Low cost wet-to-wet pressure sensor package

Claim 2

A pressure sensor package (10), characterised by: a housing defining (12) a chamber bounded in part by opposing spaced-apart top (14) and bottom (11) end walls; a pressure-sensitive die (34) disposed in a recess in the bottom end wall of said housing; said die including a peripheral edge (36) a reduced central portion (38) a top surface (40) with a piezoresistive circuit in the central portion connected to a plurality of exposed circuit elements including contact pads (42) on the peripheral edge, and a bottom surface; a lead frame (50) secured to the bottom end wall of said housing in spaced relationship with said die, said lead frame including a plurality of internal and external end portions; a plurality of wire bonds (52) interconnecting the contact pads of said die and the internal end portions of said lead frame; and bead means for suspending said die between the recess in the bottom end wall of said housing, the internal end portions of said leadframe, and intermediate portions of the bottom end wall of said housing and for protectively covering the exposed circuit elements and contact pads on said die and said wire bonds therein, without overlapping the reduced central portion of said die.

Claim 3

A pressure sensor package according to Claim 1, characterised in that said bead means comprises: elastomeric adhesive extending between the peripheral edge on the top surface of said die, the internal end portions of said lead frame, and intermediate portions of the bottom end wall of said housing.

Claim 4

A pressure sensor package, which comprises: a housing (12) defining a chamber bounded in part by opposing spaced apart top and bottom end walls; a pressure-sensitive die (34) loosely disposed in a recess in the bottom end wall of said housing; said die including a peripheral edge (36), a central diaphragm portion (38), a top surface (40) with a piezoresistive circuit in the diaphram portion (38) connected to a plurality of exposed circuit elements including contact pads (42) on the peripheral edge, and a bottom surface; a lead frame (50) secured to the bottom end wall of said housing in spaced relationship with said die, said lead frame including a plurality of internal and external end portions; a plurality of wire bonds (52) interconnecting the contact pads of said die and the internal end portions of said lead frame; a continuous lower bead (46) of elastomeric adhesive extending between the peripheral edge on the bottom surface of said die and the recess in the bottom end wall of said housing; a continuous upper bead (48) of elastomeric adhesive extending between the peripheral edge on the top surface of said die, the internal end portions of said lead frame, and intermediate portions of the bottom end wall of said housing; said upper bead protectively covering the exposed circuit elements and contact pads on said die and said wire bonds therein, without overlapping the diaphragm portion of said die; means defining a fluid port (20) in the top end wall of said housing; and means defining a fluid port (28) opening onto the recess in the bottom end wall of said housing.

Claim 5

A pressure sensor package, which comprises: a housing (12) defining a chamber bounded in part by opposing spaced apart top and bottom end walls; a pressure-sensitive die (34) loosely disposed in a recess in the bottom end wall of said housing; said die including a peripheral edge (36), a central diaphragm portion (38), a top surface (40) with a piezoresistive circuit in the diaphram portion (38) connected to a plurality of exposed circuit elements including contact pads (42) on the peripheral edge, and a bottom surface; a lead frame (50) secured to the bottom end wall of said housing in spaced relationship with said die, said lead frame including a plurality of internal and external end portions; a plurality of wire bonds (52) interconnecting the contact pads of said die and the internal end portions of said lead frame; a continuous lower bead (46) of elastomeric adhesive extending between the peripheral edge on the bottom surface of said die and the recess in the bottom end wall of said housing; a continuous upper bead (48) of elastomeric adhesive extending between the peripheral edge on the top surface of said die, the internal end portions of said lead frame, and intermediate portions of the bottom end wall of said housing; said upper bead protectively covering the exposed circuit elements and contact pads on said die and said wire bonds therein, without overlapping the diaphragm portion of said die; means defining a fluid port (20) in the top end wall of said housing; and means defining a fluid port (28) opening onto the recess in the bottom end wall of said housing.

Claim 6

A pressure sensor package according to any preceding Claim characterised in that said housing comprises: a top cover (14) including outer end and an enlarged inner end terminating in the top end wall; a bottom cover (16) including outer end and an enlarged inner end terminating in the bottom end wall; and a surrounding side wall (18) interconnecting the inner ends of said top and bottom covers in relative spaced-apart relationship.

Claim 7

A pressure sensor package according to Claim 4 characterised in that said top and bottom covers and said side wall are formed from thermoplastic.

Claim 8

A pressure sensor package according to any preceding Claim characterised by: longitudinal ribs (24) on the outer ends of said top and bottom covers adjacent their respective end walls for securing tubing thereon.

Claim 9

A pressure sensor package according to any of Claims 2 to 6 characterised in that elastomeric adhesive comprises room temperature vulcanizing silicone rubber.

Claim 10

A pressure sensor package according to Claim 7 characterised in that said elastometric adhesive comprises Fluorosilicone rubber.

Claim 11

A pressure sensor according to any preceding Claim characterised by: means defining a fluid port (28) opening onto the recess in the bottom end wall of said housing.

Claim 12

A pressure sensor package according to any preceding Claim, characterised by means defining a fluid port in the top end wall of said housing.