Microfabricated silicon thermopile sensor

• US 5,982,014 A
• Filed: 05/30/1997
• Issued: 11/09/1999
• Est. Priority Date: 05/30/1997
• Status: Expired due to Fees

• Current Assignee: Themalytics Incorporated
• Original Assignee: The Thermalytics Incorporated
• Inventors: Paige, David F.
• Primary Examiner(s): WILLIAMS, ALEXANDER O
• Application Number:
  US08/850,262
• Time in Patent Office: 893 Days
• Field of Search: 257/467, 257/327, 257/9, 257/347, 257/712, 136/225, 136/212, 136/224, 136/230, 250/338.1, 250/338.4, 250/332, 250/349
• US Class Current: 257/467
• CPC Class Codes: G01K 7/028 using microstructures, e.g. made of silicon
• CPC Class Codes: G01N 25/482 concerning the temperature responsive elements measuring temperature or quantity of heat, thermally-sensitive elements G01K; thermoelectric devices H10N10/00, H10N15/00
• CPC Class Codes: H10N 10/17 characterised by the structure or configuration of the cell or thermocouple forming the device

Abstract

A microfabricated thermopile optimized as a differential temperature sensor provides differential temperature sensing between opposite edges of the device. A plurality of the thermopile sensors are stacked to increase the number of couples possible with an attendant increase in sensitivity.

Claims

1. A thermopile sensor for measuring differential temperatures between an external object to be measured contacting the sensing edge and a reference object contacting the reference edge of the thermopile sensor, comprising:

a) a base layer, comprising;

i) a reference heat sink;

ii) a sensing heat sink; and

iii) an etched area separating said reference and said sensing heat sinks;

b) an electrically insulating layer on said base layer and spanning said etched area;

c) a plurality of alternating p-type and n-type thermopile arms formed in an electrically conducting layer on said electrically insulating layer and spanning said etched area, wherein said alternating p-type and n-type thermopile arms have an electrical connection between each alternating pair of said p-type and n-type thermopile arms;

d) a thermal reference area at an outside edge of said reference heat sink; and

e) a thermal sensing area at an outside edge of said sensing heat sink.

2. A thermopile sensor according to claim 1, wherein said p-type thermopile arms contain boron dopant.

3. A thermopile sensor according to claim 1, wherein said n-type thermopile arms contain phosphorus dopant.

4. A thermopile sensor for measuring differential temperatures between an external object to be measured contacting the sensing edge and a reference object contacting the reference edge of the thermopile sensor, comprising:

a) a base layer, comprising;

i) a reference heat sink;

ii) a sensing heat sink; and

iii) an etched area separating said reference and said sensing heat sinks;

b) an electrically insulating layer on said base layer and spanning said etched area;

c) a pair of p-type and n-type thermopile arms formed in an electrically conducting layer on said electrically insulating layer and spanning said etched area, wherein said pair of p-type and n-type thermopile arms have an electrical connection between said p-type and n-type thermopile arms;

d) a thermal reference area at an outside edge of said reference heat sink; and

e) a thermal sensing area at an outside edge of said sensing heat sink.

5. A thermopile sensor according to claim 4, wherein said p-type thermopile arm contain boron dopant.

6. A thermopile sensor according to claim 4, wherein said n-type thermopile arm contain phosphorus dopant.

7. A thermopile sensor for measuring differential temperatures, comprising a stacked plurality of thermopile sensors according to claim 4.