JP4451752B2 - Heat dissipation member and semiconductor parts - Google Patents

Description

  The present invention relates to a semiconductor heat dissipation member.

  In Patent Document 1, one surface of a U-shaped spring is fixed to the upper surface of a CPU, and the other surface is brought into contact with a top plate of a metal casing, whereby the heat of the CPU is decreased. A technique for dissipating heat to a housing via a housing is disclosed.

JP-A-7-202083

  In the technique described in Patent Document 1, in order to efficiently dissipate the heat of the CPU to the housing, it is necessary to fix the U-shaped spring to the housing by screwing or the like to increase the contact surface between them. . However, when both are fixed, mechanical stress is applied to the CPU. When the CPU is a BGA (Ball Grid Array), if this stress is large, soldering of the CPU to the board may be peeled off. In order to reduce the stress applied to the CPU, it is conceivable to use an elastic metal such as phosphor bronze for the U-shaped spring. However, an elastic metal such as phosphor bronze is inferior in heat dissipation compared to a metal generally used as a heat sink such as copper or aluminum. For this reason, the heat of the CPU cannot be efficiently radiated to the housing. Moreover, in the technique described in Patent Document 1, the U-shaped spring is fixed to the top plate of the housing, so that maintenance workability is deteriorated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to efficiently dissipate heat of a semiconductor chip to a housing. Another object is to prevent the maintenance workability from deteriorating.

  In order to solve the above problems, in the present invention, a metal foil for radiating heat from a semiconductor chip is provided on an elastic flat plate. A fixing member for fixing the flat plate to the side surface of the metal housing is provided.

For example, the present invention is a heat dissipating member for radiating a semiconductor chip, and is for fixing the flat plate to a side surface of a metal housing that houses a flat plate having elasticity and a substrate including the semiconductor chip. A fixing member that also serves as heat dissipation, and a metal foil that is provided on a contact surface of the flat plate with the semiconductor chip, for radiating heat of the semiconductor chip to the housing via the fixing member, The fixing member is a U-shaped plate whose one end is bent into an L shape, and the flat plate is attached to the bent portion, and the U-shaped plate penetrates both surfaces of the U-shaped portion. A screw hole for screwing the U-shaped plate is formed on the side surface of the housing .

  According to the present invention, since the elastic flat plate is used, the mechanical stress applied to the semiconductor chip when it is fixed to the housing can be reduced. Further, since the metal foil for radiating the semiconductor chip is provided on the flat plate, the heat of the semiconductor chip can be radiated to the housing even when a metal having elasticity but inferior heat dissipation is used on the flat plate. In addition, since the flat plate is fixed to the side surface of the metal casing, it is possible to prevent the maintenance workability from being deteriorated.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is a schematic cross-sectional view showing a state in which a semiconductor component according to an embodiment of the present invention is attached to a side surface of a housing.

  As shown in the figure, a semiconductor component 1 of this embodiment includes a BGA type semiconductor chip (for example, a drawing LSI) 11, and a heat radiating plate 12 for radiating the heat of the semiconductor chip 11 to the side surface 4 of a metal housing. And a heat conductive material (for example, a heat conductive sheet) 13 for transmitting the heat of the semiconductor chip 11 to the heat radiating plate 12. The heat conductive material 13 also functions as an adhesive that adheres the heat sink 12 to the surface of the semiconductor chip 11. The semiconductor chip 11 is attached to the module substrate 2 with solder balls. When the device on which the semiconductor component 1 of this embodiment is mounted is a navigation device, the substrate module 2 is, for example, a CIS (Car Information System) module. The board module 2 may be further mounted on the main board 1. In addition, the heat radiating plate 12 is attached to the side surface 4 of the metal casing with screws 5.

  2A and 2B are schematic views of the heat radiating plate 12. FIG. 2A is a front view, FIG. 2B is a top view, FIG. 2C is a bottom view, and FIG. 2D is a left side view. is there. As illustrated, the heat radiating plate 12 includes a flat plate 121, a metal foil 122, and a fixed plate 123.

  The flat plate 121 has higher elasticity (spring property) than an aluminum plate, a copper plate, or the like often used for an existing heat sink. By giving elasticity to the flat plate 121, when the heat sink 12 to which the semiconductor chip 11 is attached is fixed to the side surface 4 of the housing, mechanical stress applied to the semiconductor chip 11 can be reduced. As the flat plate 121, for example, a phosphor bronze plate is used.

  The metal foil 122 is attached to the contact surface of the flat plate 121 with the semiconductor chip 11 by, for example, an adhesive. The metal foil 122 has higher heat dissipation than a phosphor bronze plate or the like often used for an existing spring plate. By providing the metal foil 122 with high heat dissipation on the contact surface of the flat plate 121 with the semiconductor chip 11, the heat of the semiconductor chip 11 can be efficiently transmitted to the fixed plate 123. For the metal foil 122, for example, aluminum foil or copper foil is used. In addition, the thickness of the metal foil 122 should just be thin (elasticity) of the grade which does not inhibit the elasticity of the flat plate 121. Therefore, the metal foil 122 includes a thin plate.

  The fixing plate 123 is a member for fixing the flat plate 121 to which the metal foil 122 is attached to the side surface 4 of the metal casing. The fixed plate 123 is a U-shaped plate in which an end A of one surface is bent in an L shape, and the flat plate 121 is formed by caulking 124 or the like so that the bent portion 1231 is in contact with the metal foil 123. Fixed to. The fixing plate 123 is a metal plate with high heat dissipation such as an aluminum plate or a copper plate. By using a metal plate with high heat dissipation for the fixing plate 123, the heat of the semiconductor chip 11 transmitted through the metal foil 123 can be efficiently radiated to the side surface 4 of the metal casing. In addition, the fixing plate 123 has a screw hole portion 1232 for screwing the fixing plate 123 to the side surface 4 of the metallic housing formed so as to penetrate both surfaces of the U-shaped portion B. As shown in FIG. 1, screws 5 are passed through screw holes 1232 and screw holes (not shown) provided in the side surface 4 of the housing, and tightened so that a force is applied in a direction in which the U-shaped portion B is closed. Thus, by attaching the fixing plate 123 to the side surface 4 of the housing, a part of mechanical stress applied at the time of screw tightening can be absorbed by the U-shaped portion B. Therefore, mechanical stress applied to the semiconductor chip 11 attached to the heat sink 12 can be reduced.

  The embodiment of the present invention has been described above.

  According to this embodiment, since the elastic flat plate 121 is used for the heat radiating plate 12, mechanical stress applied to the semiconductor chip 11 when it is fixed to the housing can be reduced. Therefore, the heat sink 12 suitable for the semiconductor chip 11 that is easily peeled off from the substrate 2 due to mechanical stress such as the BGA type can be provided. Further, since the metal foil 122 for radiating the semiconductor chip 11 is provided on the flat plate 121, even when a metal having elasticity but inferior heat dissipation is used for the flat plate 121, the heat of the semiconductor chip 11 is efficiently transmitted to the housing. Can dissipate heat well. Moreover, since the heat sink 12 is fixed to the side surface 4 of the housing, it is possible to prevent the maintenance workability from deteriorating.

  In addition, this invention is not limited to said embodiment, Many deformation | transformation are possible within the range of the summary. For example, in the above embodiment, different materials (metal plates) are used for the flat plate 121 and the fixed plate 123, and the two are combined by caulking or the like. However, the present invention is not limited to this. The same material (the material of the flat plate 121, that is, a metal plate having elasticity) may be used for the flat plate 121 and the fixing plate 123, and both may be integrally formed. Then, the metal foil 122 provided on the contact surface of the integrally formed plate with the semiconductor chip 11 is extended to the contact surface with the side surface 4 of the housing of the integrally formed plate, so that the heat of the semiconductor chip 11 is accommodated. You may make it heat-radiate to the side surface 4 of a body.

  Further, in the above embodiment, the heat radiating plate 12 is attached to the side surface 4 of the housing with the screws 5, but the heat radiating plate 12 may be attached to the side surface 4 of the housing with a stopper or adhesive other than the screws. Good.

FIG. 1 is a schematic sectional view showing a state in which a semiconductor component according to an embodiment of the present invention is attached to a side surface of a housing. 2A and 2B are schematic views of the heat radiating plate 12. FIG. 2A is a front view, FIG. 2B is a top view, FIG. 2C is a bottom view, and FIG. 2D is a left side view. is there.

Explanation of symbols

  1: semiconductor component, 2: module substrate, 3: main substrate, 4: side surface of metal housing, 5: screw, 11: semiconductor chip, 12: heat sink, 13: heat conduction material, 121: flat plate, 122 : Metal foil, 123: Fixed plate, 1232: Screw hole

Claims (3)

A heat dissipating member for dissipating the semiconductor chip,
An elastic flat plate;
A fixing member that also serves as heat dissipation for fixing the flat plate to a side surface of a metal housing that houses a substrate including the semiconductor chip,
A metal foil provided on a contact surface of the flat plate with the semiconductor chip for radiating heat of the semiconductor chip to the housing through the fixing member ;
The fixing member is a U-shaped plate whose one end is bent into an L shape, and the flat plate is attached to the bent portion.
The U-shaped plate has screw holes for screwing the U-shaped plate on the side surface of the housing, which are formed so as to penetrate both surfaces of the U-shaped portion. Heat dissipation member. The heat dissipating member according to claim 1 ,
The flat plate is a phosphor bronze plate,
The metal foil is a copper foil or an aluminum foil,
The heat radiating member, wherein the fixing member is a copper plate or an aluminum plate. The heat dissipating member according to claim 1 or 2 ,
A semiconductor chip of BGA (Ball Grid Array) in contact with the metal foil of the heat radiating member via a heat conductive material;
And a substrate on which the semiconductor chip is mounted.

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