JPH0648865Y2 - Heat sink fin mounting mechanism for semiconductor devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a heat dissipation fin mounting mechanism for a semiconductor device for mounting an air cooling heat dissipation fin on a resin-sealed power semiconductor device.

<Prior Art> Generally, a resin-sealed power semiconductor device emits high heat when it is driven, and therefore, a cooling radiating fin is mounted. In the conventional semiconductor device, the heat radiation fins are fixed by screwing as shown in FIGS.

That is, a thermosetting encapsulation resin (epoxy resin) is used to shield the inside of the semiconductor device 1 from the outside during the resin encapsulation process.
3 is filled and heat-cured. At this time, the thermosetting encapsulating resin 3 causes cure shrinkage (epoxy resin generally causes 0,2% to 1,0% cure shrinkage in the longitudinal direction. However, this also depends on heating conditions. ). Therefore, the semiconductor device itself may be deformed like a bow. Therefore, as shown in FIG. 11, it is necessary to take measures such as supplementing the outer frame 4 with a reinforcing member 5 such as a beam or making the metal base substrate 6 on the back surface have substantially the same area as the semiconductor device 1.

Next, the semiconductor device 1 on which the resin sealing step has been completed is set on the air-cooling heat radiation fins 2 and tightened and fixed by the screws 7. At this time, in order to improve the heat dissipation effect, the heat dissipation silicon grease must be applied to the metal base substrate 6 side or the air cooling heat dissipation fin 2 side.

<Problems to be Solved by the Invention> As shown in FIGS. 7 to 10, the semiconductor device 1 is provided with a cooling fin 2 for air cooling.
In the case of mounting on the metal base substrate 6 on the back surface of the semiconductor device 1, heat-radiating silicon grease is applied, the substrate 6 is set on the heat-radiating fin 2 for air cooling, and then it is fastened and fixed to the screw 7. However, since the metal base substrate 6 is forcibly fastened to the air-conditioning heat radiating fins 2 by the screw 7, if the metal base substrate 6 has a certain amount of warp, the reaction force of screw tightening on the metal base substrate 6 is exerted. As a result, a shearing force is applied, strain is also applied to the power semiconductor element 1a inside the semiconductor device, and sometimes the power semiconductor element 1a is destroyed.

Further, the reaction force is always applied to the screw 7, and the screw 7 may loosen during long-term storage.

Further, internal heat generated during operation of the semiconductor device 1 is transmitted to the air-cooling heat dissipation fins 2 only through the metal base substrate 6, and heat dissipation efficiency also deteriorates. Therefore, the cooling fin 2 for air cooling
It is inevitable to upsize.

In view of the above, the present invention does not require screw fastening when mounting a heat dissipation fin on a semiconductor device, prevents destruction of a power semiconductor element, improves the reliability of the semiconductor device, and reduces the size of the heat dissipation fin. An object of the present invention is to provide a heat dissipation fin mounting mechanism for a semiconductor device, which can realize a simplified heat dissipation fin mounting process.

<Means for Solving the Problems> In order to achieve the above-mentioned object, the heat dissipation fin mounting mechanism of the semiconductor device according to the present invention has a heat dissipation fin as shown in FIGS.
15 and the semiconductor element 12 in the outer frame 11 inserted and mounted in the recess 17 formed in the heat dissipation fin 15.
A semiconductor device 14 in which the resin is sealed with a thermosetting sealing resin 13
The structure consists of and.

<Operation> In the above means for solving problems, the semiconductor internal element 12 is provided with the outer frame 11
Then, these are inserted into the recesses 17 of the heat dissipation fins 15.

After that, in order to shut off the semiconductor internal element 12 and the outside air,
A thermosetting sealing resin 13 is filled in the outer frame 11 for resin sealing.

At this time, a curing shrinkage action occurs in the thermosetting sealing resin 13,
The outer frame 11 warps in a bow shape due to the hardening and shrinking action. Due to this warping force, the outer frame 11 is sandwiched between the recesses 17 of the heat radiation fins 15, and the semiconductor device 14 is fixed to the heat radiation fins 15.

Thus, the heat dissipation fin 15 is provided with the recess 17 for inserting and mounting the semiconductor device 14, and after inserting the semiconductor device 14 into the recess 17, the semiconductor internal element 12 is resin-sealed with the thermosetting sealing resin 13. Therefore, when the semiconductor device 14 is inserted and fixed in the heat dissipation fin 15, the outer frame 11 due to the curing shrinkage characteristic of the thermosetting sealing resin 13 is used.
The semiconductor device can be fixed to the heat dissipation fin without screwing.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a state in which a heat dissipation fin is attached to a semiconductor device by using the attachment mechanism of the embodiment of the present invention.
The same figure shows the same front view, FIG. 3 shows the same plan view, FIG. 4 shows the same side view, FIG. 5 shows the same heat radiating fin perspective view, and FIG. It is a figure which shows the state of.

As shown in the figure, in the heat dissipation fin mounting mechanism of the semiconductor device of this embodiment, the semiconductor internal element 12 in the outer frame 11 is sealed with the thermosetting sealing resin 13.
A semiconductor device 14 formed by resin sealing with
For mounting the semiconductor device 14 in the heat dissipation fin 15 is formed with a recess 17,
An outer frame formed by the curing shrinkage characteristics of the thermosetting sealing resin 13 in the recess 17
The semiconductor device 14 is inserted and fixed by utilizing the warp of 11.

As shown in FIGS. 1 to 4, the outer frame 11 is formed in a box shape having a semiconductor internal element insertion opening 18 that vertically penetrates so that the semiconductor internal element 12 is fitted therein. The semiconductor device 14 is formed in the recess 17 of the heat dissipation fin 15 at the bottom of both side walls of the outer frame 11.
6 is inserted and fixed, a protrusion 19 which is warped in the A direction is formed to protrude outward due to the curing and shrinking characteristics of the sealing resin 13, as shown in FIG.

As shown in FIG. 1, the semiconductor internal device 12 is connected to the metal base substrate 21, the power semiconductor device 23 mounted on the metal base substrate 21 via the heat spreader 22, and connected to the metal base substrate 21 to input / output externally. It is composed of tab terminals 24 and the like. In the semiconductor internal element 12, the metal base substrate 21 is fixed to the outer frame 11, silicon oil 25 is injected into the outer frame 11, and then the resin is sealed with a thermosetting sealing resin (epoxy resin) 13. . As a result, the metal base substrate 21 warps in the B direction due to the curing shrinkage characteristic C of the sealing resin 13, as shown in FIG. In FIG. 1, reference numeral 26 is a bonding wire that connects the power semiconductor element 23 and the metal base substrate 21.

The heat dissipation fin 15 is made of a normal aluminum extruding agent as its material, and as shown in FIG. And projections 27.

The recess 17 is arranged in the center of the heat dissipation fin body 15a, and is provided so as to penetrate the body 15a in the front-rear direction (see FIG. 5). The recess 17 is formed with a semiconductor internal element mounting groove 28 into which the semiconductor internal element 12 (metal base substrate 21) is inserted and fixed, and a projection of the outer frame 11 which is formed continuously from the mounting groove 28 in the left-right direction. An outer frame guide groove 29 in which 19 is inserted and fixed is formed. In the width direction D of the guide groove 29, as shown in FIG. 1, when the outer frame 11 is fixed to the recess 17, the outer frame 11 can be fixed by using the warp due to the curing shrinkage property of the resin 13.
It is set to minimize the gap between the protrusions 19 of the eleven.

Next, the procedure for attaching the semiconductor device 14 and the heat dissipation fin 15 will be described with reference to FIGS.

As shown in FIG. 1, the semiconductor internal element 12 not resin-sealed
Are fixed to the outer frame 11, and these are recessed in the cooling fin 15 for air cooling.
Insert in 17. At this time, the outer frame 11 and the semiconductor internal element
If the heat dissipating fins 15 are heated to some extent before the heat dissipating fins 15 are attached to the heat dissipating fins 15, they will expand and become easier to insert.

After that, in order to shut off the semiconductor internal element 12 and the outside air,
A thermosetting sealing resin 13 is filled in the outer frame 11 for resin sealing.

At this time, the thermosetting sealing resin 13 has a curing shrinkage action (see C in FIG. 6). Due to this curing shrinkage action, the outer frame 11
The protrusion 19 is pulled upward and pressed against the guide groove 29 of the recess 17 of the heat dissipation fin 15. Further, the reaction force also presses down the mounting groove 28 of the recessed portion 7 of the heat dissipation fin 15 downward (direction B) (this state is shown in FIG. 6), that is, the semiconductor device 14. The outer frame 11 warps in a bow shape due to the curing shrinkage of the thermosetting sealing resin 13, and the warping force causes the outer frame 11 to be sandwiched in the recess 17 of the air-cooling heat dissipation fin 15. As a result, the semiconductor device 14 is fixed to the heat radiation fins 15 for air cooling.

Thus, the heat dissipation fin 15 is provided with the recess 17 for inserting and mounting the semiconductor device 14, and after inserting the semiconductor device 14 into the recess 17, the semiconductor internal element 12 is resin-sealed with the thermosetting sealing resin 13. Therefore, when the semiconductor device 14 is inserted and fixed in the heat dissipation fin 15, the outer frame 11 due to the curing shrinkage characteristic of the thermosetting sealing resin 13 is used.
The semiconductor device can be fixed to the heat dissipation fin without screwing.

Therefore, unlike the conventional case, the shearing force generated at the time of screw tightening is not applied, the strain is not applied to the power semiconductor element inside the semiconductor device, and the semiconductor element is not destroyed.

Further, conventionally, since the heat dissipation fin and the semiconductor device are fixed by screw tightening, a reaction force is always applied to the screw and the screw loosens for long-term storage.However, the present invention requires screw tightening. Since it does not, rattling due to loosening of screws can be prevented, and the heat radiation fin can be fixed over a long period of time.
Therefore, the reliability of the semiconductor device itself is improved.

Furthermore, since the semiconductor device has a structure embedded inside the heat dissipation fin for air cooling, internal heat generated during operation of the semiconductor device is transmitted to the heat dissipation fin through the outer frame and the metal base substrate, resulting in a more efficient heat dissipation effect. The reliability of the semiconductor device can be improved and the heat dissipation fin can be miniaturized.

Furthermore, since the resin sealing step and the semiconductor device and air-cooling heat radiation fin mounting step can be performed at the same time, the conventional screw tightening step can be reduced and the heat radiation fin mounting step can be simplified.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

For example, although the heat dissipation fin of the above-described embodiment is formed with a plurality of pleated protrusions, it may have different shapes depending on the usage conditions and purpose of use of the semiconductor device.

Further, instead of the metal base substrate, a substrate with a ceramic system may be used.

<Effects of the Invention> As is apparent from the above description, according to the present invention, the heat dissipation fin is provided with the recess for inserting and mounting the semiconductor device, and after the semiconductor device is inserted into the recess, the semiconductor internal element is thermoset and sealed. Since it is resin-sealed with a resin, before the semiconductor device is inserted and fixed in the heat dissipation fin, it can be fixed by using the warp of external force due to the curing shrinkage property of the thermosetting encapsulation resin, and the semiconductor can be fixed in the heat dissipation fin without screws. The device can be fixed.

Therefore, as in the past, the shearing force generated during screw tightening is no longer applied, the power semiconductor element inside the semiconductor device is not distorted, the semiconductor element is not destroyed, and the looseness of the screw causes Rattle can be prevented, the heat dissipation fin can be fixed over a long period of time, and the reliability of the semiconductor device itself is improved.

Further, since the semiconductor device has a structure embedded inside the heat dissipation fin, internal heat generated during operation of the semiconductor device is transmitted to the heat dissipation fin through the outer frame and the metal base substrate, and a more efficient heat dissipation effect can be expected. The reliability of the semiconductor device is improved, and the heat dissipation fin can be downsized.

Further, since the resin sealing step and the semiconductor device and heat radiation fin attaching step can be performed at the same time, the conventional screw tightening step can be reduced, and the heat radiation fin attaching step can be simplified, which has an excellent effect.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state in which a heat dissipation fin is attached to a semiconductor device by using the attachment mechanism of the embodiment of the present invention.
The same figure shows the same front view, FIG. 3 shows the same plan view, FIG. 4 shows the same side view, FIG. 5 shows the same heat radiating fin perspective view, and FIG. It is a figure which shows the state of. FIG. 7 is a front view showing an example in which a heat dissipation fin is attached to a semiconductor device by conventional screw fastening, FIG. 8 is a side view thereof, FIG. 9 is a plan view thereof, and FIG. 10 is a sectional view thereof. FIG. 11 is a front view of the semiconductor device, and FIG. 12 is a perspective view of the heat dissipation fin. 11: Outer frame, 12: Semiconductor internal element, 13: Thermosetting sealing resin, 14:
Semiconductor device, 15: heat dissipation fin, 17: recess.

Claims (1)

[Scope of utility model registration request] 1. A semiconductor device in which a heat radiation fin and a semiconductor element in an outer frame are inserted and mounted in a concave portion formed in the heat radiation fin, and a semiconductor element in an outer frame is resin-sealed with a thermosetting sealing resin in a state of being inserted and mounted. A heat dissipation fin mounting mechanism for a semiconductor device including the device.