Abstract:
This invention provides a semiconductor device and its manufacturing method capable of mounting a plurality of semiconductor elements without reducing the reliability of the semiconductor device. More specifically, this invention provides a semiconductor device and its manufacturing method comprising: a printed wiring board with a wiring pattern; a first semiconductor element mounted on a predetermined location on the printed wiring board and having a plane with a first region in which an electrode pad is formed and a second region, the internal region of the first region; an auxiliary member mounted on the second region of the first semiconductor element and having a plane with a first region in which a wiring pattern is formed and a second region, the internal region of the first region; and a second semiconductor element mounted on the second region of the auxiliary member and having a plane with an electrode pad formed; and wherein: the electrode pad of the first semiconductor element and the wiring pattern of the printed wiring board are electrically connected to each other; the electrode pad of the second semiconductor element and the wiring pattern of the auxiliary member are electrically connected to each other; the wiring pattern of the auxiliary member and the wiring pattern of the printed wiring board are electrically connected to each other; and the first semiconductor element and the second semiconductor element are resin-sealed.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a semiconductor device. More specifically, the present invention relates to a semiconductor device of chip on board (COB) type with a plurality of semiconductor elements mounted on a printed wiring board. 
     2. Prior Art 
     A conventional semiconductor manufacturing method with a plurality of semiconductor elements mounted will be described in reference to FIG. 9. A first semiconductor element  601  is adhered to a predetermined location on a printed wiring board  606  with a die bonding material  603 , as shown in FIG.  9 . Then a second semiconductor element  602  smaller than that of the first semiconductor element  601  is similarly adhered to a predetermined location with a die bonding material  608 . 
     Next, a wiring pattern  605  provided on the printed wiring board  606  and the semiconductor element  601  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  604 . Then the wiring pattern  605  and the semiconductor element  602  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  609 . 
     After that, resin sealing is achieved by an epoxy resin  607  to protect the first semiconductor element  601 , the second semiconductor element  602  and the thin wires for connection  604  and  609 . Thereby the semiconductor device is completed. 
     In the above conventional method however, the smaller the second semiconductor element becomes, the longer the thin wire for connection becomes. For this reason, the problem arises that the shape of the thin wire for connection changes to short with the adjacent thin wire for connection. As a result, the reliability of the semiconductor device becomes reduced. 
     The object of the present invention is to provide a novel and improved semiconductor device on which a plurality of semiconductor element can be mounted without reducing the reliability of the semiconductor device. 
     SUMMARY OF THE INVENTION 
     In the typical present invention to achieve the above object, there is provided a semiconductor device comprising: a printed wiring board with a wiring pattern; a first semiconductor element mounted on a predetermined location on the printed wiring board and having a plane with a first region in which an electrode pad is formed and a second region, the internal region of the first region; an auxiliary member mounted on the second region of the first semiconductor element and having a plane with a first region in which a wiring pattern is formed and a second region, the internal region of the first region; and a second semiconductor element mounted on the second region of the auxiliary member and having a plane with an electrode pad formed; and wherein: the electrode pad of the first semiconductor element and the wiring pattern of the printed wiring board are electrically connected to each other; the electrode pad of the second semiconductor element and the wiring pattern of the auxiliary member are electrically connected to each other; the wiring pattern of the auxiliary member and the wiring pattern of the printed wiring board are electrically connected to each other; and the first semiconductor element and the second semiconductor element are resin-sealed. 
     In the above-described invention, since the first and second semiconductor elements are connected by a thin wire for connection to each other, the length of the thin wire for connection can be shorter than the conventional one. As a result, even if a smaller second semiconductor element is mounted, the shape of the thin wire for connection does not change and the thin wire for connection can be prevented from shorting with the adjacent thin wire for connection, so that the semiconductor device with high reliability can be provided. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other features of the invention and the concomitant advantages will be better understood and appreciated by persons skilled in the field to which the invention pertains in view of the following description given in conjunction with the accompanying drawings which illustrate preferred embodiments. 
     FIG. 1 is a sectional view showing the structure of a semiconductor device in the first embodiment. 
     FIGS. 2 a  and  2   b  are a sectional view showing the structure of an auxiliary member in the first embodiment. 
     FIG. 3 is a sectional view showing the structure of a semiconductor device in the second embodiment. 
     FIGS. 4 a  and  4   b  are is a sectional view showing the structure of an auxiliary member in the second embodiment. 
     FIG. 5 is a sectional view showing the structure of a semiconductor device in the third embodiment. 
     FIG. 6 is a sectional view showing the structure of a semiconductor device in the fourth embodiment. 
     FIG. 7 is a sectional view showing the structure of an auxiliary member in the fourth embodiment. 
     FIG. 8 is a sectional view showing the structure of a semiconductor device in the fifth embodiment. 
     FIG. 9 is a sectional view showing a conventional method for manufacturing a semiconductor device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, the preferred embodiment of the present invention will be described in reference to the accompanying drawings. Same reference numerals are attached to components having same functions in following description and the accompanying drawings, and a description thereof is omitted. 
     (First Embodiment) 
     First, a semiconductor device in the first embodiment will be explained in reference to FIGS. 1 and 2. FIG. 1 is a sectional view showing the structure of a semiconductor device in the first embodiment. FIG. 2 is a sectional view showing the structure of an auxiliary member in the first embodiment. 
     A semiconductor integrated circuit (first semiconductor element)  101  is adhered to a predetermined location on a printed wiring board  106  with a die bonding material  103 , as shown in FIG.  1 . An auxiliary member  108  in this embodiment is adhered to a location within a wiring pattern  105  formed at the periphery of the first semiconductor element  101  with a die bonding material  103 . 
     As shown in FIG. 2, the auxiliary member  108  in this embodiment comprises a die bonding part  110  for mounting a second semiconductor element  102  and a wiring pattern part  109  for connecting electrically to the second semiconductor element  102 . 
     The second semiconductor integrated circuit (second semiconductor element)  102  is adhered to a die bonding part  110  on the auxiliary member  108  with a die bonding material  111 , similarly to the first semiconductor element  101 . 
     A wiring pattern  105  provided on the printed wiring board  106  and the first semiconductor element  101  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  104 . In addition, a wiring pattern  109  provided on the auxiliary member  108  and the second semiconductor element  102  are electrically connected to each other via a thin wire for connection  112  while the wiring pattern  109  and the wiring pattern  105  provided on the printed wiring board  106  are electrically connected to each other via a thin wire for connection  113 . 
     Further, resin sealing is achieved by an epoxy resin  107  to protect the first semiconductor element  101 , the second semiconductor element  102 , the auxiliary member  108  and the thin wires for connection  104 ,  112  and  113 . 
     Hereafter, a method for manufacturing a semiconductor device will be described in this embodiment in reference to FIGS. 1 and 2. 
     The semiconductor integrated circuit (first semiconductor element)  101  is adhered to a predetermined location on the printed wiring board  106  with the die bonding material  103 , as shown in FIG.  1 . Next, the auxiliary member  108  is adhered to a location within the wiring pattern  105  formed at the periphery of the first semiconductor element  101  with the die bonding material  103 . 
     As shown in FIG. 2, the auxiliary member  108  in this embodiment comprises the die bonding part  110  for mounting the second semiconductor element  102  and the wiring pattern part  109  for connecting electrically to the second semiconductor element  102 . 
     Next, the second semiconductor integrated circuit (second semiconductor element)  102  is adhered with the die bonding material  111 , similarly to the first semiconductor element  101 . 
     The wiring pattern  105  provided on the printed wiring board  106  and the first semiconductor element  101  are electrically connected to each other via the thin wire for connection (Au wire, Al wire and the like)  104 . 
     Next, the wiring pattern  109  provided on the auxiliary member  108  and the second semiconductor element  102  are electrically connected to each other via the thin wire for connection  112  while the wiring pattern  109  and the wiring pattern  105  provided on the printed wiring board  106  are electrically connected to each other via the thin wire for connection  113 . 
     Finally, resin sealing is achieved by the epoxy resin  107  to protect the first semiconductor element  101 , the second semiconductor element  102 , the auxiliary member  108  and the thin wires for connection  104 ,  112  and  113 . Thereby the semiconductor device is completed. 
     In this embodiment, since the wiring pattern  105  provided on the printed wiring board  106  and the second semiconductor element  102  are connected by a thin wire for connection to each other, the length of the thin wire for connection can be shorter than the conventional one. As a result, even if a smaller second semiconductor element is mounted, the shape of the thin wire for connection does not change and the thin wire for connection can be prevented from shorting with the adjacent thin wire for connection, so that the semiconductor device with high reliability can be provided. 
     (Second Embodiment) 
     In this embodiment, there is provided a semiconductor device on which a larger second semiconductor element can be mounted. Hereafter, the second embodiment will be explained in reference to FIGS. 3 and 4. FIG. 3 is a sectional view showing the structure of a semiconductor device in the second embodiment. FIG. 4 is a sectional view showing the structure of an auxiliary member in the second embodiment. 
     A semiconductor integrated circuit (first semiconductor element)  201  is adhered to a predetermined location on a printed wiring board  206  with a die bonding material  203 , as shown in FIG.  3 . The first semiconductor element  201  and a wiring pattern  205  provided on the printed wiring board  206  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  204 . 
     In this embodiment, an auxiliary member  208  is mounted on the first semiconductor element  201  and adhered with a die bonding material  212  so that a supporting part  214  with a substantially protruding shape on the auxiliary member  208  may be located within an electrode pad formed at the periphery of the first semiconductor element  201 . 
     As shown in FIG. 4, the auxiliary member  208  in this embodiment comprises a die bonding part  210  for mounting a second semiconductor element  202 , a member  213  the surface on which a wiring pattern part  209  for connecting electrically to the second semiconductor element  202  is formed and the supporting part  214  with a substantially protruding shape formed on the rear surface of the member  213 . 
     As described above, since the auxiliary member in this embodiment is mounted so that the supporting part with a substantially protruding shape may be located within an electrode pad formed at the periphery of the first semiconductor element, a larger second semiconductor element can be mounted. Also, even a second semiconductor element with an arbitrary size can be mounted. 
     The second semiconductor element  202  is adhered to a die bonding part  210  on the auxiliary member  208  with a die bonding material  215 , similarly to the first semiconductor element  201 . 
     In addition, a wiring pattern  209  provided on the auxiliary member  208  and the second semiconductor element  202  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  216  while the wiring pattern  209  provided on the auxiliary member  208  and the wiring pattern  205  provided on the printed wiring board  206  are electrically connected to each other via a thin wire for connection  217 . 
     Further, resin sealing is achieved by an epoxy resin  207  to protect the first semiconductor element  201 , the second semiconductor element  202 , the auxiliary member  208  and the thin wires for connection  204 ,  216  and  217 . 
     Hereafter, a method for manufacturing a semiconductor device will be described in this embodiment in reference to FIG.  3 . 
     The semiconductor integrated circuit (first semiconductor element)  201  is adhered to a predetermined location on the printed wiring board  206  with the die bonding material  203 , as shown in FIG.  3 . Next, the wiring pattern  205  provided on the printed wiring board  206  and the first semiconductor element  201  are electrically connected to each other via the thin wire for connection (Au wire, Al wire and the like)  204 . 
     The auxiliary member  208  is mounted on the first semiconductor element  201  and adhered with the die bonding material  212  so that the supporting part  214  with a substantially protruding shape may be located within an electrode pad formed at the periphery of the first semiconductor element  201 . 
     As shown in FIG. 4, the auxiliary member  208  in this embodiment comprises the die bonding part  210  for mounting the second semiconductor element  202 , the member  213  the surface on which a wiring pattern part  209  for connecting electrically to the second semiconductor element  202  is formed and the supporting part  214  with a substantially protruding shape formed on the rear surface of the member  213 . 
     As described above, since the auxiliary member in this embodiment is mounted so that the supporting part with a substantially protruding shape may be located within an electrode pad formed at the periphery of the first semiconductor element, a larger second semiconductor element can be mounted. In addition, since the auxiliary member is mounted after the thin wire for connection of the first semiconductor element is connected, each connection of each thin wire for connection is not disrupted even in mounting a larger semiconductor element. Also, even a second semiconductor element with an arbitrary size can be mounted. 
     Next, the second semiconductor element  202  is adhered to the die bonding part  210  on the auxiliary member  208  with the die bonding material  215 , similarly to the first semiconductor element  201 . 
     After that, the wiring pattern  209  provided on the auxiliary member  208  and the second semiconductor element  202  are electrically connected to each other via the thin wire for connection (Au wire, Al wire and the like)  216 . Then the wiring pattern  209  provided on the auxiliary member  208  and the wiring pattern  205  provided on the printed wiring board  206  are electrically connected to each other via the thin wire for connection (Au wire, Al wire and the like)  217 . 
     Finally, resin sealing is achieved by the epoxy resin  207  to protect the first semiconductor element  201 , the second semiconductor element  202 , the auxiliary member  208  and the thin wires for connection  204 ,  216  and  217 . Thereby the semiconductor device is completed. 
     In this embodiment, since the auxiliary member is mounted so that the supporting part with a substantially protruding shape provided on the auxiliary member may be located within an electrode pad formed at the periphery of the first semiconductor element, a larger second semiconductor element can be mounted. In addition, since the auxiliary member is mounted after the thin wire for connection of the first semiconductor element is connected, each connection of each thin wire for connection is not disrupted even in mounting a larger semiconductor element. Also, even a second semiconductor element with an arbitrary size can be mounted. 
     (Third Embodiment) 
     In this embodiment, a semiconductor device can be further smaller. Hereafter, the third embodiment will be explained in reference to FIG.  5 . FIG. 5 is a sectional view showing the structure of a semiconductor device in the third embodiment. 
     A semiconductor integrated circuit (first semiconductor element)  301  is adhered to a predetermined location on a printed wiring board  306  with a die bonding material  303 , as shown in FIG.  5 . The first semiconductor element  301  and a wiring pattern  305  provided on the printed wiring board  306  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  304 . 
     In this embodiment, an auxiliary member  308  consisting of, for example, an epoxy resin and the like, is mounted on the first semiconductor element  301  and adhered with a die bonding material  312  so that a supporting part with a substantially protruding shape on the auxiliary member  308  may be located within an electrode pad formed at the periphery of the first semiconductor element  301 . At this time, the auxiliary member  308  is mounted so as not to change the shape of the thin wire for connection  304 . It is to be noted that the auxiliary member  308  in this embodiment comprises a member larger than a second semiconductor element by, for example, 0.1 mm, for mounting the second semiconductor element on the surface thereof, and a supporting part with a substantially protruding shape formed on the rear surface of the member. 
     A second semiconductor element  302  is adhered to the auxiliary member  308  with a die bonding material  315 , similarly to the first semiconductor element  301 . 
     In addition, the second semiconductor element  302  and a wiring pattern  305  provided on the printed wiring board  306  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  316 . Further, resin sealing is achieved by an epoxy resin  307  to protect the first semiconductor element  301 , the second semiconductor element  302 , the auxiliary member  312  and the thin wires for connection  304  and  316 . 
     Hereafter, a method for manufacturing a semiconductor device will be described in this embodiment in reference to FIG.  5 . 
     The first semiconductor integrated circuit (first semiconductor element)  301  is adhered to a predetermined location on the printed wiring board  306  with the die bonding material  303 , as shown in FIG.  5 . Next, the wiring pattern  305  provided on the printed wiring board  306  and the first semiconductor element  301  are electrically connected to each other via the thin wire for connection (Au wire, Al wire and the like)  304 . 
     The auxiliary member  308  consisting of, for example, an epoxy resin and the like, is mounted on the first semiconductor element  301  and adhered with the die bonding material  312  so that a supporting part with a substantially protruding shape may be located within an electrode pad formed at the periphery of the first semiconductor element  301 , so as not to change the shape of the thin wire for connection  304 . It is to be noted that the auxiliary member  308  in this embodiment comprises the member larger than the second semiconductor element by, for example, 0.1 mm, for mounting the second semiconductor element on the surface thereof, and the supporting part with a substantially protruding shape formed on the rear surface of the member. 
     Next, the second semiconductor element  302  is adhered to the auxiliary member  308  with the die bonding material  315 , similarly to the first semiconductor element  201 . 
     After that, the second semiconductor element  302  and the wiring pattern  305  provided on the printed wiring board  306  are electrically connected to each other via the thin wire for connection (Au wire, Al wire and the like)  316 . 
     Finally, resin sealing is achieved by an epoxy resin  307  to protect the first semiconductor element  301 , the second semiconductor element  302 , the auxiliary member  312  and the thin wires for connection  304  and  316 . Thereby the semiconductor device is completed. 
     In this embodiment, since the second semiconductor element and the wiring pattern provided on the printed wiring board are directly connected, a small auxiliary member can be used without forming a wiring pattern on the auxiliary member. As a result, since the width of the resin-application area in the semiconductor device is reduced, the size of the semiconductor device can be small. In addition, since the auxiliary member is mounted so that the supporting part with a substantially protruding shape provided on the auxiliary member may be located within an electrode pad formed at the periphery of the first semiconductor element, a larger second semiconductor element can be mounted. In addition, since the auxiliary member is mounted after the thin wire for connection of the first semiconductor element is connected, each connection of each thin wire for connection is not disrupted even in mounting a larger semiconductor element. Also, even a second semiconductor element with an arbitrary size can be mounted. 
     (Fourth Embodiment) 
     In this embodiment, a semiconductor element forming a potential on the rear surface of the second semiconductor element, for example, a semiconductor element with SOI structure, can be mounted. Hereafter, the fourth embodiment will be explained in reference to FIGS. 6 and 7. FIG. 6 is a sectional view showing the structure of a semiconductor device in the fourth embodiment. FIG. 7 is a sectional view showing the structure of an auxiliary member in the fourth embodiment. 
     A first semiconductor element  401  is adhered to a predetermined location on a printed wiring board  406  with a die bonding material  403 , as shown in FIG.  6 . The first semiconductor element  401  and a wiring pattern  405  provided on the printed wiring board  406  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  404 . 
     In this embodiment, an auxiliary member  408  is mounted on the first semiconductor element  401  and adhered with a die bonding material  403  so that a supporting part with a substantially protruding shape on the auxiliary member  408  may be located within an electrode pad formed at the periphery of the first semiconductor element  401 . At this time, the auxiliary member  408  is mounted so as not to change the shape of the thin wire for connection. It is to be noted that the auxiliary member  408  consisting of, for example, an epoxy resin and the like, in this embodiment comprises a member larger than the second semiconductor element by, for example, 0.5 mm, for mounting the second semiconductor element on the surface thereof, and the supporting part with a substantially protruding shape formed on the rear surface of the member, as shown in FIG.  7 . The reason for this is that it is necessary to provide a region for forming a connection part to connect with other wiring patterns. 
     An electroconductive film, for example, Au plate and the like, is formed at a predetermined region on the surface of a member in this embodiment including a die bonding part for mounting the second semiconductor element. The member can be electrically connected to the rear surface of the mounted second semiconductor element via this electroconductive film while the member on which the electroconductive film at a predetermined region where the second semiconductor element is not mounted is formed can be electrically connected to other wiring patterns via a thin wire for connection. 
     Since a member larger than the second semiconductor element by about 0.5 mm is adopted as an auxiliary member in this embodiment, an electroconductive film for connecting with all over the rear surface of the second semiconductor element can be formed and a connection part for connecting a thin wire for connection can be formed. 
     A second semiconductor element  402  is adhered to a die bonding part on which an electroconductive film  414  is formed with a die bonding material  415 . 
     In addition, the second semiconductor element  402  and a wiring pattern  405  provided on the printed wiring board  406  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  416 . An electroconductive film part (cavity part)  414  on the auxiliary part  408  and a wiring pattern (ground pattern) provided on the printed wiring board  406  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  418 . 
     Further, resin sealing is achieved by an epoxy resin  407  to protect the first semiconductor element  401 , the second semiconductor element  402 , the auxiliary member  408  and the thin wires for connection  404 ,  416  and  418 . 
     Hereafter, a method for manufacturing a semiconductor device will be described in this embodiment in reference to FIGS. 6 and 7. 
     The first semiconductor element  401  is adhered to a predetermined location on the printed wiring board  406  with the die bonding material  403 , as shown in FIG.  6 . Next, the wiring pattern  405  provided on the printed wiring board  406  and the first semiconductor element  401  are electrically connected to each other via the thin wire for connection (Au wire, Al wire and the like)  404 . 
     The auxiliary member  408  is mounted on the first semiconductor element  401  and adhered with the die bonding material  403  so that a supporting part with a substantially protruding shape may be located within an electrode pad formed at the periphery of the first semiconductor element  401 , so as not to change the shape of the thin wire for connection. It is to be noted that the auxiliary member  408  consisting of, for example, an epoxy resin and the like, in this embodiment comprises the member larger than the second semiconductor element by, for example, 0.5 mm, for mounting the second semiconductor element on the surface thereof, and the supporting part with a substantially protruding shape formed on the rear surface of the member, as shown in FIG.  7 . The reason for this is that it is necessary to provide a region for forming a connection part to connect with other wiring patterns. 
     An electroconductive film, for example, Au plate and the like, is formed at a predetermined region on the surface of a member in this embodiment including a die bonding part for mounting the second semiconductor element. The member can be electrically connected to the rear surface of the mounted second semiconductor element via this electroconductive film while the member on which the electroconductive film at a predetermined region where the second semiconductor element is not mounted is formed can be electrically connected to other wiring patterns via a thin for connection. 
     Since a member larger than the second semiconductor element by about 0.5 mm is adopted as an auxiliary member in this embodiment, an electroconductive film for connecting with all over the rear surface of the second semiconductor element can be formed and a connection part for connecting a thin wire for connection can be formed. 
     Next, a second semiconductor element  402  is adhered to a die bonding part on which an electroconductive film  414  is formed with a die bonding material  415 . 
     After that, the second semiconductor element  402  and a wiring pattern  405  provided on the printed wiring board  406  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  416 . The electroconductive film part (cavity part)  414  on the auxiliary part  408  and a wiring pattern provided on the printed wiring board  406  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  418 . 
     Further, resin sealing is achieved by the epoxy resin  407  to protect the first semiconductor element  401 , the second semiconductor element  402 , the auxiliary member  408  and the thin wires for connection  404 ,  416  and  418 . Thereby the semiconductor device is completed. 
     In this embodiment, since the electroconductive film part (cavity part) on the auxiliary member and a wiring pattern (ground pattern) provided on the printed wiring board can be electrically connected, a semiconductor element on the rear surface of which a potential needs to be placed can be mounted. 
     (Fifth Embodiment) 
     In this embodiment, the height at which resin sealing is achieved is lowered to make the film in the semiconductor device thin. Hereafter, the fifth embodiment will be explained in reference to FIG.  8 . FIG. 8 is a sectional view showing the structure of a semiconductor device in the fifth embodiment. 
     As shown in FIG. 8, a printed wiring board used in this embodiment is a multi-layer printed wiring board having a first layer  516  and a second layer  518 . A first substantially recessed part  522  with roughly same depth as the height of a first semiconductor element  501  is formed on the first layer  516 . And a second substantially recessed part  523  with roughly same depth as the sum of the height of a second semiconductor element  502  and the height of an auxiliary member  513  and which has a diameter larger than that of the first substantially recessed part is formed on the second layer  518  on the first substantially recessed part  522 . 
     The first semiconductor element  501  is adhered to the first substantially recessed part  522  on the first layer  516  on the multi-layer printed wiring board with a die bonding material  503 . The first semiconductor element  501  and a wiring pattern  517  provided on the multi-layer printed wiring board (the first layer)  516  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  504 . 
     In this embodiment, the auxiliary member  513  is mounted on the first semiconductor element  501  and adhered with a die bonding material  503  so that a supporting part with a substantially protruding shape on the auxiliary member  513  may be located within an electrode pad formed at the periphery of the first semiconductor element  501 . At this time, the auxiliary member  513  is mounted so as not to change the shape of the thin wire for connection. It is to be noted that the auxiliary member  513  consisting of, for example, an epoxy resin and the like, in this embodiment comprises a member larger than the second semiconductor element by, for example, 0.5 mm, for mounting the second semiconductor element  502  on the surface thereof, and the supporting part with a substantially protruding shape formed on the rear surface of the member. 
     An electroconductive film (not shown), for example, Au plate and the like, is formed at a predetermined region on the surface of a member in this embodiment including a die bonding part for mounting the second semiconductor element and a connection part for connecting a thin wire for connection with other wiring patterns. It is to be noted that the auxiliary member in this embodiment comprises a member larger than the second semiconductor element by, for example, 0.5 mm. The reason for this is that it is necessary to provide a region for forming a connection part to connect with other wiring patterns. 
     The second semiconductor element  502  is adhered to a die bonding part on which an electroconductive film is formed with a die bonding material  515 . 
     In addition, the second semiconductor element  502  and the printed wiring board (the second layer)  518  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  520 . The electroconductive film part (cavity part) on the auxiliary part  513  and a wiring pattern (ground pattern)  519  provided on the printed wiring board (the second layer)  518  are electrically connected to each other via a thin wire for connection (Au wire, Al wire and the like)  521 . 
     Further, resin sealing is achieved by an epoxy resin  507  to protect the first semiconductor element  501 , the second semiconductor element  502 , the auxiliary member  513  and the thin wires for connection  504 ,  520  and  521 . 
     Hereafter, a method for manufacturing a semiconductor device will be described in this embodiment in reference to FIG.  8 . 
     As shown in FIG. 8, a printed wiring board used in this embodiment is a multi-layer printed wiring board having the first layer  516  and the second layer  518 . The first substantially recessed part  522  with roughly same depth as the height of the first semiconductor element  501  is formed on the first layer  516 . And the second substantially recessed part  523  with roughly same depth as the sum of the height of the second semiconductor element  502  and the height of an auxiliary member  513  and which has a diameter larger than that of the first substantially recessed part is formed on the second layer  518  on the first substantially recessed part  522 . 
     First, the first semiconductor element  501  is adhered to the first substantially recessed part  522  on the first layer  516  on the multi-layer printed wiring board with the die bonding material  503 . The first semiconductor element  501  and the wiring pattern  517  provided on the multi-layer printed wiring board (the first layer)  516  are electrically connected to each other via the thin wire for connection (Au wire, Al wire and the like)  504 . 
     After that, the auxiliary member  513  is mounted on the first semiconductor element  501  and adhered with a die bonding material  503  so that a supporting part with a substantially protruding shape on the auxiliary member  513  may be located within an electrode pad formed at the periphery of the first semiconductor element  501 . At this time, the auxiliary member  513  in this embodiment is mounted so as not to change the shape of the thin wire for connection. It is to be noted that the auxiliary member  513  consisting of, for example, an epoxy resin and the like, in this embodiment comprises a member larger than the second semiconductor element by, for example, 0.5 mm, for mounting the second semiconductor element  502  on the surface thereof, and the supporting part with a substantially protruding shape formed on the rear surface of the member. 
     The electroconductive film (not shown), for example, Au plate and the like, is formed at a predetermined region on the surface of a member in this embodiment including a die bonding part for mounting the second semiconductor element and a connection part for connecting a thin wire for connection with other wiring patterns. It is to be noted that the auxiliary member in this embodiment comprises the member larger than the second semiconductor element by, for example, 0.5 mm. The reason for this is that it is necessary to provide a region for forming a connection part to connect with other wiring patterns. 
     Next, the second semiconductor element  502  is adhered to the die bonding part on which an electroconductive film is formed with the die bonding material  515 . 
     Then, the second semiconductor element  502  and the printed wiring board (the second layer)  518  are electrically connected to each other via the thin wire for connection (Au wire, Al wire and the like)  520 . Further, the electroconductive film part (cavity part) on the auxiliary part  513  and a wiring pattern (ground pattern) provided on the printed wiring board (the second layer)  518  are electrically connected to each other via the thin wire for connection (Au wire, Al wire and the like)  521 . 
     Further, resin sealing is achieved by an epoxy resin  507  to protect the first semiconductor element  501 , the second semiconductor element  502 , the auxiliary member  513  and the thin wires for connection  504 ,  520  and  521 . Thereby the semiconductor device is completed. 
     In this embodiment, since a multi-layer printed wiring board having a substantially recessed part the depth of which is adjusted as the thickness of the semiconductor element and auxiliary member to be mounted is used, the height at which resin sealing is achieved is lowered. Thereby the size of the semiconductor device can be thin. 
     In the above-described invention, since the length of the thin wire for connection can be shorter than the conventional one by the auxiliary member, the shape of the thin wire for connection does not change and the thin wire for connection can be prevented from shorting with the adjacent thin wire for connection, so that the semiconductor device with high reliability can be provided.