Abstract:
Even when only one of semiconductor packages mounted by carrying out infrared reflow is defective, it is required to carry out infrared reflow again to dismount this defective semiconductor package from a mounting board. At this time, stress of heat is also applied to the other non-defective semiconductor packages. For this reason, if infrared reflow is carried out beyond a number of times of infrared reflow specified for non-defective semiconductor packages, the operation of each non-defective semiconductor package cannot be assured. In this case, it is inevitable to discard the semiconductor packages together with the mounting board. To solve this problem, a magnetic material is passed through a hole penetrating a protection member and a package board and the relevant semiconductor package is fixed over a mounting board by this magnetic material. To supply power to the semiconductor package, electromagnetic induction by coils provided in the package board and the mounting board is used.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The disclosure of Japanese Patent Application No. 2009-257318 filed on Nov. 10, 2009 including the specification, drawings and abstract is incorporated herein by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to semiconductor packages and systems and in particular to a semiconductor package and a system wherein necessity for mounting to a mounting board by solder is obviated. 
     There are conventionally known technologies for mounting a ball grid array package  10  (hereafter, abbreviated as BGA  10 ) over a mounting board  11  as illustrated in  FIG. 1 . (Refer to Patent Document 1.) In the technology disclosed in Patent Document 1, BGA  10  is comprised of a package board  13 , a semiconductor element  14 , a protection member  15 , and a solder ball  16 . The package board  13  is comprised of a core base material  17  composed of glass cloth, resin, or the like and solder resist  18  covering the upper surface and lower surface of the core base material  17  in the drawing. 
     An opening is provided in the solder resist  18  covering the upper surface of the core base material  17  and a bonding pad formed over the core base material  17  is exposed from this opening. This bonding pad is coupled to a wiring pattern provided in the upper surface of the core base material  17  and this wiring pattern is coupled to a via hole so provided that it penetrates the core base material  17 . 
     The semiconductor element  14  and this bonding pad are coupled together through a bonding wire  21  and as a result, the semiconductor element  14  and the package board  13  are electrically coupled together. In the lower surface of the core base material  17 , a substantially oval ball land is formed. This ball land is coupled with the above-mentioned via hole so formed that it penetrates the core base material  17  and is electrically coupled to the semiconductor element  14  through the following: the wiring pattern provided in the upper surface of the core base material  17 , a bonding pad, and a bonding wire  21  bonded with this bonding pad. This ball land is exposed from an opening provided in the solder resist  18  covering the lower surface of the core base material  17 . Before the BGA  10  is mounted to the mounting board  11 , the solder ball  16  is placed over a ball land by a ball placer, not shown. The placed solder ball  16  is joined to the ball land by IR reflow processing or the like and the joined solder ball  16  makes an external connection terminal electrically coupled with the semiconductor element  14 . The protection member  15  protects the semiconductor element  14  and the bonding wire  21 . 
     Similarly with the package board  13 , the mounting board  11  is comprised of a core base material  25  and solder resist  26  covering the upper surface and lower surface thereof in the drawing. In the upper surface of the core base material  25 , there is formed an area (mounting area) where the BGA  10  is mounted. In this mounting area, there is formed a substantially oval junction land corresponding to a solder ball  16  joined to a ball land of the BGA  10 . This junction land is exposed from an opening formed in the solder resist  26  covering the upper surface of the mounting board  11 . The junction land is electrically coupled with some other mounted electronic component or a power supply through a wiring pattern formed in the upper surface of the mounting board  11 . When the BGA  10  is mounted to the mounting board  11 , the solder balls  16  of the BGA  10  are abutted against the above-mentioned junction lands provided in the mounting board  11 . Subsequently, the BGA  10  and the mounting board  11  are subjected to IR reflow and as a result, the solder balls  16  are joined to the junction lands of the mounting board  11  and mounting of the BGA  10  to the mounting board  11  is completed. 
     Patent Document 2 discloses a technology for fixing a semiconductor package over a circuit board. In this technology, the semiconductor package is fixed over the circuit board by: passing a bolt through an insertion hole in the semiconductor package and inserting the bolt into a communication hole in the circuit board; and screwing a nut onto the tip of the bolt that penetrates the circuit board and is protruded therefrom. 
     Patent Document 3 discloses a non-contact power supply system using electromagnetic induction based on a printed coil. 
     Patent Document 4 discloses that in an electrical apparatus provided with a primary coil and a secondary coil, power is transmitted to the secondary coil in a non-contact manner by supplying a current to the primary coil. 
     Non-patent Document 1 discloses a technology related to measurement of 2.4 GHz RF signal quality. Non-patent Document 2 discloses a technology related to communication through an antenna using a coil.
     [Patent Document 1] Japanese Unexamined Patent Publication No. 2007-12690   [Patent Document 2] Japanese Unexamined Patent Publication No. Hei 07(1995)-161865   [Patent Document 3] Japanese Unexamined Patent Publication No. 2007-157985   [Patent Document 4] Japanese Unexamined Patent Publication No. 2004-064851   [Non-patent Document 1] Koichi Nose et al., “A 0.016 mm 2 , 2.4 GHz RF signal Quality Measurement Macro for RF Test and Diagnosis” IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 43, NO. 4 April 2008, pp 1038-1046   [Non-patent Document 2] Kiichi Niitsu et al., “An inductive-Coupling Link for 3D Integration of 90 nm CMOS Processor and a 65 nm CMOS SRAM” ISSCC Dig. Tech. Papers, pp. 480-482, February 2009.   

     SUMMARY 
     The present inventors founds that the technology disclosed in Patent Document 1 involves the following problems. As mentioned above, the BGA  10  in  FIG. 1  is mounted to the mounting board  11  using solder balls  16 . When a semiconductor package (equivalent to the BGA  10  in  FIG. 1 ) including a semiconductor element (pellet) is mounted to a mounting board by solder, the following takes place: it is difficult to dismount a once mounted semiconductor package and mount a different non-defective semiconductor package to the identical mounting board again. The reason for this is as follows. Usually, semiconductor packages should be screened through quality inspection or the like and non-defectives should be shipped. Nevertheless, a defective may be produced among mounted semiconductor packages because of stress applied during mounting, deterioration with age, or the like. Therefore, even in cases where one semiconductor package is defective, for example, when multiple semiconductor packages are mounted to a mounting board to build a system, it used to be inevitable to take the following measure: it used to be inevitable to discard the value-added mounting board mounted with non-defective semiconductor packages in its entirety. The reason for this is as follows: 
     To mount semiconductor packages using solder balls, it is required to carry out infrared reflow (hereafter, referred to as IR reflow) as described in Patent Document 1. In this IR reflow, a mounting board itself mounted with the semiconductor packages is placed in a furnace for IR reflow and heat is applied to the entire semiconductor packages mounted over the mounting board. Therefore, stress of heat arising from the IR reflow is applied to all the semiconductor packages mounted over the mounting board. 
     The maximum number of times of IR reflow that can be carried out on semiconductor packages is prescribed beforehand. In case of NEC Electronics Corporation, for example, it is prescribed that IR reflow in which heat at 260 degrees may be carried out up to twice on semiconductor packages specified as IR60-103-2. When a system is built over a mounting board at the corporation, IR reflow is carried out to mount multiple semiconductor packages. Even if one semiconductor package thereafter becomes defective and this semiconductor package is found to be a defective, IR reflow must be carried out again to dismount this defective semiconductor package. To carry out IR reflow, as mentioned above, the mounting board itself must be placed in a furnace. As a result, stress of heat arising from the IR reflow is also applied to the other non-defective semiconductor packages. To replace the defective semiconductor package with a non-defective semiconductor package and mount it over the mounting board, IR reflow must be carried out once again. That is, even when it is desired to dismount only a defective semiconductor package mounted over a mounting board and replace it with a non-defective semiconductor package, stress of heat arising from IR reflow is also applied to non-defective semiconductor packages. Therefore, IR reflow can be carried out beyond the number of time of IR reflow prescribed for non-defective semiconductor packages. With respect to non-defective semiconductor packages, in this case, it cannot be assured that those semiconductor packages are non-defective. 
     In this case, with respect to semiconductor packages that are mounted over a mounting board and should be otherwise non-defective, it cannot be assured that they are non-defective. Eventually, therefore, all of them must be discarded together with the mounting board. 
     Conventional technologies pose a technical problem to be solved when a semiconductor package is mounted to a mounting board by solder. That is, it is impossible to dismount the once mounted semiconductor package and mount a different semiconductor package over the identical mounting board. Therefore, if a defective semiconductor package is produced in the processes of manufacturing and mounting semiconductor packages, it results in increase in cost. 
     A semiconductor package according to the invention includes: a package board including a coil that supplies power based on an induced current passed in response to change in magnetic flux; a pellet provided over the package board and including a circuit that operates based on power supplied from the coil; a protection member covering the package board and protecting at least the pellet; a first hole penetrating the protection member; and a second hole surrounded with a wiring forming the coil and penetrating the package board. 
     A semiconductor manufacturer who manufactures and sells semiconductor packages ships semiconductor packages having at least the above-mentioned configuration as a product. A customer supplied with these semiconductor packages from the semiconductor manufacturer carries out the following processing to mount semiconductor packages over a mounting board: a fixing member, for example, a magnetic material is passed through the first hole and the second hole in each semiconductor package. The mounting board over which the semiconductor packages are mounted is separately provided with a coil. This mounting board is provided with a hole (here, tentatively referred to as third hole) surrounded with a wiring forming this coil and penetrating the mounting board. Therefore, the customer supplied with the above-mentioned semiconductor packages passes the fixing member passed through the first and second holes provided in each semiconductor package also through the third hole and thereby fixes the semiconductor package over the mounting board. As an example, a configuration in which the following measure is taken is possible: the fixing member is passed through the third hole as well as the first and second holes and passed along side surfaces of the mounting board and each semiconductor package to form one closed loop; and the semiconductor package is thereby fixed over the mounting board. To configure this magnetic material in a closed loop, joints can be welded by heat. As another example, the magnetic material may be formed in an open loop in which part of the loop is discontinuous, not in a complete closed loop and each semiconductor package is thereby fixed over the mounting board. When the magnetic material is formed in an open loop, welding by heat is unnecessary and each semiconductor package is fixed over the mounting board by hooking it on the mounting board by the open-looped magnetic material. As a result, it is unnecessary for the customer to carry out IR reflow to mount the semiconductor packages over the mounting board. 
     To dismount one of the thus mounted semiconductor packages, IR reflow is unnecessary. That is, it is unnecessary to place them in a furnace together with the mounting board to apply heat to the entire semiconductor packages mounted over the mounting board. Specifically, the magnetic material fixing a semiconductor package to be dismounted over the mounting board only has to be mechanically cut. Therefore, it is unnecessary to apply heat to the semiconductor package that must be dismounted from the mounting board. In case of semiconductor packages mounted over a mounting board using a magnetic material configured in an open loop, welding by heat is not originally carried out. To dismount such a semiconductor package from the mounting board, therefore, the semiconductor package can be dismounted from the mounting board by changing the shape of the magnetic material by physical force. Consequently, it is possible to dismount a defective semiconductor package among multiple semiconductor packages mounted over a mounting board and instead mount a non-defective semiconductor package over this mounting board. As a result, when one of semiconductor packages mounted over a mounting board is defective, it is unnecessary to discard all of them together with the mounting board unlike conventional technologies. 
     When a semiconductor package is mounted over a mounting board as mentioned above, there is a concern about power supply to the semiconductor package. A circuit included in the semiconductor package mounted without use of solder balls is operated by supplying power from the mounting board to the semiconductor package by the principle described below: 
     The mounting board is provided with a power supply IC that supplies alternating-current voltage whose voltage value varies based on the frequency. When alternating-current voltage outputted from the power supply IC is applied to a coil provided in the mounting board, the current passed through this coil is also varied. In response to variation in the current passed through the coil provided in the mounting board, the magnetic flux produced by this coil also changes. Based on this change in magnetic flux, an induced current arising from the phenomenon of electromagnetic induction is passed through the coil included in the package board. In consideration of that, for example, recent circuits operate on direct-current voltage, power is supplied to a circuit included in the pellet of a semiconductor package by rectifying this induced current and the circuit operates. When the fixing member used to fix each semiconductor package over the mounting board is magnetic material, the magnetic material contributes to reduction of the amount of flux leakage and supply of a sufficient amount of power from the mounting board to each semiconductor package. 
     According to the foregoing, it is possible to dismount a defective semiconductor package among multiple semiconductor packages mounted over a mounting board; and instead mount a non-defective semiconductor package over this mounting board. This makes it possible to solve the following problem associated with conventional technologies: it is difficult to dismount a mounted semiconductor package and mount a different non-defective semiconductor package over the identical mounting board again. 
     According to the invention, it is possible to mechanically mount a semiconductor package over a mounting board without use of heat. Therefore, even though a defective semiconductor package is produced in product development, increase in cost can be suppressed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a drawing illustrating the configuration of a semiconductor package according to a conventional technology; 
         FIG. 2  is a drawing illustrating the configuration of a system in a first embodiment; 
         FIG. 3  is a drawing illustrating a modification to the first embodiment; 
         FIG. 4  is a drawing illustrating a modification to the first embodiment; 
         FIG. 5  is a drawing illustrating a modification to the first embodiment; 
         FIG. 6  is a drawing illustrating a modification to the first embodiment; 
         FIG. 7  is a drawing illustrating the configuration of a system in a second embodiment; 
         FIG. 8  is a drawing illustrating the configuration of a system in a third embodiment; and 
         FIG. 9  is a drawing illustrating a system in the third embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereafter, description will be given to embodiments of the invention disclosed in this specification with reference to the drawings. The scope of right of the invention is determined by the description in “What is claimed is” and should not be construed in a limited way by the following description of the embodiments. 
     First Embodiment 
       FIG. 2  illustrates a system  200  in the first embodiment. The system  200  is, for example, a system developed by an assembled product manufacturer supplied with semiconductor packages from a semiconductor manufacturer. The system  200  includes a mounting board  201 . The mounting board  201  is a board used by the assembled product manufacturer to mount semiconductor packages supplied from the semiconductor manufacturer. The mounting board  201  includes a power supply IC, typified by a battery or the like, that converts externally supplied power into a predetermined voltage and outputs it. The mounting board  201  in this embodiment includes a power supply IC that outputs alternating-current voltage based on inputted voltage.  FIG. 2  schematically illustrates this power supply IC as alternating-current voltage source  202 . The power supply IC is essentially mounted over one main surface of the mounting board  201  but in  FIG. 2 , the power supply IC is schematically shown as alternating-current voltage source  202  inside the mounting board. The alternating-current voltage source  202  is coupled to a wiring extended in a wiring layer internal to the mounting board  201 . 
     The mounting board  201  includes a coil  203 . This coil  203  is formed using, for example, a wiring extended over the one main surface of the mounting board  201  or using a wiring extended in an internal wiring layer when the mounting board has a predetermined number of wiring layers therein.  FIG. 2  illustrates an example in which the mounting board  201  is a multilayer board having multiple wiring layers therein. A first turn of the coil  203  is formed by a wiring extended in one wiring layer provided in the mounting board  201 ; and a second turn of the coil  203  is formed by a wiring extended in a wiring layer different from the one wiring layer. That is, in this example in  FIG. 2 , the number of turns of the coil  203  is two. In cases where the mounting board  201  has more than two wiring layers, the number of turns of the coil  203  can be further increased similarly using the following wirings: wirings extended in wiring layers respectively different from the wiring layers where the wirings for the first and second turns of the coil  203  are located. This coil  203  is coupled to the alternating-current voltage source  202  that outputs alternating-current voltage and has alternating-current voltage inputted thereto. 
     In the mounting board  201 , there are a hole  215  surrounded with a wiring forming the coil  203  and penetrating the mounting board and a hole  216  provided separately from the hole  215  and penetrating the mounting board  201 . A fixing member, for example, a magnetic material (a representative example is an iron core) is passed through these holes  215  and  216  and this will be described in detail later. Though two holes, the hole  215  and the hole  216 , are provided in this example, the number of holes may be one as described later. 
     Over the one main surface of the mounting board  201 , there is provided a package board  204 . The package board  204  is a board for the semiconductor manufacturer to place a pellet  210 , or a semiconductor chip in which a circuit for implementing desired functions is formed. Similarly with the mounting board  201 , the package board  204  has a predetermined number of wiring layers therein and in each wiring layer, a wiring formed of metal is extended. The package board  204  in this embodiment includes a coil  205 . This coil  205  is formed by, for example, a wiring extended in a wiring layer provided in the package board  204 . Specifically, a first turn of the coil  205  is formed by a wiring extended in one wiring layer provided in the package board  204 ; and a second turn of the coil  205  is formed by a wiring extended in a wiring layer different from the one wiring layer. That is, in this example in  FIG. 2 , the number of turns of the coil  205  is two. In cases where the package board  204  has more than two wiring layers, the number of turns of the coil  205  can be further increased similarly using the following wirings: wirings extended in wiring layers respectively different from the wiring layers where the wirings for the first and second turns of the coil  205  are located. 
     Over the package board  204 , there are provided electrode pads  206  and  207 . The coil  205  is coupled with the electrode pads  206  and  207 . Over the package board  204 , there is provided a semiconductor chip in which a circuit for implementing desired functions is formed, that is, a pellet  210 . The electrode pads  206  and  207  and the circuit formed in the pellet  210  are electrically coupled together through bonding wires  208 ,  209  and electrode pads (not shown) formed in the pellet  210 . Therefore, the coil  205  and the circuit formed in the pellet  210  are electrically coupled together. In the above-mentioned example, the coil  205  is electrically coupled with the circuit included in the pellet  210  through the bonding wires. However, the coupling between the coil  205  and the circuit included in the pellet  210  is not limited to this example. When the pellet  210  and the package board  204  are flip-chip bonded together, for example, the above-mentioned bonding wire  208  is not used. In this case, the circuit included in the pellet  210  is coupled through solder balls or the like and when these solder balls or the like are bonded with a wiring layer provided in the package board  204 , the coil  205  and the circuit included in the pellet  210  are electrically coupled together. 
     One main surface of the package board  204  where the pellet  210  is formed is covered with a protection member  211  that protects at least the pellet  210 . The protection member  211  is composed of, for example, molding resin. In this embodiment, the objects, such as the pellet  210 , bonding wire  208 , and electrode pads  206  and  207 , to be protected formed in the one main surface are protected by this protection member  211 . In cases where the protection member  211  is formed of molding resin, the objects, such as the electrode pads  206  and  207 , to be protected formed in the one main surface are sealed with the protection member  211  formed of molding resin. 
     In the example in  FIG. 2 , at least the following holes are respectively present in the protection member  211  and the package board  204 : a first hole penetrating the protection member  211  and a second hole surrounded with a wiring forming the coil  205  and penetrating the package board  204 . Since  FIG. 2  illustrates an embodiment, however, a hole  212  is depicted as a more detailed concrete example in the drawing. The hole  212  is obtained by aligning the first hole and the second hole with each other and connecting the first and second holes together and penetrates the protection member  211  and the package board  204 .  FIG. 2  is depicted on the assumption that there is a hole  213  provided separately from the hole  212  and penetrating the protection member  211  and the package board  204 . The hole  213  may be divided into a hole penetrating the protection member and a hole penetrating the package board. A fixing member, for example, a magnetic material (a representative example is an iron core) is passed through the holes  212  and  213  and this will be described in detail later. The hole  212  is aligned so that it connects with the hole  215  and the hole  212  and the hole  215  together form one hole penetrating the protection member  211 , package board  204 , and mounting board  201 . This is the same with the hole  213  and the hole  216 . In this example in  FIG. 2 , two holes are provided as the hole  212  and the hole  213 ; however, the number of holes penetrating the package board  204  and the protection member  211  may be one as described later. 
     The semiconductor manufacturer ships a semiconductor package  217  including at least the following to a customer as a product: the package board including the coil  205 ; the pellet  210  provided over the package board  204  and having a circuit for implementing desired functions formed therein; the protection member  211  covering the package board  204  and sealing at least the pellet  210 ; the hole  212  surrounded with a wiring forming the coil  205  and penetrating the protection member  211  and the package board  204 ; and the hole  213  provided separately from the hole  212  and penetrating the protection member  211  and the package board  204 . This semiconductor package  217  may include another constituent element, for example, a necessary object such as an electrode pad and a bonding wire, needless to add. 
     The customer, for example, an assembled product manufacturer who purchased this semiconductor package  217  need mount this semiconductor package  217  over the mounting board  201 . Consequently, the assembled product manufacturer passes a fixing member, specifically, a magnetic material for fixing the semiconductor package  217  over the mounting board  201  through the following: the holes  212  and  213  provided in the package board  204  of the purchased semiconductor package  217  and the holes  215  and  216  provided in the mounting board  201 . The assembled product manufacturer forms this fixing member in a desired shape and fixes, that is, mounts the semiconductor package  217  over the mounting board  201 . When the fixing member is a magnetic material, the configuration of the system  200  is preferable in terms of power supply to the circuit included in the pellet  210  described later. A possible example of the fixing member is such a magnetic material  214  in a closed loop as illustrated in  FIG. 2 . In this case, the magnetic material  214  runs from the upper surface of the protection member  211 , goes through the hole  212  and the hole  215 , and is extended to the lower surface of the mounting board  201 . Thereafter, the magnetic material  214  is extended in the lower surface of the mounting board  201 , goes through the hole  216  and the hole  213 , and reaches the upper surface of the protection member  211 . Further, the magnetic material  214  is extended in the upper surface of the protection member  211  and reaches the hole  212 . As a result, the magnetic material  214  forms a closed loop. When the fixing member is such a magnetic material as a ferrite core, welding by heat is required to form the magnetic material in a closed loop. Therefore, the assembled product manufacturer uses a required apparatus to carrying welding to form the closed-looped magnetic material  214 . The magnetic material as the fixing member for fixing the semiconductor package  217  over the mounting board  201  need not be formed in a closed loop. Instead, it may be formed in an open loop in which part of the magnetic material  214  shown in  FIG. 2  is discontinuous and interrupted. Also in this case, the semiconductor package  217  can be fixed over the mounting board  201  unless the gap portion of the magnetic material in an open loop is too large. In addition, when this open-looped magnetic material is used, necessity for welding by heat is obviated. 
     When the above-mentioned mounting is completed, the system  200  illustrated in  FIG. 2  is obtained. However, the configuration of the system  200  is not limited to that illustrated in  FIG. 2  and includes various modifications.  FIG. 3  to  FIG. 6  schematically explain modifications to the configuration of the system  200  based on top views of the protection member  211  in  FIG. 2 . To fix the semiconductor package  217  over the mounting board  201 , at least one hole only has to exist as illustrated in  FIG. 3 , for example. In this case, the fixing member  214  runs from the upper surface of the protection member  211 , is extended in the hole  212  and penetrates the package board  204 , and is extended in the hole  215  and penetrates the mounting board  201 . The fixing member  214  further goes along the lower surface of the mounting board  201 , a side surface of the mounting board  201 , a side surface of the package board  204 , and a side surface of the protection member  211 . Then it is extended to the upper surface of the protection member  211 . As a result, the fixing member  211  forms a closed loop. In the example in  FIG. 3 , the fixing member  214  need not be a closed loop and may be an open loop as mentioned above.  FIG. 4  is a top view of the protection member  211  in  FIG. 2 . In addition to the holes  212  and  213 , more holes may be provided in the semiconductor package  217 . As illustrated in  FIG. 5 , for example, three holes, that is, the holes  212 ,  213 ,  218  may be provided along one side of the protection member  211 . The mounting board  201  is also provided with a hole penetrating the mounting board  201  in correspondence with the hole  218 . As illustrated in  FIG. 6 , the following measure may be taken: the holes  212  and  213  are provided along one side of the protection member  211 ; and the additional hole  218  penetrating the protection member  211  and the package board  204  is provided in proximity to the side opposite the one side. In this case, the semiconductor package  217  is fixed over the mounting board  201  at three points; therefore, it can be more firmly fixed. 
     The wiring forming the coil  205  may surround the hole  213  as well as the hole  212 . This configuration is effective in increasing the number of turns of the coil  205 . As mentioned above, one turn of the coil  205  is formed in each wiring layer provided in the package board  204 . For this reason, there may be the following cases even when it is desired to make the number of turns of the coil  205  larger than the number of the wiring layers provided in the package board  204 : the number of turns of the coil  205  cannot be made larger than the number of the wiring layers provided in the package board  204  just by ensuring that the wiring forming the coil  205  surrounds only the hole  212 . 
     Consequently, the wiring forming the coil  205  is routed so as to surround the hole  213 . This makes it possible to achieve a number of turns twice the number of the wiring layers provided in the package board  204 . To simply increase a number of turns, it is unnecessary to form a wiring so that it surrounds the hole  213 . In consideration of flux leakage, described later, that occurs during power supply, however, it is desirable to ensure that the wiring for the coil  205  surrounds the hole  213 . 
     As mentioned above, the semiconductor package  217  can be mounted over the mounting board  201  without carrying out IR reflow on solder balls. The circuit included in the pellet  210  of the semiconductor package  217  does not operate unless sufficient power is supplied to the circuit. Consequently, consideration will be given to the validity of power supplied to this circuit in this embodiment. 
     First, alternating-current voltage having a predetermined frequency is applied from the alternating-current voltage source  202  to the coil  203 . Since the current passed through the coil  203  varies with a certain frequency, the magnetic flux produced by the coil  203  also changes in response to change in the current passed through the coil  203 . The variation in the magnetic flux produced by the coil  203  produces induced electromotive force in the coil  205  based on the phenomenon of electromagnetic induction. Based on this induced electromotive force produced in response to the change in the magnetic flux produced by the coil  203 , an induced current is passed through the coil  205 . This induced current flows into the power supply line formed in the pellet  210  and the circuit is supplied with power. The circuit formed in the pellet  210  operates based on this power. The magnitude of induced electromotive force produced in the coil  205  varies according to the number of turns of the coil  203  and the number of turns of the coil  205 . To obtain a desired voltage, therefore, the number of turns of the coil  203  and the number of turns of the coil  205  only have to be adjusted. It is unnecessary to provide a step-up circuit or a step-down circuit for converting voltage values. Since recent circuits formed in the pellet  210  operate on direct-current voltage, however, it is required to take the following measure in actual designing: any of the semiconductor packages  217  is provided with a rectification circuit. 
     The induced electromotive force produced in the coil  205  is also influenced by the amount of flux leakage that does not interlink with the coil  205  in the magnetic flux produced by the coil  203 . When the coil  203  and the coil  205  are ideally coupled together and the coupling coefficient is 1, flux leakage does not occur. Since in reality, this coupling coefficient cannot be 1, however, it is required to take reduction in induced electromotive force due to flux leakage as well into account in real designing. This is because when the induced electromotive force is reduced, power that can be supplied to the pellet  210  is also reduced. Consequently, the measure illustrated in  FIG. 2  as well is taken to reduce the amount of flux leakage as much as possible. That is, the magnetic material  214 , for example, an iron core, adopted as the fixing member is passed through the hole  212  and the hole  213 . The magnetic material  214  assumes a role of a fixing member that fixes and mounts the semiconductor package  217  over the mounting board  201 . In addition, it also assumes a role of reducing the amount of flux leakage in the magnetic flux produced from the coil  204  to ensure the certain magnitude of induced electromotive force of the coil  205 . 
     Even though the magnetic material  214  is passed as mentioned above, flux leakage is also caused by the following: a gap produced between the magnetic material  214  and the coil  203  and a gap produced between the magnetic material  214  and the coil  205 . In reality, therefore, the loss of induced electromotive force is inevitable even with the magnetic material  214  provided. However, the loss of induced electromotive force can be largely suppressed by using a magnetic material  214 , for example, a ferrite core sufficiently high in magnetic permeability to fix the semiconductor package  217  over the mounting board  201 . This is because most of the magnetic flux produced by the coil  203  goes through the magnetic material  214  and interlinks with the coil  205 . In this case, it is possible to disregard a gap between the coil  203  and the magnetic material  214  and a gap between the coil  205  and the magnetic material  214 . 
     Even though the above contrivance is made in an attempt to suppress reduction in induced electromotive force and ensure power that can be supplied to the pellet  210 , the following takes place when the system  200  is actually designed: power that can be transmitted to the pellet  210  is lost by the impedance of the coil  205  itself. In reality, as mentioned above, it is required to provide a semiconductor package  217  with a rectification circuit; therefore, it is required to also take the loss of power due to this rectification circuit into account. Further, power may be lost by eddy current depending on the shape of the coil  205 . The hysteresis loss of this power must also be taken into account. 
     In consideration of the foregoing, it is appropriate to suppose that several tens of percent of power inputted to the coil  203  in the mounting board  201  is lost in real designing. 
     Meanwhile, recent circuits formed in the pellet  210  operate based on a direct-current voltage of 1 V or so supplied to the power supply line provided in the pellet  210 . Even though power based on the voltage outputted by the alternating-current voltage source  202  is lost several tens of percent or so before it is supplied to the circuit included in the pellet  210 , it is supposed that: a direct-current voltage of 1 V or so can be sufficiently supplied to the power supply line provided in the pellet  210  by setting the peak-to-peak value of alternating-current voltage supplied by the alternating-current voltage source  202  to 2 V or so. 
     The foregoing is a restriction imposed on the following when the coil  203  and the coil  205  are configured as a transformer and power is supplied from the mounting board  201  to the circuit formed in the pellet  210 : the value of voltage supplied by the alternating-current voltage source  202  taken into account when the system  200  is actually designed. Even though the restriction on the voltage value is met, however, a structural restriction must also be met to actually implement the system  200 . In the system  20  in  FIG. 2 , it is of a problem whether or not the structure of the coil  203 , coil  205 , and magnetic material  214  is realistic in supplying power to the pellet  210 . (This is because when the cross-sectional area of the magnetic material is realistic, the cross-sectional area of a hole through which the magnetic material  214  is passed is also realistic.) 
     Consequently, consideration will be given to structural restrictions on the coil  203 , coil  205 , and magnetic material  214 . A structural restriction on the coil  203  and the coil  205  is their number of turns required to supply required power to the circuit formed in the pellet  210 . The reason for this is as follows. When the magnetic material  217 , for example, a ferrite core sufficiently high in magnetic permeability is used to fix the semiconductor package  214  over the mounting board  201 , the following takes place: the magnetic flux produced by the coil  203  is almost all passed through the magnetic material  214  and interlinks with the coil  205 . Therefore, a gap between the coil  203  and the magnetic material  214  and a gap between the coil  205  and the magnetic material  214  can be disregarded. Thus, when a number of turns is too large as compared with the number of wiring layers provided in the mounting board  201  or the package board  204 , the following takes place: even when the alternating-current voltage source  202  outputs alternating-current voltage whose peak-to-peak value is 2V, sufficient power cannot be supplied to the circuit included in the pellet  210  with the coil  203  or coil  205  formed using a wiring extended in the wiring layer. This is because in consideration of that the system  200  is actually mounted over a small produce, it is not realistic to take the following measure: the number of the wiring layers in the package board  204  or the mounting board  201  is increased to make the package board  204  or the mounting board  201  too thick. 
     A possible structural restriction on the magnetic material  214  is the cross-sectional area and length of the magnetic material  214 . The induced electromotive force produced in the coil  205  is based on change in magnetic flux interlinked with the coil  205 . Mathematically, it is based on the amount of change per unit time in the density of magnetic flux interlinked with the coil  205  as according to Faraday&#39;s law. As mentioned above, the magnetic flux produced by the coil  203  substantially goes through the magnetic material  214  and interlinks with the coil  205 . In consideration of these, the cross-sectional area of the magnetic material  214  relates to magnetic flux density and is thus important. With respect to the length of the magnetic material  214 , meanwhile, it can be supposed from the above viewpoint that it only has to be the extent that the semiconductor package  217  can be fixed over the mounting board  201 . 
     So, it turns out that consideration must be given to the numbers of turns of the coil  203  and the coil  205  and the cross-sectional area of the magnetic material  214 . It is known from an analysis of a transformer that the maximum density Bm of magnetic flux that can be passed through the magnetic material  214 , for example, an iron core is Bm=V/(√2π*f*S*N), where π is circumference ratio; f is the frequency of alternating-current voltage; S is the cross-sectional area of the magnetic material  214 , for example, an iron core; and N is the number of turns of a coil wound around the iron core (for example, the number of turns of each of the coil  203  and the coil  205  when the coil  203  and the coil  205  are identical in number of turns). Here, 3.14 will be taken as the circumference ratio π and 2V, which is the peak-to-peak value of voltage outputted by the alternating-current voltage source  202 , will be substituted for V. 2 GHz=2*10 9 , which is a typical frequency at which the oscillation of voltage is actually achieved, will be substituted for the frequency f of alternating-current voltage. 
     The rest is the cross-sectional area of the magnetic material  214  and the maximum magnetic flux density Bm. When these values are determined, the number of turns N of each of the coil  203  and the coil  205  is determined from the above expression. This N refers to the number of turns N obtained when the maximum magnetic flux density is passed through the magnetic material  214  and this means that a number of turns not less than N is required. As an example, it will be assumed that a ferrite core is used as the magnetic material  214 . In this case, Bm is 0.5 T or so and 0.5 is substituted for Bm. On the assumption that the cross section of the iron core is, for example, a square measuring 1 mm per side, 1.0*10 −6  square meters is adopted for the cross-sectional area of the iron core. In this case, the cross section of the iron core is sufficiently smaller than the area of the upper surface or lower surface of the protection member  211  or package board  204  of the semiconductor package  217 . Therefore, the opening area of the hole  212 , hole  213 , hole  215 , or hole  216  does not become larger than necessary. In the semiconductor package  217  illustrated in  FIG. 2 , specifically, for example, the thickness of the protection member  211  is 200 μm and the length of longitudinal sides and the length of horizontal sides are each 10 mm or so. Naturally, this is also the case with the package board  204 . 
     Therefore, in an example in which the cross-sectional area of the iron core is 1.0*10 −6  square meters, the structure of the actual system  200  is not unrealistically restricted even with the size of the protection member  211  or the package board  204  taken into account. 
     Using the numeric values in the above example, the minimum number of turns N required for the coil  203  and the coil  205  to implement the following will be determined: the circuit formed in the pellet  210  is operated by supplying alternating-current voltage whose peak-to-peak value is 2V from the alternating-current voltage source  202 . 
     When the number of turns N is actually calculated, N&gt;V/(√2*π*f*S*Bm)=2/(4.44*2*10 9 *1*10 −6 *0.5)=0.45*10 −3 . That is, the number of turns only has to be 1 at least. Therefore, it is supposed that a larger-than-necessary number of turns is not necessary for the coil  203  or the coil  205 . 
     It is understood from the foregoing that the system  200  in this embodiment has an appropriate structural size in terms of real design and is realistic in terms of technology. According to this embodiment, therefore, it is possible to adopt a structure that enables the practical manufacture of products and mount the semiconductor package  217  over the mounting board  201  without carrying out IR reflow on solder balls. Further, it is possible to supply sufficient power to the circuit included in the pellet  210  of the semiconductor package  217  to operate the circuit. 
     Description will be given to a manufacturing method for this system  200 . The wiring pattern of wirings extended in the wiring layers provided in the package board  204  is designed so that the coil  205  is formed in a desired position in the package board  204  of the semiconductor package  217 . Then the package board  204  with this coil  205  formed therein is prepared. Required constituent elements, such as the pellet  210 , are formed thereover using publicly known manufacturing techniques and the pellet  210  and the like are sealed with the protection member  211 . Subsequently, the hole  212  penetrating the protection member  211  and the package board  204  is formed by drilling so that it is surrounded with the wiring forming the coil  205  based on the position where the coil  205  is formed. At the same time, the hole  213  is formed by drilling so that it penetrates the protection member  211  and the package board  204 . As a result, the semiconductor package  217  is manufactured. As mentioned above, the semiconductor manufacturer ships the thus formed semiconductor packages  217  to the customer. The customer designs the wiring pattern of wirings extended in the wiring layers provided in the mounting board  201  so that the coil  203  is also formed in the mounting board  201 . Then the customer prepares a mounting board with the coil  203  formed therein. The hole  215  penetrating the mounting board  201  is formed by drilling so that it is surrounded with the wiring forming the coil  203  based on the position where the coil  203  is formed. At the same time, the hole  216  is formed by drilling so that it penetrates the mounting board  201 . Thereafter, the customer aligns each semiconductor package and mounts each semiconductor package  217  over the mounting board  201  by the above-mentioned technique and the system  200  is thereby formed. 
     Second Embodiment 
     Description will be given to the second embodiment.  FIG. 7  illustrates a system  700  in the second embodiment of the invention disclosed in this specification. It is different from the first embodiment in that: multiple semiconductor packages, that is, a first semiconductor package  718  and a second semiconductor package  719  are stacked over a mounting board  701 ; the second semiconductor package  719  has an antenna  717  and though not shown in the drawing, the first semiconductor package also has the same antenna as the antenna  717 . Hereafter, concrete description will be given to the configuration of the system  700 . Portions overlapping with the content of the description of the first embodiment will be omitted as appropriate. 
     As in the first embodiment, the mounting board  701  is provided with a coil  703 , which is supplied with alternating-current voltage from an alternating-current voltage source  702 . As in the first embodiment, further, holes  711  and  712  are formed. 
     Over the mounting board  701 , the first semiconductor package  718  is formed. The first semiconductor package  718  includes a package board  704 . This package board  704  has a coil  705  formed therein as in the first embodiment and though not shown in the drawing, a pellet that operates with power supplied is also provided over the package board. Though not shown in the drawing, constituent elements, such as a bonding wire, required for electrical coupling between the pellet and the coil  705  are also provided in the package board  704 . Unlike the first embodiment, however, the same antenna as the above-mentioned antenna  717  is provided over the package board  704  and this antenna is coupled to the circuit included in the pellet formed in the package board  704 . This antenna wirelessly radiates and transmits signals from the pellet and outputs received signals to the circuit included in the pellet. This antenna is, for example, a planar spiral antenna formed of a wiring extended over the package board  704 . A protection member  706  sealing the pellet and the antenna is provided over the package board  704 . As in the first embodiment, holes  713  and  714  are formed and the holes  713  and  714  connect with the holes  711  and  712  as the result of alignment; therefore, holes penetrating the protection member  706 , package board  704 , and mounting board  701  are formed. As in the first embodiment  1 , the hole  713  is divided into a first hole penetrating the protection member and a second hole surrounded with a wiring forming the coil  705  and penetrating the package board  704 . Similarly, the hole  714  is also divided into two holes. 
     Over the protection member  706  included in the first semiconductor package  718 , the package board  707  included in the second semiconductor package  719  is provided. The package board  707  is also provided with a coil  708  similarly with the package board  704  of the first semiconductor package  718 . This coil  708  is coupled to a pellet  710  provided over the package board  707 . As a result, the circuit formed in the pellet  710  and the coil  708  are electrically coupled together. Unlike the first embodiment, the antenna  717  is provided over the package board  707 . This antenna  717  is coupled to the circuit included in the pellet  710  formed in the package board  707 . This antenna  717  wirelessly radiates and transmits signals form the pellet  710  and outputs received signals to the circuit included in the pellet  710 . This antenna  717  is, for example, a planar spiral antenna formed of a wiring extended over the package board  707 . A protection member  709  sealing the pellet  710  and the antenna  717  is provided over the package board  707 . As in the first embodiment, holes  715  and  716  are formed and the holes  715  and  716  connect with the holes  713  and  714  by alignment. As a result, the holes  715  and  716  also connect with the holes  711  and  712  in the mounting board  701 . Therefore, one can argue that holes penetrating the protection member  709 , package board  707 , protection member  706 , package board  704 , and mounting board  701  are formed. As in the first embodiment, the hole  715  is divided into two holes, a hole penetrating the protection member  709  and a hole surrounded with a wiring forming the coil  708  and penetrating the package board  707 . The hole  716  is also divided into a hole penetrating the protection member  709  and a hole penetrating the package board  707 . 
     As in the first embodiment, a fixing member, for example, a magnetic material  720  is passed through the holes  711  and  712 ,  713  and  714 , and  715  and  716 ; and the first semiconductor package  718  and the second semiconductor package  719  are mounted over the mounting board  701 . When a magnetic material is adopted as the fixing member, the magnetic material  720  is, for example, a ferrite core as in the first embodiment. 
     In the second embodiment, the first semiconductor package  718  and the second semiconductor package  719  are used to implement the system  700 . For this reason, it is required to electrically couple together the circuit included in the pellet of the first semiconductor package  718  and the circuit included in the pellet  710  of the second semiconductor package  719 . This is because: when this electrical coupling is achieved, electrical signals can be communicated between the circuit included in the pellet of the first semiconductor package  718  and the circuit included in the pellet  710  of the second semiconductor package  719 ; and thus a system for achieving desired functions is built. 
     In the second embodiment, consequently, the circuit included in the pellet of the first semiconductor package  718  and the circuit included in the pellet  710  of the second semiconductor package  719  are electrically coupled together by taking the following measure: the antenna provided in the first semiconductor package  718  and the antenna  717  provided in the second semiconductor package are caused to wirelessly communicate with each other. More specific description will be given. The antenna provided in the first semiconductor package  718  radiates signals from the circuit included in the pellet provided in the first semiconductor package  718  and transmits them to the antenna  717  of the second semiconductor package  719 . The antenna  717  receives signals from the antenna provided in the first semiconductor package  718  and outputs the received signals to the circuit included in the pellet  710 . 
     Similarly, the antenna  717  receives and radiates signals from the circuit included in the pellet  710  and outputs them to the antenna provided in the first semiconductor package  718 . The antenna outputs the signals received from the antenna  717  to the circuit included in the pellet provided in the first semiconductor package  718 . 
     Thus signals are communicated between the first semiconductor package  718  and the second semiconductor package  719 . Since signals are wirelessly communicated between the antennas, it is required that the signals outputted from these antennas should have a frequency with which wireless communication is enabled. For example, the signals are required to have a frequency of 2 GHz or so, which is used in wireless LAN, Bluetooth, and the like. Non-patent Document 2 mentioned above describes that spiral antennas 240 μm square can carry out wireless communication within a range of up to 120 μm using a frequency of 1.2 GHz or so. Consequently, consideration will be given to the following based on the thickness of each member forming recent semiconductor packages: the size of each of the antenna  717  in the system  700  illustrated in  FIG. 7  and the antenna included in the first semiconductor package  718 . 
     In  FIG. 7 , the thickness of each of the package board  704  and the package board  707  is, for example, 300 μm. The thickness of each of the pellet included in the first semiconductor package  718  and the pellet  710  included in the second semiconductor package  719  is 120 μm. The thickness of each of the protection member  706  and the protection member  709  is 200 μm. The antenna included in the first semiconductor package  718  is formed over the package board  704  and the antenna  717  included in the second semiconductor package  719  is formed over the package board  707 . Thus the distance between these antennas is shortest when they are vertically opposed to each other and the shortest distance is 500 μm, which is the sum of the thickness of the protection member  706  and the thickness of the package board  707 . As mentioned above, Non-patent Document 1 discloses that spiral antennas 240 μm square can carry out wireless communication within a range of up to 120 μm using a frequency of 1.2 GHz or so. In consideration of this, wireless communication can be carried out when each of the antenna included in the first semiconductor package  718  and the antenna  717  included in the second semiconductor package  719  is a spiral antenna approximately 1000 μm square. 
     When these antennas are not so arranged that they are vertically opposed to each other, the distance between the antennas is increased and thus it is required to increase the size of each antenna. As described in relation to the first embodiment, however, the package boards  704 ,  707  and the protection members  706 ,  709  are each 10 mm in longitudinal length and in horizontal length. Therefore, it is supposed that increase in the size of the spiral antenna provided in each semiconductor package can be sufficiently coped with. Therefore, one can argue that this embodiment can be technically implemented. 
       FIG. 7  illustrates an example in which the two semiconductor packages are stacked and mounted over the mounting board  701 . However, the number of the semiconductor packages stacked over the mounting board  701  may be greater than two. For example, a third semiconductor package may be additionally stacked over the second semiconductor package  719  in  FIG. 7 . In this case, a flat spiral antenna is also provided over the package board of the third semiconductor package. The antenna included in the third semiconductor package wirelessly communicates with the antenna included in the first semiconductor package  718  and the antenna  717  included in the second semiconductor package  719 . However, when the antenna included in the third semiconductor package and the antenna included in the first semiconductor package are caused to wirelessly communicate with each other, the distance between the two antennas is increased. For this reason, there is a possibility that direct wireless communication cannot be carried out between the two antennas depending of the size of these antennas. In this case, for example, the following measure can be taken: signals are once transmitted to the antenna  717  included in the second semiconductor package  719  and their intensity is amplified at the amplifier circuit provided in the second semiconductor package  719 ; and then the signals are transmitted from the antenna provided in the second semiconductor package  719  to the antenna included in the first semiconductor package  718 . 
     Third Embodiment 
       FIG. 8  illustrates the configuration of a system  800  in the third embodiment. Hereafter, the description of constituent elements overlapping with the above description will be omitted.  FIG. 8  is a top view of the system  800 . In the example in  FIG. 8 , multiple semiconductor packages are mounted over a mounting board  801 . In this top view, the respective semiconductor packages are indicated by a protection member  802 , a protection member  806 , and a protection member  810 . In the third embodiment, as seen from  FIG. 8 , the multiple semiconductor packages are mounted over the plane of one main surface of the mounting board  801  unlike the second embodiment. Similarly with the protection member  709  in the second embodiment, the protection member  802  protects a pellet and the like provided over a package board though they are not shown in the drawing. A hole  803  and a hole  804  are formed in the upper surface of the protection member  802  and penetrate the protection member  802  and the package board, not shown. In the mounting board  801 , holes penetrating the mounting board  801  are provided in positions corresponding to the hole  803  and the hole  804 . The semiconductor package including the protection member  802  is fixed over the mounting board  801  by a fixing member  805  passed through these holes. 
     Similarly with the protection member  709  in the second embodiment, the protection member  806  also protects a pellet and the like provided over a package board though they are not shown in the drawing. In the example in  FIG. 8 , therefore, a hole  808  and a hole  809  are formed in the upper surface of the protection member  806  and penetrate the protection member  806  and the package board, not shown. In the mounting board  801 , holes penetrating the mounting board  801  are provided in positions corresponding to the hole  808  and the hole  809 . The semiconductor package including the protection member  806  is fixed over the mounting board  801  by a fixing member  807  passed through these holes. 
     In the package boards corresponding to the protection member  802  and the protection member  806 , antennas different in shape from those in the second embodiment are provided. More specific description will be given. In the third embodiment, such antennas  901  and  902  as illustrated in  FIG. 9  are provided. In  FIG. 9 , the holes  808 ,  809  of the semiconductor package including the protection member  806  and the fixing member  807  are omitted. In actuality, however, the semiconductor package including the protection member  806  has the holes  808  and  809  formed therein and is provided with the fixing member  807  as illustrated in  FIG. 8 . In this case, similarly with the embodiments described up to this point, the semiconductor package including the protection member  806  is provided in its package board with a coil. This coil is so provided that it surrounds the fixing member  807  passed through the hole  808  and the hole  809 . Also in the mounting board, there is provided a separate coil coupled with a power supply IC and the fixing member  807  is surrounded with this separate coil provided in the mounting board. Similarly with the embodiments described up to this point, power is supplied to the circuit included in the pellet of the semiconductor package including the protection member  806 . The power is supplied through the coil provided in the package board of the semiconductor package including the protection member  806 . With respect to the fixing members, the fixing member  805  may form a closed loop or an open loop integrally with the fixing member  807 . This makes it unnecessary to provide a separate coil coupled with the power supply IC in the mounting board. 
     In the example in  FIG. 9 , the semiconductor package including the protection member  802  has the antenna  901 . The semiconductor package including the protection member  806  has the antenna  902 . In the second embodiment, the antennas for electrically coupling the respective semiconductor packages are formed as flat spiral antenna over the package boards included in the respective semiconductor packages. In the third embodiment, meanwhile, the individual semiconductor packages are mounted over the plane of the mounting board  801 ; therefore, the shape of each antenna is different from that in the second embodiment. More specific description will be given. It is required to communicate signals between the semiconductor package including the protection member  802  and the semiconductor package including the protection member  806 . Therefore, the spiral shape of the antenna  901  and the spiral shape of the antenna  902  are opposed to each other. For this reason, each of the antennas  901 ,  902  is not formed only of a wiring extended over the package board included in the relevant semiconductor package. They are formed also using wirings extended in wiring layers in the package boards included in the respective semiconductor packages. When the antenna  901  and the antenna  902  are formed as mentioned above, it is possible to effectively increase the range within which communication can be carried out between antennas and wireless communication between the antennas  901  and  902  is enabled. Therefore, it is possible to communicate signals between the semiconductor package including the protection member  802  and the semiconductor package including the protection member  806 . The invention disclosed in this specification can be hence implemented even when the two semiconductor packages are mounted over the plane of the one main surface of the mounting board  801 . 
     With reference to  FIG. 8  again, the semiconductor package mounted over the mounting board  801  and including the protection member  810  is not provided with a hole or a fixing member. This is based on the assumption that the semiconductor package including the protection member  810  is a semiconductor package equivalent to a conventional technology in which the invention disclosed in this specification is not implemented. One example of possible cases is that the semiconductor package including the protection member  810  is a semiconductor package from a competitor to which the invention disclosed in this specification is not applied. To operate the system  800 , even in this case, it is required to communicate signals between the semiconductor package including the protection member  802  and the semiconductor package including the protection member  810 . This is because the system  800  is operated when the circuits respectively included in the semiconductor packages mounted over the mounting board  801  communicate signals therebetween. 
     The semiconductor package including the protection member  810  is mounted over the mounting board  801  using solder balls as illustrated in  FIG. 1 . Thus the technique illustrated in  FIG. 9  cannot be adopted for implementing the following: the semiconductor package including the protection member  802  and the semiconductor package including the protection member  806  are wirelessly electrically coupled together using the antenna  901  and the antenna  902 . 
     In this case, consequently, the following measure can be taken: signals outputted by the semiconductor package including the protection member  802  using the antenna are received by a spiral antenna provided in the mounting board  801 ; and these received signals are transmitted to the semiconductor package including the protection member  810  by a route by way of a solder ball. More specific description will be given. Though not shown in the drawing, the mounting board  801  is provided with the spiral antenna in such a shape as that of the coil  703  in  FIG. 7 . Over the package board of the semiconductor package including the protection member  802 , there is provided a spiral antenna in such a shape as that of the antenna  717  in  FIG. 7 . The spiral shape of this spiral antenna provided in the mounting board  801  and the spiral shape of this spiral antenna provided in the semiconductor package including protection member  802  like the antenna  717  in  FIG. 7  are opposed to each other. This configuration makes it possible to transmit signals outputted by the semiconductor package including the protection member  802  to the semiconductor package including the protection member  810  after they are received at the mounting board  801 . 
     This is the same with the electrical coupling between the semiconductor package including the protection member  806  and the semiconductor package including the protection member  810 . However, it is unnecessary to purposely separately provide the mounting board  801  with a spiral antenna corresponding to the semiconductor package including the protection member  806  in the following cases: cases where the antenna provided in the mounting board  801  and receiving signals from the semiconductor package including the protection member  802  and the semiconductor package including the protection member  806  can communicate with each other in terms of distance. 
     Up to this point, description has been given to embodiments of the invention. However, other modifications those skilled in the art can conceive are also included in these embodiments. The scope of right of the invention is determined by “What is claimed is” and should not be construed as limited to the description of the embodiments.