JPS6161703B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a circuit board on which a plurality of heat generating elements such as semiconductor elements are mounted, and a heat dissipating member made of a material with good thermal conductivity, the heat dissipating member being formed of a material with good thermal conductivity. A liquid cooling module for evaporative cooling, comprising: a liquid cooling module for evaporative cooling, which is installed so as to be airtight between the heating element and the circuit board; It is about improvement.

In recent years, liquid cooling modules for boiling cooling as described above have been used in order to cope with the heat generation caused by the increased integration of semiconductor devices. In addition, there is a demand for higher density mounting of semiconductor elements, and in order to realize these demands, a method is required to mount a three-dimensional circuit board with a large number of semiconductor elements mounted on the side of a block-shaped board. Moreover, each heating element must be mounted as close as possible. In such cases, the amount of heat generated by each heating element is quite large and the three-dimensional substrates are close to each other, so in conventional liquid cooling modules, the bubbles generated from the facing and adjacent heating elements interact with each other, causing both heating elements to The drawback was that partial film boiling was likely to occur between the two, resulting in a decrease in cooling efficiency.

Further, as shown in FIG. 1, a cold plate 3 is connected to the upper surface of the heat dissipating member 2 of the liquid cooling module main body 1 having the above-described configuration, and the cooling water passage 4 in the cold plate 3 is connected to the upper surface of the heat dissipating member 2 as shown by the arrow. Conventionally, a method of forced cooling by passing cooling water through the cold plate 3 has also been adopted, but in this case, although the cooling capacity of the cold plate 3 itself is large, on the other hand, the cold plate 3
The disadvantage is that the thermal resistance between the heat dissipating member 2 and the heat dissipating member 2 is high. In the figure, 5 is a ceramic circuit board, 6 is a heating element such as a semiconductor element mounted on the circuit board 5, and 7 is a refrigerant liquid.

The present invention is intended to solve the various drawbacks mentioned above, and provides a liquid cooling module with excellent cooling efficiency that takes advantage of the cold plate method and can prevent partial film boiling between adjacent heating elements. The purpose is to

An embodiment of the invention will now be described with reference to FIG. In the drawings, members having the same configuration as the conventional one are represented by the same reference numerals.

In the figure, reference numeral 11 denotes a heat dissipating member made of a material with good thermal conductivity.
3 is integrally connected to the inner plate 12.
The heating elements 5 are attached to the circuit board 5 so that the lower surface of the periphery thereof is brought into close contact with the upper surface of the periphery of the circuit board 5 so as to cover each heating element 5. Inner plate 12 and outer plate 1
A fluid passage 14 is formed between the two. A refrigerant liquid 7 is sealed in the space above the circuit board 5 that is sealed by the inner plate 12, and each heating element 30, which is formed by mounting a large number of semiconductor elements 32 on the circumferential surface of a base 31, is placed in this refrigerant liquid 7. Immersed. As the refrigerant liquid, an inert, insulating, and low boiling point (boiling point of about 40 to 60°C) is used, such as fluorocarbon, and the space 15 that does not contain the refrigerant liquid 7 is filled only with the gas of the refrigerant liquid 7. be satisfied. The inner plate 12 is provided with a U-shaped separation part 16 that separates and closes off the adjacent heating elements 30.
0 is also arranged in a plane in the direction perpendicular to the plane of the drawing, it is of course provided so as to surround each heating element.

The presence of this separation part 15 makes it possible to prevent bubbles generated from adjacent heating elements 30 from interacting with each other and causing partial film boiling between the heating elements 30 and 30. The bubbles generated by the heat efficiently transfer heat to the inner plate 12.
The heat transferred to the inner plate 12 is
It is absorbed by the cooling water 19 supplied from the cooling water 7, passed through the fluid passage 14, and discharged from the discharge port 18, and radiated to the outside. Therefore, it is possible to improve the cooling efficiency of the heating element. Note that the refrigerant vapor in the space 15 condenses on the wall surface of the inner plate 12 and falls.

In the above explanation, an example has been described in which a heating element formed by mounting a large number of semiconductor elements on a base body is mounted on a circuit board, but the present invention is also applicable to cases where a heating element such as a semiconductor element is mounted directly on a circuit board. Of course, it will be done.

As described above, according to the present invention, the problem of thermal resistance between the conventional heat dissipating member and the cold plate is solved by adopting a heat dissipating member in which a cold plate is integrated with the conventional heat dissipating member, and the cold plate method is adopted. In addition to taking advantage of the above advantages, it is possible to prevent partial film boiling between adjacent heating elements by the action of the separation section provided on the inner plate, and it is possible to improve cooling efficiency.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a liquid cooling module employing a conventional cold plate, and FIG. 2 is a front sectional view showing an embodiment of a liquid cooling module according to the present invention.
In the figure, 5 is a ceramic circuit board, 7 is a refrigerant liquid,
11 is a heat radiation member, 12 is an inner plate, 13 is an outer plate, 14 is a fluid passage, 15 is a space,
16 is a separation part, 17 is an inlet, 18 is an outlet, 1
9 is cooling water, and 30 is a heating element.

Claims (1)

[Claims] 1. A heat dissipating member made of a material with good thermal conductivity is placed on a circuit board on which a plurality of heat generating elements are mounted, and is placed between the heat dissipating member and the circuit board so that a space is formed around the heat generating elements. In a liquid cooling module for boiling cooling, which is installed so that airtightness is maintained and a refrigerant liquid is sealed in the space so that the heating element is immersed therein, the heat radiating member:
an inner plate having a separation portion that separates and closes off the heating elements adjacent to each other facing the circuit board; and an outer plate forming a fluid passage between the inner plate and the fluid passage. A liquid cooling module characterized by having a water passage means for passing a cooling fluid therein.