JP2015225873A - Package for housing semiconductor element, and semiconductor device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a package for housing a semiconductor element in which electric short circuit of a lead member and a substrate can be suppressed, and to provide a semiconductor device including the same.SOLUTION: A package 2 for housing a semiconductor element includes a metal substrate 21 having a mounting region R, on the upper surface of which a power semiconductor element is mounted, a frame 22 provided on the metal substrate 21 so as to surround the mounting region R, and a lead member 23 provided at a part of the frame 22 so as to penetrate the frame 22 from the outside, and having a flange 23a abutting against the outer side face of the frame 22. In the plan view, the flange 23a protrudes farther outward than the side face of the metal substrate 21.

Description

  The present invention particularly relates to a package for housing a semiconductor element in which a power semiconductor element is mounted, and a semiconductor device in which the power semiconductor element is mounted.

  Currently, power semiconductor devices are being developed as future technologies. Development of a package for housing a semiconductor element suitable for the power semiconductor element is underway (see, for example, Patent Document 1 below). A power semiconductor element is a semiconductor element used for controlling a power supply. The power semiconductor element is suitable for changing alternating current to direct current, driving a motor, and charging a battery.

  The power semiconductor element storage package includes a substrate on which the power semiconductor element is mounted, a frame provided on the substrate, and a lead member penetrating the frame.

International Publication No. 2012/098799

  A large current flows through the power semiconductor element. Therefore, depending on the amount of current flowing through the lead member, there is a possibility that the lead member and the substrate are electrically short-circuited.

  An object of the present invention is to provide a package for housing a semiconductor element capable of suppressing an electrical short circuit between a lead member and a substrate, and a semiconductor device including the same.

  A package for housing a semiconductor element according to an embodiment of the present invention includes a metal substrate having a mounting area on which a power semiconductor element is mounted on an upper surface, a frame provided on the metal substrate and surrounding the mounting area, A lead member provided in a part of the frame body and having a flange portion that penetrates the frame body from the outside of the frame body and abuts against an outer surface of the frame body, the flange portion in plan view The metal substrate protrudes outside the frame body from the side surface of the metal substrate.

  A semiconductor device according to an embodiment of the present invention is electrically connected to the package for housing a semiconductor element and a part of the lead member provided on the mounting region and located in the frame body via a wire. And a lid provided on the frame so as to cover the power semiconductor element.

  The present invention can provide a package for housing a semiconductor element capable of suppressing an electrical short circuit between a lead member and a substrate, and a semiconductor device including the same.

It is the mounting structure which concerns on one Embodiment of this invention, Comprising: The state which removed the cover body is shown. 1 is a package for housing a semiconductor element according to an embodiment of the present invention, and is an external perspective view seen from one direction. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external perspective view of a package for housing a semiconductor device according to an embodiment of the present invention, as seen from a lead member side to a frame body side. FIG. 4 is an exploded perspective view of the semiconductor element storage package shown in FIG. 3. It is a top view of the package for semiconductor element accommodation. It is a side view of the package for semiconductor element accommodation, Comprising: The state which looked at the lead member from the side is shown. FIG. 6 is a cross-sectional view of the package for housing a semiconductor element along AA in FIG. 5. It is a side view of the package for semiconductor element accommodation, Comprising: The state which looked at the lead member from the front is shown.

  Hereinafter, a semiconductor element storage package and a semiconductor device according to an embodiment of the present invention will be described with reference to the drawings.

<Configuration of semiconductor element storage package and semiconductor device>
The semiconductor device 1 includes a semiconductor element housing package 2 and a power semiconductor element 3. The semiconductor device 1 is used for equipment that needs to improve power conversion efficiency, such as a power transmission system, a train, an automobile, a power conditioner, an air conditioner, or a server machine.

  The power semiconductor element 3 is characterized by low resistance, high-temperature operation, and high thermal conductivity, and by reducing power loss, it is possible to reduce the amount of heat generation, and thus to realize downsizing of the power converter. it can. The power semiconductor element 3 is used for, for example, a power transmission system with reduced power loss, a vehicle with a miniaturized inverter device, a household appliance with energy saving, a personal computer with a compact AC adapter, a solar system with highly efficient power change, etc. Can be used.

  The power semiconductor element 3 is not made of a Si-based device material such as silicon but a GaN-based power device material such as gallium nitride or a SiC-based power device material such as silicon carbide. The power semiconductor element 3 can be manufactured using a power device material, for example, using a sublimation method, a solution method (flux method), a high temperature CVD method, or the like.

  A semiconductor device 1 according to an embodiment of the present invention includes a semiconductor element storage package 2 and a part of a lead member 23 provided in a frame 22 provided on a mounting region R of the semiconductor element storage package 2. And a power semiconductor element 3 electrically connected via a wire, and a lid 4 provided on the frame 22 so as to cover the power semiconductor element 3. The semiconductor element storage package 2 includes a metal substrate 21 having a mounting region R on which an upper surface of the power semiconductor element 3 is mounted, a frame 22 provided on the metal substrate 21 and surrounding the mounting region R, and a frame. A lead member 23 provided in a part of the body 22 is provided with a flange portion 23 a that penetrates the frame body 22 from the outside of the frame body 22 and contacts the outer surface of the frame body 22. The flange 23 a protrudes out of the frame body 22 from the side surface of the metal substrate 21.

  The metal substrate 21 is a plate-like member formed in a rectangular shape when viewed in plan. The metal substrate 21 is made of a metal material such as copper, iron-nickel-cobalt alloy, copper-molybdenum alloy, or copper-tungsten alloy. The metal substrate 21 is made of a material that quickly dissipates heat generated from the power semiconductor element 3 to an external mounting substrate on which the semiconductor device 1 is mounted. The metal substrate 21 can function as a ground.

Further, the thermal conductivity of the metal substrate 21 is set to, for example, 10 W / m · K or more and 500 W / m · K or less. The thermal expansion coefficient of the metal substrate 21 is set to, for example, 5 ppm / ° C. or more and 20 ppm / ° C. or less. When the metal substrate 21 is a metal material, for example, the ingot is manufactured to have a predetermined shape by adopting a metal processing method such as a well-known rolling method, punching method, or etching method.

  The metal substrate 21 is formed in a rectangular shape. For example, one side width of the metal substrate 21 is set to 10 mm to 30 mm, the other side width is set to 20 mm to 40 mm, and the thickness is set to 0.3 mm to 3 mm.

  Further, the metal substrate 21 is coated with a metal having excellent corrosion resistance and good wettability with the bonding material on the outer surface. Specifically, the metal substrate 21 is preferably deposited with a nickel plating layer and a gold plating layer sequentially by a plating method. Note that the plating thickness of the nickel plating layer is, for example, not less than 0.5 μm and not more than 9 μm. The plating thickness of the gold plating layer is, for example, not less than 0.5 μm and not more than 5 μm. These metal plating layers can effectively suppress the metal substrate 21 from being oxidized and corroded.

  Moreover, the power semiconductor element 3 may be directly provided in the upper main surface of the metal substrate 21, and the power semiconductor element 3 may be provided through the insulating substrate which consists of an insulating material. The insulating substrate is made of a ceramic material such as alumina ceramic or aluminum nitride ceramic.

  The frame body 22 seals the power semiconductor element 3 on the metal substrate 21. The frame body 22 is provided on the metal substrate 21. The frame 22 surrounds the mounting region R on the metal substrate 21. As shown in FIG. 5, the frame 22 has a quadrangular shape having four sides in plan view, and three of the four sides are made of the metal member 22 a and the remaining one of the four sides is an insulating member. 22b. The frame body 22 is provided on the metal substrate 21 via a bonding material. The bonding material is, for example, a brazing material such as silver-copper brazing or silver brazing.

  The metal member 22a has a U-shape in which three plates are continuously connected. The metal member 22a can be manufactured by bending two places on one metal plate. The metal member 22a is made of, for example, a metal material such as copper, a stainless alloy, an iron-nickel alloy, or an iron-nickel-cobalt alloy. The metal member 22a has a side width of 10 mm to 30 mm, the other side width of 10 mm to 30 mm, and a thickness of 0.5 mm or more, for example, between two opposing sides in plan view. It is set to 2 mm or less. The metal member 22a has a thickness in the vertical direction set to 2 mm or more and 20 mm or less. The thermal conductivity of the metal member 22a is set to, for example, 10 W / m · K or more and 500 W / m · K or less. The thermal expansion coefficient of the metal member 22a is set to, for example, 5 ppm / ° C. or more and 20 ppm / ° C. or less.

The insulating member 22 b has a rectangular shape that fixes the lead member 23. The insulating member 22b has a hole in which the lead member 23 is provided through a single plate. The insulating member 22b is brazed to the upper surface of the metal substrate 21 and the end surface of the metal member 22a so as to block the opening of the metal member 22a. The insulating member 22b can be produced by firing a ceramic material. The insulating member 22b is made of a ceramic material such as alumina ceramic, aluminum nitride ceramic, or mullite ceramic. In the insulating member 22b, for example, one side width in the longitudinal direction is set to 11 mm to 34 mm and the other side width in the short direction is set to 0.5 mm to 2 mm in plan view. In addition, the insulating member 22b has a vertical thickness that matches the vertical thickness of the metal member 22a, and is set to 2 mm or more and 20 mm or less. The thermal conductivity of the insulating member 22b is set to, for example, 20 W / m · K or more and 160 W / m · K or less. Insulating member 22b
The thermal expansion coefficient is set to, for example, 2 ppm / ° C. or more and 10 ppm / ° C. or less.

  The insulating member 22b is provided with three through holes H. The through hole H is for fitting one end of the lead member 23 together. The through hole H is circular and has a diameter of 0.7 mm or more and 4 mm or less and a length that matches the side width of the insulating member 22b. The three through holes H are spaced apart from each other by a constant distance. The interval is set so that adjacent lead members 23 are not electrically short-circuited, that is, creeping discharge does not occur.

  A metallized pattern p is formed around the through hole H on the outer surface of the insulating member 22b. The metallized pattern p is annular and serves as a base for brazing the flange 23a of the lead member 23. The flange 23a is fixed to the metallized pattern p through a brazing material. The metallized pattern p is made of a metal material in which a nickel plating layer is provided on a base metal layer such as molybdenum, tungsten, or manganese. The metallized pattern p is set to have an outer diameter of 1 mm or more and 8 mm or less when the outer surface of the insulating member 22b is viewed from the side.

  An insulating substrate may be provided on the metal substrate 21. The insulating substrate is a so-called submount member that is interposed between the power semiconductor element 3 and the metal substrate 21 so that the power semiconductor element 3 is not electrically short-circuited with the metal substrate 21. The insulating substrate is set to a size that allows the power semiconductor element 3 to be provided, and to fit within the frame body 22. The insulating substrate is an insulating substrate, for example, an inorganic material such as aluminum oxide, aluminum nitride, or silicon nitride, an organic material such as epoxy resin, polyimide resin, or ethylene resin, or ceramic such as alumina or mullite. It consists of material or glass ceramic material. Or it consists of a composite material which mixed several materials among these materials.

  The lead member 23 is a member that allows current to flow. The lead member 23 has a long shape, and includes a cylindrical portion and an annular flange portion 23a provided at a part of the outer peripheral portion of the cylindrical portion. The cylindrical portion and the flange portion 23a are integrally molded. The lead member 23 is made of a metal material such as copper, iron-nickel alloy, iron-nickel-cobalt alloy, for example. The ingot made of these metal materials is manufactured to have a predetermined shape by adopting a known metal working method such as a rolling method, a punching method or an etching method. The thermal conductivity of the lead member 23 is set to, for example, 10 W / m · K or more and 400 W / m · K or less. Further, the thermal expansion coefficient of the lead member 23 is set to, for example, 5 ppm / ° C. or more and 20 ppm / ° C. or less.

  The cylindrical portion of the lead member 23 has a diameter of 0.5 mm or more and 2 mm or less and a length of 10 mm or more and 30 mm or less so that a large current can flow. The flange 23a of the lead member 23 has a diameter of 1 mm or more and 8 mm or less and a thickness of 0.1 mm or more and 1 mm or less. In addition, the diameter of the cylindrical portion of the lead member 23 is set to a size that fits the diameter of the through hole H of the insulating member 22b. The diameter of the flange portion 23a is larger than the diameter of the through hole H, and is set to a size such that the side surface of the flange portion 23a abuts on the outer surface of the insulating member 22b.

  In a state where the lead member 23 is fixed to the insulating member 22b, a part of the lead member 23 protruding from the inside of the frame body 22 is electrically connected to the power semiconductor element 3 through a wire. That is, the power semiconductor element 3 provided on the mounting region R is electrically connected to a part of the lead member 23 located in the frame body 22 via the wire. As a result, the lead member 23 is electrically connected to the power semiconductor element 3.

The seal ring 6 is brazed onto the frame 22 via a bonding material such as a brazing material. In addition,
The brazing material is made of, for example, silver, copper, gold, aluminum, or magnesium, and may contain an additive such as nickel, cadmium, or phosphorus. The seal ring 6 is a frame-like member that overlaps the frame body 22 provided on the metal substrate 21 when viewed in plan. The seal ring 6 is made of a buffer material having excellent thermal conductivity such as iron, nickel, or cobalt. The seal ring 6 is connected to the frame body 22 using a solid bonding material. A bonding material is disposed on the frame body 22, the seal ring 6 is stacked on the bonding material, and heat is applied to the seal ring 6, so that the bonding material melts and the seal ring 6 and the frame body 22 are connected. The Furthermore, the melted bonding material is cooled and solidified, whereby the seal ring 6 is fixed to the frame body 22 via the bonding material.

  A lid 4 is provided on the seal ring 6. The lid body 4 has a function of sealing a space surrounded by the metal substrate 21 and the frame body 22. The lid 4 is provided on the seal ring 6 in order to hermetically seal the power semiconductor element 3. Moreover, the cover body 4 consists of metal materials, such as an iron-nickel-cobalt alloy or an iron-nickel alloy, for example. The thermal expansion coefficient of the lid body 4 is set to, for example, 5 ppm / ° C. or more and 20 ppm / ° C. or less. Further, the lid body 4 is set, for example, such that one side width is 10 mm or more and 30 mm or less, the other side width is 10 mm or more and 30 mm or less, and the thickness is 0.2 mm or more and 1 mm or less. The lid 4 has a rectangular shape and is brazed onto the seal ring 6 via a brazing material, for example. Alternatively, the lid 4 is welded to the seal ring 6 by resistance seam welding, laser seam welding, electron beam welding, or the like.

  The power semiconductor element 3 may be directly bonded and fixed to the mounting region R of the metal substrate 21 or may be bonded and fixed on an insulating substrate located in the mounting region R. Then, an electrode provided on the upper surface of the power semiconductor element 3 is electrically connected to the lead member 23 via a bonding wire or the like. Next, the lid body 4 is joined onto the frame body 22 via the seal ring 6, and the power semiconductor element 3 is hermetically housed inside the metal substrate 21, the frame body 22, and the lid body 4 to form the semiconductor device 1. . That is, after mounting the power semiconductor element 3, the semiconductor device 1 is formed by sealing with the lid 4.

  In the package 2 for housing a semiconductor element according to the present embodiment, the flange portion 23a protrudes out of the frame body 22 from the side surface of the metal substrate 21 located immediately below the insulating substrate 22b in plan view. The distance between the flange 23a and the metal substrate 21 can be increased. That is, the creeping distance between the flange 23a and the metal substrate 21 can be increased. That is, since the metal substrate 21 does not exist immediately below the flange portion 23a, even if a large current flows through the lead member 23, dielectric breakdown hardly occurs, and the lead member 23 and the metal substrate 21 are not easily short-circuited. Therefore, it is possible to maintain good insulation between the flange 23a and the metal substrate 21. In particular, the package 2 for housing a semiconductor element using the power semiconductor element 3 may cause a high-frequency high current to flow through the lead member 23, and a discharge phenomenon occurs between the lead member 23 and the metal substrate 21. It may occur that the metal substrate 21 is electrically connected. Among the lead members 23, the flange portion 23 a outside the frame body 22 connected to an external electronic device is short-circuited with the metal substrate 21 because the distance from the metal substrate 21 is shorter than other portions. There is a great risk of it. Therefore, it is possible to prevent the lead member 23 and the metal substrate 21 from being electrically short-circuited by separating the flange portion 23a from the metal substrate 21 and increasing the creepage distance.

  Moreover, in this embodiment, it is suppressing that the electric current which flows into the lead member 23 concentrates on the specific location of the collar part 23a, making the connection part with the insulating member 22b favorable by making the collar part 23a annular. Can do. That is, if the flange portion 23a has a corner, current concentration occurs at the corner, and as a result, there is a high possibility of causing dielectric breakdown with the metal substrate 21. Then, it can suppress that the collar part 23a and the metal substrate 21 are electrically short-circuited by making the collar part 23a cyclic | annular.

  In the present embodiment, the insulating member 22b, which is a part of the frame body 22 connected to the lead member 23, has a side surface on the outer side of the frame body 22 that is more than the side surface of the metal substrate 21 positioned directly below the insulating substrate 22b. The side surface of the metal substrate 21 protrudes out of the frame body 22, that is, the outer surface of the insulating member 22 b is provided closer to the inner side of the frame body 22, so that the flange portion 23 a of the lead member 23 is made of metal. It can be separated from the substrate 21. As a result, the creepage distance between the flange 23a of the lead member 23 and the side surface of the metal substrate 21 can be increased, and the two members can be prevented from being electrically short-circuited.

  As another embodiment, the insulating member 22b is provided so that both end portions protrude in the outer direction of the frame body 22 from the side wall portion of the metal member 22a joined to the insulating member 22b in a top view. Alternatively, the seal ring 6 may be provided in the inner direction of the frame body 22 from the side surface of the insulating member 22b to which the outer peripheral surface is joined to the flange portion 23a when viewed from above. As a result, the creepage distance between the lead member 23 and the metal member 22a and the seal ring 6 can be increased, and the lead member 23, the metal member 22a and the seal ring 6 are prevented from being electrically short-circuited. Can do.

  In the present embodiment, the frame 22 has three sides made of the metal member 22a, one side made of the insulating member 22b, and the lead member 23 provided on the insulating member 22b. The surrounding electric field shielding effect can be improved by enclosing with a metal material except for the portion where the lead member 23 is provided. It is possible to make it difficult for extra power signals to be input from the surroundings to the power semiconductor element 3, and to prevent the power semiconductor element 3 from malfunctioning. Furthermore, the heat generated by the power semiconductor element 3 can be easily dissipated to the outside, and changes in the electrical characteristics of the power semiconductor element 3 can be suppressed.

  Furthermore, in this embodiment, the seal ring 6 is continuously provided from the metal member 22a to the insulating member 22b, so that the lid 4 is joined to the semiconductor element housing package 2 by a joining method such as seam welding. In this case, even if stress is generated in each part due to the difference in thermal expansion coefficient among the metal member 22a, the insulating member 22b, and the lid body 4, the seal ring 6 is relieved by deformation, and each joint is bonded. There exists an effect that the possibility that a crack, peeling, etc. may arise in a section or insulating member 22b can be controlled.

  The present invention is not limited to the above-described embodiments, and various changes and improvements can be made without departing from the scope of the present invention.

<Semiconductor Element Storage Package and Semiconductor Device Manufacturing Method>
Here, a semiconductor element storage package and a method for manufacturing a semiconductor device including the same will be described. The metal substrate 21, the metal member 22 a, and the seal ring 6 are formed into a predetermined shape by using a metal processing method such as a well-known cutting process or punching process, for example, from an ingot produced by casting an iron-nickel-cobalt alloy into a mold. Produced.

  When the insulating member 22b of the frame body 22 is made of, for example, an aluminum oxide sintered body, an organic binder, a plasticizer, a solvent, a dispersant, etc. are added to raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide. A green sheet is formed by mixing and adding to form a paste by a doctor blade method, a calendar roll method, or the like.

The flat green sheet is punched with a mold so that the through hole H is shaped into a predetermined shape. Further, the insulating member 22b is formed at a position corresponding to a joint portion with the metal substrate 21, a joint portion with the metal member 22a, a joint portion with the seal ring 6, and a joint portion with the flange portion 23a of the lead member 23. A metallized pattern p containing manganese or the like is formed. And the insulating member 22b of the frame 22 is produced by baking at the temperature of about 1600 degreeC and cut | disconnecting in a predetermined shape. The metallized pattern p is provided with a nickel plating layer on the surface of a molybdenum-manganese alloy formed by firing.

  Next, for example, the lead member 23 is formed into a predetermined shape by using a known metal working method such as cutting, punching, or pressing an ingot produced by casting an iron-nickel-cobalt alloy into a mold. Is done. At this time, the flange portion 23 a is also formed integrally with the cylindrical portion of the lead member 23. The lead member 23 is inserted into the through hole H of the insulating member 22b from the outside, and the metallized pattern p formed on the outer surface of the insulating member 22b and the side surface of the flange portion 23a of the lead member 23 are brought into contact with each other. Both members are connected via a brazing material.

  Next, the metal substrate 21, the metal member 22a, the insulating member 22b to which the lead member 23 is connected, and the seal ring 6 are fixed through a bonding material such as a brazing material. Specifically, the metal substrate 21 is disposed so that the side surfaces of the U-shaped ends of the metal member 22a and the inner surface of the insulating substrate 22b abut on the upper surface, and the upper surface of the frame body 22 is sealed. Rings 6 are arranged and fixed through brazing materials. At this time, the insulating member 22b has an outer surface on which the metallized pattern p is provided protrudes outward from the side surface of the metal substrate 21 positioned immediately below the insulating member 22b, and the end portion of the insulating member 22b in a plan view. Are fixed to the metal substrate 21 and the metal member 22a so as to protrude outward from the outer surface of the adjacent metal member 22a. In this way, the semiconductor element storage package 2 can be manufactured.

  In addition, a green sheet is used for the insulating substrate, similarly to the insulating member 22 b of the frame body 22. Then, an insulating substrate having a predetermined shape is produced by firing them. The insulating substrate is bonded to the mounting region R surrounded by the frame body 22 on the upper main surface of the metal substrate 21 via a bonding material.

  Here, a method for manufacturing a semiconductor device will be described. The semiconductor device includes a power semiconductor element 3 and a lid 4 in a package 2 for housing a semiconductor element. The lid 4 is made into a predetermined shape using a known metal working method such as cutting or punching, for example, an ingot produced by casting an iron-nickel-cobalt alloy into a mold. The power semiconductor element 3 is bonded and fixed to an insulating substrate and is electrically connected to the lead member 23 via a bonding wire or the like. The lid body 4 is provided by seam welding on the frame body 22 via the seal ring 6. That is, in the semiconductor device 1, the power semiconductor element 3 is hermetically sealed by the lid 4.

DESCRIPTION OF SYMBOLS 1 Semiconductor device 2 Package for semiconductor element 21 Metal substrate 22 Frame body 22a Metal member 22b Insulating member 23 Lead member 23a Eave part 3 Power semiconductor element 4 Cover body 6 Seal ring R Mounting area H Through hole p Metallized pattern

Claims (6)

A metal substrate having a mounting region on which the power semiconductor element is mounted;
A frame provided on the metal substrate and surrounding the mounting area;
A lead member provided in a part of the frame body, having a flange that penetrates the frame body from outside the frame body and contacts an outer surface of the frame body;
The package for housing a semiconductor element, wherein the flange portion protrudes out of the frame body from a side surface of the metal substrate in a plan view. The package for housing a semiconductor device according to claim 1,
A package for housing a semiconductor element, wherein the flange is annular. A package for housing a semiconductor device according to claim 1 or 2,
A package for housing a semiconductor element, wherein a part of the frame body connected to the lead member protrudes outside the frame body from a side surface of the metal substrate. The package for housing a semiconductor device according to claim 1,
The frame has a quadrangular shape having four sides in plan view, three of the four sides are made of a metal member, and the other one of the four sides is made of an insulating member, and the lead member Is provided on the insulating member. A package for housing a semiconductor element according to claim 4,
A seal ring is provided on the frame body along an upper portion of the frame body, and the seal ring is provided continuously from the metal member to the insulating member. Package for element storage. A package for housing a semiconductor element according to any one of claims 1 to 5,
A power semiconductor element provided on the mounting region and electrically connected to a part of the lead member located in the frame body via a wire;
A lid provided on the frame to cover the power semiconductor element;
A semiconductor device comprising:

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