JP2001237503A - Wiring board and its thermal sheet and its thermal substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a mounting substrate with high density for achieving efficient cooling or constant temperature. SOLUTION: Conductive foil application substrates (2a and 2b) where conductive foil (3) is provided onto at least one surface are provided, a pattern circuit (4) where the conductive foil (3) is treated for forming and linear grooves (6a and 6b) where a specific place of the conductive foil (3) is locally recessed or is eliminated for forming are provided, the upper surfaces of the grooves (6a and 6b) are blocked for forming a fluid a fluid path (6) with a small sectional area, and a fluid-supplying device (9) for supplying fluid to the fluid path (6) is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board for appropriately maintaining the temperature of a mounting board on which electronic components are mounted, a heat sheet thereof, and a heat board thereof.

[0002]

2. Description of the Related Art As a conventional technique, a metal heat radiating plate having a large number of fins or a heat pipe is provided on a mounting board to radiate heat generated from an electronic component (IC) to the outside. there were.

[0003]

However, the above-mentioned prior art becomes large and the heat radiation efficiency decreases.
The present invention is to form a fluid path through which a fluid flows in a conductor foil-clad substrate or a conductor sheet constituting a wiring board,
It is an object of the present invention to obtain a novel wiring board having a small size and high heat dissipation (heat transfer) efficiency, a heat sheet thereof, and a heat board thereof.

[0004]

Means for Solving the Problems The present invention is configured as follows to achieve the above object. That is, a fluid passage having a small cross-sectional area is formed in a conductive sheet fixed to the wiring board. Further, the fluid path is formed by forming a linear groove on the surface of the sheet and closing the upper surface of the groove. In this case, the grooves are formed by etching a sheet made of the conductor. Also, a conductor foil-clad substrate provided with a conductor foil on at least one surface is provided, a predetermined portion of the conductor foil is notched or removed to form a linear groove, and the upper surface of the groove is closed and small. A fluid passage having a cross-sectional area is formed. In this case, the groove is formed by etching the conductor foil. Further, a micropump is provided on the conductor foil-clad substrate, and the micropump allows a fluid to flow through a fluid path. Also, a conductor foil-clad substrate provided with a conductor foil on at least one surface is provided, and a pattern circuit formed by removing both sides of the conductor foil-clad substrate, leaving a necessary portion of the conductor foil, A linear groove formed by locally recessing or removing a predetermined portion of the conductive foil other than the pattern circuit is provided, and a top surface of the groove is closed to form a fluid path having a small cross-sectional area, A fluid supply device for supplying a fluid to the fluid path is provided. In this case, the pattern circuit and the groove are formed by etching the conductive foil. Further, a fluid path is formed in a mounting portion of the electronic component connected to the pattern circuit. Further, a mounting portion of an electronic component connected to the pattern circuit is connected to a conductor foil on which a fluid path is formed by a through hole. Further, a part of the fluid path of the conductor foil-clad substrate having the pattern circuit and the fluid path is laterally separated from the mounting portion of the electronic component, and the separated fluid path is spread in a plane at a predetermined pitch. is there. In addition, a micropump is provided on the conductive foil-clad substrate having the pattern circuit and the fluid path, and the micropump allows a fluid to flow through the fluid path. A heating device (12) for heating the fluid path (6) is provided.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a cross-sectional view of a mounting board showing a first embodiment of the present invention, FIG. 2 is a plan view for explaining FIG. 1, FIG. 3 is an enlarged cross-sectional view of a portion A in FIG. 1, and FIG. FIG. 5 is an enlarged cross-sectional view of a part B of FIG. 1, FIG. 6 is an enlarged cross-sectional view of a part C of FIG. 1, FIG.
FIG. 8 is a cross-sectional view of a main part of a mounting board according to a third embodiment of the present invention.

In FIGS. 1 and 2, reference numeral 1 denotes a mounting board, and a large number of electronic components (I
C, LSI) 20, 20,... The wiring board 2 has a two-layer structure in this embodiment, and the conductor foil 3 is provided on each surface of two conductor foil-clad boards 2a and 2b each having a conductor foil 3 such as a copper foil or an aluminum foil. It has a predetermined pattern circuit 4, an electronic component mounting portion 5, and a patterned fluid path 6 formed by etching, and a through hole 7 is formed at a predetermined position on each of the conductor foil-clad substrates 2a and 2b. ing.

[0007] The fluid passage 6 allows a fluid (refrigerant fluid) such as water or air to flow, and is formed as follows. First, as shown in the lower part of FIGS. 3 and 4, when forming the fluid path 6 in the conductor foils 3a, 3b on the opposite side of the conductor foil-clad substrates 2a, 2b, ,
In a state where the conductor foil-clad substrates 2a and 2b are separated from each other,
At predetermined positions of the conductor foils 3a, 3b on the opposite side of 2b, the grooves 6a,
The conductor foil-clad substrates 2a and 2b are opposed to each other so that the grooves 6a and 6b face each other, and the conductor foils 3a and 3b on the opposite sides are integrally fixed (or fused). To form a fluid path 6. When the cross-sectional area of the fluid passage 6 may be small, one of the grooves 6a and 6b may be omitted. When it is desired to increase the cross-sectional area of the fluid path 6, the conductor foils 3a and 3b at the bottoms of the grooves 6a and 6b may be completely removed.

When the fluid path 6 is formed in the conductor foil 3 on the outer surface of each of the conductor foil-clad substrates 2a and 2b, as shown in the upper part of FIG. 6c made thin by etching, etching or laser processing
On the other hand, a groove 6d facing the groove 6c is formed in a separate conductor foil (sheet) 3d in the same manner as described above, and then the conductor foil 3d is made to face the grooves 6c, 6d. Fixed (or fused) to the conductor foil 3c on the outer surface side to
To form When the cross-sectional area of the fluid passage 6 may be small, one of the grooves 6c and 6d may be omitted as shown in FIG. When it is desired to increase the cross-sectional area of the fluid passage 6, the conductor foil-clad substrates 2a, 2b
The conductor foil 3c corresponding to the fluid path 6 on the side may be completely removed. The fluid path 6 is, as shown in FIG.
The electronic component 20 that generates heat during operation is formed in a meandering shape at a portion facing the mounting portion 5.

The communication between the fluid passages 6 formed on the upper and lower surfaces of the conductor foil-clad substrates 2a and 2b, or the heat transfer between the fluid passage 6 and the mounting portion 5 and between the fluid passage 6 and the pattern circuit 4 are shown in FIG. As shown in FIG. 5, the process is performed through the through hole 7.
That is, as shown in FIG. 3, the fluid passage 6 corresponding to the electronic component 20a on the left side of FIG. 1 has a first through hole 7a penetrating the upper substrate on the side adjacent to the fluid passage 6. And
The first through hole 7a connects the mounting portion 5 on which the electronic component 20a is mounted and the inner conductive foil 3 (3a) to cause heat exchange between the electronic component 20a and the fluid path 6.

An electronic component 20b at the middle between the right and left in FIG.
The upper and lower fluid passages 6, 6 corresponding to are as shown in FIG.
E.g. two second piercings through the upper substrate between each fluid path 6
A through hole 7b is formed so that a coolant fluid such as water or air can flow through the upper and lower fluid paths 6, 6 from the upper side to the lower side, for example, through the second through hole 7b. The upper and lower fluid paths 6, 6 corresponding to the right electronic component 20c in FIG. 1 have third through holes penetrating the two substrates between the fluid paths 6, as shown in the left part of FIG. 7c is formed so that a refrigerant fluid such as water or air can flow vertically through the upper and lower fluid paths 6 and 6, for example, in series through the third through hole 7c.

A thermal substrate 8 is provided on the right side of the mounting substrate 1 described above. As shown in FIGS. 1 and 2, the thermal substrate 8 has two sets of fluid passages 6 (6-1, 2) that are formed by etching a conductive foil 3 such as a copper foil or an aluminum foil on the lower surface and laying the conductive foil 3 in a meandering manner.
6-2), and micro pumps 9 (9a, 9a, 9b, 9b) are connected to both ends of each of the fluid paths 6-1 and 6-2. Each micro pump 9 comprises a water pump,
The driving is controlled by the control circuit 10. This control circuit 1
Numeral 0 controls the driving amount of each micropump 9 by inputting a signal from a temperature sensor 11 provided at the center of each of the fluid passages 6-1 and 6-2, and controls the temperature of each of the electronic components 20a and 20b. Are adjusted to appropriate temperatures. The fluid passage 6 may be a set.

In this embodiment, the electronic component 20 in which the fluid path 6-1 on the left side of the thermal board 8 is provided at the center on the left and right sides of the mounting board 1
b, and the fluid path 6-2 on the right side of the thermal board 8 is connected to the fluid path 6 corresponding to the electronic component 20a provided on the left side of the mounting board 1. Control circuit 10
By controlling the driving amount of each micro pump 9 by inputting the signals of the temperature sensors 11, 11,
The temperatures of a and 20b are set to appropriate temperatures. In FIG. 5, reference numeral 7d denotes a fourth through hole for connecting the fluid path 6 on the thermal board 8 side and the fluid path on the mounting board 1 side.

When the thermal substrate 8 is used for heat dissipation as described above, the thermal substrate 8 may be cooled by using a Peltier element. By doing so, the heat radiation effect of the thermal substrate 8 can be enhanced by reducing the size. Further, the outside air may be circulated to the surface of the thermal board 8 by a fan to enhance the heat radiation effect of the thermal board 8.

Reference numeral 12 denotes a heating device for heating the thermal substrate 8. The heating device 12 includes, for example, a surface heater 12a.
In FIG. 1, the temperature sensors 13 are fixed on the upper surface side of the thermal substrate 8 and the temperature sensors 13 are provided at the center of the mounting portions 5 of the left and right electronic components 20a and 20b. The control device 10 inputs the signal 13 to control the amount of current supplied to the surface heater 12a. As shown in FIG. 2, the heating device 12 connects a plus line L1 and a minus line L2 to predetermined fluid paths 6, for example, upstream and downstream ends of a fluid path 6-1 on the left side of the thermal board 8, and The fluid path 6-1 is a heater circuit, and the control device 1
In accordance with 0, the signals from the temperature sensors 13 and 13 may be input to control the amount of electricity supplied to the fluid passage 6-1. Providing such a heating device 12 is effective, for example, in raising the initial temperature of the electronic component to a predetermined value and stabilizing the operation at the time of startup.

According to the first embodiment, the fluid path 6 through which a fluid (refrigerant fluid) such as water or air flows is formed in the conductor foil 3 of the conductor foil-clad boards 2a and 2b constituting the wiring board 2. As a result, the heat transfer amount can be increased by reducing the size. Also, since the fluid path 6 is spread in a meandering manner on the surface of the substrate, the heat radiation area can be increased without increasing the thickness, and the high-density mounting substrate can be reduced in size and efficiently cooled. it can.

FIGS. 6 and 7 show a second embodiment. 1 and 2, reference numeral 15 denotes a mounting board, which is a soft board 17;
A wiring board 16 formed with a predetermined pattern circuit 18 is provided on the upper surface of the electronic component 20.
It is equipped with. A heat board 21 is provided on the upper surface of the mounting board 15.
Put on. This thermal substrate 21 is formed of a fluid path 24 formed by etching a conductive foil 23 on the lower surface of a soft substrate 22.
Having.

The fluid passage 24 is formed as follows. That is, a conductive foil-clad substrate 21a having a conductive foil (copper foil) 23a provided on the lower surface is provided, and the conductive foil 23a is etched or laser-processed to form a serpentine groove 2 on the lower surface.
4a, while the groove 2 facing the groove 24a is formed on the upper surface of a separate conductor foil (sheet) 23b in the same manner as described above.
4b, and then the conductor foil 23b is connected to each of the grooves 24a,
The fluid path 24 is formed by adhering (or fusing) to the conductor foil 23a on the conductor foil-clad substrate 21a side so that 24b faces each other. When the cross-sectional area of the fluid passage 24 may be small, one of the grooves 24a and 24b may be omitted. When it is desired to increase the cross-sectional area of the fluid path 24, the conductor foil 23a corresponding to the fluid path 24 on the conductor foil-clad substrate 21a side may be completely removed.

FIG. 8 shows a third embodiment. In FIG.
Reference numeral 15 denotes a mounting board similar to that of the above-described second embodiment. Reference numeral 25 denotes a heat sheet placed on the mounting board 15 and has a meandering fluid path 26. This fluid path 26 forms meandering grooves 26a, 26b formed by etching on opposing surfaces of two sheet-shaped conductor foils (copper foils) 25a, 25b, and then forms both conductor foils 25a, 25b. To each groove 26a,
26b is formed by facing and integrally fixing (or fusing) such that they face each other.

According to the second and third embodiments, the thermal substrate 2
1 and the heat sheet 25 are formed independently, so that they can be obtained at low cost and can be easily adapted to a mounting board of a different type, an existing mounting board, and the like. In addition,
Each of the fluid paths described above may be formed by plating (electroless plating).

[0020]

As is apparent from the above description, according to the present invention, since a fluid path having a small cross-sectional area is formed in a conductor foil or a conductor sheet, the fluid path is formed in the wiring board or the mounted electronic component. The high-density mounting board can be made small and efficiently cooled or kept at a constant temperature.

[Brief description of the drawings]

FIG. 1 is a sectional view of a mounting board according to a first embodiment of the present invention.

FIG. 2 is an explanatory plan view of FIG. 1;

FIG. 3 is an enlarged sectional view of a portion A in FIG.

FIG. 4 is an enlarged sectional view of a portion B in FIG. 1;

FIG. 5 is an enlarged sectional view of a portion C in FIG. 1;

FIG. 6 is a sectional view of a main part of a mounting board according to a second embodiment of the present invention.

FIG. 7 is an explanatory plan view of FIG. 5;

FIG. 8 is a sectional view of a main part of a mounting board according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mounting board 2 Wiring board 3 Conductor foil 4 Pattern circuit 5 Electronic component mounting part 6 Fluid path 7 Through hole 8 Heat board 9 Micro pump 10 Control circuit 11 Temperature sensor 12 (6-1) Heating device 12a Surface heater 13 Temperature sensor L1 plus line L2 minus line 15 mounting board 16 wiring board 17 board 18 pattern circuit 20 electronic component 21 heat board 22 board 23 conductor foil 24 fluid path 25 heat sheet 25a conductor foil 25b conductor foil 26 fluid path

Claims (13)

[Claims] 1. A conductive sheet (25a, 25b) fixed to a wiring board (16) is provided.
A heat sheet for a wiring board, wherein a fluid passage (26) having a small cross-sectional area is formed in b). 2. A linear groove (26a, 26b) is formed on the surface of a conductor sheet (25a, 25b).
2. The heat sheet for a wiring board according to claim 1, wherein the upper surface of 26b) is closed to form a fluid passage having a small cross-sectional area. 3. The heat sheet for a wiring board according to claim 2, wherein the grooves (26a, 26b) are formed by etching a conductive sheet (25a, 25b). 4. A conductive foil-clad substrate (21a) having a conductive foil (23) provided on at least one surface, and a predetermined portion of the conductive foil (23) is notched or removed to form a linear groove (21). 2
4a, 24b), and the upper surface of the groove (24a, 24b) is closed to form a fluid path (24) having a small cross-sectional area. 5. The groove (24a, 24b) is formed by etching a conductive foil (23).
The thermal board of the wiring board described. 6. A micropump (9) is provided on a conductor foil-clad substrate (2a, 2b), and a fluid is caused to flow through a fluid passage (6) by the micropump (9). A thermal board for the wiring board according to 5. 7. A conductor foil-clad board (2a, 2b) provided with a conductor foil (3) on at least one surface, and the conductor foil (3a) is provided on a surface of the conductor foil-clad board (2a, 2b). ) And a linear groove (6a, 6b) formed by locally recessing or removing a predetermined portion of the conductor foil (3). (6a, 6
A wiring board characterized by forming a fluid passage (6) having a small cross section by closing the upper surface of (b) and providing a fluid supply device (9) for supplying a fluid to the fluid passage (6). 8. A pattern circuit (4) and a groove (6a, 6b).
8. The wiring board according to claim 7, wherein the wiring board is formed by etching a conductive foil. 9. The wiring board according to claim 7, wherein a fluid path (6) is formed in the mounting portion (5) of the electronic component (20) connected to the pattern circuit (4). 10. A mounting portion (5) of an electronic component (20) to be connected to a pattern circuit (4) and a conductive foil (3) having a fluid path (6) connected by a through hole (7). The wiring board according to any one of claims 7 to 9, wherein: 11. An electronic component (20) comprising a part of a fluid path (6).
The wiring board according to any one of claims 7 to 10, wherein the mounting portion (5) is laterally separated from the mounting portion (5), and the separated fluid passages (6) are spread in a plane at a predetermined pitch. . 12. The fluid path (6) is connected to a micropump (9), and the micropump (9) allows the fluid to flow through the fluid path (6). The wiring board according to the item. 13. A heating device (1) for heating a fluid passage (6).
The wiring board according to any one of claims 7 to 12, wherein 2) is provided.