US5367196A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Molded plastic semiconductor package including an aluminum alloy heat spreader
Assignee: Advanced Technology Interconnect Inc
•
Filing: 1992-09-17
•
Granted: 1994-11-22
•
Expires: 2012-09-17
Abstract
Abstract There is provided a molded plastic electronic package having improved thermal dissipation. A heat spreader, formed from aluminum or an aluminum alloy, is partially encapsulated in the molding resin. Forming a black anodization layer on the surface of the heat spreader improves both thermal dissipation and adhesion to the molding resin.
Inventors
- 👤 Deepak Mahulikar
- 👤 Jeffrey S. Braden
- 👤 Szuchain F. Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:48
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/10; H10W74/111; H10W74/124; H10W76/00; H10W76/10; H10W40/00; H10W40/70; H10W40/77; H10W40/778; H10W72/00; H10W72/071; H10W72/073; H10W72/07331; H10W72/07336; H10W72/07337; H10W72/07338; H10W72/075; H10W72/077; H10W72/30; H10W72/351; H10W72/353; H10W72/354; H10W72/381; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; H10W72/5525; H10W72/851; H10W72/874; H10W72/884; H10W90/00; H10W90/701; H10W90/731; H10W90/736; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
83 words
A semiconductor package, comprising: at least one semiconductor device; a heat spreader formed from an aluminum based material and at least partially coated with an adhesion enhancing layer; a leadframe having a plurality of inner and outer leads, said inner leads electrically interconnected to said semiconductor device; and a molding resin encapsulating said semiconductor device, said inner leads of said leadframe and at least a portion of said heat spreader wherein said molding resin and said adhesion enhancing layer are the same color.
Claim 2
Dependent Claim
83 words
A semiconductor package, comprising: at least one semiconductor device; a heat spreader formed from an aluminum based material and at least partially coated with an adhesion enhancing layer; a leadframe having a plurality of inner and outer leads, said inner leads electrically interconnected to said semiconductor device; and a molding resin encapsulating said semiconductor device, said inner leads of said leadframe and at least a portion of said heat spreader wherein said molding resin and said adhesion enhancing layer are the same color.
Claim 3
Dependent Claim
18 words
The semiconductor package of claim 1 wherein said heat spreader is formed from aluminum or an aluminum alloy.
Claim 4
Dependent Claim
35 words
The semiconductor package of claim 2 wherein said adhesion enhancing layer is selected from the group consisting of anodized aluminum, chromium, zinc, a mixture of chromium and zinc, and a mixture of chromium and phosphorous.
Claim 5
Dependent Claim
19 words
The semiconductor package of claim 3 wherein said adhesion enhancing layer is a co-deposited layer of chromium and zinc.
Claim 6
Dependent Claim
23 words
The semiconductor package of claim 4 wherein the ratio of zinc to chromium in said co-deposited layer is in excess of about 4:1.
Claim 7
Dependent Claim
15 words
The semiconductor package of claim 3 wherein said adhesion enhancing layer is a anodized aluminum.
Claim 8
Dependent Claim
22 words
The semiconductor package of claim 6 wherein both said molding resin and said adhesion enhancing layer have a gray to black color.
Claim 9
Dependent Claim
22 words
The semiconductor package of claim 7 wherein said heat spreader is formed from an aluminum alloy of the 3xxx or 6xxx series.
Claim 10
Dependent Claim
16 words
The semiconductor package of claim 8 wherein said heat spreader is formed from aluminum alloy 3003.
Claim 11
Dependent Claim
17 words
The semiconductor package of claim 8 wherein said adhesion enhancing layer is an integral color anodization layer.
Claim 12
Dependent Claim
24 words
The semiconductor package of claim 10 wherein said adhesion enhancing layer has an average pore diameter of from about 50 to about 500 angstroms.
Claim 13
Dependent Claim
21 words
The semiconductor package of claim 10 wherein said heat spreader is in thermal contact with said at least one semiconductor device.
Claim 14
Dependent Claim
24 words
The semiconductor package of claim 12 wherein a thermal grease maintains said at least one semiconductor device in thermal contact with said heat spreader.
Claim 15
Dependent Claim
26 words
The semiconductor package of claim 13 wherein a thermally enhanced polymer adhesive maintains said at least one semiconductor device in thermal contact with said heat spreader.
Claim 16
Dependent Claim
17 words
The semiconductor package of claim 14 wherein said thermally enhanced polymer adhesive is a silver filled epoxy.
Claim 17
Dependent Claim
103 words
A semiconductor package, comprising: at least one semiconductor device; a heat spreader formed from an aluminum alloy of the 3xxx or 6xxx series and at least partially coated with a black integral color anodization layer, said heat spreader being in thermal contact with said semiconductor device; a leadframe having a plurality of inner and outer leads, said inner leads electrically interconnected to said at least one semiconductor device; and a molding resin encapsulating said semiconductor device, said inner leads of said leadframe and all but one surface of said heat spreader wherein said molding resin and said anodization layer are the same color.
Claim 18
Dependent Claim
103 words
A semiconductor package, comprising: at least one semiconductor device; a heat spreader formed from an aluminum alloy of the 3xxx or 6xxx series and at least partially coated with a black integral color anodization layer, said heat spreader being in thermal contact with said semiconductor device; a leadframe having a plurality of inner and outer leads, said inner leads electrically interconnected to said at least one semiconductor device; and a molding resin encapsulating said semiconductor device, said inner leads of said leadframe and all but one surface of said heat spreader wherein said molding resin and said anodization layer are the same color.
Claim 19
Dependent Claim
24 words
The semiconductor package of claim 16 wherein a thermal grease maintains said at least one semiconductor device in thermal contact with said heat spreader.
Claim 20
Dependent Claim
26 words
The semiconductor package of claim 16 wherein a thermally enhanced polymer adhesive maintains said at least one semiconductor device in thermal contact with said heat spreader.
Claim 21
Dependent Claim
112 words
A semiconductor package, comprising: at least one semiconductor device; a heat spreader formed from aluminum or an aluminum alloy and at least partially coated with an anodization layer, said heat spreader being in thermal contact with said semiconductor device; a cover which in combination with said heat spreader shields said semiconductor device from a molding resin; a leadframe disposed between and bonded to both said heat spreader and to said cover, said leadframe having a plurality of inner and outer leads, said inner leads electrically interconnected to said at least one semiconductor device; a molding resin encapsulating said cover and at least a portion of said aluminum or aluminum alloy heat spreader.
Claim 22
Dependent Claim
112 words
A semiconductor package, comprising: at least one semiconductor device; a heat spreader formed from aluminum or an aluminum alloy and at least partially coated with an anodization layer, said heat spreader being in thermal contact with said semiconductor device; a cover which in combination with said heat spreader shields said semiconductor device from a molding resin; a leadframe disposed between and bonded to both said heat spreader and to said cover, said leadframe having a plurality of inner and outer leads, said inner leads electrically interconnected to said at least one semiconductor device; a molding resin encapsulating said cover and at least a portion of said aluminum or aluminum alloy heat spreader.
Claim 23
Dependent Claim
23 words
The semiconductor package of claim 19 wherein said leadframe is bonded to both said heat spreader and to said cover by an epoxy.
Claim 24
Dependent Claim
19 words
The semiconductor package of claim 20 wherein both said molding resin and said anodization layer have a black color.
Claim 25
Dependent Claim
22 words
The semiconductor package of claim 21 wherein said heat spreader is formed from an aluminum alloy of the 3xxx or 6xxx series.
Claim 26
Dependent Claim
16 words
The semiconductor package of claim 22 wherein said anodization layer is an integral color anodization layer.
Claim 27
Dependent Claim
24 words
The semiconductor package of claim 22 wherein a thermal grease maintains said at least one semiconductor device in thermal contact with said heat spreader.
Claim 28
Dependent Claim
26 words
The semiconductor package of claim 22 wherein a thermally enhanced polymer adhesive maintains said at least one semiconductor device in thermal contact with said heat spreader.
Claim 29
Dependent Claim
96 words
A semiconductor package, comprising: at least one semiconductor device; a metallic heat spreader at least partially coated with a codeposited layer of chromium and zinc, said heat spreader being in thermal contact with said at least one semiconductor device; a leadframe having a plurality of inner and outer leads, said inner leads electrically interconnected to said semiconductor device; and a molding resin encapsulating said semiconductor device, said inner leads of said leadframe and a portion of said metallic heat spreader wherein said codeposited layer of chromium and zinc and said molding resin are the same color.
Claim 30
Dependent Claim
96 words
A semiconductor package, comprising: at least one semiconductor device; a metallic heat spreader at least partially coated with a codeposited layer of chromium and zinc, said heat spreader being in thermal contact with said at least one semiconductor device; a leadframe having a plurality of inner and outer leads, said inner leads electrically interconnected to said semiconductor device; and a molding resin encapsulating said semiconductor device, said inner leads of said leadframe and a portion of said metallic heat spreader wherein said codeposited layer of chromium and zinc and said molding resin are the same color.
Claim 31
Dependent Claim
19 words
The semiconductor package of claim 26 wherein the ratio of zinc to chromium is in excess of about 4:1.
Claim 32
Dependent Claim
21 words
The semiconductor package of claim 26 wherein said metallic heat spreader is formed from anodized aluminum or an anodized aluminum alloy.
Claim 33
Dependent Claim
19 words
The semiconductor package of claim 26 wherein said metallic heat spreader is formed from copper or a copper alloy.
References Cited (Backward Citations)
US3770600A
Cited
US3784440A
Cited
US4121980A
Cited
US4092697A
Cited
US4589010A
Cited
US4461924A
Cited
US4767674A
Cited
US4707724A
Cited
US4926242A
Cited
US4766095A
Cited
US4640625A
Cited
US4713150A
Cited
US4888449A
Cited
US5013871A
Cited
US4939316A
Cited
US5155299A
Cited
US5023398A
Cited
US5055967A
Cited
US5124783A
Cited
US4994314A
Cited
US5038940A
Cited
US5015803A
Cited
US5098796A
Cited
US5073521A
Cited
US5098864A
Cited
US5181969A
Cited
US5066368A
Cited
US5122858A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-11-21 | 1998-05-23 | 1998-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-21 | 2002-05-23 | 2002-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-21 | 2006-05-23 | 2006-11-22 | $7700.00 | Window Closed / Lapsed |