Ryan,
        Already saw it on the Plexus website, it's about the only reference
work I've found in the public domain so far. It appears any studies done by
the big OEMs are 'hush-hush'. The Plexus study addressed OSP finishes and
no-clean processes only. I am looking towards creation of a DOE
incorporating an O2 environment and OA chemistry, along with with
HASL/Gold/Tin substrate finishes using a variety of pad geometries and
stencil modifications. This reflects where we are today in our processes, to
provide 'real-world' results for what will work best under these current
conditions. Contact me off TechNet if you would like to discuss further
specifics of our projects and share information. Based on your response
being the only one received thus far, either nobody else has problems (yeah,
right) or they don't feel comfortable discussing it in a public forum. I
look forward to speaking with you....

Mike McMonagle
PCA Process Engineering Supervisor
K*Tec Electronics
1111 Gillingham Lane
Sugar Land, TX  77478
(281) 243-5639 Phone
(281) 243-5539 Fax
[log in to unmask]

> -----Original Message-----
> From: Ryan Grant [SMTP:[log in to unmask]]
> Sent: Friday, September 24, 1999 9:31 AM
> To:   [log in to unmask]
> Subject:      Re: [TN] 0402 Land Patterns?
>
> Mike,
>         Check out "Tombstoning of 0402 and 0201 Components: A study
> examining
> the effects of various Process and Design Parameters on Ultra-Small
> Passive Devices" in the NEPCON 99 proceedings.  I would be greatly
> interested in your results.  We are conducting our own studies as well.
>
>
>                         Thanks
>
> Ryan Grant
> Process Development Engineer
> MCMS
> (208) 898-1145
> FAX (208) 898-2789
> [log in to unmask]
>
> >-----Original Message-----
> >From:  McMonagle, Michael R. [SMTP:[log in to unmask]]
> >Sent:  Thursday, September 23, 1999 11:59 AM
> >To:    [log in to unmask]
> >Subject:       [TN] 0402 Land Patterns?
> >
> >        We are looking at current trends in 0402 land patterns and
> effects
> >on tombstoning. This will result in a DOE incorporating the current
> >varieties of existing designs to improve post-reflow quality levels. It
> will
> >also incorporate various surface finishes and stencil modifications. I
> would
> >like feedback on any types of pad layouts (and stencil design) we have
> not
> >yet considered, to allow incorporation into the DOE. We are currently
> >looking at following land patterns:
> >
> >- IPC Standard Layout
> >- SMT Plus Layout
> >- Siemens Inverted Horseshoe
> >- Round Pads (Layout TBD)
> >
> >        Any help that could be offered (either via TechNet or offlline)
> >would be greatly appreciated, including references to studies previously
> >conducted....
> >
> >Mike McMonagle
> >PCA Process Engineering Supervisor
> >K*Tec Electronics
> >1111 Gillingham Lane
> >Sugar Land, TX  77478
> >(281) 243-5639 Phone
> >(281) 243-5539 Fax
> >[log in to unmask]
> >
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