JPH03211864A - Heat radiating device for functional element of electronic equipment - Google Patents

Abstract

PURPOSE:To radiate the heat produced by a functional element more efficiently in a stable state by providing radiation fins to the outer surface of the cavity section of a sealed container. CONSTITUTION:The heat produced by a semiconductor element 2 is absorbed by the working liquid 4 in a liquid reservoir 3a adjacent to the element 2 and the vapor of the liquid 4 produced by the heat of the element 2 moves upward and reaches a cavity section 3b. After reaching the cavity 3b, the vapor further moves toward the end of the cavity 3b along the upper surface of the cavity 3b. While the vapor move in such way, the heat of the vapor is removed by radiation fins 5 and the vapor is condensed to the liquid which returns to the liquid reservoir 3a along the lower surface of the cavity 36. As the internal heat movement by the vaporization and liquefaction of the working liquid 4 continues, the semiconductor element 2 which is the heat source is effectively cooled. Therefore, the heat of a functional element can be radiated to the outside effectively and stably and the reliability, etc., of the element can be improved.

Description

[Detailed Description of the Invention] [Summary] Regarding a heat dissipation device for a functional element of an electronic device, the purpose of the present invention is to provide a heat dissipation device that can more effectively and stably discharge the heat generated by the functional element. In a heat dissipation device for a functional element mounted on a substrate arranged vertically in parallel to A sealed container in which a predetermined amount of working fluid is sealed, the container comprising a cavity located above and extending in a horizontal direction perpendicular to the substrate and continuous with the liquid pool, and the cavity of the sealed container. radiating fins provided on the external surface of the radiator.

[Industrial application field]

The present invention relates to a heat dissipation device for a functional element mounted on a substrate arranged vertically in parallel within a housing of an electronic device.

[Conventional technology]

In order to effectively cool functional elements such as semiconductor elements and optical semiconductor elements mounted on the substrates of electronic devices, especially optical communication equipment, thermal diffusion through natural or forced air convection, or Peltier elements and connections thereto are used. Methods such as heat dissipation using heat dissipation fins have been put into practical use.

[Problem to be solved by the invention]

However, with the recent dramatic increase in transmission speed,
Functional elements can be cooled more effectively, and their stability and
There is a strong need for a highly reliable heat dissipation device.

[Means for Solving the Problems] In order to solve the above problems, according to the present invention, in a heat dissipation device for a functional element mounted on a substrate arranged vertically in parallel in a housing of an electronic device, the function a liquid pool located in the horizontal direction perpendicular to the element and in direct or indirect contact with the element; and a liquid pool located above the liquid pool and extending in the horizontal direction perpendicular to the substrate and continuous with the liquid pool. The present invention is characterized in that it includes a sealed container having a cavity in which a predetermined amount of working fluid is sealed, and heat radiation fins provided on the outer surface of the cavity of the sealed container.

[Function] The heat of the functional element is absorbed as heat of vaporization by the working fluid in the liquid pool located in the horizontal direction perpendicular to the functional element, and the vapor reaches the upper cavity. By moving within the cavity in a horizontal direction perpendicular to the substrate, heat is removed by heat dissipation fins provided on the external surface of the cavity and liquefied, while this heat is discharged to the outside from the fins. The functional element is effectively cooled by a series of such processes occurring one after another.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

1 to 3 are diagrams showing a first embodiment of a heat dissipation device for a functional element of an electronic device according to the present invention, and FIGS. 4 to 6 are diagrams showing a second embodiment. .

First, to explain the first embodiment, referring to FIGS. 1 to 3, a board 1 (only a portion of which is shown) that stands up vertically is disposed in a box-shaped casing (not shown) with an open front and is detachable. A semiconductor element 2 is placed on this substrate 1. Above the semiconductor element 2 (on the left side in FIG. 3),
The sealed container 3, in which the liquid pool portion 3a directly contacts the entire surface thereof, has heat resistance and has a predetermined amount of a room-temperature liquid volatile substance (working fluid) 4 sealed therein that evaporates when the temperature exceeds a predetermined temperature. For example, it is attached via a conductive adhesive (not shown). Although not shown, the sealed container 3 can also be mechanically fixed to the semiconductor element 2 using, for example, plastic screws. In addition to a liquid pool part 3a having a rectangular cross section both inside and outside, the sealed container 3 has a liquid pool part 3a located above the pool part 3a and extending in a horizontal direction perpendicular to the group Fi1 (to the left in FIG. 3). It has a cavity 3b continuous to 3a. On the upper surface of the cavity 3b, which has a rectangular cross section both inside and outside, a plurality of so-called heat radiation fins 5 having a large surface area are regularly arranged upright so that heat can be diffused well into the air.

In the heat dissipation device of this embodiment having the above configuration, the heat of the semiconductor element 2 is absorbed as heat of vaporization of the working fluid 4 in the liquid pool 3a that is in close contact with the semiconductor element 2, and the vapor moves to the upper part of the interior and forms the cavity. This leads to part 3b.

Then, it further moves toward the end (to the left away from the substrate 1 in FIG. 3) along its internal upper surface. At this time, the heat of the steam is removed by the heat radiation fins 5 (therefore, the heat radiation fins 5 radiate this heat into the atmosphere), the steam is condensed and liquefied, and flows along the lower surface of the cavity 3b to the liquid pool 3a. Internal heat transfer occurs continuously due to vaporization and liquefaction of the working fluid 4,
As a result, the semiconductor element 2, which is a heat source, is effectively cooled. Further, since the device is configured compactly in this way, the dedicated space in the in-plane direction of the board can be reduced, and the board mounting density can be improved.

Note that although the hydraulic fluid 4 is a liquid at room temperature, it may be specified (desired)
It is possible to use a condensable liquid that vaporizes when the temperature exceeds , such as ethanol or chlorofluorocarbon. Further, the sealed container 3 is preferably formed of a good thermal conductor, such as aluminum or copper.

Next, referring to FIGS. 4 to 6 to describe the second embodiment, the cavity 13b of the sealed container 13 of this embodiment has a cylindrical shape, unlike that of the first embodiment.

The cylindrical cavity 13b has the appearance of perpendicularly penetrating the center of a plurality of rectangular plates (radiating fins 15) arranged at predetermined intervals, and is joined to them.

Therefore, regarding the series of internal heat transfers in which the heat of the semiconductor element 2 is taken away by the working fluid 4 in the liquid pool 13a and the heat is discharged to the outside from the radiation fins 15, the above-mentioned first
Although there is no particular difference from the embodiment, according to this structure, the air flow around the cavity 13b can be significantly promoted due to its smooth appearance (cylindrical shape), and the surface area of the heat dissipation fins 15 is larger (larger and better). It can be expected to have a heat dissipation effect.

Finally, to briefly explain several different embodiments, the embodiment shown in FIG. 7 is a modification of the first and second embodiments, and the liquid pool 23a of the sealed container 23 is
It has a structure in which the semiconductor element 2, which is a heat source, is placed on top of the liquid pool 23a. This configuration is for effective use of the substrate portion exclusively occupied by the semiconductor element 2, and as a result, the amount (height) of the sealed container protruding from the substrate 1 can be suppressed, or by that much. A large number of radiation fins 25 can be provided.

The embodiment shown in FIG. 8 is also a modification of the first and second embodiments (or the embodiment shown in FIG. 7), but the functional element 32, which is a heat source, does not come into direct contact with the liquid pool 23a. They differ greatly in points. That is, a so-called Beltier element 3o is interposed between these members. The purpose of this configuration is not only to simply cool the functional element 32, but also to intentionally (remotely control) maintain its temperature constant and stable. FIG. 8(a) shows a structure in which the Vertier element 3o and the liquid pool 23a are placed in this order on the functional element 32;
b) shows a structure in which the liquid pool portion 23a is buried within the substrate 1. The functional element 32 to which this embodiment can be applied is a module whose cooling temperature must be kept low (and maintained with high precision), such as an ultra-high-speed optoelectronic composite module housing an optical semiconductor element and its driving circuit in a package. A cage module etc. can be considered.

Needless to say, it is possible to radiate the heat of the functional elements to the outside more effectively by attaching and using a forced air cooling device consisting of a cooling fan or the like to all of the above-mentioned embodiments. be.

〔Effect of the invention〕

The heat of the functional elements can be effectively and stably discharged to the outside by heat transfer due to the vaporization and liquefaction of the working fluid, making it possible to dramatically improve the reliability of these elements.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a first embodiment of a heat dissipation device for a functional element of an electronic device according to the present invention, FIG. 2 is a cross-sectional plan view of the main part of the first embodiment as seen from the front of the board, and FIG. 3 is a board FIG. 4 is a perspective view of the second embodiment. FIG. 5 is a front cross-sectional view of the main parts of the second embodiment. FIG. 6 is a cross-section of the second embodiment. FIG. 7 is a cross-sectional side view of another embodiment, and FIG. 8 is a side view of still another embodiment. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Semiconductor element, 3... Sealed container, 3a... Liquid pool part, 3b...
Cavity part, 4... Volatile substance t (working fluid), 5... Radiation fin, 13... Sealed container, 13a...
・Liquid pool part, 13b... Cavity part, 1
5... Heat radiation fin, 23... Sealed container,
23a...Liquid pool part, 23b...Cavity part,
25...Radiation fin, 32...Functional element. Heat radiation! ! Perspective view of the first embodiment of the device No. 1 = Cross-sectional view of the first embodiment seen from the side of the country board Perspective view of the second embodiment Diagram Front view of the second embodiment Different embodiment No. 7 Yet another embodiment figure

Claims (1)

[Claims] 1. In a heat dissipation device for functional elements (2, 32) mounted on a substrate (1) arranged vertically in parallel in the housing of an electronic device, in a horizontal direction perpendicular to the functional elements (2, 32). A liquid pool (3) located and in direct or indirect contact with this
a, 13a, 23a) and the liquid pool portion (3a, 13a
, 23a) and extends in the horizontal direction perpendicular to the substrate (1).
), a sealed container (3, 13, 23) in which a predetermined amount of hydraulic fluid (4) is sealed, and a cavity (3b, 13b, 23b) continuous to the container (3, 13, 23); 23)
A heat dissipation device for a functional element of an electronic device, characterized in that it has a heat dissipation fin (5, 15, 25) provided on an external surface of a cavity (3b, 13b, 23b).