WO2019090497A1

WO2019090497A1 - High characteristic impedance multilayer circuit board and manufacturing method therefor

Info

Publication number: WO2019090497A1
Application number: PCT/CN2017/109824
Authority: WO
Inventors: 邱小平
Original assignee: 惠州市兴顺和电子有限公司
Priority date: 2017-11-08
Filing date: 2017-11-08
Publication date: 2019-05-16

Abstract

A high characteristic impedance multilayer circuit board, comprising a substrate (1) and multiple layers of inner-layer circuit board layers (2), characteristic impedance layers (3) and outer-layer circuits (4) provided on both sides of the substrate (1), the inner-layer circuit board (2) being composed of a PP sheet (22) and a copper foil (21); the characteristic impedance layer (3) is a copper-clad substrate (3). A guide groove (31) is further provided at an edge of the copper-clad substrate (3). A manufacturing method for the multilayer circuit board is also comprised. The multilayer circuit board meets the requirement of high characteristic impedance, effectively avoiding the inner-layer shifting problem, improving the production efficiency, and also improving the product yield.

Description

High characteristic impedance multilayer circuit board and manufacturing method thereof

Technical field

The invention relates to the technical field of circuit boards, in particular to a circuit board manufacturing method and the obtained circuit board.

Background technique

The characteristic impedance of the board is an important measure of the performance of the board, which affects the stability of the board work. The characteristic impedance refers to the resistance encountered in the transmission signal line of the circuit when the high-frequency signal is transmitted, and is the sum of the three of the electrical impedance, the capacitive reactance and the inductive reactance. When designing the PCB, the impedance of the board trace must be controlled to avoid signal reflection and other electromagnetic interference and signal integrity problems as much as possible to ensure the stability of the actual use of the PCB board. In general, the thicker the thickness of the board, the greater the impedance. Therefore, the characteristic impedance of the board is usually increased by increasing the thickness of the board. Increasing the thickness of the board uses increasing the thickness of the medium, that is, increasing the thickness and number of the intermediate PP sheets. However, this method causes the problem of the sliding plate due to a large amount of resin melting during the pressing, and for this reason, the method can increase the thickness of the medium to be limited, and it is difficult to meet the specific high characteristic impedance value requirement.

Summary of the invention

It is an object of the present invention to provide a method and a circuit board for a circuit board having high characteristic impedance.

The technical solution of the present invention is: a high-characteristic impedance multilayer circuit board comprising a substrate, a plurality of layers of PP sheets and copper foils forming circuit board layers on both sides of the substrate, and a characteristic impedance layer disposed between the circuit board layers. The characteristic impedance layer is a copper clad substrate.

Preferably, the characteristic impedance layer further comprises a PP resin sheet on the copper clad laminate copper foil layer.

Preferably, the upper edge of the copper-clad substrate is provided with a flow guiding groove.

Preferably, the flow guiding groove comprises a plurality of first grooves perpendicular to the edge of the copper clad plate and a second groove parallel to the edge of the copper clad plate, and the plurality of first grooves are in communication with the second communication.

Preferably, the second communication is located 0.5-1 cm at the edge of the copper clad plate, and the first trench is located inside the second trench.

The invention also provides a method for manufacturing the high characteristic impedance multilayer circuit board, comprising the following steps:

(1) Position estimation: Calculate the position of the characteristic impedance layer according to the number of circuit board layers. Insert the characteristic impedance layer on the two sides of the substrate according to the number of circuit board layers; if the number of circuit boards on the substrate side is singular, the characteristics The impedance layer is disposed at a position close to the substrate;

(2) production of inner layer circuit board and characteristic impedance layer line;

(3) Lamination: take the circuit board substrate, and place PP sheets and copper foils on both sides in turn, and stack the copper-clad substrates in sequence;

(4) positioning the laminated circuit board with pins;

(5) After positioning, press-fit to obtain a multilayer circuit board.

Compared with the prior art, the multi-layer circuit board of the present invention satisfies the requirement of high characteristic impedance, increases the thickness of the copper-clad substrate through the inner layer, and effectively avoids the problem of the inner-layer skateboard caused by the method of increasing the PP sheet, and improves the problem. Production efficiency, while also improving product yield.

DRAWINGS

1 is a schematic structural view of the high-impedance multilayer circuit board;

2 is a schematic view showing the structure of a characteristic impedance layer in the high-impedance multilayer circuit board.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments, and it should be noted that the implementation is The examples are merely preferred embodiments of the invention and are not intended to limit the invention.

The multi-layer high-characteristic impedance circuit board according to the present invention is a circuit board used to meet specific requirements, which requires a specific impedance of the circuit board to be high and signal transmission to be stable. The existing production method increases the thickness of the circuit board by increasing the thickness of the circuit board by increasing the thickness of the circuit board between the inner circuit boards, but the circuit board achieves a higher specific impedance, but in the production process, especially after the circuit board is laminated. In the process of integration, since the PP sheets between the inner circuit boards are thick, the PP sheets subjected to high temperature melting during pressing are in a fluid state, often causing the inner layers to slide with each other, resulting in quality problems of the circuit boards and even scrapping.

As shown in FIG. 1 , the multi-layer high-performance impedance circuit board of the present invention comprises a substrate 1 , and a plurality of inner layer circuit board layers 2 and a characteristic impedance layer 3 , an outer layer line 4 and an inner layer circuit board are disposed on both sides of the substrate 1 . 2 is composed of a PP sheet 22 and a copper foil 21.

The characteristic impedance layer 3 is a copper clad substrate. Further, the characteristic resistance layer may also add a PP resin sheet on the copper foil layer of the copper clad substrate. As shown in the figure, a flow guiding groove 31 is further disposed at the edge of the copper clad substrate 3, and the guiding groove 31 can effectively prevent the resin from flowing out of the edge of the circuit board when the fusion is melted. The guiding groove 31 includes a first groove communicating with the second groove and the second communication. The plurality of first grooves 311 are perpendicular to the edge of the copper clad plate, the second groove 312 is parallel to the edge of the copper clad plate, and the second communication is located at the edge of the copper clad plate. At -1 cm, the first groove is located inside the second groove.

The high-impedance multilayer circuit board manufacturing method adopts the following steps: (1) Position estimation: calculating the position of the characteristic impedance layer according to the number of circuit board layers, and taking the intermediate layer insertion characteristics according to the number of circuit board layers on both sides of the substrate Impedance layer; if the number of circuit boards on the substrate side is a single number, the characteristic impedance layer is placed close to the substrate; (2) the inner circuit board and the characteristic impedance layer line are fabricated; (3) the laminate: the circuit board substrate is taken, PP sheets are placed at intervals on both sides. Copper foil, and stacking the copper substrate in sequence; (4) positioning the laminated circuit board with pins; (5) positioning and pressing to obtain a multilayer circuit board.

The multi-layer circuit board of the invention satisfies the requirement of high characteristic impedance, increases the thickness of the copper-clad substrate through the inner layer, effectively avoids the problem of the inner layer skateboard caused by the method of increasing the PP sheet, improves the production efficiency, and also improves the efficiency. Product yield.

Claims

a high-impedance multilayer circuit board comprising a substrate, a plurality of layers of PP sheets and copper foils on the two sides of the substrate, further comprising: a characteristic impedance layer disposed between the circuit board layers, the characteristic The impedance layer is a copper clad substrate.
The high-impedance multilayer wiring board according to claim 1, wherein the characteristic impedance layer further comprises a PP resin sheet on the copper-clad substrate copper foil layer.
The high-impedance multilayer wiring board according to claim 2, wherein the upper edge of the copper-clad substrate is provided with a flow guiding groove.
The high characteristic impedance multilayer wiring board according to claim 3, wherein the flow guiding groove comprises a plurality of first grooves perpendicular to an edge of the copper clad plate and a second groove parallel to an edge of the copper clad plate. A plurality of first trenches are in communication with the second communication.
The high-impedance multilayer wiring board according to claim 4, wherein the second communication is located 0.5-1 cm at the edge of the copper clad, and the first trench is located inside the second trench.
A method of manufacturing a circuit board according to any of claims 1-5, comprising the steps of:

(1) Position estimation: Calculate the position of the characteristic impedance layer according to the number of circuit board layers, and insert the characteristic impedance layer on the two sides of the substrate according to the number of circuit board layers;

(2) production of inner layer circuit board and characteristic impedance layer line;

(3) Lamination: take the circuit board substrate, and place PP sheets and copper foils on both sides in turn, and stack the copper-clad substrates in sequence;

(4) positioning the laminated circuit board with pins;

(5) After positioning, press-fit to obtain a multilayer circuit board.
The method for fabricating a high-impedance multilayer circuit board according to claim 6, wherein in the step (1), when the number of circuit boards on the substrate side is a single number, the characteristic impedance layer is set. In the position close to the substrate.