US5424249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making mold-packaged pressure sensing semiconductor device
Assignee: Mitsubishi Electric Corp
•
Filing: 1993-12-15
•
Granted: 1995-06-13
•
Expires: 2013-12-15
Abstract
Abstract A pressure sensor element (50) is bonded to a die bonding pad (4). The pressure sensor element (50) is thereafter entirely covered with epoxy resin (11) and completely packaged. Following this, the epoxy resin (11) is locally removed at a portion above a diaphragm (5) of the pressure sensor element (50). As a result, the diaphragm (5) is exposed. In this method, the diaphragm (5) is uncovered without using a special metallic mold which prohibits the epoxy resin (11) from flowing into a space above the diaphragm (5). A gold wire (8) is also molded by the package sealing. Thus, a resulting package-molded pressure sensing semiconductor device is highly reliable under adverse environmental conditions and considerably cost-effective.
Inventors
- 👤 Kiyoshi Ishibashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:04
CPC Classifications
G; G01; G01L; G01L19/00; G01L19/0061; G01L19/0084; G01L19/14; G01L19/147; H; H10; H10W; H10W72/00; H10W72/50; H10W72/531; H10W72/536; H10W72/5363; H10W72/551; H10W72/552; H10W72/5522; H10W74/00; H10W74/10; H10W90/00; H10W90/701; H10W90/751; H10W90/756; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
126 words
A method of manufacturing a mold-packaged pressure sensing semiconductor device, the method comprising the steps of: (a) preparing a pressure sensor element which has a diaphragm; (b) fully covering said pressure sensor element with a molding resin so that said pressure sensor element is entirely package sealed; and (c) removing said molding resin at a portion above said diaphragm, thereby forming a window through which said diaphragm is exposed; wherein said step (c) includes the steps of: (c-1) mechanically removing said portion of said molding resin above said diaphragm halfway so that said diaphragm remains still covered with said molding resin; and (c-2) completely removing said molding resin remaining above said diaphragm by a chemical method, thereby forming a window through which said diaphragm is exposed.
Claim 2
Independent Claim
126 words
A method of manufacturing a mold-packaged pressure sensing semiconductor device, the method comprising the steps of: (a) preparing a pressure sensor element which has a diaphragm; (b) fully covering said pressure sensor element with a molding resin so that said pressure sensor element is entirely package sealed; and (c) removing said molding resin at a portion above said diaphragm, thereby forming a window through which said diaphragm is exposed; wherein said step (c) includes the steps of: (c-1) mechanically removing said portion of said molding resin above said diaphragm halfway so that said diaphragm remains still covered with said molding resin; and (c-2) completely removing said molding resin remaining above said diaphragm by a chemical method, thereby forming a window through which said diaphragm is exposed.
Claim 3
Dependent Claim
67 words
A method of claim 1, wherein said step (b) includes the steps of: (b-1) preparing a metallic mold which has a cavity; (b-2) setting said pressure sensor element to said cavity of said metallic mold; (b-3) implanting said molding resin into said cavity, thereby sealing said pressure sensor element; and (b-4) taking out said pressure sensor element now package sealed from said cavity off said metallic mold.
Claim 4
Dependent Claim
37 words
A method of claim 2, wherein, in said step (b-3), said molding resin is implanted into said cavity under such an implantation pressure that said diaphragm is not destroyed by the implantation pressure of said molding resin.
Claim 5
Dependent Claim
43 words
A method of claim 1, further comprising the steps of: (d) preparing a lead; and (e) wire bonding said pressure sensor element and said lead with a bonding wire; wherein said bonding wire is sealed with said molding resin in said step (b).
Claim 6
Dependent Claim
26 words
A method of claim 1, wherein said step (c-1) includes the step of (c-1-1) injecting abrasives on said molding resin at said portion above said diaphragm.
Claim 7
Dependent Claim
23 words
A method of claim 5, wherein said step (c-1-1) includes the step of: polishing away said molding resin by a sand blasting method.
Claim 8
Dependent Claim
25 words
A method of claim 1, wherein said step (c-1) includes the step of: (c-1-1) chipping off said portion of said molding resin above said diaphragm.
Claim 9
Dependent Claim
21 words
A method of claim 7, wherein said step (c-1-1) includes the step of: chipping off said molding resin using a grinder.
Claim 10
Dependent Claim
29 words
A method of claim 1, wherein said step (c-2) includes the step of: (c-2-1) completely dissolving said molding resin at said portion above said diaphragm and exposing said diaphragm.
Claim 11
Dependent Claim
51 words
A method of claim 9, wherein said step (c-2-1) includes the steps of: completely dissolving said molding resin at said portion above said diaphragm with a few drops of fuming nitride acid and exposing said diaphragm; thereafter cleaning said diaphragm in water; thereafter dehydrating said diaphragm; and thereafter drying said diaphragm.
Claim 12
Dependent Claim
17 words
A method of claim 10, wherein said diaphragm is dehydrated using ethanol in said step of dehydrating.
Claim 13
Independent Claim
105 words
A method of manufacturing a mold-packaged pressure sensing semiconductor device, the method comprising the steps of: (a) preparing a pressure sensor element which has a diaphragm; (b) fully covering said pressure sensor element with a molding resin so that said pressure sensor element is entirely package sealed; and (c) removing said molding resin at a portion above said diaphragm, thereby forming a window through which said diaphragm is exposed; wherein said step (b) includes the step of: (b-1) package sealing said pressure sensor element in a manner that said molding resin has a thinner thickness at a portion above said diaphragm than at other portions.
Claim 14
Independent Claim
105 words
A method of manufacturing a mold-packaged pressure sensing semiconductor device, the method comprising the steps of: (a) preparing a pressure sensor element which has a diaphragm; (b) fully covering said pressure sensor element with a molding resin so that said pressure sensor element is entirely package sealed; and (c) removing said molding resin at a portion above said diaphragm, thereby forming a window through which said diaphragm is exposed; wherein said step (b) includes the step of: (b-1) package sealing said pressure sensor element in a manner that said molding resin has a thinner thickness at a portion above said diaphragm than at other portions.
Claim 15
Dependent Claim
102 words
A method of claim 12, wherein said step (b-1) includes the steps of: (b-1-1) preparing a metallic mold having a cavity defined by an inner surface having a projection which corresponds to said diaphragm; (b-1-2) setting said pressure sensor element to said cavity of said metallic mold so that said diaphragm is situated opposite said projection; (b-1-3) implanting said molding resin into said cavity and sealing said pressure sensor element, whereby said pressure sensor element as package-sealed has a recess at a portion occupied by said projection; and (b-1-4) thereafter taking out said pressure sensor element now package-sealed from said metallic mold.
Claim 16
Dependent Claim
37 words
A method of claim 13, wherein, in said step (b-1-3), said molding resin is implanted into said cavity under such an implantation pressure that said diaphragm is not destroyed by the implantation pressure of said molding resin.
Claim 17
Dependent Claim
31 words
A method of claim 13, wherein said step (c) includes the step of: (c-1) chemically removing said molding resin still remaining at a bottom of said recess and exposing said diaphragm.
Claim 18
Dependent Claim
32 words
A method of claim 15, wherein said step (c-1) includes the step of: (c-1-1) dissolving and removing said molding resin still remaining at a bottom of said recess, thereby exposing said diaphragm.
Claim 19
Dependent Claim
51 words
A method of claim 16, wherein said step (c-1-1) includes the steps of: dissolving said molding resin remaining at the bottom of said recess with a few drops of fuming nitride acid and exposing said diaphragm; thereafter cleaning said diaphragm in water; thereafter dehydrating said diaphragm; and thereafter drying said diaphragm.
Claim 20
Dependent Claim
12 words
A method of claim 17, wherein said diaphragm is dehydrated using ethanol.
References Cited (Backward Citations)
US4188708A
Cited
JPS55163855A
Cited
JPS5984448A
Cited
JPS60183743A
Cited
US4691575A
Cited
US4838089A
Cited
US4823605A
Cited
US5209120A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-06-12 | 1998-12-12 | 1999-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-12 | 2002-12-12 | 2003-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-12 | 2006-12-12 | 2007-06-13 | $7700.00 | Window Closed / Lapsed |