In a message dated 04/28/2000 1:17:19 PM Central Daylight Time,
[log in to unmask] writes:

<< Steve,

 Just curious...is this the 35mm package with the big heat slug on the back?
 We place alot of the 'C6201 & 'C6701 parts. We had tried them with a
 Glenbrook unit and had the same results...very dark and barely able to make
 out the balls. In looking at x-ray units to purchase recently, I had several
 of the vendors x-ray these parts to see what the penetration was like. It
 seems that we needed 90-100Kv minimum to get a decent picture.  Glenbrook
 can't get there.

 On a related note, if you are placing the heavy heat-sinked part, did you
 have a problem with the balls collapsing too much under the weight?  That's
 a problem we've had since TI switched to this packaging.  We end up having
 to 'shim' the parts to get enough standoff distance. Just curious, as we're
 still searching for an efficient way to place and reflow these.

 Regards,


 Rick Thompson
 Ventura Electronics Assembly
 2665A Park Center Dr.
 Simi Valley, CA 93065

 +1 (805) 584-9858 voice
 +1 (805) 584-1529 fax
 [log in to unmask] >>

Hi Rick!

We already had 5-boards loaded before we ran into the xray problem, so I went
and reflowed them before I stopped the line. I want to make sure our customer
knows the problem we have before I continue on...

But I did reflow the 5-boards that we had already placed and did notice that
the balls had collapsed a LOT more than I'm used to seeing...so in a word
yes, I'm seeing the same thing that you see.

Can I ask how you go about "shimming" these parts? Something that you do
yourself, or something that you send the parts out and have done?

Do you know if Texas Instruments is aware of the problem?...or is this one of
the same kinda deals as palladium plating was with them.

You know how that went; "There's nothing wrong with palladium plating...you
just gotta find the right flux to use...simple!" ...and it may go the same
way with this deal; "There's nothing wrong with this part, you just gotta
find a way to shim it...simple!"

Thanks for the heads-up Rick!!

-Steve Gregory-

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