Building the ELM329 CAN Device - Part II

So I finally had (made) some time to finish the front side of the first ELM329 pcb. The process is basically identical to the back-side where I used a stencil to apply solder paste, then place the components (obviously making sure the polarity is correct for diodes/LEDs etc), and toss it into the toaster oven. This side was a little more work actually since it had a few more components, and it had some 'odd' components such as the USB Chip that has all the pins connected underneath etc.

Paste Applied and Components Placed

When it was time to put the pcb in the toaster oven I took two pieces of aluminum foil and roll them up to make little 'offsets' to place the board on. This way the rack wouldn't be touching the components that were on the bottom side and possibly disturb them.

Sitting on it's 'fancy' mount

The problem components were the 2 aluminum caps which you can see in the above picture being closest to the front. They were not very stable and one even fell off in the oven! While they may be a LOT cheaper than the Tantalum caps, I'm tempted to switch back to those since they don't seem to be that wobbly. You can even tell in the picture that they are leaning.

The baking seemed to take longer than last time, but keeping a keen eye on it, eventually the solder paste started to reflow. The voltage regulator took the longest, probably because it has a large heatsink area. At first glance everything seemed OK, But i'll have to take closer look with a magnifier to make sure everything flowed the way it was supposed to. Of course as soon as I turned off the oven and opened the door a little whisp of smoke came from 'somewhere' so who knows what I fried...

Fresh out of the oven - Hmmm tasty!

After letting it cool down I manually soldered the header pins in place (1x for OBD and 1x for USB). Now I just need to finish up the USB cable so I can test it out and see if I screwed up anything beyond repair. Also the bottom-side components stayed neatly in place so with some tweaking this method of making PCBs is definitely viable.

Lastly here are a few more pictures of the unique soldermask color.. depending on the light it looks either purple or blue-ish (mostly purple though)

It's Purple!

No it's Blue!