On 09/06/2017 04:27 PM, Frank Kimmey wrote:
> Bob,
> Try taking a look at PCD mag a couple of months back.

Thank you Frank.

I just did a search on round / rounded pad at pcdandf.com.

This is the only thing that came up with that I thought was relevant: 
http://pcdandf.com/pcdesign/index.php/current-issue/239-tech-tips/10607-tech-tips-1602

I keep my print copies and will give them a review later for a more 
recent article.  I'll reply back if I find it.

Thanks again,

Bob








> There was a good article on improved CPk due to percentage of rounding.
> Off the top of my useless brain I think it was like 30% but You should look to verify.
> Good luck,
> FNK
>
> Frank N Kimmey CID+
> Electrical Engineer / PCB Design
> VeriFone Inc
> 1400 W Stanford Ranch Road, Suite 200
> Rocklin, CA 95765 USA
> W: 1-916-625-1818
> M: 1-916-833-9877
> [log in to unmask]
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Cochran
> Sent: Wednesday, September 06, 2017 1:23 PM
> To: [log in to unmask]
> Subject: [TN] rounded SMT pads...
>
> Hello,
>
> Assuming it exists, where can I find the latest and greatest IPC recommendation for SMT rounded pad shapes?  I'm hoping that such a recommendation exists as a rule for SMT pads and that every particular package doesn't have its own recommendation.
>
> BTW, I'm familiar with the radius definition provided here by Wolfram:
> http://mathworld.wolfram.com/RoundedRectangle.html
>
> However, my Altium tool requires me to specify it in terms of a percentage ( half of the
>           shortest side of the pad ).
>
> I'm hoping it's specified in one of these two forms.
>
> Thank you,
>
> Bob
>
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