High etching factor control method, circuit board production method and circuit board
By setting the etching amount to more than 1.5 times the copper thickness in the acidic etching of the circuit board, the problem that conventional etching equipment cannot meet the high-quality etching requirements of high-frequency lines is solved, and the circuit board production with high etching factors is realized, reducing costs and simplifying the process.
Patent Information
- Application Number
- CN202411993259.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-04-25
AI Technical Summary
In the prior art, conventional etching equipment cannot meet the requirements of high-quality etching of circuit boards, especially in high-frequency lines with antenna designs, etching factors 2-4 are not sufficient to meet customer needs.
By pre-setting the etching amount during the acid etching process of the circuit board, it reaches more than 1.5 times the thickness of the circuit board copper, thereby controlling the etching factor to achieve a high etching factor of 6-9.
This enables the acquisition of high etch factor circuit boards without the need for expensive equipment, reducing production costs and simplifying production processes.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of circuit board manufacturing, and in particular to a high etching factor control method, a circuit board production method and a circuit board. Background Art
[0002] At present, the mainstream technology for producing printed circuit boards in China is the subtractive process, that is, on the copper-clad substrate, through drilling, hole metallization, pattern transfer, electroplating, etching and other processes, part of the copper foil is selectively removed to form a conductive pattern, among which the etching process is the main factor affecting the quality of pattern etching. At present, the etching quality of the circuit sidewall is usually evaluated by the etching factor, which is the ratio of the etching depth to the side etching width. The larger the ratio, the better the etching quality and the more vertical the circuit sidewall is.
[0003] The etching factor is closely related to the etching equipment, etching solution type and parameter control. Generally, for alkaline etching, the etching factor can reach 2-3, and for acid etching, it can reach 3-4. For more advanced vacuum etching processes with two fluids, it is reported that it can reach 4-6, but it requires expensive equipment investment.
[0004] However, for conventional printed circuit board design, an etching factor of 2-4 is sufficient, but for high-frequency circuits with antenna design, an etching factor of 2-4 cannot meet customers' high-quality etching requirements; if a vacuum etching process with two fluids is used to meet high-quality etching requirements, expensive equipment investment is required, which will significantly increase costs. Summary of the invention
[0005] Based on this, it is necessary to provide a high etching factor control method, a circuit board production method and a circuit board to address the problem that conventional etching equipment in the prior art cannot meet the high-quality etching requirements of circuit boards.
[0006] A high etching factor control method includes: presetting an etching amount according to different circuit board acid etching requirements, wherein the etching amount is more than 1.5 times the copper thickness of the circuit board, the copper thickness is the designed thickness of the circuit board circuit layer, and the etching amount is the difference between the line width of the circuit board graphic anti-corrosion layer and the line width of the circuit after etching.
[0007] In one embodiment, the etching amount is 1.5-2.0 times the copper thickness of the circuit board.
[0008] In one embodiment, the etching amount is more than 2.0 times the copper thickness of the circuit board.
[0009] A circuit board production method adopts a high etching factor control method, comprising:
[0010] Cutting materials;
[0011] drilling;
[0012] Apply dry film;
[0013] LDI circuit production;
[0014] Acid etching, etching the circuit board according to the preset etching amount;
[0015] Remove the film.
[0016] In one of the embodiments, before the cutting, line width compensation is performed on a preset circuit board to obtain a circuit board line width compensation value, and the circuit board line width compensation value is equal to or more than 1.5 times the etching amount or the copper thickness of the circuit board.
[0017] In one embodiment, the circuit board line width compensation value is 1.5-2.0 times the copper thickness.
[0018] In one embodiment, before the circuit board is stripped, it is determined whether the etching amount of the circuit board line reaches a preset threshold. If so, the subsequent circuit board etching is performed according to the circuit board etching speed. Otherwise, the etching is performed according to the circuit board line width compensation value ±0.2mil as the speed value.
[0019] In one embodiment, after the line width of the circuit board is supplemented, the line width compensation value is completely etched before the film can be stripped.
[0020] In one embodiment, when etching the circuit board, the circuit board is placed with the antenna layer facing downward, and the film is not removed after etching, and the etching amount of the circuit board line is measured using a line width meter.
[0021] A circuit board is manufactured by a circuit board production method.
[0022] The above-mentioned high etching factor control method, circuit board production method and circuit board, during the acid etching process of the circuit board, makes the etching amount reach more than 1.5 times the copper thickness of the circuit board, so as to obtain a high etching factor of 6-9. The etching factor can be controlled by simply controlling the etching amount. At this time, conventional etching equipment can be used to complete the production process, and there is no need to use equipment with a two-fluid vacuum etching process for etching, which effectively reduces the processing cost of the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a schematic diagram of the cross-sectional structure of the circuit board after etching of the high etching factor control method, the circuit board production method and the circuit board of the present invention;
[0024] Figure 2 The high etching factor control method, circuit board production method and etching factor change curve of the circuit board of the present invention are shown;
[0025] Figure 3An enlarged view of one side of the circuit observed after the circuit board is etched for the high etching factor control method, circuit board production method and circuit board of the present invention;
[0026] Figure 4 An enlarged view of the overall circuit observed after the circuit board etching measurement of the high etching factor control method, the circuit board production method and the circuit board of the present invention;
[0027] Figure 5 It is a schematic diagram of the structure of a circuit board slicing diagram after etching of a high etching factor control method, a circuit board production method and a circuit board of the present invention;
[0028] Figure 6 It is a schematic diagram of the circuit board compensation structure of the high etching factor control method, circuit board production method and circuit board of the present invention. DETAILED DESCRIPTION
[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.
[0030] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. On the contrary, when an element is said to be "directly" connected to another element, there is no intermediate element.
[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.
[0032] like Figure 1 As shown, a high etching factor control method includes: pre-setting an etching amount X according to different circuit board acid etching requirements, the etching amount X is more than 1.5 times the circuit board copper thickness T, the copper thickness T is the designed thickness of the circuit board circuit layer, the etching amount X is the difference between the line width of the circuit board graphic anti-corrosion layer and the line width of the circuit after etching; the etching amount X is 1.5-2.0 times the circuit board copper thickness T; the etching amount X is more than 2.0 times the circuit board copper thickness T.
[0033] The etching factor is controlled by controlling the ratio of the etching amount X to the copper thickness T. When the ratio of the etching amount X to the copper thickness T reaches 1.5 or more, a stable etching factor (6-9) can be obtained, and the etching amount X=X1+X2.
[0034] Etching factor formula: Etching factor (6-9) = X / T (ratio ≥ 1.5) = (W-W2) / T (ratio ≥ 1.5)
[0035] Furthermore, in order to ensure etching quality and etching efficiency, the etching amount X is 1.5-2.0 times the copper thickness. Of course, the etching amount X can also be designed according to actual needs, for example, the etching amount X is designed to be more than 2.0 times the copper thickness T of the circuit board.
[0036] like Figure 1 and Figure 2 As shown, according to the formula etching factor (6-9) = X / T (ratio ≥ 1.5), different etching amounts X are used for etching when the copper thickness T of the circuit board is 0.6mil, 1.2mil, and 2.4mil, and the ratio of etching amount X to copper thickness T and etching factor are calculated. The specific test data are as follows:
[0037]
[0038] Table 1
[0039] Based on the above test data, we can get Figure 2 The etching factor variation curve shown in the figure shows that, through the above test data and the curve, it can be known that, under the condition of the same copper thickness T, different etching amounts X are used for etching, and finally products with different etching factors are obtained. By ensuring that the ratio of the etching amount X to the copper thickness T is greater than 1.5, a circuit board with an etching factor greater than 6 and less than 9 can be obtained.
[0040] like Figure 5 As shown, it can also be seen from the sliced circuit board that when the ratio of etching amount X to copper thickness T is greater than 1.5, copper thickness T is 33.00815μm, W1-W2=3.91856μm, according to the calculation formula of etching factor, T / 0.5(W1-W2), because Figure 5 It is just a slice image of one side of the circuit board, so the etching factor = T / (W1-W2) = 33.00815 / 3.91856 = 8.42, so the etching factor obtained is 8.42, which is between 6-9.
[0041] In this way, a high etching factor control method, a circuit board production method and a circuit board can achieve a high etching factor of 6-9 by making the etching amount reach more than 1.5 times the copper thickness of the circuit board during the acid etching of the circuit board. The etching factor can be controlled by simply controlling the etching amount. At this time, conventional etching equipment can be used to complete the production process, and there is no need to use equipment with a two-fluid vacuum etching process for etching, which effectively reduces the processing cost of the circuit board.
[0042] Furthermore, in the existing production process, in order to test the etching factor, the circuit board needs to be sliced and then the etching factor of the slices needs to be tested. However, in the circuit board produced by the present control method, it is only necessary to control the etching amount X during the production process, and the etching amount X is kept at more than 1.5 times the copper thickness T. In this way, a circuit board with an etching factor of 6-9 can be obtained, thereby eliminating the subsequent slicing process for testing the etching factor, simplifying the production steps, and improving production efficiency.
[0043] A circuit board production method adopts a high etching factor control method, comprising:
[0044] S1. Cutting materials: Cutting circuit boards according to the material specifications, dimensions and quantities required by the engineering MI;
[0045] S2, drilling, drilling the circuit board according to the engineering MI file;
[0046] S3, dry film is applied on both sides of the circuit board to facilitate LDI pattern transfer;
[0047] S4, LDI circuit production, using LDI laser imaging method to transfer the pattern, and obtain the outer layer circuit pattern after development;
[0048] S5. Acid etching: etching the circuit board according to the preset etching amount X. The etching amount X is preset according to different circuit boards. The etching amount X needs to be guaranteed to be more than 1.5 times the copper thickness of the processed circuit board to ensure that the circuit board has an etching factor of 6-9.
[0049] S6. Remove the protective dry film to obtain a complete circuit pattern.
[0050] like Figure 6 As shown, in one embodiment, in order to ensure that the line width of the circuit board after etching meets the design requirements, before the cutting, it also includes performing line width compensation on the preset circuit board to obtain the circuit board line width compensation value Y, and the circuit board line width compensation value Y is equal to more than 1.5 times the etching amount X or the circuit board copper thickness T. Circuit board line width compensation value Y = Y1 + Y2 = X1 + X2
[0051] In the prior art, when etching a circuit board, the anti-corrosion layer can prevent the top and bottom surfaces of the circuit board from being etched by the etching liquid, but it cannot effectively prevent the side of the circuit from being etched away by the etching liquid, resulting in the circuit of the manufactured circuit board failing to meet the processing requirements. Therefore, in this embodiment, before the material is cut, the etching amount X or more than 1.5 times the copper thickness T of the circuit board is used as the circuit board line width compensation value Y, that is, before cutting the material, the etching amount X is used as the circuit board line width compensation value Y, so that the overall width of the circuit board line increases before etching, and in the subsequent etching process, the etching amount X is exactly the circuit board line width compensation value Y, so that when the etching is completed and the etching amount X requirement is reached, it can be ensured that the circuit board line width after etching meets the requirements.
[0052] Preferably, the circuit board line width compensation value Y is 1.5-2.0 times the copper thickness.
[0053] In one embodiment, before the circuit board is stripped, it is determined whether the etching amount X of the circuit board of the first board reaches a preset threshold value. If yes, the subsequent circuit boards are etched according to the etching speed of the circuit board. Otherwise, the etching is performed according to ±0.2mil of the circuit board line width compensation value as the speed value.
[0054] When etching the circuit board, place the circuit board with the antenna layer facing downward, and do not remove the film after etching. Use a line width meter to measure the etching amount of the circuit board line.
[0055] During the etching process, it is necessary to ensure that the etching amount reaches the target requirement, that is, the etching amount X must be guaranteed to be more than 1.5 times the copper thickness T. Therefore, after the etching is completed, it is necessary to confirm whether the etching amount X meets the requirements. At this time, since the etching amount is detected and calculated during the processing, it is necessary to measure the etching amount X before stripping the film. Specifically, before the film stripping step, the circuit etching amount X is measured. If the etching amount X meets the requirements, the subsequent circuit boards are etched according to the etching speed of the first board circuit board; if the etching amount does not meet the target requirements, the etching speed is adjusted, and the etching is continued at a speed of ±0.2mil of the circuit board line width compensation value to ensure that the etching amount X meets the processing requirements. In the prior art, the etching amount is tested after the film is stripped. If the etching amount does not meet the requirements, the circuit board is marked as an unqualified board. The present application detects and calculates the etching amount before stripping the film. If the etching amount does not meet the requirements, etching can be continued until the etching amount meets the requirements, and the circuit board can be remedied.
[0056] During the measurement process, a line width meter is used for measurement. At this time, due to the transparent characteristics of the dry film, the upper line width edge line of the circuit and the width of the dry film resist layer (pattern width) can be observed through the dry film during the test. At this time, if the line width meter is used to observe one side of the circuit (such as Figure 3As shown), the single-side etching amount X1 can be directly measured. At this time, the etching amount X is equal to 2 times the single-side etching amount X1. Figure 4 As shown), the width of the upper line W2 and the width W (pattern width) of the dry film resist layer can be measured, and the etching amount can be directly calculated. At this time, the etching amount X is equal to the width of the dry film resist layer W (pattern width) minus the overall width of the upper line width W2. At this time, the etching amount is measured by a line width measuring instrument.
[0057] After measuring / calculating the etching amount X, it is also necessary to determine whether the etching amount X at the current stage meets the target requirements. If it does not meet the requirements, the subsequent circuit boards that need to be etched need to adjust the etching speed and etch at a speed of ±0.2mil of the circuit board line width compensation value until the etching amount X meets the requirements. After etching is completed, the film is de-dried, which can ensure that the circuit board after de-dried film meets the high etching factor requirements.
[0058] In one embodiment, after the line width of the circuit board is compensated, the film can be stripped only after the line width compensation value is completely etched to avoid the compensated line width remaining and making the line width too wide to meet the processing requirements.
[0059] A circuit board is manufactured by a circuit board production method.
[0060] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0061] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.
Claims
1. A high etching factor control method, characterized in that: include: According to the acid etching requirements of different circuit boards, the etching amount is pre-set, and the etching amount is more than 1.5 times the copper thickness of the circuit board. The copper thickness is the designed thickness of the circuit board circuit layer, and the etching amount is the difference between the line width of the circuit board graphic anti-corrosion layer and the line width of the circuit after etching.
2. The high etching factor control method according to claim 1, characterized in that: The etching amount is 1.5-2.0 times the copper thickness of the circuit board.
3. The high etching factor control method according to claim 1, characterized in that: The etching amount is more than 2.0 times the copper thickness of the circuit board.
4. A method for producing a circuit board, characterized in that: The high etching factor control method according to any one of claims 1 to 3 comprises: Cutting materials; drilling; Apply dry film; LDI circuit production; Acid etching, etching the circuit board according to the preset etching amount; Remove the film.
5. The circuit board production method according to claim 4, characterized in that: Before the cutting, the method further includes performing line width compensation on a preset circuit board to obtain a circuit board line width compensation value, wherein the circuit board line width compensation value is equal to or more than 1.5 times the etching amount or the copper thickness of the circuit board.
6. The circuit board production method according to claim 4, characterized in that: The circuit board line width compensation value is 1.5-2.0 times the copper thickness.
7. The circuit board production method according to claim 4, characterized in that: Before the circuit board is stripped, it is determined whether the etching amount of the circuit board line reaches the preset threshold. If yes, the subsequent circuit board is etched according to the circuit board etching speed. Otherwise, the etching is performed according to the circuit board line width compensation value ±0.2mil as the speed value.
8. The circuit board production method according to claim 5, characterized in that: After the line width of the circuit board is compensated, the film can only be stripped after the line width compensation value is completely etched.
9. The circuit board production method according to claim 7, characterized in that: When etching the circuit board, place the circuit board with the antenna layer facing downward, and do not remove the film after etching. Use a line width meter to measure the etching amount of the circuit board line.
10. A circuit board, characterized in that: The circuit board is manufactured by the circuit board production method described in any one of claims 4 to 9.