JPS6234450Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device suitable for cooling, for example, semiconductor elements mounted on a substrate.

Since jet cooling can obtain a heat transfer coefficient that is one to two orders of magnitude higher than forced convection cooling, it is used in electronic devices and the like that require high cooling efficiency.

Figure 1 is an explanatory diagram of the properties of a jet flow, where 1 is a nozzle with a circular cross section, 2 is an object to be cooled, and the case where air is blown from nozzle 1 at right angles to the plane of the object 2 to be cooled to cool it by a three-dimensional jet flow. In the figure, A is a free jet region, B is an impinging jet region, and C is a wall jet region. After the jet hits the object 2 to be cooled, it becomes a wall jet centered at the junction D and reaches the plane of the object 2 to be cooled. In addition to the impinging jet region, which shows a high heat transfer coefficient of 10 ² to ^{10 3} Kca/m ² hr ℃, the wall jet region, which occupies most of the area, has a lower forced heat transfer coefficient than the former. It has been experimentally confirmed that it exhibits a convection heat transfer coefficient. Therefore, the area that exhibits particularly high cooling efficiency is limited, and in order to obtain higher overall cooling efficiency, a higher pressure, larger diameter jet is required, and a larger power source is also required. The problem arises that it becomes uneconomical.

The present invention is intended to solve these problems, and aims to provide a cooling device that can economically increase the cooling efficiency using three-dimensional jet flow.

Embodiments of the present invention will be described below with reference to FIGS. 2 to 6.

2 and 3 both show embodiments of the present invention, 10 is a nozzle with a circular cross section, 11 is a nozzle with a circular cross section;
12 is a substrate, 13 is a heating element such as a semiconductor element mounted on the substrate 12, and 14 is a cooling fin made of a material with good thermal conductivity.

As is clear from FIG. 4, the cooling fins 14 are provided with a large number of fins 15 radially in the wall jet region of the three-dimensional jet.

In this way, since the fins 15 are arranged radially so that the space between adjacent fins widens toward the end, the boundary layers E and E do not intersect, as shown in FIG. 5, and effective flow and heat transfer are achieved. In addition, since a large number of fins 15 are provided radially in the wall jet region where air flow is poor, the heat conduction area increases and the air flow is not obstructed, thereby improving the cooling efficiency of the wall jet region. can be raised.

Figure 6 is an experimental pressure-specific heat resistance diagram.
indicates the case where the cooling surface is a flat plate, and G indicates the case where radial cooling fins are provided. Cooling efficiency is improved by applying radial cooling fins in a three-dimensional jet flow.
It was confirmed that it improved by more than 40%.

As explained above, according to the present invention, the cooling efficiency of the three-dimensional jet stream can be increased with a simple configuration.

It should be noted that the present invention can also be applied to other objects to be cooled, such as jet cooling used on the inner surface of the turbine blades of jet engines.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of jet properties, Figures 2 and 3
The figures are all front sectional views of the embodiments of the present invention.
5 is a plan view of the cooling fin, FIG. 5 is a partial plan view thereof, and FIG. 6 is a pressure-specific heat resistance diagram. In the figure, 1 and 10 are nozzles with a circular cross section, A is a free jet region, B is an impinging jet region, C is a wall jet region,
12 is a substrate, 13 is a heating element, 14 is a cooling fin,
15 is Finn.

Claims (1)

[Scope of utility model registration request] In a cooling device that sprays fluid onto an object to be cooled from a nozzle with a circular cross section and cools the object with a three-dimensional jet, a plurality of fins are arranged in a wall jet region of the three-dimensional jet in a radial manner so that the spaces between adjacent fins widen toward the end. A cooling device characterized by being provided with.