Anti-warping rigid press board

Abstract

This utility model relates to the field of printed circuit board manufacturing technology and discloses an anti-warping rigid lamination board. Both the first and second core boards are used to carry signal lines, and both the first and second adhesive layers are used to separate the signal lines and bond the anti-warping rigid lamination board. The first and second stacks, made of different materials, are bonded together. The thermal shrinkage of the first stack is greater than that of the second stack. To address the mixed lamination of the first and second stacks, a buffer layer is bonded to the side of the second stack away from the first stack to adjust the shrinkage balance between the first and second stacks. This ensures that the anti-warping rigid lamination board achieves symmetrical thermal shrinkage force balance after lamination, thus improving the warping problem. The structure is simple and facilitates control of warping deformation caused by mixed lamination of different materials, ensuring that the degree of warping meets the conventional control process requirements of printed circuit boards.

Description

Technical Field

[0001] This utility model relates to the field of printed circuit board manufacturing technology, and in particular to an anti-warping rigid pressing plate. Background Technology

[0002] In traditional printed circuit board (PCB) manufacturing, single-material layers are laminated together. However, with increasingly faster signal transmission speeds, better materials are needed to avoid signal loss and meet transmission requirements. During manufacturing, signal loss is influenced not only by the materials used but also by the length of the signal lines on each layer. Since higher-loss materials are more expensive than lower-loss materials, to save on material costs, layer stack-up designs typically use higher-loss materials for layers with longer signal lines, while other layers use conventional materials. In standard PCB routing designs, only one or two layers have relatively long traces, necessitating the use of higher-loss materials. The remaining layers, with shorter signal lines, can use conventional materials with lower loss levels. This approach not only ensures that overall signal loss remains within a predetermined range but also reduces PCB production costs.

[0003] The copper-clad laminates used in each layer of a rigid laminate will shrink after lamination and heating. When the same material is used for lamination and the pattern design is consistent, the shrinkage of each layer is basically similar. However, when different materials are mixed and laminated, the shrinkage coefficients of different material layers will vary after lamination, making the rigid laminate prone to warping. Severe warping of the rigid laminate has a significant impact on subsequent PCB sizing, the uniformity of copper grinding on the board surface, and the final assembly of the finished circuit board.

[0004] In existing technologies, such as Figure 1 and Figure 2 As shown, the rigid press plate 1 includes a first material layer 2 and a second material layer 3. If the shrinkage of the first material layer 2 and the second material layer 3 is the same after being heated and pressed, the rigid press plate 1 will present a flat plate shape after pressing. However, the shrinkage of the first material layer 2 and the second material layer 3 is often different, which causes the rigid press plate 1 to present a warped plate shape after pressing. Moreover, the greater the difference in the shrinkage of the two, the greater the degree of warping deformation.

[0005] Therefore, there is an urgent need for a rigid anti-warping press plate that can improve the problem of board warping. Through new composition structure and processing methods, the warping deformation caused by the mixing and pressing of different materials can be controlled to ensure that the degree of warping meets the conventional control process requirements of printed circuit boards. Utility Model Content

[0006] The purpose of this utility model is to provide a rigid press plate that prevents warping.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] Anti-warping rigid laminated sheet, including:

[0009] The first stack includes a first core board and a first adhesive layer, wherein the first core board and the first adhesive layer are bonded together.

[0010] The second stack includes a second core board and a second adhesive layer, which are bonded together; the first stack and the second stack are bonded together, and the heat shrinkage of the first stack is greater than that of the second stack.

[0011] A buffer layer is attached to the side of the second stack away from the first stack.

[0012] As an optional technical solution for anti-warping rigid laminated plate, the thermal shrinkage of the buffer layer is greater than that of the first laminate.

[0013] As an optional technical solution for anti-warping rigid press-fit plates, the melting point of the buffer layer is greater than 220 degrees Celsius.

[0014] As an optional technical solution for anti-warping rigid press-fit plates, the melting point of the buffer layer is 250 degrees Celsius.

[0015] As an optional technical solution for anti-warping rigid press-fit plates, the buffer layer is provided in multiple layers, with the multiple buffer layers stacked together.

[0016] As an optional technical solution for anti-warping rigid laminated board, the total number of layers of the first core board, the first adhesive layer, the second core board, and the second adhesive layer is greater than 8.

[0017] As an optional technical solution for anti-warping rigid laminated plates, both sides of the first core plate and / or the second core plate are covered with copper foil.

[0018] As an optional technical solution for anti-warping rigid press-fitting plates, the copper foil is electrolytic copper foil.

[0019] As an optional technical solution for anti-warping rigid laminated plates, copper foil is attached to both sides of the first adhesive layer and / or the second adhesive layer.

[0020] As an optional technical solution for anti-warping rigid press-fit plate, outer protective steel plates are respectively attached to the outer sides of the first stack and the buffer layer.

[0021] The beneficial effects of this utility model are:

[0022] The anti-warping rigid press plate provided by this utility model includes a first layer, a second layer, and a buffer layer. The first and second layers are bonded together. The first layer includes a first core board and a first adhesive layer, which are bonded together. The second layer includes a second core board and a second adhesive layer, which are bonded together. Both the first and second core boards are used to carry signal lines, and both the first and second adhesive layers are used to separate the signal lines and bond together the anti-warping rigid press plate. The shrinkage of the first and second layers, due to their different materials, varies. The heat shrinkage of the first layer is greater than that of the second layer. The thermal shrinkage of the second layer, in response to the mixed pressing of the first and second layers, can be adjusted by placing a buffer layer on the side of the second layer away from the first layer, based on the difference in thermal shrinkage of the materials. This balance of shrinkage between the first and second layers is achieved by attaching a buffer layer to the side of the second layer away from the first layer. The shrinkage of the buffer layer and the shrinkage of the second layer work together to counteract the shrinkage of the first layer, so that the anti-warping rigid press plate achieves a symmetrical balance of forces due to thermal shrinkage on both sides after pressing, thus improving the warping problem of the board surface. The structure is simple and easy to control the warping deformation caused by the mixed pressing of different materials, ensuring that the degree of warping meets the conventional control process requirements of printed circuit boards. Attached Figure Description

[0023] Figure 1 This is a schematic diagram showing the composition and structure of rigid press-fit plates in existing technology;

[0024] Figure 2 This is a schematic diagram of the deformation of a rigid press plate in the prior art;

[0025] Figure 3 This is a schematic diagram showing the composition of the anti-warping rigid press plate provided in a specific embodiment of this utility model.

[0026] In the picture:

[0027] 1. Rigid pressed plate; 2. First material layer; 3. Second material layer;

[0028] 10. Copper foil;

[0029] 100. First laminate; 101. First core board; 102. First adhesive layer;

[0030] 200. Second laminate; 201. Second core board; 202. Second adhesive layer;

[0031] 300, buffer layer; 400, outer steel plate. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0033] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0036] like Figure 3As shown in the figure, this utility model discloses an anti-warping rigid press plate, including a first stack 100, a second stack 200, and a buffer layer 300. The first stack 100 and the second stack 200 are bonded together. The first stack 100 includes a first core board 101 and a first adhesive layer 102, which are bonded together. The second stack 200 includes a second core board 201 and a second adhesive layer 202, which are bonded together. Both the first core board 101 and the second core board 201 are used to carry signal lines, and both the first adhesive layer 102 and the second adhesive layer 202 are used to separate the signal lines and act as adhesive to bond and assemble the anti-warping rigid press plate.

[0037] Specifically, both sides of the first core board 101 and the second core board 201 are covered with copper foil 10. The copper foil 10 is electrolytic copper foil, which can be used in most printed circuit boards, primarily in rigid boards. It is understood that both sides of the first adhesive layer 102 and the second adhesive layer 202 are also covered with copper foil 10. The copper foil 10 is a conductor in the printed circuit board, responsible for the transmission of current and signals. Simultaneously, the copper foil 10 can serve as a reference plane, helping to control the impedance of the transmitted signal lines, playing a role in interconnection, insulation, and support; it can also be used as a shielding layer to suppress electromagnetic interference.

[0038] For example, the first adhesive layer 102 and the second adhesive layer 202 can be semi-cured sheets made of resin materials, such as polypropylene. However, different types of resins have different compositions and different coefficients of thermal expansion and contraction. When the first adhesive layer 102 and the second adhesive layer 202 are symmetrically pressed together using two different resin materials, the amount of shrinkage will differ.

[0039] Therefore, the shrinkage amounts of the first laminate 100 and the second laminate 200, which are made of different materials, are also different. The thermal shrinkage amount of the first laminate 100 is greater than that of the second laminate 200. For the mixed pressing of the first laminate 100 and the second laminate 200, the shrinkage balance of the first laminate 100 and the second laminate 200 can be adjusted by attaching a buffer layer 300 to the side of the second laminate 200 away from the first laminate 100, based on the difference in thermal shrinkage of the materials. The shrinkage amount of the buffer layer 300 and the shrinkage amount of the second laminate 200 together counteract the shrinkage amount of the first laminate 100, so that the anti-warping rigid press plate achieves a symmetrical force balance of thermal shrinkage on both sides after pressing, thereby improving the warping problem of the board surface. The structure is simple and easy to control the warping deformation caused by the mixed pressing of different materials, so as to ensure that the degree of warping meets the conventional control process requirements of printed circuit boards.

[0040] In this embodiment, the total number of layers of the first core board 101, the first adhesive layer 102, the second core board 201, and the second adhesive layer 202 is greater than 8. This method of constructing an anti-warping rigid press board is mainly used in products with 8 or more layers. The first stack 100 and the second stack 200 are made of different materials. The material of the second stack 200 is used as the main material and is designed in the lower half of the anti-warping rigid press board. The material of the first stack 100 is used as a non-main material and is designed in the upper half of the anti-warping rigid press board. The anti-warping rigid press board can be successfully constructed with only one pressing, simplifying the operation.

[0041] Furthermore, outer protective steel plates 400 are respectively attached to the outer sides of the first stack 100 and the buffer layer 300, which can help the anti-warping rigid pressing plate keep the plate surface flat and protect the structural stability of the anti-warping rigid pressing plate.

[0042] Multiple tests have shown that different materials used in the buffer layer 300 have varying degrees of effect on improving the warping of the anti-warping rigid laminate. The softer the material of the buffer layer 300, the greater the improvement in warping and the better the effect. It is understood that the thermal shrinkage of the buffer layer 300 should be greater than that of the first laminate 100; that is, the thermal shrinkage of the buffer layer 300 should be greater than that of both the first laminate 100 and the second laminate 200. This prevents the anti-warping rigid laminate from bending towards the first laminate 100, ensuring that the buffer layer 300 effectively improves the warping problem of the laminate surface.

[0043] Optionally, the melting point of the buffer layer 300 should be greater than 220 degrees Celsius. The buffer layer 300 needs to be able to withstand high temperatures without melting and without adhering to the copper foil 10 and the outer protective steel plate 400. For conventional rigid laminated plates, the maximum lamination temperature is 220 degrees Celsius, meaning the material of the buffer layer 300 must at least meet the requirement of not melting at 220 degrees Celsius and not adhering to the copper foil 10 and the outer protective steel plate 400. As a preferred embodiment, it is optimal for the material of the buffer layer 300 to have a melting point of 250 degrees Celsius.

[0044] The test results also show that in anti-warping rigid laminates, the larger the proportion of the buffer layer 300, the greater the warping reduction and the better the improvement effect. Therefore, anti-warping rigid laminates can be configured with multiple buffer layers 300, stacked to increase the total thickness of the buffer layers 300, depending on the actual situation. Anti-warping rigid laminates can not only improve warping by using buffer layers 300 of different materials, but also further improve the effect by adjusting the amount of material used in the buffer layers 300, thus improving the operability of manufacturing anti-warping rigid laminates. When the warping problem is severe, a softer material should be preferred as the buffer layer 300, and multiple buffer layers 300 should be stacked when necessary to better solve the warping problem.

[0045] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An anti-warping rigid press-fit plate, characterized in that, include: A first stack (100) includes a first core board (101) and a first adhesive layer (102), wherein the first core board (101) and the first adhesive layer (102) are bonded together. The second stack (200) includes a second core board (201) and a second adhesive layer (202), which are bonded together; the first stack (100) and the second stack (200) are bonded together, and the heat shrinkage of the first stack (100) is greater than that of the second stack (200); A buffer layer (300) is attached to the side of the second stack (200) away from the first stack (100).

2. The anti-warping rigid press plate according to claim 1, characterized in that, The thermal shrinkage of the buffer layer (300) is greater than that of the first stack (100).

3. The anti-warping rigid press plate according to claim 1, characterized in that, The buffer layer (300) has a melting point greater than 220 degrees Celsius.

4. The anti-warping rigid press plate according to claim 3, characterized in that, The buffer layer (300) has a melting point of 250 degrees Celsius.

5. The anti-warping rigid press plate according to claim 1, characterized in that, The buffer layer (300) is provided in multiple layers, and the multiple buffer layers (300) are stacked.

6. The anti-warping rigid press plate according to claim 1, characterized in that, The total number of layers of the first core board (101), the first adhesive layer (102), the second core board (201), and the second adhesive layer (202) is greater than 8.

7. The anti-warping rigid press plate according to claim 1, characterized in that, Both sides of the first core board (101) and / or the second core board (201) are covered with copper foil (10).

8. The anti-warping rigid press plate according to claim 7, characterized in that, The copper foil (10) is an electrolytic copper foil.

9. The anti-warping rigid press plate according to claim 1, characterized in that, Both sides of the first adhesive layer (102) and / or the second adhesive layer (202) are covered with copper foil (10).

10. The anti-warping rigid press-fit plate according to any one of claims 1-9, characterized in that, The outer outer sides of the first stack (100) and the buffer layer (300) are respectively fitted with outer protective steel plates (400).

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