Michael -
I think what Doug is trying to point out is that the requirement for fungus
resistance is already posted in the laminate material specification in most
cases (ref. IPC-4101 table 5) as a part of the basic resin system
qualification. Accordingly, an additional requirement stipulated in the
purchase order would not be required, and may only cloud the issue by
imposition of additional specifications.
Regards - Kelly
-----Original Message-----
From: Hiteshew, Michael <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Friday, December 03, 1999 4:42 PM
Subject: Re: [TN] Fungicidal Laminate
Hi Doug,
We've been discussing this same issue here at Lockheed. According to
IPC-6012 (Qualification and Performance Specification for Rigid Printed
Boards) - Section 3.11 (p17), "Special Requirements", reads in part:
"When specified on the procurement documentation, some or all of the
special requirements listed in the following paragraphs shall apply. ...".
Section 3.11.3, which follows this statement, covers fungus resistance.
Notice the key words "When specified..". This qualifying comment occurs
again in Appendix A (p27). In addition, MIL-HDBK-454, Section 4.4, "Fungus
Testing", reads in part:
"Group II materials should be subjected to the fungus test specified
in MIL-STD-810...". Under Group II materials are epoxy glass-fiber laminates
and epoxy resin. Also listed is polyurethane, the main component in Type UR
conformal coating. Type AR (acrylic) is listed as a Group I (fungus inert)
material.
So it sounds like these organic materials are fungus nutrients and,
depending on your application environment, may need to treated with
fungicide. Since this is a special requirement, it will need to specified on
the procurement documentation.
Michael Hiteshew
Lockheed Martin Launching Systems
[log in to unmask]
(410) 682-1259
> ----------
> From: Douglas O. Pauls[SMTP:[log in to unmask]]
> Reply To: TechNet E-Mail Forum.;[log in to unmask]
> Sent: Friday, December 03, 1999 7:34 AM
> To: [log in to unmask]
> Subject: Re: [TN] Fungicidal Laminate
>
> In a message dated 12/02/1999 2:54:44 PM US Eastern Standard Time,
> [log in to unmask] writes:
>
> >
> > It seems to be my week for strange requests.
> > Does anyone know of a fungicidally treated FR4 laminate? Or of any
> > fungicidal treatment which can be applied to an assembled circuit
> board.
> >
>
> I can't really see the need for a fungicide. Most IPC specs have the
> requirement that the base material, such as laminate, mask, and coating be
> non-nutrient in nature, which means it would not support growth of a
> fungus.
>
> Doug Pauls - CSL
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