Rudy, You are SO right !! As we all discover at some point in our lives, "you really do get what you pay for" .... I'm having a difficult time trying to justify to Purchasing that just becuase a laminate manufacturer or (worse yet) distributor says his material meets say Mil-S-13949/4, that doesn't mean we can indiscriminately "drop" it into out processing line and not expect anything to change!! At 10:54 PM 7/9/97 -0400, you wrote: >In a message dated 97-07-09 05:27:25 EDT, you write: > >>Having seen lots of SIR data from OTHER facilities, the problem could be a >>fault in the tester, or technique. Did good old Bob retire around that >time? >> Did water quality in the rinse system change? Did the DI water unit >>suddenly go south? There are lots of factors that can cause poor SIR. > Don't >>assume any one factor is the problem. > >Sir Doctor Guru of SIR > >You run two pieces of laminate, one from vendor A, the other from vendor B, >through the same process, and one passes easily, the other fails miserably, >and you repeat this test, with 100% reproducability.... if you can make >another deduction from this data, TechNet is awaiting your assessment....:-) >> >>I do agree that no two laminates are the same. Varying levels of porosity >>and varying resin compositions can dramatically effect SIR, or at least >their >>processing characteristics. >> >Sir Doctor: > >Most of the poor, overstressed PCB fabricators have only their vendors to >(pick one) 1. turn to for assistance 2. blame, and having been in both >positions more than once, it is clear to me that we all need to see what the >options are. I for one, and suspect many others, never considered that >laminate could vary to this extent. This was a great learning experience >for me, and I was hoping to spread the benefits.... > >Yours in science, and PCB fabrication: > >Rudy Sedlak >RD Chemical > >*************************************************************************** >* TechNet mail list is provided as a service by IPC using SmartList v3.05 * >*************************************************************************** >* To subscribe/unsubscribe send a message <to: [log in to unmask]> * >* with <subject: subscribe/unsubscribe> and no text in the body. * >*************************************************************************** >* If you are having a problem with the IPC TechNet forum please contact * >* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * >*************************************************************************** > > *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************