Patent Publication Number: US-2011049702-A1

Title: Semiconductor package and method of producing the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2009-195737, filed on Aug. 26, 2009, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to semiconductor packages and methods of producing (or fabricating) the same. 
     2. Description of the Related Art 
     A semiconductor package that is mounted with semiconductor devices may be mounted on a wiring board, a mother board and the like for use in electronic equipments. The semiconductor package is used in various fields including information processing and communication. In order to radiate heat generated from the semiconductor device during operation, the semiconductor package itself is provided with a heat radiation function to release heat. In the semiconductor package having the semiconductor device directly bonded on the wiring board by flip-chip bonding, a radiator plate is often provided on a back surface of the semiconductor device to radiate heat. The radiator plate may be referred to as a heat slug or a heat spreader, and a metal material or the like having a relatively high heat conduction is used to form the radiator plate. 
       FIGS. 1A through 1C  are cross sectional views for explaining examples of a conventional semiconductor package having a radiator plate. 
       FIG. 1A  illustrates a semiconductor package  100 - 1  including a substrate  16 , a semiconductor device  11 , and a radiator plate  14 . The radiator plate  14  has a recess  12  for accommodating a semiconductor device  11 . The radiator plate  14  is for radiating from a surface thereof the heat generated from the semiconductor device  11  and transferred via thermal grease  13 . The radiator plate  14  is fixed to the substrate  16  using a bonding agent  15 . A surface  16   a  of the substrate  16 , opposite to the surface mounted with the semiconductor device  11 , is provided with connection terminals  17  having solder balls  18  formed thereon. The connection terminals  17  and the solder balls  18  form external connection terminals for connecting the semiconductor package  100 - 1  to a wiring board, a mother board or the like. 
       FIG. 1B  illustrates a semiconductor package  100 - 1  including a substrate  20  with a cavity  19  for accommodating the semiconductor device  11 , and a radiator plate  21 . In  FIG. 1B , those parts that are the same as those corresponding parts in  FIG. 1A  are designated by the same reference numerals, and a description thereof will be omitted. 
       FIG. 1C  illustrates a semiconductor package  100 - 3  including a substrate  23  with a cavity for accommodating the semiconductor device  11  and a radiator plate  24 . In  FIG. 1C , those parts that are the same as those corresponding parts in  FIG. 1A  are designated by the same reference numerals, and a description thereof will be omitted. Regions of the cavity, other than regions occupied by the semiconductor device  11  and the radiator plate  24 , are filled by a filler material  22 . An example the semiconductor package  100 - 3  is proposed in a Japanese Laid-Open Patent Publication No. 2004-523128. 
       FIG. 2  is a side view illustrating an example of a conventional apparatus for aligning and bonding a radiator plate  26  and a semiconductor device  11 . This apparatus carries out the alignment or, correcting of parallelism, as follows. That is, a sensor  27  measures a distance between a back surface  11   b  of the semiconductor device  11  and a surface  26   a  of the radiator plate  26  opposing the back surface  11   b , in order to detect the degree of parallelism between the surfaces  11   b  and  26   a . The distance measurement may be made optically, for example. Based on the results of the measurement, a parallelism correcting mechanism  28  controls the position of the radiator plate  26 , and sets the degree of parallelism between the surfaces  11   b  and  26   a  to a predetermined value before bonding the radiator plate  26  onto the semiconductor device  11 . An air bearing or the like may be used for a slider mechanism of the parallelism correcting mechanism  28 , as proposed in a Japanese Laid-Open Patent Publication No. 2006-049732, for example. 
     Conventionally, when assembling the semiconductor package having the radiator plate, the parallelism between the back surface of the semiconductor device and the opposing surface of the radiator plate must be maintained. For this reason, a complex mechanism or apparatus is required to produce the semiconductor package, and complex processes must consequently be carried out. As a result, it may be difficult to simplify the production processes or, to reduce the production cost or, to improve the quality of the semiconductor package that is produced. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a general object of the present invention to provide a novel and useful semiconductor package and method of producing the same, in which the problem described above may be suppressed. 
     Another and more specific object of the present invention is to provide a semiconductor package and a method of producing the same, which may simplify the production processes or, reduce the production cost or, improve the quality of the semiconductor package that is produced. 
     According to one aspect of the present invention, there is provided a method of producing a semiconductor package, comprising setting a radiator member on a semiconductor device that is mounted on a wiring board, the radiator member having a convex surface part on at least a part of a first surface thereof opposite to a second surface thereof to be bonded to the semiconductor device; and pressing the convex surface part of the radiator member towards the semiconductor device in order to align the radiator member and the semiconductor device automatically and to become substantially parallel to each other. 
     According to one aspect of the present invention, there is provided a semiconductor package comprising a wiring board; a semiconductor device mounted on the wiring board; and a radiator member provided on the semiconductor device, wherein the radiator member includes a convex surface part on at least a part of a first surface thereof opposite to a second surface thereof bonded to the semiconductor device. 
     Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A through 1C  are cross sectional views for explaining examples of a conventional semiconductor package having a radiator plate; 
         FIG. 2  is a side view illustrating an example of a conventional apparatus for aligning and bonding a radiator plate  26  and a semiconductor device; 
         FIGS. 3A through 3D  are diagrams for explaining a radiator member in a first embodiment of the present invention; 
         FIGS. 4A through 4C  are cross sectional views for explaining a radiator member in a second embodiment of the present invention; 
         FIGS. 5A and 55  are side views for explaining an automatic alignment in a third embodiment of the present invention; 
         FIG. 6  is a flow chart for explaining a method of producing the semiconductor package in the third embodiment of the present invention; 
         FIG. 7  is a cross sectional view illustrating a semiconductor package in a fourth embodiment of the present invention; and 
         FIG. 8  is a side view for explaining the automatic alignment in a fifth embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
       FIGS. 3A through 3D  are diagrams for explaining a radiator member in a first embodiment of the present invention. 
     In this embodiment, a bonding surface  31   b  of a radiator member (or radiator plate)  31 , opposing a semiconductor device  32 , is bonded to a back surface  32   a  of the semiconductor device  32  via a bonding layer  33 . The radiator member  31  has a radiating surface  31   a  opposite to the bonding surface  31   b . A smooth convex surface part  34  is formed in at least a portion of the radiating surface  31   a . In other words, the smooth convex surface part  34  may be formed on the entire radiating surface  31   a . The smooth convex surface part  34  may be formed by an arbitrary curved surface, including a semispherical surface, having a peak (or apex). This peak may be provided in a central region of the radiating surface  31   a . Of course, a peripheral region surrounding the peak of the smooth convex surface part  34  may have a concave shape. 
     In a semiconductor package requiring heat radiation for releasing the heat outside the semiconductor package, the heat radiation efficiency may be improved by maintaining the parallelism between the semiconductor device and the radiator member to a predetermined value. Hence, in this embodiment, the smooth convex surface part  34  of the radiator member  31  may be used to automatically align the bonding surface  31   b  of the radiator member  31  and the back surface  32   a  of the semiconductor device  32 . 
       FIG. 3A  is a side view illustrating a first example in which a portion of the radiating surface  31   a  of the radiator member  31  forms the smooth convex surface part  34 . In this example, the central portion of the radiating surface  31   a  forms the smooth convex surface part  34 , and a peripheral portion of the radiating surface  31   a  forms a flat surface. 
       FIG. 3B  is a side view illustrating a second example in which the entire radiating surface  31   a  of the radiator member  31  forms the smooth convex surface part  34 . 
     The automatic alignment of the bonding surface  31   b  of the radiator member  31  and the back surface  32   a  of the semiconductor device  32  will be described later in more detail in conjunction with a third embodiment. 
     The bonding layer  33  may be formed by a TIM (Thermal Interface Material) such as resins, including silicon polymer resins. The TIM is not limited to resins, and may include metals such as indium, alloys such as indium alloys, carbon-containing resins, and carbon-containing metals or alloys. 
       FIGS. 3C and 3D  respectively are a plan view and a side view illustrating the radiator member  31  illustrated in  FIG. 3A . In the example illustrated in  FIG. 3C , the radiator member  31  has a square shape having a side W that is 15 mm to 60 mm or, a rectangular shape having a longer side W 1  that is 15 mm to 60 mm, for example. The radiator plate  31  has a thickness d of 1 mm to 3 mm, for example. A height h of the peak of the smooth convex surface part  34  relative to the radiating surface  31   a  of the radiator member  31  is 40 μm, for example, if the square shape has the side W that is 40 mm. 
     The radiator member  31  may be made of any sufficiently thermally conductive material. For example, the sufficiently thermally conductive material includes OFC (Oxygen-Free Copper) C1020, silver, aluminum, and alloys of any of such metals. 
     The radiator member  31  may be formed by a suitable known process, including a forging, cutting, and machining processes. 
     In  FIGS. 3A and 3B , the semiconductor device  32  is mounted on a wiring board  35 . The wiring board  35  is formed by a PGA (Pin Grid Array) in these examples. However, the wiring board  35  is of course not limited to the PGA, and boards having other formats may be used, including a LGA (Land Grid Array) and a BGA (Ball Grid Array). In addition, the wiring board  35  may be formed by a mother board or the like that is often used in electronic equipments. 
     In a gap between the radiator member  31  and the wiring board  35 , other semiconductor devices, such as chip capacitors and passive devices or passive parts, may be mounted on the upper surface of the wiring board  35  in each of  FIGS. 3A and 3B . 
     According to this first embodiment, the smooth convex surface part  34  of the radiator member  31  may be used to automatically align the bonding surface  31   b  of the radiator member  31  and the back surface  32   a  of the semiconductor device  32  when producing the semiconductor package. Because the parallelism between the bonding surface  31   b  of the radiator member  31  and the back surface  32   a  of the semiconductor device  32  may easily be secured, the effect of radiating the heat generated from the semiconductor device  32  may be improved. Hence, the quality and the productivity of the semiconductor package may be improved. 
     Modification of First Embodiment 
     In a modification of the first embodiment, the smooth convex surface part  34  of the radiator member  31  may be made of a material different from a material forming other portions of the radiator member  31 . The smooth convex surface part  34  may be made of a metal or a resin that may withstand a pressing force applied from a press machine. When using the resin, the resin may be coated on a central region  36  of the radiating surface  31   a  of the radiator member  31  in  FIG. 3C , formed into a smooth mountain shape, and cured for use in automatically aligning the bonding surface  31   b  of the radiator member  31  and the back surface  32   a  of the semiconductor device  32 . After this automatic alignment, the resin may be removed from the radiating surface  31   a . For example, the resin may be removed in order to planarize the radiating surface  31   a  and to facilitate bonding of radiator fins (not illustrated) having flat bonding surfaces onto the planarized radiating surface  31   a  of the radiator member  31 . 
     According to this modification of the first embodiment, the radiating surface  31   a  of the radiator member  31  may be planarized after the automatic alignment. Hence, the radiator fins having the flat bonding surfaces may easily be bonded onto the planarized radiating surface  31   a  of the radiator member  31 . 
     Second Embodiment 
       FIGS. 4A through 4C  are cross sectional views for explaining a radiator member in a second embodiment of the present invention. In  FIGS. 4A through 4C , those parts that are the same as those corresponding parts in  FIGS. 3A through 3D  are designated by the same reference numerals, and a description thereof will be omitted. 
     In this embodiment, the semiconductor package includes a wiring board  45  (one of  45   a ,  45   b , and  45   c ), a semiconductor device  32 , and a radiator member  42  (one of  42   a ,  42   b , and  42   c ). The semiconductor device  32  mounted on the wiring board  45   a  via bumps  49  is accommodated within a recess  41  of the radiator member  42   a  or, the semiconductor device  32  mounted on the wiring board  45   b  or  45   c  via bumps  49  is accommodated within a cavity  43  of the wiring board  45   b  or  45   c.    
       FIG. 4A  illustrates a first example in which the recess  41  is formed in the radiator member  42   a  in order to secure a space for accommodating the semiconductor device  32 . A bonding surface  46   a  of the radiator member  42   a  is bonded on the wiring board  45   a  via a bonding layer  47 , and is bonded on a back surface (upper surface in  FIG. 4A )  32   a  of the semiconductor device  32  via a bonding layer  33 . 
       FIG. 4B  illustrates a second example in which the cavity  43  is formed in the wiring board  45   b  in order to secure a space for accommodating the semiconductor device  32 . The radiator member  42   b  is bonded on a peripheral part  44  of the wiring board  45   b  via a bonding layer  47 , and is bonded on a back surface (upper surface in  FIG. 4B ) of the semiconductor device  32  via a bonding layer  33 . 
       FIG. 4C  illustrates a third example in which the cavity  43  is formed in the wiring board  45   c  in order to secure a space for accommodating the semiconductor device  32 . The radiator member  42   c  is bonded on a peripheral part  44  of the wiring board  45   b  via a bonding layer  47 , and is bonded on a back surface (upper surface in  FIG. 4C ) of the semiconductor device  32  via a bonding layer  33 . Further, regions of the cavity  43 , other than regions occupied by the semiconductor device  32  and the radiator member  42   c , may be filled by a filler material  43 A. 
     For example, the bonding layers  33  and  37  may be made of silicon polymer type resins. 
     In  FIG. 4A , a width D of a peripheral wall  48  of the radiator member  42   a , defining the recess  41 , is 2 mm to 3 mm, for example. In addition, a depth Ca of the recess  41  is 0.5 mm to 0.9 mm, for example. 
     The depth Ca of the recess  41  in  FIG. 4A  may be set to a value smaller than a sum of a thickness of the semiconductor device  32 , a thickness of the bonding layer  33 , and a height of the bumps  49 . By setting the depth Ca to such a value, the radiator member  42   a  may pivot and/or rotate about the peak of the smooth convex surface part thereof, without causing contact between the peripheral wall  48  of the radiator member  42   a  and the wiring board  45   a , in order to easily arrange the back surface  32   a  of the semiconductor device  32  to become parallel to the bonding surface  46   a  of the radiator member  42   a  by the automatic alignment. Further, by setting the depth Ca to the value smaller than the sum described above, a gap may be formed between the peripheral wall  48  of the radiator member  42   a  and the wiring board  45   a . However, the bonding layer  47  may sufficiently fill this gap by suitably setting the thickness of the bonding layer  47 . As a result, the peripheral wall  48  of the radiator member  42   a  may be positively bonded to the wiring board  45   a.    
     A depth Cb of the cavity  43  in  FIG. 4B  may be set to a value smaller than a sum of the thickness of the semiconductor device  32 , the thickness of the bonding layer  33 , and the height of the bumps  49 . By setting the depth Cb to such a value, the radiator member  42   b  may pivot and/or rotate about the peak of the smooth convex surface part thereof, without causing contact between the radiator member  42   b  and the peripheral part  44  of the wiring board  45   b , in order to easily arrange the back surface  32   a  of the semiconductor device  32  to become parallel to the bonding surface of the radiator member  42   b  by the automatic alignment. Further, by setting the depth Cb to the value smaller than the sum described above, a gap may be formed between the radiator member  42   b  and the peripheral part  44  of the wiring board  45   b . However, the bonding layer  47  may sufficiently fill this gap by suitably setting the thickness of the bonding layer  47 . As a result, the radiator member  42   b  may be positively bonded to the peripheral part  44  of the wiring board  45   b.    
     An automatic alignment, similar to the automatic alignment achieved in  FIG. 4B , may be achieved in  FIG. 4C . 
     The wiring boards  45   a ,  45   b , and  45   c  in  FIGS. 4A ,  4 B and  4 C employ the PGA, however, other formats may be used, including the LGA and the BGA. In addition, the wiring boards  45   a ,  45   b , and  45   c  may be formed by a mother board or the like that is often used in electronic equipments. 
     When the semiconductor device is accommodated within a closed space formed by the recess of the radiator member or by the cavity of the wiring board, it may be difficult to measure a distance between the back surface of the semiconductor device and the opposing, bonding surface of the radiator member. Further, it may be difficult to set a direction in which the radiator member or the wiring board is to be pressed. According to this second embodiment, however, the automatic alignment may be made with ease using the radiator member having the smooth convex surface part with the peak. As a result, a series of bonding processes may be carried out with a high precision, and the semiconductor package may be produced to have a sufficient heat radiating effect. Hence, the quality and the productivity of the semiconductor package may be improved. 
     Third Embodiment 
       FIGS. 5A and 5B  are side views for explaining the automatic alignment in the third embodiment of the present invention. In  FIGS. 5A and 5B , those parts that are the same as those corresponding parts in  FIGS. 3A through 3D  are designated by the same reference numerals, and a description thereof will be omitted. 
     The automatic alignment may use the smooth convex surface part of the radiator member in order to self-align the bonding surface of the radiator member and the opposing, back surface of the semiconductor device to become parallel to each other. This automatic alignment may require a pressing force of the press machine, but may not require a measuring mechanism, a control mechanism or the like to be provided on the press machine. 
       FIG. 5A  illustrates a state where the bonding surface  31   b  of the radiator member  31  and the back surface  32   a  of the semiconductor device  32  are parallel to each other. 
     On the other hand,  FIG. 5B  illustrates a state where the bonding surface  31   b  of the radiator member  31  and the back surface  32   a  of the semiconductor device  32  are not parallel to each other. In this state, amongst a left end point P, a center point Q, and a right end point R on the back surface  32   a  of the semiconductor device  32 , the left end point P contacts (or hits) the bonding surface  31   b  of the radiator member  31  via the bonding layer  33 . This contact at one end occurs because the bonding surface  31   b  and the back surface  32   a  are not parallel to each other due to causes which may include an uneven thickness of the radiator member  31  or, an error in the direction of the pressing force applied by the press machine on the radiator member or the wiring board. It may be difficult to solve each of the causes independently during each production stage of the semiconductor package. In addition, if the semiconductor device and the radiator member are bonded in a stage where the contact at one end occurs, a void may be generated in a space where the semiconductor device and the radiator member are not bonded together. When such a void is generated, a sufficient heat radiating effect may not be obtained, and a sufficient bonding strength may not be achieved between the semiconductor device and the radiator member. Accordingly, it is desirable to avoid the contact at one end between the semiconductor device and the radiator member, and to positively align the semiconductor device and the radiator member to become parallel to each other. 
       FIG. 5B  illustrates a state where the semiconductor device  32  and the radiator member  31  are in contact at one end. When the pressing force is applied in a direction X, the back surface  32   a  of the semiconductor device  32  is pushed at the left end point P via the bonding layer  33 . As a result, the thickness of the bonding layer  33  having fluidity decreases at the left end point P, and the radiator member  31  and the semiconductor device  32  substantially make contact with each other at the left end point P. Consequently, a relatively strong reaction occurs between the radiator member  31  and the semiconductor device  32  at the left end point P. On the other hand, the reaction between the radiator member  31  and the semiconductor device  32  does not occur at the center point Q and the right end point R, and substantially no load is applied at the center point Q and the right end point R. Because the radiator member  31  as a whole is pushed in the direction X by a pressing plate N of the press machine, the coupling (or inertia coupling) of the radiator member  31  becomes unbalanced. 
     The unbalanced coupling of the radiator member  31  causes the radiator member  31  to pivot and/or rotate in a direction A about the left end point P. This pivoting and/or rotating motion of the radiator member  31  aligns the bonding surface  31   b  of the radiator member  31  and the back surface  32   a  of the semiconductor device  32  in a direction to become parallel to each other until the coupling of the radiator member  31  becomes balanced. In other words, the alignment achieved by the pivoting and/or rotating motion of the radiator member  31  continues until the coupling of the radiator member  31  becomes balanced and the bonding surface  31   b  of the radiator member  31  and the back surface  32   a  of the semiconductor device  32  become parallel to each other, as illustrated in  FIG. 5A . In the parallel state illustrated in  FIG. 5A , the pressure (or stress) generated in the direction X is substantially the same at each of the points P, Q and R, and the coupling of the radiator member  31  is substantially balanced in this state. Furthermore, the distance between the bonding surface  31   b  of the radiator member  31  and the back surface  32   a  of the semiconductor device  32  may be determined by the pressing force of the pressing plate N of the press machine in the direction X, depending on properties such as the viscosity of the bonding layer  33 . Hence, the automatic alignment of the radiator member  31  and the semiconductor device  32  for parallelism may be carried out without requiring a measuring mechanism, a control mechanism or the like to be provided on the press machine. 
     It is assumed that the bonding layer  33  has fluidity in the description given above with respect to the behavior of the radiator member  31 . However, the bonding layer  33  may be made of a relatively hard material, such as a metal, because the coupling of the radiator member  31  may be balanced in a similar manner, and the automatic alignment of the radiator member  31  and the semiconductor device  32  may be achieved in a similar manner. 
       FIG. 6  is a flow chart for explaining a method of producing the semiconductor package in the third embodiment of the present invention. The semiconductor package production process illustrated in  FIG. 6  includes a radiator member setting step (or process) S 101 , an automatic alignment step (or process) S 102 , and a bonding layer during step (or process) S 103 . It is assumed for the sake of convenience that the semiconductor package illustrated in  FIG. 3A  is produced. 
     The wiring board  35  mounted with the semiconductor device  32  is prepared in order to carry out the step S 101 . The following processes are carried out in the step S 101 . First, the bonding layer  33  is coated on the back surface  32   a  of the semiconductor device  32 . The TIM used for the bonding layer  33  may be a silicon polymer resin, for example. A known resin coating technique may be employed in order to coat the TIM material and cause the TIM material to become semi-cured (or partially cured). Then, the radiator member  31  having the smooth convex surface part  34  is set on the bonding layer  33  provided on the semiconductor device  32 . The TIM used for the bonding layer  33  is not limited to resins, and may include metals such as indium, alloys such as indium alloys, carbon-containing resins, and carbon-containing metals or alloys. Furthermore, relatively hard materials having substantially no fluidity, such as metals, may be used for the TIM of the bonding layer  33 . 
     In the step S 102 , the press machine presses the radiator member  31  towards the semiconductor device  32 , in order to carry out the above described automatic alignment of the radiator member  31  and the semiconductor device  32 . 
     In the step S 103 , a known resin curing technique is employed in order to cure the bonding layer  33 . 
     In a case where a bonding layer  47  is provided between radiator member  42   a  and the wiring board  45   a  as illustrated in  FIG. 4A  or, between the radiator member  42   b  and the wiring board  45   b  as illustrated in  FIG. 4B , in addition to the bonding layer  33  between the radiator member  42   a  or  42   b  and the semiconductor device  32 , the automatic alignment may be carried out while securing a sufficient thickness for the bonding layer  47 . For example, the thickness of the bonding layer  47  may be 0.2 mm to 0.25 mm. 
     According to the third embodiment, the automatic alignment of the radiator member and the semiconductor device may be carried out without requiring a measuring mechanism, a control mechanism or the like to be provided on the press machine. For this reason, the productivity and the quality of the semiconductor package may be improved. 
     Modification of Third Embodiment 
     In a modification of the third embodiment, convex surface part  34  may be removed after the automatic alignment of the step S 102  described above. For example, a step S 104 A may be carried out to remove the convex surface part  34  after the step S 102  and before the bonding layer  33  is cured in the step S 103 , as indicated by dotted lines in  FIG. 6 . Alternatively, a step S 104 B may be carried out to remove the convex surface part  34  after the bonding layer  33  is cured in the step S 103 , as indicated by dotted lines in  FIG. 6 . 
     Fourth Embodiment 
       FIG. 7  is a cross sectional view illustrating a semiconductor package in a fourth embodiment of the present invention. In  FIG. 7 , those parts that are the same as those corresponding parts in  FIG. 4A  are designated by the same reference numerals, and a description thereof will be omitted. Further, the illustration of the bumps  49  and the like is omitted in  FIG. 7  for the sake of convenience. 
     A semiconductor package  70  illustrated in  FIG. 7  includes radiator fins  72  provided on a radiator member  71  via a bonding layer  73 . The provision of the radiator fins  72  may further improve the heat radiating efficiency of the radiator member  71 . The shape and the material used for the radiator fins  72  may be selected arbitrarily, from known shapes and materials, for example. The bonding layer  73  provided on a radiating surface  71   a  of the radiator member  71  may be formed by a sheet type or a gel type TIM, such as a silicon polymer resin. Cooling fins  74  may further be provided on the radiator fins  72  as illustrated in  FIG. 7 , in order to further improve the heat radiating efficiency by forced convection of air or the like. 
     According to the fourth embodiment, the heat radiating efficiency may further be improved by the provision of the radiator fins  72 , compared to a case where no radiator fins  72  are provided on the radiator member  73 . As a result, the performance of the semiconductor package  70  may further be improved. 
     Fifth Embodiment 
       FIG. 8  is a side view for explaining the automatic alignment in a fifth embodiment of the present invention. In  FIG. 8 , those parts that are the same as those corresponding parts in  FIG. 4A  are designated by the same reference numerals, and a description thereof will be omitted. 
     The semiconductor package production process for this fifth embodiment may be similar to that described above in conjunction with  FIG. 6 , except that a plurality of semiconductor elements are arranged two-dimensionally on the wiring board. 
     In  FIG. 8 , a plurality of semiconductor devices  32   p ,  32   q ,  32   r , and  32   s  are provided on a wiring board  81 , and a plurality of radiator members  82   p ,  82   q ,  82   r , and  82   s  are provided on the corresponding semiconductor devices  32   p ,  32   q ,  32   r , and  32   s . In a state illustrated in  FIG. 8 , the pressing plate N of the press machine presses the smooth convex surface parts  34  of each of the radiator members  82   p ,  82   q ,  82   r , and  82   s  in the direction X, in order to automatically align the radiator members  82   p ,  82   q ,  82   r , and  82   s  and the semiconductor devices  32   p ,  32   q ,  32   r , and  32   s , simultaneously. 
     The automatic alignment of the radiator members  82   p ,  82   q ,  82   r , and  82   s  and the semiconductor devices  32   p ,  32   q ,  32   r , and  32   s  for achieving the parallelism may be carried out in a similar manner as the third embodiment described above in conjunction with  FIGS. 5A and 5B . 
     A retainer (or a support frame)  83  indicated by phantom lines in  FIG. 8  may be used when pressing the smooth convex surface parts  34  of each of the radiator members  82   p ,  82   q ,  82   r , and  82   s  in the direction X by the pressing plate N of the press machine, in order to prevent the radiator members  82   p ,  82   q ,  82   r , and  82   s  from sliding in a direction parallel to the surface (or mounting surface, which is the upper surface in  FIG. 8 ) of the wiring board  81  by restricting movements thereof. 
     According to the fifth embodiment, it is possible to automatically align and bond a plurality of radiator members and a plurality of semiconductor devices, simultaneously. As a result, the productivity and the production cost of the semiconductor package may be improved. 
     Further, the present invention is not limited to these embodiments, but various variations and modifications may be made without departing from the scope of the present invention.