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1. (WO2017153590) LEAD-FRAME STRUCTURE, LEAD-FRAME, SURFACE MOUNT ELECTRONIC DEVICE AND METHODS OF PRODUCING SAME

Pub. No.:    WO/2017/153590    International Application No.:    PCT/EP2017/055726
Publication Date: Fri Sep 15 01:59:59 CEST 2017 International Filing Date: Sat Mar 11 00:59:59 CET 2017
IPC: H01L 23/495
H01L 21/48
C25D 5/02
C25D 5/34
C25D 5/48
C23C 18/16
C23C 18/54
H01L 23/31
C25D 3/46
C23C 18/18
C23C 18/42
Applicants: ATOTECH DEUTSCHLAND GMBH
Inventors: NEOH, Din-Ghee
BARTHELMES, Jürgen
Title: LEAD-FRAME STRUCTURE, LEAD-FRAME, SURFACE MOUNT ELECTRONIC DEVICE AND METHODS OF PRODUCING SAME
Abstract:
In order to provide a more reliable and cost-efficient way of producing lead-frames or lead- frames structures which expose treated silver surfaces as well as to provide surface mount electronic devices using such lead-frames or lead-frames structures, a method comprising the following method steps carried out in this order is provided: (a) providing a lead-frame body structure having two main sides, said lead-frame body structure exclusively exposing a copper surface on each one of said main sides; (b) depositing a silver coating on at least one of said main sides, so that said at least one of said main sides at least partially exposes an untreated silver surface; and (c) electrolytically treating said untreated silver surface on said at least one of said main sides generated in method step (b) with a treatment solution containing at least one hydroxide compound selected from alkali metal hydroxides, alkaline earth metal hydroxides, ammonium hydroxides and mixtures thereof, wherein the lead-frame body structure is a cathode, thereby producing a lead-frame structure which comprises at least two lead-frame entities each one having two faces and at least partially exposing said treated silver surface; wherein said at least one of said two faces of at least one of said lead-frame entities either exclusively exposes said treated silver surface or wherein said at least one of said two faces of said at least one of said lead-frame entities partially exposes said treated silver surface and partially exposes said copper surface, wherein, on each one of said two faces of each one of said lead-frame entities which partially exposes said treated silver surface, the area of said copper surface is smaller than the area of said treated silver surface.