A method for compensating the outer layer circuitry of a circuit board

Abstract

This invention discloses a compensation method for the outer layer of a circuit board to optimize the compensation values ​​of circuits in different regions based on copper thickness. The compensation values ​​include parameters such as line-to-line distance, line-to-copper distance, minimum metal ring size of vias, compensation values ​​for dense circuits, compensation values ​​for sparse circuits, compensation values ​​for independent circuits, compensation values ​​for cursor points, compensation values ​​for BGAs, and compensation values ​​for ICs, thereby improving the reliability and accuracy of the circuit board.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit board manufacturing, and particularly relates to a compensation method for outer layer circuit of a circuit board. BACKGROUND

[0002] PCB (Printed Circuit Board) is an important electronic component and is a carrier for supporting electronic components and realizing electrical interconnection. With the rapid development and wide application of integrated circuits, the types and applications of electronic devices are rapidly developing, and electronic products are also more intelligent and miniaturized. To match this, the types of PCBs are constantly updated, and the precision and reliability requirements of PCBs are also increasingly high. The circuits arranged on the PCBs are increasingly dense, and in particular, when ensuring signal transmission of electronic products, the precision of the circuits on the PCBs is a key factor affecting signal transmission. Therefore, in the PCB manufacturing industry, improving the process capability of fine circuits on the PCBs is a key to producing PCBs with higher precision and reliability.

[0003] The positive film alkaline manufacturing process of the outer layer circuit of the PCB is as follows: outer layer exposure, outer layer development, pattern plating, film stripping, etching, solder mask, text printing, and surface treatment. In the etching process, due to the side etching effect, there is an error between the etched circuit and the engineering design, which affects the precision of the circuit. Therefore, in actual production, compensation needs to be performed on the outer layer circuit to ensure the electrical performance and reliability of the circuit board.

[0004] The purpose of the present application is to provide a systematic compensation method for the positive film alkaline manufacturing process of the outer layer circuit of the circuit board to improve the reliability and precision of the circuit board. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a compensation method for the outer layer circuit of a circuit board, which optimizes the compensation value according to different completed copper thickness requirements to improve the reliability and precision of the circuit board.

[0006] The technical solution of the present application is as follows:

[0007] A compensation method for the outer layer circuit of a circuit board, which selects different compensation values according to the completed copper thickness, comprises the following steps:

[0008] When the completed copper thickness is 27-42 um, the minimum distance between lines is 2.5 mil, the minimum distance between a line and copper is 2.5 mil, the minimum metal ring of a via is 3.5 mil, the compensation for dense circuits is 1.6 mil, the compensation for sparse circuits is 1.8 mil, the compensation for independent circuits is 2.2 mil, the compensation for cursor points is 4 mil, the compensation for BGA is 2.8 mil, and the compensation for IC is 2.6 mil.

[0009] When the finished copper thickness is 43-61um, the minimum line-to-line spacing is 2.5mil, the minimum line-to-copper distance is 2.5mil, the minimum via metal ring is 3.8mil, the dense line compensation is 2mil, the sparse line compensation is 2.4mil, the independent line compensation is 2.8mil, the cursor point compensation is 5.2mil, the BGA compensation is 3.6mil, and the IC compensation is 3.4mil;

[0010] When the finished copper thickness is 62-78um, the minimum line-to-line spacing is 3.8mil, the minimum line-to-copper distance is 3.5mil, the minimum via metal ring is 5mil, the dense line compensation is 2.8mil, the sparse line compensation is 3.2mil, the independent line compensation is 3.6mil, the cursor point compensation is 6.4mil, the BGA compensation is 4.8mil, and the IC compensation is 4.6mil;

[0011] When the finished copper thickness is 79-96um, the minimum line-to-line spacing is 4.2mil, the minimum line-to-copper distance is 4mil, the minimum via metal ring is 5.5mil, the dense line compensation is 3.2mil, the sparse line compensation is 3.8mil, the independent line compensation is 4.8mil, the cursor point compensation is 7.2mil, the BGA compensation is 6mil, and the IC compensation is 5.4mil;

[0012] When the finished copper thickness is 97-116um, the minimum line-to-line spacing is 4.8mil, the minimum line-to-copper distance is 4.5mil, the minimum via metal ring is 6mil, the dense line compensation is 4mil, the sparse line compensation is 5mil, the independent line compensation is 6mil, the cursor point compensation is 8.8mil, the BGA compensation is 7.2mil, and the IC compensation is 6.6mil;

[0013] When the finished copper thickness is 117-126um, the minimum line-to-line spacing is 5.4mil, the minimum line-to-copper distance is 5mil, the minimum via metal ring is 6.5mil, the dense line compensation is 5.2mil, the sparse line compensation is 6.2mil, the independent line compensation is 7.2mil, the cursor point compensation is 10mil, the BGA compensation is 8.4mil, and the IC compensation is 7.8mil;

[0014] When the finished copper thickness is 127-150um, the minimum line-to-line spacing is 6mil, the minimum line-to-copper distance is 5.6mil, the minimum via metal ring is 7mil, the dense line compensation is 6.4mil, the sparse line compensation is 7.6mil, the independent line compensation is 8.8mil, the cursor point compensation is 11.2mil, the BGA compensation is 9.6mil, and the IC compensation is 9mil.

[0015] Further, when the dense line position spacing is insufficient, the finished copper thickness of the circuit board is above 35um, the compensation value is reduced, and the maximum reduction is 0.4mil.

[0016] Further, it also includes a line close to the outermost of the copper-free hole, and the additional compensation of 1 mil is based on the original compensation.

[0017] Further, when the etching copper is greater than 1.5 oz, the compensation for the square pattern is designed to increase the sharp corner compensation at the four corners of the square according to different finished copper thickness.

[0018] Further, in the sharp corner design, the intersection of each sharp corner and the square cursor point is set as P and Q, the vertex of the square cursor point is set as O, the length of OP is set as A, the length of OQ is set as B, and A = B = 0.25 mm; the included angle between the two edges of the sharp corner and the corresponding edge of the square cursor point is 15°.

[0019] Further, it also includes a solder ring at an independent position, and the compensation is increased by 2-3 mil based on the normal compensation, and the independent line connecting the solder ring position is added with a tear drop.

[0020] Further, it also includes a dense area of lines, and the lines are segmented and compensated by independent lines.

[0021] Further, when the etching character is increased, the line width compensation is increased, and at least reaches the independent line compensation value.

[0022] Further, when the finished copper thickness corresponding line width compensation is insufficient, the copper reduction method is adopted.

[0023] Compared with the prior art, the compensation method of the outer layer circuit of the circuit board provided by the present application has the beneficial effects that:

[0024] The compensation method of the outer layer circuit of the circuit board provided by the present application optimizes the line compensation value of different areas according to the finished copper thickness, and improves the reliability and precision of the circuit board. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0026] Figure 1 is a schematic diagram of different areas in the compensation method of the outer layer circuit of the circuit board of the present application;

[0027] Figure 2 is a schematic diagram of the sharp corner compensation design at the four corners of the square according to different finished copper thickness for the square pattern in the compensation method of the outer layer circuit of the circuit board of the present application;

[0028] Figure 3 is a compensation schematic diagram of a solder ring in an independent position in the compensation method of the outer layer circuit of the circuit board of the present application;

[0029] Figure 4 is a wire threading between densely arranged holes in the compensation method of the outer layer circuit of the circuit board of the present application. DETAILED DESCRIPTION

[0030] In order to make the technical solutions in the embodiments of the present application better understood by the person skilled in the art, and make the above-mentioned purposes, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application are further described below.

[0031] It should be noted that the description of the embodiments is used to help understand the present application, but does not constitute a limitation of the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0032] As shown in Figure 1 the different regions in the present application are defined as follows:

[0033] Independent region: a single circuit / PAD whose circuit / PAD is located in a sparse region;

[0034] Sparse region: a region whose circuit / PAD has a spacing greater than twice the line width and is sparsely distributed, or a region that can still meet the spacing requirements after compensation according to the sparse region;

[0035] Dense region: a region whose circuit / PAD has a spacing less than the line width and is densely distributed;

[0036] Open region: two types of regions, namely, a copper-free region in a unit and a copper-free region in a blank space, a region having no any pattern in a 10mm*20mm region.

[0037] The compensation method of the outer layer circuit of the circuit board of the present application selects different compensation values according to the completed copper thickness, including:

[0038] When the completed copper thickness is 27-42um, the minimum spacing between lines is 2.5mil, the minimum distance from a line to copper is 2.5mil, the minimum metal ring of a via is 3.5mil, the compensation of dense circuit is 1.6mil, the compensation of sparse circuit is 1.8mil, the compensation of independent circuit is 2.2mil, the compensation of a cursor point is 4mil, the compensation of BGA is 2.8mil, and the compensation of IC is 2.6mil;

[0039] When the finished copper thickness is 43-61 um, the minimum line-to-line spacing is 2.5 mil, the minimum line-to-copper distance is 2.5 mil, the minimum via metal ring is 3.8 mil, the dense line compensation is 2 mil, the sparse line compensation is 2.4 mil, the isolated line compensation is 2.8 mil, the cursor dot compensation is 5.2 mil, the BGA compensation is 3.6 mil, and the IC compensation is 3.4 mil;

[0040] When the finished copper thickness is 62-78 um, the minimum line-to-line spacing is 3.8 mil, the minimum line-to-copper distance is 3.5 mil, the minimum via metal ring is 5 mil, the dense line compensation is 2.8 mil, the sparse line compensation is 3.2 mil, the isolated line compensation is 3.6 mil, the cursor dot compensation is 6.4 mil, the BGA compensation is 4.8 mil, and the IC compensation is 4.6 mil;

[0041] When the finished copper thickness is 79-96 um, the minimum line-to-line spacing is 4.2 mil, the minimum line-to-copper distance is 4 mil, the minimum via metal ring is 5.5 mil, the dense line compensation is 3.2 mil, the sparse line compensation is 3.8 mil, the isolated line compensation is 4.8 mil, the cursor dot compensation is 7.2 mil, the BGA compensation is 6 mil, and the IC compensation is 5.4 mil;

[0042] When the finished copper thickness is 97-116 um, the minimum line-to-line spacing is 4.8 mil, the minimum line-to-copper distance is 4.5 mil, the minimum via metal ring is 6 mil, the dense line compensation is 4 mil, the sparse line compensation is 5 mil, the isolated line compensation is 6 mil, the cursor dot compensation is 8.8 mil, the BGA compensation is 7.2 mil, and the IC compensation is 6.6 mil;

[0043] When the finished copper thickness is 117-126 um, the minimum line-to-line spacing is 5.4 mil, the minimum line-to-copper distance is 5 mil, the minimum via metal ring is 6.5 mil, the dense line compensation is 5.2 mil, the sparse line compensation is 6.2 mil, the isolated line compensation is 7.2 mil, the cursor dot compensation is 10 mil, the BGA compensation is 8.4 mil, and the IC compensation is 7.8 mil;

[0044] When the finished copper thickness is 127-150 um, the minimum line-to-line spacing is 6 mil, the minimum line-to-copper distance is 5.6 mil, the minimum via metal ring is 7 mil, the dense line compensation is 6.4 mil, the sparse line compensation is 7.6 mil, the isolated line compensation is 8.8 mil, the cursor dot compensation is 11.2 mil, the BGA compensation is 9.6 mil, and the IC compensation is 9 mil.

[0045] In the present application, when the position interval of the dense circuit is insufficient, the circuit board with copper thickness of 35um or more is completed, the compensation value is reduced, and at most 0.4mil is reduced, and the interval is preferentially ensured.

[0046] In the present application, the line closest to the outermost of the copper-free hole is additionally compensated by 1mil on the basis of the original compensation. For example, the line closest to the NPTH hole is compensated by 2mil, and the independent line close to the NPTH hole is compensated by 3mil.

[0047] Due to the side etching effect of the etching solution during etching, the four corners of the square pattern become irregular round blunt shapes. Therefore, in the present application, when the etching copper is greater than 1.5oz, the compensation for the square pattern is designed according to the different completed copper thickness by increasing the sharp corner compensation at the four corners of the square. Specifically, as shown in the figure, Figure 2 In the sharp corner design, the intersection of each sharp corner and the square cursor point is set as P and Q, the vertex of the square cursor point is set as O, the length of OP is set as B, the length of OQ is set as A, and A=B=0.25mm; the included angle between the two edges of the sharp corner and the corresponding edges of the square cursor point is 15°.

[0048] In the present application, the solder ring at the independent position is compensated by 2-3mil on the basis of the normal compensation due to the large amount of side etching at the independent position during etching, and the independent line connecting the solder ring position is added with a tear drop, as shown in the figure, Figure 3 The arrow in the figure Figure 3 represents the added tear drop.

[0049] In the present application, in the dense area of the circuit, the lines passing through the holes between the dense holes are segmented and compensated by independent lines, as shown in the figure, Figure 4 The highlighted line in the figure needs to be compensated by an independent line.

[0050] In the present application, when etching characters, the line width compensation is increased, and at least reaches the independent line compensation value, so as to prevent the characters from being etched off during etching.

[0051] It should be noted that when the completed copper thickness corresponding to the line width compensation is insufficient, the copper reduction method is adopted.

[0052] The compensation method for the outer layer circuit of the circuit board provided by the present application is suitable for the outer layer positive film circuit compensation, optimizes the line compensation value of different areas with the completed copper thickness, and improves the reliability and precision of the circuit board.

[0053] The above detailed description is made to the embodiments of the present application, but the present application is not limited to the described embodiments. Various changes, modifications, replacements and variations made to the embodiments without departing from the principles and spirits of the present application still fall within the protection scope of the present application.

Claims

1. A method of compensating for an outer layer circuit of a wiring board, characterized by, Different compensation values are selected according to the finished copper thickness, including: When the finished copper thickness is 27-42um, the minimum distance between lines is 2.5mil, the minimum distance between line and copper is 2.5mil, the minimum metal ring of via is 3.5mil, the dense line compensation is 1.6mil, the sparse line compensation is 1.8mil, the independent line compensation is 2.2mil, the cursor point compensation is 4mil, the BGA compensation is 2.8mil, and the IC compensation is 2.6mil; When the finished copper thickness is 43-61um, the minimum distance between lines is 2.5mil, the minimum distance between line and copper is 2.5mil, the minimum metal ring of via is 3.8mil, the dense line compensation is 2mil, the sparse line compensation is 2.4mil, the independent line compensation is 2.8mil, the cursor point compensation is 5.2mil, the BGA compensation is 3.6mil, and the IC compensation is 3.4mil; When the finished copper thickness is 62-78um, the minimum distance between lines is 3.8mil, the minimum distance between line and copper is 3.5mil, the minimum metal ring of via is 5mil, the dense line compensation is 2.8mil, the sparse line compensation is 3.2mil, the independent line compensation is 3.6mil, the cursor point compensation is 6.4mil, the BGA compensation is 4.8mil, and the IC compensation is 4.6mil; When the finished copper thickness is 79-96um, the minimum distance between lines is 4.2mil, the minimum distance between line and copper is 4mil, the minimum metal ring of via is 5.5mil, the dense line compensation is 3.2mil, the sparse line compensation is 3.8mil, the independent line compensation is 4.8mil, the cursor point compensation is 7.2mil, the BGA compensation is 6mil, and the IC compensation is 5.4mil; When the finished copper thickness is 97-116um, the minimum distance between lines is 4.8mil, the minimum distance between line and copper is 4.5mil, the minimum metal ring of via is 6mil, the dense line compensation is 4mil, the sparse line compensation is 5mil, the independent line compensation is 6mil, the cursor point compensation is 8.8mil, the BGA compensation is 7.2mil, and the IC compensation is 6.6mil; When the finished copper thickness is 117-126um, the minimum distance between lines is 5.4mil, the minimum distance between line and copper is 5mil, the minimum metal ring of via is 6.5mil, the dense line compensation is 5.2mil, the sparse line compensation is 6.2mil, the independent line compensation is 7.2mil, the cursor point compensation is 10mil, the BGA compensation is 8.4mil, and the IC compensation is 7.8mil; When the finished copper thickness is 127-150um, the minimum distance between lines is 6mil, the minimum distance between line and copper is 5.6mil, the minimum metal ring of via is 7mil, the dense line compensation is 6.4mil, the sparse line compensation is 7.6mil, the independent line compensation is 8.8mil, the cursor point compensation is 11.2mil, the BGA compensation is 9.6mil, and the IC compensation is 9mil; The line closest to the outermost of the copper-free hole is additionally compensated by 1mil based on the original compensation. When the etching of the bottom copper is greater than 1.5 oz, for the compensation of the square pattern, according to different finished copper thickness, the sharp corner compensation design is added to the four corners of the square; in the sharp corner design, the intersection of each sharp corner and the square cursor point is set as P and Q, the vertex of the square cursor point is O, the length of OP is set as A, the length of OQ is set as B, and A=B=0.25 mm; the included angle between the two edges of the sharp corner and the corresponding edge of the square cursor point is 15°; The welding ring at the independent position is compensated by increasing the compensation value by 2-3 mil, and the independent line is connected to the welding ring position to add a tear drop; In the dense line area, the independent line is used for segmented compensation between the dense hole rows; When the distance between the dense line positions is insufficient, the compensation value is reduced for the circuit board with the finished copper thickness greater than 35 um, and the maximum reduction is 0.4 mil; When the line width compensation corresponding to the finished copper thickness is insufficient, the copper reduction is used.

2. The method of compensating for outer layer wiring of a wiring board according to claim 1, wherein, ​

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