What a coincidence, this months edition of "Printed Circuit Fabrication"
magazine (miller freeman / www.pcfab.com) has done a 2.5 page article on
the same subject.
It mentions several references that I can re-type if you wish, however
the only standard that gets mentioned
is ANSI/IPC-EG-140 1988 (although I could not find it mentioned in the
text).
>-----Original Message-----
>From: Stephen R. Gregory [SMTP:[log in to unmask]]
>Sent: Friday, May 28, 1999 5:52 AM
>To: [log in to unmask]
>Subject: Re: [TN] Hollow fibers
>
>In a message dated 5/27/99 8:59:20 PM Pacific Daylight Time,
>[log in to unmask] writes:
>
>> Thank you for the information. Have you heard of hollow fiber and any spec
>> or standard for that?
>
>Hi there,
>
>While I'm no laminate guru, my "doggie" did turn-up these two leads:
>
>Hollow Fibers in Woven Laminates
>A. Shukla, T. Dishongh, M. Pecht, and D. Jennings
>Printed Circuit Fabrication, Vol. 20, No. 1, January 1997
>------------------------------------------------------------------------
>ABSTRACT:
>
>Electronic packaging substrates with fine-line circuitry, such as those used
>in laminated multichip modules (MCM-L) and plastic ball grid arrays (PBGAs),
>are generally fabricated with layers of copper clad composite laminates. The
>conducting copper provides electrical interconnections and power distribution
>for the system, while composite laminates furnish mechanical support for the
>structure along with insulative resistance.
>
>Most laminates are comprised of several plys of glass fabrics embedded in a
>polymeric resin, where the fabric acts as a structural reinforcement by
>offsetting the resin's inherent mechanical and thermomechanical weaknesses. A
>popular fabric fiber material used in the electronics industry for laminate
>reinforcement is E-glass due to cost high strength, water resistance, and
>bond stability with resins.
>
>*****************************************************************************
>*
>**************
>
>Hollow Fibres in PCB, MCM-L and PBGA Laminates May Induce Reliability
>Degradation
>
>A. Shukla, M. Pecht, J. Jordan, K. Rogers, and D. Jennings
>Circuit World, Vol. 23, No. 2, 1997
>------------------------------------------------------------------------
>ABSTRACT:
>
>The presence of hollow fibres in laminates used in printed circuit boards,
>multichip module laminated substrates and plastic ball grid arrays has a
>potentially significant impact on reliability. Hollow fibres are vacuous
>glass filaments in E-glass laminate reinforcements and are seen as a
>reliability problem since they can provide paths for failure mechanisms such
>as conductive filament formation. This paper discusses the manufacture of
>woven fabric laminates and the cause of hollow fibres Experiments conducted
>to assess the occurrence of hollow fibres in laminates are then presented
>long with the key reliability issue.
>
>
>
>So try and find some way to get your hands on those articles and you may find
>out what you need....
>
>-Steve Gregory-
>
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