JPH03292799A - Heat dissipating structure of printed wiring board unit - Google Patents

Abstract

PURPOSE:To improve a semiconductor module in heat dissipating property by a method wherein a connector block is formed of an integral type connector block provided with a recess to which a cap is fitted, and a heat conductive material is interposed between the cap and the recess of the connector block. CONSTITUTION:A connector block 32 is formed of metal material, and a recess 33 where the cap 20 of a semiconductor module 6 is housed is provided to the block 32. A spring contact 26 is inserted into the connector block 32 as hermetically sealed up with glass, and one end of the contact 26 is connected to a printed wiring board 4 by soldering. A thermally conductive insulating material 34 of silicone sheet, silicone compound, or the like is interposed between the recess 33 and the cap 20 of a semiconductor module 6, and the semiconductor module 6 is screwed down to a printed wiring board 4 by the use of a pressing piece 28. An adequate insulating sheet is interposed between the metal connector block 32 and the printed wiring board 4.

Description

[Detailed Description of the Invention] Table of Contents Overview Field of Industrial Application Conventional Technology Problems to be Solved by the Invention Means for Solving the Problems Implementation Examples Summary of the Effects of the Invention Concerning the heat dissipation structure of a printed wiring board unit The aim of this paper is to provide a heat dissipation structure for a printed wiring board unit that improves the efficiency of heat dissipation from a semiconductor module mounted with heat-generating components. , a semiconductor module is constructed by attaching a cap that collectively seals the semiconductor component and the multilayer wiring thin film, providing external connection pads on the outer periphery of the insulating substrate, and attaching heat dissipation fins to the other surface. , in a printed wiring board unit that is attached to a printed wiring board by a first holding member and electrically connects the semiconductor module and the printed wiring board via contacts of a connector block mounted on the printed wiring board, the connector block is formed from an integral connector block having a recess into which the cap is fitted, and a thermally conductive material is interposed between the cap and the recess of the connector block to radiate heat from the cap to the connector block. Configure.

Industrial applications This invention relates to the heat dissipation structure of printed wiring board units.

When mounting a 1g printed wiring board for communication equipment, etc.,
A plurality of electronic components such as ICs and LSIs are mounted on a printed wiring board to form a printed wiring board unit (electronic circuit pancase), and the plurality of printed wiring board units are mounted along guide rails provided on the panel. It is inserted and plugged into a back wiring board via a connector to form an electronic device such as a communication device. In these electronic devices, high-density packaging of semiconductor components such as ICs and LSIs is progressing, and the generation of heat due to the power consumption of semiconductor components increases the temperature inside the electronic device, so it is important to suppress this temperature rise. This has become a serious problem. Especially L
In a printed wiring board unit in which a semiconductor module on which a heat generating component such as an SI is mounted is mounted on a printed wiring board, it is desired to improve the efficiency of heat dissipation from the semiconductor module.

Prior Art FIG. 12 is a perspective view of a conventional example in which a semiconductor module prototyped by the present inventors is mounted on a printed wiring board.
The figure is an exploded sectional view of the semiconductor module portion of FIG. 12. The printed wiring board unit 2 is configured by mounting four semiconductor modules 6 on a printed wiring board 4, and plugs this printed wiring board unit 2 into a back wiring board (not shown) via one or more connectors 8. The electronic device is configured by making the in-connection.

The semiconductor module 6 is constructed as shown in FIG. That is, a multilayer wiring thin film 12 in which copper and polyimide are alternately laminated is formed on a ceramic substrate 1o, an LSI pair chip 14 is bonded on the ceramic substrate 1o with a die bonding adhesive, and a chip component 16 is bonded on the multilayer wiring thin film 12. The pads of the LSI 14 and the pads of the multilayer wiring thin film 12 are connected by bonding wires 15. External connection pads 18 are formed on the outer peripheral surface of the ceramic substrate 1o. The LSI 14 and the multilayer wiring thin film 12 are collectively sealed with a cap 20, and nitrogen gas is filled inside the cap 2o.

A radiation fin 22 is bonded to the back surface of the ceramic substrate 10 using an adhesive such as silver-epoxy.

The multilayer wiring thin film 12 made of alternating layers of copper and polyimide is formed on the ceramic substrate 1o because it is not possible to directly form a miniaturized pattern corresponding to the number of LSI pads on the ceramic substrate 1o. Although only a pattern of about 100 μm can be formed on the substrate 10, a fine pattern of about 25 μm can be formed on the multilayer wiring thin film 12.

A connector block 24 with built-in spring contacts 26 is mounted on the printed wiring board 4, and the semiconductor module 6 is attached to the printed wiring board 4 by aligning the holding metal fittings 28 and 30 from above and below the printed wiring board 4. It will be installed. LSI 14 and chip components 16 mounted on the conductor pattern of the printed wiring board 4 and the ceramic substrate 1°
The electrical connection is achieved by the spring contact 26 coming into pressure contact with the external connection pad 18.

FIG. 14 schematically shows the state of adhesion of the radiation fins 22 of the semiconductor module 6, and the radiation fins 22 are adhered to the ceramic substrate IO using a thermally conductive silicone adhesive 21. Further, the LSI 14 is bonded to the ceramic substrate 10 using a silver-epoxy adhesive 13, and the cap 20 is similarly bonded to the ceramic substrate 10 using a silver-epoxy adhesive 19.

Therefore, the heat generated by the LS I I 4 of the semiconductor module 6 is radiated by the heat radiating fins 22 via the ceramic substrate 10.

Problems to be Solved by the Invention In the printed wiring board unit as described above, the heat generated by the semiconductor module 6 is radiated through the radiation fins 22 to cool the semiconductor module 6 to an operating temperature range. LSI14 mounted on a ceramic substrate
When the amount of heat generated is large, the semiconductor module 6 is not sufficiently cooled by heat radiation only through the radiation fins 22, and there is a problem in that it is difficult to keep the temperature of the semiconductor module below a predetermined temperature.

In addition, although the fins 22 are bonded to the back surface of the ceramic substrate 10 using a silicone adhesive 21, the heat dissipating fins 22
15, when the area of the base portion 22a becomes large, air bubbles cannot be removed from the adhesive 21 when the radiation fins 22 are bonded, and air bubbles 28 are formed in the adhesive 21 as shown in FIG.
may be formed. When the air bubbles 28 are formed in the adhesive 21 in this manner, the thermal resistance increases in the air bubble portions, resulting in a problem that the efficiency of heat radiation from the heat radiation fins 22 deteriorates. Furthermore, the cap 20 is attached with an adhesive 19.
is bonded to the surface of the ceramic substrate 10 by
There were problems in that it took time to position the cap and the surface of the substrate was stained by the adhesive 19.

The present invention has been made in view of the above points, and its purpose is to provide a printed wiring board that overcomes the drawbacks of the above-mentioned conventional technology and improves the efficiency of heat dissipation from a semiconductor module mounted with heat generating components. The purpose is to provide a heat dissipation structure for the unit.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention mounts a semiconductor component on one surface of an insulating substrate and forms a multilayer wiring thin film, and then packages the semiconductor component and the multilayer wiring thin film together. A first semiconductor module is constructed by attaching a sealing cap to the insulating substrate, providing external connection pads on the outer periphery of the insulating substrate, and attaching heat dissipation fins to the other surface.
In a printed wiring board unit that is attached to a printed wiring board by a holding member and electrically connects the semiconductor module and the printed wiring board through contacts of a connector block mounted on the printed wiring board, the connector block is attached to the cap. The connector block is formed from an integral connector block having a recess into which the connector block is fitted, and a heat conductive material is interposed between the cap and the recess of the connector block to radiate heat from the cap to the connector block. .

Instead of the above configuration, a heat conductive material may be interposed between the cap and the printed wiring board so that the heat of the cap is directly radiated to the printed wiring board.

Furthermore, an opening is provided in a portion of the printed wiring board on which the semiconductor module is mounted that faces the cap, and a convex portion that projects toward the cap is provided on a surface opposite to the surface of the printed wiring board to which the first holding member is attached. The second pressing member may be attached, and a heat conductive material may be interposed between the cap and the convex portion of the second pressing member to radiate heat from the cap to the second pressing member.

Function: In addition to heat dissipation from the heat dissipation fins, the heat dissipation efficiency from the semiconductor module can be increased by actively dissipating heat from the sealing cap. Thereby, even if the heat generation from the heat generating components built into the semiconductor module increases, the semiconductor module can be cooled to a predetermined operating temperature or lower.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description of each embodiment, components that are substantially the same as those of the conventional example shown in FIGS. 12 to 15 will be described with the same reference numerals.

First, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. Similar to the conventional example shown in FIG. 13, the ceramic substrate 10 is formed with a multilayer wiring thin film in which copper and polyimide (not shown) are alternately laminated, and an LSI is die-bonded directly onto the ceramic substrate 10 to form a multilayer wiring. Chip components are mounted on the thin film. and,
A multilayer wiring thin film with LSI and chip components mounted on a ceramic substrate 10 is collectively sealed in a camp 20, and the camp 20 is filled with nitrogen gas. A heat dissipation fin 22 made of aluminum, for example, is bonded to the back surface of the ceramic substrate 10 with a transfer conductive silicone adhesive, and a spring contact 26 is pressed onto the outer peripheral surface of the ceramic substrate 10 for external connection. A band is formed to configure the semiconductor module 6.

Reference numeral 32 designates an integral connector block made of a metal material, and has a recess 33 in which the cap 20 of the semiconductor module 6 is accommodated.

A spring contact 26 is glass-metically sealed and inserted into the connector block 32, and one end of the spring contact 26 is connected to the printed wiring board 4 by soldering. Recess 33 of connector block 32
A heat conductive material 34 such as a heat conductive insulating sheet or a silicon compound is interposed between the cap 20 of the semiconductor module 6 and the cap 20 of the semiconductor module 6, and the semiconductor module 6 is screwed onto the printed wiring board 4 using a presser metal fitting 28. It is attached with a stopper. Although not shown, a suitable insulating sheet is interposed between the metal connector block 32 and the printed wiring board 4. In the mounting state shown in FIG.
is strongly pressed between the cap 20 and the connector block 32.

However, heat generated from heat generating components such as an LSI built into the semiconductor module 6 is mainly radiated from the heat radiating fins 22 bonded to the back surface of the ceramic substrate 10. In addition to this,
In this embodiment, since the cap 20 of the semiconductor module 6 is connected to the connector block 32 via the heat conductive material 34, the heat generated from the heat generating components is transmitted between the cap 20, the heat conductive material 34, the connector block 32, and the printed wiring board. Heat is also radiated through 4.

Next, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. In this embodiment, the connector block 24
The shape is the same as that of the conventional example shown in FIGS. 12 and 13, and the heat conductive material 34 is interposed in the gap between the cap 20 of the semiconductor module 6 and the printed wiring board 4, as shown in FIGS. 12 and 13. This is different from the conventional example illustrated in the drawings and the first embodiment described above. That is, in this embodiment, the height of the cap 20 and/or the connector block 24 is appropriately adjusted to form an appropriate gap between the cap 20 and the printed wiring board 4, and a suitable thickness is formed in this gap. A thermally conductive agent 34 similar to that of the first embodiment described above is interposed, and a very simple structure makes it possible to dissipate heat even from the cap side of the semiconductor module 6.

5 and 6 show a third embodiment of the present invention,
An opening 4a is provided in a portion of the printed wiring board 4 on which the semiconductor module 6 is mounted facing the cap 20, and a presser metal fitting 36 through which a convex portion 36a protrudes toward the cap 20 is printed from the side opposite to the presser metal fitting 28. It is fixed to the wiring board 4 with screws. Then, the convex portion 36a of the presser metal fitting 36 and the cap 2 of the semiconductor module 6 are connected to each other.
A heat conductive material 34 similar to that of the first embodiment described above is interposed between the holes. According to this embodiment, in addition to the heat dissipation from the heat dissipation fins 22, heat can be dissipated from the cap side of the semiconductor module 6 to the metal presser fitting 36, which further improves the efficiency of heat dissipation from the semiconductor module 6. be able to.

Next, a desirable structure of the radiation fin will be described with reference to FIGS. 7 and 8. Referring to FIG. 7, the radiation fin 40 is formed of a base portion 40a and a fin portion 40b, and the base portion 40a is provided with a plurality of through holes 41 having a diameter of approximately 0.5 to 1 mm. By configuring the radiation fins 40 in this way, the silicone adhesive 2
When the heat dissipation fin 40 is bonded to the ceramic substrate 10 using the adhesive 21, air bubbles in the adhesive 21 penetrate the through holes 41, which are provided in the base portion 40a of the heat dissipation fin 400. Since the adhesive can escape to the outside through the adhesive 21, air bubbles are not formed in the adhesive 21 as in the conventional example shown in FIG. /Recon adhesive 2
Since 1 is a conductive adhesive, its thermal conductivity is much higher than that of air, and the heat radiation efficiency through the radiation fins 40 can be improved compared to the conventional example.

Referring to FIG. 8, the radiation fin 42 of this embodiment has a protrusion in addition to a base portion 42a and a fin portion 42b. 42c
is formed on the opposite side of the fin 1ff142b).

By configuring the radiation fins 42 in this way, air bubbles in the adhesive 21 can be released to the outside, and the distance between the protrusions 42c and the ceramic substrate 10 can be reduced. Compared to the embodiment shown in the figure, the thermal resistance at the adhesive part can be reduced, and the heat dissipation fin 4
It is possible to improve heat dissipation efficiency through 2.

Next, a cap mounting structure suitable for use in the present invention will be described with reference to FIGS. 9 to 11. A groove 44 corresponding to the mounting portion of the cap of the semiconductor module 6 is formed in the ceramic substrate 10'. Referring to FIG. 10, the cap 20' is formed with a horizontally bent mounting part 45, which is inserted into the groove 44 of the ceramic substrate 10' and the silver-epoxy adhesive 19 is inserted into the groove 44 of the ceramic substrate 10'.
The cap 20' is fixed to the ceramic substrate 10'. 46 is a ground pattern formed on the ceramic substrate 10'. According to this configuration, since the cap 20' is made of metal, the LSI housed therein can be
It is possible to completely shield semiconductor components such as Furthermore, since the grooves 44 are provided in the ceramic substrate 10', positioning of the cap 20' is facilitated, and the adhesive can be prevented from coming out of the grooves 44.

FIG. 11 shows a mounting structure for the cap 20 that does not have a horizontal mounting portion 45, which facilitates positioning of the cap 20 as in the embodiment shown in FIG. is prevented.

Effects of the Invention Since the present invention is constructed as described in detail above, it is possible to provide a printed wiring board unit with improved heat dissipation efficiency from a semiconductor module on which heat generating components are mounted. Further, the positioning of the sealing cap attached to the ceramic substrate can be easily achieved.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the first embodiment of the present invention, Fig. 2 is an exploded perspective view of the first embodiment, Fig. 3 is a sectional view of the second embodiment of the invention, and Fig. 4 is an exploded perspective view of the second embodiment. Figure 5 is a cross-sectional view of the third embodiment of the present invention, Figure 6 is an exploded perspective view of the third embodiment, Figure 7 is a cross-sectional view of one embodiment with heat dissipation fins attached, and Figure 8 is a cross-sectional view of the third embodiment of the present invention. 9 is a cross-sectional view of a state in which heat dissipation fins of other embodiments are bonded; FIG. 9 is a perspective view of a board provided with a cap mounting groove; FIG.
11 is a sectional view of the cap installed state, FIG. 12 is a perspective view of a conventional example in which a semiconductor module is mounted on a printed wiring board, FIG. 13 is a sectional view of the semiconductor module in FIG. 12, and FIG.
The figure is a sectional view showing the state of adhesion of conventional heat dissipation fins, and FIG. 15 is a diagram illustrating problems in the conventional example. 2...Multilayer wiring thin film, 4...LSI. 0...Sealing cap, 2 40 42...Radiation fin, 4.32...Connector block, 6...Spring contact, 8.30.36...Mounting bracket, 4...Heat conductive material.

Claims (5)

[Claims] 1. Semiconductor components (14) on one side of the insulating substrate (4)
is mounted, a multilayer wiring thin film (12) is formed, a cap (20) is attached to collectively seal the semiconductor component (14) and the multilayer wiring thin film (12), and the insulating substrate (
A semiconductor module (6) configured by providing an external connection pad (18) on the outer periphery of the semiconductor module (4) and attaching a heat dissipation fin (22) to the other surface is attached to the first holding member (6).
28), and electrically connected the semiconductor module (6) and the printed wiring board (4) via the contacts (26) of the connector block mounted on the printed wiring board. In the printed wiring board unit, the connector block is an integrated connector block (3) having a recess (33) into which the cap (20) is fitted.
2), the cap (20) and the connector block (32);
A heat radiation structure for a printed wiring board unit, characterized in that a heat conductive material (34) is interposed between the cap (20) and the recess (33) to radiate heat from the cap (20) to the connector block (32). 2. Semiconductor components (14) on one side of the insulating substrate (4)
is mounted, a multilayer wiring thin film (12) is formed, a cap (20) is attached to collectively seal the semiconductor component (14) and the multilayer wiring thin film (12), and the insulating substrate (
A semiconductor module (6) configured by providing an external connection pad (18) on the outer periphery of the semiconductor module (4) and attaching a heat dissipation fin (22) to the other surface is attached to the first holding member (6).
28) to the printed wiring board (4), and electrically connects the semiconductor module (6) and the printed wiring board (4) through the contacts (26) of the connector block (24) mounted on the printed wiring board. In the printed wiring board unit connected to the printed wiring board (4), a heat conductive material (34) is interposed between the cap (20) and the printed wiring board (4) to transfer heat from the cap (20) to the printed wiring board (4). A heat dissipation structure for a printed wiring board unit that dissipates heat. 3. Semiconductor components (14) on one side of the insulating substrate (4)
is mounted, a multilayer wiring thin film (12) is formed, a cap (20) is attached to collectively seal the semiconductor component (14) and the multilayer wiring thin film (12), and the insulating substrate (
A semiconductor module (6) configured by providing an external connection pad (18) on the outer periphery of the semiconductor module (4) and attaching a heat dissipation fin (22) to the other surface is attached to the first holding member (6).
28) to the printed wiring board (4), and electrically connects the semiconductor module (6) and the printed wiring board (4) through the contacts (26) of the connector block (24) mounted on the printed wiring board. In the printed wiring board unit connected to the semiconductor module (6), an opening (4a) is provided in a portion of the printed wiring board (4) on which the semiconductor module (6) is mounted facing the cap (20), and the first holding member (28) is connected to the printed wiring board unit. ) has a convex portion (36a) projecting toward the cap (20) on the surface opposite to the surface of the printed wiring board (4) to which the second pressing member (3) is attached.
6), and then attach the cap (20) and the protrusion (3).
A heat dissipation structure for a printed wiring board unit, characterized in that a heat conductive material (34) is interposed between the cap (20) and the cap (20) to dissipate the heat to the second holding member (36). 4. The heat dissipation fins (22, 40, 42) are attached to the other surface of the insulating substrate (10) with an adhesive, and the base portion (
4. The heat dissipation structure for a printed wiring board unit according to claim 1, wherein a plurality of through holes (41) are formed in each of the holes (40a, 42a). 5. A groove (44) corresponding to the attachment part of the cap (20) was formed on one surface of the insulating substrate (10'), and the attachment part of the cap (20) was glued into the groove (44). A heat dissipation structure for a printed wiring board unit according to any one of claims 1 to 4.