Circuit board PTH hole processing method and circuit board

Abstract

The invention discloses a circuit board PTH hole processing method, which comprises the steps of dividing a circuit board into an independent area and a dense area according to the distribution density of preset PTH holes on the circuit board before drilling, obtaining a compensation value a1 of the preset PTH holes in the independent area according to a preset board thickness H and a preset hole copper thickness h, and setting the compensation value a2 of the preset PTH holes in the dense area, and a2 is smaller than a1, and then the diameter d of the to-be-processed via hole is obtained according to the preset diameter D of the preset PTH hole and the obtained compensation value, so that the processing precision of each PTH hole in the circuit board can be improved, and the processing quality of the circuit board can be improved. In addition, the invention also discloses a circuit board formed by the circuit board PTH hole processing method.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board processing, and in particular to a circuit board drilling method and a circuit board. Background Art

[0002] In the process of circuit board manufacturing, the inner layer circuit pattern is usually made first, and then multiple core boards are pressed together to form a multilayer board, and then the PTH holes used to connect the interlayer current and signal transmission are processed. When processing PTH holes, it is usually necessary to drill through holes on the multilayer board first, and then form a copper layer on the inner edge of the through hole by electroplating.

[0003] When processing via holes, it is usually necessary to add a certain amount of compensation based on the preset diameter of the PTH hole according to the circuit board thickness required by the customer and the copper thickness in the PTH hole. However, for mil-level PTH holes, that is, PTH holes with a finished product tolerance of ±0.025mm, due to the diverse production processes of circuit boards, each production process and the distribution position of PTH holes are likely to affect the aperture of the finished holes, which ultimately leads to the finished holes failing to meet customer requirements. When external electronic components are assembled on the circuit board, problems such as cold soldering or failure to successfully assemble are prone to occur, which seriously affects the processing quality of the circuit board. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a circuit board drilling method to improve the processing accuracy of each PTH hole on the circuit board, which is conducive to improving the processing quality of the circuit board.

[0005] The circuit board PTH hole processing method according to an embodiment of the present invention comprises the following steps: S1: dividing the circuit board into an independent area and a dense area according to a preset distribution density of PTH holes on the circuit board, wherein the distribution density of PTH holes in the dense area is greater than the distribution density of PTH holes in the independent area; S2: adjusting the compensation value of the preset PTH hole according to the preset board thickness H and the preset hole copper thickness h, obtaining the compensation value of the preset PTH hole located in the independent area as a1, and adjusting the compensation value of the preset PTH hole located in the dense area to a2, wherein a2<a1; S3: according to the preset diameter D of the preset PTH hole and the compensation value, obtaining the diameter d of the via hole to be processed, wherein the diameter d of the via hole located in the independent area is d1, d1=D+a1, and the diameter d of the via hole located in the dense area is d2, d2=D+a2; S3: adjusting the diameter of the drill according to the obtained diameter of the via hole to process the via hole; S4: electroplating, forming a copper layer in the via hole by electroplating to obtain the preset PTH hole.

[0006] The circuit board PTH hole processing method according to the embodiment of the present invention has at least the following beneficial effects: By adopting the circuit board PTH hole processing method of the embodiment of the present invention, before drilling, the circuit board is first divided into an independent area and a dense area according to the distribution density of the preset PTH holes on the circuit board, and the PTH hole distribution density in the dense area is greater than the PTH hole distribution density in the independent area. Therefore, the compensation value a1 of the preset PTH hole in the independent area can be obtained according to the preset board thickness H and the preset hole copper thickness h, and the compensation value of the preset PTH hole in the dense area is adjusted to a2, so that a2<a1, that is, the compensation value of the preset PTH hole in the dense area is set to a smaller value than a1, and then the via hole diameter d to be processed is obtained according to the preset diameter D of the preset PTH hole and the obtained compensation value. Therefore, when the preset diameter D is the same, the via hole diameter d2 located in the dense area will be smaller than the via hole diameter d1 located in the independent area, thereby reducing the situation in which the hole copper thickness is smaller and the finished hole diameter is greater than the preset diameter D due to less liquid flowing into the via hole during electroplating in the dense area, thereby improving the processing accuracy of each PTH hole on the circuit board, and thus facilitating the improvement of the processing quality of the circuit board.

[0007] According to some embodiments of the present invention, in step S3, the compensation value of the preset PTH hole located in the dense area is set to a2, where a2=a1-1mil.

[0008] According to some embodiments of the present invention, step S4 further includes: performing tin spraying surface treatment on the circuit board after electroplating, and spraying a tin layer on the surface of the circuit board and the surface of the copper layer in the via.

[0009] According to some embodiments of the present invention, in step S2, the compensation value of the preset PTH hole located in the independent area is adjusted to b1, b1>a1, and the compensation value of the preset PTH hole located in the dense area is adjusted to b2, b1>b2>a2.

[0010] According to some embodiments of the present invention, in step S2, the compensation value of the preset PTH hole located in the independent area is adjusted to b1, b1=a1+1mil, and the compensation value of the preset PTH hole located in the dense area is adjusted to b2, b2=a2+1mil.

[0011] According to some embodiments of the present invention, in step S2, X sets of plate thickness standards and Y sets of copper thickness standards are set, where 2≤X, 1≤Y, and X and Y are integers. When the preset hole copper thickness h is in the same group of copper thickness standards, the compensation value is set according to the preset board thickness H. Among them, X=3, the first group of plate thickness standards is H≤118.11mil, the second group of plate thickness standards is 118.11mil<H≤157.48mil, and the third group of plate thickness standards is H>157.48mil. In two adjacent groups of plate thickness standards, the compensation value corresponding to the latter group of plate thickness standards is 1mil larger than the compensation value corresponding to the former group of plate thickness standards; Obtain compensation values ​​corresponding to one set of plate thickness standards, select a plate thickness standard according to the preset plate thickness H, and adjust the compensation value corresponding to the preset plate thickness H.

[0012] According to some embodiments of the present invention, in step S2, when the preset board thickness H is in the same group of board thickness standards, the compensation value is set according to the preset hole copper thickness h. Wherein, Y=2, the first group of copper thickness standards is 1.2mil≤h<1.4mil, the second group of copper thickness standards is h≥1.4mil, and the compensation value corresponding to the second group of copper thickness standards is 1mil greater than the compensation value corresponding to the first group of copper thickness standards; Obtain compensation values ​​corresponding to one set of copper thickness standards, select a copper thickness standard according to the preset copper thickness h, and adjust the compensation value corresponding to the preset copper thickness h.

[0013] According to some embodiments of the present invention, in step S3, n groups of drill bits are provided, n≥2, and n is an integer, and the diameter difference between each two adjacent groups of drill bits is 0.025 mm. In the step S3, the drill diameter Q1 of the mth group of drills and the drill diameter Q2 of the m+1th group of drills are obtained according to the via diameter, 1≤m≤n-1, wherein Q1≤d<Q2, when |d-Q1|<|d-Q2|, the mth group of drills is selected, and when |d-Q1|≥|d-Q2|, the m+1th group of drills is selected.

[0014] According to some embodiments of the present invention, the step S3 further comprises: adjusting the drill diameter according to the preset hole diameter tolerance T of the PTH hole, When 0.025mml≤T<0.5mm, obtain the drill diameter Q1 of the mth group of drills and the drill diameter Q2 of the m+1th group of drills according to the via diameter d, wherein Q1≤d<Q2, when |d-Q1|<|d-Q2|, select the mth group of drills, and when |d-Q1|≥|d-Q2|, select the m+1th group of drills; When T≥0.5mm, the drill diameter Q1 of the mth group of drills and the drill diameter Q2 of the m+1th group of drills are obtained according to the via diameter d, wherein Q1≤d<Q2, when |d-Q1|<0.015mm, the mth group of drills is selected, and when |d-Q1|≥0.015mm, the m+1th group of drills is selected.

[0015] The circuit board according to the embodiment of the present invention is formed by the circuit board PTH hole processing method of any of the above embodiments.

[0016] The circuit board according to the embodiment of the present invention has at least the following beneficial effects: By adopting the circuit board PTH hole processing method of any of the above embodiments, the compensation value of the preset PTH hole at each position can be obtained more accurately, thereby improving the processing accuracy of each PTH hole on the circuit board, which is beneficial to improving the processing quality of the circuit board and facilitating the subsequent connection between the circuit board and other external electronic components.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. DETAILED DESCRIPTION

[0018] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0019] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0020] An embodiment of the present invention provides a method for processing a PTH hole of a circuit board, comprising the following steps: S1: dividing the circuit board into an independent area and a dense area according to a preset distribution density of PTH holes on the circuit board, wherein the distribution density of PTH holes in the independent area is less than the distribution density of PTH holes in the dense area; S2: adjusting the compensation value of the preset PTH hole according to the preset board thickness H and the preset hole copper thickness, setting the compensation value of the preset PTH hole located in the dense area to a1, and adjusting the compensation value of the preset PTH hole located in the independent area to a2, wherein a2>a1; S3: according to the preset diameter D of the preset PTH hole and the compensation value, the diameter d of the via hole to be processed is obtained, wherein the diameter d of the via hole located in the dense area is d1, d1=D+a1, and the diameter d of the via hole located in the independent area is d2, d2=D+a2; S3: adjusting the drill diameter according to the obtained via hole diameter to process the via hole; S4: electroplating, forming a copper layer in the via hole to obtain a preset PTH hole.

[0021] During the processing of the circuit board, the compensation value obtained according to the preset board thickness H and the preset hole copper thickness h can be applied to the processing of a single independently set PTH hole. However, in the actual processing of the circuit board, the number of PTH holes is usually more than one, and the PTH holes in some areas are densely distributed. Compared with the processing of a single independently set PTH hole, in the area where the PTH holes are densely distributed, the amount of plating solution that can enter the via hole during electroplating will be less than the amount of plating solution that enters the via hole in the area where the PTH holes are independently set. As a result, the copper layer thickness formed on the inner wall of the via hole in the area where the PTH holes are densely distributed is smaller, and it is easy for the diameter of the finished hole to be larger than the preset diameter D.

[0022] To this end, by adopting the circuit board PTH hole processing method of the embodiment of the present invention, before drilling, the circuit board is divided into an independent area and a dense area according to the distribution density of the preset PTH holes on the circuit board, and the PTH hole distribution density in the dense area is greater than the PTH hole distribution density in the independent area. Therefore, according to the preset board thickness H and the preset hole copper thickness h, the compensation value a1 of the preset PTH hole in the independent area can be obtained, and the compensation value of the preset PTH hole in the dense area is adjusted to a2, so that a2<a1, that is, the compensation value of the preset PTH hole in the dense area is adjusted to a smaller value than a1, and then according to the preset diameter D of the preset PTH hole and The compensation value obtained is the diameter d of the via hole to be processed. Specifically, the diameter of the via hole located in the independent area is d1, d1=D+a1, and the diameter d of the via hole located in the dense area is d2, d2=D+a2. Therefore, when the preset diameter D is the same, the diameter d2 of the via hole located in the dense area will be smaller than the diameter d1 of the via hole located in the independent area. This can reduce the situation in which the hole copper thickness is smaller and the finished hole diameter is larger than the preset diameter D in the dense area due to less potion flowing into the via hole during electroplating. This can improve the processing accuracy of each PTH hole on the circuit board, which is beneficial to improving the processing quality of the circuit board.

[0023] It can be understood that the board thickness refers to the overall thickness of the circuit board, which is specifically the sum of the thickness of the multilayer board obtained during lamination and the thickness of the surface copper formed on the surface of the multilayer board after electroplating. When measuring the thickness of the circuit board, the center value of the thickness at each location of the circuit board can be taken.

[0024] It can be understood that the hole copper thickness refers to the thickness of the copper layer formed on the inner wall of the via hole after processes such as electroplating.

[0025] In some embodiments, in step S3, the compensation value of the preset PTH hole located in the dense area is adjusted to a2, where a2=a1-1mil.

[0026] By adopting the above method, the compensation value of the PTH hole in the dense area is adjusted to be 1 mil less than the compensation value a1 of the PTH hole in the independent area, thereby being able to better control the tolerance of the PTH finished hole within ±0.025 mm, wherein 1 mil=0.025 mm, thereby reducing the risk of the difference between the diameter of the PTH finished hole obtained in the dense area and the preset diameter D exceeding the tolerance range, thereby facilitating the improvement of the processing accuracy of each PTH hole in the dense area, and further facilitating the improvement of the processing quality of the circuit board.

[0027] It is understandable that, depending on the required tolerance range of the PTH hole, the difference between a2 and a1 can be appropriately increased or decreased, as long as the difference between the diameter of the PTH finished hole obtained in the dense area and the preset diameter D is within the set tolerance range.

[0028] In some embodiments, step S4 further includes: performing tin spraying surface treatment on the circuit board after electroplating, and spraying a tin layer on the surface of the circuit board and the surface of the copper layer in the via hole.

[0029] By adopting the above method, the tin spraying surface treatment can spray a tin layer on the surface of the circuit board and the surface of the copper layer in the through hole. The tin layer can greatly improve the welding quality between the circuit board and the external electronic components, and reduce the risk of cold soldering or poor soldering between the external electronic components and the circuit board. In addition, the tin layer can also protect the surface copper on the surface of the circuit board and the copper layer on the inner wall of the through hole, and reduce the risk of oxidation of the surface copper on the surface of the circuit board and the copper layer on the inner wall of the through hole.

[0030] It is understandable that in some embodiments, the circuit board is roughened before the tin-spraying surface treatment, and the roughening treatment can cause a certain amount of erosion to the copper layer on the inner wall of the via hole, thereby improving the bonding force between the tin layer and the surface copper of the circuit board, and between the tin layer and the copper layer on the inner wall of the via hole, making the structure of the circuit board more stable. In addition, when the tin layer is formed on the surface of the copper layer on the inner wall of the via hole by the tin-spraying surface treatment, the thickness of the tin layer needs to be greater than the thickness of the eroded copper, thereby facilitating the improvement of the welding performance of the circuit board.

[0031] In some embodiments, in step S2, the compensation value of the preset PTH hole located in the independent area is adjusted to b1, b1>a1, and the compensation value of the preset PTH hole located in the dense area is adjusted to b2, b1>b2>a2.

[0032] Since a layer of tin will be attached to the copper layer on the inner wall of the via hole during the roughening process, the diameter of the PTH hole will be further reduced, which can easily lead to the diameter of the obtained PTH finished hole being smaller than the preset diameter D.

[0033] To this end, by adopting the circuit board PTH hole processing method of the embodiment of the present invention, the compensation value of the PTH hole can be adjusted for the circuit board that needs to be subjected to tin-spraying surface treatment. Specifically, the compensation value of the preset PTH hole located in the independent area can be adjusted to b1, b1>a1, and the compensation value of the preset PTH hole located in the dense area can be adjusted to b2, b1>b2>a2, that is, for the circuit board that needs to be subjected to tin-spraying surface treatment, the compensation value of the preset PTH hole is adjusted to a larger value than the compensation value of the preset PTH hole on the circuit board that does not need to be subjected to tin-spraying surface treatment. Therefore, when the preset diameter D is the same, the via hole diameter of the circuit board that needs to be subjected to tin-spraying surface treatment will be larger than the via hole diameter of the circuit board that does not need to be subjected to tin-spraying surface treatment. Therefore, the thickness of the tin layer formed during the surface tin-spraying treatment can be compensated, and the situation that the diameter of the PTH finished hole is smaller than the preset diameter D due to the formation of the tin layer during the tin-spraying surface treatment can be reduced. Therefore, the processing accuracy of each PTH hole on the circuit board that needs to be subjected to tin-spraying treatment can be improved, which is conducive to improving the processing quality of the circuit board.

[0034] It can be understood that for circuit boards that need to be tin-sprayed, the compensation value of the preset PTH holes located in the dense area needs to be smaller than the compensation value of the preset PTH holes located in the independent area. This can reduce the situation in which the hole copper thickness is smaller and the finished hole diameter is larger than the preset diameter D due to less liquid medicine flowing into the via hole in the dense area during electroplating. This can improve the processing accuracy of each PTH hole on the circuit board that needs to be tin-sprayed, which is beneficial to improving the processing quality of the circuit board.

[0035] In some embodiments, in step S2, the compensation value of the preset PTH hole located in the independent area is adjusted to b1, b1=a1+1mil, and the compensation value of the preset PTH hole located in the dense area is adjusted to b2, b2=a2+1mil.

[0036] By adopting the above method, for the circuit board that needs to be tin-sprayed, the preset PTH hole compensation value of the independent area is adjusted to a1+1mil, that is, 1mil is added to the preset PTH hole compensation value of the independent area of ​​the circuit board that does not need to be tin-sprayed, thereby compensating for the thickness of the tin layer formed during the surface tin-spraying treatment, reducing the situation where the diameter of the PTH finished hole in the independent area is smaller than the preset diameter D due to the formation of the tin layer during the tin-spraying surface treatment, and can control the tolerance of the PTH finished hole on the circuit board that needs to be tin-sprayed to within ±0.025mm as much as possible, thereby improving the processing accuracy of the PTH hole in the independent area. Similarly, for circuit boards that require tin spraying, the preset PTH hole compensation value in the dense area is adjusted to a2+1mil, that is, 1mil is added to the preset PTH hole compensation value in the dense area of ​​the circuit board that does not require tin spraying. This can compensate for the thickness of the tin layer formed during the surface tin spraying process, reduce the situation where the diameter of the PTH finished hole in the dense area is smaller than the preset diameter D due to the formation of the tin layer during the tin spraying surface treatment, and can control the tolerance of the PTH finished hole on the circuit board that requires tin spraying to within ±0.025mm as much as possible, thereby improving the processing accuracy of the PTH holes in the dense area.

[0037] In some embodiments, in step S2, set X group of plate thickness standards and set Y group of copper thickness standards, where 2≤X, 1≤Y, and X and Y are integers, when the preset hole copper thickness h is in the same group of copper thickness standards, set the compensation value according to the preset plate thickness H, where X=3, the first group of plate thickness standards is H≤118.11mil, the second group of plate thickness standards is 118.11mil<H≤157.48mil, and the third group of plate thickness standards is H>157.48mil; In two adjacent groups of plate thickness standards, the compensation value corresponding to the latter group of plate thickness standards is 1 mil greater than the compensation value corresponding to the former group of plate thickness standards; obtain the compensation value corresponding to one group of plate thickness standards, select the plate thickness standard according to the preset plate thickness H, and adjust the compensation value corresponding to the preset plate thickness H.

[0038] By adopting the above method, three groups of plate thickness standards are set, so that when the actual circuit board is processed, the corresponding plate thickness standard can be selected according to the preset plate thickness H of the circuit board, and the compensation value corresponding to the plate thickness standard can be quickly adjusted, so that the processing of the circuit board can be more convenient. Specifically, the first group of plate thickness standards is H≤118.11mil, the second group of plate thickness standards is 118.11mil<H≤157.48mil, and the third group of plate thickness standards is H>157.48mil. Therefore, when setting the compensation value, the compensation value corresponding to one group of plate thickness standards is first obtained. Since the compensation value corresponding to the latter group of plate thickness standards in two adjacent groups of plate thickness standards is 1mil larger than the compensation value corresponding to the former group of plate thickness standards, the compensation value corresponding to each group of plate thickness standards can be adjusted, and then the corresponding group of plate thickness standards can be selected according to the preset plate thickness H, and the compensation value corresponding to the group of plate thickness standards can be quickly adjusted. In this process, there is no need to measure and obtain the compensation value corresponding to each set of plate thickness standards. It is only necessary to first obtain the compensation value corresponding to one set of plate thickness standards to adjust the compensation values ​​corresponding to other sets of plate thickness standards, thereby making the selection of compensation values ​​more convenient.

[0039] It is understandable that obtaining the compensation value corresponding to one set of plate thickness standards can be specifically performed by slicing and measuring the first plate after drilling and electroplating, thereby obtaining a set of compensation values ​​of plate thickness standards corresponding to the thickness of the first plate.

[0040] In some embodiments, in step S2, when the preset board thickness H is in the same group of board thickness standards, a compensation value is set according to a preset hole copper thickness h, wherein Y=2, the first group of copper thickness standards is 1.2mil≤h<1.4mil, the second group of copper thickness standards is h≥1.4mil, and the compensation value corresponding to the second group of copper thickness standards is 1mil greater than the compensation value corresponding to the first group of copper thickness standards; the compensation value corresponding to one group of copper thickness standards is obtained, the copper thickness standard is selected according to the preset copper thickness h, and the compensation value corresponding to the preset copper thickness h is adjusted.

[0041] By adopting the above method, two groups of copper thickness standards are set, so that when the actual circuit board is processed, the corresponding copper thickness standard can be selected according to the preset copper thickness h of the circuit board, and the compensation value corresponding to the copper thickness standard can be quickly adjusted, thereby making the processing of the circuit board more convenient. Specifically, the first group of copper thickness standards is 1.2mil≤h<1.4mil, and the second group of copper thickness standards is h≥1.4mil. Therefore, when setting the compensation value, the compensation value corresponding to one group of copper thickness standards is first obtained. Since the compensation value corresponding to the latter group of copper thickness standards is 1mil larger than the compensation value corresponding to the former group of copper thickness standards in the two adjacent groups of copper thickness standards, the compensation value corresponding to each group of copper thickness standards can be obtained, and then the corresponding group of copper thickness standards can be selected according to the preset copper thickness h, and the compensation value corresponding to the group of copper thickness standards can be quickly adjusted. In this process, there is no need to measure and obtain the compensation value corresponding to each group of copper thickness standards. It is only necessary to first obtain the compensation value corresponding to one group of copper thickness standards to deduce the compensation values ​​corresponding to other groups of copper thickness standards, thereby making the selection of compensation values ​​more convenient.

[0042] It is understandable that obtaining the compensation value corresponding to one set of copper thickness standards can be specifically performed by slicing and measuring the first board after drilling and electroplating, thereby obtaining a set of compensation values ​​of copper thickness standards corresponding to the copper thickness of the first board.

[0043] Referring to the table below, a comparative analysis is conducted on the preset PTH hole compensation values ​​at different positions on the same circuit board and the preset PTH hole compensation values ​​at the same position on different circuit boards. According to the analysis, when setting the compensation value, it is only necessary to obtain the PTH hole compensation value of one set of board thickness standards and one set of copper thickness standards in a specific area according to whether the circuit board is subjected to tin-spraying surface treatment, and then the compensation value corresponding to the preset board thickness H and the preset copper thickness h in the independent area and the dense area on each circuit board can be obtained.

[0044]

[0045] In some embodiments, in step S3, n groups of drill bits are provided, n≥2, and n is an integer, and the difference in diameter between each two adjacent groups of drill bits is 0.025 mm. In step S3, the drill bit diameter Q1 of the mth group of drill bits and the drill bit diameter Q2 of the m+1th group of drill bits are obtained according to the diameter of the via hole, 1≤m≤n-1, wherein Q1≤d<Q2, when |d-Q1|<|d-Q2|, the mth group of drill bits is selected, and when |d-Q1|≥|d-Q2|, the m+1th group of drill bits is selected.

[0046] By adopting the above method, multiple groups of drill bits are provided, so that after obtaining the compensation value and obtaining the diameter d of the via hole to be processed, the drill bit diameter closest to d can be selected, and since the difference in diameter between each two adjacent groups of drill bits is 0.025 mm, the accuracy of via hole processing can be greatly improved, and thus the processing accuracy of PTH holes can be greatly improved, which is beneficial to improving the processing quality of circuit boards. In some embodiments, step S3 further includes: adjusting the drill diameter according to a preset PTH hole diameter tolerance T, When 0.025mml≤T<0.5mm, obtain the drill diameter Q1 of the mth group of drills and the drill diameter Q2 of the m+1th group of drills according to the via hole diameter d, wherein Q1≤d<Q2, when |d-Q1|<|d-Q2|, select the mth group of drills, and when |d-Q1|≥|d-Q2|, select the m+1th group of drills; When T≥0.5mm, obtain the drill diameter Q1 of the mth group of drills and the drill diameter Q2 of the m+1th group of drills according to the via diameter d, where Q1≤d<Q2, and when |d-Q1|<0.015mm, select the mth group of drills; when |d-Q1|≥0.015mm, select the m+1th group of drills.

[0047] In the above method, by setting two drill selection methods, a more suitable drill selection method can be selected according to the tolerance requirement of the preset PTH hole, thereby making the processed PTH finished hole closer to the preset PTH hole.

[0048] Specifically, when the tolerance T is required to be 0.025mml≤T<0.5mm, first obtain the drill diameter Q1 of the mth group of drills and the drill diameter Q2 of the m+1th group of drills according to the via hole diameter d, where Q1≤d<Q2, that is, obtain two groups of drills with diameters adjacent to the via hole diameter d, and then select the group of drills closest to the via hole diameter. For example, when d=0.568mm, obtain the drill diameter Q1=0.55mm of the mth group of drills, |d-Q1|=|0.568-0.55|=0.018mm; obtain the drill diameter Q2=0.575mm of the m+1th group of drills, |d-Q2|=|0.568-0.575|=0.007mm, so a drill with a drill diameter of 0.575mm can be selected for via hole processing, thereby improving the processing accuracy of PTH holes.

[0049] When the tolerance T is required to be T≥0.5mm, due to the large tolerance value, a group of drills with a drill diameter located in front of the via hole diameter d can be directly obtained, that is, the mth group of drills, and the drill diameter is Q1. It is only necessary to determine the value of |d-Q1|. When |d-Q1|<0.015mm, select the mth group of drills. When |d-Q1|≥0.015mm, select a group of drills with a drill diameter located behind the via hole diameter d, that is, the m+1th group of drills, and the drill diameter is Q2. For example, when d=0.512mm, the drill diameter Q1=0.5mm of the mth group of drills is obtained, and |d-Q1|=|0.568-0.55|=0.012mm<0.015mm. Therefore, the mth group of drills, that is, the drills with a drill diameter of Q1=0.5mm, can be selected for via hole processing, thereby improving the processing accuracy of PTH holes.

[0050] An embodiment of the present invention further provides a circuit board, which is formed by the circuit board PTH hole processing method of any of the above embodiments.

[0051] In an embodiment of the present invention, by adopting the circuit board PTH hole processing method of any of the above embodiments, the compensation value of the preset PTH hole at each position can be obtained more accurately, thereby improving the processing accuracy of each PTH hole on the circuit board, which is beneficial to improving the processing quality of the circuit board and facilitating the subsequent connection between the circuit board and other external electronic components.

[0052] The present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A circuit board PTH hole processing method, characterized in that: The following steps are involved: S1: dividing the circuit board into an independent area and a dense area according to a preset distribution density of PTH holes on the circuit board, wherein the distribution density of PTH holes in the dense area is greater than the distribution density of PTH holes in the independent area; S2: adjusting the compensation value of the preset PTH hole according to the preset board thickness H and the preset hole copper thickness h, obtaining the compensation value of the preset PTH hole located in the independent area as a1, and adjusting the compensation value of the preset PTH hole located in the dense area to a2, wherein a2<a1; S3: according to the preset diameter D of the preset PTH hole and the compensation value, obtaining the diameter d of the via hole to be processed, wherein the diameter d of the via hole located in the independent area is d1, d1=D+a1, and the diameter d of the via hole located in the dense area is d2, d2=D+a2; S3: adjusting the diameter of the drill according to the obtained diameter of the via hole to process the via hole; S4: electroplating, forming a copper layer in the via hole by electroplating to obtain the preset PTH hole.

2. The circuit board PTH hole processing method according to claim 1, characterized in that: In the step S3, the compensation value of the preset PTH hole located in the dense area is set to a2, a2 ​​= a1-1 mil.

3. The circuit board PTH hole processing method according to claim 1, characterized in that: The step S4 further includes: performing tin spraying surface treatment on the circuit board after electroplating, and spraying a tin layer on the surface of the circuit board and the surface of the copper layer in the via hole.

4. The circuit board PTH hole processing method according to claim 3, characterized in that: In the step S2, the compensation value of the preset PTH hole located in the independent area is adjusted to b1, b1>a1, and the compensation value of the preset PTH hole located in the dense area is adjusted to b2, b1>b2>a2.

5. The circuit board PTH hole processing method according to claim 4, characterized in that: In the step S2, the compensation value of the preset PTH hole located in the independent area is adjusted to b1, b1=a1+1mil, and the compensation value of the preset PTH hole located in the dense area is adjusted to b2, b2=a2+1mil.

6. The circuit board PTH hole processing method according to claim 1, characterized in that: In step S2, set X group of plate thickness standards and set Y group of copper thickness standards, where 2≤X, 1≤Y, and X and Y are integers. When the preset hole copper thickness h is in the same group of copper thickness standards, the compensation value is set according to the preset board thickness H. Among them, X=3, the first group of plate thickness standards is H≤118.11mil, the second group of plate thickness standards is 118.11mil<H≤157.48mil, and the third group of plate thickness standards is H>157.48mil. In two adjacent groups of plate thickness standards, the compensation value corresponding to the latter group of plate thickness standards is 1mil greater than the compensation value corresponding to the former group of plate thickness standards; Obtain compensation values ​​corresponding to one set of plate thickness standards, select a plate thickness standard according to the preset plate thickness H, and adjust the compensation value corresponding to the preset plate thickness H.

7. The circuit board PTH hole processing method according to claim 6, characterized in that: In step S2, when the preset board thickness H is in the same set of board thickness standards, the compensation value is set according to the preset hole copper thickness h. Wherein, Y=2, the first group of copper thickness standards is 1.2mil≤h<1.4mil, the second group of copper thickness standards is h≥1.4mil, and the compensation value corresponding to the second group of copper thickness standards is 1mil greater than the compensation value corresponding to the first group of copper thickness standards; Obtain compensation values ​​corresponding to one set of copper thickness standards, select a copper thickness standard according to the preset copper thickness h, and adjust the compensation value corresponding to the preset copper thickness h.

8. The circuit board PTH hole processing method according to claim 1, characterized in that: In step S3, n groups of drill bits are provided, n≥2, and n is an integer, and the diameter difference between each two adjacent groups of drill bits is 0.025 mm. In the step S3, the drill diameter Q1 of the mth group of drills and the drill diameter Q2 of the m+1th group of drills are obtained according to the via hole diameter, 1≤m≤n-1, wherein Q1≤d<Q 2, when |d-Q1|<|d-Q2|, the mth group of drills is selected, and when |d-Q1|≥|d-Q2|, the m+1th group of drills is selected.

9. The circuit board PTH hole processing method according to claim 8, characterized in that: The step S3 further comprises: adjusting the drill diameter according to the preset PTH hole diameter tolerance T, When 0.025mml≤T<0.5mm, obtain the drill diameter Q1 of the mth group of drills and the drill diameter Q2 of the m+1th group of drills according to the via diameter d, wherein Q1≤d<Q 2, when |d-Q1|<|d-Q2|, select the mth group of drills, and when |d-Q1|≥|d-Q2|, select the m+1th group of drills; When T≥0.5mm, the drill diameter Q1 of the mth group of drills and the drill diameter Q2 of the m+1th group of drills are obtained according to the via diameter d, wherein Q1≤d<Q2, when |d-Q1|<0.015mm, the mth group of drills is selected, and when |d-Q1|≥0.015mm, the m+1th group of drills is selected.

10. A circuit board, characterized in that: The circuit board PTH hole is formed by processing using the circuit board PTH hole processing method described in any one of claims 1 to 9.

Images