Molded packaging method for a sensing die having a pressure sensing diaphragm
First Claim
1. A method of forming a package for a sensing die having a pressure sensing diaphragm, said diaphragm having a first surface and a second surface disposed opposite said first surface, comprising the steps of:
- mounting said sensing die overlying a hole of a die bond pad;
enclosing said sensing die within a mold; and
introducing a molding material into said mold to form said package.
22 Assignments
0 Petitions
Accused Products
Abstract
A method forms a plastic package (28) for a sensing die (10) having a pressure sensitive diaphragm (22), wherein the diaphragm (22) has a first surface (24) and a second surface (26) disposed opposite the first surface (24). According to this method, the sensing die (10) is mounted overlying a hole (18) in a die bond pad (16), which is used to support the sensing die (10) in the package (28). Next, the sensing die (10) is enclosed within a mold (12,14), and a molding material is introduced into the mold'"'"'s interior to form the package (28) around the sensing die (10). During molding, the pressures on the first and second surfaces (24,26) of the diaphragm (22) are sufficiently equal to substantially prevent damage to the sensing die (10).
-
Citations
23 Claims
-
1. A method of forming a package for a sensing die having a pressure sensing diaphragm, said diaphragm having a first surface and a second surface disposed opposite said first surface, comprising the steps of:
-
mounting said sensing die overlying a hole of a die bond pad;
enclosing said sensing die within a mold; and
introducing a molding material into said mold to form said package. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
said mold has a top part and a bottom part;
said first portion of said die coat touches said top part of said mold to form a first sensing hole in said package; and
a second portion of said die coat touches said bottom part of said mold to form a second sensing hole in said package.
-
-
8. The method of claim 7 wherein:
-
said die bond pad is connected to a lead frame; and
said lead frame comprises a plurality of leads radiating out in a direction away from said die bond pad.
-
-
9. The method of claim 8 wherein:
-
said package is plastic; and
said step of introducing a molding material comprises injection molding.
-
-
10. The method of claim 3 wherein said die coat substantially covers all of said diaphragm.
-
11. The method of claim 3 wherein said die coat is a gel.
-
12. The method of claim 3 wherein said die coat is a material substantially similar to silicone gel.
-
13. The method of claim 3 wherein said die coat comprises silicone gel.
-
14. The method of claim 3 wherein said die coat is a material having a Young'"'"'s modulus between about 2.0 and 4.0 MPa and having a coefficient of thermal expansion between about 150 and 300 ppm.
-
15. The method of claim 3 further comprising the step of substantially removing said die coat following said step of introducing a molding material.
-
16. The method of claim 1 wherein, during said step of introducing a molding material, said molding material passes through said hole of said die bond pad and contacts said second surface of said diaphragm.
-
17. A method of forming a package for a sensing die supported in said package by a die bond pad, said sensing die having a pressure sensing diaphragm, and said diaphragm having a first surface and a second surface disposed opposite said first surface, comprising the steps of:
-
mounting said sensing die overlying a hole of said die bond pad wherein said second surface of said diaphragm faces said hole;
coating said sensing die with a die coat wherein said die coat covers at least said first surface of said diaphragm and at least said second surface of said diaphragm;
enclosing said sensing die within a mold; and
forming said package by introducing a molding material into said mold wherein said die coat contacts a first portion of said mold to substantially exclude said molding material so that a first sensing hole is formed in said package. - View Dependent Claims (18, 19, 20, 21, 22, 23)
-
Specification