What is a padring on a chip?

A padring is the structure around the outside edge of an IC die that contains large bond pads, ESD protection diodes, and input/output drivers used to connect the die to its package.

How does a padring connect a chip to its package?

Tiny wires are bonded between the leads of the leadframe and the bond pads in the padring, electrically connecting the die to the outside world.

What padring was used in the Google shuttle?

The Google shuttle used the Caravel harness, which includes a padring provided as part of the Caravel design from Efabless.

What padring is used in the Tiny Tapeout shuttles?

For SKY130, the OpenFrame padring is used. For IHP and GF180 custom padframes are used.

Padring

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November 13, 2020

We need to make sure we can package the IC after the wafer has been diced into individual dies.

A common way of packaging ICs is to connect them to a leadframe by bonding tiny wires between the leads of the leadframe and the pads on the die.

The big bond pads around the outside of the IC often include ESD protection diodes, Input/Output drivers and so on.

This picture shows raven, an IC from Efabless. You can see around the edge there are the big bond pads and the power and ground lines. This structure is called a padring.

raven

The padring used in the Google shuttle is included in Caravel.

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