Patent US5075258A successfully refreshed from Google Patents.
US5075258A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for plating tab leads in an assembled semiconductor package
Assignee: Motorola Solutions Inc
•
Filing: 1990-07-31
•
Granted: 1991-12-24
•
Expires: 2010-07-31
Abstract
Abstract A method for improving the bonding characteristics of TAB semiconductor packages to circuit boards is achieved by plating additional amounts of tin on the TAB semiconductor package leads after final package assembly is complete. Residues from the plating step are removed from the package assembly to prevent contamination. Stresses that were developed in the plated material during the plating step are removed by heating the leads.
Inventors
- 👤 Francis J. Carney
- 👤 Cary B. Powell
- 👤 George F. Carney
- 👤 Marion I. Simmons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:29
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/456; H10W70/457; H10W70/01; H10W70/04; H10W72/00; H10W72/071; H10W72/077; H10W72/701
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
70 words
A method for improving bonding characteristics of the outer leads of an assembled TAB semiconductor package after intermetallic compounds have formed on the leads which comprises: plating tin with an immersion plating process onto the TAB leads thereby coating intermetallic compounds with tin; rinsing the package to completely remove residual plating solution; and heating the plated leads to eliminate plating induced stresses created in the tin during the plating process.
Claim 2
Independent Claim
70 words
A method for improving bonding characteristics of the outer leads of an assembled TAB semiconductor package after intermetallic compounds have formed on the leads which comprises: plating tin with an immersion plating process onto the TAB leads thereby coating intermetallic compounds with tin; rinsing the package to completely remove residual plating solution; and heating the plated leads to eliminate plating induced stresses created in the tin during the plating process.
Claim 3
Dependent Claim
17 words
The method of claim 1 including complete immersion of the TAB semiconductor package in the plating solution.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein the plating process results in a tin plating less than one micron thick.
Claim 5
Dependent Claim
72 words
A process for improved circuit board bonding of TAB semiconductor package outer leads which comprises: plating tin on the outer leads using an immersion tin process wherein the entire packaged semiconductor device is immersed in a tin plating solution with a temperature of less than 70 degrees centrigrade; removing residual plating solution from the packaged semiconductor device; and heating the plated outer leads to remove plating induced stresses in the plated tin.
Claim 6
Dependent Claim
72 words
A process for improved circuit board bonding of TAB semiconductor package outer leads which comprises: plating tin on the outer leads using an immersion tin process wherein the entire packaged semiconductor device is immersed in a tin plating solution with a temperature of less than 70 degrees centrigrade; removing residual plating solution from the packaged semiconductor device; and heating the plated outer leads to remove plating induced stresses in the plated tin.
Claim 7
Dependent Claim
62 words
A process for preparing an assembled TAC semiconductor package having a plurality of leads for bonding to a circuit board which comprises: plating the leads of the TAB semiconductor package; and removing plating residue from the TAB package by rinsing the plated package with deionized water until the water, after flowing over the assembly, has a resistance greater than one million ohms.
Claim 8
Dependent Claim
62 words
A process for preparing an assembled TAC semiconductor package having a plurality of leads for bonding to a circuit board which comprises: plating the leads of the TAB semiconductor package; and removing plating residue from the TAB package by rinsing the plated package with deionized water until the water, after flowing over the assembly, has a resistance greater than one million ohms.
Claim 9
Dependent Claim
23 words
The method of claim 5 wherein the plating step is an immersion plating by immersing the TAB semiconductor package in a plating solution.
Claim 10
Dependent Claim
32 words
The method of claim 6 further including immersion plating with a solution temperature within a range from 25 to 70 degrees centigrade, and an immersion period ranging from one to fifteen minutes.
Claim 11
Dependent Claim
22 words
The method of claim 5 further including heating the plated leads to remove stresses induced in the plating by the plating step.
Claim 12
Dependent Claim
30 words
The method of claim 9 wherein stresses developed in the plating during the plating step are relieved by heating the plating to a temperature between 100 and 225 degrees centigrade.
References Cited (Backward Citations)
US4065625A
Cited
US3988518A
Cited
US4234631A
Cited
DE3040676A1
Cited
US4486511A
Cited
US4695481A
Cited
US4776508A
Cited
US4883774A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-23 | 1995-06-24 | 1995-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-23 | 1999-06-24 | 1999-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-23 | 2003-06-24 | 2003-12-24 | $7700.00 | Window Closed / Lapsed |