JP2013217835A

JP2013217835A - Semiconductor physical quantity sensor

Info

Publication number: JP2013217835A
Application number: JP2012090130A
Authority: JP
Inventors: Kazuya Nohara; 一也野原
Original assignee: Panasonic Corp
Current assignee: Panasonic Corp
Priority date: 2012-04-11
Filing date: 2012-04-11
Publication date: 2013-10-24

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor physical quantity sensor capable of suppressing breakage of interdigital electrodes positioned on both outermost sides without reducing the sensor sensitivity.SOLUTION: A semiconductor physical quantity sensor includes: an anchor part 6; a movable electrode part 8 that is swingably supported by the anchor part 6 via a swing part 12; and a fixed electrode part 10 (11) that is engaged with the movable electrode part 8 in a comb-teeth shape. A pair of first interdigital electrodes 10Ta' and 10Ta' (11Ta' and 11Ta') which is positioned on both outermost sides out of interdigital parts 10T (11T) of the fixed electrode part 10 (11) is made shorter than other second interdigital electrodes 10Ta" (11Ta"), thereby keeping the natural frequency away from the frequency during a sensor manufacturing process. In addition, the plurality of second interdigital electrodes 10Ta" (11Ta") are formed to have the same length as each other, to ensure the capacitance.

Description

本発明は、可動電極部と固定電極部とが櫛歯状に噛合される半導体物理量センサに関する。 The present invention relates to a semiconductor physical quantity sensor in which a movable electrode portion and a fixed electrode portion are meshed in a comb shape.

従来の半導体物理量センサとして、互いに櫛歯状に噛合される可動電極部と固定電極部とを備え、可動電極部の櫛歯電極と固定電極部の櫛歯電極との間の静電容量変化によって加速度を検知できるようにした加速度センサがある（例えば、特許文献１参照）。 As a conventional semiconductor physical quantity sensor, a movable electrode unit and a fixed electrode unit meshed with each other in a comb-teeth shape are provided, and a capacitance change between the comb-teeth electrode of the movable electrode unit and the comb-teeth electrode of the fixed electrode unit There is an acceleration sensor that can detect acceleration (see, for example, Patent Document 1).

しかし、このように電極を櫛歯状に形成した場合、固定電極部の最両側に配置される櫛歯電極の固有振動数が、それ以外の中央部側の櫛歯電極の固有振動数よりも低くなる。このため、センサ製造工程中に印加される衝撃の周波数が最両側の櫛歯電極の固有振動数と一致し易くなり、最両側の櫛歯電極が共振して付け根部分から折損してしまう恐れがあった。 However, when the electrodes are formed in a comb-like shape in this way, the natural frequency of the comb-shaped electrodes arranged on the outermost sides of the fixed electrode portion is higher than the natural frequency of the other comb-shaped electrodes on the center side. Lower. For this reason, the frequency of the impact applied during the sensor manufacturing process tends to coincide with the natural frequency of the comb electrodes on the both sides, and the comb electrodes on the both sides may resonate and break from the root portion. there were.

これに対して、特許文献１の加速度センサでは、固定電極部の両側の櫛歯電極の長さが中央部側の櫛歯電極よりも短く形成されているため、両側の櫛歯電極の固有振動数を上記センサ製造工程中の周波数よりも高くして共振を避けることができる。 On the other hand, in the acceleration sensor of Patent Document 1, since the comb electrodes on both sides of the fixed electrode portion are formed shorter than the comb electrodes on the center side, the natural vibration of the comb electrodes on both sides is formed. The number can be made higher than the frequency during the sensor manufacturing process to avoid resonance.

特開２００２−１３１３３１号公報JP 2002-131331 A

しかしながら、上記従来技術にあっては、固定電極部の最両側の櫛歯電極の長さが中央部側の櫛歯電極よりも短く形成されているが、櫛歯電極は、全体が櫛歯部分の中央部から両側に向かって段階的に短く形成されている。このため、可動電極部の櫛歯電極と固定電極部の櫛歯電極との間の静電容量が全体として減少し（対向面積が減少し）、センサ感度が低下してしまう恐れがあった。 However, in the above prior art, the length of the comb electrode on the both sides of the fixed electrode portion is shorter than that of the comb electrode on the center side. It is formed to be shorter step by step from the center to both sides. For this reason, the electrostatic capacitance between the comb-teeth electrode of the movable electrode part and the comb-teeth electrode of the fixed electrode part is reduced as a whole (the facing area is reduced), and the sensor sensitivity may be lowered.

そこで、本発明は、センサ感度を低下させることなく、最両側に配置される櫛歯電極の破損を抑制することの可能な半導体物理量センサを得ることを目的とする。 Therefore, an object of the present invention is to obtain a semiconductor physical quantity sensor capable of suppressing the breakage of comb-tooth electrodes arranged on the outermost sides without reducing the sensor sensitivity.

上記目的を達成するために、本発明の第１の特徴は、アンカー部と、前記アンカー部にばね部を介して揺動自在に支持される可動電極部と、前記可動電極部に櫛歯状に噛合される固定電極部と、を備え、前記固定電極部は、櫛歯部分のうち最両側に配置される一対の第１の櫛歯電極と、前記第１の櫛歯電極間に配置される複数の第２の櫛歯電極とを有しており、前記第１の櫛歯電極を、前記第２の櫛歯電極よりも短く形成するとともに、前記第２の櫛歯電極を、互いに等しい長さに形成したことを要旨とする。 In order to achieve the above object, the first feature of the present invention is that an anchor part, a movable electrode part supported by the anchor part via a spring part so as to be swingable, and a comb-like shape on the movable electrode part A fixed electrode portion meshed with the first comb-teeth electrode, and the fixed electrode portion is disposed between the first comb-teeth electrode and the pair of first comb-teeth electrodes disposed on the outermost side of the comb-teeth portion. A plurality of second comb electrodes, the first comb electrodes are formed shorter than the second comb electrodes, and the second comb electrodes are equal to each other. The gist is that the length is formed.

第２の特徴は、前記可動電極部に、前記第１の櫛歯電極を短くしたことで形成される空きスペース部分を埋める拡張部を設けたことを要旨とする。 The second feature is that the movable electrode portion is provided with an extension portion that fills an empty space portion formed by shortening the first comb electrode.

第３の特徴は、前記第１の櫛歯電極の付け根部分に、当該第１の櫛歯電極よりも幅広となる補強部を設けたことを要旨とする。 The gist of the third feature is that a reinforcing portion that is wider than the first comb electrode is provided at the base of the first comb electrode.

第４の特徴は、アンカー部と、前記アンカー部にばね部を介して揺動自在に支持される可動電極部と、前記可動電極部に櫛歯状に噛合される固定電極部と、を備え、前記固定電極部は、櫛歯部分のうち最両側に配置される一対の第１の櫛歯電極と、前記第１の櫛歯電極間に配置される１つ又は複数の第２の櫛歯電極とを有しており、前記第１の櫛歯電極の付け根部分に、当該第１の櫛歯電極よりも幅広となる補強部を設けるとともに、前記第２の櫛歯電極を、前記第１の櫛歯電極よりも長く形成したことを要旨とする。 A fourth feature includes an anchor portion, a movable electrode portion that is swingably supported by the anchor portion via a spring portion, and a fixed electrode portion meshed with the movable electrode portion in a comb-tooth shape. The fixed electrode portion includes a pair of first comb electrodes disposed on the outermost side of the comb portion, and one or a plurality of second comb teeth disposed between the first comb electrodes. And a reinforcing portion that is wider than the first comb electrode at the base portion of the first comb electrode, and the second comb electrode is connected to the first comb electrode. The gist is that the electrode is longer than the comb-tooth electrode.

第５の特徴は、前記可動電極部の前記第２の櫛歯電極の先端部と対向する位置に、前記第２の櫛歯電極の先端部が入り込む凹部を設けたことを要旨とする。 The fifth feature is summarized in that a concave portion into which the distal end portion of the second comb-tooth electrode enters is provided at a position facing the distal end portion of the second comb-tooth electrode of the movable electrode portion.

第６の特徴は、前記補強部を、前記第１の櫛歯電極の付け根部分から前記固定電極部の基部に向かって円弧状に拡幅させたことを要旨とする。 A sixth feature is summarized in that the reinforcing portion is widened in an arc shape from a base portion of the first comb electrode toward a base portion of the fixed electrode portion.

本発明の第１の特徴によれば、最両側に配置される一対の第１の櫛歯電極が、それ以外の第２の櫛歯電極よりも短く形成されているので、問題となる第１の櫛歯電極の固有振動数をセンサ製造工程中の周波数よりも高くすることができる。これにより、第１の櫛歯電極がセンサ製造工程中の周波数で破損してしまうのを抑制することができる。また、第１の櫛歯電極を除く複数の第２の櫛歯電極は、互いに等しい長さに形成されているため、それぞれが長い状態のままを保つことができ、センサ感度が低下してしまうのを回避することができる。 According to the first feature of the present invention, the pair of first comb electrodes arranged on the outermost sides are formed shorter than the other second comb electrodes, so that the first problem is The natural frequency of the comb-tooth electrode can be made higher than the frequency during the sensor manufacturing process. Thereby, it can suppress that a 1st comb-tooth electrode will be damaged at the frequency in a sensor manufacturing process. In addition, since the plurality of second comb electrodes excluding the first comb electrodes are formed to have the same length, each of them can be kept in a long state, resulting in a decrease in sensor sensitivity. Can be avoided.

また、本発明の第４の特徴によれば、第１の櫛歯電極の付け根部分に、その第１の櫛歯電極よりも幅広となる補強部を設けたので、その補強部によって第１の櫛歯電極の強度を高めることができる。これにより、第１の櫛歯電極がセンサ製造工程中の周波数で破損してしまうのを抑制することができる。また、それ以外の第２の櫛歯電極を、第１の櫛歯電極よりも長く形成したので、第１の櫛歯電極の補強部による可動電極部側との対向面積の減少分を第２の櫛歯電極の延長部分で補うことができ、センサ感度が低下してしまうのを回避することができる。 Further, according to the fourth feature of the present invention, the reinforcing portion that is wider than the first comb electrode is provided at the base portion of the first comb electrode. The strength of the comb electrode can be increased. Thereby, it can suppress that a 1st comb-tooth electrode will be damaged at the frequency in a sensor manufacturing process. In addition, since the other second comb electrode is formed longer than the first comb electrode, the reduction in the area facing the movable electrode side by the reinforcing portion of the first comb electrode is reduced to the second. It can be compensated by the extension part of the comb-tooth electrode, and it can be avoided that the sensor sensitivity is lowered.

本発明にかかる半導体物理量センサの第１実施形態を概略的に示す平面図である。1 is a plan view schematically showing a first embodiment of a semiconductor physical quantity sensor according to the present invention. 図１中のＡ−Ａ線に沿った概略断面図である。It is a schematic sectional drawing in alignment with the AA in FIG. 本発明にかかる半導体物理量センサの第２実施形態を概略的に示す平面図である。It is a top view showing roughly a 2nd embodiment of a semiconductor physical quantity sensor concerning the present invention. 本発明にかかる半導体物理量センサの第３実施形態を概略的に示す平面図である。It is a top view which shows schematically 3rd Embodiment of the semiconductor physical quantity sensor concerning this invention. 本発明にかかる半導体物理量センサの第４実施形態を概略的に示す平面図である。It is a top view which shows roughly 4th Embodiment of the semiconductor physical quantity sensor concerning this invention. 本発明にかかる半導体物理量センサの第５実施形態を概略的に示す平面図である。It is a top view which shows roughly 5th Embodiment of the semiconductor physical quantity sensor concerning this invention. 図６中のＢ−Ｂ線に沿った概略断面図である。It is a schematic sectional drawing in alignment with the BB line in FIG. 本発明にかかる半導体物理量センサの第６実施形態を概略的に示す平面図である。It is a top view which shows roughly 6th Embodiment of the semiconductor physical quantity sensor concerning this invention.

以下、本発明の実施形態について図面を参照しつつ詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[第１実施形態]
図１および図２は、本発明にかかる半導体物理量センサの第１実施形態を示した図であり、本実施形態では、半導体物理量センサとして加速度センサ１を例にとって説明するものとする。 [First embodiment]
FIG. 1 and FIG. 2 are diagrams showing a first embodiment of the semiconductor physical quantity sensor according to the present invention. In this embodiment, the acceleration sensor 1 is described as an example of the semiconductor physical quantity sensor.

本実施形態の加速度センサ１は、図２に示すように、上下に配置される２枚のガラス基板２、３と、これら２枚のガラス基板２、３に挟まれるシリコン基板４とを備えている。ガラス基板２、３は絶縁層となり、シリコン基板４は半導体層となる。これらガラス基板２、３とシリコン基板４とは、最終的に陽極接合などによって一体に接合される。 As shown in FIG. 2, the acceleration sensor 1 according to the present embodiment includes two glass substrates 2 and 3 disposed above and below, and a silicon substrate 4 sandwiched between the two glass substrates 2 and 3. Yes. The glass substrates 2 and 3 become insulating layers, and the silicon substrate 4 becomes a semiconductor layer. The glass substrates 2 and 3 and the silicon substrate 4 are finally bonded together by anodic bonding or the like.

シリコン基板４には、図１に示すように、公知の半導体プロセスにより間隙５を形成することで、周縁部を取り囲む略矩形状のアンカー部６が形成されている。また、このアンカー部６の更に外周は、絶縁性の周囲フレーム７によって囲繞されるようになっている。この周囲フレーム７は、２枚のガラス基板２、３の外周縁部間に固着される。なお、本実施形態では、矩形状のアンカー部６の短辺方向（図中上下方向）をＹ方向、長辺方向（図中左右方向）をＸ方向として以下説明するものとする。 As shown in FIG. 1, a substantially rectangular anchor portion 6 surrounding the peripheral edge portion is formed on the silicon substrate 4 by forming a gap 5 by a known semiconductor process. Further, the outer periphery of the anchor portion 6 is surrounded by an insulating peripheral frame 7. The peripheral frame 7 is fixed between the outer peripheral edges of the two glass substrates 2 and 3. In the present embodiment, the short side direction (vertical direction in the figure) of the rectangular anchor portion 6 is assumed to be the Y direction, and the long side direction (left and right direction in the figure) is assumed to be the X direction.

アンカー部６の間隙５を隔てた内側には錘を兼ねた可動電極部８が形成されており、かつ、間隙９を隔てたＹ方向略中央部には一対の第１固定電極部１０および第２固定電極部１１が形成されている。これら第１、第２固定電極部１０、１１は、間隙９を介して非導通状態で配置されている。なお、アンカー部６は、ガラス基板２、３に陽極接合等により固定されている。 A movable electrode portion 8 also serving as a weight is formed inside the gap 5 of the anchor portion 6, and a pair of first fixed electrode portions 10 and a first fixed electrode portion 10 are formed at a substantially central portion in the Y direction across the gap 9. Two fixed electrode portions 11 are formed. The first and second fixed electrode portions 10 and 11 are arranged in a non-conductive state with a gap 9 interposed therebetween. The anchor portion 6 is fixed to the glass substrates 2 and 3 by anodic bonding or the like.

また、可動電極部８は、その長辺となるＸ方向の両辺とアンカー部６のＸ方向の両辺との間に形成されるばね部１２を介して揺動自在に支持されており、物理量としての加速度の印加によって可動電極部８の移動が許容されるようになっている。このとき、図２に示すように、可動電極部８の両面とガラス基板２、３との間には空隙部δ１、δ２が設けられており、その空隙部δ１、δ２によって可動電極部８の変位が可能となっている。 Further, the movable electrode portion 8 is supported so as to be swingable via spring portions 12 formed between both sides in the X direction, which are the long sides, and both sides in the X direction of the anchor portion 6, and as a physical quantity The movement of the movable electrode portion 8 is allowed by application of the acceleration. At this time, as shown in FIG. 2, gaps δ1 and δ2 are provided between both surfaces of the movable electrode portion 8 and the glass substrates 2 and 3, and the gaps δ1 and δ2 define the movable electrode portion 8. Displacement is possible.

アンカー部６、可動電極部８、第１、第２固定電極部１０、１１およびばね部１２は、シリコン基板４を、例えば、反応性イオンエッチング等により垂直エッチング加工することで形成されている。 The anchor part 6, the movable electrode part 8, the first and second fixed electrode parts 10 and 11, and the spring part 12 are formed by subjecting the silicon substrate 4 to vertical etching processing, for example, by reactive ion etching or the like.

図１に示すように、可動電極部８は、Ｙ方向両側にＸ方向に沿って配置される一対の電極幹部８１、８２と、これら電極幹部８１、８２のＸ方向中央部間を連結する櫛歯基部８３とによって略Ｈ字状に形成されている。そして、可動電極部８の櫛歯基部８３には、それぞれ複数の櫛歯電極８４ａ、８５ａがＸ方向の一方側と他方側とに向けて突出する第１櫛歯部分８４および第２櫛歯部分８５が設けられている。 As shown in FIG. 1, the movable electrode portion 8 includes a pair of electrode trunk portions 81 and 82 arranged along the X direction on both sides in the Y direction, and a comb that connects between the X direction center portions of the electrode trunk portions 81 and 82. The tooth base 83 is formed in a substantially H shape. The comb-teeth base 83 of the movable electrode portion 8 includes a first comb-teeth portion 84 and a second comb-teeth portion in which a plurality of comb-teeth electrodes 84a and 85a project toward one side and the other side in the X direction. 85 is provided.

一方、固定電極部１０、１１は、可動電極部８の櫛歯基部８３を挟んで、一対の電極幹部８１、８２間に左右対称に配置されており、互いに対向する側とは反対側、つまり、アンカー部６の短辺となるＹ方向の両辺に位置する側が基部１０ａ、１１ａとなっている。そして、それら基部１０ａ、１１ａには、可動電極部８の櫛歯基部８３に向かって複数の櫛歯電極１０Ｔａ、１１Ｔａが突出する第３櫛歯部分１０Ｔおよび第４櫛歯部分１１Ｔが設けられている。また、基部１０ａ、１１ａは、図２に示すように、その基部１０ａ、１１ａの上面全体が上側のガラス基板２に、かつ、下面一部が下側のガラス基板３にそれぞれ陽極接合等により固定されている。 On the other hand, the fixed electrode portions 10 and 11 are disposed symmetrically between the pair of electrode trunk portions 81 and 82 with the comb base portion 83 of the movable electrode portion 8 interposed therebetween, and are opposite to the sides facing each other, that is, The sides located on both sides in the Y direction, which are the short sides of the anchor portion 6, are the base portions 10a and 11a. The base portions 10a and 11a are provided with a third comb-tooth portion 10T and a fourth comb-tooth portion 11T in which a plurality of comb-tooth electrodes 10Ta and 11Ta project toward the comb-tooth base portion 83 of the movable electrode portion 8. Yes. Further, as shown in FIG. 2, the bases 10a and 11a are fixed to the upper glass substrate 2 with the entire upper surfaces of the bases 10a and 11a and a part of the lower surface to the lower glass substrate 3 by anodic bonding or the like. Has been.

図１に示すように、可動電極部８の第１櫛歯部分８４と固定電極部１０の第３櫛歯部分１０Ｔとが互いに噛合されているとともに、可動電極部８の第２櫛歯部分８５と固定電極部１１の第４櫛歯部分１１Ｔとが互いに噛合されている。このとき、第１櫛歯部分８４の櫛歯電極８４ａと第３櫛歯部分１０Ｔの櫛歯電極１０Ｔａとの間、および第２櫛歯部分８５の櫛歯電極８５ａと第４櫛歯部分１１Ｔの櫛歯電極１１Ｔａとの間には、Ｙ方向に対して互いに逆となる側にそれぞれ所定の検知部が設けられている。そして、それぞれの検知部間のギャップに蓄積した静電気の変化（静電容量変化）を検出するようになっている。 As shown in FIG. 1, the first comb tooth portion 84 of the movable electrode portion 8 and the third comb tooth portion 10 T of the fixed electrode portion 10 are meshed with each other, and the second comb tooth portion 85 of the movable electrode portion 8. And the fourth comb tooth portion 11T of the fixed electrode portion 11 are meshed with each other. At this time, between the comb electrode 84a of the first comb tooth portion 84 and the comb electrode 10Ta of the third comb tooth portion 10T, and between the comb electrode 85a of the second comb tooth portion 85 and the fourth comb tooth portion 11T. Predetermined detection parts are provided between the comb-teeth electrodes 11Ta on opposite sides to the Y direction. And the change of the static electricity (capacitance change) accumulated in the gap between each detection part is detected.

ばね部１２は、可動電極部８のＹ方向両側とＸ方向両側とに位置して、合計４箇所設けられている。それぞれのばね部１２は、例えば、連続する一本の細長い線状部を複数段のつづら折り状に折曲した状態で形成することができ、ばね部１２全体で可動電極部８の変位を許容するように弾発力をもって支持している。 The spring portion 12 is provided at a total of four locations on both sides in the Y direction and both sides in the X direction of the movable electrode portion 8. Each spring portion 12 can be formed, for example, in a state in which a continuous long and thin linear portion is bent in a plurality of stages, and the displacement of the movable electrode portion 8 is allowed throughout the spring portion 12. Support with elasticity.

このとき、アンカー部６と可動電極部８との間には、その可動電極部８のＸ方向およびＹ方向への変位量を制限するストッパー部１３が配置されている。これにより、過大な加速度の入力によって、可動電極部８がアンカー部６に衝突して固着してしまうのを防止できるようにしている。 At this time, between the anchor part 6 and the movable electrode part 8, a stopper part 13 for restricting the amount of displacement of the movable electrode part 8 in the X direction and the Y direction is arranged. Accordingly, it is possible to prevent the movable electrode portion 8 from colliding with the anchor portion 6 and being fixed due to an excessive acceleration input.

可動電極部８とアンカー部６とは、ばね部１２を介して互いに電気的に導通されており、アンカー部６の一対の長辺のＸ方向中央部には、可動電極部８と電気的に導通する端子１４、１５が設けられている。また、固定電極部１０、１１の基部１０ａ、１１ａには、その固定電極部１０、１１と直接導通する端子１６、１７が設けられている。 The movable electrode portion 8 and the anchor portion 6 are electrically connected to each other via a spring portion 12. The pair of long sides of the anchor portion 6 are electrically connected to the movable electrode portion 8 at the center in the X direction. Conductive terminals 14 and 15 are provided. Further, terminals 16 and 17 that are directly connected to the fixed electrode portions 10 and 11 are provided on the base portions 10 a and 11 a of the fixed electrode portions 10 and 11.

そして、図２に示すように、上側のガラス基板２には、各端子１４〜１７に対応した部位にそれぞれテーパ状の開口部２Ｈがエッチングにより穿設され、これら開口部２Ｈの内周にそれぞれ設けた配線２Ｈｃを各端子１４〜１７に導通させてある。 Then, as shown in FIG. 2, the upper glass substrate 2 has a tapered opening 2H formed by etching at portions corresponding to the terminals 14 to 17, respectively. The provided wiring 2Hc is electrically connected to the terminals 14-17.

このように構成された加速度センサ１は、印加される加速度によって可動電極部８が固定電極部１０、１１に対してＹ方向に変位する。これにより、第１櫛歯部分８４と第３櫛歯部分１０Ｔとの間の静電容量、および第２櫛歯部分８５と第４櫛歯部分１１Ｔとの間の静電容量が変化する。そして、それらの静電容量変化は、電気信号として各端子１４〜１７から配線２Ｈｃを介して外部に取り出され、それらの静電容量信号を処理することにより、印加された加速度の大きさを検知することができる。 In the acceleration sensor 1 configured as described above, the movable electrode portion 8 is displaced in the Y direction with respect to the fixed electrode portions 10 and 11 by the applied acceleration. Thereby, the electrostatic capacitance between the 1st comb-tooth part 84 and the 3rd comb-tooth part 10T, and the electrostatic capacitance between the 2nd comb-tooth part 85 and the 4th comb-tooth part 11T change. These capacitance changes are taken out as electrical signals from the terminals 14 to 17 via the wiring 2Hc, and the magnitude of the applied acceleration is detected by processing these capacitance signals. can do.

ここで、本実施形態では、固定電極部１０、１１の櫛歯部分１０Ｔ、１１Ｔのうち最両側に配置される一対の第１の櫛歯電極１０Ｔａ′，１０Ｔａ′、１１Ｔａ′，１１Ｔａ′を、それ以外の第２の櫛歯電極１０Ｔａ″、１１Ｔａ″よりも短く形成してある。このとき、第２の櫛歯電極１０Ｔａ″、１１Ｔａ″は、一対の第１の櫛歯電極１０Ｔａ′，１０Ｔａ′、１１Ｔａ′，１１Ｔａ′間の中央部側に複数（本実施形態では３つずつ）配置され、それらが互いに等しい長さで形成されるようになっている。なお、本実施形態では、最両側の第１の櫛歯電極１０Ｔａ′、１１Ｔａ′を短くしたことにより、この短くした分だけ第１の櫛歯電極１０Ｔａ′、１１Ｔａ′の先端方向に空きスペース部分Ｓ１、Ｓ２が設けられることになる。 Here, in the present embodiment, a pair of first comb electrodes 10Ta ′, 10Ta ′, 11Ta ′, 11Ta ′ arranged on the outermost sides of the comb-tooth portions 10T, 11T of the fixed electrode portions 10, 11 are It is formed shorter than the other second comb electrodes 10Ta ″ and 11Ta ″. At this time, a plurality of second comb-tooth electrodes 10Ta ″ and 11Ta ″ are provided on the central portion side between the pair of first comb-tooth electrodes 10Ta ′, 10Ta ′, 11Ta ′ and 11Ta ′ (three in this embodiment). ) Arranged so that they are of equal length to each other. In the present embodiment, since the first comb electrodes 10Ta ′ and 11Ta ′ on the outermost sides are shortened, an empty space portion is formed in the tip direction of the first comb electrodes 10Ta ′ and 11Ta ′ by this shortening. S1 and S2 are provided.

以上の構成により、第１実施形態の加速度センサ１によれば、固定電極部１０（１１）の櫛歯部分１０Ｔ（１１Ｔ）のうち最両側に配置される第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）を、それ以外の第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）よりも短くしている。これにより、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の固有振動数を中央部側の第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）よりも高くすることができる。したがって、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の固有振動数をセンサ製造工程中に印加される衝撃の周波数から遠ざけることが可能となる。これにより、その第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）がセンサ製造工程中の周波数に共振して破損、ひいては折損してしまうのを抑制することができる。 With the above configuration, according to the acceleration sensor 1 of the first embodiment, the first comb-tooth electrode 10Ta ′ (11Ta) disposed on the outermost side of the comb-tooth portion 10T (11T) of the fixed electrode portion 10 (11). ′) Is shorter than the other second comb electrodes 10Ta ″ (11Ta ″). Thereby, the natural frequency of the first comb-tooth electrode 10Ta ′ (11Ta ′) can be made higher than that of the second comb-tooth electrode 10Ta ″ (11Ta ″) on the center side. Therefore, the natural frequency of the first comb-tooth electrode 10Ta ′ (11Ta ′) can be kept away from the frequency of the impact applied during the sensor manufacturing process. As a result, it is possible to prevent the first comb electrode 10Ta ′ (11Ta ′) from being damaged due to resonance with the frequency during the sensor manufacturing process, and thus breaking.

また、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）を短くした場合にも、それらを除く中央部側の第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）は、互いに等しい長さで形成されて互いに長いままの状態を保つことができる。これにより、それら第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）と可動電極部８の櫛歯電極８４ａ（８５ａ）との対向面積を大きく確保することができ、それら両者間の静電容量が減少するのを防止できる。したがって、静電容量が減少するのは短くした第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）側のみであるため、静電容量の減少を最小限度にとどめてセンサ感度が大きく低下してしまうのを回避することができる。 Further, even when the first comb-teeth electrode 10Ta ′ (11Ta ′) is shortened, the second comb-teeth electrode 10Ta ″ (11Ta ″) on the center side excluding them is formed with the same length. It is possible to maintain the state of being long for each other. As a result, a large facing area between the second comb-tooth electrode 10Ta ″ (11Ta ″) and the comb-tooth electrode 84a (85a) of the movable electrode portion 8 can be secured, and the capacitance between them can be reduced. Can be prevented. Therefore, since the capacitance is reduced only on the first comb electrode 10Ta ′ (11Ta ′) which has been shortened, the reduction in the capacitance is minimized and the sensor sensitivity is greatly reduced. Can be avoided.

[第２実施形態]
図３は、本発明の第２実施形態を示した図であり、上記第１実施形態と同一構成部分には同一符号を付して重複する説明を省略して述べるものとする。 [Second Embodiment]
FIG. 3 is a diagram showing a second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

本実施形態の加速度センサ１Ａが、上記第１実施形態の加速度センサ１と主に異なる点は、可動電極部８に、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の先端方向に設けられた空きスペース部分Ｓ１（Ｓ２）に迫り出す拡張部２０を設けたことにある。勿論、その空きスペース部分Ｓ１（Ｓ２）は、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）を、第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）よりも短くしたことで形成されるものである。 The acceleration sensor 1A of the present embodiment is mainly different from the acceleration sensor 1 of the first embodiment in that the movable electrode portion 8 is provided in the distal direction of the first comb electrode 10Ta ′ (11Ta ′). This is because the extended portion 20 that protrudes to the empty space portion S1 (S2) is provided. Of course, the empty space portion S1 (S2) is formed by making the first comb-tooth electrode 10Ta ′ (11Ta ′) shorter than the second comb-tooth electrode 10Ta ″ (11Ta ″). .

本実施形態では、空きスペース部分Ｓ１（Ｓ２）の全体が拡張部２０によって埋められるようになっている。その他の構成は第１実施形態の加速度センサ１と同様である。 In the present embodiment, the entire empty space portion S 1 (S 2) is filled with the expansion unit 20. Other configurations are the same as those of the acceleration sensor 1 of the first embodiment.

以上の構成により、第２実施形態の加速度センサ１Ａによれば、上記第１実施形態と同様の作用効果に加えて、可動電極部８に拡張部２０を設けたことにより、その可動電極部８の重量を拡張部２０の分だけ増すことができる。これにより、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）を短くしたことによる感度低下を、可動電極部８の重量増分によって補うことができる。 With the above configuration, according to the acceleration sensor 1A of the second embodiment, in addition to the same effects as those of the first embodiment, the movable electrode portion 8 is provided with the extended portion 20 by providing the movable electrode portion 8 with the extended electrode 20. Can be increased by the extension 20. Thereby, the sensitivity fall by shortening 1st comb-tooth electrode 10Ta '(11Ta') can be supplemented by the weight increment of the movable electrode part 8. FIG.

[第３実施形態]
図４は、本発明の第３実施形態を示した図であり、上記第２実施形態と同一構成部分には同一符号を付して重複する説明を省略して述べるものする。 [Third embodiment]
FIG. 4 is a diagram showing a third embodiment of the present invention, in which the same components as those in the second embodiment are denoted by the same reference numerals and redundant description is omitted.

本実施形態の加速度センサ１Ｂが、上記第２実施形態の加速度センサ１Ａと主に異なる点は、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の付け根部分に補強部２１を設けたことにある。この補強部２１は、櫛歯電極１０Ｔａ′（１１Ｔａ′）の付け根部分から固定電極部１０（１１）の基部１０ａ（１１ａ）に亘って、その櫛歯電極１０Ｔａ′（１１Ｔａ′）よりも幅広に形成されている。 The acceleration sensor 1B according to the present embodiment is mainly different from the acceleration sensor 1A according to the second embodiment in that a reinforcing portion 21 is provided at the base portion of the first comb electrode 10Ta ′ (11Ta ′). . The reinforcing portion 21 is wider than the comb-tooth electrode 10Ta ′ (11Ta ′) from the base portion of the comb-tooth electrode 10Ta ′ (11Ta ′) to the base portion 10a (11a) of the fixed electrode portion 10 (11). Is formed.

具体的には、図４に示すように、本実施形態では、補強部２１が櫛歯電極１０Ｔａ′（１１Ｔａ′）と基部１０ａ（１１ａ）との間に形成された直角のコーナー部分を埋める三角状に形成されている。その他の構成は第２実施形態と同様である。 Specifically, as shown in FIG. 4, in the present embodiment, the reinforcing portion 21 is a triangle that fills a right-angled corner portion formed between the comb-tooth electrode 10Ta ′ (11Ta ′) and the base portion 10a (11a). It is formed in a shape. Other configurations are the same as those of the second embodiment.

以上の構成により、第３実施形態の加速度センサ１Ｂによれば、上記第１および第２実施形態と同様の作用効果に加えて、補強部２１によって第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の強度を付け根部分で増大することができる。これにより、その第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）が付け根部分から破損（折損）してしまうのをより抑制することができるようになる。 With the above configuration, according to the acceleration sensor 1B of the third embodiment, in addition to the same effects as those of the first and second embodiments, the first comb electrode 10Ta ′ (11Ta ′) is provided by the reinforcing portion 21. Can be increased at the base. As a result, the first comb electrode 10Ta ′ (11Ta ′) can be further prevented from being broken (broken) from the base portion.

なお、本実施形態では、特徴部分を上記第２実施形態の加速度センサ１Ａに適用した場合を例示したが、もちろん、上記第１実施形態の拡張部２０が設けられていない加速度センサ１にあっても適用することができる。 In the present embodiment, the case where the characteristic portion is applied to the acceleration sensor 1A of the second embodiment is illustrated, but of course, in the acceleration sensor 1 in which the expansion unit 20 of the first embodiment is not provided. Can also be applied.

[第４実施形態]
図５は、本発明の第４実施形態を示した図であり、上記第３実施形態と同一構成部分には同一符号を付して重複する説明を省略して述べるものとする。 [Fourth embodiment]
FIG. 5 is a diagram showing a fourth embodiment of the present invention. The same components as those in the third embodiment are denoted by the same reference numerals, and redundant description is omitted.

本実施形態の加速度センサ１Ｃが、上記第３実施形態の加速度センサ１Ｂと主に異なる点は、補強部２１Ａを、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の付け根部分から固定電極部の基部１０ａ（１１ａ）に向かって、滑らかに拡幅する円弧状に形成したことにある。その他の構成は第３実施形態と同様である。 The acceleration sensor 1C of the present embodiment is mainly different from the acceleration sensor 1B of the third embodiment in that the reinforcing portion 21A is moved from the base portion of the first comb-tooth electrode 10Ta ′ (11Ta ′) to the fixed electrode portion. That is, it is formed in a circular arc shape that smoothly widens toward the base 10a (11a). Other configurations are the same as those of the third embodiment.

以上の構成により、第４実施形態の加速度センサ１Ｃによれば、上記第１〜第３実施形態と同様の作用効果を得ることができるとともに、補強部２１Ａを内側が滑らかに連続する円弧形状としてある。これにより、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の付け根部分への応力集中を緩和することができ、その第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の破損抑制効果をより一層高めることができる。 With the above configuration, according to the acceleration sensor 1C of the fourth embodiment, the same operational effects as those of the first to third embodiments can be obtained, and the reinforcing portion 21A is formed in an arc shape that smoothly continues on the inside. is there. As a result, the stress concentration on the base portion of the first comb-tooth electrode 10Ta ′ (11Ta ′) can be alleviated, and the damage-suppressing effect of the first comb-tooth electrode 10Ta ′ (11Ta ′) can be further enhanced. be able to.

[第５実施形態]
図６および図７は、本発明にかかる半導体物理量センサの第５実施形態を示した図であり、本実施形態では、半導体物理量センサとして加速度センサ１Ｄを例にとって説明するものとする。 [Fifth Embodiment]
6 and 7 are diagrams showing a fifth embodiment of the semiconductor physical quantity sensor according to the present invention. In this embodiment, the acceleration sensor 1D will be described as an example of the semiconductor physical quantity sensor.

本実施形態の加速度センサ１Ｄは、図７に示すように、上下に配置される２枚のガラス基板２、３と、これら２枚のガラス基板２、３に挟まれるシリコン基板４とを備えている。ガラス基板２、３は絶縁層となり、シリコン基板４は半導体層となる。これらガラス基板２、３とシリコン基板４とは、最終的に陽極接合などによって一体に接合される。 As shown in FIG. 7, the acceleration sensor 1 D of this embodiment includes two glass substrates 2 and 3 that are arranged above and below, and a silicon substrate 4 that is sandwiched between the two glass substrates 2 and 3. Yes. The glass substrates 2 and 3 become insulating layers, and the silicon substrate 4 becomes a semiconductor layer. The glass substrates 2 and 3 and the silicon substrate 4 are finally bonded together by anodic bonding or the like.

シリコン基板４には、図６に示すように、公知の半導体プロセスにより間隙５を形成することで、周縁部を取り囲む略矩形状のアンカー部６が形成されている。また、このアンカー部６の更に外周は、絶縁性の周囲フレーム７によって囲繞されるようになっている。この周囲フレーム７は、２枚のガラス基板２、３の外周縁部間に固着される。なお、本実施形態では、矩形状のアンカー部６の短辺方向（図中上下方向）をＹ方向、長辺方向（図中左右方向）をＸ方向として以下説明するものとする。 As shown in FIG. 6, a substantially rectangular anchor portion 6 surrounding the peripheral portion is formed on the silicon substrate 4 by forming a gap 5 by a known semiconductor process. Further, the outer periphery of the anchor portion 6 is surrounded by an insulating peripheral frame 7. The peripheral frame 7 is fixed between the outer peripheral edges of the two glass substrates 2 and 3. In the present embodiment, the short side direction (vertical direction in the figure) of the rectangular anchor portion 6 is assumed to be the Y direction, and the long side direction (left and right direction in the figure) is assumed to be the X direction.

また、可動電極部８は、その長辺となるＸ方向の両辺とアンカー部６のＸ方向の両辺との間に形成されるばね部１２を介して揺動自在に支持されており、物理量としての加速度の印加によって可動電極部８の移動が許容されるようになっている。このとき、図７に示すように、可動電極部８の両面とガラス基板２、３との間には空隙部δ１、δ２が設けられており、その空隙部δ１、δ２によって可動電極部８の変位が可能となっている。 Further, the movable electrode portion 8 is supported so as to be swingable via spring portions 12 formed between both sides in the X direction, which are the long sides, and both sides in the X direction of the anchor portion 6, and as a physical quantity The movement of the movable electrode portion 8 is allowed by application of the acceleration. At this time, as shown in FIG. 7, gaps δ1 and δ2 are provided between both surfaces of the movable electrode portion 8 and the glass substrates 2 and 3, and the gaps δ1 and δ2 define the movable electrode portion 8. Displacement is possible.

図６に示すように、可動電極部８は、Ｙ方向両側にＸ方向に沿って配置される一対の電極幹部８１、８２と、これら電極幹部８１、８２のＸ方向中央部間を連結する櫛歯基部８３とによって略Ｈ字状に形成されている。そして、可動電極部８の櫛歯基部８３には、それぞれ複数の櫛歯電極８４ａ、８５ａがＸ方向の一方側と他方側とに向けて突出する第１櫛歯部分８４および第２櫛歯部分８５が設けられている。 As shown in FIG. 6, the movable electrode portion 8 includes a pair of electrode trunk portions 81, 82 arranged along the X direction on both sides in the Y direction, and a comb connecting the X direction center portions of the electrode trunk portions 81, 82. The tooth base 83 is formed in a substantially H shape. The comb-teeth base 83 of the movable electrode portion 8 includes a first comb-teeth portion 84 and a second comb-teeth portion in which a plurality of comb-teeth electrodes 84a and 85a project toward one side and the other side in the X direction. 85 is provided.

一方、固定電極部１０、１１は、可動電極部８の櫛歯基部８３を挟んで、一対の電極幹部８１、８２間に左右対称に配置されており、互いに対向する側とは反対側、つまり、アンカー部６の短辺となるＹ方向の両辺に位置する側が基部１０ａ、１１ａとなっている。そして、それら基部１０ａ、１１ａには、可動電極部８の櫛歯基部８３に向かって複数の櫛歯電極１０Ｔａ、１１Ｔａが突出する第３櫛歯部分１０Ｔおよび第４櫛歯部分１１Ｔが設けられている。また、基部１０ａ、１１ａは、図７に示すように、その基部１０ａ、１１ａの上面全体が上側のガラス基板２に、かつ、下面一部が下側のガラス基板３にそれぞれ陽極接合等により固定されている。 On the other hand, the fixed electrode portions 10 and 11 are disposed symmetrically between the pair of electrode trunk portions 81 and 82 with the comb base portion 83 of the movable electrode portion 8 interposed therebetween, and are opposite to the sides facing each other, that is, The sides located on both sides in the Y direction, which are the short sides of the anchor portion 6, are the base portions 10a and 11a. The base portions 10a and 11a are provided with a third comb-tooth portion 10T and a fourth comb-tooth portion 11T in which a plurality of comb-tooth electrodes 10Ta and 11Ta project toward the comb-tooth base portion 83 of the movable electrode portion 8. Yes. Further, as shown in FIG. 7, the bases 10a and 11a are fixed to the upper glass substrate 2 and the lower surface part thereof is fixed to the lower glass substrate 3 by anodic bonding or the like. Has been.

図６に示すように、可動電極部８の第１櫛歯部分８４と固定電極部１０の第３櫛歯部分１０Ｔとが互いに噛合されているとともに、可動電極部８の第２櫛歯部分８５と固定電極部１１の第４櫛歯部分１１Ｔとが互いに噛合されている。このとき、第１櫛歯部分８４の櫛歯電極８４ａと第３櫛歯部分１０Ｔの櫛歯電極１０Ｔａとの間、および第２櫛歯部分８５の櫛歯電極８５ａと第４櫛歯部分１１Ｔの櫛歯電極１１Ｔａとの間には、Ｙ方向に対して互いに逆となる側にそれぞれ所定の検知部が設けられている。そして、それぞれの検知部間のギャップに蓄積した静電気の変化（静電容量変化）を検出するようになっている。 As shown in FIG. 6, the first comb tooth portion 84 of the movable electrode portion 8 and the third comb tooth portion 10 T of the fixed electrode portion 10 are engaged with each other, and the second comb tooth portion 85 of the movable electrode portion 8. And the fourth comb tooth portion 11T of the fixed electrode portion 11 are meshed with each other. At this time, between the comb electrode 84a of the first comb tooth portion 84 and the comb electrode 10Ta of the third comb tooth portion 10T, and between the comb electrode 85a of the second comb tooth portion 85 and the fourth comb tooth portion 11T. Predetermined detection parts are provided between the comb-teeth electrodes 11Ta on opposite sides to the Y direction. And the change of the static electricity (capacitance change) accumulated in the gap between each detection part is detected.

そして、図７に示すように、上側のガラス基板２には、各端子１４〜１７に対応した部位にそれぞれテーパ状の開口部２Ｈがエッチングにより穿設され、これら開口部２Ｈの内周にそれぞれ設けた配線２Ｈｃを各端子１４〜１７に導通させてある。 Then, as shown in FIG. 7, the upper glass substrate 2 has a tapered opening 2H formed by etching at a portion corresponding to each of the terminals 14 to 17, and each of the openings 2H has an inner periphery. The provided wiring 2Hc is electrically connected to the terminals 14-17.

ここで、本実施形態では、固定電極部１０、１１の櫛歯部分１０Ｔ、１１Ｔのうち最両側に配置される一対の第１の櫛歯電極１０Ｔａ′，１０Ｔａ′、１１Ｔａ′，１１Ｔａ′の付け根部分に、その第１の櫛歯電極よりも幅広となる補強部２１を設けている。 Here, in the present embodiment, the roots of the pair of first comb-tooth electrodes 10Ta ′, 10Ta ′, 11Ta ′, 11Ta ′ arranged on the outermost sides of the comb-tooth portions 10T, 11T of the fixed electrode portions 10, 11 are used. A reinforcing portion 21 that is wider than the first comb electrode is provided in the portion.

また、それ以外の一対の第１の櫛歯電極１０Ｔａ′，１０Ｔａ′、１１Ｔａ′，１１Ｔａ′間に配置される第２の櫛歯電極１０Ｔａ″、１１Ｔａ″を、第１の櫛歯電極１０Ｔａ′、１１Ｔａ′よりも長く形成してある。 Further, the second comb electrodes 10Ta ″, 11Ta ″ arranged between the other pair of first comb electrodes 10Ta ′, 10Ta ′, 11Ta ′, 11Ta ′ are replaced with the first comb electrodes 10Ta ′. , 11Ta ′.

さらに、本実施形態では、第２の櫛歯電極１０Ｔａ″、１１Ｔａ″を長くしたことにより、可動電極部８の第２の櫛歯電極１０Ｔａ″、１１Ｔａ″の先端部と対向する位置に、その先端部が入り込む凹部２５が設けられている。 Furthermore, in the present embodiment, the second comb-tooth electrodes 10Ta ″ and 11Ta ″ are lengthened, so that the positions of the movable electrode portion 8 facing the tip portions of the second comb-tooth electrodes 10Ta ″ and 11Ta ″ are increased. A concave portion 25 into which the tip portion enters is provided.

以上の構成により、第５実施形態の加速度センサ１Ｄによれば、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の付け根部分に補強部２１を設けたので、その補強部２１によって第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の強度を高めることができる。これにより、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）がセンサ製造工程中の周波数で破損してしまうのを抑制することができる。 With the above configuration, according to the acceleration sensor 1D of the fifth embodiment, the reinforcing portion 21 is provided at the base portion of the first comb-tooth electrode 10Ta ′ (11Ta ′). The strength of the tooth electrode 10Ta ′ (11Ta ′) can be increased. Thereby, it can suppress that the 1st comb-tooth electrode 10Ta '(11Ta') breaks at the frequency in a sensor manufacturing process.

また、それ以外の第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）を、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）よりも長く形成したので、センサ感度が低下してしまうのを回避することができる。すなわち、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の付け根部分に補強部２１を設ける構成では、その補強部２１によって第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の櫛歯電極８４ａ（８５ａ）との対向面積がＡ１分だけ減少してしまうこととなる。しかしながら、第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）を第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）よりも長くすることで、その減少分を第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）の延長部分でＡ２分だけ補うことができ、センサ感度の低下を防止できる。 Further, since the other second comb-tooth electrode 10Ta ″ (11Ta ″) is formed longer than the first comb-tooth electrode 10Ta ′ (11Ta ′), it is possible to avoid a decrease in sensor sensitivity. Can do. That is, in the configuration in which the reinforcing portion 21 is provided at the base portion of the first comb-tooth electrode 10Ta ′ (11Ta ′), the reinforcing portion 21 causes the comb-tooth electrode 84a (85a) of the first comb-tooth electrode 10Ta ′ (11Ta ′). ) Will be reduced by A1. However, by making the second comb-teeth electrode 10Ta ″ (11Ta ″) longer than the first comb-teeth electrode 10Ta ′ (11Ta ′), the decrease is reduced to the second comb-teeth electrode 10Ta ″ (11Ta ″). It is possible to compensate for A2 by the extended portion of the sensor, and it is possible to prevent a decrease in sensor sensitivity.

また、本実施形態では、可動電極部８の第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）の先端部と対向する位置に、その第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）の先端部が入り込む凹部２５を設けている。そのため、可動電極部８が減少するのは長くした第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）の先端部と対向する位置のみであるため、可動電極部８の重量の減少を最小限度にとどめてセンサ感度が低下してしまうのを抑制できる。 Further, in the present embodiment, the tip of the second comb electrode 10Ta ″ (11Ta ″) is located at a position facing the tip of the second comb electrode 10Ta ″ (11Ta ″) of the movable electrode portion 8. A recessed portion 25 is provided. Therefore, the movable electrode portion 8 is reduced only at the position facing the tip of the elongated second comb-tooth electrode 10Ta ″ (11Ta ″), so that the weight reduction of the movable electrode portion 8 is minimized. Thus, it is possible to suppress a decrease in sensor sensitivity.

なお、本実施形態が上記第３実施形態と異なる点は、本実施形態では第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）を３つ（複数）用いるようにしているが、第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）は１つでもいい点である。また、第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）を複数用いた場合には、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）よりも長ければ、それらを必ずしも等しい長さに形成する必要がない点である。 Note that the present embodiment differs from the third embodiment in that three (plural) second comb electrodes 10Ta ″ (11Ta ″) are used in the present embodiment. One electrode 10Ta ″ (11Ta ″) is sufficient. Further, when a plurality of second comb-tooth electrodes 10Ta ″ (11Ta ″) are used, it is necessary to form them in equal length if they are longer than the first comb-tooth electrodes 10Ta ′ (11Ta ′). There is no point.

[第６実施形態]
図８は、本発明の第６実施形態を示した図であり、上記第５実施形態と同一構成部分には同一符号を付して重複する説明を省略して述べるものとする。 [Sixth Embodiment]
FIG. 8 is a diagram showing a sixth embodiment of the present invention. The same components as those in the fifth embodiment are denoted by the same reference numerals, and redundant description is omitted.

本実施形態の加速度センサ１Ｅが、上記第５実施形態の加速度センサ１Ｄと主に異なる点は、補強部２１Ａを第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の付け根部分から固定電極部の基部１０ａ（１１ａ）に向かって、滑らかに拡幅する円弧状に形成したことにある。また、本実施形態では、第２の櫛歯電極１０Ｔａ″（１１Ｔａ″）の先端部を受け入れる凹部２５Ａにあっても円弧状に形成している。その他の構成は第５実施形態と同様である。 The acceleration sensor 1E of the present embodiment is mainly different from the acceleration sensor 1D of the fifth embodiment in that the reinforcing portion 21A is changed from the root portion of the first comb electrode 10Ta ′ (11Ta ′) to the base portion of the fixed electrode portion. 10a (11a) is formed in an arc shape that smoothly widens. In the present embodiment, the second comb-shaped electrode 10Ta ″ (11Ta ″) is formed in an arc shape even in the concave portion 25A that receives the tip portion. Other configurations are the same as those of the fifth embodiment.

以上の構成により、第６実施形態の加速度センサ１Ｅによれば、上記第５実施形態と同様の作用効果を得ることができるとともに、補強部２１Ａを内側が滑らかに連続する円弧形状としてある。これにより、第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の付け根部分への応力集中を緩和することができ、その第１の櫛歯電極１０Ｔａ′（１１Ｔａ′）の破損抑制効果をより一層高めることができる。 With the above configuration, according to the acceleration sensor 1E of the sixth embodiment, the same operational effects as those of the fifth embodiment can be obtained, and the reinforcing portion 21A has an arc shape in which the inner side is smoothly continuous. As a result, the stress concentration on the base portion of the first comb-tooth electrode 10Ta ′ (11Ta ′) can be alleviated, and the damage-suppressing effect of the first comb-tooth electrode 10Ta ′ (11Ta ′) can be further enhanced. be able to.

以上、本発明の好適な実施形態について説明したが、本発明は上記実施形態には限定されず、種々の変形が可能である。 The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various modifications can be made.

例えば、上記実施形態では、半導体物理量センサとして加速度センサを例示したが、これに限ることなく、可動電極を変位させる物理量であれば、その物理量の検出センサとして本発明を適用できる。 For example, in the above embodiment, the acceleration sensor is exemplified as the semiconductor physical quantity sensor. However, the present invention is not limited to this, and the present invention can be applied as a detection sensor for the physical quantity as long as the physical quantity displaces the movable electrode.

１、１Ａ、１Ｂ、１Ｃ、１Ｄ、１Ｅ加速度センサ（半導体物理量センサ）
６アンカー部
８可動電極部
１０、１１固定電極部
１０Ｔ第３櫛歯部分（固定電極部の櫛歯部分）
１０Ｔａ′ 第１の櫛歯電極
１０Ｔａ″ 第２の櫛歯電極
１１Ｔ第４櫛歯部分（固定電極部の櫛歯部分）
１１Ｔａ′ 第１の櫛歯電極
１１Ｔａ″ 第２の櫛歯電極
１２ばね部
２０拡張部
２１、２１Ａ補強部 1, 1A, 1B, 1C, 1D, 1E Acceleration sensor (Semiconductor physical quantity sensor)
6 Anchor part 8 Movable electrode part 10, 11 Fixed electrode part 10T 3rd comb tooth part (comb tooth part of a fixed electrode part)
10Ta ′ first comb-tooth electrode 10Ta ″ second comb-tooth electrode 11T fourth comb-tooth portion (comb-tooth portion of the fixed electrode portion)
11Ta '1st comb-tooth electrode 11Ta "2nd comb-tooth electrode 12 Spring part 20 Expansion part 21, 21A Reinforcement part

Claims

An anchor part,
A movable electrode portion swingably supported by the anchor portion via a spring portion;
A fixed electrode part meshed with the movable electrode part in a comb-tooth shape,
The fixed electrode portion includes a pair of first comb electrodes disposed on the outermost side of the comb-tooth portion, and a plurality of second comb electrodes disposed between the first comb-tooth electrodes. And
A semiconductor physical quantity sensor characterized in that the first comb-teeth electrode is formed shorter than the second comb-teeth electrode, and the second comb-teeth electrodes are formed to have the same length.

2. The semiconductor physical quantity sensor according to claim 1, wherein the movable electrode portion is provided with an extension portion that fills an empty space portion formed by shortening the first comb electrode. 3.

3. The semiconductor physical quantity sensor according to claim 1, wherein a reinforcing portion that is wider than the first comb electrode is provided at a base portion of the first comb electrode. 4.

An anchor part,
A movable electrode portion swingably supported by the anchor portion via a spring portion;
A fixed electrode part meshed with the movable electrode part in a comb-tooth shape,
The fixed electrode portion includes a pair of first comb electrodes disposed on the outermost side of the comb portion, and one or a plurality of second comb electrodes disposed between the first comb electrodes. And
A reinforcing portion that is wider than the first comb-teeth electrode is provided at the base of the first comb-teeth electrode, and the second comb-teeth electrode is formed longer than the first comb-teeth electrode. A semiconductor physical quantity sensor characterized by that.

5. The semiconductor physical quantity according to claim 4, wherein a concave portion into which the tip portion of the second comb electrode is inserted is provided at a position of the movable electrode portion facing the tip portion of the second comb electrode. Sensor.

The said reinforcement part was expanded in circular arc shape toward the base of the said fixed electrode part from the base part of the said 1st comb-tooth electrode, The any one of Claims 3-5 characterized by the above-mentioned. Semiconductor physical quantity sensor.