DIY Surface Mount Board Beginner

Hello! I’ve used arduino and now teensy for a while and I’m looking to delve a little deeper in! I’m wanting to design my own PCB with a Teensy microcontroller directly built in but I’m not even quite sure where to start! Mostly for the microcontroller and bootloader boards themselves. Is it a good idea to just follow the schematics posted for teensy to get them all connected correctly? Any references or advice would be most welcome! Thanks!
 
You have a pretty steep learning curve ahead. I suggest you start with something a lot simpler than a BGA package. Assuming you want to do surface mount, you could look at doing SOIC packages, 805 Rs and Cs. The Atmel ATTiny chips are easy to work with. Once you get a couple of simple boards under your belt, tackling a complex one is a lot easier.
 
Oh and as far as the soldering goes I was going to try my hand at reflow soldering with a heat gun, from what I can tell that might only take me 1 or 2 (or 10) tries to hopefully get an acceptable result!
 
I suspect a heat gun is not going to be a good experience, you need accurate temperature control and
low airflow speed, or all the little parts are blown off the board.

Hot air rework stations have low speed air pump and the nozzle has a thermcouple right at the outlet
to get fine temperature control.

However for actually making boards a reflow oven is a good technique, whole board done in one go,
with least mess. I use an adapted sandwich toaster, works very well - I moved the heating element
at the bottom to alongside the one at the top, which turned out to be fairly straightforward.

Note that you need soldermask on a PCB to use a reflow oven reliably, bare copper traces do not absorb
IR radiation so the groundplane will be slow to heatup.
 
I'd look at the thermal relief stuff in particular. I know way too many people who have cooked components (especially fuses) because they didn't think about that.
 
Thanks! I think I found a good board to reference that he linked to on the page for his bootloader chip here! It looks more we’ll documented than Paul’s schematics.

https://github.com/thewknd/teensy-boards/tree/master/Teensy 3.2 reference board clone

That's a good board to start with. All of the packages have leads, which makes visual inspection and re-work possible. I recommend using a stencil with solder paste and a toaster oven to assemble a board like that. OSH Stencils is a good source of stencils, jigs, and paste. I would recommend trying a 4 mil stainless, frameless stencil and lead paste. Use the jig and stencil to apply the paste to the board. It should apply cleanly with paste only on the footprints. Use a good pair of tweezers to set parts on their footprints and place in the toaster oven. I like to cook it around 250F for about 6 minutes to get everything warmed up before stepping the temperature up to 450F for 1 to 2 minutes (I start a timer after the toaster oven has reached 450F). You should visually inspect the board for bridges before powering. A good soldering iron and wick can be used to clean any bridges that are found.
 
nolansneeder,
I think I was where you are about 2 - 3 years ago.
I designed a board with all of the interface circuitry (12V to 5V stuff, signal conditioning, 232 TTL to transmission level, LED drivers, etc...) on a SMD board, but put the Teensy on as a through hole component (along with DB9/15/25 connectors, etc...) that's added after I put the SMD components down.
I use Upverter with great success (upverter.com). Design board, send of to OshPark for a PCB and Digikey for components (or PCBWay in China for a complete PCBA - stuffed).
I got a small $11 hot plate that can do a 2" x 4" PCBA reflow quite well. I also get the stencils from OshStencils...

I've made boards that I would be happy buying from a professional source, at home. My projects have been system monitors for an RV, and my latest is a 30 channel data acquisition / display system driving a 3.5" touchscreen display that I use in an experimental 200+mph airplane. I've been flying with this for 100+ hours of flight time so far with great results. (simple, 2 layer PCB use in the above system. There's a second board and Teensy 3.6 that goes next to the engine that talks to the board above via RS232 that collects temperatures, pressures, etc... in the engine compartment.
PXL_20220617_203203338.jpg
PXL_20220617_203151676.jpg

These Teensy's are AWESOME, and I'm a hack at best so to be able to build things like this at home, Paul has given us a huge foundation to build some awesome projects. I may, in the future, try to do as you are suggesting and build the Teensy functionality right into my board, but I've got some learning to do before I try that. Taking the smaller step of installing the Teensy onto a PCBA was a great step for me before going further, and it gives me some awesome functionality easy.

I might even consult with an electrical engineer who knows something about laying out PCB's.
 
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