Best Annealing Process?

what temperature?

Molten silver absorbs oxygen into solution and when it freezes the oxygen shows up as bubbles inside and on the surface. This need an inert gas shield to stop.

So if you are heating this above melting the cooldown will cause disturbance of the part as it seats and you will not get it level.

If just low temp heat soak annealing...why? differntial expansion to substrate makes cracks etc?

In another life I sold various IR emitters for industrial processes. I did several projects for PC board manufacturers as well as annealing the big rods of silicon used for wafers at Hemlock Semiconductor. These were all versions of focused short wave infra-red from T3 lamps. It's very controllable and the watt density can be surprising.

Just Google "focused infra red lamps" or go here: http://www.noblelight.net/products/

or here: http://www.researchinc.com/ This company used to be big in solder reflow machines. They may have something for you.

We use a similar process with Indium alloys, the alloy is held under vacuum in a small bell jar sitting on a pump base then heated using an induction coil around the bell jar.

What die attach adhesive are you using?

Do you mean cure the adhesive, rather than anneal the adhesive.

If you are depositing Ag and need to anneal the silver then the process is rather simple. Heat to ~ 80% of the melt temperature.

But, this will not work for any semiconductor structure other than wafer bonding (using other material).

More detail, what is it you are trying to accomplish?