JPH05315782A - Heat dissipating structure of printed circuit board - Google Patents

Abstract

PURPOSE:To provide a heat dissipating structure having a high cooling efficiency and requiring no increase of the width of circuit package for dissipating heat generated by printed circuit boards in a mounting structure consisting of the circuit packages in which circuits are formed by mounting parts on printed circuit boards and the front-open box or frame having shelves in which the circuit pakages are housed and plug-in connected guided by the metal groove shape members installed vertically opposite to each other. CONSTITUTION:A heat dissipating structure for printed circuit boards, is provided with an earth layer 2 consistiang of a conductive layer laid over the whole surface of the inner layer, printed circuit boards 1 having plated sliding surfaces 3 which are placed at both edges thereof, which slide on metal groove shape members 8, and which are electrically connected to the earth layer 2, a means for transferring heat generated by a part 4 to the earth layer 2, and a means for dissipating heat by bringing the plated sliding surfaces 3 electrically connected to the earth layer 2 into contact with the metal groove shape members 8 of a shelf 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit package in which components are mounted on a printed wiring board to form a circuit, and a box or frame body having an open front, which guides metal groove-like members provided vertically opposed to each other. The present invention relates to a heat dissipation structure for a printed wiring board in a mounting structure including a shelf in which a circuit package is inserted and attached, and a plug-in connection is performed to store the circuits in parallel.

A shelf mounting structure in which circuit packages using a printed wiring board are housed side by side has advantages such as high packing density, good maintainability, and standardization of design and manufacturing. , It is necessary to give sufficient consideration to the heat generated from the mounted components.

[0003]

2. Description of the Related Art FIG. 3 shows an example of a conventional component heat radiation structure, and FIG. 4 shows another example of the conventional component heat dissipation structure. (A) is a side view and (b) is a front view.

A normal electronic device having a mounting structure in which circuit packages of printed wiring boards are arranged in parallel on a shelf is either natural air cooling or forced air cooling by a fan as heat generation processing. As shown in FIG. 3, the conventional component heat radiation structure is such that a heat sink 48 for heat radiation is closely attached to the back surface of the component 4 and the heat sink 48 passes through the heat sink 48 by convection of a space provided between the circuit packages at the time of parallel mounting. Cool the part 4.

In an IC package, a chip is fixed to a substrate, and a cover is hermetically attached to the chip. As another example, as shown in FIGS. In some cases, the heat sink 49 that goes around the 41 side is used.

[0006]

However, in the component heat radiation structure of FIG. 3, when used in an IC package, the heat sink 48 is not attached near the heat source of the IC. That is, the chip is usually fixed to the substrate of the package, and the heat sink 48 is attached to the cover that covers the chip, so that heat resistance is generated accordingly. Furthermore, since the heat sink 48 is tightly fixed with an adhesive, a work process is required, and the product name notation of the IC is hidden, so that it is not possible to confirm the readability after mounting. Therefore, the notation is added on another side or the like. There must be. Therefore, according to the structure shown in FIG. 4, the heat sink 49 extends around the substrate surface (abdominal surface 41) of the package. However, since the heat sink 49 is adhered and fixed with an adhesive, there is a similar problem. Furthermore, if the heatsink 49 is displaced when it is fixed, there is a risk that it may come into contact with the lead terminals of the IC and cause a short circuit. The heat sinks 48 and 49 have their fins traveled in the mounting height direction of the component 4 to expand the heat radiation area. Therefore, if the heat sinks 48 and 49 are used, the width dimension of the circuit package must be increased accordingly. However, the minimum unit, No. 1, will definitely increase. There are problems such as.

In view of the above problems, it is an object of the present invention to provide a heat dissipation structure which has a good cooling efficiency and which does not need to widen the circuit package.

[0008]

As shown in the principle explanatory view of FIG. 1, [1] a circuit package in which components are mounted on a printed wiring board to form a circuit, and a box or frame body with an open front A heat dissipation structure for a printed wiring board in a mounting structure including a shelf in which a circuit package is inserted by being guided by metal groove-shaped members which are vertically opposed to each other, and which is connected in a plug-in manner and stored in parallel. , A ground layer 2 consisting of a conductor layer covering the entire inner layer
And a printed wiring board 1 provided on both edges with a sliding plating surface 3 which slides on the metal groove member 8 and is electrically connected to the ground layer 2, and heat transfer means for transferring the heat generated by the component 4 to the ground layer 2. And a heat radiating means for radiating heat by bringing the sliding plating surface 3 electrically connected to the ground layer 2 into contact with the metal groove member 8 of the shelf 9 to achieve the heat radiating structure of the printed wiring board of the present invention. .. [2] In addition, the above heat transfer means includes a heat transfer plate 51 of a good heat transfer material that is in close contact with the abdominal surface 41 of the component 4 to be mounted, and a plurality of heat transfer members of a good heat transfer material that is hung vertically on the heat transfer plate 51 A heat transfer member 5 including a pin 52,
Conductive to the ground layer 2 and adhere a good heat transfer material to the inner surface,
Through hole 6 or via 66 for inserting 52 for heat transfer
And the heat dissipation structure of the printed wiring board described above.

[0009]

In other words, the ground layer 2 provided on the printed wiring board 1 is
It is a large conductor layer over the entire surface, is a good heat conductor and is also a heat radiator.

It is convenient for the heat transfer member to transfer the heat generated by the component 4 to the ground layer 2 for those that receive heat from the abdominal surface 41 of an IC or the like without having to go around the heat transfer member.

As the heat transfer means, for example, the heat transfer pin 52
The heat transfer member 5 is composed of a heat transfer plate 51 which is vertically provided, and a through hole 6 or a via 66 which is electrically connected to the ground layer 2 provided on the printed wiring board 1. The heat transfer pin 52 is fitted to the through hole 6 or the via 66 to transfer heat to the ground layer 2. This heat transfer plate 52 only needs to perform heat transfer, does not need a heat radiation fin itself, only adds a plate thickness in the height direction of the component 4, which is very small, and the width dimension of the circuit package 99 is 1
It can often be done without increasing the number of issues.

Further, by the heat radiating means, the sliding plating surface 3 at which both edges of the ground layer 2 conduct is brought into contact with the metal groove member 8 of the shelf 9 to transfer heat to the large heat capacity shelf 9 and radiate it. .. Further, the product name notation on the back surface of the component 4 can be directly viewed without any hiding.

Thus, according to the present invention, the heat generated from the circuit package is transferred to the shelf having a large heat capacity and the whole is air-cooled, so that the heat dissipation structure is efficiently cooled and the circuit package does not need to be widened. It becomes possible.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in the drawings. Throughout the drawings, the same reference numerals denote the same objects. FIG. 2 shows an embodiment of the present invention, (a) is a heat transfer configuration diagram of a mounted component, and (b) is a heat transfer configuration diagram to a shelf.

This embodiment is applied to a circuit package having a large amount of heat generation, such as an ECL integrated circuit of a logic circuit and an A / D converter of an analog circuit, which is used in a radio transmitter / receiver.

As shown in FIG. 2A, the circuit package
The circuit 99 is composed of a printed wiring board 1 and components 4 mounted on the printed wiring board 1. The printed wiring board 1 is a multi-layer printed wiring board made of a glass epoxy base material, and the entire area is 70 μm in the central portion.
A grounding layer 2 made of a conductor layer of m thick copper foil is arranged, and two conductor layers are laminated on both sides of the grounding layer 2 for circuit wiring, and interlayer connection is made by through holes 6 and vias 66.

To mount the surface-mounting type heat-generating component 4, a heat transfer plate 51, which is in close contact with the abdominal surface 41 and has a thickness of 1.5 mm and a thickness of 1.5 mm, and a heat transfer pin 52 of a steel wire of 1φ × 4 mm are provided on one surface thereof. A heat transfer member 5 formed by welding a plurality of pieces in a predetermined arrangement and the heat transfer pin.
A 0.5 mm thick synthetic resin plate insulating plate 7 having a slightly larger outer shape is placed on the surface side of 52, and a via 66 reaching the ground layer 2 is provided at a predetermined position on the mounting surface side of the component 4 of the printed wiring board 1. It is provided with copper plating on the inner surface and solder plating on it.
The heat transfer plate 51 is adhered and fixed to the belly surface 41 of the component 4 with an adhesive, the insulating plate 7 is passed through the heat radiating pins 52 to be overlapped, and the heat radiating pins 52 are fitted into the vias 66 at predetermined positions to be attached to the printed wiring board 1. Fix tightly.

By the insulating plate 7, even if the circuit conductor layer is exposed on the surface, it is electrically insulated so as not to come into contact with the heat transfer plate 51. Further, in the case of a terminal lead insertion type heat generating component 44, a heat transfer member 55, which is also composed of a heat transfer plate 53 provided with protruding heat transfer pins 52, is closely fixed to the abdominal surface 41 of the component 44, and the insulating plate 77 is attached. Are placed one on top of the other and are placed in a predetermined manner to be electrically connected to the ground layer 2, and the heat transfer pins 54 are fitted into the through holes 6 having the inner surfaces plated, and the heat transfer pins 54 protruding to the opposite surface are fixed by soldering.

Of course, this soldering is performed by the printed wiring board 2
This is performed in the same process as the soldering of the terminal lead 42 of the component 44 inserted through the through hole 6 connected to the circuit. Thus, the heat generated by the components 4,44 is transmitted through the heat transfer members 5,55 to the ground layer 2
In addition, heat is transferred in a short and efficient manner, and the mounting height of the component 4 is only increased by 2 mm, and the width dimension of the circuit package 99 does not need to be increased.

As shown in FIG. 2B, the heat transfer from the ground layer 2 to the shelf 9 is caused by the contact surface of the edge of the printed wiring board 1 sliding on the metal groove member 8 of the shelf 9. The conductive pressing member 81 formed by corrugating an elastic stainless steel ribbon is welded and fixed to one inner side surface of the metal groove-shaped member 8 by electrically connecting to the ground layer 2 and stacking the copper plating and the nickel plating to form the sliding plating surface 3. When the printed wiring board 1 is inserted into the groove, the elastic pressing member 81 presses it to one side to surely bring the sliding plating surface 3 into close contact with the metal groove-shaped member 8, and the sliding plating surface 3 on the opposite side. Heat is transferred through the elastic pressing member 81, and the heat of the ground layer 2 is transferred to the metal groove member 8
The heat is transferred to the shelf 9 and is radiated.

The shelf 9 is large in size, has a large heat capacity, and has a large heat radiation effect by air cooling. The above embodiment is an example, and the mechanism, shape, material,
The dimensions are not limited to those mentioned above.

[0022]

As described above, the heat dissipation structure of the printed wiring board according to the present invention prevents the heat generated by the components mounted on the printed wiring board.
Heat is transferred to the shelf with a large heat capacity through the ground layer, and the whole is air-cooled, so it is cooled efficiently, and the width of the circuit package is minimized and it is not necessary to widen it. The heat dissipation structure is obtained, the reliability of the heat-generating component is improved, and the cooling efficiency is improved, so that high-density mounting can be achieved.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention.

FIG. 2 shows an embodiment of the present invention (a) heat transfer configuration diagram of mounted parts (b) heat transfer configuration diagram to shelf

FIG. 3 is a conventional example of a component heat radiation structure.

FIG. 4 Another conventional example (a) Side view (b) Front view

[Explanation of symbols]

1 Printed wiring board 2 Ground layer 3
Sliding plating surface 4,44 Parts 5,55 Heat transfer member 6
Through hole 7,77 Insulation plate 8 Metal groove member 9
Shelf 41 Vent 42 Terminal lead 48,4
9 Heat sink 51,53 Heat transfer plate 52,54 Heat transfer pin 66
Via 81 Elastic pressing member 99 Circuit package

Claims (2)

[Claims] 1. A circuit package in which components are mounted on a printed wiring board to form a circuit, and a box body or frame body having an open front surface,
A heat dissipation structure for a printed wiring board in a mounting structure including a shelf in which a circuit package is inserted and attached by being guided by metal groove-shaped members provided to face each other vertically, and a plug-in connection is made and stored in parallel. A printed wiring provided with a ground layer (2) consisting of a conductor layer over the entire surface, and a sliding plating surface (3) which is slid on both sides of the metal groove member (8) and is electrically connected to the ground layer (2). The plate (1), the heat transfer means for transferring the heat generated by the component (4) to the ground layer (2), and the sliding plating surface (3) conducted to the ground layer (2) are connected to the shelf.
A heat dissipation structure for a printed wiring board, comprising: a heat dissipation means for contacting the metal groove-shaped member (8) to dissipate heat. 2. The heat transfer plate according to claim 1, wherein the heat transfer plate (51) is made of a good heat transfer material and is in close contact with the ventral surface (41) of the component (4) to be mounted.
A plurality of heat transfer pins (52) made of a good heat transfer material that are hung vertically on the heat transfer plate (51)
And a through hole (6) that conducts heat to the ground layer (2) and adheres a good heat transfer material to the inner surface, and inserts the heat transfer pin (52) to transfer heat. ) Or via (66), the heat dissipation structure of the printed wiring board.