A PCB containing a cavity and a manufacturing method thereof

Abstract

The present invention discloses a PCB containing a cavity and a manufacturing method thereof. The PCB containing a cavity comprises: a top core board, a bottom core board and at least one middle core board; the top core board comprises a first accommodating hole; the bottom core board comprises a second accommodating hole; the PCB containing a cavity further comprises a tripod column; the tripod column penetrates the first accommodating hole, the second accommodating hole, and the cavity of the PCB containing a cavity; the tripod column comprises a hollow column, and a copper column is arranged in the hollow column; the copper column is respectively connected to the copper layer of the top core board and the copper layer of the bottom core board. By adopting the above technical scheme, the tripod column with the copper column inside can support the cavity, so that the top of the cavity is not easy to collapse, which is conducive to the production of a larger cavity and a continuous cavity with multiple signal lines arranged side by side. The copper column can also play a certain shielding role and improve the signal crosstalk resistance between the signal lines; when the cavity expands due to heat, the tripod column with the copper column inside can play a pulling role to ensure that the cavity is heat-resistant and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of PCBs, and in particular to a cavity-containing PCB and a manufacturing method thereof. Background Art

[0002] As the communication electronics field gradually develops towards high frequency and high speed of signals, higher requirements are put forward for the low loss transmission of high frequency and high speed signals and impedance continuity of signal lines in PCB. In high-speed products, it is hoped that the dielectric constant and dielectric loss factor of materials will become lower and lower, but no matter how the material formula is improved, it is impossible to reduce the dielectric constant and dielectric loss factor of materials infinitely. Therefore, in 112G and 224G high-speed PCB applications, the reduction of dielectric loss has encountered a bottleneck.

[0003] PCBs with cavities have become one of the solutions for future high-speed PCBs because the dielectric constant and dielectric loss factor of air are much lower than those of conventional resin substrates of current PCBs. However, the existing cavity PCB manufacturing process still has some limitations: 1) When the cavity is designed to be large, the cavity expands due to heat, which can easily lead to delamination and explosion, resulting in poor reliability. 2) When multiple groups of circuits are designed in the same cavity or the cavity is designed to be wide, the top of the cavity is easily collapsed by other external forces, affecting the shape of the cavity.

[0004] Therefore, there is an urgent need to develop a cavity-containing PCB that can maintain the cavity shape of the PCB with a large cavity design and improve the reliability of the cavity. Summary of the invention

[0005] The present invention provides a cavity-containing PCB and a manufacturing method thereof, so as to solve the problem that the cavity design is large and easy to collapse, and the problem that the cavity is easy to expand when heated and has poor reliability.

[0006] According to one aspect of the present invention, a cavity-containing PCB is provided, comprising: a top core board, a bottom core board and at least one middle core board; the top core board comprises a first receiving hole; the bottom core board comprises a second receiving hole;

[0007] The cavity-containing PCB further includes a tripod column; the tripod column passes through the first accommodating hole, the second accommodating hole, and the cavity of the cavity-containing PCB;

[0008] The tripod pillars include hollow pillars, in which copper pillars are arranged; the copper pillars are respectively connected to the copper layer of the top core board and the copper layer of the bottom core board.

[0009] Optionally, the top core plate includes a first substrate groove; the bottom core plate includes a second substrate groove; the tripod column includes an upper part and a lower part; the upper part includes a first hollow column and a first protruding eaves, and the first hollow column is connected to the first protruding eaves; the lower part includes a second hollow column and a second protruding eaves, and the second hollow column is connected to the second protruding eaves;

[0010] The first protruding eaves are located in the first substrate groove; the second protruding eaves are located in the second substrate groove;

[0011] At least a portion of the first hollow column overlaps with the second hollow column; at least a portion of the outer surface of the first hollow column fits with the inner surface of the second hollow column.

[0012] Optionally, the first hollow column includes a protruding point extending from the inside to the outside; the second hollow column includes a designed hole;

[0013] The protruding point is engaged with the designed hole.

[0014] Optionally, the first eaves include a plurality of first openings; the second eaves include a plurality of second openings;

[0015] The first opening is provided with a first electroplated copper; the second opening is provided with a second electroplated copper; the first electroplated copper, the second electroplated copper and the copper column are an integrated structure.

[0016] Optionally, a waterproof structure is provided on the fitting surface between the outer surface of the first hollow column and the inner surface of the second hollow column.

[0017] Optionally, the tripod pillars include resin material.

[0018] According to another aspect of the present invention, there is provided a method for manufacturing a cavity-containing PCB, comprising:

[0019] Prepare a top core board, a bottom core board, an intermediate core board, a prepreg sheet and a tripod column; the tripod column comprises a hollow column;

[0020] Drilling a hole in the top core plate to form a first receiving hole; drilling a hole in the bottom core plate to form a second receiving hole;

[0021] A groove is formed in the middle core plate to form a first cavity opening; a groove is formed in the prepreg to form a second cavity opening;

[0022] The top core board, the bottom core board, the middle core board and the prepreg are stacked in sequence; the first cavity opening and the second cavity opening constitute the cavity of the cavity-containing PCB;

[0023] Inserting the tripod column; the tripod column passes through the first receiving hole, the second receiving hole, and the cavity of the cavity-containing PCB;

[0024] Pressing the top core board, the bottom core board, the middle core board and the prepreg at high temperature;

[0025] Copper is electroplated on the hollow column, the top core board and the bottom core board to form a copper column in the hollow column; the copper column is connected to the copper layer of the top core board and the copper layer of the bottom core board respectively.

[0026] Optionally, the tripod column includes an upper part and a lower part; the upper part includes a first hollow column and a first protruding eaves, and the first hollow column is connected to the first protruding eaves; the lower part includes a second hollow column and a second protruding eaves, and the second hollow column is connected to the second protruding eaves;

[0027] After drilling a hole in the top core plate to form a first receiving hole; after drilling a hole in the bottom core plate to form a second receiving hole, slotting the middle core plate to form a first cavity opening; before slotting the prepreg to form a second cavity opening, the method further includes:

[0028] Etching the top core board and the bottom core board to form a first substrate groove located on the surface of the top core board and a second substrate groove located on the surface of the bottom core board;

[0029] Inserting the tripod pillar comprises:

[0030] The lower component is inserted through the second receiving hole; the second protrusion is located in the second substrate groove; the upper component is inserted through the first receiving hole, and at least part of the outer surface of the first hollow column is in contact with the inner surface of the second hollow column; the first protrusion is located in the first substrate groove.

[0031] The first eaves include a plurality of first openings; the second eaves include a plurality of second openings;

[0032] Electroplating copper in the hollow column, the top core board and the bottom core board to form a copper column in the hollow column includes:

[0033] Copper is electroplated on the hollow column, the first opening and the second opening to form a copper column in the hollow column, a first electroplated copper is formed in the first opening, and a second electroplated copper is formed in the second opening; the first electroplated copper, the second electroplated copper and the copper column are an integrated structure.

[0034] Optionally, the top core board, the bottom core board, the middle core board and the prepreg are pressed at high temperature, including:

[0035] The top core board, the bottom core board, the middle core board and the prepreg are pressed together at high temperature, and the air in the cavity is simultaneously extracted.

[0036] The technical solution of the present invention is to set a tripod column with a copper column in the cavity, the tripod column passes through the first accommodating hole, the second accommodating hole, and the cavity, and the copper column is respectively connected to the copper layer of the top core board and the copper layer of the bottom core board. On the one hand, it supports the cavity so that the top of the cavity is not easy to collapse, which is conducive to the production of a larger cavity and a continuous cavity with multiple signal lines in side by side. The height of the cavity can be kept constant to ensure the impedance stability of the signal line. The copper column can also play a certain shielding role, improve the signal crosstalk resistance between the signal lines, and is conducive to the transmission of the signal in the cavity, thereby improving the integrity of the signal; on the other hand, the top core board and the bottom core board can be pulled. When the cavity expands due to heat, the tripod column with the copper column can play a pulling role to ensure that the cavity is heat-resistant and reliable.

[0037] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 It is a schematic structural diagram of a PCB containing a cavity provided by an embodiment of the present invention;

[0040] Figure 2 is along Figure 1 A schematic diagram of a cross-sectional structure of the A-A' section;

[0041] Figure 3 It is a schematic structural diagram of another type of PCB with a cavity provided by an embodiment of the present invention;

[0042] Figure 4 It is a structural schematic diagram of a tripod column provided by an embodiment of the present invention;

[0043] Figure 5 is a structural schematic diagram of an upper component provided by an embodiment of the present invention;

[0044] Figure 6 is a structural schematic diagram of a lower component provided by an embodiment of the present invention;

[0045] Figure 7It is a schematic structural diagram of another type of PCB with a cavity provided by an embodiment of the present invention;

[0046] Figure 8 is a structural schematic diagram of a first protruding eave provided by an embodiment of the present invention;

[0047] Fig. 9 is a structural schematic diagram of a second protruding eave provided by an embodiment of the present invention;

[0048] Fig.10 This is another schematic diagram of a PCB structure containing a cavity provided by an embodiment of the present invention;

[0049] Fig.11 It is a flow chart of a method for manufacturing a cavity-containing PCB provided by an embodiment of the present invention;

[0050] Fig.12 It is a flow chart of another method for manufacturing a PCB containing a cavity provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0052] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0053] Figure 1 is a schematic structural diagram of a cavity-containing PCB provided by an embodiment of the present invention, Figure 2 is along Figure 1 A schematic diagram of a cross-sectional structure of the A-A' section. Figure 1 and Figure 2The cavity-containing PCB includes a top core board 10, a bottom core board 20 and at least one middle core board 30, and the top core board 10, the bottom core board 20 and the middle core board 30 are bonded and fixed by a prepreg 40. The top core board 10 includes a first receiving hole 11; the bottom core board includes a second receiving hole 21; the cavity-containing PCB also includes a tripod column 50; the tripod column 50 passes through the first receiving hole 11, the second receiving hole 21, and the cavity 80 of the cavity-containing PCB. The tripod column 50 includes a hollow column 60, and a copper column 06 is arranged in the hollow column 60; the copper column 06 is respectively connected to the copper layer 101 of the top core board 10 and the copper layer 201 of the bottom core board 20.

[0054] Specifically, the hollow column 60 of the tripod column 50 can enter the cavity 80 through the first accommodating hole 11 and / or the second accommodating hole 21, and the hollow column 60 can be used as a channel connecting the top core board 10 and the bottom core board 20, and the copper column 06 can be formed by electroplating in the channel. The copper column 06 is combined with the copper layer 101 of the top core board 10 and the copper layer 201 of the bottom core board 20 into a whole, and the copper column 06 can be connected and fixed in the cavity of the cavity-containing PCB, and the copper column 06 can also be prevented from falling. The copper column 06 has a certain rigidity and can well support and fix the cavity 80.

[0055] For example, continue to refer to Figure 1 and Figure 2 , a signal line 110 is arranged inside the cavity 80, and the signal line 110 can transmit high-frequency and high-speed signals. The high-frequency electromagnetic field around the signal line 110 will partially propagate in the air, which will reduce the dielectric constant and dielectric loss factor of the medium felt by the signal during the copper wire transmission process, thereby achieving the effect of increasing the signal transmission speed and reducing the dielectric loss during the transmission process. The copper column 06 arranged in the tripod column 50 can be a solid copper column, which can better support the cavity 80, and can also connect the copper column 06 to an electrical signal with a fixed potential, which can shield at least part of the signals between adjacent signal lines and prevent the signals of adjacent signal lines from interfering with each other.

[0056] In the embodiment of the present invention, a tripod column with a copper column inside is arranged in the cavity, the tripod column passes through the first accommodating hole, the second accommodating hole, and the cavity, and the copper column is respectively connected to the copper layer of the top core board and the copper layer of the bottom core board. On the one hand, it supports the cavity so that the top of the cavity is not easy to collapse, which is conducive to the production of a larger cavity and a continuous cavity with multiple signal lines in side by side, and can keep the height of the cavity constant to ensure the impedance stability of the signal line. The copper column can also play a certain shielding role, improve the signal anti-crosstalk ability between the signal lines, and is conducive to the transmission of the signal in the cavity, thereby improving the integrity of the signal; on the other hand, the top core board and the bottom core board can be pulled. When the cavity expands due to heat, the tripod column with the copper column inside can play a pulling role to ensure that the cavity is heat-resistant and reliable.

[0057] In an optional embodiment, the copper layer 101 connected to the copper pillar 06 can be used as a part of the circuit pattern of the top core board 10, and the copper layer 201 connected to the copper pillar 06 can be used as a part of the circuit pattern of the bottom core board 20. The copper pillar 06 can connect the circuit pattern of the top core board 10 and the circuit pattern of the bottom core board 20. In this way, the through holes of the cavity-containing PCB can be reduced, which is conducive to increasing the size of the cavity 80, and can also simplify the process and improve production efficiency.

[0058] In an optional embodiment, the tripod pillar 50 includes a resin material that is resistant to high temperatures and has certain rigidity, elasticity, and chemical stability, such as a polytetrafluoroethylene material.

[0059] Optional, Figure 3 is a schematic diagram of the structure of another type of PCB with a cavity provided by an embodiment of the present invention. Figure 4 Schematic diagram of the structure of a tripod column provided by an embodiment of the present invention. Figure 3 and Figure 4 , the top core plate 10 includes a first substrate groove 12; the bottom core plate includes a second substrate groove 22; the tripod column 50 includes an upper part 51 and a lower part 52; the upper part includes a first hollow column 61 and a first protrusion 72, and the first hollow column 61 is connected to the first protrusion 62; the lower part 52 includes a second hollow column 62 and a second protrusion 72, and the second hollow column 62 is connected to the second protrusion 72. The first protrusion 71 is located in the first substrate groove 12; the second protrusion 72 is located in the second substrate groove 22; at least part of the first hollow column 61 overlaps with the second hollow column 62; at least part of the outer surface of the first hollow column 61 is in contact with the inner surface of the second hollow column 62.

[0060] Exemplary, reference Figure 3 and Figure 4 The outer diameter of the first hollow column 61 can be equal to the inner diameter of the second hollow column 62, the first hollow column 61 and the second hollow column 62 can be partially nested and fitted, the first protrusion 71 can be inserted into the first substrate groove 12, the second protrusion 72 can be inserted into the second substrate groove 22, the upper component 51 can be inserted into the cavity 80 through the first accommodating hole 11, and the lower component 52 can be inserted into the cavity 80 through the second accommodating hole 21, and the upper component 51 and the lower component 52 can be connected by the nesting and fitting of the first hollow column 61 and the second hollow column 62. The first hollow column 61 and the second hollow column 62 have an overlapping area, which can make the channel formed by the first hollow column 61 and the second hollow column 62 airtight, which is conducive to electroplating copper in the channel; the first protrusion 71 is inserted into the first substrate groove 12, and the second protrusion 72 is inserted into the second substrate groove 22, which is conducive to fixing the tripod column 50 and preventing the tripod column 50 from shifting and falling off during the process of electroplating copper to form the copper column 06.

[0061] In an optional embodiment, the outer surfaces of the first hollow column 61 and the second hollow column 62 and the overlapping contact surfaces may be waterproofed. For example, a waterproof coating may be applied to the fitting area of ​​the first hollow column 61 and the second hollow column 62 to prevent chemical copper and other chemicals from seeping out during the copper electroplating process and damaging the signal line 110 in the cavity 80.

[0062] Optional, Figure 5 is a schematic structural diagram of an upper component provided by an embodiment of the present invention, Figure 6 Schematic diagram of the structure of a lower component provided by an embodiment of the present invention. Figure 5 and Figure 6 The first hollow column 61 includes a protruding point 601 extending from the inside to the outside; the second hollow column 62 includes a designed hole 602, and the protruding point 601 engages with the designed hole 602. Figure 7 As shown. In this way, the first hollow column 61 and the second hollow column 62 can be closely matched to ensure that the tripod column 50 is stable and does not loosen. The tripod column 50 is made of resin material, and the resin has a certain elasticity, which can ensure the airtightness of the channel formed by the first hollow column 61 and the second hollow column 62.

[0063] Optional, Figure 8 is a schematic structural diagram of a first protruding eave provided by an embodiment of the present invention, Fig. 9 is a schematic structural diagram of a second protruding eave provided by an embodiment of the present invention, Fig.10 This is another schematic diagram of a PCB structure containing a cavity provided by an embodiment of the present invention, referring to Figure 5-10 The first protruding eaves 71 include a plurality of first openings 701; the second protruding eaves 72 include a plurality of second openings 702. The first electroplated copper 91 is disposed in the first opening 701; the second electroplated copper 92 is disposed in the second opening 702; the first electroplated copper 91, the second electroplated copper 92 and the copper column 06 are an integrated structure, as shown in FIG. Fig.10 In this way, the connection between the copper pillar 06 and the top core board 10 and the bottom core board 20 can be further increased, ensuring that the copper pillar 06 is not easy to fall off.

[0064] The embodiment of the present invention further provides a method for manufacturing a PCB containing a cavity, which is used to manufacture the PCB containing a cavity provided in the embodiment of the present invention. Fig.11 1 is a flow chart of a method for manufacturing a cavity-containing PCB provided by an embodiment of the present invention. Fig.11 , the preparation method comprises:

[0065] S1001. Prepare a top core board, a bottom core board, an intermediate core board, a prepreg sheet and a tripod column; the tripod column includes a hollow column.

[0066] Among them, the prepared top core board, bottom core board, and middle core board are core boards on which the inner layer circuit patterns have been prepared.

[0067] S1002, drilling a hole in the top core board to form a first receiving hole; drilling a hole in the bottom core board to form a second receiving hole.

[0068] Specifically, holes can be drilled at positions corresponding to the tripod columns of the top core plate and the bottom core plate, and the sizes of the first accommodating hole and the second accommodating hole correspond to the outer diameters of the two ends of the hollow column of the tripod column.

[0069] S1003, slotting the middle core plate to form a first cavity opening; slotting the prepreg to form a second cavity opening;

[0070] Specifically, grooves are formed at positions of the middle core plate and the prepreg corresponding to the cavities.

[0071] S1004, stacking the top core board, the bottom core board, the middle core board and the prepreg in order; the first cavity opening and the second cavity opening constitute a cavity containing the cavity PCB.

[0072] S1005, inserting a tripod column; the tripod column passes through the first receiving hole, the second receiving hole, and the cavity containing the cavity PCB.

[0073] Exemplarily, two ends of the hollow column of the tripod column are respectively clamped in the first receiving hole and the second receiving hole to connect the top core plate and the bottom core plate.

[0074] S1006, high temperature pressing of the top core board, bottom core board, middle core board and prepreg.

[0075] S1007, electroplating copper on the hollow column, the top core board and the bottom core board to form a copper column in the hollow column; the copper column is respectively connected to the copper layer of the top core board and the copper layer of the bottom core board.

[0076] Exemplarily, a solid copper column is electroplated in a hollow column, and an entire layer of copper is electroplated on the outer surface of the top core board and the bottom core board, and then the entire layer of copper on the outer surface of the top core board and the bottom core board is patterned to obtain the outer layer circuit pattern of the top core board and the outer layer circuit pattern of the bottom core board.

[0077] In the embodiment of the present invention, a tripod column with a copper column inside is arranged in the cavity, the tripod column passes through the first accommodating hole, the second accommodating hole, and the cavity, and the copper column is respectively connected to the copper layer of the top core board and the copper layer of the bottom core board. On the one hand, it supports the cavity so that the top of the cavity is not easy to collapse, which is conducive to the production of a larger cavity and a continuous cavity with multiple signal lines in side by side, and can keep the height of the cavity constant to ensure the impedance stability of the signal line. The copper column can also play a certain shielding role, improve the signal anti-crosstalk ability between the signal lines, and is conducive to the transmission of the signal in the cavity, thereby improving the integrity of the signal; on the other hand, the top core board and the bottom core board can be pulled. When the cavity expands due to heat, the tripod column with the copper column inside can play a pulling role to ensure that the cavity is heat-resistant and reliable.

[0078] Optionally, the tripod column includes an upper part and a lower part, the upper part includes a first hollow column and a first protruding eaves, the first hollow column is connected to the first protruding eaves, the lower part includes a second hollow column and a second protruding eaves, the second hollow column is connected to the second protruding eaves, Fig.12 FIG. 1 is a flow chart of another method for manufacturing a cavity-containing PCB provided by an embodiment of the present invention. Fig.12 , the preparation method comprises:

[0079] S2001, prepare the top core board, the bottom core board, the middle core board, the prepreg sheet and the tripod column; the tripod column includes a hollow column;

[0080] S2002, drilling a hole in the top core board to form a first receiving hole; drilling a hole in the bottom core board to form a second receiving hole.

[0081] S2003, etching the top core board and the bottom core board to form a first substrate groove located on the surface of the top core board and a second substrate groove located on the surface of the bottom core board.

[0082] S2004, slotting the middle core plate to form a first cavity opening; slotting the prepreg to form a second cavity opening;

[0083] S2005, stacking the top core board, the bottom core board, the middle core board and the prepreg in sequence; the first cavity opening and the second cavity opening constitute a cavity containing the cavity PCB.

[0084] S2006, insert the lower component through the second receiving hole; the second protrusion is located in the second substrate groove; insert the upper component through the first receiving hole, and at least part of the outer surface of the first hollow column is in contact with the inner surface of the second hollow column; the first protrusion is located in the first substrate groove; the tripod column passes through the first receiving hole, the second receiving hole, and the cavity containing the cavity PCB.

[0085] S2007, high temperature pressing of top core board, bottom core board, middle core board and prepreg.

[0086] S2008, electroplating copper on the hollow column, the top core board and the bottom core board to form a copper column in the hollow column; the copper column is respectively connected to the copper layer of the top core board and the copper layer of the bottom core board.

[0087] Exemplarily, the outer diameter of the first hollow column can be equal to the inner diameter of the second hollow column, the first hollow column and the second hollow column can be partially nested and fitted, the first protrusion can be inserted into the first substrate groove, the second protrusion can be inserted into the second substrate groove, and the upper part and the lower part can be connected by the first hollow column and the second hollow column being nested and fitted. The first hollow column and the second hollow column 62 have an overlapping area, which can make the channel formed by the first hollow column and the second hollow column airtight, which is conducive to electroplating copper in the channel; the first protrusion is inserted into the first substrate groove, and the second protrusion is inserted into the second substrate groove, which is conducive to fixing the tripod column and preventing the tripod column from shifting or falling off during the process of electroplating copper to form a copper column.

[0088] Optionally, the first protrusion includes a plurality of first openings; the second protrusion includes a plurality of second openings; copper is electroplated in the hollow column, the top core board and the bottom core board, and a copper column is formed in the hollow column, including: electroplating copper in the hollow column, the first opening and the second opening, forming a copper column in the hollow column, forming a first electroplated copper in the first opening, and forming a second electroplated copper in the second opening; the first electroplated copper, the second electroplated copper and the copper column are an integrated structure. In this way, the connection between the copper column and the top core board and the bottom core board can be further increased to ensure that the copper column is not easy to fall off.

[0089] Optionally, high-temperature pressing of the top core board, the bottom core board, the middle core board and the semi-cured sheet includes: high-temperature pressing of the top core board, the bottom core board, the middle core board and the semi-cured sheet, and simultaneously extracting the air in the cavity.

[0090] Specifically, during the high-temperature pressing process, vacuuming can make the cavity a vacuum environment, which is conducive to fixing the tripod column and making the upper and lower parts fit tightly. In addition, the dielectric constant and dielectric loss factor of the vacuum are smaller than those of air, which can further reduce dielectric loss and improve the integrity of signal transmission.

[0091] The method for manufacturing a PCB with a cavity provided in an embodiment of the present invention is used to prepare a PCB with a cavity provided in any embodiment of the present invention, and has corresponding technical features and beneficial effects of a PCB with a cavity. For contents not fully described in the embodiment of the method for manufacturing a PCB with a cavity, reference can be made to the above description of the PCB with a cavity, and will not be repeated here. Similarly, the PCB with a cavity provided in an embodiment of the present invention also has functional modules and beneficial effects capable of executing the method for manufacturing a PCB with a cavity provided in an embodiment of the present invention. For contents not fully described in the embodiment of the PCB with a cavity, reference can be made to the above description of the method for manufacturing a PCB with a cavity, and will not be repeated here.

[0092] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A cavity-containing PCB, characterized in that: include: A top core plate, a bottom core plate and at least one middle core plate; the top core plate comprises a first receiving hole; the bottom core plate comprises a second receiving hole; The cavity-containing PCB further comprises a tripod column; the tripod column passes through the first accommodating hole, the second accommodating hole, and the cavity of the cavity-containing PCB; The tripod pillars include hollow pillars, and copper pillars are arranged inside the hollow pillars; the copper pillars are respectively connected to the copper layer of the top core board and the copper layer of the bottom core board; The top core plate includes a first substrate groove; the bottom core plate includes a second substrate groove; the tripod column includes an upper part and a lower part; the upper part includes a first hollow column and a first protruding eaves, and the first hollow column is connected to the first protruding eaves; the lower part includes a second hollow column and a second protruding eaves, and the second hollow column is connected to the second protruding eaves; The first protrusion is located in the first substrate groove; The second protrusion is located in the second substrate groove; At least a portion of the first hollow column overlaps with the second hollow column; at least a portion of the outer surface of the first hollow column fits with the inner surface of the second hollow column.

2. The cavity-containing PCB according to claim 1, characterized in that: The first hollow column includes a protruding point extending from the inside to the outside; the second hollow column includes a designed hole; The protruding point is engaged with the designed hole.

3. The cavity-containing PCB according to claim 1, characterized in that: The first eaves include a plurality of first openings; the second eaves include a plurality of second openings; The first opening is provided with a first electroplated copper; the second opening is provided with a second electroplated copper; the first electroplated copper, the second electroplated copper and the copper column are an integrated structure.

4. The cavity-containing PCB according to claim 1, characterized in that: A waterproof structure is provided on the fitting surface between the outer surface of the first hollow column and the inner surface of the second hollow column.

5. The cavity-containing PCB according to claim 1, characterized in that: The tripod pillars include resin material.

6. A method for manufacturing a cavity-containing PCB, characterized in that: include: Prepare a top core board, a bottom core board, an intermediate core board, a prepreg sheet and a tripod column; the tripod column comprises a hollow column; Drilling a hole in the top core plate to form a first receiving hole; Drilling a hole in the bottom core plate to form a second receiving hole; A groove is formed in the middle core plate to form a first cavity opening; a groove is formed in the prepreg to form a second cavity opening; The top core board, the bottom core board, the middle core board and the prepreg are stacked in sequence; the first cavity opening and the second cavity opening constitute the cavity of the cavity-containing PCB; Inserting the tripod column; the tripod column passes through the first receiving hole, the second receiving hole, and the cavity of the cavity-containing PCB; Pressing the top core board, the bottom core board, the middle core board and the prepreg at high temperature; Copper is electroplated on the hollow column, the top core board and the bottom core board to form a copper column in the hollow column; the copper column is connected to the copper layer of the top core board and the copper layer of the bottom core board respectively.

7. The method for manufacturing a cavity-containing PCB according to claim 6, characterized in that: The tripod column comprises an upper part and a lower part; the upper part comprises a first hollow column and a first protruding eaves, and the first hollow column is connected to the first protruding eaves; the lower part comprises a second hollow column and a second protruding eaves, and the second hollow column is connected to the second protruding eaves; Drilling a hole in the top core plate to form a first receiving hole; drilling a hole in the bottom core plate to form a second receiving hole, and then slotting the middle core plate to form a first cavity opening; Before the prepreg is grooved to form the second cavity opening, the method further comprises: Etching the top core board and the bottom core board to form a first substrate groove located on the surface of the top core board and a second substrate groove located on the surface of the bottom core board; Inserting the tripod pillar comprises: The lower component is inserted through the second receiving hole; the second protrusion is located in the second substrate groove; the upper component is inserted through the first receiving hole, and at least part of the outer surface of the first hollow column is in contact with the inner surface of the second hollow column; the first protrusion is located in the first substrate groove.

8. The method for manufacturing a cavity-containing PCB according to claim 7, characterized in that: The first eaves include a plurality of first openings; the second eaves include a plurality of second openings; Electroplating copper in the hollow column, the top core board and the bottom core board to form a copper column in the hollow column includes: Copper is electroplated on the hollow column, the first opening and the second opening to form a copper column in the hollow column, a first electroplated copper is formed in the first opening, and a second electroplated copper is formed in the second opening; the first electroplated copper, the second electroplated copper and the copper column are an integrated structure.

9. The method for manufacturing a cavity-containing PCB according to claim 7, characterized in that: The top core board, the bottom core board, the middle core board and the prepreg are pressed together at high temperature, including: The top core board, the bottom core board, the middle core board and the prepreg are pressed together at high temperature, and the air in the cavity is simultaneously extracted.

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