FPC circuit board is also called flexible circuit board, abbreviated as "soft board," commonly known as FPC in the industry. It is a printed circuit boardmade of flexible insulating substrates (mainly polyimide or polyester film) and has many rigid printed circuits. The board does not have the advantages, for example, it can be freely bent, wound, folded, and used. FPC can greatly reduce the volume of electronic products, and is suitable for the development of electronic products in the direction of high density, miniaturization and high reliability. Therefore, FPC is used in aerospace, Military, mobile communications, laptop computers, computer peripherals, PDAs, digital cameras and other fields or products have been widely used.
The process of producing FPC is complicated, from cutting and drilling to packaging and shipping, there are more than 20 processes required in the middle. In this long production process, according to customer needs, a variety of auxiliary materials will be used. The base material of FPC is generally double-sided or single-sided copper foil, which is the basis of the entire FPC, and the electrical performance of the FPC is determined by it. Other auxiliary materials are only used to assist in installation and adapt to the use environment. There are mainly the following:
1. FR4- is hard in texture and has different thicknesses of 0.15-2.0mm. It is mainly used on the opposite side of the FPC welding place as a reinforcement to facilitate the welding and stable and reliable;
FR-4 is the code name of a flame-resistant material grade. It represents a material specification that the resin material must be able to extinguish by itself after burning. It is not a material name, but a material grade. Therefore, the current general circuit There are many types of FR-4 grade materials used in the board, but most of them are composite materials made of so-called Tera-Function epoxy resin, Filler and glass fiber.
2. PI tape-soft texture and bendable, it is mainly used for thickening and strengthening the golden finger area, which is convenient for plugging and unplugging;
PI tape, its full name is polyimide tape. PI tape is based on polyimide film and imported organic silicon pressure-sensitive adhesive. It has the properties of high and low temperature resistance, acid and alkali resistance, solvent resistance, electrical insulation (level H), and radiation protection. It is suitable for shielding of wave soldering tin on electronic circuit boards, protecting gold fingers, high-end electrical insulation, motor insulation, and fixing the positive and negative poles of lithium batteries.
3. Steel sheet-hard texture, the same function as FR4, used to strengthen the welding place, more beautiful than FR4, groundable, higher hardness than FR4;
The steel sheet is made of imported stainless steel after heat treatment and fine grinding. It has the characteristics of high precision, strong pulling force, good smoothness, toughness and not easy to break.
4. TPX anti-adhesive film-a high-performance and high-temperature resistant resin barrier release film, used in the circuit board pressing process, through a special process design, it can be used to block multiple layers of buried vias and blind vias after resin overflow In the pressing process, it has a good effect of resisting glue and plugging holes.
5. EIM electromagnetic film-affixed to the surface of the FPC to shield signal interference;
EIM electromagnetic film is a vacuum sputtering method, which can plate shielding materials on substrates of different substrates (PET/PC/glass, etc.) to achieve EMI electromagnetic interference shielding with extremely low resistance.
6. Conductive glue-used for the connection and pressing of the steel sheet and FPC, conductive, and can realize the grounding function of the steel sheet;
Conductive adhesive is an adhesive that has certain conductivity after curing or drying. It is mainly composed of resin matrix, conductive particles, dispersing additives, auxiliary agents, etc. It can connect a variety of conductive materials together to form an electrical path between the connected materials. In the electronics industry, conductive adhesive has become an indispensable new material.
7. 3M adhesive tape-mainly used for pasting FR4 and FPC with a thickness of 0.4mm and above, and assembling and fixing FPC and customer products;
The use of FPC auxiliary materials will ultimately be determined according to the customer's use environment and functional requirements.
As a professional FPC manufacturer, our company has been involved in and researched and developed in the communication fields of digital cameras, car satellite orientation devices, LCD TVs, notebook computers, medical instruments, smart robots, mobile phones, etc. We are very grateful to many customers for their cooperation with us. Support, willing to work together with us, welcome more customers to discuss cooperation.