Embedded circuit board and manufacturing method thereof

Abstract

The invention discloses an embedded circuit board and a manufacturing method thereof. The embedded circuit board comprises a first circuit substrate, an inner layer circuit substrate and a second circuit substrate which are stacked in sequence, the first circuit substrate comprises a first base material layer and a first circuit layer, and a high-frequency transmission circuit layer is arranged on the surface, away from the first circuit layer, of the first base material layer; the second circuit substrate comprises an electromagnetic shielding body; the inner layer circuit substrate is provided with a through groove, the position of the electromagnetic shielding body corresponds to that of the through groove, the through groove, the first circuit substrate and the second circuit substrate enclose to form a mounting groove, and the high-frequency transmission circuit layer is located on the bottom surface of the mounting groove. The embedded circuit board further comprises a first electronic component and a second electronic component, and the first electronic component and the second electronic component are contained in the mounting groove and arranged on the two opposite sides of the high-frequency transmission line layer.

Description

Technical Field

[0001] This application relates to the field of circuit boards, and more particularly to an embedded circuit board and a method for manufacturing the same. Background Technology

[0002] High-frequency, high-speed printed circuit boards (PCBs) face challenges in signal transmission integrity. Signals are prone to reflection and crosstalk during transmission, and the higher the frequency and the faster the transmission rate, the more severe the signal loss. Therefore, preventing electromagnetic interference is crucial in the design of high-frequency circuits, as high-frequency signals can easily radiate and influence surrounding electronic devices, causing performance degradation and signal distortion. Furthermore, the rapid miniaturization and multifunctionality of electronic products necessitate minimizing the number of discrete components and the size of the PCB while simultaneously increasing functionality and reliability. Summary of the Invention

[0003] In view of this, this application provides an embedded circuit board that can solve the above-mentioned technical problems and a method for manufacturing the same.

[0004] This application provides an embedded circuit board, comprising a first circuit board, an inner circuit board, and a second circuit board stacked sequentially. The first circuit board includes a first substrate layer and a first circuit layer. A high-frequency transmission line layer is provided on the surface of the first substrate layer opposite to the first circuit layer. The second circuit board includes an electromagnetic shield. The inner circuit board is located between the first circuit board and the second circuit board. The inner circuit board has a through slot. The electromagnetic shield is positioned corresponding to the through slot. The through slot, the first circuit board, and the second circuit board surround each other to form a mounting slot. The high-frequency transmission line layer is located on the bottom surface of the mounting slot. The embedded circuit board further includes at least one first electronic component and at least one second electronic component. The first electronic component is housed in the mounting slot and electrically connected to the inner circuit board. The second electronic component is housed in the mounting slot and electrically connected to the inner circuit board. The first electronic component and the second electronic component are disposed on opposite sides of the high-frequency transmission line layer.

[0005] In some embodiments, the mounting groove further includes a first sidewall and a second sidewall disposed opposite to the bottom surface, the first electronic component is mounted on the first sidewall, the second electronic component is mounted on the second sidewall, and the second circuit board is pressed to the inner circuit board by an adhesive layer, the adhesive layer fixing the first electronic component to the first sidewall and the adhesive layer fixing the second electronic component to the second sidewall.

[0006] In some embodiments, the first electronic component includes a first electrode and a first component body, the first electrode being electrically connected to the inner circuit board, and the surface of the first component body exposed in the mounting groove being covered with a thermally conductive and microwave-absorbing material layer; the second electronic component includes a second electrode and a second component body, the second electrode being electrically connected to the inner circuit board, and the surface of the second component body exposed in the mounting groove being covered with a thermally conductive and microwave-absorbing material layer.

[0007] In some embodiments, the embedded circuit board further includes a first thermally conductive adhesive and a second thermally conductive adhesive. The first thermally conductive adhesive is disposed between the first electronic component and the first circuit board and between the second electronic component and the first circuit board. The first thermally conductive adhesive is located at the bottom of the through slot and is arranged on opposite sides of the high-frequency transmission line layer. The second thermally conductive adhesive is disposed on the side of the first electronic component and the second electronic component away from the first thermally conductive adhesive and covers the surface of the thermally conductive and wave-absorbing material layer opposite to the first thermally conductive adhesive.

[0008] In some embodiments, the second circuit board further includes a second circuit layer and a first conductive structure, the electromagnetic shield is located on one side of the second circuit layer, the first conductive structure is located on the surface of the electromagnetic shield away from the second circuit layer, and the first conductive structure is connected to the second thermally conductive adhesive; the first circuit board is provided with a second conductive structure, the second conductive structure penetrates the first substrate layer and the first circuit layer and is connected to the first thermally conductive adhesive.

[0009] In some embodiments, a first pad is provided on the surface of the first circuit layer opposite to the first substrate layer, and the first pad is electrically connected to the first circuit layer and the second conductive structure.

[0010] In some embodiments, the second circuit layer has a second pad on the surface opposite to the electromagnetic shield, and the second pad is electrically connected to the second circuit layer, the electromagnetic shield, and the first conductive structure.

[0011] A second aspect of this application provides a method for manufacturing an embedded circuit board, comprising the following steps:

[0012] A first circuit board is provided, wherein a high-frequency transmission line layer is provided on the surface of the first circuit board;

[0013] A second circuit board is provided, the second circuit board including an electromagnetic shield;

[0014] An inner circuit board is provided, the inner circuit board is located between the first circuit board and the second circuit board, the inner circuit board is provided with a through slot, and the position of the electromagnetic shield corresponds to the through slot.

[0015] The first circuit board, the second circuit board, and the inner circuit board are stacked sequentially. The through slot surrounds the first circuit board and the second circuit board to form a mounting slot. The high-frequency transmission line layer is located on the bottom surface of the mounting slot.

[0016] At least one first electronic component and at least one second electronic component are housed in the mounting slot. The first electronic component and the second electronic component are electrically connected to the inner circuit board. The first electronic component and the second electronic component are disposed on opposite sides of the high-frequency transmission line layer.

[0017] In some embodiments, the first electronic component includes a first electrode and a first component body, the first electrode being electrically connected to the inner circuit board, and the surface of the first component body exposed in the mounting groove being covered with a thermally conductive and microwave-absorbing material layer.

[0018] In some embodiments, the second electronic component includes a second electrode and a second component body, the second electrode being electrically connected to the inner circuit board, and the second component body being exposed on the surface of the mounting groove and covered with a thermally conductive and microwave-absorbing material layer.

[0019] In the embedded circuit board provided in this application, the second circuit board is provided with an electromagnetic shield. The high-frequency transmission line layer is located in the space enclosed by the first circuit board, the second circuit board, the inner circuit board, the first electronic component, and the second electronic component, forming an electromagnetic shield to prevent electromagnetic interference. There is no need to set up an additional side electromagnetic shielding structure, which can reduce the overall size of the product and conform to the trend of thinness. Attached Figure Description

[0020] Figure 1 This is a cross-sectional schematic diagram of a first substrate provided in one embodiment of this application.

[0021] Figure 2 In order to be in Figure 1 A cross-sectional schematic diagram of a high-frequency transmission line layer formed on the first substrate is shown.

[0022] Figure 3 In order to be in Figure 2 A cross-sectional schematic diagram of the first adhesive layer and the inner circuit board laminated on the structure shown.

[0023] Figure 4 In order to be in Figure 3 The diagram shows a cross-sectional view highlighting the first and second line layers based on the structure shown.

[0024] Figure 5 In order to be in Figure 4 A cross-sectional schematic diagram of the first thermally conductive adhesive applied to the structure shown.

[0025] Figure 6 In order to be in Figure 5 A cross-sectional schematic diagram showing the installation of the first and second electronic components on the structure shown.

[0026] Figure 7 In order to be in Figure 6 A cross-sectional schematic diagram of the second thermally conductive adhesive formed on the structure shown.

[0027] Figure 8 In order to be in Figure 7 A cross-sectional schematic diagram of a fourth adhesive layer and a second circuit board bonded together on the structure shown.

[0028] Figures 9A to 9D This is a cross-sectional schematic diagram of a second circuit board prepared according to an embodiment of this application.

[0029] Figure 10 In order to be in Figure 8 The diagram shows a cross-sectional view of the fourth and fifth line layers formed based on the structure shown.

[0030] Figure 11 In order to be in Figure 10 The diagram shows cross-sectional views of the fourth and fifth conductive structures formed based on the structure shown.

[0031] Figure 12 In order to be in Figure 11 A cross-sectional diagram showing a through hole formed on the structure shown.

[0032] Figure 13 In order to be in Figure 12 A cross-sectional schematic diagram showing the formation of the first and second anti-weld layers based on the structure shown.

[0033] Figure 14 This is a cross-sectional schematic diagram of an embedded circuit board provided in one embodiment of this application.

[0034] Explanation of main component symbols

[0035]

[0036]

[0037]

[0038]

[0039] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0040] To better understand the above-mentioned objectives, features, and advantages of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the features in the embodiments of this application can be combined with each other.

[0041] The following description sets forth numerous specific details to provide a thorough understanding of the embodiments of the present invention. The described embodiments are only a part of, and not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the embodiments of the present invention.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the invention pertain. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the invention.

[0043] Please see Figures 1 to 14 This application provides a method for manufacturing an embedded circuit board 100, comprising the following steps:

[0044] S1: Please refer to Figure 1 A first substrate 10 is provided, the first substrate 10 including a first substrate layer 11 and a metal layer disposed on at least one side of the first substrate layer 11. In this embodiment, the first substrate 10 includes a substrate layer and a first metal layer 12 and a second metal layer 13 disposed on opposite sides of the first substrate layer 11, the first metal layer 12 and the second metal layer 13 being made of copper. That is, the first substrate 10 is a double-sided copper-clad laminate.

[0045] S2: Please refer to Figure 2 The first metal layer 12 is etched, and a high-frequency transmission line layer 14 is formed on the surface of the first substrate layer 11 opposite to the second metal layer 13. This yields the first circuit board 20.

[0046] S3: Please refer to Figure 3 The inner layer circuit board 30 is pressed onto the surface of the first substrate layer 11 away from the second metal layer 13 by the first adhesive layer 21, and the inner layer circuit board 30 covers the surface of the first adhesive layer 21 away from the first substrate layer 11.

[0047] In this embodiment, the inner layer circuit board 30 includes a first inner layer circuit board 31, a second inner layer circuit board 32, and a third inner layer circuit board 33. The inner layer circuit board 30 is provided with a through slot 34, which penetrates the first inner layer circuit board 31, the second inner layer circuit board 32, and the third inner layer circuit board 33. The high-frequency transmission line layer 14 and a portion of the first substrate layer 11 are exposed through the through slot 34.

[0048] The first inner layer circuit board 31 includes a first inner layer circuit 311 and a first base layer 312, with the first base layer 312 located on the surface of the first inner layer circuit 311 facing away from the first adhesive layer 21. The second inner layer circuit board 32 includes a second inner layer circuit 321 and a second base layer 322. The second inner layer circuit board 32 is pressed against the first inner layer circuit board 31 via a second adhesive layer 22, with the second inner layer circuit board 32 located on the surface of the second adhesive layer 22 facing away from the first base layer 312, and the second inner layer circuit 321 located on opposite sides of the second base layer 322. The second inner layer circuit board 32 and the first inner layer circuit board 31 are electrically connected via a first conductive structure 41. The third inner layer circuit board 33 includes a third inner layer circuit 331 and a third base layer 332. The third inner layer circuit board 33 is pressed against the second inner layer circuit board 32 via a third adhesive layer 23, with the third inner layer circuit 331 located on the surface of the third adhesive layer 23 facing away from the second inner layer circuit 321, and the third inner layer circuit 331 located on the surface of the third base layer 332 facing away from the third adhesive layer 23. The third inner layer circuit board 33 and the second inner layer circuit board 32 are electrically connected through the second conductive structure 42.

[0049] S4: Please refer to Figure 4 Parts of the first adhesive layer 21, second adhesive layer 22, third adhesive layer 23, first base layer 312, second base layer 322, and third base layer 332 are removed, so that the first inner layer circuit 311 and the second inner layer circuit 321 protrude from the surface of the through groove 34 relative to the surface of the first adhesive layer 21, second adhesive layer 22, third adhesive layer 23, first base layer 312, second base layer 322, and third base layer 332 exposed on the surface of the through groove 34. That is, the protruding portions of the first inner layer circuit 311 and the second inner layer circuit 321 serve as connection ports for subsequent connection to electrodes of electronic components.

[0050] S5: Please refer to Figure 5 A first thermally conductive adhesive 51 is formed on the surface of the first substrate layer 11 opposite to the second metal layer 13, and the first thermally conductive adhesive 51 is located at the bottom of the through groove 34. In this embodiment, the first thermally conductive adhesive 51 is arranged on opposite sides of the high-frequency transmission line layer 14, and there are a plurality of first thermally conductive adhesive 51 on each side. The number of first thermally conductive adhesive 51 corresponds to the number of electronic components subsequently installed.

[0051] S6: Please refer to Figure 6A first electronic component 601 and a second electronic component 602 are mounted on the surface of the first thermally conductive adhesive 51 facing away from the first substrate layer 11. The first electronic component 601 and the second electronic component 602 are disposed on opposite sides of the high-frequency transmission line layer 14. The first electronic component 601 includes a first electrode (not shown) and a first component body 611. The first electrode of the first electronic component 601 is electrically connected to the first inner layer circuit 311 and the second inner layer circuit 321. The surface of the first component body 611 exposed in the through groove 34 is covered with a thermally conductive and wave-absorbing material layer 62, and the surface of the first component body 611 facing the first thermally conductive adhesive 51 is also covered with a thermally conductive and wave-absorbing material layer 62. The second electronic component 602 includes a second electrode (not shown) and a second component body 612. The second electrode of the second electronic component 602 is electrically connected to the first inner layer circuit 311 and the second inner layer circuit 321. The surface of the second component body 612 exposed in the through slot 34 is covered with a thermally conductive and microwave-absorbing material layer 62, and the surface of the second component body 612 facing the first thermally conductive adhesive 51 is also covered with a thermally conductive and microwave-absorbing material layer 62. The thermally conductive and microwave-absorbing material layer 62 is composed of thermally conductive and microwave-absorbing materials, mainly composed of magnetic powder, thermally conductive powder, and hydrogen-containing silicone oil. While conducting heat and absorbing microwaves, it also has insulation properties and can be directly attached to the surface of the electronic component without causing other electrical problems.

[0052] In this embodiment, the number of first electronic components 601 and second electronic components 602 is multiple and equal. The number of first electronic components 601 and second electronic components 602 corresponds to the number of first thermally conductive adhesives 51. Multiple first electronic components 601 are arranged on one side of the high-frequency transmission line layer 14, and multiple second electronic components 602 are arranged on the other side of the high-frequency transmission line layer 14. Viewed along the second inner layer line 321 towards the first inner layer line 311, the arrangement of the high-frequency transmission line layer 14, the multiple first electronic components 601, and the multiple second electronic components 602 forms an overall "non-standard" shape, thus forming an electromagnetic barrier, eliminating the need for a separate electromagnetic shielding structure.

[0053] S7: Please refer to Figure 7 A second thermally conductive adhesive 52 is formed on the side of the first electronic component 601 and the second electronic component 602 opposite to the first thermally conductive adhesive 51. The second thermally conductive adhesive 52 covers the surface of the thermally conductive and microwave-absorbing material layer 62 opposite to the first thermally conductive adhesive 51. The second thermally conductive adhesive 52 works in conjunction with the thermally conductive and microwave-absorbing material layer 62 to conduct the heat generated by the first electronic component 601 and the second electronic component 602, which is beneficial for heat dissipation.

[0054] S8: Please refer to Figure 8The second circuit board 70 is pressed onto the third inner circuit board 33 via the adhesive layer 24, and the second circuit board 70 covers the surface of the adhesive layer 24 away from the surface of the third inner circuit board 331. The second circuit board 70 includes a second substrate layer 72 and a third metal layer 73, and the third metal layer 73 covers the surface of the second substrate layer 72 away from the surface of the adhesive layer 24. The second circuit board 70 is connected to the second thermally conductive adhesive 52 through a first conductive structure 76. The second thermally conductive adhesive 52 is located between the first conductive structure 76 and the thermally conductive and wave-absorbing material layer 62. The first conductive structure 76 can conduct the heat generated by the first electronic component 601 and the second electronic component 602 to the outside of the embedded circuit board 100 through the second thermally conductive adhesive 52, thereby achieving heat dissipation. The second circuit board 70, the through slot 34 of the inner circuit board 30, and the first circuit board 20 surround to form a mounting groove 35. The high-frequency transmission line layer 14 is located at the bottom of the mounting groove 35, and the first electronic component 601 and the second electronic component 602 are mounted on the side wall of the mounting groove 35. The through groove 34 forms the mounting groove 35.

[0055] Please refer to Figures 9A to 9D The method for manufacturing the second circuit board 70 may include:

[0056] A second substrate 71 is provided, comprising a second substrate layer 72 and a third metal layer 73 located on one side of the second substrate layer 72. A first opening 74 is formed on the surface of the second substrate layer 72 opposite to the third metal layer 73, and an electromagnetic shield 75 is formed within the first opening 74, covering the third metal layer 73 and exposed on the surface of the first opening 74. A first conductive structure 76 is formed on the surface of the electromagnetic shield 75 opposite to the third metal layer 73.

[0057] In this embodiment, the third metal layer 73, the electromagnetic shield 75, and the first conductive structure 76 are made of copper. The electromagnetic shield 75 and the first conductive structure 76 are formed by electroplating. In other embodiments, the electromagnetic shield 75 may be made of other materials capable of forming electromagnetic shielding.

[0058] S9: Please refer to Figure 10 The second metal layer 13 and the third metal layer 73 are etched to form a first circuit layer 131 and a second circuit layer 731. The first substrate layer 11 is exposed from the first circuit layer 131, and the second substrate layer 72 is exposed from the second circuit layer 731.

[0059] S10: Please refer to Figure 11A first blind via 81 is formed on the surface of the first circuit layer 131 opposite to the first substrate layer 11, penetrating the first circuit layer 131, the first substrate layer 11, and the second adhesive layer 22. A third conductive structure 83 is formed within a portion of the first blind via 81, through which the first circuit layer 131 is electrically connected to the first inner layer circuit 311. A second conductive structure 77 is formed within a portion of the first blind via 81, through which the first circuit layer 131 is connected to the first thermally conductive adhesive 51, allowing heat to be conducted from the first thermally conductive adhesive 51 to the second conductive structure 77, thereby dissipating the heat generated by the first electronic component 601 and the second electronic component 602 from the embedded circuit board 100. A second blind via 82 is formed on the surface of the second circuit layer 731 opposite to the second substrate layer 72, penetrating the second circuit layer 731, the second substrate layer 72, and the adhesive layer 24. A fourth conductive structure 84 is formed within the second blind via 82, and the second circuit layer 731 is electrically connected to the third inner layer circuit 331 through the fourth conductive structure 84.

[0060] S11: Please refer to Figure 12 A through-hole 85 is formed on the surface of the second circuit layer 731 opposite to the second substrate layer 72. The through-hole 85 penetrates the first circuit substrate 20, the first adhesive layer 21, the inner circuit substrate 30, the adhesive layer 24, and the second circuit substrate 70. An electroplated layer 86 is formed on the inner surface of the through-hole 85 to achieve electrical conduction of the circuits in each layer of the embedded circuit board 100.

[0061] In this embodiment, the electroplated layer 86 is made of copper. In some embodiments, the electroplated layer 86 may also be made of other conductive metals.

[0062] S12: Please refer to Figure 13 A first solder resist layer 91 is formed on the surface of the first circuit layer 131 opposite to the first substrate layer 11, covering the first substrate layer 11 and exposed on the surface of the first circuit layer 131. A first groove 93 is provided on the first solder resist layer 91, with a portion of the first circuit layer 131 exposed in the first groove 93. A second solder resist layer 92 is formed on the surface of the second circuit layer 731 opposite to the second substrate layer 72, covering the second substrate layer 72 and exposed on the surface of the second circuit layer 731. A second groove 94 is provided on the second solder resist layer 92, with a portion of the second circuit layer 731 exposed in the second groove 94.

[0063] S13: Please refer to Figure 14A first pad 95 is formed in a first groove 93, and a second pad 96 is formed in a second groove 94. The first pad 95 covers the first circuit layer 131 and is exposed on the surface of the first groove 93. The first pad 95 is electrically connected to the first circuit layer 131 and the second conductive structure 77. Simultaneously, the first pad 95 dissipates the heat generated by the first electronic component 601 and the second electronic component 602 from the embedded circuit board 100 via the thermally conductive and microwave-absorbing material layer 62, the first thermally conductive adhesive 51, the second conductive structure 77, and the first circuit layer 131. The second pad 96 covers the second circuit layer 731 and is exposed on the surface of the second groove 94. The second pad 96 is electrically connected to the second circuit layer 731, the electromagnetic shield 75, and the first conductive structure 76. Simultaneously, the second pad 96 dissipates the heat generated by the first electronic component 601 and the second electronic component 602 from the embedded circuit board 100 via the thermally conductive and microwave-absorbing material layer 62, the second thermally conductive adhesive 52, the first conductive structure 76, and the second circuit layer 731.

[0064] Please see Figure 14 This application also provides an embedded circuit board 100, which includes a first circuit board 20, an inner circuit board 30, and a second circuit board 70 stacked sequentially. The first circuit board 20 includes a first substrate layer 11 and a first circuit layer 131, and a high-frequency transmission line layer 14 is provided on the surface of the first substrate layer 11 facing away from the first circuit layer 131. The second circuit board 70 and the high-frequency transmission line layer 14 are located on the same side of the first circuit board 20. The inner circuit board 30 is located between the first circuit board 20 and the second circuit board 70, and a through groove 34 of the inner circuit board 30 surrounds the first circuit board 20 and the second circuit board 70 to form a mounting groove 35. The high-frequency transmission line layer 14 is located on the bottom surface 351 of the mounting groove 35. The embedded circuit board 100 also includes at least one first electronic component 601 and at least one second electronic component 602, which are housed in the mounting groove 35 and are electrically connected to the inner circuit board 30. The first electronic component 601 and the second electronic component 602 are disposed on opposite sides of the high-frequency transmission line layer 14.

[0065] In this application, the high-frequency transmission line layer 14 is located within the space enclosed by the first circuit board 20, the second circuit board 70, the inner circuit board 30, the first electronic component 601, and the second electronic component 602, forming an electromagnetic shield that can prevent electromagnetic interference. It eliminates the need for additional side electromagnetic shielding structures, reduces the overall product size, conforms to the trend of thinness, and improves the product's efficiency.

[0066] In some embodiments, the first circuit board 20 is pressed together with the inner circuit board 30 by a first adhesive layer 21. The first circuit board 20 includes a first substrate layer 11 and a first circuit layer 131, and the first adhesive layer 21 covers the surface of the first substrate layer 11 away from the first circuit layer 131.

[0067] In some embodiments, the second circuit board 70 is pressed together with the inner circuit board 30 by an adhesive layer 24. The second circuit board 70 includes a second substrate layer 72 and a second circuit layer 731. The adhesive layer 24 covers the surface of the second substrate layer 72 that is away from the second circuit layer 731.

[0068] By laminating the adhesive layers, the first circuit board 20, the second circuit board 70, and the inner circuit board 30 can be bonded more firmly. Furthermore, a portion of the first adhesive layer 21 and a portion of the adhesive layer 24 have contact areas with the first electronic component 601 and the second electronic component 602, making the first electronic component 601 and the second electronic component 602 bonded more securely to the inner circuit board 30.

[0069] In some embodiments, the mounting groove 35 further includes a first sidewall 352 and a second sidewall 353 disposed opposite to the bottom surface 351. The first sidewall 352 is located on the surface of the inner circuit board 30 exposed in the mounting groove 35 and located on one side of the high-frequency transmission line layer 14, and the second sidewall 353 is located on the surface of the inner circuit board 30 exposed in the mounting groove 35 and located on the opposite side of the high-frequency transmission line layer 14. A first electronic component 601 is located on the first sidewall 352, and a second electronic component 602 is located on the second sidewall 353. By disposing the first electronic component 601 and the second electronic component 602 on the sidewalls of the mounting groove 35, the first electronic component 601 and the second electronic component 602 can provide support for the mounting groove 35 and prevent the interior of the embedded circuit board 100 from collapsing.

[0070] In some embodiments, the embedded circuit board 100 includes a plurality of first electronic components 601 and a plurality of second electronic components 602. The plurality of first electronic components 601 are arranged along a first sidewall 352 on one side of the high-frequency transmission line layer 14 in a direction perpendicular to the thickness of the embedded circuit board 100. The plurality of second electronic components 602 are arranged along a second sidewall 353 on the other side of the high-frequency transmission line layer 14 in a direction perpendicular to the thickness of the embedded circuit board 100. That is, the plurality of first electronic components 601 and the plurality of second electronic components are arranged sequentially on opposite sides of the high-frequency transmission line layer 14, roughly in a "☐" shape, forming electromagnetic shielding.

[0071] In some embodiments, the first electronic component 601 includes a first electrode and a first component body 611. The first electrode is electrically connected to the inner circuit board 30 facing the first sidewall 352. The surface of the first component body 611 exposed in the mounting groove 35 is covered with a thermally conductive and microwave-absorbing material layer 62. The thermally conductive and microwave-absorbing material layer 62 covering the surface of the first electronic component 601 exposed in the mounting groove 35 helps to dissipate the heat generated by the first electronic component 601.

[0072] In some embodiments, the second electronic component 602 includes a second electrode and a second component body 612. The second electrode is electrically connected to the inner circuit board 30 facing the second sidewall 353. The surface of the second component body 612 exposed in the mounting groove 35 is covered with a thermally conductive and microwave-absorbing material layer 62. The thermally conductive and microwave-absorbing material layer 62 covering the surface of the second electronic component 602 exposed in the mounting groove 35 helps to dissipate the heat generated by the second electronic component 602.

[0073] In some embodiments, the thermally conductive and microwave absorbing material layer 62 is composed of thermally conductive and microwave absorbing material, which is mainly composed of magnetic powder, thermally conductive powder and hydrogen-containing silicone oil. While conducting heat and absorbing electromagnetic wave energy, it also has insulation properties and can be directly attached to the surface of electronic components without causing other electrical problems.

[0074] In some embodiments, the thickness of the thermally conductive and microwave-absorbing material layer 62 can be 0.5 mm to 3 mm, enabling it to absorb electromagnetic energy in the 0.5 GHz to 18 GHz frequency band, with a maximum electromagnetic energy absorption of -6 dB. This is just an example; this application does not impose any special limitations on the thickness of the thermally conductive and microwave-absorbing material layer 62.

[0075] In some embodiments, a first thermally conductive adhesive 51 is disposed on the side of the first electronic component 601 facing the first circuit board 20, and a second thermally conductive adhesive 52 is disposed on the side of the first electronic component 601 facing the second circuit board 70. The first thermally conductive adhesive 51 is located between the first electronic component 601 and the first circuit board 20, and is located on the bottom surface 351 of the mounting groove 35. The first thermally conductive adhesive 51 covers the surface of the thermally conductive and microwave-absorbing material layer 62 facing away from the surface of the first component body 611. The second thermally conductive adhesive 52 is located between the first electronic component 601 and the second circuit board 70, and covers the surface of the thermally conductive and microwave-absorbing material layer 62 facing away from the surface of the first component body 611. The first thermally conductive adhesive 51 and the second thermally conductive adhesive 52, together with the thermally conductive and microwave-absorbing material layer 62 wrapped around the outer surface of the first electronic component 601, conduct away the heat generated by the first electronic component 601, thereby achieving a heat dissipation function.

[0076] In some embodiments, a first thermally conductive adhesive 51 is disposed on the side of the second electronic component 602 facing the first circuit board 20, and a second thermally conductive adhesive 52 is disposed on the side of the second electronic component 602 facing the second circuit board 70. The first thermally conductive adhesive 51 is located between the second electronic component 602 and the first circuit board 20, and is located on the bottom surface 351 of the mounting groove 35. The first thermally conductive adhesive 51 covers the surface of the thermally conductive and microwave-absorbing material layer 62 facing away from the surface of the second component body 612. The second thermally conductive adhesive 52 is located between the second electronic component 602 and the second circuit board 70, and covers the surface of the thermally conductive and microwave-absorbing material layer 62 facing away from the surface of the second component body 612. The first thermally conductive adhesive 51 and the second thermally conductive adhesive 52, together with the thermally conductive and microwave-absorbing material layer 62 wrapped around the outer surface of the second electronic component 602, conduct away the heat generated by the second electronic component 602.

[0077] In some embodiments, the inner layer circuit board 30 includes a first inner layer circuit board 31, a second adhesive layer 22, a second inner layer circuit board 32, a third adhesive layer 23, and a third inner layer circuit board 33, which are stacked sequentially. The first inner layer circuit board 31 includes a first base layer 312 and first inner layer circuits 311 disposed on one side of the first base layer 312, with the first inner layer circuits 311 covering the surface of the first base layer 312 facing away from the second adhesive layer 22. The second inner layer circuit board 32 includes a second base layer 322 and second inner layer circuits 321 disposed on opposite sides of the second base layer 322. The third inner layer circuit board 33 includes a third base layer 332 and third inner layer circuits 331 disposed on one side of the third base layer 332, with the third inner layer circuits 331 covering the surface of the third base layer 332 facing away from the third adhesive layer 23. The first inner layer circuits 311 are electrically connected to the second inner layer circuits 321 through a first conductive structure 41, which penetrates the first inner layer circuits 311, the first base layer 312, and the second adhesive layer 22. The third inner layer circuit 331 and the second inner layer circuit 321 are electrically connected through the second conductive structure 42, which penetrates the third inner layer circuit 331, the third base layer 332 and the third adhesive layer 23.

[0078] In some embodiments, the first circuit board 20 is electrically connected to the inner circuit board 30 via a third conductive structure 83. The second circuit board 70 is electrically connected to the inner circuit board 30 via a fourth conductive structure 84. The second circuit board 70 is connected to the second thermally conductive adhesive 52 via a first conductive structure 76. The first circuit board 20 is connected to the first thermally conductive adhesive 51 via a second conductive structure 77. The first conductive structure 76 and the second conductive structure 77 serve to conduct heat generated by the electronic components. For example, the first conductive structure 76 and the second conductive structure 77 dissipate the heat generated by the first electronic component 601 and the second electronic component 602 from the embedded circuit board 100 through the first thermally conductive adhesive 51 and the second thermally conductive adhesive 52, thereby achieving heat dissipation.

[0079] In some embodiments, the embedded circuit board 100 further includes a first solder resist layer 91 and a second solder resist layer 92. The first solder resist layer 91 covers the surface of the first circuit layer 731 facing away from the first substrate layer 11. The second solder resist layer 92 covers the surface of the second circuit layer 731 facing away from the second substrate layer 72.

[0080] In some embodiments, the surface of the first circuit layer 131 facing away from the first substrate layer 11 is provided with a first pad 95, which is electrically connected to the first circuit layer 131 and the second conductive structure 77. Simultaneously, the first pad 95 can dissipate the heat generated by the first electronic component 601 and the second electronic component 602 from the embedded circuit board 100 via the thermally conductive and microwave-absorbing material layer 62, the first thermally conductive adhesive 51, the second conductive structure 77, and the first circuit layer 131.

[0081] In some embodiments, the surface of the second circuit layer 731 facing away from the electromagnetic shield 75 is provided with a second pad 96, which is electrically connected to the second circuit layer 731, the electromagnetic shield 75, and the first conductive structure 76. Simultaneously, the second pad 96 can dissipate the heat generated by the first electronic component 601 and the second electronic component 602 from the embedded circuit board 100 via the thermally conductive and microwave-absorbing material layer 62, the second thermally conductive adhesive 52, the first conductive structure 76, and the second circuit layer 731.

[0082] In some embodiments, the embedded circuit board 100 further includes a through-hole 85 that penetrates the first circuit board 20, the first adhesive layer 21, the inner circuit board 30, the adhesive layer 24, and the second circuit board 70. An electroplated layer 86 is formed on the inner surface of the through-hole 85. In some embodiments, the electroplated layer 86 may be made of copper. This allows for electrical conduction between the first circuit board 20, the inner circuit board 30, and the second circuit board 70.

[0083] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. An embedded circuit board, characterized in that, include: A first circuit board, the first circuit board includes a first substrate layer and a first circuit layer, and a high-frequency transmission line layer is provided on the surface of the first substrate layer opposite to the first circuit layer; The second circuit board includes an electromagnetic shielding body. An inner circuit board is located between the first circuit board and the second circuit board. The inner circuit board has a through slot. The position of the electromagnetic shield corresponds to the through slot. The through slot, the first circuit board, and the second circuit board surround each other to form a mounting slot. The high-frequency transmission line layer is located on the bottom surface of the mounting slot. At least one first electronic component is housed in the mounting slot and is electrically connected to the inner circuit board. At least one second electronic component is housed in the mounting slot and electrically connected to the inner circuit board. The first electronic component and the second electronic component are disposed on opposite sides of the high-frequency transmission line layer.

2. The embedded circuit board as described in claim 1, characterized in that, The mounting groove further includes a first sidewall and a second sidewall disposed opposite to the bottom surface. The first electronic component is mounted on the first sidewall, and the second electronic component is mounted on the second sidewall. The second circuit board is pressed to the inner circuit board by an adhesive layer. The adhesive layer fixes the first electronic component to the first sidewall and the adhesive layer fixes the second electronic component to the second sidewall.

3. The embedded circuit board as described in claim 1, characterized in that, The first electronic component includes a first electrode and a first component body. The first electrode is electrically connected to the inner circuit board, and the surface of the first component body exposed in the mounting groove is covered with a thermally conductive and microwave-absorbing material layer. The second electronic component includes a second electrode and a second component body. The second electrode is electrically connected to the inner circuit board, and the surface of the second component body exposed in the mounting groove is covered with a thermally conductive and microwave-absorbing material layer.

4. The embedded circuit board as described in claim 3, characterized in that, The embedded circuit board further includes a first thermally conductive adhesive and a second thermally conductive adhesive. The first thermally conductive adhesive is disposed between the first electronic component and the first circuit board and between the second electronic component and the first circuit board. The first thermally conductive adhesive is located at the bottom of the through slot and is arranged on opposite sides of the high-frequency transmission line layer. The second thermally conductive adhesive is disposed on the side of the first electronic component and the second electronic component opposite to the first thermally conductive adhesive, and the second thermally conductive adhesive covers the surface of the thermally conductive and microwave-absorbing material layer opposite to the first thermally conductive adhesive.

5. The embedded circuit board as described in claim 4, characterized in that, The second circuit board further includes a second circuit layer and a first conductive structure. The electromagnetic shield is located on one side of the second circuit layer, and the first conductive structure is located on the surface of the electromagnetic shield away from the second circuit layer. The first conductive structure is connected to the second thermally conductive adhesive. The first circuit board is provided with a second conductive structure, which penetrates the first substrate layer and the first circuit layer and is connected to the first thermally conductive adhesive.

6. The embedded circuit board as described in claim 5, characterized in that, The first circuit layer has a first pad on its surface opposite to the first substrate layer, and the first pad is electrically connected to the first circuit layer and the second conductive structure.

7. The embedded circuit board as described in claim 5, characterized in that, The second circuit layer has a second pad on its surface away from the electromagnetic shield, and the second pad is electrically connected to the second circuit layer, the electromagnetic shield, and the first conductive structure.

8. A method for manufacturing an embedded circuit board, characterized in that, Includes the following steps: A first circuit board is provided, wherein a high-frequency transmission line layer is provided on the surface of the first circuit board; A second circuit board is provided, the second circuit board including an electromagnetic shield; An inner circuit board is provided, the inner circuit board is located between the first circuit board and the second circuit board, the inner circuit board is provided with a through slot, and the position of the electromagnetic shield corresponds to the through slot. The first circuit board, the second circuit board, and the inner circuit board are stacked sequentially. The through slot surrounds the first circuit board and the second circuit board to form a mounting slot. The high-frequency transmission line layer is located on the bottom surface of the mounting slot. At least one first electronic component and at least one second electronic component are housed in the mounting slot. The first electronic component and the second electronic component are electrically connected to the inner circuit board. The first electronic component and the second electronic component are disposed on opposite sides of the high-frequency transmission line layer.

9. The method for manufacturing an embedded circuit board as described in claim 8, characterized in that, The first electronic component includes a first electrode and a first component body. The first electrode is electrically connected to the inner circuit board. The surface of the first component body exposed in the mounting groove is covered with a thermally conductive and microwave-absorbing material layer.

10. The method for manufacturing an embedded circuit board as described in claim 8, characterized in that, The second electronic component includes a second electrode and a second component body. The second electrode is electrically connected to the inner circuit board, and the surface of the second component body exposed in the mounting groove is covered with a thermally conductive and microwave-absorbing material layer.

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