Edwin, The PBGAs are made of organic materials. Plastic, epoxy, etc. absorb moisture. Ceramic, silicon, glass,and metals are inorganic and don't absorb moisture so they have no problem. Be carefull because some packages can be epoxy sealed ceramic which can be very moisture sensitive in the right situation. Only hermetic packages can be considered insensitive to moisture problems (like corrosion or popcorning). Even flip chip ceramic parts with organic underfills need to be tested to insure they pose no significant moisture sensitivities. Hope this helps Russ Winslow Six Sigma -----Original Message----- From: Edwin Maximo <[log in to unmask]> To: [log in to unmask] <[log in to unmask]> Date: Monday, November 16, 1998 4:45 PM Subject: [TN] Moisture sensitive Hi there!! Just being curious, why do PBGAs are moisture sensitive than CBGA, is it because of the substrate? Any comments or inputs will be appreciated. Regards, Edwin Maximo Value Engineer Electronic Assemblies Inc. [log in to unmask] Edwin Maximo Value Engineer Electronic Assemblies Inc. Phils. phone no - (632) 823 7317 fax no - (632) 759 8629 email - [log in to unmask] ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################