IP Library Granted Patent US 7,795,060
Granted Patent B2
US 7,795,060 · App. 12/200,574 · Granted Sep 14, 2010

Lead cutter and method of fabricating semiconductor device

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Quick Facts
Patent No.
US 7,795,060
App. No.
12/200,574
Granted
Sep 14, 2010
Kind
B2
Abstract

Aimed at stably forming sheared surfaces of leads of semiconductor devices, and at raising ratio of formation of plated layers onto the sheared surfaces of the leads, a lead cutter has a die 106 , and a cutting punch 110 having a cutting edge at least on the surface facing the die, wherein clearance T between the die 106 and the cutting punch 110 is set within the range from not smaller than 2.3% and smaller than 14.0% of the total thickness of the leads to be cut and plated layers formed on the upper and the lower surfaces thereof.

Claims (6)

1. A method of fabricating a semiconductor device comprising:

cutting leads of a semiconductor device, each of said leads having plated layers formed on the upper and the lower surfaces thereof, with a lead cutter including a die, and a cutting punch having a cutting edge at least on the surface facing said die,

wherein the clearance between said die and said cutting punch is set within the range from not smaller than 2.3% and smaller than 14.0% of the total thickness of one of the leads to be cut and plated layers formed on the upper and the lower surfaces of said lead.

2. The method of fabricating a semiconductor device as claimed in claim 1 , wherein the thickness of the plated layers formed on the upper and the lower surfaces of each of said leads is respectively 5 μm or smaller.

3. The method of fabricating a semiconductor device as claimed in claim 1 , wherein said plated layers are composed of a lead-free solder.

4. The method of fabricating a semiconductor device as claimed in claim 1 , wherein said plated layers are composed of nickel/gold, nickel/palladium, or nickel/palladium/gold.

Assignments (3)
CHANGE OF ADDRESS Recorded Nov 29, 2017
From: RENESAS ELECTRONICS CORPORATION
To: RENESAS ELECTRONICS CORPORATION
Reel/Frame 044928/0001 →
CHANGE OF NAME Recorded Oct 28, 2010
From: NEC ELECTRONICS CORPORATION
To: RENESAS ELECTRONICS CORPORATION
Reel/Frame 025214/0304 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 28, 2008
From: KUMAMOTO, TOORU
To: NEC ELECTRONICS CORPORATION
Reel/Frame 021458/0373 →