Printed Circuit Board

A printed circuit board, or PCB, is a self-contained module of interconnected electronic components found in devices ranging from common beepers, or pagers, and radios to sophisticated radar and computer systems. The circuits are formed by a thin layer of conducting material deposited, or "printed," on the surface of an insulating board known as the substrate. Individual electronic components are placed on the surface of the substrate and soldered to the interconnecting circuits. Contact fingers along one or more edges of the substrate act as connectors to other PCBs or to external electrical devices such as on-off switches. A printed circuit board may have circuits that perform a single function, such as a signal amplifier, or multiple functions.
There are three major types of printed circuit board construction: single-sided, double-sided, and multi-layered. Single-sided boards have the components on one side of the substrate. When the number of components becomes too much for a single-sided board, a double-sided board may be used. Electrical connections between the circuits on each side are made by drilling holes through the substrate in appropriate locations and plating the inside of the holes with a conducting material. The third type, a multi-layered board, has a substrate made up of layers of printed circuits separated by layers of insulation. The components on the surface connect through plated holes drilled down to the appropriate circuit layer. This greatly simplifies the circuit pattern.
Components on a printed circuit board are electrically connected to the circuits by two different methods: the older "through hole technology" and the newer "surface mount technology." With through hole technology, each component has thin wires, or leads, which are pushed through small holes in the substrate and soldered to connection pads in the circuits on the opposite side. Gravity and friction between the leads and the sides of the holes keeps the components in place until they are soldered. With surface mount technology, stubby J-shaped or L-shaped legs on each component contact the printed circuits directly. A solder paste consisting of glue, flux, and solder are applied at the point of contact to hold the components in place until the solder is melted, or "reflowed," in an oven to make the final connection. Although surface mount technology requires greater care in the placement of the components, it eliminates the time-consuming drilling process and the space-consuming connection pads inherent with through hole technology. Both technologies are used today.
Two other types of circuit assemblies are related to the printed circuit board. An integrated circuit, sometimes called an IC or microchip, performs similar functions to a printed circuit board except the IC contains many more circuits and components that are electrochemically "grown" in place on the surface of a very small chip of silicon. A hybrid circuit, as the name implies, looks like a printed circuit board, but contains some components that are grown onto the surface of the substrate rather than being placed on the surface and soldered.
Wonderful PCB (HK) Limited, with over 15 years experience of producing PCB, fabricates printed circuit boards for customers in many industries worldwide, including communications/telecom/IT, medical electronics, consumer electronics (mobile phones, computers, LED lighting, etc.), and the automobile industry. We supply high-precision, high-density, double-sided and multilayer custom PCBs and PCBA services for customers in many countries.

About PCB service

1. Installation and welding of parts
the last step is the installation and welding the parts. Both THT and SMT parts use of machinery and equipment to install is placed on the PCB.
THT parts are usually called the Wave Soldering (Wave Soldering) way of welding. This allows all parts to a welding on the PCB.First to pin cut close to the board, and slightly bent so that parts can be fixed. Then the PCB will be moved to the co solvent on the waves of make contact to help at the bottom of the solvent, it can be on the base metal of the oxide to get rid of. After the heated PCB, the move to the melting of solder, at the bottom and contact after welding is completed.
Automatic welding of SMT parts way is called to flow back to welding (Over Reflow Soldering).Contains co solvent and solder paste in welding, the parts installed on the PCB after the first treatment time, was a PCB again after heating treatment. For PCB cooling after welding is completed, the next is to prepare the final test of PCB board.

2. Proofing
PCB's Chinese name is called printed circuit board, also known as printed circuit boards; printed circuit board is an important electronic component is electronic components support body? The provider of the electrical connection in the electronic components. Because it is made of so called electronic printing "printed circuit board.
PCB proofing is refers to the pilot production of printed circuit board before mass production is mainly used for electronic engineers in the design of circuit? And complete the PCB Layout to the factory after small batch trial-produce process is the PCB proofing. And PCB proofing production quantity generally no specific boundary is an engineer in product design has been finished to confirm and complete the test before we call it PCB proofing.

Flex circuits

Flex circuits are often used as connectors in various applications where flexibility, space savings, or production constraints limit the serviceability of rigid circuit boards or hand wiring. A common application of flex circuits is in computer keyboards; most keyboards use flex circuits for the switch matrix.
In LCD fabrication, glass is used as a substrate. If thin flexible plastic or metal foil is used as the substrate instead, the entire system can be flexible, as the film deposited on top of the substrate is usually very thin, on the order of a few micrometres.
Organic light-emitting diodes (OLEDs) are normally used instead of a back-light for flexible displays, making a flexible organic light-emitting diode display.
Most flexible circuits are passive wiring structures that are used to interconnect electronic components such as integrated circuits, resistor, capacitors and the like, however some are used only for making interconnections between other electronic assemblies either directly or by means of connectors.
In the automotive field, flexible circuits are used in instrument panels, under-hood controls, circuits to be concealed within the headliner of the cabin, and in ABS systems. In computer peripherals flexible circuits are used on the moving print head of printers, and to connect signals to the moving arm carrying the read/write heads of disk drives. Consumer electronics devices make use of flexible circuits in cameras, personal entertainment devices, calculators, or exercise monitors.
Flexible circuits are found in industrial and medical devices where many interconnections are required in a compact package. Cellular telephones are another widespread example of flexible circuits.
Flexible solar cells have been developed for powering satellites. These cells are lightweight, can be rolled up for launch, and are easily deployable, making them a good match for the application. They can also be sewn into backpacks or outerwear.

If you need expert flexible circuit board service, please contact wonderful02@wonderfulpcb.com.