AnsweredAssumed Answered

bare chip ground's purpose

Question asked by yckim on Apr 25, 2017
Latest reply on May 3, 2017 by mthahira


I'd like to use bare chip like HMC1081 and HMC-ALH382.

I have multi layer PCB cutting 1 copper  and 1 layer substrate(Teflon) as cavity PCB.

So I can see second copper layer. But the process is hard to make.

I found other solution. It is using through hole with metal like coin PCB.

I'm wondering what purpose is bare chip's bottom ground. I think it would be heat sink and GND for signal.

When I check on datasheet. they use microstirp line wihtout transformation. I know there are same ground microstip line and chip. If I use coin PCB, Do I have to transform microstip line to CPW for wiring signal and ground? or whatever is it okay?, If I wired signal and ground.

Please let me know bare chip ground's purpose.

Thank you!