Patent Publication Number: US-9425123-B2

Title: Electronic device having heat conducting member

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based on Japanese Patent Application No. 2014-237656 filed on Nov. 25, 2014, the disclosure of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to an electronic device including a semiconductor module, a wiring substrate and a case member, and radiating heat generated in the semiconductor module through a heat conducting member. 
     BACKGROUND 
     For example, an electronic control unit disclosed in JP 2014-154745 A (patent literature 1) is an electronic device including a semiconductor module, a wiring substrate and a case member, and radiating heat generated in the semiconductor module through the case member. 
     The electronic control unit disclosed in the patent literature 1 includes a semiconductor module, a substrate, a frame end and a first heat conducting member. The substrate and the frame end correspond to the wiring substrate and the case member. 
     The semiconductor module includes a body with a rectangular parallelepiped shape, and terminal portions projecting from a side surface of the body. The semiconductor module further includes a first metallic board exposing from a surface of the body portion opposing to the substrate. The first metallic board corresponds to the terminal portion. The substrate has a first wiring pattern to which the first metallic board is electrically connected, and second wiring patterns to which the terminal portions are connected. The frame end is made of metal. The frame end includes a body portion opposing to the substrate, to which the semiconductor module is electrically connected. The frame end further includes a first specific shape portion projecting from the body portion toward the substrate and forming a small first clearance with the first wiring pattern. In order to form the small first clearance, the first specific shape portion projects to a position nearer the first wiring pattern than a surface of the body of the semiconductor module opposing to the frame end. The first heat conducting member has an electrical insulation property and is disposed in the first clearance. 
     Heat generated in the semiconductor module is conducted to the first specific shape portion through the first metallic board, the first wiring pattern and the first heat conducting member. Then, the heat is radiated outside through the body portion of the frame end. 
     SUMMARY 
     In the electronic control unit described above, the body portion of the frame end has the first specific shape portion projecting toward the substrate and to the position nearer the first wiring pattern than the surface of the body of the semiconductor module opposing to the frame end. Therefore, the frame end has a complicated shape. 
     When the first specific shape portion is arranged near the semiconductor module, a distance from the semiconductor module to the first specific shape portion decreases, and thermal resistance of a heat conducting passage decreases. As a result, heat radiation performance increases. On the other hand, possibility of a short between the semiconductor module and the first specific shape portion increases. 
     Conversely, when the first specific shape portion is arranged far from the semiconductor module, the distance from the semiconductor module to the first specific shape portion increases, and the possibility of the short between the semiconductor module and the first specific shape portion decreases. On the other hand, the thermal resistance of the heat conducting passage increases, and the heat radiation performance decreases. 
     It is an object of the present disclosure to provide an electronic device having a case member with a simple shape, and capable of restricting a short and increasing heat radiation performance. 
     According to an aspect of the present disclosure, an electronic device includes a semiconductor module, a wiring substrate, a case member, a heat conducting member. The semiconductor module has a body portion with a rectangular parallelepiped shape and a plurality of terminal portions projecting from two of four side surfaces of the body portion. The two of the four side surfaces of the body portion are referred to as terminal projecting surfaces. The other two of the four side surfaces of the body portion are referred to as terminal non-projecting surfaces. The wiring substrate has a wiring pattern and a heat conducting pattern. The wiring pattern has a plurality of connecting portions each electrically connected to a corresponding one of the terminal portions. The wiring pattern also has a surface that is covered with a solder resist at least at a part. The heat conducting pattern has a surface that is not covered with the solder resist at least at a part. The heat conducting pattern is disposed adjacent to at least one of the terminal non-projecting surfaces of the body portion on a surface of the wiring substrate. The case member is opposed to the wiring substrate and spaced from the wiring substrate. The heat conducting member thermally connects a predetermined portion of the wiring pattern and the heat conducting pattern to a predetermined heat conduction region of the case member. The predetermined heat conduction region is a surface of the case member opposing to the wiring substrate and is located further from the wiring substrate than a surface of the body portion opposing to the case member. 
     According to a structure described above, the electronic device includes the heat conducting member. The heat conducting member thermally connects the predetermined portion of the wiring pattern and the heat conducting pattern to the predetermined heat conduction region of the case member. The predetermined heat conduction region is the surface of the case member opposing to the wiring substrate and is located further from the wiring substrate than the surface of the body portion opposing to the case member. Therefore, the case member needs not to have a portion projecting toward the wiring substrate and to a position nearer the wiring pattern than the surface of the body portion opposing to the case member. Hence, heat can be radiated from the case member with a simple shape. Since the projecting portion of the case member is not arranged near the semiconductor module, a short is less likely to occur. Also, the electronic device includes the wiring substrate having the heat conducting pattern. The heat conducting pattern is disposed adjacent to at least one of the terminal non-projecting surfaces of the body portion on the surface of the wiring substrate. Hereinafter, areas of the surface of the wiring substrate adjacent to the terminal non-projecting surfaces of the body portion are referred to as terminal non-corresponding areas. Areas of the surface of the wiring substrate adjacent to the terminal projecting surfaces are referred to as terminal corresponding areas. That is, the heat conducting pattern is disposed at one of the terminal non-corresponding areas of the surface of the wiring substrate and has the surface that is not covered with the solder resist at least at a part. The wiring pattern, which is electrically connected to at least one of the terminal portions, is disposed at one of the terminal corresponding areas of the surface of the wiring substrate. On the other hand, the wiring pattern is not disposed at any of the terminal non-corresponding areas of the surface of the wiring substrate. Therefore, the heat conducting pattern can be disposed at the one of the terminal non-corresponding areas. As such, an area of a heat conducting passage can be increased compared to a case where the heat is conducted to the case member only through the wiring pattern. Also, since the heat conducting pattern has the surface that is not covered with the solder resist at least at a part, thermal resistance can be decreased and heat radiation performance can be increased. As a result, an occurrence of the short can be restricted and the heat radiation performance can be increased without complicating a shape of the case member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description made with reference to the accompanying drawings, in which like parts are designated by like reference numbers and in which: 
         FIG. 1  is a cross-sectional view of a motor control device according to a first embodiment; 
         FIG. 2  is a plan view of a FET module shown in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view taken along a line III-III in  FIG. 2 ; 
         FIG. 4  is a cross-sectional view taken along a line IV-IV in  FIG. 2 ; 
         FIG. 5  is a cross-sectional view taken along a line V-V in  FIG. 2 ; 
         FIG. 6  is a plan view of a wiring substrate shown in  FIG. 1 ; 
         FIG. 7  is a cross-sectional view taken along a line VII-VII in  FIG. 6 ; 
         FIG. 8  is a cross-sectional view taken along a line VIII-VIII in  FIG. 6 ; 
         FIG. 9  is a cross-sectional view taken along a line IX-IX in  FIG. 6 ; 
         FIG. 10  is a plan view of the motor control device according to the first embodiment; 
         FIG. 11  is a cross-sectional view taken along a line XI-XI in  FIG. 10 ; 
         FIG. 12  is a cross-sectional view taken along a line XII-XII in  FIG. 10 ; 
         FIG. 13  is a cross-sectional view taken along a line XIII-XIII in  FIG. 10 ; 
         FIG. 14  is a plan view of a wiring substrate according a modification of the first embodiment; 
         FIG. 15  is a cross-sectional view of a FET module of a second embodiment taken along a line corresponding to the line of  FIG. 2 ; 
         FIG. 16  is a cross-sectional view of the FET module of the second embodiment, taken along a line corresponding to the line IV-IV of  FIG. 2 ; 
         FIG. 17  is a cross-sectional view of the FET module of the second embodiment, taken along a line corresponding to the line V-V of  FIG. 2 ; 
         FIG. 18  is a cross-sectional view of a motor control device of the second embodiment, taken along a line corresponding to the line XI-XI of  FIG. 2 ; 
         FIG. 19  is a cross-sectional view of the motor control device of the second embodiment, taken along a line corresponding to the line XII-XII of  FIG. 2 ; and 
         FIG. 20  is a cross-sectional view of the motor control device of the second embodiment, taken along a line corresponding to the line XIII-XIII of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure will be described. In the embodiments, an example where an electronic device according the present disclosure is employed to a motor control device equipped to a vehicle and controlling a motor will be described. 
     First Embodiment 
     A structure of a motor control device of a first embodiment will be described with reference to  FIG. 1  to  FIG. 13 . Hereinafter, a vertical direction and a horizontal direction in the description correspond to a vertical direction and a horizontal direction in the drawings. Namely, “right”, “left”, “upper” “lower”, “top” and “bottom” correspond to respective directions in the drawings. 
     A motor control device  1  (electronic device) shown in  FIG. 1  is equipped to a vehicle and controls a motor assisting a steering of a steering wheel. The motor control device  1  includes a FET module  10  (semiconductor module), a wiring substrate  11 , a case member  12  and a heat conducting member  13 . 
     The FET module  10  is a surface-mounted element composing an inverter circuit. 
     As shown in  FIG. 2 , the FET module  10  includes a body portion  100 , drain terminal portions  101 , source terminal portions  102  and a gate terminal potion  103  in appearance. 
     The body portion  100  is made of resin and has a rectangular parallelepiped shape. 
     The drain terminal portions  101  provide drain terminals of the FET module  10 . There are four drain terminal portions  101  projecting from one of four side surfaces of the body portion  100 , such as a right side surface in  FIG. 2 . 
     The source terminal portions  102  provide source terminals of the FET module  10 . There are three source terminal portions  102  projecting from another one of the four side surfaces of the body portion  100 , such as a left side surface in  FIG. 2 . 
     The gate terminal portion  103  provides a gate terminal of the FET module  10 . The gate terminal portion  103  projects from the left side surface of the body portion  100 . The gate terminal portion  103  is shown lower than the source terminal portions  102  in  FIG. 2 , that is, located adjacent to further another side surface of the body portion  100 , such as a lower side surface in  FIG. 2 . Hereinafter, two of the four side surfaces of the body portion  100  from which the drain terminal portions  101 , the source terminal portions  102  and the gate terminal portion  103  project are referred to as terminal projecting surfaces. The other two of the four side surfaces of the body portion  100  from which the drain terminal portions  101 , the source terminal portions  102  and the gate terminal portion  103  do not project are referred to as terminal non-projecting surfaces. 
     As shown in  FIG. 3  to  FIG. 5 , the FET module  10  structurally includes a semiconductor chip  104 , a drain terminal member  105  (first terminal member), a source terminal member  106  and a gate terminal member  107 . In  FIG. 3  to  FIG. 5 , the drain terminal member  105 , the source terminal member  106  and the gate terminal member  107  are shown with dimensions emphasized compared to actual dimensions in the vertical direction for easier understanding. 
     The drain terminal member  105  is a thin metallic plate. The drain terminal member  105  includes the drain terminal portions  101 . The drain terminal portions  101  project from a bottom portion of the terminal projecting surface of the body portion  100 . The drain terminal member  105  further includes a predetermined portion other than the drain terminal portions  101 . Hereinafter, the predetermined portion of the drain terminal member  105  is referred to as a drain predetermined portion. The drain predetermined portion is electrically connected to a drain that is provided at a bottom surface of the semiconductor chip  104 . The drain predetermined portion has a bottom surface exposed from a surface of the body portion  100  opposing to the wiring substrate. That is, the drain predetermined portion is exposed from a bottom surface of the body portion  100 . In other words, the bottom surface of the drain predetermined portion is not covered with the body portion  100 . 
     As shown in  FIG. 3  and  FIG. 5 , the source terminal member  106  is a thin metallic plate. The source terminal member  106  includes the source terminal portions  102 . The source terminal portions  102  project from a bottom portion of the terminal projecting surface of the body portion  100 . The source terminal member  106  further includes a predetermined portion other than the source terminal portions  102 . Hereinafter, the predetermined portion of the source terminal member  106  is referred to as a source predetermined portion. The source predetermined portion is electrically connected to a source that is provided at a top surface of the semiconductor chip  104 . The source predetermined portion is implanted in the body portion  100 . 
     As shown in  FIG. 4 , the gate terminal member  107  is a thin metallic plate. The gate terminal member  107  includes the gate terminal portion  103 . The gate terminal portion  103  projects from the bottom portion of the terminal projecting surface of the body portion  100 . The gate terminal member  107  further includes a predetermined portion other than the gate terminal portion  103 . Hereinafter, the predetermined portion of the gate terminal member  107  is referred to as a gate predetermined portion. The gate predetermined portion is electrically connected to a gate that is provided at the top surface of the semiconductor chip  104 , through a wire (not illustrated). The gate predetermined portion is implanted in the body portion  100 . 
     The wiring substrate  11  shown in  FIG. 1  wires the FET module  10 . As shown in  FIG. 6  to  FIG. 9 , the wiring substrate  11  includes a substrate base  110 , wiring patterns  111  to  113 , heat conducting patterns  114 ,  115  and solder resist  116 . 
     The substrate base  110  is a resin board having an electrical insulation property. 
     The wiring pattern  111  is a member made of metal and having a thin plate shape. The wiring pattern  111  wires the drain terminal portions  101 . Also, the wiring pattern  111  conducts heat generated in the body portion  100 . The body portion  100  is arranged at a center portion of the wiring substrate  11  shown in  FIG. 6  in a state where the drain terminal portions  101  project form the right side surface of the body portion  100  and the source terminal portions  102  and the gate terminal portion  103  project from the left side surface of the body portion  100 . The wiring pattern  111  extends from the center portion of the wiring substrate  11  in a right direction, and extends in the vertical direction. The wiring pattern  111  has four connecting portions  111   a  to  111   d , which are electrically connected to the drain terminal portions  101 . The connecting portions  111   a  to  111   d  are arranged in the vertical direction at a right section of the center portion of the wiring substrate  11 . The wiring pattern  111  also has a connecting portion  111   e , which is electrically connected to the drain predetermined portion. The connecting portion  111   e  is disposed at the center portion of the wiring substrate  11 . The connecting portions  111   a  to  111   d  continuously extend from the connecting portion  111   e.    
     The wiring pattern  112  shown in  FIG. 6  and  FIG. 7  is a member made of metal and having a thin plate shape. The wiring pattern  112  wires the source terminal portions  102 . Also, the wiring pattern  112  conducts the heat generated in the body portion  100 . As shown in  FIG. 6 , the wiring pattern  112  extends in an upper direction along a left section of the center potion, and extends in a left direction. The wiring pattern  112  has three connecting portions  112   a  to  112   c , which are electrically connected to the source terminal portions  102 . The connecting portions  112   a  to  112   c  are arranged in the vertical direction at the left section of the center portion of the wiring substrate  11 . 
     The wiring pattern  113  shown in  FIG. 6  and  FIG. 8  is a member made of metal and having a thin plate shape. The wiring pattern  113  wires the gate terminal portion  103 . Also, the wiring pattern  113  conducts the heat generated in the body portion  100 . As shown in  FIG. 6 , the wiring pattern  113  extends in a lower direction along the left section of the center potion and extends in the left direction. The wiring pattern  113  is disposed lower than the wiring pattern  112 . The wiring pattern  113  has one connecting portion  113   a , which is electrically connected to the gate terminal portion  103 . The connecting portion  113   a  is disposed at the left section of the center portion of the wiring substrate  11  and lower than the wiring pattern  112 . 
     The heat conducting patterns  114 ,  115  shown in  FIG. 6  and  FIG. 9  are members made of metal and have a thin plate shape. The heat conducting patterns  114 ,  115  conduct the heat generated in the body portion  100 . As shown in  FIG. 6 , the heat conducting patterns  114 ,  115  extend in the horizontal direction at a portion above the center portion and a portion under the center portion. That is, the heat conducting pattern  114 ,  115  are located at opposite sides of the center portion of the wiring substrate  11 . In other words, the heat conducting patterns  114 ,  115  are disposed at portions of the surface of the wiring substrate  11 , the portions being adjacent to the terminal non-projecting surfaces the body portion  100 . Hereinafter, areas of the surface of the wiring substrate  11  adjacent to the terminal non-projecting surfaces of the body portion  100  are referred to as terminal non-corresponding areas. Areas of the surface of the wiring substrate  11  adjacent to the terminal projecting surfaces are referred to as terminal corresponding areas. The heat conducting patterns  114 ,  115  are disposed along the terminal non-projecting surfaces of the body portion  100  and disposed near the body portion  100 . The heat conducting patterns  114 ,  115  are integrally formed with the wiring pattern  111 . 
     The solder resist  116  shown in  FIG. 6  to  FIG. 9  is a member having the electrical insulation property. The solder resist  116  protects the surface of the wiring substrate  11 . Also, the solder resist  116  regulates flow of solder that is used for electrically connecting the FET module  10  to the wiring patterns  111  to  113 . The solder resist  116  covers the surface of the substrate base  110  of the wiring substrate  11 , except for the connecting portions  111   a  to  111   e ,  112   a  to  112   c ,  113   a , a predetermined portion of the wiring pattern  111  and the heat conducting patterns  114 ,  115 . The predetermined portion is a part of the wiring pattern  111  other than a first portion between the connecting portion  111   a  and the connecting portion  111   b  and a second portion between the connecting portion  111   c  and the connecting portion  111   d . Also, the predetermined portion of the wiring pattern  111  is adjacent to the connecting portions  111   a  to  111   e ,  112   a  to  112   c  and  113   a . Hereinafter, the predetermined portion of the wiring pattern  111  is referred to as a non-covered portion of the wiring pattern  111 . Therefore, surfaces of the connecting portions  111   a  to  111   e ,  112   a  to  112   c ,  113   a  of the wiring patterns  111  to  113  and the non-covered portion of the wiring pattern  111  are exposed from the solder resist  116 , that is, not covered with the solder resist  116 . The surfaces of the heat conducting patterns  114 ,  115  are entirely exposed from the solder resist  116 , that is, are not covered with the solder resist  116 . 
     As shown in  FIG. 10 , the body portion  100  is arranged at the center portion of the wiring substrate  11  in the state where the drain terminal portions  101  project form the right side surface of the body portion  100  and the source terminal portions  102  and the gate terminal portion  103  project from the left side surface of the body portion  100 . As shown in  FIG. 11  to  FIG. 13 , the drain terminal portions  101  are electrically connected to the connecting portions  111   a  to  111   d  through the solder  14 , and the drain predetermined portion is electrically connected to the connecting portion  111   e  through the solder  14 . As shown in  FIG. 10  and  FIG. 11 , the source terminal portions  102  are electrically connected to the connecting portions  112   a  to  112   c  through the solder  14 . As shown in  FIG. 10  and  FIG. 12 , the gate terminal portion  103  is electrically connected to the connecting portion  113   a  through the solder  14 . 
     The case member  12  shown in  FIG. 1  is a metallic board covering and protecting the wiring substrate  11  to which the FET module  10  is electrically connected. As shown in  FIG. 11  to  FIG. 13 , the case member  12  opposes to the wiring substrate  11  and is spaced from the wiring substrate  11 . A surface of the case member  12  opposing to the wiring substrate  11  is located higher than a surface of the body portion  100  opposing to the case member  12 . That is, the surface of the body portion  100  opposing to the case member  12  is located further from the wiring substrate  11  than the surface of the body portion  100  opposing to the case member  12 . 
     The heat conducting member  13  is a gel member having the electrical insulation property. The heat conducting member  13  thermally connects the wiring patterns  111  to  113  and the heat conducting patterns  114 ,  115  to the case member  12 . As shown in  FIG. 10  to  FIG. 13 , the heat conducting member  13  thermally connects predetermined portions of the wiring patterns  111  to  113  and the heat conducting patterns  114 ,  115  to the surface of the case member  12  opposing to the wiring substrate  11 , the predetermined portions of the wiring patterns  111  to  113  are nearby areas of the connecting portions  111   a  to  111   d ,  112   a  to  112   c ,  113   a . For example, the predetermined portions of the wiring patterns  111  to  113  correspond to areas of the wiring patterns  111  to  113  that overlap with the heat conducting member  13 . Also, the heat conducting member  13  thermally connects the body portion  100 , the drain terminal potions  101 , the source terminal portions  102  and the gate terminal portion  103  to the surface of the case member  12  opposing to the wiring substrate  11 . That is, the predetermined portions of the wiring patterns  111  to  113 , the heat conducting patterns  114 ,  115 , the body portion  100 , the drain terminal portions  101 , the source terminal portions  102  and the gate terminal portion  103  are thermally connected to a predetermined heat conduction region of the case member  12  through the heat conducting member  13 . The predetermined heat conduction region is a part of the surface of the case member  12  opposing to the wiring substrate  11 . The predetermined heat conduction region is located further from the wiring substrate  11  than the surface of the body portion  100  opposing to the case member  12 . As a result, the surface of the non-covered portion of the wiring pattern  111  and surfaces of the heat conducting patterns  114 ,  115  are thermally connected to the predetermined heat conduction region of the case member  12  through the heat conducting member  13  without the solder resist  116 . Surfaces of the first portion and the second portion of the wiring pattern  111  are thermally connected to the predetermined heat conduction region of the case member  12  through the solder resist  116  and the heat conducting member  13 . 
     Next, radiation of the motor control device of the first embodiment will be described with reference to  FIG. 10  to  FIG. 13 . 
     In the motor control device  1  shown in  FIG. 10  to  FIG. 13 , when an electronic current flows to the FET module  10 , the semiconductor chip  104  generates heat. As shown in  FIG. 10  to  FIG. 12 , the heat generated in the semiconductor chip  104  is conducted to the case member  12  through the drain terminal member  105 , the solder  14 , the wiring pattern  111  and the heat conducting member  13 , in a region other than the first portion and the second portion of the wiring pattern  111 . On the other hand, in the first portion and the second portion of the wiring pattern  111 , the heat generated in the semiconductor chip  104  is conducted to the case member  12  through the drain terminal member  105 , the solder  14 , the wiring pattern  111 , the solder resist  116  and the heat conducting member  13 . As shown in  FIG. 10  and  FIG. 13 , the heat generated in the semiconductor chip  104  is conducted to the case member  12  through the drain terminal member  105 , the solder  14 , the wiring pattern  111 , the heat conducting patterns  114 ,  115  and the heat conducting member  13 . Also, as shown in  FIG. 10  to  FIG. 13 , the heat generated in the semiconductor chip  104  is conducted to the case member  12  through the heat conducting member  13  from the body portion  100 , the drain terminal portions  101 , the source terminal portions  102  and the gate terminal portion  103 . Finally, the heat generated in the semiconductor chip  104  is radiated outside from the case member  12 . 
     Next, effects of the electronic device of the first embodiment will be described. 
     According to the first embodiment, the motor control device  1  includes the heat conducting member  13 . The heat conducting member  13  thermally connects the wiring patterns  111  to  113  of the wiring substrate  11  and the like to the predetermined heat conduction region of the case member  12 . Therefore, the case member  12  needs not to have a portion projecting toward the wiring substrate  11  and to a position nearer the wiring patterns  111  to  113  and the like than the surface of the body portion  100  opposing to the case member  12 . Hence, the heat generated in the semiconductor chip  104  can be radiated from the case member  12  with a simple shape. Since the case member  12  does not have the projecting portion near the FET module  10 , the short is less likely to occur. Also, the motor control device  1  includes the wiring substrate  11  having the heat conducting patterns  114 ,  115 . The heat conducting patterns  114 ,  115  are disposed at the terminal non-corresponding areas of the surface of the wiring substrate  11 . The surfaces of the heat conducting patterns  114 ,  115  are not covered with the solder resist  116 . The wiring patterns  111  to  113 , which are electrically connected to the drain terminal portions  101 , the source terminal portions  102  and the gate terminal portion  103 , are disposed at the terminal corresponding areas of the surface of the wiring substrate  11 . On the other hand, the wiring patterns  111  to  113  need not to be disposed at the terminal non-corresponding areas of the surface of the wiring substrate  11 . Therefore, the heat conducting patterns  114 ,  115  can be disposed at the terminal non-corresponding areas. As such, an area of a heat conducting passage can be increased compared to a case where the heat is conducted to the case member  12  only through the wiring patterns  111  to  113 . Also, since the surfaces of the heat conducting patterns  114 ,  115  are not covered with the solder resist  116 , thermal resistance can be further decreased. That is, heat radiation performance can be increased. As a result, an occurrence of the short can be restricted and the heat radiation performance can be increased without complicating a shape of the case member  12 . 
     According to the first embodiment, the predetermined portion of the wiring pattern  111 , which is thermally connected to the heat conducting member  13 , is exposed from the solder resist  116 , except for the connecting portions  111   a  to  111   e , the first portion and the second portion of the wiring pattern  111 . In the example shown in  FIGS. 11 to 13 , the predetermined portion of the wiring pattern  111  is directly in contact with the heat conducting member  13 , except for the connecting portions  111   a  to  111   e , the first portion and the second portion of the wiring pattern  111 . Therefore, the thermal resistance can be decreased compared to a case where the entirety of the predetermined portion of the wiring pattern is covered with the solder resist  116 . 
     The solder resist  116  is the member restricting the flow of the solder. In a case where the solder resist  116  does not cover the first portion and the second portion and a portion between the connecting portion  111   b  and the connecting portion  111   c , that is, the portions between the connecting portions are fully exposed, melting solder flows to the portions between the connecting portions. As a result, the FET module  10  is unexpectedly displaced when the FET module  10  is soldered. In the present embodiment, the first portion and the second portion are covered with the solder resist  116 . That is, the predetermined portion of the wiring pattern  111  is not covered with the solder resist  116  except for the first portion and the second portion. Therefore, the melting solder can be restricted from flowing to the first portion and the second portion, and the FET module  10  is less likely to be displaced. Furthermore, the predetermined portion of the wiring pattern  111  has portions that are not covered with the solder resist  116 , and the portions are adjacent to the connecting portions  111   a  to  111   e . Therefore, the thermal resistance of the heat conducting passage can be decreased and the heat radiation performance can be increased compared to a case where the portions that are not covered with the solder resist  116  are far from the connecting portions  111   a  to  111   e.    
     According to the first embodiment, the heat conducting patterns  114 ,  115  are disposed along the terminal non-projecting surfaces of the body portion  100 . Therefore, a distance from the body portion  100  to the heat conducting patterns  114 ,  115  decreases, and the thermal resistance of the heat conducting passage decreases. As a result, the heat radiation performance can be increased. 
     According to the first embodiment, the FET module  10  has the drain terminal member  105 . The drain terminal member  105  includes the drain terminal portions  101  and the drain predetermined portion. The drain predetermined portion is exposed from the bottom surface of the body portion  100  and electrically connected to the connecting portion  111   e . Therefore, the area of the heat conducting passage from the semiconductor chip  104  to the wiring pattern  111  can be increased compared to a case where only the drain terminal portions  101  are electrically connected to the connecting portions  111   a  to  111   d . As a result, the thermal resistance of the heat conducting passage can be decreased and the heat radiation performance can be increased. 
     According to the first embodiment, the heat conducting member  13  thermally connects the body portion  100 , the drain terminal portions  101 , the source terminal portions  102  and the gate terminal portion  103  to the predetermined heat conduction region of the case member  12 . The heat generated in the semiconductor chip  104  can be conducted to the case member  12  through the body portion  100 , the drain terminal portions  101 , the source terminal portions  102 , the gate terminal portion  103  and the heat conducting member  13 . Therefore, the area of the heat conduction passage can be increased compared to a case where the heat generated in the semiconductor chip  104  is conducted to the case member  12  only through the wiring patterns  111  to  113 , the heat conducting patterns  114 ,  115  and the heat conducting member  13 . As a result, the thermal resistance can be decreased and the heat radiation performance can be increased. 
     According to the first embodiment, the heat conducting patterns  114 ,  115  are integrally formed with the wiring pattern  111 . Therefore, a structure of the wiring substrate  11  can be simplified. 
     According to the first embodiment, a semiconductor module composing the motor control device  1  is the FET module  10 . Therefore, in the motor control device  1  including the FET module  10 , the occurrence of the short can be restricted and the heat radiation performance can be increased without complicating the shape of the case member  12 . 
     Although an example where the heat conducting patterns  114 ,  115  are disposed at the terminal non-corresponding areas of the wiring substrate  11  is described in the first embodiment, the present disclosure is not limited to the example. The heat conducting pattern may be disposed on at least one of the terminal non-corresponding areas. 
     Although an example where the entirety of the surfaces of the heat conducting patterns  114 ,  115  is not covered with the solder resist  116  is described in the first embodiment, the present disclosure is not limited to the example. At least a part of the surfaces of the heat conducting patterns  114 ,  115  is not covered with the solder resist  116 . 
     Although an example where the predetermined portion of the wiring pattern  111 , which is thermally connected to the heat conducting member  13 , is exposed from the solder resist  116 , except for the connecting portions  111   a  to  111   e , the first portion and the second portion of the wiring pattern  111  is described in the first embodiment, the present disclosure is not limited to the example. At least a part of the predetermined portion of the wiring pattern  111 , other than the connecting portions  111   a  to  111   e , is exposed from the solder resist  116 . 
     Although a case where the heat conducting patterns  114 ,  115  are integrally formed with the wiring pattern  111  is described, the present disclosure is not limited to the example. Although heat conductivity decreases slightly, the heat conducting patterns may not be integrally formed with the wiring pattern  111  or may be separately formed with the wiring pattern  111 . 
     In the first embodiment, as shown in  FIG. 6 , a part of the wiring pattern  111  extending in the vertical direction is exposed from the solder resist  116 , except for the first portion and the second portion. The present disclosure is not limited to the embodiment. As shown in  FIG. 14 , the entirety of the wiring pattern  111  extending in the vertical direction may be exposed from the solder resist the heat conducting member  13 . The entirety of the wiring pattern  111  extending in the vertical direction is thermally connected to the case member  12  through the heat conducting member  13 . Therefore, an area of a heat conducting passage having lower thermal resistance can be increased. As a result, the heat radiation performance can be further increased. 
     Second Embodiment 
     A motor control device of a second embodiment will be described. 
     The motor control device of the second embodiment has a FET module having a different structure from the motor control device of the first embodiment. 
     Since the structure of the motor control device of the second embodiment other than the FET module is similar to the first embodiment, the description thereof will not be repeated. The structures of the FET module and the motor control device will be described with reference to  FIG. 15  to  FIG. 20 . 
     As shown in  FIG. 15  to  FIG. 17 , a FET module  20  structurally includes a semiconductor chip  204 , a drain terminal member  205 , a source terminal member  206  (a second terminal member) and a gate terminal member  207 . 
     The semiconductor chip  204  and the drain terminal member  205  shown in  FIG. 15  to  FIG. 17  are the same chip and the same member as the semiconductor chip  104  and the drain terminal member  105  of the first embodiment. 
     The source terminal member  206  shown in  FIG. 15  and  FIG. 17  is the same member as the source terminal member  106  of the first embodiment. However, differently from the source terminal member  106  of the first embodiment, a predetermined portion of the source terminal member  206  other than source terminal portions  202  and disposed above the semiconductor chip  204  is exposed from a surface of a body portion  200  opposing to a case member  22 . That is, the predetermined portion of the source terminal member  206  is exposed from an upper surface of the body portion  200 . 
     The gate terminal member  207  shown in  FIG. 15  is the same member as the gate terminal member  107  of the first embodiment. 
     As shown in  FIG. 18  to  FIG. 20 , the drain terminal portions  201 , the source terminal portions  202  and the gate terminal portion  203  are electrically connected to connecting portions  211   b ,  211   d ,  211   e ,  212   b  and  213   a  through solder  24 . The connecting portions  211   b ,  211   d ,  211   e ,  212   b ,  213   a  are portions of wiring patterns  211 ,  212 ,  213  disposed in a wiring substrate  21 . That is, similar to the drain terminal portions  101 , the source terminal portions  102 , the gate terminal portion  103  of the first embodiment, the drain terminal portions  201 , the source terminal portions  202 , the gate terminal portion  203  are electrically connected to the corresponding connecting portions. 
     A heat conducting member  23  thermally connects predetermined portions of the wiring patterns  211  to  213 , the heat conducting patterns  214 ,  215 , the body portion  200 , the drain terminal portions  201 , the source terminal portions  202  and the gate terminal portion  203  to a surface of the case member  22  opposing to the wiring substrate  21 . The predetermined portions of the wiring patterns  211  to  213  are nearby areas of the connecting portions  211   b ,  211   d ,  211   e ,  212   b  and  213   a . Similar to the heat conducting member  13  of the first embodiment, the heat conducting member  23  thermally connects the corresponding portions to the surface of the case member  22  opposing to the wiring substrate  21 . 
     Next, radiation of the motor control device  2  of the second embodiment will be described with reference to  FIG. 18  to  FIG. 20 . 
     In the motor control device  2  shown in  FIG. 18  to  FIG. 20 , when an electronic current flows to the FET module  20 , the semiconductor chip  204  generates heat. The heat generated in the semiconductor chip  204  is radiated outside through a heat conducting passage similar to the motor control device  1  of the first embodiment. Since the predetermined portion of the source terminal member  206  is exposed from the upper surface of the body portion  200 , the heat generated in the semiconductor chip  204  is conducted to the case member  22  through the source terminal member  206  and the heat conducting member  23 , and radiated from the case member  22 . 
     Next, effects of the electronic device of the second embodiment will be described. 
     According to the second embodiment, since the electronic device of the second embodiment has the similar structure to the first embodiment, similar effects to the first embodiment can be achieved. 
     According to the second embodiment, the FET module  20  has the source terminal member  206 . The source terminal member  206  includes the source terminal portions  202  and the predetermined portion disposed above the semiconductor chip  204 . The predetermined portion of the source terminal member  206  is exposed from the upper surface of the body portion  200 . The heat generated in the semiconductor chip  204  is conducted to the case member  22  through the source terminal member  206  and the heat conducting member  23 . Therefore, an area of the heat conducting passage can be increased more than the motor control device  1  of the first embodiment. As a result, thermal resistance can be decreased and the heat radiation performance can be increased compared to the motor control device  1  of the first embodiment. 
     Although an example where the predetermined portion of the source terminal member  206  is exposed from the upper surface of the body portion  200  is described in the second embodiment, the present disclosure is not limited to the example. The predetermined portion of the source terminal member  206  may be exposed from terminal non-projecting surfaces of the body portion  200 . Also, the gate terminal member  207  may be exposed. 
     Although an example where the heat conducting patterns  214 ,  215  are integrally formed with the wiring pattern  211 , similar to the first embodiment, is described in the second embodiment, the present disclosure is not limited to the example. Although the heat conductivity decreased slightly, the heat conducting patterns  214 ,  215  may not be integrally formed with the wiring pattern  211  or may be separately formed with the wiring pattern  211 . 
     Although an example where the wiring substrate  21  has the same structure as the wiring substrate  11  of the first embodiment is described in the second embodiment, the present disclosure is not limited to the example. The wiring substrate  21  may have the same structure as the wiring substrate  11  of the modification of the first embodiment. In this case, similar effects to the modification of the first embodiment can be achieved. 
     While only the selected exemplary embodiments and examples have been chosen to illustrate the present disclosure, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made therein without departing from the scope of the disclosure as defined in the appended claims. Furthermore, the foregoing description of the exemplary embodiments and examples according to the present disclosure is provided for illustration only, and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.