JP4702219B2 - Cooling system - Google Patents

Description

  The present invention relates to a cooling device, and more particularly, to a cooling device that improves the high-efficiency heat dissipation effect of an element that generates a large amount of heat, such as pin electronics of a memory tester or LSI tester, or an electronic circuit that requires temperature control.

  As the operating speed of LSI modules is increasing, the integration density of LSI modules is also increasing. Therefore, the amount of heat generated by each high-density LSI module, which is a heating element, is increasing. Under such circumstances, there is a need for a more efficient cooling device for high-density LSI module mounted semiconductor devices.

  An LSI module mounting semiconductor device generally has a large number of LSI modules mounted on one surface of a printed circuit board and is externally connected via terminal pins formed on the other surface. In order to cool the LSI module mounted semiconductor device, the entire semiconductor device is cooled by forced air cooling, or is cooled by liquid cooling in which the entire semiconductor device is immersed in a cooling medium.

FIG. 3 is a plan view (a), a bb ′ sectional view (b) of FIG. 3 (a), and a cc ′ sectional view (c) of FIG.
In these drawings, 1 is a printed circuit board, 2 is a shield case, and 3 is a high-density LSI device arranged in a lattice shape, and is fixed on both sides with the printed circuit board 1 in between. Reference numeral 4 denotes an O-ring which is pressed against the gold land 11 formed on the substrate surface to form a sealing portion 27.

  Reference numeral 5 denotes a plurality of connectors provided at the peripheral edge of the substrate. Shield cases 2 are provided on both sides of the printed circuit board 1, and a flow accommodating part 25 that surrounds and accommodates the heat generating element 3 is formed between the printed circuit board 1 and the shield case 2. That is, the bottom wall 21 constituting the shield case 2 and the pair of side walls 22 and the side walls 23 facing each other are directed from the bottom wall 21 and the one side wall 22 facing each other toward the printed circuit board 1 and the other side wall 23. Alternatingly, partition walls 24 that do not reach the printed circuit board 1 and the opposite side walls are stretched.

  As a result, a distribution accommodating portion 25 is formed between the printed circuit board 1 and the shield case case 2 so as to surround and accommodate the heat generating element 3, and this is a path through which the cooling medium 7 flows in the direction indicated by the arrow. 6a is an inflow port for allowing the cooling medium 7 to flow into the flow accommodating portion 25, and 6b is an outflow port for allowing the cooling medium 7 to flow out.

  In the configuration described above, in the drawing, the cooling medium flowing in from the inflow port 6 a below the right end flows along the partition wall 24 and reverses at the side wall 22. Then, it further flows along the partition wall 24, reverses at the side wall 23, and flows out from the outlet 6 b below the left end in the figure while repeating meandering in the direction indicated by the arrow. Note that although there is a gap between the surface of the printed circuit board 1 and the partition wall 24, not all of the cooling medium 7 flowing through the flow accommodating portion 25 flows in the direction of the arrow, but most of the cooling medium flows in the direction of the arrow. .

  According to the above-described configuration, the heat generating element 3 that is a heat generating part attached in the flow accommodating part 25 and the cooling member 32 attached to the surface of the heat generating element 3 are provided with the cooling medium 7 appropriately temperature-controlled in the shield case 2. Cooling is performed by press-fitting with a necessary pressure from an external refrigerator through the inflow port 6a. The cooling medium 7 press-fitted into the flow accommodating portion 25 from the inflow port 6a takes away heat from the flow heating element 3 as indicated by an arrow, and is discharged to the outside from the outflow port 6b.

  In addition, there exist some which were shown by the following patent documents as a prior art of a semiconductor cooling device.

Japanese Patent Laid-Open No. 10-51165

By the way, in the said prior art, most of the cooling media 7 which flowed in from the inflow port 6a heads for the outflow port 6b, meandering between the partition walls 24 in the arrow direction. Therefore, there are the following problems.
1) Since there is only one refrigerant flow path, the flowing refrigerant is gradually heated, and the temperature of the heating elements (IC, LSI, etc.) 3 differs on the same substrate.

2) Therefore, when the heating element to be cooled in the first stage is heated by the load and when it is not, the difference in temperature between the heating elements that come later becomes large.
3) In the memory tester, it is the driver and comparator mounted on the PE (pin electronics) that cause the temperature to increase due to the operation, and then the timing generator in the PE. The latter gives the accuracy of the tester. For this purpose, there are those that require temperature control as well as removal of heat generation.

4) Recent CMOS-based ICs have a difference in power consumption between operating and non-operating of 10 times or more, and such a structure cannot provide suitable characteristics.
5) Since the sealing part of the printed circuit board 1 and the shield case 2 is in contact with the metal foil (gold land) formed on the surface of the substrate by packing, the refrigerant leaks significantly depending on the surface state of the substrate.

  The present invention has been made to solve the above problems, and provides a cooling device that reduces the temperature difference between the cooling medium on the inflow side and the outflow side and reduces the leakage of the cooling medium from the shield case and the printed circuit board. The purpose is to do.

In order to solve the above problems, a cooling device according to the present invention is as follows.
A plurality of heating elements mounted in a grid on the printed circuit board;
A cooling jacket that covers the plurality of heating elements and is provided in parallel to the printed circuit board ;
A plurality of flow path members that are opposed to the respective rows of the heating elements mounted in a lattice shape and have a coupling flow path provided on the inner upper side of the cooling jacket;
An ejection hole formed in the plurality of flow path members so as to oppose each of the plurality of heating elements; an inlet provided in one of each of the coupling flow paths for allowing a refrigerant fluid to flow in via the distribution flow path;
An outlet for allowing the refrigerant fluid flowing in from the inlet to flow out from the other side of the combined flow path;
A collecting channel for collecting and flowing out the refrigerant fluid flowing out from the outlet;
One side is fixed to both sides of the flow path member across the flow of the refrigerant fluid, and is provided by connecting the distribution flow path and the collective flow path, and is perpendicular to the plane of the cooling jacket and the other side. A partition provided with a length that does not reach the surface of the printed circuit board ,
The inlet and the outlet are disposed between the partition and the partition, and the refrigerant fluid flows out of the outlet through the coupling channel from the inlet;
The refrigerant fluid that has flowed into the coupling channel from the inlet through the distribution channel is ejected above the heating element that is disposed to face the ejection hole, and the ejected refrigerant fluid is ejected through the outlet. characterized by being configured to flow out from the set flow path Te.

In claim 2 , in the cooling device according to claim 1 ,
The contact portion between the peripheral edge of the cooling jacket and the surface of the printed circuit board is a metal plate having a smooth surface that is liquid-tightly fixed on the printed circuit board, and packing of an elastic body attached to the peripheral edge of the cooling jacket. It is characterized by sealing through.

In claim 3, in the cooling device according to claim 1 or 2,
The refrigerant fluid is adjusted to a predetermined temperature and pressure.

In claim 4 , in the cooling device according to any one of claims 1 to 3 ,
The cooling jacket is provided on both sides of the printed circuit board.

As explained above, according to claim 1 of the cooling device according to the present invention,
A plurality of heating elements mounted in a grid on the printed circuit board;
A cooling jacket that covers the plurality of heating elements and is provided in parallel to the printed circuit board ;
A plurality of flow path members that are opposed to the respective rows of the heating elements mounted in a lattice shape and have a coupling flow path provided on the inner upper side of the cooling jacket;
An ejection hole formed in the plurality of flow path members so as to oppose each of the plurality of heating elements; an inlet provided in one of each of the coupling flow paths for allowing a refrigerant fluid to flow in via the distribution flow path;
An outlet for allowing the refrigerant fluid flowing in from the inlet to flow out from the other side of the combined flow path;
A collecting channel for collecting and flowing out the refrigerant fluid flowing out from the outlet;
One side is fixed to both sides of the flow path member across the flow of the refrigerant fluid, and is provided by connecting the distribution flow path and the collective flow path, and is perpendicular to the plane of the cooling jacket and the other side. A partition provided with a length that does not reach the surface of the printed circuit board ,
The inlet and the outlet are disposed between the partition and the partition, and the refrigerant fluid flows out of the outlet through the coupling channel from the inlet;
The refrigerant fluid that has flowed into the coupling channel from the inlet through the distribution channel is ejected above the heating element that is disposed to face the ejection hole, and the ejected refrigerant fluid is ejected through the outlet. and configured to flow out from the set flow path Te.
As a result, the temperature of the sprayed refrigerant can be made substantially the same, and the temperature difference between the heating elements can be reduced.

  The contact portion between the peripheral edge of the cooling jacket and the surface of the printed circuit board includes a metal plate having a smooth surface that is liquid-tightly fixed on the printed circuit board and an elastic packing attached to the peripheral edge of the cooling jacket. Since the cooling medium was adjusted to a predetermined temperature and pressure, the adhesion between the end portion of the cooling jacket and the printed circuit board was increased, and the leakage of the cooling medium could be reduced.

  Furthermore, since cooling jackets are provided on both sides of the printed circuit board, efficient cooling can be performed.

FIG. 1 is a block diagram showing an example of an embodiment of a cooling device of the present invention.
In FIG. 1, reference numeral 30 denotes a printed circuit board formed in a rectangular shape, and heating elements (IC, LSI, etc.) 31 are mounted on both sides of the printed circuit board 30 in a grid pattern. Reference numeral 32 denotes a cooling jacket, which is fixed in a liquid-tight manner so as to cover almost the entire front and back surfaces of the printed circuit board 30 including the heat generating elements 31.

  A partition 32 b that does not reach the surface of the printed circuit board 30 is provided above the inside of the cooling jacket 32, and a flow path member 32 a that constitutes a combined flow path, which will be described later, is provided. 33 is formed. Reference numeral 34 denotes a connector which is disposed outside the cooling jacket and transmits and receives an electrical signal to the heating element 30.

  Reference numeral 35 denotes a distribution channel formed along one side in the cooling jacket, and 36 denotes a collective channel formed along the other side in the cooling jacket so as to face the distribution channel 35. One end of the distribution flow path and the collective flow path is closed, the other end of the distribution flow path 35 is provided with an inlet 35a of the cooling medium 7, and the other end of the collective flow path 36 is flowed of the cooling medium 7. An outlet 35b is provided.

37 is a plurality of combined flow paths formed by connecting the distribution flow path 35 and the collective flow path 36, and is provided at three positions in the illustrated example, substantially perpendicular to the distribution flow path and the collective flow path, and It is arranged equally.
38a is an inlet for allowing the cooling medium to flow from the distribution flow path 35 to the coupling flow path 37, and 38b is for flowing the cooling medium from the heat generating element accommodating portion 33 in which the heat generating elements are disposed to the collective flow path 36. It is an outlet.

  Reference numeral 39 denotes a plurality of ejection holes formed approximately equally in the coupling flow path 37, and each ejection hole 39 is disposed substantially at the center of the heating element 30 fixed to the printed circuit board.

FIG. 2 is a diagram showing a fixed state of the printed circuit board 30 and the cooling jacket 32. In the figure, reference numeral 40 denotes a metal plate, which is formed along the peripheral end of the cooling jacket 32. At least one surface of the metal plate is processed smoothly by polishing or the like, and the other surface is liquid-tightly fixed by an adhesive 41. Reference numeral 42 denotes an elastic packing such as an O-ring, which is disposed in a groove 43 formed in accordance with a predetermined standard at the peripheral end of the cooling jacket 32.
With such a configuration, the cooling jacket and the printed circuit board are fixed in a liquid-tight manner by applying pressure by a fastening member (not shown).

Returning to FIG. 1, the cooling medium (for example, Florinert 3M product name) 7 that is adjusted to a predetermined temperature and pressure (for example, 2 kgf / cm ² ) from the cooling medium inlet 35 a and flows into the cooling medium inflow path 35 a is distributed. The flow path 35 is filled. And it flows in into the joint channel 37 through the three inflow ports 38a provided in this distribution channel, respectively.

The cooling medium 7 that has flowed into the coupling flow path 37 flows into the heating element housing portion 33 from the ejection holes 39, and is ejected above the heating elements 31 fixed below the ejection holes 39 to cool the heating elements 31.
Next, the cooling medium filled in the heat generating element accommodating portion 33 flows out to the collective flow path 36 through the four outlets 38 b arranged on both sides of the coupling flow path 37. The cooling medium 7 that has flowed out to the collective flow path 36 flows out of the cooling jacket via the cooling medium outflow path 35b.

  According to the above configuration, the cooling medium 7 filled in the distribution flow path 35 flows into the coupling flow path 37 almost simultaneously through the inflow port 38 a and is almost simultaneously injected into the heat generating element 31 to fill the heat generating element accommodating portion 33. The cooled cooling medium 7 flows out into the collecting channel almost simultaneously.

Therefore, each heating element 31 is always cooled by a cooling medium having substantially the same pressure and temperature, so that a difference in cooling temperature does not occur depending on the arrangement location.
Moreover, since the cooling jacket and the printed circuit board are fixed via a smooth metal plate, the cooling medium does not leak out.

  The above description merely shows a specific preferred embodiment for the purpose of explanation and illustration of the present invention. In the present embodiment, an example in which three coupling channels are provided has been described. However, the present invention is not limited to this embodiment and can be increased or decreased. Further, the number of heating elements is not limited to the present embodiment. Furthermore, the shape of the printed circuit board, the shape of the cooling jacket, the shape of the ejection holes, and the pressure can be appropriately changed. Therefore, the present invention is not limited to the above-described embodiments, and includes many changes and modifications without departing from the essence thereof.

It is the XX cross section block diagram of the top view (a) and (a) figure which shows one example of the cooling device which relates to this invention. It is explanatory drawing which shows the junction part of the cooling jacket of this invention, and a printed circuit board. It is a top view (a) which shows an example of the cooling device of a prior art example, b-b 'sectional drawing (b) of the (a) figure, and c-c' sectional drawing (c) of the (a) figure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,30 Printed circuit board 2 Shield case 3 High density LSI device 4, 41 O-ring 5, 34 Connector 6a, 38a Inlet 6b, 38b Outlet 7 Cooling medium 11 Gold land 21 Bottom wall 22, 23 Side wall 25 Distribution accommodating part 27 Sealing part 31 Heating element 32 Cooling jacket 33 Heating element accommodating part 35 Distribution flow path 35a Cooling medium inflow port 35b Cooling medium outflow port 36 Collective flow path 37 Coupling flow path 39 Spout 40 Metal plate 41 Adhesive 42 Elastic packing (O ring)
43 Groove

Claims (4)

A plurality of heating elements mounted in a grid on the printed circuit board;
A cooling jacket that covers the plurality of heating elements and is provided in parallel to the printed circuit board ;
A plurality of flow path members that are opposed to the respective rows of the heating elements mounted in a lattice shape and have a coupling flow path provided on the inner upper side of the cooling jacket;
An ejection hole formed in the plurality of flow path members so as to oppose each of the plurality of heating elements; an inlet provided in one of each of the coupling flow paths for allowing a refrigerant fluid to flow in via the distribution flow path;
An outlet for allowing the refrigerant fluid flowing in from the inlet to flow out from the other side of the combined flow path;
A collecting channel for collecting and flowing out the refrigerant fluid flowing out from the outlet;
One side is fixed to both sides of the flow path member across the flow of the refrigerant fluid, and is provided by connecting the distribution flow path and the collective flow path, and is perpendicular to the plane of the cooling jacket and the other side. A partition provided with a length that does not reach the surface of the printed circuit board ,
The inlet and the outlet are disposed between the partition and the partition, and the refrigerant fluid flows out of the outlet through the coupling channel from the inlet;
The refrigerant fluid that has flowed into the coupling channel from the inlet through the distribution channel is ejected above the heating element that is disposed to face the ejection hole, and the ejected refrigerant fluid is ejected through the outlet. cooling apparatus characterized by being configured so as to flow out from the set flow path Te.   The contact portion between the peripheral edge of the cooling jacket and the surface of the printed circuit board is a metal plate having a smooth surface that is liquid-tightly fixed on the printed circuit board, and packing of an elastic body attached to the peripheral edge of the cooling jacket. The cooling device according to claim 1, wherein the cooling device is sealed through a gap. The cooling device according to claim 1 or 2, wherein the refrigerant fluid is adjusted to a predetermined temperature and pressure.   The cooling device according to claim 1, wherein the cooling jacket is provided on both surfaces of the printed circuit board.

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