CN211240255U

CN211240255U - High-frequency low-loss glue-layer-free FPC

Info

Publication number: CN211240255U
Application number: CN201922078015.0U
Authority: CN
Inventors: 林均秀; 胡可; 曾宪悉; 刘志勇; 黄志刚; 杨婵
Original assignee: ZHUHAI TOPSUN ELECTRONIC TECHNOLOGY CO LTD
Current assignee: Zhuhai Zhongjing Yuansheng Electronic Technology Co.,Ltd.
Priority date: 2019-11-27
Filing date: 2019-11-27
Publication date: 2020-08-11
Anticipated expiration: 2029-11-27

Abstract

The utility model discloses and provides a high frequency low-loss does not have glue film FPC can satisfy the transmission requirement of high frequency signal low-loss, can also satisfy medical industry and relapse the high temperature digestion and the disinfection requirement of acid-base nature. The high-frequency low-loss glue-layer-free FPC comprises a first LCP substrate, wherein copper foils are compounded on the upper surface and the lower surface of the first LCP substrate; an inner layer circuit is arranged on the copper foil on the first LCP substrate, a second LCP substrate is compounded on the copper foil on the first LCP substrate, and a copper foil is compounded on the second LCP substrate; the copper foil below the first LCP substrate is equipped with lower floor's circuit, and the copper foil above the second LCP substrate is equipped with upper circuit, and upper circuit, inlayer circuit, lower floor's circuit three switch on each other. The utility model discloses be applied to the technical field that FPC production was made.

Description

High-frequency low-loss glue-layer-free FPC

Technical Field

The utility model relates to a FPC, in particular to high frequency low-loss does not have glue film FPC.

Background

Along with the development of mobile phone communication, the signal frequency is increased, and the requirement for reducing the dielectric loss of the FPC for signal transmission is also reduced, so that the quality is not influenced by overlarge signal loss. In this case, the conventional FPC does not satisfy the low loss requirement. In addition, if the traditional FPC is applied to the medical industry, repeated high-temperature cooking and alkaline cleaning and disinfection requirements of the medical industry are difficult to meet.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that prior art is not enough to overcome, provide a high frequency low-loss no glue film FPC, can satisfy the low-loss transmission requirement of high frequency signal, can also satisfy medical industry and relapse the high temperature digestion and the alkaline cleaning and disinfecting requirement.

The utility model adopts the technical proposal that: the high-frequency low-loss non-adhesive layer FPC comprises a first LCP substrate, wherein copper foils are compounded on the upper surface and the lower surface of the first LCP substrate.

Further, be equipped with the inlayer circuit on the copper foil above the first LCP substrate, compound on the copper foil above the first LCP substrate has the second LCP substrate, compound has the copper foil above the second LCP substrate.

Further, the copper foil below the first LCP substrate is provided with a lower layer circuit, the copper foil above the second LCP substrate is provided with an upper layer circuit, and the upper layer circuit, the inner layer circuit and the lower layer circuit are mutually conducted.

The utility model has the advantages that: the copper foil and LCP are compounded into a copper-clad plate, and the FPC is manufactured on the copper-clad plate, so that a double-sided plate, a three-layer plate and a multi-layer plate with more than three layers can be manufactured. And no additional adhesive glue layer is needed between the inner layers of the multilayer board. LCP can also be used as a coverlay film to achieve a true "glue-free" fully-laminated LCP FPC from the coverlay film to the inner layer, and the entire FPC can be free of PI, epoxy glue, and acrylic glue components. The utility model discloses produce a brand-new, full-folding LCP's FPC, possess excellent high frequency low loss performance to and can bear medical industry's the cleaning and disinfecting repeatedly, this kind of FPC also can be applied to millimeter wave communication.

Drawings

FIG. 1 is a double-sided copper-clad plate made by compounding copper foil and LCP film;

FIG. 2 is a schematic diagram of a double-sided board after a dry film is attached;

FIG. 3 is a schematic diagram of film alignment of inner layer circuit of a double-sided board;

FIG. 4 is a schematic view of exposure development;

FIG. 5 is a schematic diagram after etching of the lines;

FIG. 6 is a schematic view showing the dry film removal after etching;

FIG. 7 is a schematic view of the outer laminate after lamination;

FIG. 8 is a schematic view of a laminated multi-layer board after drilling;

FIG. 9 is a schematic of a multilayer board with black holes, and after copper plating;

FIG. 10 is a schematic diagram of a multi-layer board after being pasted with a dry film;

FIG. 11 is a schematic diagram illustrating alignment of a multi-layer board with a film attached to the board surface during pattern transfer;

FIG. 12 is a schematic representation of a multilayer plate after exposure and development;

FIG. 13 is a schematic representation of a multilayer board after etching;

FIG. 14 is a schematic representation of a multiwall sheet after demolding;

FIG. 15a is a schematic representation of a multilayer sheet after lamination of a PI cover film;

figure 15b is a schematic representation of a multi-layer laminated LCP cover film.

Detailed Description

As shown in fig. 1, the stack is formed by directly laminating two copper foils and one LCP. Due to the physical properties of LCP films, high temperature lamination is required when making LCP covered copper plates.

As shown in figure 2, after LCP copper clad laminate is cut into single piece, dry films are pasted on two sides of the copper clad laminate.

As shown in fig. 3, the inner layer circuit film is used for the alignment exposure on the inner layer copper foil surface dry film, the other surface copper foil of the material is the outer layer, and the layer of copper foil is protected and reserved for the outer layer. Therefore, the film is not needed, and the whole exposure can be directly carried out.

As shown in fig. 4, the dry film is developed after exposure, the dry film in the circuit area is retained, and the dry film in the gap area is removed. The dry film on the other side is entirely retained.

The developed plate is etched and the copper foil is half removed in the gap area without dry film protection, as shown in fig. 5.

After the dry film is removed, the inner layer forms the desired circuit, as shown in fig. 6. The outer copper foil will remain intact.

As shown in fig. 7, the outer copper-clad plate can be a single-sided copper-clad plate or a double-sided copper-clad plate without one copper, and the LCP layer is connected to the inner circuit. And special pressing to form three-layer plate. This assembly press does not require adhesive due to the physical properties of the LCP. This would apply to a special stitching technique.

As shown in fig. 8, the multilayer board is drilled, and via holes, mounting holes, auxiliary holes, and the like are drilled. According to the requirement of the product, a through hole can be drilled, and a blind hole can be drilled by laser.

FIG. 9 is a schematic view showing a black hole and a copper plated film. When the low-density multilayer board is used, black holes are preferentially adopted to replace copper deposition, and copper plating parameters are adjusted to ensure reliable copper plating. The holes should be properly cleaned before the black holes.

As shown in fig. 10, dry films are attached to both sides of the three-layer plate.

As shown in fig. 11, the two-sided wiring film is used for alignment exposure on the two-sided dry film.

As shown in fig. 12, the dry film is developed after exposure, the dry film in the line region is retained, and the dry film in the gap region is removed.

The developed plate is etched and the copper foil is half removed in the gap areas without dry film protection, as shown in fig. 13.

After the dry film is removed, the outer layer will form the desired circuit, as shown in fig. 14.

As shown in fig. 15a, a PI cover film was laminated on the outer layer wire to form a protective layer on the wire, which would form a multilayer board with no adhesive on the inner layer.

As shown in fig. 15b, the LCP film may also be pressed onto the profile as the cover film is used to form an adhesive-free cover film. This results in a fully-stacked LCP multi-layer FPC free of adhesive from the cover film to the inner layer. This would use a special lamination technique due to the LCP physical properties.

LCP FPC with pressed covering film is processed by surface treatment of bonding pad gold immersion, OSP and the like, electrical property of the product is detected, and single piece cutting or needed makeup quantity is cut. And packaging to obtain the finished product.

To sum up, the utility model provides a brand-new no glue layer LCP FPC, it is much excellent to experience the relatively traditional PI FPC of high frequency loss. Especially, the FPC with the full-stack LCP does not contain PI, epoxy glue and acrylic glue, and can meet the requirement of repeated cleaning and disinfection in the medical industry.

By using the technology, the inner layer production is repeated, and the LCP multilayer FPC with high layer number can be manufactured.

The utility model discloses be applied to the technical field that FPC production was made.

While the embodiments of the present invention have been described in terms of practical embodiments, they are not intended to limit the scope of the invention, and modifications of the embodiments and combinations with other embodiments will be apparent to those skilled in the art in light of the present description.

Claims

1. The utility model provides a high frequency low-loss does not have glue film FPC which characterized in that: the high-frequency low-loss glue-layer-free FPC comprises a first LCP substrate, wherein copper foils are compounded on the upper surface and the lower surface of the first LCP substrate; be equipped with the inlayer circuit on the copper foil above the first LCP substrate, compound on the copper foil above the first LCP substrate has the second LCP substrate, compound has the copper foil above the second LCP substrate.

2. The high-frequency low-loss adhesive-layer-free FPC according to claim 1, wherein: the copper foil below the first LCP substrate is provided with a lower layer circuit, the copper foil above the second LCP substrate is provided with an upper layer circuit, and the upper layer circuit, the inner layer circuit and the lower layer circuit are mutually conducted.