Molded Differential PRT Pressure Sensor
First Claim
1. A packaged differential pressure sensor, comprising:
- an exposed die flag in which a first vent hole is formed;
a differential pressure sensor transducer die comprising a sensor diaphragm located between a backside and topside of the differential pressure sensor transducer die and sensor circuitry located on the topside of the differential pressure sensor transducer die, where the backside of the differential pressure sensor transducer is affixed to the exposed die flag so that a backside of the sensor diaphragm is directly vented to the environment through the first vent hole in the exposed die flag;
a cap structure in which a second vent hole is located, where the cap structure is attached to the topside of the differential pressure sensor transducer die and so that the topside of the sensor diaphragm is vented to the environment through the second vent hole in the cap structure;
one or more electrical connectors that are electrically coupled to the sensor circuitry located on the topside of the differential pressure sensor transducer die; and
a molded body formed at least partially around the electrical connectors and around the differential pressure sensor transducer die without covering the first vent hole in the exposed die flag or the second vent hole in the cap structure, where the molded body covers the sensor circuitry located on the topside of the differential pressure sensor transducer die.
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0 Petitions
Accused Products
Abstract
A method and apparatus are described for fabricating an exposed differential pressure sensor (30) which protects interior electrical components (37) formed on a topside surface of a differential pressure sensor transducer die (31) from corrosive particles using a molding compound (39), but which vents both sides of a piezoresistive transducer sensor diaphragm (33) through a first vent hole (42) formed in an exposed die flag (36) and a second vent hole (38) formed in an exposed cap structure (33), enabling the sensor diaphragm (33) to sense differential pressure variations directly or indirectly through a protective gel.
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Citations
20 Claims
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1. A packaged differential pressure sensor, comprising:
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an exposed die flag in which a first vent hole is formed; a differential pressure sensor transducer die comprising a sensor diaphragm located between a backside and topside of the differential pressure sensor transducer die and sensor circuitry located on the topside of the differential pressure sensor transducer die, where the backside of the differential pressure sensor transducer is affixed to the exposed die flag so that a backside of the sensor diaphragm is directly vented to the environment through the first vent hole in the exposed die flag; a cap structure in which a second vent hole is located, where the cap structure is attached to the topside of the differential pressure sensor transducer die and so that the topside of the sensor diaphragm is vented to the environment through the second vent hole in the cap structure; one or more electrical connectors that are electrically coupled to the sensor circuitry located on the topside of the differential pressure sensor transducer die; and a molded body formed at least partially around the electrical connectors and around the differential pressure sensor transducer die without covering the first vent hole in the exposed die flag or the second vent hole in the cap structure, where the molded body covers the sensor circuitry located on the topside of the differential pressure sensor transducer die. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for packaging an exposed differential pressure sensor, comprising:
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affixing a piezoresistive transducer die to a die flag so that a differential sensor diaphragm formed on the piezoresistive transducer die has a backside that is vented through a first vent hole formed in the die flag; attaching a cap structure having a second vent hole to a topside of the piezoresistive transducer die so that the differential sensor diaphragm formed on the piezoresistive transducer die has a topside that is vented through the second vent hole in the cap structure; electrically connecting circuitry located on the topside of the piezoresistive transducer die to one or more electrical connectors; and forming a molded body at least partially around the one or more electrical connectors and around the piezoresistive transducer die to cover at least the circuitry on the topside of the piezoresistive transducer die without covering the first vent hole in the exposed die flag or the second vent hole in the cap structure. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A packaged differential sensor, comprising:
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a piezoresistive transducer die having a differential sensor diaphragm with first and second sensor surfaces; an exposed pad attached to the piezoresistive transducer die having a first vent hole located in the exposed pad for venting the first sensor surface of the differential sensor diaphragm to a first external environment; a cap structure attached to the piezoresistive transducer die having a second vent hole located in the cap structure for venting the second sensor surface of the differential sensor diaphragm to a second external environment; a housing formed to surround and protect the piezoresistive transducer die without covering the first and second vent holes; and at least a first electrical connector protruding through said housing that is electrically coupled to the piezoresistive transducer die. - View Dependent Claims (18, 19, 20)
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Specification