Patent Publication Number: US-2023139725-A1

Title: Power module

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Chinese application no. 202111300339.X, filed on Nov. 4, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND 
     Technical Field 
     The disclosure relates to a power module. Particularly, the disclosure relates to a power module with good heat dissipation efficiency. 
     Description of Related Art 
     Currently, in application to electric vehicles, data centers, artificial intelligence, machine learning, etc., it is required that a power module can achieve high-performance power transmission, and has an internal structure of compact arrangement so as to increase power density. Such a power module generates high heat during operation. Currently, a plurality of heat dissipation fins are disposed in combination with fans to improve the heat dissipation performance of the power module. However, since heat dissipation fins and fans are relatively space-occupying, it may be difficult for the power module to meet the requirements of compact arrangement. 
     SUMMARY 
     The disclosure provides a power module that achieves good heat dissipation. 
     In the disclosure, a power module includes a first shell, a second shell, a circuit board assembly, and a heat dissipation encapsulation. The second shell is closed relative to the first shell and forms an accommodating space together with the first shell. The circuit board assembly is disposed in the accommodating space, and includes a circuit board body, a plurality of power components disposed on the circuit board body, and a plurality of electrical connectors electrically connected to the circuit board body. The electrical connectors are exposed from the first shell. The heat dissipation encapsulation is filled in the accommodating space and covers the circuit board assembly. 
     In an embodiment of the disclosure, the circuit board body includes a first surface and a second surface opposite to each other. A part of the power components is disposed on the first surface of the circuit board body, and another part of the power components is disposed on the second surface of the circuit board body. 
     In an embodiment of the disclosure, the circuit board body is an insulated metal substrate. The circuit board body includes a heat dissipation layer, an insulating layer, and a circuit layer stacked in sequence. The power components are disposed on the circuit layer. 
     In an embodiment of the disclosure, the heat dissipation layer is thermally coupled to the second shell. 
     In an embodiment of the disclosure, a thickness of the heat dissipation layer is greater than a thickness of the insulating layer, and the thickness of the heat dissipation layer is greater than a thickness of the circuit layer. 
     In an embodiment of the disclosure, the electrical connectors include a plurality of electrically conductive pillars. The circuit board body includes a first surface. At least a part of the power components is disposed on the first surface. The first shell includes a plurality of holes. The electrically conductive pillars protrude from the first surface, pass through the holes, and protrude from the first shell. 
     In an embodiment of the disclosure, the electrical connectors include a plurality of electrically conductive bars connected to side edges of the circuit board body. The first shell includes a plurality of sidewalls and a plurality of through slots located on the sidewalls. The electrically conductive bars are located in the through slots and spaced apart from the first shell. 
     In an embodiment of the disclosure, each of the electrically conductive bars is in a shape of a U-shaped bar. 
     In an embodiment of the disclosure, the electrically conductive bars are flush with or below a surface of the first shell away from the second shell. 
     In an embodiment of the disclosure, the electrical connectors are located around the power components. 
     In an embodiment of the disclosure, the power components include an inductor, a transistor, a coil transformer, or a planar transformer. 
     In an embodiment of the disclosure, a thermal conductivity coefficient of the second shell is greater than or equal to a thermal conductivity coefficient of the first shell, and the heat dissipation encapsulation is thermally coupled to the second shell. 
     In an embodiment of the disclosure, a material of the first shell includes metal or a ceramic material. 
     In an embodiment of the disclosure, a material of the second shell includes aluminum or copper. 
     In an embodiment of the disclosure, the first shell is a box, and the second shell is a thermally conductive plate. 
     In an embodiment of the disclosure, the first shell is a plate, and the second shell is a thermally conductive box. 
     In an embodiment of the disclosure, a thermal conductivity coefficient of the second shell is greater than or equal to a thermal conductivity coefficient of the first shell, and a surface area of the second shell is greater than a surface area of the first shell. 
     In an embodiment of the disclosure, the power module does not include a heat dissipation fin. 
     In an embodiment of the disclosure, the heat dissipation encapsulation is in direct contact with the first shell and the second shell. 
     In an embodiment of the disclosure, the heat dissipation encapsulation is in direct contact with the power components. 
     Based on the foregoing, the second shell of the power module according to the embodiments of the disclosure is closed relative to the first shell and forms the accommodating space together with the first shell. The circuit board assembly is disposed in the accommodating space and includes the power components. The heat dissipation encapsulation is filled in the accommodating space and covers the circuit board assembly. In the power module of the disclosure, with the above design, the heat dissipation encapsulation filled in the accommodating space can effectively transfer the high heat generated by the circuit board assembly to the shells to improve the heat dissipation efficiency. Compared with the conventional structure, which needs to lower the temperature using heat dissipation fins that occupy a larger space, the power module of the disclosure has a smaller volume and a more compact component arrangement, thereby achieving high power density. 
     To make the aforementioned more comprehensible, several embodiments accompanied with drawings are described in detail as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure. 
         FIG.  1    is a schematic view of appearance of a power module according to an embodiment of the disclosure. 
         FIG.  2    is a perspective view of the power module of  FIG.  1   . 
         FIG.  3    is a schematic view of a first shell of the power module of  FIG.  1    being moved up. 
         FIG.  4    is a schematic side view of the circuit board assembly of the power module of  FIG.  1   . 
         FIG.  5    is a schematic side view of a circuit board assembly of a power module according to another embodiment of the disclosure. 
         FIG.  6    is a schematic view of a power module according to another embodiment of the disclosure. 
         FIG.  7    is a schematic view of a power module according to another embodiment of the disclosure. 
         FIG.  8    is a schematic view of a power module according to another embodiment of the disclosure. 
         FIG.  9    is a perspective view of the power module of  FIG.  8   . 
         FIG.  10    is a schematic perspective view of a power module according to another embodiment of the disclosure. 
         FIG.  11    is a schematic view of a first shell of the power module of  FIG.  10    being moved up. 
         FIG.  12    is a schematic side view of a circuit board assembly of the power module of  FIG.  10   . 
         FIG.  13    is a schematic side view of a circuit board assembly of a power module according to another embodiment of the disclosure. 
         FIG.  14    is a schematic view of a power module according to another embodiment of the disclosure. 
         FIG.  15    is a schematic view of a power module according to another embodiment of the disclosure. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
       FIG.  1    is a schematic view of appearance of a power module according to an embodiment of the disclosure.  FIG.  2    is a perspective view of the power module of  FIG.  1   .  FIG.  3    is a schematic view of a first shell of the power module of  FIG.  1    being moved up. With reference to  FIG.  1    to  FIG.  3   , a power module  100  of this embodiment includes a first shell  110 , a second shell  120 , a circuit board assembly  130  ( FIG.  2   ), and a heat dissipation encapsulation  160  ( FIG.  2   ). 
     The second shell  120  is closed relative to the first shell  110  and forms an accommodating space  125  ( FIG.  2   ) together with the first shell  110 . As shown in  FIG.  3   , in this embodiment, the first shell  110  is a box, and the second shell  120  is a thermally conductive plate, but the shapes of the first shell  110  and the second shell  120  are not limited thereto. The first shell  110  includes a plurality of sidewalls  114  and a top plate  113 . In addition, in this embodiment, a thermal conductivity coefficient of the second shell  120  is greater than or equal to a thermal conductivity coefficient of the first shell  110 . A material of the first shell  110  is, for example, metal or a ceramic material. A material of the second shell  120  is, for example, a material with high thermal conductivity, such as aluminum or copper. Nonetheless, the materials of the first shell  110  and the second shell  120  are not limited thereto. 
     As shown in  FIG.  2   , the circuit board assembly  130  is disposed in the accommodating space  125 . The circuit board assembly  130  includes a circuit board body  131 , a plurality of power components  140 ,  141 , and  142  disposed on the circuit board body  131 , and a plurality of electrical connectors  150  electrically connected to the circuit board body  131 . In this embodiment, the power components  140 ,  141 , and  142  include a transformer (e.g., the power component  140 ), an inductor (e.g., the power component  141 ), and a transistor (e.g., the power component  142  of  FIG.  4   ). Nonetheless, the types of the power components  140 ,  141 , and  142  are not limited thereto. 
       FIG.  4    is a schematic side view of the circuit board assembly  130  of the power module  100  of  FIG.  1   . With reference to  FIG.  4   , in this embodiment, the circuit board body  131  is a multilayer circuit board. The circuit board body  131  includes a first surface  132  and a second surface  133  opposite to each other. The power components  140  and  141  are disposed on the first surface  132  of the circuit board body  131 , and the power component  142  is disposed on the second surface  133  of the circuit board body  131 . 
     With reference back to  FIG.  2   , the electrical connectors  150  are located around the power components  140  and  141 . The electrical connectors  150  are electrically connected to the circuit board body  131  and are exposed from the first shell  110 . Specifically, in this embodiment, the electrical connectors  150  include a plurality of electrically conductive pillars  152 . The first shell  110  includes a plurality of holes  112 . The electrically conductive pillars  152  protrude from the first surface  132  of the circuit board body  131 , pass through the holes  112  of the first shell  110 , and protrude from the first shell  110 . Therefore, the circuit board assembly  130  of the power module  100  may be connected to an external motherboard (not shown) through the portion of the electrically conductive pillars  152  protruding from the first shell  110 . 
     In addition, the heat dissipation encapsulation  160  is filled in the accommodating space  125  and covers the circuit board assembly  130 . In this embodiment, the heat dissipation encapsulation  160  covers the power components  140 ,  141 , and  142 , and is filled in the space between the circuit board body  131  and the first shell  110  and the space between the circuit board body  131  and the second shell  120 . In other words, the heat dissipation encapsulation  160  is thermally coupled to the circuit board assembly  130 , the first shell  110 , and the second shell  120 . In this embodiment, the heat dissipation encapsulation  160  is in direct contact with the first shell  110 , the second shell  120 , and the power components  140 ,  141 , and  142 . 
     Therefore, during operation of the power module  100 , the high heat generated by the power components  140 ,  141 , and  142  may be conducted to the first shell  110  and the second shell  120  through the heat dissipation encapsulation  160  to improve the heat dissipation efficiency. The power module  100  may subsequently be connected to a water cooler (not shown), so that the heat energy conducted to the first shell  110  and the second shell  120  can be taken away by the water cooler to lower the temperature of the power module  100 . 
     In an embodiment, since the power module  100  is connected to the motherboard through the electrical connectors  150  protruding from the first shell  110 , the water cooler may be disposed on a surface of the second shell  120  away from the first shell  110 , but the position of the water cooler is not limited thereto. 
     It is worth mentioning that, as shown in  FIG.  2   , in this embodiment, the power module  100  does not include heat dissipation fin disposed therein. Compared with the conventional structure, which needs to lower the temperature using heat dissipation fins that occupy a larger space, the power module  100  of this embodiment has a smaller volume and a more compact component arrangement. Therefore, the power density of the power module  100  of this embodiment can be significantly improved. 
     In an embodiment, the dimensions of length, width, and height of the power module  100  may be 200 millimeters (mm), 100 mm, and 57 mm. In another embodiment, the dimensions of length, width, and height of the power module  100  may be 120 mm, 60 mm, and 35 mm. Under such small sizes, the power module  100  achieves high current transmission, which may reach up to 1,000 amperes, and has good performance. 
       FIG.  5    is a schematic side view of a circuit board assembly of a power module according to another embodiment of the disclosure. With reference to  FIG.  5   , the main difference between a circuit board assembly  130   a  of  FIG.  5    and the circuit board assembly  130  of  FIG.  4    lies in the types of a circuit board body  131   a  and the circuit board body  131 . In this embodiment, the circuit board body  131   a  is an insulated metal substrate (IMS). The circuit board body  131   a  includes a heat dissipation layer  134 , an insulating layer  135 , and a circuit layer  136  stacked in sequence. A thickness of the heat dissipation layer  134  is greater than a thickness of the insulating layer  135 , and the thickness of the heat dissipation layer  134  is greater than a thickness of the circuit layer  136 , which achieves better heat dissipation. Since the bottom of the circuit board body  131   a  is the heat dissipation layer  134 , it achieves better heat dissipation. In addition, in this embodiment, the power components  140 ,  141 , and  142  are each disposed on the circuit layer  136 , namely on the first surface  132 . 
       FIG.  6    is a schematic view of a power module according to another embodiment of the disclosure. With reference to  FIG.  6   , the main difference between a power module  100   b  of  FIG.  6    and the power module  100  of  FIG.  2    lies in the shapes of a first shell  110   b  and the first shell  110  and the shapes of a second shell  120   b  and the second shell  120 . In this embodiment, the first shell  110   b  is a plate  113 , and the second shell  120   b  is a thermally conductive box. Nonetheless, the shapes of the first shell  110   b  and the second shell  120   b  are not limited thereto. 
     Likewise, in this embodiment, a thermal conductivity coefficient of the second shell  120   b  is greater than or equal to a thermal conductivity coefficient of the first shell  110   b.  A material of the first shell  110   b  is, for example, metal or a ceramic material. A material of the second shell  120   b  is, for example, a material with high thermal conductivity, such as aluminum or copper. Nonetheless, the materials of the first shell  110   b  and the second shell  120   b  are not limited thereto. 
     Since a size and a surface area of the second shell  120   b  are greater than a size and a surface area of the first shell  110   b,  and the thermal conductivity coefficient of the second shell  120   b  is greater than or equal to the thermal conductivity coefficient of the first shell  110   b,  the power module  100   b  of this embodiment achieves better heat dissipation. 
       FIG.  7    is a schematic view of a power module according to another embodiment of the disclosure. With reference to  FIG.  7   , the main difference between a power module  100   c  of  FIG.  7    and the power module  100  of  FIG.  2    lies in the types of a power component  143  ( FIG.  7   ) and the power components  140 ,  141 , and  142  ( FIG.  2   ). In this embodiment, the power component  143  includes two planar transformers. 
     In other words, in the power module  100   c,  the power component  143  as required may be selected depending on the requirements. Then, the heat energy generated by the power component  143  may be conducted to the first shell  110  and the second shell  120  by utilizing the heat dissipation encapsulation  160 . Later, the heat energy may be taken away by a water cooler (not shown) to achieve good heat dissipation and high power density. 
       FIG.  8    is a schematic view of a power module according to another embodiment of the disclosure.  FIG.  9    is a perspective view of the power module of  FIG.  8   . With reference to  FIG.  8    to  FIG.  9   , the main difference between a power module  100   d  of  FIG.  9    and the power module  100  of  FIG.  2    lies in the types of a plurality of electrical connectors  150   d  and the electrical connectors  150 . 
     In this embodiment, the electrical connectors  150   d  include a plurality of electrically conductive bars  154  connected to side edges  137  of the circuit board body  131  to be conductive with the circuit board body  131 . Each of the electrical connectors  150   d  is in a shape of, for example, a U-shaped bar. The electrical connectors  150  are exposed from the first shell  110 , and the opening of the U-shape faces outwards. 
     Specifically, the first shell  110  includes a plurality of sidewalls  114   d,  a plurality of through slots  116  located on the sidewalls  114   d,  a plate  113   d  connected to the sidewalls  114   d,  and a plurality of recessed holes  117  located on the plate  113   d.  The positions of the recessed holes  117  correspond to the positions of the through slots  116 . In this embodiment, the first shell  110  is, for example, metal. The electrically conductive bars  154  are located in the through slots  116  and the recessed holes  117  and are spaced apart from the first shell  110  to prevent a short circuit. In this embodiment, the electrically conductive bars  154  are flush with or below a surface (i.e., an upper surface) of the first shell  110  away from the second shell  120 . In other words, the electrically conductive bars  154  do not extend beyond the upper surface of the first shell  110 . 
     When the power module  100   d  of this embodiment is mounted on the motherboard, electrically conductive ribs of the motherboard (not shown) may extend into U-shaped recessed grooves of the electrical connectors  150   d  to be aligned with and conductive with the power module  100   d.  Specifically, the electrically conductive rib of the motherboard is in a shape of, for example, a cylinder (but not limited thereto). The outer contour of the electrically conductive rib corresponds to the inner contour of the U-shaped recessed groove of the electrical connectors  150   d . Therefore, when the power module  100   d  is mounted on the motherboard, the electrically conductive ribs of the motherboard are inserted into the U-shaped recessed groove of the electrical connectors  150   d.  In other words, the electrical connectors  150   d  contacts/encloses a part of the electrically conductive ribs of the motherboard and are conductive. 
       FIG.  10    is a schematic perspective view of a power module according to another embodiment of the disclosure.  FIG.  11    is a schematic view of a first shell of the power module of  FIG.  10    being moved up.  FIG.  12    is a schematic side view of a circuit board assembly of the power module of  FIG.  10   . With reference to  FIG.  10    to  FIG.  12   , the main difference between a power module  100   e  of  FIG.  10    and the power module  100  of  FIG.  2    lies in the types of a power component  144  ( FIG.  10   ) and the power components  140  and  141  ( FIG.  2   ). 
     In this embodiment, the power component  144  includes a coil transformer. Nonetheless, the types of the power component  144  are not limited thereto. As shown in  FIG.  12   , the power component  144  (a coil transformer) is disposed on the first surface  132  of the circuit board body  131 , and the power component  142  (a transistor) is disposed on the second surface  133  of the circuit board body  131 . 
       FIG.  13    is a schematic side view of a circuit board assembly of a power module according to another embodiment of the disclosure. With reference to  FIG.  13   , the main difference between a power module  100   f  of  FIG.  13    and the power module  100   e  of  FIG.  12    lies in the following. In this embodiment, the circuit board body  131   a  is an insulated metal substrate (IMS). The circuit board body  131   a  includes the heat dissipation layer  134 , the insulating layer  135 , and the circuit layer  136  stacked in sequence. The power component  144  (a coil transformer) and the power components  142  (a transistor) are each disposed on the circuit layer  136 . 
       FIG.  14    is a schematic view of a power module according to another embodiment of the disclosure. With reference to  FIG.  14   , the main difference between a power module  100   g  of  FIG.  14    and the power module  100   e  of  FIG.  11    lies in that, in this embodiment, the first shell  110   b  is a plate  113 , and the second shell  120   b  is a thermally conductive box. Nonetheless, the shapes of the first shell  110   b  and the second shell  120   b  are not limited thereto. 
     Likewise, in this embodiment, the thermal conductivity coefficient of the second shell  120   b  is greater than or equal to the thermal conductivity coefficient of the first shell  110   b.  The material of the first shell  110   b  is, for example, metal or a ceramic material. The material of the second shell  120   b  is, for example, a material with high thermal conductivity, such as aluminum or copper. Nonetheless, the materials of the first shell  110   b  and the second shell  120   b  are not limited thereto. 
     Since the size and the surface area of the second shell  120   b  are greater than the size and the surface area of the first shell  110   b,  and the thermal conductivity coefficient of the second shell  120   b  is greater than or equal to the thermal conductivity coefficient of the first shell  110   b,  the power module  100   g  of this embodiment achieves better heat dissipation. 
       FIG.  15    is a schematic view of a power module according to another embodiment of the disclosure. With reference to  FIG.  15   , the main difference between a power module  100   h  of  FIG.  15    and the power module  100   e  of  FIG.  11    lies in the types of the electrical connectors  150   d  and the electrical connectors  150 . In this embodiment, the electrical connectors  150   d  include the electrically conductive bars  154  connected to the side edges  137  of the circuit board body  131 . 
     A first shell  110   d  includes the sidewalls  114   d,  the through slots  116  located on the sidewalls  114   d,  the plate  113   d  connected to the sidewalls  114   d,  and the recessed holes  117  located on the plate  113   d.  The positions of the recessed holes  117  correspond to the positions of the through slots  116 . The electrically conductive bars  154  are located in the through slots  116  and the recessed holes  117  and are spaced apart from the first shell  110   d.    
     When the power module  100   h  of this embodiment is mounted on the motherboard, the electrically conductive ribs of the motherboard (not shown) may extend into the U-shaped recessed grooves of the electrical connectors  150   d  to be aligned with and conductive with the power module  100   h.  Specifically, the electrically conductive rib of the motherboard is in a shape of, for example, a cylinder (but not limited thereto). The outer contour of the electrically conductive rib corresponds to the inner contour of the U-shaped recessed groove of the electrical connectors  150   d.  Therefore, when the power module  100   h  is mounted on the motherboard, the electrically conductive ribs of the motherboard are inserted into the U-shaped recessed groove of the electrical connectors  150   d.  In other words, the electrical connectors  150   d  contacts/encloses a part of the electrically conductive ribs of the motherboard and are conductive. 
     In summary of the foregoing, the second shell of the power module according to the embodiments of the disclosure is closed relative to the first shell and forms the accommodating space together with the first shell. The circuit board assembly is disposed in the accommodating space and includes the power components. The heat dissipation encapsulation is filled in the accommodating space and covers the circuit board assembly. In the power module of the disclosure, with the above design, the heat dissipation encapsulation filled in the accommodating space can effectively transfer the high heat generated by the circuit board assembly to the shells to improve the heat dissipation efficiency. Compared with the conventional structure, which needs to lower the temperature using heat dissipation fins that occupy a larger space, the power module of the disclosure has a smaller volume and a more compact component arrangement, thereby achieving high power density. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure covers modifications and variations provided that they fall within the scope of the following claims and their equivalents.