US5311399A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High power ceramic microelectronic package
Assignee: CMC INTERCONNECT TECHNOLOGIES Inc
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Filing: 1992-06-24
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Granted: 1994-05-10
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Expires: 2012-06-24
Abstract
Abstract A microelectronic package comprising a ceramic substrate (22) having a first surface bonded to a metal heat sink (25) and a second surface (30) opposite said first surface and having at least one metallized island (32) bonded to a lead frame (26), wherein the island has a uniform pullback (35) of metallization from the edge (36) of the substrate.
Inventors
- 👤 Felician A. Zell
- 👤 Gerald R. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:02
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/60; H10W70/67; H10W70/69; H10W70/692; H10W40/00; H10W40/10; H10W70/40; H10W70/479
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
93 words
A microelectronic package comprising a ceramic substrate having an edge, a first surface bonded to a metal heat sink and a second surface opposite said first surface and having at least one metallized island bonded to a lead frame, wherein said island has a controlled length uniform pullback of metallization from the edge of said substrate, wherein the metallization pullback length is within the range sufficient to reduce residual tensile stress in said substrate compared to a substrate having no controlled length metallization pullback at the substrate surface bonded to a lead frame.
Claim 2
Dependent Claim
93 words
A microelectronic package comprising a ceramic substrate having an edge, a first surface bonded to a metal heat sink and a second surface opposite said first surface and having at least one metallized island bonded to a lead frame, wherein said island has a controlled length uniform pullback of metallization from the edge of said substrate, wherein the metallization pullback length is within the range sufficient to reduce residual tensile stress in said substrate compared to a substrate having no controlled length metallization pullback at the substrate surface bonded to a lead frame.
Claim 3
Dependent Claim
25 words
The microelectronic package of claim 1 further having a controlled length uniform pullback of metallization from substantially the entire outer perimeter of the second surface.
Claim 4
Dependent Claim
12 words
The microelectronic package of claim 1 wherein said substrate comprises aluminum nitride.
Claim 5
Dependent Claim
22 words
The microelectronic package of claim 1 wherein the metallization pullback is within the range of about 5 mils to about 10 mils.
Claim 6
Dependent Claim
27 words
The microelectronic package of claim 1 wherein at least one of said metal sink and said lead frame is bonded to said substrate by a braze material.
Claim 7
Dependent Claim
30 words
The microelectronic package of claim 5 wherein said braze material comprises at least one element selected from the group consisting of silver, nickel, copper, gold, mixtures thereof, and alloys thereof.
Claim 8
Dependent Claim
18 words
The microelectronic package of claim 6 wherein said braze material is substantially free from titanium, zirconium, and hafnium.
Claim 9
Dependent Claim
31 words
The microelectronic package of claim 1 further having a die attach area on said second surface electrically isolated from said island and a semiconductor device bonded to the die attach area.
Claim 10
Dependent Claim
16 words
The microelectronic package of claim 8 wherein the semiconductor device is an RF oscillator or amplifier.
Claim 11
Dependent Claim
79 words
The microelectronics package of claim 1 having at least one additional separate island bonded to a corresponding separate lead frame, wherein said at least one additional separate island has a controlled length uniform pullback of metallization from the edge of said substrate, wherein the metallization pullback length is within the range sufficient to reduce residual tensile stress in said substrate compared to a substrate having no controlled length metallization pullback at the substrate surface bonded to a lead frame.
Claim 12
Dependent Claim
12 words
The microelectronics package of claim 10 wherein said substrate comprises aluminum nitride.
Claim 13
Dependent Claim
12 words
The microelectronics package of claim 2 wherein said substrate comprises aluminum nitride.
Claim 14
Dependent Claim
86 words
A ceramic substrate having an edge and at least one metallized surface, said surface containing a metallized die attach area and at least one metallized island electrically isolated from the die attach area, said island having a controlled length uniform pullback of metallization from the edge of the substrate, wherein the metallization pullback length is within the range sufficient to reduce residual tensile stress in said substrate compared to a substrate having no controlled length metallization pullback at the substrate surface bonded to a lead frame.
Claim 15
Dependent Claim
86 words
A ceramic substrate having an edge and at least one metallized surface, said surface containing a metallized die attach area and at least one metallized island electrically isolated from the die attach area, said island having a controlled length uniform pullback of metallization from the edge of the substrate, wherein the metallization pullback length is within the range sufficient to reduce residual tensile stress in said substrate compared to a substrate having no controlled length metallization pullback at the substrate surface bonded to a lead frame.
Claim 16
Dependent Claim
34 words
The ceramic substrate of claim 13 having at least two metallized islands electrically isolated from the die attach area, said islands having a controlled length uniform pullback metallization from the edge of the substrate.
Claim 17
Dependent Claim
22 words
The ceramic substrate of claim 13 wherein the metallization pullback is within the range of about 5 mils to about 10 mils.
Claim 18
Dependent Claim
24 words
The ceramic substrate of claim 13 further having a controlled length uniform pullback of metallization from substantially the entire outer perimeter of said surface.
Claim 19
Dependent Claim
22 words
The ceramic substrate of claim 16 wherein the metallization pullback is within the range of about 5 mils to about 10 mils.
Claim 20
Dependent Claim
13 words
The ceramic substrate of claim 13 wherein the ceramic substrate comprises aluminum nitride.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-05-09 | 1997-11-08 | 1998-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-09 | 2001-11-08 | 2002-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-09 | 2005-11-08 | 2006-05-10 | $7700.00 | Window Closed / Lapsed |