JPH0682768B2 - Heat dissipation control device - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a heat dissipation control device that enhances heat dissipation of a semiconductor device in which a semiconductor element such as an IC is mounted on a substrate.

(Technical background of the invention and its problems) Conventionally, as this type of heat dissipation control device, for example, JATEC
Published by `` Research and Development of Heat Pipe Tech
nology ", pages 328 to 335, published by TPCotter," PRIN
There is a so-called micro heat pipe described in "CIPLES AND PROSPECTS FOR MICRO HEAT PIPES". That is, in this product, an oxide film is applied to a silicon substrate, and the oxide film is etched to form a groove with a triangular or quadrangular cross section, and the groove is sealed with heat-resistant glass as a heat dissipation plate to distribute the refrigerant. It was formed in the channel and the refrigerant was enclosed. Therefore, even if the semiconductor element is locally heated, the refrigerant in the refrigerant flow passage formed by sealing the groove is evaporated in the heating portion, and the refrigerant condensed in the low temperature portion passes through the corner portion of the refrigerant flow passage. It flows into the heating part due to the capillary phenomenon,
The heat radiation is controlled so that the silicon substrate as a whole has a uniform temperature. By the way, when the refrigerant is sealed in the refrigerant flow passage, it is difficult to seal it in the refrigerant flow passage after sealing the groove because the groove is sealed with heat-resistant glass.At the same time as sealing with the heat-resistant glass, the refrigerant is also sealed in the groove. Must. However, since the refrigerant has a high vapor pressure at room temperature, if it is attempted to seal it in the groove by this method, it must be carried out at a very low temperature without vapor pressure, but such a method is very difficult. In addition, there is a problem that the sealing property becomes poor and the reliability is low.

(Object of the Invention) The present invention was devised in view of the above problems, and after the groove portion is sealed to form the refrigerant flow passage, the refrigerant can be enclosed, the manufacturing is easy, and the sealing property is high. An object of the present invention is to provide a heat dissipation control device that can improve reliability.

(Summary of the Invention) The present invention relates to a substrate that is in thermal contact with a heating element, a heat dissipation plate that is in close contact with the surface of the substrate opposite to the heating element, and a contact surface between the substrate and the heat dissipation plate. At least a groove portion formed on one side and a space portion formed by a contact surface with the other,
The cross-sectional shape of the space has corners, and the space is configured as a refrigerant flow passage.

(Embodiment of the Invention) An embodiment of the present invention will be described with reference to the drawings. Board 1
Is for mounting an IC chip A, which is a semiconductor element of a semiconductor device, is made of a ceramic material, and a metal plate 2 for heat dissipation made of a copper plate is closely adhered to the opposite surface (back surface) of the IC chip A mounting surface. It is fixed. In addition, several fine groove portions 4 are formed in parallel on the back surface of the substrate 1 to which the metal plate 2 is adhered, and the groove portions 4 are formed in the refrigerant flow passage 3 having a quadrangular cross section by sealing with the metal plate 2. Has been done. The refrigerant 5 is enclosed in the sealed refrigerant flow passage 3, and is condensed at the corner 3a of the refrigerant flow passage 3 due to a capillary phenomenon at normal temperature.

Next, the manufacturing method will be described.

First, a plurality of fine groove portions 4 are provided in parallel on the back surface of the substrate 1 formed of a ceramic material by etching, machining, or laser beam processing. Next, the metal plate 2 is joined to the rear surface having the groove portion 4 by diffusion welding while heating it at a high temperature for a long time while lightly contacting it with a small pressing force. When the substrate 1 and the metal plate 2 are joined together, the substrate 1
The back surface side of is completely sealed, and the groove portion 4 is sealed to form the refrigerant flow passage 3. Thereafter, a pipe (not shown) communicating with the coolant flow passage 3 is connected to the metal plate 2 by machining. The pipe is a thin pipe at the connection position with the metal plate 2, is formed into a thick pipe from the middle, and a valve is attached to the portion formed in the thick pipe, and communicates with a refrigerant injection device (not shown) via this valve. It is connected. After connecting the pipe to the metal plate 2, the refrigerant press-fitting device is operated to enclose the refrigerant 5 in the refrigerant flow passage 3 through the pipe under pressure. At this time, the refrigerant 5 aggregates at the corners 3a of the refrigerant flow passage 3 due to the capillary phenomenon. After the refrigerant 5 is completely sealed in the refrigerant flow passage 3, the pipe is squeezed in the narrow tube portion while keeping the pressurized state, and the pipe is closed at the position closer to the valve than the closed position. By cutting and removing and welding the cut portion, a micro heat pipe including the substrate 1, the metal plate 2, the refrigerant flow passage 3, and the refrigerant 5 is formed. In this way, the metal plate 2 is in close contact with the back surface of the substrate 1 and the groove 4
Since the pipe for sealing the cooling medium 5 can be connected to the cooling medium flow passage 3 after it is sealed and formed in the cooling medium flow passage 3, it is necessary to seal with the conventional glass and at the same time seal the cooling medium in the groove portion. Sealing and refrigerant encapsulation can be performed very easily as compared with the above, and the sealing property is improved and reliability can be improved.

In the micro heat pipe configured as described above, when the IC chip A has a very uneven temperature distribution, the refrigerant 5 evaporates into a gas in the high temperature portion, and the central portion 3b of the refrigerant flow passage 3
To the low temperature section. The refrigerant 5 that has moved to the low temperature portion is condensed into a liquid, aggregates in the corner portion 3a, and returns to the high temperature portion again due to the capillary phenomenon. The heat generated in the IC chip A is dissipated by the heat radiation of the metal plate 2 as well as the circulating motion of the refrigerant 5, and the IC chip A is controlled to a uniform temperature as a whole, so that the IC chip A is in a good state. Can operate.

The groove 4 may be provided on the metal plate 2 side as shown in FIG. 3, or may be provided on both the substrate 1 and the metal plate 2.
Further, as shown in FIG. 4, fins 6 that enhance heat dissipation efficiency may be attached to the metal plate 2.

Further, although the refrigerant flow passage 3 of the present embodiment is shown as having a quadrangular shape, it is not limited to this, and in addition to a triangular shape as shown in FIG. 5, a polygonal shape such as a pentagon, a hexagon, etc., It may have an irregular shape, and in short, it has a corner, and the refrigerant 5 liquefied on the low temperature side due to the capillary action of this corner
Should return to the high temperature side again.

Further, although the groove portion 4 has been shown as being provided by engraving several grooves in parallel, it may be provided in an intersecting shape, one groove, or several grooves in an intersecting shape.

(Effect of the invention) As is apparent from the above, according to the present invention, the substrate closely adheres to heat dissipation, and it is not necessary to seal the refrigerant in the groove together with the seal, and the groove is sealed to form the refrigerant flow passage. later,
Since the refrigerant can be sealed in the refrigerant inflow path, the refrigerant can be sealed very easily without using a particularly difficult means, and the sealing property is improved and the reliability can be enhanced.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a heat dissipation control device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the same main portion, and FIGS. 3 to 5 are cross-sectional views showing other embodiments. is there. A: IC chip (heating element), 1 ... Substrate 2 ... Metal plate (heat dissipation plate), 3 ... Refrigerant flow passage 3a ... Corner, 4 ... Groove, 5 ... Refrigerant

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshitaka Fukuoka, No. 1, Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu factory, Toshiba Corp. (56) References JP-A-50-139969 (JP, A) JP-A-60-58648 (JP, A) IBM Technical Disclosure Bulletin Vol. 23 No. 3 August 1980 page 1057

Claims (2)

[Claims] 1. A substrate which is in thermal contact with a heating element, a heat radiating plate which is in close contact with the surface of the substrate opposite to the heat generating element, and at least one of the contact surface between the substrate and the heat radiating plate. A heat dissipation control device comprising: the groove portion and a space portion formed by a contact surface between the groove portion and the other, and the cross-sectional shape of the space portion has a corner portion, and the space portion is configured as a refrigerant flow passage. 2. The heat dissipation control device according to claim 1, wherein the space is hermetically sealed, and a refrigerant is enclosed in the space.