Shenzhen Adventure Day 25
01 Jul 2015
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
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
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!
Shenzhen Adventure Day 30
06 Jul 2015
The smell clock is a device I built for the Shenzhen manufacturing bootcamp. While we were there,
we had a challenge to build a prototype on a tight budget. The assignment was to build something
that could denote the passage of time.
I decided, while walking around the market, that these little bottle top humidifiers were really cool:
So I knew I had to incorporate them. I walked around the market scoping out
prices and couldn’t find them for a good deal. Just when I was about to give
up, I found them at a price I could afford – if I recall it was a few dollars
a piece, but I needed a lot.
I laser cut a case for each humidifier out of acrylic and opened up each humidifier and attached a wire
to trigger the toggle switch.
In order for it to look nice, I needed some good looking bottles, so I hit the grocery store, where I found:
A bicycle built from toothpaste.
I didn’t find any nice bottles, so I ended up using some ugly ones.
The design uses 4x4 grid of individually controllable humidifiers connected to an arduino mega. Each of the bottle is filled with different fragrances.
I ended up running into trouble with the plastic case, so I cut a new one from wood.
And the finished product:
Thailand Adventure Day 38
14 Jul 2015
Note the change of location!
While I was in Thailand visiting my friend there; I had the fortune of being
able to visit his family’s rice processing factory. They’re basically the
world’s largest Thai Jasmine Rice processing company.
That’s a lot of rice!
Unprocessed rice comes in like this.
Lots of random stuff mixed in…
The junk gets removed in big gravity sifters.
Look at that junk!
The rice is then polished…
An array of polishers.
Then, an electronic separator uses jets of air to eliminate non rice things.
This uses some fancy machine vision to detect rice/non-rice.
The finished products
Shown are two different grades of rice
There is also some cool stuff going on to make sure the rice is of the right quality.
Measures transparency, whiteness, and the milling degree to judge quality.
There were several other tests as well, including an amylose test.
Shenzhen Adventure Day 51
27 Jul 2015
Well, my travels in Asia are over. What better way to wrap things up
than to make tea ceremony with mom and take photos on a shenzhen-selfie stick.