JP2008166642A - Semiconductor device with radiating member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device with a radiating member capable of raising an insulation performance without spoiling any radiating ability. <P>SOLUTION: While a heat conduction being carried out from a radiating surface 1B of a resin package 1A to a heat receiving surface 2A of a radiating member 2 at a heating time caused by operating a semiconductor device 1, since the heat conduction is also carried out from periphery portions of the radiating surface 1B of the resin package 1A to heat receiving surfaces 3A, 3A of insulating heat transmission strips 3, 3 constituted by aluminum nitride having a higher thermal conductivity than the resin package 1A, the radiating ability is fully ensured. Further, since the insulating heat transmission strips 3, 3 constituted by the aluminum nitride having a higher insulation than the radiating member 2 are provided in a shoulder portion of the radiating member 2 in a body, a spatial distance from a reed 1C to an exposed surface 2C excluding the shoulder portion of the radiating member 2 increases, and consequently the insulation performance is raised. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor device with a heat radiating member having a structure in which a heat receiving surface of a heat radiating member is in contact with a heat radiating surface of a package of a semiconductor device having leads.

  In general, a high-voltage semiconductor device that handles large power such as a DIP-IPM (Dual Inline Package Intelligent Power Module) is packaged with resin. Since such a semiconductor device generates heat with its operation, a metal heat dissipating member called a cooling fin or a heat sink is attached to the resin package (see, for example, Patent Document 1).

  In general, this type of semiconductor device with a heat radiating member has a resin package of the same size regardless of the application because of productivity and cost. For this reason, depending on the application, there may be a shortage of a spatial distance and a creepage distance that are paths through which a high voltage leaks from a lead projecting as an external connection terminal to the resin package to a grounded heat dissipation member. In this case, depending on the use environment conditions such as temperature and humidity, a high voltage may leak from the lead to the heat radiating member, and insulation deterioration may occur in the semiconductor device with the heat radiating member.

Therefore, in Patent Document 1, by providing a protrusion for increasing the creepage distance between the external terminal (lead) and the cooling fin (heat radiating member) in the main body (resin package) of the power semiconductor device, A technique for improving insulation is disclosed.
JP 2004-193467 A (Abstract, FIG. 2)

  By the way, in the prior art described in Patent Document 1, the width of the heat receiving surface of the cooling fin (heat radiating member) that contacts the heat radiating surface of the main body (resin package) of the power semiconductor device is larger than the width of the heat radiating surface. Since it is set to be small, there is a problem that the heat radiation performance from the main body (resin package) of the power semiconductor device to the cooling fin (heat radiation member) is lowered.

  Then, this invention makes it a subject to provide the semiconductor device with a heat radiating member which can improve insulation performance, without impairing heat radiating performance.

  The semiconductor device with a heat radiating member according to the present invention is a semiconductor device with a heat radiating member having a structure in which the heat receiving surface of the heat radiating member is in contact with the heat radiating surface of the package of the semiconductor device having a lead, and the heat radiating member is a portion facing the lead The insulating heat transfer member is integrally provided on a shoulder portion extending from a portion facing the peripheral portion of the heat radiating surface of the package, and the insulating heat transfer member is higher in insulation than the heat radiating member and is more heated than the package. The insulating heat transfer member is made of a material having high conductivity, and is characterized in that a heat receiving surface is provided in contact with the peripheral portion of the heat radiating surface of the package.

  In the semiconductor device with a heat radiating member according to the present invention, when heat is generated by the operation of the semiconductor device, the heat is conducted from the heat radiating surface of the package to the heat receiving surface of the heat radiating member, and the insulating property is made of a material having higher thermal conductivity than the package. The heat receiving surface of the heat transfer member is also thermally conducted from the peripheral portion of the heat radiating surface of the package, so that sufficient heat radiating performance is ensured. An insulating heat transfer member made of a material having a higher insulating property than the heat radiating member is integrally provided on the shoulder of the heat radiating member facing the lead. Since the spatial distance to the exposed surface excluding the shoulder is increased, sufficient insulation performance against high voltage leakage is ensured.

  In the semiconductor device with a heat radiating member of the present invention, the heat radiating surface of the package is a flat surface, and the heat radiating member has a protrusion on the shoulder that is flush with the insulating heat transfer member. It is preferable that a heat receiving surface that forms a flat surface continuous with the heat receiving surface of the insulating heat transfer member is formed in the part. In this case, a semiconductor device with a heat dissipation member having high heat dissipation performance and insulation performance can be configured for a highly versatile semiconductor device in which the heat dissipation surface of the package is a flat surface.

  In this case, by setting the width of the protrusion of the heat radiating member to be small, it is possible to increase the creeping distance from the lead to the protrusion and further improve the insulation performance. Also, by setting the projection length of the protrusion of the heat dissipation member to be long and increasing the thickness of the insulating heat transfer member accordingly, the spatial distance from the lead to the exposed surface excluding the shoulder of the heat dissipation member is increased. Thus, the insulation performance can be further improved.

  In the semiconductor device with a heat radiating member of the present invention, the insulating heat transfer member is preferably formed in an L-shaped cross-sectional shape covering the side surface of the shoulder portion of the heat radiating member over the direction away from the lead. In this case, it is possible to greatly increase the insulation distance by greatly increasing the spatial distance from the lead to the exposed surface excluding the shoulder of the heat dissipation member.

  Here, as a material of the insulating heat transfer member in the semiconductor device with a heat radiating member of the present invention, as long as it has characteristics that are higher in insulation than the heat radiating member and higher in heat conductivity than the package, An appropriate material such as a composite material with a resin material can be used, but it is preferable that the volume resistivity is 10 to 12 Ωm or more and the thermal conductivity is 180 W / m · K or more. In this respect, aluminum nitride is suitable as the material for the insulating heat transfer member.

  According to the semiconductor device with a heat dissipation member according to the present invention, it is possible to sufficiently ensure the heat dissipation performance during heat generation due to its operation, and at the same time, it is possible to sufficiently ensure the insulation performance against high voltage leakage due to its operation. .

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a semiconductor device with a heat dissipation member according to the invention will be described with reference to the drawings. In this description, the same or similar components are denoted by the same reference numerals, and redundant description may be omitted. Here, in the drawings to be referred to, FIG. 1 is a cross-sectional view of a semiconductor device with a heat radiating member according to an embodiment, and FIG. 2 is an enlarged cross-sectional view of a main part of the semiconductor device with a heat radiating member shown in FIG.

  As shown in FIG. 1, in a semiconductor device with a heat dissipation member according to an embodiment, a resin package 1A of a semiconductor device 1 has a flat heat dissipation surface 1B. The heat radiating surface 1B, the heat receiving surface 2A of the heat radiating member 2 facing the heat radiating surface 1B, and the heat receiving surfaces 3A, 3A of the pair of insulating heat transfer pieces 3 and 3 are interposed through a thin silicon grease layer 4 having a small thermal resistance. It is in close contact.

  The semiconductor device 1 is a high-voltage semiconductor device that handles a large amount of power, such as DIP-IPM, and generates heat in accordance with its operation. The semiconductor device 1 has a plurality of leads 1C and 1C protruding from both side surfaces of the resin package 1A, and each lead 1C and 1C is connected to the conductive layer 5B of the printed circuit board 5 by solder 5A.

  The heat dissipating member 2 is formed in a block shape wider than the resin package 1A of the semiconductor device 1 by an aluminum alloy or copper alloy having high thermal conductivity, and a plurality of heat dissipating fins are formed in a portion not shown. Yes. As shown in FIG. 2, the heat radiating member 2 has both L-shaped shoulders extending from the portion facing the leads 1C and 1C of the semiconductor device 1 to the portion facing the peripheral portion of the heat radiating surface 1B of the resin package 1A. By being cut out thinly, a protrusion 2B having a heat receiving surface 2A is formed between the shoulder portions.

  The insulating heat transfer pieces 3 and 3 correspond to the insulating heat transfer member of the present invention, and have a higher insulating property than the heat radiating member 2 and a higher thermal conductivity than the resin package 1A, that is, a volume. It is formed into an L-shaped cross-section using aluminum nitride having a resistivity of 10 to 12 Ωm or more and a thermal conductivity of 180 W / m · K or more as a material.

  These insulative heat transfer pieces 3 and 3 are embedded in and integrally joined to the L-shaped thinly cut portions of both shoulder portions of the heat radiating member 2, and the pieces 3 </ b> B and 3 </ b> B are integrally connected to the heat radiating member 2. The upper surface of the shoulder portion of the heat radiating member 2 is covered by forming the same surface as the protrusion 2B and continuing to the protrusion 2B. The heat receiving surfaces 3B and 3B formed on the pieces 3B and 3B of the insulating heat transfer pieces 3 and 3 are in close contact with the peripheral portion of the heat radiating surface 1B of the resin package 1A via the silicon grease layer 4.

  On the other hand, the other pieces 3C and 3C of the insulating heat transfer pieces 3 and 3 cover the side surface of the shoulder portion of the heat radiating member 2 long in the direction away from the leads 1C and 1C. The other pieces 3C and 3C The side surface of the member 2 is flush with the exposed surface 2C.

  In the semiconductor device with a heat radiating member of the embodiment configured as described above, when the semiconductor device 1 generates heat due to the operation of the semiconductor device 1, the protrusion 2B of the heat radiating member 2 from the heat radiating surface 1B of the resin package 1A through the silicon grease layer 4 is used. A silicon grease layer is also conducted from the peripheral portion of the heat radiating surface 1B of the resin package 1A to the heat receiving surfaces 3A and 3A of the insulating heat transfer pieces 3 and 3B which are continuously conducted on both sides of the heat receiving surface 2A. Therefore, the heat dissipation performance is sufficiently ensured.

  Here, the upper surface of the shoulder portion of the heat radiating member 2 covers the insulating heat transfer pieces 3, 3 B so as to face the peripheral portion of the heat radiating surface 1 B of the resin package 1 A. Since the other pieces 3C and 3C of the heat pieces 3 and 3 cover the side surface of the shoulder portion of the heat radiating member 2 in a direction away from the leads 1C and 1C, a high voltage is applied from the leads 1C and 1C toward the heat radiating member 2. The leaking spatial distance is a large distance from the leads 1C and 1C to the exposed surface 2C on the side surface excluding the shoulder portion of the heat radiating member 2. Further, the creeping distance at which a high voltage leaks from the leads 1C and 1C toward the heat radiating member 2 is also a large distance to the narrow protrusion 2B of the heat radiating member 2. Therefore, sufficient insulation performance against high voltage leakage is ensured.

  Therefore, according to the semiconductor device with a heat radiating member of one embodiment, the heat radiating performance at the time of heat generation due to its operation is sufficient for a highly versatile semiconductor device in which the heat radiating surface 1B of the resin package 1A is a flat surface. At the same time, it is possible to sufficiently ensure insulation performance against high-voltage leakage caused by the operation.

  The semiconductor device with a heat radiating member according to the present invention is not limited to the above-described embodiment, and the structure of the main part thereof can be changed to a structure as shown in FIGS.

  In the main part structure of the first modification shown in FIG. 3, the insulating heat transfer pieces 3, 3 in the main part structure shown in FIG. 2 are formed in a flat plate shape having only one piece 3B, 3B. And in the peripheral part of the heat radiating surface 1B of the resin package 1A facing the heat receiving surfaces 3A, 3A of the one piece 3B, 3B, a flat insulating heat transfer made of the same material as the insulating heat transfer pieces 3, 3 is provided. The pieces 6 and 6 are embedded.

  In the main part structure of the second modification shown in FIG. 4, the upper surface of the heat radiating member 2 in the main part structure shown in FIG. 3 is formed as a flat surface without the protrusions 2 </ b> B. And the protrusion 1D which protrudes between the flat insulating heat-transfer pieces 6 and 6 is formed in the lower surface of 1 A of resin packages. In this modified example, heat conduction is improved from the peripheral surface of the protrusion 1D of the resin package 1A to the side surfaces of the insulating heat transfer pieces 6 and 6, and accordingly, the heat dissipation performance is improved.

  In the main structure of the third modified example shown in FIG. 5, both the shoulder portions of the block-shaped heat radiation member 2 wider than the resin package 1A of the semiconductor device 1 are greatly cut out, so that the heat radiation member 2 has a protruding length. A long protrusion 2B is formed. Insulating heat transfer pieces 7, 7 formed in an L-shaped cross-sectional shape along the peripheral surface of the protrusion 2 </ b> B from the upper surface are integrally joined to both shoulder portions of the heat radiating member 2 that are largely cut out. Has been. Correspondingly, on the lower surface of the resin package 1A, a recess 1E into which the one piece 7A, 7A of the insulating heat transfer piece 7, 7 is fitted together with the protrusion 2B of the heat radiating member 2 is formed.

  In the main structure of the third modification, heat conduction is performed from the peripheral surface of the recess 1E of the resin package 1A to the side surfaces of the insulating heat transfer pieces 7 and 7A. improves. Further, the creeping distance at which a high voltage leaks from the leads 1C and 1C toward the protrusion 2B of the heat radiating member 2 increases along the recess 1E of the resin package 1A, so that the insulation performance is improved accordingly.

  Moreover, in the semiconductor device with a heat radiating member according to the present invention, the insulating heat transfer pieces 3, 3, 6, 6, 7, and 7 described above are used to prevent condensation when the heat radiating member 2 is water-cooled. It can be configured to generate heat when energized.

It is sectional drawing of the semiconductor device with a heat radiating member which concerns on one Embodiment of this invention. It is an expanded sectional view of the principal part of the semiconductor device with a heat radiating member shown in FIG. It is an expanded sectional view which shows the 1st modification of the principal part shown in FIG. It is an expanded sectional view which shows the 2nd modification of the principal part shown in FIG. It is an expanded sectional view which shows the 3rd modification of the principal part shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor device, 1A ... Resin package, 1B ... Heat dissipation surface, 1C ... Lead, 1D ... Projection, 1E ... Recess, 2 ... Heat dissipation member, 2A ... Heat reception surface, 2B ... Projection, 2C ... Exposed surface, 3 ... Insulating heat transfer piece, 3A ... heat receiving surface, 3B ... one piece, 3C ... other piece, 4 ... silicon grease layer, 5 ... printed circuit board, 5A ... solder, 5B ... conductive layer, 6 ... insulating heat transfer piece, 7 ... Insulating heat transfer piece.

Claims (4)

A semiconductor device with a heat dissipation member having a structure in which a heat receiving surface of a heat dissipation member is in contact with a heat dissipation surface of a package of a semiconductor device having a lead,
The heat dissipating member has an insulating heat transfer member provided integrally on a shoulder portion extending from a portion facing the lead to a portion facing a peripheral portion of the heat dissipating surface of the package,
The insulating heat transfer member is made of a material having higher insulation than the heat dissipation member and higher thermal conductivity than the package,
A semiconductor device with a heat radiating member, wherein the insulating heat transfer member is provided with a heat receiving surface in contact with a peripheral portion of the heat radiating surface of the package.   The heat radiating surface of the package is configured as a flat surface, and the heat radiating member has a protrusion that is flush with the insulating heat transfer member on the shoulder, and the protrusion has an insulating heat transfer member. 2. The semiconductor device with a heat radiating member according to claim 1, wherein a heat receiving surface forming a flat surface continuous with the heat receiving surface is formed.   3. The heat dissipation member according to claim 1, wherein the insulating heat transfer member is formed in an L-shaped cross-sectional shape that covers a side surface of a shoulder portion of the heat dissipation member over a direction away from the lead. With semiconductor device.   The semiconductor device with a heat radiating member according to claim 1, wherein the material of the insulating heat transfer member is aluminum nitride.

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