Micromachine transducer with cantilevered movable portion

• US 5,626,779 A
• Filed: 05/31/1994
• Issued: 05/06/1997
• Est. Priority Date: 06/07/1993
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Okada, Hiroyuki
• Primary Examiner(s): Walberg, Teresa J.
• Assistant Examiner(s): VALENCIA, RAPHA
• Application Number:
  US08/250,829
• Time in Patent Office: 1,071 Days
• Field of Search: 219/200-201, 338/2, 338/4, 338/6, 338/36, 338/47, 338/42, 83/15-16, 83/170, 29/621.1, 73/862.474, 73/862.627, 73/862.634, 73/862.639, 73/514.21-514.24, 73/514.33, 73/514.36, 73/514.38, 73/514.37
• US Class Current: 219/201
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: G01P 15/02 by making use of inertia forces using solid seismic massesG01P15/14 takes precedence
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 2015/0828 the mass being of the paddle type being suspended at one of its longitudinal ends

Abstract

The micromachine includes a movable portion, an unmovable portion surrounding the movable portion, a connecting portion for connecting the movable portion with the unmovable portion in a cantilever fashion, and a support member for connecting the movable portion with the unmovable portion at a location other than a location at which the movable portion is connected with the unmovable portion through the connecting portion. The support member is formed of weaker material than material of which all of the portions are formed, with respect to any one of properties which all of the portions have. Thus, only the support member can be cut off by applying energy effective to the one of properties thereto after the micromachine has been packaged.

Claims

1. A micromachine comprising:

a movable portion;

an unmovable portion surrounding said movable portion;

a connecting portion which connects said movable portion with said unmovable portion in a cantilever fashion; and

a support member which connects said movable portion with said unmovable portion at a location other than a location at which said movable portion is connected with said unmovable portion through said connecting portion,

said support member being formed of weaker material than material of which all of said portions are formed, with respect to any one of a number of physical properties shared by all of said portions,

whereby said support member is adapted to be cut off by applying energy effective to said any one of properties thereto after said micromachine has been packaged.

2. A micromachine in accordance with claim 1 wherein said micromachine comprises an acceleration sensor.

3. A micromachine comprising:

a movable portion;

an unmovable portion surrounding said movable portion;

a connecting portion which connects said movable portion with said unmovable portion in a cantilever fashion; and

a support member which connects said movable portion with said unmovable portion at a location other than a location at which said movable portion is connected with said unmovable portion through said connecting portion,

said support member being formed of thermally fusible material, said material generating heat therein when an electrical current is applied thereto due to a resistance thereof,

whereby said support member is cut off by applying an electrical current thereto.

4. A micromachine in accordance with claim 3 wherein at least said connecting portion among all of said portions comprises electrically conductive diffusion layer formed by injecting impurities thereinto.

5. A micromachine in accordance with claim 3 wherein all of said portions are provided with metal wirings formed by means of a metal deposition process.

6. A micromachine in accordance with claim 3 wherein all of said portions comprise an electrically conductive diffusion layer formed by injecting impurities thereinto or are provided with metal wirings formed by means of metal deposition process in dependence on the order of steps involved in a process for fabricating said micromachine.

7. A micromachine comprising:

a movable portion;

an unmovable portion surrounding said movable portion;

a connecting portion for connecting said movable portion with said unmovable portion in a cantilever fashion; and

a support member for connecting said movable portion with said unmovable portion at a location other than a location at which said movable portion is connected with said unmovable portion through said connecting portion,

said support member being formed of material having a lower melting point than a melting point of material of which all of said portions are formed,

whereby said support member is cut off by applying heat thereto.

8. A micromachine in accordance with claim 7 wherein all of said portions are made of silicon, and said support member comprises plastic adhesive.

9. A micromachine comprising:

a movable portion;

an unmovable portion surrounding said movable portion;

a connecting portion which connects said movable portion with said unmovable portion in a cantilever fashion; and

a support member which connects said movable portion with said unmovable portion at a location other than a location at which said movable portion is connected with said unmovable portion through said connecting portion,

said support member having a characteristic frequency different from that of all of said portions,

whereby said support member is cut off by applying said characteristic frequency of said support member thereto.

10. A micromachine in accordance with claim 9 wherein all of said portions are made of silicon, and said support member is made of carbon.