Which package and pad (the size) can I use for 10GHz circuit?

[cdz]

Hi all,

I design a circuit operating at 10GHz and finished layout. Now I want to add the pad and consider the package. Does anyone know which package and pad (the size) I can use for 10GHz and where to get the model for the package and the pad. I am use 90nm technology.

Also someone told me that for 10GHz, I cannot use the ESD. In this case, can the chip be easy damage if I touch the chip? Thanks in advance.

CDZ

 

[ESDSolutions]

Re: package and pad

Hi

I cannot help you for the package information but for ESD it is indeed possible that your current ESD solution (provided by the foundry I guess) will add too much parasitic capacitance and/or adds resistance in the pad to circuit connection.

The person that told you that you cannot use the ESD was probably right: Adding the ESD will ruin your 10GHz performance. However, without any ESD protection (e.g. just a RF bondpad) you are heading for failures during bonding/assembly or transportation of the IC's. I am assuming that you are using a thin gate oxide device at the input/output circuits. These tend to be VERY sensitive to ESD and must be protected. If this is a student work you probably can get along with that but if this is to be a real product you should get an ESD expert to help you before throwing away this expensive mask-set/shuttle area!

You should first discuss this constraint with the IO/PAD provider or foundry. Do you have an idea of the amount of parasitic capacitance your circuit can tolerate?

For 10GHz I assume somewhere between 100-200fF. Foundries typically claim to have low-cap solutions but most are tested without sensitive elements in parallel so they cannot prove effectiveness. Proprietary/patented solutions exist in the market including for 90nm technology.

 

[mohamedabouzied]

Re: package and pad

For ESD,
you can reduced esd pads
, so that you have compromized between full esd protection and no esd protection.

for the package,
I think it depends on other factors not only the frequency of operation.
but keep in mind, you should have a good model"spice model which comes from the foundary or the fab. that you will do packaging in" for the package to simulate your design in presence of the package parasitic inductance, capacitance and resistance.

salam
MohamedAbouzied