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Project Notes

#171 SMD Practice Boards

A collection of notes, kits and resources for hand-soldering surface mount devices

Notes

Through-hole and DIP components have historically made it really easy for the electronics hobbyist to hand-solder a project together.

These days it’s getting harder to avoid surface mount components due to

  • availability or cost of through-hole/DIP pacakges
  • or that some newer components may only be available in surface mount packages

One effective solution is to use a “module” if one is available. These are generally small boards holding surface mount chip(s) and supporting circuitry but provide pins or sockets for easy external connections. Although mainly geared for microcontroller market, there are many that are also relevant for standalone analog or digital circuits. An example is this CurrentSensorModule.

However as I’ve found, surface-mount devices can be quite easy to use in a hobby project even in the absence of a suitable module. The challenge kind of breaks down into two categories:

  • larger pitch SMDs which can quite easily be soldered with traditional techniques
  • small pitch SMD packages that generally require drag or reflow soldering techniques
    • e.g TSSOP/TQFP packages with a pitch of 0.80 or lower
    • magnifier and lots of flux! .. pretty much essential
    • I haven’t quite mastered this yet ;-(

To get started, there are some pretty cheap practice boards available, like this:

SMD Kit#2 test

Surface Mount Nomenclature

SMD Practice Kit #1

Obtained from a seller on aliexpress for under USD1 per board.

This is an example of a basic practice board

  • with 0603, 0805, 1206, SOT-23 and SOP-16 components.
  • After welding, it can be powered 7V to 15V and an LED will light up if all 0603, 0805, 1206 resistors and diodes soldered correctly
  • there’s no test circuit for the SOT-23 and SOP-16 components

Here’s the test circuit showing a pass on my practice board (yay! … though you can see I bodged the SOP16 a bit):

SMD Kit#1 test

SMD Practice Kit #2

Obtained from a seller on aliexpress for around USD2.50 per board.

This is an example of a pretty full-featured practice board with a wide range of components from 0402 to 1206 and SOP-8/16.

  • central feature is a classic 4017/555 strobe circuit - similar to the RingCounter project
  • all components are laid out in circuits with clear test points

parts and instructions

Here’s a quick video of the test circuit in action:

SMD Kit#2 demo

Credits and References

About LEAP#171 SMDCMOS555 Timer
Project Source on GitHub Project Gallery Return to the LEAP Catalog

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is just my personal collection of projects. Two main themes have emerged in recent years, sometimes combined:

  • electronics - usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting
  • scale modelling - I caught the bug after deciding to build a Harrier during covid to demonstrate an electronic jet engine simulation. Let the fun begin..
To be honest, I haven't quite figured out if these two interests belong in the same GitHub repo or not. But for now - they are all here!

Projects are often inspired by things found wild on the net, or ideas from the many great electronics and scale modelling podcasts and YouTube channels. Feel free to borrow liberally, and if you spot any issues do let me know (or send a PR!). See the individual projects for credits where due.