Intelligence Inside: Layers Of Printed Circuit Boards

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Printed circuit boards bring a lot of wonders not only on how electronic devices work, but also on how they support electric components in performing their respective functions. Some people may actually think that, because of the simple appearance of these boards, creating one is easy.

PCBHowever, contrary to their appearance, printed screen boards are even more complicated than the normal looking motherboard, because it involves different essential parts, each of which being crucial to the functionality of not only the board itself, but also the components and the device itself. A person who wants to know more about the PCB must also know how it is made and what materials are being used to create it.

Printed circuit boards are like lasagnas- they are formed with different materials which are layered alternatively and are placed or laminated together with heat so that the end product will be a single object. The materials used in each layer may vary depending on the type of electronic device they support and on the size of such device.
The following are the basic layers of printed circuit boards:

1. Substrate

This is the base material of printed circuit boards. Usually made of fiberglass, this part gives these boards thickness, rigidity, and form (making them suitable for use in some electronic devices, such as tablets). When looking at printed screen boards, the substrate is usually the base part. It is also the thickest and the heaviest of all the layers of these boards since it is the layer that supports all the other layers.

2. Copper layer

This is the layer laminated to the substrate, and this can be attached either on one or both sides of the substrate. This is the part where all the conduction and transmission of electric current occurs. This layer is responsible for the transmission of signals to the components attached onto these boards. Also, this layer may indicate how expensive the electronic device is. The more copper layers it has, the more expensive it is.

Another thing to take note is that it is this part, and not the substrate, that is used in multi-layer boards. For instance, if a person is talking about a six-layer board, it means that such board has six copper layers, not six substrates.

3. Solder mask

This layer on top of the copper layer gives these boards the green color (or any other color, depending on the manufacturer). When electronic devices such as computers are opened, boards with green-colored surfaces have solder masks. This layer is placed on top of the copper layer to insulate the latter from contact with other metals and conductive bits. Because of its insulating capability, solder masks are where the traces of connections are drawn, and when they are overlaid on the copper layer, the copper traces appear.

4. Silkscreen

This is the white layer on top of the solder mask. This layer adds numbers, letters, and symbols to the printed screen boards so that people can easily assemble these boards. Of course, the silkscreen layer also emphasizes important details regarding proper board assembly.


A person who is well-experienced in handling printed circuit boards may label more layers and more parts. Nevertheless, it is essential to know these basic layers (as well as the electronic devices on which they are attached) because in troubleshooting boards, these layers are the ones being checked and repaired, along with the components that are attached to them. Understanding these boards means understanding how each layer works, and how these layers coordinate their efforts to produce that unique kind of intelligence associated with electronics.