A single-sided PCB circuit board is a type of printed circuit board. Only one side of the PCB board has wiring (can be perforated or non-porous), the other side is covered by a substrate or directly insulated with ink, without any wiring and placed under strong light. ). The cross-section contains copper foil only on the side with the wiring.
Generally, a single-sided PCB circuit board is obtained by etching a copper-clad board. The copper-clad board is composed of a board base and a copper foil. The board base usually uses insulating materials such as glass fiber, and is covered with a layer of copper foil (usually oxygen-free copper). After the copper foil is etched, there is a zigzag of copper foil left and right. These copper foils are called traces. The functions of these traces are equivalent to those in the circuit schematic, they are responsible for connecting the pins of the components together. There are holes in the copper foil for mounting electronic components, called drill holes. The copper foil used for soldering the component pins is called a pad. Obviously, a single-sided PCB circuit board can provide fixed and assembled mechanical support for electronic components, and can achieve electrical connection or insulation between electronic components. In addition, we can see that many single-sided PCB circuit boards are printed with component numbers and some graphics, which facilitates component insertion, inspection, and maintenance.
(1) Phenolic paper substrate Phenolic paper substrate (commonly known as, cardboard, rubber board, V0 board, flame retardant board, red letter copper clad board, 94V0. The most commonly used product models for phenolic paper based copper clad board are FR-1 (flame-retardant) and XPC (non-flame-retardant) Type) Two types. The single-sided copper clad plate can be easily judged by the color of the characters behind the plate. Generally, the red letter is FR-1 (flame-retardant), and the blue letter is XPC (non-flame-retardant). Compared with other types of plates, this type of plate is cheapest.
(2) Epoxy glass cloth substrate Epoxy glass fiber cloth substrate (commonly known as epoxy board, glass fiber board, fiberboard, FR4), epoxy glass fiber cloth substrate is a type of epoxy resin as the adhesive, and electronic grade glass fiber cloth as a reinforcing material Substrate. Its adhesive sheet and thin copper-clad inner core are important base materials for making multilayer printed circuit boards. The working temperature is higher, and its performance is less affected by the environment. In terms of processing technology, it has great advantages over glass fiber cloth substrates made of other resins. This type of product is mainly used for double-sided PCBs. It is also about twice as expensive as phenolic paper substrates, and the commonly used thickness is 1.5MM.
(Three) composite substrate Composite substrate (commonly known as powder board, etc., cem-1 sheet is also called 22F in some places in the country) It mainly refers to CEM-1 and CEM-3 composite base copper clad sheet. Wood pulp fiber paper or cotton pulp fiber paper is used as the core material reinforcement material, and glass fiber cloth is used as the surface layer reinforcement material, both of which are impregnated with flame-retardant epoxy-coated copper clad board, which is called CEM-1. Glass-fiber paper is used as the core material reinforcement material, and glass fiber cloth is used as the surface layer reinforcement material. They are all impregnated with flame-retardant epoxy resin, and the copper-clad board is called CEM-3. These two types of copper-clad laminates are the most common composite-based copper-clad laminates. This type of sheet is cheaper than FR4 type sheet.
Due to the excellent adhesion between epoxy resin and copper foil, the copper foil has high adhesion strength and working temperature, and can be dipped in molten tin at 260 ° C without blistering. Epoxy-impregnated glass cloth laminates are less affected by humidity. The most excellent material for UHF printed wiring is copper clad PTFE glass cloth laminate. For electronic equipment with flame retardant requirements, flame-retardant copper-clad laminates are also used. The principle is to impregnate non-combustible or flame-resistant resin with insulating paper or glass cloth to make the copper-clad phenolic paper produced. Laminates, copper-clad epoxy paper laminates, copper-clad epoxy glass cloth laminates, copper-clad epoxy phenolic glass cloth laminates, in addition to the similar properties of similar copper-clad laminates, Flame retardant.
Single-sided PCBs are almost inseparable from the electronic equipment we can see, ranging from electronic watches, calculators, general-purpose computers, to computers, communication electronics, military weapon systems, as long as there are electronic components such as integrated circuits, PCBs are used for electrical interconnection between them. It provides mechanical support for fixed assembly of various electronic components such as integrated circuits, realizes wiring and electrical connection or electrical insulation between various electronic components such as integrated circuits, and provides required electrical characteristics such as characteristic impedance. At the same time, it provides the solder resist pattern for automatic soldering, and the identification characters and graphics for component insertion, inspection, and maintenance.