A lot of people who are new to electronics often find themselves intimidated by soldering and working with printed circuit boards (PCB). You needn’t be. Circuit boards are not nearly as fragile, “high-tech,” and complicated as they superficially appear. The process of working with them can be very straight-forward, as long as you follow some simple preparations, procedures, and precautions.
We’ve covered the basics of soldering countless times here on Make:, so we won’t touch on that here. What follows is a collection of tips and tricks for working with PCBs beyond just soldering the components (called “populating”) onto the board. Some of these are basics that are too often missed, others are more advanced trickery. Hopefully, they will all be helpful, whether you’re a newbie or a seasoned wirenut.
Organizing, Sorting, and Planning Are More Important Than You Think
When you first get into electronics and start putting together kits, those kits usually come with a components check list and each step in the build process is designed to be ticked off as you progress through the project instructions. You are always highly encouraged to inventory all of the parts in the kit before you start and to mark off each step as completed. This is a great habit to never get out of. A lot of the perceived complexity of electronics work is thanks to lots of tiny little parts to track and dozens (and dozens) of solder joins to lay down onto a tiny and over-populated PCB. By just being careful, methodical, and organized, you alleviate a lot of the problem. Taking the time to set up a PCB project, inventorying and sorting the parts into temporary parts bins or bags, reading through all of the instructions, and sort of blocking out the build in your head will all pay off in the end.
Give Your Boards a Bath
When you first get into electronics, it seems counter-intuitive that you have to expose your circuits to cleaning solutions, but cleaning your PCBs should always be part of your circuit-building regimen. And you want to clean the board before you populate it and after. Make: contributor Ross Hershberger writes: “Cleanliness is next to solderliness. Freshly scrubbed copper takes solder with less heat and wets more thoroughly, so always scrub or otherwise de-oxidize your boards before soldering. I use isopropyl alcohol and a fine abrasive like a Scotch Brite. Or a pen eraser followed by alcohol. For bad corrosion, use a glass fiber “pen.” Steel wool may leave fibers that can cause shorts.” Here’s a brief piece on Maker.io about options available for board cleaning, but in the end, for most of us, it comes down to using rubbing alcohol and the exes’ toothbrush.
Populate Lowest to Highest
PCBs can be very tightly populated on a board and can soon become very crowded, leaving you with little room for getting your components, your iron, and your solder wire to the area where they are needed. One way of improving your board-soldering mojo is to plan how you’re going to populate the board beforehand. Solder on your components, across the board, starting with the lowest (usually the resistors) and moving up. That way, big components won’t get in the way when you’re trying to install low-lying ones right next to them.
Use a Pair of Tweezers
Get yourself a pair of electronics tweezers. Even if you’re not mainly working with surface-mount components, which are tiny enough to require such tweezers, adding through-hole components to the board is much easier with tweezers than trying to get parts in place with your fat and meaty end-effectors.
Use a Component Lead Tool
Component lead bending tools, often branded by a supplier and given away as swag, are a great little addition to your electronics toolbox. Along with pre-planning and organizing, having the discipline to keep your circuits neat, tidy, and tight to the board, will pay off in the end. Precisely bending component leads to the proper lead width can help in that process.
Use a Loupe or Magnifying Glass
For successful PCB work, especially troubleshooting soldering issues like cold joins and solder bridges, you will need some form of magnification. Always have a glass, jeweler’s loupe, or magnifying visor on hand to inspect your work as you go.
Use Poster Putty as Helping Hands
One of the great underutilized uses for poster putty is as a holder for small objects while working on them. You can use it in place of conventional helping hands tools in electronics assembly. You can press PCBs right down into it and it won’t usually leave any visible residue. You’ll obviously want to clean your board afterwards, but you would do that anyway. Once you start incorporating the use of this material into your electronics workflow, you’ll likely find yourself grabbing it over the hands in many situations. [From 5 Fantastic Uses for Poster Putty.]
Steady Your Headers in a Breadboard
Here’s a great trick for making sure that you solder your header pins straight and square onto a PCB. Use a breadboard to hold the pins in place while you soldering them onto the PCB. Insert the header pins into a breadboard and then align your circuit board on top. Slot the pins through the PCB holes and solder as normal.
Glue Your Stand-Offs
We love this little hack, which comes from former Make: contributor Matt Mets. Glue down your hexagonal aluminum standoffs inside your project box to make a quick, removable mount for a PCB-based project. First off, attach the stand-offs to the PCB using screws, as normal. But instead of drilling holes and screwing the other ends of the stand-offs to the project box, glue them into the bottom of the case. Now, if you ever need to swap out the board, just unscrew it! The glue is sturdy enough (for non high-vibration applications) to be functionally permanent, but the stand-offs can also be removed (rubbing alcohol de-bonds hot glue) if you decide you want to re-purpose the box.
Use Hot Glue as Insulation and More
[From Darbin Orvar’s Awesome Hot Glue Hacks.]
Hot glue can be used as an insulator on PCBs and many other electronic components. You just want to avoid using hot glue on thermally sensitive parts or components that produce a lot of heat. You can use hot glue to insulate desired components, secure wires in place, provide strain relief, to seal, and to waterproof.
Here are a few additional tips taken from a discussion I started on my Facebook page asking friends for PCB advice.
Plan Your Enclosure First
[From Chris Akiba Wang] A lot of people jump directly to the PCB. The first thing I do when approaching a printed circuit board is to think about the enclosure. Any product that you want to look decently finished or professional needs an enclosure. Choosing an enclosure requires that you think about the end user and how your product will be used by them. Is it portable, does it need to be waterproof? Low cost? etc. The enclosure you then choose will put boundaries on the PCB size and shape. Once that’s selected, then you can go to town on the board itself.
Cutting PCB Fiberglass
[From Windell Oskay] If you need to physically cut fiberglass (FR4) circuit boards, avoid using tools like saws or rotary tools– the fiberglass is very hard on your tools and produces hazardous dust. A shear is the right tool to use. Heavy duty tin snips or bolt cutters can be used, with relative ease and precision.
There are obviously many other dimensions to working with PCBs that we didn’t cover here. SparkFun has an excellent introduction to PCBs which will fill in many of the other basics and offer additional tips.
[Thanks to everyone on my FB page who contributed to this discussion.]