US4512950A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lead alloy soft solder containing radioactive particles used to make more reliable semiconductor devices
Assignee: Mitsubishi Electric Corp
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Filing: 1983-03-02
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Granted: 1985-04-23
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Expires: 2003-03-02
Abstract
Abstract PCT No. PCT/JP83/00065 Sec. 371 Date Oct. 31, 1983 Sec. 102(e) Date Oct. 31, 1983 PCT Filed Mar. 2, 1983 PCT Pub. No. WO83/03163 PCT Pub. Date Sep. 15, 1983.A soft solder of Pb alloy for semiconductor devices that contains 1 to 65 wt % of Sn or In or both, the balance being Pb and incidental impurities which include less than 50 ppb of radioisotopes and the count of radioactive alpha-particles being not more than 0.5 CPH/cm2. The solder exhibits high adhesive strength and good wettability. The properties of this material may be further improved by addition of 1 to 10 wt % of Ag.
Inventors
- 👤 Naoyuki Hosoda
- 👤 Naoki Uchiyama
- 👤 Ryusuke Kawanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:02
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/26; B23K35/262; H; H10; H10W; H10W70/00; H10W70/60; H10W70/67; H10W70/69; B23K35/268; H10W72/00; H10W72/20; H10W76/00; H10W76/60; H10W70/68; H10W70/682; H10W72/071; H10W72/073; H10W72/07331; H10W72/07337; H10W72/30; H10W72/351; H10W72/352; H10W72/50; H10W72/551; H10W72/552; H10W72/5524; H10W90/00; H10W90/701; H10W90/751; H10W90/754
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
50 words
A soft solder of Pb alloy for semiconductor devices that contains 1 to 65 wt% of Sn or In or both, the balance being Pb and incidental impurities which include less than 50 ppb of radioisotopes and the count of radioactive alpha-particles being not more than 0.5 CPH/cm 2 .
Claim 2
Dependent Claim
50 words
A soft solder of Pb alloy for semiconductor devices that contains 1 to 65 wt% of Sn or In or both, the balance being Pb and incidental impurities which include less than 50 ppb of radioisotopes and the count of radioactive alpha-particles being not more than 0.5 CPH/cm 2 .
Claim 3
Dependent Claim
57 words
A soft solder of Pb alloy for semiconductor devices that contains 1 to 65 wt% of Sn or In or both and 1 to 10 wt% of Ag, the balance being Pb and incidental impurities which include less than 50 ppb of radioisotopes and the count of radioactive alpha-particles being not more than 0.5 CPH/cm 2 .
Claim 4
Dependent Claim
57 words
A soft solder of Pb alloy for semiconductor devices that contains 1 to 65 wt% of Sn or In or both and 1 to 10 wt% of Ag, the balance being Pb and incidental impurities which include less than 50 ppb of radioisotopes and the count of radioactive alpha-particles being not more than 0.5 CPH/cm 2 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-22 | 1988-10-22 | 1989-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-22 | 1992-10-22 | 1993-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-22 | 1996-10-22 | 1997-04-23 | $7700.00 | Window Closed / Lapsed |