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Table of Contents
It is often necessary to re-bond a bare die. Typical reasons include:
- Original bond wires were accidentally destroyed during decap
- Device was obtained as a bare die from a third party
- FIB edit could not be done with device in package due to mechanical constraints
: Has anyone tried wirebonding to FIBbed pads?
Several firms sell refurbished wire bonders and provide service, support, and parts. Some of these companies will also do custom bonding projects for single dies or small lots.
Surface preparation
If any existing bonds, or pieces of them, are still on the pads these must be removed first.
Pads should be clean and undamaged.
: Get a photo of a nice clean pad that copper bond wire was etched off of
Mounting
The die must be secured firmly to its new package to keep it from moving around. AZ has had good experiences using a tiny dot of cyanoacrylate adhesive, although silver epoxy or Crystalbond would likely work fine as well. Make sure the volume of adhesive is low enough that it doesn't squeeze out and get on the top of the die.
Re-bonding
Bonding to a clean, once-bonded pad should be essentially the same as bonding to a never-bonded pad. Contact resistance may be a little higher and reliability reduced, but this isn't a big concern if you just want to dump the firmware.
: Get a nice clean shot of a good bond pad
