JP2016162836A - Package for mounting electronic component, electronic device and electronic module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a package for mounting an electronic component, an electronic device and an electronic module that can excellently radiate heat occurring from an electronic component.SOLUTION: An electronic component mounting package 1 is configured by alternately laminating highly thermal conductive metal plates 3 and 4 and a low thermal expansion metal plate 2 having a lower thermal expansion property than the highly thermal conductive metal plates 3 and 4 so that the highly thermal conductive metal plates 3 and 4 are arranged on the uppermost layer and the lowermost layer. The electronic component mounting package 1 includes a heat sink 6 having a mounting portion 5 for the electronic component on the upper surface of the highly thermal conductive metal plate 3, and a frame body 7 joined to the upper surface of the highly thermal conductive metal plate 3 so as to surround the mounting portion 5. The radiating plate 6 has an extension portion 6a which extends more outwardly than the frame 7 in plan view. A thin portion 10 having a lower surface 4d which is smaller in thickness than the central portion 4b of the highly thermal conductive metal plate 4 and located above the lower surface 4c of the central portion 4b is formed at at least a part of the outer peripheral portion 4a of the highly thermal conductive metal plate 4 located at the extension portion 6a.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an electronic component mounting package for mounting electronic components, an electronic device using the same, and an electronic module.

  Conventionally, as an electronic component mounting package for mounting an electronic component, a high thermal conductivity metal plate made of a material having higher thermal conductivity than a low thermal expansion metal plate described later, and thermal expansion of the high thermal conductivity metal plate Low thermal expansion metal plates having a coefficient of thermal expansion smaller than the coefficient are stacked alternately so that the high thermal conductivity metal plates are arranged in the uppermost layer and the lowermost layer, and adjacent high thermal conductivity metal plates and low thermal expansion properties A metal plate is joined to each other with a brazing material, and a heat radiating plate having an electronic component mounting portion on the top surface of the high thermal conductivity metal plate disposed in the uppermost layer, and the outermost portion surrounding the mounting portion. An electronic component mounting package is used that includes a thermal expansion coefficient of a low thermal expansion metal plate and a frame made of a material having an approximate thermal expansion coefficient, which is bonded to the upper surface of a high thermal conductivity metal plate disposed in an upper layer. (For example, Patent reference 1).

  Then, using the electronic component mounting package having such a configuration, an electronic component such as a semiconductor element is mounted on the mounting portion located in the frame, and the electronic component is attached to the frame body, for example, by a bonding wire or the like. In order to dissipate the heat generated from the electronic components and guided to the heat sink to the outside space below the heat sink, and electrically connected to the metallized layer to which the lead terminals are attached. An electronic device is manufactured by attaching a heat sink (heat sink).

  In such an electronic component mounting package, in order to fix the electronic component mounting package to the radiator using screws or the like, the heat radiating plate extends outward from the frame body in plan view. In some cases, it is configured to have an extending portion.

JP 2008-109126 A

  In the electronic component mounting package having the above-described configuration, silver (Ag) is interposed between the low thermal expansion metal plate and the high thermal conductivity metal plate so that the high thermal conductivity metal plate is disposed in the uppermost layer and the lowermost layer. )-A brazing material preform such as copper (Cu) brazing is sandwiched, and a high thermal conductivity metal plate and a low thermal expansion metal plate are alternately stacked. Further, on the high thermal conductivity metal plate disposed in the uppermost layer. The frame body is stacked so as to sandwich a preform of a brazing material such as silver-copper brazing, and put in this state in a high temperature furnace (for example, about 800 ° C. when using silver-copper brazing), and has low thermal expansion It is produced by melting a preform of a brazing material sandwiched between a metal plate and a high thermal conductivity metal plate and between the high thermal conductivity metal plate and a frame, and then taking it out from a high temperature furnace. Accordingly, the low thermal expansion metal plate, the high thermal conductivity metal plate, and the frame body are joined by the brazing material.

  By the way, when taking out from the high-temperature furnace and cooling, the portion sandwiched between the frame and the low thermal expansion metal plate in the high thermal conductivity metal plate arranged in the uppermost layer is the frame and the low thermal expansion metal plate. Since the thermal expansion coefficient of the metal plate is smaller than the thermal expansion coefficient of the high thermal conductive metal plate, it is restrained by the frame body and the low thermal expansion metal plate, and therefore heat in a plane direction that is perpendicular to the stacking direction of the metal plates. Shrinkage is suppressed.

  On the other hand, in the high thermal conductive metal plate arranged in the uppermost layer, in the portion corresponding to the extension portion, the surface portion exposed to the external space is thermally contracted in the plane direction with cooling. On the other hand, also in the high thermal conductivity metal plate arranged in the lowermost layer, the surface portion exposed to the external space is thermally contracted in the surface direction with cooling.

  As described above, in the electronic component mounting package having the above-described configuration, the range of the surface portion to be thermally contracted is arranged in the lowermost layer as compared with the high thermal conductive metal plate arranged in the uppermost layer. A high heat conductive metal plate becomes larger. Thereby, compared with the high thermal conductivity metal plate arranged in the uppermost layer, the high thermal conductivity metal plate arranged in the lowermost layer has a larger shrinkage stress toward the center in the surface direction, and after cooling In an electronic component mounting package, there is a tendency for upward warping.

  When an electronic device is manufactured as described above using an electronic component mounting package that causes such upward warping, when the electronic component mounting package is fixed to the radiator via the extension portion, The lower surface of the heat sink and the installation surface of the heat sink opposite to the heat sink cannot be brought into surface contact, and an air gap is generated between the lower surface of the heat sink and the installation surface of the heat sink, particularly below the mounting portion. The presence of the air gap deteriorates the thermal conductivity between the heat radiating plate and the heat radiator, and causes a problem that heat generated from the electronic component cannot be dissipated well through the heat radiator.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic component mounting package capable of dissipating heat generated from an electronic component satisfactorily, an electronic device and an electronic module using the same. Is to provide.

  An electronic component mounting package according to an aspect of the present invention includes a first metal plate, a second metal plate having a thermal expansion coefficient smaller than that of the first metal plate, an uppermost layer, and The first metal plate is formed by alternately laminating so that the first metal plate is disposed in the lowermost layer, and joining the adjacent first metal plate and the second metal plate, respectively. An electronic component comprising: a heat radiating plate having an electronic component mounting portion in the center of the upper surface of the plate; and a frame joined to the upper surface of the first metal plate disposed in the uppermost layer so as to surround the mounting portion. In the mounting package, the heat radiating plate has an extending portion extending outward from the frame body in a plan view, and the extending portion of the first metal plate disposed in the lowermost layer At least part of the outer peripheral portion located at a thickness smaller than the central portion of the first metal plate, and Wherein the thin portion having a lower surface positioned above than the lower surface of the central portion of the first metal plate is formed.

  An electronic device according to an aspect of the present invention includes the above-described electronic component mounting package and an electronic component mounted on the mounting portion. An electronic module according to an aspect of the present invention is disposed below the electronic device described above and a first metal plate disposed in the lowermost layer, and the electronic component mounting package is disposed via the extending portion. And a radiator sheet disposed between the radiator and the first metal plate disposed in the lowermost layer.

  According to the electronic component mounting package according to one aspect of the present invention, the first metal plate is disposed on at least a part of the outer peripheral portion of the first metal plate disposed in the lowermost layer, which is located in the extending portion. Since a thin part having a lower surface located lower than the lower surface of the central part of the first metal plate is formed in comparison with the central part, cooling in the joining process of joining the metal plates together The shrinkage stress toward the center in the surface direction, which occurs in the surface portion exposed to the external space of the first metal plate disposed in the lowermost layer at the time, is reduced as compared with the case where the thin portion is not formed. Can do.

  Thereby, it is possible to prevent the electronic component mounting package from being warped in the upward direction, or to reduce the amount of upward warping generated in the electronic component mounting package.

  In the former case, the electronic component mounting package is not warped or warped downward, and at least below the mounting portion, a highly thermally conductive metal plate disposed in the bottom layer and It is possible to make a surface contact with an installation surface of an object to be attached such as a radiator to which the electronic component mounting package is attached without a gap. Therefore, the thermal conductivity between the heat sink and the attachment object is improved, and the heat generated from the electronic component can be dissipated well.

  On the other hand, in the latter case, the distance between the lower surface of the heat sink and the mounting surface of the attachment object such as a radiator is shortened below the mounting portion by the thickness of the outer peripheral portion made thinner. Accordingly, in combination with the reduction in the amount of warp, the gap between the lower surface of the heat sink and the installation surface of the attachment target, which is generated below the mounting portion, can be made minute. Therefore, the thermal conductivity between the heat sink and the attachment object is improved, and the heat generated from the electronic component can be dissipated well.

  According to the electronic device according to one aspect of the present invention, since the electronic component mounting package described above is included, an electronic device that can favorably dissipate heat generated from the electronic component can be realized. In addition, according to the electronic module according to one aspect of the present invention, since the electronic device is provided, the heat generated from the electronic component can be dissipated well through the radiator and the heat radiating sheet.

It is the perspective view which looked at the electronic component mounting package 1 which concerns on one Embodiment of this invention from upper direction. It is the perspective view which looked at the electronic component mounting package 1 shown in FIG. 1 from below. FIG. 2 is a plan view of the electronic component mounting package 1 shown in FIG. 1. FIG. 2 is a front view of the electronic component mounting package 1 shown in FIG. 1. FIG. 2 is a side view of the electronic component mounting package 1 shown in FIG. 1. It is sectional drawing of the package 1 for electronic component mounting in the AA line shown in FIG. It is sectional drawing of the package 1 for electronic component mounting in the BB line shown in FIG. FIG. 2 is an exploded perspective view of the electronic component mounting package 1 shown in FIG. 1. It is a perspective view which shows one Embodiment of the electronic apparatus 11 comprised using the electronic component mounting package 1 shown in FIG. It is a figure for demonstrating the effect | action of distance shortening between the lower surface of the heat sink 6 and the installation surface of an attachment target object by providing the thin part 10. FIG. It is sectional drawing which shows one Embodiment of the electronic module 16 comprised using the electronic device 11 shown in FIG.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the drawing, an electronic component mounting package and an electronic device are provided in a virtual xyz space and are placed on an xy plane. In the present embodiment, the upper, upper, and upper portions indicate the positive direction of the virtual z axis, and the lower, lower surface, and lower portion indicate the negative direction of the virtual z axis.

  FIG. 1 is a perspective view of an electronic component mounting package 1 according to an embodiment of the present invention as viewed from above, and FIG. 2 is a perspective view of the electronic component mounting package 1 shown in FIG. 1 as viewed from below. is there. 3 is a plan view of the electronic component mounting package 1 shown in FIG. 1, FIG. 4 is a front view of the electronic component mounting package 1 shown in FIG. 1, and FIG. 5 is an electronic component shown in FIG. 2 is a side view of the mounting package 1. FIG. 6 is a cross-sectional view of the electronic component mounting package 1 taken along line AA shown in FIG. 3, and FIG. 7 is a cross-sectional view of the electronic component mounting package 1 taken along line BB shown in FIG. FIG. 8 is an exploded perspective view of the electronic component mounting package 1 shown in FIG. FIG. 9 is a perspective view showing an embodiment of an electronic device 11 configured using the electronic component mounting package 1 shown in FIG. 1, and shows a state viewed from above.

  The electronic component mounting package 1 according to the present embodiment includes first metal plates (hereinafter referred to as “high thermal conductive metal plates”) 3 and 4 and thermal expansion coefficients of the high thermal conductive metal plates 3 and 4. The second metal plate (hereinafter referred to as “low thermal expansion metal plate”) 2 having a small thermal expansion coefficient is alternately arranged so that the high thermal conductive metal plates 3 and 4 are arranged in the uppermost layer and the lowermost layer. And the adjacent high thermal conductive metal plates 3 and 4 and the low thermal expansion metal plate 2 are joined by a brazing material (not shown) such as silver (Ag) -copper (Cu) brazing. A heat dissipation plate 6 having a three-layer structure having a mounting portion 5 for the electronic component 12 at the center in the surface direction of the upper surface of the highly thermally conductive metal plate 3 disposed in the upper layer, and an uppermost layer so as to surround the mounting portion 5 A frame body 7 joined to the upper surface of the high thermal conductivity metal plate 3 disposed on the upper surface of the frame body 7; A metallized layer 8 kicked, one end portion is joined to the metallized layer 8, and a lead terminal 9 extending outwardly of the frame 7.

  And in the planar view, the heat sink 6 has the extension part 6a extended to the outer side rather than the frame 7, Out of the outer peripheral part 4a of the highly heat conductive metal plate 4 arrange | positioned in the lowest layer Further, at least a part of the outer peripheral portion 4a located in the extending portion 6a is thinner than the central portion 4b of the high heat conductive metal plate 4, and the central portion 4b of the high heat conductive metal plate 4 is formed. A thin portion 10 having a lower surface 4d located above the lower surface 4c is formed.

  9 includes an electronic component mounting package 1, an electronic component 12 such as a semiconductor element mounted on the mounting portion 5 of the electronic component mounting package 1, an electronic component 12, and a metallized layer 8. And a bonding wire 13 for electrically connecting the two.

  The low thermal expansion metal plate 2 constituting the heat radiating plate 6 is made of a material having a smaller thermal expansion coefficient than the high thermal conductivity metal plates 3 and 4, for example, a metal material such as molybdenum (Mo), tungsten (W), or the like. It is made of an alloy (copper-molybdenum sintered body, copper-tungsten sintered body, etc.), and is formed and used in a predetermined shape by applying a conventionally known metal working method such as rolling or punching. In the present embodiment, the low thermal expansion metal plate 2 is made of molybdenum.

  On the other hand, the high thermal conductive metal plates 3 and 4 constituting the heat radiating plate 6 are materials having higher thermal conductivity than the low thermal expansion metal plate 2, for example, metals such as copper, silver, aluminum (Al), gold (Au), etc. It is made of a material or an alloy thereof, and is used after being formed into a predetermined shape by applying a conventionally known metal working method such as rolling or punching. In this embodiment, the high heat conductive metal plates 3 and 4 are both made of copper. The high heat conductive metal plate 3 and the high heat conductive metal plate 4 may be made of different materials. For example, the material of the high heat conductive metal plate 3 is more thermally conductive than the material of the high heat conductive metal plate 4. A material with a high rate may be selected.

  In addition, when the high heat conductive metal plates 3 and 4 are made of copper, the material is not limited to pure copper, and if the heat conductivity is good and the low thermal expansion metal plate 2 and sufficient bonding strength can be obtained, Various copper alloys mainly composed of copper may be used. Similarly, when the high thermal conductive metal plates 3 and 4 are made of a material such as silver or aluminum, it is not necessary to be pure metal.

  In this embodiment, each metal plate 2-4 is formed so that it may have the same shape and magnitude | size in planar view. Specifically, each of the metal plates 2 to 4 has a shape in which a rectangle is partially cut out at both ends in the longitudinal direction in plan view, and more specifically, each short side The central portion has a rotationally symmetric shape provided with U-shaped notches extending along the longitudinal direction.

  Moreover, as for the external dimension of each metal plate 2-4, the dimension of a longitudinal direction is 10-30 mm, and the dimension of the width direction is 5-10 mm, for example. In addition, in each metal plate 2-4, a longitudinal direction is a direction where a long side extends, and a width direction is a direction where a short side extends.

  Moreover, the thickness of each metal plate 2-4 is selected so that the thickness of the high heat conductive metal plates 3 and 4 may be larger than the thickness of the low thermal expansion metal plate 2 in the present embodiment. The thickness of the conductive metal plates 3 and 4 is 0.2 to 0.8 mm, and the thickness of the low thermal expansion metal plate 2 is 0.1 to 0.4 mm. In addition, the thickness of the high heat conductive metal plate 3 and the thickness of the high heat conductive metal plate 4 may be the same or different.

  The heat radiating plate 6 is laminated in the order of the high thermal conductivity metal plate 3, the low thermal expansion metal plate 2, and the high thermal conductivity metal plate 4 so that the outlines thereof match each other in plan view. The lower surface and the upper surface of the low thermal expansion metal plate 2, and the lower surface of the low thermal expansion metal plate 2 and the upper surface of the high thermal conductivity metal plate 4 are joined by a brazing material.

Frame 7, alumina _(Al 2 _{O 3)} sintered material, aluminum nitride (AlN) sintered material, mullite _{(3Al 2 O 3 · 2SiO 2} ) sintered material, made of a ceramic such as glass ceramic insulation The material is made of a body and is selected from materials whose thermal expansion coefficient and thermal expansion coefficient of the low thermal expansion metal plate 2 are similar. In the present embodiment, the frame body 7 is made of an alumina (Al ₂ O ₃ ) -based sintered body.

  The frame body 7 is formed in a frame shape in plan view, and in the present embodiment, in the plan view, the surface direction of the upper surface of the high thermal conductive metal plate 3 is in the center of the surface direction of the plate material having a rectangular outer shape. The rectangular opening is formed by providing a rectangular opening in a plan view having a size slightly larger than the mounting portion 5 provided in the central portion.

  Further, since the frame body 7 is provided with the extending portion 6 a in the heat radiating plate 6, the frame size is formed so as to be smaller than the outer size dimensions of the metal plates 2 to 4. In the present embodiment, the frame body 7 is selected such that the dimension of the long side in the rectangular outer shape is shorter than the distance between the U-shaped cutouts formed in each of the metal plates 2 to 4. And the dimension of the short side in the rectangular external shape is selected so that it may correspond to the dimension of the width direction in each metal plate 2-4.

  The frame body 7 has, in plan view, the long sides of the rectangular outer shape thereof coincide with the long sides of the high thermal conductivity metal plate 3 disposed in the uppermost layer, and the high thermal conductivity metal. It is arranged on the high heat conductive metal plate 3 so as to be located in the center between the U-shaped notches formed in the plate 3, and the lower surface and the high heat conduction by the brazing material such as silver-copper brazing. The upper surface of the conductive metal plate 3 is bonded to the heat radiating plate 6. Thereby, the mounting part 5 provided in the center part of the surface direction of the upper surface of the high heat conductive metal plate 3 is surrounded by the frame body 7.

  Here, since the length of the long side in the rectangular outer shape of the frame body 7 is shorter than the distance between the U-shaped notches formed in the respective metal plates 2 to 4, it is arranged as described above. By joining the frame body 7 and the heat radiating plate 6, a part of the heat radiating plate 6 extends outward from the frame body 7 in plan view. The portion extending outward from the frame body 7 in this way is the extension portion 6a. In this embodiment, the extension part 6a exists in the both sides of the frame 7 regarding the longitudinal direction of the heat sink 6, ie, the direction where the long side in each metal plate 2-4 is extended, respectively. The two extending portions 6a are portions used for fixing the electronic component mounting package 1 to an attachment object such as a radiator (heat sink).

  A metallized layer 8 is provided on the upper surface of the frame body 7. In the present embodiment, the metallized layer 8 is provided on both sides of the opening with respect to the extending direction of the short side of the rectangular outer shape of the frame body 7. When the frame body 7 is made of metal, ceramics, resin, glass or the like is provided between the metallization layer 8 and the frame body 7 in order to insulate the metallized layer 8 from the metal constituting the frame body 7. It is sufficient to interpose an insulator.

If the frame 7 is made of an alumina sintered body, for example, an organic binder or solvent suitable for raw material powders such as alumina, silicon oxide (SiO ₂ ), magnesium oxide (MgO), and calcium oxide (CaO). , Plasticizer, dispersing agent, etc. are mixed and made into a mud-like shape, and a ceramic green sheet (ceramic green sheet) is formed by adopting a doctor blade method or a calender roll method. Conductive paste made by mixing an appropriate organic binder and solvent with metal material powder such as tungsten, molybdenum, manganese (Mn), copper, silver, nickel, gold, palladium (Pd) A predetermined metallized layer on a ceramic green sheet by screen printing or the like. After printing applied to the pattern of the ceramic green sheet laminating a plurality, it is produced by firing at a temperature of about 1600 ° C..

  The metallized layer 8 is effective for oxidative corrosion of the metallized layer 8 by depositing a metal having excellent corrosion resistance such as nickel and gold on the exposed surface to a thickness of 1 to 20 μm by plating. In addition, the connection of the bonding wire to the metallized layer 8 can be strengthened. Therefore, the metallized layer 8 is desirably coated with a metal having excellent corrosion resistance such as nickel and gold and excellent bonding properties on the exposed surface to a thickness of 1 to 20 μm.

  The lead terminal 9 is a strip-shaped metal piece made of a metal such as copper, copper alloy, iron-nickel-cobalt, or iron-nickel, and has one end in the longitudinal direction so as to extend outward of the frame body 7. The part is bonded to the metallized layer 8.

  The electronic component mounting package 1 of the present invention has an outer periphery of the high thermal conductivity metal plate 4 before joining, which is arranged in the lowermost layer of the high thermal conductivity metal plates 3 and 4 constituting the heat radiating plate 6. The thin part 10 is formed in at least a part of the outer peripheral part 4a located in the extending part 6a of the part 4a.

  As described above, the thin-walled portion 10 is thinner than the central portion 4b of the high thermal conductivity metal plate 4, and is a lower surface positioned above the lower surface 4c of the central portion 4b of the high thermal conductivity metal plate 4. In this embodiment, the thickness is gradually reduced as the distance from the central portion 4b increases. More specifically, the lower surface 4d has a curved surface convex outward, that is, an R surface. It is formed to become. The lower surface 4d may not be the R surface, but may be a simply inclined C surface.

  Since the high thermal conductive metal plate 4 is made of a relatively soft material having a small longitudinal elastic modulus such as copper and silver as described above, the thin portion 10 is formed by pressing the outer peripheral portion 4a of the high thermal conductive metal plate 4 or the like. In this embodiment, the thin portion 10 is formed over the entire circumference of the outer peripheral portion 4a of the high thermal conductive metal plate 4.

  The electronic component mounting package 1 of the present embodiment is manufactured as follows. First, by performing a punching process using a mold, the low thermal expansion metal plate 2 punched into a predetermined shape, and by performing a punching process using a mold, the same as the low thermal expansion metal plate 2 is performed. By punching using a metal mold and a high thermal conductivity metal plate 3 punched to have a shape and an outer dimension, the metal sheet is punched to have the same shape and outer dimension as the low thermal expansion metal plate 2. At the same time, a highly thermally conductive metal plate 4 in which the thin-walled portion 10 is formed by pressing the outer peripheral portion 4a and a frame body 7 formed in a predetermined shape and having the metallized layer 8 attached thereto are prepared.

  Next, a brazing material such as a silver-copper braze between the low thermal expansion metal plate 2 and the high thermal conductivity metal plates 3, 4 so that the high thermal conductivity metal plates 3, 4 are arranged in the uppermost layer and the lowermost layer. Sandwich the preform. At this time, the high thermal conductivity metal plates 3 and 4 and the low thermal expansion metal plate 2 are alternately stacked so that the thin portion 10 faces downward, and further, on the high thermal conductivity metal plate 3 disposed in the uppermost layer. The frame body 7 is overlapped so as to sandwich a preform of a brazing material such as silver-copper brazing. In addition, a notch (not shown) such as a C surface or an R surface is formed in one corner portion in plan view of the high thermal conductivity metal plate 4 arranged in the lowermost layer so that the shape is different from the other corner portions. In addition, by detecting the cutout by an image recognition means or the like, it is possible to reliably stack the surface of the high thermal conductive metal plate 4 on which the thin portion 10 is formed downward.

  Then, lead terminals 9 are overlaid on each metallized layer 8 so as to sandwich a preform of a brazing material such as silver-copper brazing. In this state, it is put into a high-temperature furnace (for example, about 800 ° C. when silver-copper brazing is used), between the low thermal expansion metal plate 2 and the high thermal conductivity metal plates 3 and 4, and the high thermal conductivity metal plate. The preform of the brazing material sandwiched between 3 and the frame body 7 and between the metallized layer 8 and the lead terminal 9 is melted. After that, the electronic component mounting package 1 is obtained by taking out from the high temperature furnace and cooling, and joining the low thermal expansion metal plate 2, the high thermal conductivity metal plates 3, 4, the frame body 7, and the lead terminal 9 with the brazing material. Is produced.

  In the electronic device 11 of the present embodiment, a desired electronic component 12 is mounted on the mounting portion 5 in the electronic component mounting package 1 manufactured as described above, and the electronic component 12 mounted on the mounting portion 5 is mounted. And the metallized layer 8 are manufactured by electrically connecting them with a bonding wire 13. Furthermore, the structure (not shown) where the electronic component 12 and the heat sink 6 were electrically connected by the bonding wire 13 may be sufficient.

  In the present embodiment, as described above, the high thermal conductivity metal plate 4 before joining, which is to be disposed in the lowermost layer, is formed on the central portion 4b of the high thermal conductivity metal plate 4 over the entire circumference of the outer circumferential portion 4a. Compared to the lower surface 4c of the central portion 4b of the central portion 4b of the high thermal conductive metal plate 4, the thin portion 10 having the lower surface 4d is formed. The shrinkage stress toward the center in the surface direction, which occurs in the surface portion exposed to the external space of the high thermal conductivity metal plate 4 disposed in the lowermost layer, is reduced as compared with the case where the thin portion 10 is not formed. Can do.

  Thereby, in the electronic component mounting package 1 after cooling, it is possible to prevent upward warping, in other words, there is no warping or downward warping. The amount of warping in the upward direction that occurs in the electronic component mounting package 1 after cooling can be reduced.

  In the electronic component mounting package 1 after cooling, in a state where no warp is generated or a state where a downward warp is generated, the highly thermally conductive metal disposed in the lowermost layer at least below the mounting portion 5 The plate 4 and the installation surface of the object to be attached to which the electronic component mounting package 1 is attached can be brought into surface contact with no gap. Therefore, compared with the case where the upward warp occurs, the thermal conductivity between the heat sink 6 and the object to be attached is improved, and the heat generated from the electronic component 12 can be dissipated well.

  On the other hand, in the electronic component mounting package 1 after cooling, as shown in FIG. 10, even if the upward warping has occurred, as the thickness of the outer peripheral portion 4 a is reduced by the thin portion 10, as shown in FIG. 5, the distance between the lower surface of the heat radiating plate 6 and the installation surface S of the object to be attached is shortened, and coupled with the reduction in the amount of warpage, the heat radiating plate 6 is generated below the mounting portion 5. The gap between the lower surface and the installation surface of the attachment object can be made minute.

  Here, FIG. 10 is a view for explaining the action of shortening the distance between the lower surface of the heat radiating plate 6 and the installation surface S of the attachment object by providing the thin portion 10. In FIG. 10, for easy understanding, the warp generated in the electronic component mounting package 1 is exaggerated and the frame body 7 is omitted. Moreover, in FIG. 10, the external shape of the electronic component mounting package when the thin portion 10 is not formed is indicated by imaginary lines.

  Therefore, even if it is warped upward, compared to the case where the thin portion 10 is not formed, the thermal conductivity between the heat sink 6 and the object to be attached is improved, and the heat generated from the electronic component 12 is reduced. It can dissipate well.

  In addition, in the electronic component mounting package 1 after cooling, which state is in a state in which no warp is generated, a state in which a downward warp is generated, or a state in which the electronic component mounting package 1 is slightly warped in the upward direction? Depends on the thickness of each of the metal plates 2 to 4 and the shape and outer dimensions of the heat radiating plate 6 and the frame 7.

  In the above embodiment, the thin-walled portion 10 is realized by chamfering the outer peripheral portion 4a of the high thermal conductive metal plate 4 into an R-surface shape. However, in other embodiments, the thin-walled portion 10 has a high thermal conductivity. It may be realized by chamfering the outer peripheral portion 4a of the metal plate 4 in the shape of a C plane, or by providing a step between the outer peripheral portion 4a and the central portion 4b and parallel to the lower surface 4c of the central portion 4b. The lower surface 4d may be formed. In addition, when fixing the electronic component mounting package 1 to an attachment object such as a radiator by chamfering the outer peripheral portion 4a of the high thermal conductive metal plate 4 into an R surface shape, When the outer peripheral part 4a of the highly heat conductive metal plate 4 and the installation surface of the object to be attached are in contact with each other, it is possible to reduce scratches generated on the surfaces of the heat sink 6 and the radiator.

  Moreover, in said embodiment, although the thin part 10 is formed over the perimeter of the outer peripheral part 4a of the high heat conductive metal plate 4, it is not limited to this. For example, as in the case of the electronic component mounting package 1 described above, when the extending portions 6a are provided on both sides of the frame body 7 in a plan view, the longitudinal direction of the radiator plate 6, that is, a plan view. In the direction in which one extension portion 6a, the frame body 7 and the other extension portion 6a are arranged, the contraction stress that occurs in the center of the surface direction that occurs when cooling is the largest, With respect to the longitudinal direction of 6, warping upward occurs. Therefore, in such a case, the thin-walled portion 10 is formed in at least portions of the outer peripheral portion 4a of the high thermal conductive metal plate 4 corresponding to both ends in the longitudinal direction of the heat-radiating plate 6, thereby 6, the shrinkage stress that causes the upward warping can be reduced, and the longitudinal direction of the heat radiating plate 6 even if the upward warping occurs with respect to the longitudinal direction of the radiating plate 6. The distance between the lower surface of the heat radiating plate 6 and the installation surface of the object to be attached can be shortened by the thin wall portions 10 provided at both ends of the heat sink. In the above embodiment, the thin portion 10 is formed in the surface portion exposed to the external space of the high thermal conductivity metal plate 4, but the low thermal conductivity metal plate 2 of the high thermal conductivity metal plate 4 is further formed. In the surface portion on the side, a thin portion (not shown) having an upper surface located below the upper surface of the central portion 4b of the high thermal conductive metal plate 4 may be formed. That is, thin portions may be formed on both the upper and lower surfaces of the outer peripheral portion of the high thermal conductive metal plate 4.

  Moreover, in said embodiment, although the heat sink 6 is made into the 3 layer structure, in another embodiment, it is good also as a heat sink comprised by the multilayer rather than 3 layers. In this case, since the high thermal conductivity metal plate and the low thermal expansion metal plate need to be alternately laminated so that the high thermal conductivity metal plate is disposed in the uppermost layer and the lowermost layer, What is necessary is just to comprise by an odd number layer. In this case, the materials of the high thermal conductivity metal plates may be the same or different from each other. Similarly, the material of each low thermal expansion metal plate may be the same as each other or different from each other.

  FIG. 11 is a cross-sectional view illustrating an embodiment of an electronic module 16 configured using the electronic device 11 illustrated in FIG. 9. The electronic module 16 according to the present embodiment is arranged below the high thermal conductivity metal plate 4 arranged in the lowermost layer in the electronic device 11 shown in FIG. 9, and via the extending portion 6a, the electronic device 11 is fixed, and a heat-dissipating sheet 15 having high heat conductivity, disposed between the heat-dissipating metal plate 4 and the heat-dissipating member 14 disposed in the lowermost layer. It consists of

  The radiator 14 is made of a metal material having a high thermal conductivity such as copper or aluminum, and has an installation surface 14a to which the electronic device 11 is attached. The heat dissipation sheet 15 is realized by, for example, a graphite sheet.

  In the electronic module 16 according to this embodiment, the heat radiation sheet 15 is sandwiched between the lower surface of the heat radiation plate 6 and the installation surface 14a of the heat radiator 14 in the electronic device 11 shown in FIG. It is produced by fastening the extension portion 6a and the radiator 14 with the screws so that the shaft portions of the fixing screws are respectively disposed in the notch grooves provided in.

  In this embodiment, since the heat radiating sheet 15 having high thermal conductivity is disposed between the electronic device 11 and the heat radiator 14 instead of grease, the heat generated from the electronic component 12 is guided to the heat radiating plate 6. Heat can be effectively conducted to the radiator 14. Therefore, the heat generated from the electronic component 12 can be dissipated satisfactorily through the radiator 14.

DESCRIPTION OF SYMBOLS 1 Electronic component mounting package 2 Low thermal expansion metal plate 3 High thermal conductivity metal plate 4 High thermal conductivity metal plate 4a Outer peripheral part 4b Central part 4c Lower surface 4d Lower surface 5 Mounting part 6 Heat sink 6a Extension part 7 Frame 8 Metallization layer DESCRIPTION OF SYMBOLS 9 Lead terminal 10 Thin part 11 Electronic device 12 Electronic component 13 Bonding wire 14 Radiator 15 Radiation sheet 16 Electronic module

Claims (9)

The first metal plate and the second metal plate having a thermal expansion coefficient smaller than the thermal expansion coefficient of the first metal plate are arranged so that the first metal plate is disposed in the uppermost layer and the lowermost layer. The first metal plate and the second metal plate that are stacked alternately are joined to each other, and an electronic component mounting portion is provided at the center of the upper surface of the first metal plate that is disposed in the uppermost layer. A heat sink,
An electronic component mounting package including a frame joined to an upper surface of a first metal plate disposed in an uppermost layer so as to surround the mounting portion;
The heat radiating plate has an extending portion that extends outward from the frame body in plan view,
At least a part of the outer peripheral portion of the first metal plate disposed in the lowermost layer located in the extending portion is thinner than the central portion of the first metal plate, and the first metal A package for mounting electronic components, wherein a thin portion having a lower surface located above the lower surface of the central portion of the plate is formed.   2. The electronic component mounting package according to claim 1, wherein the thin portion is formed so that the thickness gradually decreases as the distance from the central portion increases.   The electronic component mounting package according to claim 2, wherein a lower surface of the thin portion is a curved surface that protrudes outward. The extension portions are provided on both sides of the frame body in plan view,
In a plan view, when the first direction is a direction in which one of the extending portions, the frame body, and the other extending portion are aligned, the thin-walled portion is at least each end of the first direction in the outer peripheral portion. The electronic component mounting package according to claim 1, wherein the electronic component mounting package is formed in a portion.   5. The electronic component mounting package according to claim 1, wherein the thin portion is formed over the entire circumference of the first metal plate disposed in the lowermost layer.   6. The electronic component mounting package according to claim 1, wherein the first metal plate is made of copper, and the second metal plate is made of molybdenum.   The electronic component mounting package according to claim 1, wherein the frame body is made of ceramics. The electronic component mounting package according to any one of claims 1 to 7,
An electronic device comprising: an electronic component mounted on the mounting portion. An electronic device according to claim 8;
A radiator that is disposed below the first metal plate disposed in the lowermost layer and to which the electronic component mounting package is fixed via the extension portion,
An electronic module comprising: a first metal plate disposed in the lowermost layer; and a heat dissipating sheet disposed between the heat radiator.

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