JP6702813B2 - Composite substrate, electronic device and electronic module - Google Patents

Description

The present invention relates to a composite substrate including an insulating substrate and a metal plate bonded to an upper surface and a lower surface of the insulating substrate, an electronic device, and a method for manufacturing the composite substrate.

BACKGROUND ART Conventionally, a copper circuit formed in a circuit pattern on an upper surface of an insulating substrate as a composite substrate used for an electronic device mounted with an electronic component such as an IGBT (Insulated Gate Bipolar Transistor) such as a power module or a switching module. What is used is one in which plates are joined, and a copper radiator plate for radiating heat generated from electronic components mounted on a circuit board is joined to the lower surface. The circuit board and the heat dissipation plate are joined to the upper surface or the lower surface of the insulating substrate with a brazing material containing an active metal or the like (see, for example, Patent Document 1).

The composite substrate is, for example, an electronic device in which electronic components are mounted on a metal plate on the upper surface side of an insulating substrate, and is mounted on an external member such as a motherboard or a radiator included in various electronic devices.

In the above-mentioned composite substrate and electronic device, in recent years, it has become necessary to cope with an increase in the amount of heat generated from the mounted electronic components. On the other hand, it is conceivable that the metal plate on the lower surface is made thicker than the metal plate on the upper surface to enhance heat dissipation to the outside.

JP-A-8-139420

However, if the metal plate on the lower surface of the insulating substrate is made thicker than the metal plate on the upper surface, the influence of the thermal expansion of the relatively thick metal plate on the lower surface side of the insulating substrate becomes large, and the heat generated during mounting as an electronic device causes the composite The entire substrate tends to warp upward in the outer peripheral portion. In this case, since the outer peripheral portion of the composite substrate is less likely to adhere to an external member for heat dissipation or the like, heat conduction from the composite substrate (electronic device) to the external member is reduced, and heat dissipation can be effectively improved. difficult.

A composite substrate according to one aspect of the present invention includes an insulating substrate having an upper surface and a lower surface, a first metal plate bonded to the upper surface of the insulating substrate, and a lower surface of the insulating substrate, and the first metal A laminated body including a second metal plate that is thicker than the plate is provided, and the laminated body has a rectangular shape in plan view, and is curved upward in an intermediate portion between the central portion and the outer peripheral portion in plan view. The upper end of the convex portion is located above the other portion in the portion close to the corner portion of the laminated body .

An electronic device according to one aspect of the present invention includes the composite substrate having the above configuration and an electronic component mounted on the first metal plate.

An electronic module according to an aspect of the present invention includes the electronic device having the above configuration and an external member joined to the electronic device via a bonding material.

According to the composite substrate of one aspect of the present invention, because of the above-described configuration, when heat is applied during mounting on an external member, stress is generated such that the peripheral portion of the convex portion warps upward in the laminate. .. The peripheral portion of the convex portion corresponds to the outer peripheral portion and the central portion of the laminate (composite substrate) in plan view. Therefore, the thermal stress can increase the flatness of the entire composite substrate. Therefore, it is possible to improve the adhesion to the external member, and it is possible to provide a composite substrate that is advantageous in improving the heat dissipation as an electronic device, for example.

The central portion of the composite substrate may be curved downward in plan view due to the stress generated in the peripheral portion of the convex portion. In this case as well, for example, the electronic component is mounted on the first metal plate at the central portion. If so, the distance from the electronic component to the external member can be kept small, so that the heat dissipation can be improved.

According to the electronic device of one aspect of the present invention, since it includes the composite substrate having the above-described configuration, it is easy to suppress the outer peripheral portion of the laminate from warping upward when mounted on an external member, It is possible to provide an electronic device in which the adhesion to an external member and the heat dissipation can be easily improved.

According to the electronic module of one aspect of the present invention, since the electronic device including the composite substrate having the above-described configuration is mounted on the external member, the adhesiveness between the electronic device and the external member is high, and the heat dissipation property is high. A high electronic module can be provided.

(A) is a top view which shows the composite substrate of embodiment of this invention, (b) is sectional drawing in the AA line of (a), (c) is sectional drawing in the BB line. .. It is sectional drawing which shows the electronic device of embodiment of this invention. It is a top view which shows the electronic module of embodiment of this invention. (A) is a top view which shows the modification of the composite substrate shown in FIG. 1, (b) is sectional drawing in the AA line of (a), (c) is sectional drawing in the BB line. is there. It is sectional drawing which expands and shows the principal part of the composite substrate shown in FIG. It is sectional drawing which shows the modification of the electronic device shown in FIG. It is sectional drawing which shows the modification of the electronic module shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The distinction between upper and lower sides in the following description is for convenience, and does not limit the upper and lower sides when the composite substrate, the electronic device, and the electronic module are actually used. Further, in each of the following drawings, in order to make the shape and the like easy to understand, the dimension including the curvature may be emphasized more than the actual dimension.

(Composite substrate)
FIG. 1A is a plan view showing a composite substrate of an embodiment of the present invention, and FIG. 1B is a sectional view taken along the line AA of FIG. 1A. The composite substrate 10 includes a laminated body 9 including an insulating substrate 1, a first metal plate 2 bonded to the upper surface of the insulating substrate 1, and a second metal plate 3 bonded to the lower surface of the insulating substrate 1. .. The composite substrate 10 may include an auxiliary member (not shown) such as a plating film or a resin film other than the laminated body 9.

The laminated body 9 composed of the insulating substrate 1, the first metal plate 2, and the second metal plate 3 is a portion that basically constitutes the composite substrate 10. For example, a part of the upper surface of the first metal plate 2 is used as a mounting portion for electronic components. Further, a part or the whole of the lower surface of the second metal plate 3 is used as a portion for connecting to an external member. The external member is an electronic circuit, a heat dissipation member, or the like included in various devices such as an electronic device, a vehicle, or an industrial machine, and the composite substrate 10 is electrically and thermally connected thereto. Details of the external member will be described later.

The insulating substrate 1 functions as a base body that holds the first metal plate 2 and the second metal plate 3 while ensuring electrical insulation. The electronic component 4 is mounted on the upper surface of the first metal plate 2 to form an electronic device 20 described later, and the lower surface of the second metal plate 3 is connected to an external member to form an electronic module 30 described later. In this case, the heat generated in the electronic component 4 is conducted to the external member through the first metal plate 2, the insulating substrate 1 and the second metal plate 3.

The insulating substrate 1 has a rectangular shape or a plate shape in which corners are curved (chamfered) in a plan view. The insulating substrate 1 is made of an electrically insulating material, for example, a material such as a silicon nitride sintered body, an aluminum oxide sintered body, a mullite sintered body, a silicon carbide sintered body or an aluminum nitride sintered body. Become. Among these materials, when importance is attached to thermal conductivity that affects heat dissipation, a silicon nitride sintered body, a silicon carbide sintered body, an aluminum nitride sintered body, or the like is used. Further, when considering the mechanical strength, for example, a silicon nitride sintered body or a silicon carbide sintered body is used.

When the insulating substrate 1 is made of a ceramic material having a relatively large mechanical strength such as a silicon nitride sintered body, a thicker (thicker) first metal plate 2 and a second metal plate 3 are used. Even in this case, it is possible to reduce the possibility that mechanical damage such as cracks will occur in the insulating substrate 1. Therefore, it is possible to realize the composite substrate 10 capable of passing a larger current while achieving miniaturization.

The thinner insulating substrate 1 is better in terms of thermal conductivity. However, in consideration of mechanical strength and electrical insulation, it should not be too thin. The thickness of the insulating substrate 1 is, for example, about 0.1 mm to 1 mm, and may be selected according to the size of the composite substrate 10 or the thermal conductivity or strength of the material used. The size of the insulating substrate 1 is, for example, about 5 to 50 mm in length and about 10 to 60 mm in width in plan view.

If the insulating substrate 1 is made of, for example, a silicon nitride sintered body, it can be manufactured as follows. First, a slurry prepared by adding and mixing an appropriate organic binder, a plasticizer and a solvent to raw material powders such as silicon nitride, aluminum oxide, magnesium oxide and yttrium oxide is formed into a sheet by a method such as a doctor blade method or a calendar roll method. Form to form a ceramic green sheet. Next, this ceramic green sheet is subjected to an appropriate punching process or the like to have a predetermined shape, and if necessary, a plurality of sheets are laminated to be processed into a molded body. Then, this molded body is fired at a temperature of 1600 to 2000° C. in a non-oxidizing atmosphere such as a nitrogen atmosphere. The insulating substrate 1 can be manufactured by the above steps.

The first metal plate 2 is bonded to the upper surface of the insulating substrate 1, and the second metal plate 3 is bonded to the lower surface of the insulating substrate 1. The first metal plate 2 and the second metal plate 3 are formed of a metal material such as copper or an alloy containing copper as a main component. In the composite substrate 10 and the electronic device 20, the thickness of the second metal plate 3 is set to be twice the thickness of the first metal plate 2 or more. As a specific example, the thickness of the first metal plate 2 is set to about 0.4 to 0.6 mm, and the thickness of the second metal plate 3 is set to about 0.8 to 1.2 mm. In this case, the thickness of the second metal plate 3 may be set to a thickness exceeding 1.2 mm in consideration of improvement of heat dissipation, suppression of deformation of the laminate 9 due to thermal stress, economy, and the like. ..

The first metal plate 2 and the second metal plate 3 are attached to the insulating substrate 1 after forming a copper original plate (not shown) by a predetermined metal working such as die punching or etching. Alternatively, the copper original plate may be bonded to the upper surface or the lower surface of the insulating substrate 1, and then the original plate may be subjected to processing such as etching to form the first metal plate 2 or the second metal 3. The first metal plate 2 and the second metal plate 3 are joined to the insulating substrate 1 by a joining method such as brazing. The brazing material is, for example, silver brazing material, and silver brazing material to which an active metal material such as titanium is further added may be used.

Further, the laminated body 9 included in the composite substrate 10 has a convex portion 9a curved upward in an intermediate portion between the central portion and the outer peripheral portion in a plan view. The center portion of the stacked body 9 in plan view is, for example, a portion surrounded by an inner virtual line (two-dot chain line) in FIG. In the case of the rectangular laminated body 9, the center and its vicinity are the central portion. The outer peripheral portion of the laminated body 9 in a plan view is, for example, a portion outside the outer virtual line (two-dot chain line) in FIG. The rectangular laminated body 9 is a rectangular frame-shaped portion along the outer periphery thereof.

The outer periphery of the laminated body 9 is the outer edge of the member located on the outermost side when viewed from above, and corresponds to the outer periphery of the insulating substrate 1 in this example. That is, it can be considered that the central portion and the outer peripheral portion of the laminated body 9 in plan view correspond to the central portion and the outer peripheral portion of the insulating substrate 1 in plan view, respectively.

According to the composite substrate 10 of such an embodiment, because of the above-described configuration, when heat is applied during mounting on an external member, a stress such that the peripheral portion of the convex portion 9a in the laminated body 9 warps upwards. Occurs. The peripheral portion of the convex portion 9a corresponds to the outer peripheral portion and the central portion of the stacked body 9 (composite substrate 10) in plan view. Therefore, the thermal stress can increase the flatness of the entire composite substrate 10. Therefore, the adhesion to the external member can be improved, and for example, it is possible to provide the composite substrate 10 that is advantageous for improving the heat dissipation as the electronic device 20.

In other words, by bending the laminated body 9 in the above-described form (in an M-shape in a vertical cross-sectional view), the heat at the time of mounting causes a deformation to flatten the entire laminated body 9 conversely. be able to. The deformation due to the stress is in the opposite direction to the deformation in which the outer peripheral portion of the composite substrate (not shown) in the prior art is warped upward. Therefore, the flatness of the composite substrate 10 is improved in the electronic device (electronic module) after mounting. This can be regarded as a result of the convex portion 9a being stretched in the lateral direction due to thermal stress at the time of mounting.

In order to obtain the above effects, the height of the convex portion 9a may be set to about 20 μm to 80 μm. The height of the convex portion 9a is, for example, the distance from the virtual level surface L0 to the upper surface of the convex portion 9a in the vertical sectional view as shown in FIG. Is. When there are a plurality of convex portions 9a (a plurality of plural maximal portions are present), the height of each convex portion 9a is individually defined, and the height of these convex portions 9a is defined. Is within the above range.

The virtual level surface may be set arbitrarily, but the level surface L0 in the above example is located at the position of the upper surface of the stacked body 9, that is, the position where the position of the upper surface of the first metal plate 2 is the lowest. It is set. In the case of this example, the central portion of the upper surface of the rectangular first metal plate 2 is the level surface L0.

(Method of manufacturing composite substrate)
The composite substrate 10 of the embodiment can be manufactured by a manufacturing method including the following steps, for example. However, the manufacturing method of the composite substrate 10 is not limited to this example, and can be appropriately changed depending on the type or size of the material used, productivity, economic efficiency, and the like.

First, the insulating substrate 1 is manufactured by the method as described above. For the insulating substrate 1, the outer dimensions are set and the material to be used is selected according to the outer dimensions of the composite substrate 10 to be manufactured, predetermined characteristics, economy, and the like. For example, a rectangular (square or rectangular) insulating substrate 1 having a thickness of about 0.1 mm to 1 mm and a side dimension of about 5 to 60 mm in plan view is prepared by firing a ceramic green sheet. To do.

Next, the 1st metal plate 2 and the 2nd metal plate 3 are produced. First metal plate 2 and second metal plate 3
Can be produced by subjecting a copper original plate such as oxygen-free copper to predetermined metal working such as cutting, rolling and etching. The first metal plate 2 and the second metal plate 3 are, for example, manufactured as flat plates having outer dimensions slightly smaller than the insulating substrate 1 in plan view. At this time, the dimensions at the time of metal working are adjusted so that the thickness of the second metal plate 3 is about twice the thickness of the first metal plate 2. The sizes (dimensions) of the first metal plate 2 and the second metal plate 3 in plan view depend on the sizes of the first metal plate 2 and the second metal plate 3 in the composite substrate 10 to be manufactured in plan view. It may be adjusted appropriately. For example, at least one of the first metal plate 2 and the second metal plate 3 to be manufactured may have a size larger than that of the insulating substrate 1 in plan view.

Next, the first metal plate 2 and the third metal plate 3 are bonded to the insulating substrate 1. This joining can be performed, for example, by a joining method using a brazing material (not shown) such as silver brazing. The silver solder is, for example, a silver-copper solder such as JIS standard BAg-8.

The brazing material may further contain, as an additive, at least one metal material selected from molybdenum, titanium and zirconium, hafnium and niobium as an active metal for joining. With regard to these metal materials, molybdenum, titanium and zirconium are suitable as the active metal for the above-mentioned applications, considering the effectiveness as an active metal, the workability of brazing, and the economical efficiency (cost).

When heating the laminated body 9 (an unbonded temporary laminated body) in which the second metal plate 3, the insulating substrate 1 and the first metal plate 2 are laminated in this order from the bottom, the temporary laminated body has a predetermined shape (the above-mentioned longitudinal section). Apply a load that causes it to deform into an M-shape when viewed. For example, when the temporary laminate is turned upside down and heated, a downward load is applied to the intermediate portion. As a specific example, a jig having an appropriate mass is placed on the second metal plate 3 (on the lower surface before being turned over) and heated. Due to this load, the intermediate portion of the temporary laminate is deformed during heating, and the composite substrate 10 including the laminate 9 having a predetermined shape can be manufactured. That is, during heating, the intermediate portion is convex downward due to the force caused by the mass of the jig, and the downward direction at this time is upward in the example of FIG. 1, so that the intermediate portion as shown in FIG. It is possible to obtain a laminated body 9 that is curved upward in a convex shape.

(Electronic device)
FIG. 2 is a sectional view showing the electronic device 20 according to the embodiment of the present invention. The electronic device 20 of the embodiment is basically configured by the composite substrate 10 having the above configuration and the electronic component 4 mounted on the first metal plate 2. 2, the same parts as those in FIG. 1 are designated by the same reference numerals. In FIG. 2, the electronic component 4 and the composite substrate 10 are shown separately, and the direction in which the electronic component 4 is mounted is shown by an arrow. The direction in which the electronic device 20 is mounted on the external member 5 is indicated by an arrow. In each of the following drawings, as in the case of FIG. 2, the constituent members may be shown separately, and the direction of mounting or the like may be shown by an arrow.

The electronic component 4 is mounted on the central portion of the upper surface of the first metal plate 2, which has a rectangular shape in plan view, for example. The electronic component 4 is, for example, a semiconductor device such as a transistor, an LSI (Large Scale Integrated circuit) for a CPU (Central Processing Unit), an IGBT (Insulated Gate Bipolar Transistor), or a MOS-FET (Metal Oxide Semiconductor-Field Effect Transistor). is there. The electronic component 4 is not limited to a semiconductor element, and may be appropriately selected from various electronic components including a sensor element such as a temperature sensor element and a passive component such as a capacitive element, or may be plural. Also, different types of electronic components (not shown) may be mounted.

The electronic component 4 is joined to the upper surface of the first metal plate 2 by a joining method such as joining via a joining material (not shown) for the component. The joining material for parts is made of, for example, metal or conductive resin. The joining material for components is, for example, solder (tin-lead eutectic solder or the like), gold-tin (Au-Sn) alloy, tin-silver-copper (Sn-Ag-Cu) alloy, or the like.

A plating film (not shown) may be formed on the surface of the first metal plate 2 by a plating method. According to this configuration, the wettability of the bonding material for the component is improved, so that the strength of bonding the electronic component 4 to the upper surface of the first metal plate 2 can be improved. The plating film may be a metal having high conductivity and corrosion resistance, and is, for example, a plating film of nickel, cobalt, silver, copper, gold or the like. The plating film may be an alloy material containing these metal materials as a main component, or may be a film in which a plurality of layers are sequentially deposited. The plating film may have a thickness of 0.1 to 10 μm, for example.

The semiconductor element mounted as the electronic component 4 is electrically connected to an external electric circuit (not shown) by a conductive connecting material (not shown) such as a bonding wire. The external electric circuit is included in the external member 5, and various signals or a predetermined potential such as ground is exchanged between the semiconductor element and the external electric circuit.

For example, when the external member 5 is a circuit board (motherboard or the like) of a device having an electronic control mechanism such as a computer or an automobile, information that is the basis of calculation is transmitted from the external member 5 to the electronic component 4, and the electronic component 4 externally. The calculation result or the stored information is transmitted to the electric circuit.

Further, the heat generated by the operation of the electronic component 4 is conducted to the second metal plate 3 as described above, and is conducted from the second metal plate 3 to the external member 5. In this case, the circuit board may promote heat transfer and heat dissipation to the outside. Further, an external member 5 for heat dissipation other than the external electric circuit may be joined to the second metal plate 3 to promote heat dissipation to the outside.

(Electronic module)
FIG. 3 is a plan view showing the electronic module of the embodiment of the present invention. The electronic device 20 of the embodiment is basically configured by the electronic device 20 having the above-described configuration and the external member 5 to which the electronic device 20 is joined via the joining material 6. In FIG. 3, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals.

The joining material 6 is a low melting point brazing material such as solder. Examples of the solder include tin-lead solder (eutectic solder, etc.), tin-copper solder, tin-silver-copper solder, tin-silver-bismuth solder, and the like. For example, the electronic device 20 and the external member 5 can be joined to each other by aligning the electronic device 20 with the solder paste and then heating and melting the solder paste.

The external member 5 is, for example, as described above, various members that form an electronic circuit portion in a computer, various control devices for vehicles, industrial machines, communication devices, and the like. The external member 5 may have a function of an external electric circuit having an electronic circuit, or may have a function of radiating heat. In the example shown in FIG. 3, the electronic device 20 is bonded and mounted to a motherboard (external member 5) included in an electronic device such as a computer.

According to the electronic module 30 of such an embodiment, as described above, the thermal stress at the time of mounting causes the laminated body 9 to extend at the convex portion 9a. This deformation acts in the direction opposite to the direction in which the outer peripheral portion of the laminated body 9 becomes flat in the upward direction. That is, a stress that flattens the entire laminated body 9 that has been bent before mounting is generated.

Note that, for example, as in the example shown in FIG. 3, the central portion of the laminate 9 (composite substrate 10) in plan view may be curved downward due to the stress generated in the peripheral portion of the convex portion 9a. However, in this case as well, if the electronic component 4 is mounted on the first metal plate 2 in the central portion, for example, the distance from the electronic component 4 to the external member 5 can be suppressed to a small value, so that the heat dissipation can be improved. It is possible.

When the central portion of the laminated body 9 (composite substrate 10) is curved downward, the height of the curved portion (the distance from the portion other than the curved portion of the lower surface of the second metal plate 3 to the lower end of the curved portion in side view) ) May be in the range of, for example, about 20 to 80 μm. Within this range, the effect of reducing the distance between the electronic component 4 and the external member 5 in the curved portion can be effectively obtained, and the second metal plate 3 (composite substrate 10) in the intermediate portion and the outer peripheral portion can be obtained. The distance between the lower surface of) and the external member 5 can be kept relatively small to ensure high heat transfer.

(Modified example of composite substrate)
4A is a plan view showing a modified example of the composite substrate 10 shown in FIG. 1, FIG. 4B is a cross-sectional view taken along line AA of FIG. 4A, and FIG. FIG. 4 is a sectional view taken along line BB in FIG. Further, FIG. 5 is an enlarged schematic sectional view of a main part of the composite substrate 10 shown in FIG. 4 and 5, the same parts as those in FIGS. 1 to 3 are designated by the same reference numerals. The electronic device 20 and the electronic module 30 may include the composite substrate 10 of this modification.

In the example shown in FIG. 4, the laminated body 9 has a rectangular shape in a plan view, and the upper end of the convex portion 9 a is located above the other portions in the portions near the corners of the laminated body 9. In other words, the height of the convex portion 9a is higher in the portion near the corner of the stacked body 9 than in other portions. In the example shown in FIG. 4A, the heights of the convex portions 9a are shown as L1, L2, and L3 in order from the portion having the shortest distance from the level surface L0. For example, if the size of the insulating substrate 1 in plan view is about 50 to 60 mm as described above, the composite substrate 10 has a distance L1 from the center point of L0 of about 6 to 58 mm and L2 is L0. Is about 15 to 54 mm, and L3 is about 23 to 49 mm from L0.

When the height of the convex portion 9a is set to about 20 to 80 μm as described above, the height of the highest portion (L3) of the upper surface of the convex portion 9a is about 40 to 80 μm near the corner. I wish I had it. Further, in this case, the height of the highest portion (L2) of the upper surface of the convex portion 9a may be about 20 to 60 μm near the side portion other than the corner portion. Further, in this case, the height of the convex portion 9a in the region L1 is less than about 40 μm, and is 1 μm or more.

The height of the protrusion 9a and the distribution of the height are measured by observing a cross section of the laminate 9 cut in the thickness direction and measuring the height of the protrusion 9a with a metallographic microscope or the like. You can Further, the height of the convex portion 9a can be measured by using a measuring device such as a shadow moire method, and specifically, it can be measured by various commercially available measuring devices.

Further, in the example shown in FIG. 4, for example, as shown in FIG. 5, the slope of the side surface of the convex portion 9a in the portion close to the corner of the laminated body 9 is larger on the outer peripheral side of the laminated body 9 than on the central portion side. May be FIG. 5 is a cross-sectional view schematically showing an enlarged main part of the composite substrate 10 shown in FIG. 5, the same parts as those in FIG. 4 are designated by the same reference numerals.

The gradient of the side surface of the convex portion 9a corresponds to the angle θ of the angle formed between the side surface of the convex portion 9a and the virtual horizontal plane L in the longitudinal sectional view as in the example shown in FIG. 5, for example. When the side surface of the convex portion 9a is a curved surface and is a curved line in a longitudinal sectional view, the angle θ formed by the tangent line S to the curved line and the horizontal plane L is the above gradient. The virtual horizontal plane L is, for example, a plane parallel to the virtual level plane L0 in the above example.

When the angle formed between the side surface of the convex portion 9a and the horizontal surface (side surface inclination) is not constant in the length direction of the side surface, the average value of the angle can be regarded as the gradient. Further, this average value can be substituted with an angle formed by a virtual horizontal plane and a virtual straight line connecting a maximum-shaped portion (vertex or the like) of the convex portion 9a and the lower end of the side surface of the convex portion 9a.

In this case, it is possible to make a larger room (deformation margin) for upward deformation in the side surface of the convex portion 9a on the outer peripheral side of the stacked body 9. That is, the outer peripheral portion of the laminated body 9 where it is desired to suppress the upward warp more effectively can have more room for deformation until such warp occurs. Therefore, it is possible to effectively suppress upward warpage of the outer peripheral portion of the stacked body 9 in the electronic module 30.

Therefore, it is possible to provide the electronic module 30 that is advantageous in improving the adhesion between the electronic device 20 and the external member 5 and the heat dissipation. Further, the electronic device 20 and the composite substrate 10 in which such an electronic module 30 is easily manufactured can be provided.

(Modification of electronic device)
FIG. 6 is a cross-sectional view showing a modified example of the electronic device 20 shown in FIG. In FIG. 6, the same parts as those in FIGS. 1 to 3 are denoted by the same reference numerals.

In the example shown in FIG. 6, the composite substrate 10 is turned upside down and used to form the electronic device 20. As described above, the upper and lower sides when the composite substrate 10 is actually used are not limited to the above-described embodiment and its modified examples (such as the examples shown in FIGS. 1 to 6), but as shown in the example of FIG. The second metal plate 3 may be used so as to face upward, and the electronic component 4 may be mounted on the second metal plate 3. Further, the first metal plate 2 may be mounted facing the external member 5.

The electronic device 20 of the form shown in FIG. 6 also includes the composite substrate 10 of the embodiment as in the case of the electronic device 20 shown in FIG. Deformation occurs such that the substrate 10 becomes flat. Therefore, the electronic device 20 having high adhesion to the external member 5 can be obtained.

Further, since the electronic component 4 is mounted on the second metal plate 3 having a relatively large thickness, it is possible to effectively enhance the conduction of heat from the electronic component 4 to the composite substrate 10. Also, this heat can be effectively dissipated to the outside from the side surface of the second metal plate 3 having a relatively large area. Further, since the total thickness of the first metal plate 2 and the second metal plate 3 is about the same as that of the electronic device 20 of the above-described embodiment, heat conduction from the electronic component 4 to the external member 5 is also effectively generated. . Therefore, it is possible to provide the electronic device 20 having high heat dissipation from the electronic component 4.

(Modification of electronic module)
FIG. 7 is a sectional view showing a modification of the electronic module 30 shown in FIG. In FIG. 7, the same parts as those in FIGS. 1 to 3 are denoted by the same reference numerals.

In the example shown in FIG. 7, the composite substrate 10 is mounted on the external member 5 in the vertical direction. As described above, the direction including the upper and lower sides when the composite substrate 10 is actually used is not limited to the above-described embodiment and its modification.

Further, in the example shown in FIG. 7, a plurality of electronic components 4 are mounted on the composite substrate 10. As described above, the number of electronic components 4 is not limited to one, and a plurality may be provided, or a plurality of different types may be mounted. When a plurality of electronic components 4 are mounted, the electronic module 30 is effectively enhanced.

Even in the case of the electronic device 20 and the electronic module 30 shown in FIG. 7, the composite substrate 10 of the embodiment is included, as in the case of the electronic device 20 shown in FIG. 2 and the electronic module 30 shown in FIG. Thus, the electronic module 30 can be effectively flattened at the time of mounting to have high adhesion between the electronic device 20 and the external member 5.

The plurality of electronic components 4 to be mounted may be of the same type (for example, a plurality of semiconductor elements for storage) or different from each other (for example, a semiconductor integrated circuit element, a sensor element, and a passive component). And the like).

The external member 5 on which the electronic device 20 is mounted is not limited to the motherboard or the like in the above-described example, and may be the heat dissipation member 5 (5A) including heat dissipation fins and the like. As a result, the electronic module 30 having improved heat dissipation can be obtained.

The external member 5 may be the bus bar 5 (5B) or the like. The bus bar 5 (5B) is electrically connected to a power source part such as a battery in various vehicles equipped with an electric motor, for example. This effectively manages and controls the power supply of a vehicle having an electric conduction mechanism such as a hybrid vehicle or an electric vehicle.

1... Insulating substrate 2... 1st metal plate 3... 2nd metal plate 4... Electronic component 5... External member 5 (5A)... External member (heat dissipation member)
5 (5B)...External member (bus bar)
6... Joining material 9... Laminated body
10...Composite substrate
20..Electronic device
30..Electronic module L0..Virtual level surface

Claims (4)

An insulating substrate having an upper surface and a lower surface,
A first metal plate bonded to the upper surface of the insulating substrate;
A second metal plate that is joined to the lower surface of the insulating substrate and is thicker than the first metal plate;
The laminated body has a rectangular shape in a plan view , and has a convex portion curved upward in an intermediate portion between a central portion and an outer peripheral portion in a planar view , and an upper end of the convex portion is the laminated body. A composite substrate that is located above the other parts of the body near the corners . The gradient of the side surface of the convex portion in a portion near the corner portion of the laminate, composite substrate according to claim 1 is greater than the central portion side in the outer peripheral side of the laminate. A composite substrate according to claim 1 or 2 , and
An electronic device comprising: an electronic component mounted on the first metal plate. An electronic device according to claim 3 ;
An electronic module comprising the electronic device and an external member bonded via a bonding material.

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