JPS6147700A - Electronic circuit package assembling structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an assembly structure of an electronic circuit package, and in particular to a method for dissipating heat from circuit elements such as integrated circuit elements (hereinafter referred to as LSI) mounted on a printed circuit board. The present invention relates to an assembly structure for an electronic circuit package that has excellent effects.

2. Description of the Related Art Conventionally, electronic circuit packages used in electronic devices of this type are constructed by mounting a plurality of circuit elements such as LSIs on a printed circuit board. Since the circuit elements often include several high-power circuit elements, a structure in which forced air cooling is generally performed using a blower is common, but the operating environment is extremely poor and the electronic circuit components cannot be used. In process control equipment that must be isolated from the outside air, and electronic computers that are densely packed due to the recent development of circuit element technology, heat from one circuit element is transferred to the refrigerant by direct conduction. A conduction cooling structure is used.

FIG. 5 is a side view showing an example of a conventional electronic circuit package having this type of heat conduction heat dissipation structure, in which the upper surface of a plurality of circuit elements 2 such as LSIs directly attached to a printed circuit board 1 is shown. , a structure is adopted in which the cooling plate 3 is crimped to a fixture 4 and screws 5. According to this structure, the circuit element 2
The heat from the cooling plate 3 is transmitted to the cooling plate 3 and released to a coolant 6 such as water flowing inside the cooling plate 3. However, in the conventional structure described above, the contact portion between the circuit element 2 and the cooling plate 3 poses a problem in terms of heat transfer. That is, in order to maintain good heat dissipation characteristics for each circuit element 2, it is necessary to make the surface heights of a plurality of circuit elements 2 the same, and to maintain a uniform height for each circuit element 2. However, it is necessary to ensure that the contact with the cooling plate 3 is uniform due to variations in the external shape of the circuit element 2, warping or twisting of the printed circuit board 10, lifting or tilting of the circuit element 2 with respect to the printed circuit board side, etc. It was difficult to keep it that way. Figure 5 shows this in extreme detail.

FIG. 6 is a diagram showing the structure of another conventional example that partially solves the above-mentioned problem. A good heat conductive material 7f having Since it has little flexibility, it has the disadvantage that variations in the height of each circuit element must be precisely aligned. Figure 6 shows this to an extreme.

Problems to be Solved by the Invention The purpose of the present invention is to solve the above-mentioned drawbacks, namely, insufficient thermal contact due to lack of flexibility in the thickness direction of the good heat conductive material, and heat transfer paths due to the interposition of the conductive material. Solve the problem of length. An object of the present invention is to provide an electronic circuit package assembly structure.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a printed circuit board with a plurality of elastic bodies each having a protruding central portion housed in the center of the upper surface and contacts arranged around the printed circuit board. A socket is mounted, a circuit element is mounted facing the elastic body accommodated in each of the plurality of sockets, and a common heat dissipation cooling body is mounted on the plurality of circuit elements facing the printed circuit board. By tightening and assembling these cooling bodies and the printed circuit board, the central protrusion of the elastic body in the socket is pressed by the circuit elements, and the repulsive elastic force causes each of the plurality of circuit elements to It is designed to provide sufficient contact pressure for heat conduction between the cooling body and the cooling body.

Operation Since the present invention is configured as described above, each of the plurality of circuit elements comes into close contact with the heat dissipation cooling body due to the repulsion elastic force caused by the compression of the elastic body, thereby reducing the heat generated from the circuit elements. This heat can be sufficiently dissipated through the cooling body.

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, which shows a perspective view of an embodiment of the present invention,
The electronic circuit package assembly structure of the present invention includes a printed circuit board 10, a plurality of sockets 20 mounted on the printed circuit board 10, and a plurality of circuit elements 30 mounted on each of these sockets.
and a refrigerant injection pipe 51° flow path 52. Refrigerant discharge pipe 53't-
The cooling body 50 has a cooling body 50, a spacer 60 for holding and fixing the cooling body 50, and a screw 70.

FIG. 2 is a perspective view of the circuit element 30 as seen from the bottom surface, in which a chip 32 is mounted on the bottom surface of the case 3L, a cap 33 is attached to protect the chip 32, and there are multiple entrances and exits on the four sides. Mold/34 is provided.

FIG. 3 is a sectional view taken along the line A-A in FIG. 1 before the cooling body 50 is installed, and FIG. 4 is a sectional view taken along the line A-A in FIG. 1 after the cooling body 50 is installed. 23
These multiple contacts 21 are arranged around the
is attached to the printed circuit board LO by soldering. In addition, a leaf spring 22 that is shaped like a cap and has a notch around the periphery is housed in the center of the housing 23. It is not fixed, but slides within the 8 parts inside the housing. Before installing the cooling body 50 shown in FIG. 3, the leaf spring 22 was in contact with the cap 33, and at this time the input/output bin 34 was in contact.)
21 in a slidably contacting state. Next, as shown in FIG. 4, when the cooling body 501c is attached to the spacer 60 on the printed circuit board 10 using the screws 70, a spring force corresponding to the displacement amount t is generated in the plate spring 22. The circuit element 30 is brought into close contact with the cooling body 50.

In addition, the stiffness of the spring and the height of the spacer 60 + 11'i5 are taken into account in the design so that the plate spring 22 generates a force larger than the holding force between the contact 2L and the mold/output mold/34, and the above holding force is taken into account. Free movement of circuit element 30 is restricted;
There is no problem in the close contact between the circuit element 30 and the cooling body 50.

With the above configuration, variations in the external shape of the circuit element 30, warping or twisting of the printed circuit board, floating or tilting of the circuit element 30 with respect to the printed circuit board, etc. can be prevented by the board spring 22.
This allows for uniform and stable contact with the cooling body 50. Further, the heat generated in the chip 32 is transmitted to the case 31, and the heat generated by the chip 32 is transferred to the cooling body 5 through the above-mentioned close contact surface.
In FIG.

In this embodiment, the refrigerant is circulated inside the cooling body, but heat pipes, copper or aluminum may be used to transport the refrigerant to a long distance and then dissipate the heat. Alternatively, the cooling body itself may be a heat sink formed of a large number of fins.

Bellows, coil springs, etc. may be used instead of leaf springs, and elastic bodies such as elastic materials such as rubber may also be used.

Effects of the Invention As explained above, according to the present invention, since the circuit element to be cooled is pressed against the cooling body by the elastic body in the socket, variations in the height of the circuit elements are absorbed and the cooling body It is said that uniform and stable close contact can be obtained without interposing a thermally conductive material between the circuit element and the circuit element, and that the heat transfer path is formed in the shortest possible length, enabling efficient heat dissipation. effective.

[Brief explanation of the drawing]

Fig. 2 is a perspective view showing the assembly structure of an electronic circuit package according to the present invention, Fig. 2 is a perspective view of a circuit element used in the invention, and Fig. 3 is a partial cross-sectional view taken along A-A of Fig. 1, showing a cooling body. FIG. 4 is a partial sectional view taken along the line A-A in FIG. 1 with a cooling body mounted; FIG. 5 is a side sectional view showing an example of the assembly structure of a conventional electronic circuit package; FIG. 6 is a side sectional view showing another conventional example. 1...Printed circuit board, 2...Circuit element, 3...Cooling body, 4...Mounting tool, 5...
...Screw, 6...Refrigerant, 7...
Good thermal conductive material, io...Printed circuit board, 20.
...Socket, 21 ...Contact, 2
2... Leaf spring, 23... Housing,
30...Circuit element, 31...Case,
32... Chip, 33... Group/Cap, 34
...Input/output bin, 5o...Cooling body, 51
・・・・Injection pipe, 52・・・Flow path, 53
...Discharge pipe, 60...Spacer, 70
・・・・・・Screw, B・Old・Leaf spring slide part, 1-
1. Displacement amount, m... Height of the spacer 60. 1st time tea 3rd time 4th figure

Claims (1)

[Claims] a printed circuit board; a plurality of sockets that are mounted on the printed circuit board and house an elastic body whose center portion protrudes from the center of the upper surface and are provided with contacts around the periphery; consisting of a plurality of circuit elements mounted facing each other, and a common cooling body disposed on the plurality of circuit elements facing the printed circuit board,
By tightening and assembling the printed circuit board and the cooling body, the central protrusion of the elastic body in the socket is pressed by the circuit element, and the repulsive elastic force causes each of the plurality of circuit elements to contact the cooling body. What is claimed is: 1. An electronic circuit package assembly structure characterized in that the electronic circuit package assembly structure is configured such that contact pressure sufficiently effective for heat conduction can be obtained between the steps.