Soldering vs. breadboard layouts
March 22, 2019 • article
Wires are the veins of any circuit. Nowadays most circuits are built using printed circuit boards (PCBs), and what used to be wires has become lanes of copper on a carrier board. This technique is quite involved and rather complicated: the circuit has to be designed, then converted into a PCB layout, and then it is etched out of a copper sheet. In modern PCBs there can be multiple layers (2,4, or even more) and the size of PCBs ranges from a few mm2 to desk-size. It sure can be intimidating as an electronics enthusiast to see these works of art!
The sheer number of lanes is mind-boggling! Compare this to an old-fashioned electronics construction from the 1950s:
As electronic hobbyists we can probably relate much more with the second image ;-) But nowadays it is possible, even for hobbyists, to design our own PCBs! Designing a PCB like the one shown above is perhaps still a bit too much to aspire, but it is quite straightforward and surprisingly easy to design your own PCB nowadays.
Needless to say, modern PCBs require you to solder the components into place. There is another option in the shape of so-called perf boards or prototyping boards: These are PCBs that come with pre-drilled holes that have a copper contact pad around each mounting hole. The typical spacing for these holes is 2.54mm which fits most through-hole-technology (THT) components (but be careful with surface-mount devices, SMD, they usually don't fit). Here you can see a few such perf boards:
These perf boards is what many hobbyists use for creating prototypes of their projects, and more often than not, this will be the only way, shape, or form that their projects sees the light of day ?? But it works, and I have used perf boards for most of my homemade projects. They are simple to use, perhaps a bit costy, but they are a healthy compromise between a PCB and a flywire construction on your kitchen table. Here you can see a typical perf board construction:
But, as I said above, with a perf board you have to know how to solder. What is the other alternative? Well, we mentioned it last week's blog post: you could use a breadboard. Breardboards are reusable, not terribly expensive, and they are designed to work with standard 2.54mm THT components (just like perf boards). Here you can see a typical breadboard setup:
The big question: what is right for you? When you start electronics, is it better to get a couple of perf boards and solder? Or should you rather stick to breadboards and hold off with the soldering for a while?
In the following I have complied a list of pros and cons that I can think of and that may help you to make your decision. Let me know in the comments if I forgot anything important!
- The electrical connection is always guaranteed (provided you know how to solder).
- The electric connections are very rigid: even small vibrations of the PCB do not lead to problems down the road since wires don't come loose easily.
- Soldering components on a perf board is very space-efficient. A breadboard that has the same functionality is typically larger. If space is a concern, choose a perf board and solder your components into place.
- With perf boards (and, of course, with custom PCBs) it is possible to use advanced layout techniques. What do I mean by that? When you build circuits that use radio frequency (RF) or if you are building switch-mode power supplies that work in the kHz domain the routing of cables is important. In particular, huge wire loops can be disadvantageous for the efficiency of your circuit. With a perf board (and with a custom PCB of course) you have more flexibility to route the wires exactly the way you want.
- The connections are more permanent in nature. Sure, you can always try to desolder a component, but for some components this is very difficult, if not impossible. For integrated circuits (ICs) I recommend using sockets so that you can easily remove them later. Still, a soldered component can be a headache to extract, so think about it before committing to a design choice :)
- Designing and manufacturing a custom PCB can be very time-consuming: either you manufacture it at home (which is possible, but you need supplies) or you order it online. Either way, you have to wait and cannot just go ahead and tinker. Alternatively when using a perf board there is no delay. But keep in mind that perf boards and custom PCBs are single-use items and therefore difficult to repurpose for a different project in the future.
- Soldering can be difficult for beginners and may keep you from achieving some first success. Keep it in mind :)
- Rapid prototyping is possible, it only takes a few minutes until a circuit is completed. You have an idea? Quickly take it to the breadboard. By the time your hypothetical soldering iron is heated up you will already be finished with the main part of the circuit!
- Breadboards are beginner-friendly because they are cheap and easy to work with.
- Breadboards are eco-friendly because they can easily be disassembled and used for the next project.
- The amount of special equipment and tools is minimal. It does not take a lot of tools to get started with a breadboard.
- Breadboards do not fit all devices: for some ICs or more specialized components, special adapter PCBs are needed that break out the pins of that component in the 2.54mm spacing required by breadboards.
- The circuits can become a bit messy and hard to understand due to a myriad of cables and wires. Therefore breadboards are typically best used for simple circuits; if there are too many connections, consider spreading the circuit out into functional blocks on multiple breadboards.
- The electric connection is not always perfect: small vibrations can lead to wires getting loose over time, so always double-check your connections.
The bottom line
In the end of the day, you need to decide. I have a few general guidelines that I like to follow:
- Is it a permanent project you want keep using?
- Does it have to be small and fit in a constrained area? Then use a perf board and solder.
- Is it a small experiment where you need to keep changing components? Is it something you want everybody to be able to build themselves with minimal effort? Choose a breadboard instead!
As always, I am eager to hear your opinion on this! What is your approach to the soldering-vs-breadboard debate? Let me know in the comments!