Learn all about different types of PCB(Printed Circuit Board) – Single Sided PCB, Double Layer PCB, Multilayer PCB, Rigid PCB, Flex PCB, Rigid-Flex PCB.

A PCB (Printed Circuit Board) or PWB (Printed Wiring Board) is a complex circuitry of copper tracks on a heat resistant material called PCB substrate. Electronic components are soldered on this Circuit Board to control flow of electricity in a preset matter for the electronic device to work in a manner that it was designed for.

Single Sided or Single Layer Types of PCB

Single Sided PCB is the simplest low cost PCB or printed circuit board. These types of PCB has only one single layer of the base substrate (Fiberglass) and one single conductive (copper) layer. Holes for electronic components are generally not plated through. Layout for the electronic components is on one side and the conductive circuit is on the other side. Since, there is only conductive layer forming the circuit, it is called single sided PCB or One Layer PCB or Single Layer PCB.

Double Sided PCB or Double Layer PCB

These types of PCB have one single layer of the base substrate but conductive (copper) layer on both sides of the substrate. Solder mask is applied on both sides of the board.

Holes for electronic components have to be plated through for conductivity on both the circuits. Conductive holes in the PCB allow circuits on one side to attach to circuits on the other side. Electronic components are soldered on both sides. Both through-hole electronic components and surface mount components (SMD) can be soldered on either side of this type of PCB. SMD components can be soldered with surface mount technology. Since, there are two or double conductive layer forming the circuit; it is called Double Sided PCB or Two Layer PCB.

Multilayer PCB

Multilayer PCB is a Printed Circuit Board with more than 2 layers. These types of PCB must have a minimum of 3 conductive layers of conductive material or copper layer. All the layers are interconnected with copper plated holes. The layers can be 4, 6, 8…upto 40 layers.

All the active and passive electronic components are assembled on top and bottom layers. All the inner stacked layers are meant for routing. Both through-hole electronic components and Surface Mount Components (SMD) can be soldered on either side of this type of PCB. SMD components can be soldered with Surface Mount Technology and other PCBA tools. 

Rigid Printed Circuit Board

We all know that a PCB can be Single Sided PCB, Double Sided PCB or Multilayer PCB. At the same time a PCB can be Rigid, Flexible or Rigid-Flex (Combination or Rigid and Flexible PCB). Rigid PCB is Solid, inflexible Printed Circuit Board.

So, Rigid Circuit Board is a PCB that we cannot bend or force out of shape. It is not flexible. A Rigid PWB can be Single Sided, Double Sided or Multilayer. Once a Rigid Circuit Board is manufactured they cannot be modified or folded into any other shape.

Flex PCB or Flexible Printed Circuit Board

Flex PCB is also called Flexible PCB or Flex FPC or Flex circuit or Flex Print or Flexi Circuits. As the name suggests, these Flex PCB are flexible and can be folded and are not hard as Rigid PCB. Flexible material and shape helps easy handling and transportation of these Types of PCB without any damage. A Flex PCB can be single sided PCB, double-sided PCB or multilayer PCB.

The substrate of a flexible board is made of flexible plastic (thin insulating polymer film), polyimide or a similar polymer or Kapton. Conductive copper circuit is printed on this substrate and a protection coating of thin polymer is applied to protect the circuits. The copper tracks have component layouts. Generally SMD Components are soldered on a Flexible PWB using Surface Mount Technology (SMT).

Rigid Flex Printed Circuit Board

Rigid flex PCB is a hybrid combination of a Rigid PCB and a Flex PCB. Most simple form of a rigid-flex printed circuit board consists of a rigid circuit board joint to a flexible circuit board.

Rigid flex printed circuit board consist of both rigid and flexible substrates that are laminated together to form a single circuit board. Double sided or multilayer Rigid Flex Circuit Boards are interconnected by plated through holes (PTH).

Different Types of PCB Material

PCB Materials for Base of a Printed Circuit Board can be Resin Based, Fiberglass Based, Epoxy Glass, Metal Board, Flame retardant (UL94-V0, UL94-V1).