JPH06334079A - Hybrid ic - Google Patents

Abstract

PURPOSE:To provide a hybrid IC equipped with a heat sink storing no dust or the like which can be manufactured through a simple process and can exhibit high heat dissipation efficiency regardless of the fixing direction. CONSTITUTION:One opening of an aluminium rectangular frame 2 is blocked by a metal base board and a semiconductor device is mounted on the surface of the metal base board surrounded by the frame body. Pins piercing the through part on the peripheral surface of the frame body are connected with a semiconductor device through lead wires. A sealing material is then filled in the frame body and the other opening thereof is blocked, and heat sinks 5a, 5b are secured to the rear of the metal base board. The heat sink 5a, 5b has a plurality of heat dissipation fins 14 connected through connecting parts 15 wherein the imaginary lines L1, L2 connecting the ends of the fins are inclining against the extending direction of four sides of the frame body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid IC that can be used in severe environments such as aircraft, space equipment, nuclear equipment, construction machinery, vehicle equipment, and communication equipment. It is an elevated one.

[0002]

2. Description of the Related Art As is well known, the degree of integration of semiconductors in electronic equipment is increasing year by year, and as a result, miniaturization and multifunctionalization of control equipment are being pursued in all fields. A conventional heat dissipation structure in a hybrid IC incorporating such a highly integrated semiconductor device is merely to attach a heat sink having a heat dissipation fin or a heat sink having an infinite number of heat dissipation pins to a package.

[0003]

However, in the heat sink having the radiation fins, if the radiation fins are oriented in the vertical direction, cool air can flow between the radiation fins from below to exhibit the radiation function as designed. However, if the heat radiation fins are oriented in the horizontal direction, it is difficult for cold air from below to flow between the heat radiation fins in the upper part, so that the heat radiation function as designed cannot be achieved as a whole. That is, since the heat radiation effect is remarkably different depending on the direction of the heat radiation fin, there is a limitation in the mounting direction. In addition, since the conventional heat sink does not sufficiently consider the easiness of air flow between the heat radiating fins, the heat radiating effect is low, and thus the heat sink becomes large and bulky. In addition, a heat sink with heat dissipation pins has no restrictions on the mounting direction, but since the numerous heat dissipation pins must be erected on the base, the manufacturing process is complicated, and if the distance between the heat dissipation pins is narrow, dust will accumulate. If the distance between the heat radiation pins is increased to the extent that dust is not collected, the heat radiation function will be degraded. Therefore, it has been desired to develop a hybrid IC that has a high heat dissipation efficiency regardless of the mounting direction, is easy to manufacture, and has a heat sink that does not collect dust and the like.

[0004]

The present invention has been proposed in view of the above, and a metal base surrounded by a frame is formed by applying a metal base substrate to one opening of a metal rectangular frame to close it. Mount the semiconductor device on the surface of the substrate, connect the pins inserted in the through portion of the peripheral surface of the frame body to the semiconductor device with lead wires, fill the sealing material in the frame body, and open the other opening of the frame body. A heat sink is fixed on the back surface of the metal base substrate, the heat sink has a plurality of heat radiation fins arranged in parallel, the heat radiation fins are connected by connecting portions, and virtual lines connecting the ends of the heat radiation fins are connected to the four sides of the frame body. Is inclined with respect to the extending direction of.

[0005]

When the device is mounted in a vertical state, the virtual straight line at the end of the heat radiation fin is inclined with respect to the side of the frame. When the surrounding air warms up due to the heat radiation from the radiation fins, an airflow is generated between the radiation fins, whereby cold air flows from the bottom to the top.
As for the heat radiation fins of the heat sink, the end portions of the heat radiation fins located above the heat radiation fins project sideways rather than the end portions of the heat radiation fins located below, so that the rising cold air will successively reach the end portions of the projecting heat radiation fins. In each case, it is introduced between the radiation fins. Therefore, the cool air is sufficiently introduced not only between the radiating fins located in the lower portion but also between the radiating fins located in the upper portion. Therefore, regardless of the mounting direction of the hybrid IC, the cooling function according to the heat radiation area of the heat radiation fin can be exhibited.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the hybrid IC 1 includes a rectangular frame body 2 having open upper and lower surfaces, a rectangular metal base substrate 3 made of a titanium alloy, a copper alloy, or the like and closing one opening of the rectangular frame body 2. Metal base substrate 3 surrounded by frame 2
Of the semiconductor device 4 mounted on the front surface of the metal base substrate 3, the heat sink 5 mounted on the back surface of the metal base substrate 3, and the like. The opening is closed.

The rectangular frame body 2 is an extremely short rectangular tubular body obtained by cutting an aluminum mold material to a predetermined length (6 mm in this embodiment), and in the embodiment shown in the drawings, a square whose one side length is 51 mm. A female screw hole 8 is integrally formed on the inner side of the corner portion as a fixing portion, and a mounting portion 9 is integrally formed on the outer side, and ridges 10 are formed at predetermined intervals (5 mm in this embodiment) on the inner surface of each side. Formed,
Through holes serving as through portions 11 are formed at a predetermined pitch on the circumferential surface at positions that do not interfere with the ridges 10. The mounting portion 9 may be annular as shown in FIG.
As shown in FIG. 2, when the notch is formed in a predetermined direction, the frame 2
Is easy to discriminate, and the mounting direction of the heat sink 5 which will be described later is less likely to be wrong.

Then, the rectangular frame 2 is subjected to alumite treatment after the cutting process is completed. In the case of alumite treatment, aluminum oxide is excellent in corrosion resistance, abrasion resistance, and insulation resistance, but its thermal conductivity is extremely low, so it should be thinned to 2 to 4 μm. It is desirable to leave a catch. Further, when the metal base substrate 3 is a copper alloy, it is desirable to perform surface treatment to prevent electrolytic corrosion.

The metal base substrate 3 is a metal plate having a size that closes the opening of the frame body 2, and has a thickness of 3 mm in the illustrated embodiment.
It is a square titanium alloy. In order to mount the semiconductor device 4 on the metal base substrate 3, the first circuit layer is vapor-deposited, then the first circuit pattern is vapor-deposited on the insulating layer, and the second circuit pattern is further vapor-deposited. It can be performed by a method similar to the conventional method such as vapor deposition. The number of semiconductor devices 4 can be set appropriately.

When the semiconductor device 4 is mounted on the metal base substrate 3, each electrode of each semiconductor device 4 and the inner end of the pin 12 inserted into the through hole of the frame 2 are connected by the lead wire 13. To do. An insulating material may be separately interposed between the pin 12 and the inner peripheral surface of the through hole. After completion of this wiring work, the frame 2 is filled with the sealing material 6 to fix and protect the lead wires 13 and the like, and the sealing surface material 7 is filled thereon to form the sealing surface layer. The other surface of the frame 2 is closed by the sealing surface layer.

The sealing material 6 is, for example, an epoxy resin, and the sealing surface material 7 is, for example, a lining material mixed with metal powder. When the sealing surface layer 7 is formed of the sealing surface material 7 containing metal powder, it is possible to prevent the intrusion of noise and the invasion of cosmic rays and the like, and prevent malfunction and destruction of the semiconductor.

Next, the heat sink 5 will be described. In this embodiment, as shown in FIG.
First heat sink 5a attached to one half (right side in the figure)
And the second heat sink 5b attached to the other half (left side in the figure)
Each is made by extruding aluminum into a predetermined length (15 to 20 mm in this embodiment) and cut into a predetermined length.

As shown in FIGS. 2 and 4, the first heat sink 5a has a plurality of heat dissipating fins 14 arranged at predetermined intervals (about 3 mm in this embodiment), and a connecting portion 15 formed between the heat dissipating fins 14. The radiation fins 14 located at both ends are integrally formed with mounting portions 16 having mounting holes 16 '. Then, the heat radiation fin 14 described above
Is about 1 with respect to the center line L0 of the frame body 2 in the mounted state.
The end on the second heat sink 5b side, that is, the end near the center line L0 is aligned on the virtual straight line L1 inclined at 0 degrees, and extends in a direction orthogonal to the virtual straight line L1 and has substantially the same length. Set. Therefore, each radiating fin 14 is not parallel or orthogonal to each side of the frame body 2 in the mounted state, and is always at a position inclined (about 10 degrees).

Further, the adjacent connecting portions 15 and 15 are alternately arranged at different positions so that the adjacent connecting portions are not located on the same straight line. In this way, the connecting portion 15
.., the expansion can be absorbed by the inclination of the adjacent radiating fins 14, 14 even if the connection portion 15 expands due to thermal expansion, and the deformation or displacement of the entire heat sink 5 can be suppressed to a minimum. This allows the heat sink 5
The thermal stress due to expansion and contraction of the metal base substrate 3,
The influence on the frame 2 can be suppressed. Further, the extension of the entire heat sink 5 can be absorbed by bending the arm portion 16 ″ of the mounting portion 16.

It should be noted that if the extruded mold material is cut into a predetermined length, the length of the connecting portion 15 becomes the same as the length of the heat radiating fins 14 and the air flow is obstructed. Therefore, as shown in FIG. , The portion on the metal base substrate 3 side is left as the connecting portion 15, and other unnecessary portions are cut off. Similarly, the mounting portion 16 also has a portion on the side of the metal base substrate 3 left, and other unnecessary portions are cut off so that a short screw can be used.

On the other hand, the second heat sink 5b is symmetrical with the first heat sink 5a, and the configuration of each part is the same as that of the first heat sink 5a. That is, the second heat sink 5
The radiating fins 14 of b are aligned on an imaginary straight line L2 whose end on the first heat sink 5a side (end near the center line L0 of the frame 2) is inclined about 10 degrees with respect to the center line L0 of the frame 2. Cage,
It extends in a direction orthogonal to the virtual straight line L2. Further, the connection parts 15 of the second heat sink 5b are arranged such that the adjacent parts are alternately changed in position.

In order to attach the first and second heat sinks 5a and 5b having the above-mentioned structure to the back surface of the metal base substrate 3, the end surface of the metal base substrate 3 where the connecting portion 15 and the attachment portion 16 are left is brought into contact with the back surface of the metal base. , The frame 2, the metal base substrate 3, and the heat sink are overlapped with each other, a screw 17 is inserted into the mounting hole, and a tip portion of the screw 17 is inserted into the through hole of the metal base substrate 3 to make a tip. The male screw part of is screwed into the female screw hole 8 of the frame body 2 and tightened. In this way, the first and second heat sinks 5a, 5a, 5
When b is attached, the end surfaces of the heat sinks 5a and 5b are in close contact with the back surface of the metal base substrate 3, and the imaginary straight line L1 and the second line of the end portion of the heat radiation fin 14 of the first heat sink 5a
A virtual straight line L at the end of the radiation fin 14 of the heat sink 5b
2 and are located in the shape of a letter.

The hybrid I thus constructed
When C1 is mounted on the printed circuit board 18, the printed circuit board 18 has an opening portion larger than the frame 2 (one side in this embodiment).
(60 mm square hole) 19 is opened, one end of the flat fixing tab 20 is fixed to the mounting portion 9 of the frame body 2 with a screw, and the other end of the tab 20 is opened in the opening portion 19 of the printed circuit board 18. Secure to the rim. When the hybrid IC 1 is fixed to the printed circuit board 18 in this manner, a through void having a width of about 2.5 mm is formed between the opening edge of the opening 19 and the frame 2.

As shown in FIG. 1, when the printed circuit board 18 is mounted on the equipment in a horizontal state, the heat generated from the semiconductor device 4 is transferred from the metal base board 3 to the heat sinks 5a and 5a.
b of the heat sink 5a, 5b
Heat is dissipated from the surface of No. 4 into the air. Since the air warmed by this heat radiation has a smaller specific gravity than the surrounding air, it rises in the space between the radiation fins 14, and the warm air that has risen passes through the through air gap between the frame 2 and the printed circuit board 18. As a result of such an ascending airflow, cold air flows between the radiating fins 14 from below. Therefore, each radiating fin 14 is cooled by the cool air supplied from below, that is, the heat generated from the semiconductor device 4 can be efficiently released, and the semiconductor is cooled.

When the heat generation amount is large like a power IC, a hybrid IC is used by using a step fixing tab 20 'bent in a crank shape as shown by a dotted line in FIG.
Opening 1 in printed circuit board 18 when 1 is fixed
Even if 9 is not enlarged, the cross-sectional area of the through space between the frame 2 and the opening edge can be increased, and the heat dissipation effect can be further enhanced.

On the other hand, when the printed circuit board 18 is mounted on the equipment in a vertical state, the virtual straight lines L1 and L2 at the end portions of the first and second heat sinks 5a and 5b described above are in the shape of a V shape, that is, As shown in FIG. 2, the heat radiating fins 14 on the left and right are mounted in such a manner that the distance between the radiating fins 14 is gradually narrowed from the lower side to the upper side. When mounted in this manner, each of the radiation fins 14 is in an inclined state in which the end on the center line L0 side of the frame 2 is low and the outer end is high. Therefore, the warm air warmed between the radiating fins 14 flows more easily than when the radiating fins 14 are positioned horizontally, and flows in the first heat sink 5a along the inclined lower surface of the radiating fins 14 in the upper right direction in FIG. ,
In the second heat sink 5b, it flows obliquely to the upper left in FIG. 2, and when it rises to the upper end of the inclined fins 14, it rises almost vertically as it is.

When the above-mentioned air flow is generated between the heat radiating fins 14, cool air flows from the bottom to the top in the cool air passage 21 formed between the first heat sink 5a and the second heat sink 5b. Further, in the cold air flow passage 21, the end portion of the heat radiation fin 14 located above the end portion of the heat radiation fin 14 located below protrudes inward, so that the inside of the cool air flow passage 21 rises. The cold air successively strikes the protruding end portions of the radiation fins 14 and is introduced between the radiation fins 14 each time. Therefore, the radiation fins 14 located at the bottom
Cool air is sufficiently introduced not only between the heat radiation fins 14 located above but also between the heat radiation fins 14 and the cooling function according to the heat radiation area of the heat radiation fins 14 can be exhibited.

Although the two heat sinks 5 which are the first heat sink 5a and the second heat sink 5b are provided in the embodiment described above, the number of the heat sinks 5 is not limited to two, and a plurality of heat radiation fins 14 are provided. May be arranged in parallel, the radiation fins 14 may be connected to each other by a connecting portion, and a virtual line connecting the ends of the radiation fins 14 may be inclined with respect to the extending direction of the four sides of the frame body 2.

The second embodiment shown in FIG. 6 is a hybrid IC 1'wherein one opening of the frame 2 is closed by a metal base substrate 3 and the other opening is closed by a metallic lid member 22 such as aluminum. Is. In this case, one end (upper end) of the ridge 10 of the frame 2 is cut out to form a lid receiving portion. Therefore, when the heat sink 5, the metal base substrate 3, and the lid member 22 are fastened together with the fixing screws after the frame body 2 is filled with the sealing material 6, the lid member 22 contacts the lid receiving portion and is fixed at a predetermined position. To be done. Further, in the present embodiment, a plurality of cut-out through-holes 11 are formed on the lower end surface of the frame body 2 at a predetermined pitch, and the pins 12 inserted into the respective cut-out through-holes 11 and the electrodes of the semiconductor device 4 are lead wires 13. In the case of power use, the pin 12 can be bent upward as shown by the dotted line in the figure.

[0025]

As described above, according to the present invention, the imaginary line connecting the ends of the radiation fins is inclined with respect to the extending direction of the four sides of the frame body, so that the heat sink mounting direction, that is, the hybrid IC. It is possible to reliably introduce cool air between the radiating fins regardless of the mounting direction, and to fully exert the cooling function according to the total surface area of the radiating fins. Therefore, the actual heat dissipation efficiency is high regardless of the mounting direction. In particular, in the invention described in claim 2, the virtual line at the end of the first heat sink and the virtual line at the end of the second heat sink are set in a V shape, so that cool air can be efficiently introduced between the heat radiation fins. Therefore, the heat dissipation efficiency can be further improved. Further, the rectangular frame body can be manufactured by cutting the mold material into a predetermined length, so that it is easy to manufacture. Further, since the distance between the heat radiating fins can be set larger than the distance between the heat radiating pins, it is difficult for dust and the like to collect and maintenance is easy. Further, in the invention described in claim 3, since the sealing material is filled in the frame body and the sealing surface layer containing the metal powder is formed thereon to close the other opening portion of the frame body, noise caused by noise is generated. In addition to being able to prevent invasion, it is not easily affected by radiation and has excellent environmental resistance. Therefore, it can be used not only for the control of construction equipment that is used in a bad environment but also for the space equipment that is easily exposed to radiation. Furthermore, in the invention described in claim 4, since the other opening of the frame is closed by the metallic lid member, the environment resistance can be further improved with a simple structure.

[Brief description of drawings]

FIG. 1 is a front view of a hybrid IC with a right half sectioned.

FIG. 2 is a bottom view of a hybrid IC with a partial cross section.

FIG. 3 is a plan view of a frame body.

FIG. 4 is a plan view of a first heat sink.

5A is a right side view of the first heat sink shown in FIG. 4, and FIG. 5B is a left side view.

FIG. 6 is a cross-sectional view of a main part of the hybrid IC in which the other opening of the frame is closed with a metal lid member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hybrid IC 2 Frame 3 Metal base substrate 4 Semiconductor device 5 Heat sink 6 Sealing material 7 Sealing surface material 10 Convex strip 11 Penetration part formed on the peripheral surface of the frame 12 Pins 13 Lead wire 14 Radiating fin 15 Radiating fin 15 Connection part 18 Printed circuit board 21 Cold air flow path 22 Metal lid material

Claims (4)

[Claims] 1. A metal base substrate is applied to one opening of a metal rectangular frame body to close it, and a semiconductor device is mounted on the surface of the metal base substrate surrounded by the frame body. The pin inserted in the through portion and the semiconductor device are connected by a lead wire, the frame body is filled with a sealing material to close the other opening of the frame body, and the heat sink is fixed to the back surface of the metal base substrate. A hybrid characterized in that a plurality of heat radiating fins are arranged in parallel, the heat radiating fins are connected by a connecting portion, and virtual lines connecting the end portions of the heat radiating fins are inclined with respect to the extending directions of the four sides of the frame body. IC. 2. A first heat sink is fixed to one half of the rear surface of the metal base substrate, and a second heat sink is fixed to the other half thereof, and a virtual line connecting the end portions of the first heat sink on the second heat sink side and the first heat sink of the second heat sink. The hybrid IC according to claim 1, wherein an imaginary line connecting the end portions on the heat sink side is positioned in a V shape. 3. The method according to claim 1 or 2, wherein the frame body is filled with a sealing material, and a sealing surface layer containing metal powder is formed thereon to close the other opening of the frame body. Hybrid I
C. 4. The hybrid IC according to claim 1, wherein the other opening of the frame is closed with a metallic lid member.