Printed circuit board (PCB)
A printed circuit board (PCB) is a substrate for electronic components which also enables them to be electrically connected. It consists of an electrically insulating base material on or within which conductive structures, usually made of copper, are arranged.
These so-called conductor tracks connect the electronic components in accordance with the intended circuit. The components can, for example, be mounted directly onto the surface using SMD technology or secured and electrically connected via through-hole mounting and made electrically contact.
Structure and Types
Depending on the application, printed circuit boards differ in terms of material, structure and the number of conductive layers. For rigid printed circuit boards, glass-fibre-reinforced epoxy resin (FR-4) is frequently used as the substrate material.
In addition to rigid printed circuit boards, there are flexible printed circuit boards (FPCBs), which are based, for example, on polyimide films. They can be bent and adapted to curved mounting surfaces. Combinations of rigid and flexible sections are also possible.
Printed circuit boards in LED technology
In modern LED luminaires, printed circuit boards often play an important role in heat dissipation as well as providing electrical connections. Depending on the design, metal-core-based printed circuit boards or boards with suitable thermal interfaces are used for this purpose, for example.
SMD LEDs are mounted on the surface of the printed circuit board. In COB technology, on the other hand, several LED chips can be arranged and connected directly onto a common substrate.
In the case of flexible LED strips, the printed circuit board serves both as a mechanical substrate and to supply power to the individual LEDs. The width of the conductor tracks, the thickness of the copper and the PCB design influence, amongst other things, the electrical load capacity, voltage drops and heat generation.