Circuit board with heat dissipation structure and manufacturing method thereof

Abstract

A circuit board with a heat dissipation structure and a manufacturing method thereof. The circuit board with the heat dissipation structure includes a multilayer circuit substrate, an electronic component, a first memory metal heat conduction part, and a metal shielding cover. A window is formed in the first side of the multilayer circuit substrate, and the multilayer circuit substrate includes a metal part exposed at one end of the window away from the first side. The sidewall of the multilayer circuit substrate exposed from the window is covered with a metal film, the metal shielding cover is arranged on the first side of the multilayer circuit substrate and covers the window, the electronic component is installed in the window, and the first memory metal heat conduction part is arranged on the surface of the electronic component facing the metal film. When the temperature of the first memory metal heat conduction part is lower than the first memory temperature, the first memory metal heat conduction part is in contact with the electronic component and is separated from the metal film. When the temperature of the first memory metal heat conduction part is higher than the first memory temperature, the first memory metal heat conduction part deforms and abuts between the electronic component and the metal film.

Description

Technical Field

[0001] This invention relates to the field of circuit boards, and more particularly to a circuit board with a heat dissipation structure and a method for manufacturing the same. Background Technology

[0002] With the development of 5G technology, electronic products are becoming increasingly integrated and miniaturized, leading to higher assembly densities and greater power consumption. Consequently, the heat dissipation requirements for circuit boards in electronic products are also increasing. Currently, the heat dissipation performance of circuit boards cannot meet these demands. Summary of the Invention

[0003] In view of this, the present invention provides a circuit board with a heat dissipation structure, which has good heat dissipation effect and simple structure.

[0004] A method for manufacturing a circuit board with a heat dissipation structure that has good heat dissipation performance and simple process is also provided.

[0005] A circuit board with a heat dissipation structure includes a multilayer circuit board, electronic components, a first memory metal heat-conducting part, and a metal shield. A window is formed inward from a first side of the multilayer circuit board, and the multilayer circuit board includes an exposed metal portion at one end corresponding to the window and facing away from the first side. A metal film covers the sidewall of the multilayer circuit board exposed from the window. The metal shield is disposed on the first side of the multilayer circuit board and covers the window. The electronic components are mounted inside the window, and the first memory metal heat-conducting part is disposed on the surface of the electronic components facing the metal film. When the temperature of the first memory metal heat-conducting part is lower than a first memory temperature, the first memory metal heat-conducting part is in contact with the electronic components and separated from the metal film. When the temperature of the first memory metal heat-conducting part is higher than the first memory temperature, the first memory metal heat-conducting part deforms and abuts against the electronic components and the metal film.

[0006] As one aspect of this application, the circuit board with a heat dissipation structure further includes a second memory metal heat-conducting part disposed on the surface of the electronic component away from the metal part; wherein, when the temperature of the second memory metal heat-conducting part is lower than the second memory temperature, the second memory metal heat-conducting part contacts the electronic component and is separated from the metal shield; when the temperature of the second memory metal heat-conducting part is higher than the second memory temperature, the second memory metal heat-conducting part deforms and abuts against the electronic component and the metal shield.

[0007] As one embodiment of this application, the middle regions of the first memory metal heat-conducting part and the second memory metal heat-conducting part are respectively fixed to the electronic component. After deformation, the temperature of the first memory metal heat-conducting part is higher than the first memory temperature and the temperature of the second memory metal heat-conducting part is higher than the second memory temperature. The end of the first memory metal heat-conducting part abuts against the metal film, and the end of the second memory metal heat-conducting part abuts against the metal shield.

[0008] As one embodiment of this application, the first shape memory metal thermal conductive part is fixed to the electronic component by adhesive, magnetic attraction or welding, and the second shape memory metal thermal conductive part is fixed to the electronic component by adhesive, magnetic attraction or welding.

[0009] As one aspect of this application, the first shape memory metal thermal conductive part includes at least one of nickel-titanium alloy, iron-based alloy, or copper-based alloy, and the second shape memory metal thermal conductive part includes at least one of nickel-titanium alloy, iron-based alloy, or copper-based alloy.

[0010] A method for manufacturing a circuit board with a heat dissipation structure includes the following steps:

[0011] A multilayer circuit board is provided, and a window is formed inward from a first side of the multilayer circuit board. The multilayer circuit board includes a metal portion disposed and exposed at one end corresponding to the window away from the first side. The sidewall of the multilayer circuit board exposed from the window is covered with a metal film.

[0012] An electronic component is installed within the opening, and a first memory metal heat-conducting portion is provided on the surface of the electronic component facing the metal film. When the temperature of the first memory metal heat-conducting portion is lower than a first memory temperature, the first memory metal heat-conducting portion is in contact with the electronic component and separated from the metal film; when the temperature of the first memory metal heat-conducting portion is higher than the first memory temperature, the first memory metal heat-conducting portion deforms and abuts against the electronic component and the metal film.

[0013] A metal shield is provided on the first side of the multilayer circuit board, and the metal shield covers the window.

[0014] As one embodiment of this application, the surface of the electronic component facing away from the metal portion is further provided with a second memory metal heat-conducting portion; after the metal shielding cover covers the opening, when the temperature of the second memory metal heat-conducting portion is lower than the second memory temperature, the second memory metal heat-conducting portion contacts the electronic component and is separated from the metal shielding cover; when the temperature of the second memory metal heat-conducting portion is higher than the second memory temperature, the second memory metal heat-conducting portion deforms and abuts against the electronic component and the metal shielding cover.

[0015] As one embodiment of this application, the middle regions of the first memory metal heat-conducting part and the second memory metal heat-conducting part are respectively fixed to the electronic component. After deformation, the temperature of the first memory metal heat-conducting part is higher than the first memory temperature and the temperature of the second memory metal heat-conducting part is higher than the second memory temperature. The end of the first memory metal heat-conducting part abuts against the metal film, and the end of the second memory metal heat-conducting part abuts against the metal shield. The first memory metal heat-conducting part is fixed to the electronic component by adhesive, magnetic attraction or welding, and the second memory metal heat-conducting part is fixed to the electronic component by adhesive, magnetic attraction or welding.

[0016] As one aspect of this application, the first shape memory metal thermal conductive part includes at least one of nickel-titanium alloy, iron-based alloy, or copper-based alloy, and the second shape memory metal thermal conductive part includes at least one of nickel-titanium alloy, iron-based alloy, or copper-based alloy.

[0017] As one embodiment of this application, the fabrication of the multilayer circuit board includes the following steps:

[0018] A double-sided metal substrate is provided, comprising a first metal foil, a first dielectric layer and a second metal foil stacked sequentially.

[0019] The first metal foil is fabricated to form a first circuit layer, wherein the first circuit layer includes a window area;

[0020] A first single-sided panel with a first opening is pressed onto the side of the first dielectric layer opposite to the second metal foil, and the window area is exposed from the first opening;

[0021] The first single-sided board is fabricated with circuitry so that a second circuit layer is formed on the side of the first single-sided board that is away from the first circuit layer.

[0022] A second single-sided panel is pressed onto the second circuit layer, and then a second opening is made through the second single-sided panel to expose the window area, thereby obtaining an intermediate structure, wherein the window area, the first opening and the second opening constitute a window;

[0023] A metal film is disposed on the sidewall of the intermediate structure exposed from the window, and circuitry is fabricated on the intermediate structure, such that a third circuit layer is formed on the side of the intermediate structure corresponding to the second metal foil, and a fourth circuit layer is formed on the side of the intermediate structure opposite to the second metal foil. The third circuit layer includes a metal portion corresponding to the window.

[0024] A cover film is provided to cover the third circuit layer and the fourth circuit layer, wherein the metal portion is exposed from the cover film.

[0025] The circuit board with a heat dissipation structure and its manufacturing method disclosed in this application have a first shape memory metal thermal conductive portion on the surface of the electronic component embedded in the multilayer circuit board. When the first shape memory metal thermal conductive portion is below a first shape memory temperature, i.e., when the heat generation of the electronic component is low, the first shape memory metal thermal conductive portion is only in contact with the electronic component and separated from the metal film, and the heat of the electronic component is conducted outward through the metal portion electrically connected to it. When the first shape memory metal thermal conductive portion is above the first shape memory temperature, i.e., when the heat generation of the electronic component is high, the first shape memory metal thermal conductive portion deforms to abut against the electronic component and the metal film. At this time, the electronic component can not only directly transfer heat to the metal portion electrically connected to it and diffuse it outward, but also accelerate the heat conduction through the first shape memory metal thermal conductive portion, thereby improving the heat dissipation efficiency.

[0026] Furthermore, the electronic components embedded in the multilayer circuit board have a second shape memory metal thermal conductive portion on their surface facing the metal shield. When the temperature of the second shape memory metal thermal conductive portion is lower than the second shape memory temperature, i.e., when the heat generation of the electronic component is low, the second shape memory metal thermal conductive portion only contacts the electronic component and is separated from the metal shield. The heat of the electronic component is conducted outward through the metal portion electrically connected to it or diffused to other areas of the multilayer circuit board. When the temperature of the second shape memory metal thermal conductive portion is higher than the second shape memory temperature, the second shape memory metal thermal conductive portion deforms to abut against the electronic component and the metal shield. At this time, the second shape memory metal thermal conductive portion can quickly transfer the heat of the electronic component to the metal shield, and then the heat diffuses outward through the metal shield, thereby accelerating the conduction and diffusion of heat to the electronic component and improving heat dissipation efficiency. Attached Figure Description

[0027] Figure 1 This is a cross-sectional schematic diagram of a multilayer circuit board with windows according to an embodiment of this application.

[0028] Figure 2 In order to be in Figure 1 The diagram shows a cross-sectional view of an electronic component with a first memory metal heat-conducting part inside the window.

[0029] Figure 3 This is a cross-sectional schematic diagram of a circuit board with a heat dissipation structure according to an embodiment of this application.

[0030] Figure 4 for Figure 3 The diagram shows a cross-sectional view of a circuit board with a heat dissipation structure in another usage state.

[0031] Figure 5 This is a cross-sectional schematic diagram of a double-sided metal substrate according to an embodiment of this application.

[0032] Figure 6 for Figure 5 The diagram shows a cross-sectional view of the double-sided metal substrate after circuit fabrication.

[0033] Figure 7 In order to be in Figure 6 The diagram shows a cross-sectional view of a first single-sided panel with a first opening, laminated onto a double-sided metal substrate after the circuit is fabricated.

[0034] Figure 8 for Figure 7 The diagram shows a cross-sectional view of the first single-sided PCB after circuit fabrication.

[0035] Figure 9 In order to be in Figure 8 The diagram shows a cross-sectional view of the second single-sided panel being pressed onto the first single-sided panel after the circuit fabrication is completed.

[0036] Figure 10 This is a cross-sectional schematic diagram of the intermediate structure according to one embodiment of this application.

[0037] Figure 11 for Figure 10 The diagram shows a cross-sectional view of the intermediate structure after a metal film has been placed on it and circuitry has been fabricated.

[0038] Figure 12 for Figure 11 The diagram shows a cross-sectional view of the intermediate structure after the circuit fabrication is covered with a cover film.

[0039] Explanation of main component symbols

[0040] Multilayer circuit board 10

[0041] First side 10a

[0042] Window 101

[0043] Metal Department 103

[0044] Side wall 104

[0045] Metal film 105

[0046] Connecting pad 106

[0047] Connecting part 102

[0048] Electronic Components 30

[0049] First shape memory metal heat-conducting part 40

[0050] Second shape memory metal heat-conducting part 45

[0051] Metal shield 50

[0052] Shielded cavity 55

[0053] Double-sided metal substrate 11

[0054] First metal foil 111

[0055] First dielectric layer 113

[0056] Second metal foil 115

[0057] First line layer 112

[0058] Window area 110

[0059] First opening 120

[0060] First single-sided panel 12

[0061] Third metal foil 121

[0062] Second dielectric layer 123

[0063] Second line layer 122

[0064] Second single-sided panel 13

[0065] Second opening 130

[0066] Intermediate structure 10A

[0067] Fourth metal foil 131

[0068] Third dielectric layer 133

[0069] Third line layer 116

[0070] Fourth line layer 132

[0071] Covering membrane 17

[0072] Metal protective layer 107

[0073] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0074] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0075] 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 this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0076] Shape memory metals are special metallic materials that undergo plastic deformation within a certain temperature range and then recover their original macroscopic shape within another temperature range. The high-temperature phase of shape memory metals has high structural symmetry, typically exhibiting an ordered cubic structure. Below the memory temperature (Ms temperature, Martensite start temperature), the single-oriented high-temperature phase transforms into martensite variants with different orientations. When this material is deformed below the Ms temperature to form a component, the martensite variants in unfavorable stress directions continuously decrease, while those in favorable directions continuously grow, eventually transforming into a component with ordered martensite of a single orientation. If reheated above the Ms point, this low-symmetry, single-oriented martensite undergoes a reverse transformation, forming the previously single-oriented high-temperature phase. Corresponding to this reversible transformation of the microstructure, the macroscopic shape of the material at high temperature is recovered; this is known as single-pass shape memory. A shape memory element that, after certain processing, can recover its low-temperature shape when cooled below Ms is called a two-pass shape memory effect.

[0077] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0078] Please see Figures 1 to 4 This application provides a method for manufacturing a circuit board with a heat dissipation structure, which includes the following steps:

[0079] Step S1, please refer to Figure 1 A multilayer circuit board 10 is provided, and a window 101 is formed inward along the thickness direction from the first side 10a of the multilayer circuit board 10. The multilayer circuit board 10 includes a metal part 103 disposed and exposed at one end of the window 101 away from the first side 10a, and the sidewall 104 exposed from the window 101 of the multilayer circuit board 10 is covered with a metal film 105.

[0080] In some embodiments, the multilayer circuit board 10 may further include a connecting pad 106 disposed within the window 101 and electrically connected to the metal portion 103.

[0081] Preferably, the circuit layer located on the first side 10a of the multilayer circuit board 10 is exposed near the connection portion 102 of the window 101.

[0082] For step S2, please refer to [link / reference]. Figure 2 An electronic component 30 is installed within the opening 101, and a first shape memory metal heat-conducting portion 40 is provided on the surface of the electronic component 30 facing the metal film 105. When the temperature of the first shape memory metal heat-conducting portion 40 is lower than the first shape memory temperature, the first shape memory metal heat-conducting portion 40 only contacts the electronic component 30 and is separated from the metal film 105; preferably, the first shape memory metal heat-conducting portion 40 is in contact with the surface of the electronic component 30. When the temperature of the first shape memory metal heat-conducting portion 40 is higher than the first shape memory temperature, the first shape memory metal heat-conducting portion 40 deforms to abut between the electronic component 30 and the metal film 105, thereby rapidly transferring the heat of the electronic component 30 to the metal film 105 through the first shape memory metal heat-conducting portion 40. The heat then diffuses outward through the multilayer circuit board 10, especially the metal portion 103, thereby accelerating the conduction and diffusion of heat from the electronic component 30 and improving heat dissipation efficiency.

[0083] In this embodiment, the middle region of the first memory metal heat-conducting part 40 can be fixed to the electronic component 30. When the temperature of the first memory metal heat-conducting part 40 is higher than the first memory temperature, the end of the first memory metal heat-conducting part 40 deforms and abuts against the metal film 105. The first memory metal heat-conducting part 40 can be fixed to the electronic component 30 by means of, but not limited to, adhesive, magnetic attraction, welding, etc.

[0084] Preferably, the area where the first memory metal heat-conducting part 40 is fixed to the electronic component 30 corresponds to the heat source area of ​​the electronic component 30.

[0085] In some other embodiments, the first shape memory metal heat-conducting part 40 can also be fixed to the electronic component 30 through other parts, and after deformation, it can also be supported by the metal film 105 through other parts.

[0086] The first memory metal heat-conducting part 40 may include, but is not limited to, at least one of nickel-titanium alloy, iron-based alloy, and copper-based alloy.

[0087] In this embodiment, the electronic component 30 may also have a second shape memory metal heat-conducting part 45 on the surface away from the metal part 103. When the temperature of the second shape memory metal heat-conducting part 45 is lower than the second shape memory temperature, the second shape memory metal heat-conducting part 45 only contacts the electronic component 30; preferably, the second shape memory metal heat-conducting part 45 is in contact with the surface of the electronic component 30. When the temperature of the second shape memory metal heat-conducting part 45 is higher than the second shape memory temperature, the second shape memory metal heat-conducting part 45 deforms, causing it to bulge / warp in the direction away from the electronic component 30.

[0088] In this embodiment, the middle region of the second shape memory metal heat-conducting part 45 can be fixed to the electronic component 30. When the temperature of the second shape memory metal heat-conducting part 45 is higher than the second shape memory temperature, the end of the second shape memory metal heat-conducting part 45 deforms and warps away from the electronic component 30. The second shape memory metal heat-conducting part 45 can be fixed to the electronic component 30 by means of, but not limited to, adhesive, magnetic attraction, welding, etc.

[0089] Preferably, the area where the second shape memory metal heat-conducting part 45 is fixed to the electronic component 30 corresponds to the heat source area of ​​the electronic component 30.

[0090] In some other embodiments, the second shape memory metal heat-conducting part 45 can also be fixed to the electronic component 30 through other parts, and after deformation, it can also be other parts that protrude in a direction away from the electronic component 30.

[0091] The second shape memory metal heat-conducting part 45 may include, but is not limited to, at least one of nickel-titanium alloy, iron-based alloy, and copper-based alloy.

[0092] In this embodiment, the connection terminal (not shown in the figure) of the electronic component 30 can be electrically connected to the connection pad 106 by means of, but not limited to, soldering, conductive adhesive, etc.

[0093] Step S3, please refer to Figure 3 and Figure 4 A metal shielding cover 50 is provided on the first side 10a of the multilayer circuit board 10, and the metal shielding cover 50 covers the window 101. The metal shielding cover 50, the metal film 105 and the metal part 103 cooperate to form a shielding cavity 55 to provide electromagnetic shielding for the electronic component 30.

[0094] When the temperature of the second memory metal heat-conducting part 45 is lower than the second memory temperature, the second memory metal heat-conducting part 45 is separated from the metal shield 50. When the temperature of the second memory metal heat-conducting part 45 is higher than the second memory temperature, the second memory metal heat-conducting part 45 deforms to abut against the electronic component 30 and the metal shield 50, thereby rapidly transferring the heat of the electronic component 30 to the metal shield 50 through the second memory metal heat-conducting part 45. Then, the heat diffuses outward through the metal shield 50, thereby accelerating the conduction and diffusion of heat to the electronic component 30 and improving heat dissipation efficiency.

[0095] Preferably, the metal shielding cover 50 is installed on the circuit layer of the first side 10a of the multilayer circuit board 10 near the connection portion 102 of the window 101, which is beneficial to improving the electromagnetic shielding effect.

[0096] The multilayer circuit board 10 can be a three-layer circuit board, a four-layer circuit board, a five-layer circuit board, etc. In this embodiment, the multilayer circuit board 10 is described as a four-layer circuit board.

[0097] The multilayer circuit board 10 can be manufactured by, but is not limited to, the following method, which includes the following steps:

[0098] Step S11, please refer to Figure 5 A double-sided metal substrate 11 is provided, including a first metal foil 111, a first dielectric layer 113 and a second metal foil 115 stacked sequentially along the thickness direction.

[0099] Step S12, please refer to Figure 6 The first metal foil 111 is fabricated to form a first circuit layer 112, wherein the first circuit layer 112 includes a window area 110.

[0100] In some embodiments, the window area 110 may include a plurality of connecting pads 106.

[0101] Step S13, please refer to Figure 7 A first single panel 12 with a first opening 120 is pressed onto the side of the first dielectric layer 113 away from the second metal foil 115, and the window area 110 is exposed from the first opening 120.

[0102] The first single-sided panel 12 includes a third metal foil 121 and a second dielectric layer 123 stacked sequentially along the thickness direction. The side of the second dielectric layer 123 facing away from the third metal foil 121 is bonded to the first circuit layer 112.

[0103] Step S14, please refer to Figure 8 The first single-sided panel 12 is fabricated to form a second circuit layer 122 on the side of the first single-sided panel 12 that is opposite to the first circuit layer 112.

[0104] Step S15, please refer to Figure 9 and Figure 10 A second single-panel panel 13 is pressed onto the second circuit layer 122, and then a second opening 130 is made through the second single-panel panel 13 to expose the window area 110, thereby obtaining an intermediate structure 10A. The window area 110, the first opening 120, and the second opening 130 constitute a window 101.

[0105] In some embodiments, the second opening 130 may be formed by means of, but not limited to, laser cutting, mechanical cutting, drilling, etc.

[0106] The second single-sided panel 13 includes a fourth metal foil 131 and a third dielectric layer 133 stacked sequentially along the thickness direction. The side of the third dielectric layer 133 facing away from the fourth metal foil 131 is bonded to the second circuit layer 122.

[0107] Step 16, please refer to Figure 11 A metal film 105 is provided on the sidewall 104 of the intermediate structure 10A exposed from the window 101, and circuitry is fabricated on the intermediate structure 10A, forming a third circuit layer 116 on the side of the intermediate structure 10A corresponding to the second metal foil 115, and a fourth circuit layer 132 on the side of the intermediate structure 10A opposite to the second metal foil 115. The third circuit layer 116 includes a metal portion 103 corresponding to the window 101.

[0108] In some embodiments, a metal layer (not shown) may be formed at the bottom of the window 101 at the same time as the metal film 105 is formed, and then the metal layer is removed.

[0109] The metal film 105 and the metal layer can be formed by, but not limited to, electroplating, and the metal layer can be removed by, but not limited to, laser ablation.

[0110] Step 17, please refer to Figure 12 A cover film 17 is provided to cover the third circuit layer 116 and the fourth circuit layer 132, wherein the metal part 103 is exposed from the cover film 17.

[0111] In this embodiment, the fourth circuit layer 132 is exposed from the cover film 17 near the connection portion 102 of the window 101.

[0112] In some embodiments, the method for fabricating the multilayer circuit board 10 may further include step S18, see [link to relevant documentation]. Figure 1 The surface of the metal film 105 is treated to form a metal protective layer 107, for example, to form an electroless gold layer.

[0113] The metal portion 103 exposed from the cover film 17 and the connection portion of the fourth circuit layer 132 exposed from the cover film 17 near the window 101 can also be processed to form a metal protective layer, for example, to form a metallized gold layer.

[0114] Please see Figure 3 and Figure 4One embodiment of this application discloses a circuit board 100 with a heat dissipation structure, comprising a multilayer circuit board 10, an electronic component 30, a first memory metal heat-conducting portion 40, and a metal shield 50. The multilayer circuit board 10 includes a window 101 extending inward along its thickness direction from a first side 10a of the multilayer circuit board 10, and a metal portion 103 disposed at the end of the window 101 facing away from the first side 10a and exposed thereout. A metal film 105 covers the sidewall 104 of the multilayer circuit board 10 exposed from the window 101. The metal shield 50 is disposed on the first side 10a of the multilayer circuit board 10 and covers the window 101. The electronic component 30 is mounted within the window 101, and the first memory metal heat-conducting portion 40 is disposed on the surface of the electronic component 30 facing the metal film 105. Specifically, when the temperature of the first memory metal heat-conducting part 40 is lower than the first memory temperature, the first memory metal heat-conducting part 40 only contacts the electronic component 30 and is separated from the metal film 105. Preferably, the first memory metal heat-conducting part 40 is attached to the surface of the electronic component 30. When the temperature of the first memory metal heat-conducting part 40 is higher than the first memory temperature, the first memory metal heat-conducting part 40 deforms to abut against the electronic component 30 and the metal film 105, thereby quickly transferring the heat of the electronic component 30 to the metal film 105 through the first memory metal heat-conducting part 40. Then, the heat diffuses outward through the multilayer circuit board 10, especially the metal part 103, thereby accelerating the conduction and diffusion of heat to the electronic component 30 and improving the heat dissipation efficiency.

[0115] In this embodiment, the middle region of the first memory metal heat-conducting part 40 can be fixed to the electronic component 30. When the temperature of the first memory metal heat-conducting part 40 is higher than the first memory temperature, the end of the first memory metal heat-conducting part 40 deforms and abuts against the metal film 105. The first memory metal heat-conducting part 40 can be fixed to the electronic component 30 by means of, but not limited to, adhesive, magnetic attraction, welding, etc.

[0116] Preferably, the area where the first memory metal heat-conducting part 40 is fixed to the electronic component 30 corresponds to the heat source area of ​​the electronic component 30.

[0117] In some other embodiments, the first shape memory metal heat-conducting part 40 can also be fixed to the electronic component 30 through other parts, and after deformation, it can also be supported by the metal film 105 through other parts.

[0118] The first memory metal heat-conducting part 40 may include, but is not limited to, at least one of nickel-titanium alloy, iron-based alloy, and copper-based alloy.

[0119] In this embodiment, the circuit board 100 with a heat dissipation structure may further include a second shape memory metal heat-conducting part 45 disposed on the surface of the electronic component 30 away from the metal part 103. When the temperature of the second shape memory metal heat-conducting part 45 is lower than the second shape memory temperature, the second shape memory metal heat-conducting part 45 only contacts the electronic component 30 and is separated from the metal shield 50; preferably, the second shape memory metal heat-conducting part 45 is in contact with the surface of the electronic component 30. When the temperature of the second shape memory metal heat-conducting part 45 is higher than the second shape memory temperature, the second shape memory metal heat-conducting part 45 deforms to abut between the electronic component 30 and the metal shield 50, thereby rapidly transferring the heat of the electronic component 30 to the metal shield 50 through the second shape memory metal heat-conducting part 45, and then the heat diffuses outward through the metal shield 50, thereby accelerating the conduction and diffusion of heat on the electronic component 30 and improving heat dissipation efficiency.

[0120] In this embodiment, the middle region of the second shape memory metal heat-conducting part 45 can be fixed to the electronic component 30. When the temperature of the second shape memory metal heat-conducting part 45 is higher than the second shape memory temperature, the end of the second shape memory metal heat-conducting part 45 deforms and warps away from the electronic component 30. The second shape memory metal heat-conducting part 45 can be fixed to the electronic component 30 by means of, but not limited to, adhesive, magnetic attraction, welding, etc.

[0121] Preferably, the area where the second shape memory metal heat-conducting part 45 is fixed to the electronic component 30 corresponds to the heat source area of ​​the electronic component 30.

[0122] In some other embodiments, the second shape memory metal heat-conducting part 45 can also be fixed to the electronic component 30 through other parts, and after deformation, it can also be other parts that protrude in a direction away from the electronic component 30.

[0123] The second shape memory metal heat-conducting part 45 may include, but is not limited to, at least one of nickel-titanium alloy, iron-based alloy, and copper-based alloy.

[0124] In this embodiment, the multilayer circuit board 10 may further include a connecting pad 106 disposed within the window 101 and electrically connected to the metal portion 103. The connection terminal (not shown) of the electronic component 30 may be electrically connected to the connecting pad 106 by means of, but not limited to, soldering, conductive adhesive, etc.

[0125] Preferably, the circuit layer on the first side 10a of the multilayer circuit board 10 is exposed near the connection portion 102 of the window 101. The metal shielding cover 50 is installed on the circuit layer on the first side 10a of the multilayer circuit board 10 near the connection portion 102 of the window 101, which helps to improve the electromagnetic shielding effect.

[0126] The multilayer circuit board 10 can be a three-layer circuit board, a four-layer circuit board, a five-layer circuit board, etc.

[0127] The circuit board with a heat dissipation structure and its manufacturing method disclosed in this application have a first shape memory metal heat-conducting part 40 on the surface of an electronic component 30 embedded in the multilayer circuit board 10. When the first shape memory metal heat-conducting part 40 is below a first shape memory temperature, i.e., when the heat generation of the electronic component 30 is low, the first shape memory metal heat-conducting part 40 is only in contact with the electronic component 30 and separated from the metal film 105, and the heat of the electronic component 30 is conducted outward through the metal part 103 electrically connected to it. When the first shape memory metal heat-conducting part 40 is above the first shape memory temperature, i.e., when the heat generation of the electronic component 30 is high, the first shape memory metal heat-conducting part 40 deforms so that it abuts between the electronic component 30 and the metal film 105. At this time, the electronic component 30 can not only directly transfer heat to the metal part 103 electrically connected to it and diffuse it outward, but also accelerate the heat conduction through the first shape memory metal heat-conducting part 40, thereby improving the heat dissipation efficiency.

[0128] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above as a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A circuit board with a heat dissipation structure, comprising a multilayer circuit board, electronic components, a first memory metal heat-conducting part, and a metal shielding cover, characterized in that, A window is formed inward from the first side of the multilayer circuit board, and the multilayer circuit board includes a metal part disposed and exposed at one end opposite to the first side of the window. The sidewall of the multilayer circuit board exposed from the window is covered with a metal film. A metal shield is disposed on the first side of the multilayer circuit board and covers the window. The metal shield, the metal film and the metal part cooperate to form a shielding cavity. The electronic component is installed in the shielding cavity, and the first memory metal heat-conducting part is disposed on the surface of the electronic component facing the metal film. Specifically, when the temperature of the first memory metal heat-conducting part is lower than the first memory temperature, the first memory metal heat-conducting part is in contact with the electronic component and separated from the metal film; when the temperature of the first memory metal heat-conducting part is higher than the first memory temperature, the first memory metal heat-conducting part deforms and abuts against the electronic component and the metal film.

2. The circuit board with a heat dissipation structure as described in claim 1, characterized in that, The circuit board with a heat dissipation structure also includes a second memory metal heat-conducting part disposed on the surface of the electronic component away from the metal part; Specifically, when the temperature of the second memory metal heat-conducting part is lower than the second memory temperature, the second memory metal heat-conducting part contacts the electronic component and is separated from the metal shield; when the temperature of the second memory metal heat-conducting part is higher than the second memory temperature, the second memory metal heat-conducting part deforms and abuts against the electronic component and the metal shield.

3. The circuit board with a heat dissipation structure as described in claim 2, characterized in that, The middle regions of the first memory metal heat-conducting part and the second memory metal heat-conducting part are respectively fixed to the electronic component. After deformation, the temperature of the first memory metal heat-conducting part is higher than the first memory temperature and the temperature of the second memory metal heat-conducting part is higher than the second memory temperature. The end of the first memory metal heat-conducting part abuts against the metal film, and the end of the second memory metal heat-conducting part abuts against the metal shield.

4. The circuit board with a heat dissipation structure as described in claim 2, characterized in that, The first shape memory metal thermal conductive part is fixed to the electronic component by adhesive, magnetic attraction or welding, and the second shape memory metal thermal conductive part is fixed to the electronic component by adhesive, magnetic attraction or welding.

5. The circuit board with a heat dissipation structure as described in claim 2, characterized in that, The first shape memory metal thermal conductive part includes at least one of nickel-titanium alloy, iron-based alloy or copper-based alloy, and the second shape memory metal thermal conductive part includes at least one of nickel-titanium alloy, iron-based alloy or copper-based alloy.

6. A method for manufacturing a circuit board with a heat dissipation structure, comprising the following steps: A multilayer circuit board is provided, and a window is formed inward from a first side of the multilayer circuit board. The multilayer circuit board includes a metal portion disposed and exposed at one end corresponding to the window away from the first side. The sidewall of the multilayer circuit board exposed from the window is covered with a metal film. An electronic component is installed within the opening, and a first memory metal heat-conducting portion is provided on the surface of the electronic component facing the metal film. When the temperature of the first memory metal heat-conducting portion is lower than a first memory temperature, the first memory metal heat-conducting portion is in contact with the electronic component and separated from the metal film; when the temperature of the first memory metal heat-conducting portion is higher than the first memory temperature, the first memory metal heat-conducting portion deforms and abuts against the electronic component and the metal film. A metal shield is provided on the first side of the multilayer circuit board, the metal shield covers the window, and the metal shield, the metal film and the metal part cooperate to form a shielding cavity.

7. The method for manufacturing a circuit board with a heat dissipation structure as described in claim 6, characterized in that, The electronic component is further provided with a second memory metal heat-conducting part on the surface away from the metal part; After the metal shielding covers the window, when the temperature of the second memory metal heat-conducting part is lower than the second memory temperature, the second memory metal heat-conducting part contacts the electronic component and is separated from the metal shielding; when the temperature of the second memory metal heat-conducting part is higher than the second memory temperature, the second memory metal heat-conducting part deforms and abuts between the electronic component and the metal shielding.

8. The method for manufacturing a circuit board with a heat dissipation structure as described in claim 7, characterized in that, The middle regions of the first and second memory metal heat-conducting parts are respectively fixed to the electronic components. After deformation, the temperature of the first memory metal heat-conducting part is higher than the first memory temperature and the temperature of the second memory metal heat-conducting part is higher than the second memory temperature. The end of the first memory metal heat-conducting part abuts against the metal film, and the end of the second memory metal heat-conducting part abuts against the metal shield. The first memory metal heat-conducting part is fixed to the electronic components by adhesive, magnetic attraction or welding, and the second memory metal heat-conducting part is fixed to the electronic components by adhesive, magnetic attraction or welding.

9. The method for manufacturing a circuit board with a heat dissipation structure as described in claim 7, characterized in that, The first shape memory metal thermal conductive part includes at least one of nickel-titanium alloy, iron-based alloy or copper-based alloy, and the second shape memory metal thermal conductive part includes at least one of nickel-titanium alloy, iron-based alloy or copper-based alloy.

10. The method for manufacturing a circuit board with a heat dissipation structure as described in claim 6, characterized in that, The fabrication of the multilayer circuit board includes the following steps: A double-sided metal substrate is provided, comprising a first metal foil, a first dielectric layer and a second metal foil stacked sequentially. The first metal foil is fabricated to form a first circuit layer, wherein the first circuit layer includes a window area; A first single-sided panel with a first opening is pressed onto the side of the first dielectric layer opposite to the second metal foil, and the window area is exposed from the first opening; The first single-sided board is fabricated with circuitry so that a second circuit layer is formed on the side of the first single-sided board that is away from the first circuit layer. A second single-sided panel is pressed onto the second circuit layer, and then a second opening is made through the second single-sided panel to expose the window area, thereby obtaining an intermediate structure, wherein the window area, the first opening and the second opening constitute a window; A metal film is disposed on the sidewall of the intermediate structure exposed from the window, and circuitry is fabricated on the intermediate structure, such that a third circuit layer is formed on the side of the intermediate structure corresponding to the second metal foil, and a fourth circuit layer is formed on the side of the intermediate structure opposite to the second metal foil. The third circuit layer includes a metal portion corresponding to the window. A cover film is provided to cover the third circuit layer and the fourth circuit layer, wherein the metal portion is exposed from the cover film.

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