Package substrate

Abstract

According to the package board of the present invention, each soldering pad formed on the top surface of the package board, on which an IC chip is to be mounted, is small (133 to 170 μm in diameter), so the metallic portion occupied by the soldering pads on the surface of the package board is also small. On the other hand, each soldering pad formed on the bottom surface of the package board, on which a mother board, etc. are to be mounted, is large (600 μm in diameter), so the metallic portion occupied by the soldering pads on the surface of the package board is also large. Consequently, a dummy pattern 58 M is formed between conductor circuits 58 U and 58 U for forming signal lines on the IC chip side surface of the package board thereby to increase the metallic portion on the surface and adjust the rate of the metallic portion between the IC chip side and the mother board side of the package board, protecting the package board from warping in the manufacturing processes, as well as during operation.

1. A package board having  comprising: 
 a core board on each surface of which ;  
 a plurality of conductor circuits are  formed with an interlaminar resin insulating layer therebetween on each surface of the core board,  
 wherein a plurality of soldering pads are formed on an IC chip mounted side surface, as well as  of said core board and on an other side surface of said core board to be connected to another board, so that said soldering pads on the other side surface are larger than those  said soldering pads on said IC chip side surface of said package board, and said IC chip mounted side surface has a dummy pattern for improving the mechanical strength of the package board is  comprising a metal and formed between signal line conductor circuit patterns formed on said IC chip mounted side surface of said core board  such that a rate of metallic portions on said IC chip mounted side surface and the other side surface is adjusted to improve mechanical strength of the package board.  
 
     
     
       2. A package board having  comprising: 
 a core board on each surface of which ;  
 a plurality of conductor circuits are  formed with an interlaminar resin insulating layer therebetween on each surface of the core board,  
 wherein a plurality of soldering pads are formed on an IC chip mounted side surface, as well as  of said core board and on an other side surface of said core board to be connected to another board, so that said soldering pads on the other side surface are larger than those  said soldering pads on said IC chip side surface of said package board, and said IC chip mounted side surface has a dummy pattern for improving the mechanical strength of the package board is  comprising a metal and formed between signal line conductor circuit patterns of an outermost layer formed on said IC chip mounted side surface of said core board  such that a rate of metallic portions on said IC chip mounted side surface and the other side surface is adjusted to improve mechanical strength of the package board.  
 
     
     
       3. A package board having  comprising: 
 a core board on each surface of which ;  
 a plurality of conductor circuits are  formed with an interlaminar resin insulating layer therebetween on each surface of the core board,  
 wherein a plurality of soldering pads are formed on an IC chip mounted side surface, as well as  of said core board and on an other side surface of said core board to be connected to another board, so that said soldering pads on the other side surface are larger than those  said soldering pads on said IC chip side surface of said package board, and said IC chip mounted side surface has a dummy pattern for improving the mechanical strength of the package board is  comprising a metal and formed between signal line conductor circuit patterns on the core board formed on said IC chip mounted side surface of said core board  such that a rate of metallic portions on said IC chip mounted side surface and the other side surface is adjusted to improve mechanical strength of the package board.  
 
     
     
       4. A package board comprising:
   a core board;        a plurality of conductor circuits formed with an interlaminar resin insulating layer therebetween on each surface of the core board,        wherein a plurality of soldering pads are formed on a surface of an IC chip mounted side of the core board and on an other side surface of the core board to be connected to another board, so that said soldering pads on the other side surface are larger than said soldering pads on said IC chip side, and a dummy pattern comprising a metal and formed between signal line conductor circuit patterns formed on said IC chip mounted side such that a rate of metallic portions on said IC chip mounted side and the other side is adjusted to improve mechanical strength of the package board.      
     
     
       5. A package board comprising:
   a core board;        a plurality of conductor circuits formed with an interlaminar resin insulating layer therebetween on each surface of the core board,        wherein a plurality of soldering pads are formed on a surface of an IC chip mounted side of the core board and on an other side surface of the core board to be connected to another board, so that said soldering pads on the other side surface are larger than said soldering pads on said IC chip side, and a dummy pattern comprising a metal and formed between signal line conductor circuit patterns of an outmost layer formed on said IC chip mounted side such that a rate of metallic portions on said IC chip mounted side and the other side is adjusted to improve mechanical strength of the package board.      
     
     
       6. A package board comprising:
   a core board;        a plurality of conductor circuits formed with an interlaminar resin insulating layer therebetween on each surface of the core board,        wherein a plurality of soldering pads are formed on a surface of an IC chip mounted side of the core board and on an other side surface of the core board to be connected to another board, so that said soldering pads on the other side surface are larger than said soldering pads on said IC chip side, and a dummy pattern comprising a metal and formed between signal line conductor circuit patterns on the core board formed on said IC chip mounted side such that a rate of metallic portions on said IC chip mounted side and the other side is adjusted to improve mechanical strength of the package board.      
     
     
       7. A package board according to  claim 1 , wherein the metal comprising the dummy pattern and a metal comprising the plurality of conductor circuits are a same metal.  
     
     
       8. A package board according to  claim 2 , wherein the metal comprising the dummy pattern and a metal comprising the plurality of conductor circuits are a same metal.  
     
     
       9. A package board according to  claim 3 , wherein the metal comprising the dummy pattern and a metal comprising the plurality of conductor circuits are a same metal.  
     
     
       10. A package board according to  claim 4 , wherein the metal comprising the dummy pattern and a metal comprising the plurality of conductor circuits are a same metal.  
     
     
       11. A package board according to  claim 5 , wherein the metal comprising the dummy pattern and a metal comprising the plurality of conductor circuits are a same metal.  
     
     
       12. A package board according to  claim 6 , wherein the metal comprising the dummy pattern and a metal comprising the plurality of conductor circuits are a same metal.