Figure 1: Rows of completed circuit boards after assembly.

Explaining how and why a circuit board works is comparable to explaining the purpose of human anatomy or a plumbing system in a home. At first it looks like an overwhelming system of parts that is too complicated for someone to fathom where to begin. But when you trace back a single line and start identifying parts you already know, then the enigma starts to fade, and you’ll start to understand how most electronics work. If this is your first encounter with circuit board assembly, then let’s start with the base and then add on more details as we go - ironically, that is a vague explanation of how a circuit board is made; layer by layer.

The base level that the circuit is built up from is usually a type of rigid material, such as fiberglass. Next is at least one layer of copper, but the amount of layers and thickness of those layers depends on how complicated of a circuit board you will be creating. A soldermask is applied and then the boards are silkscreened with letters, numbers, and lines that make correctly assembling the boards easier for humans to read. Afterwards, the components get added to the board in a few different ways, and attached using solder. Surface mount technology uses a pick and place machine to connect components to the board. Some components are through-hole components that require jumper wires to lead through the circuit board. Hand soldering tiny components to the board may be the best option for small scale runs.   

Figure 2: Blank circuit boards ready for components. 

When assembling a circuit board, there are a few things you want to avoid. You always want a closed circuit. That means that the circuit will work because the electricity will be able to flow through the entire circuit and will continue to have a connection. Open circuits mean something has broken or is not connected to the rest of the system, so most of the time the system will then not work or can create more complications, like a short in the system. A short circuit can be caused by a disruption between low and high voltages, which can then cause overheating and components to not work.

With the decrease of cost and more availability of parts, circuit boards can add more functionality to a wide variety of products. Today, every industry is affected by circuit board technology. With innovations in the materials it takes to construct a circuit board, using flexible boards or stretchy batteries, Wearable technology is flooding the market with devices that can gather data about you and your surroundings. That’s where the connection between the technology we use throughout the day and the Internet of Things meet. We are wearing these devices that can pick up on pollution, how active you are, and a number of different things so that we can better understand our environment and ourselves. The important bridge is what we do with this information. The cool thing is that the advancements in technology allow us to better research ourselves without really thinking about it, and enjoying the convenience of having a mini computer in our pocket or on our wrists; smartphones having the same capabilities as most computers and smart watches mix aesthetics with functionality.

Circuit Board assembly has come a long way - from massive boards wrapped in wires to form the connections to slivers of copper-plated fiberglass with the same amount of abilities from the tiny components soldered in place. One development people are working on is more high-performance flexible circuit boards and data printed in 5D, or information laser written into glass, to protect the information forever. Considering the advancements circuits have made in the past 50 years, it will be interesting to see what innovations lay ahead.