Method of manufacturing a force sensor having an electrode which changes resistance or electrostatic capacitance in response to force
First Claim
1. A method of manufacturing a sensor utilizing change of electrostatic capacitance, the method comprising:
- a step of preparing a first substrate where a working area is defined at a central portion thereof, a flexible area is defined at a periphery of the working area and a fixed area is defined at a periphery of the flexible area, and preparing a second substrate for being disposed in a manner opposite to a lower surface of the first substrate;
a step of implementing processing to either the lower surface of the first substrate or an upper surface of the second substrate, or both of the surfaces so that a cavity portion of a capacitance element can be formed between said working and flexible areas of the first substrate and an opposite ares of the second substrate;
a step of providing electrodes so that the capacitance element can be formed between the lower surface of the first substrate constituting an upper wall surface of said cavity portion for said capacitance element and the upper surface of the second substrate constituting a lower wall surface of said cavity portion for the capacitance element;
a step of joining the lower surface of the fixed area of the first substrate to the upper surface of the second substrate so as to form said cavity portion for said capacitance element;
a step of digging a portion of at least the flexible area of the first substrate from the upper surface to thereby form grooves having a first depth; and
a step of implementing etching to bottom portions of the grooves until their depths reach a second depth so that a flexible portion is formed by a portion of the flexible area of the first substrate, a weight body is formed by a portion of the working area of the first substrate and a pedestal is formed by a portion of the fixed area of the first substrate thus to form a sensor structural body wherein bending takes place in the flexible portion on the basis of force applied to the weight body;
to manufacture a sensor having a function to measure physical action on the basis of change of electrostatic capacitance values of the capacitance elements.
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Accused Products
Abstract
A first substrate of the three layer structure composed of a lower layer portion consisting of silicon, a middle layer portion consisting of SiO2 and an upper layer portion consisting of silicon is prepared. Impurity is doped into the lower layer portion so that it has conductivity. The lower surface of the lower layer portion is etched to form a diaphragm portion and a pedestal portion, and then a second substrate consisting of glass is joined to the portion therebelow. By the electrodes on the second substrate and the diaphragm portion, capacitance elements are formed. Grooves are dug by a dicing blade from the upper surface of the upper layer portion thereafter to downwardly dig the bottom portions of the grooves by etching until the upper surface of the lower layer portion is exposed. When the respective unit areas are cut off, there is obtained a structure in which a weight body is positioned at the central portion of the diaphragm portion and a pedestal is formed at the periphery thereof. Piezo resistance elements may be used in place of the capacitance elements.
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Citations
41 Claims
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1. A method of manufacturing a sensor utilizing change of electrostatic capacitance, the method comprising:
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a step of preparing a first substrate where a working area is defined at a central portion thereof, a flexible area is defined at a periphery of the working area and a fixed area is defined at a periphery of the flexible area, and preparing a second substrate for being disposed in a manner opposite to a lower surface of the first substrate; a step of implementing processing to either the lower surface of the first substrate or an upper surface of the second substrate, or both of the surfaces so that a cavity portion of a capacitance element can be formed between said working and flexible areas of the first substrate and an opposite ares of the second substrate; a step of providing electrodes so that the capacitance element can be formed between the lower surface of the first substrate constituting an upper wall surface of said cavity portion for said capacitance element and the upper surface of the second substrate constituting a lower wall surface of said cavity portion for the capacitance element; a step of joining the lower surface of the fixed area of the first substrate to the upper surface of the second substrate so as to form said cavity portion for said capacitance element; a step of digging a portion of at least the flexible area of the first substrate from the upper surface to thereby form grooves having a first depth; and a step of implementing etching to bottom portions of the grooves until their depths reach a second depth so that a flexible portion is formed by a portion of the flexible area of the first substrate, a weight body is formed by a portion of the working area of the first substrate and a pedestal is formed by a portion of the fixed area of the first substrate thus to form a sensor structural body wherein bending takes place in the flexible portion on the basis of force applied to the weight body; to manufacture a sensor having a function to measure physical action on the basis of change of electrostatic capacitance values of the capacitance elements. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of manufacturing a sensor utilizing change of electrostatic capacitance, the method comprising:
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a step of preparing a first substrate where a working area is defined at a central portion thereof, a flexible area is defined at a periphery of the working area and a fixed area is defined at a periphery of the flexible area, and preparing a second substrate for being disposed in a manner opposite to a lower surface of the first substrate; a step of implementing processing to either the lower surface of the first substrate or an upper surface of the second substrate, or both of the surfaces so that a cavity portion for capacitance element can be formed between said working and flexible areas of the first substrate and an opposite area of the second substrate; a step of providing electrodes so that capacitance element can be formed between a surface of the first substrate constituting an upper wall surface of said cavity portion for said capacitance element and a surface of the second substrate constituting a lower wall surface of said cavity portion for said capacitance element; a step of joining the lower surface of the fixed area of the first substrate to the upper surface of the second substrate so as to form said cavity portion for said capacitance element; a step of digging the fixed area and the flexible area of the first substrate from the upper surface to thereby form grooves having a first depth; and a step of implementing etching to bottom portions of the grooves until their depths reach a second depth so that a flexible portion is formed by a portion of the flexible area of the first substrate and a weight body is formed by a portion of the working area of the first substrate thus to form a sensor structural body wherein bending takes place in the flexible portion on the basis of force applied to the weight body; to manufacture a sensor having a function to measure physical action on the basis of change of electrostatic capacitance values of the capacitance element. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A method of manufacturing a sensor utilizing a piezo resistance element, the method comprising:
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a step of preparing a body substrate wherein a working area is defined at a central portion, a flexible area is defined at a periphery of the working area, and a fixed area is defined at a periphery of the flexible area; a step of forming piezo resistance elements in the flexible area on a lower surface of the body substrate so that resistance values of said piezo resistance elements change on the basis of mechanical deformation; a step of digging a portion of at least the flexible area of the body substrate from an upper surface to thereby form grooves having a first depth; and a step of implementing etching to bottom portions of the grooves until their depths reach a second depth so that a flexible portion is formed by a portion of the flexible area of the body substrate, a weight body is formed by a portion of the working area of the body substrate and a pedestal is formed by a portion of the fixed area of the body substrate thus to form a sensor structural body wherein bending takes place in the flexible portion on the basis of force applied to the weight body; to manufacture said sensor having a function to measure physical action on the basis of change of resistance values of the piezo resistance elements. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32)
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33. A method of manufacturing a sensor utilizing a piezo resistance elements, the method comprising:
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a step of preparing a body substrate wherein a working area is defined at a central portion, a flexible area is defined at a periphery of the working area, and a fixed area is defined at a periphery of the flexible area; a step of forming piezo resistance elements in the flexible area on a lower surface of the body substrate so that resistance values of said piezo resistance elements change on the basis of mechanical deformation; a step of digging the fixed area and the flexible area of the body substrate from an upper surface to thereby form grooves having a first depth; and a step of implementing etching to bottom portions of the grooves until their depths reach a second depth so that a flexible portion is formed by a portion of the flexible area of the body substrate and a weight body is formed by a portion of the working area of the body substrate thus to form a sensor structural body wherein bending takes place in the flexible portion on the basis of force applied to the weight body; to manufacture said sensor having a function to measure physical action on the basis of change of said resistance values of the piezo resistance elements. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40, 41)
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Specification