confused, IO, bond pad etc

[R1kky]

i finally confused - help me please to clarify in comparison - what is io, what is bond pad, what connection between them?

 

[dick_freebird]

The bond pad is where you stick the wire (or bump, or
column, or ball...). An I/O cell may, or may not (library
developer's choice) integrate the pad with the input or
output buffer circuitry. As a rule it's better to bundle
it all up with its active circuitry, protection, keep-outs
and so on so people can just plop down a known good
off-chip connection.

An "io" might be, for example, a tri-state CMOS output
driver with a pad and ESD protection and even a segment
of a standard power bus ring (so everything just butts
together). Or for analog, it could be just a pad or a pad
plus simple ESD clamps. Lot of variation & styles.

 

[R1kky]

so, i understood next

1. there are typical pads used for the placing bumps or stick the wires (for flip chip and wire bond cases)
2. typically there are ESD/latch-up (btw, what does latch-up mean in few simple words?) protections between io and pads

 

[erikl]

... what does latch-up mean in few simple words?

Here you can find them!

 

[dick_freebird]

In the context of I/Os and bond pads, pad cells will have
explicit layout features aimed at making sure all of the
parasitic elements that sustain latchup are shunted to
keep them off, and spurious substrate / well currents
are prevented from throwing minority carriers out into
the substrate where they might trigger parasitic elements
that don't follow such additional rules.