Abstract:
A semiconductor integrated circuit device according to the present invention comprises, a semiconductor chip formed with a semiconductor integrated circuit, at least one pair of previous-stage power supply terminals provided on the semiconductor chip and connected to a power supply line, a plurality of pairs of subsequent-stage power supply terminals provided on the semiconductor chip and connected to the power supply line connected commonly to the at least one pair of previous-stage power supply terminals, at least one previous-stage line providing a connection between the at least one pair of previous-stage power supply terminals, and subsequent-stage lines equal in number to the plurality of pairs of subsequent-stage power supply terminals and each providing a connection between the corresponding one of the plurality of pairs of subsequent-stage power supply terminals, wherein the at least one pair of previous-stage power supply terminals and the plurality of pairs of subsequent-stage power supply terminals are connected to each other to form a closed circuit when they are mounted on a mounting board.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to a semiconductor integrated circuit device and to a mounting board. More particularly, it relates to a semiconductor integrated circuit device with improved reliability. 
   A mounting board for mounting thereon a semiconductor integrated circuit device having a plurality of power supply terminals and a plurality of signal terminals is used to supply a power supply voltage to the semiconductor integrated circuit device and perform signal input/output operations between the semiconductor integrated circuit device and the outside. Referring to the drawings, a conventional mounting board for mounting thereon a semiconductor integrated circuit device having a plurality of power supply terminals and a plurality of signal terminals will be described herein below. 
     FIG. 4  shows a structure of the conventional mounting board for mounting thereon the semiconductor integrated circuit device. 
   As shown in  FIG. 4 , a semiconductor integrated circuit device  2400  is mounted on a mounting board  2000  composed of a first-layer sub-board  2100  and a second-layer sub-board  2600 . The first-layer sub-board  2100  is disposed on the second-layer sub-board  2600 . 
   The semiconductor integrated circuit device  2400  comprises: signal terminal cells  2431  to  2446  formed on the semiconductor integrated circuit device; and power supply terminal cells  2451  to  2453 ,  2461  to  2463 ,  2471  to  2473 , and  2481  to  2483  formed on the individual edge portion portions of the semiconductor integrated circuit device. 
   The signal terminal cells  2431  to  2446  are formed with respective signal terminal electrodes  2331  to  2346  for performing signal input/output operations between the semiconductor integrated circuit device  2400  and the outside. 
   The power supply terminal cells  2451  to  2453 ,  2461  to  2463 ,  2471  to  2473 , and  2481  to  2483  are formed with respective power supply electrodes  2351  to  2353 ,  2361  to  2363 ,  2371  to  2373 , and  2381  to  2383  for supplying the power supply voltage to the inside of the semiconductor integrated circuit device  2400 . 
   The sub-board  2100  is provided with: input/output terminals  2101  to  2116 ; power supply terminals  2121  to  2123 ; signal lines  2201  to  2216 ; power supply lines  2251  to  2253 ; and power supply lines  2261  to  2263 ,  2271  to  2273 , and  2281  to  2283 . The input/output terminals  2101  to  2116  and the signal terminal electrodes  2331  to  2346  placed on the semiconductor integrated circuit device  2400  are connected to each other by the signal lines  2201  to  2216 . 
   The power supply terminals  2121  to  2123  and the power supply electrodes  2351  to  2353  provided in the semiconductor integrated circuit device  2400  are connected to each other by the power supply lines  2251  to  2253 . Between the power supply terminals  2121  to  2123  and the power supply electrodes  2351  to  2353 , the power supply lines  2251  to  2253  are branched to be connected also to contact lines  2651  to  2653 , respectively. 
   The electrodes  2361  to  2363 ,  2371  to  2373 , and  2381  to  2383  on the semiconductor integrated circuit device  2400  are connected to contact lines  2661  to  2663 ,  2671  to  2673 , and  2681  to  2683  by the power supply lines  2261  to  2263 ,  2271  to  2273 , and  2281  to  2283 , respectively. 
   The sub-board  2600  comprises power supply lines  2601  to  2603 . The power supply line  2601  is connected to the power supply lines  2251 ,  2261 ,  2271 , and  2281  on the sub-board  2100  via the contact lines  2651 ,  2661 ,  2671 , and  2681 , respectively. 
   Likewise, the power supply line  2602  is connected to the power supply lines  2252 ,  2262 ,  2272 , and  2282  on the sub-board  2100  via the contact lines  2652 ,  2662 ,  2672 , and  2682 , respectively. 
   The power supply line  2603  is also connected to the power supply lines  2253 ,  2263 ,  2273 , and  2283  on the sub-board  2100  via the contact lines  2653 ,  2663 ,  2673 , and  2683 , respectively. 
   A description will be given to the operation of the mounting board  2000  thus constructed. 
   If signals are inputted from the signal terminals  2101  to  2116 , the signals are inputted to the electrodes  2331  to  2346  of the semiconductor integrated circuit device  2400  through the signal lines  2201  to  2216  formed on the sub-board  2100 , respectively. Conversely, signals outputted from the semiconductor integrated circuit device  2400  are outputted from the electrodes  2331  to  2346  to the signal terminals  2101  to  2116  through the signal lines  2201  to  2216 . In short, the signals are outputted by a route absolutely opposite to the route for the input signals. 
   A description will be given next to the supply of the power supply voltage. 
   The power supply voltage supplied from the power supply terminal  2121  is supplied to the electrode  2351  of the semiconductor integrated circuit device  2400  through the line  2251  formed on the sub-board  2100 . Subsequently, the power supply voltage is supplied to the inside of the semiconductor integrated circuit device  2400  via the power supply terminal cell  2451 . At the same time, the power supply voltage supplied from the power supply terminal  2121  is supplied to the power supply electrodes  2361 ,  2371 , and  2381  successively through the power supply line  2251  formed on the sub-board  2100 , the contact line  2651 , the power supply line  2601  formed on the sub-board  2600 , and the contact lines  2661 ,  2671 , and  2681 . Subsequently, the power supply voltage is supplied to the inside of the semiconductor integrated circuit device  2400  via the power supply terminal cells  2461 ,  2471 , and  2481 . 
   The power supply voltage supplied from the power supply terminal  2122  is supplied to the electrode  2352  of the semiconductor integrated circuit device  2400  through the line  2252  formed on the sub-board  2100 . Subsequently, the power supply voltage is supplied to the inside of the semiconductor integrated circuit device  2400  via the power supply terminal cell  2452 . At the same time, the power supply voltage supplied from the power supply terminal  2122  is supplied to the power supply electrodes  2362 ,  2372 , and  2382  successively through the power supply line  2252  formed on the sub-board  2100 , the contact line  2652 , the power supply line  2602  formed on the sub-board  2600 , and the contact lines  2662 ,  2672 , and  2682 . Subsequently, the power supply voltage is supplied to the inside of the semiconductor integrated circuit device  2400  via the power supply terminal cells  2462 ,  2472 , and  2482 . 
   The power supply voltage supplied from the power supply terminal  2123  is supplied to the electrode  2353  of the semiconductor integrated circuit device  2400  through the line  2253  formed on the sub-board  2100 . Subsequently, the power supply voltage is supplied to the inside of the semiconductor integrated circuit device  2400  via the power supply terminal cell  2453 . At the same time, the power supply voltage supplied from the power supply terminal  2123  is supplied to the power supply electrodes  2363 ,  2373 , and  2383  successively through the power supply line  2253  formed on the sub-board  2100 , the contact line  2653 , the power supply line  2603  formed on the sub-board  2600 , and the contact lines  2663 ,  2673 , and  2683 . Subsequently, the power supply voltage is supplied to the inside of the semiconductor integrated circuit device  2400  via the power supply terminal cells  2463 ,  2473 , and  2483 . 
   The foregoing conventional structure using the two-layer mounting board composed of the two sub-boards has the problem of increased fabrication cost for the mounting board. 
   To solve the problem, a method may be adopted which provides the semiconductor integrated circuit device  2400  with, e.g., only the power supply terminal cells  2451  to  2453  of the power supply terminals cells that have been provided conventionally on the four edge portions and supplies the power supply voltage to the entire semiconductor integrated circuit device  2400  from the inside thereof. If the power supply voltage is supplied to the entire semiconductor integrated circuit device  2400  from the inside thereof, however, there are cases where the semiconductor integrated circuit device  2400  does not operate normally due to a voltage drop or the like which prevents a sufficient current from being supplied to an end of the circuit. This leads to the conclusion that, since a current supplying ability which tends to be insufficient may cause the malfunctioning of the semiconductor integrated circuit device  2400 , the foregoing method is impractical. 
   SUMMARY OF THE INVENTION 
   The present invention has been achieved to solve the foregoing problems and it is therefore an object of the present invention to provide a mounting board which is low in fabrication cost and a semiconductor integrated circuit device to be mounted on the mounting board. 
   A semiconductor integrated circuit device according to the present invention comprises: a semiconductor chip formed with a semiconductor integrated circuit; at least one pair of previous-stage power supply terminals provided on the semiconductor chip and connected to a power supply line; a plurality of pairs of subsequent-stage power supply terminals provided on the semiconductor chip and connected to the power supply line connected commonly to the at least one pair of previous-stage power supply terminals; at least one previous-stage line providing a connection between the at least one pair of previous-stage power supply terminals; and subsequent-stage lines equal in number to the plurality of pairs of subsequent-stage power supply terminals and each providing a connection between the corresponding one of the plurality of pairs of subsequent-stage power supply terminals, the at least one pair of previous-stage power supply terminals and the plurality of pairs of subsequent-stage power supply terminals being connected to each other to form a closed circuit when they are mounted on a mounting board. 
   According to the present invention, the at least one pair of previous-stage power supply terminals and the plurality of pairs of subsequent-stage power supply terminals form the closed circuit when they are mounted on the mounting board. In the semiconductor integrated circuit device, therefore, the power supply terminals forming each of the pairs are at equal potentials. Consequently, a sufficient power supply voltage is supplied from each of the pairs of power supply terminals to the entire semiconductor integrated circuit device. 
   Preferably, each of the previous-stage and subsequent-stage lines is composed of a material lower in electric resistance than a material composing the pairs of previous-stage and subsequent-stage power supply terminals. 
   This minimizes a voltage drop in at least one of the previous-stage and subsequent-stage lines. 
   The semiconductor integrated circuit device may further comprise: a previous-stage center power supply terminal disposed between the at least one pair of previous-stage power supply terminals and connected to a power supply line other than the foregoing power supply line; and a plurality of subsequent-stage center power supply terminals each disposed between the corresponding one of the plurality of pairs of subsequent-stage power supply terminals and connected to the power supply line connected commonly to the previous-stage center power supply terminal, the previous-stage center power supply terminal and the plurality of subsequent-stage center power supply terminals being connected to each other when they are mounted on the mounting board. 
   Preferably, the pairs of previous-stage and subsequent-stage power supply terminals are positioned such that respective minimum distances are provided between the at least one pair of previous-stage power supply terminals and between each of the plurality of pairs of subsequent-stage power supply terminals. 
   This minimizes a voltage drop in at least one of the lines providing connections between the previous-stage power supply terminals and between the subsequent-stage power supply terminals when the semiconductor integrated circuit device is mounted on the mounting board. 
   The previous-stage center power supply terminal may be connected to a first power supply line, the at least one pair of previous-stage power supply terminals may be composed of a plurality of second to N-th pairs connected to second to N-th power supply lines, and the plurality of pairs of subsequent-stage power supply terminals may be composed of a plurality of second to N-th pairs connected to the second to N-th power supply lines. 
   The semiconductor integrated circuit device may further comprise: at least one signal terminal provided eternally of the at least one pair of previous-stage power supply terminals or the plurality of pairs of subsequent-stage power supply terminals. 
   The arrangement achieves separation between a region provided with the signal lines and a region provided with the power supply lines in the semiconductor integrated circuit device and thereby suppresses the degradation of signals and the power supply voltage induced by noise. 
   A mounting board according to the present invention comprises: a board having a mounting region for mounting thereon a semiconductor integrated circuit device; at least one pair of previous-stage power supply input electrodes disposed within the mounting region and connected to a power supply line; a plurality of pairs of subsequent-stage power supply input electrodes disposed within the mounting region and connected to the power supply line connected commonly to the at least one pair of previous-stage power supply input electrodes; and a line for connecting the at least one pair of previous-stage power supply input electrodes and the plurality of pairs of subsequent-stage power supply input electrodes to each other, the at least one pair of previous-stage power supply input electrodes and the plurality of pairs of subsequent-stage power supply input electrodes being connected to each other to form a closed circuit with the semiconductor integrated circuit device being mounted on the mounting region. 
   According to the present invention, the at least one pair of previous-stage input electrodes and the plurality of pairs of subsequent-stage power supply terminals form the closed circuit when the semiconductor integrated circuit device is mounted on the mounting board. In the semiconductor integrated circuit device, therefore, power supply terminals in each of pairs connected to the at least one pair of previous-stage power supply input electrodes and to the plurality of pairs of subsequent-stage power supply input electrodes are at equal potentials. What results is a mounting board capable of supplying a sufficient power supply voltage to the entire semiconductor integrated circuit device. 
   The mounting board may further comprise: a previous-stage center power supply input electrode disposed between the at least one pair of previous-stage power supply input electrodes and connected to a power supply line other than the foregoing power supply line; a plurality of subsequent-stage center input electrodes each disposed between the corresponding one of the plurality of pairs of subsequent-stage power source input electrodes and connected to the power supply line connected commonly to the previous-stage center power supply input electrode; and a line connecting the previous-stage center power supply input electrode and the subsequent-stage center power supply input electrodes to each other. 
   The previous-stage center power supply input electrode may be connected to a first power supply line, the at least one pair of previous-stage power supply input electrodes may be composed of a plurality of second to N-th pairs connected to second to N-th power supply lines, and the plurality of pairs of subsequent-stage power supply input electrodes may be composed of a plurality of second to N-th pairs connected to the second to N-th power supply lines. 
   A device and board assembly according to the present invention comprises: a semiconductor integrated circuit device comprising a semiconductor chip formed with a semiconductor integrated circuit, at least one pair of previous-stage power supply terminals provided on the semiconductor chip and connected to a power supply line, a plurality of pairs of subsequent-stage power supply terminals provided on the semiconductor chip and connected to the power supply line connected commonly to the at least one pair of previous-stage power supply terminals, at least one previous-stage line providing a connection between the at least one pair of previous-stage power supply terminals, and subsequent-stage lines equal in number to the plurality of pairs of subsequent-stage power supply terminals and each providing a connection between the corresponding one of the plurality of pairs of subsequent-stage power supply terminals; and a mounting board comprising a board having a mounting region for mounting thereon a semiconductor integrated circuit device, at least one pair of previous-stage power supply input electrodes disposed within the mounting region and connected to the at least one pair of previous-stage power supply terminals, a plurality of pairs of subsequent-stage power supply input electrodes disposed within the mounting region and connected to the plurality of respective pairs of subsequent-stage power supply terminals, and a line for connecting the at least one pair of previous-stage power supply input electrodes and the plurality of pairs of subsequent-stage power supply input electrodes to each other, the semiconductor integrated circuit device being mounted on the mounting region. 
   According to the present invention, the at least one pair of previous-stage power supply input electrodes and the plurality of pairs of subsequent-stage power supply input electrodes form a closed circuit when the semiconductor integrated circuit device is mounted on the mounting board. In the semiconductor integrated circuit device, therefore, the power supply terminals in each of the pairs connected to the at least one pair of previous-stage power supply input electrodes and to the plurality of pairs of subsequent-stage power supply input electrodes are at equal potentials. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a mounting board according to an embodiment of the present invention; 
       FIG. 2  shows a semiconductor integrated circuit device according to the embodiment of the present invention; 
       FIG. 3  shows a structure obtained when the semiconductor integrated circuit device of  FIG. 2  is mounted on the mounting board of  FIG. 1  in the present embodiment; and 
       FIG. 4  shows a structure of a conventional mounting board for mounting thereon a semiconductor integrated circuit device. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to the drawings, an embodiment of the present invention will be described. 
     FIG. 1  shows a mounting board according to the embodiment of the present invention.  FIG. 2  shows a semiconductor integrated circuit device according to the present embodiment.  FIG. 3  shows a structure obtained when the semiconductor integrated circuit device of  FIG. 2  is mounted on the mounting board of  FIG. 1  in the present embodiment. 
   As shown in  FIG. 1 , a mounting board  100  comprises: a board  100   a  having a rectangular mounting region M for mounting thereon an IC device; signal terminals  101  to  116  provided on the individual edge portions of the board  100   a ; power supply terminals  121  to  124  also provided on the individual edge portions of the board  100   a ; electrodes  131  to  146 ,  151 ,  152   a ,  152   b ,  153   a ,  153   b ,  154   a ,  154   b ,  161 ,  162   a ,  162   b ,  163   a ,  163   b ,  164   a ,  164   b ,  171 ,  172   a ,  172   b ,  173   a ,  173   b ,  174   a ,  174   b ,  181 ,  182   a ,  182   b ,  183   a ,  183   b ,  184   a , and  184   b  provided on the individual edge portions of the mounting region M for connection with the IC device; signal lines  201  to  216 ; and power supply lines  221  to  224 ,  251  to  254 ,  262  to  264 ,  272  to  274 , and  282  to  284 . 
   Each of the signal terminals  101  to  116 , the power supply terminals  121  to  124 , the electrodes  131  to  146 ,  151 ,  152   a ,  152   b ,  153   a ,  153   b ,  154   a ,  154   b ,  161 ,  162   a ,  162   b ,  163   a ,  163   b ,  164   a ,  164   b ,  171 ,  172   a ,  172   b ,  173   a ,  173   b ,  174   a ,  174   b ,  181 ,  182   a ,  183   a ,  183   b ,  184   a , and  184   b  for connection with the semiconductor integrated circuit device, the signal lines  201  to  216 , the power supply lines  221  to  224 ,  251  to  254 ,  262  to  264 ,  272  to  274 , and  282  to  284  is provided on the board  100   a.    
   The power supply terminals  121  to  124  are connected to the electrodes  151 ,  152   b ,  153   b , and  154   b  by the power supply lines  221  to  224 , respectively. 
   The electrode  151  is connected to each of the electrodes  161 ,  171 , and  181  by the power supply line  251 . 
   The electrodes  152   a ,  153   a , and  154   a  are connected to the electrodes  182   b ,  183   b , and  184   b  by the power supply lines  252 ,  253 , and  254 , respectively. 
   The electrodes  152   b ,  153   b , and  154   b  are connected to the electrodes  162   a ,  163   a , and  164   a  by the power supply lines  262 ,  263 , and  264 , respectively. 
   The electrodes  162   b ,  163   b , and  164   b  are connected to the electrodes  172   a ,  173   a , and  174   a  by the power supply lines  272 ,  273 , and  274 , respectively. 
   The electrodes  172   b ,  173   b , and  174   b  are connected to the electrodes  182   a ,  183   a , and  184   a  by the power supply lines  282 ,  283 , and  284 , respectively. 
   A description will be given next to a semiconductor integrated circuit device (hereinafter referred to as the IC device)  400  used in the present embodiment. 
   As shown in  FIG. 2 , the IC device  400  comprises: signal terminal cells  431  to  446  provided on the individual edge portions thereof; power supply terminal cells  451 ,  452   a ,  452   b ,  453   a ,  453   b ,  454   a ,  454   b ,  461 ,  462   a ,  462   b ,  463   a ,  463   b ,  464   a ,  464   b ,  471 ,  472   a ,  472   b ,  473   a ,  473   b ,  474   a ,  474   b ,  481 ,  482   a ,  482   b ,  483   a ,  483   b ,  484   a , and  484   b  also provided on the individual edge portions; and metal lines  552  to  554 ,  562  to  564 ,  572  to  574 , and  582  to  584 . 
   The signal terminal cells  431  to  446  are provided with respective electrodes  331  to  346  for providing a connection between the inside and outside of the IC device  400 . 
   The power supply terminal cells  451 ,  452   a ,  452   b ,  453   a ,  453   b ,  454   a ,  454   b ,  461 ,  462   a ,  462   b ,  463   a ,  463   b ,  464   a ,  464   b ,  471 ,  472   a ,  472   b ,  473   a ,  473   b ,  474   a ,  474   b ,  481 ,  482   a ,  482   b ,  483   a ,  483   b ,  484   a , and  484   b  are provided with respective electrodes  351 ,  352   a ,  352   b ,  353   a ,  353   b ,  354   a ,  354   b ,  361 ,  362   a ,  362   b ,  363   a ,  363   b ,  364   a ,  364   b ,  371 ,  372   a ,  372   b ,  373   a ,  373   b ,  374   a ,  374   b ,  381 ,  382   a ,  382   b ,  383   a ,  383   b ,  384   a , and  384   b  for providing a connection between the inside and outside of the IC device  400 . 
   The metal lines  552  to  554  provide connections between the power supply terminal cells  352   a  and  352   b , the power supply terminal cells  353   a  and  353   b , and the power supply terminal cells  354   a  and  354   b , respectively. 
   The metal lines  562  to  564  provide connections between the power supply terminal cells  362   a  and  362   b , the power supply terminal cells  363   a  and  363   b , and the power supply terminal cells  364   a , and  364   b , respectively. 
   The metal lines  572  to  574  provide connections between the power supply terminal cells  372   a  and  372   b , the power supply terminal cells  373   a  and  373   b , and the power supply terminal cells  374   a  and  374   b , respectively. 
   The metal lines  582  to  584  provide connections between the power supply terminal cells  382   a  and  382   b , the power supply terminal cells  383   a  and  383   b , and the power supply terminal cells  384   a  and  384   b , respectively. 
   A description will be given next to a device and board assembly  600  composed of the IC device  400  mounted on the mounting region M of the mounting board  100  with reference to FIG.  3 . 
   In the device and board assembly  600  composed of the IC device  400  mounted on the mounting board  100 , the electrode  331  is connected to the electrode  131  on the mounting board  100 , as shown in FIG.  3 . Likewise, the electrodes  332 ,  333 ,  334 ,  335 ,  336 ,  337 ,  338 , and  339  are connected to the electrodes  132 ,  133 ,  134 ,  135 ,  136 ,  137 ,  138 , and  139 , respectively. The electrodes  340 ,  341 ,  342 ,  343 ,  344 ,  345 , and  346  are connected to the electrodes  140 ,  141 ,  142 ,  143 ,  144 ,  145 , and  146 , respectively. The electrodes  351 ,  352   a ,  352   b ,  353   a ,  353   b ,  354   a , and  354   b  are connected to the electrodes  151 ,  152   a ,  152   b ,  153   a ,  153   b ,  154   a , and  154   b , respectively. The electrodes  361 ,  362   a ,  362   b ,  363   a ,  363   b ,  364   a , and  364   b  are connected to the electrodes  161 ,  162   a ,  162   b ,  163   a ,  163   b ,  164   a , and  164   b , respectively. The electrodes  371 ,  372   a ,  372   b ,  373   a ,  373   b ,  374   a , and  374   b  are connected to the electrodes  171 ,  172   a ,  172   b ,  173   a ,  173   b ,  174   a , and  174   b , respectively. The electrodes  381 ,  382   a ,  382   b ,  383   a ,  383   b ,  384   a , and  384   b  are connected to the electrodes  181 ,  182   a ,  182   b ,  183   a ,  183   b ,  184   a , and  184   b , respectively. 
   The operation of the device and board assembly  600  thus constructed according to the present embodiment will be described with reference to  FIGS. 1  to  3 . 
   If the power supply voltage is applied to the power supply terminal  121  provided on the mounting board  100 , the power supply voltage is supplied to the electrodes  151 ,  161 ,  171 , and  181  disposed on the mounting board  100  through the power supply line  221  formed on the mounting board  100 . Then, the power supply voltage is supplied from the electrodes  151 ,  161 ,  171 , and  181  to the electrodes  351 ,  361 ,  371 , and  381  provided on the power supply terminal cells  451 ,  461 ,  471 , and  481  of the IC device  400 , respectively, whereby the power supply voltage is supplied to the inside of the IC device  400 . 
   The power supply voltage applied to the power supply terminals  122 ,  123 , and  124  is supplied to the electrodes  152   b ,  153   b , and  154   b  disposed on the mounting board  100  and to the electrodes  162   a ,  163   a , and  164   a  also disposed on the mounting board  100  through the power supply lines  222 ,  223 , and  224 , respectively. 
   Subsequently, the power supply voltage is supplied from the electrodes  152   b ,  153   b , and  154   b  to the electrodes  352   b ,  353   b , and  354   b  provided on the power supply terminal cells  452   b ,  453   b , and  454   b  of the IC device  400 , whereby the power supply voltage is supplied to the inside of the IC device  400 . 
   Next, the power supply voltage supplied to the electrodes  352   b ,  353   b , and  354   b  provided on the power supply terminal cells  452   b ,  453   b , and  454   b  of the IC device  400  is supplied to the power supply terminal cells  452   a ,  453   a , and  454   a  provided with the power supply terminal cell  451  interposed between themselves and the electrodes  352   b ,  353   b , and  354   b  through the metal lines  552 ,  553 , and  554 , respectively. Then, the power supply voltage supplied to the power supply terminal cells  452   a ,  453   a , and  454   a  is supplied to the electrodes  152   a ,  153   a , and  154   a  disposed on the mounting board  100  via the electrodes  352   a ,  353   a , and  354   a  formed on the power supply terminal cells  452   a ,  453   a , and  454   a , respectively. 
   Next, the power supply voltage supplied to the electrodes  152   a ,  153   a , and  154   a  is supplied to the electrodes  182   b ,  183   b , and  184   b  through the power supply lines  252 ,  253 , and  254 , respectively. Subsequently, the power supply voltage is supplied to the electrodes  382   b ,  383   b , and  384   b  provided on the power supply terminal cells  482   b ,  483   b , and  484   b  of the IC device  400  via the electrodes  182   b ,  183   b , and  184   b , respectively, whereby the power supply voltage is supplied to the inside of the IC device  400 . 
   Next, the power supply voltage supplied to the electrodes  382   b ,  383   b , and  384   b  is supplied to the power supply terminal cells  482   a ,  483   a , and  484   a  provided with the power supply terminal cell  481  interposed between themselves and the electrodes  382   b ,  383   b , and  384   b  through the metal lines  582 ,  583 , and  584 , respectively. Then, the power supply voltage supplied to the power supply terminal cells  482   a ,  483   a , and  484   a  is supplied to the electrodes  182   a ,  183   a , and  184   a  disposed on the mounting board  100  via the electrodes  382   a ,  383   a , and  384   a  formed on the power supply terminal cells  482   a ,  483   a , and  484   a , respectively. 
   Next, the power supply voltage supplied to the electrodes  182   a ,  183   a , and  184   a  is supplied to the electrodes  172   b ,  173   b , and  174   b  through the power supply lines  282 ,  283 , and  284 , respectively. Subsequently, the power supply voltage is supplied to the electrodes  372   b ,  373   b , and  374   b  provided on the power supply terminal cells  472   b ,  473   b , and  474   b  of the IC device  400  via the electrodes  172   b ,  173   b , and  174   b , respectively, whereby the power supply voltage is supplied to the inside of the IC device  400 . 
   Next, the power supply voltage supplied to the electrodes  372   b ,  373   b , and  374   b  is supplied to the power supply terminal cells  472   a ,  473   a , and  474   a  provided with the power supply terminal cell  471  interposed between themselves and the electrodes  372   b ,  373   b , and  374   b  through the metal lines  572 ,  573 , and  574 , respectively. Then, the power supply voltage supplied to the power supply terminal cells  472   a ,  473   a , and  474   a  is supplied to the electrodes  172   a ,  173   a , and  174   a  disposed on the mounting board  100  via the electrodes  372   a ,  373   a , and  374   a , formed on the power supply terminal cells  472   a ,  473   a , and  474   a , respectively. 
   Next, the power supply voltage supplied to the electrodes  172   a ,  173   a , and  174   a  is supplied to the electrodes  162   b ,  163   b , and  164   b  through the power supply lines  272 ,  273 , and  274 , respectively. Subsequently, the power supply voltage is supplied to the electrodes  362   b ,  363   b , and  364   b  provided on the power supply terminal cells  462   b ,  463   b , and  464   b  of the IC device  400  via the electrodes  162   b ,  163   b , and  164   b , respectively, whereby the power supply voltage is supplied to the inside of the IC device  400 . 
   Next, the power supply voltage supplied to the electrodes  362   b ,  363   b , and  364   b  is supplied to the power supply terminal cells  462   a ,  463   a , and  464   a  provided with the power supply terminal cell  461  interposed between themselves and the electrodes  362   b ,  363   b , and  364   b  through the metal lines  562 ,  563 , and  564 , respectively. Then, the power supply voltage supplied to the power supply terminal cells  462   a ,  463   a , and  464   a  is supplied to the electrodes  162   a ,  163   a , and  164   a  disposed on the mounting board  100  via the electrodes  362   a ,  363   a , and  364   a  formed on the power supply terminal cells  462   a ,  463   a , and  464   a , respectively. 
   In short, when the power supply voltage is applied, potentials equal to the power supply voltage are achieved at all the power supply terminal cells. 
   According to the present embodiment, the lines which achieve equal potentials at the individual power supply terminal cells, i.e., the lines (lines  552  to  554 ,  562  to  564 ,  572  to  574 , and  583  to  584 ) each providing a connection between the corresponding one of the plurality of pairs of power supply terminal cells in the IC device  400  are provided within the IC device  400 . This allows mounting of the IC device  400  which should supply each of different voltages obtained from different power supplies to each of the plurality of edge portions of the single-layer mounting board  100 . 
   Preferably, the lines (lines  552  to  554 ,  562  to  564 ,  572  to  574 , and  583  to  584 ) each providing a connection between the corresponding one of the plurality of pairs of power supply terminal cells in the IC device  400  are composed of a material having a lowest resistance of all the materials composing the IC device  400 . This minimizes a voltage drop in at least one of the lines provided in the IC device  400 . 
   The wiring length in the IC device  400  is reduced preferably by minimizing the distances between the power supply terminal cells connected in pairs by the lines based on design rules for fabricating the IC device  400 , as in the present embodiment. This minimizes a voltage drop in at least one of the lines provided in the IC device  400 . 
   Although the IC device  400  according to the present embodiment is provided with four types of power supply terminal cells, it is not limited thereto. A maximum permissible number of power supply terminal cells determined by the respective lengths of the edges of the IC device  400  can be provided on the individual edge portions. As a result, the types of power supply terminals can be increased substantially without limitation by elongating the individual edge portions of the IC device  400  so that the circuit is designed with extremely high flexibility. 
   By further providing signal terminal cells externally of power supply terminal cells which are connected in pairs by lines as in the IC device  400  according to the present embodiment, separation is achieved between a region provided with the signal lines and a region provided with the power supply lines in the IC device  400 . This suppresses the degradation of signals and a power supply voltage induced by noise. 
   Since the mounting board  100  according to the present embodiment can be separated into a region provided with the signal lines and a region provided with the power supply lines, the degradation of the signals and the power supply voltage induced by noise can be suppressed. 
   Although the mounting board  100  according to the present embodiment is provided with the foul types of power supply lines, it is not limited thereto. The number of power supply lines can be maximized within the limits imposed by the area of the mounting surface of the IC device  400 . This significantly relaxes restrictions on the design of the mounting board. 
   Alternatively, the power supply terminal cells provided on the IC device  400  according to the present embodiment may also be replaced with terminals each performing a buffer operation or terminals composing a regulator generating a desired voltage from a reference power supply or the like. 
   Although the metal lines have been used as means for providing connections between the power supply terminals and the electrodes, a conductive material other than metal may also be used. 
   Although the present embodiment has used the metal lines as means for providing connections between the individual power supply terminal cells formed on the IC device  400 , a conductive material other than metal may also be used. 
   Although the present embodiment has particularly described the method in which the power supply voltage is supplied from the individual edge portions of the IC device  400 , arbitrary signals may also be inputted and outputted instead of the power supply voltage. 
   According to the present invention, there is provided a mounting board which is low in fabrication cost and a semiconductor integrated device to be mounted on the mounting board.