Edwin, The major concern over popcorning is delamination on top of the die. This can lead to condensation, which can cause ECM between ball bonds or corrosion of the bond pads. It can also cause shifting, which lead to fatigue of the ball bonds and eventual liftoff. I would strongly recommend not using these components. Craig -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Louis, Edwin @ CSE Sent: Thursday, July 12, 2001 9:30 AM To: [log in to unmask] Subject: [TN] PEMs If one receives PEMs from the manufacturer which are supposedly dry and handled correctly but are found to have internal delamination by acoustic spectroscopy, whether this is an automatic sentence of popcorning when the devices are put through convection reflow. Is there air inside the part that can cause popcorning of a dry part when no outward signs of delamination or popcorning is visible.Also, ---------------------------------------------------------------------------- ----- 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 ---------------------------------------------------------------------------------