Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Technology Stocks : Advanced Micro Devices - Moderated (AMD) -- Ignore unavailable to you. Want to Upgrade?

To: pgerassi who wrote (78133)	4/24/2002 12:31:52 AM
From: Bill Jackson	Read Replies (1) \| Respond to of 275872

Pete, Well, a lot depends on the bump melt temperature versus the connection between the die and the spreader. Since metals have a sharp melting point and if you pick the bump solder alloy so it melts at a eutectic point, that will be a sharp melting point. Then use another alloy for the spreader soldering that is molten while the bumps are still hard and it can be done. To make it easy do it in vacuo between cleaned surfaces and you will not need fluxes. As to bumps? are they not on the substrate onto which the die is placed? Can you then do it the other way around and solder the lid to the back of the die with a higher mp solder and then use a lower bump melt temperature as you place the lid + die onto the substrate connector? That way the lid stays solid and the bumps melt as the lid is placed on the part. I can see both ways would need close tolerances to make sure the solder layer is as thin as possible(although this is not as critical as compound thinness, since metals conduct better than most compounds) Bill