A method for controlling local area expansion and contraction of a PCB

Abstract

The application discloses a control method for expansion and contraction of a local area of a PCB (Printed Circuit Board), which comprises the following steps: designing a site; manufacturing the site; manufacturing the site in the longitude and latitude directions of the process edge of a unit area, and obtaining the original coordinate value of the site according to original data; obtaining the offset coordinate value of the site, obtaining the actual coordinate value of the site after pressing, and calculating the offset coordinate value of the site; calculating the expansion and contraction coefficient of the unit area by using the corresponding edge length value and the offset coordinate value; and segmentally manufacturing an expansion and contraction file according to the expansion and contraction coefficient of the corresponding unit area.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of PCB boards, and particularly relates to a control method for local area expansion and contraction of a PCB board. BACKGROUND

[0002] In a manufacturing process flow of a printed circuit board, board expansion and contraction has an important influence on the final process precision of a product. In the actual application of the board expansion and contraction law, most of the time, the overall expansion and contraction range of the board is controlled by 3 or 4 peripheral alignment holes, and the problem of local expansion and contraction of the board is not considered and solved. In particular, when high-layer back plates and uneven copper residues are dealt with, local expansion and contraction is often more obvious. According to the previous method of measuring and calculating the expansion and contraction coefficient, the alignment accuracy problem cannot be solved, and even the positioning deviation problem in the later process is aggravated, resulting in scrap. SUMMARY

[0003] Therefore, it is necessary to provide a control method for local area expansion and contraction of a PCB board to solve the alignment accuracy problem.

[0004] A control method for local area expansion and contraction of a PCB board, comprising

[0005] S1, alignment point design, the number of alignment points is determined according to the number of PCB board spliced boards and process precision requirements, and the number value of the alignment points in the longitudinal and latitudinal directions of the unit area process edge is obtained through formula derivation;

[0006] S2, alignment point manufacturing; the alignment points are manufactured in the longitudinal and latitudinal directions of the unit area process edge, and the original coordinate values of the alignment points are obtained according to original data;

[0007] S3, offset coordinate value of the alignment point is obtained, actual coordinate value of the alignment point is obtained after pressing, and the offset coordinate value of the alignment point is calculated by comparing the original coordinate value and the actual coordinate value of the alignment point.

[0008] S4, expansion and contraction coefficient is calculated, and the expansion and contraction coefficient of the unit area is calculated by using the corresponding edge length value and the offset coordinate value of the unit area;

[0009] S5, expansion and contraction file manufacturing, the expansion and contraction file is manufactured in sections according to the expansion and contraction coefficient of the corresponding unit area, and the later process of each unit area is adjusted and optimized.

[0010] In one embodiment, in S1, when the number of spliced boards is less than or equal to four, the number of alignment points in the longitudinal and latitudinal directions is the same; the number of alignment points is [n] >= Max(X,Y)*Z / △P, △P is an acceptable expansion and contraction size error value; Z is the expansion and contraction control precision; Max(X,Y) is the longer edge length value in the longitudinal and latitudinal directions, and [n] is an upward integer value.

[0011] In one of the embodiments, in S1, when the total number of the panels is greater than four, the number of the latitude and longitude directions of the alignment points is the number of the latitude and longitude direction units plus 1.

[0012] In one of the embodiments, △P=0.075mm.

[0013] In one of the embodiments, the calculation formula of the expansion and contraction coefficient is: X coefficient=(X''+△X) / CAM X, Y coefficient=(Y''+△Y) / CAM Y, θ deflection coefficient=(θ+△θ) / 90°, X'', Y'' are the length values of the corresponding edges of the unit area, θ is the angle between the original coordinate point of the alignment point and the actual coordinate point of the alignment point, △X is the change value of the alignment point in the X direction, △Y is the change value of the alignment point in the Y direction, △θ is the change value of the angle θ in the vertical direction, the default value of θ is 90°, CAM X and CAM Y are the design values of the original file drill tape, i.e. the standard values.

[0014] In one of the embodiments, the change values of the alignment point in the X, Y directions and the deflection angle in the corresponding panel latitude and longitude directions are obtained by integration, i.e. △X=∫f(x)dx, △Y=∫f(y)dy,

[0015] △θ= .

[0016] In one of the embodiments, the change rate in the corresponding latitude and longitude directions is calculated as: f(x)=(X’-X) / (Y’-Y), f(y)=(Y’-Y) / (X’-X), X, Y, X', Y' are the coordinate values of the points inside the panel.

[0017] In one of the embodiments, the position of the alignment point is distinguished from the position of the positioning hole.

[0018] In one of the embodiments, the original alignment point of the latitude and longitude direction is a common alignment point.

[0019] In one of the embodiments, the alignment point is a marker point.

[0020] In one of the embodiments, the method for making the expansion and contraction file is:

[0021] S11, determining the unit area that produces expansion and contraction;

[0022] S12, recording the expansion and contraction coefficient of the unit area that produces expansion and contraction into the CAM file of the corresponding area;

[0023] S13, revising the CAM file of the corresponding area to obtain a revised CAM file;

[0024] S14, compensating the unit area that produces expansion and contraction according to the revised CAM file.

[0025] S15, repositioning the spliced board.

[0026] The method for obtaining the expansion and contraction coefficient of the unit area of the PCB board determines the number of positioning points according to the number of spliced boards of the PCB board and the process precision requirement, obtains the number value of the positioning points in the longitudinal and latitudinal directions of the process edge of the unit area through formula derivation, makes the positioning points in the longitudinal and latitudinal directions of the process edge of the unit area, obtains the original coordinate value of the positioning points according to the original data, obtains the actual coordinate value of the positioning points after pressing, calculates the offset coordinate value of the positioning points by comparing the original coordinate value and the actual coordinate value of the positioning points, calculates the expansion and contraction coefficient of the unit area by using the corresponding edge length value and the offset coordinate value of the unit area; segmentally making the expansion and contraction file, adjusting and optimizing the post-process of each unit area, effectively reducing the negative influence of the unit area expansion and contraction of the board on the graphic precision of the printed circuit board, providing basis for optimizing the corresponding circuit design, and making the circuit board gradually get rid of the influence of local expansion and contraction. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A flow chart of a PCB board local area expansion and contraction control method of the present application;

[0028] Figure 2 A schematic structural diagram of a PCB board before and after pressing of a PCB board local area expansion and contraction control method of the present application;

[0029] Figure 3 A schematic structural diagram of a unit area positioning point setting of a PCB board local area expansion and contraction control method of the present application;

[0030] Figure 4 A schematic structural diagram of a unit area compensation after reduction of a PCB board local area expansion and contraction control method of the present application;

[0031] Figure 5 A schematic structural diagram of a unit area compensation after expansion of a PCB board local area expansion and contraction control method of the present application;

[0032] Figure 6 A schematic structural diagram of a unit area compensation after deflection of a PCB board local area expansion and contraction control method of the present application. DETAILED DESCRIPTION

[0033] In order to make the above objectives, features and advantages of the present application more clear and easily understood, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different manners according to the teachings of the present application, and thus the present application is not limited to the specific embodiments described below. Instead, the present application is well suited to the use of a variety of embodiments and obvious modifications thereof.

[0034] It should be noted that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can be present. In contrast, when an element is referred to as being "directly connected" to another element, there are no intervening elements present.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this description, the singular forms "a", "an" and "the" include plural references unless the context clearly dictates otherwise. The term "and / or" includes any and all combinations of one or more of the associated listed items.

[0036] As shown in Figure 1 , Figure 2 , Figure 3 A method for controlling the expansion and contraction of a local area of a PCB board, comprising

[0037] S1, designing the alignment points 100, determining the number of alignment points 100 according to the number of PCB board panels and the process accuracy requirements, and obtaining the number value of the alignment points 100 in the longitudinal and latitudinal directions of the process edge of the unit area through formula derivation;

[0038] S2, manufacturing the alignment points 100; manufacturing the alignment points 100 in the longitudinal and latitudinal directions of the process edge of the unit area, and obtaining the original coordinate value of the alignment points 100 according to the original data;

[0039] S3, obtaining the offset coordinate value of the alignment points 100, obtaining the actual coordinate value of the alignment points 100 after pressing, and calculating the offset coordinate value of the alignment points 100 by comparing the original coordinate value and the actual coordinate value of the alignment points 100;

[0040] S4, calculating the expansion and contraction coefficient, calculating the expansion and contraction coefficient of the unit area by using the corresponding edge length value and the offset coordinate value of the unit area;

[0041] S5, expansion and contraction file manufacturing, manufacturing the expansion and contraction file in sections according to the expansion and contraction coefficient of the corresponding unit area, and adjusting and optimizing the subsequent processes of each unit area.

[0042] In one of the embodiments, in S1, when the number of the panels is less than or equal to four, the number of the alignment points 100 in the warp and weft directions is the same; the number of the alignment points 100 is [n]≥Max(X,Y)*Z / △P,△P-acceptable size error value of expansion and contraction; Z-expansion and contraction control accuracy; Max(X,Y)-the length value of the longer side in the warp and weft directions, and [n] is the upward integer value.

[0043] In one of the embodiments, in S1, when the total number of the panels is greater than four, the number of the alignment points 100 in the warp and weft directions is the number of the unit in the warp and weft directions plus 1.

[0044] In one of the embodiments,△P=0.075mm.

[0045] In one of the embodiments, the expansion and contraction coefficient calculation formula is: X coefficient=(X''+△X) / CAM X, Y coefficient=(Y''+△Y) / CAM Y, θ deflection coefficient=(θ+△θ) / 90°, X'', Y'' are the length values of the corresponding edges of the unit area, θ is the angle between the original coordinate point of the alignment point 100 and the actual coordinate point of the alignment point 100,△X is the change value of the alignment point 100 in the X direction,△Y is the change value of the alignment point 100 in the Y direction,△θ is the change value of the angle θ in the vertical direction, the default value of θ is 90°, and CAM X and CAM Y are the design values of the original file drill tape, i.e. the standard values.

[0046] In one of the embodiments, the change values of the alignment points in the X and Y directions and the deflection angle in the corresponding panel warp and weft directions are obtained by integration, i.e.△X=∫f(x)dx,△Y=∫f(y)dy,

[0047] △θ= .

[0048] In one of the embodiments, the change rate in the corresponding warp and weft directions is calculated as: f(x)=(X’-X) / (Y’-Y), f(y)=(Y’-Y) / (X’-X), X, Y, X', Y' are coordinate values of the points inside the panel.

[0049] In one of the embodiments, the position of the alignment point 100 is distinguished from the position of the positioning hole.

[0050] In one of the embodiments, the origin alignment point 100 in the warp and weft directions is a common alignment point 100.

[0051] In one of the embodiments, the alignment point 100 is a marking point.

[0052] In one of the embodiments, the production method of the expansion and contraction file is:

[0053] S11, determine the unit area that generates expansion and contraction;

[0054] S12, record the expansion and contraction coefficient of the unit area that generates expansion and contraction into the CAM file corresponding to the area;

[0055] S13, revise the CAM file corresponding to the area to obtain a revised CAM file;

[0056] S14, compensate for the unit area that generates expansion and contraction according to the revised CAM file;

[0057] S15, reposition the panel.

[0058] Usually, the positioning holes of the PCB board we design are four points of a board, distributed at four corner points. In order to prevent mistakes, the four points are usually designed as a right trapezoidal four points. By measuring the length of the actual two right angles and the length of the theoretical value, the change value is obtained, and the corresponding expansion and contraction coefficient in two directions is calculated, and the feedback is given to the engineering completion data ratio change. Because the current PCB board is usually composed of multiple panels, the expansion and contraction coefficients of each panel are different, and calculating the expansion and contraction coefficient of the whole board can easily lead to a great reduction in the accuracy of the expansion and contraction coefficient, providing incorrect information for subsequent processing and production. Therefore, the application provides a method for calculating the expansion and contraction coefficient of a unit area. According to different accuracy requirements, different unit areas can be selected to calculate the expansion and contraction coefficient. For example, 1 SET, 1 PCS. The panel in the application is SET.

[0059] Embodiment 1: when the number of panels is less than or equal to four;

[0060] A control method for local area expansion and contraction of a PCB board, comprising

[0061] S1, design the alignment point 100, and set the same number of alignment points 100 on the warp and weft directions on both sides of the unit area process edge; the number and spacing of the alignment points 100 can be further adjusted according to the accuracy requirements;

[0062] S2, make the alignment point 100, make the alignment point 100 on the warp and weft directions on both sides of the unit area process edge and obtain the original coordinate value of the alignment point 100; the original coordinate of the alignment point 100 is set as P(X, Y);

[0063] S3, obtain the offset coordinate value of the site 100, obtain the actual coordinate value of the site 100 after pressing, calculate the offset coordinate value of the site 100 by comparing the original coordinate value and the actual coordinate value of the site 100; the actual coordinate value is set as P'(X', Y'), the direction vector of the expansion and contraction is PP'(X'-X, Y'-Y), and the change rate corresponding to the latitude and longitude directions can be calculated as: the change rate f(x) of the X direction is (X'-X) / (Y'-Y), the change rate f(y) of the Y direction is (Y'-Y) / (X'-X), the change of angle θ is Δθ=arccos((X'-X)2 / √((X'-X)2+(Y'-Y)2)), and the offset coordinate value of the site 100 is obtained by integration in the form of ΔX=∫f(x)dx, ΔY=∫f(y)dx, and Δθ=arccos((X'-X)2 / √((X'-X)2+(Y'-Y)2));

[0064] S4, calculate the expansion and contraction coefficient, calculate the expansion and contraction coefficient of the unit area by using the corresponding edge length value and the offset coordinate value of the unit area;

[0065] Then the expansion and contraction coefficient of the unit area in the corresponding direction is: X coefficient=(X''+△X) / CAM X, Y coefficient=(Y''+△Y) / CAM Y, and θ deflection coefficient=(θ+△θ) / 90°, that is, the expansion and contraction coefficients of different points are obtained; X'', Y'' are the length values of the edges corresponding to the unit area, θ is the angle between the original coordinate point of the site 100 and the actual coordinate point of the site 100, △X is the change value of the site 100 in the X direction, △Y is the change value of the site 100 in the Y direction, and △θ is the change value of the angle θ in the vertical direction. The default value of θ is 90°, which is the angle between the latitude and longitude perpendicular directions, and CAM X and CAM Y are the design values of the original file drill tape, that is, the standard values;

[0066] S5, expansion and contraction file making, according to the expansion and contraction coefficient of the corresponding unit area, the expansion and contraction file is made in sections, and the subsequent process of each unit area is adjusted and optimized; different expansion and contraction files are made according to different expansion and contraction coefficients of different unit areas.

[0067] Embodiment 2: when the number of assembled boards is greater than four;

[0068] A control method for local area expansion and contraction of a PCB, comprising

[0069] S1, site 100 design, determine the number of latitude and longitude direction sites 100 on both sides of the process edge of the unit area according to the number of assembled boards; for example, one assembled M*N board, the number of latitude and longitude direction sites 100 is M+1, N+1;

[0070] S2, making the alignment point 100, making the alignment point 100 in the longitudinal and latitudinal direction on both sides of the unit area process edge and obtaining the original coordinate value of the alignment point 100; the original coordinate value of the alignment point 100 is set as P(X, Y);

[0071] S3, obtaining the offset coordinate value of the alignment point 100, obtaining the actual coordinate value of the alignment point 100 after pressing, and calculating the offset coordinate value of the alignment point 100 by comparing the original coordinate value and the actual coordinate value of the alignment point 100; the actual coordinate value is set as P'(X', Y'), and the direction vector of the expansion and contraction is PP'(X'-X, Y'-Y), so the change rate corresponding to the longitudinal and latitudinal direction can be calculated: the change rate f(x) of X direction is (X'-X) / (Y'-Y), the change rate f(y) of Y direction is (Y'-Y) / (X'-X), the change △θ of angle θ is arccos((X'-X)2 / √((X'-X)2+(Y'-Y)2)), and the offset coordinate value △X of the alignment point 100 is obtained by integration: △X=∫f(x)dx, △Y=∫f(y)dx, and △θ=arccos((X'-X)2 / √((X'-X)2+(Y'-Y)2));

[0072] S4, calculating the expansion and contraction coefficient, calculating the expansion and contraction coefficient of the unit area by using the length value of the corresponding edge of the unit area and the offset coordinate value;

[0073] Then the expansion and contraction coefficient of the corresponding direction of the unit area is: X coefficient=(X''+△X) / CAM X, Y coefficient=(Y''+△Y) / CAM Y, and θ deflection coefficient=(θ+△θ) / 90°, that is, the expansion and contraction coefficients of different points are obtained; X'', Y'' are the length values of the corresponding edges of the unit area, θ is the included angle between the original coordinate point of the alignment point 100 and the actual coordinate point of the alignment point 100, △X is the change value of the alignment point 100 in X direction, △Y is the change value of the alignment point 100 in Y direction, and △θ is the change value of the angle θ in the vertical direction; the default value of θ is 90°, which is the vertical angle of longitude and latitude; CAM X and CAM Y are the design values of the original file drill tape, that is, the standard values;

[0074] S5, expansion and contraction file making, making expansion and contraction files in sections according to the expansion and contraction coefficients of the corresponding unit areas, and adjusting and optimizing the post-process of each unit area; different expansion and contraction files are made according to different expansion and contraction coefficients of different unit areas.

[0075] Thus, the method for obtaining the expansion coefficient of the unit area of the PCB plate determines the number of the alignment points 100 according to the number of the spliced plates and the process precision requirement, obtains the number value of the alignment points 100 in the longitudinal and latitudinal directions of the unit area process edge through formula derivation, makes the alignment points 100 in the longitudinal and latitudinal directions of the unit area process edge, and obtains the original coordinate value of the alignment points 100 according to the original data, obtains the actual coordinate value of the alignment points 100 after pressing, calculates the offset coordinate value of the alignment points 100 by comparing the original coordinate value and the actual coordinate value of the alignment points 100, and calculates the expansion coefficient of the unit area by using the corresponding edge length value and the offset coordinate value of the unit area; the expansion file is made in sections, the post-process of each unit area is adjusted and optimized, the negative influence of the expansion of the unit area of the plate on the graphic precision of the printed circuit board is effectively reduced, the basis is provided for optimizing the corresponding circuit design, and the circuit board is gradually freed from the influence of local expansion.

[0076] Further, when the number of spliced plates is less than or equal to four, the adaptive number of alignment points 100 is arranged in the longitudinal and latitudinal directions on both sides of the unit area process edge, and the number of the alignment points 100 is n≥Max(X,Y)*Z / △P,△P is an acceptable expansion size error value; Z is the precision to be controlled; Max(X,Y) is the longer edge length value in the longitudinal and latitudinal directions, and [n] is an upward integer value.

[0077] Because it is impossible to arrange an infinite number of alignment points 100 on two edges of a spliced plate, the adaptive number of corresponding points is arranged according to the precision requirement to control the expansion coefficient.△P is an acceptable size error value,△P=0.075mm, Z is the precision to be controlled, which is determined according to the actual precision requirement, and is generally not less than 4 / 1000, otherwise the number of the alignment points 100 is too large, which affects the arrangement of other positioning holes, Max(X,Y) is the longer edge length value in the longitudinal and latitudinal directions, that is, the longer edge value in the two mutually perpendicular edges of a spliced plate, when the number n of the alignment points 100 is calculated, the calculated value is usually a decimal value, but the value of the alignment points 100 needs to be an integer value, so we use the upward value method to make n an integer value, for example, if the calculated n value is 5.2, we take n as 6.

[0078] Thus, the number of the adaptive alignment points 100 of the unit area can be obtained through the formula of the number of the alignment points 100, which ensures the accuracy of the expansion coefficient and does not hinder the arrangement of other positioning holes.

[0079] Further, the alignment points 100 need to be distinguished from the positioning hole patterns actually punched by X-ray, the X-ray punching positioning hole only punches the positioning hole for the post-process, and the alignment points 100 only record the position coordinate value.

[0080] Further, the site 100 is only a marking point, and the marking of the site 100 will be removed in the subsequent die sinking process, and will not be left on the plate to affect the subsequent process.

[0081] As shown in Figure 4 、 Figure 5 、 Figure 6 Further, the method for making the expansion file is as follows:

[0082] S11, determining a unit area to be expanded;

[0083] S12, recording the expansion coefficient of the unit area to be expanded in the CAM file of the corresponding area;

[0084] S13, revising the CAM file of the corresponding area to obtain a revised CAM file;

[0085] S14, compensating the unit area to be expanded according to the revised CAM file; for example, if the unit area is reduced, the CAM file is enlarged by a preset ratio during the modification, so that the unit area actually compressed after the reduction can meet the normal ratio and can be spliced with other plates; if the unit area is expanded, the CAM file is reduced by a preset ratio during the modification, so that the unit area actually compressed after the expansion can meet the normal ratio and can be spliced with other plates; if the unit area is deflected, the CAM file is adjusted by a preset ratio during the modification, so that the unit area actually compressed after the deflection can meet the normal ratio and can be spliced with other plates.

[0086] S15, repositioning the plate. Whether it is expansion or reduction, the repositioning is performed in the direction close to the zero coordinate point. When the plate is divided into unit areas by a single SET, the original connectivity of the line will not be affected, and the unit area can be directly modified and repositioned according to the expansion coefficient.

[0087] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not conflict, they should be considered within the scope of the present disclosure.

[0088] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A method for controlling the expansion and contraction of a local area of a PCB board, characterized by: Comprising S1, determining the number of alignment points according to the number of PCB boards and the process precision requirements, and obtaining the number of alignment points in the longitudinal and latitudinal directions of the process edge of the unit area through formula derivation; S2, making alignment points; the alignment points are made in the longitudinal and latitudinal directions of the process edge of the unit area, and the original coordinate values of the alignment points are obtained according to the original data; S3, obtaining the offset coordinate values of the alignment points, obtaining the actual coordinate values of the alignment points after pressing, and calculating the offset coordinate values of the alignment points by comparing the original coordinate values and the actual coordinate values of the alignment points; S4, calculating the expansion and contraction coefficient, and calculating the expansion and contraction coefficient of the unit area by using the length value of the corresponding edge of the unit area and the offset coordinate value; S5, expansion and contraction file making, according to the expansion and contraction coefficient of the corresponding unit area, segmented expansion and contraction file making, and adjusting and optimizing the post-process of each unit area; In S1, when the number of boards is less than or equal to four, the number of alignment points in the longitudinal and latitudinal directions is the same; the number of alignment points is: [n]≥Max(X,Y)*Z / △P,△P-acceptable expansion and contraction size error value; Z-expansion and contraction control precision; Max(X,Y)-the longer edge length value in the longitudinal and latitudinal directions, and [n] is the integer value taken upward; In S1, when the total number of boards is greater than four, the number of alignment points in the longitudinal and latitudinal directions is the unit number in the longitudinal and latitudinal directions plus 1.

2. The method of claim 1, wherein the method further comprises: determining a target thickness of the PCB board; and adjusting the thickness of the PCB board to the target thickness. △P=0.075mm.

3. The method of claim 1, wherein the method further comprises: determining a target thickness of the PCB board; and adjusting the thickness of the PCB board to the target thickness. The expansion and contraction coefficient calculation formula is: X coefficient=(X”+△X) / CAM X, Y coefficient=(Y”+△Y) / CAM Y, θ deflection coefficient=(θ+△θ) / 90°, X”, Y” are the length values of the corresponding edges of the unit area, θ is the included angle between the original coordinate point of the alignment point and the actual coordinate point of the alignment point, △X is the change value of the alignment point in the X direction, △Y is the change value of the alignment point in the Y direction, △θ is the change value of the angle θ along the vertical direction, the default value of θ is 90°, CAM X and CAM Y are the design values of the original file drilling tape, that is, the standard values.

4. The method of claim 3, wherein the method further comprises: applying a first voltage to the first electrode; and applying a second voltage to the second electrode. The change values of the alignment points in the X, Y directions and the deflection angle in the corresponding plate longitudinal and latitudinal directions are obtained by integration, that is, △X=∫f(x)dx, △Y=∫f(y)dy, △θ= The change rate of the corresponding longitudinal and latitudinal directions is calculated: f(x)=(X'-X) / (Y'-Y), f(y)=(Y'-Y) / (X'-X), X, Y, X', Y' are all coordinate values of points inside the plate.

5. The method of claim 1, wherein the method further comprises: applying a first voltage to the first electrode; and applying a second voltage to the second electrode. The position of the alignment point is different from that of the positioning hole.

6. The method of claim 1, wherein the method further comprises: applying a first voltage to the first electrode; and applying a second voltage to the second electrode. The origin alignment point in the longitudinal and latitudinal directions is a common alignment point.

7. The method of claim 1, wherein the method further comprises: applying a first voltage to the first electrode; and applying a second voltage to the second electrode. The alignment point is a mark point.

8. The method of claim 1, wherein the method further comprises: applying a first voltage to the first electrode; and applying a second voltage to the second electrode. The expansion and contraction file making method is: S11, determining the unit area that produces expansion and contraction; S12, entering the expansion and contraction coefficient of the unit area that produces expansion and contraction into the CAM file of the corresponding area; S13, revising the CAM file of the corresponding area to obtain a revised CAM file; S14, compensating the unit area that produces expansion and contraction according to the revised CAM file; S15, repositioning the boards.

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