I think it is right that we should have the choice of component technology,
ie. sheared edges, no plating or complete covering by a solderable surface.
Thus we have the choice to use a component which is lower cost or go to the
higher reliability type. The problem is deciding which to use at an early
stage in the design.
Too often, the Designer/Purchasing Department make an uninformed decision
based on cost and the Process Engineer/QA Department then end up arguing
about a fait accompli.
Design for Manufacture eh?
PS can anybody persuade Earl Moon to return to the fold?
Regards
Eric Dawson
> -----Original Message-----
> From: Dave Hillman [SMTP:[log in to unmask]]
> Sent: Friday, October 25, 2002 11:18 PM
> To: [log in to unmask]
> Subject: Re: [TN] Side and Toe Fillets...
>
> Hi Steve! Ooh - good time for a soapbox! I had the opportunity to
> participate in the J001C revision discussion of this issue and quite a
> discussion it was! As Mel Parish pointed out, the 001C specification does
> not require a side fillet and therefore the committee felt that the
> nonwettable side statement was more of a statement than a requirement thus
> it should not be included in the specification. I presented that opinion
> that the only 001 specification included the nonwettable side statement
> and
> that the statement provided a large number of assembly folks a logical,
> science base reason for not having formed a solder joint side fillet. As
> other TechNet comments have echoed most assemblers would rather not have
> components with sheared sides but many times are not given a choice. Alas,
> specification development by democracy is not always a perfect process and
> I will be re-submitting a 001 comment to reinstate the nonwettable side
> statement in the specification. I suggest other folks who feel that the
> nonwettable side statement provides benefit should also make their
> opinions
> known to the 001 committee during the specification revision comment
> process. Ok, time for another Diet Coke!
>
> Dave Hillman
> Rockwell Collins
> [log in to unmask]
>
>
>
>
> Steve Gregory <[log in to unmask]>@ipc.org> on 10/24/2002 09:06:34 AM
>
> Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please
> respond
> to [log in to unmask]
>
> Sent by: TechNet <[log in to unmask]>
>
>
> To: [log in to unmask]
> cc:
>
> Subject: [TN] Side and Toe Fillets...
>
>
> Hi All!
>
> I've got a situation here with a SMT socket. It's a SAMTEC CLT-105-02-L-D.
> The leads are made from stamped pre-plated stock, so the sides and toes of
> the leads have exposed copper, and of course doesn't wet during reflow.
>
> In J-STD-001B, it used to say under 9.2.6.1 Flat, Ribbon, "L" and Gull
> Wing
> Leads:
> "Leads not having wettable sides or ends by design (such as leads stamped
> or sheared from pre-plated stock) are not required to have side or end
> fillets.
>
> In J-STD-001C it has no mention of that under the same section, in
> J-STD-001C the section number has changed, it's 9.2.6.8.
>
> So if you have leads that are made from pre-plated stock and have the
> sides
> and toes not wet because of the exposed copper, is it now a defect? If it
> is, how in the heck are you going to get the sides and toes to wet?
>
> Thanks!
>
> -Steve Gregory-
>
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