Setting up an SMT Assembly Line

The LumenPnP solves one part of making your own PCBAs, but there's more to the process than just placing parts! In this article, we'll show you what you need to set up your own SMT line. 

Solder Paste

The first step in getting your boards populated is applying solder paste. There are a vast array of different kinds, but there are two that are a great starting point:

This paste is excellent. The "GC" in its name literally stands for "game changer," and for good reason. It's a bit more expensive, but greatly reduces the chance of bridging or cold joints that saves hours of rework time. This is what we use at Opulo for all of our boards.


Chipquick Solder Paste

This paste is a great starter choice. It is "low temp," meaning a smaller or less powerful reflow oven should be able to handle reflowing it without an issue. 

Solder Stencil

As for your stencil, we find that the stencils you can get made at your board shop are excellent quality, and work great for a mid-scale line. We get our stencils from PCBWay.

Getting your stencil "framed" means the steel stencil is mounted on an aluminum frame, which makes it much easier to use. We highly recommend the "Electropolishing" finishing option, as it's only a few dollars more, and makes the paste release from the stencil much easier.

Electropolishing option when buying a paste stencil

For accurate and repeatable paste application, you'll also need a paste printer. A paste printer is a jig that perfectly aligns your stencil to your board in a repeatable manner, making it really easy to line everything up.

3040 Solder Paste Printer

At Opulo, we use a few 3040 Solder Paste Printers, and they work excellently. Once they're set, they hold their alignment well.


The LumenPnP is a workhorse for SMT population. After configuration, it's just a matter of placing your pasted board onto the machine, hitting "run," and letting the LumenPnP populate your board for you.


LumenPnP Desktop Pick and Place

The LumenPnP can populate passives as small as 0402, at up to 1200 chips per hour. It's capable of placing large ICs as well, including TQFP-100 chips with 0.5mm pitch leads, and even QFN parts with 0.4mm pitch pads.

No pick and place is complete without feeders. The LumenPnP feeders automatically serve up components to the vacuum tip of the pick and place, fully automating SMT population.

LumenPnP 8mm Feeder for Desktop Pick and Place

LumenPnP 8mm Feeder

There are variants of the feeder for both 8mm and 12mm tape, supporting the vast majority of components.

A pick and place is the beating heart of an SMT line, so it's critical that you have a reliable, precise machine that you know is producing accurate placements.



Making many improvements to its predecessor, the T-937 is a fantastic reflow oven that can reach up to 350 Celsius, supporting practically every type of solder paste. We've tried many reflow ovens, and this model has all the non-negotiable features at a reasonable cost.


The Controleo3 is a great reflow oven with a small form factor. Based on a standard toaster oven, this machine is smaller and gets to temp quicker than other options. The Controleo3 is a stable and reliable design that's been around for many years.

Wrapping Up

With all your components placed and soldered, you can perform any quality control checks, programming, and functional testing for your board.

We hope this helps illustrate how you can easily assemble your own boards in-house! If you have any questions about this process, or would like more information about getting started, please feel free to email us at