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With many uses including automotive, medical, defence, space and more; there are numerous different types of printed circuit boards that are classified according to their design specifications, manufacturing processes and application requirements. Other designs for PCBs are manufactured to meet consumers’ needs.
Each PCB is a self-contained board with connected electronic and electrical components – used in various devices including computer systems, pagers, radios, mobile phones, radar systems and many more.
The circuits are created by depositing a layer of conducting material, the substrate, on the outside of an insulating board. Separate components on the surface of the substrate are soldered to the connected circuits. The PCB’s components are connected to the circuits, either by through-hole or surface mount technology.
Before choosing a PCB for a particular application, consider the space required, its stress handling properties and its electrical and mechanical stability, along with the working temperature for electronics that work in harsh environments.
Single-sided PCBs
The most common type of printed circuit board is the single-sided PCB, manufactured with one copper conductive layer above the substrate. The electrical components are placed or soldered on one side of the board. The whole circuit is visible on the board’s other side. Conductive paths can’t overlap or intersect, so they take up a lot of space.
This type of PCB is best suited to basic and low-cost electronic and electrical instruments such as power supplies, calculators, LED lighting boards, timing circuits, FM radios and so on. Simple to design, they are cost-effective – suitable for low-density designs and easy to repair if something goes wrong.
Double-sided PCBs
A double-sided PCB has a thin layer of a conducting material, usually copper, applied to both sides of the board. Small holes in the circuit board enable the metal parts to connect from one side to the other. This type of PCB can use either through-hole or surface mount technology.
A double-sided PCB is used for many different applications including mobile phones, testing equipment, power monitoring, HVAC applications, amplifiers, UPS systems and more. With several advantages, including being more compact than their single-sided counterparts; they can be made at a relatively low cost and are flexible.
The increased circuit density means they are suitable for advanced electronic systems.
Multilayer PCBs
A multilayer PCB has more than two copper layers. This category normally includes any board with at least three conductive layers. Manufactured in a “sandwich” style, using numerous double-sided conductive layers and an equal number of insulating material sheets; they are bonded and laminated together, at a high temperature and pressure, to eliminate any air gaps, ensuring the final PCB is extremely stable.
The multi-layer PCB is used for more complex applications such as laptops, computers, tablets, mobile phones, medical equipment, GPS trackers and other devices. A more compact in size, they are robust and flexible, making them suitable for high-speed circuits.
Rigid PCBs
A rigid PCB can’t be folded or twisted. The base material of the PCB is a rigid substrate, giving it greater strength. It is composed of multiple layers, including copper, substrate, solder mask and silkscreen layers. These are all adhered together with heat and an adhesive. A rigid PCB can be single or double-sided, or multi-layered.
They are used for GPS equipment, laptops, computers, tablets, mobile phones and control tower instrumentation. They are also used for complex medical devices including X-rays, CAT scans, heart monitors, MRI systems, temperature sensors and more.
Low noise, they are cost-effective, lightweight, compact, easy to repair and absorb vibrations.
Flex PCBs
A flexible printed circuit board is made up of many components and printed circuits arranged on a flexible substrate. This type of PCB is commonly made from PEEK (Polyether ether ketone) polyamide, or a transparent conductive polyester film. These PCBs are manufactured from the same components as rigid printed circuit boards. However, they are designed to flex to the required shape for the application.
Flex PCBs are available in single, double and multilayer configurations. They are used for LCD fabrication, organic light-emitting diode fabrication (known as OLED fabrication), flex solar cells, the automotive industry, mobile phones, cameras and more complex electronics products.
Eliminating connectors, they save space, increase reliability and provide high-speed circuitry with thermal management.
Rigid-flex PCBs
Rigid-flex PCBs are hybrid circuit boards that combine elements from both flexible and rigid printed circuit boards. This produces a PCB that can be flexed or folded. Commonly shaped into a flexed curve, with the flexible portion often used for connecting rigid boards to enable narrower conductor lines and smaller, lighter boards; these PCBs can remove the need for bulky connectors.
The design can be more complex, as the boards are constructed in 3D, allowing for greater performance. Often used in medical devices, the aerospace industry and consumer electronics; this type of board has 360-degree flexibility, shock resistance and greater reliability. It requires less space and has fewer solder joints, offering greater connection reliability.
Precise and efficient PCB assembly services are increasingly in demand to satisfy the booming electronics manufacturing industry. Contact Sellectronics for further information on our professional PCB assembly services to find out what we can do for your business.