Semiconductor device

1. A semiconductor device comprising:

(a) a semiconductor element, which is provided with a plurality of electrodes for input and output of an electric signal on the periphery of a bottom surface of the semiconductor element; and

(b) a wiring substrate which is provided with:

a film substrate,

a wiring pattern formed on the film substrate and having at least one inner lead as a terminal portion, and

a reinforcing film, made of material having smaller thermal expansion than the film substrate, and formed on at least one surface of the film substrate in a region of the wiring substrate where the wiring pattern is not formed and capable of substantially preventing the film substrate from expanding,

wherein the semiconductor element is connected to the wiring pattern, and the semiconductor element and the wiring substrate are sealed with a resin,

wherein said connection between the semiconductor element and the wiring pattern is a thermo-compressed bonded connection formed by thermo-compression bonding the electrodes of the semiconductor element to inner leads of the wiring pattern, the inner leads are aligned at positions corresponding to the respective electrodes,

wherein said bonded connection is such that at least one inner lead of the wiring pattern directly contacts an electrode of the semiconductor element,

wherein said reinforcing film is bonded onto the film substrate, and has sides, at least one of which extends along a direction in which the inner leads are provided, and

wherein the height of the reinforcing film, measured from the surface of the film substrate on which the reinforcing film is formed, is one-third to two-thirds of the height of the wiring pattern.

2. The semiconductor device according to claim 1 , wherein the reinforcing film is made of the same material as the wiring pattern.

3. A semiconductor device comprising:

(a) a semiconductor element, which is provided with a plurality of electrodes for input and output of an electric signal on the periphery of a bottom surface of the semiconductor element; and

(b) a wiring substrate which is provided with:

a film substrate,

a wiring pattern formed on the film substrate and having at least one inner lead as a terminal portion, and

a plurality of reinforcing films, made of material having a smaller coefficient of linear thermal expansion than the film substrate, is formed on both surfaces of the wiring substrate independently in a region where the wiring pattern is not formed and capable of substantially preventing the film substrate from expanding,

wherein the semiconductor element is connected to the wiring pattern, and the semiconductor element and the wiring substrate are sealed with a resin,

wherein said connection between the semiconductor element and the wiring pattern is a thermo-compressed bonded connection formed by thermo-compression bonding the electrodes of the semiconductor element to inner leads of the wiring pattern, the inner leads are aligned at positions corresponding to the respective electrodes,

wherein said bonded connection is such that at least one inner lead of the wiring pattern directly contacts an electrode of the semiconductor element,

wherein the plurality of reinforcing films are bonded onto the film substrate, are facing the inner leads, and are disposed along a direction in which the inner leads are provided, and

wherein each reinforcing film has one-third to two-thirds of the thickness of the wiring pattern.

4. The semiconductor device according to claim 3 , wherein the reinforcing films are made of the same material as the wiring pattern.

5. The semiconductor device according to claim 3 , wherein intervals between the reinforcing films adjacent to each other are larger than those between the wiring patterns adjacent to each other.

6. The semiconductor device according to claim 3 , wherein the reinforcing films are formed symmetrically on the film substrate.

7. The semiconductor device according to claim 1 , wherein the reinforcing film has a shape of triangle, quadrangle, or circle.

8. The semiconductor device according to claim 3 , wherein the reinforcing films have the shape of a triangle or quadrangle, and the reinforcing films are adjacent with their one sides facing to each other.

9. The semiconductor device according to claim 1 , wherein the reinforcing film shields a rays.

10. The semiconductor device according to claim 1 , wherein the reinforcing film is formed separately from the wiring pattern.

11. The semiconductor device according to claim 1 , wherein the film substrate is made of insulating material such as polyimide resin and polyester resin.

12. The semiconductor device according to claim 1 , wherein the reinforcing film is a metallic film which is made of metal.

13. A wiring substrate comprising:

a film substrate having a wiring pattern that includes at least one inner lead as a terminal portion; and

a reinforcing film,

wherein the reinforcing film, made of material having a smaller coefficient of linear thermal expansion than the film substrate, is formed on the film substrate in a region where the wiring pattern is not formed and capable of substantially preventing the film substrate from expanding,

wherein a semiconductor element and the wiring pattern are connected to each other by a thermo-compressed bonded connection formed by thermo-compression bonding electrodes of the semiconductor element to inner leads of the wiring pattern, the semiconductor element being provided with a plurality of the electrodes for input and output of an electric signal on the periphery of a bottom surface of the semiconductor element, the inner leads are aligned at positions corresponding to the respective electrodes,

where said bonded connection is such that at least one inner lead of the wiring pattern directly contacts an electrode of the semiconductor element,

wherein said reinforcing film is bonded onto the film substrate and has sides, at least one of which extends along a direction in which the inner leads are provided, and

wherein the height of the reinforcing film, measured from the surface of the film substrate on which the reinforcing film is formed, is one-third to two-thirds of the height of the wiring pattern.

14. A semiconductor device comprising:

(a) a semiconductor element, which is provided with a plurality of bump electrodes for input and output of an electric signal on the periphery of a bottom surface of the semiconductor element; and

(b) a wiring substrate which is provided with:

a film substrate,

a wiring pattern formed on the film substrate and having at least one inner lead as a terminal portion, and

a reinforcing film, made of material having a smaller coefficient of linear thermal expansion than the film substrate, and formed in a region where the wiring pattern is not formed on at least one surface of the film substrate and capable of substantially preventing the film substrate from expanding;

wherein the semiconductor element is connected to the wiring pattern, and the semiconductor element and the wiring substrate are sealed with a resin,

wherein the semiconductor element has a bump electrode at a connecting section to the wiring pattern, and the semiconductor element and the wiring pattern (i) electrically connected with each other by connection of the bump electrode and the wiring pattern, and, (ii) after the bump electrode and the wiring pattern are connected, sealed with the resin supplied to a spacing between the semiconductor element and the wiring substrate,

wherein said connection between the semiconductor element and the wiring pattern is a thermo-compressed bonded connection formed by thermo-compression bonding the bump electrodes of the semiconductor element to inner leads of the wiring pattern, the inner leads are aligned at positions corresponding to the respective bump electrodes,

wherein said bonded connection is such that at least one inner lead of the wiring pattern directly contacts the respective bump electrode of the semiconductor element,

wherein said reinforcing film is bonded onto the film substrate, and has sides, at least one of which extends along a direction in which the inner leads are provided, and

wherein the height of each reinforcing film, measured from the surface of the film substrate on which the respective reinforcing film is formed, is one-third to two-thirds of the height of the wiring pattern.

15. The semiconductor device according to claim 14 , wherein the reinforcing film is on that surface of the film substrate on which the wiring pattern is formed.

16. The semiconductor device according to claim 14 , wherein the reinforcing film and the wiring pattern are made of the same material.

17. The semiconductor device according to claim 1 , wherein at least one of the sides of the reinforcing film is parallel to a direction in which the inner leads are provided.

18. The semiconductor device according to claim 1 , wherein the reinforcing film is a single section having the shape of a quadrangle.

19. The semiconductor device according to claim 13 , wherein at least one of the sides of the reinforcing film is parallel to a direction in which the inner leads are provided.

20. The semiconductor device according to claim 13 , wherein the reinforcing film is a single section having the shape of a quadrangle.

21. The semiconductor device according to claim 14 , wherein at least one of the sides of the reinforcing film is parallel to a direction in which the inner leads are provided.

22. The semiconductor device according to claim 14 , wherein the reinforcing film is a single section having the shape of a quadrangle.