JP2006278607A - Surface-mounting resin-made hollow package and semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin-made hollow package which efficiently radiates heat generated from a semiconductor element to the outside and is superior in bonding stability at packaging. <P>SOLUTION: The resin-made hollow package is composed of a hollow 20 having a bottom surface 4 for mounting a semiconductor element, leads 1, 2 for establishing electric conduction between the semiconductor element 7 mounted in the hollow 20 and a substrate 17, and a resin molding forming the package body 3. Its bottom surface comprises a package lower surface 5 located nearer to the hollow 20 than the bottom surface 6 of the package body. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a resin hollow package for mounting a semiconductor element and a semiconductor device using the same. More specifically, the present invention relates to a resin-made hollow package structure for a semiconductor element that can be applied to a variety of hollow package lead structures having high bonding reliability to a substrate and excellent heat dissipation.

  In recent years, a semiconductor package having a hollow structure (hereinafter referred to as “hollow package”) on which a semiconductor element such as a solid-state imaging element is mounted has been known to employ a resin as a package base (package body) for the purpose of cost reduction. Yes. As a package structure, DIP (Dual Inline Package) is the mainstream, but in recent years, surface mount type SOP (Small Outline Package) and QFP (Quad Flat Package) have been adopted, and further SON (Small Outline). The leadless package structure such as Non Leaded Package (QFN) and QFN (Quad Flat Non Leaded Package) is also being studied. This is because the hollow package is required to be reduced in size and thickness, and the surface mount technology of the hollow package is also being studied.

  On the other hand, the density of semiconductor elements such as solid-state imaging elements has been increasing, and accordingly, the heat generated when operating in a hollow package is increasing. If the generated heat increases, the function of the semiconductor element itself may be lowered, and a structure that can dissipate heat from the hollow package is strongly desired. However, in the resin hollow package for the purpose of reducing the cost, the thermal conductivity of the resin as the package base is lower than that of the ceramic hollow package, and the heat dissipation is low.

In order to enhance the heat dissipation effect of this resin hollow package, a material with high thermal conductivity such as a metal plate is embedded in the bottom surface of the hollow portion, the bottom surface of the hollow package, or from the inside to the bottom surface of the hollow package. Conventionally, a structure for improving the thermal conductivity of the semiconductor element and effectively dissipating the heat generated from the semiconductor element has been proposed (see Patent Documents 1 and 2).
Japanese Patent No. 2996888 Japanese Patent No. 3080236

  In resin hollow packages in which a material with high thermal conductivity such as a metal plate is embedded in the bottom of the hollow part, the bottom of the hollow package, or in the interior, the heat generated from the semiconductor element is efficiently transferred to the bottom of the hollow package. However, in order to dissipate heat from the bottom surface of the hollow package, it is necessary to generate air convection near the bottom surface of the hollow package to release the heat. That is, effective heat dissipation cannot be expected unless there is an air layer near the bottom of the hollow package. However, conventionally, in a hollow package after mounting on a substrate, there is almost no gap between the bottom surface and the substrate, and since there is no air layer, a high heat dissipation effect cannot be expected.

  Also, during mounting, the mounting paste such as solder is melted by heat with the bottom surface of the hollow package as the reference surface, and the lead is joined to the substrate. However, if a metal plate is installed on or near the bottom surface of the hollow package, The bottom surface of the hollow package may swell, and the positioning accuracy of the mounting height may be reduced. Furthermore, due to the expansion of the metal plate accompanying the heat at the time of mounting the board, the board may be pushed up, causing problems such as peeling and cracking in the mounting paste such as solder, which may cause a decrease in mounting strength or poor bonding. .

  Accordingly, an object of the present invention is to provide a resin-made hollow package that can effectively dissipate heat generated from a semiconductor element to the outside and has excellent bonding stability during mounting.

  The resin-made hollow package of the present invention constitutes a package body with a hollow portion having a bottom surface for mounting a semiconductor element, leads for realizing electrical continuity between the semiconductor element mounted in the hollow portion and the outside. A resin hollow package made of a resin molded body is characterized in that a bottom surface portion of the package is provided on the bottom surface portion of the package body located on the hollow portion side of the bottom surface of the package body.

  According to this configuration, since the lower surface portion of the package is positioned on the hollow portion side from the bottom surface of the package body, a gap is generated between the substrate and the lower surface portion of the package even after mounting, and an air layer is secured. That is, when heat generated from the semiconductor element is transmitted to the lower surface portion of the package, convection occurs in the air layer, and heat can be radiated more effectively.

  It is preferable that the package lower surface portion located on the hollow portion side from the bottom surface of the package body has at least the same size as the bottom surface of the semiconductor element. The wider the lower surface of the package, the more the air layer increases, and the convection effect increases and the heat dissipation improves. In addition, if the lower surface of the package is positioned so as to be recessed more greatly on the hollow portion side, in addition to an increase in the air layer, the thickness of the resin portion on the bottom surface of the hollow portion is reduced, so that heat is transferred to the lower surface of the package. The speed increases and a further heat dissipation effect is obtained. The concave shape of the lower surface portion of the package can be easily obtained by preparing and molding the same shape as a convex structure in a molding die.

  In order to cause strong convection in the air layer between the substrate and the lower surface portion of the package and to enable effective heat dissipation, this air gap in the gap between the substrate and the lower surface portion of the package is exchanged. It is preferable to form an air flow passage communicating with the outside. Specifically, in the case where a plurality of notches and through-holes are formed in the forming resin layer (the bottom surface portion of the package main body) surrounding the lower surface portion of the package, or leads are arranged on two peripheral portions of the package main body, In the case where notches and openings are formed in the part, leads are arranged in the four peripheral parts, a plurality of through holes are formed in the substrate surface under the package lower surface part, or an opening having a smaller area than the area of the package lower surface part is formed. By providing it on the substrate, an air flow passage can be formed. Through this airflow path, a strong convection is generated in the air layer in the gap between the substrate and the package lower surface due to the temperature difference between the semiconductor device hermetically sealed in the hollow portion with the lid material and the surrounding area. Can do.

  When higher heat dissipation is required, an island portion made of a metal body having at least the same size as the bottom surface of the semiconductor element may be provided on the bottom surface of the hollow portion, the lower surface portion of the package, or the inside thereof. The wider the island, the greater the heat dissipation effect. The island portion has an effect of increasing heat conduction to the lower surface portion of the package, and the installation position may be any of the bottom surface of the hollow portion, the lower surface portion of the package, or the resin layer inside thereof. The island part is easily obtained by resin molding using a part that is connected to a lead frame via a suspension lead and pressed down (depressed) in advance to a target position after molding.

  By installing the island portion, the heat generated from the semiconductor element is effectively transmitted to the lower surface portion of the package, and the heat is dissipated by the convection of the air layer. Even if an island is installed on the bottom of the package, the shape is exposed on the hollow side of the bottom of the package body, and even if the metal plate expands due to heat during board mounting, the board will not be pushed up. Therefore, there is no possibility of causing peeling or cracking in the mounting paste such as solder. Accordingly, it is possible to obtain a resin-made hollow package with high heat dissipation, in which bonding stability during mounting is ensured.

  Furthermore, in the present invention, a metal plate that is the same as or wider than the bottom surface of the hollow portion can be fixed to the lower surface of the inner lead via an insulating layer. The thickness of the metal plate is preferably thicker, and it is more preferable to select a thickness at which the metal plate is exposed to both the bottom surface of the hollow portion and the lower surface portion of the package. A metal plate having a high thermal conductivity occupies between the bottom surface of the hollow portion and the lower surface portion of the package, and a portion (the lower surface portion of the package) in contact with the air layer is used as the metal plate, whereby high heat dissipation can be obtained. In this case, since the upper die can be firmly clamped by the upper die and the lower surface of the metal plate can be firmly clamped by the lower die, the resin burrs that are likely to be generated on the exposed lower surface of the metal plate and the upper surface of the inner lead can be formed. It can be extremely reduced, and the burden on the subsequent resin burr removal process can be greatly reduced.

  When the metal plate is fixed to the lower surface of the inner lead via an insulating layer, there is a difference in height between the thickness of the lead and the thickness of the insulating layer between the exposed upper surface of the inner lead and the upper surface of the metal plate serving as the bottom surface of the hollow portion. Arise. By setting the height difference to a height close to the thickness of the semiconductor element, it is possible to reduce the height difference between the semiconductor element and the upper surface of the inner lead, and a stable electrical connection is possible. Preferably, if the thickness of the semiconductor element and the thickness including the lead and the insulating layer are made the same, it is possible to provide a more stable and short distance for electrical joining, and to provide a low-cost hollow package. In addition, this structure can greatly reduce the risk of a short circuit due to an impact caused by vibration or the like.

  The metal plate is selected from the group consisting of copper, iron, stainless steel, aluminum and alloys containing these metals, preferably a copper alloy. Surface treatment can be applied to the entire surface or a part as required. For example, gold, silver, nickel, solder, or the like may be plated. In addition, by forming concave and convex portions in the shape of circles, squares, etc. on the upper or lower surface, or upper and lower surfaces of the metal plate, the adhesion with the resin is increased and the heat dissipation is further increased as the specific surface area increases. It becomes possible to raise. Further, by forming the stepped portion at the side end portion of the metal plate, an effect of increasing the specific surface area of the metal plate and enhancing the heat dissipation effect and enhancing the adhesion between the metal plate and the resin can be obtained.

  Exposing the semiconductor mounting surface, that is, the upper surface of the metal plate, provides a higher heat dissipation effect, but there are products that require insulation between the semiconductor element and the resin hollow package, and a resin layer may be provided on the upper surface of the metal plate. Is possible. At this time, in order to avoid the risk of a short circuit at the joint between the semiconductor element and the inner lead, it is preferable that the upper surface of the resin layer and the upper surface of the inner lead are not on the same plane but have a height difference.

  The present invention can also be applied to a thin hollow package. That is, the present invention can also be applied to a non-lead type surface mount type high heat radiation resin hollow package such as SON and QFN.

  First, by using a lead frame formed so as to leave the lower surface of the outer lead that becomes the substrate mounting surface by etching a part of the lower surface of the lead, the lower surface of the outer lead is exposed near the periphery of the bottom surface of the package body. It can be applied to the type of hollow package.

  Secondly, the present invention can be applied to a hollow package of a type in which a lead is bent and the lower surface of the outer lead of the lead is exposed near the periphery of the bottom surface of the package body.

  In the two types of surface mount type hollow packages, the outer leads serving as mounting terminals to the substrate are exposed in the vicinity of the peripheral edge of the bottom surface of the package body, so that the hollow package can be thinned and the lower surface of the package below the hollow portion can be formed. An air layer can be secured and heat dissipation by convection can be obtained.

  Also, in the two types of non-lead type surface mount type hollow packages, an island portion made of a metal plate having at least the same size as the bottom surface of the semiconductor element is installed in the bottom surface of the hollow portion, the lower surface portion of the package, or the inside thereof. can do. Alternatively, a metal plate that is the same as or wider than the bottom surface of the hollow portion can be fixed to the lower surface of the inner lead via an insulating layer. As a result, a higher heat dissipation effect can be obtained. By adopting a structure in which the island portion or the lower surface of the metal plate is exposed to the lower surface portion of the package, convection in the air layer becomes active, and the heat dissipation effect of the present invention can be further enhanced.

  In the structure where the lower surface of the metal plate is exposed on the lower surface of the package, as described above, when forming with the mold, the upper surface of the inner lead is firmly clamped with the upper mold of the mold and the lower surface of the metal plate is firmly clamped with the lower mold. Therefore, resin burrs that are likely to occur on the exposed lower surface of the metal plate and the upper surface of the inner lead can be extremely reduced, and the burden on the subsequent resin burrs removal step can be greatly reduced. In addition to exposing the lower surface of the metal plate to the lower surface of the package, the heat dissipation effect is further enhanced by exposing the upper surface of the metal plate to the bottom surface of the hollow portion that is the mounting surface of the semiconductor element, and in addition, resin burrs are reduced. Even higher effects can be obtained.

  Also, by positioning the height at the bottom surface of the package body at the periphery of the metal plate exposed as the bottom surface of the package, even if the metal plate expands due to heat during board mounting, Since it does not swell, it can be mounted with high precision, and the bottom of the package body pushes up the board, causing problems such as peeling and cracking in mounting paste such as solder, resulting in reduced mounting strength or poor bonding I won't let you.

  In non-lead type surface mount resin hollow packages such as SON and QFN, by forming a step on the bent end surface of the lower surface of the outer lead exposed on the bottom surface of the package body, resin burrs on the exposed lower surface of the outer lead are reduced. As a result, the dimensional accuracy of the exposed portion is improved. The stepped portion can be formed by half press or half etching.

  According to the present invention, it is possible to provide a resin-made hollow package for a semiconductor element that ensures excellent heat dissipation, improves mounting accuracy on a substrate, and does not cause defects such as peeling and cracking in a mounting paste such as solder. it can. In addition to DIP, SOP, QFP, etc., the present invention can provide the same effect with a surface-mount type resin hollow package, and can also provide a thin resin hollow package with extremely high heat dissipation.

  Hereinafter, embodiments of the present invention will be described based on examples shown in the drawings.

  FIG. 1 is a sectional view showing a resin hollow package according to an embodiment of the present invention. In the resin hollow package shown in the figure, the upper surface of the inner lead 1 of the lead is exposed in the hollow portion 20, and the outer lead 2 is gull-wing bent (SOP, QFP type) outside the package body 3 made of a resin molded body. Is given. A package lower surface portion 5 is provided on the bottom surface portion of the package body 3 so as to be recessed toward the hollow portion 20 rather than the bottom surface (hereinafter referred to as “package bottom surface”) 6.

  FIG. 2 shows a semiconductor device using the resin hollow package of FIG. In the semiconductor device shown in the figure, the semiconductor element 7 is fixed to the bottom surface 4 of the hollow portion, the semiconductor element 7 and the inner lead 1 are electrically connected using an electrical bonding material 8, and the lid 9 is attached to the package body 3. It is obtained by adhering to the upper surface of the substrate and hermetically sealing, and is bonded to the mounting substrate 17 using a mounting paste 18. This semiconductor device includes an air layer 19 in a gap between the package lower surface portion 5 and the mounting substrate 17 as shown in the figure. Here, the heat generated by the operation of the semiconductor element 7 is transmitted from the bottom surface 4 of the hollow portion to the package lower surface portion 5 and radiated to the outside air. However, the provision of the air layer 19 causes convection. It becomes an easy environment and it becomes possible to enhance the heat dissipation effect.

  FIG. 3 shows a resin hollow package having a structure in which the island portion 10 is exposed on the bottom surface 4 of the hollow portion. The island portion 10 may be located anywhere as long as it is between the bottom surface 4 of the hollow portion and the lower surface of the package lower surface portion 5. Even if the island portion 10 is exposed on the lower surface of the package lower surface portion 5, the package lower surface portion 5 is located closer to the hollow portion 20 than the package bottom surface 6, so that the island portion 10 expands due to heat during mounting. However, there is no risk of causing defects such as cracking and peeling in the mounting paste without contacting the mounting substrate. Further, the island portion 10 can be easily obtained by resin molding by connecting the island portion 10 to the lead frame via the suspension lead and pressing (depressed) in advance to the target position after molding. it can.

  FIG. 4 shows a resin hollow package having a structure in which a metal plate 11 is fixed to the lower surface of the inner lead 1 of FIG. The thickness of the metal plate 11 is preferably thicker, and higher heat dissipation can be obtained by using a metal plate having a thickness exposed on both the bottom surface 4 of the hollow portion and the lower surface portion 5 of the package. Furthermore, by forming the concavo-convex portions on the upper surface or the lower surface or the upper and lower surfaces of the metal plate 11, the adhesion with the resin is increased, and the heat dissipation can be further enhanced as the specific surface area is increased.

  FIG. 5 shows a lead frame formed so as to leave the lower surface of the outer lead 2 to be a substrate mounting surface by etching the lower surface of the lead, and the lower surface of the outer lead 2 is exposed near the periphery of the package bottom surface 6. Surface mount type resin hollow package is shown.

  FIG. 6 shows a surface mount type resin hollow package having a structure having an island portion 10 in addition to the configuration of FIG. It is also possible to reduce the thickness of the island portion 10 by etching or the like as necessary.

  FIG. 7 shows a surface mount type resin hollow package having a structure in which a metal plate 11 is fixed to the lower surface of the inner lead 1 of FIG. In the structure of FIG. 7, a resin layer 13 is provided on the upper surface of the metal plate 11.

  FIG. 8 shows a surface mount type resin hollow package in which the lead is bent at the bent portion 16 to form the outer lead 2 and the lower surface of the outer lead 2 is exposed near the periphery of the package bottom surface 6. Indicates.

  FIG. 9 shows a surface mount type resin hollow package having an island part 10 in addition to the configuration of FIG.

  FIG. 10 shows a surface mount type resin hollow package in which a metal plate 11 is fixed to the lower surface of the inner lead 1 of the bent lead of FIG. 8 via an insulating layer 12. In particular, in the case of a surface mount type hollow package, the mounting substrate and the package bottom surface 6 are substantially on the same surface, and heat radiation from the package bottom surface 6 has not been expected in the past. Since the lower surface portion of the metal plate 11 serving as the lower surface portion 5 is located on the hollow portion 20 side and an air layer is secured, heat dissipation by convection is possible. As shown in FIG. 11, a resin layer 13 may be provided on the upper surface of the metal plate 11.

  FIG. 12 is an enlarged sectional view of the lead portion of FIG. 10, which is a bent end surface portion of the outer lead 2, and a step portion 15 is formed on the end surface portion of the lead bent portion 16. Due to the step portion 15, resin burrs are hardly generated on the end face of the outer lead 2, and an outer lead having high dimensional accuracy can be provided. Further, by providing the step portion 14 at the side end portion of the metal plate 11, the adhesiveness with the resin is enhanced, and it becomes possible to prevent the interface peeling and the airtightness from being lowered. FIG. 13 shows a semiconductor device using the resin hollow package of FIG.

  A method for manufacturing the semiconductor device shown in FIG. 13 will be described below.

  First, a SON type or QFN type lead frame as shown in the figure is prepared, and a bent portion 16 is formed in the lead. A metal plate 11 is fixed to the lower surface of the inner lead 1 formed by the lead bent portion 16 via an insulating layer 12 so that the lead and the metal plate 11 are integrated. For example, the metal plate 11 may be selected from the group consisting of copper, iron, stainless steel, aluminum, and alloys containing these metals, and may be plated with gold, silver, nickel, solder, or the like as necessary. The lead and the metal plate 11 are mounted on a molding die, and insert molding is performed by transfer molding or injection molding of a heat-resistant resin such as epoxy resin or thermoplastic resin in a cavity of the molding die. Here, in order to form the concave structure of the package lower surface portion 5, the same shape may be formed into a convex structure with a molding die.

  The conditions for performing transfer molding differ depending on the epoxy resin or the like. Generally, the molding temperature is 150 to 200 ° C., the molding pressure is 1 to 50 MPa, the molding time is 1 to 40 seconds, preferably the molding temperature is 165 to 185 ° C., the molding pressure is 5 to 30 MPa, and the molding time is 3 to 20 seconds. To do. After molding by the above molding method, heat may be applied as necessary to cure the resin. Since resin burrs are generated on the exposed lead surface of the molded body, it is necessary to remove the resin burrs in a later step.

  In the case of the structure of the present invention, the inner lead, outer lead and metal plate exposed on the surface of the molded body are firmly clamped by the molding die, respectively, so that the exposed inner lead upper surface, outer lead lower surface and metal plate upper and lower surfaces are The generated resin burrs can be extremely reduced. In general, high-pressure water is used when removing the resin burrs. However, when high-pressure water is applied to the molded body, the strength of the interface between the resin and the lead tends to decrease. In the case of the structure of the present invention, the step portion 15 is formed on the exposed end surface portion of the outer lead 2 and the step portion 14 is formed on the side end portion of the metal plate 11 so that the resin, the lead, and the metal plate are in close contact with each other. It is highly resistant and prevents the occurrence of peeling and prevents airtightness from being reduced.

  After fixing the semiconductor element 7 such as a solid-state imaging element to the bottom surface 4 of the hollow portion of the resin hollow package obtained as described above with an adhesive or the like, the inner lead 1 and the semiconductor element 7 are connected with the electrical bonding material 8. The semiconductor device of the present invention as shown in FIG. 13 is obtained by connecting and sealing the hollow portion 20 with the lid member 9 with an adhesive or the like and hermetically sealing.

It is sectional drawing which shows the resin-made hollow packages by one Example of this invention. It is sectional drawing which shows the state which mounted the semiconductor device using the resin-made hollow packages of FIG. 1 on the board | substrate. It is sectional drawing which shows the resin-made hollow packages which have an island part by one Example of this invention. It is sectional drawing which shows the resin-made hollow packages which have the metal plate fixed through the insulating layer by one Example of this invention. It is sectional drawing which shows the surface mount type resin hollow package by one Example of this invention. It is sectional drawing which shows the surface mount type resin hollow package which has an island part by one Example of this invention. It is sectional drawing which shows the surface mount type resin hollow package which has the metal plate fixed through the insulating layer by one Example of this invention. It is sectional drawing which shows the surface mount type resin hollow package which formed the bending part in the lead | read | reed by one Example of this invention. It is sectional drawing which shows the surface mounting type resin hollow package which forms a bending part in the lead | read | reed by one Example of this invention, and has an island part. It is sectional drawing which shows the surface mount type resin hollow package which forms the bending part in the lead | read | reed by one Example of this invention, and has the metal plate fixed through the insulating layer. It is sectional drawing which shows the surface mounting type resin hollow package which forms the bending part in the lead | read | reed by one Example of this invention, and has the resin layer on the metal plate fixed through the insulating layer, and a metal plate. FIG. 11 is an enlarged cross-sectional view showing the vicinity of a bent lead portion in FIG. 10. It is sectional drawing which shows the semiconductor device using the resin-made hollow packages of FIG.

Explanation of symbols

1 Inner lead 2 Outer lead 3 Package body (resin molding)
4 Bottom of the hollow part (Semiconductor element mounting surface)
5 Package bottom surface 6 Package bottom surface (bottom surface of package body)
7 Semiconductor element 8 Electrical joining material 9 Lid material 10 Island part 11 Metal plate 12 Insulating layer 13 Resin layer 14 Step part of metal plate
15 Lead stepped portion 16 Lead bent portion 17 Mounting substrate 18 Mounting paste 19 Air layer 20 Hollow portion

Claims (13)

  A resin hollow comprising a hollow portion having a bottom surface for mounting a semiconductor element, a lead for realizing electrical continuity between the semiconductor element mounted in the hollow portion and the outside, and a resin molded body constituting the package body In the package, a resin-made hollow package characterized in that a bottom surface portion of the package is provided with a lower surface portion of the package located closer to the hollow portion than the bottom surface of the package body.   The resin hollow package according to claim 1, wherein an island portion made of a metal plate having at least the same size as the bottom surface of the semiconductor element is provided in the bottom surface of the hollow portion, the lower surface portion of the package, or the inside thereof.   2. The resin hollow package according to claim 1, wherein a metal plate that is the same as or wider than the bottom surface of the hollow portion is fixed to the lower surface of the inner lead via an insulating layer.   The resin hollow package according to claim 3, wherein at least a part of an upper surface of the metal plate is exposed on a bottom surface of the hollow portion.   The resin hollow package according to claim 3, wherein a resin layer is formed on an upper surface of the metal plate.   The resin hollow package according to claim 3, wherein uneven portions are formed on an upper surface, a lower surface, or an upper and lower surface of the metal plate.   The resin hollow package according to claim 3, wherein a step portion is formed on at least a part of a side end portion of the metal plate.   The lead is formed so as to leave a lower surface of the outer lead to be a substrate mounting surface by etching a part of the lower surface portion, and the lower surface of the outer lead is exposed in the vicinity of the periphery of the bottom surface of the package body. The resin-made hollow package in any one of 1-7.   The resin hollow package according to any one of claims 1 to 7, wherein a lead is bent, and a lower surface of an outer lead of the lead is exposed near a peripheral edge of a bottom surface of the package body.   The resin hollow package according to claim 9, wherein a stepped portion is formed on a bent end surface portion of a lower surface of the outer lead.   The resin-made hollow package according to any one of claims 1 to 10, wherein an airflow passage that communicates a gap between the substrate and the package lower surface portion and the outside is formed.   12. A semiconductor device using the resin hollow package according to claim 1, wherein the semiconductor element is fixed to the bottom surface of the hollow portion of the resin hollow package, and the inner lead of the lead frame and the semiconductor element are electrically connected. Device in which the hollow part of the resin hollow package is hermetically sealed with a lid material.   The semiconductor device according to claim 12, wherein an air flow path is formed to communicate the gap between the substrate and the package lower surface portion and the outside.

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