JP4427876B2

JP4427876B2 - Semiconductor angular velocity sensor

Info

Publication number: JP4427876B2
Application number: JP2000220922A
Authority: JP
Inventors: 岳志伊藤; 宗男頼永; 祐史樋口
Original assignee: Denso Corp; Nippon Soken Inc
Current assignee: Denso Corp; Soken Inc
Priority date: 1999-07-22
Filing date: 2000-07-21
Publication date: 2010-03-10
Anticipated expiration: 2020-07-21
Also published as: JP2001091265A

Description

【０００１】
【発明の属する技術分野】
本発明は、車両、飛行機、ロボット等の運動体の運動状態を測定するのに用いられる、加速度センサや角速度センサ等の半導体よりなる振動子を用いた半導体力学量センサに関する。
【０００２】
【従来の技術】
一般に、この種の半導体力学量センサは、シリコン基板等の半導体基板をエッチング等のマイクロマシン加工技術を用いて加工することにより形成され、基部と、所定方向に振動する振動子と、該振動子及び該基部を連結する複数個の梁部とを備え、該振動子の振動に基づいて力学量（角速度、加速度等）を検出するようにしている。
【０００３】
例えば、角速度センサにあっては、振動子を所定方向に駆動振動させ、角速度が印加されたとき、コリオリ力によって駆動振動の方向及び角速度の回転軸に直交する方向へ発生する振動（検出振動）に基づいて、当該角速度を検出する。また、加速度センサにあっては、振動子に加速度が印加されたときに発生する所定方向への振動（検出振動）に基づいて、当該加速度を検出する。
【０００４】
【発明が解決しようとする課題】
しかしながら、従来の半導体力学量センサにおいては、センサの加工誤差（例えばエッチングの際の加工誤差）が生じることは避けがたい。この加工誤差により、振動子には、上記の駆動振動や検出振動といった正規の振動に対して、当該正規の振動以外の不要振動が発生するため、これが測定誤差の原因となっている。
【０００５】
本発明者等は、この不要振動は、振動子と基部とを連結する複数個の梁部に原因があるのではないかと考えた。つまり、従来の半導体力学量センサにおいては、例えば特開平６−１２３６３１号公報に記載されているように、複数個の梁部の各々が１本の棒状梁よりなる構成であるため、回転剛性が弱く、振動子の振動中に各梁にねじれ等が発生しやすく、そのねじれ等が不要振動を引き起こすと考えられる。
【０００６】
本発明は上記事情に鑑み、半導体力学量センサにおいて、振動子の振動を阻害することなく回転剛性を高めた梁部の構成を実現することを目的とする。
【０００７】
【課題を解決するための手段】
上記目的を達成するため、請求項１記載の発明では、半導体基板を加工することにより形成され、基部（１０）と、所定方向に振動する振動子（２０、３０）と、この振動子及び該基部を連結する複数個の梁部（２１、３１）とを備える半導体角速度センサにおいて、該複数個の梁部のそれぞれを、平行に離間して配置された一対の梁（２２、２３、３２、３３）と、これら一対の梁を連結する連結部（２４、３４）とから構成し、
上記一対の梁を、コの字形状をなす第１の梁（２２、３２）と、この第１の梁の外周側にて該第１の梁に対して相似形に配置されたコの字形状をなす第２の梁（２３、３３）とから構成するとともに、これらコの字形状をなす第１及び第２の梁における互いに平行な一対の平行棒部（２２ａ、２３ａ、３２ａ、３３ａ）を該振動子の振動方向にたわむようにし、該平行棒部の一端を接続する接続棒部（２２ｂ、２３ｂ、３２ｂ、３３ｂ）同士を連結部（２４、３４）にて連結させたことを特徴としている。
【０００８】
回転剛性を高めるだけならば、梁部を単に太いものとすればよいが、それだけでは、センサとして必要な変位をとることが困難となり振動子の振動を阻害してしまう。本発明によれば、梁部の構成を、平行に離間配置して連結された一対の梁構成としているから、振動子の振動を阻害することなく回転剛性を高めた梁部の構成を実現することができる。
【００１０】
また、本発明によれば、相似形状に平行配置されたコの字形状をなす第１及び第２の梁において、振動子の振動方向に撓む部分である平行棒部で連結せず、振動子の振動に関与しない接続棒部同士にて連結しているから、より効果的に振動子の振動を阻害しない梁部の構成を実現できる。
請求項２記載の発明では、連結部（２４、３４）は、振動子（２０、３０）が振動する前記所定方向と直交する方向に延びた形状であることを特徴としている。
【００１１】
また、請求項３記載の発明によれば、第１の梁（２２、３２）と第２の梁（２３、３３）との間隔において、接続棒部（２２ｂ、２３ｂ、３２ｂ、３３ｂ）同士の間隔を平行棒部（２２ａ、２３ａ、３２ａ、３３ａ）同士の間隔よりも大きくしている。第１の梁の平行棒部と第２の梁の平行棒部とは長さが異なるため変位に差が生じるが、本発明によれば連結部を充分に長くできるから、そのような変位の相違を吸収しやすくでき、より効果的に振動を阻害しないようにできる。
【００１２】
また、請求項４記載の発明によれば、連結部（２４、３４）を、一対の梁部（２２、２３、３２、３３）と略同一の幅を有する梁形状としたことを特徴としている。連結部が太すぎると連結部による一対の梁部の固定が強すぎて、振動を阻害する恐れがあり、また、センサの加工上、連結部が細すぎると加工しにくくなるため、連結部を、一対の梁部と略同一の幅とすることが好ましい。
【００１３】
また、請求項５記載の発明によれば、接続棒部（２２ｂ、２３ｂ、３２ｂ、３３ｂ）同士の間隔（Ｗ１）と平行棒部（２２ａ、２３ａ、３２ａ、３３ａ）同士の間隔（Ｗ２）との比（Ｗ１／Ｗ２）が５以上であることを特徴としている。これは、接続棒部同士の間隔即ち連結部（２４、３４）の長さについて、検討した結果、得られたもので、上記比（Ｗ１／Ｗ２）が５以上であれば、不要振動の低減効果を最大限に発揮させることができる。
【００１４】
また、請求項６記載の発明では、半導体基板を加工することにより形成され、基部（１０）と、所定方向に振動する振動子（２０、３０）と、この振動子及び基部を連結する複数個の梁部（２１、３１）とを備え、該振動子の振動に基づいて角速度を検出するようにした振動型の半導体角速度センサにおいて、該複数個の梁部が、互いに平行に配置された第１、第２の梁（２２、２３、３２、３３）から構成され、この第１、第２の梁は折り返し部（２２ｂ、２３ｂ、３２ｂ、３３ｂ）を備え、この折り返し部において、第１、第２の梁を連結する連結棒（２４、３４）を有し、この連結棒により第１の梁と第２の梁との間に２つのＬ字状の空間が形成され、また、Ｌ字状の空間が該連結棒に対して対称的に配置されるものであり、
第１、第２の梁（２２、２３、３２、３３）は、折り返し部を除く部分（２２ａ、２３ａ、３２ａ、３３ａ）が前記所定方向にたわむようになっていることを特徴としている。
【００１５】
本発明のような梁部の構成を採用することにより、振動子の振動を阻害することなく回転剛性を高めた梁部の構成を実現することができ、不要振動を大幅に低減することができる。
【００１６】
さらに、不要振動を低減するために、請求項６記載の半導体力学量センサについて、本発明者等が検討した結果によれば、請求項７記載の発明のように、折り返し部（２２ｂ、２３ｂ、３２ｂ、３３ｂ）において、第１、第２の梁（２２、２３、３２、３３）のそれぞれの梁幅をほぼ同じとすることが好ましい。
【００１７】
また、請求項８記載の発明のように、連結棒（２４、３４）を、第１の梁（２２、３２）から第２の梁（２３、３３）に渡ってほぼ同じ幅とすることが好ましい。更には、請求項９記載の発明のように、請求項７の発明と請求項８の発明とを組み合わせたものとすることが好ましい。
【００１８】
連結部や梁部の折り返し部に肉厚の部分が存在すると、連結部や折り返し部の質量が増加し、この影響が不要振動に影響すると考えられるが、その点、上記請求項７〜請求項９の発明によれば、そのような肉厚部を低減することができるため、不要振動が低減されると考えられる。
【００１９】
また、請求項１０記載の発明では、連結棒（２４、３４）は、前記所定方向と直交する方向に延びていることを特徴としている。
また、請求項１１に記載の発明では、半導体基板を加工することにより形成され、基部（１０）と、所定方向に振動する振動子（２０、３０）と、この振動子及び基部を連結する複数個の梁部（２１、３１）とを備え、振動子の振動に基づいて角速度を検出するようにした振動型の半導体角速度センサにおいて、
複数個の梁部は、それぞれが、平行に離間して配置された一対の梁（２２、２３、３２、３３）と、これら一対の梁を連結する連結部（２４、３４）とから構成されており、
一対の梁は、それぞれがコの字型に屈曲した屈曲部（２２ｂ、２３ｂ、３２ｂ、３３ｂ）を有する形状であって、屈曲部を除く部分（２２ａ、２３ａ、３２ａ、３３ａ）が前記所定方向にたわむようになっており、
連結部は、一対の梁における屈曲部同士を連結していることを特徴としている。
また、請求項１２に記載の発明では、連結部（２４、３４）は、前記所定方向と直交する方向に延びた形状であることを特徴としている。
なお、上記各手段の括弧内の符号は、後述する実施形態に記載の具体的手段との対応関係を示すものである。
【００２０】
【発明の実施の形態】
以下、本発明を図に示す実施形態について説明する。図１は、本発明の半導体力学量センサとしての角速度センサ１００の一実施形態を示す平面図であり、図２は、図１中のＡ−Ａ断面を含む一部断面斜視図である。角速度センサ１００は、シリコン基板等の半導体基板にエッチング加工を施すことにより溝を形成し、当該基板を矩形枠状の基部１０と、この基部１０における枠内に位置して可動する可動部とに区画している。
【００２１】
可動部は、図１に示す様に、略矩形状の駆動用振動子２０と、駆動用振動子２０を取り囲む矩形枠状の検出用振動子３０と、駆動用振動子２０及び検出用振動子３０を連結する複数個（図示例では４個）の駆動用梁部２１と、検出用振動子３０及びその外周の基部１０を連結する複数個（図示例では４個）の検出用梁部３１と、を備えている。
【００２２】
ここで、本実施形態では、駆動用振動子２０及び検出用振動子３０は本発明でいう振動子である。駆動用振動子２０は、駆動用梁部２１を介して検出用振動子３０と一体化されており、さらに言うならば、駆動用振動子２０は検出用振動子３０及び検出用梁部３１を介在させてはいるが、駆動用梁部２１を介して基部１０に連結されている。よって、駆動用梁部２１及び検出用梁部３１は共に、本発明でいう梁部に相当するものである。
【００２３】
各々の駆動用梁部２１は、コの字形状をなす第１の梁２２と、この第１の梁２２の外周側にて第１の梁２２に対して相似形に配置されたコの字形状をなす第２の梁２３とよりなる一対の梁を備えている。そして、これら一対の梁２２、２３は、平行に離間して配置されており、一対の梁２２、２３の一端側が駆動用振動子２０に接続され、他端側が検出用振動子３０における枠内周面に接続されている。
【００２４】
また、駆動用梁部２１の第１の梁２２及び第２の梁２３においては、上記コの字形状における互いに平行な一対の平行棒部２２ａ及び２３ａが、その長手方向と直交する方向にたわむようになっているため、駆動用振動子２０は図１中の矢印Ｘ方向に振動可能となっている。そして、第１の梁２２及び第２の梁２３のうち平行棒部２２ａ、２３ａの一端を接続する接続棒部２２ｂ、２３ｂ同士が、梁形状の連結部２４により連結されている。
【００２５】
一方、各々の検出用梁部３１は、コの字形状をなす第１の梁３２と、この第１の梁３２の外周側にて第１の梁３２に対して相似形に配置されたコの字形状をなす第２の梁３３とよりなる一対の梁を備えている。そして、これら一対の梁３２、３３は、平行に離間して配置されており、一対の梁３２、３３の一端側が検出用振動子３０に接続され、他端側が基部１０における枠内周面から突出した突出部に接続されている。
【００２６】
また、検出用梁部３１の第１の梁３２及び第２の梁３３においては、上記コの字形状における互いに平行な一対の平行棒部３２ａ及び３３ａが、その長手方向と直交する方向にたわむようになっているため、検出用振動子３０は、上記基板平面内にて駆動用振動子２０の振動方向と略直交する方向（図１中の矢印Ｙ方向）に振動可能となっている。そして、第１の梁３２及び第２の梁３３のうち平行棒部３２ａ、３３ａの一端を接続する接続棒部３２ｂ、３３ｂ同士が、梁形状の連結部３４により連結されている。
【００２７】
また、図３は駆動用梁部２１及び検出用梁部３１の寸法説明図である。両梁部２１、３１のいずれにおいても、第１の梁２２、３２と第２の梁２３、３３との間隔において、接続棒部２２ｂ、２３ｂ、３２ｂ、３３ｂ同士の間隔Ｗ１は平行棒部２２ａ、２３ａ、３２ａ、３３ａ同士の間隔Ｗ２よりも大きくなっている。また、梁形状をなす連結部２４、３４の幅は上記一対の梁と略同一の幅を有することが好ましい。例えば、上記間隔Ｗ１は５０μｍ、上記間隔Ｗ２は１０μｍ、また、各梁２２、２３、３２、３３及び連結部２４、３４の幅Ｗ３は１０μｍとできる。
【００２８】
また、検出用振動子３０の外周部には、この外周部と対向する基部１０の内周部に向かって突出する櫛歯状の突起部３５が形成されており、この突起部３５とかみ合うように当該基部１０の内周部からも櫛歯状の突起部１１が形成されており、両方の突起部１１、３５により、本センサ１００の検出電極部が構成されている。
【００２９】
かかる構成を有する角速度センサ１００の作動について述べる。まず、図示しないが電磁駆動もしくは容量駆動等により、駆動用振動子２０を図１に示す矢印Ｘ方向に振動（駆動振動）させる。この駆動振動のもと、図１に示す様に、紙面垂直方向の軸周りに角速度Ωがセンサ１００に印加されると、駆動用振動子２０に駆動振動方向と直交する矢印Ｙ方向にコリオリ力が発生する。
【００３０】
このコリオリ力は駆動用梁部２１から検出用振動子３０に伝わり、検出用振動子３０と駆動用振動子２０とが図１に示す矢印Ｙ方向に一体に振動（検出振動）する。そして、この検出振動により、上記両突起部１１、３５間の距離が変化する。この距離変化を基部１０に形成された図示しない配線部等を介して、当該両突起部１１、３５間の容量変化として検出することにより、上記角速度Ωが検出されるのである。
【００３１】
ところで、本実施形態によれば、各梁部２１、３１の構成を、平行に離間配置して連結された一対の梁構成としているから、各振動子２０、３０の振動を阻害することなく回転剛性を高めた梁部の構成を実現することができる。ちなみに、回転剛性を高めるだけならば、梁部を単に太いものとすればよいが、それだけでは、センサとして必要な変位をとることが困難となり、振動子の振動を阻害してしまう。
【００３２】
また、本実施形態によれば、相似形状に平行配置されたコの字形状をなす第１及び第２の梁２２、２３、３２、３３において、各振動子２０、３０の振動方向に撓む部分である平行棒部２２ａ、２３ａ、３２ａ、３３ａで連結せず、振動子の振動に関与しない接続棒部２２ｂ、２３ｂ、３２ｂ、３３ｂ同士にて連結しているから、より効果的に振動子２０、３０の振動を阻害しない梁部の構成を実現できる。
【００３３】
本実施形態の梁部構成の具体的な作用を図４の作用説明図を用いて説明する。図４中の左右方向が振動子における狙いの振動方向である。従来のセンサにおいては、駆動用振動子２０と検出用振動子３０とを連結する梁部Ｊ１が１本のコの字形状のものであり、回転剛性が弱く、駆動用振動子２０は振動狙いの振動方向よりも、やや斜め（図中では斜め上方）方向に振動してしまい、これが不要振動となる。
【００３４】
一方、本実施形態の梁部構成では、回転剛性を高め、且つ、振動子の振動を阻害しないようにしているから、駆動用振動子２０は狙いの方向に振動する。よって、本実施形態によれば、不要振動を低減できるため、角速度が０の状態でも出力が発生するオフセットを抑制し、測定精度の高い角速度センサを提供することができる。
【００３５】
本実施形態の効果を、図５を用いて改めて説明する。図５（ａ）には、梁形状を４種類用意し、これらの梁による不要振動を角速度として算出したデータを示す。梁形状▲１▼はコンベンショナルな梁である。梁形状▲２▼は”ＡＰｒｅｃｉｓｉｏｎＹａｗＲａｔｅＳｅｎｓｏｒｉｎＳｉｌｉｃｏｎＭｉｃｒｏｍａｃｈｉｎｉｎｇ”（ＴＲＡＮＳＤＵＣＥＲＳ’９７ｐｐ．８４７−８５０，１９９７ＩＥＥＥ）に掲載されたＦｉｇ．８に類似した２重梁構造のものである。
【００３６】
梁形状▲３▼と▲４▼は、本実施形態のものであり、連結部の長さを変えたものである。梁形状▲４▼の方が梁形状▲３▼よりも長くなっている。図５（ａ）から、コンベンショナルな梁形状▲１▼に比べ、梁形状▲２▼、▲３▼、▲４▼の方が不要振動を大きく低減できることがわかる。
【００３７】
つまり、本実施形態では、各梁部２１、３１が、互いに平行に配置された第１の梁２２、３２、第２の梁２３、３３から構成され、この第１、第２の梁は折り返し部としての接続棒部２２ｂ、２３ｂ、３２ｂ、３３ｂを備え、この折り返し部において、第１、第２の梁を連結する連結棒としての連結部２４、３４を有し、この連結棒により第１の梁と第２の梁との間に２つのＬ字状の空間が形成され、また、Ｌ字状の空間が該連結棒に対して対称的に配置されているものとなっている。
【００３８】
そして、このような梁部２１、３１の構成を採用することにより、振動子２０、３０の振動を阻害することなく回転剛性を高めた梁部の構成を実現することができ、図５（ａ）に示す様に、不要振動を大幅に低減することができる。
【００３９】
また、図５（ｂ）は、さらに、梁形状▲２▼、▲３▼、▲４▼による効果の違いをより厳密に見たものであり、梁形状▲２▼に比べ、連結部を有する梁形状▲３▼、▲４▼の方が不要振動を抑制する効果が大きく、さらに梁形状▲３▼に比べ、連結部の長い梁形状▲４▼の方が効果が大きい。
【００４０】
さらに、本実施形態によれば、各梁部２１、３１における第１の梁２２、３２と第２の梁２３、３３との間隔において、接続棒部同士の間隔Ｗ１を平行棒部同士の間隔Ｗ２よりも大きくしているため、連結部２４、３４を充分に長くでき、結果的に、第１の梁の平行棒部と第２の梁の平行棒部とに生じる変位の相違を吸収しやすくでき、より効果的に振動を阻害しないようにできる。
【００４１】
連結部の長さについて、さらに厳密に検討した結果を図６に示す。この図６は、連結部２４、３４の長さＷ１と平行棒部２２ａ、２３ａ、３２ａ、３３ａ同士の間隔（梁間隔）Ｗ２との比Ｗ１／Ｗ２に対する不要振動出力を調べたものである。長さＷ１は、上記図３に示した接続棒部２２ｂ、２３ｂ、３２ｂ、３３ｂ同士の間隔Ｗ１に相当するものである。
【００４２】
Ｗ１とＷ２との比が１（Ｗ１／Ｗ２＝１）に対して、Ｗ１とＷ２との比が５以上になると、その効果が大きいといえる。そして、比Ｗ１／Ｗ２が５あたりで効果は飽和しており、比Ｗ１／Ｗ２が５以上あれば十分と言える。つまり、接続棒部２２ｂ、２３ｂ、３２ｂ、３３ｂ同士の間隔Ｗ１と平行棒部２２ａ、２３ａ、３２ａ、３３ａ同士の間隔Ｗ２との比Ｗ１／Ｗ２が、５以上であることが好ましく、それにより、不要振動の低減効果が最大限に発揮される。
【００４３】
また、連結部が太すぎると連結部による一対の梁部の固定が強すぎて、振動を阻害する恐れがあり、更に、センサの加工上、連結部が細すぎると加工しにくくなるため、連結部２４、３４の幅を、一対の梁部２２、２３、３２、３３と略同一の幅とすることが好ましい。
【００４４】
図７には、連結部の形状による効果の違いを示す。図７の梁形状▲５▼、▲６▼は両方とも本実施形態のものである。梁形状▲５▼は、外側の梁と内側の梁とが連結部にて接続される領域（つまり、接続棒部）においても、同様の梁幅となっている（さらに、連結部も梁と同様の梁幅となっている）が、梁形状▲６▼は、外側の梁が連結部にて接続される領域（接続棒部）において、内側の梁よりもその幅が大きくなっているものである。
【００４５】
この図７から、連結部（連結棒）２４、３４にて連結される領域（接続棒部、折り返し部）２２ｂ、２３ｂ、３２ｂ、３３ｂにおいて、外側の梁（第２の梁）２３、３３と内側の梁（第１の梁）２２、３２との梁幅は同等であることが好ましいと言える。
【００４６】
また、連結部（連結棒）２４、３４は、内側の梁（第１の梁）２２、３２に連結する部位から外側の梁（第２の梁）２３、３３に連結する部位に渡ってほぼ同じ幅であることが好ましいといえる。これは、連結部や梁部の折り返し部に肉厚の部分が存在すると、連結部や折り返し部の質量が増加し、この影響が不要振動に影響すると考えられるためである。
【００４７】
ここで、本実施形態の具体的な効果を図８に示す。図８は、本角速度センサ１００と従来の角速度センサとの梁部の加工誤差に対する不要振動振幅の度合を調べた一例である。本角速度センサ１００においては、梁部の各寸法Ｗ１〜Ｗ３を、上記の図３を参照して述べた具体的寸法とした。また、従来のものにおいては、図４に示したような１本の梁よりなる梁部Ｊ１を持つものとし、梁部Ｊ１の幅を１５μｍとした。図８からわかるように、本実施形態（破線）によれば加工誤差があっても従来（実線）に比べて不要振動を大幅に低減できている。
【００４８】
なお、上記実施形態では、駆動用梁部２１及び検出用梁部３１共に、平行に離間配置して連結された一対の梁構成としているが、当該構成を、これら各梁部２１、３１のうちどちらか一方のみに適用したものであっても良い。即ち、駆動用梁部２１のみを本発明でいう梁部としても良いし、検出用梁部３１のみを本発明でいう梁部としても良い。また、本発明は、角速度センサ以外にも、加速度センサ等の半導体力学量センサに適用可能である。
【図面の簡単な説明】
【図１】本発明に係る角速度センサの一実施形態を示す平面図である。
【図２】図１中のＡ−Ａ断面を含む一部断面斜視図である。
【図３】図１に示す角速度センサにおける梁部の寸法説明図である。
【図４】図１に示す角速度センサの作用説明図である。
【図５】梁形状の違いによる不要振動を角速度として算出したデータを示す図である。
【図６】連結部の長さＷ１と平行棒部同士の間隔Ｗ２との比Ｗ１／Ｗ２に対する不要振動出力を調べた結果を示す図である。
【図７】連結部の形状による不要振動出力への影響を調べた結果を示す図である。
【図８】本発明の角速度センサと従来の角速度センサとの梁部の加工誤差に対する不要振動振幅の度合示すグラフである。
【符号の説明】
１０…基部、２０…駆動用振動子、２１…駆動用梁部、
２２…駆動用梁部の第１の梁、２３…駆動用梁部の第２の梁、
２４…駆動用梁部の連結部、３０…検出用振動子、３１…検出用梁部、
３２…検出用梁部の第１の梁、３３…検出用梁部の第２の梁、
３４…検出用梁部の連結部、２２ａ、２３ａ、３２ａ、３３ａ…平行棒部、
２２ｂ、２３ｂ、３２ｂ、３３ｂ…接続棒部。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor dynamic quantity sensor using a vibrator made of a semiconductor such as an acceleration sensor or an angular velocity sensor, which is used to measure a motion state of a moving body such as a vehicle, an airplane, or a robot.
[0002]
[Prior art]
Generally, this type of semiconductor dynamic quantity sensor is formed by processing a semiconductor substrate such as a silicon substrate using a micromachine processing technique such as etching, and includes a base, a vibrator that vibrates in a predetermined direction, the vibrator, A plurality of beam portions connecting the base portions are provided, and mechanical quantities (angular velocity, acceleration, etc.) are detected based on vibrations of the vibrator.
[0003]
For example, in an angular velocity sensor, when a vibrator is driven to vibrate in a predetermined direction and an angular velocity is applied, vibration generated in the direction perpendicular to the direction of the driving vibration and the rotational axis of the angular velocity by Coriolis force (detected vibration) Based on the above, the angular velocity is detected. In the acceleration sensor, the acceleration is detected based on vibration (detection vibration) in a predetermined direction that occurs when acceleration is applied to the vibrator.
[0004]
[Problems to be solved by the invention]
However, in the conventional semiconductor dynamic quantity sensor, it is unavoidable that a sensor processing error (for example, a processing error during etching) occurs. Due to this processing error, an unnecessary vibration other than the normal vibration is generated in the vibrator with respect to the normal vibration such as the drive vibration and the detection vibration described above, and this causes a measurement error.
[0005]
The present inventors considered that this unnecessary vibration may be caused by a plurality of beam portions connecting the vibrator and the base. That is, in the conventional semiconductor dynamic quantity sensor, as described in, for example, Japanese Patent Laid-Open No. 6-123631, each of the plurality of beam portions is configured by a single bar-shaped beam. It is weak, and it is considered that twisting or the like is likely to occur in each beam during vibration of the vibrator, and that twisting or the like causes unnecessary vibration.
[0006]
SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to realize a configuration of a beam portion with increased rotational rigidity without hindering vibration of a vibrator in a semiconductor dynamic quantity sensor.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a base (10), a vibrator (20, 30) that vibrates in a predetermined direction, a vibrator, In a semiconductor angular velocity sensor comprising a plurality of beam portions (21, 31) connecting base portions, each of the plurality of beam portions is paired with a pair of beams (22, 23, 32,. 33) and connecting portions (24, 34) for connecting the pair of beams ,
The pair of beams includes a first beam (22, 32) having a U-shape and a U-shape arranged in a similar shape to the first beam on the outer peripheral side of the first beam. A pair of parallel bar portions (22a, 23a, 32a, 33a) parallel to each other in the first and second beams having the U-shape are configured with the second beams (23, 33) having a shape. The connecting rod portions (22b, 23b, 32b, 33b) that connect one end of the parallel rod portions are connected by connecting portions (24, 34) so as to bend in the vibration direction of the vibrator . .
[0008]
If the rotational rigidity is only increased, the beam portion may be simply thickened. However, it is difficult to obtain the necessary displacement as a sensor, and the vibration of the vibrator is hindered. According to the present invention, since the configuration of the beam portion is a pair of beam configurations that are spaced apart and connected in parallel, the configuration of the beam portion with improved rotational rigidity is achieved without hindering the vibration of the vibrator. be able to.
[0010]
Further , according to the present invention, the first and second beams having a U-shape arranged in parallel in a similar shape are not connected by the parallel bar portion that is a portion bent in the vibration direction of the vibrator, and the vibrator Since the connecting rod portions that are not involved in the vibration of the two are connected to each other, the configuration of the beam portion that does not hinder the vibration of the vibrator more effectively can be realized.
The invention according to claim 2 is characterized in that the connecting portions (24, 34) have a shape extending in a direction perpendicular to the predetermined direction in which the vibrator (20, 30) vibrates.
[0011]
According to the invention described in claim 3, the connection rod portions (22 b, 23 b, 32 b, 33 b) are spaced apart from each other in the distance between the first beam (22, 32) and the second beam (23, 33). The interval is made larger than the interval between the parallel bar portions (22a, 23a, 32a, 33a). Since the parallel bar portion of the first beam and the parallel bar portion of the second beam are different in length, there is a difference in displacement. According to the present invention, the connecting portion can be made sufficiently long. It can be easily absorbed and vibrations can be prevented more effectively.
[0012]
According to a fourth aspect of the present invention, the connecting portion (24, 34) has a beam shape having substantially the same width as the pair of beam portions (22, 23, 32, 33). . If the connecting part is too thick, the pair of beam parts by the connecting part is too strong and may interfere with vibration, and if the connecting part is too thin for processing the sensor, it is difficult to process. The width is preferably substantially the same as the pair of beam portions.
[0013]
According to the invention described in claim 5, the interval (W1) between the connecting rod portions (22b, 23b, 32b, 33b) and the interval (W2) between the parallel rod portions (22a, 23a, 32a, 33a). The ratio (W1 / W2) is 5 or more. This is obtained as a result of studying the distance between the connecting rod portions, that is, the length of the connecting portions (24, 34). If the ratio (W1 / W2) is 5 or more, unnecessary vibration is reduced. The effect can be maximized.
[0014]
According to a sixth aspect of the present invention, a base (10), a vibrator (20, 30) that vibrates in a predetermined direction, and a plurality of parts that connect the vibrator and the base are formed by processing a semiconductor substrate. and a beam portion (21, 31), in the vibration-type semiconductor angular velocity sensor which is adapted to detect the angular velocity based on a vibration of the vibrator, the several beam portions plurality is disposed parallel to one another 1 and second beams (22, 23, 32, 33), the first and second beams are provided with folded portions (22b, 23b, 32b, 33b), in which the first, There are connecting rods (24, 34) for connecting the second beam, and two L-shaped spaces are formed between the first beam and the second beam by the connecting rod. all SANYO where Jo space is symmetrically disposed with respect to said connecting rod,
First, second beam (22, 23, 32, 33), the portion excluding the folded portion (22a, 23a, 32a, 33a) is characterized that you have become flexed in the predetermined direction.
[0015]
By adopting the configuration of the beam portion as in the present invention, the configuration of the beam portion with improved rotational rigidity can be realized without impeding the vibration of the vibrator, and unnecessary vibration can be greatly reduced. .
[0016]
Furthermore, according to the result of the study by the present inventors on the semiconductor dynamic quantity sensor according to claim 6 to reduce unnecessary vibration, the folded portion (22b, 23b, 32b, 33b), the first and second beams (22, 23, 32, 33) preferably have substantially the same beam width.
[0017]
Further, as in the invention described in claim 8, the connecting rods (24, 34) have substantially the same width from the first beam (22, 32) to the second beam (23, 33). preferable. Furthermore, it is preferable to combine the invention of claim 7 and the invention of claim 8 as in the invention of claim 9.
[0018]
If there is a thick part in the connection part or the folded part of the beam part, the mass of the connection part or the folded part increases, and this influence is considered to affect unnecessary vibrations. According to the invention of No. 9, since such a thick part can be reduced, it is considered that unnecessary vibration is reduced.
[0019]
In the invention according to claim 10, the connecting rods (24, 34) are characterized by extending in a direction orthogonal to the predetermined direction.
Further, in the invention described in claim 11, formed by processing a semiconductor substrate, a base (10), vibrators (20, 30) that vibrate in a predetermined direction, and a plurality of parts that connect the vibrator and the base. In a vibration-type semiconductor angular velocity sensor comprising a plurality of beam portions (21, 31) and detecting an angular velocity based on vibration of a vibrator,
Each of the plurality of beam portions includes a pair of beams (22, 23, 32, and 33) that are spaced apart in parallel, and a connection portion (24 and 34) that connects the pair of beams. And
Each of the pair of beams has a shape having bent portions (22b, 23b, 32b, 33b) each bent in a U-shape, and the portions excluding the bent portions (22a, 23a, 32a, 33a) are in the predetermined direction. And bend to
The connecting portion is characterized in that the bent portions of the pair of beams are connected to each other.
Further, the invention according to claim 12 is characterized in that the connecting portion (24, 34) has a shape extending in a direction orthogonal to the predetermined direction.
In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments shown in the drawings will be described below. FIG. 1 is a plan view showing an embodiment of an angular velocity sensor 100 as a semiconductor dynamic quantity sensor of the present invention, and FIG. 2 is a partial cross-sectional perspective view including a cross section AA in FIG. The angular velocity sensor 100 forms a groove by etching a semiconductor substrate such as a silicon substrate, and forms the substrate into a rectangular frame-shaped base portion 10 and a movable portion that is movable within the frame of the base portion 10. It is partitioned.
[0021]
As shown in FIG. 1, the movable portion includes a substantially rectangular driving vibrator 20, a rectangular frame-like detecting vibrator 30 surrounding the driving vibrator 20, the driving vibrator 20, and the detecting vibrator. A plurality of (four in the illustrated example) driving beam portions 21 that connect 30, and a plurality of (four in the illustrated example) detection beam portions 31 that connect the detection vibrator 30 and the outer base 10 thereof. And.
[0022]
Here, in the present embodiment, the driving vibrator 20 and the detection vibrator 30 are the vibrators referred to in the present invention. The drive vibrator 20 is integrated with the detection vibrator 30 via the drive beam portion 21. More specifically, the drive vibrator 20 includes the detection vibrator 30 and the detection beam portion 31. Although it is interposed, it is connected to the base portion 10 via the driving beam portion 21. Therefore, both the driving beam portion 21 and the detection beam portion 31 correspond to the beam portion in the present invention.
[0023]
Each driving beam portion 21 includes a first beam 22 having a U-shape and a U-shape arranged in a similar shape to the first beam 22 on the outer peripheral side of the first beam 22. A pair of beams including a second beam 23 having a shape is provided. The pair of beams 22 and 23 are spaced apart from each other in parallel, and one end side of the pair of beams 22 and 23 is connected to the driving vibrator 20 and the other end side is within the frame of the detection vibrator 30. Connected to the circumference.
[0024]
Further, in the first beam 22 and the second beam 23 of the driving beam portion 21, the pair of parallel rod portions 22a and 23a in the U-shape are bent in a direction perpendicular to the longitudinal direction. Therefore, the driving vibrator 20 can vibrate in the direction of the arrow X in FIG. The connecting rod portions 22b and 23b that connect one end of the parallel rod portions 22a and 23a out of the first beam 22 and the second beam 23 are connected by a beam-shaped connecting portion 24.
[0025]
On the other hand, each of the detection beam portions 31 includes a first beam 32 having a U-shape and a coaxial beam disposed on the outer peripheral side of the first beam 32 with respect to the first beam 32. A pair of beams each including a second beam 33 having a shape of a letter is provided. The pair of beams 32 and 33 are spaced apart from each other in parallel, and one end side of the pair of beams 32 and 33 is connected to the detection vibrator 30, and the other end side is from the frame inner peripheral surface of the base 10. It is connected to the protruding part.
[0026]
In addition, in the first beam 32 and the second beam 33 of the detection beam portion 31, the pair of parallel rod portions 32a and 33a in the U-shape are bent in a direction perpendicular to the longitudinal direction. Therefore, the detection vibrator 30 can vibrate in a direction (in the direction of arrow Y in FIG. 1) substantially orthogonal to the vibration direction of the drive vibrator 20 within the substrate plane. The connecting rod portions 32 b and 33 b that connect one end of the parallel rod portions 32 a and 33 a among the first beam 32 and the second beam 33 are coupled by a beam-shaped coupling portion 34.
[0027]
FIG. 3 is an explanatory diagram of dimensions of the driving beam portion 21 and the detection beam portion 31. In both of the beam portions 21 and 31, the interval W1 between the connecting rod portions 22b, 23b, 32b, and 33b is the parallel rod portion 22a, between the first beams 22 and 32 and the second beams 23 and 33. It is larger than the interval W2 between 23a, 32a and 33a. Moreover, it is preferable that the width | variety of the connection parts 24 and 34 which make a beam shape has a width | variety substantially the same as a pair of said beam. For example, the interval W1 may be 50 μm, the interval W2 may be 10 μm, and the widths W3 of the beams 22, 23, 32, 33 and the connecting portions 24, 34 may be 10 μm.
[0028]
In addition, a comb-like protrusion 35 is formed on the outer periphery of the detection transducer 30 so as to protrude toward the inner periphery of the base 10 facing the outer periphery. Further, a comb-like projection 11 is formed also from the inner peripheral portion of the base 10, and both the projections 11 and 35 constitute a detection electrode portion of the sensor 100.
[0029]
The operation of the angular velocity sensor 100 having such a configuration will be described. First, although not shown, the drive vibrator 20 is vibrated (driven vibration) in the direction of the arrow X shown in FIG. 1 by electromagnetic drive or capacitive drive. Under this driving vibration, as shown in FIG. 1, when an angular velocity Ω is applied to the sensor 100 around the axis perpendicular to the paper surface, the Coriolis force is applied to the driving vibrator 20 in the direction of the arrow Y perpendicular to the driving vibration direction. Will occur.
[0030]
This Coriolis force is transmitted from the drive beam portion 21 to the detection vibrator 30, and the detection vibrator 30 and the drive vibrator 20 vibrate integrally (detection vibration) in the arrow Y direction shown in FIG. And the distance between both the said projection parts 11 and 35 changes with this detection vibration. The angular velocity Ω is detected by detecting the change in distance as a change in capacitance between the protrusions 11 and 35 via a wiring portion (not shown) formed on the base 10.
[0031]
By the way, according to this embodiment, since the structure of each beam part 21 and 31 is made into a pair of beam structure arranged in parallel and spaced apart, it rotates without inhibiting the vibration of each vibrator 20 and 30. The configuration of the beam portion with increased rigidity can be realized. Incidentally, if the rotational rigidity is only increased, the beam portion may be simply made thick. However, it is difficult to obtain the necessary displacement as a sensor, and the vibration of the vibrator is hindered.
[0032]
Further, according to the present embodiment, the first and second beams 22, 23, 32, 33 having a U-shape arranged in parallel with similar shapes bend in the vibration direction of the vibrators 20, 30. Since the connecting rod portions 22b, 23b, 32b, and 33b that are not connected by the parallel bar portions 22a, 23a, 32a, and 33a and that are not involved in the vibration of the vibrator are connected to each other, the vibrator 20 is more effectively used. , 30 can be realized without obstructing the vibration.
[0033]
The specific operation of the beam configuration of the present embodiment will be described with reference to the operation explanatory diagram of FIG. The horizontal direction in FIG. 4 is the target vibration direction in the vibrator. In the conventional sensor, the beam portion J1 that connects the driving vibrator 20 and the detection vibrator 30 has a single U-shape, the rotational rigidity is weak, and the driving vibrator 20 aims at vibration. It vibrates in a slightly diagonal direction (in the figure, diagonally upward) from the vibration direction of the above, and this becomes unnecessary vibration.
[0034]
On the other hand, in the beam configuration of the present embodiment, the rotational rigidity is increased and the vibration of the vibrator is not hindered, so that the driving vibrator 20 vibrates in a target direction. Therefore, according to this embodiment, since unnecessary vibration can be reduced, it is possible to provide an angular velocity sensor with high measurement accuracy by suppressing an offset in which an output is generated even when the angular velocity is zero.
[0035]
The effect of this embodiment will be described again with reference to FIG. FIG. 5A shows data obtained by preparing four types of beam shapes and calculating unnecessary vibration due to these beams as an angular velocity. The beam shape (1) is a conventional beam. The beam shape {circle around (2)} is shown in FIG. 1 of “A Precision Yaw Rate Sensor in Silicon Micromachining” (TRANSDUCERS '97 pp. 847-850, 1997 IEEE). 8 having a double beam structure similar to FIG.
[0036]
The beam shapes {circle over (3)} and {circle around (4)} are those of this embodiment, and the length of the connecting portion is changed. The beam shape (4) is longer than the beam shape (3). From FIG. 5A, it can be seen that the unnecessary vibrations can be greatly reduced in the beam shapes {circle around (2)}, {circle around (3)}, and {circle around (4)} compared to the conventional beam shape {circle around (1)}.
[0037]
That is, in this embodiment, each beam part 21 and 31 is comprised from the 1st beam 22 and 32 and the 2nd beam 23 and 33 which are mutually arrange | positioned in parallel, and these 1st and 2nd beams are return | folded. Connecting bar portions 22b, 23b, 32b, and 33b as parts, and at the folded portion, there are connecting portions 24 and 34 as connecting rods for connecting the first and second beams. Two L-shaped spaces are formed between the second beam and the second beam, and the L-shaped spaces are arranged symmetrically with respect to the connecting rod.
[0038]
Further, by adopting such a configuration of the beam portions 21 and 31, it is possible to realize a configuration of the beam portion with increased rotational rigidity without hindering the vibration of the vibrators 20 and 30, and FIG. As shown in (), unnecessary vibration can be greatly reduced.
[0039]
In addition, FIG. 5 (b) shows the difference in effect due to the beam shapes (2), (3), and (4) more strictly. Compared with the beam shape (2), it has a connecting portion. The beam shapes {circle over (3)} and {circle around (4)} have a greater effect of suppressing unnecessary vibration, and the beam shape {circle around (4)} having a longer connecting portion is more effective than the beam shape {circle around (3)}.
[0040]
Furthermore, according to the present embodiment, in the distance between the first beams 22 and 32 and the second beams 23 and 33 in the respective beam portions 21 and 31, the interval W1 between the connecting rod portions is set to the interval W2 between the parallel rod portions. The connecting portions 24 and 34 can be made sufficiently long, and as a result, the difference in displacement generated between the parallel bar portion of the first beam and the parallel bar portion of the second beam can be easily absorbed. The vibration can be prevented more effectively.
[0041]
FIG. 6 shows the result of a more rigorous study on the length of the connecting portion. FIG. 6 shows the unnecessary vibration output with respect to the ratio W1 / W2 between the length W1 of the connecting portions 24, 34 and the interval (beam interval) W2 between the parallel rod portions 22a, 23a, 32a, 33a. The length W1 corresponds to the interval W1 between the connecting rod portions 22b, 23b, 32b, 33b shown in FIG.
[0042]
When the ratio between W1 and W2 is 1 (W1 / W2 = 1), and the ratio between W1 and W2 is 5 or more, the effect is great. The effect is saturated when the ratio W1 / W2 is around 5, and it can be said that the ratio W1 / W2 is 5 or more. That is, it is preferable that the ratio W1 / W2 of the interval W1 between the connecting rod portions 22b, 23b, 32b, 33b and the interval W2 between the parallel rod portions 22a, 23a, 32a, 33a is 5 or more, which is unnecessary. The effect of reducing vibration is maximized.
[0043]
Also, if the connecting part is too thick, the pair of beam parts by the connecting part is too strong and may interfere with vibration, and further, if the connecting part is too thin for processing the sensor, it is difficult to process. It is preferable that the widths of the portions 24 and 34 are substantially the same width as the pair of beam portions 22, 23, 32, and 33.
[0044]
In FIG. 7, the difference in the effect by the shape of a connection part is shown. Both beam shapes (5) and (6) in FIG. 7 are those of this embodiment. The beam shape {circle over (5)} has the same beam width in the region where the outer beam and the inner beam are connected by the connecting portion (that is, the connecting rod portion) (in addition, the connecting portion is also connected to the beam). The beam shape (6) has a larger width than the inner beam in the area where the outer beam is connected at the connecting part (connecting bar). It is.
[0045]
From FIG. 7, in the regions (connecting bar portions, folded portions) 22b, 23b, 32b, 33b connected by the connecting portions (connecting rods) 24, 34, the outer beams (second beams) 23, 33 and It can be said that the beam widths of the inner beams (first beams) 22 and 32 are preferably equal.
[0046]
Further, the connecting portions (connecting rods) 24 and 34 extend from a portion connected to the inner beams (first beams) 22 and 32 to a portion connected to the outer beams (second beams) 23 and 33. It can be said that the same width is preferable. This is because if there is a thick portion in the connection part or the folded part of the beam part, the mass of the connection part or the folded part increases, and this influence is considered to affect unnecessary vibration.
[0047]
Here, the specific effect of this embodiment is shown in FIG. FIG. 8 shows an example in which the degree of unnecessary vibration amplitude with respect to the processing error of the beam portion between the present angular velocity sensor 100 and the conventional angular velocity sensor is examined. In the present angular velocity sensor 100, each dimension W1 to W3 of the beam portion is set to the specific dimension described with reference to FIG. Further, the conventional one has a beam portion J1 made of one beam as shown in FIG. 4, and the width of the beam portion J1 is 15 μm. As can be seen from FIG. 8, according to the present embodiment (broken line), even if there is a machining error, unnecessary vibration can be greatly reduced as compared with the conventional case (solid line).
[0048]
In the above-described embodiment, the driving beam portion 21 and the detection beam portion 31 are both configured as a pair of beams that are spaced apart and connected in parallel. It may be applied to only one of them. That is, only the driving beam portion 21 may be a beam portion referred to in the present invention, and only the detection beam portion 31 may be a beam portion referred to in the present invention. Further, the present invention can be applied to a semiconductor dynamic quantity sensor such as an acceleration sensor in addition to the angular velocity sensor.
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment of an angular velocity sensor according to the present invention.
2 is a partial cross-sectional perspective view including an AA cross section in FIG. 1; FIG.
3 is a dimension explanatory diagram of a beam portion in the angular velocity sensor shown in FIG. 1. FIG.
4 is an operation explanatory diagram of the angular velocity sensor shown in FIG. 1. FIG.
FIG. 5 is a diagram illustrating data obtained by calculating unnecessary vibration due to a difference in beam shape as an angular velocity.
FIG. 6 is a diagram showing a result of examining an unnecessary vibration output with respect to a ratio W1 / W2 between a length W1 of a connecting portion and a spacing W2 between parallel rod portions.
FIG. 7 is a diagram showing the results of examining the influence on the unnecessary vibration output by the shape of the connecting portion.
FIG. 8 is a graph showing the degree of unnecessary vibration amplitude with respect to a beam processing error between the angular velocity sensor of the present invention and a conventional angular velocity sensor.
[Explanation of symbols]
10 ... Base, 20 ... Driving vibrator, 21 ... Driving beam,
22 ... the first beam of the driving beam, 23 ... the second beam of the driving beam,
24 ... Connecting portion of driving beam portion, 30 ... detecting vibrator, 31 ... detecting beam portion,
32 ... 1st beam of the beam part for detection, 33 ... 2nd beam of the beam part for detection,
34 ... Connecting part of the beam part for detection, 22a, 23a, 32a, 33a ... Parallel bar part,
22b, 23b, 32b, 33b ... connecting rod part.

Claims

Formed by processing a semiconductor substrate,
A base (10), a vibrator (20, 30) that vibrates in a predetermined direction, and a plurality of beam portions (21, 31) connecting the vibrator and the base,
In a vibration type semiconductor angular velocity sensor configured to detect an angular velocity based on vibration of the vibrator,
Each of the plurality of beam portions includes a pair of beams (22, 23, 32, 33) that are spaced apart from each other in parallel and a connection portion (24, 34) that connects the pair of beams. Has been
The pair of beams is a U-shaped first beam (22, 32) and a U-shape arranged in a similar shape to the first beam on the outer peripheral side of the first beam. A second beam (23, 33) having a shape,
A pair of parallel bars (22a, 23a, 32a, 33a) parallel to each other in the U-shape of the first and second beams are bent in the predetermined direction,
The connecting portions (24, 34) connect the connecting rod portions (22b, 23b, 32b, 33b) that connect one ends of the parallel rod portions in the U-shape of the first and second beams. a semiconductor angular velocity sensor, characterized in that are.

2. The semiconductor angular velocity sensor according to claim 1, wherein the connecting portions (24, 34) have a shape extending in a direction orthogonal to the predetermined direction.

In the distance between the first beam (22, 32) and the second beam (23, 33), the distance between the connecting rod portions (22b, 23b, 32b, 33b) is the parallel rod portion (22a, 23a). 32a, 33a) is larger than the interval between the semiconductor angular velocity sensors according to claim 1 or 2.

The connection portion (24, 34) has a beam shape having substantially the same width as the pair of beams ( 22, 23, 32, 33), according to any one of claims 1 to 3. The semiconductor angular velocity sensor as described .

The ratio between the interval between the connecting rod portions (22b, 23b, 32b, 33b) and the interval between the parallel rod portions (22a, 23a, 32a, 33a) is 5 or more. The semiconductor angular velocity sensor as described.

Formed by processing a semiconductor substrate,
A base (10), a vibrator (20, 30) that vibrates in a predetermined direction, and a plurality of beam portions (21, 31) connecting the vibrator and the base,
In a vibration type semiconductor angular velocity sensor configured to detect an angular velocity based on vibration of the vibrator,
The plurality of beam portions are composed of first and second beams (22, 23, 32, 33) arranged in parallel to each other, and the first and second beams are turned portions (22b, 23b, 32b, 33b), and at the folded portion, the connecting portion (24, 34) for connecting the first and second beams is provided.
With this connecting rod, two L-shaped spaces are formed between the first beam and the second beam, and the L-shaped spaces are arranged symmetrically with respect to the connecting rod. Ri shall der,
Said first, second beam (22, 23, 32, 33), the portion excluding the folded portion (22a, 23a, 32a, 33a) is characterized that you have become flexed in the predetermined direction Semiconductor angular velocity sensor.

The beam width of each of the first and second beams (22, 23, 32, 33) is substantially the same in the folded portion (22b, 23b, 32b, 33b). A semiconductor angular velocity sensor according to claim 1.

The connecting rod (24, 34) has substantially the same width from the first beam (22, 32) to the second beam (23, 33). Semiconductor angular velocity sensor.

In the folded portion (22b, 23b, 32b, 33b), the beam widths of the first and second beams (22, 23, 32, 33) are substantially the same,
The connecting rod (24, 34) has substantially the same width from the first beam (22, 32) to the second beam (23, 33). The semiconductor angular velocity sensor as described.

The semiconductor angular velocity sensor according to any one of claims 6 to 9, wherein the connecting rods (24, 34) extend in a direction orthogonal to the predetermined direction.

Formed by processing a semiconductor substrate,
A base (10), a vibrator (20, 30) that vibrates in a predetermined direction, and a plurality of beam portions (21, 31) connecting the vibrator and the base,
In a vibration type semiconductor angular velocity sensor configured to detect an angular velocity based on vibration of the vibrator,
The plurality of beam portions, each, a pair of beams which are spaced apart in parallel (22, 23, 32, 33), because the consolidated portion for connecting the pair of beams and (24, 34) is configured,
Each of the pair of beams has a shape having bent portions (22b, 23b, 32b, 33b) each bent in a U shape, and the portions excluding the bent portions (22a, 23a, 32a, 33a) Bends in a certain direction,
The semiconductor angular velocity sensor , wherein the connecting portion connects the bent portions of the pair of beams .

The semiconductor angular velocity sensor according to claim 11, wherein the connecting portion (24, 34) has a shape extending in a direction orthogonal to the predetermined direction.