Six-axis force sensor

• US 20030140713A1
• Filed: 01/10/2003
• Published: 07/31/2003
• Est. Priority Date: 01/11/2002
• Status: Active Grant

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Ohsato, Takeshi, Hirabayashi, Yusuke
• Granted Patent: US 6,823,744 B2
• Time in Patent Office: Days
• US Class Current: 73/862.041
• CPC Class Codes: G01L 5/162 of piezoresistors

Abstract

A six-axis force sensor 1 consists of a sensor chip having a six-axis force sensor function formed using a semiconductor substrate 2 and film-forming technology. Connecting parts 5A to 5D are each made up of a high-rigidity bridge part and a low-rigidity elastic part. Semiconductor strain resistance devices Sya1-Sya3, Syb1-Syb3, Sxa1-Sxa3, and Sxb1-Sxb3 consisting of active layers are disposed on the front sides of the connecting parts. The elastic parts of the connecting parts absorb excess strains acting on the connecting parts and suppress the occurrence of strain spread over the whole semiconductor substrate. Because forces and moments of six specified axis components cause strains to occur selectively in corresponding strain resistance devices, by suitably combining measured results from selected resistance devices it is possible to effectively separate an applied external force into six components of force and moment and greatly suppress other axis interference in the measured results. As a results six components of force and moment of an external force can be measured with good reproducibility on the basis of the strains arising in the resistance devices disposed on the connecting parts.

Claims

1. A six-axis force sensor comprising a thin plate-shaped sensor chip formed using a substrate by semiconductor film-forming processes and having a six-axis force sensor function, the sensor chip comprising an action part to which an external force is applied, a support part to be fixed to an external structure, and a plurality of connecting parts each connecting together the action part and the support part and having a rigid bridge part joined to the action part and an elastic part joined to the support part, wherein each of the multiple connecting parts has a plurality of strain resistance devices each comprising an active layer formed on at least one of front and rear faces thereof in an area thereof where deformation strain effectively arises and each electrically connected to corresponding electrodes disposed in the support part.

2. A six-axis force sensor according to claim 1, wherein the connecting parts are disposed around the action part with uniform spacing and so that adjacent connecting parts are mutually perpendicular.

3. A six-axis force sensor according to claim 1, wherein the action part is square and each of the connecting parts is formed in a T-shape made by its elastic part and its bridge part and is disposed at a respective one of the four sides of the action part.

4. A six-axis force sensor according to claim 1, wherein the strain resistance devices are disposed on the surface of the bridge part of the respective connecting part near the boundary between the bridge part and the action part.

5. A six-axis force sensor according to claim 1, wherein the strain resistance devices are disposed on a narrowed portion formed in the bridge part of the respective connecting part.

6. A six-axis force sensor according to claim 1, wherein the strain resistance devices are disposed on the bridge part of the respective connecting part in parallel with the length direction of the bridge part and arranged side by side in a line in a direction perpendicular to the length direction of the bridge part.

7. A six-axis force sensor according to claim 1, wherein a resistance device for temperature compensation is provided on the support part.

8. A six-axis force sensor according to claim 1, wherein a guard interconnection at a ground potential is provided so as to surround a non-ground interconnection of a strain resistance device.

9. A six-axis force sensor according to claim 1, wherein a bias electrode for applying a bias potential is formed on the substrate.

10. A six-axis force sensor according to claim 1, wherein at least one of the strain resistance devices is disposed on the rear side of the substrate in an area corresponding to an area on the front side of the substrate where strain resistance devices are disposed on one of the bridge parts.

11. A six-axis force sensor comprising:

a thin plate-shaped sensor chip formed using a substrate by semiconductor film-forming processes and having a six-axis force sensor function and comprising at least an action part for receiving an external force and a support part supporting the action part; and

a structural body provided around the sensor chip and comprising an external force application part to which an external force is applied, a plinth part for supporting the sensor chip, an external force buffering mechanism fixing the external force application part to the plinth part, and an external force transmitting part,

wherein the external force application part and the action part are linked by the external force transmitting mechanism.

12. A six-axis force sensor according to claim 11, wherein the sensor chip further comprises four connecting parts connecting together the action part and the support part and a plurality of strain resistance devices fabricated by semiconductor film-forming processes on deformable parts of the substrate.

13. A six-axis force sensor according to claim 11 or 12, wherein an insulating member is provided between the sensor chip and the plinth part.