In addition to its flexibility, wrought copper foil also has the characteristics of hard smoothness. The matte side of ED copper foil is often treated with special treatment to improve its bonding ability. It is a flexible material that can be made into many thicknesses and widths. Electrodeposited copper foil has a shiny surface on one side and a dull matte surface on the other side. It can be electrodeposited ( for short: ED) or plated. ConductorCopper foil is suitable for use in flexible circuits. Other important characteristics in adhesives are lower dielectric constant, higher insulation resistance, high glass transition temperature and low moisture absorption.2. The advantages combined with materials with the same characteristics can be dimensionally stable after dry welding or after multiple lamination cycles. Polyimide insulating films are usually combined with polyimide or acrylic adhesives, and polyester insulating materials are generally combined with polyester adhesives. Nevertheless, they are suitable for use in products such as telephones and other products that do not require exposure to harsh environments. In low temperature applications, they exhibit rigidity.
Polyesters have a melting point of 250☌ and a glass transition temperature (Tg) of 80☌, which limits their use in applications that require a large amount of end welding. Polyester, also known as polyethylene ethylene terephthalate ), whose physical properties are similar to polyimide, has a low dielectric constant, absorbs very little moisture, but is not resistant to high temperatures.
Polyimide material is non-flammable, has stable geometric dimensions, has high tear strength, and has the ability to withstand welding temperatures. Nearly 80% of all flexible circuit manufacturers in the United States use polyimide film materials, and about 20% use polyester film materials. Adhesive layers provide environmental protection and electrical insulation, and can eliminate a thin film, and the ability to have multiple layers with fewer adhesive layers.There are many types of insulating film materials, but the most commonly used are polyimide and polyester materials. It is an adhesive layer, which is formed by coating adhesive on both sides of an insulating film. Another material is sometimes used in flexible circuits. The adhesive bonds the rigid member and the flexible circuit together. In some flexible circuits, rigid members formed of aluminum or stainless steel are used, which can provide dimensional stability, provide physical support for the placement of components and wires, and relieve stress. The copper foil forms a conductive layer. They are also used as protective coverings to isolate the circuit from dust and moisture, and to reduce stress during flexure. In a multi-layer design, it is bonded to the inner layer. Insulating filmThe insulating film forms the basic layer of the circuit, and the adhesive bonds the copper foil to the insulating layer. In the structure of a flexible circuit, the materials composed are insulating film, conductor and adhesive. This kind of circuit can be bent freely, folded light weight, small size, good heat dissipation, easy installation, and breaks through the traditional interconnection technology. By embedding the circuit design on the thin and flexible plastic sheet, a large number of precision components are stacked in a narrow and limited space to form a flexible circuit. It is made of polyester film or polyimide as a substrate with high reliability and excellent flexibility. FPC defect automatic inspection has become an inevitable trend in industrial development.Flexible circuit (FPC) is a technology developed by the United States for the development of space rocket technology in the 1970s.
Pcb news manual#
Traditional manual inspection methods have been unable to meet production needs. With the rapid development of the electronics industry, the design of circuit boards is becoming more and more high-precision and high-density.
Pcb news free#
Also known as flexible circuit boards, it is favored for its excellent characteristics such as light weight, thin thickness, and free bending and folding. It has the characteristics of high wiring density, light weight, thin thickness and good bendability.
Flexible circuit board (FPC for short) is a flexible printed circuit board with high reliability and excellent reliability, which is made of polyimide woven glass fabric copper-clad laminates or polyester film as the base material.
0 kommentar(er)
