As a requirement for my masters degree I am required to produce a project researching one aspect of media. I wanted to continue my work on the Button Masher while creating a new and interesting method of communication and programming. I wanted to have a system that wasn’t as large as the Button Masher but it was still as fun. I also wanted to have an open API to allow for users to program their own experiences if they would like.
As a starting point I wanted to find some existing solution for my buttons and LEDs as the headaches associated to created a homemade solution. Wiring was shoddy and it was really time consuming creating the actual board. I wanted to find something that was modular and would allow me to focus on the software and community aspect of the project.
To my luck I found exactly what I was looking for at sparkfun.com The product was called the Button Pad but the only issue was that they did not make this anymore. This was a let down but I knew there had to be a way for me to make these boards at home. I decided if I could make them on a PCB they would be much more stable and movable then if I made it by hand.
I started asking around if anyone knew about PCB fabrication service that was cheap and did short runs. To my luck I found this service called iTead Studio They provided really cheap prices on short runs of boards. It was only $25 for 10 boards the size of the button pad. Since the project was open sourced I was able to simply just download the eagle files off the sparkfun website, convert them to gerbers and then just send them to the company. A week later I got an email stating they were shipped and a few days later the boards were at my door.
The boards were perfect and it was now time to purchase the components I needed for the board. This part was challenging as I found out that getting specific chips in small quantities was going to be tricky. DigiKey and Fernell didn’t want to sell less then 100 and I only needed 10. I didn’t even know if the boards were even going to work. To my luck a quick search on ebay brought exactly what I needed to find. I found all my parts in 10 pieces and ordered them all for another $25.
After about 3 weeks everything arrived.
The next step was the solder mask. This was probably the biggest headache of the whole process. Professional companies use PCB stencils and solder paste in order to make attaching the individual chips and components quick and easy.
I found a link on Hack-A-Day suggesting you could just use ferric chloride like you would when making home made PCBs. By using too thick of copper my attempt at my first stencil was a failure.
Next I wanted to try something different. I had a CNC machine that I could use but I didn’t think it had the resolution for the small SOC32 packages. I tried first with some plastic thinking that it would be useful in testing my gcode and seeing if the CNC machine could do it.
Alright thats a bit better. This still wasn’t a useable stencils but I was getting close. The next attempt was going to be my last. I went to the hardware store and purchased some very thin Tin. I don’t know the exact thickness of it but it was less then 0.16 inches. Using this flat piece I was finally able to make a pretty professional looking solder stencil.