Patent JPS5084981A successfully refreshed from Google Patents.
US5554569A
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US
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Method and apparatus for improving interfacial adhesion between a polymer and a metal
Assignee: Motorola Solutions Inc
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Filing: 1994-06-06
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Granted: 1996-09-10
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Expires: 2014-06-06
Abstract
Abstract A leadframe (11) and a method for improving adhesion of a polymer (17, 19) to the leadframe (11). The leadframe (11) has a flag (14) having a top surface (15) and a bottom surface (18), and leads (12). Microscopic locking features (31) are formed in the top surface (15) and the bottom surface (18) of flag (14) by bombarding the flag (14) with a grit material. Thus, the top and bottom surfaces (14, 18) are roughened. A semiconductor die (13) is attached to the flag (14) by a die attach material (17) and the flag (13), the semiconductor material (13), and portions of the leads (12) are encapsulated by a molding compound. The pits improve the adhesion of the die attach material (17) and the molding compound (19) to the leadframe (11).
Inventors
- 👤 Sankaranarayanan Ganesan
- 👤 Howard M. Berg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:31
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/01; H10W70/04; H10W70/048; H10W70/40; H10W70/411; H10W70/421; H10W70/424; H10W74/00; H10W74/01; H10W72/00; H10W72/851; H10W72/874; H10W72/884; H10W72/90; H10W72/931; H10W90/00; H10W90/701; H10W90/731; H10W90/736; H10W90/751; H10W90/756; Y; Y10; Y10S; Y10S438/00; Y10S438/964; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121; Y10T29/49169; Y10T29/49171
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
82 words
A method for improving an interfacial adhesion between a polymer and one of a metal surface or a metal alloy surface, comprising the steps of: providing the one of a metal surface or a metal alloy surface; bombarding the one of a metal surface or a metal alloy surface with a grit material, the grit material suspended in a gaseous carrier medium; and encapsulating a portion of the one of a metal surface or a metal alloy surface with a molding compound.
Claim 2
Independent Claim
82 words
A method for improving an interfacial adhesion between a polymer and one of a metal surface or a metal alloy surface, comprising the steps of: providing the one of a metal surface or a metal alloy surface; bombarding the one of a metal surface or a metal alloy surface with a grit material, the grit material suspended in a gaseous carrier medium; and encapsulating a portion of the one of a metal surface or a metal alloy surface with a molding compound.
Claim 3
Dependent Claim
39 words
The method of claim 1, wherein the step of bombarding the one of a metal surface or a metal alloy surface with a grit material further comprises gritblasting the one of a metal surface or a metal alloy surface.
Claim 4
Dependent Claim
44 words
The method of claim 1, wherein the step of providing the one of a metal surface or a metal alloy surface includes providing a semiconductor leadframe having a surface, the semiconductor leadframe selected from the group consisting of a metal and a metal alloy.
Claim 5
Dependent Claim
19 words
The method of claim 3, wherein the step of providing a semiconductor leadframe includes providing a copper semiconductor leadframe.
Claim 6
Dependent Claim
56 words
The method of claim 3, wherein the step of bombarding the one of a metal surface or a metal alloy surface with a grit material includes bombarding the one of a metal surface or a metal alloy surface until the surface of one of a metal surface or a metal alloy surface has microscopic locking features.
Claim 7
Dependent Claim
48 words
The method of claim 1, wherein the step of encapsulating a portion of the one of a metal surface or a metal alloy surface with a molding compound includes mounting a semiconductor die to the portion of the one of a metal surface or a metal alloy surface.
Claim 8
Dependent Claim
37 words
The method of claim 1, wherein the step of bombarding the one of a metal or metal alloy surface with a grit material includes altering the one of a metal or metal alloy surface to have undulations.
Claim 9
Independent Claim
65 words
A method for improving interfacial adhesion between a polymer and a semiconductor leadframe, comprising the steps of: providing the semiconductor leadframe; roughening a portion of the semiconductor leadframe using a grit material carried via a gaseous medium; mounting at least one semiconductor die to the semiconductor leadframe; and encapsulating the at least one semiconductor die and a portion of the semiconductor leadframe in the polymer.
Claim 10
Independent Claim
65 words
A method for improving interfacial adhesion between a polymer and a semiconductor leadframe, comprising the steps of: providing the semiconductor leadframe; roughening a portion of the semiconductor leadframe using a grit material carried via a gaseous medium; mounting at least one semiconductor die to the semiconductor leadframe; and encapsulating the at least one semiconductor die and a portion of the semiconductor leadframe in the polymer.
Claim 11
Dependent Claim
22 words
The method of claim 8, wherein the step of providing the semiconductor leadframe includes providing the semiconductor leadframe as a copper alloy.
Claim 12
Dependent Claim
22 words
The method of claim 8, wherein the step of providing the semiconductor leadframe includes providing the semiconductor leadframe as an iron-nickel alloy.
Claim 13
Dependent Claim
32 words
The method of claim 8, wherein the step of providing the semiconductor leadframe includes providing the semiconductor leadframe plated with a metal selected from the group palladium-nickel alloy, nickel, silver, and gold.
Claim 14
Dependent Claim
44 words
The method of claim 8, wherein the step of roughening a portion of the semiconductor leadframe includes roughening a portion of the semiconductor leadframe includes using a grit material selected from the group consisting of sand, silicon dioxide, aluminum oxide, silicon carbide, and bicarbonates.
Claim 15
Dependent Claim
54 words
The method of claim 8, wherein the step of roughening a portion of the semiconductor leadframe includes blowing the grit material at the portion of the semiconductor leadframe in the gaseous carrier medium, wherein the grit material arrives at the semiconductor leadframe at a pressure ranging between approximately 0.20 megaPascals and approximately 0.70 megaPascals.
Claim 16
Dependent Claim
35 words
The method of claim 8, wherein the step of roughening a portion of the semiconductor leadframe includes providing the gaseous carrier medium as a gas selected from the group consisting of nitrogen, argon, and air.
Claim 17
Dependent Claim
26 words
The method of claim 8, wherein the step of roughening a portion of the semiconductor leadframe includes roughening a plurality of portions of the semiconductor leadframe.
Claim 18
Dependent Claim
25 words
The method of claim 8, wherein the step of roughening a portion of the semiconductor leadframe includes forming microscopic locking features on the semiconductor leadframe.
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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) | 1999-09-10 | 2000-03-11 | 2000-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-10 | 2004-03-11 | 2004-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-10 | 2008-03-11 | 2008-09-10 | $7700.00 | Window Closed / Lapsed |