Semiconductor storage device and method of manufacturing the same
According to one embodiment, coupling capacitance in a state in which a first heat radiation member is arranged between parallel flat plates of a first capacitor formed by a surface of a housing opposed to one surface of a printed circuit board and the printed circuit board is smaller than coupling capacitance in a state in which an integrally formed object having a relative dielectric constant of 5.8 is arranged between the first capacitor to cover a first radiating region containing the controller and the first nonvolatile semiconductor memories.
1. A semiconductor storage device comprising:
a printed circuit board mounted with, on one surface, respectively via a plurality of bumps, a plurality of first nonvolatile semiconductor memories and a controller that controls reading of data from and writing of data in the first nonvolatile semiconductor memories;
a housing that is formed of a conductive material and houses the printed circuit board; and
a first heat radiation member that is interposed between a surface of the housing opposed to one surface of the printed circuit board and the controller and first nonvolatile semiconductor memories and thermally connects the controller and first nonvolatile semiconductor memories and the housing, wherein
coupling capacitance in a state in which the first heat radiation member is arranged between a first capacitor formed by the surface of the housing opposed to one surface of the printed circuit board and the printed circuit board is smaller than coupling capacitance in a state in which an integrally formed object having a relative dielectric constant of 5.8 is arranged between the first capacitor to cover a first radiating region containing the controller and the first nonvolatile semiconductor memories.
2. A storage device comprising:
a plurality of first nonvolatile semiconductor memories;
a controller coupled to the plurality of first nonvolatile semiconductor memories;
a printed circuit board, wherein the first nonvolatile semiconductor memories and the controller are mounted on one surface of the printed circuit board,
a housing made of a conductive material and faces the printed circuit board; and
a first heat radiation sheet interposed between a surface of the housing opposed to the one surface of the printed circuit board and the controller and plurality of first nonvolatile semiconductor memories, wherein the first heat radiation sheet thermally connects the controller and plurality of first nonvolatile semiconductor memories with the housing, wherein
the first heat radiation sheet is divided into a plurality of pieces and the divided pieces of the first heat radiation sheet are arranged at intervals to suppress an increase in the coupling capacitance of the device or to suppress thermal cross talk with each other.
3. The storage device according to claim 2 , wherein the divided pieces of the first heat radiation sheet are arranged to respectively correspond to the controller and the first nonvolatile semiconductor memories.
4. The storage device according to claim 2 , wherein at least one of the divided pieces of the first heat radiation sheet is arranged over two or more of the controller and the first nonvolatile semiconductor memories.
5. The storage device according to claim 2 , wherein
the first heat radiation sheet has the divided pieces and a tabular section including the divided pieces on a surface thereof, and
the divided pieces and the tabular section are integrally molded.
6. The storage device according to claim 2 , wherein the first heat radiation sheet is obtained by setting a fluid injected into a surface of the housing opposed to one surface of the printed circuit board.
7. The storage device according to claim 2 , wherein the first heat radiation sheet has flexibility and is closely attached to the surface of the housing opposed to one surface of the printed circuit board, the controller, and the first nonvolatile semiconductor memories.
8. The storage device according to claim 2 , further comprising:
a plurality of second nonvolatile semiconductor memories, reading of data from and writing of data in which are controlled by the controller, mounted on the other surface of the printed circuit board, and
a second heat radiation sheet interposed between the second nonvolatile semiconductor memories and an inner surface of the housing opposed to the other surface of the printed circuit board, wherein the second heat radiation member is configured to and thermally connects the second nonvolatile semiconductor memories with the housing, and
wherein the second heat radiation sheet is divided into a plurality of pieces and the divided pieces of the second heat radiation sheet are arranged at intervals.
9. The storage device according to claim 8 , wherein the divided pieces of the second heat radiation sheet are arranged to respectively correspond to the second nonvolatile semiconductor memories.
10. The storage device according to claim 8 , wherein at least one of the divided pieces of the second heat radiation sheet is arranged over two or more of the second nonvolatile semiconductor memories.
11. The storage device according to claim 8 , wherein
the second heat radiation sheet has the divided pieces and a tabular section including the divided pieces on a surface thereof, and
the divided pieces and the tabular section are integrally molded.
12. The storage device according to claim 8 , wherein the second heat radiation sheet is obtained by setting a fluid injected into a surface of the housing opposed to the other surface of the printed circuit board.
13. The storage device according to claim 8 , wherein the second heat radiation sheet has flexibility and is closely attached to the surface of the housing opposed to the other surface of the printed circuit board and the second nonvolatile semiconductor memories.
14. The storage device according to claim 2 , wherein each piece of the first heat radiation sheet divided into the plurality of pieces is arranged corresponding to a portion of the controller and the first nonvolatile semiconductor memories.
15. The storage device according to claim 14 , wherein the controller and the plurality of first nonvolatile semiconductor memories are mounted on the one side of the printed circuit board as a cluster in a substantially rectangular shape; and
the first heat radiation sheet is not arranged on the first nonvolatile semiconductor memories positioned at corners of the cluster in the substantially rectangular shape.
16. The storage device according to claim 8 , wherein each piece of the second heat radiation sheet divided into the plurality of pieces is arranged corresponding to a portion of the second nonvolatile semiconductor memories.