US5394607A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of providing low cost heat sink
Assignee: Texas Instruments Inc
•
Filing: 1993-05-20
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Granted: 1995-03-07
•
Expires: 2013-05-20
Abstract
Abstract The invention disclosed herein is a device and method in which a heat sink (22) is attached to support leads (18) of a leadframe (10) via a welding or mechanical joining technique. The method is performed prior to semiconductor device packaging and is usually performed after the leadframe is etched or stamped, and before it is cut into strips.
Inventors
- 👤 Tony Chiu
- 👤 Robert Alvarez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:20
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/70; H10W40/77; H10W40/778; H10W70/00; H10W70/40; H10W70/421; H10W72/00; H10W72/071; H10W72/077; H10W72/701; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
50 words
A method, comprising: providing a lead frame having lead fingers and multiple support leads each having an end integral with said lead frame and a free end; providing one and only one heat spreader per lead frame; and attaching said heat spreader to said free ends of said support leads.
Claim 2
Independent Claim
50 words
A method, comprising: providing a lead frame having lead fingers and multiple support leads each having an end integral with said lead frame and a free end; providing one and only one heat spreader per lead frame; and attaching said heat spreader to said free ends of said support leads.
Claim 3
Dependent Claim
15 words
The method of claim 1, wherein said support leads are welded to the heat spreader.
Claim 4
Dependent Claim
23 words
The method of claim 1, wherein pillows or spacing pads provide an attachment means for attaching the heat spreader to the support leads.
Claim 5
Dependent Claim
20 words
The method of claim 1, wherein couplings provide an attachment means for attaching the heat spreader to the support leads.
Claim 6
Dependent Claim
17 words
The method claim 4, wherein said heat spreader and said support leads are welded to said couplings.
Claim 7
Dependent Claim
13 words
The method of claim 1, wherein said support leads overlap said heat sink.
Claim 8
Dependent Claim
13 words
The method of claim 1, wherein said lead frame has four support leads.
Claim 9
Dependent Claim
21 words
The method of claim 3, wherein said heat spreader and said support leads are welded to said pillows or spacing pads.
Claim 10
Dependent Claim
25 words
The method of claim 3, wherein junctions between said heat spreader and said couplings and junctions between said support leads and said couplings are crimped.
Claim 11
Dependent Claim
26 words
The method of claim 3, wherein junctions between said heat spreader and said couplings and junctions between said support leads and said couplings are press fit.
Claim 12
Dependent Claim
15 words
The method of claim 3, wherein said support leads do not overlap said heat sink.
Claim 13
Dependent Claim
17 words
The method of claim 1, wherein said heat spreader includes extensions for attachment to said support leads.
Claim 14
Dependent Claim
13 words
The method of claim 12, wherein said extensions and said support leads overlap.
Claim 15
Dependent Claim
25 words
The method of claim 1, wherein said heat sink includes an insulating coating or layer on at least all areas that contact said lead fingers.
Claim 16
Dependent Claim
17 words
The method of claim 3, wherein said heat sink is welded to said pillows or spacing pads.
Claim 17
Independent Claim
52 words
A method, comprising: providing a lead frame having lead fingers and support leads each having an end integral with said lead frame and a free end, said support leads not extending into said lead fingers; providing a heat spreader; and attaching said heat spreader to said free ends of said support leads.
Claim 18
Independent Claim
52 words
A method, comprising: providing a lead frame having lead fingers and support leads each having an end integral with said lead frame and a free end, said support leads not extending into said lead fingers; providing a heat spreader; and attaching said heat spreader to said free ends of said support leads.
Claim 19
Dependent Claim
13 words
The method of claim 16, wherein said attaching is accomplished through mechanical means.
Claim 20
Dependent Claim
13 words
The method of claim 16, wherein said attaching is accomplished through welding means.
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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) | 1998-03-06 | 1998-09-05 | 1999-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-03-06 | 2002-09-05 | 2003-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-03-06 | 2006-09-05 | 2007-03-07 | $7700.00 | Window Closed / Lapsed |