Circuit board and electronic equipment

Abstract

The utility model provides a circuit board and electronic equipment. The embodiment of the utility model provides a circuit board. A power module is embedded in the circuit board. Wherein the power module comprises a power chip and a heat transfer unit which are fixedly connected, and a phase change material is accommodated in the heat transfer unit. The heat dissipation efficiency of the circuit board can be improved to a certain extent.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, specifically to a circuit board and electronic device. Background Technology

[0002] Power devices are typically used as electronic switches in electronic devices. For example, IGBTs (Insulated Gate Bipolar Transistors), MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), and transistors can be placed on circuit boards as electronic switches, and the conduction or disconnection of these electronic switches can be easily controlled to control the operation of electronic devices.

[0003] However, power devices generate heat during operation, and excessively high operating temperatures can reduce the lifespan of electronic devices. Utility Model Content

[0004] In view of this, the embodiments of this application aim to provide a circuit board and electronic device that can improve the heat dissipation efficiency of the circuit board to a certain extent.

[0005] In a first aspect, embodiments of this application provide a circuit board in which a power module is embedded; wherein the power module includes a power chip and a heat transfer unit fixedly connected, and the heat transfer unit contains a phase change material.

[0006] In some embodiments, the power chip and the heat transfer unit are connected by sintering or welding.

[0007] In some embodiments, the heat transfer unit includes a cover and a base welded together, with the cover and the base forming a containment space for containing phase change material.

[0008] In some embodiments, the number of containment spaces is multiple.

[0009] In some embodiments, a groove is provided on one surface of the heat transfer unit, and the power chip is disposed in the groove.

[0010] In some embodiments, the power chip has a first surface and a second surface that are opposite to each other, and a side surface located between the first surface and the second surface; wherein the second surface and the side surface are in contact with the groove wall of the groove.

[0011] In some embodiments, the heat transfer unit includes a first heat transfer unit and a second heat transfer unit, and the power chip is disposed between the first heat transfer unit and the second heat transfer unit.

[0012] In some embodiments, the first heat transfer unit has a first heat transfer surface facing the power chip, the second heat transfer unit has a second heat transfer surface facing the power chip, and the power chip has a first surface facing the first heat transfer surface and a second surface facing the second heat transfer surface; wherein the area of ​​the first heat transfer surface is the same as the area of ​​the first surface; and / or, the area of ​​the second heat transfer surface is the same as the area of ​​the second surface.

[0013] In some embodiments, the power chips are multiple and are fixedly connected to the same heat transfer unit.

[0014] In some embodiments, the circuit board has a multi-layer structure, including a core layer located inside the multi-layer structure, and the power module is embedded in the core layer.

[0015] In some embodiments, the circuit board includes a metal layer located outside the multilayer structure, the metal layer being used to connect a heat sink.

[0016] Secondly, embodiments of this application provide an electronic device, which is equipped with a circuit board as described above.

[0017] In several embodiments of this application, by including a heat transfer unit with a phase change material in the power module embedded in the circuit board, the heat generated by the power chip can be absorbed by the phase change of the phase change material, thereby improving the heat dissipation efficiency of the power chip and thus improving the overall heat dissipation efficiency of the circuit board, thereby extending the service life of the electronic device with the circuit board. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a circuit board provided in an embodiment of this application.

[0019] Figure 2 This is a schematic diagram of a heat transfer unit provided in an embodiment of this application.

[0020] Figure 3 This is a schematic diagram illustrating the change of phase change material relative to temperature and heat within a heat transfer unit, as provided in an embodiment of this application.

[0021] Figure 4 This is a schematic diagram of a heat transfer unit provided in an embodiment of this application; wherein a cover and a base are shown.

[0022] Figure 5 This is a schematic diagram of the structure of a base provided in an embodiment of this application.

[0023] Figure 6 This is a schematic diagram of a power module provided in an embodiment of this application.

[0024] Figure 7 This is a schematic diagram of a power module provided in an embodiment of this application; wherein a first heat transfer unit and a second heat transfer unit are shown.

[0025] Figure 8 This is a schematic diagram of a power module provided in an embodiment of this application; wherein, multiple power chips are shown mounted on the same heat transfer unit.

[0026] Figure 9 This is a schematic diagram of a circuit board provided in an embodiment of this application; wherein a heat sink is installed. Detailed Implementation

[0027] The technical solutions of 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. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] In related technologies, power chips can be used as electronic switches, and control circuits can be turned on or off by sending control signals to the power chip. A power chip is a semiconductor device; for example, it can be an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), or a transistor.

[0029] During operation, power chips generate heat. Typically, power chips are mounted on the surface of a circuit board, allowing some of the heat to dissipate into the air. Alternatively, heat sinks or other structures can be installed on the circuit board to accelerate the heat dissipation efficiency of the power chip.

[0030] However, due to circuit layout requirements, power chips sometimes need to be embedded inside the circuit board. In this case, the power chip relies on the circuit board's thermal conductivity for heat dissipation. In some situations, the power chip may experience short-term overload, generating a significant amount of heat in a short period. If the circuit board cannot quickly dissipate the heat generated by the power chip, it will lead to excessive thermal stress within the circuit board, reducing its lifespan.

[0031] Therefore, it is necessary to provide a technical solution that can accelerate the heat dissipation rate of power chips. This is especially important in situations where power chips experience short-term overload, as it can improve the heat dissipation efficiency of the power chips.

[0032] Please see Figure 1This application provides a circuit board 100. The circuit board 100 has a power module 102 embedded in it; wherein, the power module 102 includes a power chip 104 and a heat transfer unit 106 fixedly connected, and the heat transfer unit 106 contains a phase change material 108.

[0033] In this embodiment, the power chip 104 and the heat transfer unit 106 are embedded together within the circuit board 100. Thus, the heat generated by the power chip 104 can be rapidly dissipated through the heat transfer unit 106. Further details can be found in the following references. Figure 1 and Figure 2 The heat transfer unit 106 contains a phase change material 108. When the power chip 104 experiences a short-term overload, the large amount of heat generated by the power chip 104 can be quickly absorbed by the phase change material 108 in the heat transfer unit 106, thereby improving the heat dissipation efficiency of the power chip 104. For example, the heat transfer unit 106 may contain a phase change material 108. The heat emitted by the power chip 104 will cause the temperature near the power chip 104 to rise, resulting in a phase change in the phase change material 108. For example, please refer to [further details omitted]. Figure 1 , Figure 2 and Figure 3 The power chip 104 operates at high power, such as during a short-term overload, generating a large amount of heat. This causes a phase change material 108 in the heat transfer unit 106 to undergo a phase change. During this phase change, the phase change material 108 absorbs a significant amount of heat, thus accelerating the heat dissipation efficiency of the power chip 104. For example, the phase change material 108 in the heat transfer unit 106 is initially solid. As the power chip 104 generates more heat and the surrounding temperature rises, the phase change material 108 undergoes a phase change from solid to liquid. In some embodiments, the phase change material can change from liquid to gas, or from solid to gas. In some embodiments, the phase change material can be a low-melting-point alloy, a low-melting-point organic material such as paraffin wax, or distilled water.

[0034] In this embodiment, the heat transfer unit 106 has a housing, within which a receiving space 110 is formed. A phase change material 108 is disposed within the receiving space 110. The housing is made of a material with good thermal conductivity and requires a certain stress strength and structural stability. For example, the housing is made of a metallic material. The metallic materials used for the housing include, but are not limited to, gold, silver, and copper.

[0035] In some cases, the heat transfer efficiency at the interface between the power chip 104 and the heat transfer unit 106 may limit the overall heat dissipation efficiency of the power chip 104 to some extent. A connection method with good heat transfer capability can be used to fix the power chip 104 and the heat transfer unit 106 together. In some embodiments, the power chip 104 and the heat transfer unit 106 are connected by sintering or welding. Specifically, a sintered layer obtained by a sintering process (e.g., nano-silver sintering) has excellent thermal conductivity and stability. In some embodiments, welding can also result in the power chip 104 and the heat transfer unit 106 having lower thermal resistance and better stability.

[0036] Please see Figure 1 and Figure 4 In some embodiments, the heat transfer unit 106 may include a fixed cover 112 and a base 114, the cover 112 and the base 114 forming a receiving space 110 for receiving the phase change material 108.

[0037] In this embodiment, a receiving space 110 is formed within the heat transfer unit 106, and the phase change material 108 is contained within this receiving space 110. To facilitate the placement of the phase change material 108 into the receiving space 110, a receiving groove 115 is provided within the base 114 of the heat transfer unit 106. After the phase change material 108 is placed into the receiving groove 115, the cover 112 and the base 114 are fixedly connected. Furthermore, after the cover 112 and the base 114 are fixedly connected, a sealed receiving space 110 is formed between the cover 112 and the base 114. The phase change material 108 can undergo a phase change after absorbing heat within this receiving space 110. Since the receiving space 110 is a sealed space, the phase change material 108 undergoing the phase change will not leak or be lost, allowing the phase change material 108 in the heat transfer unit 106 to be reused repeatedly. For example, when the power chip 104 experiences a short-term overload, it generates a large amount of heat. The phase change material 108 in the heat transfer unit 106 absorbs this heat and undergoes a phase change, changing from a solid state to a solid-liquid mixture or a liquid state. When the power chip 104 returns to a more stable operating state or stops operating, as the heat transfer unit 106 absorbs less heat and dissipates more heat, the phase change material 108 may gradually return from a liquid or solid-liquid mixture to a solid state.

[0038] In this embodiment, the cover 112 and the base 114 can also be connected by sintering or welding. This results in good thermal conductivity and stability between the cover 112 and the base 114.

[0039] Please refer to the following: Figure 4 and Figure 5In some embodiments, the number of receiving spaces 110 is multiple. A plurality of receiving slots 115 may be provided in the base 114, and each receiving slot 115 may contain a phase change material 108. After the cover 112 and the base 114 are fixedly connected, the cover 112 and the plurality of receiving slots 115 respectively form a sealed receiving space 110. In some embodiments, the phase change materials 108 in the plurality of receiving spaces 110 may have different phase change temperatures. By separating and placing multiple phase change materials 108 in independent sealed spaces, gradient storage and release of thermal energy in different temperature ranges can be achieved, thereby improving the adaptability of the thermal management system to complex operating conditions. Of course, in some embodiments, the phase change materials 108 in the plurality of receiving spaces 110 may be the same. The volume of the plurality of receiving slots 115 may be the same, and adjacent receiving slots 115 may be separated by partition walls 117. In some embodiments, the partition walls 117 may be made of a material with a certain degree of elasticity. When the phase change material 108 undergoes a phase change, the spacer wall 117 can compensate for the displacement through its own deformation, which can maintain the airtightness of the containment space 110 and alleviate the stress caused by the volume change of the phase change material 108 during the phase change.

[0040] In some embodiments, the arrangement density of the receiving slots 115 can be adaptively designed according to the thermal distribution characteristics of the circuit board 100. High heat load areas can be provided with a dense array of receiving slots 115 with smaller spacing, thereby enhancing local heat dissipation by increasing the capacity of phase change material 108 per unit volume.

[0041] In this embodiment, multiple receiving spaces 110 may correspond to the same power chip 104. Of course, in some embodiments, multiple receiving spaces 110 may also correspond to one or more power chips 104 respectively, and those skilled in the art can arrange them according to actual needs.

[0042] Please refer to the following: Figure 4 and Figure 6 In some embodiments, a groove 116 is provided on one surface of the heat transfer unit 106, and the power chip 104 is disposed in the groove 116.

[0043] In this embodiment, by placing the power chip 104 within the groove 116 of the heat transfer unit 106, the power module 102 as a whole has a relatively regular shape. Specifically, the groove 116 can be formed on any surface of the heat transfer unit 106, and the power chip 104 can be fixed within the groove 116. In some embodiments, the depth of the groove 116 is the same as the thickness of the power chip 104, so that the power chip 104, after being placed in the groove 116, can completely fill the groove 116. Furthermore, after the power chip 104 is placed within the groove 116, the surface of the power module 102 where the groove 116 is placed can also be relatively flat. Of course, in some embodiments, the depth of the groove 116 and the thickness of the power chip 104 may not be the same.

[0044] In some embodiments, the groove 116 can be disposed on the surface of the cover 112 facing away from the base 114. Thus, the groove 116 can be formed on the cover 112 first, and then the cover 112 can be connected to the base 114. Of course, in some embodiments, the cover 112 can be fixedly connected to the base 114 before forming the groove 116. In this case, the groove 116 is not limited to being disposed on the cover 112, but can also be disposed on the base 114. In some embodiments, after forming the groove 116 on the cover 112, the power chip 104 can be installed in the groove 116 first, and then the cover 112 can be connected to the base 114. Alternatively, the cover 112 can be fixedly connected to the base 114 before the power chip 104 is installed in the groove 116.

[0045] In some embodiments, the power chip 104 has a first surface 120 and a second surface 122 that are opposite to each other, and a side surface 124 located between the first surface 120 and the second surface 122; wherein the second surface 122 and the side surface 124 are in contact with the groove wall 118 of the groove 116.

[0046] In this embodiment, the contact area between the power chip 104 and the heat transfer unit 106 has a certain impact on the heat dissipation efficiency of the power chip 104. A larger contact area between the power chip 104 and the heat transfer unit 106 is beneficial to accelerating the heat dissipation efficiency of the power chip 104. A smaller contact area between the power chip 104 and the heat transfer unit 106 will reduce the heat dissipation efficiency of the power chip 104.

[0047] In this embodiment, to increase the contact area between the power chip 104 and the heat transfer unit 106, the power chip 104 is disposed within the groove 116 of the heat transfer unit 106, with its second surface 122 facing the heat transfer unit 106 contacting the bottom wall of the groove 116, and its side surface 124 contacting the side wall of the groove 116, thus achieving a larger contact area between the power chip 104 and the heat transfer unit 106. In some embodiments, the first surface 120 of the power chip 104 can be used to connect pins for external connections, resulting in a more reasonable overall structure.

[0048] Please see Figure 7 In some embodiments, the heat transfer unit 106 includes a first heat transfer unit 126 and a second heat transfer unit 128, and the power chip 104 is disposed between the first heat transfer unit 126 and the second heat transfer unit 128.

[0049] In some cases, the power chip 104 generates a large amount of heat during operation. A single heat transfer unit 106 may be insufficient to dissipate the heat generated by the power chip 104 in a short time. In this embodiment, to accelerate the heat dissipation of the power chip 104, two heat transfer units 106 can be provided, namely a first heat transfer unit 126 and a second heat transfer unit 128. The power chip 104 is disposed between the first heat transfer unit 126 and the second heat transfer unit 128. This accelerates the heat dissipation of the power chip 104. Specifically, the first surface 120 of the power chip 104 is fixedly connected to the first heat transfer unit 126, and the second surface 122 of the power chip 104 is fixedly connected to the second heat transfer unit 128. Alternatively, in some embodiments, a groove 116 can be provided in the first heat transfer unit 126 to house the power chip 104, and the second heat transfer unit 128 can be fixedly connected to the second surface 122 of the power chip 104 facing away from the first heat transfer unit 126. Similarly, a groove 116 can be provided in the second heat transfer unit 128 to house the power chip 104. The first heat transfer unit 126 and the first surface 120 of the power chip 104 facing away from the second heat transfer unit 128 are fixedly connected. In some embodiments, grooves 116 can also be provided on the surfaces of the first heat transfer unit 126 and the second heat transfer unit 128 facing each other, forming a receiving space between the first heat transfer unit 126 and the second heat transfer unit 128, in which the power chip 104 can be installed.

[0050] In some embodiments, the first heat transfer unit 126 has a first heat transfer surface 130 facing the power chip 104, and the second heat transfer unit 128 has a second heat transfer surface 132 facing the power chip 104. The power chip 104 has a first surface 120 facing the first heat transfer surface 130 and a second surface 122 facing the second heat transfer surface 132. The area of ​​the first heat transfer surface 130 is the same as the area of ​​the first surface 120; and / or, the area of ​​the second heat transfer surface 132 is the same as the area of ​​the second surface 122.

[0051] In some embodiments, the power chip 104 generates a large amount of heat when operating at high power. If the contact area between the heat transfer unit 106 and the chip surface is insufficient, it may lead to an increase in interface thermal resistance, affecting heat dissipation efficiency. In this embodiment, by setting the area of ​​the first heat transfer surface 130 to be the same as the area of ​​the first surface 120, and / or the area of ​​the second heat transfer surface 132 to be the same as the area of ​​the second surface 122, the contact area of ​​the heat transfer interface can be maximized, which can effectively reduce the thermal resistance of the contact interface and improve the heat conduction efficiency.

[0052] In a specific example, the area of ​​the first surface 120 is the same as the area of ​​the first heat transfer surface 130, and the area of ​​the second surface 122 is the same as the area of ​​the second heat transfer surface 132. In this case, the heat generated by the power chip 104 during high-power operation can be quickly dissipated.

[0053] Please see Figure 8 In some embodiments, the power chips 104 are multiple and are fixedly connected to the same heat transfer unit 106.

[0054] Due to space constraints in the circuit board 100, each power chip 104 may be matched with a heat transfer unit 106, potentially leading to insufficient space. To quickly dissipate heat from multiple power chips 104 and accommodate the space limitations of the circuit layout, in this embodiment, multiple power chips 104 may need to be integrated into the same heat transfer unit 106. Specifically, multiple power chips 104 can be fixed side-by-side to the same surface of the heat transfer unit 106 by sintering or welding, with each power chip 104's surface forming a stable contact with the heat transfer unit 106. Alternatively, in some embodiments, multiple grooves 116 can be provided on the surface of the heat transfer unit 106, each groove matching the size of a single power chip 104, with each power chip 104 positioned within a groove 116, resulting in a more reasonable overall configuration for the power module 102.

[0055] In this embodiment, a receiving space can be provided within the heat transfer unit 106 to correspond to the multiple power chips 104. Of course, in some embodiments, the heat transfer unit may also have multiple receiving spaces internally, each corresponding to one power chip. Alternatively, in some embodiments, several receiving spaces may correspond to one power chip. For example, if there are 10 receiving spaces, one receiving space may correspond to one power chip, two receiving spaces may correspond to one power chip, or one receiving space may correspond to two power chips. Naturally, those skilled in the art can arrange the spaces according to actual needs.

[0056] Please see Figure 9 In some embodiments, the circuit board 100 has a multi-layer structure, including a core layer 138 located inside the multi-layer structure, and the power module 102 is embedded in the core layer 138.

[0057] In this embodiment, the circuit board 100 adopts a multi-layer structure design. The circuit board 100 includes a core layer 138 located inside the multi-layer structure, and the power module 102 is embedded in the core layer 138. The circuit board 100 may include multiple conductive layers and insulating layers stacked alternately, wherein the core layer 138 may include an insulating material layer wrapped by two core conductive layers. The core layer 138 has a first side and a second side. A first insulating layer 140 and a first conductive layer 142 are provided on the first side of the core layer 138, and a second insulating layer 144 and a second conductive layer 146 are provided on the second side. The power chip 104 is located on the first side. A via is provided in the first insulating layer 140 at the position corresponding to the power chip 104, and conductive material is disposed in the via, so that the power chip 104 is electrically connected to the first conductive layer 142. A via is also provided in the second insulating layer 144 at the position corresponding to the heat transfer unit 106, and heat-conducting material is contained therein, so that the heat of the heat transfer unit 106 can be easily conducted into the second conductive layer 146, facilitating heat diffusion in the heat transfer unit 106.

[0058] In some embodiments, a third insulating layer 148 and a third conductive layer 150 are also provided on the second side adjacent to the second conductive layer 146 to achieve corresponding circuit functions. In some cases, the multiple insulating layers are formed of a material with high thermal conductivity to facilitate heat dissipation. In some embodiments, the third conductive layer 150 serves as the outermost metal layer of the multilayer structure in the circuit board 100 and is further used to connect the heat sink 152.

[0059] In this embodiment, the third conductive layer 150 can be made of a metal with high thermal conductivity, such as copper or aluminum, and is stably connected to the external heat sink 152 by welding or mechanical fixing. Specifically, when the power module 102 generates heat during operation, the heat diffuses outward from the core layer 138 to the third conductive layer 150. In some embodiments, the heat can also be directly conducted to the outer third conductive layer 150 via thermally conductive vias. Heat can be quickly transferred to the heat sink 152 through the third conductive layer 150. In this way, heat can be quickly dissipated through the heat sink 152.

[0060] This application also provides an electronic device. The electronic device is equipped with the aforementioned circuit board. The electronic device can be a power conversion device, such as an inverter or converter.

[0061] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications or equivalent substitutions made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A circuit board, characterized by, The circuit board has an embedded power module; wherein the power module includes a power chip and a heat transfer unit that are fixedly connected, and the heat transfer unit contains a phase change material. A groove is provided on one surface of the heat transfer unit, and the power chip is disposed in the groove.

2. The circuit board according to claim 1, characterized in that, The power chip and the heat transfer unit are connected by sintering or welding.

3. The circuit board according to claim 1, characterized in that, The heat transfer unit includes a fixed cover and a base, which together form a containment space for accommodating the phase change material.

4. The circuit board of claim 3, wherein The number of containment spaces is multiple.

5. The circuit board of claim 1, wherein, The power chip has a first surface and a second surface that are opposite to each other, and a side surface located between the first surface and the second surface; The second surface and the side surface are in contact with the groove wall.

6. The circuit board according to claim 1, characterized in that, The power chips are multiple and are fixedly connected to the same heat transfer unit.

7. The circuit board of claim 1, wherein The circuit board has a multi-layer structure, including a core layer located inside the multi-layer structure, and the power module is embedded in the core layer.

8. The circuit board according to claim 7, characterized in that, The circuit board includes a metal layer located on the outside of the multilayer structure, the metal layer being used to connect a heat sink.

9. A circuit board, characterized by The circuit board has an embedded power module; wherein the power module includes a power chip and a heat transfer unit that are fixedly connected, and the heat transfer unit contains a phase change material. The heat transfer unit includes a first heat transfer unit and a second heat transfer unit, and the power chip is disposed between the first heat transfer unit and the second heat transfer unit.

10. The circuit board of claim 9, wherein, The first heat transfer unit has a first heat transfer surface facing the power chip, the second heat transfer unit has a second heat transfer surface facing the power chip, and the power chip has a first surface facing the first heat transfer surface and a second surface facing the second heat transfer surface. Wherein, the area of ​​the first heat transfer surface is the same as the area of ​​the first surface; and / or, the area of ​​the second heat transfer surface is the same as the area of ​​the second surface.

11. The circuit board of claim 9, wherein The power chip and the heat transfer unit are connected by sintering or welding.

12. The circuit board according to claim 9, characterized in that, The heat transfer unit includes a fixed cover and a base, which together form a containment space for accommodating the phase change material.

13. The circuit board of claim 12, wherein, The number of containment spaces is multiple.

14. The circuit board according to claim 9, characterized in that, The circuit board has a multi-layer structure, including a core layer located inside the multi-layer structure, and the power module is embedded in the core layer.

15. The circuit board of claim 14, wherein, The circuit board includes a metal layer located on the outside of the multilayer structure, the metal layer being used to connect a heat sink.

16. An electronic device, comprising: The electronic device is equipped with a circuit board as described in any one of claims 1 to 15.

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