Semiconductor device having an improved connection arrangement between a semiconductor pellet and base substrate electrodes and a method of manufacture thereof

Abstract

A semiconductor device comprising a semiconductor pellet mounted on a pellet mounting area of the main surface of a base substrate, in which first electrode pads arranged on the back of the base substrate are electrically connected to bonding pads arranged on the main surface of the semiconductor pellet. The base substrate is formed of a rigid substrate, and its first electrode pads are electrically connected to the second electrode pads arranged on its reverse side. The semiconductor pellet is mounted on the pellet mounting area of the main surface of the base substrate, with its main surface downward, and its bonding pads are connected electrically with the second electrode pads of the base substrate through bonding wires passing through slits formed in the base substrate.

1. A semiconductor device comprising:
 (a) a rigid substrate having a first main surface and a second main surface opposite to the first main surface;    (b) a semiconductor pellet mounted on the first main surface of the rigid substrate, the semiconductor pellet having a plurality of semiconductor circuit elements and a plurality of bonding pads;    (c) a plurality of electrode pads formed on the second main surface of the rigid substrate; and    (d) a plurality of bonding wires for electrically connecting the bonding pads of the semiconductor pellet with the electrode pads;    wherein the semiconductor pellet is mounted facedown on the rigid substrate, the rigid substrate has slits that extend from the first main surface to the second main surface and expose the bonding pads of the semiconductor pellet, the bonding wires extend through the slits in the rigid substrate to connect the bonding pads and the electrode pads, and bump electrodes are formed on said electrode pads.    
     
     
       2. A semiconductor device according to  claim 1 , wherein the bonding pads are arranged at the periphery of the semiconductor pellet and the slits are formed along the directions of rows of the bonding pads. 
     
     
       3. A semiconductor device according to  claim 2 , wherein the electrode pads are located on both sides of the slits. 
     
     
       4. A semiconductor device according to  claim 3 , wherein the electrode pads located on one side of the slits and under the semiconductor pellet are power supply pads, and the electrode pads located on the other side of the slits and outside the semiconductor pellet are signal pads. 
     
     
       5. A semiconductor device according to  claim 1 , further comprising a first resin sealing body covering the semiconductor pellet. 
     
     
       6. A semiconductor device according to  claim 5 , further comprising a second resin sealing body formed in the slits and covering the bonding wires. 
     
     
       7. A semiconductor device according to  claim 1 , wherein said rigid substrate is formed by glass fibers impregnated with epoxy resin. 
     
     
       8. A method of manufacturing a semiconductor device in which a semiconductor pellet is mounted on a pellet mounting area of the main surface of a rigid base substrate and in which first electrode pads arranged on the back of the rigid base substrate are electrically connected to bonding pads arranged on the main surface of the semiconductor pellet, said method comprising:
 a step of mounting the semiconductor pellet, with its main surface downward, on the pellet mounting area of the main surface of the rigid base substrate    a step of electrically connecting the bonding pads of the semiconductor pellet and second electrode pads electrically connected to the first electrode pads of the rigid base substrate and arranged on the back of the rigid base substrate through bonding wires passing through slits formed on the rigid base substrate; and    a step of forming bump electrodes on the first electrode pads.    
     
     
       9. A method of manufacturing a semiconductor device according to  claim 9 , further comprising a step of forming by transfer molding a resin sealing body that covers the periphery of the main surface of the rigid base substrate and seals the bonding wires, after the step of electrically connecting the bonding wires. 
     
     
       10. A semiconductor device according to  claim 10 , wherein said rigid substrate is formed by glass fibers impregnated with polyimide resin. 
     
     
       11. A semiconductor device comprising:
 (a) a rigid substrate having a first main surface and a second main surface opposite to the first main surface;    (b) a semiconductor pellet mounted on the first main surface of the rigid substrate, the semiconductor pellet having a plurality of semiconductor circuit elements and a plurality of bonding pads;    (c) a plurality of electrode pads formed on the second main surface of the rigid substrate; and    (d) a plurality of bonding wires for electrically connecting the bonding pads of the semiconductor pellet with the electrode pads;    wherein the semiconductor pellet is mounted facedown on the rigid substrate, the rigid substrate has slits that extend from the first main surface to the second main surface and expose the bonding pads of the semiconductor pellet, and the bonding wires extend through the slits in the rigid substrate to connect the bonding pads and the electrode pads;    wherein the bonding pads are arranged at the periphery of the semiconductor pellet and the slits are formed along the directions of rows of the bonding pads.    
     
     
       12. A semiconductor device according to  claim 11 , wherein the electrode pads are located on both sides of the slits. 
     
     
       13. A semiconductor device according to  claim 12 , wherein the electrode pads located on one side of the slits and under the semiconductor pellet are power supply pads, and the electrode pads located on the other side of the slits and outside the semiconductor pellet are signal pads. 
     
     
       14. A semiconductor device comprising:
 a substrate of a quadrilateral shape having a first pair of opposed edges and a second pair of opposed edges, said substrate having a first main surface, a second main surface opposite to said first main surface and a first slit and a second slit each extending from said first main surface to said second main surface, said first slit extending along one of said first pair of opposed edges, said second slit extending along the other of said first pair of opposed edges, said substrate having first electrode pads on said second main surface in a first area between said first and second slits, second electrode pads on said second main surface in a second area between said first slit and said one of the first pair of opposed edges, and third electrode pads on said second main surface in a third area between said second slit and the other of the first pair of opposed edges;    a semiconductor pellet having a main surface with semiconductor elements and bonding pads, said semiconductor pellet being mounted on said first main surface of substrate such that said bonding pads are arranged to be in line with said first and second slits;    bonding wires extending through said first and second slits in said substrate and electrically connecting said bonding pads and said first to third electrode pads, respectively;    a resin member sealing said semiconductor pellet and said bonding wires; and    bump electrodes arranged on said second main surface of said substrate in said first to third areas in a direction of said first pair of opposed edges and being electrically connected with said first to third electrode pads,    wherein said bump electrodes in said second and third areas are arranged to form plural rows in a direction of at least one of said second pair of opposed edges, respectively.    
     
     
       15. A semiconductor device according to  claim 14 , wherein said semiconductor pellet has a quadrilateral shape and has a third pair of opposed edges and a fourth pair of opposed edges, wherein said bonding pads are arranged in a peripheral portion of said main surface and extend along said third pair of opposed edges. 
     
     
       16. A semiconductor device according to  claim 15 , wherein said semiconductor pellet is mounted on said first main surface opposite to said first area, wherein said substrate has a larger size than that of said semiconductor pellet, and wherein said bump electrodes in said second and third areas are located outside said third pair of opposed edges. 
     
     
       17. A semiconductor device according to  claim 14 , wherein the number of said bump electrodes in said second and third areas is larger than the number of said bump electrodes in said first area. 
     
     
       18. A semiconductor device according to  claim 14 , wherein said semiconductor pellet has a rear surface opposite to said main surface, and wherein said rear surface of said semiconductor pellet is exposed from said resin member. 
     
     
       19. A semiconductor device according to  claim 14 , wherein the number of said bump electrodes in said second area is larger than the number of said bump electrodes in said first area. 
     
     
       20. A semiconductor device according to  claim 14 , wherein said semiconductor pellet has a rear surface opposite to said main surface, and wherein said rear surface of said semiconductor pellet is exposed from said resin member. 
     
     
       21. A semiconductor device according to  claim 14 , wherein said first electrode pads extend along said first and second slits, respectively, said second electrode pads extend along said first slit, and said third electrode pads extend along said second slit, wherein said first to third electrode pads are arranged at a first pitch, respectively, wherein said bonding pads in said first and second slits are arranged at a second pitch which is smaller than said first pitch, respectively, wherein said bonding wires in said first slit alternately connect said bonding pads in said first slit with said first and second electrode pads, and wherein said bonding wires in said second slit alternately connect said bonding pads in said second slit with said first and third electrode pads. 
     
     
       22. A semiconductor device comprising:
 a substrate of a quadrilateral shape having first to fourth edges, said substrate having a first main surface, a second main surface opposite to said first main surface and first to fourth slits extending from said first main surface to said second main surface, said first to fourth slits respectively extending along said first to fourth edges and defining a first area of said substrate surrounded by said first to fourth slits and a second area of said substrate extending outside said first to fourth slits, said substrate having first electrode pads on said second main surface in said first area and second electrode pads on said second main surface in said second area;    a semiconductor pellet having a main surface with semiconductor elements and bonding pads, said semiconductor pellet being mounted on said first main surface of substrate such that said bonding pads are arranged in line with said first to fourth slits;    bonding wires extending through said first to fourth slits in said substrate and electrically connecting said bonding pads and said first and second electrode pads, respectively;    a resin member sealing said semiconductor pellet and said bonding wires; and    bump electrodes arranged on said second main surface of said substrate in said first and second areas and being electrically connected with said first and second electrode pads,    wherein said bump electrodes in said second area are arranged to form a plurality of rows such that said plurality of rows are formed relative to one another to surround said first area of substrate.    
     
     
       23. A semiconductor device according to  claim 22 , wherein said semiconductor pellet has a quadrilateral shape and has first to fourth edges, wherein said bonding pads are arranged in a peripheral portion of said main surface and extend along said first to fourth edges of said semiconductor pellet. 
     
     
       24. A semiconductor device according to  claim 23 , wherein said semiconductor pellet is mounted on said first main surface opposite to said first area, wherein said substrate has a larger size than that of said semiconductor pellet, and wherein said bump electrodes in said second area are located outside said first to fourth edges of said semiconductor pellet. 
     
     
       25. A semiconductor device according to  claim 22 , wherein said first and second electrode pads extending along said first to fourth slits, respectively, and are arranged at a first pitch, wherein said bonding pads extend along said first and second electrode pads and are arranged at a second pitch which is smaller than said first pitch, and wherein said bonding wires alternately connect said bonding pads with said first and second electrode pads. 
     
     
       26. A method of manufacturing a semiconductor device comprising the steps of:
 ( a )  providing a semiconductor pellet and a substrate, said semiconductor pellet having a circuit system and bonding pads formed on a main surface thereof, said substrate having a first surface, a second surface opposite to said first surface, electrode pads formed on said second surface and a slit passing through said substrate from said first surface to said second surface;      ( b )  mounting said semiconductor pellet over said substrate such that said main surface of said semiconductor pellet is faced to said first surface of said substrate and said bonding pads are arranged to be aligned with said slit in a plan view, and such that a portion of said slit is arranged at the outside of said semiconductor pellet in said plan view;      ( c )  electrically connecting said electrode pads of said substrate with said bonding pads of said semiconductor pellet by bonding wires via said slit respectively;      ( d )  after the step  ( c ) , forming a resin sealing body on said first and second surfaces of said substrate, said resin sealing body formed on said first surface side of said substrate being positioned around of said semiconductor pellet in a plane view, said resin sealing body on said first and second surfaces of said substrate being formed in unitary to each other via said slit, and sealing said bonding wires; and      ( e )  forming bump electrodes on said second surface of said substrate such that said bump electrodes are electrically connected to said electrode pads of said substrate,        wherein said resin sealing body in the step  ( d )  is formed by a transfer molding method using a molding die;        wherein said resin sealing body includes a first portion on said first surface of said substrate, a second portion on said second surface of said substrate and a third portion in said slit; and        wherein from said first to third portions of said resin sealing body are continuously formed to one another.     
     
     
       27. A method of manufacturing a semiconductor device according to  claim 26 , wherein said molding die has an upper die and a lower die, wherein said lower die of said molding die has a cavity defined by a recess of said lower die, wherein the step ( d )  includes a step of setting assembly comprising said substrate and said semiconductor pellet at said molding die such that a part of said bonding wires and said electrode pads are placed in said cavity defined by said recess of said lower die, and wherein said resin material is supplied into said cavity through said slit of said substrate by said transfer molding method.   
     
     
       28. A method of manufacturing a semiconductor device according to  claim 26 , wherein said resin material is made from resin containing filler. 
     
     
       29. A method of manufacturing a semiconductor device according to  claim 26 , wherein said substrate is a rigid substrate formed of a glass fiber impregnated with resin. 
     
     
       30. A method of manufacturing a semiconductor device according to  claim 29 , wherein said resin included in said substrate is epoxy resin, polyimide resin or maleimide resin. 
     
     
       31. A method of manufacturing a semiconductor device according to  claim 29 , wherein said bonding wires are formed of gold, wherein connection of said bonding wires is accomplished by ultrasonic thermo- compression bonding in the step  ( c ). 
     
     
       32. A method of manufacturing a semiconductor device according to  claim 26 , wherein said bump electrodes are formed such that a thickness of in a thickness direction of said substrate is smaller than a height of each of said bump electrodes in said thickness direction of said substrate. 
     
     
       33. A method of manufacturing a semiconductor device according to  claim 32 , wherein said bump electrodes are formed of a Pb- Sn alloy.   
     
     
       34. A method of manufacturing a semiconductor device according to  claim 32 , wherein said bump electrodes are formed to provide an electrical and mechanical connection to a mounting board, at the side of said second surface of said substrate. 
     
     
       35. A method of manufacturing a semiconductor device according to  claim 26 , wherein said bonding pads are arranged in a first direction along a side of said semiconductor pellet, wherein said portion of said slit arranged at the outside of said semiconductor pellet is along said side of said semiconductor pellet, wherein said resin sealing body in the step ( d )  is formed by a transfer molding method, and wherein the formation of said resin sealing body includes a step of providing a resin material in said slit from a second direction which is substantially perpendicular to said first direction.   
     
     
       36. A semiconductor device comprising:
 ( a )  a semiconductor pellet and a substrate, said semiconductor pellet having a circuit system and bonding pads formed on a main surface thereof, said substrate having a first surface, a second surface opposite to said first surface, electrode pads formed on said second surface and a slit passing through said substrate from said first surface to said second surface;      ( b )  wherein said semiconductor pellet is mounted over said substrate such that said main surface of said semiconductor pellet is faced to said first surface of said substrate and said bonding pads are arranged to be aligned with said slit in a plan view, and such that a portion of said slit is arranged at the outside of said semiconductor pellet in said plan view;      ( c )  wherein said electrode pads of said substrate are electrically connected with said bonding pads of said semiconductor pellet by bonding wires via said slit;      ( d )  a resin sealing body formed on said first and second surfaces of said substrate, said resin sealing body formed on said first surface side of said substrate being positioned around of said semiconductor pellet in a plane view, said resin sealing body on said first and second surfaces of said substrate being formed in unitary to each other via said slit, and sealing said bonding wires; and      ( e )  bump electrodes formed on said second surface of said substrate such that said bump electrodes are electrically connected to said electrode pads of said substrate, respectively,        wherein said resin sealing body includes a first portion on said first surface of said substrate, a second portion of said second surface of said substrate and a third portion in said slit; and        wherein from said first to third portions of said resin sealing body are continuously formed to one another.     
     
     
       37. A semiconductor device according to  claim 36 , wherein said substrate is a rigid substrate formed of a glass fiber impregnated with resin. 
     
     
       38. A semiconductor device according to  claim 37 , wherein said resin included in said substrate is epoxy resin, polyimide resin or maleimide resin. 
     
     
       39. A semiconductor device according to  claim 37 , wherein said bonding wires are formed of gold, and wherein connection of said bonding wires is accomplished by ultrasonic thermo- compression bonding.   
     
     
       40. A semiconductor device according to  claim 36 , wherein said resin material is made from resin containing filler. 
     
     
       41. A semiconductor device according to  claim 36 , wherein said bump electrodes are formed such that a thickness of in a thickness direction of said substrate is smaller than a height of each of said bump electrodes in said thickness direction of said substrate. 
     
     
       42. A semiconductor device according to  claim 41 , wherein said bump electrodes are formed of a Pb- Sn alloy.   
     
     
       43. A semiconductor device according to  claim 41 , wherein said bump electrodes are formed to provide an electrical and mechanical connection to a mounting board, at the side of said second surface of said substrate. 
     
     
       44. A semiconductor device according to  claim 36 , wherein said bonding pads are arranged in a first direction along a side of said semiconductor pellet, and wherein said portion of said slit arranged at the outside of said semiconductor pellet is along said side of said semiconductor pellet.