[PCB_FORUM] Re: 0402, 0603 round pads

  • From: "Macindoe, Gary" <Gary.Macindoe@xxxxxxx>
  • To: icu-pcb-forum@xxxxxxxxxxxxx
  • Date: Thu, 4 Jan 2007 17:25:57 -0600

Thanks for the reply George.  So Tek isn't using round pads for 0402s
and 0603s?

The round pad thing could just be a legacy thing.

 

Gary

 

  

Gary E. MacIndoe

PCB Design Engineer

Longmont, Colorado

 

amd.com

gary.macindoe@xxxxxxx

________________________________

From: icu-pcb-forum-bounce@xxxxxxxxxxxxx
[mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx] On Behalf Of
george.h.patrick@xxxxxxxxxxxxxx
Sent: Thursday, January 04, 2007 4:20 PM
To: icu-pcb-forum@xxxxxxxxxxxxx
Subject: [PCB_FORUM] Re: 0402, 0603 round pads

 

 

15 years ago when I was setting up the SMD libraries at a previous
employer, we were told by a consultant that wave soldered joints were
better if the pads had a radius instead of a "sharp" corner.  This was
supposedly because the meniscus of the molten solder conformed more
easily to a curved surface than a corner.  I guess you could consider a
round pad to be "fully radiused" :)

 

YMMV.  I don't recall if it helped the yields or not.

 

-- 
George Patrick
Tektronix, Inc.
Central Engineering, EDS Applications Support
P.O. Box 500, M/S 39-512
Beaverton, OR 97077-0001
* 503-627-5272 (voice)     * 503-627-5587 (fax)
http://www.tektronix.com <http://www.tektronix.com/>     
http://www.pcb-designer.com <http://www.pcb-designer.com/> 
 
"Off-Grid and Proud of it!"

        -----Original Message-----
        From: icu-pcb-forum-bounce@xxxxxxxxxxxxx
[mailto:icu-pcb-forum-bounce@xxxxxxxxxxxxx] On Behalf Of Macindoe, Gary
        Sent: Thursday, January 04, 2007 15:05
        To: icu-pcb-forum@xxxxxxxxxxxxx
        Subject: [PCB_FORUM] 0402, 0603 round pads

        Hey guys,

         

        Man has it been quiet (or am I not receiving forum e-mails?).

         

        So, I've been looking at some designs from a couple of other
groups within the company.

        Both of them have their 0402 and 0603 foot prints with round
pads (0402 = rd25).

         

        Is anyone out there also using round pads for 0402s and 0603s,
and why?

         

        They have oval pads for their 0805s and 1206s also.

         

        I still have square or rectangular for all of the above.  Could
it have something to do

        with lead free?

         

        Thanks and Happy New Year!

         

        Gary

         

         

        Gary E. MacIndoe

        PCB Design Engineer

        Longmont, Colorado

         

        amd.com

        gary.macindoe@xxxxxxx

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