Heat dissipation structure of semiconductor device

Abstract

A heat dissipation structure of a semiconductor device with excellent heat dissipation applicable to surface-mount thin semiconductor devices is provided, and preferably a heat dissipation structure of a semiconductor device also with excellent insulating reliability is provided. In a heat dissipation structure 101 of a semiconductor device 10, the semiconductor device 10 has an electric bonding surface 11a electrically connected with a substrate 20 and a heat dissipation surface 11b on an opposite side thereof, wherein the heat dissipation surface 11b is bonded or contacted to a heat spreader 31 via a non-insulated member 32, and the heat spreader 31 is bonded or contacted to a heat sink 30 via an insulated member 41.

Claims

1. A heat dissipation structure of a semiconductor device, the semiconductor device having an electric bonding surface electrically connected with a substrate and a heat dissipation surface on an opposite side thereof, wherein the heat dissipation surface is bonded or contacted to a conductive member with high thermal conductivity via a non-insulated member, the conductive member with high thermal conductivity is bonded or contacted to a heat dissipation part via a first insulated member, and the thickness of the conductive member with high thermal conductivity is greater than that of the semiconductor device, the conductive member with high thermal conductivity, in a top view, is less than the heat dissipation part, and in a situation where the semiconductor device and the conductive member with high thermal conductivity are both set as a substantially rectangular shape in a top view, length of each side of the conductive member with high thermal conductivity is greater than the sum of twice the thickness of the conductive member with high thermal conductivity and length of each side of the semiconductor device.

2. The heat dissipation structure of a semiconductor device according to claim 1, wherein the first insulated member, in a top view, is greater than the conductive member with high thermal conductivity.

3. The heat dissipation structure of a semiconductor device according to claim 1, wherein a second insulated member is configured between the substrate and the conductive member with high thermal conductivity in a manner of covering the periphery of the semiconductor device and at least one part of a pattern of the substrate.

4. The heat dissipation structure of a semiconductor device according to claim 3, wherein the second insulated member is configured in a manner of occupying a space between the substrate and the heat dissipation part.

5. The heat dissipation structure of a semiconductor device according to claim 4, wherein the second insulated member has a through-hole for fixing to the heat dissipation part.

6. The heat dissipation structure of a semiconductor device according to claim 3, wherein the second insulated member is configured through an insulation heat-resistant resin formed or cut processed product, an insulation heat-resistant tape, an insulation heat-resistant sealing element, or a combination of any two or more thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a general sectional view of a heat dissipation structure 101 according to a first embodiment of the present invention.

(2) FIG. 2 is a general sectional view of a heat dissipation structure 102 according to a second embodiment of the present invention.

(3) FIG. 3 is a general sectional view of a heat dissipation structure 102A of a varying example of the second embodiment of the present invention.

(4) FIG. 4(a) is a general stereogram of a lead type discrete part 1 of the prior art, and FIG. 4(b) is a general stereogram of a surface-mount semiconductor device 10 like a GaN device developed in recent years.

(5) FIG. 5(a) is a general sectional view of a heat dissipation structure 201 of the prior art, and FIG. 5(b) is a general sectional view of a heat dissipation structure 201A as a varying example thereof.

DESCRIPTION OF THE EMBODIMENTS

(6) Several embodiments of the present invention are described below with reference to the accompanying drawings.

First Embodiment

(7) FIG. 1 is a general sectional view of a heat dissipation structure 101 according to a first embodiment of the present invention.

(8) As shown in FIG. 1, in the heat dissipation structure 101, on a heat sink 30 (e.g., thermal conductivity is above 190 W/mk) as an example of having a conductive heat dissipation part, a heat spreader 31 as an example of a non-insulated thermal diffusion device (having a conductive heat dissipation part) is carried via a thin sheet-like insulated part 41 in a manner of bonding or contacting. On the heat spreader 31, a semiconductor device 10 as an example of a heating element and received in an ultrathin package 11 is carried, in a manner of bonding or contacting the heat dissipation surface 11b downwards, via the thin non-insulated part 32. The electrode 12 of the electric bonding surface 11a is electrically connected to a lower surface pattern 22 of the substrate 20 through welding or the like.

(9) In the semiconductor device 10, the electrodes 12 and the heat dissipation electrode 13 are configured on an inner side relative to the appearance of the package 11, and are controlled to be a substantial package thickness T1. The package thickness T1, for example, is preferably below 2 mm.

(10) The thickness T2 of the heat spreader 31, is preferably, for example, above 2 mm, and the size thereof is greater than that of the semiconductor device 10 but less than that of the heat spreader 30. If the length of one side of the semiconductor device 10 is set as L1, the length L2 of each side of the heat spreader 31 is preferably set as above L1+2T2. As a material thereof, for example, high thermal conductivity metal whose thermal conductivity is above 190 W/mk may be listed, specifically, copper or aluminum may be listed, but it is not limited to the materials.

(11) As the non-insulated part 32, for example, the material whose thermal conductivity is above 20 W/mk may be listed, specifically, solder or graphite may be listed, but it is not limited to the materials.

(12) The insulated part 41, for example, is set as a member whose thermal conductivity is 1 W/mk to 10 W/mk and withstanding voltage is above 1500 V, and in order to ensure an insulation distance, it is preferably greater than the heat spreader 31.

(13) According to the heat dissipation structure 101, the heat dissipation surface 11b of the semiconductor device 10 is contacted to the heat spreader 31 in a non-insulating manner, and the heat spreader 31 contacts the heat sink 30 in a non-insulating manner. Thus, heat produced by the semiconductor device 10 is transferred to the heat spreader 31 from the heat dissipation surface 11b via the non-insulated part 32 to be diffused, and then is transferred to the heat sink 30 via the insulated part 41, which thus has excellent heat dissipation.

Second Embodiment

(14) FIG. 2 is a general sectional view of a heat dissipation structure 102 according to a second embodiment of the present invention. In addition, like reference signs are marked for components the same as those of the first embodiment, and the following focuses on describing their differences.

(15) As shown in FIG. 2, in the heat dissipation structure 102, in addition to the structure of the heat dissipation structure 101 of the first embodiment, a sectional horizontal L-shaped insulated part 42 is further inserted between the substrate 20 and the heat spreader 31 in a manner of covering the periphery of the semiconductor device 10 and the pattern of the substrate 20 (a pattern that at least can become a high voltage difference with the heat spreader 31). However, it is not limited to insertion of the insulated part 42, as long as it is configured through coating of the same insulating material or the like in a manner that the insulating material is present on the periphery of the semiconductor device 10. That is, it is set as a structure having an insulating layer of an insulating material in a space sandwiched between the substrate 20 and the heat spreader 31 on the periphery of the semiconductor device 10.

(16) As the insulated part 42, for example, an insulation heat-resistant resin (e.g., PolyPhenylenesulfide (PPS)) formed or cut processed product, an insulation heat-resistant tape, an insulation heat-resistant resin (e.g., epoxy or silicone or the like) sealing element, or a combination of any two or more thereof may be listed, but it is not limited to the materials.

(17) Preferably, a bonding or contacting portion of the heat spreader 31 to the package 11 of the semiconductor device 10 is higher than the surrounding.

(18) According to the heat dissipation structure 102, the heat dissipation surface 11b of the semiconductor device 10 is contacted to the heat spreader 31 in a non-insulating manner, and the heat spreader 31 contacts the heat sink 30 in an insulating manner, and then the periphery of the semiconductor device 10 and the pattern of the substrate 20 are covered by the insulated part 42. Thus, the structure can have excellent heat dissipation and can also avoid damage to insulation.

Varying Example of the Second Embodiment

(19) FIG. 3 is a general sectional view of a heat dissipation structure 102A of a varying example of the second embodiment of the present invention. In addition, like reference signs are marked for components the same as those of the first embodiment, and the following focuses on describing their differences.

(20) As shown in FIG. 3, in the heat dissipation structure 102A, in place of the insulated part 42 in the structure of the heat dissipation structure 102 of the second embodiment, an insulated part 42A that occupies the remaining space is inserted between the substrate 20 and the heat sink 30, and is fixed to a screw hole 30a disposed on the heat sink 30 by using a screw 50. The insulated part 42A, between the substrate 20 and the heat sink 30, not only covers the semiconductor device 10, but also covers the entire periphery also including a lower surface (also including a lower surface pattern 22) of the substrate 20, the non-insulated part 32, the heat spreader 31 and the insulated part 41.

(21) As the non-insulated part 32, solder or graphite or the like may be listed, but it is not limited to the materials.

(22) As the heat spreader 31, for example, copper-made heat spreaders may be listed, but it is not limited thereto. The thickness T2, for example, is preferably above 2 mm. If the length of one side of the semiconductor device 10 is set as L1, the size (the length of each side is set as L2) is preferably greater than L1+2T2 but less than the heat sink 30.

(23) As the insulated part 41, an insulated sheet (e.g., the thermal conductivity is 5 W/mk) may be listed, but it is not limited thereto.

(24) As the heat sink 30, for example, an aluminium-made heat sink may be listed, but it is not limited thereto.

(25) According to the heat dissipation structure 102A, similar to the heat dissipation structure 102 of the second embodiment, the heat dissipation surface 11b of the semiconductor device 10 is contacted to the heat spreader 31 in a non-insulating manner, and the heat spreader 31 contacts the heat sink 30 in an insulating manner, and then the surrounding of the electrodes 12 of the semiconductor device 10 is covered by the insulated part 42A. Thus, the structure can have excellent heat dissipation and can also avoid damage to insulation.

(26) The structures of the embodiments described above and the varying examples thereof may also be combined with each other as long as there are no special obstructive factors or the like.

(27) In addition, the present invention can be implemented with other various forms without departing from its purport or main features. Therefore, the implementations or embodiments described are merely simple illustrations in all aspects, and should not be construed as limitations. The scope of the present invention is shown by the claims and is not subject to any constraint of the text of the specification. Then, variations or changes within the equivalent scope of the claims all fall within the scope of the present invention.