US5347709A
Expired / Lapsed
US
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Method of making lead frame
Assignee: Yamaha Corp
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Filing: 1993-06-08
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Granted: 1994-09-20
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Expires: 2013-06-08
Abstract
Abstract A lead frame at least provides a semiconductor-element-mounting portion, plural leads and plural auxiliary leads. The auxiliary leads are arranged to be associated with plural leads, while a tie bar is provided and connected among the leads. According to a method of making the lead frame, an IC-chip mounting process, a wire-bonding process, a sealing process, a resin-cutting process and a dambar-cutting process are sequentially effected on the lead frame. After effecting the dambar-cutting process, a thin-plating process is effected so as to form a thin-plated layer, approximately having a thickness of 5 μm to 15 μm, on the leads. Then, the leads are bent by a predetermined bending process. Thereafter, a thick-plating process is effected so as to form an uniform thick-plated layer, approximately having a thickness of 15 μm to 100 μm, on the leads. After effecting the thick-plating process, a trimming process is effected on the leads. Incidentally, the thin-plating process can be effected after the bending process and before the thick-plating process.
Inventors
- 👤 Yoshihisa Maejima
- 👤 Seiya Nishimura
- 👤 Masayoshi Takabayashi
- 👤 Tokuyoshi Ohta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:15
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/40; H10W70/421; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
146 words
A method of making a lead frame comprising the steps of: mounting an IC chip on a semiconductor-element-mounting portion of the lead frame having a plurality of leads extending therefrom and a plurality of auxiliary leads associated with said plurality of leads; effecting a wire-bonding process on said lead frame; sealing said lead frame with a thermosetting plastic; effecting a resin-cutting process on said lead frame so as to partially remove a resin plastic from said lead frame; effecting a dambar-cutting process so as to cut down a dambar which is provided and connected among said leads; effecting a bending process on said plurality of leads; effecting a plating process using a predetermined material on said plurality of leads so as to form a plated layer on each of said plurality of leads after effecting said bending process; and effecting a trimming process on said leads.
Claim 2
Independent Claim
146 words
A method of making a lead frame comprising the steps of: mounting an IC chip on a semiconductor-element-mounting portion of the lead frame having a plurality of leads extending therefrom and a plurality of auxiliary leads associated with said plurality of leads; effecting a wire-bonding process on said lead frame; sealing said lead frame with a thermosetting plastic; effecting a resin-cutting process on said lead frame so as to partially remove a resin plastic from said lead frame; effecting a dambar-cutting process so as to cut down a dambar which is provided and connected among said leads; effecting a bending process on said plurality of leads; effecting a plating process using a predetermined material on said plurality of leads so as to form a plated layer on each of said plurality of leads after effecting said bending process; and effecting a trimming process on said leads.
Claim 3
Dependent Claim
36 words
A method of making a lead frame as recited in claim 1 wherein said predetermined material used in said plating process is soldering flux so that a solder-plated layer is formed on each of said leads.
Claim 4
Dependent Claim
41 words
A method of making a lead frame as recited In claim 1 wherein said plated layer formed on each of said leads is controlled such that a thickness of said plated layer is made uniform with respect all of said leads.
Claim 5
Dependent Claim
50 words
A method of making a lead frame as recited in claim 1 wherein said predetermined material used in said plating process is soldering flux and a thickness of a solder-plated layer formed on each of said leads is controlled to be in a range of 15 μm to 100 μm.
Claim 6
Independent Claim
168 words
A method of making a lead frame comprising the steps of: mounting an IC chip on a semiconductor-element-mounting portion of the lead frame having a plurality of leads extending therefrom and a plurality of auxiliary leads associated with said plurality of leads; effecting a wire-bonding process on said lead frame; sealing said lead frame with a thermosetting plastic; effecting a resin-cutting process on said lead frame so as to partially remove a resin plastic from said lead frame; effecting a dambar-cutting process so as to cut down a dambar which is provided and connected among said leads; effecting a thin-plating process so as to form a thin-plated layer on each of said leads after effecting said dambar-cutting process; effecting a bending process on said plurality of leads after effecting said thin-plating process; effecting a thick-plating process on said plurality of leads so as to form a thick-plated layer on each of said plurality of leads after effecting said bending process; and effecting a trimming process on said leads.
Claim 7
Independent Claim
168 words
A method of making a lead frame comprising the steps of: mounting an IC chip on a semiconductor-element-mounting portion of the lead frame having a plurality of leads extending therefrom and a plurality of auxiliary leads associated with said plurality of leads; effecting a wire-bonding process on said lead frame; sealing said lead frame with a thermosetting plastic; effecting a resin-cutting process on said lead frame so as to partially remove a resin plastic from said lead frame; effecting a dambar-cutting process so as to cut down a dambar which is provided and connected among said leads; effecting a thin-plating process so as to form a thin-plated layer on each of said leads after effecting said dambar-cutting process; effecting a bending process on said plurality of leads after effecting said thin-plating process; effecting a thick-plating process on said plurality of leads so as to form a thick-plated layer on each of said plurality of leads after effecting said bending process; and effecting a trimming process on said leads.
Claim 8
Dependent Claim
48 words
A method of making a lead frame as recited in claim 5 wherein a thickness of said thin-plated layer is set in a range of 5 μm to 15 μm, while a thickness of said thick-plated layer is set in a range of 15 μm to 100 μm.
Claim 9
Independent Claim
163 words
A method of making a lead frame comprising the steps of: mounting an IC chip on a semiconductor-element-mounting portion of the lead frame having a plurality of leads extending therefrom and a plurality of auxiliary leads associated with said plurality of leads; effecting a wire-bonding process on said lead frame; sealing said lead frame with a thermosetting plastic; effecting a resin-cutting process on said lead frame so as to partially remove a resin plastic from said lead frame; effecting a dambar-cutting process so as to cut down a dambar which is provided and connected among said leads; effecting a bending process on said plurality of leads; effecting a thin-plating process so as to form a thin-plated layer on each of said leads after effecting said bending process; effecting a thick-plating process on said plurality of leads so as to form a thick-plated layer on each of said plurality of leads after effecting said thin-plating process; and effecting a trimming process on said leads.
Claim 10
Independent Claim
163 words
A method of making a lead frame comprising the steps of: mounting an IC chip on a semiconductor-element-mounting portion of the lead frame having a plurality of leads extending therefrom and a plurality of auxiliary leads associated with said plurality of leads; effecting a wire-bonding process on said lead frame; sealing said lead frame with a thermosetting plastic; effecting a resin-cutting process on said lead frame so as to partially remove a resin plastic from said lead frame; effecting a dambar-cutting process so as to cut down a dambar which is provided and connected among said leads; effecting a bending process on said plurality of leads; effecting a thin-plating process so as to form a thin-plated layer on each of said leads after effecting said bending process; effecting a thick-plating process on said plurality of leads so as to form a thick-plated layer on each of said plurality of leads after effecting said thin-plating process; and effecting a trimming process on said leads.
Claim 11
Dependent Claim
48 words
A method of making a lead frame as recited in claim 7 wherein a thickness of said thin-plated layer is set in a range of 5 μm to 15 μm, while a thickness of said thick-plated layer is set in a range of 15 μm to 100 μm.
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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) | 1997-09-19 | 1998-03-21 | 1998-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-19 | 2002-03-21 | 2002-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-19 | 2006-03-21 | 2006-09-20 | $7700.00 | Window Closed / Lapsed |