How to Select FR4 Thickness

How to Select FR4 Thickness

When ordering a laminate board for a PCB project, the designer or electrical engineer must specify the FR4 PCB thickness. This is measured in inch-based units, such as the thousandth of an inch, or thou, or millimeters, depending on which is most appropriate for the setting. The thickness of a sheet of FR4 ranges widely depending on the needs of the project, but it tends to range from ten thou to three inches.
While board thickness may not seem like a significant factor in the design of a PCB, in reality, it is an essential feature. Board thickness affects several aspects of the board’s functionality, which is why several factors are considered in determining the thickness of a board for design. These include the following.To get more news about fr4 board, you can visit pcbmake official website.

Space: Thinner May Be Better
If space concerns the designer, a thinner FR4 board tends to be preferable. This is a predominant factor for the manufacture of smaller devices, like USB connectors and many Bluetooth accessories. Even for larger projects, smaller FR4 PCBs tend to be favored to save space within the device.

Connections: The Wrong One Could Result in Damage
A two-sided PCB design requires an edge connector to join the two sides. This can be a major limiting factor for the final size of the PCB since PCB edge connectors only fit a particular set of PCB thicknesses. The mating portion of a connector has to fit snugly on the side of the PCB, or else risk slippage or damage to the PCB. This is one of the primary reasons why circuit design comes before choosing materials for the circuit.

Impedance Matching: Essential to Maintaining Board Function
Every multi-layered board acts as a capacitor on adjacent layers. This is why the thickness of this board is so important — the thickness of the PCB FR4 determines the thickness of the dielectric, which in turn affects the value of the capacitance.
This is an especially key factor for some high-frequency PCBs, such as RF and microwave designs. High-frequency designs focus on impedance matching as an essential component to maintain optimal board function, so getting the right capacitance for each layer is crucial.