JP2009026957A - Insulating fin and heat sink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent troubles caused by the pressure of a cooling medium after an insulating fin is mounted at the aperture of a case that forms a cooling medium passage. <P>SOLUTION: An insulating fin 10 includes a conductive layer 14 for mounting electronic components, which is formed on the upper surface of an insulating substrate 12 made of ceramic; and a fin base portion 18 and a plurality of heat radiating fins 16, which are formed on the lower surface of the insulating substrate 12. The insulating substrate 12 is formed in such a size that it may overlap the periphery of the aperture of a case 30, when it is arranged so that the insulating fin 10 may choke up the aperture of the case 30, which forms the cooling medium passage, where the cooling medium circulates. Accordingly, if the pressure of the cooling medium is added to the mounting portion or its periphery, after the insulating fin 10 is mounted at the aperture of the case 30, troubles due to lack of strength can be prevented, because the insulating substrate 12 of high rigidity exists at the mounting portion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an insulating fin and a heat sink.

Conventionally, as an insulating fin, a fin base in which a conductor layer for mounting an electronic component formed on one surface of a ceramic insulating substrate and a plurality of radiating fins formed on the other surface of the insulating substrate are erected. The thing provided with the thermal radiation layer which has a part is known. For example, in Patent Document 1, a copper plate (first copper plate) on one surface of a double-sided copper-clad substrate is used as a conductor layer, a copper plate (second copper plate) on the other surface is used as a fin base portion, and a plurality of fin base portions are provided. An insulating fin provided with radiating fins standing up is disclosed. This double-sided copper-clad substrate is obtained by adhering a copper plate to both sides of a ceramic substrate via an Ag-Cu brazing material. Moreover, when the thickness of the ceramic substrate is 0.635 mm and the thickness of the first copper plate as the conductor layer is 0.3 mm, the thickness of the second copper plate as the fin base portion is 0.15 mm to 0.3 mm ( The warpage is suppressed by setting the thickness of the first copper plate / the thickness of the second copper plate = 1 to 2). These insulating fins are cooled by water flowing through the copper case in this state after joining the rim of the copper case opening and the outer edge of the fin base after inserting the radiation fin from the opening of the copper case serving as a water passage. ing.
JP 2005-11922 A

  However, in the insulating fin of Patent Document 1, when water is passed through the copper case, water pressure is applied to the joint portion between the opening edge of the copper case and the outer edge of the fin base portion, but the thickness of the fin base portion is 0.3 mm. Since it was thin, the joint portion could not withstand water pressure and could leak water.

  The main object of the insulating fin of the present invention is to prevent troubles caused by the pressure of the refrigerant after being attached to the opening of the case forming the refrigerant passage.

  The present invention adopts the following means in order to achieve the main object described above.

The insulating fin of the present invention is
A conductor layer for mounting electronic parts formed on one surface of a ceramic insulating substrate, and a heat radiating layer formed on the other surface of the insulating substrate with a plurality of heat radiating fins standing on the fin base portion. Insulating fins,
The insulating substrate is formed to have a size that overlaps with the periphery of the opening of the case when the insulating fin is disposed so as to close the opening of the case forming a refrigerant passage through which the refrigerant flows.

  With this insulating fin, when the insulating fin is disposed and attached so as to close the opening of the case forming the refrigerant passage, the insulating substrate overlaps with the periphery of the opening of the case. Therefore, even if the pressure of the refrigerant is applied to the attachment part or its periphery after attaching the insulating fins to the opening of the case, there is a problem due to the lack of strength because a rigid insulating substrate exists in the attachment part. Can be prevented.

  In the insulating fin of the present invention, it is preferable that the insulating substrate is mainly composed of silicon nitride ceramics or aluminum nitride ceramics, and the conductor layer and the heat dissipation layer are mainly composed of aluminum or an aluminum alloy. Here, the Young's modulus is about an order of magnitude smaller for aluminum and its alloys than for silicon nitride ceramics and aluminum nitride ceramics. For this reason, the significance of applying the present invention is high. Note that silicon nitride ceramics, aluminum nitride ceramics, aluminum, and aluminum alloys are preferable in this respect because they have high thermal conductivity and easily release heat efficiently. Here, the fin base portion is preferably formed by casting so as to surround the outer periphery of the insulating substrate. Since aluminum or aluminum alloy has a lower melting point than copper or copper alloy used in Patent Document 1, it is easy to form a fin base portion by casting. The heat dissipating fins may be integrally formed with the fin base portion by casting. For example, it is conceivable to join the radiating fin to the fin base portion with a brazing material or the like, but in that case, the thermal conductivity may deteriorate at the joint portion. For this reason, it is preferable to integrally mold the radiating fin and the fin base portion. In order to integrally form the radiating fin and the fin base, for example, the molten metal may be poured into a mold shaped like the fin base with the radiating fin, or after the metal layer having the height of the radiating fin is formed, the heat is radiated. The fins may be cut out and manufactured, but the former is preferable in view of manufacturing costs.

In the insulating fin of the present invention, it is preferable that a thickness t1 of the fin base portion facing the conductor layer is 0.7 to 1.5 times the thickness t0 of the conductor layer. Generally, the thickness of the conductor layer is set to about 0.5 mm in order to prevent destruction of solder (joining material) for mounting electronic components. Here, since the thickness t1 of the fin base portion facing the conductor layer is 0.7 to 1.5 times the thickness t0 of the conductor layer, efficient cooling of the electronic component and the insulating fin member It is possible to achieve both prevention of destruction (for example, prevention of destruction of the bonding material between the insulating fin and the electronic component and prevention of destruction of the boundary between the insulating substrate and the heat dissipation layer). This will be described in detail below. When the thickness ratio r (= t1 / t0) exceeds a value of 5, the rigidity of the heat dissipation layer increases, so that warping can be effectively prevented, but on the other hand, thermal resistance increases. In addition, a boundary between the insulating substrate and the heat dissipation layer and a bonding material (solder or the like) for mounting an electronic component may be destroyed due to a difference in thermal expansion with the insulating substrate in a heat cycle. When the thickness ratio r is 2 to 5, the thermal resistance decreases, but the warpage increases due to the bimetal principle. In this case as well, a load is applied to the boundary between the insulating substrate and the heat dissipation layer and the bonding material for mounting the electronic component. Take it. In view of this point, as a result of intensive research, the inventors have suppressed the warpage to a value equal to or greater than that when the thickness ratio is 5 if the thickness ratio r is 1.5 or less. In addition, it has been found that the heat resistance is lowered because the fin base portion of the heat dissipation layer is thin. Further, when the thickness ratio r is set to a value of 1 or less, warping occurs in the opposite direction. However, if the thickness ratio r is a reciprocal of the value 1.5, that is, a value of 0.7 or more, the warp is improved. It can be suppressed. From the above, by making the thickness ratio r in the range of 0.7 to 1.5, it is possible to achieve both efficient cooling of the electronic component and prevention of the destruction of the insulating fin member. Here, when the insulating substrate is mainly composed of silicon nitride ceramics or aluminum nitride ceramics, and the conductor layer and the heat dissipation layer are mainly composed of aluminum or aluminum alloy, warpage is likely to occur because of a large difference in thermal expansion coefficient. The thickness ratio r is highly significant in the range of 0.7 to 1.5. By the way, the coefficient of thermal expansion is exemplified by 2.3 × 10 ⁻⁶ / K for silicon nitride ceramics and 4.4 × 10 ⁻⁶ / K for aluminum nitride ceramics. It is considerably large as 5 × 10 ⁻⁶ / K.

  Thus, in the insulating fin of the present invention in which the thickness ratio r is 0.7 to 1.5, the thickness t1 is 0.8 mm or less, and the thickness of the insulating substrate is the thickness t0, t1. Thinner is preferred. In this way, it is possible to suppress warpage more satisfactorily, and it is possible to quickly transmit heat generated by the electronic component mounted on the conductor layer to the heat radiating fins.

  The insulating fin of the present invention may include a reinforcing portion formed thicker than the thickness t1 on the outer peripheral side of the heat dissipation layer. The reinforcing portion may be provided so as to come into contact with the peripheral edge of the opening of the case when the opening of the case is closed. If it carries out like this, when an insulation fin is attached to a case by the presence of a reinforcement part, it can prevent that a trouble arises by insufficient strength.

The heat sink of the present invention is
A case forming a refrigerant passage through which the refrigerant flows;
Any of the above-described insulating fins arranged so as to close the opening of the case and to make the radiating fins contact the refrigerant;
It is equipped with.

  In this heat sink, even if the pressure of the refrigerant is applied to the attachment part and its surroundings after attaching the insulating fin to the opening of the case, the insulation substrate exists in the attachment part, so that the problem is caused by insufficient strength. Can be prevented. Such a heat sink may include a pressing member that presses a portion of the insulating fin where the insulating substrate is present against the periphery of the opening of the case. In this way, since the holding strength is given by the insulating substrate made of ceramic with high rigidity, the deformation of the insulating fin due to the pressure of the refrigerant can be suppressed even if the fin base portion is thin. .

  Next, embodiments of the present invention will be described with reference to the drawings. 1 is a plan view of the insulating fin 10, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. 3 is a rear view of the insulating fin 10.

  The insulating fin 10 includes a ceramic insulating substrate 12, two conductor layers 14 formed on the upper surface of the insulating substrate 12, and a plurality of radiating fins 16 on a fin base portion 18 formed on the lower surface of the insulating substrate 12. A standing heat dissipation layer 19 and a reinforcing portion 20 formed on the outer peripheral side of the fin base portion 18 are provided. In this embodiment, the insulating fins 10 are formed in a rectangular shape having a length of 50 mm and a width of 100 mm.

The insulating substrate 12 electrically insulates the power module PM (for example, MOSFET, IGBT, etc., see FIG. 6) as an electronic component mounted on the conductor layer 14 and the radiating fins 16 formed in the radiating layer 19. is there. In this embodiment, the insulating substrate 12 is made of silicon nitride ceramics having a thickness of 0.3 mm (thermal conductivity: 80 W / mK, thermal expansion coefficient: 2.3 × 10 ⁻⁶ / K) so that the vertical and horizontal lengths of the insulating fins 10 are increased. Compared to a slightly smaller rectangular shape.

The conductor layer 14 is a circuit pattern on which the power module PM can be mounted. In the present embodiment, 0.5 mm thick aluminum (thermal conductivity 222 W / mK, thermal expansion coefficient 23.5 × 10 ⁻⁶ / K) or It is formed in a rectangular shape of 30 mm × 34 mm from an aluminum alloy.

  The fin base portion 18 of the heat dissipation layer 19 is formed so as to cover the lower surface of the insulating substrate 12. In this embodiment, the fin base portion 18 is made of aluminum or aluminum alloy having a thickness of 0.5 mm. That is, the thickness of the portion of the fin base portion 18 facing the conductor layer 14 is 0.5 mm. A plurality of heat radiation fins 16 are formed on the lower surface of the fin base portion 18 in a region facing the conductor layer 14. Each radiating fin 16 is a cylinder made of aluminum or aluminum alloy having a diameter of 1.5 mm, and is integrally formed with the fin base portion 18. However, the heat radiating fins 16 may be brazed to the fin base portion 18.

  The reinforcing portion 20 is formed with a thickness of 1.3 mm from aluminum on the outer peripheral side of the fin base portion 18. The reinforcing portion 20 reaches the periphery of the upper surface of the insulating substrate 12 so as to cover the outer periphery of the insulating substrate 12 from the fin base portion 18 formed on the lower surface of the insulating substrate 12. The end face 20a of the reinforcing portion 20 reaching the periphery of the upper surface of the insulating substrate 12 and each conductor layer 14 are spaced by a few millimeters so as to be surely electrically insulated. Of the reinforcing portion 20, the thickness tx below the insulating substrate 12 from the lower surface (fin base portion 18 side) and the thickness ty above the insulating substrate 12 from the upper surface (conductor layer 14 side) are both 0.5 mm. It has become.

  Next, the relationship between the thickness of the conductor layer 14, the thickness of the fin base portion 18, and the warp will be described. In order to investigate this relationship, the warping when thermal stress was generated was measured using a test piece 30 mm long by 30 mm wide rather than using the insulating fin 10 itself. The test piece was formed by using a silicon nitride ceramic with a thickness of 0.3 mm as an insulating substrate, and forming an aluminum layer (corresponding to the conductor layer 14) with a thickness of 0.5 mm (= t0) on the upper surface of the insulating substrate. What formed the aluminum layer (equivalent to the fin base part 18) of thickness 0.5-6mm (= t1) on the lower surface was used. Specifically, nine kinds of test pieces having a thickness t1 of 0.5 mm, 0.7 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 2 mm, 3 mm, and 6 mm were used. And the curvature which generate | occur | produces when these test pieces were heated from 20 degreeC to 120 degreeC was measured. The result is shown in FIG.

  FIG. 4 is a graph when the horizontal axis represents the thickness ratio r (= t1 / t0) and the vertical axis represents the warp. As is apparent from this graph, no warp occurs when the thickness ratio r is 1, and when the thickness ratio r is between 1 and 2.4, the warp increases as the thickness ratio r increases. In the range from 2.4 to 12, the warp became smaller as the thickness ratio r was larger. The reason why no warp occurs when the thickness ratio r is 1 is that there is no difference in thermal expansion between the upper and lower surfaces of the insulating substrate. Further, when the thickness ratio r is in the range from 2.4 to 12, it is considered that as the ratio r increases, the rigidity of the fin base portion increases and the warpage decreases. On the other hand, when the thickness ratio r is in the range from 1 to 2.4, the larger the ratio r, the larger the thermal expansion difference. However, the lower the rigidity of the fin base portion, the greater the ratio r, the larger the thermal expansion difference. It is thought that the warpage increased with the increase of. Further, FIG. 4 shows that if the thickness ratio r is 1.5 or less, the warpage can be suppressed to be equal to or greater than that when the thickness ratio is 5. If the thickness ratio r is set to a value of 1 or less, warping occurs in the opposite direction. However, considering the result of FIG. 4, the thickness ratio r is an inverse of the value 1.5, that is, a value of 0. If it is 7 or more, it is considered that warpage can be satisfactorily suppressed, and the strength can be maintained. From the above, the thickness ratio r is preferably in the range of 0.7 to 1.5.

  Next, an example of a method for manufacturing the insulating fin 10 will be described with reference to FIG. FIG. 5 is a manufacturing process diagram of the insulating fin 10.

  First, a spacer 22 having a width of several millimeters is fitted into the center of each side of the insulating substrate 12, and the insulating substrate 12 with the spacer 22 fitted therein is put into the cavity 42 of the mold 40 (see FIG. 5A). The spacer 22 is made of pure aluminum (melting point: 670 ° C.) and is formed in a C shape. In addition, the mold 40 can be separated into a lower mold and an upper mold, but FIG. 5 shows a mold in which the lower mold and the upper mold are integrated for convenience. The cavity 42 is a space shaped like the outer shape of the insulating fin 10. At this time, the distance from the bottom surface of the cavity 42 (the surface where the holes for forming the heat radiating fins 16 are formed) to the lower surface of the insulating substrate 12 matches the thickness of the fin base portion 18, so The distance to the top surface of 12 matches the thickness of the conductor layer 14. Subsequently, a molten metal of an aluminum alloy (melting point: about 600 ° C.) having a melting point lower than that of the pure aluminum spacer 22 is prepared. Then, the mold 40 is heated to the same degree as the melting point of the aluminum alloy (for example, the range of (melting point−200 ° C.) to (melting point + 50 ° C.)). Since the space around the insulating substrate 12 is narrow, at 200 to 300 ° C., which is generally set in a die by aluminum die casting, there is a possibility that the molten metal may solidify during casting and cannot be completely covered, There is a possibility that both do not react with the surface layer and are not joined. For this reason, it is necessary to make the mold temperature near the melting point so that the molten metal does not solidify during filling. Further, if the mold temperature is too high, the spacer 22 melts or the mold wears up, and therefore the upper limit of the mold temperature is determined so that such a problem does not occur.

  Then, the prepared molten metal is injected into the cavity 42 through an injection port (not shown) of the mold 40 (see FIG. 5B). Then, the molten metal overflowed after the cavity 42 is filled with the molten metal is discharged through a discharge port (not shown). The casting pressure at this time is set in the range of 10 to 40 MPa. By doing so, the molten metal is accumulated in the entire periphery of the insulating substrate 12. At this time, the spacer 22 does not melt because the melting point is higher than the temperature of the molten metal. Therefore, the position of the insulating substrate 12 disposed in the cavity 42 is maintained as it is during casting. Subsequently, the mold 40 is cooled. Then, the molten metal accumulated in the cavity 42 is solidified. Thereafter, the molded product is taken out from the mold 40 and trimmed to trim the outer shape (see FIG. 5C). In the obtained molded product, since the entire surface of the insulating substrate 12 is covered with an aluminum alloy, a mask is formed in accordance with the shape of the conductor layer 14 and then subjected to electrolytic processing or etching. By doing so, the two conductive layers 14 are formed on the upper surface of the insulating substrate 12, and the insulating fin 10 in which the reinforcing portion 20 is formed around the insulating substrate 12 is completed (see FIG. 5D). In this insulating fin 10, the heat radiating fin 16 is integrally formed with the fin base portion 18.

  Next, a usage example of the insulating fin 10 will be described. FIG. 6 is a cross-sectional view of a heat sink 50 using the insulating fin 10.

  The heat sink 50 includes a case 30 having an upper opening and insulating fins 10 that close the upper opening. The case 30 has a bottom surface portion 32 and a side wall portion 34 erected around the bottom surface portion 32. Further, the upper end surface of the side wall portion 34 that forms the periphery of the upper opening of the case 30 and the lower surface of the reinforcing portion 20 of the insulating fin 10 are joined in a liquid-tight manner through a heat conductive adhesive layer. Further, the insulating substrate 12 of the insulating fin 10 is formed to have a size overlapping with the upper end surface of the side wall portion 34. Note that the side wall portion 34 of the case 30 and the reinforcing portion 20 of the insulating fin 10 may be fastened with screws in a state where a liquid-tight gasket is interposed therebetween. The insulating fins 10 are arranged such that the heat radiating fins 16 are accommodated inside the case 30. A nickel layer 24 is formed on each conductor layer 14 of the insulating fin 10, and a power module PM such as an IGBT or a MOSFET is joined to the nickel layer 24 via a solder 26. The nickel layer 24 is provided to improve solder wettability, and is formed, for example, by applying nickel phosphorus plating to the upper surface of the conductor layer 14. Then, a refrigerant (for example, cooling water) is circulated through the refrigerant passage 52 surrounded by the case 30 and the insulating fins 10. By doing so, the heat generated by the operation of the power module PM is transmitted to the heat radiating fins 16 and then transferred to the refrigerant by heat exchange between the heat radiating fins 16 and the refrigerant.

  According to the insulating fin 10 described in detail above, even if the pressure of the refrigerant is applied to the attachment portion and its periphery after the insulation fin 10 is attached to the opening of the case 30, the insulating substrate 12 having high rigidity exists in the attachment portion. Therefore, it is possible to prevent problems caused by insufficient strength. In addition, since the thick reinforcing portion 20 is provided as compared with the fin base portion 18, the effect can be obtained more remarkably. In addition, since the insulating substrate 12 is made of silicon nitride ceramic with high rigidity, the conductor layer 14 and the fin base portion 18 are made of aluminum with low rigidity or an alloy thereof, so that it is highly significant to apply the present invention. In addition, since aluminum or an alloy thereof has a lower melting point than copper or a copper alloy, it is suitable for casting the insulating substrate 12 with the fin base portion 18. Note that silicon nitride ceramics, aluminum, and aluminum alloys are preferable in this respect because they have high thermal conductivity and easily release heat efficiently. Furthermore, since the thickness t1 of the portion of the fin base portion 18 facing the conductor layer 14 is 0.7 to 1.5 times (in this embodiment, 1 time) the thickness t0 of the conductor layer 14, the electronic component This makes it possible to achieve both efficient cooling and prevention of breakage of the insulating fin member. Further, the thickness t1 is 0.8 mm or less (0.5 mm in the present embodiment), and the thickness of the insulating substrate 12 is smaller than the thickness t0 of the conductor layer 14 and the thickness t1 of the fin base portion 18, and thus warps. The heat generated by the electronic component mounted on the conductor layer 14 can be quickly transmitted to the heat radiating fins 16.

  Here, after the insulating fin 10 is attached to the opening of the case 30, in order to investigate the effect that no trouble occurs even if the pressure of the refrigerant is applied to the attachment portion or the periphery thereof, the insulating fin having a changed size of the insulating substrate is opened. It was attached to a water-cooled case with a part size of 80 mm × 30 mm and examined for deformation when a water pressure of 0.2 MPa was applied. The amount of deformation of the insulating fin manufactured using an insulating substrate slightly smaller than the opening (79 mm × 29 mm) was 62 μm, but the same size as the opening (80 mm × 30 mm) or larger than the opening (82 mm × The amount of deformation when an insulating fin was manufactured using an insulating substrate of 32 mm) was 54 μm. From the above, it has been found that the deformation amount is reduced by 13% when the insulating substrate is sized to overlap the periphery of the opening of the water cooling case. Conventionally, an insulating substrate has been required to have low thermal expansion, insulation, and high thermal conductivity, but in the present invention, it is also used as a strength member to achieve both efficient cooling of electronic components and prevention of destruction of the insulating fin member. ing.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  For example, in the embodiment described above, the insulating fin 10 is manufactured by casting the insulating substrate 12. However, the heat dissipating fin 16, the fin base portion 18, and the reinforcing portion 20 are integrally formed by casting, and the insulating substrate 12 is formed on the molded product. The insulating fins 10 may be manufactured by brazing the conductor layers 14 sequentially. In that case, you may abbreviate | omit the part which covers the periphery of the upper surface of the insulated substrate 12 among the reinforcement parts 20. FIG.

  In the embodiment described above, the reinforcing portion 20 is formed so as to cover the outer peripheral surface of the insulating substrate 12 and the peripheral edge of the upper surface of the insulating substrate 12, but the upper portion of the reinforcing portion 20 from the upper surface of the insulating substrate 12 is omitted. The reinforcing portion 120 (see FIG. 7) may be formed, or the portion of the reinforcing portion 20 that covers the outer peripheral surface of the insulating substrate 12 or the upper portion of the insulating substrate 12 is omitted, while the lower surface of the insulating substrate 12 is omitted. A reinforcing portion 220 (see FIG. 8) having a thickness greater than that of the fin base portion 18 may be formed on the lower side.

  In the embodiment described above, the insulating fin 10 includes the single insulating substrate 12, but may include the insulating substrate 112 (see FIG. 9) divided into a plurality according to the conductor layer 14. However, considering the strength, it is advantageous to use one insulating substrate 12.

  In the embodiment described above, the reinforcing portion 20 has the same thickness on the upper side from the upper surface of the insulating substrate 12 and the thickness on the lower side from the lower surface of the insulating substrate 12, but the reinforcing portion 320 in FIG. 10 (a) and FIG. 10 (b). As in the reinforcing portion 420, the lower thickness from the lower surface of the insulating substrate 12 may be thicker than the upper thickness from the upper surface. In this way, the fin base portion 18 can be further reinforced. Such a structure is particularly effective when rigidity is difficult to obtain, such as when the fin base portion 18 is made of pure aluminum. In addition, it is not preferable to make the portion above the upper surface of the insulating substrate 12 out of the reinforcing portions 20, 320, and 420 in consideration of mounting electronic components on the conductor layer 14, but the case 30 of the insulating substrate 12 is not preferable. The portion around the opening is preferably thick because it is the portion most stressed by the refrigerant pressure when attached to the case 30.

  In the above-described embodiment, the insulating fin 10 and the case 30 are joined via the heat conductive adhesive layer. However, as shown in FIG. 11, the insulating fin 10 faces the upper end surface of the side wall portion 34 of the case 30. A frame-like pressing member 60 is disposed in the portion, and a screw 38 is passed through the pressing member 60 and the reinforcing portion 20 and screwed into a screw hole 36 provided in the side wall portion 34 of the case 30 to be tightened. Both may be joined. When the material strength of the case 30 is weak, a reinforcing material may be embedded in the case 30 and a screw hole 36 may be formed there. Here, a gasket 34 a is fitted into the upper end surface of the side wall portion 34, and the liquid tightness between the insulating fin 10 and the case 30 is secured by the gasket 34 a. Also in this case, since a part of the insulating substrate 12 overlaps with the upper end surface of the side wall portion 34 of the case 30, the insulating substrate 12 having high rigidity gives the holding strength, and the fin base portion 18 Even if it is thin, it can suppress that the insulation fin 10 deform | transforms with the pressure of a refrigerant | coolant. When the screw 38 hits the insulating substrate 12, a hole or a notch may be made in the insulating substrate 12, and the screw 38 may be passed therethrough.

It is a top view of the insulation fin 10 of this embodiment. It is AA sectional drawing of FIG. It is a rear view of the insulation fin 10 of this embodiment. It is a graph showing the relationship between thickness ratio r (= t1 / t0) and curvature. It is a manufacturing-process figure of the insulation fin 10 of this embodiment. It is explanatory drawing which shows the usage example of the insulation fin 10 of this embodiment. It is sectional drawing of the insulation fin of another embodiment. It is sectional drawing of the insulation fin of another embodiment. It is sectional drawing of the insulation fin of another embodiment. It is sectional drawing of the insulation fin of another embodiment. It is sectional drawing of the insulation fin of another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Insulation fin, 12 Insulation board | substrate, 14 Conductor layer, 16 Radiation fin, 18 Fin base part, 19 Radiation layer, 20 Reinforcement part, 20a End surface, 22 Spacer, 24 Nickel layer, 26 Solder, 30 Case, 32 Bottom part, 34 Side wall portion, 34a gasket, 36 screw hole, 38 screw, 40 mold, 42 cavity, 50 heat sink, 52 refrigerant passage, 60 pressing member, 112 insulating substrate, 120, 220, 320, 420 reinforcing portion.

Claims (8)

A conductor layer for mounting electronic parts formed on one surface of a ceramic insulating substrate, and a heat radiating layer formed on the other surface of the insulating substrate with a plurality of heat radiating fins standing on the fin base portion. Insulating fins,
The insulating substrate is formed in a size that overlaps with the periphery of the opening of the case when the insulating fin is disposed so as to close the opening of the case forming a refrigerant passage through which the refrigerant flows.
Insulating fins. The insulating substrate is mainly composed of silicon nitride ceramics or aluminum nitride ceramics, and the conductor layer and the heat dissipation layer are mainly composed of aluminum or an aluminum alloy.
The insulating fin according to claim 1. The fin base portion is formed by casting so as to surround the outer periphery of the insulating substrate.
The insulating fin according to claim 2. The thickness t1 of the portion facing the conductor layer in the fin base portion is 0.7 to 1.5 times the thickness t0 of the conductor layer.
The insulation fin of any one of Claims 1-3. The thickness t1 is 0.8 mm or less, and the thickness of the insulating substrate is thinner than the thicknesses t0 and t1.
The insulating fin according to claim 4. The insulating fin according to any one of claims 1 to 5,
An insulating fin provided with a reinforcing portion formed thicker than the thickness t1 on the outer peripheral side of the heat dissipation layer. A case forming a refrigerant passage through which the refrigerant flows;
The insulating fin according to any one of claims 1 to 6, wherein the insulating fin is disposed so as to close the opening of the case and to contact the heat radiating fin with the refrigerant.
Heat sink with. A heat sink according to claim 7,
The heat sink provided with the press member which presses the part in which the said insulated substrate exists among the said insulation fins with respect to the periphery of the opening of the said case.

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