On 22 Mar 2004 at 10:36, Jason Lineback wrote:

> Hello
>
> Is there a trend coming to use round pads for SMT components?

Theoretically, there should be.

The major PRO might be the much better paste release and cleaner
stencils. Some studies (IIRC) showed better mechanical performance of
solder joints. For PCB design, the rounded corner may be the
additional 10 µm clearance you need for a difficult routing.

Disadvantage may be that anything which is not really round or oblong
(radius = half of the smaller dimension) is no standard gerber
aperture. It can be drawn, then it can happen that CAM at the fab
house runs draw to flash and replaces the drawn rounded rectangles by
classic rectangels > sometimes DRC problems, spacings etc.
Or it can be defined as Gerber Macro or custom aperture, then your
data may fall apart because of gerber """standard"""
misinterprertations.

Regards
Matthias Mansfeld
--
Matthias Mansfeld Elektronik * Leiterplattenlayout, Bestueckung
Am Langhoelzl 11, 85540 Haar; Tel.: 089/4620 093-7, Fax: -8
Internet: http://www.mansfeld-elektronik.de
GPG http://www.mansfeld-elektronik.de/gnupgkey/mansfeld.asc

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