Printed circuit boards are boards that support the wiring in most electronic devices like beepers, pagers, radios, and computers. You will recognize them easily as most of them are colored green, although other PCBs come in different colors. Simple electronic devices only have one layer, while complicated devices can contain up to 12 layers. An example of a complicated PCB is a motherboard of a computer.
Designing a board that fit into industry standard specifications can help companies keep down the cost of their end products and increase its long term reliability. That means customers will keep coming back.
The Types of Printed Circuit Boards
Single- Sided – Simple electronic devices use a single- sided board. All of the components of these electronics are found all on one side.
Double- Sided – If the components are too much for a single- sided board, they make another board for the other components. The electrical connections on each board are connected by drilling holes in the surface and covering it with a conducting material like metal.
Multi- layered – Devices with complicated components require a multi- layered PCB. They are made up of layers of printed circuits that is connected by plated holes.
How the Components inside the Circuits are Connected
Through Hole Technology – With the Hole Technology, the components contain thin wires pushed through a small plated hole in the surface. They are then soldered to pads on the other side of the circuit either manually or by the use of automated machine.
Surface Mount Technology – With the newest technology, L-shaped or J-shaped legs on the components are directly placed on the surface. This technology saves a lot of time and costs.
Manufacturers today use both of these technologies.
The Structure of a Printed Circuit Board
FR4 – The surface or what they call the substrate, is made of a fiberglass. It is also known as simply FR4. This material gives printed circuits board its thickness. There are also cheaper per boards like the phenolics and epoxies. They do not have the durability that FR4 offers. You will know these kind of materials when you smell them. They smell really bad. Also, they are mostly found in low-end electronics.
Copper – Found on the next layer is the copper foil. It is usually laminated to the board. They use adhesive and heat in laminating the cover. On industry standard PCBs, the copper foil is found on both sides. Electronics that are priced lower only have copper on one side.
Try to avoid lower-end electronics as it doesn’t last longer. PCBs with higher power use more copper compared to a standard PCB.
Solder mask – Most of the PCBs you’ll see are colored green. The solder mask, which is found on top of copper gives printed circuit boards its green color.
Silkscreen – This is needed to better understand the board. The silkscreen, which is applied, on the solder mask layer, add numbers, letters, and symbols to the board to make it easier to assemble. Silkscreen color is white, but you may still use other color like black or gray. What’s important is it can be seen in the board.
Printed Circuit Boards can be complicated for people not familiar with the product. If you use an electronic device and you want to know how that thing works, check its PCB. Just an important reminder though: if you are not at all familiar with the components of a printed circuit board, try not to touch anything if you still want your electronic device to work.
Some boards are very sensitive. What you can do is just take a look at it and be amazed at how such a little thing could give life to an electronic device.
Printed Circuit Boards can be complicated for people not familiar with the product. If you use an electronic device and you want to know how that thing works, check www.pcbnet.com.