Mr. Kim:
Are you saying that your customers are demanding dielectric thicknesses
which are unachievable without squeezing out an excessive amount of resin
due to the available prepreg thicknesses? For example, asking for a 0.40 mm
(.0015") spacing between two layers where two plies of 7628 is too thin and
two plies of 7628 plus one ply of 1080 is too thick?
If that's the case, I'm not sure what you can do except tell them why you
can't do it, or what will happen if you do. They should understand, and be
able to modify their design. If it's a controlled impedance issue, they can
adjust trace widths to compensate for small changes in dielectric thickness.
Your material supplier should give you info on resin content and scaled
(finished) thickness of their various prepregs/cores and the recommended
lamination parameters.
Or is it that they're asking for otherwise unachievable constructions, say
with only one ply of 1080 between 1 oz copper foil?
Timothy Reeves
ECD Circuit Board Division
13626 South Freeman Road
Mulino, OR 97042
[log in to unmask]
(503) 829-9108 (800) 228-8198 FAX (503) 829-5482
> ----------
> From: [log in to unmask]
> Sent: Thursday, October 21, 1999 6:19 PM
> Subject: Re: Adequate Resin Content
>
> Thanks, Mr McGlaughlin.
> I'll check it.
> But I couldn't find out any specification or guideline for adequate coat
> thickness
> of specific glass style.
>
> Regards,
>
> Tal Young Kim
>
> -----Original Message-----
> From: McGlaughlin, Jeffrey A [mailto:[log in to unmask]]
> Sent: Thursday, October 21, 1999 8:26 PM
> To: [log in to unmask]
> Subject: Re: [TN] Adequate Resin Content
>
>
> MIL-S-13949 is a dead issue. It has been superceded by IPC-4101. Check the
> IPC homepage for coat and availability.
> Jeffrey A. McGlaughlin
> PCB Designer
> Battelle Memorial Institute
> Columbus Ohio
> [log in to unmask]
>
>
> -----Original Message-----
> From: [log in to unmask] [SMTP:[log in to unmask]]
> Sent: Thursday, 21 October, 1999 05:07
> To: [log in to unmask]
> Subject: [TN] Adequate Resin Content
>
> Dear Technetters ;
>
> Is MIL-S-13949H still effective?
> Nowadays, our domestic customers strongly request various
> thickness
> of
> prepregs and copper clad laminate
> for multilayer PCBs. The nominal thickness in our catalogue which
> is
> designed considering adequate resin
> content to styles for 2116, 1080, 7628, .... etc is not valid any
> more.
> My opinion is against to those requests that ignore adequate
> resin
> content
> recommended in MIL-S-13949H.
> But if so, quit this job ?
>
> Thanks and regards,
>
>
> Tal Young Kim
> Manager, Quality Assurance Team
> Doosan Corporation Electro-Materials BG
> Tel : 82-445-820-8451
> Fax : 82-445-820-8300
> E-mail:[log in to unmask]
>
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