For a mixed dielectric the print should control the ATC requirements. The print should state fabricate to IPC-6012 or IPC-6018 which communicates the general intent and use of product. The only thing the specs need to resolve is print notes that list both specifications.

I would not use the weakest material as a guide because processing on teflon materials is a strength for some board shops and weakness for others. For the few board shops that can process teflon materials well, this is the most reliable material they have because of the low CTEs.

Randy
 
Randy Reed, CQE
Reliability Lab
Viasystems Group Inc.
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503.992.4421-direct  l   503.545.0150-cell
-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Chris Mahanna
Sent: Monday, March 21, 2011 9:10 AM
To: [log in to unmask]
Subject: [IPC-600-6012] mixed stack thermal shock temps

Hi everyone,
We are testing product for a 6012 contract, but the product is mixed Rogers/GF.
6012 Optional Thermal Shock is required, but no other advise is given.

So, in your opinion do we run it at:

-40/85 (GX/GY)
-55/125 (GF)
-65/105 (6018A) ?

I know, ask the end customer, but I'm wondering what the answer is from a broader industry perspective.

Thanks,
Chris


Chris Mahanna
Robisan Laboratory Inc.
6502 E. 21st Street
Indianapolis, Indiana 46219
317-353-6249


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