Patent Publication Number: US-2013228319-A1

Title: Cooling device

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a cooling device. 
     Japanese Laid-Open Patent Publication No. 2008-211147 describes a coupling structure for coupling a pipe to a heat exchanger. The coupling structure includes two plates that are pressed and formed in conformance with each other. Each plate includes a peripheral portion and a shallow recess formed by the remaining portion of the plate. The peripheral portion includes a groove, which has a semicircular cross-section and connects the edge of the peripheral portion with the recess. The two plates are stacked so that their recesses face each other and their grooves face each other. A pipe is fitted to the grooves. In this state, the two plates are brazed and fixed to each other so that the plates are in contact with the pipe in a manner impervious to liquids. An annular first protrusion, which is formed along the outer circumference of the pipe, comes in contact with the edge of the entire groove. 
     In the coupling structure, the pipe may be deformed by heat when brazed. This may result in displacement of the pipe. More specifically, the brazing is performed at, for example, 600° C., at which aluminum components may expand or contract. This may bend the main body of the cooling device and displace the pipe. Further, the heat may deform the pipe. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a cooling device that allows for a pipe to be coupled to its main body without being displaced. 
     To achieve the above object, one aspect of the present invention is a cooling device provided with a main body including a first shell plate and a second shell plate each having a peripheral portion. The first shell plate and the second shell plate are integrated together by brazing the peripheral portions, and the main body includes a coolant passage and a port. A pipe is coupled to the main body. The pipe allows for circulation of coolant in the coolant passage through the port. A resin portion is molded on an outer surface of the main body at where the pipe is coupled to the main body to fix the pipe to the main body. 
     Other aspects and advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a front view of an inverter module according to one embodiment of the present invention; 
         FIG. 1B  is a plan view of the inverter module shown in  FIG. 1A ; 
         FIG. 2A  is a front view of the inverter module shown in  FIG. 1A  in a state in which a resin portion is eliminated; 
         FIG. 2B  is a plan view of the inverter module shown in  FIG. 1A  in a state in which the resin portion is eliminated; 
         FIG. 3  is a cross-sectional view showing the inverter module of  FIG. 1A  where a pipe is coupled; 
         FIG. 4  is a circuit diagram of the inverter module shown in  FIG. 1A ; 
         FIG. 5A  is a front view showing a main body and insulating substrates of the cooling device of  FIG. 1A ; 
         FIG. 5B  is a plan view showing the main body and insulating substrates of the cooling device of  FIG. 1A ; 
         FIG. 6  is a cross-sectional view taken along VI-VI in  FIG. 5B ; 
         FIG. 7A  is a front view illustrating a manufacturing process of the inverter module; 
         FIG. 7B  is a plan view showing the inverter module of  FIG. 7A ; 
         FIG. 8A  is a front view illustrating a manufacturing process of the inverter module; 
         FIG. 8B  is a plan view showing the inverter module of  FIG. 8A ; 
         FIG. 9  is a cross-sectional view showing the inverter module of  FIG. 1A  where a pipe is coupled and illustrating a manufacturing process of the inverter module; 
         FIG. 10  is a front view showing the inverter module; 
         FIG. 11  is a front view showing the inverter module; 
         FIG. 12  is a front view showing the inverter module; 
         FIG. 13  is a cross-sectional view showing a modification of an inverter module where a pipe is coupled; 
         FIG. 14  is a partial cross-sectional view showing a modification of an inverter module; 
         FIG. 15A  is a partial cross-sectional view showing a modification of an inverter module; 
         FIG. 15B  is a partial side view showing the inverter module of  FIG. 15A ; 
         FIG. 16A  is a partial cross-sectional view showing a modification of an inverter module; and 
         FIG. 16B  is a partial side view showing the inverter module of  FIG. 16A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A vehicle inverter according to one embodiment of the present invention will now be described with reference to the drawings. 
     Referring to  FIGS. 1A and 1B , an inverter module  10  includes a cooling device. The inverter module  10  is resin-molded and includes substrates on which semiconductor elements (chips) are mounted. As shown in  FIGS. 1A to 2B , the inverter module  10  includes a water-cooling type cooling device  20 , four insulating substrates  31 ,  32 ,  33  and  34 , six transistors (chips) Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6 , six diodes (chips) D 1 , D 2 , D 3 , D 4 , D 5 , and D 6 , and a molded resin portion  40 . The resin portion  40  may be formed from, for example, epoxy resin. 
       FIG. 4  shows the circuit configuration of the inverter module  10 . The inverter module  10  includes an inverter  50 , which converts DC power supplied from an external device, to AC power. Then, the inverter  50  supplies the AC power to a travel motor  60 . This drives the motor  60 , which produces rotation. 
     In detail, the inverter  50  includes a plurality of arms, namely, a U-phase arm, a V-phase arm, and a W-phase arm arranged in parallel between a power supply line and a ground line. The arms include two series-connected transistors (IGBT) Q 1  and Q 2 , Q 3  and Q 4 , and Q 5  and Q 6 , respectively. Diodes D 1 , D 2 , D 3 , D 4 , D 5 , and D 6  are arranged between the collector and emitter of the transistors Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6 , respectively. Each diode allows for current to pass from the emitter to the collector of the corresponding transistor. 
     As shown in  FIGS. 1A to 2B , the insulating substrates  31 ,  32 ,  33 , and  34  are formed by direct brazed aluminum (DBA) substrates. Each DBA substrate includes a ceramic substrate  35 , an aluminum layer  36 , which is formed on a first surface of the ceramic substrate  35 , and an aluminum layer  37 , which is formed on a second surface of the ceramic substrate  35 . The aluminum layer  36  is patterned on the first surface of the ceramic substrate  35 . In the same manner, the aluminum layer  37  is patterned on the second surface of the ceramic substrate  35 . 
     The cooling device  20  includes a main body  21 , which is a tetragonal box having a low profile, a resin inlet pipe  22 , and a resin outlet pipe  23 . The main body  21  of the cooling device  20  is formed from aluminum. As shown in  FIG. 6 , the main body  21  includes an upper plate  24 , which functions as a first shell plate, a lower plate  25 , which functions as a second shell plate, and inner fins  26 , which are undulated. A peripheral portion of the upper plate  24  and a peripheral portion of the lower plate  25  are swaged together. In this state, the peripheral portions of the upper plate  24  and the lower plate  25  are brazed to each other. This brazes the upper plate  24  and the lower plate  25  at their peripheral portions in the main body  21 . The inner fins  26  are also brazed to and between the upper plate  24  and lower plate  25 . 
     The main body  21  includes a coolant passage P 1  (refer to  FIGS. 3 and 6 ). The inlet pipe  22  is coupled to the upper surface of the main body  21  and allows for coolant to be supplied into the main body  21  through a first port  90   a  (refer to  FIGS. 5A and 5B ), which is formed in the main body  21 . In the same manner, the outlet pipe  23  is coupled to the upper surface of the main body  21  and allows for coolant to be discharged from the main body  21  through a second port  90   b  (refer to  FIGS. 5A and 5B ), which is formed in the main body  21 . More specifically, a pump sends coolant into the main body  21  through the inlet pipe  22  and discharges the coolant from the main body  21  through the outlet pipe  23 . 
     As described above, the pipes  22  and  23  allows for coolant to circulate through the ports  90   a  and  90   b,  which are formed in the main body  21 . 
     The insulating substrates  31 ,  32 ,  33 , and  34 , on which the transistors (chips) Q 1  to Q 6  and the diodes (chips) D 1  to D 6  functioning as semiconductor elements are mounted, are brazed to the surface of the main body  21 . In detail, the four insulating substrates  31 ,  32 ,  33 , and  34  are brazed and joined with the upper surface of the main body  21  of the cooling device  20 . That is, the aluminum layer  36  under the ceramic substrate  35  in each of the four insulating substrates  31 ,  32 ,  33 , and  34  is brazed and joined with the upper surface of the cooling device  20 . 
     The aluminum layer  37  on the ceramic substrate  35  in the insulating substrate  31  is a wiring material. The transistor (chip) Q 1  and the diode (chip) D 1  are soldered and joined with the upper surface of the aluminum layer  37 . The aluminum layer  37  on the ceramic substrate  35  in the insulating substrate  32  is a wiring material. The transistor (chip) Q 3  and the diode (chip) D 3  are soldered and joined with the upper surface of the aluminum layer  37 . The aluminum layer  37  on the ceramic substrate  35  in the insulating substrate  33  is a wiring material. The transistor (chip) Q 5  and the diode (chip) D 5  are soldered and joined with the upper surface of the aluminum layer  37 . The aluminum layer  37  on the ceramic substrate  35  in the insulating substrate  34  is a wiring material. The transistors (chips) Q 2 , Q 4 , and Q 6  and the diodes (chips) D 2 , D 4 , and D 6  are soldered and joined with the upper surface of the aluminum layer  37 . 
     The collector terminals on the upper surfaces of the transistors Q 1 , Q 3 , and Q 5  and the cathode terminals on the upper surfaces of the diodes D 1 , D 3 , and D 5  are joined with a conductive plate  70 , which functions as an external connection terminal, by solder  71 . The collector terminal on the upper surface of the transistor Q 2 , the cathode terminal on the upper surface of the diode D 2 , and the aluminum layer  37  in the insulating substrate  31  (the emitter of the transistor Q 1  and the anode of the diode D 1 ) are joined with a conductive plate  72 , which functions as an external connection terminal, by solder  73 . Further, the collector terminal on the upper surface of the transistor Q 4 , the cathode terminal on the upper surface of the diode D 4 , and the aluminum layer  37  in the insulating substrate  32  (i.e., the emitter of the transistor Q 3  and the anode of the diode D 3 ) are joined with a conductive plate  74 , which functions as an external connection terminal, by solder  75 . The collector terminal on the upper surface of the transistor Q 6 , the cathode terminal on the upper surface of the diode D 6 , and the aluminum layer  37  in the insulating substrate  33  (i.e., the emitter of the transistor Q 5  and the anode of the diode D 5 ) are joined with a conductive plate  76 , which functions as an external connection terminal, by solder  77 . A conductive plate  78 , which functions as an external connection terminal, is soldered to the aluminum layer  37  on the ceramic substrate  35  in the insulating substrate  34 . The conductive plates  70 ,  72 ,  74 ,  76 , and  78  are formed from copper. The conductive plates  70 ,  72 ,  74 ,  76 , and  78  each include a first end a second end. The first ends of the conductive plates  70 ,  72 ,  74 ,  76 , and  78  are electrically connected to the corresponding transistors Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6  and the corresponding diodes D 1 , D 2 , D 3 , D 4 , D 5 , and D 6 . 
     The second end of the conductive plate  70  is bent upward. In the same manner, the second end of the conductive plate  72  is bent upward. The second end of the conductive plate  74  is bent upward. The second end of the conductive plate  76  is bent upward. The second end of the conductive plate  78  is bent upward. 
     Six connection pin seats  80 ,  81 ,  82 ,  83 ,  84 , and  85  are fixed to the upper surface of the main body  21  of the cooling device  20 . Three connection pins  86 , which function as external connection terminals, are fixed to each of the connection pin seats  80 ,  81 ,  82 ,  83 ,  84 , and  85 . The connection pins  86  are formed from copper. One of the three connection pins  86  forms a gate voltage application line, and the two remaining connection pins  86  forming an emitter voltage detection line and an emitter temperature detection line. The three connection pins  86  include first terminals electrically connected by wires W formed by a wiring material, or wire-bonded, to the transistors (chips) Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6 . 
     The three connection pins  86  include the first terminals, which are electrically connected to the corresponding transistors Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6 , and second terminals, which are bent upward. 
     The resin portion  40  covers the components arranged on the upper surface of the main body  21  of the cooling device  20  (i.e., the insulating substrates  31 ,  32 ,  33 , and  34 , the transistors Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6 , the diodes D 1 , D 2 , D 3 , D 4 , D 5 , and D 6 , the conductive plates  70 ,  72 ,  74 ,  76 , and  78 , the connection pins  86 , and the wire W). The conductive plates  70 ,  72 ,  74 ,  76 , and  78  include upright portions  70   a,    72   a,    74   a,    76   a,  and  78   a  with upper ends exposed from the resin portion  40 . In the same manner, the three connection pins  86 , which are connected to each of the transistors Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6 , include upright portions  86   a  with upper ends exposed from the resin portion  40 . 
     The portion where the inlet pipe  22  is coupled to the main body  21  of the cooling device  20  and the portion where the outlet pipe  23  is coupled to the main body  21  are formed as shown in  FIG. 3 . 
     As shown in  FIG. 3 , the main body  21  has a top panel  21   a,  which includes the first port  90   a  and the second port  90   b,  and a positioning part  91 , which projects upward and entirely around each of the first port  90   a  and second port  90   b.  The inlet pipe  22  and the outlet pipe  23  each have a thick lower end, which includes a recess  27  open downward and extending along the entire circumference of the pipe. The main body  21  closes the opening of the recess  27 . The positioning part  91  is arranged in the recess  27 . An O-ring  28  is set in the recess  27 . 
     The resin portion  40  fixes the main body  21  of the cooling device  20  with the inlet pipe  22  and the outlet pipe  23 . The O-ring  28  is in close contact with the top panel  21   a  of the main body  21  and also with the bottom surface of the recess  27 . As a result, the main body  21  and the inlet pipe  22  are in contact with each other in a manner impervious to liquid, and the main body  21  and the outlet pipe  23  are also in contact with each other in a manner impervious to liquid. 
     Also, the positioning part  91 , which positions the O-ring  28  relative to the main body  21 , is formed on the main body  21  where the inlet pipe  22  is coupled to the main body  21  and where the outlet pipe  23  is coupled to the main body  21 . Further, a positioning part  29 , which positions the O-ring  28  relative to the main body  21 , is formed on the inlet pipe  22  and the outlet pipe  23  where the inlet pipe  22  is coupled to the main body  21  and where the outlet pipe  23  is coupled to the main body  21 . The positioning part  91  positions the O-ring  28  from a radially inner side, and the positioning part  29  positions the O-ring  28  from a radially outer side. 
     The operation of the inverter module  10  will now be described. 
     Coolant is supplied to the inlet pipe  22  of the cooling device  20 . The coolant enters the main body  21  of the cooling device  20  through the inlet pipe  22 . The coolant flows through the main body  21  of the cooling device  20  toward the outlet pipe  23 . Then, the coolant enters the outlet pipe  23  to be discharged from the outlet pipe  23 . The six transistors Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6  of the inverter module  10  each generate heat when undergoing a switching operation. The six diodes D 1 , D 2 , D 3 , D 4 , D 5 , and D 6  generate heat when activated. The heat generated by the transistors Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6  is transferred to the main body  21  of the cooling device  20  through the insulating substrates (DBA substrates)  31 ,  32 ,  33 , and  34 , which transfer heat to the coolant flowing through the main body  21  of the cooling device  20 . In the same manner, the heat generated by the six diodes D 1 , D 2 , D 3 , D 4 , D 5 , and D 6  is transferred to the main body  21  of the cooling device  20  through the insulating substrates (DBA substrates)  31 ,  32 ,  33 , and  34 , which transfer heat to the coolant flowing through the main body  21  of the cooling device  20 . 
     A method for manufacturing the inverter module  10  will now be described with reference to  FIGS. 1A to 3  and  FIGS. 5A to 9 . 
     Referring to  FIGS. 5A to 6 , the insulating substrates (DBA substrates)  31 ,  32 ,  33 , and  34  are prepared. The aluminum layer  36  is patterned on one surface of the ceramic substrate  35 , and the aluminum layer  37  is patterned on the other surface of the ceramic substrate  35 . The peripheral portions of the upper plate  24  and lower plate  25 , which form the main body  21  of the cooling device  20 , are swaged and brazed together. Further, the undulated inner fins  26  are also brazed between the upper plate  24  and the lower plate  25 . At the same time, the insulating substrates (DBA substrates)  31 ,  32 ,  33 , and  34  are brazed to the upper surface of the main body  21  of the cooling device  20 . In detail, the aluminum layer  36  under the ceramic substrate  35  in each of the four insulating substrates  31 ,  32 ,  33 , and  34  is brazed to the upper surface of the cooling device  20 . The brazing is performed at about 600° C. This integrates the main body  21  of the cooling device with the insulating substrates  31 ,  32 ,  33 , and  34 . 
     Subsequently, referring to  FIGS. 7A and 7B , each of the transistors Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6  and each of the diodes D 1 , D 2 , D 3 , D 4 , D 5 , and D 6  are soldered to the upper surface of the aluminum layer  37  on the ceramic substrate  35  in the corresponding one of the insulating substrates  31 ,  32 ,  33 , and  34 . 
     At the same time, the conductive plates  70 ,  72 ,  74 ,  76 , and  78  are soldered to the transistors Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6  and the diodes D 1 , D 2 , D 3 , D 4 , D 5 , and D 6 . Further, the connection pin seats  80 ,  81 ,  82 ,  83 ,  84 , and  85 , on which the connection pins  86  are fixed, are fixed to the upper surface of the main body  21  of the cooling device  20 . 
     Referring to  FIGS. 8A and 8B , the connection pins  86  are joined with the corresponding transistors (chips) Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6  by the wire W. Subsequently, the inlet pipe  22  and the outlet pipe  23  are mounted on the main body  21  of the cooling device  20 . In detail, referring to  FIG. 9 , the O-ring  28  is held between the main body  21  and the lower end of each of the inlet pipe  22  and outlet pipe  23 . In this state, the inlet pipe  22  and the outlet pipe  23  are arranged upright on the main body  21  of the cooling device  20 . 
     As shown in  FIGS. 1A to 2B , the resin portion  40  is used to seal and integrate the components mounted on the main body  21  of the cooling device  20 . The components mounted on the main body  21  of the cooling device  20  include the portion where the main body  21  and the inlet pipe  22  are coupled, the portion where the main body  21  and the outlet pipe  23  are coupled, the insulating substrates  31 ,  32 ,  33 , and  34 , the transistors Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6 , the diodes D 1 , D 2 , D 3 , D 4 , D 5 , and D 6 , the conductive plates  70 ,  72 ,  74 ,  76 , and  78 , the connection pins  86 , and the wire W. The resin portion  40  is molded at about 120° C. This fixes the inlet pipe  22  and the outlet pipe  23  to the main body  21  with the resin portion  40 . Thus, the inlet pipe  22  and the outlet pipe  23  can be fixed to the main body  21  with the resin portion  40  at the same time as when sealing the semiconductor elements (the transistors Q 1 , Q 2 , Q 3 , Q 4 , Q 5 , and Q 6  and the diodes D 1 , D 2 , D 3 , D 4 , D 5 , and D 6 ), which are soldered, with the resin portion  40 . 
     In this manner, after brazing the upper plate  24 , the lower plate  25 , the inner fins  26 , and the insulating substrates (DBA substrates)  31 ,  32 ,  33 , and  34 , which form the main body  21  of the cooling device  20 , the pipes  22  and  23  are fixed to the main body  21  when the main body  21  is resin-sealed. The resin-sealing is performed at the same time as when sealing the circuit components of the module (the transistors Q 1  to Q 6 , the diodes D 1  to D 6 , the conductive plates  72 ,  74 ,  76 , and  78 , the connection pins  86 , and the wire W). Unlike when brazing the pipes  22  and  23  to the main body  21  of the cooling device  20 , the pipes  22  and  23  can be exchanged with other pipes whenever necessary using the main body  21  of the cooling device  20  as a common part. 
     More specifically, as shown in  FIG. 10 , straight pipes  22   a  and  23   a  may be coupled to the main body  21  of the cooling device  20  and extended upright from the upper surface of the main body  21 . Alternatively, as shown in  FIG. 11 , L-shaped pipes  22   b  and  23   b  may be coupled to the main body  21  so that the pipes  22   b  and  23   b  extend horizontally and in the longitudinal direction of the main body  21  of the cooling device  20 . 
     As shown in  FIG. 12 , pipes  22   c  and  23   c  may be coupled to the main body  21  so that the pipes  22   c  and  23   c  extend diagonally relative to the upper surface of the main body  21  of the cooling device  20 . More specifically, the upper longitudinal surface of the main body  21  is horizontal, and the pipes  22   c  and  23   c  are inclined relative to the upper surface of the main body  21 . 
     The above embodiment has the advantages described below. 
     (1) The cooling device  20  includes the main body  21  and pipes (i.e., the inlet pipe  22  and the outlet pipe  23 ). The inlet pipe  22  is coupled to the main body  21  and supplies the coolant through the first port  90   a,  which is formed in the main body  21 . The outlet pipe  23  is coupled to the main body  21  and discharges coolant through the second port  90   b,  which is formed in the main body  21 . The resin portion  40  is molded onto a coupling portion, that is, the outer surface of the main body  21  where the pipes (i.e., the inlet pipe  22  and the outlet pipe  23 ) are coupled to the main body  21 . 
     The conventional structure is susceptible to heat deformation that may occur in a brazing process. In contrast, the present embodiment molds the resin portion  40  subsequent to brazing. This prevents displacement of the inlet pipe  22  and the outlet pipe  23  that would be caused the heat generated during the brazing. In detail, the brazing is performed at about 600° C., whereas the resin molding is performed at about 120° C. Thus, in comparison with the convention structure, the structure of the present embodiment is less susceptible to heat deformation that would occur during the brazing. 
     In this manner, displacement of the pipes  22  and  23  relative to the main body  21  of the cooling device  20  caused by heat is prevented. As a result, the cooling device  20  can coupled the pipes  22  and  23  to the main body  21  while suppressing displacement of the pipes  22  and  23 . 
     The conventional structure brazes and fixes coupled portions of a coolant passage. In contrast, the present embodiment increases flexibility at coupled portions of a coolant passage. Further, the inlet pipe  22  and the outlet pipe  23  are fixed to the main body  21  when resin-sealing the module components (i.e., the transistors Q 1  to Q 6 , the diodes D 1  to D 6 , the conductive plates  72 ,  74 ,  76 , and  78 , the connection pins  86 , and the wire W). This reduces processing steps and allows for a decrease in the accuracy required for formation of the brazed components. 
     (2) The O-ring  28 , which functions as a seal, is arranged between each pipe (i.e., the inlet pipe  22  and the outlet pipe  23 ) and the main body  21  to increase the seal between the pipe and main body  21 . In particular, the O-ring  28  is used as the seal and thus provides superior sealing. 
     (3) The positioning part  91  and positioning part  29  for the O-ring  28  are formed on the pipes (i.e., the inlet pipe  22  and the outlet pipe  23 ) and the main body  21  at each portion where a pipe is coupled to the main body  21 . This facilitates positioning of the O-ring  28 . 
     It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the present invention may be embodied in the following forms. 
     Referring to  FIG. 13 , a structure coupling the main body  21  of the cooling device  20  and the pipe  22  ( 23 ) does not need an O-ring. Instead, a flange  95  arranged on the pipe  22  ( 23 ) may be held in contact with the top panel  21   a  of the main body  21 , and the resin portion  40  may seal the surrounding of the flange  95  and the top panel  21   a.    
     As shown in  FIG. 14 , pipes  110  and  111  may be formed integrally with a resin portion  41 . More specifically, a first port  100  and a second port  101  are formed in the top panel  21   a  of the main body  21  of the cooling device  20 . The pipes  110  and  111  are simultaneously formed when the resin portion  41  is molded. The first port  100  is in communication with the inlet pipe  110 , and the second port  101  is in communication with the outlet pipe  111 . 
     In this manner, the resin portion  41  may be molded on the outer surface of the main body  21  around the ports formed in the main body  21  (around the first port  100  and second port  101 ). At the same time, the pipes (i.e., the inlet pipe  110  in communication with the first port  100  and the outlet pipe  111  in communication with the second port  101 ) may be formed integrally with the resin portion  41 . 
     In this case, the resin portion  41  is molded after brazing is performed. This prevents the inlet pipe  110  and the outlet pipe  111  (i.e., coolant inlet and outlet) from being deformed by the heat generated in the brazing process. This prevents deformation of the pipes. In detail, the pipes  110  and  111  are not susceptible to heat deformation because they are coupled to the main body  21  after the upper plate  24 , the lower plate  25 , and the undulated inner fins  26  are brazed together (refer to  FIG. 6 ) and the insulating substrates  31 ,  32 ,  33 , and  34  are brazed to the main body  21  of the cooling device. This prevents displacement of the pipes  110  and  111  relative to the main body  21  of the cooling device  20  that would be caused by heat. As a result, the pipes  110  and  111  can be coupled to the main body  21  without being displaced. This structure also reduces the number of components. 
     Although the inlet pipe  22  and the outlet pipe  23  are formed from resin, the pipes may be formed from other materials. 
     Although the insulating substrates  31 ,  32 ,  33 , and  34  are DBA substrates, the insulating substrates may be direct brazed copper (DBC) substrates, each including a ceramic substrate  35  sandwiched by copper layers. 
     Although the ports (i.e., the first port  90   a  and the second port  90   b ) are formed in the upper plate  24  in  FIG. 3 , the ports may be formed in the lower plate  25 . Further, as shown in  FIGS. 15A and 15B , the ports (i.e., the first port  90   a  and the second port  90   b ) may be formed between the upper plate  24  and the lower plate  25 . 
     Although the ports (the first port  100  and the second port  101 ) are formed in the upper plate  24  in  FIG. 14 , the ports may be formed in the lower plate  25 . As shown in FIGS.  16 A and  16 B, the ports (i.e., the first port  100  and the second port  101 ) may be formed between the upper plate  24  and the lower plate  25 . 
     Although the ports (i.e., the first port  100  and the second port  101 ) are formed in the upper plate  24  in  FIG. 14 , the first port  100  may be formed in the upper plate  24 , and the second port  101  may be formed in the lower plate  25 . Alternatively, the first port  100  may be formed in the lower plate  25 , and the second port  101  may be formed in the upper plate  24 . 
     It is only required that resin be molded over at least one of where the inlet pipe  22  is coupled to the main body  21  and where the outlet pipe  23  is coupled and the main body  21  to fix the pipe to the main body  21 . More specifically, for example, the inlet pipe  22  may be coupled to the main body  21  by performing resin molding, and the outlet pipe  23  may be brazed to the main body  21 . Alternatively, the outlet pipe  23  may be coupled to the main body  21  by performing resin molding, and the inlet pipe  22  may be brazed to the main body  21 . 
     Although the present invention is applied to an inverter that functions as a power conversion device, the invention may be applied to other types of power conversion device, such as a converter. 
     The present examples and embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.