Wirebonding Factory Tour

Shenzhen Adventure Day 25

Wirebonding is a technique you’re probably familiar with if you’ve ever taken apart a cheap toy.

It’s a slightly harder technique to employ than using a standard packaged chip, but if employed correctly can help reduce cost (raw die is cheaper), footprint, and weight. The cost per wire is really small!

Basically, rather than solder a chip down, you paste it down and then solder a small wire from the chip die to the board and then cover it in goop to protect it.

This technique used to be really hard to access, but with more automation costs have come down drastically making this an interesting technique for a cost-concious engineer.

The factory boss here was a very friendly lady, and she gave us an awesome tour!

Example of a finished wire bonded board.

A worker, by hand, places the tiny raw dies onto the circuit boards using little wooden chopsticks.

The dies are really tiny to be working with by hand!

An employee configures the machine. In the upper left, you can see a wiring diagram, as well as a computer showing the current alignment.

The wirebonding machine drops small conductive wires from the bond points.

Go! Go! Go!

After wire bonding:

Ok… maybe this is before, I can’t recall. The wires are hard to see…

If there is a mistake, a worker uses a machine to correct it. The machine has knobs which scale each human movement down by a factor of 10. This allows them to do the detailed work needed to operate on these tiny wires.

Afterwards, the boards have protective goop placed on them.

Goop laying machine.

The boards then go into an oven to cure the goop to a hard shell.

They can also do clear goops!