行時以外の消費電力を節減できるため、タイヤ内部に装着する時に必須となる電池の寿命を伸ばすことができる。
【００４２】
図１０は自動車走行時にタイヤが受ける振動のスペクトラム図である。また図１１はタイヤの一部に取り付けた振動センサの波形を模擬的に示す。５０〜１００Ｈｚに存在する振動ピークを検知すれば走行／停止の判断が可能である。
【００４３】
圧力センサの中央部に質量部を設け振動に対する受感度周波数を５０〜１００Ｈｚに設計し振動検知感度をより高める。
【００４４】
図１２は、図１に示したセンサをタイヤ圧センサのタイヤへ装着した実施例である。
【００４５】
図１のセンサのダイヤフラムの平面方向を車輪の回転軸（車軸）の長手方向に平行に取り付けるためセンサが最上位置と最下位置の時にダイヤフラムの質量部がタイヤの上下振動を高感度で検知する。圧力センサは、図１１の波形のように振動と回転遠心力と重力および圧力を同時に検出するが、振動の変化は図１０に示すように数１０Ｈｚ〜１００Ｈｚであり、回転による遠心力も圧力の変動周期数ｍｉｎ　〜１ｈｒに比べて２桁の周期差があるため前述の図８に示す構成によりフィルターを用いて両者を弁別検知できる。また、停止時の圧力センサ出力を基準値としてＭＰＵのメモリに記憶しておき、走行時の出力と比較することによりタイヤ回転時に生じる遠心加速度による影響を差し引くことにより圧力だけを正確に検知することができる。
【００４６】
図１３は、図２に示したタイヤ圧センサをタイヤへの装着した別の実施例である。図２に示した１チップセンサを用いて回転，振動と圧力を別々に検知する。振動センサの受感方向を車輪の回転軸（車軸）の長手方向に直角に取り付けるためタイヤの振動を高感度で検知でき、圧力センサの受感方向は回転軸と平行になっているため回転の遠心力と振動を検知せず、圧力だけを正確に検知することができる。
【図面の簡単な説明】
【図１】本発明の第１実施例の縦断面を示し、蓋基板２にダイヤフラム２１を形成し圧力と振動センサを兼ねた構造で、サーフェースマウントの樹脂パッケージ実装品を示す図。
【図２】本発明の第２実施例の縦断面を示し、回路基板に圧力センサ（１３，１４，２１）とは別に、振動センサ（１４，１５）及び信号処理回路１１の一部に温度センサを形成した１チップセンサの構造図。
【図３】本発明の第３実施例の縦断面を示し、サーフェースマウントのパッケージ実装時に配線基板４１０にＣＣＢ４１で結線する実装構造図。
【図４】本発明の第４実施例の縦断面を示し、樹脂パッケージの形態は回路基板１と蓋基板２の接合界面の絶縁膜１２を側面全周に亘って囲み樹脂パッケージした実装品を示す。
【図５】本発明の第５実施例の縦断面を示し、回路基板１側に一部にダイヤフラム２１を形成し圧力と振動センサを兼ねた構造で、配線基板４１０にＣＣＢ４１で結線するサーフェースマウントの樹脂パッケージ実装品を示す。
【図６】ウエファ状態で回路基板１と蓋基板２を接合した後チップ周辺の溝部をダイシングしペレタイズするプロセスの説明図。
【図７】本発明のセンサ組み立て体のプロセスフロー図。
【図８】本発明をタイヤ圧センサに適用したときの構成ブロック図。
【図９】本発明のタイヤ圧センサの検知アルゴリズムの要点説明図。
【図１０】自動車走行時にタイヤが受ける振動のスペクトラム図。
【図１１】タイヤの一部に取り付けた振動センサの波形を説明する図。
【図１２】本発明をタイヤ圧センサのタイヤへの装着実施例図。
【図１３】本発明をタイヤ圧センサのタイヤへの装着した別の実施例図。
【符号の説明】
１…半導体回路基板、２…蓋基板、３…接着剤、４…リードフレーム、５…ボンディングワイヤ、６…樹脂モールド、１１…信号処理回路、１２…酸化膜、
１３…圧力センサ可動電極、１４，１６…固定電極、１５…可動電極、２１…ダイヤフラム、２２…質量体、２５…空隙、１００…囲い、４１０…配線基板。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an assembly of sensors for detecting pressure, temperature, vibration, and the like. Further, the present invention relates to a tire monitor sensor for detecting tire pressure, temperature, and vibration as a field to which the present invention is applied.
[0002]
[Prior art]
Conventional tire monitor sensors of this type include, for example, Japanese Patent Application Laid-Open No. 2000-2000.
Japanese Patent Application Laid-Open No. 355203 and Japanese Patent Application Laid-Open No. 2001-174357 are known. As for the pressure sensor described in Japanese Patent Application Laid-Open No. 2000-355203, a method has been proposed in which a control circuit is operated when a minute vibration of a tire is detected, thereby minimizing power consumption. Japanese Unexamined Patent Publication No. 2001-174357 proposes to improve the detachability of a tire and reduce the amount of balance correction by realizing a small and lightweight structure.
[0003]
[Problems to be solved by the invention]
Such a tire monitor sensor has been proposed to meet demands for power saving and miniaturization, but the following problems remain. In order to save power consumption and extend battery life by detecting travel with a vibration sensor, two sensors, a pressure sensor and a vibration sensor, were required. Because of the large number, it was difficult to ensure the reliability in the environment in which the automobile was used, and this was also a factor of cost increase.
[0004]
On the other hand, a sensor that integrates a pressure and temperature sensor on one substrate by semiconductor integration technology has already been realized. However, when applied to a tire monitor sensor, a separate sensor for detecting vibration is required. The same issues remain as above.
[0005]
Also, in order to protect the sensor and the signal processing LSI from moisture and dirt, a silicone gel is usually applied to the surface. However, the silicone gel is attached to the inside of the tire and is subject to vibration for a long period of time. The mounting structure remains in addition to the above problems.
[0006]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention has been made in view of this point, and has achieved a tire monitor sensor by integrating a vibration sensor and a pressure sensor to reduce the size and the number of assembling steps, and to improve the reliability by using a silicone gel-free resin package. The present invention proposes a sensor structure assembly suitable for mounting as a sensor.
[0007]
The features of the present invention include a circuit board made of semiconductor single crystal silicon on which a vibration sensor, a pressure sensor and its signal processing circuit are formed as shown in FIG. 1, and a lid made of single crystal silicon on which a diaphragm having an enclosure around the periphery is formed. A substrate wafer is air-tightly bonded, and individual chips are diced and then resin-molded and packaged. This realizes miniaturization and mass production.
[0008]
Also, as shown in FIGS. 1 and 2, since a resin is not flowed into the diaphragm since a peripheral portion of the diaphragm on the lid substrate is formed, the sensor assembly is placed on a lead frame and wire-bonded. Except for the inside of the enclosure provided around the end portion of the lead frame and the periphery of the diaphragm, that is, except for the diaphragm, molding can be performed with resin. Alternatively, as shown in FIG. 3, molding is performed except for the upper surface on which the diaphragm is formed. For this reason, a compact imposition package can be realized, protection by gel is not required, problems such as gel flow can be avoided, and highly reliable mounting is possible.
[0009]
The sensor of the present invention includes a vibration, pressure, and temperature sensor and a signal adjustment circuit, a power supply circuit, and a high-pass filter (differential sensor) provided on the output side of the sensor as shown in the block configuration of FIG. Circuit) and a signal processing circuit including a low-pass filter, a communication circuit, and a control circuit, and a lid substrate is hermetically bonded, and a diaphragm is formed on a part of the lid substrate to bend under pressure and formed on the semiconductor substrate. A capacitance is formed by a small gap of about 1 μm formed between the fixed electrode and the fixed electrode, and both pressure and vibration can be detected with high sensitivity by displacement of a mass provided at the center.
[0010]
As shown in FIGS. 6 and 7, a lid substrate is air-tightly bonded to a semiconductor circuit substrate by a wafer process, and each chip is pelletized and then resin-molded. Since the pressure is received by the diaphragm formed in a part of the lid substrate and the displacement is converted and detected as a change in capacitance, the measured pressure does not directly contact the detection sensor and signal adjustment circuit formed on the semiconductor substrate Therefore, it can be used for a long time to measure gasoline vapor and gas containing moisture.
[0011]
The sensor of the present invention works as shown in FIG. 9 by the configuration of FIG. Using the signal emitted by the vibration sensor as a trigger, the wake-up mode is set, and the pressure and temperature inside the tire are transmitted and communicated in a short time cycle, and when there is no signal from the vibration sensor, the transmission is communicated in a long time cycle. As a result, the power consumption can be minimized and the battery life can be extended.
[0012]
The one-chip sensor of the present invention shown in FIG. 2 shows an embodiment in which pressure, temperature and vibration sensors are independently provided on a semiconductor substrate. A signal processing circuit consisting of a sensor signal adjustment circuit, a power supply circuit, a high-pass filter (differential circuit) and a low-pass filter, a communication circuit and a control circuit provided on the output side of the sensor is integrated, and the lid substrate is air-tightly joined. An ultra-thin seal diaphragm, which bends by receiving pressure, is formed on a part thereof, and the pressure is transmitted and detected by contacting the movable electrode of a capacitance type pressure sensor formed on the semiconductor substrate. As described above, since the measurement pressure does not directly contact the sensor and the signal adjustment circuit formed on the semiconductor substrate, the sensor and the signal adjustment circuit can be used for a long time even in the measurement of gasoline vapor or gas containing moisture.
[0013]
The tire monitor sensor shown in FIG. 12 uses the sensor shown in FIG. 1 so that the plane direction of the diaphragm is attached parallel to the longitudinal direction of the rotation axis of the wheel, so that when the sensor is at the uppermost position and the lowermost position, the mass part of the diaphragm is Detects vertical vibration of tires with high sensitivity. The pressure sensor detects vibration and pressure at the same time as shown in FIG. 11, but the change in the vibration is as shown in FIGS. 10 (1) to (4), the achieved vibration frequency of the tire and the suspension is 10 Hz to 100 Hz, and the fluctuation period of the pressure air pressure. Since there is a two-digit period difference as compared with several minutes to 1 hour, the two can be discriminated and detected using a filter by the circuit configuration shown in FIG. Therefore, it is possible to detect both the rotational vibration and the physical quantity of the pressure with one pressure sensor. In addition, the output of the pressure sensor at the time of stop is stored in the memory of the MPU as a reference value, and by comparing it with the output at the time of traveling, the effect of centrifugal acceleration generated during tire rotation can be subtracted, so that only the pressure is accurately detected. can do.
[0014]
Further, the tire monitor sensor shown in FIG. 13 uses the one-chip sensor shown in FIG. 2 to attach the sensing direction of the vibration sensor at right angles to the longitudinal direction of the rotation axis of the wheel, so that the tire vibration can be detected with high sensitivity. In addition, since the sensing direction of the pressure sensor is parallel to the rotation axis, no rotation vibration is detected, and only the pressure can be accurately detected.
[0015]
Further, since a resistor is formed on the semiconductor substrate by the same process as the signal processing circuit for temperature detection, it is possible to detect a temperature by converting a change in resistance into a voltage.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a longitudinal section of a first embodiment of the present invention. A surface mount resin packaged product having a structure in which a diaphragm 21 is formed on a lid substrate 2 and serves as a pressure and vibration sensor is shown. The diaphragm 21 formed on the lid substrate 2 made of semiconductor single crystal silicon constitutes a movable electrode for a vibration sensor and a pressure sensor, and the fixed electrode 12 provided on the semiconductor circuit substrate 1 made of semiconductor single crystal silicon has a capacitance. To form
[0017]
The diaphragm 21 is formed by processing a part of the lid substrate 2 made of silicon single crystal as thin as about 10 μm. The diaphragm 21 responds to the pressure to change the minute gap 25 formed between the diaphragm 21 and the fixed electrode 12 formed on the upper surface of the semiconductor circuit board 1, and converts this into a change in capacitance. Process and output the signal. Design dimensions suitable for measuring several atmospheres are that the diameter of the diaphragm 21 is, for example, 0.5 mm to 2 mm, the thickness is 5 μm to 10 μm, and the gap is 0.2 μm to 1 μm.
[0018]
Vibration is detected by a mass body 22 provided at the center of the diaphragm 21. The natural frequency determined by the dimensions of the diaphragm 21 and the weight of the mass body 22 is desirably designed to be close to the natural vibration of the tire shown in FIG. 10, and the vibration is detected efficiently.
[0019]
As shown in FIGS. 6 and 7, the manufacturing process is such that the semiconductor circuit substrate 1 and the lid substrate 2 are air-tightly bonded in a wafer state, diced into individual chips, and the sensor assembly is bonded on a lead frame, and wire bonding is performed. After that, it is packaged by resin molding. An enclosure is provided around the thin portion of the diaphragm 21 so that the resin does not flow into the thin portion during the resin molding, and the entire portion is molded except for this portion and the terminal portion 41 of the lead frame 4. For this reason, a compact imposition package can be realized, protection by gel is not required, problems such as gel flow can be avoided, and highly reliable mounting is possible. In addition, miniaturization and mass production are realized.
[0020]
FIG. 2 shows a longitudinal section of a second embodiment of the present invention, and is a structural diagram of a one-chip sensor in which a pressure, vibration and temperature sensor and a signal processing circuit are formed on a circuit board. A vibration sensor, a pressure sensor, and a temperature sensor (not shown) are all formed on the semiconductor circuit board 1 side. In this example, the diaphragm 21 formed on the lid substrate 2 presses a projection on the movable electrode 15 of the pressure sensor, and changes the capacitance formed between the fixed electrode 12 formed on the semiconductor circuit substrate 1 and the pressure. Is detected. The vibration sensor is constituted by a capacitance formed by a beam-shaped movable electrode 15 and a fixed electrode 14 formed separately. The vibration sensing direction of this sensor is orthogonal to the pressure sensor, and is considered so as to be convenient for mounting a tire pressure sensor described later.
[0021]
The movable electrode 13 of the pressure sensor is made of conductive polysilicon, and a minute gap is formed between the movable electrode 13 and the fixed electrode 12 formed on the semiconductor circuit substrate 1. The fixed electrode 12 is formed on the semiconductor circuit substrate 1 via a dielectric film such as SiO _2, is insulated from the semiconductor circuit substrate 1, and is fixed by a gap formed between the fixed electrode 12 and the movable electrode 13. Form capacitance. The diaphragm 21 formed on the cover substrate 2 presses the protrusion on the movable electrode 15 to change the capacitance, and the change in pressure is detected. Design dimensions suitable for measuring a few atmospheres are that the diameter of the movable electrode 13 is, for example, 100 μm to 500 μm, the thickness is 0.5 μm to 2 μm, and the gap is 0.2 μm to 0.5 μm.
[0022]
The vibration sensor formed separately includes a beam-shaped movable electrode 15 extending in a direction perpendicular to the paper surface and a plurality of gaps of about 1 μm formed between the fixed electrode 14 and one end fixed on the semiconductor circuit board 1. Configure capacity. The beam-shaped movable electrode 15 changes its capacitance in response to a change in the vibration of the semiconductor circuit substrate 1 in the plane direction, and detects the vibration.
[0023]
The feature of the present invention is that a vibration and pressure sensor can be formed independently on the semiconductor circuit board 1 so that minute vibration can be detected. Particularly when applied to a tire pressure sensor, as shown in FIG. Since the sensing direction of the pressure sensor is orthogonal to the sensing direction of the vibration sensor, pressure and vibration can be detected independently of each other. Sensors with good sensitivity and accuracy can be mounted because they can be designed to have optimal dimensions.
[0024]
The entire manufacturing process is implemented as shown in FIGS. 6 and 7 described in the description of FIG. 1 and has similar features and effects.
[0025]
Although the capacitance is not described in detail, an active capacitance that changes according to the ambient pressure as normally used, and a reference capacitance that does not substantially change with respect to the ambient pressure are formed. Detect the ratio. That is, in the signal processing circuit 11, a CV converter that integrates a change in capacitance adjusts to a signal determined as an output signal and outputs the signal as a voltage or a frequency.
[0026]
In designing the capacitance, dimensions are designed in terms of electrical, mechanical and manufacturing process factors as follows. The dimensions of the pressure sensor are designed in consideration of the capacitance change due to the applied pressure and the strength of the diaphragm film. When the ambient pressure is P, the upper limit of the thickness h of the diaphragm is set according to the diameter 2a of the diaphragm based on the displacement w (p) obtained by the following equation (1).
[0027]
w (p) = KP · a ⁴ / h ³
K = 3 (1−ν ² ) / (16E) (1)
Here, ν is the Poisson's ratio, and E is the Young's modulus. The lower limit of the thickness h of the diaphragm is set according to the diameter 2a of the diaphragm based on the following equation (2).
[0028]
h = αa (2)
If the measurement is several atmospheres, α = 0.1 to 0.5.
[0029]
Although not shown, the temperature sensor itself is already implemented by a known method, but is formed on a semiconductor substrate and uses the resistance of conductive polysilicon formed by the same process as that of the movable electrode 13. Detect.
[0030]
Processes an output voltage of a Wheatstone bridge circuit composed of a resistance of conductive polysilicon formed on the semiconductor circuit substrate 1 and a diffusion resistance formed in a signal processing circuit 11 having a different temperature coefficient from the resistance of the conductive polysilicon. Then, the signal is adjusted to a predetermined signal level and output.
[0031]
FIG. 3 shows a longitudinal section of a third embodiment of the present invention, and shows an example of a mounting structure when a ceramic substrate is used as a material of the wiring substrate 41, for example. In this example, an example is shown in which the sensor chip described in FIG. 2 is connected to a wiring board by CCB when a surface mount package is mounted. Therefore, the through electrode 5 is formed on the circuit board 1 side.
[0032]
The solder ball 41 set at the position of the through diffusion to the lower surface formed on a part of the semiconductor circuit board 1 is connected to the electrode film on the wiring board 41. The feature of the present embodiment is that it can be mounted on the wiring board 41 in a state of another LSI chip such as an MPU, an electronic component, and a bare chip while maintaining the functions and features of the sensor described above with reference to FIG. Can be applied to various systems such as monitors in the FA and PA fields as well as power train control of automobiles.
[0033]
FIG. 4 shows a longitudinal section of a fourth embodiment of the present invention, showing a minimum required form as a form of a resin package, and excluding a top surface on which a diaphragm is formed, a bonding interface between a semiconductor circuit substrate 1 and a lid substrate 2. 2 shows a packaged product in which the insulating film of FIG. The feature of this embodiment is that the amount of the resin for the package can be saved.
[0034]
FIG. 5 shows a longitudinal section of a fifth embodiment of the present invention, in which a diaphragm 21 is formed on a semiconductor circuit board 1 and a diffusion resistance formed during a manufacturing process of the semiconductor circuit board 1 is used as a piezo resistance. A surface mount resin package mounted product having a mass part at the center of the diaphragm 21 and also serving as a pressure and vibration sensor and connected by CCB is shown. The feature of the present embodiment is that the manufacturing process is easy because there is no need to form a minute space as compared with the above-mentioned capacitance type sensor.
[0035]
6 and 7, a description will be given of a manufacturing process in which a circuit board and a lid board are joined in a wafer state, and then a groove around the chip is diced and pelletized.
[0036]
The outline is that the semiconductor circuit substrate 1 and the lid substrate 2 are air-tightly bonded in a wafer state, diced into individual chips, and the sensor assembly is bonded on a lead frame, wire-bonded, and then resin-molded and packaged. It is.
[0037]
Various techniques for air-tightly bonding wafers have been studied, and the simplest method is a structure in which the lid substrate 2 is made of glass. An electrostatic bonding technique utilizing the movement of Na ions in glass is used. In order to apply this method to the embodiments shown in FIGS. 1 to 4, high precision is required for fine processing of a glass plate. On the other hand, if a silicon substrate is used as the lid substrate 2, microscopic high-precision processing by etching can be easily performed, so that an ultrathin diaphragm microcavity can be formed. However, it is necessary to use a silicon-silicon wafer bonding technique. When directly joining each other, the operation is performed at a high temperature of 600C to 1000C. By sandwiching an Au or AL film, it is possible to use a junction having a low working temperature. Taking these restrictions into account, an optimal bonding technique is adopted, and the circuit board and the lid substrate are joined together in a wafer state to perform hermetic bonding, and the groove around the chip as shown in the enlarged view is diced and pelletized. After that, it is bonded to the lead frame 4 shown in FIGS. 1 and 2 or the ceramic substrate 410 shown in FIGS. 3, 4 and 5, and after wiring, it is resin-molded. An enclosure 100 is provided around the thin portion of the diaphragm 21 so that the resin does not flow into the thin portion during the resin molding, and the entire portion is molded except for this portion and the terminal portion 41 of the lead frame 4. By adopting this process, a small imposition package can be realized, the protection by gel is not required, problems such as gel flow can be avoided, and highly reliable mounting is possible. In addition, it has the feature of realizing miniaturization and mass production.
[0038]
FIG. 8 is a block diagram showing a configuration when the present invention is applied to a tire pressure sensor.
[0039]
The constituent elements of the block diagram include a pressure sensor 13, a vibration sensor 14, and a temperature sensor 123. On the output side of the sensor, a capacitance / voltage converter 110 and a resistance / voltage converter 113 for adjusting the level of the sensor signal are provided. , And a high-pass filter (differential circuit) 111 and a low-pass filter 112 are formed. A multiplexer MPX115 for switching these signals, an AD converter A / D116 for converting to digital values, a microprocessor unit MPU117 for performing arithmetic processing such as characteristic correction, a communication I / O circuit 118 and an oscillator OSC119 at the output of the sensor. , And a power supply circuit 120.
[0040]
FIG. 9 is an explanatory view of the main points of the detection algorithm of the tire pressure sensor according to the present invention. The following operation will be described with reference to FIG.
[0041]
The diaphragm sensors 13 and 14 can detect pressure and vibration, and the signal processing circuits 110 to 120 use a signal generated in response to vibration applied from outside by the vibration sensor as a trigger signal through a high-pass filter (differential circuit) 111. Is sent to the microprocessor unit MPU 117 to set the wake-up mode. By the microprocessor unit MPU 117, the diaphragm sensors 13 and 14 and the temperature sensor 123 measure the pressure and temperature signals, and apply the values subjected to the characteristic correction processing to the first through the low-pass filter 111, the resistance / voltage conversion circuit 113, and the multiplexer MPX115. It is transmitted once every 30 seconds. Further, when there is no signal from the vibration sensor, the microprocessor unit MPU 117 performs communication by controlling to transmit in a sleep mode once every second time period. The feature of the present embodiment is that the vibration sensor is provided on the same chip so that pressure, vibration and temperature can be detected, so that the vibration sensor detects vibration applied from the outside and accurately communicates during running / stopping. Since the power can be controlled and power consumption other than when the vehicle is running can be saved, the life of the battery, which is essential when the battery is mounted inside the tire, can be extended.
[0042]
FIG. 10 is a spectrum diagram of the vibration received by the tire when the vehicle is running. FIG. 11 schematically shows a waveform of a vibration sensor attached to a part of a tire. If a vibration peak existing at 50 to 100 Hz is detected, it is possible to determine running / stop.
[0043]
A mass part is provided at the center of the pressure sensor, and the sensitivity frequency for vibration is designed to be 50 to 100 Hz to further enhance the vibration detection sensitivity.
[0044]
FIG. 12 shows an embodiment in which the sensor shown in FIG. 1 is mounted on a tire of a tire pressure sensor.
[0045]
Since the plane direction of the diaphragm of the sensor of FIG. 1 is attached parallel to the longitudinal direction of the rotation axis (axle) of the wheel, the mass part of the diaphragm detects the vertical vibration of the tire with high sensitivity when the sensor is at the uppermost position and the lowermost position. . The pressure sensor simultaneously detects vibration, rotational centrifugal force, gravity, and pressure as shown in the waveform of FIG. 11, but changes in vibration are several tens Hz to 100 Hz as shown in FIG. Since there is a two-digit period difference as compared with the number of periods min to 1 hr, the two can be discriminated and detected using a filter by the configuration shown in FIG. In addition, the output of the pressure sensor at the time of stopping is stored in the memory of the MPU as a reference value, and only the pressure is accurately detected by subtracting the effect of the centrifugal acceleration generated when the tire rotates by comparing the output with the output during traveling. Can be.
[0046]
FIG. 13 shows another embodiment in which the tire pressure sensor shown in FIG. 2 is mounted on a tire. Rotation, vibration and pressure are separately detected using the one-chip sensor shown in FIG. The vibration sensor can detect the vibration of the tire with high sensitivity because the sensing direction of the vibration sensor is perpendicular to the longitudinal direction of the rotation axis (axle) of the wheel, and the sensitivity direction of the pressure sensor is parallel to the rotation axis. Only pressure can be accurately detected without detecting centrifugal force and vibration.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention, showing a surface mount resin package mounted product having a structure in which a diaphragm 21 is formed on a lid substrate 2 and serves as a pressure and vibration sensor.
FIG. 2 shows a longitudinal section of a second embodiment of the present invention, in which a vibration sensor (14, 15) and a part of a signal processing circuit 11 have temperature on a circuit board separately from pressure sensors (13, 14, 21). FIG. 2 is a structural diagram of a one-chip sensor on which a sensor is formed.
FIG. 3 is a vertical cross-sectional view of a third embodiment of the present invention, showing a mounting structure in which a CCB 41 is connected to a wiring board 410 when a surface mount package is mounted.
FIG. 4 is a longitudinal sectional view of a fourth embodiment of the present invention. The form of a resin package is a packaged product in which an insulating film 12 at a bonding interface between a circuit board 1 and a cover substrate 2 is surrounded over the entire side surface. Show.
FIG. 5 is a longitudinal sectional view of a fifth embodiment of the present invention, in which a diaphragm 21 is partially formed on the circuit board 1 side and serves as a pressure and vibration sensor, and is connected to a wiring board 410 by a CCB 41; This shows a resin package mounted product of the mount.
FIG. 6 is an explanatory view of a process of bonding a circuit board 1 and a cover board 2 in a wafer state and then dicing and pelletizing a groove around a chip.
FIG. 7 is a process flow diagram of the sensor assembly of the present invention.
FIG. 8 is a configuration block diagram when the present invention is applied to a tire pressure sensor.
FIG. 9 is an explanatory view of a main point of a detection algorithm of the tire pressure sensor according to the present invention.
FIG. 10 is a spectrum diagram of vibration received by a tire when the vehicle is running.
FIG. 11 is a diagram illustrating a waveform of a vibration sensor attached to a part of a tire.
FIG. 12 is a view showing an embodiment of the present invention in which a tire pressure sensor is mounted on a tire.
FIG. 13 is a view showing another embodiment in which the present invention is mounted on a tire of a tire pressure sensor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Semiconductor circuit board, 2 ... Lid board, 3 ... Adhesive, 4 ... Lead frame, 5 ... Bonding wire, 6 ... Resin mold, 11 ... Signal processing circuit, 12 ... Oxide film,
13: movable electrode of pressure sensor, 14, 16: fixed electrode, 15: movable electrode, 21: diaphragm, 22: mass body, 25: void, 100: enclosure, 410: wiring board.

Claims

A sensor fixed electrode formed on a semiconductor circuit board, a signal processing circuit connected to the electrode, a lid substrate that covers these and is hermetically bonded, and a diaphragm formed on a part of the lid substrate, which is configured to generate pressure or vibration. A sensor chip which detects and warps this as a change in capacitance, a lead frame for mounting and joining the chip, a wire bonding between the lead frame and a terminal of the circuit board, and an end portion of the lead frame and a lid diaphragm forming portion A sensor assembly characterized by being molded with resin except for (1).

2. The sensor assembly according to claim 1, wherein an enclosure is provided around a diaphragm formed on a part of said lid substrate, and molded with resin except for an end of said lead frame and an inside of said enclosure. body.

Two sensors consisting of fixed and movable electrodes formed on a semiconductor circuit board and detecting pressure and vibration as changes in capacitance, a signal processing circuit for the sensor signals, and a lid substrate that covers these and is air-tightly bonded A diaphragm formed on a part of the lid substrate, wherein the diaphragm bends by receiving an external pressure and transmits its displacement to the movable electrode for pressure detection.

4. The sensor chip according to claim 1, wherein a through electrode is formed on the circuit board side, connected to an electrode film on a wiring board via the through electrode by CCB, and an end of the electrode film and A sensor assembly characterized by being molded with resin except for the inside of an enclosure provided on an upper surface of a lid substrate or a periphery of a diaphragm.

A diaphragm formed on a semiconductor circuit board and receiving a pressure or vibration, a flexure diaphragm, a piezoresistor element and a signal processing circuit for detecting the flexure as a resistance change, a sensor chip comprising a lid substrate that covers these and is airtightly joined, and the lid A penetrating electrode is formed on the substrate side, connected to the electrode film on the wiring board by CCB via the penetrating electrode, and the end of the electrode film and the inside of the enclosure provided on the upper surface of the lid substrate or the periphery of the diaphragm are formed. A sensor assembly characterized by being molded with a resin except for the above.

6. The sensor assembly according to any one of Items 1, 2, 4, and 5, wherein the circuit board and the cover board are bonded in a wafer state, then pelletized, bonded to a lead frame and wire-bonded, or bonded to a wiring board by CCB. A sensor assembly characterized by being molded with resin except for the wiring portion and the diaphragm portion.

It comprises a pressure, vibration and temperature sensor formed on a semiconductor circuit board, a level adjustment circuit for the sensor signal, a power supply circuit, a high-pass filter (differential circuit) and a low-pass filter provided on the output side of the sensor, a communication circuit and a control circuit. A signal processing circuit, a lid substrate that covers them is hermetically bonded, a diaphragm that bends under pressure is formed on a part of the lid substrate, and a mass portion is provided in the center to enable detection of pressure and vibration, and the semiconductor A signal processing circuit formed on the substrate uses a signal generated in response to vibration applied from outside by the vibration sensor as a trigger, sets a wake-up mode, measures pressure and temperature signals, and passes a first signal through the low-pass filter. The transmission is controlled in such a manner that the signal is transmitted at a time period of no. Monitor sensor.

It comprises a pressure, vibration and temperature sensor formed on a semiconductor circuit board, a level adjustment circuit for the sensor signal, a power supply circuit, a high-pass filter (differential circuit) and a low-pass filter provided on the output side of the sensor, a communication circuit and a control circuit. A signal processing circuit, a lid substrate that covers them is hermetically bonded, a diaphragm is formed on a part of the circuit substrate to bend under pressure, and pressure is transmitted to a pressure sensor formed on the semiconductor substrate; The signal processing circuit formed above sets a wake-up mode by using a signal generated in response to vibration applied from the outside by a vibration sensor on the same semiconductor substrate, sets a wake-up mode, measures pressure and temperature signals, The signal is controlled to be transmitted in a first time cycle through a filter, and is controlled to be transmitted in a second time cycle when there is no signal from the vibration sensor. 1 chip tire monitor sensor, characterized by.

6. The tire monitor sensor according to claim 1, wherein a mass portion is provided at a center portion of the pressure sensor, and a sensitivity frequency for vibration is designed to be 50 to 100 Hz, and the vibration sensor is also used.

9. The tire monitor sensor according to claim 8, wherein the sensitivity direction (diaphragm surface) to the vibration of the pressure sensor coincides with the direction parallel to the length direction of the rotation axis of the wheel, and is attached to a part of the wheel. Tire monitor sensor.

10. The tire monitor sensor according to claim 9, wherein the sensitivity directions of the vibration sensor and the pressure sensor are perpendicular to each other, and the sensitivity direction of the vibration sensor coincides with a direction perpendicular to the length direction of the rotation axis of the wheel. A tire monitor sensor mounted on a tire.