Flip-chip pressure transducer

• US 4,763,098 A
• Filed: 04/08/1985
• Issued: 08/09/1988
• Est. Priority Date: 04/08/1985
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: McMullen, Raymond F., Glenn, Max C.
• Primary Examiner(s): Grimley, A. T.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/721,107
• Time in Patent Office: 1,219 Days
• Field of Search: 338/4, 338/36, 338/42, 338/47, 338/2, 357/26, 310/324, 310/338, 73/774, 73/777, 73/769, 73/708, 73/720-721, 73/726-727, 29/25.35, 29/610 SG
• US Class Current: 338/4
• CPC Class Codes: G01L 19/0038 being part of the housing other details about the housing G01L19/14
• CPC Class Codes: G01L 19/0084 to the outside of the housing other details about the housing see G01L19/14
• CPC Class Codes: G01L 9/0054 integral with a semiconducting diaphragm
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49103 Strain gauge making

Abstract

Disclosed is a pressure transducer comprising a pressure sensitive silicon die having a front side exposing piezoresistive means and comprising means for flip-chip mounting the die to a pressure vessel. The transducer further comprises a pressure vessel having an aperture, the pressure vessel comprising means for flip-chip mounting the die over the aperture. The die is flip-chip mounted over the aperture in the pressure vessel, and there is a hermetic seal between the pressure vessel and the die.

Claims

1. A pressure transducer comprising:

a pressure sensitive silicon die having a front side exposing piezoresistive means and comprising means for flip-chip mounting the die to a pressure vessel;

a pressure vessel having an aperture, the pressure vessel comprising means for flip-chip mounting the die over the aperture, so that the front side of the die faces the aperture;

the die being flip-chip mounted over the aperture in the pressure vessel;

a hermetic seal between the pressure vessel and the die; and

a substantially flat, optically transparent coverplate, attached to the pressure vessel and positioned opposite said piezoresistive means.

2. The apparatus of claim 1 wherein the pressure vessel comprises a chip carrier.

3. The apparatus of claim 1 wherein the pressure vessel defines an evacuated interior volume comprising the aperture.

4. A method of fabricating a pressure transducer comprising:

providing a pressure sensitive silicon die having a front side exposing poezoresistive means;

providing a pressure vessel having an aperture;

flip-chip mounting the die over the aperture in the pressure vessel so that the front side of the die faces the aperture;

providing a hermetic seal between the pressure vessel and the die; and

attaching a substantially flat, optically transparent coverplate to the pressure vessel, the coverplate being positioned opposite the piezoresistive means.

5. The method of claim 4 wherein:

the piezoresistive mens is laser-trimmed following assembly of the pressure transducer.

6. The method of claim 5 further including:

detecting the pressure on said transducer during the laser-trimming; and

terminating the laser-trimming when a desired pressure on the transducer is indicated, so that the transducer is calibrated following assembly.

7. A differential pressure transducer comprising:

a pressure sensitive silicon die having a front side exposing piezoresistive mens and comprising means for flip-chip mounting the die to a chip carrier;

a chip carrier having an aperture extending through the carrier, the chip carrier comprising means for flip-chip mounting the die over the aperture, the die being flip-chip mounted over the aperture so that the front of the die faces the aperture and wherein the end of the aperture opposite the die is uncovered; and

a hermetic seal between the chip carrier and the die, so that the die will flex in respone to a difference in pressure between the pressure in the aperture and the pressure on the back side of the die.