US4935312A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Film carrier having tin and indium plated layers
Assignee: Eneos Corp
•
Filing: 1988-12-09
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Granted: 1990-06-19
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Expires: 2008-12-09
Abstract
Abstract Film carriers for mounting electronic components such as semiconductor chips thereon have lead portions plated with a tin or tin alloy layer and further with an indium layer. The tin or tin alloy layer is 0.1-3 mu m thick and the indium layer 0.01-2 mu m thick. Alternatively, the leads have a tin or tin alloy plated portion having an indium diffusion layer, with an indium content of 0.2-50 wt %. The carriers are manufactured by a method which comprises plating the leads with tin or a tin alloy and then with indium, with or without heat treatment at 50 DEG -150 DEG C. to form an indium diffusion layer in the tin or tin alloy coating. Plating is done by electroless plating.
Inventors
- 👤 Hiroshi Nakayama
- 👤 Keijiro Suzuki
- 👤 Susumu Miyata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:51
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/244; H10; H10W; H10W70/00; H10W70/40; H10W70/453; H10W70/60; H10W70/62; H10W70/66; H05K2201/00; H05K2201/10; H05K2201/10613; H05K2201/10621; H05K2201/10681; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3473; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/929; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12681; Y10T428/12708
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
85 words
A film carrier for mounting electronic components such as semiconductor chips thereon, having lead portions of an electrically conductive material formed on a base film of said carrier, said lead portions being plated with a tin or tin alloy plated layer, an improvement wherein an indium plated layer is formed on said tin or tin alloy plated layer for preventing the generation of whiskers on said tin or tin alloy plated layer, and wherein said indium plated layer is at least 0.01 μm in thickness.
Claim 2
Dependent Claim
85 words
A film carrier for mounting electronic components such as semiconductor chips thereon, having lead portions of an electrically conductive material formed on a base film of said carrier, said lead portions being plated with a tin or tin alloy plated layer, an improvement wherein an indium plated layer is formed on said tin or tin alloy plated layer for preventing the generation of whiskers on said tin or tin alloy plated layer, and wherein said indium plated layer is at least 0.01 μm in thickness.
Claim 3
Dependent Claim
31 words
A film carrier according to claim 1 wherein said tin or tin alloy layer ranges in thickness from 0.1 to 3 μm and said indium layer from 0.01 to 2 μm.
Claim 4
Dependent Claim
19 words
A film carrier according to claim 2 wherein said indium layer ranges in thickness from 0.025 to 0.5 μm.
Claim 5
Dependent Claim
19 words
A film carrier according to claim 3 wherein said indium layer ranges in thickness from 0.025 to 0.05 μm.
Claim 6
Dependent Claim
31 words
A film carrier according to claim 1 wherein said tin or tin alloy layer ranges in thickness from 0.5 to 1 μm and said indium layer from 0.025 to 0.5 μm.
Claim 7
Dependent Claim
19 words
A film carrier according to claim 5 wherein said indium layer ranges in thickness from 0.025 to 0.05 μm.
Claim 8
Dependent Claim
22 words
A film carrier according to claim 1 wherein said tin or tin alloy layer ranges in thickness from 0.1 to 3 μm.
Claim 9
Dependent Claim
22 words
A film carrier according to claim 7 wherein said tin or tin alloy layer ranges in thickness from 0.5 to 1 μm.
Claim 10
Dependent Claim
19 words
A film carrier according to claim 1 wherein said indium layer ranges in thickness from 0.01 to 2 μm.
Claim 11
Dependent Claim
19 words
A film carrier according to claim 9 wherein said indium layer ranges in thickness from 0.025 to 0.5 μm.
Claim 12
Dependent Claim
19 words
A film carrier according to claim 10 wherein said indium layer ranges in thickness from 0.025 to 0.05 μm.
References Cited (Backward Citations)
US3585010A
Cited
US3908075A
Cited
US3821692A
Cited
US3818415A
Cited
US4010005A
Cited
US3857683A
Cited
US3988053A
Cited
JPS5236529A
Cited
US4255474A
Cited
JPS5767187A
Cited
US4511634A
Cited
JPS595583A
Cited
JPS5993898A
Cited
US4549043A
Cited
US4577056A
Cited
US4785137A
Cited
US4633050A
Cited
US4770923A
Cited
EP0193127A1
Cited
US4811170A
Cited
US4749626A
Cited
US4640438A
Cited
US4808769A
Cited
EP0281038A2
Cited
US4812421A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |