Techneters, I need your help: I'm curious about the critical temperature and time values regarding BGAs. Do the Component Manufactures have one set of limits, and do PCB Assembly Shops have another set of limits. Companies like ours are many times removed from the component manufacturers. The industry default profile slopes are generally built on solder paste characteristics. Is this a sound practice? As I travel and interface with other engineers I find that generally the solder paste manufactures recommend a maximum temperature of 230 degrees C. While the reflow oven profilers max.-out at about 220 degrees C. Then the BGA rework engineers tend to agree that 210 degrees C. is the maximum temperature. And as for times, well most discussions have them varying between 45 seconds to 90 plus seconds. Therefore: 1. Are there any general rules for the maximum temperature that BGAs can tolerate,? 2. Are there any general rules for the maximum time that BGAs can tolerate elevated temperatures? I thank you for sharing your thoughts and wisdom. thanx Bill Butman Circuit Technology Center [log in to unmask] ===== Bill Butman Circuit Technology Center 45 Research Drive Haverhill, MA 01832 __________________________________________________ Do You Yahoo!? Get personalized email addresses from Yahoo! Mail - only $35 a year! http://personal.mail.yahoo.com/ --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------