Due to the use of multiple board fabricators, our company does not specify a particular brand name of material. Rather, we specify our performance requirements needed by the core and prepreg materials. We continue to transition to SMT boards exclusively, which require two heat cycles – one for SMT and one for wave soldering through-hole parts - but we still have some straight through-hole boards that do not require two heat cycles – only wave soldering. We find that using the higher Tg material on mixed-tech boards results in better Z-axis expansion performance, less warpage and delamination and using the lower Tg material on through-hole boards reduces cost!
For example our typical Material note on our Fab drawings will read:
COPPER CLAD WOVEN EPOXY E-GLASS, 170C-Tg (MIN), 340C-Td (MIN), UL94V-0, PER IPC-4101/126 (for Through-hole and Surface-Mount designs)
- Or -
COPPER CLAD WOVEN EPOXY E-GLASS, 150C-Tg (MIN), UL94V-0, PER IPC-4101/24 (for Through-hole only designs)
This allows board shops flexibility and more consistent quoting (comparing apples to apples).
I’d be curious to know how other designers specify their material requirements and why.
Thanks,
Steven D. Roy, CID
PCB Designer
Audio Authority Corp.
2048 Mercer Road
Lexington, KY 40511-1071
(859) 233-4599 X-159
-----Original Message-----
From: DesignerCouncil
[mailto:[log in to unmask]] On Behalf Of
Silicon Valley Chapter - IPC
Sent: Friday,
September 25, 2009 1:13 AM
To: [log in to unmask]
Subject: Material Comparison
Hey Designers,
I would like to get input on the basic differences of these materials:
FR406 IS410 FR370HR
Besides perhaps their thermal and electrical characteristics is one more economical than the other two and are any of these more readily available for fabrication vendors?
(I have already reviewed the Isola website but would like to get feedback from other designers and fabricators for evaluation)
Cheers! Bob McCreight, C.I.D.
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