JP2014192346A - Printed wiring board, temperature control program therefor, temperature control method therefor, manufacturing method therefor, and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize a temperature of a printed wiring board on which a heating component is mounted.SOLUTION: A printed wiring board, on which electronic components (4, 41, 42...4N) are mounted, includes: a fluid (low boiling point solvent 18 and fluid 20) that flows while absorbing heat from the electronic components; and a flow pass (circulation path 16) formed in isolation layers (14, 14-1) on a high-temperature side and a low-temperature side or a conductor layer. The fluid having absorbed the heat from the electronic components flows through the flow pass and moves from the high-temperature side to the low-temperature side. Thus, a temperature of the printed wiring board is uniformized.

Description

The technology of the present disclosure relates to a printed wiring board on which electronic components are mounted, a thermal control program thereof, a thermal control method thereof, a manufacturing method thereof, and an electronic apparatus.

  Electronic devices such as portable terminal devices and personal computers (PCs) are being made thinner and smaller. The number of components mounted on the printed circuit board mounted on the electronic device is large, the mounting density of electronic components is increased due to thinning and miniaturization, and the heat density due to the denseness of heat generating components is increased. In a multi-functional and highly functional electronic device, for example, a CPU (Central Processing Unit) mounted on a printed wiring board is increased in speed, and the operating temperature is increased. In such a printed wiring board, measures against high temperatures are taken.

Regarding heat release from a printed wiring board, it is known to dispose a metal pipe in an insulating layer of the printed wiring board and circulate a liquid through the metal pipe (for example, Patent Document 1, Patent Document 2, Patent Document 3). ). It is known that an electronic device includes a ceramic substrate, and a cooling liquid is circulated by forming a cavity in the ceramic substrate (for example, Patent Document 4). It is known that a printed wiring board has a tube, a liquid is introduced into the tube, circulated, and cooled (for example, Patent Document 5). It is known that a cavity is formed in a substrate on which an electronic component is mounted, and this cavity is filled with a refrigerant (for example, Patent Document 6). It is known that a coolant channel formed in a printed wiring board is formed by etching a constituent material of the printed wiring board (for example, Patent Document 7).

JP 2006-032708 A Japanese Patent Laid-Open No. 2006-041024 JP 2006-041025 A Japanese Patent Laid-Open No. 02-043794 JP 07-297505 A JP 2002-329938 A JP 2006-261239 A

  By the way, in an electronic device such as a PC or a server computer, a fan (air cooling method), a conduction cooling (water cooling method), or the like is used to cool a heat generating component mounted on a printed wiring board. In an electronic device such as a portable terminal device that places importance on small size, there is a problem that mounting of cooling parts similar to that of a large electronic device is restricted and heat dissipation efficiency is low. Moreover, there are problems that heat generation and local overheating of the electronic device cause functional deterioration and uncomfortable feeling to the user.

  Therefore, in view of the above problems, an object of the disclosed technology is to equalize the temperature of the printed wiring board on which the heat generating component is mounted.

Another object of the present disclosure is to prevent overheating of an electronic device including a printed wiring board on which a heat generating component is mounted.

In order to achieve the above object, a technique of the present disclosure is a printed wiring board on which an electronic component is mounted, and a liquid that absorbs and flows heat from the electronic component, and a high-temperature side and a low-temperature side insulating layer or conductor A flow path formed in the layer is included. The liquid that has absorbed heat from the electronic component flows in the flow path and moves from the high temperature side to the low temperature side. Thereby, the printed wiring board is soaked.

  According to the disclosed technique, any of the following effects can be obtained.

  (1) Since the liquid that has absorbed the heat of the components mounted on the printed wiring board moves from the high temperature side to the low temperature side, the temperature of the printed wiring board is equalized.

  (2) By overheating, local overheating of the printed circuit board is avoided.

Other objects, features, and advantages of the present invention will become clearer with reference to the accompanying drawings and each embodiment.

It is a figure which shows an example of the printed wiring board which concerns on 1st Embodiment. It is a figure which shows the portable terminal device with which the printed wiring board was mounted. It is a figure which shows the printed wiring board containing the circulation path of a low boiling-point solvent, and its cross section. It is a figure which shows the flow of a low boiling-point solvent. It is a figure which shows soaking | uniform-heating of the printed wiring board by the flow of a low boiling-point solvent. It is a figure which shows an example of the printed wiring board which concerns on 2nd Embodiment. It is a figure which shows a micro screw and the VIIB-VIIB sectional view of FIG. It is a figure which shows an example of the control apparatus of a micro screw. It is a flowchart which shows the process sequence of flow control. It is a figure which shows the modification of the control apparatus of a micro screw. It is a flowchart which shows the process sequence of flow control. It is a figure which shows an example of the printed wiring board which concerns on 3rd Embodiment. It is a figure which shows the control apparatus of a cylinder apparatus. It is a figure which shows an example of the portable terminal device which concerns on 4th Embodiment. It is a figure which shows soaking | uniform-heating and thermal diffusion of a printed wiring board. It is a figure which shows the manufacturing process of the printed wiring board which concerns on 5th Embodiment. It is a figure which shows the circulation path of a printed wiring board.

[First Embodiment]

  FIG. 1 shows a printed wiring board according to the first embodiment. FIG. 2 shows a portable terminal device on which a printed wiring board is mounted. The configuration illustrated in FIGS. 1 and 2 is an example, and the technology of the present disclosure is not limited to the configuration illustrated in FIGS. 1 and 2.

  A plurality of electronic components 41, 42, 43,... 4N for configuring a mobile terminal device that is an example of an electronic device are mounted on the printed wiring board 2-1 illustrated in FIG. These electronic components 41, 42, 43... 4N include various types such as those that generate significant heat and others. A CPU (Central Processing Unit), a battery, an LCD (Liquid Crystal Display), and the like generate heat during operation, and thus are heat generating components. Such heat generating components serve as a heat source. Mechanical parts such as connectors are parts with low heat generation.

  In the component mounting area 6-1 of the printed wiring board 2-1, a large number of components including highly exothermic components are mounted in a concentrated manner. In the other area 6-2, parts with low heat generation and the mounting density of the parts are low. In the printed wiring board 2-1, the area 6-1 is a high temperature side including a heat source having a high component mounting density. The other area 6-2 is the low temperature side.

  This printed wiring board 2-1 is mounted on the portable terminal device 8 and housed in the housing 10 as shown in FIG. The mobile terminal device 8 is an example of an electronic device according to the present disclosure. FIG. 2 shows the printed wiring board 2-1 in the housing 10 with the rear panel removed. The housing 10 is, for example, a synthetic resin molded body. A battery 12 is installed in the housing 10 on the back side of the printed wiring board 2-1.

  FIG. 3A shows a part of the printed wiring board 2-1 including the liquid flow path cut away. FIG. 3B shows a cross section taken along line IIIB-IIIB in FIG. The printed wiring board 2-1 includes an insulating layer 14. A circulation path 16 is formed in the insulating layer 14. This circulation path 16 is an example of a flow path. This circulation path 16 is a loop-shaped flow path formed including the areas 6-1 and 6-2. As shown in FIG. 3B, the circulation path 16 is filled with a low-boiling point solvent 18 that circulates in the insulating layer 14 on the high temperature side and the low temperature side. The low boiling point solvent 18 is an example of a liquid that absorbs the heat of the electronic component 4 and flows from the high temperature side to the low temperature side.

  The low boiling point solvent 18 is, for example, a solvent such as Fluorinert (registered trademark). Fluorinate, which is an example of the low boiling point solvent 18, is excellent in thermal characteristics and has a property of rapidly transferring heat. For example, “FC72” of this fluorinate has a boiling point of 56 ° C. and a pour point of minus 90 ° C. In such a low boiling point solvent 18, the heat of the electronic component 4 (any one of electronic components 41, 42, 43... 4N or 2 or more) on the area 6-1 side is boiled and boiled. Convection occurs. This natural convection is a flow that occurs from the high temperature side to the low temperature side, and this low boiling point solvent 18 functions as a heat transfer capability.

  According to such a configuration, when the low boiling point solvent 18 on the area 6-1 side receives heat from the heat source on the area 6-1 side, the low boiling point solvent 18 has, for example, an arrow a as shown in FIG. , Flow occurs. As a result, the low-boiling point solvent 18 having a high temperature moves to the area 6-2 on the low temperature side. The low-boiling point solvent 18 on the low temperature side pushed by the low-boiling point solvent 18 moves to the high-temperature area 6-1 and absorbs heat from the area 6-1 side.

  The heat transfer is caused by the circulation of the low boiling point solvent 18, and the heat diffusion is performed by the heat transfer. That is, as shown in FIG. 5, the heat in the high-temperature area 6-1 is diffused into the low-temperature area 6-2 as shown by the arrow b. As a result, the temperature on the area 6-1 side decreases and the temperature on the area 6-2 side increases. As a result, the printed wiring board 2-1 is soaked and local overheating on the area 6-1 side can be prevented.

<Effect of the first embodiment>

  (1) In the first embodiment, the low-boiling point solvent 18 is used, and the thermal diffusion uses the self-convection property of the low-boiling point solvent 18. Due to this thermal diffusion, the low boiling point solvent 18 that has absorbed the heat of the components mounted on the printed wiring board 2-1 moves from the high temperature side to the low temperature side, so that the printed wiring board 2-1 can be uniformly heated.

  (2) Local overheating concentrated on the area 6-1 can be prevented, and heat radiation and cooling of the printed wiring board 2-1 can be achieved by heat equalization by thermal diffusion.

[Second Embodiment]

  FIG. 6 shows a printed wiring board according to the second embodiment. The configuration illustrated in FIG. 6 is an example, and the technology of the present disclosure is not limited to the configuration illustrated in FIG.

  The above-described circulation path 16 is formed on the printed wiring board 2-2. The circulation path 16 is filled with a liquid 20. As the liquid 20, the low boiling point solvent 18 described above may be used, and other solvents such as a fluid such as pure water may be used.

  A micro screw 22 is installed in the circulation path 16. The micro screw 22 is an example of a circulation means for the liquid 20. The micro screw 22 is disposed so as to be rotatable in the flow direction of the liquid 20.

  The micro screw 22 is provided with a cylindrical screw body 24 as shown in FIG. The screw body 24 is provided with a drive motor 26. A spiral wing 28 is provided on the outer surface of the screw body 24. Lead wires 30-1 and 30-2 are drawn out to the drive motor 26. The lead wire 30-1 is the anode side, and the lead wire 30-2 is the ground side. Therefore, when the spiral blade 28 is rotated together with the screw main body 24 in the liquid 20 by the drive motor 26, the micro screw 22 can cause the liquid 20 to flow by the rotation of the spiral blade 28.

  FIG. 7B shows a cross section taken along the line VIIB-VIIB in FIG. Grooves 34 are formed in the insulating layer 14 of the printed wiring board 2-2 in a circular shape. That is, the circulation path 16 includes a circular groove 34. A first metal layer 36 is formed in the groove 34, and a second metal layer 38 is formed on the surface of the metal layer 36. The metal layer 36 is an example of a ground conductor. The metal layer 38 is a protective layer for the insulating layer 14. With the metal layers 36 and 38, the liquid 20 is confined in the circulation path 16 that is the groove 34, and the liquid 20 is prevented from flowing out. The metal layer 36 is formed by, for example, copper plating. The metal layer 38 is formed by nickel-copper plating, for example. In FIG. 6 and FIG. 7, the upper surface of the groove 34 is in an open state, but is closed by a blocking member (not shown). As a result, the liquid 20 is confined and circulated inside the circulation path 16.

  Connection terminals 50-1 and 50-2 are installed on the bottom surface of the groove 34 in the installation part of the micro screw 22. The connection terminal 50-1 is insulated from the connection terminal 50-2. That is, the metal layer 38 is provided with an opening 52 for each of the connection terminals 50-1 and 50-2, and the insulating layer 54 is provided on the metal layer 36 side. The connection terminal 50-2 is connected to the metal layer 36 and is held at the ground potential (GND).

  FIG. 8 shows a control device for the micro screw 22. The control device 56-1 is configured by a computer and is mounted on the printed wiring board 2-2. The controller 56-1 includes a processor 58. The processor 58 is an example of a control unit. A ROM (Read-Only Memory) 60, a RAM (Random-Access Memory) 62, and a drive unit 64 are connected to the processor 58. The processor 58 executes an OS (Operating System) and a control program. The ROM 60 stores an OS and a control program. The RAM 62 is a work area.

  The micro screw 22 is connected to the drive unit 64. The micro screw 22 receives the drive output from the drive unit 64 and operates.

  FIG. 9 shows a processing procedure for flow control of the liquid 20. The processing procedure illustrated in FIG. 9 is an example of the thermal control program and the thermal control method of the present disclosure. In this processing procedure, the operation of the mobile terminal device 8 including the electronic component 4 mounted on the printed wiring board 2-2 is monitored by the processor 58 (S11). It is determined whether or not the mobile terminal device 8 is operating (S12). If not operating (S12-NO), the operation monitoring is continued.

  If it is operating (S12-YES), the drive motor 26 of the micro screw 22 is driven (S13). Thereby, the liquid 20 circulates in the circulation path 16.

  After this driving, operation monitoring is performed (S14). If the portable terminal device 8 continues operation (S15-NO), the driving of the micro screw 22 is continued (S13).

  If the portable terminal device 8 has stopped operating (S15-YES), the driving of the micro screw 22 is stopped (S16). In this case, the driving of the micro screw 22 may be stopped after a predetermined time has elapsed since the operation of the mobile terminal device 8 was stopped.

  FIG. 10 shows a modification of the control device for the micro screw 22. The control device 56-2 is configured by a computer and is mounted on the printed wiring board 2-2. In the control device 56-2, a temperature sensor 66 is provided in the configuration of the control device 56-1 (FIG. 8). Since the other configuration is the same as that of the control device 56-1, the same reference numerals are given and the description thereof is omitted.

  FIG. 11 shows a procedure for controlling the flow of the liquid 20. The processing procedure illustrated in FIG. 11 is an example of the thermal control program and the thermal control method of the present disclosure. In this processing procedure, the temperature sensor 66 detects the temperature of the insulating layer 14 of the printed wiring board 2-2 or the electronic component 4. The temperature is monitored based on the detected temperature (S21). It is determined whether or not the detected temperature is equal to or higher than a certain temperature (threshold) (S22). If the detected temperature is lower than a certain temperature (S22-NO), temperature monitoring is continued. In this case, the value of the constant temperature is, for example, a value about the body temperature.

  If the detected temperature is equal to or higher than a certain temperature (S22-YES), the drive motor 26 of the micro screw 22 is driven (S23). Thereby, the liquid 20 circulates in the circulation path 16.

  After this driving, temperature monitoring is performed (S24). If the detected temperature is equal to or higher than a certain temperature (S25-YES), the driving of the micro screw 22 is continued (S23).

  If the detected temperature is lower than a certain temperature (S25-NO), the driving of the micro screw 22 is stopped (S26), and the process returns to S21. The same processing procedure is continued.

<Effects of Second Embodiment>

  (1) According to such a configuration, the liquid 20 in the high-temperature area 6-1 circulates to the low-temperature area 6-2 due to the flow of the liquid 20, and heat is transferred by the flow from the high-temperature side to the low-temperature side. Can be made. Thereby, the heat equalization of the printed wiring board 2-2 is achieved.

  (2) Similar to the first embodiment, in the second embodiment, the local overheating concentrated on the area 6-1 can be prevented by the flow of the liquid 20, and by the soaking by the thermal diffusion, Heat dissipation and cooling of the printed wiring board 2-2 are achieved.

  (3) If the driving of the micro screw 22 is stopped after a lapse of a predetermined time since the operation of the mobile terminal device 8 is stopped, the heat storage state can be avoided and the temperature of the printed wiring board 2-2 can be equalized.

[Third Embodiment]

  FIG. 12 shows a printed wiring board according to the third embodiment. A cylinder device 68 is installed in the circulation path 16 of the printed wiring board 2-3. The cylinder device 68 is an example of a circulation means for the liquid 20. The cylinder device 68 is provided with a piston 70 so as to be slidable. A swing plate 74 is provided on the plunger 72 of the piston 70. In the cylinder device 68, the piston 70 is slid to move the swing plate 74 forward and backward, thereby causing the liquid 20 to flow.

  A temperature sensor 66 is installed on the insulating layer 14 of the printed wiring board 2-3. The temperature sensor 66 detects the temperature of the insulating layer 14 or the electronic component 4.

  FIG. 13 shows the control device 56-3 of the cylinder device 68. The control device 56-3 includes a drive unit 76 of the cylinder device 68 controlled by the processor 58. The drive unit 76 may be constituted by, for example, a solenoid that slides on the piston 70 of the cylinder device 68.

  In such a configuration, the temperature sensor 66 detects the temperature of the printed wiring board 2-3. If the detected temperature is equal to or higher than a certain temperature, the processor 58 gives a drive signal to the drive unit 76. This drive signal is a switching signal, for example, and performs electromagnetic control of the cylinder device 68. The flow control described above (FIG. 11) may be used for this control. By this control, the piston 70 is slid left and right in the figure (FIG. 13), and the swing plate 74 is swung. Thereby, the flow shown by the arrow c can be generated in the liquid 20 in the circulation path 16. As a result, the liquid 20 in the circulation path 16 can be circulated in the direction indicated by the arrow d, for example.

<Effect of the third embodiment>

  By such circulation, the liquid 20 superheated on the high temperature side flows to the low temperature side, heat transfer occurs, and thermal diffusion is performed. Therefore, it is possible to equalize the temperature of the printed wiring board 2-3.

[Fourth Embodiment]

  FIG. 14A shows a cross section of a mobile terminal device according to the fourth embodiment. The portable terminal device 8 includes the above-described printed wiring board 2-1.

  A casing 78 of the mobile terminal device 8 is formed by a front case 80 and a rear case 82. An LCD panel 84 is installed on the front case 80. A metal frame 86 is disposed on the back side of the LCD panel 84. A printed wiring board 2-1 and a battery 12 are disposed on the back side of the metal frame 86.

  An electronic component 44 is disposed on the upper surface of the printed wiring board 2-1. The electronic component 44 is, for example, a heat generating component. This electronic component 44 is connected to the conductor pattern of the printed wiring board 2-1 by solder 88. A diffusion sheet 90-1 is installed in close contact between the electronic component 44 and the metal frame 86. In such a configuration, the heat of the electronic component 44 is transmitted from the diffusion sheet 90-1 to the metal frame 86 and the housing 78 and diffused. That is, the diffusion sheet 90-1 is a thermal diffusion path. In this thermal diffusion path, for example, thermal diffusion of about 0.3 [W / m · K] is obtained.

  The above-described circulation path 16 is formed in the insulating layer 14 of the printed wiring board 2-1. The circulation path 16 is filled with the low boiling point solvent 18 described above, and the low boiling point solvent 18 can be circulated in the circulation path 16.

  A plurality of electronic components 45, 46, and 47 are installed on the back side of the printed wiring board 2-1. Similar to the electronic component 44, the electronic component 47 is connected to the conductor pattern of the printed wiring board 2-1 by solder 88. A diffusion sheet 90-2 is installed in close contact between the electronic components 45, 46, 47 and the rear case 82. In such a configuration, heat generated by the electronic components 45, 46, 47 is transmitted from the diffusion sheet 90-2 to the rear case 82 and diffuses to the rear case 82 side. That is, the diffusion sheet 90-2 is a thermal diffusion path. In this thermal diffusion path, as described above, for example, thermal diffusion of about 0.3 [W / m · K] is obtained.

  14B shows a cross section along line XIVB-XIVB in FIG. 14A. As described above, the circulation path 16 formed in the insulating layer 14 of the printed wiring board 2-1 circulates over the areas 6-1 and 6-2 (FIG. 3), and fills the circulation path 16. The low-boiling point solvent 18 thus moved can move from the high temperature side to the low temperature side. Since the circulation path 16 and the low boiling point solvent 18 are as described above, description thereof will be omitted.

  FIG. 15 shows soaking and thermal diffusion of the printed wiring board 2-1 due to the movement of the low boiling point solvent 18. For example, the low-boiling point solvent 18 that has absorbed heat from the electronic components 44 and 47 and has a high temperature boils by endotherm, moves from the high temperature side to the low temperature side, and moves the heat. Arrows e, f, g, and h indicate heat transfer by the low boiling point solvent 18. By this heat transfer, the printed wiring board 2-1 is soaked.

  The heat of the electronic component 44 is diffused to the metal frame 86 as indicated by arrows i and j by the diffusion sheet 90-1. The heat of the electronic component 47 is diffused to the rear case 82 by the diffusion sheet 90-2 as indicated by arrows k and l.

<Effect of the fourth embodiment>

  According to such a configuration, thermal diffusion by the diffusion sheets 90-1 and 90-2 can be obtained along with the soaking by circulation of the low boiling point solvent 18 on the printed wiring board 2-1 side. Thereby, local overheating of the mobile terminal device 8 is prevented, and a cooling effect by heat radiation is obtained.

[Fifth Embodiment]

  FIG. 16 shows a process for manufacturing a printed wiring board according to the fifth embodiment. This manufacturing process is an example of a method for manufacturing a printed wiring board according to the present disclosure.

  This manufacturing process shows, for example, a process of forming the circulation path 16 of the printed wiring board 2-1. The printed wiring board 2-1 used in this manufacturing process includes an insulating layer 14-1 on the upper layer side and an insulating layer 14-2 on the lower layer side.

<Formation process of printed wiring board 2-1>

  The insulating layers 14-1 and 14-2 of the printed wiring board 2-1 are formed of an insulating resin. An insulating layer 14-2 is formed, a conductor layer 92 is formed on the upper surface of the insulating layer 14-2, and an insulating layer 14-1 is sequentially formed on the upper surface of the conductor layer 92. The conductor layer 92 formed between the insulating layer 14-1 and the insulating layer 14-2 is a copper pattern. The printed wiring board 2-1 of this embodiment is a laminate having a three-layer structure of insulating layers 14-1, 14-2 and a conductor layer 92. The printed wiring board on which the circulation path 16 is formed is not limited to such a laminate. That is, a two-layer structure, only an insulating layer or only a conductor layer, or a laminate of four or more layers may be used.

<Processing of groove 34>

  As shown in FIG. 16A, a groove 34 is formed in the insulating layer 14-1 by UV processing or laser processing. This UV processing and laser processing are examples, and other processing methods such as etching processing may be used for the groove 34. For example, an excimer laser can be used for laser processing. In the laser processing, laser irradiation is performed from the laser processing machine 94 to the inclined position of the groove 34. Thereby, the groove part 34 of a fixed depth and a fixed width is formed. As shown in FIG. 17A, the groove portion 34 is processed into a circular shape, whereby the above-described circulation path 16 is obtained. When the micro screw 22 and the cylinder device 68 described above are installed, the groove portion 34 having a necessary width may be formed. The depth and width of the groove 34 may be selected according to the thickness of the printed wiring board 2-1, such as the thickness of the insulating layer 14-1.

<Surface Treatment Process of Printed Wiring Board 2-1 Including Groove 34>

  After processing the groove 34 formed in the insulating layer 14-1, the inner wall surface is subjected to desmear treatment. By this desmear process, the wall surface is adjusted to a flat surface, for example.

  After the desmear process, the insulating layer 14-1 including the groove 34 is subjected to a surface process as shown in FIG. In this surface treatment, the metal layer 36 is formed by plating. For example, gold is used for the metal layer 36. The metal layer 36 is preferably made of a metal material or conductor material having corrosion resistance in addition to gold. As a result of this surface treatment, the circulation path 16 is formed by the groove 34 whose inner wall is covered with the metal layer 36. Note that the above-described metal layer 38 (B in FIG. 7) may be formed on the metal layer 36.

<Filling step of low boiling point solvent 18>

  Prior to filling the low-boiling point solvent 18 into the circulation path 16, a conductor layer 96 is formed on the metal layer 36 as shown in FIG. The conductor layer 96 may be a metal foil such as a copper foil. By providing the conductor layer 96, the metal layer 36 is covered with the conductor layer 96 and the upper surface side of the groove 34 is closed with the conductor layer 96. Instead of the conductor layer 96, an insulating layer may be used.

  The circulation path 16 is filled with a low boiling point solvent 18 as shown in FIG. For this filling, for example, a dispenser may be used. When the circulation path 16 is closed, the circulation path 16 may be perforated and filled with the low boiling point solvent 18 with a dispenser and then closed.

  In this embodiment, the low boiling point solvent 18 is used in the circulation path 16, but the above-described liquid 20 may be used instead of the low boiling point solvent 18. The circulation path 16 is formed in the insulating layer 14-1, but may be formed in the conductor layer 92. Moreover, it may replace with the printed wiring board 2-1, and may be the printed wiring boards 2-2 and 2-3.

<Effect of Fifth Embodiment>

  (1) According to the fifth embodiment, the circulation path 16 can be easily formed on a wiring board such as the printed wiring board 2-1.

  (2) The circulation path 16 can be formed across the aforementioned areas 6-1 and 6-2 of the printed wiring board 2-1. Thereby, the flow path which circulates the low boiling point solvent 18 to the high temperature side and the low temperature side can be formed.

[Other Embodiments]

  a) In the embodiment described above, the mobile terminal device 8 is exemplified as the electronic device on which the printed wiring boards 2-1, 2-2, and 2-3 are mounted. However, the technology of the present disclosure is not limited to this. The present invention can be applied to a printed wiring board mounted on an electronic device such as a personal computer. That is, the technology of the present disclosure can be widely applied as long as the heat generating component is mounted on the printed wiring board.

  b) In the first embodiment, the low boiling point solvent 18 is exemplified as the liquid circulating in the circulation path 16. In the second embodiment, the liquid 20 to be circulated through the circulation path 16 is forcedly circulated by the circulation means, and therefore may be a liquid other than the low boiling point solvent 18. However, also in the second embodiment, the low boiling point solvent 18 may be used as the liquid 20. That is, the technique of this indication does not exclude the forced circulation of the low boiling point solvent 18, for example.

  c) In the above embodiment, the circulation path 16 is a terminal configuration, but as shown in FIG. 17B, there is a terminal opening at the ends of the printed wiring boards 2-1, 2-2, 2-3. The circulation path 16 may be used. A refrigerant tank for storing refrigerant such as the low boiling point solvent 18 and the liquid 20 may be installed in the terminal opening of the circulation path 16, and the refrigerant may be circulated from the refrigerant tank to the circulation path 16.

  d) In the above embodiment, the areas 6-1 and 6-2 (FIG. 1) are clearly shown as examples on the printed wiring boards 2-1, 2-2, and 2-3, but the invention is not limited to this. These areas 6-1 and 6-2 exist in a scattered manner, and a plurality thereof may be mixed.

As described above, the most preferable embodiment of the present disclosure has been described, but the present invention is not limited to the above description. It goes without saying that various modifications and changes can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the embodiments for carrying out the invention. It goes without saying that such modifications and changes are included in the scope of the present invention.

2-1, 2-2, 2-3 Printed wiring board 4, 41, 42, 43, 44, 45, 46, 47... 4N, electronic component 6-1, 6-2 area 8 portable terminal device 10 housing Body 12 Battery 14, 14-1, 14-2 Insulating layer 16 Circulating path 18 Low boiling point solvent 20 Liquid 22 Micro screw 24 Screw body portion 26 Drive motor 28 Spiral feather 30-1, 30-2 Lead wire 34 Groove portion 36 First Metal layer 38 Second metal layer 50-1, 50-2 Connection terminal 52 Opening 54 Insulating layer 56-1, 56-2, 56-3 Controller 58 Processor 60 ROM
62 RAM
64 Drive portion 66 Temperature sensor 68 Cylinder device 70 Piston 72 Plunger 74 Oscillating plate 76 Drive portion 78 Housing 80 Front case 82 Rear case 84 LCD panel 86 Metal frame 88 Solder 90-1, 90-2 Diffusion sheet 92 Conductor layer 94 Laser beam machine 96 Conductor layer

Claims (8)

A printed wiring board on which electronic components are mounted,
A liquid that absorbs and flows heat from the electronic component;
A flow path formed in the insulating layer or conductor layer on the high temperature side and the low temperature side, and the liquid that has absorbed heat from the electronic component moves from the high temperature side to the low temperature side;
A printed wiring board comprising:   The printed wiring board according to claim 1, wherein the liquid is a low boiling point solvent and a refrigerant containing the low boiling point solvent. A circulating means for circulating the liquid in the flow path;
The printed circuit board according to claim 1, wherein the circulating means moves the liquid that has absorbed heat from the electronic component from the high temperature side to the low temperature side. Furthermore, a temperature sensor that detects the temperature of the electronic component, the insulating layer, or the conductor layer;
Control means for operating the circulating means when the temperature detected by the temperature sensor exceeds a certain temperature;
The printed wiring board according to claim 3, comprising: A thermal control program for causing a computer mounted on a printed circuit board to execute,
Determine whether the detection temperature of the printed circuit board, the electronic component or the liquid circulating through the printed circuit board exceeds a certain temperature,
When the detected temperature exceeds a certain temperature, the liquid is circulated by a circulation means.
Thermal control program for executing processing. A thermal control method for a printed circuit board on which electronic components are mounted,
Form a flow path in the insulating layer or conductor layer,
At least a liquid that has absorbed heat from the electronic component is circulated from the high temperature side to the low temperature side of the insulating layer or the conductor layer through the flow path. A method of manufacturing a printed wiring board on which electronic components are mounted,
Form a flow path in the insulation layer or conductor layer on the high temperature side and low temperature side,
A method of manufacturing a printed wiring board, comprising filling the flow path with a liquid that flows by absorbing heat of at least an electronic component. An electronic device including a printed wiring board on which electronic components are mounted,
A liquid that absorbs and flows heat from the electronic component;
A flow path formed in the insulating layer or conductor layer on the high temperature side and the low temperature side, and the liquid that has absorbed heat from the electronic component moves from the high temperature side to the low temperature side;
An electronic device comprising:

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