JP5151933B2 - Heat sink for electronic equipment - Google Patents

Description

  The present invention relates to a radiator for an electronic device that is small and has good heat dissipation efficiency.

  In general, in an electronic device, an electronic component constituting an electronic circuit is mounted on a printed board, and the printed board is accommodated in a housing. Cases are hermetically sealed, those that are opened with slits or the like so that the outside air can pass through, and those that have a built-in fan and forcibly take outside air into the case. In any case, electronic components made of semiconductor elements that consume a large amount of power, such as CPUs and LSIs, tend to generate heat and deteriorate easily in a high-temperature environment. ) Means must be provided. In particular, the heat dissipating means is indispensable when the environment temperature of the environment in which the electronic device is used for controlling the aircraft engine is high. For this reason, a method like patent document 1 is proposed.

JP 2001-284862 A

  By the way, in an aircraft engine electronic control device, which is an electronic device used to control a jet engine, the aircraft engine electronic control device is used to control the jet engine that is the object of control for the purpose of minimizing electrical wiring and reducing the weight of the aircraft. It is installed in the vicinity. The aircraft engine electronic control device is also installed in the vicinity of the jet engine for the purpose of improving the maintainability of the jet engine by integrating the aircraft engine electronic control device and the jet engine. Furthermore, the above-described installation is performed because the aircraft fuselage cannot secure a space for installing the aircraft engine electronic control unit.

  Since the aircraft engine electronic control device is installed in the vicinity of the jet engine and has a high environmental temperature, it is necessary to provide heat dissipation means. However, although the outside air temperature is low at a high altitude, the air concentration is low, so the cooling effect cannot be expected only by air cooling. Therefore, not only relying on air cooling, but also installing a radiator to cool by heat conduction.

  In conventional electronic control units for aircraft engines, a heat sink is sandwiched between an electronic component that generates a large amount of heat and a printed circuit board, a heat sink is installed on the surface of an electronic component that generates a large amount of heat, or the copper foil area of the printed circuit board To increase heat conduction by copper foil. In any case, since the electronic engine control device for an aero engine has a sealed or semi-sealed structure for the printed circuit board, the heat radiating plate is attached to the case so that heat is transferred from the heat radiating plate in the case to the case. It is necessary to contact directly or indirectly.

  However, in the conventional aircraft engine electronic control device such as Patent Document 1, when the heat sink is in contact from the front side of the board, the height difference due to the work accuracy of the board or the height of the component itself is different. Therefore, when it is pressed to ensure contact, stress may be generated in the solder portion, and engine vibration or the like may be transmitted strongly. In addition, since there are solder protrusions and mounted parts on the back of the substrate, it is difficult to reliably contact the heat sink from the back side. In an environment where the altitude is high and the air concentration is low, a cooling effect cannot be expected only by air cooling. Thus, in the conventional electronic control device for an aircraft engine, it is difficult to secure a heat conduction path, and it is difficult to make the heat radiating means small in size and heat radiating efficiency.

  Then, the objective of this invention is providing the heat radiator for electronic devices which solves the said subject and has small heat dissipation efficiency.

In order to achieve the above object, according to the present invention, a printed circuit board on which an electronic component is mounted is provided with a conductive pillar that penetrates the printed circuit board and connects to a terminal of the electronic component, and the electronic component on the printed circuit board is mounted. A heat radiating plate is pressed against the opposite surface of the printed circuit board through an insulating sheet covering the end face of the conductor pillar , and the printed circuit board is formed in a lattice shape by crossing a plurality of vertical ribs and horizontal ribs. The heat radiating plate is integrally provided on the vertical rib and the horizontal rib in a rectangular area surrounded by the vertical rib and the horizontal rib, and the heat radiating block is accommodated in the housing. It is a radiator for electronic equipment.

  The electronic component may be a surface mount component, and the conductor pillar may be in contact with a mounting conductor foil to which a terminal of the electronic component is fixed.

  The printed circuit board is a double-sided mounting board, and other electronic components are mounted on the surface opposite to the surface on which the electronic components are mounted, and the heat sink is mounted on the printed circuit board where the other electronic components are mounted. Then, you may have the recessed part spaced apart from the said printed circuit board, and the convex part which approached the said printed circuit board in the location in which the said electronic component was mounted.

  The present invention exhibits the following excellent effects.

  (1) A cooling structure for an electronic circuit that can be used even in a thin air environment that is small and has good heat dissipation efficiency and is not affected by the work accuracy of the substrate or the circuit design.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, a radiator 1 for an electronic device according to the present invention includes a conductor pillar 5 that penetrates a printed board 3 and is connected to a terminal 4 of the electronic component 2. The heat sink 7 is pressed against the opposite surface of the printed circuit board 3 where the electronic component 2 is mounted via the insulating sheet 6 covering the end surface of the conductor pillar 5.

  In FIG. 1, the insulating sheet 6 is illustrated away from the printed board 3, but the heat radiating plate 7 is pressed in the direction of the arrow so that the insulating sheet 6 is in close contact with the printed board 3. The printed circuit board 3 is a laminate of multi-layer insulator plates, and conductive foils (not shown) for power, ground, signals, etc. are provided between the front and back surfaces of the printed circuit board 3 and between the insulator plates. It is done. The conductor pillar 5 is also called a via and is a member that is conventionally known for electrical connection. In the present invention, considering that the conductor column 5 is made of a metal such as copper having excellent thermal conductivity, the conductor column 5 is used as a member for heat conduction.

  The insulating sheet 6 is made of a material having electrical insulation and good thermal conductivity, for example, a silicone resin. Even if the insulating sheet 6 is said to have good heat conductivity, if it is too thick, the heat conduction becomes poor. Even though the insulating sheet 6 has electrical insulation, if it is too thin, conduction may occur due to mechanical breakage, so it is preferable that the insulating sheet 6 be thick to some extent.

  The electronic component 2 is a surface mount component. On the surface on which the electronic component 2 is mounted, a mounting conductor foil (not shown) is formed by a solder ball or the like to which the terminal 4 of the electronic component 2 is fixed. Are joined. The conductor pillar 5 is electrically connected to a signal conductor foil (not shown) for transmitting the signal of the terminal 4 of the electronic component 2 to another place of the printed circuit board 3.

  The printed circuit board 3 is a double-sided mounting board. Another electronic component 8 is mounted on the surface opposite to the surface on which the electronic component 2 is mounted. The heat sink 7 includes a recess 19 that is separated from the printed circuit board 3 in order to avoid other electronic components 8, and a protrusion 20 that is close to the printed circuit board 3 where the electronic component 2 is mounted (see FIG. 5). Have.

  As shown in FIG. 2, a radiator 1 for an electronic device according to the present invention includes an electronic component 2 on which a heat sink 7 according to the present invention is installed on a printed circuit board 3 and a heat sink 7 according to the present invention. A non-electronic component 9 is mounted. The electronic component 2 is composed of a semiconductor element that consumes a large amount of power because of a high element integration density, a fast operation clock, a large load current, etc., and has a limit in temperature at which normal operation can be maintained.

  The printed circuit board 3 is attached to a heat radiation block 10 that is a heat radiation means and a reinforcement means for the entire printed circuit board 3. The heat dissipation block 10 is made of aluminum, for example.

  As shown in FIG. 3, in the electronic device radiator 1 according to the present invention, a printed circuit board 3 is attached to a heat dissipation block 10. The heat dissipation block 10 has a predetermined height in the thickness direction of the printed circuit board 3. The heat dissipation block 10 includes a plurality of ribs 11 and 12 that are arranged at appropriate intervals in the vertical and horizontal directions when viewed from above. The plurality of ribs 11 and 12 extend in the vertical and horizontal directions of the printed circuit board 3 and intersect to form a lattice shape. A boss (not shown) in which a screw can be fitted is formed at a place where the vertical rib 11 and the horizontal rib 12 intersect, and a screw through hole is provided at a place corresponding to the printed circuit board 3 with respect to the boss. (Not shown) is formed.

  The electronic device radiator 1 includes a housing 13 that houses the printed circuit board 3 and the heat dissipation block 10. The housing 13 has a sealed structure or a semi-sealed structure by closing a lid (not shown). In the case of the sealed structure, there is no hole through which air enters and exits the housing 13, and air does not enter or exit the housing 13. In the case of a semi-hermetic structure, the housing 13 is provided with a slit or a fan, and air enters and exits the inside and outside of the housing 13.

  The electronic device radiator 1 has a structure in which a lattice-shaped heat dissipation block 10 is accommodated in a housing 13. This is a structure for enhancing mechanical strength such as vibration resistance. On the other hand, since the housing 13 has a sealed structure or a semi-sealed structure, air cooling of the printed circuit board 3 due to the inflow of air cannot be expected. In addition, air cooling efficiency is low because the air is thin at high altitudes. Therefore, by providing the heat dissipation block 10, the heat of the printed circuit board 3 is conducted to the housing 13 by heat conduction.

  As shown in FIG. 4, in the heat dissipation block 10, a plurality of bosses 14 are formed where the vertical ribs 11 and the horizontal ribs 12 intersect. Each boss 14 has a screw hole for fixing the printed circuit board 3 with a screw. In the heat dissipation block 10, a large number of square areas surrounded by the vertical ribs 11 and the horizontal ribs 12 are formed. These areas include an area where the heat sink 7 is provided and closed, and an area where the heat sink 7 is not provided and penetrates vertically.

  The heat dissipating block 10 is manufactured by cutting out, and the heat dissipating plate 7 is manufactured by cutting off the thin plate when the heat dissipating block 10 is cut out.

  As shown in FIG. 5, in an electronic device radiator 1 according to the present invention, a printed circuit board 3 on which an electronic component 2 is mounted is fixed to a heat dissipation block 10 with screws. The electronic component 2 is, for example, a CPU. An insulating sheet 6 that covers the end surface of the conductor pillar 5 (see FIG. 1) is provided on the opposite surface of the printed circuit board 3 where the electronic component 2 is mounted. The insulating sheet 6 is pressed against the printed circuit board 3 by the heat radiating plate 7. The heat radiating plate 7 is provided integrally with the heat radiating block 10.

  Another electronic component 8 is mounted on the surface of the printed circuit board 3 opposite to the surface on which the electronic component 2 is mounted. The other electronic component 8 is, for example, a capacitor, and is mounted in a large number so as to surround the electronic component 2 in a top view. The heat radiating plate 7 includes a concave portion 19 that is separated from the printed circuit board 3 at a place where the other electronic component 8 is mounted, and a convex portion 20 that is close to the printed circuit board 3 at a position where the electronic component 2 is mounted. Have. In the present embodiment, the top view shape and size of the convex portion 20 are the same as the top view shape and size of the electronic component 2. As a result, only the portion of the heat radiating plate 7 that directly faces the electronic component 2 of the heat radiating block 10 is raised to form a convex portion 20 and press the insulating sheet 6 against the printed circuit board 3. Since the recess 19 of the heat sink 7 is separated from the printed circuit board 3, the other electronic components 8 do not interfere with the heat sink 7.

  As shown in FIG. 6, the electronic device radiator 1 is an aircraft engine electronic control device used for controlling the jet engine 16, for example. The jet engine 16 has a structure in which the outer periphery of the fan case 17 is surrounded by an outer shell 18 called a nacelle. The electronic device radiator 1 is installed outside the fan case 17 and inside the outer shell 18. Since the inside of the fan case 17 is hot, the environmental temperature of the electronic device radiator 1 is high, for example, 70 ° C.

  Hereinafter, operation | movement of the heat radiator 1 for electronic devices of this invention is demonstrated.

  The heat generated in the electronic component 2 is conducted to the conductor column 5 because the conductor column 5 is in contact with the terminal 4 of the electronic component 2. Since the conductor pillar 5 is a member having excellent thermal conductivity, the heat from the electronic component 2 is conducted to the insulating sheet 6 covering the end face of the conductor pillar 5. Since the insulating sheet 6 is a member having excellent thermal conductivity, heat from the conductor pillar 5 is conducted to the heat radiating plate 7. Since the heat radiating plate 7 and the heat radiating block 10 are members having excellent thermal conductivity, the heat of the heat radiating plate 7 is conducted to the housing 13 via the heat radiating block 10.

  In this way, heat intensively generated in the electronic component 2 spreads to the housing 13 having a large surface area and a large volume. Since the housing 13 has a large surface area, the cooling effect by air cooling is great even at high altitudes where the air is thin. Therefore, the heat of the electronic component 2 is released from the housing 13 to the outside, and the electronic component 2 is effectively cooled.

  As described above, according to the present invention, the heat sink 7 is pressed against the opposite surface of the printed circuit board 3 where the electronic component 2 is mounted via the insulating sheet 6 covering the end surface of the conductor pillar 5. Therefore, the structure of the heat sink 7 is simplified.

  In the present invention, unlike the conventional case, no member is attached to the electronic component 2, so that no mechanical stress is applied to the electronic component 2.

  In the present invention, the heat sink 7 can be incorporated into the printed circuit board 3 without any additional work or design change, and it is necessary after manufacturing an electronic device that does not use the heat sink 7 and investigating temperature characteristics. In other words, a so-called retrofitting of incorporating the heat sink 7 is possible.

  Since the present invention is cooled by heat conduction to the heat radiating plate 7, it is effective as a cooling means for electronic equipment in a thin air environment (high altitude or in a ground vacuum facility).

  In the present invention, since the heat radiating plate 7 is provided in the heat radiating block 10 to which the printed circuit board 3 is attached, the printed circuit board 3 can be easily attached and detached, and maintenance is facilitated.

  In the present invention, since the heat dissipating plate 7 has the concave part 19 spaced from the printed circuit board 3 at the place where the electronic component 8 is mounted and the convex part 20 close to the printed circuit board 3 at the place where the electronic part 2 is mounted, Even if another electronic component 8 is mounted on the surface opposite to the surface on which the electronic component 2 is mounted, the heat radiating plate 7 can be prevented from interfering with the other electronic component 8.

  In the present invention, the heat radiating plate 7 is pressed against the opposite surface of the substrate 3 where the electronic component 2 is mounted via the insulating sheet 6 covering the end surface of the conductor pillar 5. The present invention can also be applied to a BGA type electronic component 2 in which the terminals 4 are arranged in a grid and the electronic component 2 is mounted on the printed circuit board 3 with solder balls.

It is principal part sectional drawing of the heat radiator for electronic devices which shows one Embodiment of this invention. It is a perspective view of the printed circuit board used for the heat radiator for electronic devices of FIG. It is a three-dimensional assembly drawing of the radiator for electronic devices of FIG. FIG. 2 is a partially enlarged perspective view of a heat radiating plate and a heat radiating block used in the electronic device radiator of FIG. 1. It is sectional drawing including the heat dissipation block of the radiator for electronic devices of FIG. (A) is a front view of the jet engine in which the radiator for electronic equipment of FIG. 1 is disposed, and (b) is a side view of the jet engine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat radiator for electronic devices 2 Electronic component 3 Printed circuit board 4 Terminal 5 Conductor pillar 6 Insulation sheet 7 Heat sink 8 Other electronic components 10 Heat radiation block 13 Case

Claims (3)

The printed circuit board on which the electronic component is mounted is provided with a conductive pillar that penetrates the printed circuit board and is connected to the terminal of the electronic component, and the conductive pillar on the opposite surface of the printed board on which the electronic component is mounted. A heat radiating plate is pressed through an insulating sheet covering the end surface of the printed circuit board, and the printed circuit board is attached to a heat radiating block formed in a lattice shape by intersecting a plurality of vertical ribs and horizontal ribs, A heat radiation for electronic equipment , wherein the heat radiation block is housed in a casing, and is provided integrally with the vertical rib and the horizontal rib in a rectangular area surrounded by the vertical rib and the horizontal rib. vessel.   2. The radiator for an electronic device according to claim 1, wherein the electronic component is a surface-mounted component, and the conductor pillar is in contact with a mounting conductor foil to which a terminal of the electronic component is fixed.   The printed circuit board is a double-sided mounting board, and other electronic components are mounted on the surface opposite to the surface on which the electronic components are mounted, and the heat sink is mounted on the printed circuit board where the other electronic components are mounted. 3. A radiator for an electronic device according to claim 1, further comprising: a concave portion spaced apart from the printed board; and a convex portion approaching the printed board at a place where the electronic component is mounted.

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