FPC based on high-frequency FRCC and FCCL single panel and manufacturing process thereof

Abstract

The invention discloses an FPC (Flexible Printed Circuit) based on a high-frequency FRCC and an FCCL single panel. The FPC comprises at least one FRCC and at least one FCCL single panel, wherein the FRCC and the FCCL single panel are pressed together; the FRCC comprises a first copper foil layer, a first low dielectric glue layer and a second low dielectric glue layer; the FCCL single panel includes, in order, a second copper foil layer and an insulating polymer layer which is a polymer layer in a cured state. According to the invention, the FRCC without the LCP layer is matched with the high-frequency FCCL single panel to manufacture a three-layer or 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 transfer 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 structure based on the high-frequency FRCC and the FCCL single panel.

Description

technical field [0001] The present invention relates to the technical field of FPC (flexible circuit board) and its preparation, in particular to a kind of FPC and technology based on high-frequency FRCC and FCCL (flexible copper clad substrate) single panel. 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 FPC 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 Circuit) has the characteristics of flexibility and t...

AI Technical Summary

Problems solved by technology

[0003] In the field of high-frequency materials used in the FPCFPC process, the high-frequency boards currently used in the industry are mainly LCP boards and PTFE fiberboards. However, this material is also limited by the process technology, and the requirements for FPC manufacturing lamination equipment are extremely high. It needs to be pressed in a higher temperature environment (minimum >280°C) and the pressing time is too long to use fast press equipment, which leads to processing difficulties, which also leads to easy loss of pressing equipment, high pressing costs, and 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 leads to poor reliability and a decline in reliability; therefore, the industry needs to increase equipment to ensure quality with multi-layer LCP boards and rely on AOI equipment for multi-index inspections, which affects the yield and efficiency of finished FPCs, and further aggravates the use of high-frequency FPCFPC Factors such as rising end costs

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 FCCL single-sided panel needs to be coated again. After pressing the copper foil on the other side, the process is complicated and the efficiency is low

For other FRCC substrates at present, it is difficult to meet 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

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