JP4477963B2 - Heat dissipating element for heat-generating element - Google Patents

Description

The present invention relates to a heat sink of the main IGBT (Insulated Gate Bipolar Transistor) heating element which is joined to the heat radiation fins of lattice heat sink the heat generating element cooling, such as calling hot body.

Conventionally, as a heat sink for cooling an exothermic element such as an IGBT, a base plate having a heating element held on one surface has been used, and a plurality of radiating fins are arranged in a comb shape or a lattice shape on the other surface of the base plate. A relatively inexpensive heat sink that is installed and configured is often used. For example, as described in Patent Document 1, a lattice heat sink in which lattice heat dissipating fins are stacked on a base plate and joined by brazing or the like is often used.
Such a lattice-type heat sink can be manufactured at a relatively low cost because the fins are made of extruded shapes and have a relatively simple structure obtained by brazing to an aluminum base plate.
Japanese Patent Laid-Open No. 2004-47789

  Conventional heat sinks have not always had sufficient heat dissipation performance. Therefore, when efficiently cooling a semiconductor element having a high heat generation density, a fluorine compound (for example, manufactured by Sumitomo 3M Co., Ltd.) is used as a heat pipe working liquid instead of a lattice heat sink in order to improve the cooling performance. In general, a boiling cooling heat sink using Fluorinert FX-3250 (trade name) or the like, or a heat sink made of copper heat pipe having high thermal conductivity is used.

  However, the boiling cooling type heat sink using the fluorine compound working fluid in the case of cooling the element having a high heat generation density as described above is complicated and expensive. In addition, a fluorine compound having a large global warming potential is often used as a refrigerant, and although relatively good cooling performance can be obtained, its use is being avoided year by year from the viewpoint of preventing environmental deterioration.

  On the other hand, in a heat sink using a heat pipe, the generated heat is transferred from the base plate to the heat radiating fins arranged on the heat pipe to dissipate the heat. In the case of a relatively low configuration, that is, in a configuration in which the length of the heat radiating portion in the heat pipe provided with the fin is relatively short, the efficient thermal conductivity from the heat pipe to the heat radiating fin is lacking. For this reason, there is a disadvantage that heat is not sufficiently dissipated.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cooling heat dissipating element for a heat-generating element joined with heat dissipating fins, capable of producing a high-performance and light-weight grid heat sink and having improved heat dissipating efficiency.

This invention is made | formed in view of the said situation, and the subject of this invention is achieved by the following means.
That is, the present invention
(1) A heat radiating body in which a plurality of adjacent vertical fins and a horizontal fin provided by intersecting the adjacent vertical fins are joined to each other, and is fixed from the joint base of the heat radiating fin to the heat radiating body. in height, the distance between the vertical fin 1b adjacent to one of the vertical fin 1a a, the distance from the vertical fin 1b to extension end portion 2a of the distance or the horizontal fin until the next vertical fin and B The thickness t1 of the vertical fin 1b is in the range of 0.4 to 8 mm, the thickness t2 of the vertical fin 1a is in the range of 0.4 to 5 mm, and the distance A and the distance B are 1.0. 6 ≦ A / B ≦ 1. 25
Cooling heat radiator of the heat generating element formed by joining the heat dissipating fins to satisfy the relational expression, and (2) a vertical fin adjacent a plurality of phases, transverse provided by intersecting the vertical fin to the adjacent to each A heat dissipating body having heat dissipating fins having fins, wherein the thickness of one vertical fin 1b of adjacent vertical fins is t1 and the other vertical fin at a certain height from the base of the heat dissipating fin to the heat dissipating body. The thickness of the fin 1a is t2, and the distance A between the vertical fin 1a and the vertical fin 1b is in the range of 2 to 30 mm. The distance from the vertical fin 1b to the next vertical fin or the extension of the horizontal fin the distance B to the end 2a in the range of 2 to 30 mm, the t1 and t2 is 1.2 ≦ t1 / t2 ≦ 2.9
The heat-radiating element for cooling the heat-generating element joined with the heat- dissipating fins is provided.

  According to the heat dissipating fin according to the present invention, the heat dissipating performance of the fin can be improved by controlling the distance between the fins and the thickness of the vertical fin in a specific relationship in the heat sink in which the elements of high heat generation are joined. . Therefore, it is possible to provide a grid heat sink having high performance and light weight, and it is particularly suitable for an application where a large amount of heat needs to be processed and a reduction in weight is required like a vehicle control device.

Hereinafter, a preferred embodiment of the radiation fin used in the present invention will be described in detail with reference to FIGS. In addition, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

FIG. 1 shows an example of a radiation fin used in the present invention. FIG. 1A is a front view showing the entire heat dissipating fin. The heat radiating fins are formed of vertical fins 1a and vertical fins 1b, and horizontal fins 2 arranged substantially horizontally between the adjacent vertical fins. In the figure, reference numeral 3 denotes a joining base portion of the radiating fin to the radiating body. Reference numeral 2a denotes an extended end portion of the lateral fin. An enlarged view of the vicinity of the joint base 3 with respect to the heat dissipating body of the heat dissipating fin is shown in FIG. In the figure, A is the distance from one vertical fin 1a to the adjacent vertical fin 1b at a certain height from the joint base 3, and B is the next vertical fin or the next vertical fin 1b at the same height. This is the distance to the end of the horizontal fin. Further, t1 and t2 are the thickness at a certain height from the interface base 3 of the vertical fin 1 b and 1 a, respectively.
The present inventors have found that by controlling A and B or t1 and t2 shown in FIG. 1 to an appropriate relationship, the heat radiation performance of the heat radiation fin can be increased and the weight can be reduced.

In one preferred embodiment, the distance A between two fins of the lattice fin profile is 1.0 6 ≦ A / B ≦ 1. 25 is satisfied. Thereby, the pressure loss of the cooling fluid between the fins A is made smaller than B, the flow velocity of the cooling fluid between the fins A is increased, and the heat radiation efficiency of the surface between the fins A is improved. A / B is 1 . More preferably, 08 ≦ A / B ≦ 1.2. Distance A is 2 ~30mm, distance B is also 2 ~30mm.

In another preferred embodiment, the thickness of the vertical fin of the lattice shape material satisfies 1.2 ≦ t1 / t2 ≦ 2.9 . By making the wall thickness t1 thicker than t2, the heat of the element is more efficiently transmitted to the fins. Thereby, the weight of the fin can be further reduced as compared with the conventional equal thickness fin shown in FIG. t1 / t2 is more preferably 1.3 ≦ t1 / t2 ≦ 2.5, and more preferably 1.5 ≦ t1 / t2 ≦ 2.
The thickness of t1 itself is 0.4 to 8 mm.
The thickness of t2 itself is 0.4 to 5 mm.

  FIG. 2 is an enlarged view of the vicinity of the joint base portion of the heat sink with an equal thickness fin that is a conventional grid-type heat radiation fin. In the figure, A ′ is the distance from one vertical fin 21a to the adjacent vertical fin 21b at a certain height from the joint base 23 to the heat radiating body, and B ′ is from the vertical fin 21b at the same height. This is the distance to the next vertical fin or horizontal fin extending end 22a. Moreover, t21 and t22 are the thickness in the fixed height from the joining base part 23 of the vertical fins 21a and 21b, respectively. Here, A ′ = B ′ and t21 = t22.

In the present invention, 1.0 6 ≦ A / B ≦ 1. More preferably, both the formulas 25 and 1.2 ≦ t1 / t2 ≦ 2.9 are satisfied.
Moreover, the raw material of the radiation fin used in the present invention is not particularly limited, but aluminum alloy, aluminum, copper, and copper alloy are preferable. Moreover, although there is no limitation in particular also in the manufacturing method of a radiation fin, it can manufacture by normal extrusion molding, casting, brazing, welding, and soldering, for example.
Further, the number of horizontal fins between the vertical fins is not particularly limited, but there are preferably 2 to 50, and the distance between the horizontal fins is preferably 2 to 30 mm.

Moreover, it is preferable that the radiation fin used for this invention is comprised so that the thickness of a vertical fin may become thin as it distances from the joining base part 3 joined to heat radiators, such as a base plate of a heat sink, directly or indirectly. Since the temperature of the vertical fins decreases as the distance from the joining base 3 decreases, the amount of heat transfer also decreases, so that the fins can be made thinner and lighter, the opening area can be increased, and the pressure loss of the cooling fluid can be reduced. The difference between the thickest portion and the thin portion of one vertical fin can be appropriately determined depending on the fin shape, fluid physical properties, flow velocity, etc., but is preferably 0.3 to 5 mm.

FIGS. 3A and 3B are diagrams schematically showing the structure of each part of an example of a heat sink in which heat radiating fins according to the present invention are used, wherein FIG. 3A is a plan view, FIG. 3B is a back view, and FIG. d) It is the side view seen from the arrow direction in (c).
As shown in FIG. 3, a plurality of heat dissipating fins used in the present invention are juxtaposed on the other surface of the base plate 11 in which a heat generating element 14 such as an IGBT as a heating element is fixedly held on one surface. It is preferable that the lattice-type heat radiation fins 13 are formed and used.
The base plate 11 and the grid-type radiating fins 13 may be integrally formed by extrusion molding of aluminum, or each radiating fin is manufactured by brazing, soldering, welding, or caulking to the base plate 11. Can do. In FIG. 3, a brazing sheet 12 is sandwiched between the base plate 11 and the fins 13 and brazed and joined.
The heat sink is cooled by being blown from the arrow F. In the figure, H indicates the height of the grid-type heat generating fins 13.

Moreover, although the vertical fin shown in FIG. 1 is made thin in the direction away from the joint base with the base plate, of course, in the present invention, it may have the same thickness over the entire length of the vertical fin.
1 shows a case where there are one vertical fin 1a and 1b, but the heat dissipating fin of the present invention has a plurality of structures shown in FIG. 1 from the beginning by, for example, aluminum extrusion molding. It may have a plurality of 1a and 1b, which are integrally formed.

In each part structure schematically shown in FIG. 3, a heat sink was manufactured with lattice fins having the dimensions shown in Tables 1 and 2, and a heat dissipation experiment was performed to evaluate the performance. The values of A, B, t1, and t2 in Tables 1 and 2 are measured at a height of 5 mm from the joint. As the fins 13 in FIG. 3, the shapes (number of horizontal fins, etc.) shown in the front view of FIG. 1 are arranged side by side in the same direction over the entire surface of the base plate 11. The base plate 11 uses a 300 × 300 × 20 mm dimension A3003 aluminum alloy, and the brazing sheet 12 is sandwiched between the base plate 11 and the fins 13 and brazed. The fin 13 uses an A1070 aluminum alloy, and the height H is 120 mm. The thickness of the lateral fin is 0.6 mm. The element 14 having a calorific value of 1.6 kW in total, with a calorific value of 0.6 kW on the leeward side and a calorific value of 1 kW on the leeward side, was mounted as shown in FIG. Cooling was performed using a turbofan, and a wind of 6 m / s was blown through the duct. The temperature rise of the element was measured by embedding a thermocouple in the vicinity of the joint surface between the base surface 11 and the element 14.
Table 1 shows the measurement results when the inter-fin distances A and B are changed.

As shown in Table 1, 1.0 6 ≦ A / B ≦ 1. No. 25 satisfying 1 to 3, the length of A is No. 1. 1 to 3 but 1.0 6 ≦ A / B ≦ 1. No. 25 not satisfying. Compared to 7 and 8, excellent heat dissipation performance was shown. Similarly, 1.0 6 ≦ A / B ≦ 1. No. 25 satisfying 4 to 6, the length of A is No. 4-6, but 1.0 6 ≦ A / B ≦ 1. No. 25 not satisfying. Excellent heat dissipation performance compared to 9 and 10.

  Next, Table 2 shows the measurement results when the thicknesses t1 and t2 are changed.

In Table 2, No. 1 satisfying 1.2 ≦ t1 / t2 ≦ 2.9 . Nos. 11 to 13 have A and B values of No. 11 to No. 13. No. 11 to 13 are the same. Compared to 7, it showed excellent heat dissipation performance despite its thin wall and light weight. Similarly, No. 1 satisfying 1.2 ≦ t1 / t2 ≦ 2.9 . 14 to 16, the values of A and B are No. No. 14 to 16 are the same. Despite being thinner and lighter than 9 and 19, it showed excellent heat dissipation performance. Further, 1.0 6 ≦ A / B ≦ 1. No. 25 and 1.2 ≦ t1 / t2 ≦ 2.9 . Nos. 17 and 18 showed particularly excellent heat dissipation performance with respect to other examples and comparative examples having similar values of A.
As described above, by controlling A, B, t1, and t2 within the range defined in the present invention, excellent heat dissipation performance can be obtained and the weight can be reduced.

It is a front view which shows the radiation fin used for this invention. It is an enlarged view near the base part of the radiation fin of FIG. It is an enlarged view near the junction part of the conventional grid type radiation fin. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically each part structure of an example of the heat sink using a radiation fin based on this invention, (a) is a top view, (b) is a back view, (c) is a front view, (d) is a side view FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Vertical fin 2 Horizontal fin 2a The extended end part of a horizontal fin 3 Joining base 11 Base board 12 Brazing sheet 13 Lattice-type radiation fin 14 Element 21a, 21b Vertical fin 22 Horizontal fin 22a Extended end part 23 of a horizontal fin base

Claims (2)

A heat radiating body having a plurality of adjacent vertical fins and a horizontal fin provided by intersecting the adjacent vertical fins, and having a certain height from the joint base of the heat radiating fins to the heat radiating body in, the distance between the vertical fin 1b adjacent to one of the vertical fin 1a a, the distance from the vertical fin 1b to extension end portion 2a of the distance or the horizontal fin until the next vertical fin is B, the longitudinal The thickness t1 of the fin 1b is in the range of 0.4 to 8 mm, the thickness t2 of the vertical fin 1a is in the range of 0.4 to 5 mm, and the distance A and the distance B are 1.0 6 ≦ A / B ≦ 1. 25
A heat dissipating element for cooling a heat-generating element joined with a heat dissipating fin, characterized by satisfying the relational expression: A heat radiating body having a plurality of adjacent vertical fins and a horizontal fin provided by intersecting the adjacent vertical fins, and having a certain height from the joint base of the heat radiating fins to the heat radiating body , The thickness of one vertical fin 1b of adjacent vertical fins is t1, the thickness of the other vertical fin 1a is t2, and the distance A between the vertical fin 1a and the vertical fin 1b is in the range of 2 to 30 mm. located, from said vertical fin 1b the distance B to the extension end portion 2a of the distance or the horizontal fin to the next vertical fin in the range of 2 to 30 mm, the t1 and t2 is 1.2 ≦ t1 / t2 ≦ 2.9
A heat dissipating element for cooling a heat-generating element joined with a heat dissipating fin, characterized by satisfying the relational expression:

Images