US5315155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic package with stress relief channel
Assignee: Olin Corp
•
Filing: 1992-07-13
•
Granted: 1994-05-24
•
Expires: 2012-07-13
Abstract
Abstract There is provided an electronic package assembly having a leadframe and buffer bonded to a metallic base. To reduce the stress generated by the coefficient of thermal expansion mismatch, the buffer is mounted on a pedestal. The cross sectional area of the pedestal is less than that of the buffer, such that the at least a portion of the buffer overhangs the pedestal.
Inventors
- 👤 Brian E. O'Donnelly
- 👤 Brian Mravic
- 👤 Jacob Crane
- 👤 Deepak Mahulikar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:07
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/70; H10W40/77; H10W42/00; H10W42/121; H10W72/00; H10W72/071; H10W76/00; H10W76/10; H10W76/12; H10W76/13; H10W76/134; H10W70/00; H10W70/60; H10W70/67; H10W70/68; H10W70/682; H10W72/073; H10W72/07351; H10W72/07352; H10W72/30; H10W72/321; H10W72/351; H10W72/352; H10W72/353; H10W72/354; H10W72/381; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; H10W72/5524; H10W72/851; H10W72/874; H10W72/884; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
82 words
An electronic package assembly, comprising: a leadframe having a plurality of leads, the inner ends of which define a central region; a base containing a recessed channel defining a pedestal disposed adjacent said central region, said recessed channel having a depth of up to 50% the depth of that portion of said base adjacent said recessed channel; a buffer bonded to said pedestal with a portion of said buffer overhanging said pedestal; and a sealing glass bonding said base to said leadframe.
Claim 2
Dependent Claim
82 words
An electronic package assembly, comprising: a leadframe having a plurality of leads, the inner ends of which define a central region; a base containing a recessed channel defining a pedestal disposed adjacent said central region, said recessed channel having a depth of up to 50% the depth of that portion of said base adjacent said recessed channel; a buffer bonded to said pedestal with a portion of said buffer overhanging said pedestal; and a sealing glass bonding said base to said leadframe.
Claim 3
Dependent Claim
20 words
The electronic package assembly of claim 1 wherein said pedestal is defined by a continuous recessed channel in said base.
Claim 4
Dependent Claim
29 words
The electronic package assembly of claim 2 wherein said pedestal has a cross sectional area of from about 60% to about 90% the cross sectional area of said buffer.
Claim 5
Dependent Claim
29 words
The electronic package assembly of claim 3 wherein said pedestal has a cross sectional area of from about 70% to about 80% the cross sectional area of said buffer.
Claim 6
Dependent Claim
28 words
The electronic package assembly of claim 3 wherein said recessed channel has a depth of from about 20% to about 40% the thickness of said adjacent base region.
Claim 7
Dependent Claim
83 words
An electronic package assembly, comprising: a leadframe having a plurality of leads, the inner ends of which define a central region; a metallic base containing a recessed channel forming a pedestal disposed within said central region, said recessed channel having a depth of up to 50% the depth of that portion of said base adjacent said recessed channel; a buffer brazed to said pedestal with a portion of said buffer overhanging said pedestal; and a sealing glass bonding said base to said leadframe.
Claim 8
Dependent Claim
83 words
An electronic package assembly, comprising: a leadframe having a plurality of leads, the inner ends of which define a central region; a metallic base containing a recessed channel forming a pedestal disposed within said central region, said recessed channel having a depth of up to 50% the depth of that portion of said base adjacent said recessed channel; a buffer brazed to said pedestal with a portion of said buffer overhanging said pedestal; and a sealing glass bonding said base to said leadframe.
Claim 9
Dependent Claim
29 words
The electronic package assembly of claim 6 wherein said pedestal has a cross sectional area of from about 60% to about 90% the cross sectional area of said buffer.
Claim 10
Dependent Claim
17 words
The electronic package assembly of claim 7 wherein said bases formed from copper, aluminum, or alloys thereof.
Claim 11
Dependent Claim
18 words
The electronic package assembly of claim 8 wherein said base is formed from a nickel plated copper alloy.
Claim 12
Dependent Claim
17 words
The electronic package assembly of claim 9 wherein said base is formed from either copper alloy C197.
Claim 13
Dependent Claim
43 words
The electronic package assembly of claim 8 wherein said base is formed from an aluminum alloy and coated with an anodization layer in at least those portions of said base which either are exposed to the outside environment or contact said sealing glass.
Claim 14
Dependent Claim
25 words
The electronic package assembly of claim 11 wherein said base is formed from aluminum alloy 3003 and said anodization layer is an integral black color.
References Cited (Backward Citations)
US4149910A
Cited
US4185139A
Cited
US4202700A
Cited
JPS57192050A
Cited
US4491622A
Cited
US5099310A
Cited
US4784974A
Cited
US4656499A
Cited
US4451540A
Cited
US4532222A
Cited
US4752521A
Cited
US4805009A
Cited
US4704626A
Cited
US4715892A
Cited
US4882212A
Cited
US4978052A
Cited
US4872047A
Cited
US4761518A
Cited
US4756754A
Cited
US4769345A
Cited
US4961106A
Cited
US4839716A
Cited
US4796083A
Cited
JPS6425443A
Cited
US4952531A
Cited
US5047371A
Cited
US5023398A
Cited
US5015803A
Cited
US5012386A
Cited
US5066368A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-05-23 | 1997-11-22 | 1998-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-23 | 2001-11-22 | 2002-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-23 | 2005-11-22 | 2006-05-24 | $7700.00 | Window Closed / Lapsed |