Stress balancing method of PCB (Printed Circuit Board) and PCB

Abstract

The invention relates to the technical field of printed circuit board manufacturing, and discloses a stress balancing method of a PCB and the PCB, and the method comprises the steps: preparing the PCB based on nickel plating parameters, carrying out the warping detection of the PCB, carrying out the warping detection of the PCB, obtaining a warping detection result of the PCB, and obtaining a stress balancing result of the PCB according to the warping detection result under the condition that the PCB is warped. And determining the warping direction of the PCB, adjusting the nickel plating parameters according to the warping direction to obtain new nickel plating parameters, and preparing a new PCB based on the new nickel plating parameters, and so on until the prepared PCB reaches stress balance. Therefore, under the condition that the PCB is warped, the stress of the nickel layer is changed by continuously updating the nickel plating parameters, so that the stress among all layers of materials of the PCB is balanced, and the purpose of solving the warpage problem of the printed circuit board can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of printed circuit board manufacturing, and particularly to a stress balance method for a PCB board and a PCB board. Background Art

[0002] As a core component of modern electronic devices, a printed circuit board (PCB) is used to carry various electronic components to achieve electrical connections between the electronic components. A printed circuit board usually includes a core board layer, a PP layer (semi-cured layer), a copper layer, a nickel layer, a gold layer, an ink layer, etc. During the preparation process of the printed circuit board, due to the different shrinkage and expansion stresses of the materials of each layer of the printed circuit board, it is difficult to achieve stress balance between the materials of each layer of the prepared printed circuit board, which in turn leads to the problem of warping of the printed circuit board.

[0003] Currently, when customers customize printed circuit boards, they may have specified requirements for material types, residual copper rates, or residual ink rates. This results in only being able to improve the warping problem of the printed circuit board by adjusting the thickness of the copper layer or the ink layer of the printed circuit board. However, a single factor has limited effectiveness in improving the warping problem of the printed circuit board.

[0004] Therefore, there is an urgent need for a diversified stress balance method to solve the warping problem of printed circuit boards. Summary of the Invention

[0005] Embodiments of the present invention provide a stress balance method for a PCB board and a PCB board to solve the warping problem of printed circuit boards.

[0006] A stress balance method for a PCB board includes: Preparing a PCB board according to nickel plating parameters; Performing warping detection on the PCB board to obtain a warping detection result of the PCB board; If the warping detection result indicates that the PCB board has not warped, it is determined that the PCB board has achieved stress balance; If the warping detection result indicates that the PCB board has warped, according to the warping detection result, determine the warping direction of the PCB board, where the warping direction is the direction corresponding to the inner side of the convex part of the PCB board; According to the warping direction, adjust the nickel plating parameters to obtain new nickel plating parameters, and return to execute the step of preparing the PCB board according to the nickel plating parameters until the PCB board achieves stress balance.

[0007] In the above stress balance method for a PCB board, optionally, the nickel plating parameters include current density; The adjusting the nickel plating parameters according to the warping direction to obtain new nickel plating parameters includes: If the warping direction is the first direction, increase the current density according to a preset unit density to obtain the new current density, where the first direction is perpendicular to the nickel layer of the PCB board and points to the core board layer of the PCB board; If the warping direction is the second direction, decrease the current density according to the unit density to obtain the new current density, where the first direction and the second direction are opposite to each other; Among them, the stress of the nickel layer in the PCB board prepared according to the increased current density increases. Conversely, the stress of the nickel layer in the PCB board prepared according to the decreased current density decreases.

[0008] For the above stress balance method of the PCB board, optionally, the nickel plating parameters include the nickel plating time; Adjusting the nickel plating parameters according to the warping direction to obtain the new nickel plating parameters includes: If the warping direction is the first direction, increase the nickel plating time according to a preset unit time to obtain the new nickel plating time; If the warping direction is the second direction, decrease the nickel plating time according to a preset unit time to obtain the new nickel plating time; Among them, the stress of the nickel layer in the PCB board prepared according to the increased nickel plating time increases. Conversely, the stress of the nickel layer in the PCB board prepared according to the decreased nickel plating time decreases.

[0009] For the above stress balance method of the PCB board, optionally, the nickel plating parameters further include the type of nickel plating solution, and the type of nickel plating solution includes nickel sulfate solution and nickel sulfamate solution; Adjusting the nickel plating parameters according to the warping direction to obtain the new nickel plating parameters includes: If the warping direction is the first direction and the type of nickel plating solution used to prepare the PCB board is the nickel sulfate solution, change the type of nickel plating solution to the nickel sulfamate solution; If the warping direction is the second direction and the type of nickel plating solution used to prepare the PCB board is the nickel sulfamate solution, change the type of nickel plating solution to the nickel sulfate solution; Among them, the stress of the nickel layer in the PCB board based on the nickel sulfate solution is greater than the stress of the nickel layer in the PCB board based on the nickel sulfamate solution.

[0010] For the above stress balance method of the PCB board, optionally, the PCB board is a multi-layer PCB board, the multi-layer PCB board includes a first nickel layer and a second nickel layer, and the nickel plating parameters include the first nickel plating parameters corresponding to the first nickel layer and the second nickel plating parameters corresponding to the second nickel layer.

[0011] For the above stress balance method of the PCB board, optionally, the nickel plating parameters include a first current density corresponding to the first nickel layer and a second current density corresponding to the second nickel layer; The adjusting the nickel plating parameters according to the warping direction to obtain the new nickel plating parameters includes: If the warping direction is the third direction, increasing the second current density by a preset unit density to obtain the new second current density, and / or decreasing the first current density by the unit density to obtain the new first current density, where the third direction is perpendicular to the core board layer of the PCB board and points to the first nickel layer; If the warping direction is the fourth direction, increasing the first current density by a preset unit density to obtain the new first current density, and / or decreasing the second current density by the unit density to obtain the new second current density, where the fourth direction is opposite to the third direction.

[0012] For the above stress balance method of the PCB board, optionally, the nickel plating parameters include a first nickel plating time corresponding to the first nickel layer and a second nickel plating time corresponding to the second nickel layer; The adjusting the nickel plating parameters according to the warping direction to obtain the new nickel plating parameters includes: If the warping direction is the third direction, increasing the second nickel plating time by a preset unit time to obtain the new second nickel plating time, and decreasing the first nickel plating time by the unit time to obtain the new first nickel plating time; If the warping direction is the fourth direction, increasing the first nickel plating time by a preset unit time to obtain the new first nickel plating time, and decreasing the second nickel plating time by the unit time to obtain the new second nickel plating time.

[0013] For the above stress balance method of the PCB board, optionally, the nickel plating parameters include a first chemical solution type corresponding to the first nickel layer and a second chemical solution type corresponding to the second nickel layer; The adjusting the nickel plating parameters according to the warping direction to obtain the new nickel plating parameters includes: If the warping direction is the third direction, and the first chemical solution type used for preparing the first nickel layer is nickel sulfate chemical solution, and the second chemical solution type used for preparing the second nickel layer is nickel sulfamate chemical solution, then use the nickel sulfamate chemical solution as the new first chemical solution type, and / or use the nickel sulfate chemical solution as the new second chemical solution type; If the warping direction is the fourth direction, and the first chemical solution type used for preparing the first nickel layer is the nickel sulfamate chemical solution, and the second chemical solution type used for preparing the second nickel layer is the nickel sulfate chemical solution, then use the nickel sulfate chemical solution as the new first chemical solution type, and / or use the nickel sulfamate chemical solution as the new second chemical solution type.

[0014] For the above PCB board stress balance method, optionally, the method for warping detection of the PCB board includes: one or more of visual inspection method, micrometer measurement method, coordinate measuring machine method, and laser measurement method.

[0015] A PCB board is prepared by the PCB board stress balance method described in any one of the above.

[0016] The present invention discloses a stress balance method and a PCB board for a PCB board. The method prepares a PCB board based on nickel plating parameters, performs warping detection on the PCB board, and obtains the warping detection result of the PCB board. Furthermore, in the case of warping of the PCB board, according to the warping detection result, the warping direction of the PCB board is determined. According to the warping direction, the nickel plating parameters are adjusted to obtain new nickel plating parameters, and a new PCB board is prepared based on the new nickel plating parameters, and so on, until the prepared PCB board reaches stress balance. It can be seen that in the case of warping of the PCB board, the present invention changes the stress of the nickel layer by continuously updating the nickel plating parameters, so that the stress between the materials of each layer of the PCB board reaches stress balance, and the purpose of solving the warping problem of the printed circuit board can be achieved. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a flowchart for implementing the stress balance method of the PCB board in an embodiment of the present invention; Figure 2 It is a partial flowchart for implementing the stress balance method of the PCB board in an embodiment of the present invention; Figure 3 It is a schematic structural diagram of a PCB board in an embodiment of the present invention; Figure 4 It is a partial implementation flowchart of a stress balance method for a PCB board in an embodiment of the present invention; Figure 5 It is a partial implementation flowchart of a stress balance method for a PCB board in an embodiment of the present invention; Figure 6 It is a schematic structural diagram of a PCB board in an embodiment of the present invention; Figure 7 It is a partial implementation flowchart of a stress balance method for a PCB board in an embodiment of the present invention; Figure 8 It is a partial implementation flowchart of a stress balance method for a PCB board in an embodiment of the present invention; Figure 9 It is a partial implementation flowchart of a stress balance method for a PCB board in an embodiment of the present invention. Specific embodiments

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0020] It should be understood that the present invention can be implemented in different forms and should not be construed as limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout.

[0021] It should be understood that when an element or layer is referred to as being "on", "adjacent to", "connected to" or "coupled to" another element or layer, it can be directly on, adjacent to, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on", "directly adjacent to", "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or portions, these elements, components, regions, layers and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or portion from another element, component, region, layer or portion. Thus, without departing from the teachings of the present invention, the first element, component, region, layer or portion discussed below may be referred to as the second element, component, region, layer or portion.

[0022] Spatial relationship terms such as "under", "below", "beneath", "underneath", "above", "over", etc. are used herein for convenience in describing the relationship of one element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relationship terms are intended to include different orientations of the device in use and operation. For example, if the device in the figures is flipped, then an element or feature described as "under" or "beneath" or "underneath" another element or feature will be oriented "above" the other element or feature. Thus, the exemplary terms "under" and "beneath" can include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or other orientation) and the spatial descriptors used herein are to be interpreted accordingly.

[0023] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, specify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. As used herein, the term "and / or" includes any and all combinations of the associated listed items.

[0024] To fully understand the present invention, detailed structures and steps will be set forth in the following description in order to explain the technical solutions proposed by the present invention. The preferred embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention may have other embodiments.

[0025] The present invention discloses a stress balance method for a PCB board and a PCB board. The method prepares the PCB board based on nickel plating parameters, performs warpage detection on the PCB board, and obtains the warpage detection result of the PCB board. Furthermore, in the case where the PCB board warps, according to the warpage detection result, the warpage direction of the PCB board is determined. According to the warpage direction, the nickel plating parameters are adjusted to obtain new nickel plating parameters, and a new PCB board is prepared based on the new nickel plating parameters, and so on until the prepared PCB board reaches stress balance. It can be seen that in the case where the PCB board warps, the present invention changes the stress of the nickel layer by continuously updating the nickel plating parameters, so that the stress between the materials of each layer of the PCB board reaches stress balance, and the purpose of solving the warpage problem of the printed circuit board can be achieved.

[0026] In one embodiment, as Figure 1 shown, it is a flowchart of the implementation of a stress balance method for a PCB board disclosed in an embodiment of the present invention. The method specifically includes the following steps: S101: Prepare a PCB board according to nickel plating parameters.

[0027] It can be understood that the nickel plating parameters refer to the parameters required for the processing of the nickel layer during the preparation of the PCB board. In this embodiment, the parameters required for the processing of other layers of the PCB board (such as copper layer, ink layer, and gold layer, etc.) are not specifically limited.

[0028] In a specific implementation, in this embodiment, when preparing the PCB board for the first time, an initial parameter can be preset as the nickel plating parameter. This initial parameter is generally applicable to the processing of the nickel layer in most PCB boards. After the PCB board is prepared, the step of performing warpage detection on the PCB board to obtain the warpage detection result of the PCB board is executed.

[0029] It should be noted that the number of PCB boards prepared according to the nickel plating parameters in this embodiment can be one or more. When the number of PCB boards is more than one, warpage detection needs to be performed on each PCB board respectively.

[0030] S102: Perform warpage detection on the PCB board to obtain the warpage detection result of the PCB board.

[0031] In a specific implementation, in this embodiment, the temperature and humidity during the working process of the PCB board can be simulated, and then warpage detection is performed on the PCB board to obtain the warpage detection result of the PCB board. Among them, the methods for performing warpage detection on the PCB board include but are not limited to one or more of visual detection method, dial indicator measurement method, coordinate measuring method, and laser measurement method.

[0032] In one embodiment, in this embodiment, the warpage degree of the PCB board can be obtained by performing warpage detection on the PCB board, and it is determined whether the warpage degree of the PCB board is greater than a preset curvature threshold. If the warpage degree is greater than the curvature threshold, it is determined that the PCB board is warped. If the warpage degree is less than or equal to the curvature threshold, it is determined that the PCB board is not warped, that is, the PCB board reaches stress balance. Among them, the curvature threshold includes but is not limited to 0.35%, 0.75%, etc. In this embodiment, the specific value of the curvature threshold is not limited.

[0033] Among them, in this embodiment, the warpage degree of the PCB board can be calculated in the following manner: Obtain the warpage height and the substrate length (or diagonal length) of the PCB board, and input the warpage height and the substrate length (or diagonal length) into the warpage degree calculation formula to obtain the warpage degree of the PCB board. The warpage height refers to the maximum height of the convex part of the PCB board. The warpage degree calculation formula is as follows: It should be noted that when there are multiple PCB boards in this embodiment, warpage detection is performed on each PCB board separately to obtain the warpage detection result corresponding to each PCB board. When the number of warpage detection results indicating that the PCB board is not warped exceeds a preset first number, it is determined that the PCB board reaches stress balance. When the number of warpage detection results indicating that the PCB board is not warped exceeds a preset first number, it is determined that the PCB board reaches stress balance. When the number of warpage detection results indicating that the PCB board is not warped is lower than a preset second number, it is determined that the PCB board does not reach stress balance.

[0034] S103: If the warpage detection result indicates that the PCB board is not warped, it is determined that the PCB board reaches stress balance.

[0035] After determining that the PCB board reaches stress balance, perform the PCB board preparation task according to the current nickel plating parameters.

[0036] S104: If the warpage detection result indicates that the PCB board is warped, determine the warpage direction of the PCB board according to the warpage detection result. The warpage direction is the direction corresponding to the inner side of the convex part of the PCB board.

[0037] It can be understood that the warpage detection result in this embodiment can include the warpage direction of the PCB board. When performing warpage detection on the PCB board, the warpage direction of the PCB board can be obtained synchronously.

[0038] S105: Adjust the nickel plating parameters according to the warpage direction to obtain new nickel plating parameters, and return to execute the step of preparing the PCB board according to the nickel plating parameters until the PCB board reaches stress balance.

[0039] That is to say, when the PCB board prepared based on the nickel plating parameters does not reach stress balance, the nickel plating parameters are adjusted to obtain new nickel plating parameters. Then, a new PCB board is prepared based on the new nickel plating parameters, and the warpage of the PCB board is detected. If the PCB board still does not reach stress balance, the nickel plating parameters are continuously adjusted to obtain new nickel plating parameters, and so on, until the PCB board prepared based on the nickel plating parameters reaches stress balance.

[0040] In a specific implementation, the nickel plating parameters in this embodiment include, but are not limited to, one or more of nickel plating time, current density, and nickel plating solution type. By adjusting one or more parameters such as nickel plating time, current density, and nickel plating solution type, the stress magnitude of the nickel layer in the prepared PCB board can be changed, thereby improving the warpage problem of the PCB board.

[0041] In summary, the present invention discloses a stress balance method for a PCB board. The method prepares a PCB board based on nickel plating parameters, detects the warpage of the PCB board, and obtains the warpage detection result of the PCB board. Furthermore, in the case of warpage of the PCB board, according to the warpage detection result, the warpage direction of the PCB board is determined. According to the warpage direction, the nickel plating parameters are adjusted to obtain new nickel plating parameters, and a new PCB board is prepared based on the new nickel plating parameters, and so on, until the prepared PCB board reaches stress balance. It can be seen that in the case of warpage of the PCB board, the present invention changes the stress of the nickel layer by continuously updating the nickel plating parameters, so that the stress between the layers of the PCB board reaches stress balance, and the purpose of solving the warpage problem of the printed circuit board can be achieved.

[0042] In one embodiment, as Figure 2 shown, the nickel plating parameters in this embodiment include current density. On this basis, step S105 can be implemented through the following steps: S201: If the warpage direction is the first direction, increase the current density according to a preset unit density to obtain a new current density. The first direction is perpendicular to the nickel layer of the PCB board and points to the core board layer of the PCB board.

[0043] Refer to Figure 3 shown, which is a schematic diagram of the first direction on the PCB board in this embodiment. Among them, 1 is the core board layer, 2 is the copper layer, 3 is the nickel layer, 4 is the gold layer, 5 is the ink layer, a is the first direction, and b is the second direction. When the warpage direction of the PCB board is the first direction, it indicates that the stress provided by the nickel layer is small, causing the PCB board to warp in the first direction. Therefore, it is necessary to increase the current density according to a preset unit density to obtain a new current density, so as to increase the stress of the nickel layer in the PCB board prepared according to the increased current density and improve the warpage problem of the PCB board.

[0044] S202: If the warping direction is the second direction, decrease the current density according to the unit density to obtain a new current density, where the first direction and the second direction are opposite to each other.

[0045] Schematic diagram reference of the second direction on the PCB Figure 3 As shown, when the warping direction of the PCB is the second direction, it indicates that the stress provided by the nickel layer is relatively large, causing the PCB to warp in the second direction. Therefore, it is necessary to decrease the current density according to the preset unit density to obtain a new current density, so as to reduce the stress of the nickel layer in the PCB prepared according to the decreased current density, thereby improving the warping problem of the PCB.

[0046] That is to say, the stress of the nickel layer in the PCB prepared according to the increased current density increases. On the contrary, the stress of the nickel layer in the PCB prepared according to the decreased current density decreases.

[0047] In summary, in this embodiment, by flexibly adjusting the current density during the nickel plating process, the stress of the nickel layer can be flexibly adjusted, so as to improve the warping problem of the printed circuit board.

[0048] In one embodiment, as Figure 4 shown, the nickel plating parameters in this embodiment include the nickel plating time. On this basis, step S105 can be implemented through the following steps: S401: If the warping direction is the first direction, increase the nickel plating time according to the preset unit time to obtain a new nickel plating time.

[0049] When the warping direction of the PCB is the first direction, it indicates that the stress provided by the nickel layer is relatively small, causing the PCB to warp in the first direction. Therefore, it is necessary to increase the nickel plating time according to the preset unit time to obtain a new nickel plating time, so as to increase the stress of the nickel layer in the PCB prepared according to the increased nickel plating time, thereby improving the warping problem of the PCB. Among them, when the nickel plating time increases, the thickness of the nickel layer in the PCB can be effectively increased, and thus the stress of the nickel layer increases.

[0050] S402: If the warping direction is the second direction, decrease the nickel plating time according to the preset unit time to obtain a new nickel plating time.

[0051] When the warping direction of the PCB is the second direction, it indicates that the stress provided by the nickel layer is relatively large, causing the PCB to warp in the second direction. Therefore, it is necessary to decrease the nickel plating time according to the preset unit time to obtain a new nickel plating time, so as to reduce the stress of the nickel layer in the PCB prepared according to the decreased nickel plating time, thereby improving the warping problem of the PCB. Among them, when the nickel plating time decreases, the thickness of the nickel layer in the PCB will also decrease, and thus the stress of the nickel layer decreases.

[0052] That is to say, in the PCB board prepared according to the increased nickel plating time, the stress of the nickel layer increases. On the contrary, in the PCB board prepared according to the decreased nickel plating time, the stress of the nickel layer decreases.

[0053] In summary, in this embodiment, by flexibly adjusting the nickel plating time during the nickel plating process, the stress of the nickel layer can be flexibly adjusted, so as to improve the warping problem of the printed circuit board.

[0054] In one embodiment, as Figure 5 shown, the nickel plating parameters in this embodiment further include the type of nickel plating solution. The type of nickel plating solution includes nickel sulfate solution and nickel sulfamate solution. On this basis, step S105 can be implemented through the following steps: S501: If the warping direction is the first direction and the type of nickel plating solution used for preparing the PCB board is nickel sulfate solution, change the type of nickel plating solution to nickel sulfamate solution.

[0055] It should be noted that the stress of the nickel layer in the PCB board prepared based on nickel sulfate solution is greater than the stress of the nickel layer in the PCB board prepared based on nickel sulfamate solution.

[0056] When the warping direction of the PCB board is the first direction, it indicates that the stress provided by the nickel layer is small. And when the type of nickel plating solution during the nickel layer processing is nickel sulfate solution, the stress of the nickel layer in the PCB board can be increased by changing the type of nickel plating solution to nickel sulfamate solution.

[0057] S502: If the warping direction is the second direction and the type of nickel plating solution used for preparing the PCB board is nickel sulfamate solution, change the type of nickel plating solution to nickel sulfate solution.

[0058] When the warping direction of the PCB board is the second direction, it indicates that the stress provided by the nickel layer is small. And when the type of nickel plating solution during the nickel layer processing is nickel sulfamate solution, the stress of the nickel layer in the PCB board can be reduced by changing the type of nickel plating solution to nickel sulfate solution.

[0059] In summary, in this embodiment, by changing the type of nickel plating solution, the stress of the nickel layer can be adjusted to a certain extent, so as to achieve the purpose of improving the warping problem of the printed circuit board.

[0060] In one embodiment, the PCB board in this embodiment is a multi-layer PCB board. The multi-layer PCB board includes a first nickel layer and a second nickel layer. The nickel plating parameters include the first nickel plating parameters corresponding to the first nickel layer and the second nickel plating parameters corresponding to the second nickel layer.

[0061] As Figure 6As shown in the figure, it is a schematic structure of a multi-layer PCB board. Among them, 1 is the core board layer, 2 / 6 are copper layers, 3 is the first nickel layer, 7 is the second nickel layer, 4 / 8 are gold layers, 5 / 9 are ink layers, c is the third direction, and d is the fourth direction.

[0062] In one embodiment, as Figure 7 shown, the nickel plating parameters in this embodiment include the first current density corresponding to the first nickel layer and the second current density corresponding to the second nickel layer. On this basis, step S105 can be implemented through the following steps: S701: If the warping direction is the third direction, increase the second current density according to the preset unit density to obtain a new second current density, and / or decrease the first current density according to the unit density to obtain a new first current density. The third direction is perpendicular to the core board layer of the PCB board and points to the first nickel layer.

[0063] The schematic diagram of the third direction in the multi-layer PCB board is as Figure 6 shown. When the warping direction is the third direction, it indicates that the stress of the first nickel layer is greater than that of the second nickel layer. Therefore, it is necessary to increase the second current density according to the preset unit density to obtain a new second current density, and / or it is necessary to decrease the first current density according to the preset unit density to obtain a new first current density, so as to improve the warping problem of the PCB board.

[0064] S702: If the warping direction is the fourth direction, increase the first current density according to the preset unit density to obtain a new first current density, and / or decrease the second current density according to the unit density to obtain a new second current density. The fourth direction is the opposite direction of the third direction.

[0065] The schematic diagram of the fourth direction in the multi-layer PCB board is as Figure 6 shown. When the warping direction is the fourth direction, it indicates that the stress of the first nickel layer is less than that of the second nickel layer. Therefore, it is necessary to decrease the second current density according to the preset unit density to obtain a new second current density, and / or it is necessary to increase the first current density according to the preset unit density to obtain a new first current density, so as to improve the warping problem of the PCB board.

[0066] In summary, in this embodiment, by separately adjusting the first current density corresponding to the first nickel layer and the second current density corresponding to the second nickel layer in the multi-layer PCB board, and through the separate control of the stress of the first nickel layer and the second nickel layer, the stress difference between the first nickel layer and the second nickel layer is achieved, and the purpose of improving the warping problem of the PCB board can be achieved.

[0067] In one embodiment, as Figure 8As shown, the nickel plating parameters in this embodiment include the first nickel plating time corresponding to the first nickel layer and the second nickel plating time corresponding to the second nickel layer. On this basis, step S105 can be implemented through the following steps: S801: If the warping direction is the third direction, increase the second nickel plating time by a preset unit time to obtain a new second nickel plating time, and decrease the first nickel plating time by the unit time to obtain a new first nickel plating time.

[0068] When the warping direction is the third direction, it indicates that the stress of the first nickel layer is greater than that of the second nickel layer. Therefore, it is necessary to increase the second nickel plating time by a preset unit time to obtain a new nickel plating time, and / or it is necessary to decrease the first nickel plating time by a preset unit time to obtain a new first nickel plating time, so as to improve the warping problem of the PCB board. That is to say, when adjusting only the first nickel plating time or the second nickel plating time is not sufficient to improve the warping problem of the PCB board, the first nickel plating time or the second nickel plating time can be adjusted simultaneously to achieve the simultaneous adjustment of the stress of the first nickel layer and the second nickel layer, thereby improving the warping problem of the PCB board.

[0069] S802: If the warping direction is the fourth direction, increase the first nickel plating time by a preset unit time to obtain a new first nickel plating time, and decrease the second nickel plating time by the unit time to obtain a new second nickel plating time.

[0070] When the warping direction is the fourth direction, it indicates that the stress of the first nickel layer is less than that of the second nickel layer. Therefore, it is necessary to decrease the second nickel plating time by a preset unit time to obtain a new second nickel plating time, and / or it is necessary to increase the first current density by a preset unit time to obtain a new first current density, so as to improve the warping problem of the PCB board.

[0071] In summary, in this embodiment, by separately adjusting the first nickel plating time corresponding to the first nickel layer and the second nickel plating time corresponding to the second nickel layer in the multi-layer PCB board, and through the separate control of the stress of the first nickel layer and the second nickel layer, the stress difference between the first nickel layer and the second nickel layer is achieved, and the purpose of improving the warping problem of the PCB board can be achieved.

[0072] In one embodiment, as Figure 9 shown, the nickel plating parameters in this embodiment include the first chemical solution type corresponding to the first nickel layer and the second chemical solution type corresponding to the second nickel layer. On this basis, step S105 can be implemented through the following steps: S901: If the warping direction is the third direction, and the first chemical solution type used to prepare the first nickel layer is nickel sulfate solution, and the second chemical solution type used to prepare the second nickel layer is nickel sulfamate solution, use nickel sulfamate solution as the new first chemical solution type, and / or use nickel sulfate solution as the new second chemical solution type.

[0073] When the warping direction is the third direction, it indicates that the stress of the first nickel layer is greater than that of the second nickel layer. Therefore, when the first chemical solution type used for preparing the first nickel layer is nickel sulfate chemical solution, the stress of the first nickel layer can be reduced by using nickel sulfamate chemical solution as the new first chemical solution type; when the first chemical solution type used for preparing the second nickel layer is nickel sulfamate chemical solution, the stress of the second nickel layer can be increased by using nickel sulfate chemical solution as the new first chemical solution type.

[0074] S902: If the warping direction is the fourth direction, and the first chemical solution type used for preparing the first nickel layer is nickel sulfamate chemical solution, and the second chemical solution type used for preparing the second nickel layer is nickel sulfate chemical solution, then use nickel sulfate chemical solution as the new first chemical solution type, and / or use nickel sulfamate chemical solution as the new second chemical solution type.

[0075] When the warping direction is the fourth direction, it indicates that the stress of the first nickel layer is less than that of the second nickel layer. Therefore, when the first chemical solution type used for preparing the first nickel layer is nickel sulfamate chemical solution, the stress of the first nickel layer can be increased by using nickel sulfate chemical solution as the new first chemical solution type; when the second chemical solution type used for preparing the second nickel layer is nickel sulfate chemical solution, the stress of the second nickel layer can be reduced by using nickel sulfamate chemical solution as the new first chemical solution type.

[0076] In summary, in this embodiment, by changing the type of nickel plating chemical solution, the stress of the nickel layer can be adjusted to a certain extent, so as to achieve the purpose of improving the warping problem of the printed circuit board.

[0077] A PCB board, characterized in that the PCB board is prepared by the stress balance method of the PCB board disclosed in any one of the above embodiments.

[0078] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A stress balancing method for a PCB board, characterized in that: include: Prepare PCB board according to nickel plating parameters; Performing a warpage detection on the PCB board to obtain a warpage detection result of the PCB board; If the warping detection result indicates that the PCB board is not warped, determining that the PCB board reaches stress balance; If the warping detection result indicates that the PCB is warped, determine the warping direction of the PCB according to the warping detection result, where the warping direction is a direction corresponding to the inner side of the protrusion of the PCB; According to the warping direction, the nickel plating parameters are adjusted to obtain new nickel plating parameters, and the step of preparing the PCB board according to the nickel plating parameters is returned to be executed until the PCB board reaches stress balance.

2. The stress balancing method of a PCB board as claimed in claim 1, characterized in that: The nickel plating parameters include current density; The step of adjusting the nickel plating parameters according to the warping direction to obtain new nickel plating parameters includes: If the warping direction is a first direction, the current density is increased according to a preset unit density to obtain a new current density, wherein the first direction is perpendicular to the nickel layer of the PCB board and points to the core board layer of the PCB board; If the warping direction is the second direction, the current density is reduced according to the unit density to obtain a new current density, and the first direction and the second direction are opposite to each other; Among them, the stress of the nickel layer in the PCB board prepared according to the increased current density increases, and conversely, the stress of the nickel layer in the PCB board prepared according to the reduced current density decreases.

3. The stress balancing method for a PCB board as claimed in claim 1, characterized in that: The nickel plating parameters include nickel plating time; The step of adjusting the nickel plating parameters according to the warping direction to obtain new nickel plating parameters includes: If the warping direction is the first direction, increasing the nickel plating time according to a preset unit time to obtain a new nickel plating time; If the warping direction is the second direction, reducing the nickel plating time according to a preset unit time to obtain a new nickel plating time; Among them, the stress of the nickel layer in the PCB board prepared according to the increased nickel plating time increases, and conversely, the stress of the nickel layer in the PCB board prepared according to the reduced nickel plating time decreases.

4. The stress balancing method for a PCB board as claimed in claim 1, characterized in that: The nickel plating parameters also include nickel plating solution types, and the nickel plating solution types include nickel sulfate solution and nickel sulfamate solution; The step of adjusting the nickel plating parameters according to the warping direction to obtain new nickel plating parameters includes: If the warping direction is the first direction, and the type of the nickel plating solution used to prepare the PCB board is the nickel sulfate solution, the type of the nickel plating solution is replaced with the nickel sulfamate solution; If the warping direction is the second direction, and the nickel plating solution used to prepare the PCB board is the nickel sulfamate solution, the nickel plating solution is replaced with the nickel sulfate solution; Among them, the stress of the nickel layer in the PCB board prepared based on the nickel sulfate solution is greater than the stress of the nickel layer in the PCB board prepared based on the nickel sulfamate solution.

5. The stress balancing method of a PCB board as claimed in claim 1, characterized in that: The PCB board is a multi-layer PCB board, the multi-layer PCB board includes a first nickel layer and a second nickel layer, and the nickel plating parameters include a first nickel plating parameter corresponding to the first nickel layer and a second nickel plating parameter corresponding to the second nickel layer.

6. The stress balancing method of a PCB board as claimed in claim 5, characterized in that: The nickel plating parameters include a first current density corresponding to the first nickel layer and a second current density corresponding to the second nickel layer; The step of adjusting the nickel plating parameters according to the warping direction to obtain new nickel plating parameters includes: If the warping direction is a third direction, the second current density is increased according to a preset unit density to obtain a new second current density, and / or the first current density is reduced according to the unit density to obtain a new first current density, and the third direction is perpendicular to the core layer of the PCB board and points to the first nickel layer; If the warping direction is the fourth direction, the first current density is increased according to a preset unit density to obtain a new first current density, and / or the second current density is reduced according to the unit density to obtain a new second current density, and the fourth direction and the third direction are opposite to each other.

7. The stress balancing method of a PCB board as claimed in claim 6, characterized in that: The nickel plating parameters include a first nickel plating time corresponding to the first nickel layer and a second nickel plating time corresponding to the second nickel layer; The step of adjusting the nickel plating parameters according to the warping direction to obtain new nickel plating parameters includes: If the warping direction is the third direction, increasing the second nickel plating time according to a preset unit time to obtain a new second nickel plating time, and reducing the first nickel plating time according to the unit time to obtain a new first nickel plating time; If the warping direction is the fourth direction, the first nickel plating time is increased according to a preset unit time to obtain a new first nickel plating time, and the second nickel plating time is reduced according to the unit time to obtain a new second nickel plating time.

8. The stress balancing method of a PCB board as claimed in claim 6, characterized in that: The nickel plating parameters include a first solution type corresponding to the first nickel layer and a second solution type corresponding to the second nickel layer; The step of adjusting the nickel plating parameters according to the warping direction to obtain new nickel plating parameters includes: If the warping direction is the third direction, and the first potion type used to prepare the first nickel layer is nickel sulfate potion, and the second potion type used to prepare the second nickel layer is nickel sulfamate potion, the nickel sulfamate potion is used as a new first potion type, and / or the nickel sulfate potion is used as a new second potion type; If the warping direction is the fourth direction, and the first potion type used to prepare the first nickel layer is the nickel sulfamate potion, and the second potion type used to prepare the second nickel layer is the nickel sulfate potion, the nickel sulfate potion is used as a new first potion type, and / or the nickel sulfamate potion is used as a new second potion type.

9. The stress balancing method for a PCB board according to any one of claims 1 to 8, characterized in that: The method for detecting the warpage of the PCB board includes: one or more of a visual detection method, a micrometer measurement method, a three-coordinate measurement method, and a laser measurement method.

10. A PCB board, characterized in that: The PCB board is prepared by the stress balancing method for a PCB board according to any one of claims 1 to 9.

Images