Art and Technology are Friends

Here’s how I do my SMD PCB assembly

I design a lot of PCBs, and assemble most of them myself. Small quantity PCB fabrication services have become so popular and abundant, I take full advantage of them.

Recently I use PCBWay a lot. Their pricing is close to the lowest (sometimes is the lowest), but the quality is still quite good. My favorite part of their service is that they offer different solder mask colors without extra charge. I don’t like green PCBs so this is a big plus!

For small boards for prototypes, batch based PCB service such as OSHPark still wins, as the shipping cost is much lower than from China. I use OSHPark for boards up to 2 sq inches, and PCBWay for larger.

Oh and PCBWay (and some other Chinese PCB fabs) offer stainless stencil for a very reasonable price. I can usually add one for $10 and it is very nice to receive PCBs and the stencil together.

Here are the photos from my typical PCB assembly using the nice stencil.

Step 1: Gather All Materials

Step 1: Gather All Materials

Clear your work area and gather all components, material, and tools. Preparing the organized BOM printed helps to reduce errors.

Step 2: Frame the PCB and align the stencil

Frame the PCB and align the stencil

I use squares made of fiberglass to secure the PCB to the desk. Then overlay and align the stencil on top, and secure it with a piece of masking tape.

View from the top

Compared to¬†Polyamide (orange plastic film) stencils, stainless stencils are easier to align to the PCB. The pads kind of “snap” into place.

Step 3: Squeegee time

Ready to stencil

Now it’s time to spread some solder paste onto the PCB. Use plenty of paste and pull the squeegee at a steady speed.

Here the stainless stencil really shines, as the paste spread very smoothly without effort.

Solder paste printed

(Ok, I could’ve done a better job, but…)

Step 4: Ready to Pick & Place

Solder paste printed

Now the PCB has solder paste beautifully printed on, I’d get busy placing components.

Step 5: Ready to Reflow

Ready to reflow
Here the boards have all the components placed and ready to reflow. Sorry I forgot to take photos during the pick & place process.

I use a small reflow oven to reflow PCBs.

 

 

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