Abstract:
A mounting jig for a semiconductor device includes an insulated circuit board positioning jig having a concave part in which an insulated circuit board is placed, a tubular contact element positioning jig disposed on an upper side of the insulated circuit board and having a plurality of positioning holes at predetermined positions to insert a plurality of tubular contact elements respectively, and a tubular contact element press-down jig having a flat plate and a plurality of projections extending from a lower surface of the flat plate. The plurality of projections includes a first length from the flat plate on a side closer to an outer circumference of the insulated circuit board, and a second length from the flat plate inside the outer circumference of the insulated circuit board. The first length is shorter than the second length.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This is a continuation-in-part application of U.S. patent application Ser. No. 14/923,941 filed on Oct. 27, 2015, which is a divisional application of U.S. patent application Ser. No. 14/204,455, filed on Mar. 11, 2014, which is based on, and claims priority to, Japanese Patent Application No. 2013-060987, filed on Mar. 22, 2013, contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF INVENTION 
     Field of the Invention 
       [0002]    The present invention relates to a mounting jig for mounting tubular contact elements with high accuracy onto a semiconductor device provided with the tubular contact elements. 
       Background Art 
       [0003]    A power semiconductor module of semiconductor devices is generally a device, wherein a semiconductor chip such as an IGBT contained in a case is mounted on an insulated circuit board, provided with external terminals for connecting the semiconductor chip and the exterior of the case. In recent years, a technology of connecting tubular contact elements to the circuit pattern of an insulated circuit board with solder has been proposed as the technology of easily and inexpensively connecting external terminals to the insulated circuit board with long term stability against mechanical stresses and vibrations (US 2009/0194884 A1). According to the technology, the tubular contact element is formed in a shape of a hollow cylindrical tube having a flange at each longitudinal end thereof, and one longitudinal end of the tubular contact element is soldered to the circuit pattern of the insulated circuit board so that the tubular contact element extends from the surface of the circuit pattern of the insulated circuit board with the longitudinal direction thereof being oriented in the vertical direction. By inserting an external terminal having a square cross section into the inner space of the tubular contact element to be press-fitted, it becomes possible to connect the external terminal to the tubular contact element with high reliability. With respect to a technology similar to that of using the tubular contact elements, a semiconductor device is disclosed in which the thickness of one end of a tubular electrode is made to be thinner than the thickness of the other end (JP-A-2011-138998).
   Patent Document 1: US 2009/0194884 A1   Patent Document 2: JP-A-2011-138998   
 
         [0006]    The external terminal of the semiconductor device provided with the tubular contact element is provided at a predetermined position. Therefore, in manufacturing the semiconductor device, the tubular contact element must be mounted on the insulated circuit board with high positioning accuracy. Poor positioning accuracy sometimes causes the tubular contact element to be mounted on the insulated circuit board inclined at some angle rather than vertical. The tubular contact element mounted at some angle will cause lack of solder inside the tube of the tubular contact element, which leads to possible reduction or instability in joining strength at the soldered joint. 
         [0007]    Accordingly, the invention was made in view of such points with an object of providing a method of manufacturing a semiconductor device in which tubular contact elements can be mounted on an insulated circuit board with high positioning accuracy, and a mounting jig for mounting the tubular contact elements on the insulated circuit board. 
       SUMMARY OF THE INVENTION 
       [0008]    For achieving the foregoing object, a method of manufacturing a semiconductor device is provided as follows. 
         [0009]    In the method of the invention, a semiconductor device includes an insulated circuit board having a circuit pattern formed on at least one surface thereof, at least one semiconductor element mounted on the insulated circuit board, a plurality of tubular contact elements joined to the circuit pattern on the insulated circuit board, a plurality of external terminals electrically connected to the respective tubular contact elements, and a case containing the insulated circuit board. In the method, the plurality of tubular contact elements is joined onto the circuit pattern on the insulated circuit board. The method uses a mounting jig having an insulated circuit board positioning jig, a tubular contact element positioning jig having a plurality of positioning holes formed at predetermined positions to insert the tubular contact elements, and a tubular contact element press-down jig. By the insulated circuit board positioning jig and the tubular contact element positioning jig, an insulated circuit board and the tubular contact elements are positioned, and the tubular contact elements are soldered to the insulated circuit board while being pressed down by the tubular contact element press-down jig. 
         [0010]    For achieving the foregoing object, a mounting jig as follows is provided. 
         [0011]    The mounting jig is a jig having an insulated circuit board positioning jig holding the insulated circuit board at a predetermined position for positioning, a tubular contact element positioning jig having a plurality of positioning holes at predetermined positions to insert a tubular contact element, and a tubular contact element press-down jig for pressing down the plurality of tubular contact elements inserted into the respective positioning holes in the tubular contact element positioning jig. 
         [0012]    According to the invention, an insulated circuit board and a plurality of tubular contact elements are positioned by an insulated circuit board positioning jig and a tubular contact element positioning jig, respectively, of a mounting jig, and the tubular contact elements are then soldered onto the insulated circuit board while being pressed down by a tubular contact element press-down jig, by which the tubular contact elements can be mounted on the insulated circuit board with high positioning accuracy. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a front view partly in section showing a semiconductor module as an embodiment of a semiconductor device manufactured by a manufacturing method according to the invention. 
           [0014]      FIG. 2  is an enlarged cross-sectional view showing a principal part of the semiconductor module shown in  FIG. 1 . 
           [0015]      FIG. 3  is a perspective view showing a tubular contact element. 
           [0016]      FIG. 4  is a schematic plan view showing the connection between the tubular contact element and the external terminal. 
           [0017]      FIGS. 5( a )-5( c )  are front views showing examples of the tubular contact element, wherein  FIG. 5( a )  shows the front view of the tubular contact element having top and bottom flanges;  FIG. 5( b )  shows the front view of the tubular contact element having the bottom flange; and  FIG. 5( c )  shows the tubular contact element having no flange. 
           [0018]      FIGS. 6( a ), 6( b )  are elevation views illustrating the mounting jig according to an embodiment of the invention in which  FIG. 6( a )  shows a portion of the mounting jig in section according to the embodiment and  FIG. 6( b )  shows an exploded view partly in section. 
           [0019]      FIG. 7  is a plan view showing the insulated circuit board positioning jig. 
           [0020]      FIG. 8  is a plan view showing the tubular contact element positioning jig. 
           [0021]      FIG. 9  is a view showing the tubular contact element press-down jig viewed from the back thereof. 
           [0022]      FIG. 10  is a partially enlarged cross-sectional view of the portion X in  FIG. 6( a )  as a portion in the vicinity of the positioning hole of the tubular contact element positioning jig. 
           [0023]      FIGS. 11( a ), 11( b )  are elevation views illustrating the mounting jig according to another embodiment of the invention in which  FIG. 11( a )  shows a portion of the mounting jig in section according to the embodiment, and  FIG. 11( b )  shows an exploded view partly in section. 
           [0024]      FIG. 12  is a partially enlarged cross-sectional view of the portion XII in  FIG. 11( a )  as a portion in the vicinity of the positioning hole of the tubular contact element positioning jig according to another embodiment of the invention. 
           [0025]      FIG. 13  is a partially enlarged cross-sectional view of the portion XIII in  FIG. 10  as a portion in the vicinity of the projection formed in the tubular contact element press-down jig. 
           [0026]      FIG. 14  is a schematic partially enlarged cross-sectional view of the portion XIII in  FIG. 10  as a portion in the vicinity of the projection, the view showing an example of a modification of the tubular contact element press-down jig in which the small projections are formed. 
           [0027]      FIG. 15  is a flow chart showing a part of a joining process in a method of manufacturing a semiconductor device according to an embodiment of the invention. 
           [0028]      FIG. 16  is an enlarged cross-sectional view of another embodiment showing a tubular contact element press-down jig. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0029]    An embodiment of each of a manufacturing method of a semiconductor device and a mounting jig according to the invention will be specifically explained with the drawings. 
         [0030]      FIG. 1  is a front view in which a part is in cross-sectional view showing a semiconductor module  1  as an embodiment of a semiconductor device manufactured by a manufacturing method according to the invention.  FIG. 2  is an enlarged cross-sectional view showing a principal part of the semiconductor module  1  shown in  FIG. 1 . 
         [0031]    The semiconductor module  1 , as is shown in  FIG. 1  and  FIG. 2 , has at least one semiconductor chip, four semiconductor chips  3 A,  3 B,  3 C, and  3 D in the illustrated embodiment, as semiconductor elements mounted on an insulated circuit board  2 . The semiconductor chips  3 A,  3 B,  3 C, and  3 D can be, for example, IGBT (Insulated Gate Bipolar Transistor) chips and FWD (Free Wheeling Diode) chips. The insulated circuit board  2  is formed of an insulating substrate  2   a , a conductor pattern layer  2   b  formed on one surface of the insulating substrate  2   a  and a metal layer  2   c  formed on the other surface of the insulating substrate  2   a . The insulating substrate  2   a  is a substrate of insulating ceramic material such as aluminum oxide, aluminum nitride or silicon nitride. The conductor pattern layer  2   b  is a layer formed into a circuit pattern with a conductor foil such as a copper foil or an aluminum foil. The metal layer  2   c  is a layer of foil such as copper foil or aluminum foil. 
         [0032]    The semiconductor chips  3 A,  3 B,  3 C, and  3 D are joined onto the conductor pattern layer  2   b  side of the insulated circuit board  2  with solder  4 . By the solder  4  or by bonding wires  5  of metal such as aluminum, the semiconductor chips  3 A,  3 B,  3 C, and  3 D are electrically connected to the conductor pattern layer  2   b.    
         [0033]    The semiconductor module  1  is provided with a plurality of tubular contact elements  6  on the conductor pattern layer  2   b  of the insulated circuit board  2 .  FIG. 3  is a perspective view showing a tubular contact element  6 . The tubular contact elements  6  is made of conductive material, copper, for example, and is, as is shown in the perspective view of  FIG. 3 , formed into a shape having a top flange  62  at one longitudinal end to be the top end of a hollow cylindrical tube  61  as a tube and a bottom flange  63  at the other longitudinal end to be the bottom end. The top flange  62  has a plurality of thicker sections  62   a  formed along the periphery thereof and a thinner section  62   b  as a section other than the thicker sections  62   a . In the same way, the bottom flange  63  has a plurality of thicker sections  63   a  and a thinner section  63   b . The bottom flange  63 , having thicker sections  63   a , facilitates discharge of flux in soldering to permit reliable soldering. The top flange  62  and the bottom flange  63  are preferably formed in the same shapes. This, however, does not exclude them from being formed into shapes different from each other. One longitudinal end of the tubular contact element  6  is joined to the conductor pattern layer  2   b  of the insulated circuit board  2  with the solder  4  so that the tubular contact element  6  extends from the surface of the conductor pattern layer  2   b  of the insulated circuit board  2  with the longitudinal direction thereof being oriented in the vertical direction. 
         [0034]    In the semiconductor module  1 , into the inner space of each of the tubular contact elements  6 , an external terminal  7  is inserted. The external terminal  7  has a cross-sectional form of a polygon, a square, for example, having diagonals each with a length a little larger than the inner diameter of the tubular contact element  6 .  FIG. 4  is a schematic plan view showing the connection between the tubular contact element  6  and the external terminal  7 . As is shown in the schematic plan view of  FIG. 4 , by inserting the external terminal  7  into the tubular contact element  6  to be fixed thereto while making the tubular contact element  6  cause plastic deformation, in other word, by making the external terminal  7  press-fitted to the tubular contact element  6 , the external terminal  7  can be connected to the tubular contact element  6  with a high degree of reliability. 
         [0035]    The insulated circuit board  2 , on which the semiconductor chips  3 A,  3 B,  3 C, and  3 D have been mounted, to which board the tubular contact elements  6  have been joined and in which board the bonding wires  5  have been wired, is contained in a case  8  ( FIG. 1 ) and the bottom end of the case  8  is bonded to the periphery of the insulated circuit board  2 . A space in a part inside the case  8  and lower than the upper lid thereof is filled with gel  9  by which the inside of the case  8  is sealed. One end of the external terminal  7  protrudes from the case  8 . 
         [0036]    The tubular contact element  6  shown in  FIG. 1  and  FIG. 2  has a shape having the top flange  62  at one longitudinal end to be the top end of the hollow cylindrical tube  61  and the bottom flange  63  at the other longitudinal end to be the bottom end. The invention, however, is not limited to the shape. As is shown in  FIGS. 5( a )-5( c ) , a front view showing examples of the tubular contact element  6 , in addition to the tubular contact element  6  ( FIG. 5( a ) ) having the top flange  62  at one longitudinal end to be the top end and the bottom flange  63  at the other longitudinal end to be the bottom end, the structure of a tubular contact element  6 A ( FIG. 5( b ) ) having the bottom flange  63  at one longitudinal end to be the bottom end and that of a tubular contact element  6 B ( FIG. 5( c ) ) having no flange at either longitudinal end are also possible. 
         [0037]    In the manufacturing process of the semiconductor module  1 , when the tubular contact elements  6  are soldered to the insulated circuit board  2 , a mounting jig  10  shown in  FIGS. 6( a ), 6( b )  is used.  FIGS. 6( a ), 6( b )  are elevation views illustrating the mounting jig  10  according to an embodiment of the invention in which  FIG. 6( a )  shows a portion of the mounting jig partly in section, and  FIG. 6( b )  shows an exploded view partly in section. The mounting jig  10  has an insulated circuit board positioning jig  11  for positioning the insulated circuit board  2 , a tubular contact element positioning jig  12  arranged over the insulated circuit board positioning jig  11  for positioning the tubular contact elements  6  and a tubular contact element press-down jig  13  arranged over the tubular contact element positioning jig  12  for pressing-down the tubular contact elements  6 . 
         [0038]      FIG. 7  is a plan view showing the insulated circuit board positioning jig  11 . The insulated circuit board positioning jig  11 , as is shown in  FIG. 7 , has a recess  111  having a plane figure the same as that of the insulated circuit board  2 . In the recess  111 , the insulated circuit board  2  is held without substantially leaving any gap. Moreover, in the vicinity of each of the upper left corner and the lower right corner on the upper surface of the insulated circuit board positioning jig  11 , a guide pin  112  of metal, of stainless steel, for example, is provided projecting therefrom. The partial cross section of the insulated circuit board positioning jig  11  shown in  FIGS. 6( a ), 6( b )  is the cross section along the line A-A viewed from the direction indicated by arrows in  FIG. 7 . 
         [0039]      FIG. 8  is a plan view showing the tubular contact element positioning jig  12 . 
         [0040]    The tubular contact element positioning jig  12 , as is shown in  FIG. 8 , has positioning holes  121  formed which penetrate the jig  12  in the thickness direction thereof each with a diameter permitting the tubular contact element  6  to be inserted. The positions of the positioning holes  121  are specified ones at which the tubular contact elements  6  are to be mounted on the insulated circuit board  2 . The size of each of the positioning holes  121  is determined to be a little (for example, on the order of 0.15 mm) larger than the outer diameter of the tubular contact element  6 , namely the outer diameter of the top flange  62  or the bottom flange  63  when the tubular contact element  6  has the top flange  62  and the bottom flange  63  or has only the bottom flange  63 . This makes the ensured positioning accuracy and easiness in inserting the tubular contact element  6  compatible. The tubular contact element positioning jig  12  has a guide hole  122  formed in the vicinity of each of the upper left corner and the lower right corner. With the guide pin  112  inserted into each of the guide holes  122 , the insulated circuit board  2  held in the insulated circuit board positioning jig  11  and the tubular contact elements  6  inserted into the positioning holes  121  in the tubular contact element positioning jig  12  are positioned. In the embodiment, the thickness of the tubular contact element positioning jig  12  is larger than the longitudinal length of the tubular contact element  6 . The tubular contact element positioning jig  12  shown partial cross-sectional view in  FIGS. 6( a ), 6( b )  is the cross section along the line B-B viewed from the direction indicated by arrows in  FIG. 8 . 
         [0041]      FIG. 9  is a view showing the tubular contact element press-down jig  13  viewed from the back thereof. As is shown in  FIG. 9 , the tubular contact element press-down jig  13  has a plurality of projections  131  formed on the back thereof facing the tubular contact element positioning jig  12 . The positions of the projections  131  are specified ones at which the projections  131  can press down the tubular contact elements  6  inserted into the tubular contact element positioning jig  12 . The size of the projection  131  is determined to be the size with which the projection  131  can be inserted into the positioning hole  121  of the tubular contact element positioning jig  12  and can press down the tubular contact element  6  and, particularly when the tubular contact element  6  has the top flange  62 , the thicker section  62   a  of the top flange  62 . Therefore, the size of the projection  131  is preferably determined to be approximately equal to the outer diameter of the top flange  62 . The shape of the projection  131  can be prism-shape or circular cylinder-shape. The projections  131  can be formed by cutting the back of the tubular contact element press-down jig  13  or also can be formed by press-fitting the projection  131  of metal into each of holes  131 ′ formed beforehand in the back of the tubular contact element press-down jig  13 . When the projection  131  is made of metal, metallic material that cannot be joined by soldering such as stainless steel or aluminum is preferably used. The length of the projection  131  is determined to be the length with which the projection  131  can press down the tubular contact element  6  in the tubular contact element positioning jig  12  when the tubular contact element press-down jig  13  is laid on the tubular contact element positioning jig  12 . The tubular contact element press-down jig  13  has guide hole  132  formed in the vicinity of each of four corners. By inserting the guide pin  112  into each of the guide holes  132 , the tubular contact elements  6  inserted in the positioning holes  121  of the tubular contact element positioning jig  12  are made positioned so that the projections  131  of the tubular contact element press-down jig  13  can press down the tubular contact elements  6 . The tubular contact element press-down jig  13  presses down the tubular contact elements  6  by its own weight. 
         [0042]    An example of a method of soldering the tubular contact elements  6  to the insulated circuit board  2  with the use of the mounting jig  10  will be explained.  FIG. 15  is a flow chart showing a part of a joining process in the method of manufacturing a semiconductor device according to an embodiment of the invention. First, the insulated circuit board positioning jig  11 , the tubular contact element positioning jig  12  and the tubular contact element press-down jig  13  are prepared (step S 1  in  FIG. 15 ). Then, on the insulated circuit board  2 , solder is applied at each of positions at which the tubular contact elements  6  are to be mounted and at each of positions at which the semiconductor chips  3 A,  3 B,  3 C, and  3 D are to be mounted. For the solder, solder paste is preferably used for being applied by printing. In the next, the semiconductor chips  3 A,  3 B,  3 C, and  3 D are placed on the conductor pattern layer  2   b  on the insulated circuit board  2  by using a device such as a mounter (automatic mounting device). Next to this, the insulated circuit board  2  is made to be held in the recess  111  of the insulated circuit board positioning jig  11  (step S 2  in  FIG. 15  (see  FIG. 6( b ) ). 
         [0043]    Following this, the tubular contact element positioning jig  12  is laid on the insulated circuit board positioning jig  11  by making the guide pins  112  thereof inserted through the guide holes  122  of the tubular contact element positioning jig  12 . This determines the positions of the tubular contact elements  6  on the insulated circuit board  2 . By using a device such as a mounter (automatic mounting device), the tubular contact elements  6  are inserted into the positioning holes  121  in the tubular contact element positioning jig  12  (step S 3  in  FIG. 15 ). 
         [0044]    Subsequent to this, the tubular contact element press-down jig  13  is laid on the tubular contact element positioning jig  12  by making the guide pins  112  of the insulated circuit board positioning jig  11  inserted through the guide holes  132  of the tubular contact element press-down jig  13 . This accomplishes the positioning of the tubular contact elements  6  in the positioning hole  121  of the tubular contact element positioning jig  12  and the projections  131  of the tubular contact element press-down jig  13 , by which the tubular contact elements  6  are pressed down toward the insulated circuit board  2  (see  FIG. 6( a ) ). With this state, the mounting jig  10 , the insulated circuit board  2  and the tubular contact elements  6  are made contained in a depressurized furnace to be heated for melting solder, by which the tubular contact elements  6  are soldered onto the conductor pattern layer  2   b  on the insulated circuit board  2  (step S 4  in  FIG. 15 ). At the same time, the semiconductor chips  3 A,  3 B,  3 C, and  3 D are soldered onto the conductor pattern layer  2   b  on the insulated circuit board  2 . 
         [0045]    By the manufacturing method according to the one embodiment of the invention, the positioning carried out while pressing down the tubular contact elements  6  with the use of the mounting jig  10  enables the tubular contact elements  6  to be mounted on the insulated circuit board  2  with ensured verticality and high positional accuracy. Moreover, the positioning carried out while pressing down the tubular contact elements  6  with the use of the mounting jig  10  makes the tubular contact elements  6  vertically pressed against the insulated circuit board  2  at soldering, which allows solder to surely go into the hollow cylindrical tube  61  of each of the tubular contact elements  6  to thereby the amount of solder in the hollow cylindrical tube  61  can be reliably secured. 
         [0046]    For explaining the preferable form of the mounting jig  10 , an enlarged fragmentary cross sectional view of the X portion in  FIG. 6( a ) , namely a portion in the vicinity of the positioning hole  121  of the tubular contact element positioning jig  12 , is shown in  FIG. 10 . The positioning hole  121  is formed of a tapered section  121   a  and a straight section  121   b . In the tapered section  121   a , the inner diameter of an opening on the side onto which the tubular contact element  6  is inserted is larger than the inner diameter of an opening on the opposite side and becomes smaller in the thickness direction. In the straight section  121   b , the inner diameter of an opening is constant. The positioning hole  121 , being formed so as to have the tapered section  121   a  on the side onto which the tubular contact element  6  is inserted, permits the tubular contact element  6  to be easily inserted into the positioning hole  121 , by which workability can be improved. 
         [0047]    As is shown in  FIG. 10 , in the positioning hole  121 , letting the length from the surface on the side onto which the tubular contact element  6  is inserted to the bottom end of the tapered section  121   a , that is, the length of the tapered section  121   a  in the thickness direction of the positioning hole  121  be a, the length from the bottom end of the tapered section  121   a  to the other surface of the tubular contact element positioning jig  12 , that is, the length of the straight section  121   b  of the positioning hole  121  be b, the total length of the positioning hole  121 , that is, the thickness of the tubular contact element positioning jig  12  be c and the inner diameter of the positioning hole  121  be d, and further letting the length of the projection  131  of the tubular contact element press-down jig  13  be e and the longitudinal length of the tubular contact element  6  be h, a structure in which the length b of the straight section  121   b  is made to be longer than the longitudinal length h of the tubular contact element  6  is a preferable form. The structure means that when the tubular contact element  6  is inserted into the positioning hole  121 , the bottom end of the tapered section  121   a  of the positioning hole  121  positions higher than the top end of the tubular contact element  6 , or means that the tubular contact element  6  is contained only in the straight section  121   b  without being contained in the tapered section  121   a . The structure enables the tubular contact element press-down jig  13  to be easily removed from the tubular contact element positioning jig  12  after the tubular contact element  6  is soldered onto the conductor pattern layer  2   b  of the insulated circuit board  2 . 
         [0048]    Compared with this, when the length b of the straight section  121   b  is shorter than the longitudinal length of the tubular contact element  6 , that is, when the bottom end of the tapered section  121   a  positions lower than the top end of the tubular contact element  6 , in other words, when a part of the tubular contact element  6  is contained in the tapered section  121   a , there is a possibility of lowering the verticality of the tubular contact element  6 . Moreover, there is a possibility of causing the tubular contact element  6  to be caught by the bottom end of the tapered section  121   a  to thereby make the tubular contact element press-down jig  13  difficult to be easily removed from the tubular contact element positioning jig  12 . Therefore, the foregoing structure is a particularly preferable form when using the tubular contact element  6  having the top flange  62  of the examples of the tubular contact elements  6  shown in  FIG. 5( a ) . 
         [0049]    A mounting jig  20  according to another embodiment of the invention will be explained by using  FIGS. 11( a ), 11( b ) . FIGS.  11 ( a ),  11 ( b ) are elevation views illustrating the mounting jig according to another embodiment of the invention in which  FIG. 11( a )  shows a portion of the mounting jig in section, and  FIG. 11( b )  shows an exploded view in which a portion of the mounting jig is in section. The mounting jig  20  shown in  FIGS. 11( a ), 11( b )  has an insulated circuit board positioning jig  21  for positioning the insulated circuit board  2 , a tubular contact element positioning jig  22  arranged over the insulated circuit board positioning jig  21  for positioning the tubular contact elements  6  and a tubular contact element press-down jig  23  arranged over the tubular contact element positioning jig  22  for pressing-down the tubular contact elements  6 . 
         [0050]    The insulated circuit board positioning jig  21  has a recess  211  and guide pins  212  having the same structures as those of the recess  111  and guide pins  112 , respectively, explained in the foregoing when compared, although they have different reference numerals. Therefore, redundant explanations with respect to the recess  211  and guide pins  212  will be omitted. The partial cross section of the insulated circuit board positioning jig  21  shown in  FIG. 11  is the cross section along the line A-A viewed from the direction indicated by arrows in  FIG. 7 . 
         [0051]    The tubular contact element positioning jig  22  has positioning holes  221  and guide holes  222  having the same structures as those of the positioning holes  121  and guide holes  122 , respectively, explained in the foregoing when compared, although they have different reference numerals. Therefore, redundant explanations with respect to the positioning holes  221  and guide holes  222  will be omitted. The tubular contact element positioning jig  22  in the embodiment differs from the tubular contact element positioning jig  12  of the mounting jig  10  explained in the foregoing in that the thickness of the tubular contact element positioning jig  22  is smaller than the longitudinal length of the tubular contact element  6 . From this, when the tubular contact element  6  is inserted in the positioning hole  221 , the top end of the tubular contact element  6  is to project upward to be higher than the top surface of the tubular contact element positioning jig  22 . The partial cross section of the tubular contact element positioning jig  22  shown in  FIGS. 11( a ), 11( b )  is the cross section along the line B-B viewed from the direction indicated by arrows in  FIG. 8 . 
         [0052]    The tubular contact element press-down jig  23  has guide holes  232  having the same structures as those of the guide holes  132  in the mounting jig  10  explained in the foregoing when compared, although they have different reference numerals. Therefore, redundant explanations with respect to the guide holes  232  will be omitted. In the illustrated embodiment, the tubular contact element press-down jig  23  has a flat bottom surface, that is, no projection is formed on the bottom surface. Therefore, the bottom surface of the tubular contact element press-down jig  23  has a shape without projections  131  shown in  FIG. 9 . However, like the tubular contact element press-down jig  13  in the mounting jig  10  explained in the foregoing, projections can be formed on the bottom surface of the tubular contact element press-down jig  23 . The tubular contact element press-down jig  23  presses down the tubular contact elements  6  projecting upward higher than the top surface of the tubular contact element positioning jig  22  with the flat bottom surface of the tubular contact element press-down jig  23  by its own weight. 
         [0053]    An example of a method of soldering the tubular contact elements  6  to the insulated circuit board  2  with the use of the mounting jig  20  can be made to be the same as the one example of the method of soldering the tubular contact elements  6  to the insulated circuit board  2  with the use of the mounting jig  10 . Therefore, redundant explanations thereof will be omitted. 
         [0054]    According to the manufacturing method of a semiconductor device using the mounting jig  20 , the positioning carried out while pressing down the tubular contact elements  6  with the use of the mounting jig  20  enables the tubular contact elements  6  to be mounted on the insulated circuit board  2  with ensured verticality and high positional accuracy. Moreover, the positioning carried out while pressing down the tubular contact elements  6  with the use of the mounting jig  20  makes the tubular contact elements  6  vertically pressed against the insulated circuit board  2  at soldering, which allows solder to surely go into the hollow cylindrical tube  61  of each of the tubular contact elements  6  to thereby the amount of solder in the hollow cylindrical tube  61  can be reliably secured. 
         [0055]    For explaining the preferable form of the mounting jig  20 , an enlarged fragmentary cross sectional view of the portion XII in  FIG. 11( a ) , namely a portion in the vicinity of the positioning hole  221  of the tubular contact element positioning jig  22 , is shown in  FIG. 12 . The positioning hole  221  is formed of a tapered section  221   a  and a straight section  221   b . In the tapered section  221   a , the inner diameter of an opening on the side onto which the tubular contact element  6  is inserted is larger than the inner diameter of an opening on the opposite side and becomes smaller in the thickness direction. In the straight section  221   b , the inner diameter of an opening is constant. The positioning hole  221 , being formed so as to have the tapered section  121   a  on the side onto which the tubular contact element  6  is inserted, permits the tubular contact element  6  to be easily inserted into the positioning hole  221 , by which workability can be improved. 
         [0056]    As is shown in  FIG. 12 , in another embodiment of the invention, a structure is provided in which letting the thickness of the tubular contact element positioning jig  22  be t and the longitudinal length of the tubular contact element  6  be h, the longitudinal length h of the tubular contact element  6  is longer than the thickness t of the tubular contact element positioning jig  22 . For example, the difference between h and t is 0.3 mm or more. The structure is provided so that the tubular contact element press-down jig  23  can press down the tubular contact element  6 . The foregoing structure can be applied to the case of using the tubular contact element  6  having the top flange  62  and to the cases of using the tubular contact elements  6 A and  6 B both having no top flanges  62 . 
         [0057]    For explaining the preferable forms of the mounting jigs  10  and  20 , a partially enlarged cross-sectional view of the portion XIII in  FIG. 10 , namely a portion in the vicinity of the projection  131  formed in the tubular contact element press-down jig  13  of the mounting jig  10 , is shown in  FIG. 13 . As is shown in  FIG. 13 , a small projection  131   a  is formed at the head of the projection  131 . The tip of the small projection  131   a  has a tapered down shape, by which the small projection  131   a  is made to be easily inserted in the hollow cylindrical tube  61  of the tubular contact element  6 . Moreover, the base of the small projection  131   a  has an outer diameter smaller than the inner diameter of the hollow cylindrical tube  61  of the tubular contact element  6 , by which the small projection  131   a  goes into the hollow cylindrical tube  61  of the tubular contact element  6  when the projection  131  presses down the tubular contact element  6 . From this, it becomes possible to carry out positioning while pressing down the tubular contact element  6  with the use of the tubular contact element press-down jig  13  having the small projection  131   a  to thereby make it possible to further improve the positioning accuracy of the tubular contact element  6 . In addition, the small projection  131   a  has a function of the upper lid of the hollow cylindrical tube  61  of the tubular contact element  6 . This can prevent molten solder from running out together with flux from the longitudinal top end of the tubular contact element  6  through the hollow cylindrical tube  61  at soldering of the tubular contact element  6  in a depressurized furnace. 
         [0058]    In  FIG. 13 , an example is shown in which the small projection  131   a  is formed in the tubular contact element press-down jig  13  of the mounting jig  10 . However, also in the mounting jig  20 , a small projection going into the hollow cylindrical tube  61  of the tubular contact element  6  can be formed in the tubular contact element press-down jig  23 . Hence, only a small projection can be also formed on the flat bottom surface of the tubular contact element press-down jig  23 . Moreover, it is also possible that a projection like the projection  131  formed in the tubular contact element press-down jig  13  is provided on the bottom surface of the tubular contact element press-down jig  23  and a small projection is provided at the head of the projection for being formed into a shape like the shape of the small projection  131   a  shown in  FIG. 13 . In either shape, it becomes possible for the mounting jig  20  to carry out positioning while pressing down the tubular contact elements  6  to thereby make it possible to further improve the positioning accuracy of the tubular contact element  6 . 
         [0059]      FIG. 14  is a schematic partially enlarged cross-sectional view of the portion XIII in  FIG. 10  as a portion in the vicinity of the projection  131 , the view showing an example of a modification of the tubular contact element press-down jig  13  in which the small projections  131   a  are formed. The small projection  131   a  is formed at the head of the projection  131  shown in  FIG. 14  and an outer peripheral section  131   b  and an inside peripheral section  131   c  at the head of the projection  131  are formed in step-like with a difference in level equal to the difference in thickness between the thicker section  62   a  and the thinner section  62   b  in the top flange  62  of the tubular contact element  6 . The outer peripheral section  131   b  and the inside peripheral section  131   c  at the head of the projection  131  being formed in step-like, the outer peripheral section  131   b  and the inside peripheral section  131   c  can contact the thicker section  62   a  and the thinner section  62   b , respectively, in the top flange  62  of the tubular contact element  6 . Therefore, at soldering of the tubular contact element  6  in a depressurized furnace, molten solder is prevented from running out together with flux from the longitudinal top end of the tubular contact element  6  through the hollow cylindrical tube  61 . 
         [0060]    As explained in  FIG. 2 , the insulated circuit board  2  is formed of an insulating substrate  2   a , a conductor pattern layer  2   b  formed on one surface of the insulating substrate  2   a , and a metal layer  2   c  formed on the other surface of the insulating substrate  2   a . The insulating substrate  2   a  may be made of ceramic, and the conductor pattern  2   b  and metal layer  2   c  may be made of cupper. Since the volume of the conductor pattern  2   b  is different from the volume of the metal layer  2   c , which is a flat layer entirely covering the insulating substrate  2   a , when the insulated circuit board  2  is heated in a furnace for bonding the contact elements to the insulated circuit board  2 , the insulated circuit board  2  may be curved due to the difference of expansion between the conductor pattern  2   b  and the metal layer  2   c . Especially, the outer area of the insulated circuit board  2  is likely to curve upwardly. 
         [0061]    In this respect, in order to fix the contact elements perpendicular to the insulated circuit board  2 , the heights of projections extending from the bottom surface of the tubular contact element press-down jig are formed differently. Namely, as shown in  FIG. 16 , the tubular contact element press-down jig  13 ′ has projections  131   a ,  131   b ,  131   c . The projection  131   a  is arranged at the outer area of the jig  13 ′, which is curved upwardly most, and the projection  131   a  is arranged in the center area of the jig  13 ′. The projection  131   b  is arranged between the projections  131   a  and  131   c . In the jig  13 ′, the insulated circuit board  2  can be curved upwardly around the outer area in the furnace. Thus, the tubular contact elements can be arranged vertically with respect to the upper surface of the insulated circuit board. 
         [0062]    The insulated circuit board positioning jig  11 , the tubular contact element positioning jig  12  and the tubular contact element press-down jigs  13 ,  13 ′ forming the mounting jig  10  are preferably made of composite ceramic material having a coefficient of linear expansion equal to or less than the coefficient of linear expansion of carbon or carbon. Similarly, the insulated circuit board positioning jig  21 , the tubular contact element positioning jig  22  and the tubular contact element press-down jig  23  forming the mounting jig  20  are preferably made of composite ceramic material having a coefficient of linear expansion equal to or less than the coefficient of linear expansion of carbon or carbon. When the jig forming the mounting jig  10  or the mounting jig  20  is formed with material having a coefficient of linear expansion larger than the coefficient of linear expansion of carbon, for example, metallic material such as aluminum, aluminum alloy or stainless steel, there is fear that a dimensional difference is caused between the jig and the insulated circuit board  2  due to a large difference between the coefficient of linear expansion of the jig and the coefficient of linear expansion of the insulated circuit board  2  to result in insufficient positioning accuracy of the tubular contact element  6  and therefore insufficient positioning accuracy of the external terminal  7 . Therefore, by providing the jig forming the mounting jig  10  or the mounting jig  20  as a jig made of composite ceramic material having a coefficient of linear expansion equal to or less than the coefficient of linear expansion of carbon or carbon, the difference between the coefficient of linear expansion of the jig and the coefficient of linear expansion of the insulated circuit board  2  is made small to make it possible to ensure the positioning accuracy of the tubular contact element  6  to finally secure the positioning accuracy of the external terminal  7 . 
         [0063]    The insulated circuit board positioning jig  11 , the tubular contact element positioning jig  12  and the tubular contact element press-down jig  13  forming the mounting jig  10 , when made of composite ceramic material having a coefficient of linear expansion equal to or less than the coefficient of linear expansion of carbon or carbon, are not required to have their material unified to the same material. Thus, different materials can be combined for being used. The same is true for the mounting jig  20 . 
         [0064]    Moreover, when the material forming the mounting jig  10  or the mounting jig  20  is chosen to be composite ceramic material having a coefficient of linear expansion equal to or less than the coefficient of linear expansion of carbon or carbon, it is preferable from the view point of easiness in processing the jig that the material can be subjected to cutting. For the composite ceramic material that has a coefficient of linear expansion equal to or less than the coefficient of linear expansion of carbon and can be subjected to cutting, there are silicon nitride series composite ceramics, alumina series composite ceramics and boron nitride series composite ceramics. For example, there are named ceramics such as Si3N4-BN composite ceramic, Al2O3-BN composite ceramic and hBN ceramic. 
         [0065]    In the manufacturing process of the semiconductor module  1 , after the tubular contact elements  6  are positioned onto the insulated circuit board  2  by using the mounting jig  10  or the mounting jig  20  to be soldered to the insulated circuit board  2 , specified wire bonding work is carried out with respect to the insulated circuit board  2 . Then, the external terminal  7  is inserted into each of the tubular contact elements  6  to be press-fitted thereto for electrical connection. After this, to the insulated circuit board  2 , the case  8  is bonded, which is then filled with the gel  9 . 
         [0066]    In the foregoing, the manufacturing method of a semiconductor device and the mounting jig according to the invention were specifically explained by the embodiments with reference to the attached drawings. The manufacturing method of a semiconductor device and the mounting jig according to the invention, however, are not limited to those described as the embodiments and shown in the attached drawings, but various modifications are possible. 
         [0067]    While the present invention has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details can be made therein without departing from the spirit and scope of the present invention.