Are the ball pad lands defined by the solder resist or is there clearance between resist and pad? i.e. x-sectionally resist resist padpadpad pcbpcbpcbpcbpcbpcbpcb or ressist padpadpad resist pcbpcbpcbpcbpcbpcbpcb If the former then the step caused by the resist can result in solderability problems on the smaller grid BGA's. Chris -----Original Message----- From: Russ Winslow [mailto:[log in to unmask]] Sent: Monday, February 08, 1999 8:50 PM To: [log in to unmask] Subject: Re: [TN] Defective BGAs? Jim, We are seeing it only on plastic BGAs with 63/37 solder balls (so far). We too saw it in isolated cases but now we see it all the time. These are pads with no (zero) solder on them and/or pads with a small icicle in the very center. We even see pads with a ring of solder surrounding a non-wetted center. The problem is, we now see it on nearly every lot we receive for reballing. Kinda makes ya wonder? -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Jim Marsico 516-595-5879 Sent: Monday, February 08, 1999 12:01 PM To: [log in to unmask] Subject: Re: [TN] Defective BGAs? Dear Russ... This is something I've noticed in the past... I thought it was an isolated case. Could you tell me the types of BGAs you see this phenomenon on? Are they predominantly ceramic? Plastic? Both? If ceramic, are the component pads on the same level as the ceramic or are they recessed? What solder alloy? Any information you can provide may be helpful. ################################################################ 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 ################################################################ ################################################################ 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 ################################################################