JP2021021745A

JP2021021745A - Strain body

Info

Publication number: JP2021021745A
Application number: JP2020185021A
Authority: JP
Inventors: 豊彦赤田; Toyohiko Akata; 四輩熊; Xiong Si-Bei; 成晃新行内; Naruaki Shingyouchi
Original assignee: Nidec Copal Electronics Corp
Current assignee: Nidec Copal Electronics Corp
Priority date: 2020-11-05
Filing date: 2020-11-05
Publication date: 2021-02-18
Anticipated expiration: 2037-02-24
Also published as: JP7073471B2

Abstract

To provide a strain body capable of improving reliability while ensuring secure electrical connection between an electrode terminal and a lead wiring terminal, and a force sensor including the strain body.SOLUTION: A strain body 16 according to an embodiment includes: a center part 161; an outer periphery part 162 enclosing surroundings of the center part; a plurality of connection parts 163 connecting the center part to the outer periphery part; a plurality of strain sensors S1 to S32 disposed on a principal face of the connection part; a plurality of reference resistances RS4 to RS30 which are disposed on the principal face of the center part and constituting bridge circuits together with the plurality of strain sensors; an electrode 171 which is disposed on the principal face of the center part and electrically connected to the plurality of strain sensors and the plurality of reference resistances, and takes detection signals from the bridge circuits; lead wiring 182 electrically connecting the electrode to the outside; and an anisotropic conductive film 181 disposed between the electrode and the lead wiring to electrically connect a terminal of the electrode and a terminal of the lead wiring.SELECTED DRAWING: Figure 13

Description

本発明の実施形態は、例えば起歪体を備えロボットアームに適用可能な６軸力覚センサ等に関する。 An embodiment of the present invention relates to, for example, a 6-axis force sensor having a strain-causing body and applicable to a robot arm.

例えばロボットアーム等に用いられ、ＸＹＺ方向の外力およびトルクを検出する６軸力覚センサが知られている（例えば、特許文献１、２参照）。 For example, a 6-axis force sensor that is used for a robot arm or the like and detects an external force and a torque in the XYZ directions is known (see, for example, Patent Documents 1 and 2).

このような力覚センサにおいて、可動部としての受力体に加えられた外力は、起歪体に伝達され、起歪体に設けられた歪センサ（歪ゲージ）の変形が電気信号に変換されて検出される。 In such a force sensor, the external force applied to the receiving body as a movable part is transmitted to the strain generating body, and the deformation of the strain sensor (strain gauge) provided on the strain generating body is converted into an electric signal. Is detected.

このような歪センサを備えた起歪体の応用範囲は、近年のコンピュータ技術や情報通信技術の進展に伴ってますます拡大する傾向にあり、起歪体の更なる小型化および高性能化が求められている。 The range of applications of strain generators equipped with such strain sensors tends to expand with the progress of computer technology and information and communication technology in recent years, and further miniaturization and higher performance of strain generators are required. It has been demanded.

特開２０１５−４２９２０９号公報JP-A-2015-429209 特開２０１３−６１３０５号公報Japanese Unexamined Patent Publication No. 2013-61305

しかしながら、起歪体の更なる小型化および高性能化に伴って、歪センサからの検知信号を外部に取り出すための電極端子の隣接間の距離であるピッチが非常に狭くなっている。そのため、電極端子の位置と検出信号を外部に取り出すためのリード配線の端子の位置とが極わずかにずれた場合でも、正常な検知信号が外部に取り出せないという事情がある。このように、従来では、電極端子とリード配線端子と間の確実な電気的接続を確保しつつ、信頼性を向上できる起歪体を提供することは困難であった。 However, with the further miniaturization and higher performance of the strain generating body, the pitch, which is the distance between the adjacent electrode terminals for extracting the detection signal from the strain sensor to the outside, becomes very narrow. Therefore, even if the position of the electrode terminal and the position of the terminal of the lead wiring for extracting the detection signal to the outside are slightly deviated, there is a circumstance that the normal detection signal cannot be extracted to the outside. As described above, conventionally, it has been difficult to provide a strain-causing body capable of improving reliability while ensuring a reliable electrical connection between the electrode terminal and the lead wiring terminal.

そこで、本発明の実施形態では、上記実情を鑑み、電極端子とリード配線端子と間の確実な電気的接続を確保しつつ、信頼性を向上できる起歪体およびその起歪体を備えた力覚センサを提供する。 Therefore, in the embodiment of the present invention, in view of the above circumstances, a strain-causing body capable of improving reliability while ensuring a reliable electrical connection between the electrode terminal and the lead wiring terminal, and a force provided with the strain-causing body. Provides a sensory sensor.

実施形態に係る起歪体は、中央部と、前記中央部の周囲を囲む外周部と、前記中央部と前記外周部とを接続する複数の接続部と、前記接続部の主表面上に設けられる複数の歪センサと、前記中央部の主表面上に設けられ、前記複数の歪センサと共にブリッジ回路を構成する複数の参照抵抗と、前記中央部の主表面上に設けられ、前記複数の歪センサおよび前記複数の参照抵抗と電気的に接続され、前記ブリッジ回路の検出信号を取り出すための電極と、前記電極と外部とを電気的に接続するリード配線と、前記電極と前記リード配線との間に設けられ、前記電極の端子と前記リード配線の端子とを電気的に接続する異方性導電フィルムと、を具備する。 The strain-causing body according to the embodiment is provided on a central portion, an outer peripheral portion surrounding the periphery of the central portion, a plurality of connecting portions connecting the central portion and the outer peripheral portion, and a main surface of the connecting portion. A plurality of strain sensors, a plurality of reference resistors provided on the main surface of the central portion and forming a bridge circuit together with the plurality of strain sensors, and the plurality of strains provided on the main surface of the central portion. An electrode that is electrically connected to the sensor and the plurality of reference resistors to take out a detection signal of the bridge circuit, a lead wiring that electrically connects the electrode and the outside, and the electrode and the lead wiring. An anisotropic conductive film provided between the electrodes and electrically connecting the terminals of the electrodes and the terminals of the lead wiring is provided.

第１実施形態に係る起歪体の全体構成を示す斜視図A perspective view showing the overall configuration of the strain-causing body according to the first embodiment. 図１の起歪体の平面構成を示す平面図A plan view showing a plan configuration of the strain-causing body of FIG. 図１の起歪体の主表面側から見た中央部および接続部を詳細に示す平面図Top view showing in detail the central portion and the connecting portion seen from the main surface side of the strain-causing body of FIG. 図３の歪センサを含む接続部の断面図Sectional drawing of the connection part including the strain sensor of FIG. 第１実施形態に係る起歪体のブリッジ回路およびフルブリッジ回路を説明するための回路図A circuit diagram for explaining a strain-causing bridge circuit and a full-bridge circuit according to the first embodiment. 検出回路と検出する力およびモーメントとの関係を示す図Diagram showing the relationship between the detection circuit and the force and moment to be detected 第１実施形態に係る起歪体の製造方法を説明するためのフローチャートA flowchart for explaining a method for manufacturing a strain-causing body according to a first embodiment. 第２実施形態に係る起歪体の裏面側から見た全体構成を示す斜視図A perspective view showing an overall configuration seen from the back surface side of the strain-causing body according to the second embodiment. 図８の破線で囲った歪増大部を拡大して示す断面図A cross-sectional view showing an enlarged portion of the strain increasing portion surrounded by the broken line in FIG. 第２実施形態に係る起歪体の主表面側から見た全体構成を示す斜視図Perspective view showing the overall configuration seen from the main surface side of the strain-causing body according to the second embodiment. 第１実施形態に係る起歪体を備えた力覚センサの外観を示す斜視図Perspective view showing the appearance of the force sensor provided with the strain-causing body according to the first embodiment. 図１１の力覚センサの分解斜視図An exploded perspective view of the force sensor of FIG. 力覚センサに実装される状態の起歪体を示す断面図Cross-sectional view showing a strain-causing body mounted on a force sensor 図１３の起歪体上に異方性導電フィルムを用いて電極とリード配線とを接続する方法を説明するための断面図A cross-sectional view for explaining a method of connecting an electrode and a lead wiring using an anisotropic conductive film on the strain-causing body of FIG. 図１３の起歪体と異方性導電フィルムとが所定の位置に配置された状態を示す平面図A plan view showing a state in which the strain-causing body and the anisotropic conductive film of FIG. 13 are arranged at predetermined positions. 図１５の実線で囲った部分を拡大して示す平面図A plan view showing an enlarged portion of the portion surrounded by the solid line in FIG. 異方性導電フィルムを用いて電極の端子とリード配線の端子とが電気的に接続されることを模式的に説明するための断面図Sectional drawing for schematically explaining that the terminal of an electrode and the terminal of a lead wiring are electrically connected by using an anisotropic conductive film. 電極パッドの位置と異方性導電フィルムの抵抗値との関係を示すグラフGraph showing the relationship between the position of the electrode pad and the resistance value of the anisotropic conductive film 第４実施形態に係る起歪体の主表面側から見た全体構成を示す斜視図Perspective view showing the whole structure seen from the main surface side of the strain-causing body which concerns on 4th Embodiment

以下、実施の形態について、図面を参照して説明する。なお、以下の説明において、実質的に同一の機能及び要素については、同一符号を付し、必要に応じて説明を行う。また、図面は模式的なものであり、厚みと平面寸法との関係や各層の厚みの比率などは現実のものと異なることがある。 Hereinafter, embodiments will be described with reference to the drawings. In the following description, substantially the same functions and elements are designated by the same reference numerals and will be described as necessary. Further, the drawings are schematic, and the relationship between the thickness and the plane dimension and the ratio of the thickness of each layer may differ from the actual ones.

（第１実施形態）
［構成］
全体構成
図１、図２を用いて第１実施形態に係る起歪体の全体構成について説明する。図１は、第１実施形態に係る起歪体の全体構成を示す斜視図である。図２は、図１の起歪体の平面構成を示す平面図である。 (First Embodiment)
[Constitution]
Overall Configuration The overall configuration of the strain-causing body according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing the overall configuration of the strain-causing body according to the first embodiment. FIG. 2 is a plan view showing a plan configuration of the strain-causing body of FIG.

図１および図２に示すように、第１実施形態に係る起歪体１６は、中央部１６１、中央部１６１の周囲を囲む外周部１６２、中央部１６１と外周部１６２とを接続する４つの接続部１６３を備える。起歪体１６は、例えばステンレス等の所定の金属等により構成される。 As shown in FIGS. 1 and 2, the strain-causing body 16 according to the first embodiment has four central portions 161 and four outer peripheral portions 162 surrounding the periphery of the central portion 161, connecting the central portion 161 and the outer peripheral portion 162. A connection portion 163 is provided. The strain generating body 16 is made of a predetermined metal such as stainless steel.

中央部１６１は、外周部１６２の角部を結んだ２本の対角線Ｌ１の交点である中心Ｏを含む。また、中央部１６１には、後述するブリッジ回路を構成するための複数の参照抵抗が設けられる。中央部１６１の角部には、外部部材である第１支持部材に固定するための４つのネジ穴１８ａが設けられる。各ネジ穴１８ａは、省スペース化のために、対角線Ｌ１の方向に沿って中心側から外側へ中空部ＯＰ１において突出するように設けられる。 The central portion 161 includes a center O which is an intersection of two diagonal lines L1 connecting the corner portions of the outer peripheral portion 162. Further, the central portion 161 is provided with a plurality of reference resistors for forming a bridge circuit described later. Four screw holes 18a for fixing to the first support member, which is an external member, are provided at the corners of the central portion 161. Each screw hole 18a is provided so as to project from the center side to the outside in the hollow portion OP1 along the direction of the diagonal line L1 in order to save space.

外周部１６２の角部には、外部部材である第１支持部材と異なる第２支持部材に固定するための４つのネジ穴１７ａが設けられる。各ネジ穴１７ａは、省スペース化のために、対角線Ｌ１の方向に沿って外側から中心側へ中空部ＯＰ１において突出するように設けられる。 The corners of the outer peripheral portion 162 are provided with four screw holes 17a for fixing to a second support member different from the first support member which is an external member. Each screw hole 17a is provided so as to project from the outside to the center side in the hollow portion OP1 along the direction of the diagonal line L1 in order to save space.

接続部１６３は、Ｘ方向またはＹ方向に沿って中心Ｏから放射状に４つ設けられている。接続部１６３には、ここでは図示しないが、ＸＹＺ方向の外力およびトルクを検出するための複数の歪センサが設けられる。接続部１６３の幅は、中心Ｏ側から外側に向かってほぼ同一となるように構成される。 Four connecting portions 163 are provided radially from the center O along the X direction or the Y direction. Although not shown here, the connection portion 163 is provided with a plurality of strain sensors for detecting external force and torque in the XYZ directions. The width of the connecting portion 163 is configured to be substantially the same from the center O side to the outside.

また、Ｚ方向に沿った起歪体１６の高さＨｚは、中央部１６１、外周部１６２、および接続部１６３において共通であるため、実質的に同一である。起歪体１６の高さＨｚは、Ｘ方向またはＹ方向に沿った外周部１６２の幅Ｗ１６２よりも大きくなるように構成される（Ｈｚ＞Ｗ１６２）。 Further, the height Hz of the strain generating body 16 along the Z direction is substantially the same because it is common to the central portion 161, the outer peripheral portion 162, and the connecting portion 163. The height Hz of the strain-causing body 16 is configured to be larger than the width W162 of the outer peripheral portion 162 along the X direction or the Y direction (Hz> W162).

さらに、外周部１６２および接続部１６３の弾性は、中央部１６１の弾性よりも大きくなるように構成される。より好ましくは、外周部１６２および接続部１６３は弾性機能を有し、中央部１６１は弾性機能を有さないように構成されることである。ここで、弾性機能とは、入力される外力およびトルクによって積極的に弾性変形が生じる機能をいう。 Further, the elasticity of the outer peripheral portion 162 and the connecting portion 163 is configured to be larger than the elasticity of the central portion 161. More preferably, the outer peripheral portion 162 and the connecting portion 163 have an elastic function, and the central portion 161 does not have an elastic function. Here, the elastic function refers to a function in which elastic deformation is positively caused by an input external force and torque.

より具体的には、中央部１６１の弾性変形の歪量は、定格荷重時に３×１０^−６以下であることが望ましく、さらに望ましくは１×１０^−６以下であることである。接続部（梁部）１６３の弾性変形は、定格荷重時に材料弾性限界内であって、歪量で２×１０^−５以上であることが望ましく、さらに望ましくは２×１０^−４以上であることである。外周部１６２の弾性変形は、定格荷重時に材料弾性限界内であって、最大撓み部分の撓み量が２０μｍ以上であることが望ましく、さらに望ましくは５０μｍ以上であることである。 More specifically, the strain amount of the elastic deformation of the central portion 161 is preferably 3 × 10 ^-6 or less, and more preferably 1 × 10 ^-6 or less at the rated load. The elastic deformation of the connecting portion (beam portion) 163 is within the material elastic limit at the rated load, and the strain amount is preferably 2 × 10 ^-5 or more, and more preferably 2 × 10 ^-4 or more. Is. The elastic deformation of the outer peripheral portion 162 is within the material elastic limit at the rated load, and the amount of deflection of the maximum bending portion is preferably 20 μm or more, and more preferably 50 μm or more.

詳細構成
図３を用いて第１実施形態に係る起歪体１６の詳細な平面構成について説明する。図３は、起歪体１６の歪センサ等が設けられた主表面側から見た中央部１６１および接続部１６３を詳細に示す平面図である。 Detailed configuration The detailed planar configuration of the strain generating body 16 according to the first embodiment will be described with reference to FIG. FIG. 3 is a plan view showing in detail the central portion 161 and the connecting portion 163 as viewed from the main surface side where the strain sensor of the strain generating body 16 is provided.

図３に示すように、接続部１６３の主表面上には、２４個の歪センサ（歪ゲージ）Ｓ１、Ｓ２、Ｓ３、Ｓ５、Ｓ７、Ｓ８、Ｓ９、Ｓ１０、Ｓ１１、Ｓ１３、Ｓ１５、Ｓ１６、Ｓ１７、Ｓ１８、Ｓ１９、Ｓ２１、Ｓ２３、Ｓ２４、Ｓ２５、Ｓ２６、Ｓ２７、Ｓ２９、Ｓ３１、Ｓ３２が設けられる。歪センサＳ１〜Ｓ３２は、後述するように金属薄膜抵抗体であって、例えばクロム（Ｃｒ）および窒素（Ｎ）を含む抵抗体（Ｃｒ−Ｎ抵抗体）である。そのため、後述するようにパターンニングのみで所望な位置に複数の歪センサＳ１〜Ｓ３２を配置できる。また、Ｃｒ−Ｎ抵抗体は、温度係数が小さいため、温度補償を容易とすることができる。歪センサＳ１〜Ｓ３２の長手方向は、Ｘ方向またはＹ方向となるように構成される。 As shown in FIG. 3, on the main surface of the connecting portion 163, 24 strain sensors (strain gauges) S1, S2, S3, S5, S7, S8, S9, S10, S11, S13, S15, S16, S17, S18, S19, S21, S23, S24, S25, S26, S27, S29, S31, S32 are provided. The strain sensors S1 to S32 are metal thin film resistors as described later, and are, for example, resistors (Cr—N resistors) containing chromium (Cr) and nitrogen (N). Therefore, as will be described later, a plurality of strain sensors S1 to S32 can be arranged at desired positions only by patterning. Further, since the Cr—N resistor has a small temperature coefficient, temperature compensation can be facilitated. The longitudinal directions of the strain sensors S1 to S32 are configured to be the X direction or the Y direction.

中央部１６１の主表面上には、８個の参照抵抗ＲＳ４、ＲＳ６、ＲＳ１２、ＲＳ１４、ＲＳ２０、ＲＳ２２、ＲＳ２８、ＲＳ３０が設けられる。参照抵抗ＲＳ４〜ＲＳ３０の形状および材料は、実質的に歪センサＳ１〜Ｓ３２と同一であり、その長手方向はＸ方向またはＹ方向となるように構成される。さらに、中央部１６１の主表面上には、中央部１６１の対角線Ｌ１の方向の一方に沿って電極１７１が設けられる。 Eight reference resistors RS4, RS6, RS12, RS14, RS20, RS22, RS28 and RS30 are provided on the main surface of the central portion 161. The shapes and materials of the reference resistors RS4 to RS30 are substantially the same as those of the strain sensors S1 to S32, and the longitudinal direction thereof is configured to be the X direction or the Y direction. Further, an electrode 171 is provided on the main surface of the central portion 161 along one of the diagonal L1 directions of the central portion 161.

歪センサと参照抵抗とが後述する４つのブリッジ回路を構成し、歪センサが後述する４つのフルブリッジ回路を構成するように、配線１７２が主表面上に配置される。配線１７２は、電極１７１の所定の端子に電気的に接続される。配線１７２の線幅は、歪センサＳ１〜Ｓ３２と参照抵抗ＲＳ４〜ＲＳ３０とを接続する部分においては小さくなるように構成される一方、その他の部分においては配線抵抗を低減するために接続部分に比べて大きくなるように構成される。 Wiring 172 is arranged on the main surface so that the strain sensor and the reference resistor form four bridge circuits described below and the strain sensor constitutes four full bridge circuits described below. The wiring 172 is electrically connected to a predetermined terminal of the electrode 171. The line width of the wiring 172 is configured to be smaller in the portion connecting the strain sensors S1 to S32 and the reference resistors RS4 to RS30, while in the other portions, in order to reduce the wiring resistance, it is compared with the connecting portion. Is configured to grow.

しかも、歪センサＳ１〜Ｓ３２、参照抵抗ＳＲ４〜ＲＳ３０、電極１７１、および配線１７２は、後述する薄膜技術を利用した製造方法を用いて、起歪体１６の同一の主表面上に一体的に形成される。そのため、歪センサＳ１〜Ｓ３２、参照抵抗ＲＳ４〜ＲＳ３０、電極１７１、および配線１７２は、起歪体１６の対角線Ｌ１において鏡像対称となるようにレイアウト構成される。 Moreover, the strain sensors S1 to S32, the reference resistors SR4 to RS30, the electrodes 171 and the wiring 172 are integrally formed on the same main surface of the strain generating body 16 by using a manufacturing method using a thin film technique described later. Will be done. Therefore, the strain sensors S1 to S32, the reference resistors RS4 to RS30, the electrodes 171 and the wiring 172 are laid out so as to be mirror-symmetrical on the diagonal line L1 of the strain generator 16.

図４を用いて起歪体１６の詳細な断面構成について説明する。図４は、図３の歪センサＳ１を含む接続部１６３の断面図である。 The detailed cross-sectional structure of the strain generating body 16 will be described with reference to FIG. FIG. 4 is a cross-sectional view of the connecting portion 163 including the strain sensor S1 of FIG.

図４に示すように、接続部１６３の主表面上に絶縁膜１７０が設けられる。絶縁膜１７０上に感歪膜としてのＣｒ−Ｎ抵抗体である歪センサＳ１が設けられる。歪センサＳ１上に銅（Ｃｕ）にて形成された電極リード膜である配線１７２が設けられる。歪センサＳ１上および配線１７２上を覆うようにオバーガラス（ＯＧ）膜１７５が設けられる。また、配線１７２と歪センサＳ１との界面および配線１７２とＯＧ膜１７５との界面には、密着性を高めるためにクロム（Ｃｒ）を含む接着膜１７２ａが設けられる。 As shown in FIG. 4, the insulating film 170 is provided on the main surface of the connecting portion 163. A strain sensor S1 which is a Cr—N resistor as a strain sensitive film is provided on the insulating film 170. Wiring 172, which is an electrode lead film formed of copper (Cu), is provided on the strain sensor S1. An overglass (OG) film 175 is provided so as to cover the strain sensor S1 and the wiring 172. Further, an adhesive film 172a containing chromium (Cr) is provided at the interface between the wiring 172 and the strain sensor S1 and the interface between the wiring 172 and the OG film 175 in order to improve the adhesion.

尚、この断面では図示していないが、中央部１６１において配線１７２に接続される電極１７１は、接着膜１７２ａ上に順次設けられた銅（Ｃｕ）と金（Ａｕ）との積層構造により構成される。 Although not shown in this cross section, the electrode 171 connected to the wiring 172 in the central portion 161 is composed of a laminated structure of copper (Cu) and gold (Au) sequentially provided on the adhesive film 172a. To.

ブリッジ回路、フルブリッジ回路
図５は、第１実施形態に係る起歪体１６のブリッジ回路およびフルブリッジ回路を示す回路図である。 Bridge Circuit, Full Bridge Circuit FIG. 5 is a circuit diagram showing a bridge circuit and a full bridge circuit of the strain generating element 16 according to the first embodiment.

図５に示すように、起歪体１６は、４つのブリッジ回路ＢＦ２、ＢＦ４、ＢＦ６、ＢＦ８と、４つのフルブリッジ回路ＢＦ１、ＢＦ３、ＢＦ５、ＢＦ７と、を備える。 As shown in FIG. 5, the strain generating body 16 includes four bridge circuits BF2, BF4, BF6, BF8 and four full bridge circuits BF1, BF3, BF5, BF7.

ブリッジ回路ＢＦ２は、２つの歪センサ（第１歪センサ）Ｓ３、Ｓ５と２つの参照抵抗ＲＳ４、ＲＳ６とを備える。電源端子Ｅと接地Ｇとの間に、順次、歪センサＳ３および参照抵抗ＲＳ４、並びに参照抵抗ＲＳ６および歪センサＳ５が直列接続される。直列接続された歪センサＳ３および参照抵抗ＲＳ４と、直列接続された参照抵抗ＲＳ６および歪センサＳ５とは、電源端子Ｅと接地Ｇの間で並列に接続される。一方の端子Ｖ−は、歪センサＳ３と参照抵抗ＲＳ４との結線に接続される。他方の端子Ｖ＋は、参照抵抗ＲＳ６と歪センサＳ５との結線に接続される。その他のブリッジ回路ＢＦ４、ＢＦ６、ＢＦ８についても、上記ブリッジ回路ＢＦ２と同様である。 The bridge circuit BF2 includes two strain sensors (first strain sensor) S3 and S5 and two reference resistors RS4 and RS6. The strain sensor S3 and the reference resistor RS4, and the reference resistor RS6 and the strain sensor S5 are sequentially connected in series between the power supply terminal E and the ground G. The strain sensor S3 and the reference resistor RS4 connected in series and the reference resistor RS6 and the strain sensor S5 connected in series are connected in parallel between the power supply terminal E and the ground G. One terminal V- is connected to the connection between the strain sensor S3 and the reference resistor RS4. The other terminal V + is connected to the connection between the reference resistor RS6 and the strain sensor S5. The other bridge circuits BF4, BF6, and BF8 are the same as those of the bridge circuit BF2.

フルブリッジ回路ＢＦ１は、４つの歪センサ（第２歪センサ）Ｓ１、Ｓ２、Ｓ７、Ｓ８により構成される。電源端子Ｅと接地Ｇとの間に、順次、歪センサＳ１およびＳ２、並びに歪センサＳ７およびＳ８が直列接続される。直列接続された歪センサＳ１およびＳ２と、直列接続された歪センサＳ７およびＳ８とは、電源端子Ｅと接地Ｇの間で並列に接続される。一方の端子Ｖ−は、歪センサＳ１、Ｓ２の結線に接続される。他方の端子Ｖ＋は、歪センサＳ７、Ｓ８の結線に接続される。その他のフルブリッジ回路ＢＦ３、ＢＦ５、ＢＦ７についても、上記フルブリッジ回路ＢＦ１と同様である。 The full bridge circuit BF1 is composed of four strain sensors (second strain sensors) S1, S2, S7, and S8. Strain sensors S1 and S2 and strain sensors S7 and S8 are sequentially connected in series between the power supply terminal E and the ground G. The strain sensors S1 and S2 connected in series and the strain sensors S7 and S8 connected in series are connected in parallel between the power supply terminal E and the ground G. One terminal V- is connected to the connection of the strain sensors S1 and S2. The other terminal V + is connected to the connection of the strain sensors S7 and S8. The other full bridge circuits BF3, BF5, and BF7 are the same as those of the full bridge circuit BF1.

上記構成において、外部から力およびトルク（モーメント）が加わると、中央部１６１の位置が外周部１６２の位置に比較して相対的に変化するため、接続部１６３が力およびトルクに応じて変形する。この接続部１６３の変形に応じ、接続部１６３に設けられた各歪センサＳ１〜Ｓ３２に応力が加わり、各ブリッジ回路および各フルブリッジ回路の各端子Ｖ−、Ｖ＋の電圧のバランスが崩れ、力およびトルクに応じた所定の検出信号が検出される。 In the above configuration, when a force and torque (moment) are applied from the outside, the position of the central portion 161 changes relative to the position of the outer peripheral portion 162, so that the connecting portion 163 is deformed according to the force and torque. .. In response to the deformation of the connection portion 163, stress is applied to the strain sensors S1 to S32 provided in the connection portion 163, and the voltage balance of the terminals V- and V + of each bridge circuit and each full bridge circuit is lost, resulting in a force. And a predetermined detection signal according to the torque is detected.

また、図６は、検出回路と検出する力およびモーメントの関係を示す図である。図６に示すように、フルブリッジ回路ＢＦ３、ＢＦ７は、Ｘ方向の力ＦｘおよびＺ方向のモーメントＭｚを検出する。フルブリッジ回路ＢＦ１、ＢＦ５は、Ｙ方向の力ＦｙおよびＺ方向のモーメントＭｚを検出する。ブリッジ回路ＢＦ２、ＢＦ６は、Ｚ方向の力ＦｚおよびＹ方向のモーメントＭｙを検出する。ブリッジ回路ＢＦ４、ＢＦ８は、Ｚ方向の力ＦｚおよびＸ方向のモーメントＭｘを検出する。上記構成により、６軸方向の力およびトルクを検出できる。 Further, FIG. 6 is a diagram showing the relationship between the detection circuit and the force and moment to be detected. As shown in FIG. 6, the full bridge circuits BF3 and BF7 detect the force Fx in the X direction and the moment Mz in the Z direction. The full bridge circuits BF1 and BF5 detect the force Fy in the Y direction and the moment Mz in the Z direction. The bridge circuits BF2 and BF6 detect the force Fz in the Z direction and the moment My in the Y direction. The bridge circuits BF4 and BF8 detect the force Fz in the Z direction and the moment Mx in the X direction. With the above configuration, force and torque in the 6-axis direction can be detected.

［製造方法］
図７は、第１実施形態に係る起歪体１６の製造方法を説明するためのフローチャートである。 [Production method]
FIG. 7 is a flowchart for explaining a method of manufacturing the strain-causing body 16 according to the first embodiment.

図７に示すように、まず起歪体１６の寸法検査等の所定の検査を行った後、起歪体１６に対して所定の前処理を行う。前処理としては、例えば検査後の起歪体１６の主表面上を、超音波や所定の薬剤等を用いた洗浄処理等が含まれる（Ｂ１）。 As shown in FIG. 7, first, a predetermined inspection such as a dimensional inspection of the strain generating body 16 is performed, and then a predetermined pretreatment is performed on the strain generating body 16. The pretreatment includes, for example, a cleaning treatment of the main surface of the strain-causing body 16 after the inspection using ultrasonic waves, a predetermined chemical, or the like (B1).

続いて、前処理後の起歪体１６の主表面上に、例えば熱酸化法等を用いて絶縁膜１７０を成膜する（Ｂ２）。 Subsequently, an insulating film 170 is formed on the main surface of the strain-causing body 16 after the pretreatment by, for example, a thermal oxidation method (B2).

続いて、例えば所定のアニーリング処理等による熱処理を起歪体１６に行い、成膜した絶縁膜１７０の絶縁性等の特性が所定値以上となるように特性出しを行う（Ｂ３）。 Subsequently, for example, a heat treatment by a predetermined annealing treatment or the like is performed on the strain generating body 16, and the characteristics such as the insulating property of the formed insulating film 170 are set to be equal to or higher than a predetermined value (B3).

続いて、絶縁膜１７０上に、例えば所定のターゲットを用いたスパッタ法等を用いて、クロム（Ｃｒ）および窒素（Ｎ）を含んだＣｒ−Ｎ薄膜を形成する。さらに、形成したＣｒ−Ｎ薄膜上にフォトレジストを塗布し、塗布したフォトレジストにパターニングを行う。具体的には、中央部１６１の参照抵抗ＲＳ４〜ＲＳ３０が配置される位置に参照抵抗ＲＳ４〜ＲＳ３０と同一の平面形状のパターンをフォトレジストに転写し、接続部１６３の歪センサＳ１〜Ｓ３２が配置される位置に歪センサＳ１〜Ｓ３２と同一の平面形状のパターンをフォトレジストに転写し、パターンが転写された部分以外のフォトレジストを除去しパターンを現像する。さらに、パターンが現像されたフォトレジストをマスクとして、所定のエッチング処理を絶縁膜１７０の表面上まで行うことで、中央部１６１および接続部１６３の所定の位置に所望の形状の参照抵抗ＲＳ４〜ＲＳ３０および歪センサＳ１〜Ｓ３２を形成する（Ｂ４）。 Subsequently, a Cr—N thin film containing chromium (Cr) and nitrogen (N) is formed on the insulating film 170 by, for example, a sputtering method using a predetermined target. Further, a photoresist is applied onto the formed Cr—N thin film, and the coated photoresist is patterned. Specifically, the same planar pattern as the reference resistors RS4 to RS30 is transferred to the photoresist at the position where the reference resistors RS4 to RS30 are arranged in the central portion 161, and the strain sensors S1 to S32 of the connection portion 163 are arranged. A pattern having the same planar shape as the strain sensors S1 to S32 is transferred to the photoresist at the position where the pattern is transferred, and the photoresist other than the portion to which the pattern is transferred is removed to develop the pattern. Further, by performing a predetermined etching process up to the surface of the insulating film 170 using the photoresist in which the pattern is developed as a mask, reference resistors RS4 to RS30 having a desired shape can be placed at predetermined positions of the central portion 161 and the connecting portion 163. And the strain sensors S1 to S32 are formed (B4).

続いて、中央部１６１および接続部１６３に、例えば上記ステップＢ４と同様の製造工程等を用いて、密着性を高めるためのクロム（Ｃｒ）薄膜による接着膜１７２ａを形成し、当該接着膜１７２ａ上に、銅（Ｃｕ）を含む所定の電極リード膜を成膜して歪センサＳ１〜Ｓ３２および参照抵抗ＲＳ４〜ＲＳ３０を電気的に接続するための配線１７２を形成する。さらに、形成した配線１７２上に、同様の製造工程によりクロム薄膜による接着膜１７２ａを形成する（Ｂ５）。 Subsequently, an adhesive film 172a made of a chromium (Cr) thin film for enhancing adhesion is formed on the central portion 161 and the connection portion 163 by using, for example, the same manufacturing process as in step B4, and on the adhesive film 172a. A predetermined electrode lead film containing copper (Cu) is formed in the film to form wiring 172 for electrically connecting the strain sensors S1 to S32 and the reference resistors RS4 to RS30. Further, an adhesive film 172a made of a chromium thin film is formed on the formed wiring 172 by the same manufacturing process (B5).

続いて、一方の対角線Ｌ１の方向に沿って、中央部１６１における配線１７２の端部の接着膜１７２ａ上に、例えば上記ステップＢ４と同様の製造工程等を用いて、銅（Ｃｕ）と金（Ａｕ）からなる積層構造を順次形成して所定の電極膜を成膜し、電極１７１を形成する（Ｂ６）。 Subsequently, along the direction of one diagonal line L1, copper (Cu) and gold (Cu) and gold (on the adhesive film 172a at the end of the wiring 172 in the central portion 161, for example, by using the same manufacturing process as in step B4 above). A laminated structure made of Au) is sequentially formed to form a predetermined electrode film, and an electrode 171 is formed (B6).

続いて、例えばＣＶＤ（Chemical Vapor Deposition）法等を用いて、電極１７１上を除く起歪体１６の主表面上に、ＯＧ膜１７５を形成する（Ｂ７）。 Subsequently, for example, by using a CVD (Chemical Vapor Deposition) method or the like, an OG film 175 is formed on the main surface of the strain-causing body 16 except on the electrode 171 (B7).

続いて、起歪体１６の主表面上に形成した歪センサＳａ１〜Ｓｂ８等に対して所定の歪特性検査およびストレス検査等を施し、形成した歪センサＳａ１〜Ｓｂ８等に要求される特性を確認する（Ｂ８）。 Subsequently, predetermined strain characteristic inspections and stress inspections are performed on the strain sensors Sa1 to Sb8 and the like formed on the main surface of the strain generating body 16, and the characteristics required for the formed strain sensors Sa1 to Sb8 and the like are confirmed. (B8).

以上の製造方法により、第１実施形態に係る起歪体１６を製造する。 The strain-causing body 16 according to the first embodiment is manufactured by the above manufacturing method.

［作用効果］
以上説明したように、第１実施形態に係る起歪体１６は、実質的に歪が生じない中央部１６１の主要面上に設けられ、複数の歪センサＳ１〜Ｓ３２と共にブリッジ回路ＢＦ２、ＢＦ４、ＢＦ６、ＢＦ８を構成する複数の参照抵抗ＳＲ４〜ＳＲ３０を備える（図３）。このように、参照抵抗ＲＳ４〜ＲＳ３０は、歪センサＳ１〜Ｓ３２と同一の起歪体１６の主表面上に一体的に設けられる。その結果、歪センサＳ１〜Ｓ３２と参照抵抗ＲＳ４〜ＲＳ３０との間に生じる温度誤差および外部ノイズの影響を低減でき、検出精度を向上することができる。 [Action effect]
As described above, the strain generating body 16 according to the first embodiment is provided on the main surface of the central portion 161 where distortion does not substantially occur, and together with the plurality of strain sensors S1 to S32, the bridge circuits BF2 and BF4, A plurality of reference resistors SR4 to SR30 constituting BF6 and BF8 are provided (FIG. 3). As described above, the reference resistors RS4 to RS30 are integrally provided on the main surface of the strain generating body 16 which is the same as the strain sensors S1 to S32. As a result, the influence of the temperature error and external noise generated between the strain sensors S1 to S32 and the reference resistors RS4 to RS30 can be reduced, and the detection accuracy can be improved.

しかも、第１実施形態に係る起歪体１６は、接続部１６３の主表面上に設けられ、一対の直列接続された複数の歪センサ（第２歪センサ）が並列に接続された並列回路により構成されるフルブリッジ回路ＢＦ２、ＢＦ４、ＢＦ６、ＢＦ８を備える（図５）。そのため、起歪体１６の感度を向上でき、検出精度を向上することができる。例えば、第１実施形態に係る起歪体１６の場合、フルブリッジ回路ＢＦ２、ＢＦ４、ＢＦ６、ＢＦ８は検出回路全体の半分を占めるため、全ての検出回路をブリッジ回路で構成する場合に比較して、感度および検出精度を２倍程度まで向上することができる。 Moreover, the strain generating body 16 according to the first embodiment is provided on the main surface of the connecting portion 163 by a parallel circuit in which a plurality of strain sensors (second strain sensors) connected in series are connected in parallel. A full bridge circuit BF2, BF4, BF6, and BF8 are provided (FIG. 5). Therefore, the sensitivity of the strain generating body 16 can be improved, and the detection accuracy can be improved. For example, in the case of the strain generating body 16 according to the first embodiment, since the full bridge circuits BF2, BF4, BF6, and BF8 occupy half of the entire detection circuit, compared with the case where all the detection circuits are configured by the bridge circuit. , Sensitivity and detection accuracy can be improved up to about twice.

また、歪センサＳ１〜Ｓ３２、参照抵抗ＲＳ４〜ＲＳ３０、電極１７１、および配線１７２は、起歪体１６の対角線Ｌ１において鏡像対称の関係となるように、そのレイアウトが構成される。さらに、接続部１６３の幅は、中心Ｏ側から外側に向かってほぼ同一となるように構成されるため、中心Ｏから外側に離れるに従って幅が狭くなる構成に比べて、歪センサＳ１〜Ｓ３２を配置するスペースを拡大できる（図３）。このように、第１実施形態に係る起歪体１６は、中央部１６１および接続部１６３の主表面上の限られたスペースに歪センサＳ１〜Ｓ３２等を配置するのに最適な構成となっている。 Further, the layout of the strain sensors S1 to S32, the reference resistors RS4 to RS30, the electrodes 171 and the wiring 172 is configured so as to have a mirror image symmetric relationship on the diagonal line L1 of the strain generating body 16. Further, since the width of the connecting portion 163 is configured to be substantially the same from the center O side toward the outside, the strain sensors S1 to S32 are configured as having a narrower width as the distance from the center O increases outward. The space for arranging can be expanded (Fig. 3). As described above, the strain generating body 16 according to the first embodiment has an optimum configuration for arranging the strain sensors S1 to S32 and the like in the limited space on the main surface of the central portion 161 and the connecting portion 163. There is.

さらに、歪センサＳ１〜Ｓ３２、参照抵抗ＲＳ４〜ＲＳ３０、電極１７１、および配線１７２は、薄膜技術を利用した製造方法により、起歪体１６の主要面上のみに設けられる（図４、図７）。そのため、高感度なセンサＳ１〜Ｓ３２を高密度かつ高精度に起歪体１６の接続部１６３に設けることができる。従って、検出精度を補うために多数（例えば９０個程度）の歪センサを配置する必要がなく、起歪体の表面上だけでなく例えば起歪体の側面上に接着剤等を用いて歪センサを貼り付ける必要もない。例えば本実施形態のような製造方法を用いない場合、歪センサの位置は、所望の位置より数百μｍ程度の誤差を生じ得るため、特定軸以外の力およびトルクが検出される多軸干渉の影響が増大する。また、例えば参照抵抗を起歪体の外部に設ける場合には温度誤差や外部ノイズが増大するため、温度誤差や外部ノイズを校正する必要もある。しかし、本実施形態では、このような不都合が生じることはない。 Further, the strain sensors S1 to S32, reference resistors RS4 to RS30, electrodes 171 and wiring 172 are provided only on the main surface of the strain generating body 16 by a manufacturing method using thin film technology (FIGS. 4 and 7). .. Therefore, the highly sensitive sensors S1 to S32 can be provided at the connection portion 163 of the strain generating body 16 with high density and high accuracy. Therefore, it is not necessary to arrange a large number (for example, about 90) strain sensors to supplement the detection accuracy, and the strain sensors are not only on the surface of the strain generating body but also on the side surface of the strain generating body, for example, by using an adhesive or the like. There is no need to paste. For example, when the manufacturing method as in this embodiment is not used, the position of the strain sensor may have an error of about several hundred μm from the desired position, so that a force and torque other than the specific axis are detected for multi-axis interference. The impact will increase. Further, for example, when the reference resistor is provided outside the strain-causing body, the temperature error and external noise increase, so that it is necessary to calibrate the temperature error and external noise. However, in this embodiment, such inconvenience does not occur.

また、Ｚ方向に沿った起歪体１６の高さＨｚは、中央部１６１、外周部１６２、および接続部１６３において実質的に同一である。起歪体１６の高さＨｚは、Ｘ方向またはＹ方向に沿った外周部１６２の幅Ｗ１６２よりも大きくなるように構成される（Ｈｚ＞Ｗ１６２）。さらに、外周部１６２および接続部１６３の弾性は、中央部１６３の弾性よりも大きくなるように構成される。外周部１６２および接続部１６３は弾性機能を有し、中央部１６３の弾性機能を有さないように構成されることがより望ましい。上記構成により、ＸＹＺ軸の各出力ゲインおよび各剛性をより適正に調整することが可能となる点で有利である。 Further, the height Hz of the strain generating body 16 along the Z direction is substantially the same in the central portion 161, the outer peripheral portion 162, and the connecting portion 163. The height Hz of the strain-causing body 16 is configured to be larger than the width W162 of the outer peripheral portion 162 along the X direction or the Y direction (Hz> W162). Further, the elasticity of the outer peripheral portion 162 and the connecting portion 163 is configured to be larger than the elasticity of the central portion 163. It is more desirable that the outer peripheral portion 162 and the connecting portion 163 have an elastic function and are configured so as not to have the elastic function of the central portion 163. The above configuration is advantageous in that each output gain and each rigidity of the XYZ axes can be adjusted more appropriately.

（第２実施形態（起歪体の裏面側の接続部に歪増大部を備える一例））
図８乃至図１０を用いて第２実施形態に係る起歪体１６Ａを説明する。第２実施形態は、起歪体の裏面側の接続部に歪増大部としての溝（溝構造）ＧＲを備える一例に関する。図８は、第２実施形態に係る起歪体１６Ａの裏面側から見た全体構造を示す斜視図である。図９は、図８の破線で囲った部分を拡大した歪増大部を示す断面図である。 (Second embodiment (an example in which a strain increasing portion is provided at a connecting portion on the back surface side of the strain generating body))
The strain generating body 16A according to the second embodiment will be described with reference to FIGS. 8 to 10. The second embodiment relates to an example in which a groove (groove structure) GR as a strain increasing portion is provided at a connecting portion on the back surface side of the strain generating body. FIG. 8 is a perspective view showing the overall structure of the strain generating body 16A according to the second embodiment as viewed from the back surface side. FIG. 9 is a cross-sectional view showing an enlarged strain increasing portion of the portion surrounded by the broken line in FIG.

図８および図９に示すように、第２実施形態に係る起歪体１６Ａは、外周部１６２と隣接する各第１接続部１６３ａの裏面側に、中央部１６１と隣接する第２接続部１６３ｂよりも発生する歪を増大させるための歪増大部ＧＲを更に備える。換言すると、歪増大部ＧＲは、裏面側における第１接続部１６３ａに発生する歪が第２接続部１６３ｂに発生する歪よりも増大するように構成されている。歪増大部ＧＲは、ここでは、第１接続部１６３ａの裏面側の一部を、Ｕ字状にくり抜いて形成した所定の溝（溝構造）である。当該溝は、中央から外周部１６２および中央部１６１へ離れる従ってその厚さが厚くなるように構成されたアーチ形状であるため、起歪体１６の厚さ方向（Ｚ方向）に凹んで構成されている。 As shown in FIGS. 8 and 9, the strain generating body 16A according to the second embodiment has a second connecting portion 163b adjacent to the central portion 161 on the back surface side of each first connecting portion 163a adjacent to the outer peripheral portion 162. The strain increasing portion GR for increasing the generated strain is further provided. In other words, the strain increasing portion GR is configured so that the strain generated in the first connecting portion 163a on the back surface side is larger than the strain generated in the second connecting portion 163b. Here, the strain increasing portion GR is a predetermined groove (groove structure) formed by hollowing out a part of the back surface side of the first connecting portion 163a in a U shape. Since the groove has an arch shape that is separated from the center toward the outer peripheral portion 162 and the central portion 161 so that the thickness thereof becomes thicker, the groove is formed to be recessed in the thickness direction (Z direction) of the strain generating body 16. ing.

歪増大部ＧＲの裏面からの高さＨｇおよび第１接続部１６３ａにおける長さＬｇは、力およびトルクの印加時において第１接続部１６３ａが塑性変形しない等の所定の条件に基づいて、適宜、設定することが可能である。例えば、歪増大部ＧＲの裏面からの高さＨｇは、起歪体１６の高さＨｚの３割以上６割以下程度であることが望ましい。例えば、歪増大部ＧＲの長さＬｇは、接続部１６３の全体の長さＬ１６３の３割以上７割以下程度であることが望ましい。尚、接続部１６３の幅Ｗ１６３は、第１および第２接続部１６３ａ、１６３ｂにおいて同一である。 The height Hg from the back surface of the strain increasing portion GR and the length Lg at the first connecting portion 163a are appropriately determined based on predetermined conditions such as the first connecting portion 163a not being plastically deformed when a force and torque are applied. It is possible to set. For example, it is desirable that the height Hg from the back surface of the strain increasing portion GR is about 30% or more and 60% or less of the height Hz of the strain generating body 16. For example, it is desirable that the length Lg of the strain increasing portion GR is about 30% or more and 70% or less of the total length L163 of the connecting portion 163. The width W163 of the connecting portion 163 is the same in the first and second connecting portions 163a and 163b.

また、第１接続部１６３ａには、ブリッジ回路を構成する８個の歪センサ（第１歪センサ）Ｓ２１等が設けられる。第２接続部１６３ｂには、フルブリッジ回路を構成する１６個の歪センサ（第２歪センサ）Ｓ１８、Ｓ２７等が設けられる。この詳細については、次の図１０を用いて詳細に説明する。 Further, the first connection portion 163a is provided with eight strain sensors (first strain sensors) S21 and the like that form a bridge circuit. The second connection portion 163b is provided with 16 strain sensors (second strain sensors) S18, S27, etc. that form a full bridge circuit. This detail will be described in detail with reference to FIG. 10 below.

図１０は、第２実施形態に係る起歪体１６Ａの主表面側から見た全体構成を示す斜視図である。尚、図１０において、電極や配線等の同様の構成についての図示を省略している。 FIG. 10 is a perspective view showing the overall configuration of the strain generating body 16A according to the second embodiment as viewed from the main surface side. Note that in FIG. 10, illustration of similar configurations such as electrodes and wiring is omitted.

図１０において、破線で囲った部分を拡大して示すように、第１接続部１６３ａには、ブリッジ回路ＢＦ２、ＢＦ４、ＢＦ６、ＢＦ８を構成する８個の歪センサ（第１歪センサ）Ｓ３、Ｓ５、Ｓ１１、Ｓ１３、Ｓ１９、Ｓ２１、Ｓ２７、Ｓ２９が設けられる。 In FIG. 10, as shown by enlarging the portion surrounded by the broken line, the first connection portion 163a includes eight strain sensors (first strain sensors) S3 constituting the bridge circuits BF2, BF4, BF6, and BF8. S5, S11, S13, S19, S21, S27, S29 are provided.

第２接続部１６３ｂには、フルブリッジ回路ＢＦ１、ＢＦ３、ＢＦ５、ＢＦ７を構成する１６個の歪センサ（第２歪センサ）Ｓ１、Ｓ２、Ｓ７、Ｓ８、Ｓ９、Ｓ１０、Ｓ１５、Ｓ１６、Ｓ１７、Ｓ１８、Ｓ２３、Ｓ２４、Ｓ２５、Ｓ２６、Ｓ３１、Ｓ３２が設けられる。ここで、第２接続部１６３ｂに設けられる第２歪センサのうち、８個の歪センサＳ１、Ｓ２、Ｓ１５、Ｓ１６、Ｓ１７、Ｓ１８、Ｓ２５、Ｓ２６は、その他の第２歪センサと比べて溝ＧＲに隣接して配置されている。そのため、これらの第２歪センサＳ１等も、第１接続部１６３ａに設けられた第１歪センサと同様に、歪量が増大され、センサ感度が増大する。 The second connection portion 163b has 16 strain sensors (second strain sensors) S1, S2, S7, S8, S9, S10, S15, S16, S17, which constitute the full bridge circuits BF1, BF3, BF5, and BF7. S18, S23, S24, S25, S26, S31, S32 are provided. Here, among the second strain sensors provided in the second connection portion 163b, the eight strain sensors S1, S2, S15, S16, S17, S18, S25, and S26 have grooves as compared with the other second strain sensors. It is located adjacent to the GR. Therefore, in these second strain sensors S1 and the like, the amount of strain is increased and the sensor sensitivity is increased as in the case of the first strain sensor provided in the first connection portion 163a.

その他の構造は、上記第１実施形態と実質的に同様であるため、その詳細な説明を省略する。また、動作に関しても、上記第１実施形態と実質的に同様であるため、その詳細な説明を省略する。 Since the other structures are substantially the same as those of the first embodiment, detailed description thereof will be omitted. Further, since the operation is substantially the same as that of the first embodiment, detailed description thereof will be omitted.

［作用効果］
第２実施形態に係る起歪体１６Ａの構造および動作によれば、少なくとも第１実施形態と同様の作用効果が得られる。 [Action effect]
According to the structure and operation of the strain generating body 16A according to the second embodiment, at least the same effects as those of the first embodiment can be obtained.

さらに、第２実施形態に係る起歪体１６Ａは、外周部１６２と隣接する各第１接続部１６３ａの裏面側に、中央部１６１と隣接する第２接続部１６３ｂよりも発生する歪を増大させるための歪増大部ＧＲを更に備える。歪増大部ＧＲは、ここでは、第１接続部１６３ａの裏面側の一部を、Ｕ字状にくり抜いて形成した所定の溝（溝構造）である（図８、図９）。 Further, the strain generating body 16A according to the second embodiment increases the strain generated on the back surface side of each of the first connecting portions 163a adjacent to the outer peripheral portion 162 as compared with the second connecting portion 163b adjacent to the central portion 161. A strain increasing portion GR for the purpose is further provided. Here, the strain increasing portion GR is a predetermined groove (groove structure) formed by hollowing out a part of the back surface side of the first connecting portion 163a in a U shape (FIGS. 8 and 9).

上記構成において、起歪体１６Ａに外部から力およびトルクが印加されると、歪増大部ＧＲが設けられた第１接続部１６３ａの厚さは第２接続部１６３ｂの厚さに比べて薄いため、第１接続部１６３ａの当該力およびトルクに応じて変形する変形量を第２接続部１６３ａの変形量に比べて増大させることができる。 In the above configuration, when a force and torque are applied to the strain generating body 16A from the outside, the thickness of the first connecting portion 163a provided with the strain increasing portion GR is thinner than the thickness of the second connecting portion 163b. , The amount of deformation of the first connecting portion 163a that deforms according to the force and torque can be increased as compared with the amount of deformation of the second connecting portion 163a.

ここで、第１接続部１６３ａに設けられた８個の第１歪センサＳ３等は、８個の参照抵抗ＲＳ４等と共に、４つのブリッジ回路ＢＦ２、ＢＦ４、ＢＦ６、ＢＦ８を構成する（図１０）。そのため、第２実施形態に係る起歪体１６Ａによれば、第１接続部１６３ａに設けられた８個の第１歪センサＳ３等の歪量を増大させることにより、４つのブリッジ回路ＢＦ２、ＢＦ４、ＢＦ６、ＢＦ８の検出精度を向上することが更に可能となる。 Here, the eight first strain sensors S3 and the like provided in the first connection portion 163a together with the eight reference resistors RS4 and the like constitute four bridge circuits BF2, BF4, BF6, and BF8 (FIG. 10). .. Therefore, according to the strain generating body 16A according to the second embodiment, the four bridge circuits BF2, BF4 are increased by increasing the amount of strain of the eight first strain sensors S3 and the like provided in the first connecting portion 163a. , BF6, BF8 can be further improved in detection accuracy.

しかも、第２接続部１６３ｂに設けられる第２歪センサのうち、８個の歪センサＳ１、Ｓ２、Ｓ１５、Ｓ１６、Ｓ１７、Ｓ１８、Ｓ２５、Ｓ２６は、その他の第２歪センサと比べて溝ＧＲに隣接して配置されているため、これらの第２歪センサＳ１等も、第１接続部１６３ａに設けられた第１歪センサと同様に、歪量が増大される。そのため、当該８個の歪センサＳ１等により構成される４つのフルブリッジ回路ＢＦ１、ＢＦ３、ＢＦ５、ＢＦ７の検出精度も向上することが更に可能となる。その結果、ＸＹＺ軸方向の力およびトルクに係る６軸方向の全ての検出精度を向上することができる点で有利である。 Moreover, among the second strain sensors provided in the second connection portion 163b, the eight strain sensors S1, S2, S15, S16, S17, S18, S25, and S26 have a groove GR as compared with the other second strain sensors. Since the second strain sensor S1 and the like are arranged adjacent to the first strain sensor, the amount of strain is increased in the second strain sensor S1 and the like as well as the first strain sensor provided in the first connection portion 163a. Therefore, it is possible to further improve the detection accuracy of the four full bridge circuits BF1, BF3, BF5, and BF7 composed of the eight strain sensors S1 and the like. As a result, it is advantageous in that all detection accuracy in the 6-axis direction related to the force and torque in the XYZ-axis direction can be improved.

尚、例えば、Ｚ軸方向の力Ｆｚが第２実施形態に係る起歪体１６Ａに加えられた場合、第１接続部１６３ａに設けられた８個の歪センサＳ３等の歪量を、同様の場合の第１実施形態に係る歪センサＳ３等と比べて、５割程度も増大できる。このように、必要に応じて、第２実施形態に係る起歪体１６Ａを適用することが可能である。 For example, when a force Fz in the Z-axis direction is applied to the strain generating body 16A according to the second embodiment, the amount of strain of the eight strain sensors S3 and the like provided in the first connecting portion 163a is similarly applied. It can be increased by about 50% as compared with the strain sensor S3 or the like according to the first embodiment of the case. In this way, the strain-causing body 16A according to the second embodiment can be applied as needed.

（第３実施形態（力覚センサに適用した一例））
図１１乃至図１８を用いて第３実施形態を説明する。第３実施形態は、第１実施形態に係る起歪体１６を力覚センサに適用した一例に関する。第３実施形態に係る力覚センサは、例えばロボットアーム等に用いられ、ＸＹＺ方向の力およびトルクを検出するための６軸力覚センサである。 (Third embodiment (an example applied to a force sensor))
The third embodiment will be described with reference to FIGS. 11 to 18. The third embodiment relates to an example in which the strain generating body 16 according to the first embodiment is applied to a force sensor. The force sensor according to the third embodiment is a 6-axis force sensor used for, for example, a robot arm or the like, for detecting a force and torque in the XYZ directions.

［構成］
図１１は、第１実施形態に係る起歪体１６を備えた力覚センサ１０の外観を示す斜視図である。図１２は、図１１の力覚センサ１０を示す分解斜視図である。 [Constitution]
FIG. 11 is a perspective view showing the appearance of the force sensor 10 including the strain-causing body 16 according to the first embodiment. FIG. 12 is an exploded perspective view showing the force sensor 10 of FIG.

図１１および図１２に示すように、力覚センサ１０は、円筒状の本体１１と、本体１１に対して動作可能な円筒状の可動体１２とを備える。本体１１は、本体１１の底部に形成された複数のネジ穴１９ａを貫通する複数の取付ネジ１９により、図示せぬロボットアームの本体に固定される。可動体１２は、その上面に図示せぬロボットアームのハンド部分を取り付けるためのハンド取付プレートとして機能する。 As shown in FIGS. 11 and 12, the force sensor 10 includes a cylindrical main body 11 and a cylindrical movable body 12 that can operate with respect to the main body 11. The main body 11 is fixed to the main body of the robot arm (not shown) by a plurality of mounting screws 19 penetrating the plurality of screw holes 19a formed in the bottom of the main body 11. The movable body 12 functions as a hand mounting plate for mounting the hand portion of the robot arm (not shown) on the upper surface thereof.

本体（ベース）１１は、力覚センサ１０の本体となるベース部材であり、可動体１２は、弾性変形が可能な起歪体１６を介在して本体１１に対して、６軸方向（Ｘ軸方向、Ｙ軸方向、Ｚ軸方向、及び各軸周り方向）に動作可能に取着されている。 The main body (base) 11 is a base member that serves as the main body of the force sensor 10, and the movable body 12 is located in a 6-axis direction (X-axis) with respect to the main body 11 via a strain-causing body 16 capable of elastic deformation. It is operably attached in the direction, the Y-axis direction, the Z-axis direction, and the direction around each axis).

すなわち、図１２に示すように、起歪体１６の中央部１６１は、複数のネジ穴１８ａをそれぞれ貫通するハンドプレート固定ネジ１８により可動体（第１支持部材）１２に固定される。起歪体１６の外周部１６２は、複数のネジ穴１７ａをそれぞれ貫通する起歪体固定ネジ１７により、本体１１（第２支持部材）に固定される。 That is, as shown in FIG. 12, the central portion 161 of the strain generating body 16 is fixed to the movable body (first support member) 12 by the hand plate fixing screws 18 penetrating the plurality of screw holes 18a, respectively. The outer peripheral portion 162 of the strain generating body 16 is fixed to the main body 11 (second support member) by the strain generating body fixing screws 17 penetrating the plurality of screw holes 17a, respectively.

起歪体１６の主表面および裏面は、Ｘ軸、Ｙ軸により形成される面と平行に配置され、起歪体１６の中心Ｏを垂直に通る線は、Ｚ軸と一致されている。上記構成において、可動体１２に外力が加えられると、可動体１２が動作し、起歪体１６の接続部１６３が変形する。上記のように、起歪体１６の接続部１６３には歪センサＳ１〜Ｓ３２が設けられているため、歪センサＳ１〜Ｓ３２により起歪体１６の変形が電気信号として検出される。 The main front surface and the back surface of the strain generating body 16 are arranged parallel to the surface formed by the X-axis and the Y-axis, and the line perpendicular to the center O of the strain-causing body 16 coincides with the Z-axis. In the above configuration, when an external force is applied to the movable body 12, the movable body 12 operates and the connecting portion 163 of the strain generating body 16 is deformed. As described above, since the strain sensors S1 to S32 are provided at the connecting portion 163 of the strain generating body 16, the deformation of the strain generating body 16 is detected as an electric signal by the strain sensors S1 to S32.

可動体１２の周面には、例えば４つの円形の開口部１３が等間隔に設けられている。すなわち、各開口部１３は、Ｘ軸方向とＹ軸方向に配置されている。開口部１３の数は、４つに限定されず、３つ以上であればよい。各開口部１３の内部にはストッパ１４が配置され、各ストッパ１４は、ストッパ取付ボルト１５により、本体１１に固定されている。 For example, four circular openings 13 are provided at equal intervals on the peripheral surface of the movable body 12. That is, each opening 13 is arranged in the X-axis direction and the Y-axis direction. The number of openings 13 is not limited to four, and may be three or more. A stopper 14 is arranged inside each opening 13, and each stopper 14 is fixed to the main body 11 by a stopper mounting bolt 15.

ストッパ１４は、可動体１２の動作範囲を規制するものであり、ストッパ１４の最外周部には、開口部１３の内面が当接可能な第１側面１４ａを備えている。すなわち、第１側面１４ａは、可動体１２の動作に伴って起歪体１６が変形した際、可動体１２の開口部１３の内面が第１側面１４ａに当接し、起歪体１６の接続部１６３の過剰な変形を防止する保護機構として機能する。 The stopper 14 regulates the operating range of the movable body 12, and the outermost peripheral portion of the stopper 14 is provided with a first side surface 14a to which the inner surface of the opening 13 can come into contact. That is, in the first side surface 14a, when the strain generating body 16 is deformed by the operation of the movable body 12, the inner surface of the opening 13 of the movable body 12 comes into contact with the first side surface 14a, and the connecting portion of the strain generating body 16 It functions as a protective mechanism to prevent excessive deformation of 163.

本体１１の内部には、起歪体１６に対向して基板２０が設けられる。基板２０は、複数のねじ穴２１ａを有し、各ネジ穴２１ａを貫通する固定ネジ２１により、本体１１に固定される。基板２０は、起歪体１６に設けられた歪センサ等と電気的に接続される。この詳細については後述する。 A substrate 20 is provided inside the main body 11 so as to face the strain generating body 16. The substrate 20 has a plurality of screw holes 21a and is fixed to the main body 11 by fixing screws 21 penetrating each screw hole 21a. The substrate 20 is electrically connected to a strain sensor or the like provided on the strain generating body 16. The details will be described later.

本体１１の底部には、開口部１１ａを閉塞するカバー２２が装着される。すなわち、カバー２２は、複数のねじ穴２３ａを有し、これらネジ穴２３ａを貫通する固定ネジ２３により、本体１１に固定される。 A cover 22 that closes the opening 11a is attached to the bottom of the main body 11. That is, the cover 22 has a plurality of screw holes 23a and is fixed to the main body 11 by the fixing screws 23 penetrating the screw holes 23a.

本体１１の側面には、検出信号を外部に伝達するための配線２５が引き出されている。配線２５は、基板２０と電気的に接続されている。 A wiring 25 for transmitting a detection signal to the outside is drawn out from the side surface of the main body 11. The wiring 25 is electrically connected to the substrate 20.

力覚センサに実装される状態の起歪体
図１３を用いて力覚センサ１０に実装される状態の起歪体１６について詳細に説明する。図１３は、力覚センサ１０に実装される状態の起歪体１６を示す断面図である。 The strain-causing body 16 mounted on the force sensor 10 will be described in detail with reference to FIG. 13. FIG. 13 is a cross-sectional view showing a strain-causing body 16 mounted on the force sensor 10.

図１３に示すように、起歪体１６の主表面上に、絶縁膜１７０が設けられ、絶縁膜１７０上に電極１７１が設けられる。さらに、力覚センサ１０に実装するために、電極１７１上に異方性導電フィルム（ＡＣＦ：Anisotropic Conductive Film）１８１が設けられる。異方性導電フィルム１８１上に、電極１７１と基板２０とを電気的に接続するためのリード配線１８２が設けられる。リード配線１８２は、ここでは、絶縁性の柔軟なフィルムと当該フィルムに配線された所定の電気回路とを備えており、可動体１２の動きに合わせて自在に曲がることが可能であるように構成されたフレキシブルプリント回路基板（ＦＰＣ：Flexible printed circuits）である。また、起歪体１６の主表面上を覆うように、保護シール１８３が設けられる。 As shown in FIG. 13, an insulating film 170 is provided on the main surface of the strain generating body 16, and an electrode 171 is provided on the insulating film 170. Further, an Anisotropic Conductive Film (ACF) 181 is provided on the electrode 171 for mounting on the force sensor 10. A lead wiring 182 for electrically connecting the electrode 171 and the substrate 20 is provided on the anisotropic conductive film 181. Here, the lead wiring 182 includes an insulating flexible film and a predetermined electric circuit wired to the film, and is configured to be able to bend freely according to the movement of the movable body 12. Flexible printed circuits (FPC). Further, a protective seal 183 is provided so as to cover the main surface of the strain generating body 16.

［検出動作］
上記構成の力覚センサ１０の検出動作について簡単に説明する。ここでは、Ｚ軸方向において可動体１２のほぼ中央部分に加えられた外力（荷重）を検出する場合を一例に挙げる。 [Detection operation]
The detection operation of the force sensor 10 having the above configuration will be briefly described. Here, a case where an external force (load) applied to a substantially central portion of the movable body 12 in the Z-axis direction is detected will be given as an example.

Ｚ軸方向において可動体１２のほぼ中央部分に外力が加えられると、外力によって可動体１２がＺ軸方向に沿って下方に移動する。本体１１は固定されており外力によっても移動しないため、可動体１２は、開口部１３の上側の内面がストッパ１４の上側の第１側面１４ａに当接するまで、下方に移動する。 When an external force is applied to a substantially central portion of the movable body 12 in the Z-axis direction, the movable body 12 moves downward along the Z-axis direction due to the external force. Since the main body 11 is fixed and does not move by an external force, the movable body 12 moves downward until the upper inner surface of the opening 13 abuts on the upper first side surface 14a of the stopper 14.

そのため、可動体１２の下面が起歪体１６の上面を加圧し、加圧された起歪体１６の接続部１６３は変形を起こす。ストッパ１４により、起歪体１６の変形は所定の範囲に限定されているため、過剰な外力による破壊から起歪体１６が保護される。起歪体１６の変形は、上述した歪センサおよび参照抵抗により検出され、ブリッジ回路およびフルブリッジ回路ＢＦ１〜ＢＦ８により電気信号に変換される。検出された電気信号は、電極１７１からリード配線１８２および基板２０を介して配線２５により外部に伝達され、外力を検出することができる。 Therefore, the lower surface of the movable body 12 pressurizes the upper surface of the strain generating body 16, and the connecting portion 163 of the pressurized strain generating body 16 is deformed. Since the deformation of the strain generating body 16 is limited to a predetermined range by the stopper 14, the strain generating body 16 is protected from destruction due to an excessive external force. The deformation of the strain generating body 16 is detected by the strain sensor and the reference resistor described above, and is converted into an electric signal by the bridge circuit and the full bridge circuits BF1 to BF8. The detected electric signal is transmitted from the electrode 171 to the outside by the wiring 25 via the lead wiring 182 and the substrate 20, and the external force can be detected.

その後、可動体１２への外力の印加が解除されると、起歪体１６の接続部１６３は、弾性変形により、元の形状に復帰する。 After that, when the application of the external force to the movable body 12 is released, the connecting portion 163 of the strain generating body 16 returns to the original shape by elastic deformation.

尚、ここでは、Ｚ軸方向における外力検出動作を一例に挙げたが、Ｘ軸方向およびＹ軸方向におけるその他の外力検出動作も同様である。また、Ｘ、Ｙ、Ｚ軸方向における各トルク検出動作についても、上記外力検出動作と実質的に同様であるため、詳細な説明を省略する。 Although the external force detection operation in the Z-axis direction is given as an example here, the same applies to other external force detection operations in the X-axis direction and the Y-axis direction. Further, since each torque detection operation in the X, Y, and Z axis directions is substantially the same as the external force detection operation, detailed description thereof will be omitted.

［異方性導電フィルム（ＡＣＦ）］
ここで、異方性導電フィルム１８１を用いて、電極１７１の端子とＦＰＣであるリード配線１８２の端子とを互いに電気的に接続するためには、主に、ＡＣＦ転写（ラミネーション）工程、ＦＰＣ位置合わせ（アライメント）工程、および圧着硬化工程の３つの工程（ＳＴ１〜ＳＴ３）が必要となる。 [Animolic Conductive Film (ACF)]
Here, in order to electrically connect the terminal of the electrode 171 and the terminal of the lead wiring 182 which is the FPC to each other by using the anisotropic conductive film 181, mainly, the ACF transfer (lamination) step and the FPC position are used. Three steps (ST1 to ST3) of an alignment step and a crimp hardening step are required.

図１４は、図１３の起歪体上に異方性導電フィルムを用いて電極とリード配線とを接続する方法を説明するための断面図である。図１４に示すように、ＡＣＦ転写工程では、起歪体１６の主表面上に配置された電極１７１上に、電極１７１の面積よりも面積が十分大きい異方性導電フィルム１８１を所定の張力を保った状態で配置する。次に、ＡＣＦ貼り合わせ用のヘッド２００を、張力を保った状態で異方性導電フィルム１８１の真上から電極１７１の表面上まで降下させ、破線で示す電極１７１の面積よりも大きい余分な異方性導電フィルム１８１を切り離す。その結果、電極１７１上に、所定の異方性導電フィルム１８１が転写される（ＳＴ１）。 FIG. 14 is a cross-sectional view for explaining a method of connecting the electrode and the lead wiring on the strain-causing body of FIG. 13 by using an anisotropic conductive film. As shown in FIG. 14, in the ACF transfer step, an anisotropic conductive film 181 having a sufficiently larger area than the area of the electrode 171 is applied with a predetermined tension on the electrode 171 arranged on the main surface of the strain generating body 16. Place it while keeping it. Next, the head 200 for ACF bonding is lowered from directly above the anisotropic conductive film 181 to the surface of the electrode 171 while maintaining the tension, and an extra difference larger than the area of the electrode 171 shown by the broken line is obtained. The anisotropic conductive film 181 is separated. As a result, a predetermined anisotropic conductive film 181 is transferred onto the electrode 171 (ST1).

図１５は、図１３の起歪体１６と異方性導電フィルム１８１とが所定の位置に配置される状態を示す平面図である。図１６は、図１５の実線で囲った部分を拡大して示す平面図である。ＦＰＣ位置合わせ工程では、電極１７１上に異方性導電フィルム１８１が張り合わされた状態で、電極１７１の端子とリード配線１８２の端子との位置合わせを行う。 FIG. 15 is a plan view showing a state in which the strain generating body 16 and the anisotropic conductive film 181 of FIG. 13 are arranged at predetermined positions. FIG. 16 is an enlarged plan view showing a portion surrounded by a solid line in FIG. In the FPC alignment step, the terminal of the electrode 171 and the terminal of the lead wiring 182 are aligned in a state where the anisotropic conductive film 181 is stuck on the electrode 171.

図１５および図１６に示すように、この工程では、起歪体１６に設けられたアライメントマークＡＭ１６と、リード配線１８２に設けられたアライメントマークＡＭＦとを所定の位置に合わせることにより、位置決めを行う。例えば、破線で示す起歪体１６のアライメントマークＡＭ１６ａ、ＡＭ１６ｂの位置と、実線で示すリード配線１８２のアライメントマークＡＭＦａ、ＡＭＦｂの位置とが、図１６に拡大して示す位置関係となるように位置が決定される。この際、起歪体１６のアライメントマークＡＭ１６ａの２つの凸部の間に、リード配線１８２のアライメントマークＡＭＦａの１つの凸部を挟むように位置合わせを行うことで、紙面の縦方向の位置ずれを防止している。また、起歪体１６のアライメントマークＡＭ１６ｂと、リード配線１８２のアライメントマークＡＭＦｂとが重なるように位置合わせを行うことで、紙面の横方向の位置ずれを防止している（ＳＴ２）。 As shown in FIGS. 15 and 16, in this step, positioning is performed by aligning the alignment mark AM16 provided on the strain generating body 16 and the alignment mark AMF provided on the lead wiring 182 at predetermined positions. .. For example, the positions of the alignment marks AM16a and AM16b of the strain generating body 16 shown by the broken line and the positions of the alignment marks AMFa and AMFb of the lead wiring 182 shown by the solid line are positioned so as to have a positional relationship enlarged in FIG. Is determined. At this time, the alignment is performed so as to sandwich one convex portion of the alignment mark AMFa of the lead wiring 182 between the two convex portions of the alignment mark AM16a of the strain generating body 16, so that the position of the paper surface is displaced in the vertical direction. Is being prevented. Further, by aligning the alignment mark AM16b of the strain generating body 16 and the alignment mark AMFb of the lead wiring 182 so as to overlap with each other, the lateral displacement of the paper surface is prevented (ST2).

図１７は、異方性導電フィルム１８１を用いて電極１７１の端子とリード配線１８２の端子とが電気的に接続されることを模式的に説明するための断面図である。図１７上段に示すように、異方性導電フィルム１８１は、導電体である導電粒子１８１ａが絶縁体である熱硬化樹脂１８１ｂの中にほぼ均一に散在された構成を備えている。そして、圧着硬化工程では、電極１７１の端子１７１ａ（ＰＡＤ）とリード配線１８２の端子１８２ａ（ＰＡＤ）との位置が合わされた状態で、リード配線１８２上から所定のヘッド２００により、対象積層体（電極１７１、異方性導電フィルム１８１、リード配線１８２）に対して、熱を与えながら圧力を加える。 FIG. 17 is a cross-sectional view for schematically explaining that the terminal of the electrode 171 and the terminal of the lead wiring 182 are electrically connected by using the anisotropic conductive film 181. As shown in the upper part of FIG. 17, the anisotropic conductive film 181 has a configuration in which conductive particles 181a, which are conductors, are substantially uniformly scattered in the thermosetting resin 181b, which is an insulator. Then, in the crimp hardening step, in a state where the terminals 171a (PAD) of the electrode 171 and the terminals 182a (PAD) of the lead wiring 182 are aligned, the target laminated body (electrode) is formed from above the lead wiring 182 by a predetermined head 200. Pressure is applied to 171, the anisotropic conductive film 181 and the lead wiring 182) while applying heat.

すると、図１７下段に示すように、端子１７１ａ、１８２ａに挟まれる位置Ａａでは、圧力によって異方性導電フィルム１８１内の導電粒子１８１ａが互いに接続し、紙面の縦方向（Ｚ軸方向）の端子１７１ａ、１８２ａを導通するための導電経路が形成される。一方、それ以外の位置Ａｂでは、圧力が低いため、異方性導電フィルム１８１内の導電粒子１８１ａが互いに接続することがなく、絶縁性が保持される。その結果、端子１７１ａ、１８２ａに挟まれる位置Ａａのみ紙面の縦方向（Ｚ軸方向）の所望の導電経路が形成される（ＳＴ３）。 Then, as shown in the lower part of FIG. 17, at the position Aa sandwiched between the terminals 171a and 182a, the conductive particles 181a in the anisotropic conductive film 181 are connected to each other by the pressure, and the terminals in the vertical direction (Z-axis direction) of the paper surface. A conductive path for conducting 171a and 182a is formed. On the other hand, at the other positions Ab, since the pressure is low, the conductive particles 181a in the anisotropic conductive film 181 do not connect to each other, and the insulating property is maintained. As a result, a desired conductive path in the vertical direction (Z-axis direction) of the paper surface is formed only at the position Aa sandwiched between the terminals 171a and 182a (ST3).

その他の構造および動作等は、上記第１実施形態と実質的に同様であるため、その詳細な説明を省略する。 Since other structures, operations, and the like are substantially the same as those in the first embodiment, detailed description thereof will be omitted.

［作用効果］
起歪体１６を備えた第３実施形態に係る力覚センサ１０の構造および動作によれば、少なくとも第１実施形態と同様の作用効果が得られる。 [Action effect]
According to the structure and operation of the force sensor 10 according to the third embodiment including the strain generating body 16, at least the same effects as those of the first embodiment can be obtained.

さらに、第３実施形態に係る起歪体１６は、所定の工程（ＳＴ１〜ＳＴ３）によって、異方性導電フィルム１８１を用いて、電極１７１の端子１７１ａとＦＰＣであるリード配線１８２の端子１８２ａとを互いに電気的に接続する（図１４〜図１７）。 Further, the strain generating body 16 according to the third embodiment uses an anisotropic conductive film 181 in a predetermined step (ST1 to ST3) to form a terminal 171a of the electrode 171 and a terminal 182a of the lead wiring 182 which is an FPC. Are electrically connected to each other (FIGS. 14 to 17).

このように、配線１７２を中央部１６１に集約し、異方性導電フィルム１８１を用いることで、電極１７１およびリード配線１８２の多数の端子１７１ａおよび１８２ａを一括して接続でき、導通性と絶縁性とを両立することができるため、製造コストの低減に有利である。 In this way, by consolidating the wiring 172 in the central portion 161 and using the anisotropic conductive film 181, a large number of terminals 171a and 182a of the electrode 171 and the lead wiring 182 can be collectively connected, and the conductivity and insulation property can be increased. It is advantageous in reducing the manufacturing cost because it is possible to achieve both.

しかも、本実施形態のように、起歪体１６の限られたスペースであって、横方向の端子１７１ａ、１８２ａの隣接間の距離が例えば０．２ｍｍ程度のファインピッチであっても、確実な電気的接続を確保でき、信頼性を向上できる。 Moreover, as in the present embodiment, even if the space of the strain generating body 16 is limited and the distance between the adjacent terminals 171a and 182a in the lateral direction is, for example, about 0.2 mm, it is reliable. Electrical connection can be secured and reliability can be improved.

また、はんだやコネクタ等の接続装置に比べ、実装装置が軽量および薄型であるため、実装スペースの低減が可能となる。 Further, since the mounting device is lighter and thinner than the connecting device such as a solder or a connector, the mounting space can be reduced.

例えば、本実施形態に係る起歪体１６のパッドの位置（端子の位置）と異方性導電フィルムの抵抗値との関係は、図１８のように示される。図１８に示すように、３つの異方性導電フィルムＡＣＦ１〜ＡＣＦ３のいずれの場合でも、パッドの位置に関係なく、その抵抗値はほぼ一定であることから、確実な電気的接続が確保されていることが分かる。また、図１８に示す抵抗値からリード配線１８２の端子１８２ａの抵抗値である０．１Ω程度を差し引くと、３つの異方性導電フィルムＡＣＦ１〜ＡＣＦ３の実質的な抵抗値は０．３５Ω〜０．４５Ω程度となる。この抵抗値は、いずれも一般的な異方導電フィルムの抵抗値の基準値よりも、十分に低い値である。 For example, the relationship between the pad position (terminal position) of the strain generating body 16 and the resistance value of the anisotropic conductive film according to the present embodiment is shown as shown in FIG. As shown in FIG. 18, in any of the three anisotropic conductive films ACF1 to ACF3, the resistance value is almost constant regardless of the position of the pad, so that a reliable electrical connection is ensured. You can see that there is. Further, when the resistance value of the terminal 182a of the lead wiring 182, which is about 0.1Ω, is subtracted from the resistance value shown in FIG. 18, the actual resistance values of the three anisotropic conductive films ACF1 to ACF3 are 0.35Ω to 0. It will be about .45Ω. This resistance value is a value sufficiently lower than the reference value of the resistance value of a general anisotropic conductive film.

また、力覚センサ１０は、可動体１２の動作範囲を規制するものであり、その最外周部に開口部１３の内面と当接可能な第１側面１４ａを有するストッパ１４を備える。このように、ストッパ１４は、非常にシンプルな形状であり、かつ６軸方向の全てに対して保護機能を有している。その結果、高感度かつ製造コストの低減化に有利な力覚センサ１０を提供することが可能となる。 Further, the force sensor 10 regulates the operating range of the movable body 12, and includes a stopper 14 having a first side surface 14a capable of contacting the inner surface of the opening 13 at the outermost peripheral portion thereof. As described above, the stopper 14 has a very simple shape and has a protective function in all six axial directions. As a result, it becomes possible to provide the force sensor 10 having high sensitivity and advantageous in reducing the manufacturing cost.

（第４実施形態（歪センサのその他の配置の一例））
図１９を用いて第４実施形態を説明する。第４実施形態は、歪センサのその他の配置の一例に関する。図１９は、第４実施形態に係る起歪体の主表面側から見た全体構成を示す斜視図である。 (Fourth Embodiment (an example of other arrangement of the strain sensor))
A fourth embodiment will be described with reference to FIG. A fourth embodiment relates to an example of another arrangement of strain sensors. FIG. 19 is a perspective view showing the overall configuration of the strain-causing body according to the fourth embodiment as viewed from the main surface side.

図１９に拡大して示すように、第４実施形態に係る起歪体１６Ｂは、第２接続部１６３ｂに設けられる８個の第２歪センサＳ１、Ｓ２、Ｓ１５、Ｓ１６、Ｓ１７、Ｓ１８、Ｓ２５、Ｓ２６が、その他の第２歪センサと同程度に溝ＧＲから十分な距離ＬＳを有して配置されている点で、第２実施形態に係る起歪体１６Ａと相違する。そのため、第２接続部１６３ｂに設けられる全ての第２歪センサは、溝ＧＲからの歪増大効果の影響を受けない。ここで、距離ＬＳは、第１接続部１６３ａに設けられる第１歪センサの歪量が、第２接続部１６３ｂに設けられる第２歪センサの歪量と比べて、例えば５割等の明らかな歪量の相違が分かる程度に設けられていることが望ましい。 As shown enlarged in FIG. 19, the strain generating body 16B according to the fourth embodiment has eight second strain sensors S1, S2, S15, S16, S17, S18, and S25 provided in the second connecting portion 163b. , S26 is different from the strain generating body 16A according to the second embodiment in that S26 is arranged with a sufficient distance LS from the groove GR to the same extent as other second strain sensors. Therefore, all the second strain sensors provided in the second connection portion 163b are not affected by the strain increasing effect from the groove GR. Here, in the distance LS, the amount of distortion of the first strain sensor provided in the first connection portion 163a is clear, for example, 50% as compared with the amount of distortion of the second strain sensor provided in the second connection portion 163b. It is desirable that it is provided so that the difference in the amount of strain can be seen.

その他の構成および動作は、第２実施形態と実質的に同様であるため、その詳細な説明を省略する。 Since other configurations and operations are substantially the same as those of the second embodiment, detailed description thereof will be omitted.

［作用効果］
第４実施形態に係る起歪体１６Ｂは、第２接続部１６３ｂに設けられる８個の第２歪センサＳ１、Ｓ２、Ｓ１５、Ｓ１６、Ｓ１７、Ｓ１８、Ｓ２５、Ｓ２６が、その他の第２歪センサと同程度に溝ＧＲから十分な距離ＬＳを有して配置されている（図１９）。 [Action effect]
The strain generating body 16B according to the fourth embodiment includes eight second strain sensors S1, S2, S15, S16, S17, S18, S25, and S26 provided in the second connecting portion 163b, and other second strain sensors. It is arranged with a sufficient distance LS from the groove GR to the same extent as (FIG. 19).

そのため、第２接続部１６３ｂに設けられる第２歪センサは溝ＧＲからの歪増大効果の影響を受けず、第１接続部１６３ａに設けられた第１歪センサＳ３、Ｓ５、Ｓ１１、Ｓ１３、Ｓ１９、Ｓ２１、Ｓ２７、Ｓ２９の歪量を、第２接続部１６３ｂに設けられた第２歪センサＳ１、Ｓ２、Ｓ７、Ｓ８、Ｓ９、Ｓ１０、Ｓ１５、Ｓ１６、Ｓ１７、Ｓ１８、Ｓ２３、Ｓ２４、Ｓ２５、Ｓ２６、Ｓ３１、Ｓ３２の歪量に比べて、増大させることができる。その結果、４つのブリッジ回路ＢＦ２、ＢＦ４、ＢＦ６、ＢＦ８の検出精度を向上することができる。 Therefore, the second strain sensor provided in the second connection portion 163b is not affected by the strain increasing effect from the groove GR, and the first strain sensors S3, S5, S11, S13, S19 provided in the first connection portion 163a. , S21, S27, S29, the amount of distortion of the second distortion sensor S1, S2, S7, S8, S9, S10, S15, S16, S17, S18, S23, S24, S25, which is provided in the second connection portion 163b. It can be increased as compared with the amount of strain of S26, S31, and S32. As a result, the detection accuracy of the four bridge circuits BF2, BF4, BF6, and BF8 can be improved.

また、第２接続部１６３ｂに設けられる全ての第２歪センサは溝ＧＲからの歪増大効果の影響を受けないため、第２歪センサの歪量を均一化できる点で有利である。 Further, since all the second strain sensors provided in the second connection portion 163b are not affected by the strain increasing effect from the groove GR, it is advantageous in that the strain amount of the second strain sensor can be made uniform.

（変形例）
以上、第１乃至第３実施形態を一例に挙げて説明したが、本発明の実施形態は、上記第１乃至第３実施形態に限定されるものではなく、必要に応じて種々の変形が可能であることは勿論である。 (Modification example)
Although the first to third embodiments have been described above as an example, the embodiments of the present invention are not limited to the first to third embodiments, and various modifications can be made as needed. Of course.

起歪体１６、１６Ａが適用可能な対象は、第３実施形態において説明した力覚センサ１０に限定されず、各種のセンサに適用可能であることは勿論である。 It goes without saying that the objects to which the strain generating bodies 16 and 16A can be applied are not limited to the force sensor 10 described in the third embodiment, and can be applied to various sensors.

その他、本発明は上記各実施形態そのままに限定されるものではなく、実施段階ではその要旨を逸脱しない範囲で構成要素を変形して具体化できる。また、上記各実施形態に開示されている複数の構成要素の適宜な組み合わせにより、種々の発明を形成できる。例えば、実施形態に示される全構成要素から幾つかの構成要素を削除してもよい。さらに、異なる実施形態にわたる構成要素を適宜組み合わせてもよい。 In addition, the present invention is not limited to each of the above embodiments as it is, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by appropriately combining the plurality of components disclosed in each of the above embodiments. For example, some components may be removed from all the components shown in the embodiments. In addition, components across different embodiments may be combined as appropriate.

１０…力覚センサ、１１…本体、１２…可動体、１４…ストッパ、１６、１６Ａ…起歪体、１６１…中央部、１６２…外周部、１６３…接続部（ビーム部）、１６１ａ…第１接続部、１６１ｂ…第２接続部、１７１…電極、１７２…配線、１８１…異方性導電フィルム（ＡＣＦ）、１８２…リード配線、Ｓ１〜Ｓ３２…歪センサ、ＲＳ４〜ＲＳ３０…参照抵抗、ＢＦ１、ＢＦ３、ＢＦ５、ＢＦ７…フルブリッジ回路、ＢＦ２、ＢＦ４、ＢＦ６、ＢＦ８…ブリッジ回路、ＧＲ…歪増大部。 10 ... force sensor, 11 ... main body, 12 ... movable body, 14 ... stopper, 16, 16A ... strain-causing body, 161 ... central part, 162 ... outer peripheral part, 163 ... connection part (beam part), 161a ... first Connection part, 161b ... Second connection part, 171 ... Electrode, 172 ... Wiring, 181 ... Anisotropic conductive film (ACF), 182 ... Lead wiring, S1 to S32 ... Distortion sensor, RS4 to RS30 ... Reference resistance, BF1, BF3, BF5, BF7 ... Full bridge circuit, BF2, BF4, BF6, BF8 ... Bridge circuit, GR ... Distortion increasing part.

実施形態に係る起歪体は、中央部と、前記中央部の周囲を囲む外周部と、前記中央部と前記外周部とを接続する複数の接続部と、前記接続部の主表面上に設けられ、ブリッジ回路を構成する複数の歪センサと、を具備し、前記複数の歪センサが、Ｚ方向の力Ｆｚ、Ｘ方向のモーメントＭｘ、及びＹ方向のモーメントＭｙを検出する複数のブリッジ回路を含む第１ブリッジ回路群と、Ｘ方向の力Ｆｘ、Ｙ方向の力Ｆｙ、及びＺ方向のモーメントＭｚを検出する複数のブリッジ回路を含む第２ブリッジ回路群とを構成する。 The strain-causing body according to the embodiment is provided on a central portion, an outer peripheral portion surrounding the periphery of the central portion, a plurality of connecting portions connecting the central portion and the outer peripheral portion, and a main surface of the connecting portion. A plurality of bridge circuits are provided, and the plurality of strain sensors detect a force Fz in the Z direction, a moment Mx in the X direction, and a moment My in the Y direction. A first bridge circuit group including the first bridge circuit group and a second bridge circuit group including a plurality of bridge circuits for detecting a force Fx in the X direction, a force Fy in the Y direction, and a moment Mz in the Z direction are configured.

Claims

In the center and
An outer peripheral portion surrounding the central portion and
A plurality of connecting portions connecting the central portion and the outer peripheral portion,
A plurality of strain sensors provided on the main surface of the connection portion, and
A plurality of reference resistors provided on the main surface of the central portion and forming a bridge circuit together with the plurality of strain sensors.
An electrode provided on the main surface of the central portion, electrically connected to the plurality of strain sensors and the plurality of reference resistors, and for extracting a detection signal of the bridge circuit.
Lead wiring that electrically connects the electrode and the outside,
A strain-causing body provided between the electrode and the lead wiring and comprising an anisotropic conductive film that electrically connects the terminal of the electrode and the terminal of the lead wiring.

The plurality of connecting portions include a first connecting portion adjacent to the outer peripheral portion and a second connecting portion adjacent to the central portion, respectively.
On the back surface side of the first connecting portion facing the main surface, a strain increasing portion configured so that the strain generated in the first connecting portion is larger than the strain generated in the second connecting portion is further provided. The strain-causing body according to claim 1.

The strain generating body according to claim 2, wherein at least one of the plurality of strain sensors constituting the bridge circuit is provided on the main surface of the first connecting portion.

The strain generating body according to claim 2 or 3, further comprising a full bridge circuit provided on the main surface of the second connecting portion and in which the plurality of strain sensors connected in series are connected in parallel.

The strain-causing body according to any one of claims 2 to 4, wherein the strain-increasing portion includes a groove formed so as to be recessed in the thickness direction of the strain-causing body.

The central portion is connected to an external first support member.
The outer peripheral portion is connected to an external second support member and is connected to the outer peripheral portion.
The strain-causing body according to any one of claims 1 to 5, wherein the elasticity of the outer peripheral portion and the connecting portion is larger than the elasticity of the central portion.

Further provided on the main surface of the central portion and the connecting portion, the plurality of strain sensors, the plurality of reference resistors, and wiring for electrically connecting the electrodes are provided.
Any of claims 1 to 6, wherein the arrangement of the plurality of strain sensors, the plurality of reference resistors, the electrodes, and the wiring is configured to be mirror-symmetrical on a diagonal line connecting the corners of the outer peripheral portion. The strain-causing body described in.

The strain-causing body according to claim 1 and
Cylindrical body and
It is provided with a cylindrical movable body that can operate with respect to the main body.
The central portion of the strain-causing body is connected to one of the main body or the movable body which is a support member.
A force sensor whose outer peripheral portion of the strain-causing body is connected to the main body which is a support member or the other of the movable body.

At least three circular openings provided around the movable body at equal intervals,
A stopper arranged inside each of the openings and having a first side surface having a first outer diameter smaller than the diameter of the opening.
The force sensor according to claim 8, further comprising a fixing member for fixing the stopper to the main body.