JP2000183277A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact, safe semiconductor device with a high breakdown voltage. SOLUTION: A semiconductor device 1 is provided with an envelope 2 that is in a bookcase type with a side surface opening 12 on one side surface of a flat box and has a bottom opening 10 on the other side surface that does not face the one side surface and a heat radiation surface 13 that is exposed from the bottom surface opening 12. Also, the semiconductor device 1 is provided with a metal base 5 for sealing the bottom surface opening 12, an insulation substrate 6 that is fixed on the reverse side of the heat radiation surface 13, a power semiconductor element 7 that is fixed on the insulation substrate 6, circuit wiring 8 that is fixed on the insulation substrate 6, an external terminal 4 that is led from at least one side surface of the envelope 2 to the outside of the envelope 2, a lid body 3 for closing the side surface opening 10, and an insulation resin 9 that is filled into the envelope 2 for sealing the metal base 5, the insulation substrate 6, the power semiconductor element 7, and the circuit wiring 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device used for electric power equipment, and more particularly to an intelligent power module mounted with a power semiconductor element, a control circuit, circuit wiring, external terminals and external electrode terminals applied to an inverter or the like. And a semiconductor device as described above.

[0002]

2. Description of the Related Art Conventionally, power semiconductor elements, control circuits, circuit wiring, external terminals and external electrodes applied to inverters and the like have been used as semiconductor devices for inverter control power devices such as energy saving direct drives or intelligent actuators. 2. Description of the Related Art Semiconductor devices such as intelligent power modules having terminals are known.

FIG. 18 is a sectional view showing the structure of such a conventional semiconductor device 51. As shown in FIG. This conventional semiconductor device 51
In the first embodiment, an insulating substrate 56 is disposed on a metal base 55, and a power semiconductor element 57, circuit wiring 58, and external terminals 54 are disposed on the insulating substrate 56. In addition, metal base 5
These electronic components arranged on 5 are sealed by an outer case 52 and a metal base 55 using an insulating resin such as polyphenylene sulfide or unsaturated polyester. And this sealed outer case 52
The inside is filled with an insulating resin 59, and these electronic components are sealed.

Further, a silicone gel filled on an insulating substrate 56 in which an insulating resin 59 is accommodated in the inner bottom of the outer case 52, an epoxy resin filled on the silicone gel, and fixed on the epoxy resin. The semiconductor device of the related art exhibits relatively excellent electrical characteristics and reliability because it is composed of the outer case 52 and a lid made of the same or different material.

[0005] In particular, in the case of a semiconductor device for a power device having a high voltage such as 4.5 kV or more, moisture absorption of the silicone gel causes a decrease in electrical characteristics. The case 52 and the metal base 55 or the lid and the epoxy resin or the like are firmly joined to each other by an adhesion method or a joint structure for suppressing generation of a gap. Further, a semiconductor device is manufactured by providing an internal structure such as a space 61 and a pressure relief valve for preventing expansion and bleeding of the silicone gel or relaxing thermal stress of the epoxy resin.

[0006]

However, the conventional semiconductor device has the following disadvantages. In other words, the outer case of the rectangular frame shape is greatly deformed by contraction or expansion due to thermal stress, and furthermore, when bonding and fixing to the metal base, only the thickness of the metal base can be obtained. It is difficult to obtain a high adhesive strength between the metal base and the metal base, and there is a fear that minute gaps and poor adhesion may occur. There is a concern that these gaps and defects such as breakage of the case may cause moisture absorption of the silicone gel, resulting in a decrease in electrical characteristics and durability. Furthermore, since the lid is grounded on the upper part of the outer case, it is necessary to fill the gap between the lid and the outer case with epoxy resin, which complicates the structure and increases the height and other dimensions, resulting in a compact overall device. It is an obstacle to the development.

[0007] The present invention has been made in view of the above points, and an object of the present invention is to provide a semiconductor device having high moisture resistance and excellent electrical characteristics.

Another object of the present invention is to provide a small, thin, and compact semiconductor device having excellent durability and reliability.

Still another object of the present invention is to provide a safe semiconductor device with low manufacturing cost.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, a feature of the present invention is that a flat box has a side opening on one side and another side not opposed to one side. An outer case having a bottom opening at the bottom, a metal base having a heat radiating surface exposed from the bottom opening and sealing the bottom opening, an insulating substrate fixed on the back of the heat radiating surface, and an insulating substrate A power semiconductor element fixed to the circuit board, a circuit wiring fixed on the insulating substrate, an external terminal led out of the outer case from at least one side surface of the outer case, and a lid for sealing the side opening. , A semiconductor device having a metal base, an insulating substrate, a power semiconductor element, and an insulating resin for sealing circuit wiring.

According to the feature of the present invention, since the entire metal base is housed in the outer case, it is possible to eliminate a joint having a gap into which moisture can enter from the outside.

Further, deformation of the outer case due to a temperature change or the like is suppressed, and the moisture resistance of the entire semiconductor device is improved.
It shows excellent electrical characteristics without deterioration due to moisture absorption.

Furthermore, since there are no external terminals on the upper surface of the semiconductor device, the size of the semiconductor device can be reduced in size and thickness.

Further, the assembling process and the attaching process to the partner device can be simplified.

Further, when an accident occurs due to an overcurrent or the like, the lid serves as a pressure relief valve, so that an explosion due to an increase in internal pressure can be prevented.

In the semiconductor device having the features of the present invention, the outer case is made of a thermosetting resin such as an epoxy resin, an unsaturated polyester resin, or a thermoplastic resin such as polyphenylene sulfide. It is desirable to use. Further, the insulating resin may be used after being mixed with a catalyst, an additive, or an inorganic filler for appropriately improving adhesion or relaxing internal stress, in addition to the main component. As the inorganic filler, fused silica powder, quartz powder, glass powder, short glass fiber, alumina, aluminum nitride and the like are used.

In a semiconductor device having the features of the present invention, the following is preferable. (1) The lid and the external terminal are integrally formed. (2) The metal base and the bottom opening are fitted. (3) The shape of the protruding portion is compatible with the insulating substrate. (4) A convex rib formed on the side surface inside the outer case and in contact with a part of the metal base by the surface is provided. (5) The side opening and the bottom opening are formed by one opening. (6) A groove is provided on the side surface of the metal base, and the rib is shaped to fit into the groove. (7) A partition plate that divides the insulating resin and the space in the outer case and partially contacts the metal base. (8) A part of the external terminal is led out from the upper surface of the surrounding case. (9) An epoxy resin is used as the insulating resin. (10) The lid is provided with an injection port for insulating resin. (11) An insulating resin injection port is provided in the outer case. (12) The surrounding case and the lid are formed of a recyclable thermoplastic resin. (13) A space that is not filled with the insulating resin in the outer case is formed on one side surface according to claim 1. (14) The cross-sectional shape of the outer case is a race track shape.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a configuration of a semiconductor device 1 according to an embodiment of the present invention. As shown in FIG. 1, the semiconductor device 1 has a side opening 10 on one side of a flat box.
And a heat dissipation surface 13 exposed from the bottom opening 12 and a bottom case 12 having a bottom surface opening 12 on the other side not opposed to one side.
A metal base 5 for hermetically sealing, an insulating substrate 6 fixed on the back surface of the heat radiating surface 13, a power semiconductor element 7 fixed on the insulating substrate 6, and a circuit wiring 8 fixed on the insulating substrate 6.
An external terminal 4 led out of the outer case 2 from at least one side surface of the outer case 2, a lid 3 for sealing the side opening 10, and a metal base 5 filled in the outer case 2. , An insulating substrate 6, a power semiconductor element 7, and an insulating resin 9 for sealing the circuit wiring 8. In addition, there is a space 11 that is not filled with the insulating resin 9 between the ceiling surface inside the surrounding case 2 and the insulating resin 9.

FIG. 2 is an external perspective view of the semiconductor device 1.
FIG. 1 is a cross-sectional view along the y direction of FIG. As shown in FIG. 2, the heat dissipation surface 13 of the metal base 5 is exposed from the bottom opening 12 of the outer case 2, the side opening 10 is sealed by the lid 3, and the external terminals 4 are led out from the lid 3. Have been. Here, the outer diameter of the entire semiconductor device is set to 100
It is set to about mm × 70 mm × 20 mm.

The outer case 2 and the lid 3 are made of, for example, a thermosetting resin such as an epoxy resin, an unsaturated polyester resin, a phenol resin, a polyimide resin, a polyurethane resin, a melamine resin, or a thermoplastic resin such as polyphenylene sulfide or polyamide. Polyphenylene ether, polyether ether ketone, polyethersulfone, or a blended polymer of these as a main component, and if necessary, a material filled with an inorganic filler is used. As the inorganic filler, a material in which fused silica powder, quartz powder, glass powder, short glass fiber, alumina, aluminum nitride, silicon nitride, boron nitride, or the like is used.

The insulating resin 9 is mainly composed of, for example, silicone gel, silicone rubber, epoxy resin, polyurethane foam, and, if necessary, alumina as an inorganic filler.
A material containing aluminum nitride, silicon nitride, fused silica powder and the like is used.

The semiconductor device 1 includes an insulating substrate 6 mounted on a metal base 5, a power semiconductor element 7, a circuit wiring 8
Are housed in the outer case 2 and these are the insulating resin 9.
, The intrusion of moisture from the outside is prevented. The outer case 2, the lid 3, the metal base 5, and the external terminal 4 are respectively bonded and joined by a method using an adhesive, a sealing material, or the like, or by a fitting method. adhesive,
Epoxy, silicone, hot melt, synthetic rubber, or the like is used as the sealing material.

Here, the moisture resistance of the semiconductor device 1 will be described with reference to FIG. FIG. 3 shows that the semiconductor device according to the related art and the semiconductor device 1 according to the embodiment of the present invention are left for a certain period of time in an environment of a temperature of 60 ° C. and a humidity of 90%, and then withstand a test voltage of 4.5 kV. This is the result of the test. As can be seen from the figure, the breakdown voltage of the semiconductor device according to the prior art is degraded as the storage time increases. However, in the case of the present invention, even when the semiconductor device is left under the environment of 60 ° C. and 90% humidity for 1000 hours, The breakdown voltage has not deteriorated. Therefore, it is understood that the semiconductor device 1 according to the present invention has significantly improved moisture resistance as compared with the conventional semiconductor device.

According to the semiconductor device 1 according to the embodiment, since the external terminals 4 are led out from one side surface of the outer case 2, the space required for the lid on the upper surface of the outer case 52 of the prior art is reduced by half. I do. In addition, since the external terminals 4 are concentrated on one side surface, the assembling method and the attachment to the partner device are facilitated. Further, the lid 3 also has a function as a pressure relief valve, and prevents an explosion due to an increase in internal pressure when an accident occurs due to an overcurrent or the like.

(First Modification) A first modification will be described with reference to FIG. FIG. 4 is an enlarged cross-sectional view of the lid 3 of the semiconductor device. As shown in FIG. 4, a feature of the first modification is that the lid 3 and the external terminal 4 are integrally formed. Further, as shown in FIG. 4, when the lid 3 is formed integrally with the external terminal 4, the lid 3 may be integrated with the metal base 5. Injection molding, transfer molding, compression molding, or the like is used as a method of integral formation.

With such a configuration, the lid 3 and the external terminal 4 can be closely attached without any gap. In addition, it is not necessary to align the lid 3 and the external terminals 4 at the time of assembling, so that positional deviation due to dimensional errors and the like and deformation of the external terminals 4 due thereto are suppressed, and the external terminals 4 can be fixed accurately. Further, the accuracy of attachment to the partner device is improved. Furthermore, since the electric field concentration at the joint between the lid 3 and the external terminal 4 is reduced, the insulation distance between the external terminals 4 can be reduced. By reducing the insulation distance, the entire semiconductor device can be reduced in size and thickness.

(Second Modification) A second modification will be described with reference to FIG. FIG. 5 is a cross-sectional view along the y direction in FIG. As shown in FIG. 5, the features of the second modification are as follows.
That is, the metal base 5 and the bottom opening 12 are fitted.
Further, the bottom opening 12 of the outer case 2 and the side surface of the metal base 5 may be tapered. The metal base 5 and the bottom opening 12 are bonded and joined by a method using an adhesive, a sealing material, or the like, or by a fitting method. Epoxy, silicone, hot melt, adhesive and sealant
Use synthetic rubber or the like.

With such a configuration, the bottom opening 12
The entire bottom surface of the metal base 5 can be secured as the heat dissipation surface 13 while suppressing the generation of a gap between the metal base 5 and the metal base 5. Further, the bottom surface of the entire semiconductor device can be planarized.
Therefore, the moisture resistance is improved and the heat dissipation is improved, so that the power semiconductor element 7 has excellent electrical characteristics with improved thermal characteristics. Further, the internal thermal stress is reduced, and the reliability is improved. It will be further thinner.

(Third Modification) A third modification will be described with reference to FIG. FIG. 6 is a cross-sectional view along the y direction in FIG. As shown in FIG. 6, the features of the third modification are as follows.
That is, a trapezoidal protrusion 14 is provided on the bottom surface of the metal base 5. Further, the protrusion 14 may be fitted to the bottom opening 12.

With such a configuration, the contact portion between the surrounding case 2 and the metal base 5 can be widened and the adhesion can be strengthened. Further, it is possible to prevent the metal base 5 from falling off from the bottom opening 12 of the outer case 2. Therefore, high reliability of the entire apparatus can be obtained together with high humidity resistance.

(Fourth Modification) A fourth modification will be described with reference to FIG. FIG. 7 is a cross-sectional view along the y direction in FIG. As shown in FIG. 7, the feature of the fourth modification is that the shape of the protrusion 14 is made to correspond to the insulating substrate 6. Further, as shown in FIG. 7, the protrusion 14 may be fitted to the bottom opening 12.

According to this structure, the contact portion between the outer case 2 and the metal base 5 is widened as in the third modification,
Adhesion can be enhanced. Further, heat of the power semiconductor element 7 can be efficiently dissipated.

(Fifth Modification) A fifth modification will be described with reference to FIG. FIG. 8 is a cross-sectional view along the x direction of FIG. As shown in FIG. 8, the feature of the fifth modification is that a convex rib 15 formed on the side surface inside the outer case 2 and in contact with a part of the metal base 5 is provided.

With this configuration, the number of contact surfaces between the outer case 2 and the metal base 5 is increased, the positioning is facilitated, and the assembling accuracy and the assembling speed are improved. That is, it is possible to obtain a semiconductor device having improved moisture resistance and excellent electrical characteristics, and having reduced manufacturing costs.

(Sixth Modification) A sixth modification will be described with reference to FIG. FIG. 9 is an external perspective view of the outer case 2. As shown in FIG. 9, the feature of the sixth modification is that the side opening 10 and the bottom opening 12 are formed by one opening.

With such a configuration, a wide area on the bottom surface of the metal base 5 can be used as the heat radiation surface 13. Therefore, the thermal characteristics of the power semiconductor element 7 are improved, the electrical characteristics are excellent, and the internal thermal stress is reduced, so that high reliability can be obtained.

(Seventh Modification) A seventh modification will be described with reference to FIG. FIG. 10 is an enlarged view of a portion of a rib 15 in a cross section along the x direction in FIG. As shown in FIG. 10, the feature of the seventh modification is that, as shown in FIG. 10A, a groove 16 is provided on the side surface of the metal base 5, and the rib 15 is shaped to fit into the groove 16. That is. FIG.
As shown in FIG. 0 (b), the ribs 21 and the grooves 20 inside the outer case 2 may have a tapered shape. Rib 15,
The groove 21 and the grooves 16 and 20 are bonded and joined by a method using an adhesive, a sealing material or the like, or by a fitting method. Epoxy, silicone, adhesive and sealing materials
Use hot melt, synthetic rubber, or the like.

With such a configuration, the contact area between the outer case 2 and the metal base 5 is increased, the route of entry of moisture from the outside is lengthened, and the positioning of the metal base 5 is facilitated. Speed is improved. Therefore, the moisture resistance is improved and the manufacturing cost can be suppressed.

(Eighth Modification) An eighth modification will be described with reference to FIG. FIG. 11 is a cross-sectional view along the x direction of FIG. As shown in FIG. 11, the features of the eighth modification are as follows.
That is, a partition plate 17 that divides the insulating resin 9 and the space 11 in the outer case 2 and partially contacts the metal base 5.

With this configuration, the insulating resin 9 and the space 11 inside the outer case 2 can be divided and the partition plate 17 can be used as a positioning guide when the outer case 2 and the metal base 5 are assembled. Can be. Therefore, the thermal stress due to the temperature change of the insulating resin 9 is dispersed,
By relaxing the thermal stress of the insulating resin applied to each electronic component in the outer case 2, deformation and disconnection of circuit wiring and external terminals can be prevented, and excellent electrical characteristics and high reliability can be obtained.

(Ninth Modification) A ninth modification will be described with reference to FIG. FIG. 12 is a cross-sectional view along the y direction in FIG. As shown in FIG. 12, the feature of the ninth modification is that
That is, a part of the external terminal 4 is led out from the upper surface of the outer case 2.

With this configuration, the space in the height direction of the outer case 2 can be reduced. That is,
By reducing the thickness of the outer case 2, the size and weight of the semiconductor device can be reduced.

(Tenth Modification) A tenth modification is shown in FIG.
3 will be described. A feature of the tenth modification is that an epoxy resin is used as the insulating resin. FIG.
Is a result of comparing partial discharge characteristics of the semiconductor device according to the related art and the tenth modification. As can be seen from the figure, the semiconductor device according to the tenth modified example has about twice the partial discharge characteristics as compared with the semiconductor device according to the related art. That is, it is possible to suppress partial discharge generated on the surface of the insulating substrate or the like and obtain excellent electric characteristics.

(Eleventh Modification) FIG. 1 shows an eleventh modification.
This will be described with reference to FIG. FIG. 14 is an enlarged view of the cover 3 in a cross section along the y direction in FIG. The feature of the eleventh modification is that an inlet 18 for the insulating resin 9 is provided in the lid 3.

With such a configuration, the insulating resin 9 can be injected after the entire semiconductor device is sealed with the lid 3. In addition, when an accident occurs due to an overcurrent or the like, it can also function as the pressure relief valve 19 against internal pressure rise. Therefore, excellent electrical performance and high reliability can be obtained by eliminating moisture absorption and foreign matter mixing in the assembly process. Further, a safe semiconductor device in which the resin is prevented from being scattered when an accident due to an overcurrent or the like occurs can be obtained.

(Twelfth Modification) FIG. 1 shows a twelfth modification.
This will be described with reference to FIG. FIG. 15 is a cross-sectional view along the y direction in FIG. A feature of the twelfth modification is that an inlet 18 for the insulating resin 9 is provided in the outer case 2.

With this configuration, it is possible to inject the insulating resin 9 after the entire semiconductor device is sealed with the lid 3. In addition, when an accident occurs due to an overcurrent or the like, it also functions as a pressure relief valve 19 against internal pressure rise.
Therefore, excellent electrical performance and high reliability can be obtained by eliminating moisture absorption and foreign matter mixing in the assembly process.
Further, a safe semiconductor device in which the resin is prevented from being scattered when an accident due to an overcurrent or the like occurs can be obtained.

(Thirteenth Modification) A feature of the thirteenth modification is that the surrounding case 2 and the lid 3 are formed of a recyclable thermoplastic resin. As the thermoplastic resin, for example, polyphenylene sulfide, polyamide, polyphenylene ether, polyether ether ketone,
Polyethersulfone or a blended polymer thereof, or a material containing any of these as a main component and further containing an inorganic filler as necessary is used. And as the inorganic filler, fused silica powder, quartz powder,
Glass powder, short glass fiber, alumina, aluminum nitride, silicon nitride, boron nitride, and the like are compounded.

With such a configuration, the surrounding case 2,
It is possible to reuse the lid 3, the scum generated when forming the lid 3 and the excess resin. Therefore,
It is possible to recycle waste resin generated during the manufacture of a semiconductor device or during its life, breakage, and the like.

(Fourteenth Modification) A fourteenth modification is shown in FIG.
This will be described with reference to FIG. FIG. 16 is a cross-sectional view along the y direction in FIG. As shown in FIG. 16, a feature of the fourteenth modification is that a space 11 that is not filled with the insulating resin 9 in the outer case 2 is formed on the side surface on the side of the lid 3.

According to such a configuration, after each electronic component is placed inside the outer case 2, the insulating resin 9 is inserted through the opening 10.
Can be filled. That is, by making the space 11 formed between the surface filled with the insulating resin 9 and the ceiling surface inside the outer case 2 a side surface, the thickness of the semiconductor device can be reduced.

(Fifteenth Modification) FIG. 1 shows a fifteenth modification.
This will be described with reference to FIG. FIG. 17 shows a cross-sectional view along the x direction of FIG. As shown in FIG. 17, a feature of the fifteenth modification is that the cross-sectional shape of the outer case 2 is a race track shape.

With this configuration, when an external force is applied or when the outer case 2 is deformed due to a temperature change, the stress generated in the outer case 2 can be dispersed. Therefore, the structural strength of the outer case 2 is increased, and a plurality of semiconductor devices can be stacked, so that high reliability and space saving can be achieved.

[0054]

According to the present invention, a semiconductor device having high moisture resistance and excellent electrical characteristics can be provided.

Further, according to the present invention, a small, thin, and compact semiconductor device having excellent durability and reliability can be provided.

Further, according to the present invention, it is possible to provide a safe semiconductor device with low manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is an external perspective view of the semiconductor device according to the embodiment of the present invention.

FIG. 3 is a diagram showing the results of a dielectric strength test of a semiconductor device.

FIG. 4 is an enlarged cross-sectional view showing a structure of a lid portion of a semiconductor device according to a first modification.

FIG. 5 is a cross-sectional view illustrating a structure of a semiconductor device according to a second modification.

FIG. 6 is a cross-sectional view illustrating a structure of a semiconductor device according to a third modification.

FIG. 7 is a cross-sectional view illustrating a structure of a semiconductor device according to a fourth modification.

FIG. 8 is a cross-sectional view illustrating a structure of a semiconductor device according to a fifth modification.

FIG. 9 is a sectional view showing a structure of an outer case according to a sixth modification;

FIG. 10 is an enlarged cross-sectional view showing a structure of a rib portion of a semiconductor device according to a seventh modification.

FIG. 11 is a sectional view showing a structure of a semiconductor device according to an eighth modification;

FIG. 12 is a cross-sectional view illustrating a structure of a semiconductor device according to a ninth modification.

FIG. 13 is a diagram showing partial discharge characteristics of a semiconductor device.

FIG. 14 is an enlarged sectional view showing a structure of a lid portion of a semiconductor device according to an eleventh modification.

FIG. 15 is a sectional view showing a structure of a semiconductor device according to a twelfth modification.

FIG. 16 is a sectional view showing a structure of a semiconductor device according to a fourteenth modification.

FIG. 17 is a cross-sectional view illustrating a structure of a semiconductor device according to a fifteenth modification.

FIG. 18 is a cross-sectional view illustrating a structure of a semiconductor device according to a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor device 2 Surrounding case 3 Lid 4 External terminal 5 Metal base 6 Insulating substrate 7 Power semiconductor element 8 Circuit wiring 9 Insulating resin 10 Side opening 11 Space 12 Bottom opening 13 Heat radiating surface 14 Protrusion 15, 21 Rib 16 , 20 groove 17 partition plate 18 inlet 19 pressure relief valve

Continued on the front page (72) Inventor Toshio Shimizu 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu Plant, Inc.

Claims (16)

[Claims] 1. A book case having a side opening on one side of a flat box, an outer case having a bottom opening on another side which is not opposed to the one side, and an outer case exposed from the bottom opening. A metal base for sealing the bottom opening, an insulating substrate fixed on the back surface of the heat dissipating surface, a power semiconductor element fixed on the insulating substrate, Fixed circuit wiring, an external terminal led out of the outer case from at least one side surface of the outer case, a lid for sealing the side opening, and a filling in the outer case, A semiconductor device comprising: the metal base, the insulating substrate, the power semiconductor element, and an insulating resin that seals the circuit wiring. 2. The semiconductor device according to claim 1, wherein said lid and said external terminal are integrally formed. 3. The semiconductor device according to claim 1, wherein said metal base and said bottom opening are fitted. 4. The semiconductor device according to claim 1, wherein a trapezoidal protrusion is provided on a bottom surface of said metal base. 5. The semiconductor device according to claim 4, wherein the shape of the projecting portion corresponds to an insulating substrate. 6. The semiconductor device according to claim 1, wherein a convex rib formed on a side surface inside the outer case and in contact with a part of the metal base is provided. 7. The semiconductor device according to claim 1, wherein said side opening and said bottom opening are formed by one opening. 8. The semiconductor device according to claim 6, wherein a groove is provided on a side surface of said metal base, and said rib is shaped to fit into said groove. 9. The semiconductor device according to claim 1, further comprising a partition plate which divides the insulating resin and the space in the outer case and a part of which is in contact with the metal base. 10. The semiconductor device according to claim 1, wherein a part of the external terminal is led out from an upper surface of the outer case. 11. The semiconductor device according to claim 1, wherein an epoxy resin is used as said insulating resin. 12. The semiconductor device according to claim 1, wherein said lid is provided with an inlet for said insulating resin. 13. The semiconductor device according to claim 1, wherein an inlet for the insulating resin is provided in the outer case. 14. The semiconductor device according to claim 1, wherein said outer case and said lid are formed of a recyclable thermoplastic resin. 15. The semiconductor device according to claim 1, wherein a space that is not filled with the insulating resin in the outer case is formed on the one side surface. 16. The semiconductor device according to claim 1, wherein the outer case has a race track shape in cross section.