JPS6344748A - Cooling structure of semiconductor device - Google Patents

Abstract

PURPOSE:To improve the cooling efficiency by a method wherein a fin forming a circulation path for circulating a refrigerant to each semiconductor device is installed and additionally its outer circumference is covered with a magnetic seal having a magnetic fluid so that the fin can be attached and detached from a cooling plate. CONSTITUTION:A fin 6 which is equipped with a circulation path 5A for a refrigerant in its inside is fixed to the surface of a semiconductor device 2 which is mounted on a printed-circuit board 1 by welding, glueing or soldering so that an outer circumference 5B of the fin 5 can be covered with a magnetic fluid 6A which is held by an N magnetic pole 8A and an S magnetic pole 8B. The refrigerant which has flowed through a flow path 3A at a cooling plate 3 in the direction as shown by an arrow F1 flows through a nozzle 11 into the circulation path 5A as shown by an arrow F2. The refrigerant flows from the circulation path 5A in the direction as shown by an arrow F3 so that the refrigerant does not leak due to the interception of the magnetic fluid 6A at a magnetic seal 6. Therefore, the refrigerant can flow directly through the fin 5. In addition, because a part E where the surface of the semiconductor device 2 comes into contact with the fin 5 is fixed, the thermal conductivity is increased and the cooling efficiency can be improved.

Description

[Detailed Description of the Invention] [Summary] By fixing fins that form a circulation path through which a refrigerant is circulated to a semiconductor element, the cooling efficiency of the refrigerant is improved, and magnetically attached to the outer periphery of the fins By providing a seal, the cooling plate can be easily inserted into and removed from the cooling plate.

[Industrial application field]

The present invention relates to a cooling structure that cools a semiconductor element such as an LSI element mounted on a printed circuit board by circulating a coolant, and in particular, a cooling structure in which a circulation path for the coolant is formed in a fin fixed to the semiconductor element, and The present invention relates to a cooling structure for semiconductor elements formed to improve cooling efficiency.

Semiconductor devices such as LSI devices, which are widely used in electronic devices, have recently become more densely packaged and faster, and electronic devices configured with a large number of these semiconductor devices are unstable. In order to achieve high performance, a cooling device is used to forcibly cool each semiconductor element.

This type of cooling device has good cooling efficiency, and
It is important to be economical and highly reliable, and a cooling device shown in FIG. 3 using a cooling plate in which a refrigerant is generally circulated is known.

FIG. 3 is a perspective view showing an outline of the cooling device.

As shown in FIG. 3, the cooling plate 3 is stacked as shown by arrow C on the printed circuit board 1 on which a plurality of semiconductor elements 2 are mounted, so that one cooling surface of the cooling plate 3 is attached to the printed circuit board 1 on which the semiconductor elements 2 are mounted. It is placed in close contact with the surface.

Therefore, the refrigerant is supplied from one port 10 of the cooling plate 3 as shown by arrow A, and is circulated as it is discharged from the other port 10 as shown by arrow B.

Through this circulation, the heat generated by each semiconductor element 2 is cooled down.

Therefore, in such a cooling structure, in order to further improve cooling efficiency, it is desired that the thermal conductivity between the semiconductor element 2 and the cooling plate be good.

C. Prior Art] Conventionally, the conventional device has an S-shaped configuration as shown in the conventional side cross-sectional view in FIG.

As shown in FIG. 4, the cooling plate 3z has a heat transfer element 15 formed by fixing a flange 12 to one end of a bellows 13 made of an elastic material and fixing a heat transfer plate 14 to the other end.
is locked through the O-ring 17, and the heat transfer plate 14 is brought into close contact with the surface 2A of the semiconductor element 2 by pressure in the direction of arrow P through the thermal sheet 16 made of a material with good thermal conductivity. It was composed of

Further, the cooling plate 3 is formed in a flow path 3A so that it is sent to a nozzle 13A and is circulated by being discharged from the interior 13A as shown by an arrow A3.

In such a configuration, when the printed circuit board l is removed from the cooling plate 3 due to a failure of the semiconductor element 2, the thermal sheet 16 covers the heat transfer plate 14 and the surface 2 of the semiconductor element 2.
Since the thermal sheet 16 is sandwiched between the thermal sheet 16 and the thermal sheet 16, it is designed to be removed by cutting off the sandwiching portion of the thermal sheet 16.

Therefore, the heat generated by the semiconductor element 2 mounted on the printed circuit board 1 is cooled by being transferred to the coolant 4 that is circulated through the thermal sheet 16 and the heat transfer plate 14 that are in close contact with the surface 2A.

[Problem that the invention seeks to solve]

Therefore, in such a configuration, the thermal sheet 16
is formed of a soft material with good heat transfer properties, and is formed so that the spring force of the bellows 13 improves the adhesion between the surface 2A and the heat transfer plate 14, and efficient heat transfer is performed.

However, in reality, each contact surface with the thermal sheet 16 causes a problem in that the heat transfer efficiency decreases and the cooling efficiency deteriorates.

It has also been considered to apply a paste-like heat transfer material instead of the thermal sheet 16, but applying such a paste causes "variations" in the applied film thickness, making it difficult to achieve uniform cooling efficiency. I had a problem not being able to get it.

[Means for solving problems]

FIG. 1 is a sectional view showing the principle of the present invention.

As shown in FIG. 1, each of the semiconductor elements (2) is provided with a fin (5) forming a circulation path (5A) for circulating a coolant (4), and the fin (5) is further provided with a cooling The outer periphery of the fin (5) (
5B) Magnetic seal (6
).

With this configuration, the above-mentioned problems are solved.

[For production]

That is, the semiconductor element is directly cooled by forming a circulation path through which a coolant circulates in the fins fixed to the semiconductor element, and allowing the coolant to flow through the circulation path from a cooling plate.

Further, the joint portion between the cooling plate and the fins is shielded by a magnetic seal so that they can be inserted into and removed from each other.

Therefore, unlike conventional methods, heat transfer is not performed through the contact surface, and cooling is performed by the refrigerant flowing directly into the wi ring path of the fins, improving thermal conductivity and improving cooling efficiency. I can figure it out.

〔Example〕

The present invention will be explained in detail below with reference to FIG.

FIG. 2 is a side sectional view of an embodiment according to the present invention. The same reference numerals indicate the same objects throughout the figures.

As shown in FIG. 2, the cooling plate 3 has a circle 18.
A magnetic seal 6 consisting of a magnet 7, an N electrode i8A, and an S electrode 8B is held in place via.

Further, a fin 5 having a refrigerant circulation path 5A provided therein is fixed to the surface of the semiconductor element 2 mounted on the printed circuit board 1 by welding, adhesion, or soldering, and the outer peripheral part 5B of the fin 5 is attached to the N electrode 8A. and S electrode 8B, respectively, and are configured to be subjected to MM by the magnetic fluid 6A held by them.

In this case, the outer peripheral portion 5B of the fin 5 is in close contact with the magnetic fluid 6A.
A ring 9 made of a soft Efi material such as stainless steel is installed in the ring 9. Normally, the magnetic fluid 6A is held by a magnetic field formed from the N electrode 8A to the S electrode 8B as shown by the dotted line, and the printed circuit board 1 and cooling When inserting and removing the fins 5 by separating them from the plate 3, care is taken to prevent the magnetic fluid 6A from adhering to the ring 9 side.

Therefore, the refrigerant flowing through the flow path 3A of the cooling plate 3 in the direction of the arrow F1 flows out from the nozzle 11 into the circulation path 5A as shown by the arrow F2, and from the circulation path 5A the refrigerant flows into the magnetic fluid of the magnetic seal 6 as shown in the arrow F3. 6A is shut off to ensure that there is no leakage.

In this way, the refrigerant is configured to be circulated by being sequentially distributed to the next circulation path 5A.

Therefore, with this configuration, the refrigerant can be directly passed through the fins 5, and since the E portion of the contact portion between the surface of the semiconductor element 2 and the fins 5 is fixed,
Thermal conductivity becomes high and cooling efficiency can be improved.

In addition, the printed A board 1 may fail due to a failure of the semiconductor element 2, etc.
When the printed i-board 1 is removed from the cooling plate 3, the refrigerant is extracted from the flow path 3A and the circulation path 5A, and the fins 5 are inserted and removed from the magnetic seal 6, thereby making it possible to easily insert and remove the printed i-board 1.

〔Effect of the invention〕

As described above, according to the present invention, it is configured such that a printed circuit board can be inserted and removed, and furthermore, the refrigerant can be directly circulated through the fins.

Therefore, by improving the heat exchange efficiency using the refrigerant, it is possible to improve the cooling efficiency compared to the conventional method, and the practical effect is great.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the principle of the present invention. FIG. 2 is a side sectional view of an embodiment according to the present invention. FIG. 3 is a perspective view of the cooling device. FIG. 4 shows a conventional side sectional view. In the figure, 1 is a printed circuit board, and 2 is a semiconductor element. 3 is a cooling plate and 4 is a refrigerant. 5 is a fin, 6 is a magnetic seal. 5A is the circulation path, 5B is the outer periphery. 6A indicates a magnetic fluid. Fusakuri Hara Chori Atomen λ A 1 Uzuki Zenakiyo 5-Mi”Hi 11/j side! 1 old sword and rabbit's 'r-Katsune Mizunetsu 3 Figure I (end of page 1 sectional view No. 4z

Claims (1)

[Scope of Claims] [1] Comprising a cooling plate (3) that circulates a refrigerant (4) and a semiconductor element (2) mounted on a printed circuit board (1), the heat generation of the semiconductor element (2) is A cooling structure for a semiconductor element cooled by circulation of the coolant (4), wherein each of the semiconductor elements (2) has fins (5) forming a circulation path (5A) for circulating the coolant (4). 1. A cooling structure for a semiconductor device, comprising: a cooling structure for cooling a semiconductor device; [2] The outer periphery (5B) of the fin (5) is shielded by a magnetic seal (6) having a magnetic fluid (6A) so that the fin (5) can be inserted into and removed from the cooling plate (3). A cooling structure for a semiconductor device according to claim 1, characterized in that: