In general, the solder joint quality suffer from poor solderability of Alloy 42, because of the lower solderability of nickel and iron. In order to achieve the same good joint quality as normal soldering (60/40 to Copper), usually higher reflow temperatures and a longer time above liquidus temperatures are needed. Several published technical articles believe that the increase in lead stuffiness is the direct cause of the reduction in fatigue life. As lead stuffiness ( ^ increase) Fatigue life ( v decrease) The order for stiffness of common lead material are: Cu < Kovar < Alloy 42 Michael Yuen PE (DfM) [log in to unmask] ---------- From: TechNet-request To: Technet Cc: leot1 Subject: Re: Alloy 42 Date: Tuesday, April 16, 1996 7:25PM Alloy 42 has/is widely used on many electronic components. As long as your lead finish is correct (i.e. correctly plated or tinned) and you do not have an oxidation problem, then you should have no problems soldering to those parts. Could your customer have been referring to solder joint cracking problems on parts with Alloy 42 base metal? Werner Engelmaier and others have published several technical articles documenting the solder joint cracking problems of Alloy 42 components. Dave Hillman Rockwell Collins [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Alloy 42 Author: [log in to unmask] at ccmgw1 Date: 4/16/96 6:32 PM We have a customer who says that a previous supplier had problems soldering some fine pitch components (15 mil) because the lead material was "Alloy 42". They had a tin/lead coating (85/15). They were also told that many component mfgrs are going to be using this material. We are not familiar with this lead material but since it is solder coated do not hink it should be a problem. Anyone have any knowledge or experience in this area? Thanks in advance for your consideration. Leo Reynolds Electronic Systems, Inc.