Dan,
We do not have a standard for applying home-plate apertures.
Dave
----- Original Message -----
From: D.Terstegge
To: [log in to unmask]
Sent: Friday, December 14, 2001 2:45 PM
Subject: Re: [TN] Homeplate apertures, how to use them
Hi Dave,
The goal is elimination of solder beads (the balls at the sides of chipcomponents). At present we're cleaning all our boards, which removes 99% of the solderbeads, but we want to anticipate on a no-clean process that we may introduce in the future. From previous Technet discussions I learned that the homeplate design is very effective in removing solder beads. Maybe I should also try some alternatives, but the question remains how to make an easy to use specification (to the stencil supplier, or to our production engineers who orders the stencil) as to what apertures should be changed to homeplate, and what apertures should be left untouched (or should be changed in another way).
Daan Terstegge
www.smtinfo.net
----- Original Message -----
From: David Fish
To: [log in to unmask]
Sent: Saturday, December 15, 2001 1:09 AM
Subject: Re: [TN] Homeplate apertures, how to use them
We do not routinely use homeplate apertures. We only use homeplate
apertures in cases where we need to reduce solder balling when using NC
fluxed pastes.
What is your goal in using this aperture shape?
Dave Fish
----- Original Message -----
From: "d. terstegge" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, December 14, 2001 6:05 AM
Subject: [TN] Homeplate apertures, how to use them
> Dear Technetters,
>
> For our stencils I have recently introduced the homeplate design for the
apertures of chipcomponents larger than 1206.
> But now a problem occurs with the guys who have to order the stencils: it
takes a lot of time, by using Gerber data, partslist and assembly drawing to
figure out which components are 1206, 1210, 1812. For a coil or tantalumcaps
with such a footprint I don't want a homeplate aperture because these parts
need a little more solder.
> So we end up with a nice specification, but very unpractical for the
production engineers.
>
> How do others deal with this ? Mabe you have suggestions on how to make
an easier-to-use specification ? Or ideas about easier ways to order a
stencil according to my spec ?
> Should I keep it simple and say "use homeplate-apertures for all
footprints larger than 1.5 * 1.5 mm ?"
>
> Daan Terstegge
> SMT Centre
> Thales Communications
> Unclassified mail
> Personal Website: http://www.smtinfo.net
>
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