Will Your suspicions are likely to be correct. There has been a great deal of information published cautioning against point to point soldering of these components which causes degradation or failure. Internally micro cracking changes the component value over time if not immediately. Typical solutions include hot air soldering techniques (skill related), preheat of the assembly and component with reduced iron temperatures, machine processing with preheat, etc. Most of the data supports something around 2 degrees C per second for temperature limitations of the components. Believe that might be a little conservative. Mel Parrish Soldering Technology International Madison, AL 256 705 5530 256 705 5538 Fax [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Will Cabrera Sent: Thursday, October 04, 2001 2:09 PM To: [log in to unmask] Subject: [TN] Leaky Capacitors Does anyone have any experience with multilayer ceramic 1206 capacitors turning into low value resistors? These are rework capacitors (manually soldered) between a PTH pin and a #22 ga wire. What are the possible causes of failure? Is flux absorption into the ceramic a possibility? My strong suspicion is that they are being damaged by heat during the rework process. ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------