CN109327969B

CN109327969B - Design method of circuit board with high-frequency impedance and loss matching

Info

Publication number: CN109327969B
Application number: CN201811456254.9A
Authority: CN
Inventors: 吴卫钟; 陈锦云
Original assignee: Anqing Huajing Electronic Technology Co ltd
Current assignee: Anqing Huajing Electronic Technology Co ltd
Priority date: 2018-11-30
Filing date: 2018-11-30
Publication date: 2021-06-29
Anticipated expiration: 2038-11-30
Also published as: CN109327969A

Abstract

A design method of a circuit board with high-frequency impedance and loss matching adopts PI copper clad laminate with H being 25um thickness as base material, modifies parameters of wiring line width W, line distance i, copper clad thickness t and ground wire grid n of PROTEL software, wherein the line width W takes one value within the range of 0.3-0.35mm, the line distance i takes one value within the range of 1-1.5mm, the copper clad thickness t takes one value within the range of 22-28um, the ground wire grid n takes one value within the range of 0.4-0.45mm, each element is packaged by PROTEL software to generate PCB, and the PCB is printed, transferred, etched, cleaned, punched and welded to obtain a complete circuit board, and the characteristic impedance of the circuit board is obtained: the single end is 50 ohms, the differential impedance is 100 ohms, and the same characteristic impedance of a circuit board obtained by a high-end material is achieved.

Description

Design method of circuit board with high-frequency impedance and loss matching

Technical Field

The invention belongs to the technical field of design and manufacture of high-frequency circuit boards, and particularly relates to the technical field of design and manufacture of a resin-based copper-clad circuit board.

Background

In the high-frequency data transmission in the prior art, impedance matching is required to be ensured, signal loss is required to be at a lower value, the difficulty is improved by using high-frequency high-speed materials in most industries at present, the matching of high-frequency impedance and loss can be well met due to the fact that Dk/Df of the high-frequency high-speed materials is lower than that of conventional materials, but the high-frequency high-speed materials are expensive, the production cost of enterprises is increased, and no good solution is provided for the defect.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, selects a Low Dk material PI polyimide resin matrix composite copper-clad plate with relatively Low cost and good high-frequency performance, performs impedance matching design on the line width, line spacing, copper-clad thickness and ground wire grids of wires on the plate in a matching way, adopts PROTEL software to design a PCB circuit, achieves the aim that the signals can be smoothly transmitted to a receiving end from a transmitting end of a power supply under the condition of minimum energy loss, so that the problems of signal reflection and other electromagnetic interference and signal integrity can be avoided as far as possible, and the stability of the practical use of the PCB can be ensured.

The invention relates to a design method of a high-frequency impedance and loss matching circuit board, wherein a PI polyimide resin matrix composite material is used as a PI copper clad plate of a base material, DK corresponding to the base material is 2.6, DF is 0.002, in the design of a high-frequency circuit, the thickness of the PI copper clad plate is different, the impedance characteristics corresponding to all data of wiring line width, line distance, copper clad thickness and ground wire grid are 50 +/-10% ohm, the line width corresponding to differential impedance of 100 +/-10% ohm is obtained by reducing 10% of the line width W on the basis of the line width corresponding to 50 +/-10% ohm, the line distance i, the copper clad thickness t and the ground wire grid n are the same as the data corresponding to 50 +/-10% ohm, and the impedance value, specification and parameters of the high-frequency circuit designed by the PI copper clad plate with different thicknesses are as follows:

the PI copper-clad plate which uses the PI polyimide resin matrix composite material with the H thickness of 25um as the base material, the corresponding DK of the PI copper-clad plate is 2.6, the DF is 0.002, and according to the high-frequency circuit function, the PROTEL software design principle diagram is adopted to modify and input the parameters of the wiring line width W, the line distance i, the copper-clad thickness t and the ground wire grid n of the PROTEL software: the method comprises the steps of obtaining a value of a line width W within the range of 0.3-0.35mm, obtaining a value of a line distance i within the range of 1-1.5mm, obtaining a value of a copper-clad thickness t within the range of 22-28um, obtaining a value of a ground wire grid n within the range of 0.4-0.45mm, modifying and inputting parameters, establishing encapsulation on each element by PROTEL software to generate a PCB, placing each element and correct wiring according to the PCB surface design, completing the PCB design, printing and outputting a PCB design drawing by using special carbon paper through an ink-jet printer, tightly pressing one surface printed with a PCB design circuit drawing against a copper-clad plate of a PI substrate, placing the copper-clad plate on a heat exchanger for hot printing, transferring circuit drawing ink marks on the carbon paper at high temperature to the copper-clad plate of the PI substrate, etching and cleaning the copper plate printed with the ink marks to obtain a PCB design high-frequency circuit board, punching and welding the elements, testing the circuit board, and (3) detecting the obtained complete circuit board to obtain the characteristic impedance of the circuit board: single ended 50 + -10% ohms, differential impedance 100 + -10% ohms.

Preferably, a PI copper clad laminate with the thickness of H ═ 25um is adopted to carry out PROTEL software wiring, and parameters of the line width W, the line distance i, the copper clad thickness t and the ground wire grid n are modified and input: the method comprises the following steps of modifying parameters, inputting parameters, establishing encapsulation for each element through PROTEL software, generating a PCB, printing, transferring, etching, cleaning, punching and welding components to obtain a complete circuit board, and detecting to obtain the characteristic impedance of the circuit board: single ended 50 + -10% ohms, differential impedance 100 + -10% ohms.

The invention adopts PI polyimide resin matrix composite material with H of 50um thickness as the PI copper clad laminate of the substrate, the corresponding DK of the PI copper clad laminate is 2.6, DF is 0.002, according to the high-frequency circuit function, the PROTEL software design principle diagram is adopted, the wiring line width W, the line distance i, the copper-clad thickness t and the parameters of the ground wire grid n of the PROTEL software are modified and input: the method comprises the steps of obtaining a value of a line width W within the range of 0.5-0.6mm, a value of a line distance i within the range of 1-1.5mm, a value of a copper-clad thickness t within the range of 33-40um, a value of a ground wire grid n within the range of 0.4-0.45mm, modifying and inputting parameters, establishing encapsulation on each element by PROTEL software to generate a PCB, placing each element and correct wiring according to the PCB surface design, completing the PCB design, printing and outputting a PCB design drawing by an ink jet printer by using special carbon paper, closely attaching one surface printed with a PCB design circuit drawing to a copper-clad plate of a PI substrate and pressing the copper-clad plate tightly, placing the copper-clad plate on a heat exchanger for hot stamping, transferring circuit drawing ink marks on the carbon paper to the copper-clad plate of the PI substrate at high temperature, etching and cleaning the copper-clad plate to obtain a PCB design high-frequency circuit board, punching and welding the components, testing the components and the components, and (3) detecting the obtained complete circuit board to obtain the characteristic impedance of the circuit board: single ended 50 + -10% ohms, differential impedance 100 + -10% ohms.

Preferably, a PI copper-clad plate with the thickness of H ═ 50um is adopted to carry out wiring line width, line distance, copper-clad thickness and ground wire grid parameters of PROTEL software for modification input: the line width is 0.5mm, the line spacing is 1mm, the copper-clad thickness is 33um, the ground wire net is 0.45mm, input through parameter modification, establish the encapsulation to each component through PROTEL software, generate PCB to through printing, rendition, etching, washing, punching, welding components and parts, obtain complete circuit board, obtain the characteristic impedance of this circuit board through detecting: single ended 50 + -10% ohms, differential impedance 100 + -10% ohms.

The invention has the beneficial effects that: the PI polyimide resin matrix composite copper clad laminate has the characteristics of relatively low cost and good high-frequency performance, meanwhile, the line width W of a signal line is designed according to the actual requirement of a product, good loss matching is realized, after Dk and the line width meet the loss requirement, the design of a reference layer is adjusted to achieve impedance matching, and the PI material and the wiring method can achieve the characteristic impedance which is the same as that of a high-end material: the single end is 50 +/-10% ohm, and the differential impedance is 100 +/-10% ohm, so that the aim of matching the high-frequency impedance and the loss is fulfilled in a mode of not increasing the production cost.

Drawings

FIG. 1 is a schematic cross-sectional view of a printed circuit board manufactured by PI material.

In the figure: 1, a PI substrate, 2, copper foil, 3, copper foil thickness, 4, line width, 5, line distance and 6, substrate thickness.

Detailed Description

The technical scheme of the invention is clearly and completely described in the following with reference to the accompanying drawings. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Fig. 1 is a schematic cross-sectional structure diagram of a circuit board obtained by producing a PCB from PI material, in which fig. 1 is a PI substrate 1, the PI substrate 1 is a polyimide resin-based composite material, 2 is a copper-clad foil, which is plated on the PI substrate 1, 3 is a copper-clad thickness, 4 is a line width, 5 is a line distance, and 6 is a substrate thickness.

The invention relates to a design method for high-frequency impedance and loss matching, wherein a PI copper clad laminate is made of a PI polyimide resin matrix composite material, DK corresponding to a substrate 1 is 2.6, DF is 0.002, in the design of a high-frequency circuit, the thickness of the PI copper clad laminate is different, the impedance characteristics corresponding to all data of a wiring line width 4, a line distance 5, a copper clad thickness 3 and a ground wire grid are 50 +/-10% ohm, the line width 4 corresponding to a differential impedance of 100 +/-10% ohm is obtained by reducing 10% of the line width 4 on the basis of the line width 4 corresponding to the impedance characteristics of 50 +/-10% ohm, the line distance 5, the copper clad thickness 3 and the ground wire grid n are the same as the data corresponding to the impedance characteristics of 50 +/-10% ohm, and the impedance values, specifications and parameters of the high-frequency circuit designed by the PI copper clad laminate with different thicknesses are as follows:

adopt the polyimide resin base combined material that base plate thickness 6 is 25um to make the copper-clad plate of PI base plate 1, the DK that the PI copper-clad plate corresponds is 2.6, the DF is 0.002, according to the high frequency circuit function, adopts PROTEL software design schematic diagram, revises the input to the wiring line width 4 of PROTEL software, line spacing 5, cover copper thickness 3, the parameter of ground wire net n: the method comprises the steps of inputting a value of a line width 4 in a range of 0.3-0.35mm, a value of a line distance 5 in a range of 1-1.5mm, a value of a copper-clad thickness 3 in a range of 22-28um, and a value of a ground wire grid n in a range of 0.4-0.45mm through parameter modification, establishing encapsulation on each element by PROTEL software to generate a PCB, placing each component and correct wiring according to the PCB surface design, completing the PCB design, printing and outputting a PCB design drawing by an ink-jet printer by using special carbon paper, tightly pressing one surface printed with a PCB design circuit drawing against a copper-clad plate of a PI substrate, placing the copper-clad plate on a heat exchanger for hot printing, transferring circuit drawing ink marks on the carbon paper at high temperature to the copper-clad plate of the PI substrate 1, etching and cleaning the copper-clad plate printed with the ink to obtain a PCB design high-frequency circuit board, punching and welding the components, testing the components and components pass, and (3) detecting the obtained complete circuit board to obtain the characteristic impedance of the circuit board: single ended 50 + -10% ohms, differential impedance 100 + -10% ohms.

In the preferred embodiment of the invention, a PI copper-clad plate with the substrate thickness of 6 being 25um is adopted to carry out PROTEL software wiring, and parameters of the line width of 4, the line distance of 5, the copper-clad thickness of 3 and the ground wire grid n are modified and input: the line width 4 is 0.3mm, the line spacing 5 is 1mm, the copper-clad thickness 3 is 22um, ground wire net n is 0.4mm, input after modifying the parameter, establish the encapsulation to each component through PROTEL software, generate PCB, and through printing, rendition, etching, washing, punching, welding components and parts, obtain complete circuit board, obtain the characteristic impedance of this circuit board through detecting: single ended 50 + -10% ohms, differential impedance 100 + -10% ohms.

The invention also provides a design method for high-frequency impedance and loss matching, which adopts a polyimide resin matrix composite material with the substrate thickness of 50um as a copper-clad plate of a PI substrate 1, the corresponding DK of the PI copper-clad plate is 2.6, the DF is 0.002, and according to the high-frequency circuit function, a PROTEL software design principle diagram is adopted to modify and input the parameters of the wiring line width 4, the line distance 5, the copper-clad thickness 3 and the ground wire grid of the PROTEL software: the method comprises the steps of obtaining a value of a line width 4 within a range of 0.5-0.6mm, obtaining a value of a line distance 5 within a range of 1-1.5mm, obtaining a value of a copper-clad thickness 3 within a range of 33-40um, obtaining a value of a ground wire grid n within a range of 0.4-0.45mm, modifying and inputting parameters, establishing encapsulation on each element by PROTEL software to generate a PCB, placing each element and correct wiring according to the PCB surface design, completing the PCB design, printing and outputting a PCB design drawing by using special carbon paper through an ink-jet printer, pressing one surface printed with a PCB design circuit drawing tightly against a copper-clad plate of a PI substrate, placing the copper-clad plate on a heat exchanger for hot printing, transferring circuit drawing ink marks on the carbon paper at high temperature to the copper-clad plate of the PI substrate, etching and cleaning the copper-clad plate to obtain a PCB design high-frequency circuit board, punching and welding the components, testing the components, and (3) detecting the obtained complete circuit board to obtain the characteristic impedance of the circuit board: single end 50 + -10% ohm, differential impedance 100 + -10% ohm;

in another preferred embodiment of the invention, a PI copper-clad plate with the thickness of 50um is adopted to carry out wiring line width 4, line distance 5, copper-clad thickness 3 and ground wire grid parameters of PROTEL software for modification input: the line width 4 is 0.5mm, the line spacing 5 is 1mm, the copper-clad thickness 3 is 33um, the ground wire net is 0.45mm, input through parameter modification, establish the encapsulation to each component through PROTEL software, generate PCB to through printing, rendition, etching, washing, punch, welding components and parts, obtain complete circuit board, obtain the characteristic impedance of this circuit board through detecting: single ended 50 + -10% ohms, differential impedance 100 + -10% ohms.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to cover the technical scope of the present invention, the equivalent substitution or change according to the technical solution and the concept of the present invention within the technical scope of the present invention.

Claims

1. A design method of a circuit board with high-frequency impedance and loss matching is characterized in that,

the method comprises the following steps: the PI copper clad laminate using PI polyimide resin based composite material as substrate has DK of 2.6 and DF of 0.002, in the design of high frequency circuit, the PI copper clad laminate has different thickness, the impedance characteristic corresponding to all data of wiring line width, line distance, copper clad thickness and ground wire grid is 50 + -10% ohm, the line width corresponding to differential impedance of 100 + -10% ohm is obtained by reducing 10% of the line width on the basis of the line width corresponding to 50 + -10% ohm, the data corresponding to the line distance, the copper clad thickness and the ground wire grid and the impedance characteristic of 50 + -10% ohm are the same, the impedance value, specification and parameter of the high frequency circuit designed by the PI copper clad laminate with different thickness are as follows:

。

2. a method for designing a circuit board with high-frequency impedance and loss matching according to claim 1, wherein: adopt the PI polyimide resin base combined material that thickness is 25um to make the PI copper-clad plate of substrate, this PI copper-clad plate corresponds DK is 2.6, DF is 0.002, according to the high frequency circuit function, adopts PROTEL software design schematic diagram, revises the input to the wiring line width of PROTEL software, line distance, cover copper thickness, the parameter of ground wire net: the line width is 0.3-0.35mm, the line distance is 1-1.5mm, the copper-clad thickness is 22-28um, the ground wire grid is 0.4-0.45mm, the components are packaged by PROTEL software after inputting parameter values, generating PCB, placing components and checking correct wiring according to PCB surface design, completing PCB design, using special carbon paper to print PCB design picture by ink-jet printer, pressing one surface printed with PCB design circuit picture tightly against the copper-clad plate of PI base material, and placing on heat exchanger to carry out hot printing, transferring the circuit picture ink on carbon paper to the copper-clad plate of PI base material at high temperature, etching and cleaning the copper plate printed with ink to obtain PCB design circuit board, punching and welding components, testing, the impedance value, specification and parameters of the obtained complete circuit board are as follows:

the characteristic impedance of the circuit board is obtained through detection: single ended 50 + -10% ohms, differential impedance 100 + -10% ohms.

3. A method for designing a circuit board for matching high-frequency impedance with loss according to claim 1 or 2, wherein: assigning and inputting a group of parameters of the wiring line width, the line distance, the copper-clad thickness and the ground wire grid of PROTEL software by adopting a PI copper-clad plate with the thickness of 25 um: the line width is 0.3mm, the line spacing is 1mm, the copper-clad thickness is 22um, the ground wire net is 0.4mm, through the input of this group of parameters, utilize PROTEL software to establish the encapsulation to each component, generate PCB to through printing, rendition, etching, washing, punch, welding components and parts, obtain complete circuit board, obtain the characteristic impedance of this circuit board through detecting: single ended 50 + -10% ohms, differential impedance 100 + -10% ohms.

4. A method for designing a circuit board with high-frequency impedance and loss matching according to claim 1, wherein: the PI copper-clad plate which adopts PI polyimide resin matrix composite material with the thickness of 50um as a base material has the corresponding DK of 2.6 and the DF of 0.002, adopts a PROTEL software design principle diagram according to the function of a high-frequency circuit, and modifies and inputs the wiring line width, the line distance, the copper-clad thickness and the parameters of a ground wire grid of the PROTEL software: the line width is 0.5-0.6mm, the line distance is 1-1.5mm, the copper-clad thickness is 33-40um, the ground wire grid is 0.4-0.45mm, after the parameters are modified and input, the PROTEL software is used to build up package for each element, to generate PCB, each element and correct wiring are placed according to the PCB surface design, to complete PCB design, the special carbon paper is used to print and output PCB design picture by ink-jet printer, one surface printed with PCB design circuit picture is tightly attached to the copper-clad plate of PI base material and pressed tightly, and put on a heat exchanger for hot printing, the circuit picture ink on the carbon paper is transferred on the copper-clad plate of PI base material at high temperature, the copper plate printed with ink is etched and cleaned at high frequency, to obtain PCB design circuit board, after punching and welding elements, the test is passed, the impedance value, specification and parameters of the obtained complete circuit board are as follows:

5. A method for designing a circuit board with high-frequency impedance and loss matching according to claim 1, wherein: modifying and inputting the parameters of the wiring line width, the line distance, the copper-clad thickness and the ground wire grid of PROTEL software by adopting a PI copper-clad plate with the thickness of 50 um: the line width is 0.5mm, the line spacing is 1mm, the copper-clad thickness is 33um, the ground wire net is 0.45mm, input through the parameter value, utilize PROTEL software to establish the encapsulation to each component, generate PCB to through printing, rendition, etching, washing, punching, welding components and parts, obtain complete circuit board, obtain the characteristic impedance of this circuit board through detecting: single ended 50 + -10% ohms, differential impedance 100 + -10% ohms.