Method of manufacturing physical quantity detector

• US 5,531,002 A
• Filed: 02/24/1995
• Issued: 07/02/1996
• Est. Priority Date: 10/12/1990
• Status: Expired due to Term

• Current Assignee: Kazuhiro Okada
• Original Assignee: Kazuhiro Okada
• Inventors: Okada, Kazuhiro
• Primary Examiner(s): Vo, Peter
• Application Number:
  US08/394,310
• Time in Patent Office: 494 Days
• Field of Search: 29/25.41, 29/414, 29/415, 29/417, 29/594, 29/595, 29/25.35, 73/718, 73/862.041-862.043, 73/862.68, 73/DIG. 4, 361/283.1, 361/283.3
• US Class Current: 29/25.41
• CPC Class Codes: G01L 1/144 with associated circuitry G01L1/146 and G01L1/148 take precedence
• CPC Class Codes: G01L 5/165 using variations in capacitance
• CPC Class Codes: G01L 5/167 using piezoelectric means
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/0922 of the bending or flexing mode type
• CPC Class Codes: G01P 15/105 by magnetically sensitive devices
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/084 the mass being suspended at more than one of its sides, e.g. membrane-type suspension, so as to permit multi-axis movement of the mass
• CPC Class Codes: Y10S 73/04 Piezoelectric
• CPC Class Codes: Y10T 29/43 Electric condenser making
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/49007 Indicating transducer

Abstract

An electrode layer is formed on the upper surface of a first substrate, and a processing for partially removing the substrate is carried out in order to allow the substrate to have flexibility. To the lower surface of the first substrate, a second substrate is connected. Then, by cutting the second substrate, a working body and a pedestal are formed. On the other hand, a groove is formed on a third substrate. An electrode layer is formed on the bottom surface of the groove. The third substrate is connected to the first substrate so that both the electrodes face to each other with a predetermined spacing therebetween. Finally, the first, second and third substrates are cut off every respective unit regions to form independent sensors, respectively. When an acceleration is exerted on the working body, the first substrate bends. As a result, the distance between both the electrodes changes. Thus, an acceleration exerted is detected by changes in an electrostatic capacitance between both the electrodes.

Claims

1. A method of manufacturing substrates for a physical quantity detector utilizing changes in an electrostatic capacitance, said method comprising the steps of:

defining a working region area, a flexible region area and a fixed region area successively on a first surface of a first substrate;

forming first electrode layers on said first surface of said first substrate at predetermined portions of said working and flexible region areas;

partially removing an opposite, second surface of said first substrate opposite said flexible region area for forming a flexible region having flexibility relative to said first substrate at said working and fixed region areas;

cutting away portions of a second substrate and connecting uncut portions of a first surface of said second substrate to said second surface of said first substrate opposite said working and fixed region areas for forming a working body at a working region of said first substrate comprised of portions of said first and second substrates and a pedestal at a fixed region of said first substrate comprised of portions of said first and second substrates; and

forming a groove on a first surface of a third substrate, forming a second electrode layer on a bottom surface of said groove and connecting said first surface of said third substrate to said first surface of said first substrate at said fixed region so that said second electrode layer faces said first electrode layers with a predetermined spacing therebetween.

2. A method of manufacturing substrates for a physical quantity detector utilizing changes in an electrostatic capacitance, said method comprising the steps of:

defining a working region area, a flexible region area and a fixed region area successively on a first surface of a first substrate;

forming first electrode layers on said first surface of said first substrate at predetermined portions of said working and flexible region areas;

partially removing an opposite, second surface of said first substrate opposite said flexible region area for forming a flexible region having flexibility relative to said first substrate at said working and fixed region areas; and

cutting away portions of a second substrate and connecting uncut portions of a first surface of said second substrate to said second surface of said first substrate opposite said working and fixed region areas for forming a working body at a working region of said first substrate comprised of portions of said first and second substrates and a pedestal at a fixed region of said first substrate comprised of portions of said first and second substrates;

forming a groove on a first surface of a third substrate, forming a second electrode layer on a bottom surface of said groove and connecting said first surface of said third substrate to said first surface of said first substrate at said fixed region so that said second electrode layer faces said first electrode layers with a predetermined spacing therebetween; and

forming a second groove on a first surface of a fourth substrate and connecting said first surface of said fourth substrate to said second surface of said second substrate at said fixed region such that said working body can move in said second groove with a predetermined degree of freedom.

3. A method of manufacturing Substrates for a physical quantity detector utilizing changes in an electrostatic capacitance, said method comprising the steps of:

defining a working region area, a flexible region area and a fixed region area successively on a first surface of a first substrate;

forming first electrode layers on said first surface of said first substrate at predetermined portions of said working and flexible region areas;

partially removing an opposite, second surface of said first substrate at said flexible region area for forming a flexible region having flexibility relative to said first substrate at said working and fixed region areas; and

forming a groove on a first surface of a second substrate and connecting said first surface of said second substrate to said second surface of said first substrate opposite said fixed region area for a working region of said second substrate at said working region area to move with a predetermined degree of freedom; and

forming a second groove on a first surface of a third substrate, forming a second electrode layer on a bottom surface of said groove and connecting said first surface of said third substrate to said first surface of said first substrate so that said second electrode layer faces said first electrode layers with a predetermined spacing therebetween.

4. A method of manufacturing substrates for physical quantity detectors utilizing changes in an electrostatic capacitance, said method comprising the steps of:

defining a plurality of unit regions on a first surface of a first substrate and, successively within each unit region, a working region area, a flexible region area and a fixed region area;

forming first electrode layers on said first surface of said first substrate at predetermined portions of said working and flexible region areas;

partially removing an opposite, second surface of said first substrate opposite said flexible region areas for forming flexible regions having flexibility relative to said first substrate at said working and fixed region areas;

cutting away portions of a second substrate and connecting uncut portions of a first surface of said second substrate to said second surface of said first substrate opposite said working and fixed region areas for forming working bodies at working regions of said first substrate comprised of portions of said first and second substrates and pedestals at fixed regions of said first substrate comprised of portions of said first and second substrates;

forming a plurality of grooves on a first surface of a third substrate, forming second electrode layers on bottom surfaces of said grooves and connecting said first surface of said third substrate to said first surface of said first substrate at said fixed regions so that said second electrode layers face said first electrode layers with a predetermined spacing therebetween; and

separating said unit regions for said detectors.

5. A method of manufacturing substrates for physical quantity detectors utilizing changes in an electrostatic capacitance, said method comprising the steps of:

defining a plurality of unit regions on a first surface of a first substrate and, successively within each unit region, a working region area, a flexible region area and a fixed region area;

forming first electrode layers on said first surface of said first substrate at predetermined portions of said working and flexible region areas;

partially removing an opposite, second surface of said first substrate opposite said flexible region areas for forming flexible regions to having flexibility relative to said first substrate at said working and fixed region areas;

cutting away portions of a second substrate and connecting uncut portions of a first surface of said second substrate to said second surface of said first substrate opposite said working and fixed region areas for forming working bodies at working regions of said first substrate comprised of portions of said first and second substrates and pedestals at fixed regions of said first substrate comprised of portions of said first and second substrates;

forming a groove on a first surface of a third substrate and connecting said first surface of said second substrate to said second surface of said first substrate at said fixed regions for said working bodies to move with a predetermined degree of freedom;

forming a plurality of second grooves on a first surface of a fourth substrate, forming second electrode layers on bottom surfaces of said grooves and connecting said first surface of said fourth substrate to said first surface of said first substrate at said fixed regions so that said second electrode layers face said first electrode layers with a predetermined spacing therebetween; and

separating said unit regions for said detectors.

6. A method of manufacturing substrates for physical quantity detectors utilizing changes in an electrostatic capacitance, said method comprising the steps of:

defining a plurality of unit regions on a first surface of a first substrate and, successively within each unit region, a working region area, a flexible region area and a fixed region area;

forming first electrode layers on said first surface of said first substrate at predetermined portions of said working and flexible region areas;

partially removing an opposite, second surface of said first substrate opposite said flexible region areas for forming flexible regions to having flexibility relative to said first substrate at said working and fixed region areas;

forming a groove on a first surface of a second substrate and connecting said first surface of said second substrate to said second surface of said first substrate at said fixed regions for said working bodies to move with a predetermined degree of freedom;

forming a plurality of second grooves on a first surface of a fourth substrate, forming second electrode layers on bottom surfaces of said grooves and connecting said first surface of said fourth substrate to said first surface of said first substrate at said fixed regions so that said second electrode layers face said first electrode layers with a predetermined spacing therebetween; and

separating said unit regions for said detectors.

7. A method of manufacturing substrates for a physical quantity detector utilizing changes in an electrostatic capacitance, said method comprising the steps of:

providing a first substrate, a second substrate and a third substrate;

connecting said first and third substrates so that there is a space between a first surface of said first substrate and a surface of said third substrate when said first substrate and said third substrate are connected;

forming a first electrode layer on said first surface of said first substrate in a working region of said first substrate and a second electrode layer on said surface of said third substrate so that said first and second electrode layers constitute a capacitance element in said space;

partially removing said first substrate for forming a flexible region in said first substrate having flexibility relative to said working region, said flexible region being adjacent said working region;

connecting said second substrate for forming a working body at said working region comprised of portions of said first substrate and said second substrate and a pedestal at a fixed region of said first substrate adjacent said flexible region successively from said working and flexible regions and comprised of portions of said first and second substrates.

8. A method of manufacturing substrates for a physical quantity detector utilizing changes in an electrostatic capacitance, said method comprising the steps of:

providing a first substrate, a second substrate, a third substrate and a fourth substrate;

connecting said first and fourth substrates so that there is a first space between a first surface of said first substrate and a surface of said fourth substrate when said first substrate and said fourth substrate are connected;

connecting said second and third substrates so that there is a second space between a first surface of said second substrate and a surface of said third substrate when said second substrate and said third substrate are connected;

forming a first electrode layer on said first surface of said first substrate in a working region of said first substrate and a second electrode layer on said surface of said fourth substrate so that said first and second electrode layers constitute a capacitance element in said first space;

partially removing said first substrate for forming a flexible region in said first substrate having flexibility relative to said working region, said flexible region being adjacent said working region;

connecting an opposite, second surface of said second substrate to an opposite, second surface of said first substrate;

cutting said second substrate for forming a working body at said working region comprised of portions of said first substrate and said second substrate such that said working body can move in said second space with a predetermined degree of freedom and a pedestal at a fixed region of said first substrate adjacent said flexible region successively from said working and flexible regions and comprised of portions of said first and second substrates.

9. A method of manufacturing substrates for a physical quantity detector utilizing changes in an electrostatic capacitance, said method comprising the steps of:

providing a first substrate, a second substrate and a third substrate;

connecting said first and third substrates so that there is a first space between a first surface of said first substrate and a surface of said third substrate when said first substrate and said third substrate are connected;

connecting said first and second substrates so that there is a second space between an opposite, second surface of said first substrate and a surface of said second substrate when said first substrate and said second substrate are connected;

forming a first electrode layer on said first surface of said first substrate in a working region and a second electrode layer on said surface of said third substrate so that said first and second electrode layers constitute a capacitance element in said first space;

partially removing said first substrate for forming a working body that can move in said second space with a predetermined degree of freedom and an adjacent flexible region in said first substrate, said flexible region having flexibility relative to said working body.