FPC multilayer board based on high-frequency FRCC and high-frequency double-sided board and manufacturing process thereof

Abstract

The invention discloses an FPC (Flexible Printed Circuit) multilayer board based on a high-frequency FRCC and a high-frequency double-sided board. The FPC multilayer board comprises at least one FRCCand at least one double-sided board, wherein the FRCC and the double-sided board are pressed together; the FRCC comprises a first copper foil layer, a first low dielectric glue layer and a second lowdielectric glue layer; the double-sided board is at least one of a PI type double-sided board and an LCP type double-sided board. According to the invention, the FRCC without the LCP layer is matchedwith the high-frequency PI type double-sided board or the LCP type double-sided board to manufacture a three-layer to six-layer FPC, the process flow for manufacturing the FPC is simple, the laser drilling process is better, the situation of retraction is not easy to occur, the FPC has lower hygroscopicity and lower Dk and Df electrical properties, fast press equipment or pressure transmission equipment can be matched, the FPC has the cost advantage, the thick film manufacturing technology is provided, and meanwhile, the FRCC with the simpler interface and the lower cost is used in the FPC multilayer board structure based on the high-frequency FRCC and the high-frequency double-sided board.

Description

technical field [0001] The invention relates to the field of FPC (flexible circuit board) and its preparation technology, in particular to an FPC multilayer board based on high-frequency FRCC (adhesive copper foil substrate) and high-frequency double-sided board and its manufacturing process. Background technique [0002] With the rapid development of information technology, considering the acceleration of global 5G and other high-speed transmission technologies for a period of time in the future, in order to meet the high-frequency and high-speed signal transmission and reduce the production cost of terminal equipment, various forms of mixed-voltage structures appear in the market Multilayer board design and application. Printed circuit boards are an indispensable material in electronic products, and as the demand for consumer electronics grows, the demand for printed circuit boards is also increasing. Due to the flexible printed circuit board (FPC, Flexible Printed Circui...

AI Technical Summary

Problems solved by technology

[0003] In the field of high-frequency materials used in the multi-layer board FPC process, the high-frequency boards currently used in the industry are mainly LCP boards and PTFE fiberboards. It is extremely high and needs to be pressed in a higher temperature environment (minimum >280°C) and the pressing time is too long to use fast press equipment, resulting in difficult processing, which also leads to easy loss of pressing equipment and high pressing costs. Low production efficiency

At the same time, the process products are prone to uneven film thickness, which will make it difficult to control the impedance value of the circuit board, and the high-temperature pressing process will cause LCP or PTFE extrusion to affect the conductivity of copper plating, resulting in an open circuit. This in turn leads to poor reliability and a decline in reliability; therefore, the industry needs to rely on AOI equipment for multi-inspection inspections on multi-layer LCP boards to ensure quality. Factors such as rising cost of FPC at the end of use appear

Although other resin films do not have the above problems, they cannot meet the market demand due to problems such as poor electrical properties or poor mechanical strength.

[0004] In addition, the coating-type LCP substrate in the industry can only be coated with a thickness of 12.5um during the coating process. If the total thickness of the LCP substrate is made to exceed 50um, the process needs to be coated multiple times, and the production of the LCP-type double-sided panel needs to go through another process. The process of laminating the copper foil on the other side is complicated and inefficient

For other FRCC substrates at present, it is difficult to satisfy the total thickness of more than 50um in one coating, and structural design or multiple coatings are required to make thick films, which may affect its UV laser processability and electrical properties due to the existence of multiple interfaces. water absorption

Images