Hi TechNet - Your right Steve/Paul, it is not necessary to xray and test every BGA on every assembly (I didn't mean to leave that impression). A reasonable sampling in plan in conjunction with good process control as outlined in JSTD-001 allows for low process cycle time and reasonable costs. I have seen some examples of where several assembly houses have a good handle on the placement gauge R&R, inspect their solder paste print and have tuned in their reflow profile - they do only sample electrical testing, no xray and are producing quality product. I think the amount of "inspection" is also part of an assemblers comfort level for the use environment their product has to live in. Dave Hillman Rockwell Collins [log in to unmask] "Stephen R. Gregory" <[log in to unmask]> on 07/30/98 06:48:32 PM Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to [log in to unmask] To: [log in to unmask] cc: Subject: Re: [TN] Glenbrook x-ray?? In a message dated 98-07-30 19:14:35 EDT, you write: [log in to unmask] (Paul Klasek) To: [log in to unmask] I concur with David ; have been watching this discussion for some time and kept out as I thought perhaps I'm the odd one out in extreme as usual ; but since Dave cracked the pot the way it is : If the process is out of window to such a degree this kind of machinery is needed ; I'd say $ much better spend would be in the process gear ; not inspection gear . >> Hey there Paul! Well since you and Dave started this, I'm gonna jump on the bandwagon too. I asked the question that I'm about to ask on another web forum a while back, and the reponses were kind of guarded...(it was like they didn't want anybody to see them answer with what some may percieve the wrong response). But my question was; why does it seem that if you want to do BGA, the consensus is you need to have xray capability? I know that xray is a tool that will allow you to see things that you normally can't see, but is it REALLY necessary? It would seem to me that if you can make sure that you lay enough paste down, put the part where it's supposed to go, and got your oven cranked-up with enough heat, you're in the BGA business...and you can do all that stuff without an xray machine. "But you can't see the solder joints dross-breath, that's why you need an xray machine.." some may say. But I didn't see everybody getting spooled-up about having xray when we started putting decoupling capacitors beneath DRAM years ago...can't see those solder joints either. So, is it really necessary? -Steve Gregory- ################################################################ 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 ################################################################