Thanks Werner
Sincerely,
Paul Reid
Program Coordinator
PWB Interconnect Solutions Inc.
235 Stafford Rd., West, Unit 103
Nepean, Ontario
Canada, K2H 9C1
613 596 4244 ext. 229
Skype paul_reid_pwb
[log in to unmask] <mailto:[log in to unmask]>
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier
Sent: December 11, 2009 3:31 PM
To: [log in to unmask]
Subject: Re: [TN] PWB Operating Temperatures
Hi Paul,
The maximum sustained operating temperature will depend on the specific base material-IPC-4101 is mute in this regard,
and I doubt you will find much on the specific base material data sheets.
I do not see anything in a real reliability concern at a constant T of 70C-certainly moisture is not an issue. The prepreg layer
layers will continue to cure to completion, which entails some changes in properties.
Also, the molecular structure of resins will change over time-this is T-dependent, which will change dielectric properties over time.
This only has consequences in very high-speed applications that have been designed to the very edge.
Werner
-----Original Message-----
From: Paul Reid <[log in to unmask]>
To: [log in to unmask]
Sent: Fri, Dec 11, 2009 3:11 pm
Subject: [TN] PWB Operating Temperatures
Hi All,
Can anyone tell me, or direct me to where I can find, the maximum sustained
operating temperature for a PWB fabricated with FR4.
What are some of the reliability concerns, at the assembled board level,
associated with a constant temperature of 70°C?
Thanks
Paul Reid
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