Kelly
We took your recommendation and looked at IPC-4101, table 5.
However, our interpretation is a little different from yours. We interpret
table 5 as a qualifying table. That is, in order to be qualified to
IPC-4101, a vendor must demonstrate they can produce material to all the
listed requirements. That's not saying that all material meets those
requirements by default.
In addition, a look through the individual specification sheets will
show that fungus resistance does not appear (on any that I can find). This
reinforces our belief that fungus resistance is a special requirement that
must be specified in addition to the base material.
I'd be interested in hearing from material and pwb manufacturers on
this.
-Mike
> ----------
> From: Kelly M. Schriver[SMTP:[log in to unmask]]
> Sent: Monday, December 06, 1999 7:36 AM
> To: TechNet E-Mail Forum.; Hiteshew, Michael
> Subject: Re: Re: [TN] Fungicidal Laminate
>
> 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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