Hi Christer - Good luck on soldering to the stainless steel - it's one of the tougher materials to solder to and takes a very aggressive flux chemistry. I can help out with your stainless steel questions - CRES stands for Corrosion Resistant Steel which is a common acronym for stainless steel. Your 18-8 description of stainless steel covers a lot of alloys - 303 is a specific stainless steel alloy that is for free machining applications. It has a lower sulfur content and a small addition of aluminum to promote the free machining aspects. The CTE of 303 is 16.4 um/mK in the 21-315 C envelope and 18.5 um/mK in the 70-1000 C envelope. With the ceramic having a CTE 7.74 um/mK of your assessment of the cracking cause sounds plausible. Dave Hillman Rockwell Collins [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Stainless steel Author: [log in to unmask] at ccmgw1 Date: 2/19/97 12:19 PM Dear Technetters. We have been trying to solder a connector of plated stainless steel to a ceramic substrate. We have not been sucessful so far. Cracks occur in the solder joint after soldering. We think the coefficient of thermal expansion in the stainless steel is to high. The material in the connector is CRES 303. (Acc to ASTM 484 and 582) What material is the connector made of? The supplier is an american company. The CRES 303 says nothing to me. Is the material an ordinary 18-8 stainless steel (18%NI and 8%Cr)? In that case the coefficient of thermal expansion is approx 18 ppm and that could explain the cracks. Regards Christer Marklund *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************