Packaging is the step everyone forgets about — and the one that stops most home fabrication projects dead. You can pattern a working device, but a die on a probe station isn’t a chip you can use. Commercial packaging means wire bonders and die attach — this guide covers a route that needs neither.
Why flip-chip
[YOUR TEXT — why flip-chip beats wire bonding at home: no capillary bonder needed, the PCB itself becomes the package, self-alignment from surface tension, etc.]
The PCB side: ENIG and plated indium
[YOUR TEXT — ordering ENIG-finish boards, electroplating indium onto the pads, plating setup, current density, what the deposit should look like.]
The die side: top metallization
[YOUR TEXT — metal stack on the die side, adhesion/barrier considerations, pad layout matching the PCB footprint.]
Dealing with the oxide problem
[YOUR TEXT — indium oxide at the bond interface, flux strategy vs. mechanical disruption, what actually worked.]
The bond
[YOUR TEXT — alignment approach, temperature/pressure profile, reflow.]
Results and what to improve
[YOUR TEXT — electrical results, yield, failure modes, next iteration.]