How to Choose the Right PCB for your Project

There are many types of PCBs on the market. The challenge is choosing the right type for your application. Keep reading to learn how to choose between the most common types of PCB.

Types of PCB

The types of PCB include single layer, double layer, and multilayer, all of which can be produced in a variety of thicknesses. Manufacturers also differentiate PCBs based on the rigidity of the substrate. This differentiation is the first thing to consider when choosing a PCB.

Flex PCBs

Building circuits with a flexible substrate provides a number of advantages. As a result, the industry trend is moving toward flexible PCBs. A big reason for this migration is the fact that OEM typically want to make their devices as small as possible, and flexible PCBs help them achieve that goal by using 3D packaging.

Flexible PCBs consist of conductive circuit patterns on a thin Polyimide or other insulating polymer film. Typically, you’ll find a similar film, or used to protect the conductor circuits.

You would use a flex PCB design in the following applications:

  • You are tight on space. Of all the types of PCB, flexiblePCBs can produce the smallest package size.
  • You need a circuit board to bend to your requirements. Only flex PCBs can bend to allow for the smallest types of devices, they bend up to 360-degrees.
  • You need high tensile strength.A flexible PCB can be bent or formed without damaging it.
  • You need a high level of design freedom and installation flexibility.Flexible PCBs can assume a variety of shapes.
  • You need a high level of reliability and durability.Flexible PCBs are more reliable than other types of PBCs, in part because the boards contain fewer interconnects.
  • Your application will generate heat. FlexiblePCBs do an excellent job of surviving in various temperatures, and you can achieve better airflow and thermal dissipation, with or without a heatsink.
  • Your application will expose the components to shock and vibration.Flexible PCBs tolerate vibration better than other types of PCB.

 

Here are some examples of typical flex PCB applications:

  • Consumer electronics.Keeping up with the top speeds that computers use to write data is easier with flexible PCBs. They also withstand the heat of a disk drive that gets hot when used for long periods. Other applications include printers, televisions, and gaming systems.
  • Automotive electronics. Automotive engineers enjoy the ability to fit flexiblePCBs into small and oddly shaped spaces. They’re also popular because they can withstand the heat generated in the engine compartment, and the vibrations while driving.
  • Smartphones. As consumers demand more capability in small hand-held devices, flexiblePCBs help engineers meet that challenge.

 

Rigid PCBs

These PCBs use a solid substrate, or rigid board, meaning that the PCB won’t bend or twist. A common material used for the PCB is FR-4, a fiberglass-epoxy laminate that is flame resistant. Other PCBs may use Teflon, ceramics, and polymers.

You would use rigid PCBs most often in applications where components are fixed and must stand up to application stress and high temperatures.

Here are some examples of typical rigid PCB applications:

 

  • Industrial electronics.Industrial uses for Rigid PCBs include robotics, gas controllers, surge suppressors and pick and place equipment.
  • Aerospace:Aerospace applications often include using copper and aluminum substrates and high temperature laminates. Examples include cockpit instruments, temperature sensors, and control tower instruments.
  • Medical:The medical industries use many flex PCBs, but large and stationary equipment such as MRI systems often use rigid PCBs.

 

The Middle Ground: Rigid-Flex Design

When engineers need the properties of both flex PCB design and rigid design, the rigid-flex PCB is the solution. Typically, these boards have conductors on both the flexible and rigid layers in a multiple layer design. A common use is for applications where there are components mounted on both sides of the rigid section, and flexible areas needed for 3D packaging.

 

Final Thoughts

Today’s printed circuit boards are the result of many inventors contributing to PCB design, starting in 1903 with Albert Hanson. Projections show the PCB industry going from 63.1 billion in 2017 to 76.9 billion by 2024. Keeping current on the various types of PCB in this changing market will help you make your projects a success.