Need info on Bond Pads and Bumps

[chuggington]

What is the difference/relation between a bump and a bond pad ? Any information or document on this would be much appreciated.

Regards,
C

 

[hakeen]

Hi

Bump (a dangerous word in English ) s put on bond-pad before making the bonding. A clumsy analogy is:
Think a soft concrete ball (bump) on a small proper floor(bond pad). In this ball a iron stick (bonding) will be stuck later. So this "concrete ball" makes the interface between the stick (bonding) and the floor.

Actually the below picture can explain it better.
https://t2.gstatic.com/images?q=tbn:ANd9GcTQGmZAIy2FCZKS7MbagI2Eg6pqxsQJxqZnJObt7weeVj6hxv5iCg

or

**broken link removed**

Cheers

 

[chuggington]

Thank you ,Hakeen. This did give me a good idea about bumps . I have a couple more of doubts too .Would the bump be specified in the synthesised netlist or is it something that would be put on after the physical design part of the chip is done ? I have bond pads which should be kept close to the IO pad - I placed it in such a way that the LB pins of the bond pad overlaps with that of the IO pad. Does that sound logical ?





Regards,C

 

[hakeen]

Hi

to be honest i mnot an advanced designerfor your questions.
I believe If you are designing an Flip Chip making IO pin and bond pad can share thesame LBs/coincide with each other. However for e.g. an SO/DIP package i cant somehow imagine that.

In Cadence forum i saw some similar designs(coinciding LB pins.They didnt have any problems it seems.

Cheers

 

[chuggington]

Thanks Hakeen !