At 07:32 AM 4/26/96 -0500, you wrote:
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>>Date: Thu, 25 Apr 1996 21:59:51 -0800
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>>From: Phil Bavaro <[log in to unmask]> (Phil Bavaro)
>>Subject: Re: TOMBSTONING
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PHIL, REPLY BELOW IN CAPS:
>>ON 4/26/96 PHIL BRAVO WROTE:
>>We are experiencing tombstoning with our 0402 chips when our nitrogen is
>>on, but when it is off, the defect goes away.  And as one would expect, the
>>solder joints are not as shiny and smooth  without the nitrogen.
>>
>>We are using SN63 fine pitch paste in a forced convection reflow oven.
>>
>>One of our suppliers (ROHM) has recommended using non-eutectic SN62 (with
>>silver)
 SOMEONE FROM FORD (CANNOT RECALL THE NAME,SORRY) HAS RESEARCHED THIS AND
FOUND THIS TRUE ALSO.
and .02" diameter round pads spaced apart .04" but we have never
>>tried this type of pad design before (square peg on a round pad)!
WE HAVE SEEN MANY OEM'S SUCH AS PANASONIC, FUJI AND OTHERS WHO HAVE USED
ROUND PADS WITH SQUARE PART TERMINATIONS IN THE PAST, NOT SURE WE'VE SEEN
THIS WITH 0402'S. WE HAVE NOT TRIED ROUND PADS HERE.
>>
>>Any suggestions or experiences would be appreciated.
>>
>>Thanks,
>>
>>Phil Bavaro
>>(619) 658-2542
>>[log in to unmask]
--------------------------------------
Jeffery L. Hempton                     Phone: 219-429-7335
Mail Stop:25-31  Fax:   4688  Email: [log in to unmask]
MESC (Magnavox),1313 Production Road, Fort Wayne, IN 46808

"And the men who hold high places, must be the ones who start,
  To mould a new reality, closer to the heart.
Philosophers and Ploughmen, each must know his part,
  To sow a new mentality, closer to the heart."--Rush-A Farewell to Kings.