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
>
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