I didn't give up on the Roland CNC. Instead, I tried to make an SMD version of the simple 'Haunted Eyes' circuit for Haunted House.

As it turns out, it wasn't that simple to convert the through hole design to surface mount. After this experience, I think the future versions of this circuit I create will be through hole.

SMD Haunted Eyes

SMD Haunted Eyes

Part Value Package
C1 47uF Panasonic_D
IC1 LM555D SO08
JP1 LONGPADS 1X02_LOCK_LONGPADS
LED1 LED0603 LED-0603
LED2 LED0603 LED-0603
R1 2.2K 0603-RES
R2 1K 0603-RES
R3 47K 0603-RES

It was a good experience learning of all the advantages and pitfalls of SMD design and milling circuits. After the semester calms down I want to start work on a breakout board (for motor control & for LED control) for the LightBlue Bean Bluetooth module.

The milling process was successful, but I wasn't sure about the depth of the cuts. I was very careful to position the end mill. I had to run the dimension cut 3 times to cut out the board.

Circuit Design Final SMD
Circuit Design Final SMD

Tinning was an easy process.

Circuit Design Final SMD

And while tinning it was a good time to get that damn adhesive off.

Circuit Design Final SMD

Using the SMD station was okay, I found the suction system to be more difficult to use than tweezers.

Circuit Design Final SMD

When I first connected the circuit, nothing happened. Under the microscope I found a number of shorts. Including one under the capacitor. This was one of the worse off boards:

Circuit Design Final SMD

Circuit Design Final SMD

Working on the other three milled circuits I ran into different problems. It seems that often I applied far too much solder paste and often missed the connection between the pads when I placed the components.

My attempts to rework the connections resulted in some visually unpleasant boards.

Circuit Design Final SMD

Circuit Design Final SMD

In the end I got one working version out of the four boards I milled.

Circuit Design Final SMD

My eagle files, class presentation and bill of materials are available for download.

© 2017. Some Rights Reserved.

Ghostium Theme by @oswaldoacauan

Proudly published with Ghost