Semiconductor device

Abstract

Reduce the moisture intrusion path in a semiconductor device. The semiconductor device (100) includes: a semiconductor element (1); a housing (2) that houses the semiconductor element (1); a packaging material (3) that is filled in the housing (2); a low moisture permeability sheet (11) that covers the packaging material (3); and a lid (12) that closes the opening of the housing (2). The low moisture permeability sheet (11) is made of a low moisture permeability material with a moisture permeability of less than or equal to 1 g / m<supgt;2< / supgt;×24 Hr. The peripheral portion of the low moisture permeability sheet (11) is clamped between the housing (2) and the lid (12).

Description

Technical Field

[0001] The present invention relates to a semiconductor device. Background Art

[0002] A semiconductor device for power control having a structure in which a semiconductor element is encapsulated in a housing is widely known. As a material of the housing, high heat-resistant and high-insulation engineering plastics such as polyphenylene sulfide (PPS) are mostly used. As a packaging material filled in the housing, a silicone gel or an epoxy resin is used. In addition, a lid for protecting the packaging material is provided on the housing. Usually, the same material as that of the housing is used for the lid. Hereinafter, the semiconductor element for power control and the semiconductor device may be referred to as a "power semiconductor element" and a "power semiconductor device", respectively.

[0003] With the SiC element conversion of the power semiconductor element and the improvement of the temperature characteristics of the Si element, the market requirements for the power semiconductor device are gradually expanding. For example, as a usage guarantee, a moisture absorption tolerance that has been used for reference tests is required. As a moisture absorption tolerance test, in a high-temperature and high-humidity bias (THB) test defined in JEITA ED-4701 102A, a storage test of applying a specified voltage is performed in an environment of, for example, a temperature of 85°C and a humidity of 85%.

[0004] If the moisture permeability in the power semiconductor device deepens, it is possible that the insulation resistance decreases at the surface of the power semiconductor element, the surface of a high-insulation component such as an insulating substrate on which the power semiconductor element is mounted, and the life of the power semiconductor device becomes short. In particular, the terminal portion of the power semiconductor element made of SiC shrinks, and since it is a portion where a high electric field is applied, the adverse effect of the decrease in the insulation resistance of the terminal portion due to moisture absorption is large.

[0005] The main paths of moisture permeability and moisture absorption of the power semiconductor device having the above structure are the bonding interface and fitting portion of the housing and the lid. For example, the following technique is disclosed in Patent Document 1 below. That is, in order to suppress the intrusion of gas, moisture, etc. caused by the use environment of the semiconductor device, a sheet is disposed on the packaging material of the semiconductor device.

[0006] Patent Document 1: Japanese Patent Laid-Open No. 2014-150204

[0007] In the technique of Patent Document 1, there is a concern that moisture may intrude from the gap due to the generation of a gap between the sheet and the housing. Summary of the Invention

[0008] The present invention has been made to solve such problems, and an object thereof is to suppress the intrusion of moisture into the semiconductor device.

[0009] The semiconductor device according to the present invention includes: a semiconductor element; a housing that houses the semiconductor element; a packaging material that is filled in the housing that houses the semiconductor element; a first low moisture permeability sheet that covers the packaging material and is made of a low moisture permeability material having a moisture permeability of less than or equal to 1 g / m 2 ×24Hr; and a lid that closes the opening of the housing, and a peripheral portion of the first low moisture permeability sheet is sandwiched between the housing and the lid.

[0010] Effects of the Invention

[0011] According to the present invention, the path for moisture to enter the semiconductor device can be reduced, and thus the intrusion of moisture into the semiconductor device is suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a cross-sectional schematic view of the semiconductor device according to Embodiment 1.

[0013] Figure 2 is a perspective view of the low moisture permeability sheet in Embodiment 1.

[0014] Figure 3 is a cross-sectional schematic view showing the manufacturing process of the semiconductor device according to Embodiment 1.

[0015] Figure 4 is a cross-sectional schematic view showing the manufacturing process of the semiconductor device according to Embodiment 1.

[0016] Figure 5 is a cross-sectional schematic view showing the manufacturing process of the semiconductor device according to Embodiment 1.

[0017] Figure 6 is a cross-sectional schematic view showing the manufacturing process of the semiconductor device according to Embodiment 1.

[0018] Figure 7 is a cross-sectional schematic view of the semiconductor device according to Embodiment 2.

[0019] Figure 8 is a top view and a cross-sectional view of the low moisture permeability sheet in Embodiment 2.

[0020] Figure 9 is a cross-sectional schematic view of the semiconductor device according to Embodiment 3.

[0021] Figure 10 is a top view of the low moisture permeability sheet in Embodiment 3.

[0022] Figure 11 is a cross-sectional schematic view showing the manufacturing process of the semiconductor device according to Embodiment 3.

[0023] Figure 12 is a cross-sectional schematic view showing the manufacturing process of the semiconductor device according to Embodiment 3.

[0024] Figure 13 is a cross-sectional schematic view showing the manufacturing process of the semiconductor device according to Embodiment 3.

[0025] Figure 14 is a cross-sectional schematic view showing the manufacturing process of the semiconductor device according to Embodiment 3.

[0026] Figure 15 is a cross-sectional schematic view of the semiconductor device according to Embodiment 4.

[0027] Figure 16 is a cross-sectional schematic view showing the manufacturing process of the semiconductor device according to Embodiment 4.

[0028] Figure 17 is a cross-sectional schematic view showing the manufacturing process of the semiconductor device according to Embodiment 4.

[0029] Figure 18 is a cross-sectional schematic view showing the manufacturing process of the semiconductor device according to Embodiment 4.

[0030] Figure 19 is a cross-sectional schematic view showing the manufacturing process of the semiconductor device according to Embodiment 4. Detailed Embodiments

[0031] <Embodiment 1>

[0032] Figure 1 is a cross-sectional schematic view of the semiconductor device 100 according to Embodiment 1. As Figure 1 shown, the semiconductor device 100 is a power semiconductor device having a structure in which a power semiconductor element, i.e., semiconductor element 1, is housed in a housing 2 and encapsulated with a packaging material 3. The semiconductor element 1 is an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) formed using silicon (Si), silicon carbide (SiC), gallium nitride (GaN), etc.

[0033] The semiconductor element 1 is mounted on an insulating substrate 4, and the insulating substrate 4 is mounted on a base plate 6. The insulating substrate 4 is composed of an insulating layer 4a, a circuit pattern 4b formed on the upper surface of the insulating layer 4a, and a circuit pattern 4c formed on the lower surface of the insulating layer 4a. The semiconductor element 1 is joined to the circuit pattern 4b via a bonding material 5, and the base plate 6 is joined to the circuit pattern 4c via a bonding material 7.

[0034] The materials of the insulating layer 4a and the circuit patterns 4b and 4c are not limited. For example, the insulating layer 4a can be made of inorganic ceramic materials such as aluminum oxide (Al 2 O 3 ), aluminum nitride (AlN), silicon nitride (Si 3 N 4 ). The circuit patterns 4b and 4c can be made of, for example, copper or its alloys, aluminum or its alloys, etc. As the bonding materials 5 and 7, solders or solder alloys made of lead (Pb), tin (Sn), etc., or sintered materials made of nano silver or nano copper particles are used. The material of the bonding material 5 and the material of the bonding material 7 can be the same as each other or different.

[0035] The material of the base plate 6 can be a metal material such as copper, aluminum, copper - molybdenum alloy (CuMo), etc., or a composite material such as aluminum - silicon carbide composite (AlSiC) or magnesium - silicon carbide composite (MgSiC).

[0036] The housing 2 is also mounted on the base plate 6, and the housing 2 is bonded to the base plate 6 using an adhesive 8 (the second adhesive).

[0037] Electrodes 9 for connection with the outside are assembled in the housing 2. The semiconductor element 1, the circuit pattern 4b, and the electrode 9 are connected or directly connected via a metal wire 10 to form an electrical circuit. As the material of the electrode 9, for example, metals mainly composed of copper (Cu) or its alloys are mostly used. In addition, a plating such as Ni can be provided on the surface of the electrode 9. As the material of the metal wire 10, aluminum (Al), copper (Cu), or their alloys are used.

[0038] The encapsulation material 3 is filled in the housing 2 to encapsulate the semiconductor element 1 and the insulating substrate 4 on which the semiconductor element 1 is mounted. The material of the encapsulation material 3 is, for example, an insulating resin such as silicone resin or epoxy resin.

[0039] And, a low - moisture - permeability sheet 11 (the first low - moisture - permeability sheet) made of a low - moisture - permeability material is provided in the housing 2 so as to cover the encapsulation material 3. In Embodiment 1, the flat - shaped low - moisture - permeability sheet 11 shown Figure 2 is used. The low - moisture - permeability material constituting the low - moisture - permeability sheet 11 is a material with low permeability of moisture and gas such as fluororesins such as polytetrafluoroethylene (PTFE), and preferably its moisture permeability is less than or equal to 1 g / m 2 ×24 Hr. In addition, the moisture permeability is defined by "Test Method for Permeation Humidity of Moisture - Proof Packaging Materials" of JIS Z0208, etc.

[0040] In order to prevent the semiconductor device 100 from being enlarged, the thickness of the low moisture permeable sheet 11 is preferably 3 mm or less, and more preferably 1 mm or less. The low moisture permeable sheet 11 may be in contact with the upper surface of the sealing material 3 .

[0041] The opening of the housing 2 is blocked by a cover 12, and the cover 12 is bonded to the housing 2 using an adhesive 13 (first adhesive). Figure 1 As shown, the peripheral edge of the low moisture permeable sheet 11 is sandwiched by the housing 2 and the cover 12. The materials of the housing 2 and the cover 12 only need to have electrical insulation properties, and can be formed of, for example, epoxy resin or polyphenylene sulfide (PPS) resin. In addition, the adhesives 8 and 13 can be conventional silicone adhesives, or can be composed of low moisture permeable materials such as acrylic resins.

[0042] Here, yes Figure 1 The structure of the semiconductor device 100 formed by the housing 2, the low moisture permeable sheet 11 and the cover 12 is described in detail. The cover 12 has a convex portion 12a of a shape that fits with the opening of the housing 2, and the housing 2 has a countersunk portion 2a at the periphery of the opening. Therefore, if the convex portion 12a of the cover 12 fits with the opening of the housing 2, the convex portion 12a and the countersunk portion 2a are opposite. The low moisture permeable sheet 11 extends above the countersunk portion 2a of the housing 2, and the periphery of the low moisture permeable sheet 11 is sandwiched between the convex portion 12a and the countersunk portion 2a.

[0043] The adhesive 13 that bonds the housing 2 and the cover 12 is placed on the portion where the low moisture permeable sheet 11 is not sandwiched (at Figure 1 The thickness direction of the adhesive 13 is the same as the thickness direction of the low moisture permeable sheet 11 at the portion sandwiched by the housing 2 and the lid 12. As a result, when the adhesive 13 is cured and shrunk, the countersunk portion 2a of the housing 2 and the convex portion 12a of the lid 12 pull each other, thereby obtaining an effect of increasing the adhesion between the countersunk portion 2a and the convex portion 12a and the low moisture permeable sheet 11 sandwiched therebetween. In particular, if the low moisture permeable sheet 11 is formed of an elastic material such as a fluororesin, the low moisture permeable sheet 11 is elastically deformed, and high adhesion is obtained with the countersunk portion 2a and the convex portion 12a.

[0044] According to the semiconductor device 100 involved in the first embodiment, the packaging material 3 that packages the semiconductor element 1 in the housing 2 is covered with the low moisture permeability sheet 11 made of a low moisture permeability material, and the peripheral edge of the low moisture permeability sheet 11 is sandwiched between the housing 2 and the cover 12, thereby making it difficult for a gap to be generated between the housing 2 and the low moisture permeability sheet 11. Therefore, the number of paths for moisture to enter the housing 2 is reduced, and moisture is prevented from entering the housing 2, thereby improving the moisture resistance of the semiconductor device 100. For example, even if a conventional silicone adhesive (moisture permeability of 10 g / m2) is used as the adhesive 13 that bonds the housing 2 to the cover 12, the moisture permeability of the semiconductor device 100 is improved. 2 ×24Hr~100g / m2 Even when the thickness of the low moisture permeable sheet 11 is about 24 Hr or less, sufficient moisture-proof effect can be obtained. In addition, since a high moisture-proof effect is obtained by the low moisture permeable sheet 11, miniaturization of the semiconductor device 100 can also be facilitated by narrowing the width of the region coated with the adhesive 13. In particular, when the semiconductor element 1 is a SiC element, its terminal portion shrinks and is a portion where a high electric field is applied, and the adverse effect of the decrease in the insulation resistance of the terminal portion due to moisture absorption is large. Therefore, the above effect is effective.

[0045] It is also possible to provide irregularities on the surface of the low moisture permeable sheet 11 to roughen the surface of the low moisture permeable sheet 11. By roughening the surface of the low moisture permeable sheet 11, the adhesiveness between the low moisture permeable sheet 11 and the encapsulation material 3 is improved, and further suppression of the moisture intrusion path can be expected. The method of roughening the low moisture permeable sheet 11 can be a physical method or a chemical method. For example, a method of providing irregularities on the surface of the mold used for molding the low moisture permeable sheet 11 can be considered.

[0046] Here, a method for manufacturing the semiconductor device 100 will be described. First, the base plate 6, the bonding material 7, the insulating substrate 4, the bonding material 5, and the semiconductor element 1 are stacked in this order, and reflow is performed in a reduced pressure or reducing gas atmosphere, and a thermal history greater than or equal to the melting temperature of the bonding material 5 and the bonding material 7 is given, thereby indirectly bonding the respective components. Next, wiring between the semiconductor elements 1 or between the semiconductor element 1 and the insulating substrate 4 is performed by ultrasonic bonding of the metal wires 10.

[0047] Next, the adhesive 8 is linearly coated on the outer peripheral portion of the base plate 6 (the bonding portion with the housing 2), the housing 2 is placed on the adhesive 8, and the adhesive 8 is thermally cured, thereby bonding the base plate 6 and the housing 2. Then, the electrode 9 assembled to the housing 2 is bonded to the insulating substrate 4 by ultrasonic bonding.

[0048] Next, as Figure 3 shown, the encapsulation material 3 is filled in the housing 2, and the encapsulation material 3 is thermally cured using an oven or the like, thereby encapsulating the semiconductor element 1. Then, as Figure 4 shown, the encapsulation material 3 is covered with the low moisture permeable sheet 11. At this time, the peripheral portion of the low moisture permeable sheet 11 is placed on the counterbore portion 2a of the housing 2.

[0049] Then, as Figure 5 shown, the adhesive 13 is linearly or dotwise coated on the edge portion of the housing 2 (the bonding portion with the lid 12). Then, as Figure 6As shown, the convex portion 12a of the lid 12 is fitted into the opening of the housing 2, and the opening of the housing 2 is blocked by the lid 12. At this time, the convex portion 12a of the lid 12 abuts on the upper surface of the peripheral portion of the low moisture permeability sheet 11. Then, the adhesive 13 is thermally cured to bond the housing 2 and the lid 12. When the adhesive 13 cures and shrinks, the counterbore portion 2a of the housing 2 and the convex portion 12a of the lid 12 pull on each other, increasing the tightness between the counterbore portion 2a and the convex portion 12a and the low moisture permeability sheet 11 clamped therebetween. Through the above steps, the Figure 1 semiconductor device 100 shown is completed.

[0050] <Embodiment 2>

[0051] Figure 7 is a cross-sectional schematic view of the semiconductor device according to Embodiment 2. In addition, Figure 8 is a top view and a cross-sectional view of the low moisture permeability sheet 11 in Embodiment 2. In Embodiment 2, the low moisture permeability sheet 11 has a convex portion 11a at its peripheral portion, i.e., the portion clamped by the housing 2 and the lid 12, and a groove 2b for inserting the convex portion 11a of the low moisture permeability sheet 11 is provided in the housing 2.

[0052] In addition, in the present embodiment, since the convex portion 11a is provided at the end of the low moisture permeability sheet 11, the end of the low moisture permeability sheet 11 is L-shaped when viewed in cross-section (as Figure 8 shown, if viewed as a whole in the cross-section of the low moisture permeability sheet 11, it is "U"-shaped). In addition, the groove 2b of the housing 2 is provided in the counterbore portion 2a. Other structures are the same as those in Embodiment 1 ( Figure 1 ).

[0053] Any method can be used to provide the convex portion 11a on the low moisture permeability sheet 11. For example, the convex portion 11a can be formed by a mold for molding the low moisture permeability sheet 11, or the Figure 2 lower surface of the flat low moisture permeability sheet 11 as shown can be machined to form the convex portion 11a.

[0054] According to the semiconductor device 100 of Embodiment 2, in addition to the same effects as those in Embodiment 1, the moisture absorption tolerance of the semiconductor device 100 can be further improved by improving the positioning accuracy of the low moisture permeability sheet 11 with respect to the housing 2 and the holding property of the low moisture permeability sheet 11.

[0055] <Embodiment 3>

[0056] Figure 9 is a cross-sectional schematic view of the semiconductor device 100 according to Embodiment 3. As Figure 9 shown, for the semiconductor device 100 of Embodiment 3, a low moisture permeability sheet 14 (second low moisture permeability sheet) is provided at the bonding interface between the housing 2 and the base plate 6. The shape of the low moisture permeability sheet 14 is asFigure 10 As shown, it is box-shaped when viewed from above and extends at the bonding interface between the housing 2 and the base plate 6 so as to surround the encapsulating material 3. The low moisture permeability material constituting the low moisture permeability sheet 14 may be the same as the low moisture permeability sheet 11 covering the encapsulating material 3, and preferably has a moisture permeability of less than or equal to 1 g / m 2 ×24Hr.

[0057] In order to prevent the semiconductor device 100 from becoming large-sized, it is preferable that the thickness of the low moisture permeability sheet 14 is less than or equal to 3 mm, and more preferably less than or equal to 1 mm. In addition, a plurality of box-shaped low moisture permeability sheets 14 may be arranged in a nested manner at the bonding interface between the housing 2 and the base plate 6.

[0058] In addition, in the present embodiment, a groove 2c for inserting a part of the low moisture permeability sheet 14 is formed at the bonding interface between the housing 2 and the base plate 6, and a groove 6a for inserting a part of the low moisture permeability sheet 14 is also formed at the bonding interface between the base plate 6 and the housing 2. Therefore, the thickness of the low moisture permeability sheet 14 is formed to be larger than the thickness of the adhesive 8 that bonds the housing 2 and the base plate 6. In addition, the low moisture permeability sheet 14 extends inside the adhesive 8. That is, the adhesive 8 is provided on both sides of the low moisture permeability sheet 14. Other structures are the same as those in Embodiment 1( Figure 1 )

[0059] The manufacturing method of the semiconductor device 100 of Embodiment 3 will be described. First, the base plate 6 having the groove 6a, the bonding material 7, the insulating substrate 4, the bonding material 5, and the semiconductor element 1 are sequentially stacked, and reflow is performed in a reduced pressure or reducing gas atmosphere to give a thermal history greater than or equal to the melting temperature of the bonding material 5 and the bonding material 7, thereby indirectly bonding the respective components. Next, wiring between the semiconductor elements 1 or between the semiconductor element 1 and the insulating substrate 4 is performed by ultrasonic bonding of the metal wires 10. As a result, the Figure 11 structure is obtained.

[0060] Next, as Figure 12 shown, the adhesive 8 is linearly applied to both sides of the groove 6a at the outer peripheral portion (bonding portion with the housing 2) of the base plate 6. In addition, as Figure 13 shown, the low moisture permeability sheet 14 is placed on the base plate 6. At this time, the lower part of the low moisture permeability sheet 14 is inserted into the groove 6a. Then, as Figure 14 shown, the housing 2 having the groove 2c is placed on the adhesive 8. At this time, the upper part of the low moisture permeability sheet 14 is inserted into the groove 2c. Then, the adhesive 8 is thermally cured to bond the base plate 6 and the housing 2.

[0061] Then, in the same manner as in Embodiment 1, the electrode 9 assembled to the housing 2 is bonded to the semiconductor element 1 or the insulating substrate 4, the semiconductor element 1 is encapsulated with the encapsulation material 3, the encapsulation material 3 is covered with the low moisture permeable sheet 11, and then the lid 12 is bonded to the housing 2. Thus, the Figure 9 semiconductor device 100 shown is completed.

[0062] In the semiconductor device 100 according to Embodiment 3, in addition to the same effects as in Embodiment 1, the effect of reducing moisture absorption generated by the adhesive 8 between the housing 2 and the base plate 6 is obtained, and the moisture absorption tolerance of the semiconductor device 100 can be further improved.

[0063] <Embodiment 4>

[0064] Figure 15 is a cross-sectional schematic view of the semiconductor device 100 according to Embodiment 4. With respect to the structure of Embodiment 3 ( Figure 9 ), the structure of the semiconductor device 100 according to Embodiment 4 is such that the thickness of the low moisture permeable sheet 14 provided at the bonding interface between the housing 2 and the base plate 6 is the same as the thickness of the adhesive 8. Since the thickness of the low moisture permeable sheet 14 is the same as the thickness of the adhesive 8, the grooves 2c provided in the housing 2 and the grooves 6a provided in the base plate 6 in Embodiment 2 are not required, which can contribute to an improvement in productivity and a reduction in processing costs.

[0065] A method for manufacturing the semiconductor device 100 according to Embodiment 4 will be described. First, the base plate 6, the bonding material 7, the insulating substrate 4, the bonding material 5, and the semiconductor element 1 are stacked in sequence, and reflow is performed in a reduced pressure or reducing gas atmosphere, and a thermal history greater than or equal to the melting temperature of the bonding material 5 and the bonding material 7 is given, thereby indirectly bonding the components. Next, wiring between the semiconductor elements 1 or between the semiconductor element 1 and the insulating substrate 4 is performed by ultrasonic bonding of the metal wires 10. As a result, the Figure 16 structure is obtained.

[0066] Next, as Figure 17 shown, the adhesive 8 is linearly applied to both sides of the position where the low moisture permeable sheet 14 is to be provided at the outer peripheral portion (bonding portion with the housing 2) of the base plate 6. Then, as Figure 18 shown, the low moisture permeable sheet 14 is placed on the base plate 6. Different from Embodiment 3, there is no groove 6a for inserting the low moisture permeable sheet 14 in the base plate 6, but the position of the low moisture permeable sheet 14 is fixed by the paste-like adhesive 8. Then, as Figure 19 shown, the housing 2 is placed on the adhesive 8, and the adhesive 8 is thermally cured, thereby bonding the base plate 6 and the housing 2.

[0067] Then, in the same manner as in Embodiment 1, the electrode 9 assembled to the housing 2 is joined to the semiconductor element 1 or the insulating substrate 4, the semiconductor element 1 is encapsulated with the encapsulation material 3, the encapsulation material 3 is covered with the low moisture permeable sheet 11, and then the lid 12 is bonded to the housing 2. Thus, the Figure 15 semiconductor device 100 shown is completed.

[0068] In addition, the respective embodiments can be freely combined, or the respective embodiments can be appropriately modified or omitted.

[0069] Description of reference numerals

[0070] 1 Semiconductor element, 2 Housing, 2a Countersunk portion, 2b Groove, 2c Groove, 3 Encapsulation material, 4 Insulating substrate, 4a Insulating layer, 4b Circuit pattern, 4c Circuit pattern, 5 Bonding material, 6 Base plate, 6a Groove, 7 Bonding material, 8 Adhesive, 9 Electrode, 10 Metal wire, 11 Low moisture permeable sheet, 11a Protrusion, 12 Lid, 12a Protrusion, 13 Adhesive, 14 Low moisture permeable sheet, 100 Semiconductor device.

Claims

1. A semiconductor device having: A semiconductor element; A housing that houses the semiconductor element; A packaging material filled in the housing that houses the semiconductor element; The first low moisture permeability sheet covers the encapsulation material and is made of a low moisture permeability material with a moisture permeability of less than or equal to 1 g / m 2 ×24Hr; and A lid that covers the first low moisture permeability sheet and blocks the opening of the housing, The peripheral portion of the first low moisture permeability sheet is clamped between the housing and the lid.

2. The semiconductor device according to claim 1, wherein, The housing has a countersunk portion at the periphery of the opening, The lid has a convex portion that fits into the opening of the housing, The first low moisture permeability sheet is clamped between the countersunk portion of the housing and the convex portion of the lid.

3. The semiconductor device according to claim 1 or 2, wherein, The housing and the lid are bonded using a first adhesive at a portion where the first low moisture permeability sheet is not clamped, The thickness direction of the first adhesive is the same as the thickness direction of the first low moisture permeability sheet at the portion clamped by the housing and the lid.

4. The semiconductor device according to claim 1 or 2, wherein, The first low moisture permeability sheet has a convex portion at the portion clamped by the housing and the lid, The housing has a groove for inserting the convex portion of the first low moisture permeability sheet.

5. The semiconductor device according to claim 1 or 2, wherein, The housing is bonded to a base plate on which the semiconductor element is mounted using a second adhesive, It also has a frame-shaped second low moisture permeability sheet that extends at the bonding interface between the housing and the base plate, and the second low moisture permeability sheet is made of a low moisture permeability material with a moisture permeability of less than or equal to 1 g / m 2 ×24Hr.

6. The semiconductor device according to claim 5, wherein, At the bonding interface between the housing and the base plate, the second adhesive is provided on both sides of the second low moisture permeability sheet.

7. The semiconductor device according to claim 5, wherein, The housing and the base plate have grooves for inserting a part of the second low moisture permeability sheet.

8. The semiconductor device according to claim 6, wherein, The housing and the base plate have grooves for inserting a part of the second low moisture permeability sheet.

9. The semiconductor device according to claim 5, wherein, The thickness of the second low moisture permeability sheet is the same as the thickness of the second adhesive.

10. The semiconductor device according to claim 6, wherein, The thickness of the second low moisture permeability sheet is the same as the thickness of the second adhesive.

11. The semiconductor device according to claim 1 or 2, wherein, Unevenness is provided on the surface of the first low moisture permeability sheet.

12. The semiconductor device according to claim 1 or 2, wherein, The low moisture permeability material is a fluororesin.

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