High-uniformity multi-layer impedance flexible circuit board and fabrication method thereof

Abstract

The invention provides a high-uniformity multi-layer impedance flexible circuit board and a fabrication method thereof. By employing a base layer, a dielectric constant of the impedance flexible circuit board using the base layer can be effectively reduced, and impedance control of the impedance flexible circuit board is improved; by combining an impedance layer material provided by the invention and by means of a formulation and synergistic effect of each constituent, the impedance flexible circuit board has lower dielectric constant compared with an impedance flexible circuit board which has the same thickness structure and uses a traditional glass fabric; the fabrication method of the circuit board is simple and is easy to operate and master, accurate alignment among layers and uniform stress are achieved, plate sliding and pressure loss can be prevented, a product is high in quality, and a positioning line is arranged by an infrared positioning emitter; and the impedance flexible circuit board after lamination is high in integral uniformity, the time that resin in a prepreg is in melting flowing is prolonged, full filling among a plurality of core board layers is ensured, flowing is uniform, the efficiency is greatly improved, and a lamination parameter is optimized.

Description

technical field [0001] The invention belongs to the technical field of PCB processing, and in particular relates to a high-uniformity multilayer impedance flexible circuit board and a preparation method thereof. Background technique [0002] With the diversification and development of electronic products, the number of circuit boards involving linear impedance control is gradually increasing. Linear impedance is simply the resistance value at both ends of the wire, which is related to the length of the wire, copper thickness, and wire width. The thickness of the wire is the key influencing factor. [0003] At present, the materials used in circuit boards in the industry mainly use glass fiber cloth (referred to as glass fiber cloth) as the reinforcing material. This kind of glass fiber cloth has a grid structure of warp and weft yarns. When coating the resin, the resin content is low and uneven, and the dielectric constant of the board dielectric layer is high due to the str...

AI Technical Summary

Problems solved by technology

[0003] At present, the materials used in circuit boards in the industry mainly use glass fiber cloth (referred to as glass fiber cloth) as the reinforcing material. This kind of glass fiber cloth has a grid structure of warp and weft yarns. When coating the resin, the resin content is low and uneven, and the dielectric constant of the board dielectric layer is high due to the structural problems of the glass fiber cloth itself. If the circuit board needs to achieve a lower dielectric constant under the same dielectric thickness , you need to use a thinner glass fiber cloth bonding sheet, but its disadvantage is that the cost is high, which is not conducive to lamination

As the current transmission frequency of electrical signals is getting higher and higher, the requirements for the dielectric constant of the board are lower, but because the structure of the glass fiber cloth itself has not undergone fundamental changes, it still cannot meet the current signal transmission rate of the high-frequency bottom line and signal integrity requirements

[0004] At present, in the lamination process of flexible circuit boards, due to the diversification of PCB product design, such as: large layout, thick bottom copper, fine impedance, instability of raw materials, and occasional errors in the operation of employees, it is easy to cause problems after lamination. The overall uniformity of the flexible circuit board is not good, and after the press has been used for a period of time, the pressure and temperature uniformity of the hot plate of the press will decrease, which will easily lead to abnormal pressing quality, large equipment consumption, reduced production efficiency, and affected product quality. increased production costs