Invention Grant
- Patent Title: Printed circuit surface finish, method of use, and assemblies made therefrom
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Application No.: US16068247Application Date: 2017-01-09
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Publication No.: US10566103B2Publication Date: 2020-02-18
- Inventor: Kunal Shah , Purvi Shah
- Applicant: LILOTREE, L.L.C.
- Agency: Kilpatrick Townsend & Stockton LLP
- International Application: PCT/US2017/012777 WO 20170109
- International Announcement: WO2017/120609 WO 20170713
- Main IPC: H01B1/02
- IPC: H01B1/02 ; H01B1/16 ; H01B13/00 ; H01L23/488 ; H01L23/498 ; H05K3/24 ; H05K3/28 ; H05K1/09 ; H05K3/34 ; H05K3/18 ; H05K1/11 ; H01L23/00 ; H05K1/18

Abstract:
A surface finish for a printed circuit board (PCB) and semiconductor wafer includes a nickel disposed over an aluminum or copper conductive metal surface. A barrier layer including all or fractions of a nitrogen-containing molecule is deposited on the surface of the nickel layer to make a barrier layer/electroless nickel (BLEN) surface finish. The barrier layer allows solder to be reflowed over the surface finish. Optionally, gold (e.g., immersion gold) may be coated over the barrier layer to create a nickel/barrier layer/gold (NBG) surface treatment. Presence of the barrier layer causes the surface treatment to be smoother than a conventional electroless nickel/immersion gold (ENIG) surface finish. Presence of the barrier layer causes a subsequently applied solder joint to be stronger and less subject to brittle failure than conventional ENIG.
Public/Granted literature
- US20190027266A1 PRINTED CIRCUIT SURFACE FINISH, METHOD OF USE,AND ASSEMBLIES MADE THEREFROM Public/Granted day:2019-01-24
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