PCB manufacturing method and PCB

Abstract

The invention discloses a PCB manufacturing method and a PCB, and the PCB manufacturing method comprises the steps: providing a daughter board which comprises a core board and a prepreg; pre-arranging the daughter boards; the arranged daughter boards are put into a sealing bag; the sealing bag is vacuumized, so that the liquid resin enters the sealing bag and fills the gap between the daughter boards; and the sealing bag is put into a pressing machine, and the arranged daughter boards are subjected to press fit. By adopting the scheme provided by the invention, the dielectric thickness of the PCB can be more accurately controlled, and the dielectric thickness of the PCB is more uniform, so that the product performance of the PCB is improved.

Description

Technical Field

[0001] The present application relates to the technical field of circuit boards, and in particular to a method for manufacturing a PCB board. Background Art

[0002] PCB boards usually require the core board and the prepreg to be pressed together. During the pressing process, the resin in the prepreg softens after being heated at high temperature to reduce the viscosity, and then flows to fill the empty area. After the core board is etched, the location with a large residual copper rate (copper area / total area) has less resin filling, and the location with a small residual copper rate has more resin filling, which will cause the dielectric thickness to become thinner. When the copper thickness of the core board is thicker (for example, reaching 3OZ), when the residual copper rate is the same, the greater the copper thickness of the core board, the larger the empty volume that needs to be filled with resin, resulting in a thinner dielectric thickness. This may not only lead to a decrease in the uniformity of the dielectric thickness, but also too thin a dielectric thickness will affect the reliability indicators of the PCB finished product, such as impedance, insertion loss, and withstand voltage.

[0003] In the related art, in order to make the dielectric thickness of the PCB more uniform, the method of first applying resin in the gaps of the core board surface pattern, and then vacuuming and curing is usually adopted. However, this solution has at least the following problems: for some closed small-pitch positions, when rolling the resin, the bubbles in the small gaps are easily covered by the resin and are not easy to escape, which will cause voids to form during pressing, affecting reliability. At the same time, when the resin is coated on the surface of the core board, due to the fluidity of the liquid resin, the coating thickness is unstable, which easily causes the dielectric thickness to exceed the tolerance range. Summary of the invention

[0004] In order to solve at least one of the above technical problems, the present application provides a PCB board manufacturing method, which can more accurately control the dielectric thickness of the PCB board and make the dielectric thickness of the PCB board more uniform. The technical solution adopted is as follows.

[0005] In the first aspect, the PCB board manufacturing method provided in the present application includes:

[0006] Providing a sub-board, the sub-board comprising a core board and a prepreg;

[0007] Prearranging the daughterboard;

[0008] Putting the arranged sub-plates into a sealed bag;

[0009] Vacuuming the sealing bag to allow the liquid resin to enter the sealing bag and fill the gaps between the sub-plates;

[0010] The sealed bag is placed in a press and the arranged sub-boards are pressed.

[0011] In some embodiments of the present application, the gap formed between two adjacent layers of the core plates is formed by:

[0012] A prepreg is stacked between two adjacent layers of the core boards.

[0013] In some embodiments of the present application, the sealing bag is a flexible sealing bag, and before evacuating the sealing bag, the PCB board manufacturing method further includes:

[0014] placing a flexible sealed bag into a pressure container;

[0015] sealing the pressure vessel;

[0016] The pressure vessel is evacuated.

[0017] In certain embodiments of the present application, the flexible sealed bag includes an inner bag and an outer bag, the outer bag is sleeved on the outer circumference of the inner bag, and evacuating the pressure container includes:

[0018] Evacuating the pressure container so that the outer bag fits the inner wall of the pressure container;

[0019] After the pressure vessel is evacuated, the PCB manufacturing method further includes:

[0020] The outer bag is evacuated to make the inner bag fit the inner wall of the pressure container;

[0021] The inner bag is evacuated to make the air pressure in the inner bag reach a preset value.

[0022] In some embodiments of the present application, placing the sealed bag into a press and pressing the arranged sub-plates comprises:

[0023] Inflating the outer bag to separate the inner bag from the outer bag;

[0024] taking out the inner bag from the outer bag;

[0025] The inner bag is placed in a press and the arranged sub-plates are pressed.

[0026] In some embodiments of the present application, after the inner bag is placed in a press and the arranged sub-boards are pressed, the method for manufacturing the PCB board further includes:

[0027] The sub-plate is milled to remove the inner pocket.

[0028] In some embodiments of the present application, the liquid suction port of the inner bag is connected to an electric valve, and evacuating the inner bag to make the air pressure in the inner bag reach a preset value includes:

[0029] When the vacuum degree in the inner bag is higher than a preset value, the electric valve is closed;

[0030] When the vacuum degree in the inner bag is reduced to a preset value, the electric valve is opened to allow liquid resin to enter the inner bag.

[0031] In some embodiments of the present application, placing the sealed bag into a press and pressing the arranged sub-plates comprises:

[0032] placing the arranged sub-plates into a cabin pressure press;

[0033] Before laminating the sub-panels and / or during laminating the sub-panels, the sealing bag is evacuated.

[0034] In some embodiments of the present application, before pre-arranging the sub-board, the PCB board manufacturing method further includes:

[0035] Providing a protective layer on the top surface of the sub-board located at the top layer and the bottom surface of the sub-board located at the bottom layer;

[0036] After the sealed bag is placed in a press and the arranged sub-boards are pressed, the PCB manufacturing method further comprises:

[0037] The protective layer is removed.

[0038] In a second aspect, the present application further provides a PCB board, which is manufactured by the PCB board manufacturing method provided in the first aspect.

[0039] The embodiments of the present application have at least the following beneficial effects: by pre-arranging the sub-boards, gaps are formed between adjacent sub-boards, and the arranged sub-boards are placed in a sealed bag, and then the sealed bag is evacuated so that liquid resin can be drawn into the sealed bag. The fluidity of the liquid resin can be used to fill the gaps between the sub-boards, thereby achieving the effect of interconnecting two adjacent core boards, and then the sealed bag containing the arranged sub-boards is pressed to obtain a PCB board product. On the one hand, by pre-stacking the core boards, the distance between two adjacent core boards can be more accurately controlled, thereby better controlling the dielectric thickness so that the dielectric thickness meets the design requirements and avoids the problem of too thin dielectric thickness in areas with a small residual copper rate. In addition, the sealing bag can be used to retain the pre-arranged boards after filling with liquid resin, thereby solving the problem of unstable thickness of liquid resin in the preset gap and avoiding excessive dielectric thickness. On the other hand, the free flow of liquid resin between the patterns on the surface of the core board helps fill the areas with smaller pattern spacing, thereby solving the problem of voids or pits formed due to the lack of resin in areas with smaller spacing, improving the resin filling effect, and making the dielectric thickness more uniform after lamination of the core boards. The PCB board products can meet reliability indicators such as dielectric thickness uniformity, impedance, insertion loss, and withstand voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The aspects and advantages described and / or attached in the embodiments of the present application will become apparent and easy to understand in conjunction with the following drawings. It should be noted that the embodiments embodied in the following drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0041] Figure 1 It is a schematic diagram of the resin flow in the sub-board during the core board pressing process in the related art;

[0042] Figure 2 A schematic diagram of the core board thickness in the related technology;

[0043] Figure 3 It is a schematic diagram of the effect of rolling resin on the core board in the related art;

[0044] Figure 4 A flow chart of a PCB board manufacturing method provided in an embodiment of the present application;

[0045] Figure 5 A schematic diagram of a sub-board in step S100 provided in an embodiment of the present application;

[0046] Figure 6 A schematic diagram of a daughter board in step S200 provided in an embodiment of the present application;

[0047] Figure 7 A schematic diagram of a sub-board in step S210 provided in an embodiment of the present application;

[0048] Figure 8 A schematic diagram of the structure of a sealing bag in a PCB board manufacturing method provided in an embodiment of the present application;

[0049] Fig. 9 A structural line diagram of a sealing bag in a PCB board manufacturing method provided in an embodiment of the present application;

[0050] Fig.10 A schematic diagram of a daughter board in step S300 provided in an embodiment of the present application;

[0051] Fig.11 A schematic diagram of a daughter board in steps S410 to S430 provided in an embodiment of the present application;

[0052] Fig.12 A schematic diagram of a daughter board in step S400 provided in an embodiment of the present application;

[0053] Fig.13 A schematic diagram of a sub-board in step S500 provided in an embodiment of the present application;

[0054] Fig.14 A schematic diagram of the structure of a PCB board provided in an embodiment of the present application.

[0055] Reference numerals:

[0056] 100, sub-board; 10, core board; 11, metal pattern; 12, protective layer; 20, semi-cured sheet; 30, sealing bag; 31, inner bag; 311, liquid suction port; 3110, rigid joint; 3111, electric valve; 312, first vacuum port; 32, outer bag; 321, first opening; 322, second opening; 323, second vacuum port; 33, vacuum equipment; 34, buffer device; 40, liquid resin; 41, liquid storage tank; 50, pressure vessel; 51, third opening; 52, fourth opening; 53, third vacuum port; 61, liquid level measuring instrument; 62, controller; 70, press; 71, pressure pump; 72, heating device; 73, exhaust device; 200, PCB board. DETAILED DESCRIPTION

[0057] Combine the following Figures 1 to 14 Embodiments of the present application are described in detail, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0058] In the description of the present application, it should be understood that if the terms "center", "middle", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, "multiple" means two or more.

[0059] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0060] See also Figures 1 to 3The PCB board usually needs to press the core board and the prepreg 20. During the pressing process, the resin in the prepreg 20 is softened by high temperature heating to reduce the viscosity, and then flows to fill the empty area between the metal patterns 11. Figure 1 The dotted arrow in the middle shows the flow direction of the resin in the prepreg 20. After etching the core board, the location with a large residual copper rate (copper area / total area) has less resin filling, and the location with a small residual copper rate has more resin filling, which will cause the dielectric thickness to become thinner. The dielectric thickness can be measured by the distance from the copper surface of the upper core board to the copper surface of the next core board (such as Figure 2 As shown in the figure). When the copper thickness of the core board is thicker, for example, when it reaches 3OZ, under the condition of the same residual copper rate, the thicker the copper thickness of the core board, the larger the empty volume that needs to be filled by the resin, thus resulting in a thinner dielectric thickness. This may not only lead to a decrease in dielectric thickness uniformity, but also a too thin dielectric thickness will affect the impedance, insertion loss, withstand voltage and other reliability indicators of the PCB finished product.

[0061] In the related art, in order to make the dielectric thickness of the PCB more uniform, the solution is usually to first apply resin in the gaps of the core board surface pattern, and then evacuate and cure. However, this solution has at least the following problems: Figure 3 For some closed small-spacing positions, when rolling the resin, the bubbles in the small gaps are easily covered by the resin and are not easy to escape, which will cause voids to form during lamination, affecting reliability. At the same time, when the resin is coated on the surface of the core board 10, due to the fluidity of the liquid resin 40, the coating thickness is unstable, which easily causes the dielectric thickness to exceed the tolerance range.

[0062] For this reason, please see Figure 4 In a first aspect, the present application proposes a PCB manufacturing method capable of solving the above-mentioned problems, comprising:

[0063] S100 provides a sub-board 100, the sub-board 100 includes a core board 10 and a prepreg 20;

[0064] S200. Pre-arrange sub-board 100;

[0065] S300. Place the arranged sub-board 100 into the sealed bag 30;

[0066] S400. The sealing bag 30 is evacuated so that the liquid resin 40 enters the sealing bag 30 and fills the gap between the sub-plates 100;

[0067] S500. Place the sealing bag 30 into the press 70 and press the arranged sub-panels 100.

[0068] In the present application, the distance between two adjacent core boards 10 can be adjusted more accurately by pre-arranging the sub-boards 100, so as to better control the dielectric thickness so that the dielectric thickness meets the design requirements. By placing the arranged sub-boards 100 into the sealing bag 30 and evacuating the sealing bag 30, on the one hand, the gas between the core boards 10 can be evacuated to avoid bubbles in the liquid resin 40 during the filling process, and on the other hand, the liquid resin 40 can be drawn into the sealing bag 30 under negative pressure, and the fluidity of the liquid resin 40 can be used to fill the liquid resin 40 into the gap between the sub-boards 100, thereby achieving the effect of connecting the two adjacent core boards 10.

[0069] Secondly, the sealing characteristics of the sealing bag 30 can be used to retain the liquid resin 40 filled in the gap, preventing the liquid resin 40 from leaking before being pressed and cured. Compared with the solution of first coating the liquid resin 40 on the surface of the core board 10 and then stacking the core boards 10, the method of the present application can prevent the liquid resin 40 from leaking before being heated and cured, thereby solving the problem of unstable thickness of the liquid resin 40 in the preset gap, avoiding excessive dielectric thickness, and avoiding the problem of too thin dielectric thickness in areas with low residual copper rates, which helps to improve the uniformity of dielectric thickness of the PCB board.

[0070] Finally, the sealed bag 30 containing the arranged daughter boards 100 is pressed together to obtain a PCB board product. The liquid resin 40 can flow freely between the patterns on the surface of the core board 10, which helps to fill the positions with smaller pattern spacing, solves the problem of forming voids or pits due to the lack of resin filling in the positions with smaller spacing, improves the filling effect of the resin, and makes the dielectric thickness of the core board 10 more uniform after lamination. The PCB board product can meet the reliability indicators such as dielectric thickness uniformity, impedance, insertion loss, and withstand voltage.

[0071] See also Figure 5 and Figure 6 In some embodiments, the gap between two adjacent core plates 10 is formed by:

[0072] S101 . Stack a prepreg 20 between two adjacent core panels 10 .

[0073] By stacking the semi-cured sheet 20 between two adjacent core boards 10, a certain distance can be created between the core boards 10. When the pre-arranged sub-boards 100 are subsequently vacuum-filled with liquid resin 40, the liquid resin 40 can enter the gap and fill the gap using the flow characteristics of the liquid resin 40, thereby achieving the effect of adjusting and controlling the dielectric thickness between the core boards 10.

[0074] It is understandable that the semi-cured sheet 20 melts due to heat during the lamination process, and can be integrated with the liquid resin 40 filled in the gap between the core boards 10 to form a connection structure between the two layers of core boards 10, thereby connecting the core boards 10. Optionally, by selecting semi-cured sheets 20 of different thickness specifications and stacking them between the two layers of core boards 10, the dielectric thickness can be adjusted. For example, in a finished PCB board, the dielectric thickness between each layer of core boards 10 can be the same or different. That is, semi-cured sheets 20 of the same thickness specification can be stacked between each layer of core boards 10, or semi-cured sheets 20 of different thickness specifications can be stacked. The specific selection can be flexibly based on the needs of product design, and this example does not limit this.

[0075] In some embodiments, see Figure 7 Before performing the above step S200 and pre-arranging the daughter board 100, the PCB board manufacturing method further includes the following steps:

[0076] S210. A protective layer 12 is provided on the top surface of the sub-board 100 located on the top layer and the bottom surface of the sub-board 100 located on the bottom layer;

[0077] After implementing the above step S500, placing the sealing bag 30 into the press 70 and pressing the arranged sub-boards 100, the PCB board manufacturing method further includes the following steps:

[0078] S700. Remove the protective layer 12.

[0079] By providing a protective layer 12 on the top and bottom surfaces of the sub-boards 100 before pre-arranging the sub-boards 100, it is possible to prevent the sub-boards 100 from being scratched during subsequent pre-arrangement, filling with liquid resin 40, lamination, and milling, or to prevent them from being covered by the liquid resin 40, so as to ensure that the performance of the top and bottom sub-boards 100 is not affected. Usually, the top surface of the top sub-board 100 and the bottom surface of the bottom sub-board 100 need to be covered with a copper foil layer, and the protective layer 12 can protect the copper foil layer from being damaged during the above-mentioned manufacturing steps of the PCB board, thereby improving the performance reliability of the finished PCB board. After the lamination is completed, the protective layer 12 is removed, and a finished PCB board with copper foil layers covering the upper and lower surfaces can be obtained.

[0080] For example, the protective layer 12 may be a high temperature resistant tape, a high temperature resistant coating, etc., and may be provided by pasting, coating, etc. Accordingly, the protective layer 12 may be separated or removed by tearing or by using a solution that can react with the material of the protective layer 12 .

[0081] As an alternative implementation, see Figures 8 to 10The sealing bag 30 may be provided with a liquid suction port 311 and a first vacuum port 312. The liquid suction port 311 is used to introduce liquid resin 40 into the sealing bag 30, and the first vacuum port 312 is used to vacuumize the sealing bag 30. The liquid resin 40 may be stored in a liquid storage tank 41, and the liquid suction port 311 is connected to the liquid storage tank 41 through a pipeline, so that the liquid resin 40 can be sucked into the sealing bag 30.

[0082] In some embodiments, see Fig.11 The sealing bag 30 is a flexible sealing bag 30. Before performing step S400 and evacuating the sealing bag 30, the PCB board manufacturing method further includes the following steps:

[0083] S410. The flexible sealed bag 30 is placed into the pressure container 50;

[0084] S420. Sealed pressure vessel 50;

[0085] S430. Evacuate the pressure vessel 50.

[0086] By using the flexible sealing bag 30, the flexible sealing bag 30 has a certain deformation ability, which can help adapt to the shape of the core board 10. When the flexible sealing bag 30 is evacuated, the flexible sealing bag 30 can be attached to the outer surface of the core board 10, which helps to better retain the liquid resin 40 filled in the gap of the core board 10, and further prevent the liquid resin 40 from leaking from the gap before solidification. The pressure container 50 itself has a certain rigidity. By placing the flexible sealing bag 30 in the pressure container 50, on the one hand, it can support and fix the flexible sealing bag 30 during the vacuuming process, thereby improving the stability of the flexible sealing bag 30 during the vacuuming process; on the other hand, the pressure container 50 itself can be evacuated (such as through the third vacuuming port 53), so that the flexible sealing bag 30 can be attached to the inner wall of the pressure container 50, providing sufficient space for the liquid resin 40 to flow in the sealing bag 30, thereby improving the filling effect of the liquid resin 40.

[0087] Optionally, the pressure container 50 may be provided with a third opening 51 and a fourth opening 52, so that the liquid suction port 311 and the first vacuum port 312 of the flexible sealing bag 30 are exposed from the third opening 51 and the fourth opening 52 in the pressure container 50, respectively, and the third opening 51 and the liquid suction port 311 and the fourth opening 52 and the first vacuum port 312 are sealed to ensure the airtightness of the pressure container 50. The first vacuum port 312 of the flexible sealing bag 30 may be made of elastic material or flexible material, and the first vacuum port 312 may be used to vacuum the flexible sealing bag 30 and also to place the sub-board 100 into the flexible sealing bag 30. For example, the first vacuum port 312 may be opened to a size that allows the sub-board 100 to pass through, and may be closed under the action of its own elasticity, or the first vacuum port 312 may be flexible and may be closed by tying, so that it may be sealed and connected to the vacuum device 33, ensuring the vacuum effect of the flexible sealing bag 30. Similarly, the liquid suction port 311 can also be set to have an elastic or flexible structure, so as to be sealed and connected with the liquid storage tank 41 and the pipeline of the liquid resin 40. Optionally, the liquid suction port 311 can be connected to the pipeline of the resin storage tank 41 through a rigid joint 3110, and similarly, the first vacuum port 312 can also be connected to the vacuum device 33 through a rigid joint 3110, so as to ensure that the inner wall of the liquid suction port 311 and the inner wall of the first vacuum port 312 of the flexible sealing bag 30 will not adhere under the negative pressure, and ensure the patency of the liquid suction port 311 and the first vacuum port 312.

[0088] As an alternative embodiment, the flexible sealing bag 30 may be placed into the sub-board 100 instead of through the first vacuum port 312, but an opening may be provided separately, and the flexible sealing bag 30 may be sealed by utilizing its own elasticity or by utilizing other auxiliary structures for tying, sealing, pasting, etc., which is not limited here.

[0089] In some embodiments, please refer to Figures 8 to 11 The flexible sealing bag 30 includes an inner bag 31 and an outer bag 32, and the outer bag 32 is sleeved on the outer periphery of the inner bag 31. When implementing the above step S430, evacuating the pressure container 50 includes the following steps:

[0090] S431. The pressure vessel 50 is evacuated so that the outer bag 32 fits the inner wall of the pressure vessel 50;

[0091] After the above step S431 of evacuating the pressure vessel 50, the PCB manufacturing method further comprises the following steps:

[0092] S440. The outer bag 32 is evacuated so that the inner bag 31 fits the inner wall of the pressure vessel 50;

[0093] S450. Evacuate the inner bag 31 so that the air pressure in the inner bag 31 reaches a preset value.

[0094] By using the combination of the inner bag 31 and the outer bag 32 for the flexible sealing bag 30, on the one hand, the outer bag 32 can be removed before the sub-board 100 is pressed, and only the inner bag 31 containing the sub-board 100 is pressed, and the outer bag 32 can be recycled and reused. After the sub-board 100 is pressed, the liquid resin 40 filled in the inner bag 31 is solidified and adhered to the inner bag 31, and the inner bag 31 can be removed by milling and other methods without affecting the recycling of the outer bag 32. On the other hand, by setting a two-layer bag structure, the sealing performance of the flexible sealing bag 30 can be further improved. By making the air pressure in the inner bag 31 reach a preset value, it can be ensured that there is a good vacuum in the inner bag 31 before filling the liquid resin 40, so as to avoid the residual air in the gap of the core board 10 from generating cavities or bubbles during the filling process of the liquid resin 40.

[0095] For example, the inner bag 31 can be made of a film material, which has sealing and high temperature resistance properties, and when the inner bag 31 is placed in the press 70 for pressing, it can ensure that the structure and sealing of the inner bag 31 are not damaged. The inner bag 31 can be made of a material that does not react with the resin. The outer bag 32 can be made of a flexible material, and the outer bag 32 can bear the weight of multiple sub-boards 100.

[0096] Optionally, a first opening 321 may be provided in the outer bag 32 at a position corresponding to the liquid suction port 311 of the inner bag 31, and the liquid suction port 311 of the inner bag 31 may be exposed from the first opening 321 of the outer bag 32 so as to be connected to the liquid storage tank 41 and the pipeline of the liquid resin 40. The first opening 321 of the outer bag 32 may also be sealed and connected to the liquid suction port 311 of the inner bag 31 or the rigid joint 3110 of the liquid suction port 311 by its own elasticity or binding, thereby ensuring the sealing between the inner bag 31 and the outer bag 32. Similarly, the outer bag 32 may also be provided with a second opening 322 corresponding to the first vacuum port 312 of the inner bag 31, and the second opening 322 may be used for placing or removing the entire inner bag 31. After the inner bag 31 is placed in the outer bag 32, the second opening 322 of the outer bag 32 and the first vacuum port 312 of the inner bag 31 may be bound together to achieve sealing. At the same time, the outer bag 32 itself can be provided with a second vacuum port 323, which is separated from the first opening 321 and the second opening 322 and is not connected to each other. The second vacuum port 323 can be used to vacuum the outer bag 32, or to inflate the outer bag 32 when the inner bag 31 and the outer bag 32 are separated.

[0097] By sequentially evacuating the pressure container 50, the outer bag 32, and the inner bag 31 in the above manner, the space in the inner bag 31 can be gradually evacuated, thereby improving the vacuum effect in the inner bag 31. By evacuating the inner bag 31, the air in the gap of the core plate 10 can be discharged, thereby preventing the liquid resin 40 from generating voids or bubbles during the filling process, thereby improving the filling effect.

[0098] In some embodiments, see Fig.12 The liquid suction port 311 of the inner bag 31 is connected to an electric valve 3111, and the electric valve 3111 is used to block the liquid resin 40 from entering the inner bag 31, or to allow the liquid resin 40 to pass into the inner bag 31. The above step S450. evacuates the inner bag 31 so that the air pressure in the inner bag 31 reaches a preset value, including:

[0099] S451. When the vacuum degree in the inner bag 31 is higher than the preset value, the electric valve 3111 is closed;

[0100] S452 . When the vacuum degree in the inner bag 31 drops to a preset value, the electric valve 3111 opens to allow the liquid resin 40 to enter the inner bag 31 .

[0101] By setting the electric valve 3111, the opening and closing state of the electric valve 3111 can be used to control the flow of the liquid resin 40, thereby ensuring that there is sufficient vacuum in the inner bag 31 before the liquid resin 40 enters the inner bag 31, avoiding the residual air in the inner bag 31 from causing bubbles when filling the liquid resin 40, thereby ensuring that the liquid resin 40 can achieve a good filling effect.

[0102] Optionally, the vacuum degree of the inner bag 31 can be detected by a liquid level measuring instrument 61. The liquid level measuring instrument 61 and the electric valve 3111 are both electrically connected to the controller 62. The controller 62 uses the liquid level measuring instrument 61 to detect the vacuum degree of the inner bag 31. When the air pressure in the inner bag 31 is higher than a preset value, the electric valve 3111 remains in a closed state, and the liquid resin 40 cannot enter the inner bag 31. The inner bag 31 is evacuated until the vacuum degree in the inner bag 31 reaches a preset value. At this time, the controller 62 controls the electric valve 3111 to open, so that the liquid resin 40 is drawn into the inner bag 31 by the vacuum device 33 to fill the gap of the sub-board 100. Exemplarily, a conductive liquid (such as mercury) can be set in the liquid level measuring instrument 61, and the level change of the conductive liquid can generate different electrical signals, thereby realizing the detection of the vacuum degree of the inner bag 31.

[0103] Optionally, a buffer device 34 may be provided between the vacuum pumping device 33 and the first vacuum pumping port 312 of the inner bag 31 . The buffer device 34 is used to store waste liquid resin 40 extracted from the inner bag 31 , and the resin volatiles may be discharged after condensation.

[0104] In some embodiments, the above step S500 of placing the sealing bag 30 into the press 70 and pressing the arranged sub-panels 100 further includes the following steps:

[0105] S510. Inflate the outer bag 32 to separate the inner bag 31 and the outer bag 32 from each other;

[0106] S520. Take out the inner bag 31 from the outer bag 32;

[0107] S530. Place the inner bag 31 into the press 70 and press the arranged sub-plates 100.

[0108] By inflating the outer bag 32, the vacuum state in the outer bag 32 can be released, so that the inner walls of the inner bag 31 and the outer bag 32 are separated from each other, and the two are separated. The sealing effect of the inner bag 31 can be used to retain the liquid resin 40 in the gap of the core board 10, so as to prevent the liquid resin 40 from flowing out or deforming before solidification, and ensure that the thickness of the core board 10 meets the design requirements after pressing. After the inner bag 31 and the outer bag 32 are separated, only the inner bag 31 is heated and pressed. In this way, only the inner bag 31 can be sacrificed after pressing, and the outer bag 32 can be recycled, thereby reducing the use cost of the flexible sealing bag 30.

[0109] In some embodiments, see Fig.13 The above step S500 of placing the sealing bag 30 into the press 70 and pressing the arranged sub-plates 100 comprises the following steps:

[0110] S501. The arranged sub-plate 100 is placed into the cabin pressure press 70;

[0111] S502 . Before laminating the sub-board 100 , evacuate the sealing bag 30 .

[0112] The cabin pressure press 70 has a sealed cabin structure, which can pressurize and heat the cabin, so that the core boards 10 can be pressed together under high temperature and high pressure to form a finished PCB board. Before pressing the sub-board 100, vacuuming can further discharge the gas in the gap of the core board 10, avoiding the formation of voids and pits in the liquid resin 40 and the prepreg 20 during the curing process.

[0113] In some embodiments, after executing the above step S502, the following steps may also be included:

[0114] S503 . During the process of pressing the sub-plate 100 , the sealing bag 30 is evacuated.

[0115] By vacuuming during the pressing process, the volatile gas in the sub-board 100 can be extracted, thereby reducing the impact of the volatile gas on the quality of the core board 10 during the pressing process.

[0116] Optionally, the sealing bag 30 may be evacuated only before the sub-plate 100 is pressed, or the sealing bag 30 may be evacuated only during the pressing process of the sub-plate 100. Alternatively, in other examples, the sealing bag 30 may be evacuated both before and during the pressing process of the sub-plate 100, which is not limited in this example.

[0117] In some embodiments, after the step S500 of placing the inner bag 31 into the press 70 and pressing the arranged sub-boards 100, the method for manufacturing the PCB board further comprises the following steps:

[0118] S600 . Mill the edge of the sub-board 100 to remove the inner bag 31 .

[0119] The milling equipment can be used to mill off the peripheral structure of the pressed core board 10, including the inner bag 31 attached to the side of the sub-board 100 with the liquid resin 40, so as to obtain a finished PCB board. Optionally, the sub-board 100 can also be designed with edge materials reserved around it, and the edge materials can be milled off during the milling. At this time, the inner bag 31 attached to the surface of the edge materials can be removed together, and finally the finished PCB board is obtained.

[0120] Optionally, the aforementioned step S700 of removing the protective layer 12 can be performed after the step S600 of milling the edge of the daughter board 100 to remove the inner bag 31. In this way, the protective layer 12 can still be retained during the process of milling the edge of the daughter board 100 to provide continuous protection for the surface of the top daughter board 100 and the bottom daughter board 100, thereby avoiding damage to the daughter board 100 during the milling process. After the daughter board 100 is milled and the inner bag 31 is removed, the protective layer 12 on the surface of the daughter board 100 is finally removed to obtain the final PCB board product.

[0121] In some embodiments, please refer to Fig.13 The cabin pressure press 70 can be fed with inert gas during operation, and the inert gas does not react with the core plate 10, resin, etc. The inert gas can be pressurized and heated by the pressure pump 71 and the heating device 72, and after reaching the set pressure and temperature, it is fed into the cabin pressure press 70, which can further improve the pressing effect of the sub-plate 100 in a high temperature and high pressure environment.

[0122] Optionally, see Fig.13 , Fig.13The middle arrow shows the flow direction of the high-temperature and high-pressure inert gas, which can be introduced through the top, bottom, and peripheral side of the cabin pressure press 70 to form an airflow around the sealing bag 30 and the sub-plate 100 placed in the cabin pressure press 70, so that the sub-plate 100 is heated and pressurized more evenly during the pressing process, thereby improving the pressing quality of the sub-plate 100. The cabin pressure press 70 can also be provided with an exhaust device 73 connected to the cabin body for extracting the inert gas to control the air pressure in the cabin body.

[0123] In some embodiments, a buffer device 34 may be provided to be connected to the sealing bag 30. The buffer device 34 has the function of storing liquid. When the sealing bag 30 is evacuated before or during lamination, the waste liquid formed by cooling the volatile gas in the sealing bag 30 and the overflowing part of the resin in the sealing bag 30 after thermal expansion can be discharged into the buffer device 34, thereby preventing the volatile gas and the overflowing resin from affecting the lamination quality of the sub-board 100, and further improving the lamination effect of the sub-board 100.

[0124] As an alternative embodiment, the press 70 is not limited to a cabin pressure press 70, and other existing pressing equipment may be used to press the sub-plate 100, which is not limited here.

[0125] Second, see Fig.14 The present application also provides a PCB board 200, which is manufactured using the PCB board manufacturing method provided in the first aspect.

[0126] In the description of this specification, if the reference terms "one embodiment", "some examples", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" appear, it means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0127] The above describes the implementation methods of the present application in detail in conjunction with the accompanying drawings, but the present application is not limited to the above implementation methods. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present application.

[0128] In the description of this application, if "," appears in the patent name, it means an "and" relationship, not an "or" relationship. For example, if the patent name is "a kind of A, B", it means that the content required to be protected by this application is: the technical solution with the subject name A and the technical solution with the subject name B.

Claims

1. A method for manufacturing a PCB board, characterized in that: include Providing a sub-board, the sub-board comprising a core board and a prepreg; Prearranging the daughterboard; Putting the arranged sub-plates into a sealed bag; Vacuuming the sealing bag to allow the liquid resin to enter the sealing bag and fill the gaps between the sub-plates; The sealed bag is placed in a press and the arranged sub-boards are pressed.

2. The PCB manufacturing method according to claim 1, characterized in that: The gap between two adjacent core plates is formed by: A prepreg is stacked between two adjacent layers of the core boards.

3. The PCB manufacturing method according to claim 1, characterized in that: The sealing bag is a flexible sealing bag. Before the sealing bag is evacuated, the PCB board manufacturing method further includes: placing a flexible sealed bag into a pressure container; sealing the pressure vessel; The pressure vessel is evacuated.

4. The method for manufacturing a PCB board according to claim 3, characterized in that: The flexible sealing bag comprises an inner bag and an outer bag, wherein the outer bag is sleeved on the outer periphery of the inner bag, and evacuating the pressure container comprises: Evacuating the pressure container so that the outer bag fits the inner wall of the pressure container; After the pressure vessel is evacuated, the PCB manufacturing method further includes: The outer bag is evacuated to make the inner bag fit the inner wall of the pressure container; The inner bag is evacuated to make the air pressure in the inner bag reach a preset value.

5. The method for manufacturing a PCB board according to claim 4, characterized in that: Placing the sealed bag into a press and pressing the arranged sub-plates comprises: Inflating the outer bag to separate the inner bag from the outer bag; taking out the inner bag from the outer bag; The inner bag is placed in a press and the arranged sub-plates are pressed.

6. The method for manufacturing a PCB board according to claim 5, characterized in that: After the inner bag is placed in a press and the arranged sub-boards are pressed, the method for manufacturing the PCB board further includes: The sub-plate is milled to remove the inner pocket.

7. The method for manufacturing a PCB board according to claim 4, characterized in that: The liquid suction port of the inner bag is connected to an electric valve, and the inner bag is evacuated to make the air pressure in the inner bag reach a preset value, which includes: When the vacuum degree in the inner bag is higher than a preset value, the electric valve is closed; When the vacuum degree in the inner bag is reduced to a preset value, the electric valve is opened to allow liquid resin to enter the inner bag.

8. The method for manufacturing a PCB according to any one of claims 1 to 7, characterized in that: Placing the sealed bag into a press and pressing the arranged sub-plates comprises: placing the arranged sub-plates into a cabin pressure press; Before laminating the sub-panels and / or during laminating the sub-panels, the sealing bag is evacuated.

9. The method for manufacturing a PCB board according to any one of claims 1 to 7, characterized in that: Before pre-arranging the sub-board, the PCB board manufacturing method also includes Providing a protective layer on the top surface of the sub-board located at the top layer and the bottom surface of the sub-board located at the bottom layer; After the sealed bag is placed in a press and the arranged sub-boards are pressed, the PCB manufacturing method further comprises: The protective layer is removed.

10. A PCB board, characterized in that: The PCB is manufactured by the PCB manufacturing method as claimed in any one of claims 1 to 9.

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