JP2008235496A - Cooling board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling board which efficiently moves heat from a plurality of heat generating elements to a channel through which a coolant circulates to efficiently dissipate heat from the heat generating element in response to an increase in the amount of generated heat. <P>SOLUTION: The cooling board includes a mounting board to which at least one heat generating element is connected thermally, and a coolant circulating means. The cooling board also includes a cooling channel layer which is connected thermally to the mounting board and through which the coolant circulates, heat conductive pins connecting the heat generating element thermally to the cooling channel layer, and a heat dissipater connected thermally to the cooling channel layer to dissipate heat moved to the cooling channel layer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cooling device that cools an element to be cooled such as a heating element by flowing a refrigerant through a fine flow path provided on a substrate or the like.

  Due to the increase in the heat generation amount and the heat generation density of CPUs, elements, etc., a high-performance heat sink excellent in heat dissipation efficiency is required. Furthermore, there is a need for a heat sink that can be made smaller and can be manufactured at low cost so as to be compatible with the environment in which it is used. Conventionally, in order to improve the performance of a heat sink, for example, the heat radiation fin is compared with the heat sink formed by joining the heat radiation fin to the other surface of the heat receiving plate where the heating element is thermally connected to one surface. An electric fan equipped with a centrifugal fan is attached to the side or top of the heat sink so that the cooling air can pass between them, and the cooling air is forcibly sent between the radiating fins by the rotation of the fan. It was released into the atmosphere.

Furthermore, heat is transferred to a position away from the heat receiving plate to which the heating element is thermally connected by a heat pipe in which one end is thermally connected to the heat receiving plate and a heat radiating fin is attached to the other end. Therefore, an electric fan for forced cooling is attached to the radiating fin, and cooling air is forcibly sent between the radiating fins by the rotation of the fan to dissipate the heat transmitted from the heating element into the atmosphere.
Even with the above-described method, it has become difficult to effectively dissipate heat corresponding to the increase in heat generated by the heating element.

  In order to cope with an increase in the amount of generated heat, a method of dissipating heat by providing a flow path and circulating a refrigerant is proposed. Japanese Patent Application Laid-Open No. 2004-134742 discloses a technique in which a microchannel (fine flow path) is provided inside a heat generating element, and a refrigerant is allowed to flow through the flow path to radiate heat. Furthermore, Japanese Patent Application Laid-Open No. 2005-33162 discloses a technique for dissipating heat by providing a flow path in an insulating layer or the like of a mounting substrate and flowing a refrigerant in the flow path.

JP 2004-134742 A JP-A-2005-33162

  According to the technique disclosed in Japanese Patent Application Laid-Open No. 2004-134742, since a microchannel (fine flow path) is provided in the heating element, electrical wiring for exchanging electrical signals in the heating element is provided. At the same time, it is necessary to connect the flow path of the refrigerant to an external heat dissipation device, but a special technique is required to satisfy these, and it has not been easy. In particular, when the size of the heat generating element is small, it is difficult to connect the refrigerant flow path and the heat dissipation device.

  According to the technique disclosed in Japanese Patent Application Laid-Open No. 2005-33162, a microchannel is provided in the substrate, and a resist insulating layer exists between the heat generating element and the microchannel. It was difficult to efficiently transmit the heat from the heating element to the microchannel. Furthermore, since the material used for the insulating layer is generally epoxy or bakelite having a low heat transfer coefficient, it is difficult to make good thermal contact between the heating element and the cooling channel.

  Accordingly, an object of the present invention is to provide a cooling substrate that can efficiently transfer the heat of the heating element to the flow path through which the refrigerant circulates and efficiently radiate the heat of the heating element in response to an increase in the amount of heat generation. It is to provide.

  The inventor has conducted extensive research to solve the above-described conventional problems. As a result, a cooling channel layer through which the refrigerant circulates is provided on the mounting substrate to which the heat generating element is thermally connected, and a heat conduction pin (for example, an electric signal is transmitted to the substrate from the heat generating element and the cooling channel layer) Pin may be used to communicate with the heat generating element), the heat of the heat generating element is efficiently transferred to the cooling channel layer refrigerant by the heat conduction pin and is radiated by the heat radiating fin or the like. It has been found.

  Furthermore, it has been found that by providing a plurality of the cooling channel layers superimposed on the mounting substrate, it is possible to efficiently move and dissipate the heat of the heating element having a higher heat generation density. Furthermore, it has been found that a large amount of heat can be dissipated to a higher degree by protruding a part of the cooling channel layer to the outside of the mounting substrate and thermally connecting the radiation fins to the protruding part.

Furthermore, it has been found that heat transfer is performed more effectively by providing a cooling channel layer to which the heat conducting pins are thermally connected, and a fine channel (microchannel) in the other cooling channel.
The present invention has been made based on the research results described above.

A first aspect of the cooling substrate according to the present invention includes a mounting substrate to which at least one heat generating element is thermally connected, and a coolant circulation means, and is thermally connected to the mounting substrate so that the coolant circulates. The cooling substrate includes a channel layer and a radiator that is thermally connected to the cooling channel layer and dissipates heat transferred to the cooling channel layer.

A second aspect of the cooling substrate of the present invention is a cooling substrate further comprising a heat conduction pin that thermally connects the heat generating element and the cooling channel layer.

  A third aspect of the cooling substrate of the present invention is a cooling substrate in which the entire cooling channel layer is formed inside the mounting substrate.

  According to a fourth aspect of the cooling substrate of the present invention, a main part of the cooling channel layer is formed inside the mounting substrate, a part of the cooling channel layer is formed outside the mounting substrate, and the radiator A cooling substrate thermally connected to the portion of the cooling channel layer;

  According to a fifth aspect of the cooling substrate of the present invention, the cooling substrate includes at least one other cooling channel layer formed to overlap the thickness direction of the mounting substrate, and the cooling channel layer, the other cooling channel layer, Are cooling substrates in communication with each other.

  A sixth aspect of the cooling substrate of the present invention is a cooling substrate in which the mounting substrate and the cooling channel layer are formed separately, and the cooling channel layer is thermally connected to one surface of the mounting substrate. is there.

  According to a seventh aspect of the cooling substrate of the present invention, the cooling substrate includes a heat receiving cover having a cooling flow path therein, and the cooling flow path of the heat receiving cover is connected to the cooling channel layer.

  An eighth aspect of the cooling substrate of the present invention is a cooling substrate in which the cooling channel of the heat receiving cover and the cooling channel layer are connected by a channel using a flexible substrate.

  A ninth aspect of the cooling substrate of the present invention is a cooling substrate in which the heat receiving cover is thermally connected to the upper surface of the heat generating element.

  A tenth aspect of the cooling substrate of the present invention is a cooling substrate in which the heat receiving cover is disposed in a thermally connected manner between the heat generating element and the mounting substrate.

  An eleventh aspect of the cooling substrate of the present invention is a cooling substrate in which the heat conducting pins use pins attached to the heat generating element for exchanging electrical signals with the substrate.

  A twelfth aspect of the cooling substrate according to the present invention is a cooling substrate in which fine flow paths are provided in the cooling channel layer and the cooling flow path, to which the heat conducting pins are thermally connected.

  In a thirteenth aspect of the cooling substrate of the present invention, a fine channel is provided in at least a part of the cooling channel layer and / or the heat source side of the cooling channel, and the remaining part has a larger area than the fine channel. A cooling substrate provided with a flow path having

  According to the cooling substrate of the present invention, a metal having good thermal conductivity can be used for the cooling channel layer, so that heat can be transferred to the cooling channel layer to improve the cooling performance. Since the microchannel is provided in a part of the cooling channel layer or another cooling channel, the thermal connection between the microchannel and the heating element is facilitated. In addition, a cooling device using a microchannel can be easily configured.

  Since the entire mounting substrate can be used as a cooling substrate, the heat from the heating element can be efficiently radiated. Since the cooling method using the inside of the mounting board does not require a separate space for a mechanism such as a pump for circulating the cooling water, it is possible to save space for the cooling parts.

  Even when a heat sink is mounted on a heating element, a smaller cooling substrate can be used than a heat sink used for a heating element mounted on a conventional substrate.

The cooling substrate of the present invention will be described with reference to the drawings.
One aspect of the cooling substrate of the present invention includes a mounting substrate to which at least one heat generating element is thermally connected, and a coolant circulation means, and is a cooling channel in which the coolant circulates by being thermally connected to the mounting substrate. A heat conduction pin that thermally connects the heating element and the cooling channel layer, and a radiator that dissipates heat that is thermally connected to the cooling channel layer and moved to the cooling channel layer. It is a cooling substrate.

  FIG. 1 is a schematic cross-sectional view illustrating one embodiment of the cooling substrate of the present invention. As shown in FIG. 1, the cooling substrate 1 of the present invention includes a mounting substrate 2 to which a heating element 5 is thermally connected on one surface, and a coolant circulation means 7, and is thermally connected to the mounting substrate. The cooling channel layer 3 in which the refrigerant circulates, the heat conduction pins 4 that thermally connect the heating elements 5 and the cooling channel layer 3, and the heat that is thermally connected to the mounting substrate 2 and moved to the cooling channel layer 3. And a heat dissipator 6 for dissipating the heat. In this aspect, the entire cooling channel layer is formed inside the mounting substrate.

  A cooling channel layer 3 provided with a cooling channel for circulating a coolant such as pure water is installed inside the mounting substrate 2 on which the heating elements of the cooling substrate 1 are mounted. The cooling channel layer 3 has a function of diffusing heat to the entire mounting board by forming a closed loop-shaped passage so as to flow through a predetermined portion of the mounting board 2 (determined by the arrangement of the heating elements), for example. The refrigerant circulates through the refrigerant circulation means 7. The cooling channel layer 3 is formed of a metal having good thermal conductivity such as copper or aluminum according to the refrigerant to be used. A heating element 5 such as a semiconductor element is mounted on one surface of the mounting substrate.

  A pin 9 for transmitting an electrical signal to the substrate is attached to the heating element 5. Among these pins, for example, a dummy pin or a ground (electrical ground) pin that is not used for an electric signal is used as the heat conduction pin 4, and the heating element 5 and the cooling channel layer 3 are formed by the heat conduction pin. Thermally connected (eg, through a socket or the like) can efficiently transfer heat from the heating element to the cooling channel layer.

When the ground pin functions as a heat conduction pin, the cooling channel layer can be shared with the ground (ground) layer.
Further, a portion of the cooling channel layer that is thermally connected to the heat generating element and the heat conducting pin and transfers heat between them is a fine channel (microchannel). The fine flow path is a flow path having a smaller cross-sectional area than the closed-loop path that forms the cooling channel layer, is connected to the closed-loop path to form a circulation path, and heat is increased by increasing the flow rate of the refrigerant flowing therethrough. The efficiency of exchange has been improved.
On the mounting board, a refrigerant circulating means 7 (in this embodiment, a pump) for circulating the refrigerant in the cooling channel layer is attached on the mounting board.

  Radiation fins 6 are attached to a part of the mounting substrate 2 so as to be thermally connected to the cooling channel layer. At this time, a heat conducting pin that performs the above-described function may be disposed between the heat radiating fin and the cooling channel layer to efficiently transfer the heat of the cooling channel layer to the heat radiating fin.

  As described above, the heat of a heating element such as a CPU mounted on the upper surface of the mounting board is transmitted through a dummy pin among the pins provided for transmission of electrical signals attached to the heating element, and mounted. It is transmitted to the cooling channel layer provided inside the substrate. The cooling channel layer is formed with a closed loop passage, and a coolant such as water is circulated in the interior by the coolant circulation means. The heat transferred to the cooling channel layer is transferred to the radiation fins provided in thermal connection with the cooling channel layer, and is radiated to the outside.

  As described above, by providing the heat conductive pins, the cooling channel layer, and the heat radiation fins on the mounting board, the heat from the heating element can be efficiently transmitted to the cooling channel layer, and the heat of the heating element can be effectively radiated. Can do. Furthermore, the cooling capacity of the cooling substrate can be further improved by providing the microchannel in the portion of the cooling channel layer corresponding to the position where the radiation fin is attached.

  In addition, due to space limitations, if the heat dissipation of the heat generating element cannot be sufficiently performed by the heat dissipation fin attached to the mounting board, a conventional heat sink is thermally connected to the upper surface of the heat generating element to provide sufficient cooling performance. May be obtained. In this case, since the heat sink attached to the upper surface of the heating element may be small, space can be saved.

  FIG. 2 is a schematic cross-sectional view illustrating another embodiment of the cooling substrate of the present invention. As shown in FIG. 2, in this aspect, the cooling substrate is the same cooling substrate except that the refrigerant circulating means of the aspect shown in FIG. 1 is replaced with a piezoelectric element. Also in this aspect, the entire cooling channel layer is formed inside the mounting substrate. That is, the cooling channel layer is provided in the mounting substrate, and the refrigerant circulation means is also provided in the mounting substrate. The refrigerant circulating means is composed of a pump using a piezoelectric element. According to this aspect, the cooling channel layer and the refrigerant circulation means 7 are integrated and disposed inside the mounting substrate. The piezoelectric element 7 is an element in which a piezoelectric body (dielectric material) is sandwiched between two electrodes. When an alternating current is passed through the electrodes of the piezoelectric element 7, the piezoelectric element 7 vibrates at a predetermined frequency. This vibration can be used to function as a pump and circulate coolant such as cooling water in the cooling channel layer.

  As described with reference to FIG. 1, heat of a heat generating element such as a CPU mounted on the upper surface of the mounting substrate is heat conduction among pins provided for transmission of electrical signals attached to the heat generating element. It is transmitted through a dummy pin (which may be a metal pin) that is not used and excellent in performance to a cooling channel layer provided inside the mounting board. The cooling channel layer is formed with a closed loop-shaped passage, and a coolant such as water circulates inside the cooling channel layer by the piezoelectric element 7 as the coolant circulation means. The heat transferred to the cooling channel layer is transferred to the radiation fins provided in thermal connection with the cooling channel layer, and is radiated to the outside.

  FIG. 3 is a schematic cross-sectional view illustrating another embodiment of the cooling substrate of the present invention. In the cooling substrate of this aspect, the main part (component mounting area) of the cooling channel layer is formed inside the mounting substrate, and a part of the cooling channel layer (heat dissipating area) is formed outside the mounting substrate. A vessel is thermally connected to the aforementioned portion of the cooling channel layer. That is, the length of the cooling channel layer in the longitudinal direction is longer than the length of the mounting substrate in the long axis direction, and a part of the cooling channel layer protrudes out of the mounting substrate.

  As shown in FIG. 3, the cooling substrate 1 of this aspect includes a mounting substrate 2 to which the heating element 5 is thermally connected on the upper surface, and a coolant circulation means 7. The cooling channel layer 3 circulates, the heat conduction pins 4 that thermally connect the heating elements 5 and the cooling channel layer 3, and the portion of the cooling channel layer 3 protruding from the mounting substrate 2 (heat dissipation area) thermally. And a radiator 6 that dissipates the heat transferred to the cooling channel layer 3.

  As is apparent from FIG. 3, an electric signal layer 8 is formed below the heat generating element, and an electric signal pin attached to the heat generating element extends downward to connect to the electric signal layer 8 to transmit the electric signal. I do. Of the electrical signal pins, a dummy pin (which may be a metal pin having excellent thermal conductivity) is used as a thermal conduction pin, and a cooling channel layer (below the electrical signal layer of the mounting substrate ( It extends to the component mounting area and is thermally connected.

  Also in this aspect, the piezoelectric element 7 is used as a pump and is provided inside the mounting substrate so as to be integrated with the cooling channel layer. The radiating fins 6 are thermally connected to the portion of the cooling channel layer (radiation area) protruding outside from the mounting substrate. In this aspect, the radiation fins 6 are thermally connected to the upper and lower surfaces of the portion of the cooling channel layer (radiation area) protruding outward from the mounting substrate. Since the cooling channel layer is formed of a metal having good thermal conductivity such as copper or aluminum, the cooling channel layer is effectively dissipated by the radiation fins.

  Of the pins provided for the transmission of electrical signals attached to the heat generating element 5 such as a CPU mounted on the upper surface of the mounting substrate 2, dummy pins that are not used and have excellent thermal conductivity 4 (which may be a metal pin) is transmitted to the cooling channel layer 3 (component mounting area) provided inside the mounting substrate 2. The cooling channel layer is formed with a closed loop-shaped passage, and a coolant such as water circulates inside the cooling channel layer by the piezoelectric element 7 as the coolant circulation means. The heat transferred to the cooling channel layer is transferred to the heat dissipating fin provided in thermal connection with the portion of the cooling channel layer protruding from the mounting substrate (heat dissipating area), and is radiated to the outside.

  FIG. 4 is a schematic cross-sectional view for explaining another aspect of the cooling substrate of the present invention. In this aspect, the cooling substrate 1 includes at least one other cooling channel layer 3B formed so as to overlap the thickness direction of the mounting substrate 2, and the cooling channel layer 3A and the other cooling channel layer 3B are mutually connected. To contact. The cooling substrate 1 of this aspect includes a mounting substrate 2 to which a plurality of heating elements 5-1, 5-2, and 5-3 are thermally connected, and refrigerant circulation means 7 A and 7 B. A cooling channel layer 3A formed in an overlapping manner in the thickness direction of the mounting substrate 2 through which the coolant circulates, at least one other cooling channel layer 3B, the heating element 5 and the cooling channel layer 3 The heat conduction pin 4 is connected thermally, and the radiator 6 is connected to the cooling channel layer 3 and dissipates the heat transferred to the cooling channel layer 3.

  As shown in FIG. 4, two heating elements 5-1 and 5-2 are mounted on the upper surface of the mounting board, and one heating element 5-3 is mounted on the lower surface of the mounting board. A cooling channel layer 3A is provided in the center of the mounting substrate, and another cooling channel layer 3B is provided in the lower part. The cooling channel layer 3A and another cooling channel layer 3B communicate with each other, and the refrigerant circulates throughout.

  The cooling channel layer 3A is divided into a component mounting area 3A-1 located in the mounting substrate and a heat dissipation area 3A-2 protruding outside the mounting substrate. In the heat radiating area 3A-2, the cooling channel layer is exposed to the outside of the mounting substrate, and the heat radiating fins 6 are attached to the upper and lower surfaces of the heat radiating fin 6 through a thermal interface material such as thermal conductive grease. A heating element 5-1 is mounted above the component mounting area 3A-1, and the heat conduction pins extend to the component mounting area 3A-1. A pump 7A using a piezoelectric element is provided integrally with the cooling channel layer at the end located in the mounting substrate of the cooling channel layer 3A.

  In another cooling channel layer 3B provided in the lower part of the mounting substrate, the heat conduction pins 4 attached to the heating elements 5-2 mounted on the upper surface of the mounting substrate are extended and thermally connected. The heat conduction pins 4 attached to the heat generating elements 5-3 mounted on the lower surface of the mounting substrate are extended and thermally connected. The electrical signal pins of the heating elements 5-1, 5-2, and 5-3 are electrically connected to the respective electrical signal layers provided in the mounting substrate. A pump 7B using a piezoelectric element is provided integrally with the cooling channel layer 3B at the end of the cooling channel layer 3B.

  The heat of the heat generating element 5-1 such as a CPU mounted on the upper surface of the mounting substrate 2 is transmitted through the heat conducting pin attached to the heat generating element, and the cooling channel layer 3A-1 ( To the component mounting area). The heat of another heating element 5-2 mounted on the upper surface of the mounting substrate and the heating element 5-3 mounted on the lower surface of the mounting substrate is transmitted to the respective heat conduction pins and provided below the mounting substrate. To the other cooling channel layer 3B. Each of the cooling channel layer and the other cooling channel layer is formed with a separate closed loop passage, and is partially connected to each other, and the piezoelectric channel elements 7A and 7B as the refrigerant circulation means are used to cool the cooling channel layer and the other cooling channel layer. A coolant such as water circulates inside the channel layer. The heat transferred to the cooling channel layer is transferred to the heat dissipating fin provided in thermal connection with the portion of the cooling channel layer protruding from the mounting substrate (heat dissipating area), and is radiated to the outside.

  According to this aspect, since the plurality of cooling channel layers are provided, the heat of the heating elements mounted on both surfaces of the mounting substrate can be radiated more effectively. Although a part of the cooling channel layer protrudes outside the mounting substrate, the plurality of cooling channel layers may be provided inside the mounting substrate.

  FIG. 5 is a schematic cross-sectional view illustrating another embodiment of the cooling substrate of the present invention. The cooling substrate of this aspect includes a heat receiving cover having a cooling flow path therein, and the cooling flow path of the heat receiving cover and the cooling channel layer are connected. That is, the cooling substrate further includes a heat receiving cover having a cooling flow path in which the coolant circulates in addition to the mounting substrate, and the cooling flow path of the heat receiving cover and the cooling channel layer provided in the mounting substrate. Has been contacted.

  As shown in FIG. 5, the cooling substrate 1 includes a mounting substrate 2 to which the heating elements 5 are thermally connected and a coolant circulation means 7, and is cooled by being thermally connected to the mounting substrate 2 and circulating the coolant. The channel layer 3, the heat receiving cover 10 having the cooling flow path 12 inside that is thermally connected to the upper surface of the heating element 5, and the heat that is thermally connected to the cooling channel layer 3 and moved to the cooling channel layer 3 And a radiator that dissipates heat. The cooling channel and the cooling channel layer are connected to each other by, for example, the flexible substrate 11. A heat conductive pin that thermally connects the heat generating element 5 and the cooling channel layer 3 may be further provided.

  In this aspect, as described above, the heat receiving cover having the cooling flow path in which the refrigerant circulates is thermally connected to the upper surface of the heating element so that the heating element can be cooled from the surface opposite to the mounting substrate. ing. The cooling channel of the heat receiving cover and the cooling channel layer provided in the mounting substrate are connected by a channel applying a flexible substrate or the like. A pump 7 using a piezoelectric element is provided integrally with the cooling channel layer 3 at the end of the cooling channel layer 3. The coolant circulates through the cooling channel of the heat receiving cover and the cooling channel layer provided inside the mounting substrate by the pump.

  A main part of heat of the heat generating element 5 such as a CPU mounted on the upper surface of the mounting substrate 2 is transmitted to a heat receiving cover attached to the upper surface of the heat generating element. The heat transmitted to the heat receiving cover is transmitted to the cooling channel layer 3 provided inside the mounting substrate 2 by the refrigerant flowing through the cooling flow path provided inside. The cooling channel and the cooling channel layer form a closed-loop passage as a whole, and a coolant such as water circulates inside. The heat transferred to the cooling channel layer is transferred to the radiation fins that are thermally connected to the cooling channel layer, and is radiated to the outside.

  FIG. 6 is a schematic cross-sectional view for explaining another aspect of the cooling substrate of the present invention. In the cooling substrate 1 of this aspect, the mounting substrate 2 and the cooling channel layer 3 are formed as separate bodies, and the heat receiving cover 10 having the cooling flow path 12 therein is provided between the heating element 5 and the mounting substrate 2. In preparation, the cooling flow path 12 of the heat receiving cover 10 and the cooling channel layer 3 are connected. That is, the cooling substrate 1 includes a cooling channel layer separately from the mounting substrate 2, and further includes a heat receiving cover having a cooling channel through which the coolant circulates between the heating element and the mounting substrate. The cooling channel of the cover and the cooling channel layer connected to the bottom of the mounting substrate are communicated with each other.

  As shown in FIG. 6, the cooling substrate 1 includes a mounting substrate 2 to which the heating element 5 is thermally connected and a coolant circulation means 7, and is thermally connected to the bottom of the mounting substrate 2 so that the coolant circulates. A cooling channel layer 3, a heat receiving cover 10 having a cooling channel 12 disposed between the heating element 5 and the mounting substrate 2 and being thermally connected to the heating element 5, and the cooling channel layer 3 being heated And a heat radiator 6 that dissipates heat transferred to the cooling channel layer 3. The cooling flow path 12 and the cooling channel layer 3 are mutually connected by the flexible substrate 11, for example.

  A main part of heat of the heat generating element 5 such as a CPU mounted on the upper surface of the mounting substrate 2 is transmitted to the heat receiving cover 10 provided between the heat generating element 5 and the mounting substrate 2. The heat transmitted to the heat receiving cover 10 is transmitted to the cooling channel layer 3 connected to the bottom of the mounting substrate 2 by the refrigerant flowing through the cooling flow path 12 provided inside. The cooling channel 12 and the cooling channel layer 3 form a closed-loop passage as a whole, and a coolant such as water circulates inside. The heat transmitted to the cooling channel layer 3 is transmitted to the radiation fins 6 provided in thermal connection with the cooling channel layer 3 and is radiated to the outside.

  As described above, the cooling performance can be further improved by providing the microchannel in the cooling flow path 12 of the heat receiving cover 10. As described above, in this embodiment, the heat generating element 5 and the cooling channel layer 3 are not thermally connected by the heat conductive pin 4, but the heat generating element 5 and the cooling channel layer are formed using the heat conductive pin 4. 3 may be thermally connected. Furthermore, as described with reference to FIG. 3 or FIG. 4, the cooling channel layer 3 may be provided with a component mounting area and a heat dissipation area.

  FIG. 7 is a schematic cross-sectional view for explaining another aspect of the cooling substrate of the present invention. As shown in FIG. 7, the cooling substrate 1 includes a cooling channel layer 3 provided in the mounting substrate 2. In this embodiment, the cooling channel layer 3 includes a fine flow path portion 13 provided in a portion on the heat source 5 side and a large area flow path portion 14 having a large area in the remaining portion. When the heat receiving cover is provided, the cooling flow path 12 may include the same fine flow path section 13 and large area flow path section 14 as described above. The features shown in FIG. 7 can be appropriately incorporated into the other modes described above.

  According to the present invention, it is possible to provide a cooling substrate capable of efficiently transferring heat of a heat generating element to a flow path through which a refrigerant circulates and efficiently dissipating heat of the heat generating element in response to an increase in the amount of heat generated. Can do.

FIG. 1 is a schematic cross-sectional view illustrating one embodiment of the cooling substrate of the present invention. FIG. 2 is a schematic cross-sectional view illustrating another embodiment of the cooling substrate of the present invention. FIG. 3 is a schematic cross-sectional view illustrating another embodiment of the cooling substrate of the present invention. FIG. 4 is a schematic cross-sectional view for explaining another aspect of the cooling substrate of the present invention. FIG. 5 is a schematic cross-sectional view illustrating another embodiment of the cooling substrate of the present invention. FIG. 6 is a schematic cross-sectional view for explaining another aspect of the cooling substrate of the present invention. FIG. 7 is a schematic cross-sectional view for explaining another aspect of the cooling substrate of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cooling board 2 Mounting board 3 Cooling channel layer 4 Heat conduction pin 5 Heat generating element 6 Radiation fin 7 Refrigerant circulation means 8 Electric signal layer 9 Electric signal pin 10 Heat receiving cover 11 Flexible substrate 12 Cooling flow path 13 Fine flow path part 14 Large area Channel part

Claims (13)

A mounting substrate to which at least one heating element is thermally connected;
A cooling channel layer that includes a refrigerant circulation means and is thermally connected to the mounting substrate and circulates the refrigerant;
A cooling substrate comprising: a heat radiator that is thermally connected to the cooling channel layer and dissipates heat transferred to the cooling channel layer.   The cooling substrate according to claim 1, further comprising a heat conductive pin that thermally connects the heat generating element and the cooling channel layer.   The cooling substrate according to claim 1 or 2, wherein the entire cooling channel layer is formed inside the mounting substrate.   A main part of the cooling channel layer is formed inside the mounting substrate, a part of the cooling channel layer is formed outside the mounting substrate, and the radiator is thermally applied to the part of the cooling channel layer. The cooling substrate according to claim 1, wherein the cooling substrate is connected.   The at least one other cooling channel layer formed to overlap the thickness direction of the mounting substrate, and the cooling channel layer and the other cooling channel layer are in communication with each other. 5. The cooling substrate according to 2 or 4.   The cooling substrate according to claim 1, wherein the mounting substrate and the cooling channel layer are formed separately, and the cooling channel layer is thermally connected to one surface of the mounting substrate.   The cooling substrate according to any one of claims 1 to 6, further comprising a heat receiving cover having a cooling flow path therein, wherein the cooling flow path of the heat receiving cover and the cooling channel layer are connected to each other.   The cooling substrate according to claim 7, wherein the cooling flow path of the heat receiving cover and the cooling channel layer are connected by a flow path using a flexible substrate.   The cooling substrate according to claim 7 or 8, wherein the heat receiving cover is thermally connected to an upper surface of the heating element.   The cooling substrate according to claim 7 or 8, wherein the heat receiving cover is arranged to be thermally connected between the heating element and the mounting substrate.   The cooling substrate according to any one of claims 1 to 10, wherein the heat conducting pin uses a pin attached to the heating element for exchanging an electric signal with the substrate.   The cooling substrate according to any one of claims 7 to 11, wherein a fine channel is provided in a portion of the cooling channel layer and the cooling channel to which the heat conducting pins are thermally connected. The fine channel is provided in at least a part on the heat source side of the cooling channel layer and the cooling channel, and the remaining part is provided with a channel having a larger area than the fine channel. The cooling substrate according to any one of 11.

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