US5684329A Expired / Lapsed US ⏱️ 0.0 years remaining

Lead frame for semiconductor device

Assignee: NIHON KOUJUNDO KAGAKU CO Ltd

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Filing: 1996-09-20

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Granted: 1997-11-04

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Expires: 2016-09-20

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Abstract

Abstract The present invention relates to a lead frame for the formation of a frame structure of an integrated circuit, more particularly, to a lead frame, for a semiconductor device, having a structure possessing excellent bondability, solder wettability, and Ag paste adhesion. A lead frame for a semiconductor device comprises a lead frame substrate; a first intermediate layer, of a Ni plating or a Ni alloy plating, provided on the lead frame substrate; a second intermediate layer, of a Ag plating or a Ag alloy plating, provided on the first intermediate layer; and an outermost layer, of a Pd plating or a Pd alloy plating, provided on the second intermediate layer, wherein the Ag alloy constituting the second intermediat layer is at least one alloy selected from Ag-Co, Ag-Fe, Ag-Pd, Ag-Au, and Ag-Pt.

Inventors

👤 Seiichi Serizawa

Bibliographic Details

Application Number —

Jurisdiction US

Data Source google_patents

Last Synchronized 2026-11-02 17:12

CPC Classifications

H; H10; H10W; H10W70/00; H10W70/40; H10W70/456; H10W70/457; H10W72/00; H10W72/071; H10W72/075; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; H10W72/59; H10W72/90; H10W72/951; H10W72/952; H10W90/00; H10W90/701; H10W90/751; H10W90/756; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12528; Y10T428/12535; Y10T428/12583

Claims Analysis

Total Claims: 6

Claim 1

Independent Claim 93 words

A lead frame for a semiconductor device, comprising: a lead frame substrate; a first intermediate layer, of a nickel (Ni) plating or a nickel (Ni) alloy plating having a thickness of 0.01-10 μm, provided on the lead frame substrate; a second intermediate layer, of a silver (Ag) plating or a silver (Ag) alloy plating having a thickness of 0.005-10 μm, provided on the first intermediate layer; and an outermost layer, of a palladium (Pd) plating or a palladium (Pd) alloy plating having a thickness of 0.005-10 μm, provided on the second intermediate layer.

Claim 2

Dependent Claim 93 words

Claim 3

Dependent Claim 33 words

The lead frame according to claim 1, wherein the Ag alloy constituting the second intermediate layer is at least one alloy selected from the group consisting of Ag-Co Ag-Fe, Ag-Pd, Ag-Au and Ag-Pt.

Claim 4

Dependent Claim 30 words

The lead frame according to claim 2, wherein the Ag alloy constituting the second intermediate layer is an alloy having a Ag content of not less than 90% by weight.

Claim 5

Dependent Claim 32 words

The lead frame according to claim 1, wherein the Pd alloy constituting the outermost layer is a Pd-Au or Pd-Ag alloy having a Pd content of not less than 60% by weight.

Claim 6

Dependent Claim 47 words

The lead frame according to claim 1, wherein the Pd alloy constituting the outermost layer is at least one alloy selected from the group consisting of Pd-Bi, Pd-Pb, Pd-I, Pd-Br, Pd-Sn, and Pd-Fe, said Pd alloys having a Pd content of not less than 95% by weight.

References Cited (Backward Citations)

US4929516A Cited

US4996116A Cited

US5463247A Cited

US5510197A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2000-11-03	2001-05-05	2001-11-04	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2004-11-03	2005-05-05	2005-11-04	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2008-11-03	2009-05-05	2009-11-04	$7700.00	Window Closed / Lapsed

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