A printed circuit board and a preparation method thereof

Abstract

The present application discloses a printed circuit board and a method for preparing the same. At least one cavity is formed in the printed circuit board, and at least one cavity communicates with the edge of the printed circuit board through a through groove. A barrier layer is provided on one side of the through groove close to the edge of the printed circuit board, and the barrier layer separates the through groove to prevent liquid intrusion. In the above manner, the present application can effectively reduce the intrusion of external solution by the barrier layer and retain the cavity structure, thereby improving the quality and reliability of the printed circuit board.

Description

Technical Field

[0001] This application is applied to the technical field of processing printed circuit boards, in particular to a printed circuit board and a preparation method thereof. Background Art

[0002] A PCB (Printed Circuit Board), also known as a printed wiring board or a printed circuit board, is an important and widely used electronic component, a support for electronic components, and also a carrier for electrical connection of electronic components.

[0003] Due to certain functional requirements, some printed circuit boards are designed into a cavity structure, and some other electronic components can be placed inside or outside, which cooperate with the printed circuit board to achieve specific functions.

[0004] However, when processing such boards, since the cavity edge is connected to the outside, after the cavity is processed and passed through a process with water washing or liquid solution, because the board has a cavity connected to the outside, water will enter the connected position and cannot be dried later, affecting subsequent processing and reliability. Summary of the Invention

[0005] This application provides a printed circuit board and a preparation method thereof to solve the problem that the printed circuit board may be water - inlet and cannot be dried.

[0006] To solve the above - mentioned technical problems, this application provides a printed circuit board, in which at least one cavity is formed, the at least one cavity is connected to the edge of the printed circuit board through a through - groove, and a barrier layer is arranged on one side of the through - groove close to the edge of the printed circuit board, and the barrier layer separates the through - groove to prevent liquid intrusion.

[0007] Wherein, when the number of the at least one cavity is multiple, the multiple cavities are arranged in an array; the cavities in the same row or the same column are respectively connected to the edge of the printed circuit board through one through - groove.

[0008] Wherein, the number of the barrier layers on one side of each through - groove close to the edge of the printed circuit board is 1 respectively; the barrier layer completely separates one side of the corresponding through - groove close to the edge of the printed circuit board, so that the corresponding through - groove is completely blocked at opposite ends of the barrier layer respectively.

[0009] Wherein, the number of the barrier layers on one side of each through - groove close to the edge of the printed circuit board is multiple respectively; the multiple barrier layers are staggered on one side of the corresponding through - groove close to the edge of the printed circuit board, and the cross - sectional area of the barrier layer is greater than one - half of the cross - sectional area of the through - groove, so as to separate the through - groove at opposite ends of the barrier layer.

[0010] Wherein, the printed circuit board includes a plurality of insulating layers and a plurality of conductive layers that are stacked and adhered in sequence; the barrier layer is integrally formed with the insulating layer.

[0011] Wherein, the thickness range of the barrier layer is 0.10 - 0.40 millimeters.

[0012] Wherein, the distance range between the barrier layer and the edge of the corresponding printed circuit board is 0.0 - 1.0 millimeters.

[0013] To solve the above technical problems, the present application also provides a method for manufacturing a printed circuit board. The printed circuit board is the printed circuit board described in any one of the above. The method for manufacturing the printed circuit board includes: preparing a plurality of base layers; performing depth control on at least one of the base layers respectively based on a preset depth control rule to form through holes and / or blind holes and through grooves, and retaining the base layer near the edge of the through groove to form a barrier layer; performing corresponding lamination on the plurality of base layers to form at least one cavity communicating with the through groove on the printed circuit board through the through holes and / or blind holes.

[0014] Wherein, the step of performing depth control on at least one of the base layers respectively based on a preset depth control rule to form through holes and / or blind holes and through grooves, and retaining the base layer near the edge of the through groove to form a barrier layer further includes: performing depth control on at least one of the base layers respectively by mechanical depth control, laser depth control or water jet based on the preset depth control rule to form through holes and / or blind holes and through grooves, and retaining the base layer near the edge of the through groove to form the barrier layer.

[0015] The beneficial effect of the present application is that, different from the prior art, a barrier layer is provided on one side of the through groove near the edge of the printed circuit board. The barrier layer separates the through groove and can effectively prevent liquid from invading into the cavity through the barrier layer when the printed circuit board undergoes a water wash or a process with liquid or solution, thereby avoiding the influence of the liquid on the subsequent reprocessing of the printed circuit board and improving the reliability of the printed circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a cross-sectional structural schematic diagram of a first direction of an embodiment of the printed circuit board provided by the present application;

[0017] Figure 2 is Figure 1 a cross-sectional structural schematic diagram of a second direction of the printed circuit board in the embodiment;

[0018] Figure 3 is Figure 1 a structural schematic diagram of another embodiment of a local position 107 in the embodiment;

[0019] Figure 4 It is a schematic flowchart of an embodiment of the method for manufacturing a printed circuit board provided by the present application. Detailed implementation manners

[0020] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0021] It should be noted that if there are directional indications (such as up, down, left, right, front, back,...) involved in the embodiments of the present application, then the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0022] In addition, if there are descriptions such as "first" and "second" involved in the embodiments of the present application, then the descriptions of "first", "second", etc. are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0023] Please refer to Figure 1-2 , Figure 1 It is a schematic cross-sectional structure diagram of a printed circuit board provided by the present application in a first direction in an embodiment. Figure 2 is Figure 1 a schematic cross-sectional structure diagram of the printed circuit board in a second direction in the embodiment. Among them, the first direction is perpendicular to the second direction.

[0024] At least one cavity 101 is formed in the printed circuit board 100 of this embodiment. Among them, at least one cavity 101 is surrounded by the printed circuit board 100. Among them, the number of at least one cavity 101 in this embodiment can be 1, 3, 5, 8, 10, 20, etc. The specific number of cavities 101 in the printed circuit board 100 can be set based on actual needs and is not limited herein. Among them, at least one cavity 101 can be used to place components or other objects, which is not limited specifically herein.

[0025] At least one cavity 101 is connected to the edge of the printed circuit board 100 through the through slot 103, that is, the through slot 103 is connected to the air outside the printed circuit board 100. In a specific application scenario, at least one cavity 101 can be connected to the edge of the printed circuit board 100 through the same through slot 103, thereby being connected to the air outside the printed circuit board 100. In another specific application scenario, at least one cavity 101 can also be connected to the edge of the printed circuit board 100 through multiple through slots 103, thereby being connected to the air outside the printed circuit board 100. Specifically, the connection between at least one cavity 101 and the through slot 103 can be set based on actual conditions, and is not limited here.

[0026] The printed circuit board 100 of this embodiment is provided with a barrier layer 102 on one side of the through slot 103 close to the edge of the printed circuit board 100 , and the barrier layer 102 separates the through slot 103 .

[0027] Through the above structure, the printed circuit board of this embodiment is equipped with a barrier layer on one side of the through groove close to the edge of the printed circuit board. When the printed circuit board undergoes water washing or a process with liquid or solution, the barrier layer can effectively prevent liquid from invading the cavity, thereby avoiding affecting the subsequent reprocessing of the printed circuit board and improving the reliability of the printed circuit board.

[0028] In other embodiments, when there are multiple cavities 101, the multiple cavities 101 may be arranged in an array, and the cavities 101 in the same row or column of the arrayed cavities 101 are connected to the edge of the printed circuit board 100 through a through slot 103. Thus, the at least one cavity 101 is connected to form a working PLN.

[0029] In a specific application scenario, the through groove 103 connects the opposite sides of each cavity 101 in the same row or column, thereby connecting each cavity 101 in the same row or column to the edge of the printed circuit board 100, so that during the pressing process or high-temperature welding process of the printed circuit board 100, the through groove 103 can be connected to the outside of the printed circuit board 100, thereby balancing the internal and external pressures of the printed circuit board 100, preventing the hot air in the cavity 101 from expanding during high-temperature operation, causing the printed circuit board 100 to be delaminated and exploded, thereby improving the reliability of the printed circuit board 100.

[0030] In other embodiments, the number of barrier layers 102 on one side of each through slot 103 near the edge of the printed circuit board 100 is 1, and the barrier layer 102 completely separates one side of the corresponding through slot 103 near the edge of the printed circuit board 100, so that the corresponding through slots 103 are completely blocked at both ends of the barrier layer 102, thereby completely preventing liquid intrusion when the printed circuit board 100 undergoes a water wash or a process with liquid or solution.

[0031] In other embodiments, the printed circuit board 100 includes a plurality of insulating layers 104 and conductive layers 105 that are sequentially stacked and bonded. Among them, the barrier layer 102 is integrally formed with the insulating layer 104. That is, the barrier layer 102 is a part of the insulating layer 104. Among them, the conductive layer 105 may include a copper layer, a silver layer, a gold layer, an aluminum layer, or other conductive metal layers.

[0032] With the above structure, during the high-temperature pressing process or high-temperature soldering process of the printed circuit board 100, the air inside at least one cavity 101 expands due to heat and will first break through the relatively fragile barrier layer 102 at the edge of the printed circuit board 100 along the corresponding through slot 103, thereby balancing the internal and external pressures of the printed circuit board 100. Thus, the printed circuit board 100 of the present application can block liquid intrusion in the water wash or solution process by the barrier layer 102, and the barrier layer 102 will not affect the air expansion in the cavity 101, resulting in delamination of the printed circuit board 100, improving the reliability of the printed circuit board 100.

[0033] In other embodiments, the insulating layer 104 includes one or more of a resin layer, a polyimide layer, a bismaleimide triazine layer, and a ceramic base layer. Since the barrier layer 102 is integrally formed with the insulating layer 104, the barrier layer 102 also includes one or more of a resin layer, a polyimide layer, a bismaleimide triazine layer, and a ceramic base layer.

[0034] In other embodiments, the thickness range of the barrier layer 102 is 0.10 - 0.40 millimeters. Specifically, it can be 0.10 millimeters, 0.15 millimeters, 0.19 millimeters, 0.21 millimeters, 0.26 millimeters, 0.28 millimeters, 0.31 millimeters, 0.35 millimeters, 0.38 millimeters, or 0.40 millimeters, etc. Specifically, it can be set based on actual requirements. The barrier layer 102 within this thickness range can be smoothly broken through by the expanding air during the high-temperature pressing process or high-temperature soldering process of the printed circuit board 100, thereby balancing the internal and external pressures of the printed circuit board 100, reducing the occurrence of delamination and explosion of the printed circuit board 100, and improving the quality and reliability of the printed circuit board 100.

[0035] In other embodiments, the distance between the barrier layer 102 and the edge of the corresponding printed circuit board 100 ranges from 0.0 to 1.0 millimeters. Specifically, it can be 0.0 millimeters, 0.1 millimeters, 0.2 millimeters, 0.3 millimeters, 0.4 millimeters, 0.5 millimeters, 0.6 millimeters, 0.7 millimeters, 0.8 millimeters, 0.9 millimeters, or 1.0 millimeters, etc., and can be specifically set based on actual situations. The barrier layer 102 within this distance range can not only prevent the printed circuit board 100 from being invaded by liquid during water washing or solution processes, but also enable the barrier layer 102 to be smoothly broken by the expanding air during the high-temperature lamination process or high-temperature soldering process of the printed circuit board 100, thereby balancing the internal and external pressures of the printed circuit board 100, reducing the occurrence of delamination and explosion of the printed circuit board 100, and improving the quality and reliability of the printed circuit board 100.

[0036] In other embodiments, solder mask layers 108 are respectively provided on opposite sides of the printed circuit board 100 to perform solder mask on opposite sides of the printed circuit board 100 through the solder mask layers 108.

[0037] Please refer to Figure 3 , Figure 3 is Figure 1 a schematic structural diagram of another embodiment of the local position 107 in the embodiment.

[0038] In this embodiment, the number of barrier layers 102 on one side of each through slot 103 close to the edge of the printed circuit board 100 is multiple, that is, a plurality of barrier layers 102 are provided inside one side of each through slot 103 close to the edge of the printed circuit board 100. When both sides of the through slot 103 communicate with the edge of the printed circuit board 100, a plurality of barrier layers 102 are respectively provided at positions on both sides of the through slot 103 close to the edge of the printed circuit board 100.

[0039] The multiple barrier layers 102 are staggeredly arranged at the position of the corresponding through slot 103 close to the edge of the printed circuit board 100, and the cross-sectional area of the barrier layer 102 is greater than one-half of the cross-sectional area of the through slot 103 to prevent liquid invasion.

[0040] In this embodiment, by providing a plurality of staggered barrier layers 102 inside one side of the through slot 103 close to the edge of the printed circuit board 100, the printed circuit board 100 can be prevented from being invaded by liquid during water washing or solution processes through the plurality of staggered barrier layers 102, and the internal and external pressures of the printed circuit board 100 can be directly balanced through the staggered barrier layers 102 during the high-temperature lamination process or high-temperature soldering process of the printed circuit board 100, reducing the occurrence of delamination and explosion of the printed circuit board 100, and improving the quality and reliability of the printed circuit board 100. Moreover, the setting of the barrier layer 102 in this embodiment can also reduce the occurrence of board residues during the high-temperature lamination process or high-temperature soldering process.

[0041] Please refer to Figure 4 , Figure 4 which is a schematic flow chart of an embodiment of the method for manufacturing a printed circuit board provided by this application.

[0042] Step S11: Prepare a multi-layer base layer.

[0043] Prepare a multi-layer base layer, where the multi-layer base layer is the base board of the printed circuit board and can be used to form the printed circuit board. Among them, the multi-layer base layer can include a multi-layer insulating layer and a multi-layer conductive layer.

[0044] Step S12: Control the depth of at least one base layer respectively based on a preset depth control rule to form through holes and / or blind holes and through slots, and retain the base layer at the edge of the through slot close to the base layer to form a barrier layer.

[0045] After obtaining the multi-layer base layer, control the depth of at least one base layer respectively based on a preset depth control rule to form through holes and / or blind holes and through slots, and retain a part of the base layer at the edge of the through slot close to the base layer to form a barrier layer.

[0046] Among them, the preset depth control rule includes the setting requirements of at least one cavity, through slot and barrier layer in the printed circuit board. Determine the preset depth control rule based on the above requirements, and then control the depth of at least one base layer respectively based on the preset depth control rule to prepare a through slot and through holes and / or blind holes for forming at least one cavity on at least one base layer, and at the same time retain the base layer at the edge of the through slot close to the base layer to form a barrier layer.

[0047] Among them, since the shape of at least one cavity can include any shape such as square, circular, oval, etc., and the size can also be set based on actual needs. Therefore, when controlling the depth, some base layers in at least one base layer may need to be controlled to form through holes, some base layers may need to be controlled to form blind holes, or some base layers in the multi-layer base layer may only need to be controlled to form through holes.

[0048] Step S13: Press the multi-layer base layers correspondingly to form at least one cavity communicating with the through slot on the printed circuit board with the through holes and / or blind holes.

[0049] After controlling the depth of the base layer, press the multi-layer base layers correspondingly to form at least one cavity communicating with the through slot on the printed circuit board with the through holes and / or blind holes.

[0050] The method for manufacturing the printed circuit board in this embodiment can be used to manufacture the printed circuit board in any of the above embodiments.

[0051] Through the above method, the method for manufacturing a printed circuit board according to this embodiment controls the depth of at least one base layer respectively based on a preset depth control rule to form vias and / or blind vias and through slots, and retains the base layer at the edge of the through slot close to the base layer to form a barrier layer. Then, multiple base layers are press-fitted correspondingly to form at least one cavity communicating with the through slot on the printed circuit board, so as to form a printed circuit board with at least one cavity inside. And at least one cavity communicates with the edge of the printed circuit board through the through slot, and a barrier layer is provided on one side of the through slot close to the edge of the printed circuit board. Thus, when the printed circuit board undergoes a water washing process or a process with liquid or solution, the barrier layer can prevent the liquid from invading into the cavity, thereby affecting the subsequent processing of the printed circuit board and the reliability of the printed circuit board. And the barrier layer can be smoothly broken by the expanded air or directly communicated during the high-temperature press-fitting process or the high-temperature soldering process of the printed circuit board, so as to balance the internal and external pressures of the printed circuit board, reduce the occurrence of delamination and explosion of the printed circuit board, and improve the quality and reliability of the printed circuit board.

[0052] In other embodiments, the step of controlling the depth of at least one base layer respectively based on a preset depth control rule to form vias and / or blind vias and through slots, and retaining the base layer at the edge of the through slot close to the base layer to form a barrier layer further includes: controlling the depth of at least one base layer respectively by mechanical depth control, laser depth control or water jet based on the preset depth control rule to form vias and / or blind vias and through slots, and retaining a part of the base layer at the edge of the through slot close to the base layer to form a barrier layer.

[0053] Controlling the depth of at least one base layer by the above depth control method can improve the depth control accuracy and precision, improve the precision of vias and / or blind vias and through slots, and further improve the reliability and quality of the printed circuit board.

[0054] The above is only the embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A printed circuit board, characterized in that, At least one cavity is formed in the printed circuit board, and the at least one cavity is communicated to the edge of the printed circuit board through a through groove to communicate with external air, and a barrier layer is arranged on one side of the through groove close to the edge of the printed circuit board, and the barrier layer separates the through groove to prevent liquid intrusion; Wherein, the number of the barrier layers on one side of each of the through grooves close to the edge of the printed circuit board is multiple; the multiple barrier layers are arranged alternately at the position where the corresponding through grooves are close to the edge of the printed circuit board, and the cross-sectional area of the barrier layer is greater than one half of the cross-sectional area of the through groove to separate the two opposite ends of the through groove at the barrier layer.

2. The printed circuit board according to claim 1, wherein When the number of the at least one cavity is multiple, the multiple cavities are arranged in an array; The cavities in the same row or the same column are respectively communicated to the edge of the printed circuit board through one through groove.

3. The printed circuit board according to claim 1, wherein The printed circuit board includes multiple insulating layers and multiple conductive layers which are laminated and adhered in sequence; The barrier layer is integrally formed with the insulating layer.

4. The printed circuit board according to claim 1, wherein The barrier layer includes one or more of a resin layer, a polyimide layer, a bismaleimide triazine layer, and a ceramic base layer.

5. The printed circuit board according to claim 1, wherein The thickness range of the barrier layer is 0.10 - 0.40 millimeters.

6. The printed circuit board according to claim 1, wherein The distance range between the barrier layer and the corresponding edge of the printed circuit board is 0.0 - 1.0 millimeters.

7. A method for preparing a printed circuit board, characterized in that, The printed circuit board is the printed circuit board according to any one of claims 1 - 6 above, and the preparation method of the printed circuit board includes: Prepare multiple base layers; Perform depth control on at least one of the base layers respectively based on a preset depth control rule to form through holes and / or blind holes and through grooves, and retain the base layer at the edge of the through groove close to the base layer to form a barrier layer; Press the multiple base layers correspondingly to form at least one cavity communicated with the through groove on the printed circuit board with the through holes and / or blind holes.

8. The method for preparing a printed circuit board according to claim 7, wherein, The step of performing depth control on at least one of the base layers respectively based on a preset depth control rule to form through holes and / or blind holes and through grooves, and retaining the base layer at the edge of the through groove close to the base layer to form a barrier layer further includes: Perform depth control on at least one of the base layers respectively by mechanical depth control, laser depth control or water jet based on the preset depth control rule to form through holes and / or blind holes and through grooves, and retain the base layer at the edge of the through groove close to the base layer to form the barrier layer.

Images