Infrared detector of the type used in infrared spectrometers

• US 5,227,631 A
• Filed: 04/30/1992
• Issued: 07/13/1993
• Est. Priority Date: 04/30/1992
• Status: Expired due to Term

• Current Assignee: Thermo Nicolet Corporation
• Original Assignee: Nicolet Instrument Corporation
• Inventors: Miller, Robert A., Hunter, Leon J. III
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Glick, Edward J.
• Application Number:
  US07/876,964
• Time in Patent Office: 439 Days
• Field of Search: 250/352, 250/370.01, 250/338.1, 250/338.3, 250/370.15
• US Class Current: 250/352
• CPC Class Codes: G01J 3/453 by correlation of the amplitudes
• CPC Class Codes: G01J 5/061 by controlling the temperature of the apparatus or parts thereof, e.g. using cooling means or thermostats
• CPC Class Codes: G01J 5/34 using capacitors, e.g. pyroelectric capacitors

Abstract

An infrared detector assembly for infrared spectrometers includes a circuit board on which electronic components and an infrared detector and cooler unit are mounted. The detector unit includes a thermal electric cooler which cools the detector and transfers heat to a flange of the detector unit. A front side heat sink is mounted to the flange to dissipate heat to the air on the front side of the circuit board. Heat is also transferred from the flange of the heat detector unit by a heat conductive post or posts through openings in the circuit board to a heat sink mounted to the back side of the circuit board. The back side heat sink can include an adjustment plate to which the circuit board is detachably mounted and which is itself mounted on an assembly which allows lateral adjustment of the position of the circuit board and the detector thereon. Adequate cooling of the detector is thus obtained through heat transfer to the front side and back side heat sinks, while allowing the entire circuit board and detector unit to be detached from the adjustment plate when it is necessary to replace the detector or the circuit board electronics.

Claims

1. An infrared detector assembly for infrared spectrometers, comprising:

(a) a circuit board with a front side and a back side, and at least one opening extending from the front side to the back side;

(b) a thermal electric cooled infrared detector unit having a window through which infrared radiation is received for detection and a flange for heat exchange;

(c) a front side heat sink mounted in i contact with the flange of the infrared detector unit to conduct heat therefrom and dissipate heat in the ambient air on the front side of the circuit board;

(d) a back side heat sink mounted on the back side of the circuit board and having at least one heat conductive post extending from the back side heat sink up through the opening in the circuit board and into heat transfer contact with the flange of the detector unit to draw heat therefrom through the post to the heat sink; and

(e) means for connecting the detector unit, the front side heat sink and the back side heat sink to the circuit board and to each other.

2. The infrared detector assembly of claim 1 wherein the at least one post is a central post and the means for connecting the detector unit and front side and back side heat sinks includes heat conductive standoff posts extending upwardly from the back side heat sink on either side of the central post through side openings formed in the circuit board on either side of the one opening, and screws through the flange extending into and threaded into threaded bores int he standoff posts to hold the flange against the front side heat sink and to hold the front side heat sink against the standoff posts.

3. The infrared detector assembly of claim 2 wherein the back side heat sink includes a block of heat conductive metal and wherein the central post and the standoff posts extend from the block.

4. The infrared detector assembly of claim 3 wherein the back side heat sink further includes an adjustment plate formed of a heat conductive metal and mounting means for detachably mounting the circuit board to the adjustment plate such that the adjustment plate presses against the heat sink block and presses the block against the back side of the circuit board such that a heat conductive path is formed from the heat sink block to the adjustment plate.

5. The infrared detector assembly of claim 4 further including a mounting fixture having a slide plate and a baseplate joined therewith, the slide plate adapted to have the adjustment plate slide thereon, and means for connecting the slide plate to the adjustment plate to allow adjustable movement of the adjustment plate with respect to the slide plate to locate the adjustment plate and the circuit board mounted thereto in a desired position.

6. The infrared detector assembly of claim 4 including a plurality of holes formed in the circuit board near the corners of the circuit board and wherein the mounting means includes fastener posts extending up from the adjustment plate and shaped and sized to fit in the holes near the corners of the circuit board to provide a snap fit of the circuit board onto the fastener posts to allow ready attaching and detaching of the circuit board to the posts at a desired spacing of the circuit board back side from the adjustment plate.

7. The infrared detector assembly of claim 4 wherein the front side heat sink has metal fins which extend upwardly at positions around the infrared detector unit which are adapted to dissipate heat into the ambient air.

8. The infrared detector assembly of claim 1 wherein the back side heat sink includes an adjustment plate formed of a heat conductive metal, mounting means for detachably mounting the circuit board to the adjustment plate such that the adjustment plate is spaced from the back side of the circuit board, a heat conductive path being formed from the flange of the detector unit through the post to the adjustment plate.

9. The infrared detector assembly of claim 8 further including a mounting fixture having a slide plate and a baseplate joined therewith, the slide plate adapted to have the adjustment plate slide thereon, and means for connecting the slide plate to the adjustment plate to allow adjustable movement of the adjustment plate with respect to the slide plate to locate the adjustment plate and the circuit board mounted thereto in a desired position.

10. The infrared detector assembly of claim 8 including a plurality of holes formed in the circuit board near the corners of the circuit board and wherein the mounting means includes fastener posts extending up from the adjustment plate and shaped and sized to fit in the holes near the corners of the circuit board to provide a snap fit of the circuit board onto the fastener posts to allow ready attaching and detaching of the circuit board to the posts at a desired spacing of the circuit board back side from the adjustment plate.

11. The infrared detector assembly of claim 8 wherein the back side heat sink further comprises a heat sink block of conductive metal from which the post extends, the heat sink block being in heat transfer contact with the adjustment plate.