Etching compensation method

Abstract

An etching compensation method comprises the following steps: dividing a to-be-compensated line contour according to a stepping value to obtain division points of the to-be-compensated line contour, respectively calculating a compensation normal vector of an analysis point consisting of a starting point, the division points and an end point of the to-be-compensated line contour, and obtaining the distance between the analysis point and an adjacent contour in the direction of the compensation normal vector, and obtaining an etching compensation value according to the distance between the analysis point and the adjacent contour in the direction of the compensation normal vector, determining a compensation boundary of the analysis point according to the etching compensation value, and connecting the compensation boundary to obtain an etching compensation contour of the line contour to be compensated. According to the etching compensation method, the stepping value is set, the spacing distance between the adjacent line contours is calculated at different positions of the line contours respectively, etching compensation is carried out respectively, the etching compensation precision is improved, and the problem of uneven etching is solved.

Description

Technical Field

[0001] The invention relates to an etching compensation method, in particular to an etching compensation method applied to a circuit board. Background Art

[0002] During the production of circuit boards, part of the copper layer needs to be removed through the etching process. During the etching process, the density of the circuit distribution of the circuit board will cause differences in the exchange speed of the solution. In the position where the gap between the circuits is relatively wide, the solution is unobstructed, the exchange is fast, and the etching amount is large. In the area with dense circuits, the gap between the circuits is relatively narrow, the solution exchange is slow, the etching amount is small, and thus the etching will be uneven. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an etching compensation method to solve the problem of uneven etching.

[0004] To achieve the above-mentioned purpose, an etching compensation method is provided, which divides the contour of the circuit to be compensated according to the step value to obtain the division points of the contour of the circuit to be compensated, calculates the compensation normal vector for the analysis points consisting of the starting point, division point and end point of the contour of the circuit to be compensated, obtains the distance between the analysis point and the adjacent contour in the direction of the compensation normal vector, obtains the etching compensation value based on the distance between the analysis point and the adjacent contour in the direction of the compensation normal vector, determines the etching compensation boundary of the analysis point according to the etching compensation value, and connects the compensation boundary to obtain the etching compensation contour of the contour of the circuit to be compensated.

[0005] Preferably, when the analysis point is a common point of two line segments, the compensation normal vector of the analysis point is the angle bisector of the two line segment normal vectors; when the analysis point is a non-line segment common point on a straight line segment, its compensation normal vector is the normal vector of the line segment at that point; when the analysis point is a non-line segment common point on an arc segment, the normal vector is the normal vector of the tangent of that point on the arc.

[0006] Preferably, when obtaining the distance between the analysis point and the adjacent contour in the direction of the compensation normal vector, a ray is drawn in the direction of the compensation normal vector until it intersects with the adjacent line contour, and the distance between the analysis point and the intersection point is the spacing distance between the analysis point and the adjacent line contour.

[0007] Preferably, when determining the etching compensation boundary of the analysis point, a circle is drawn with the absolute value of the etching compensation value as the radius and the analysis point as the center.

[0008] Preferably, if the etching compensation value is positive, the circle drawn is a positive film, otherwise it is a negative film; a positive film is to add a circle for compensation and shorten the distance between the two line contours, and a negative film is to cut the circle for compensation and increase the distance between the two contours.

[0009] Preferably, before performing etching compensation processing, an etching compensation table is obtained in advance, and the etching compensation table is obtained according to the distance value that needs to be compensated corresponding to the distance between adjacent contours in the circuit board circuit diagram. The etching compensation table includes the distance between adjacent contours and the corresponding etching compensation value.

[0010] Preferably, for consecutive analysis points with the same etching compensation value, the etching compensation boundary is determined only for the first and last analysis points in the consecutive analysis points, and the etching compensation boundary of the first and last analysis points in the consecutive analysis points are connected according to the corresponding line contour to determine the etching compensation contour.

[0011] Preferably, when determining the etching compensation boundary, if the etching compensation value of the current analysis point is the same as the etching compensation value of the previous analysis point, then there is no need to determine the etching compensation boundary for the current analysis point, and the process directly steps to the next analysis point.

[0012] Preferably, when determining the etching compensation boundary, if the etching compensation value of the current analysis point is different from the etching compensation value of the previous analysis point, the etching compensation boundary of the current analysis point is determined, and the etching compensation boundary of the previous analysis point is determined.

[0013] Preferably, the step value of the line profile compensation is set according to the accuracy of the etching compensation.

[0014] Compared with the prior art, the present invention calculates the spacing distances between adjacent line contours at different positions of the line contours by setting a step value, and performs etching compensation respectively, thereby improving the accuracy of etching compensation and solving the problem of uneven etching. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of the etching compensation method.

[0016] Figure 2 It is a schematic diagram of line segment contour division.

[0017] Figure 3 It is a schematic diagram of arc contour division.

[0018] Figure 4 It is a schematic diagram of the compensation normal vector.

[0019] Figure 5 Schematic diagram of the spacing distance and etching compensation boundary.

[0020] Figure 6 FIG. 1 is a schematic diagram of an embodiment of an etching compensation method.

[0021] Figure 7 FIG. 4 is a schematic diagram of a method for determining an etching compensation boundary in another embodiment of the etching compensation method.

[0022] Figure 8This is a schematic diagram of the etching compensation effect. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described below with reference to specific embodiments shown in the accompanying drawings.

[0024] The present invention provides an etching compensation method. Before performing compensation processing on a circuit board circuit diagram, an etching compensation table is obtained in advance based on process requirements. The etching compensation table includes the distances between adjacent contours in the circuit board circuit diagram and the corresponding distance values ​​that need to be compensated. The adjacent contours refer to adjacent contours of adjacent circuits in the circuit board circuit diagram and / or adjacent contours arranged relative to each other on the same circuit. That is, the etching compensation table includes the distances between adjacent contours of adjacent circuits in the circuit board circuit diagram and the corresponding distance values ​​that need to be compensated, and / or the distances between adjacent contours arranged relative to each other on the same circuit and the corresponding distance values ​​that need to be compensated. The data used for compensation and / or the priority of the two sets of data can be determined based on process requirements.

[0025] like Figure 1-3 As shown, in the etching compensation method of the present invention, a step value for line profile compensation is first set based on the desired etching compensation accuracy. The line profile is then divided according to the step value to obtain multiple division points. Specifically, starting from the starting point of the line profile, each point reached by a step value is a division point. Preferably, the step value is set within a range of 100 microns, and the line profile is differentiated.

[0026] The starting point of the line contour, the step-by-step division points, and the end point of the line are used as analysis points. The distance between each analysis point and the adjacent line contour is obtained respectively. The corresponding etching compensation value is found in the etching compensation table according to the distance between each analysis point, the etching compensation boundary is determined, and etching compensation is performed on the line.

[0027] When obtaining the interval distance between each analysis point and the adjacent line contour, first, calculate the compensation normal vector of each analysis point; then, with the analysis point as the starting point, draw a ray in the direction of the compensation normal vector until it intersects with the adjacent line contour, and the distance between the analysis point and the intersection point is the interval distance between the analysis point and the other line contour; according to the interval distance of each analysis point, find the corresponding etching compensation value in the etching compensation table, use the absolute value of the etching compensation value as the radius, and draw a circle with the dividing point as the center to determine the boundary of the etching compensation; finally, smooth the circle on the entire trajectory to achieve etching compensation for the contour.

[0028] When the analysis point is the common point of two line segments, the compensation normal vector of the analysis point is the angle bisector of the two line segment normal vectors, such as Figure 3As shown, when the vertex is the common point of two line segments, such as point G and point H, for point G, its compensation normal vector is the angle bisector (norm1) of the normal vector of G on line segment FG and the normal vector on line segment GH. The formula description of this point is shown in formula (2-1). (2-1) is the compensation normal vector at point G, is the normal vector of point G on line segment FG, and is the normal vector of point G on line segment GH. Similarly, the compensation normal vector (norm3) of point H is obtained by the angle bisector between the normal vector of line segment GH and the normal vector of arc segment HI.

[0029] When the analysis point is a non-segment common point on a straight line segment, its compensation normal vector is the normal vector of the line segment at that point, such as Figure 4 The normal vector norm2 of the analysis point is shown in FIG.

[0030] When the analysis point is a non-segment common point on the arc segment, the normal vector is the normal vector of the tangent line of the point on the arc, such as Figure 3 The normal vector norm4 of the analysis point is shown in FIG.

[0031] When analyzing the distance between adjacent contours of adjacent lines, the direction of the compensation normal vector points to the outside of the contour. For adjacent contours set relatively on the same line, the compensation normal vector points to the inside of the contour. When obtaining the distance between each analysis point and the adjacent line contour in the direction of the compensation normal vector, such as Figure 4 As shown in the figure, taking the analysis point J on the line profile 1 as an example, let it move along the direction of the compensation normal vector until it collides with the adjacent line profile 2, and obtains the intersection point K with the line profile 2. The distance dis between the analysis point J and the intersection point K is calculated, which is the distance between the analysis point J on the line profile and the line profile 2.

[0032] When determining the boundary of etching compensation, it is determined according to the positive and negative values ​​of the etching compensation value. If the etching compensation value is positive, the circle drawn is a positive piece, that is, a circle is added for compensation, shortening the distance between the two line contours; if the etching compensation value is negative, the circle drawn is a negative piece, that is, the circle is cut for compensation, increasing the distance between the two contours. Figure 5 As shown, taking analysis point M as an example, the etch compensation value corresponding to analysis point M is negative. With analysis point M as the center and the absolute value of the etch compensation value as the radius, a circle is drawn at point M. The drawn circle is a negative image, and the drawn circle needs to be cut to obtain the etch compensation boundary, increasing the distance between the contours. If the etch compensation value corresponding to analysis point L is positive, the circle drawn with analysis point L as the center and the etch compensation value as the radius at point L is a positive image. The circle is filled to compensate and reduce the distance between the two line contours. If the etch compensation value of the current analysis point is zero, there is no need to determine the etch compensation boundary.

[0033] By connecting the etch compensation boundaries of adjacent analysis points, a compensation profile corresponding to the circuit profile is obtained. If the etch compensation value of the next analysis point adjacent to the current analysis point is zero, the etch compensation boundary of the current analysis point is used as the end point of the current etch compensation profile segment, and the etch compensation boundary of the next analysis point with the same etch compensation value is used as the starting point of the next etch compensation profile segment. A single circuit profile to be compensated may correspond to multiple etch compensation profile segments.

[0034] like Figure 6 As shown, the specific steps of the etching compensation method are described.

[0035] S1. Set the step value according to the accuracy of etching compensation.

[0036] S2. Calculate the compensation normal vector of the starting point of the line contour, obtain the spacing distance from the adjacent line contour based on the compensation normal vector, obtain the etching compensation value based on the spacing distance from the adjacent line contour, and obtain the etching compensation boundary at the starting point position based on the etching compensation value.

[0037] S3. Arrive at the first division point based on the step value interval distance, calculate the compensation normal vector of the first division point, obtain the interval distance from the adjacent line contour based on the compensation normal vector, obtain the etching compensation value based on the interval distance from the adjacent line contour, and obtain the etching compensation boundary at the first division point position based on the etching compensation value.

[0038] S4. Arrive at the next division point based on the interval distance of the step value, calculate the compensation normal vector of the current division point at the division point, obtain the interval distance from the adjacent line contour based on the compensation normal vector, obtain the etching compensation value based on the interval distance from the adjacent line contour, and obtain the etching compensation boundary of the division point position based on the etching compensation value.

[0039] S5. Repeat step S4 until reaching the end point, calculate the compensation normal vector at the end point, obtain the spacing distance from the adjacent line contour based on the compensation normal vector, obtain the etching compensation value based on the spacing distance from the adjacent line contour, and obtain the etching compensation boundary at the end point position based on the etching compensation value.

[0040] S6. Smoothing the boundaries of the etching compensation.

[0041] By respectively calculating the spacing distances between adjacent line contours at different positions of the contour line and performing etching compensation respectively, the accuracy of etching compensation is improved.

[0042] In order to reduce the amount of data processing operations and reduce memory usage, the following method can be used when determining the etching compensation boundary.

[0043] When determining the etching compensation boundary, if the etching compensation value of the current analysis point (analysis point two) is the same as the etching compensation value of the previous analysis point (analysis point one), then the current analysis point (analysis point two) does not need to be subjected to the circle drawing operation, and the process steps to the next analysis point (analysis point three), and the compensation normal vector is calculated for the next analysis point (analysis point three), and the spacing distance from the adjacent line contour is obtained based on the compensation normal vector, and the etching compensation value is obtained based on the spacing distance from the adjacent line contour. If the etching compensation value of the next analysis point (analysis point three) is the same as the etching compensation value of the previous analysis point (analysis point two), as described above, there is no need to draw a circle for analysis point three. If the etching compensation value of the next analysis point (analysis point three) differs from that of the previous analysis point (analysis point two), a circle is redrawn for the previous analysis point (analysis point two), and the etching compensation boundary of the previous analysis point (analysis point two) is determined as the end point of the etching compensation contour for the analysis point with the same etching compensation value. Based on the etching compensation value of the next analysis point (analysis point three), a circle is drawn at the next analysis point (analysis point three) to determine the etching compensation boundary. If the etching compensation value of the next analysis point (analysis point four) after analysis point three is the same as that of analysis point three, the etching compensation boundary of analysis point three serves as the starting point of the etching compensation contour for the analysis point with the same etching compensation value. When drawing the etching compensation contour, it is only necessary to connect the starting and ending points of the etching compensation boundaries of analysis points with the same etching compensation value based on the shape of the circuit contour, and to connect the etching compensation boundaries of adjacent analysis points with different etching compensation values, greatly reducing the amount of calculation. When the starting point and end point of the etching compensation boundary of the analysis points with the same etching compensation value according to the shape of the circuit contour are determined, if the analysis points with the same etching compensation value are located in a straight line segment, the corresponding etching compensation contour is also a straight line segment; if the analysis points with the same etching compensation value are located in an arc segment, the corresponding etching compensation contour is also a concentric arc segment.

[0044] like Figure 7 As shown, the specific method and steps for determining the etching compensation boundary of the analysis point in the embodiment are as follows: S10, calculating the compensation normal vector of the analysis point of the line contour, obtaining the spacing distance from the adjacent line contour based on the compensation normal vector, obtaining the etching compensation value based on the spacing distance from the adjacent line contour, and obtaining the etching compensation boundary at the analysis point position based on the etching compensation value.

[0045] S11 , reaching the next analysis point according to the step value interval distance, calculating the compensation normal vector of the current analysis point, obtaining the interval distance from the adjacent line contour according to the compensation normal vector, and obtaining the etching compensation value according to the interval distance from the adjacent line contour.

[0046] S12: Determine whether the etching compensation value of the current analysis point is the same as the etching compensation value of the previous analysis point of the route profile. If the same, proceed to step S13; otherwise, proceed to step S14.

[0047] S13. Arrive at the next analysis point based on the interval distance of the step value, calculate the compensation normal vector of the current division point at the analysis point, obtain the interval distance with the adjacent line contour based on the compensation normal vector, obtain the etching compensation value based on the interval distance with the adjacent line contour, and execute step S13.

[0048] S14, obtaining an etching compensation boundary at the analysis point according to the etching compensation value. If the etching compensation boundary is not determined for the previous analysis point, determine the etching compensation boundary for the previous analysis point according to the etching compensation value of the previous analysis point, and execute step S13.

[0049] Repeat S11-S14 until the end point of the line contour is reached, calculate the compensation normal vector of the end point of the line contour, obtain the spacing distance with the adjacent line contour based on the compensation normal vector, obtain the etching compensation value based on the spacing distance with the adjacent line contour, and obtain the etching compensation boundary at the end point position based on the etching compensation value.

[0050] Finally, according to the shape of the line profile, the boundaries of the etching compensation are connected in sequence to obtain the etching compensation profile of the line profile.

[0051] like Figure 8 The image below shows the effects of etching compensation. The etching compensation method of the present invention can adjust the step value according to process requirements, performing etching compensation at different locations of the contour line as required, thereby improving the accuracy of etching compensation. Furthermore, by processing analysis points with the same etching compensation value, the data processing volume is reduced and the processing speed is improved.

Claims

1. An etching compensation method, characterized in that: The contour of the circuit to be compensated is divided according to the step value to obtain the division points of the contour of the circuit to be compensated, and the compensation normal vector is calculated for the analysis points consisting of the starting point, division point and end point of the contour of the circuit to be compensated, and the distance between the analysis point and the adjacent contour in the direction of the compensation normal vector is obtained. The etching compensation value is obtained according to the distance between the analysis point and the adjacent contour in the direction of the compensation normal vector, and the etching compensation boundary of the analysis point is determined according to the etching compensation value. The etching compensation boundary is connected to obtain the etching compensation contour of the contour of the circuit to be compensated.

2. The etching compensation method according to claim 1, wherein: When the analysis point is a common point of two line segments, the compensation normal vector of the analysis point is the angle bisector of the two line segment normal vectors; when the analysis point is a non-segment common point on a straight line segment, its compensation normal vector is the normal vector of the line segment at that point; when the analysis point is a non-segment common point on an arc segment, the normal vector is the normal vector of the tangent of that point on the arc.

3. The etching compensation method according to claim 1, wherein: When obtaining the distance between the analysis point and the adjacent contour in the direction of the compensation normal vector, a ray is drawn in the direction of the compensation normal vector until it intersects with the adjacent line contour. The distance between the analysis point and the intersection point is the spacing distance between the analysis point and the adjacent line contour.

4. The etching compensation method according to claim 1, wherein: When determining the etching compensation boundary of the analysis point, a circle is drawn with the absolute value of the etching compensation value as the radius and the analysis point as the center.

5. The etching compensation method according to claim 4, wherein: If the etching compensation value is positive, the circle drawn is a positive film, otherwise it is a negative film; a positive film is to add a circle for compensation and shorten the distance between the two line contours, and a negative film is to cut the circle for compensation and increase the distance between the two contours.

6. The etching compensation method according to claim 1, wherein: Before performing etching compensation processing, an etching compensation table is obtained in advance. The etching compensation table is obtained based on the distance values ​​that need to be compensated corresponding to the distances between adjacent contours in the circuit board circuit diagram. The etching compensation table includes the distances between adjacent contours and the corresponding etching compensation values.

7. The etching compensation method according to claim 1, wherein: For consecutive analysis points with the same etching compensation value, the etching compensation boundary is determined only for the first and last analysis points in the consecutive analysis points. The etching compensation boundaries of the first and last analysis points in the consecutive analysis points are connected according to the corresponding line contour to determine the etching compensation contour.

8. The etching compensation method according to claim 1, wherein: When determining the etching compensation boundary, if the etching compensation value of the current analysis point is the same as the etching compensation value of the previous analysis point, then there is no need to determine the etching compensation boundary for the current analysis point, and the process directly steps to the next analysis point.

9. The etching compensation method according to claim 1, wherein: When determining the etching compensation boundary, if the etching compensation value of the current analysis point is different from the etching compensation value of the previous analysis point, the etching compensation boundary of the current analysis point is determined, and the etching compensation boundary of the previous analysis point is determined.

10. The etching compensation method according to claim 1, wherein: The step value of line profile compensation is set according to the accuracy of etching compensation.

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