Abstract:
A semiconductor package component ( 3 ) is mounted on a substrate ( 1 ) in such a manner that an electrode ( 2 ) of the substrate ( 1 ) and an electrode of the semiconductor package component ( 3 ) are brought into contact with each other through a joining material ( 4 ). A reinforcing adhesive ( 5   c ) is applied between the substrate ( 1 ) and the outer surface of the semiconductor package component ( 3 ). Then, reflow is performed to melt the joining metal ( 4 ) with the reinforcing adhesive ( 5   c ) uncured. After the reinforcing adhesive ( 5   c ) is cured, the joining metal ( 4 ) is solidified.

Description:
TECHNICAL FIELD 
     The present invention relates to a semiconductor package component mounting method for surface-mounting a semiconductor package component on a substrate. 
     BACKGROUND ART 
     A semiconductor package component such as a BGA (Ball Grid Array) component having electrodes formed on the underside is mounted in one of the process illustrated in  FIGS. 17( a ) to 17( e )  and the process illustrated in  FIGS. 18( a ) to 18( d ) . 
     In  FIGS. 17( a ) and 17( b ) , a semiconductor package component  3  is mounted on a substrate  1  in such a manner that bump electrodes  4  of the semiconductor package component  3  come into contact with electrodes  2  on the substrate  1 . 
     In  FIG. 17( c ) , reflow is performed. In the reflow, the solder of the bump electrodes  4  melts and the semiconductor package component  3  moves to a proper position by the self-alignment effect. Then the substrate and component are cooled to the melting temperature of the solder or lower to solidify the solder, so that electrical connection between the semiconductor package component  3  and the substrate  1  is completed. 
     In  FIG. 17( d ) , a thermoset resin  5  is injected between the semiconductor package component  3  and the substrate  1  with a syringe or the like. 
     In  FIG. 17( e ) , the substrate  1  is heated to a temperature not lower than the curing temperature of the thermoset resin  5  to cure the thermoset resin  5 , thereby mechanically fixing the semiconductor package component  3  onto the substrate  1 . 
     The method illustrated in  FIGS. 17( a ) to 17( e )  involves two heating steps, the reflow in  FIG. 17( c )  and the heating in  FIG. 17( e ) . In contrast, the process illustrated in  FIGS. 18( a ) to 18( d )  involves only one heating step. 
     In  FIGS. 18( a ) and 18( b ) , the thermoset resin  5  is applied to a position  6  on the substrate  1  where the semiconductor package component  3  is to be mounted.  FIG. 19  illustrates how the thermoset resin  5  is applied. 
     In  FIG. 18( c ) , the semiconductor package component  3  is mounted on the substrate  1  in such a manner that the bump electrodes  4  of the semiconductor package component  3  come into contact with the electrode  2  on the substrate  1 . At this point, the uncured thermoset resin  5  is in contact with the substrate  1  and the underside of the semiconductor package component  3 . 
     In  FIG. 18( d ) , reflow is performed. In the reflow, the solder of the bump electrodes  4  melts. Since the thermoset resin  5  is uncured at this point in time, the semiconductor package component  3  is moved to the proper position by the self-alignment effect of the melted solder between the electrodes on the substrate  1  and the electrodes of the semiconductor package component  3 . After the thermoset resin  5  is cured by heating, the temperature decreases to a temperature not higher than the melting temperature of the solder to solidify the solder, so that the electrical connection and mechanical bonding of the semiconductor package component  3  to the substrate  1  are completed.  FIG. 20  illustrates the completion of the mounting. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature: Japanese Patent Application Laid-Open Publication No. 11-204568 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     The mounting process illustrated in  FIGS. 18 to 20  involves only one heating step. However, the quantity and position of the thermoset resin  5  to be applied are difficult to adjust, thereby causing variations in mounting quality. 
     Specifically, during the process in which the solder melts and solidifies, the uncured thermoset resin  5  is in the vicinity of or in contact with the solder. Therefore, when the application quantity of the thermoset resin  5  is reduced in order to prevent some of the uncured thermoset resin  5  from melting and being mixed with the solidifying solder to degrade the soldering quality, the strength of the mechanical bonding between the semiconductor package component  3  and the substrate  1  decreases. 
     An object of the present invention is to provide a semiconductor package component mounting method which can reduce the number of heating steps, stably maintain the quality of electrical joining between a semiconductor package component and a substrate, and ensure a sufficient strength of mechanical bonding between the semiconductor package component and the substrate. 
     Solution to Problem 
     A semiconductor package component mounting method according to the present invention includes: mounting a semiconductor package component on a substrate in such a manner that an electrode of the substrate and an electrode of the semiconductor package component are brought into contact with each other through a solidified joining metal; applying a reinforcing adhesive between the periphery of an area on the substrate where the semiconductor package component is mounted and the outer surface of the semiconductor package component in such a manner that the reinforcing adhesive does not contact the joining metal; and performing reflow to melt the joining metal while the reinforcing adhesive is uncured, curing the reinforcing adhesive, and solidifying the joining metal. 
     A semiconductor package component mounting structure according to the present invention is a structure in which a semiconductor package component is mounted onto a substrate by joining an electrode of the substrate to an electrode of the semiconductor package component with a joining metal. The mounting structure includes: a cured reinforcing adhesive which is not in contact with the joining metal, the reinforcing adhesive extending from a surface of the semiconductor package component opposite a surface facing the substrate to the substrate, wherein the cured reinforcing adhesive extends over a distance L 1  onto the opposite surface of the semiconductor package component from an end face of the semiconductor package component and extends over a distance L 2  onto the surface of the semiconductor package component facing the substrate from the end face of the semiconductor package component, the end face connecting the surface of the semiconductor package component facing the substrate and the opposite surface; and the distance L 1  over which the reinforcing adhesive extends onto the opposite surface of the semiconductor package component from the end face connecting the surface of the semiconductor package component facing the substrate and the opposite surface is equal to or greater than the distance L 2  over which the reinforcing adhesive extends onto the surface of the semiconductor package component facing the substrate from the end face of the semiconductor package component. 
     A semiconductor package component mounting method according to the present invention includes: applying a first reinforcing adhesive to a position on a substrate where a semiconductor package component is to be mounted; mounting the semiconductor package component on the substrate in such a manner that an electrode of the substrate and an electrode of the semiconductor package component are brought into contact with each other through a solidified joining metal; applying a second reinforcing adhesive between the periphery of an area on the substrate where the semiconductor package component is mounted and the outer surface of the semiconductor package component; and performing reflow to melt the joining metal and curing the first and second reinforcing adhesives while the joining metal solidifies. 
     A semiconductor package component mounting structure according to the present invention is a structure in which a semiconductor package component is mounted on a substrate by joining an electrode of the substrate to an electrode of the semiconductor package component with a joining metal. The mounting structure includes: a cured first reinforcing adhesive disposed between the substrate and a surface of the semiconductor package component facing the substrate; and a cured second reinforcing adhesive disposed from an end face connecting the surface of the semiconductor package component facing the substrate and the opposite surface of the semiconductor package component to the substrate. 
     A semiconductor package component mounting structure according to the present invention is a structure in which a semiconductor package component is mounted on a substrate by joining an electrode of the substrate to an electrode of the semiconductor package component with a joining metal. The mounting structure includes: a cured first reinforcing adhesive disposed between the substrate and a surface of the semiconductor package component facing the substrate; and a cured second reinforcing adhesive disposed from the surface of the semiconductor package component opposite the surface facing the substrate to the substrate. 
     Advantageous Effects of Invention 
     With this configuration, since the reinforcing adhesive is applied after the semiconductor package component is mounted on the substrate, and in the heating step, the reinforcing adhesive is sufficiently cured after the joining metal has melts and solidifies. Thus the number of heating steps can be reduced and the reinforcing adhesive can be readily applied in such a manner that the reinforcing adhesive does not come into contact with the joining metal in the process of melting and solidifying. In addition, the quality of electrical joining between the semiconductor package component and the substrate can be stably maintained, and a sufficient strength of the mechanical bonding between the semiconductor package component and the substrate can be ensured. 
     With this configuration, the first reinforcing adhesive is applied before the semiconductor package component is mounted on the substrate; the second reinforcing adhesive is applied after the semiconductor package component is mounted on the substrate; and, in the heating step, the first and second reinforcing adhesives are cured after the joining metal melts and solidifies. Accordingly, the number of heating steps can be reduced and, even when the application quantity of the first reinforcing adhesive is reduced in order to prevent degradation of the joining quality due to some of the first reinforcing adhesive mixed during the melting of the joining metal, the cured second reinforcing adhesive ensures a sufficient mechanical strength. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a process diagram illustrating a mounting method according to a first embodiment of the present invention; 
         FIG. 2  is a perspective view illustrating a reinforcing adhesive applied according to the first embodiment; 
         FIG. 3  is a cross-sectional view illustrating completion of mounting according to the first embodiment; 
         FIG. 4  is a plan view of a mounting method according to a second embodiment of the present invention; 
         FIG. 5  is a perspective view illustrating completion of mounting according to the second embodiment; 
         FIG. 6  is a plan view of a mounting method according to a third embodiment of the present invention; 
         FIG. 7  is a perspective view illustrating completion of mounting according to the third embodiment; 
         FIG. 8  is a process diagram of a mounting method according to a fourth embodiment of the present invention; 
         FIG. 9  is a perspective view illustrating first and second reinforcing adhesives applied according to the fourth embodiment; 
         FIG. 10  is a cross-sectional view illustrating completion of mounting according to the fourth embodiment; 
         FIG. 11  is a horizontal cross-sectional view illustrating the first and second reinforcing adhesives applied according to the fourth embodiment; 
         FIG. 12  is a plan view illustrating completion of mounting of a mounting method according to a fifth embodiment of the present invention; 
         FIG. 13  is a perspective view illustrating the completion of mounting according to the fifth embodiment; 
         FIG. 14  is a horizontal cross-sectional view illustrating the completion of mounting according to the fifth embodiment; 
         FIG. 15  is a plan view illustrating completion of mounting of a mounting method according to a sixth embodiment of the present invention; 
         FIG. 16  is a perspective view illustrating the completion of mounting according to the sixth embodiment; 
         FIG. 17  is a process diagram illustrating a conventional mounting method; 
         FIG. 18  is a process diagram illustrating another conventional mounting method; 
         FIG. 19  is a perspective view illustrating the method in  FIG. 18( b ) ; 
         FIG. 20  is a perspective view illustrating the method in  FIG. 18( c ) ; and 
         FIG. 21  is a cross-sectional view of a variation of the third embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A semiconductor package component mounting method of the present invention will be described below with respect to specific embodiments. 
     First Embodiment 
       FIGS. 1 to 3  illustrate a first embodiment of the present invention. 
     In  FIGS. 1( a ) and 1( b ) , a BGA semiconductor package component  3  is mounted on a substrate  1  in such a manner that bump electrodes  4  of the semiconductor package component  3  come into contact with electrodes  2  on the substrate  1 . 
     In  FIG. 1( c ) , reinforcing adhesives  5   c  are applied in the form of a stick from the periphery of an area on the substrate  1  where the semiconductor package component  3  is mounted over to the outer surface of the semiconductor package component  3  at regular intervals except the corner portions as illustrated in  FIG. 2 . This arrangement can reduce the application quantity of the adhesive and prevent the adhesive from unnecessarily entering between the semiconductor package component  3  and the substrate. Since the reinforcing adhesives  5   c  are applied in the form of a stick at regular intervals except the corner portions, the semiconductor package component  3  can be fixed in a balanced manner. The reinforcing adhesive  5   c  herein is a thermoset resin. The reinforcing adhesive  5   c  is applied in such a manner that the reinforcing adhesive  5   c  does not contact the bump electrodes  4 . 
     In  FIG. 1( d ) , reflow is performed. In the reflow, the solder of the bump electrodes  4  melts. Since the reinforcing adhesive  5   c  is not cured at this point, the semiconductor package component  3  is moved to a proper position by the self-alignment effect of the melted solder between the electrodes on the substrate  1  and the electrodes of the semiconductor package component  3 . 
     In  FIG. 1( e ) , the temperature further rises to cure the reinforcing adhesive  5   c . Then the temperature is decreased to the melting temperature of the solder or lower to solidify the solder, thereby completing the electrical connection and mechanical bonding of the semiconductor package component  3  and the substrate  1 . 
     In the completed mounting structure of  FIG. 3 , the reinforcing adhesive  5   c  can be readily prevented from contacting the bump electrodes  4  even if the application quantities and application positions are varied. This is because the semiconductor package component  3  is mounted on the substrate  1  as illustrated in  FIG. 1( b )  and then the reinforcing adhesive  5   c  is applied so that the reinforcing adhesive  5   c  extends from a surface  3   b  of the semiconductor package component  3  opposite a surface  3   a  facing the substrate  1  to the substrate  1  as illustrated in  FIG. 1( c ) . As illustrated in  FIG. 3 , in the completed mounting structure, the reinforcing adhesive  5   c  is away from the solder which is a joining metal. Thus, good soldering quality is achieved. A portion L 1  is convex-shaped. While a portion L 2  is concave-shaped, the portion L 2  may be convex-shaped. 
     The shape of the cured reinforcing adhesive  5   c  is made such that L 1 ≧L 2 , where L 1  is a distance over which the reinforcing adhesive  5   c  extends onto the surface  3   b  of the semiconductor package component  3  opposite the surface  3   a  facing the substrate  1  from an end face  3   c  connecting the surface  3   a  and the surface  3   b , and L 2  is a distance over which the reinforcing adhesive  5   c  extends onto the surface  3   a  facing the substrate  1  from the end face  3   c  of the semiconductor package component  3 . As a result, a great degree of reinforcement is achieved compared with a structure in which the reinforcing adhesive  5   c  is applied from the end face  3   c  of the semiconductor package component  3  to the substrate  1  as indicated by a phantom line  7  in  FIG. 3  in the step of  FIG. 1( c )  and then cured by reflow. 
     It should be noted that even when the reinforcing adhesive  5   c  is cured in the shape indicated by the phantom line  7  in  FIG. 3 , better soldering quality and a greater degree of reinforcement are achieved than in the conventional example illustrated in  FIGS. 9 to 11 . 
     A gap between the substrate  1  and the semiconductor package component  3  in this case is approximately 0.2 mm. The melting point and solidification start temperature of the solder of the bump electrodes  4  were in the range of 217° C. to 219° C. and 219° C., respectively. The viscosity of the reinforcing adhesive  5   c  was 60 Pa·s (measured with a cone and plate viscometer at 5 rpm and 25° C.) The curing start temperature of the reinforcing adhesive  5   c  was 185° C. and the curing peak temperature of the reinforcing adhesive  5   c  was 210° C. 
     The thixotropy of the reinforcing adhesive  5   c  determined from a ratio between viscosities measured with the cone and plate viscometer at 0.5 rpm and 5 rpm at 25° C. (viscosity at 0.5 rpm/viscosity at 5 rpm) was in the range of approximately 4 to 6. 
     Second Embodiment 
       FIGS. 4 and 5  illustrate a second embodiment. 
     In the first embodiment, the reinforcing adhesive  5   c  is applied to a portion except the corner portions  3   d  of the semiconductor package component  3  and cured. In the second embodiment, in the step of  FIG. 1( c ) , a reinforcing adhesive  5   c  is applied to portions of a semiconductor package component  3  including corner portions  3   d , and distances L 1  and L 2  of the cured reinforcing adhesive  5   c  are set such that L 1 ≧L 2 . The second embodiment is different from the first embodiment only in the shape of the applied reinforcing adhesive  5   c . Others are the same as in the embodiment. 
     In the second embodiment, better soldering quality and a greater degree of reinforcement than in the first embodiment are achieved. 
     Third Embodiment 
       FIGS. 6 and 7  illustrate a third embodiment. 
     In the second embodiment, the reinforcing adhesive  5   c  is applied to the portions of the semiconductor package component  3  including the corner portions  3   d  of the semiconductor package component  3  in such a manner that L 1 ≧L 2 . The third embodiment differs from the second embodiment in that L 1 =0. Specifically, the third embodiment differs from the first embodiment only in that a reinforcing adhesive  5   c  is applied in such a manner that the reinforcing adhesive  5   c  extends from an end face  3   c  that connecting a surface  3   a  of a semiconductor package component  3  facing a substrate  1  and an opposite surface  3   b  to the substrate  1 . Others are the same as in the first embodiment. 
     The reinforcing adhesive  5   c  is applied from the end face  3   c  of the semiconductor package component  3  to cover the full height of the end face  3   c  of the semiconductor package component  3  in a position where the reinforcing adhesive  5   c  is applied and the surface of the reinforcing adhesive  5   c  outside from the end face  3   c  of the semiconductor package component  3  is concave-shaped along the height of the end face  3   c  as illustrated in  FIG. 21 . A distance L 3  from the edge of the semiconductor package component  3  to the perimeter of the reinforcing adhesive  5   c  is preferably greater than a distance L 4  from the substrate  1  to the top of the semiconductor package component  3 . 
     While the shape of the surface of the reinforcing adhesive  5   c  outside from the end face  3   c  is concave-shaped along the height of the end face  3   c  in  FIGS. 7 and 21 , the completed shape of the surface of the reinforcing adhesive  5   c  may be convex-shaped as indicated by a phantom line in  FIG. 21 , depending on the viscosity of the used reinforcing adhesive  5   c.    
     According to the embodiment, better soldering quality and a greater degree of reinforcement than in the conventional art are achieved. 
     While the embodiments have been described with respect to BGA semiconductor package components  3  by way of example, the embodiments are also applicable to LGA (Land Grid Array) semiconductor package components  3 . In the case of the LGA semiconductor package component  3 , a paste containing a joining metal is applied to at least one of a set of electrodes of the semiconductor package component  3  and a set of electrodes  2  of a substrate  1  to be joined to the set of the electrodes of the semiconductor package component  3 . Then the semiconductor package component  3  can be mounted on the substrate  1  to implement the present invention. 
     Fourth Embodiment 
       FIGS. 8 to 11  illustrate a fourth embodiment of the present invention. 
     In  FIGS. 8( a ) and 8( b ) , a first thermoset resin  5   a  is applied in the form of a dot in a position  6  on a substrate  1  where a semiconductor package component  3  is to be mounted.  FIG. 9  illustrates how the first thermoset resin  5   a  is applied. 
     In  FIG. 8( c ) , the semiconductor package component  3  is mounted on the substrate  1  in such a manner that bump electrodes  4  of the semiconductor package component  3  come into contact with electrodes  2  on the substrate  1 . At this point, the uncured first thermoset resin  5   a  is disposed between and in contact with the substrate  1  and the underside of the semiconductor package component  3 . 
     In  FIG. 8 ( c - 1 ), the semiconductor package component  3  is mounted on the substrate  1  in such a manner that the bump electrodes  4  of the BGA semiconductor package component  3  come into contact with the electrodes  2  on the substrate  1 . 
     In  FIG. 8 ( c - 2 ), a second reinforcing adhesive  5   b  is applied between the periphery of the area on the substrate  1  where the semiconductor package component  3  is mounted and the outer surface of the semiconductor package component  3 , for example, at predetermined intervals, as illustrated in  FIG. 9( b ) . Here, the second reinforcing adhesive  5   b  is a thermoset resin. 
     In  FIG. 8( d ) , reflow is performed. 
       FIG. 8( d )  includes  FIGS. 8 ( d - 1 ),  8 ( d - 2 ) and  8 ( d - 3 ).  FIGS. 8 ( d - 2 ) and  8 ( d - 3 ) depict cross sections as viewed from different angles at the same point in time in the reflow to show how the first and second reinforcing adhesives  5   a  and  5   b  have changed from the state in  FIG. 8 ( d - 1 ). 
     In  FIG. 8 ( d - 1 ), the solder of the bump electrodes  4  is melted by the reflow. Since the first and second reinforcing adhesives  5   a  and  5   b  are uncured at this point in time, the semiconductor package component  3  moves to a proper position by the self-alignment effect of the melted solder between the electrodes  2  of the substrate  1  and the electrodes of the semiconductor package component  3 . 
     After the temperature further rises and the first and second reinforcing adhesives  5   a  and  5   b  are cured as illustrated in  FIGS. 8 ( d - 2 ) and  8 ( d - 3 ), the temperature is decreased to the melting point of the solder or lower to solidify the solder, thereby completing the electrical connection and mechanical bonding of the semiconductor package component  3  and the substrate  1 .  FIG. 10  is a vertical cross-sectional view illustrating the completion of the mounting.  FIG. 11  is a cross-sectional view taken horizontally along a plane of the electrodes  2  of the substrate  1 . 
     In the mounting structure completed as illustrated in  FIG. 10 , since the semiconductor package component  3  is mounted on the substrate  1  and then the second reinforcing adhesive  5   b  is applied from a surface  3   b  opposite a surface  3   a  of the semiconductor package component  3  facing the substrate  1  to the substrate  1  as illustrated in  FIG. 8 ( c - 2 ), strong joining between the substrate  1  and the semiconductor package component  3  can be provided by the cured second reinforcing adhesive  5   b  even when the quantity of the first reinforcing adhesive  5   a  is reduced to prevent the first reinforcing adhesive  5   a  from contacting the solder, and strong joining may not be provided by the first reinforcing adhesive  5   a  between the substrate  1  and the package component  3 . In addition, since the second reinforcing adhesive  5   b  is applied after the semiconductor package component  3  is mounted on the substrate  1 , the second reinforcing adhesive  5   b  is distanced from the solder which is a joining metal, irrespective of variations of the application quantity and application positions, as illustrated in  FIG. 10 . Thus, good soldering quality is achieved. 
     The shape of the cured second reinforcing adhesive  5   b  is made such that L 1 &gt;L 2 , where L 1  is a distance over which the second reinforcing adhesive  5   b  extends onto the surface  3   b  of the semiconductor package component  3  opposite the surface  3   a  facing the substrate  1  from an end face  3   c  connecting the surface  3   a  and the surface  3   b , and L 2  is a distance over which the second reinforcing adhesive  5   b  extends onto the surface  3   a  facing the substrate  1  from the end face  3   c  of the semiconductor package component  3 . As a result, a greater degree of reinforcement is achieved compared with a structure in which the second reinforcing adhesive  5   b  is applied from the end face  3   c  of the semiconductor package component  3  to the substrate  1  as indicated by a phantom line  7  in  FIG. 10  in the step of  FIG. 8( c )  and then cured by reflow. 
     It should be noted that even when the second reinforcing adhesive  5   b  is cured in the shape represented by the phantom line  7  in  FIG. 10 , better soldering quality and a greater degree of reinforcement are achieved than in the conventional example illustrated in  FIGS. 18 to 20 . 
     A gap between the substrate  1  and the semiconductor package component  3  at that point was approximately 0.2 mm. The melting point and solidification start temperature of the solder of the bump electrodes  4  were in the range of 217° C. to 219° C. and 219° C., respectively. The viscosity of the reinforcing adhesive  5   a  was 60 Pa·s (measured with a cone and plate viscometer at 5 rpm and 25° C.). The curing start temperature of the reinforcing adhesive  5   a  was 185° C. and the curing peak temperature of the reinforcing adhesive  5   a  was 210° C. 
     Fifth Embodiment 
       FIGS. 12 to 14  illustrate a fifth embodiment. 
     In the fourth embodiment, the second reinforcing adhesive  5   b  is applied to portions of the semiconductor package component  3  except the corner portions  3   d . In the fifth embodiment, a second reinforcing adhesive  5   b  is applied to portions of a semiconductor package component  3  including corner portions  3   d  of the semiconductor package component  3  in the step of  FIG. 8 ( c - 2 ). Distances L 1  and L 2  of the cured second reinforcing adhesive  5   b  are set such that L 1 ≧L 2 . The fifth embodiment is different from the fourth embodiment only in the shape of the applied second reinforcing adhesive  5   b . Others are the same as in the fourth embodiment. 
     According to the fifth embodiment, good soldering quality and a greater degree of reinforcement than in the fourth embodiment are achieved as illustrated in  FIG. 13 .  FIG. 14  is a horizontal cross-sectional view of a first reinforcing adhesive  5   a  and the second reinforcing adhesive  5   b  which are cured. 
     Sixth Embodiment 
       FIGS. 15 and 16  illustrate a sixth embodiment. 
     In the fifth embodiment, the second reinforcing adhesive  5   b  is applied to the portions of the semiconductor package component  3  including the corner portions  3   d  of the semiconductor package component  3  in such a manner that L 1 ≧L 2 . The sixth embodiment differs from the fifth embodiment in that L 1 =0. Specifically, the sixth embodiment is different from the fourth embodiment only in that a second reinforcing adhesive  5   b  is applied in such a manner that the second reinforcing adhesive  5   b  extends from an end face  3   c  connecting a surface  3   a  of a semiconductor package component  3  facing a substrate  1  and an opposite surface  3   b  to the substrate  1 . Others are the same as in the fourth embodiment. 
     According to the embodiment, good soldering quality and a greater degree of reinforcement than in the fourth embodiment are achieved. 
     While the embodiments have been described with respect to BGA semiconductor package components  3  by way of example, the embodiments are also applicable to LGA (Land Grid Array) semiconductor package components  3 . In the case of the LGA semiconductor package component  3 , a paste containing a joining metal is applied to at least one of a set of electrodes of the semiconductor package component  3  and a set of electrodes  2  of a substrate  1  to be joined to the set of the electrodes of the semiconductor package component  3 . Then the semiconductor package component  3  can be mounted on the substrate  1  to implement the present invention. 
     INDUSTRIAL APPLICABILITY 
     The present invention is useful for fabrication of various electronic devices such as mobile devices that may be subjected to drop impact.