Printed Circuit Boards and Their Depth Control Methods

Abstract

This invention discloses a printed circuit board and a depth control method thereof. The depth control method for the printed circuit board includes: acquiring a board component to be controlled for depth; measuring the thickness of the board component to be controlled for depth, obtaining a measured thickness; performing surface fitting on the measured thickness to obtain a fitted thickness; and performing depth control operations on the board component based on the fitted thickness. Through the above-described depth control method for the printed circuit board, this invention can improve the depth control accuracy of the printed circuit board through surface fitting, improve the depth control effect of the printed circuit board, and thus improve the reliability of the printed circuit board.

Description

Technical Field

[0001] This invention applies to the technical field of depth control in printed circuit boards, and particularly to printed circuit boards and their depth control methods. Background Technology

[0002] PCB (Printed Circuit Board) is an important electronic component. It serves as the support for electronic components and the carrier for the electrical interconnection of these components.

[0003] Currently, the depth control method for printed circuit boards (PCBs) often involves pre-setting a preset depth and then processing the board according to that preset depth to achieve various depth control objectives. However, in actual production, factors such as uneven board thickness can lead to insufficient accuracy in depth control based on the preset depth, making it difficult for the board depth control to meet the high-precision performance requirements of the product.

[0004] Therefore, there is an urgent need to improve the depth control accuracy of printed circuit boards. Summary of the Invention

[0005] This invention provides a printed circuit board and a method for controlling its depth, in order to solve the problem of low depth control accuracy of printed circuit boards in the prior art.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for controlling the depth of a printed circuit board. The method includes: obtaining a board component to be controlled for depth; measuring the thickness of the board component to be controlled for depth to obtain a measured thickness; performing surface fitting on the measured thickness to obtain a fitted thickness; and performing a depth control operation on the board component to be controlled for depth based on the fitted thickness.

[0007] The step prior to performing surface fitting on the measured thickness to obtain the fitted thickness after surface fitting further includes: constructing a standard coordinate system based on the positioning holes of the plate to be controlled for depth, and determining the standard plate thickness of the plate to be controlled for depth based on the standard coordinate system; the step of performing surface fitting on the measured thickness to obtain the fitted thickness after surface fitting includes: performing surface fitting on the measured thickness and the standard plate thickness to obtain the correspondence between the measured thickness and the standard plate thickness; and determining the fitted thickness of the plate to be controlled for depth based on the measured thickness and using the correspondence.

[0008] The step of performing surface fitting on the measured thickness and the standard plate thickness to obtain the correspondence between the measured thickness and the standard plate thickness includes: determining the fitting parameters for surface fitting based on the unevenness of the plate to be controlled; and performing surface fitting using the fitting parameters based on the measured thickness and the standard plate thickness to obtain the correspondence between the measured thickness and the standard plate thickness.

[0009] The step of determining the fitting parameters for surface fitting based on the unevenness of the plate to be controlled includes: determining the unevenness of the plate to be controlled based on the viscosity of the resin material of the plate to be controlled; and determining the fitting parameters for surface fitting based on the unevenness.

[0010] The step of obtaining the depth-controlled plate includes: obtaining at least one depth-controlled plate, wherein at least one depth-controlled plate is of the same type; the step of performing surface fitting on the measured thickness to obtain the fitted thickness after surface fitting includes: performing surface fitting on the measured thickness of the at least one depth-controlled plate and the corresponding standard plate thickness of the at least one depth-controlled plate to obtain the correspondence between the measured thickness of the at least one depth-controlled plate and the standard plate thickness; and determining the fitted thickness of the depth-controlled plate of the same type as the at least one depth-controlled plate using the correspondence based on the measured thickness.

[0011] The step of measuring the thickness of the plate to be controlled for depth and obtaining the measured thickness of the plate to be controlled for depth includes: drilling a through hole in the plate to be controlled for depth using a drill bit, and using the current signal generated when the drill tip of the drill bit contacts the opposite two surfaces of the plate to be controlled for depth to determine the measured thickness; wherein the through hole penetrates the opposite two sides of the plate to be controlled for depth.

[0012] The step of measuring the thickness of the depth-controlled plate to obtain the measured thickness of the depth-controlled plate includes: performing laser measurement on the depth-controlled plate to obtain the measured thickness of the depth-controlled plate.

[0013] The step of performing depth control operation on the plate to be controlled based on the fitted thickness includes: calculating the depth control depth of the plate to be controlled based on the depth control ratio of the plate to be controlled and the fitted thickness; and performing depth control operation on the plate to be controlled based on the depth control depth.

[0014] The step of controlling the depth of the plate to be controlled based on the fitted thickness includes: drilling, back drilling, or grooving the plate to be controlled based on the fitted thickness.

[0015] To solve the above-mentioned technical problems, the present invention provides a printed circuit board, which is prepared by the depth control method of the printed circuit board described in any one of the above claims.

[0016] The beneficial effects of this invention are as follows: Unlike the prior art, the depth control method for printed circuit boards of this invention first measures the thickness of the board to be controlled, obtains the measured thickness of the board to be controlled, then performs surface fitting on the measured thickness to obtain the fitted thickness after surface fitting, and finally performs depth control operation on the board to be controlled based on the fitted thickness. This can improve the depth control accuracy of printed circuit boards, improve the depth control effect of printed circuit boards, and thus improve the reliability of printed circuit boards. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating an embodiment of the method for controlling the depth of a printed circuit board provided by the present invention.

[0018] Figure 2 This is a schematic flowchart of another embodiment of the printed circuit board depth control method provided by the present invention;

[0019] Figure 3 This is a schematic diagram of the structure of a printed circuit board according to an embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship, movement, etc. between the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this invention involve descriptions such as "first," "second," etc., these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] Please see Figure 1 , Figure 1This is a flowchart illustrating an embodiment of the method for controlling the depth of a printed circuit board provided by the present invention.

[0024] Step S11: Obtain the depth plate to be controlled.

[0025] The material to be controlled for depth is obtained. In this embodiment, depth control refers to the situation where the depth of the depth control operation on the material to be controlled is less than the thickness of the material.

[0026] The controllable depth board in this embodiment can be a multi-layer circuit board or a single-layer circuit board, such as a single-layer circuit board, a two-layer circuit board, a five-layer circuit board, or a seven-layer circuit board, etc. The specific settings can be based on actual needs and are not limited here.

[0027] In this embodiment, the depth-controlled plate can be multiple plates of the same type, i.e., plates of the same specifications, the same structure, and the same design. After performing surface fitting on at least one of the depth-controlled plates, the fitting thickness of other depth-controlled plates of the same type can be determined based on the result of the surface fitting, and then the batch depth control of the depth-controlled plates can be achieved by using the result of the surface fitting.

[0028] Step S12: Measure the thickness of the plate to be controlled depth to obtain the measured thickness of the plate to be controlled depth.

[0029] After obtaining the depth-controlled plate, the thickness of the depth-controlled plate is measured to obtain the measured thickness of the depth-controlled plate.

[0030] In one specific application scenario, the thickness can be determined by the current signal generated when the drill tip contacts the opposite surfaces of the controlled-depth board during the drilling process. Drilling through holes is a standard procedure in printed circuit board (PCB) fabrication, and the thickness can be obtained using this method. In another specific application scenario, a laser device can emit a laser beam to the controlled-depth board to perform laser measurement, thus obtaining the thickness. In yet another specific application scenario, other measuring devices such as optical scanners and ultrasonic measuring instruments can also be used to measure the thickness of the controlled-depth board. Specific measurement methods are not limited here.

[0031] In the fabrication environment of printed circuit boards, the measurement of the depth of the board to be controlled during production is often easily affected by the actual production environment, such as unevenness of the board or the presence of debris in the production environment. The measured thickness may be inaccurate. Therefore, when performing depth control operation on the board to be controlled based on the measured thickness, the depth control accuracy is prone to be insufficient. Therefore, this embodiment performs data compensation for the measured thickness through the following steps.

[0032] Step S13: Perform surface fitting on the measured thickness to obtain the fitted thickness after surface fitting.

[0033] In a specific application scenario, before performing surface fitting on any depth-controlled plate, after obtaining the measured thickness, surface fitting can be performed on the measured thickness based on the standard thickness of the depth-controlled plate to obtain the fitted thickness. Surface fitting can compensate for the difference between the measured thickness and the actual standard thickness.

[0034] In one specific application scenario, the part to be controlled for depth can be removed from the production environment, and its thickness can be measured to obtain the standard thickness. In another specific application scenario, a standard coordinate system along the thickness direction of the part to be controlled for depth can be constructed using its own features, and then the standard thickness can be determined based on the features and the standard coordinate system. These features include, but are not limited to, positioning holes and the edges of the upper and lower surfaces. The specific method for obtaining the standard thickness is not limited here.

[0035] In a specific application scenario, after performing surface fitting on at least one depth-controlled plate, and obtaining the measured thickness of a new depth-controlled plate, a surface fitting can be performed on the measured thickness of the new depth-controlled plate based on the surface fitting results of the at least one depth-controlled plate, resulting in a fitted thickness. Specifically, the fitted thickness of the depth-controlled plate can be calculated using the measured thickness and the surface fitting results. The fitted thickness is an estimate of the standard thickness using the measured thickness; the more accurate the surface fitting results, the closer the fitted thickness is to the standard thickness.

[0036] Step S14: Perform depth control operation on the plate to be controlled based on the fitted thickness.

[0037] After obtaining the fitted thickness of the plate to be controlled, the depth control operation is performed on the plate based on the fitted thickness.

[0038] Since this embodiment adjusts the measured thickness through surface fitting, making the fitted thickness closer to the standard thickness, controlling the depth of the board to be controlled based on the fitted thickness can improve the depth control accuracy and quality of the board, and improve the reliability of the board.

[0039] Through the above steps, the depth control method for printed circuit boards in this embodiment first measures the thickness of the board to be controlled, obtains the measured thickness of the board to be controlled, then performs surface fitting on the measured thickness to obtain the fitted thickness after surface fitting, and finally performs depth control operation on the board to be controlled based on the fitted thickness. This can improve the depth control accuracy of printed circuit boards, improve the depth control effect of printed circuit boards, and thus improve the reliability of printed circuit boards.

[0040] Please see Figure 2 , Figure 2 This is a flowchart illustrating another embodiment of the method for controlling the depth of a printed circuit board provided by the present invention.

[0041] Step S21: Obtain the depth plate to be controlled.

[0042] At least one depth-controlled board is obtained. Specifically, this step is the same as step S11 in the previous embodiment. Please refer to the previous text, and it will not be repeated here.

[0043] Step S22: Construct a standard coordinate system based on the positioning holes of the plate to be controlled in depth, and determine the standard plate thickness of the plate to be controlled in depth based on the standard coordinate system.

[0044] A standard coordinate system is constructed based on the positioning holes of the plate to be controlled for depth, and then the standard plate thickness of the plate to be controlled for depth is determined based on the standard coordinate system. In a specific application scenario, at least three positioning holes that are not located on a straight line can be set at a preset position of the plate to be controlled for depth. A standard coordinate system for the plate to be controlled for depth is constructed based on the at least three positioning holes. Then, the coordinates of the edges of the opposite two sides of the plate to be controlled for depth are determined on the standard coordinate system, and the standard plate thickness of the plate to be controlled for depth is determined based on the above coordinates.

[0045] Step S23: Drill a through hole in the plate to be controlled for depth using a drill bit, and determine the measured thickness by using the current signal generated when the drill tip contacts the opposite two surfaces of the plate.

[0046] To measure the thickness of a controlled-depth board component, this embodiment involves drilling a through-hole in the component and using the current signal generated when the drill tip contacts opposite surfaces of the component to determine the thickness. The through-hole penetrates both sides of the component, and drilling through-holes is a standard procedure in printed circuit board (PCB) fabrication. This method allows for the measurement of the controlled-depth board thickness without requiring additional measurement steps, following the standard PCB fabrication process.

[0047] Step S24: Perform surface fitting on the measured thickness and the standard plate thickness to obtain the correspondence between the measured thickness and the standard plate thickness. Based on the measured thickness, use the correspondence to determine the fitted thickness of the plate to be controlled.

[0048] The measured thickness of the plate to be controlled for depth is fitted with a surface to obtain the correspondence between the measured thickness and the standard plate thickness. Based on the measured thickness, the fitted thickness of the plate to be controlled for depth is determined using the correspondence.

[0049] In a specific application scenario, surface fitting can be performed on the measured thickness of at least one depth-controlled plate and the standard plate thickness to obtain the correspondence between the measured thickness and the standard plate thickness of plates of the same type as the at least one depth-controlled plate. Then, based on the measured thickness, the fitted thickness of the depth-controlled plate can be determined using this correspondence. The more measurements of the depth-controlled plate and the standard plate thickness used for surface fitting, the more accurate the correspondence. That is, the correspondence is the relationship between the measured thickness and the standard plate thickness of the depth-controlled plate of that type. In another specific application scenario, surface fitting can also be performed on the measured thickness of at least one depth-controlled plate and the coordinates of its upper and lower opposite surfaces in a standard coordinate system to obtain the correspondence between the measured thickness of plates of the same type as the at least one depth-controlled plate and the coordinates of its upper and lower opposite surfaces in a standard coordinate system. Then, using this correspondence and the corresponding measured thickness, the coordinates of the upper and lower opposite surfaces of the same type of depth-controlled plate in the standard coordinate system can be determined, thereby determining its standard thickness, or directly using these coordinates for depth control.

[0050] In a specific application scenario, after obtaining the correspondence between the measured thickness and the standard thickness of a plate of the same type as at least one plate to be controlled for depth, surface fitting can be directly performed using this correspondence during subsequent surface fitting of plates of the same type as at least one plate to be controlled for depth. There is no need to construct a coordinate system to determine the standard thickness; instead, the fitted thickness is calculated directly from the measured thickness and the correspondence, improving the efficiency of obtaining the fitted thickness. This is suitable for batch depth control of plates to be controlled for depth. In other words, surface fitting can be performed on the measured thickness of at least one plate to be controlled for depth and the corresponding standard thickness of at least one plate to be controlled for depth to obtain the correspondence between the measured thickness and the standard thickness of at least one plate to be controlled for depth. Then, based on the measured thickness, the fitted thickness of the plate to be controlled for depth of the same type as at least one plate to be controlled for depth can be determined using this correspondence.

[0051] In a specific application scenario, the steps for surface fitting between the measured thickness of the PCB to be controlled for depth and the standard PCB thickness include: determining the fitting parameters for surface fitting based on the unevenness of the PCB to be controlled for depth; performing surface fitting using the fitting parameters based on the measured thickness and the standard PCB thickness to obtain the correspondence between the measured thickness and the standard PCB thickness. Since the unevenness of the printed circuit board may be caused by the melting of the prepreg, the unevenness of the PCB to be controlled for depth can be determined based on the viscosity of the resin material of the PCB to be controlled for depth, and then the fitting parameters for surface fitting can be determined based on the unevenness. The influencing factors of unevenness include, but are not limited to, the viscosity of the resin material.

[0052] In a specific application scenario, a surface fitting method combining least squares and polynomial interpolation can be used to fit the measured thickness of the depth-controlled board to the standard board thickness. Fitting parameters, such as the polynomial interpolation degree, are determined based on the viscosity and residual copper content of the prepreg laminated to the depth-controlled board. Then, surface fitting is performed based on these determined fitting parameters and the measured thickness of the depth-controlled board compared to the standard board thickness. This surface fitting method can also be used through other interpolation or multiplication methods. In this application scenario, the factors affecting unevenness include the viscosity and residual copper content of the prepreg.

[0053] The above-mentioned surface fitting scheme can correct abnormal data in the through-hole detection plate thickness scheme and improve the accuracy of plate thickness data.

[0054] Step S25: Calculate the depth control ratio and fitted thickness of the depth control plate to obtain the depth control depth of the depth control plate, and perform depth control operation on the depth control plate based on the depth control depth.

[0055] After determining the fitted thickness of the plate to be controlled for depth, the controlled depth of the plate can be calculated based on the controlled depth ratio and the fitted thickness. Finally, the controlled depth operation is performed on the plate based on the controlled depth. In this embodiment, the controlled depth includes, but is not limited to, drilling, back drilling, or grooving operations on the plate to be controlled for depth.

[0056] Since the fitted thickness calculated in this embodiment is accurate and reliable, the controlled depth calculated based on the controlled depth ratio of the plate to be controlled and the fitted thickness is also accurate and reliable. Controlling the depth of the plate to be controlled using this controlled depth can improve the controlled depth accuracy of the plate.

[0057] Through the above steps, the depth control method for printed circuit boards in this embodiment first measures the thickness of the component to be controlled, then performs surface fitting on the measured thickness to obtain the fitted thickness, and finally controls the depth of the component based on the fitted thickness. This improves the depth control accuracy and effect of the printed circuit board, thereby enhancing its reliability. Furthermore, this embodiment can calculate the fitted thickness of other similar components to be controlled based on the obtained correspondence, enabling batch measurement and depth control of components, thus improving the depth control efficiency and accuracy.

[0058] In other embodiments, the method for obtaining the measured thickness of the depth-controlled plate further includes: emitting a laser beam from a laser device onto the depth-controlled plate to perform laser measurement on the depth-controlled plate and obtain the measured thickness of the depth-controlled plate.

[0059] In other embodiments, the thickness of the plate to be controlled for depth can also be measured using other measuring devices such as optical scanners and ultrasonic measuring instruments. Specific measurement methods are not limited here.

[0060] Please see Figure 3 , Figure 3 This is a schematic diagram of a printed circuit board according to an embodiment of the present invention. This embodiment will be described with the case of back drilling for depth control. When the depth control is used to prepare other structures, the process is similar to this embodiment. This embodiment only describes the depth control and does not limit the number of layers, structure, etc. of the printed circuit board.

[0061] The printed circuit board 10 of this embodiment includes a circuit layer 15, a prepreg 14, a target circuit layer 13, and the circuit layer 15 stacked together. A through-hole 12 is provided on the printed circuit board 10, penetrating the entire printed circuit board 10. A back-drilled hole 11 is also provided on one side of the through-hole 12. The diameter of the back-drilled hole 11 is larger than that of the through-hole 12, and a stub distance 131 separates the bottom of the back-drilled hole 11 from the target circuit layer 13.

[0062] The printed circuit board 10 of this embodiment is prepared by the depth control method of the printed circuit board of any of the above embodiments. Therefore, the bottom of the back drill hole 11 of the printed circuit board 10 of this embodiment can accurately retain the stub distance 131 between it and the target circuit layer 13, without damaging the target circuit layer 13, and without excessively damaging the signal transmission between the bottom of the back drill hole 11 and the target circuit layer 13. That is, the back drill hole 11 of this embodiment has high precision.

[0063] With the above structure, the printed circuit board of this embodiment can achieve high-precision control of the back-drilled stub, resulting in high-precision back-drilled holes, thereby improving the reliability of the printed circuit board. Furthermore, it can preserve the integrity of signal transmission and reduce the impact of back-drilling on signal transmission in the metallized via.

[0064] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0065] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for controlling the depth of a printed circuit board, characterized in that, The depth control method for the printed circuit board includes: Obtain the deep component to be controlled; The thickness of the plate to be controlled is measured to obtain the measured thickness of the plate to be controlled. A standard coordinate system is constructed based on the positioning holes of the plate to be controlled in depth, and the standard plate thickness of the plate to be controlled in depth is determined based on the standard coordinate system. The measured thickness is fitted with a surface to obtain the fitted thickness; wherein, the fitting parameters for the surface fitting are determined based on the unevenness of the plate to be controlled; the measured thickness and the standard plate thickness are fitted with the fitting parameters to obtain the correspondence between the measured thickness and the standard plate thickness; the fitted thickness of the plate to be controlled is determined based on the measured thickness and the correspondence. The depth of the plate to be controlled is controlled based on the fitted thickness.

2. The method for controlling the depth of a printed circuit board according to claim 1, characterized in that, The step of determining the fitting parameters for surface fitting based on the unevenness of the controlled deep plate includes: The unevenness of the plate to be controlled is determined based on the viscosity of the resin material of the plate to be controlled. The fitting parameters for surface fitting are determined based on the aforementioned unevenness.

3. The method for controlling the depth of a printed circuit board according to claim 1, characterized in that, The steps for obtaining the depth of the plate component to be controlled include: At least one depth-controlled plate is obtained, wherein at least one depth-controlled plate is of the same type; The step of performing surface fitting on the measured thickness to obtain the fitted thickness after surface fitting includes: The measured thickness of the at least one depth-controlled plate and the corresponding standard plate thickness of the at least one depth-controlled plate are fitted with a surface to obtain the correspondence between the measured thickness of the at least one depth-controlled plate and the standard plate thickness. Based on the measured thickness, the fitted thickness of the control depth plate, which is the same type as the at least one control depth plate, is determined using the corresponding relationship.

4. The method for controlling the depth of a printed circuit board according to claim 1, characterized in that, The step of measuring the thickness of the plate to be controlled for depth to obtain the measured thickness of the plate to be controlled for depth includes: The thickness is determined by drilling a through hole in the plate to be controlled by a drill bit and using the current signal generated when the drill tip of the drill bit contacts the opposite two surfaces of the plate to be controlled. The through hole extends through both sides of the depth plate to be controlled.

5. The method for controlling the depth of a printed circuit board according to claim 1, characterized in that, The step of measuring the thickness of the plate to be controlled for depth to obtain the measured thickness of the plate to be controlled for depth includes: The thickness of the plate to be controlled by the laser is obtained by laser measurement.

6. The method for controlling the depth of a printed circuit board according to claim 1, characterized in that, The steps of performing depth control operation on the plate to be controlled based on the fitted thickness include: The depth of the controlled depth of the plate to be controlled is calculated based on the depth control ratio of the plate to be controlled and the fitted thickness. The depth control operation is performed on the plate to be controlled based on the depth control depth.

7. The method for controlling the depth of a printed circuit board according to claim 1, characterized in that, The steps of performing depth control operation on the plate to be controlled based on the fitted thickness include: Based on the fitted thickness, drilling, back drilling, or grooving operations are performed on the deep plate to be controlled.

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