Dear Mr. Wolfgang,

I think thatyou have to consider the parameters from the bonder and the
quality of PCB itself/ the die.

For the bonder parameter, you know exactly the time, pressure for the right
bonding performance and of course, the wear and tear of the aluminum wire
pointer will affect the bondability as well.

For the PCB, you have to specify to your board maker they must supply to
you boards which are ultrasonic bondable. The important factors for good
bondability PCBs are nickel thickness, nickel hardness, the gold layer and
the cleanliness of the surface going to be wire bonded.  For the die, you
usually do not have to acknowledge since they are ready for bonding.

In my experience, poor bonding come from the PCB quality and the improper
adjustment of bonder.

Hope this help.

____________________________________________________________________________
_____________


At 03:10 PM 1999/7/12 -0400, Erat, Wolfgang wrote:
>Good Day
>
>Would appreciate any and all input on reliability data / experience /
>potential failuremodes when wirebonding Alu wire to electroless nickel /
>immersion Gold boards.
>
>HiRel Automotive application
>wedgebonding
>ultrasonic wire bonding
>10 mil AL wire
>Au 3 to 5 microns
>
>appreciate your response
>
>[log in to unmask]
>
>
Albert Mok