JPH0582672A - Semiconductor device and manufacturing method thereof - Google Patents

Abstract

PURPOSE:To readily manufacture a semiconductor device having a radiation structure and enhance radiation effects. CONSTITUTION:In at least the one direction of the surface of a chip 4 and the rear surface of a stage 3, for instance in the surface direction of the chip 4, a radiation block 6 is so provided as to face onto the same surface as the package one. In this embodiment, the radiation block 6 is vacuum-chucked and fixed by a vacuum-chucking hole formed in an upper metal mold at resin molding and molded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having a heat dissipation structure.

In recent years, the amount of heat generated by semiconductor devices has increased with the high integration of semiconductor devices. Further, as the weight and the size are reduced, it is required to reduce the thickness of the package. Therefore, it is necessary to improve the heat dissipation effect while reducing the size.

[0003]

2. Description of the Related Art FIGS. 11A and 11B are sectional views of a conventional semiconductor device. 11A is a plan sectional view, FIG.
11B is a cross-sectional view taken along the line AA of FIG. 11
In (A) and (B), the semiconductor device 30 is of a so-called QFP (Quad Flat Package) type, and the semiconductor chip 3 is mounted on the island 32 in the central portion of the lead frame 31.
3 is installed. Then, the semiconductor chip 33 and the inner leads 34 of the lead frame 31 are bonded by the wires 35 and molded by the sealing resin 36.
Further, the outer leads 37 of the lead frame 31 are processed into an L shape.

Such a semiconductor device 30 is generally used for surface mounting, and heat generated from the semiconductor chip 33 during driving is naturally radiated from the sealing resin 36 and the outer leads 37.

[0005]

However, as the semiconductor chip 33 becomes higher in density and larger in size, the amount of heat generated increases. Therefore, there is a problem that natural heat dissipation cannot cope with it, which causes failure of the semiconductor chip 33.

Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a semiconductor device which can be easily manufactured and has a high heat dissipation effect.

[0007]

In the semiconductor device in which a chip is mounted on a stage of a lead frame and is resin-molded after the connection with the lead frame, the surface direction of the chip and the back surface of the stage are solved. It is solved by providing a predetermined number of heat dissipation blocks exposed on the surface of the resin-molded package in at least one of the directions. A communication hole for adsorbing and fixing the stage is formed.

In this case, the method of manufacturing a semiconductor device comprises a step of attaching a predetermined number of heat radiation blocks to at least one of the front surface direction of the chip and the back surface direction of the stage, or disposing them at predetermined intervals. A step of adsorbing and fixing the heat dissipation block through an adsorption hole formed in at least one of an upper mold and a lower mold; and a step of resin-molding the periphery of the chip having the heat dissipation block, as appropriate A communication hole is formed in the heat dissipation block arranged in the back surface direction of the stage to adsorb and fix the stage.

[0009]

As described above, the heat dissipation block is provided on at least one of the front surface direction of the chip and the rear surface direction of the stage. That is, the heat dissipation block is provided only in the front surface direction of the chip, only in the rear surface direction of the stage, or in both the front surface direction of the chip and the back surface direction of the stage.
Further, the heat dissipation block is exposed on the surface of the resin-molded package.

Since the heat dissipation block is exposed in this way, it is possible to dissipate the amount of heat generated by the chip with high efficiency.

Further, when the heat dissipation block is arranged on the back surface of the stage, a communication hole is appropriately formed in the heat dissipation block. This communication hole is used to adsorb and fix the stage through the communication hole formed in the mold during resin molding, preventing the displacement of the stage and chip during injection of the sealing resin, and using it for the stage and connection. It is possible to prevent the exposed wire from being exposed, and it is possible to reduce the thickness. Further, the communication hole formed in the heat dissipation block can be used as a screw hole or a positioning hole when attaching the external heat dissipation means after manufacturing.

[0012]

Embodiments (A) FIG. 1 shows a block diagram of a first embodiment of the present invention. In FIG. 1, a semiconductor device 1 has a chip 4 mounted on a stage 3 of a lead frame 2 having a predetermined pattern.
The inner lead 2a of the lead frame 2 is bonded with the wire 5.

On the surface of the chip 4, a heat dissipation block 6 formed of a good metal for heat dissipation (for example, aluminum)
Are fixed by an adhesive 7 which is an insulating fixing member such as an epoxy type. Then, it is molded with the sealing resin 8 and exposed so that the surface of the heat dissipation block 6 becomes the same surface as the package.

The outer lead 2 of the lead frame 2
The b is bent into an L shape for surface mounting. It should be noted that all of the leads for surface mounting are shown in the present embodiment and the following, but the same applies to lead insertion without bending.

Here, FIG. 2 shows a diagram for explaining the manufacturing method of FIG. In FIG. 2, first, the chip 4 is mounted on the stage 3 of the lead frame 2, and after bonding with the wire 5, the heat dissipation block 6 is attached to the surface of the chip 4 with the adhesive 7. On the other hand, the upper die 9a has a suction hole 1
0a is formed and communicates with a vacuum source (not shown).

Therefore, the mold portion around the chip 4 is positioned in the cavity 11 formed by the upper mold 9a and the lower mold 9b, and the heat dissipation block 6 is vacuum-adsorbed and fixed by the adsorption holes 10a. Then, the sealing resin 8 is sealed from the gate 12 to perform molding. As a result, the heat dissipation block 6 can be surely exposed on the package surface, and the amount of heat generated in the chip 4 can be dissipated with high efficiency. That is, since the heat dissipation block 6 is fixed by the suction holes 10a, it is possible to prevent the encapsulation resin 8 from entering between the upper die 9a and the heat dissipation block 6 to cause a resin burr.

In the case of a thin semiconductor device, the suction hole 1
Since the heat radiating block 6 is fixed by 0a, the stage 3 (chip 4) is not displaced due to the injection pressure of the sealing resin 8, and the stage 3 and the wire 5 are exposed on the package surface after molding and electrically short-circuited. It is possible to prevent the situation that causes

The heat radiation block 6 may be made of a polymer material such as epoxy resin for the purpose of preventing the displacement of the stage 3 (chip 4).

FIG. 3 shows a block diagram of another embodiment of FIG. In the semiconductor device 1 of FIG. 3, the heat dissipation block 6 in FIG. 1 is a heat dissipation block 6a having an inverted convex cross section, and the heat dissipation block 6a is exposed on substantially the entire surface of the package to increase the exposed area. As a result, a higher heat radiation effect can be obtained. The manufacturing method in this case is the same as in FIG. Although not shown, a slit may be formed on the exposed surface of the heat dissipation block 6a in order to further increase the exposed area of the heat dissipation block 6a.

Next, the construction and manufacturing method of the second embodiment of the present invention will be described with reference to FIG. Semiconductor device 1 in FIG.
Is attached to the back surface of the lead frame 2 on the stage 3 with an adhesive 7
The heat dissipation block 6b is attached by a. The adhesive 7a in this case may be an epoxy resin as described above,
It may be solder. That is, the adhesive used on the surface of the chip 4 must be insulative.
What is used for the back surface may be either insulating or conductive.

On the other hand, a suction hole 10b is formed in the lower mold 9b and communicates with a vacuum source (not shown). Therefore, the suction holes 10
The heat radiation block 6b is vacuum-adsorbed by b and resin molding is performed. In this case, the heat dissipation block 6b is exposed on the back surface of the package, and has the same effect as in FIGS.

Next, FIG. 5 shows a block diagram of a third embodiment of the present invention. The semiconductor device 1 in FIG. 5 is provided with the heat dissipation blocks 6 and 6b exposed on the package surface in both the front surface direction of the chip 4 and the rear surface direction of the stage 3. In this case, the heat dissipation block 6 in the surface direction of the chip 4
Are arranged at a predetermined distance from the chip 4, and the stage 3
The heat dissipation block 6b is fixed to the back surface of the adhesive with an adhesive 7a.

The recesses 13a to 13d formed on the surfaces of the heat dissipation blocks 6 and 6b are for aligning with the mold at the time of molding described later.

Here, FIG. 6 shows a diagram for explaining the manufacturing method of FIG. In FIG. 6 (A), first, the upper mold 9a is formed with a suction hole 10a communicating with a vacuum source, and the convex portion 14 for alignment is provided in the cavity 11.
a and 14b are formed. Also, the lower mold 9b is also the same.
A suction hole 10b communicating with a vacuum source is formed, and projections 14c and 14d for alignment are provided in the cavity 11.
Is formed.

Therefore, the heat dissipation block 6 is provided in the cavity 11 of the upper mold 9a, and the concave portions 13a and 13b and the convex portion 14 are provided.
A and 14b are aligned and fixed by suction through the suction holes 10a. On the other hand, the heat dissipation block 6b is provided in the cavity 11 of the lower mold 9b, and the concave portions 13c and 13d and the convex portions 14c and 14 are provided.
It is aligned at d and is fixed by suction through the suction hole 10b. Further, the heat dissipation block 6b is coated with a low temperature solder 7a such as In (indium) alloy which is melted at a mold temperature (for example, 170 ° C.).

Then, in FIG. 6 (B), a molding portion around the chip is positioned in the cavity 11 and the sealing resin 8 is sealed therein. In this case, the stage 3 is positioned on the solder 7 before encapsulation, and the solder 7 melts during molding. This forces the stage 3 to the correct position,
The enclosed sealing resin 8 is cooled and solidified, and the solder 7 is also solidified, so that the stage 3 can be molded at the correct position.

As described above, since the heat dissipation blocks 6 and 6b are exposed on the same surface as the surface of the package, higher heat dissipation can be obtained and the heat dissipation blocks 6 and 6b can be fixed. Since the molding is performed, the stage 3 and the wire 5 do not appear on the package surface even when the thickness is reduced, and an electrical short circuit can be prevented.

FIG. 7 shows a block diagram of another embodiment of FIG. In the semiconductor device 1 of FIG. 7, a heat transfer block 15, which is a heat transfer member, is interposed on the chip 4 by an insulating adhesive 7 between the chip 4 and the heat dissipation block 6, and other configurations are the same. It is similar to FIG. By interposing this heat transfer block, higher heat dissipation can be obtained.

As in the first and third embodiments,
When disposing the heat dissipation block 6 in the surface direction of the chip 4,
A screw hole may be formed in the heat dissipation block 6 and an external heat dissipation means may be attached to the screw hole.

Example (B) Example (B) is a case where a communication hole is formed in the heat dissipation block 6b arranged in the back surface direction of the stage 3 in Example (A).

FIG. 8 is a diagram for explaining the structure and manufacturing method of the fourth embodiment of the present invention. In FIG. 8, the heat dissipation block 16 is located on the back surface of the stage 3, and a communication hole 17 is formed in the heat dissipation block 16.

On the other hand, at the time of molding, suction holes 10b are formed in the lower mold 9a at positions corresponding to the communication holes 17.
That is, as compared with the case of FIG. 4, the adhesive 7a can be omitted by forming the communication hole 17.

When resin-molding such a semiconductor device 1, first, the lower die 9b is provided with the suction hole 10b and the communication hole 17.
The heat dissipation block 16 is placed by aligning the positions. Then, the stage 3 is positioned and arranged on the heat dissipation block 16 in the cavity 11 formed by the upper mold 9a, and the stage 3 is placed through the suction hole 10b and the communication hole 17.
Are fixed by vacuum adsorption. In this state, the sealing resin 8 is enclosed and molding is performed.

As a result, as in the case of FIG. 4, the heat dissipation block 16 is molded on the back surface of the package while being exposed,
It is possible to obtain a high heat dissipation effect and prevent the displacement of the stage 3 during resin encapsulation in the case of thinning.

Next, FIG. 9 shows a block diagram of a fifth embodiment of the present invention. In the semiconductor device 1 of FIG. 9, the heat dissipation block 16 in which the communication hole 17 is formed on the back surface of the stage 3 is directly arranged without interposing an adhesive, and other configurations are similar to those of FIG. ..

Here, FIG. 10 is a view for explaining the manufacturing method of FIG. In FIG. 10 (A), first, the upper mold 9a and the lower mold 9b are respectively provided with suction holes 10a, 1a.
0b is formed, and the protrusions 14a, 14 of the upper mold 9a are formed.
b and the recesses 13a and 13b are aligned with each other, the heat dissipation block 6 is arranged, and suction-fixed through the suction holes 10a. Further, the heat radiation block 16 is arranged by aligning the suction hole 10b and the communication hole 17 by the convex portions 14c and 14d and the concave portions 13c and 13d of the lower mold 9b.

Then, in FIG. 10B, the chip 4 is mounted on the heat dissipation block 16, the wire-bonded stage 3 is mounted, and the suction hole 10b and the communication hole 17 are provided.
The stage 3 is adsorbed and fixed via. Then, molding is performed with the sealing resin 8.

As a result, the two heat dissipation blocks 6, 16
Is exposed on the surface of the package, and a higher heat dissipation effect can be obtained. In this case, the manufacturing process is the same as the conventional process except that the process of disposing the heat dissipation blocks 6 and 16 is increased.

Further, in the semiconductor device 1 shown in FIG. 9, the heat transfer block 15 is interposed between the chip 4 and the heat dissipation block 6 as shown in FIG. 7, whereby a further higher heat dissipation effect can be obtained.

In the first to fifth embodiments described above, the chip 4 is shown in the face-up case, but the same effect can be obtained in the face-down case. In this case, the communication hole 1 formed in the heat dissipation block 16 arranged on the back surface of the stage 3 shown in the fourth and fifth embodiments of FIGS.
The external heat radiating means may be attached by screwing the communication hole 17 with 7 facing upward.

[0041]

As described above, according to the present invention, the heat dissipation block is provided in at least one of the front surface direction of the chip and the back surface direction of the stage, and the heat dissipation block provided in the back surface direction of the stage has a stage during manufacturing. By forming the communication hole for adsorbing and fixing the resin, the amount of heat generated from the chip can be radiated with high efficiency in a stable resin mold.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the manufacturing method of FIG.

FIG. 3 is a configuration diagram of another embodiment of FIG.

FIG. 4 is a diagram for explaining a configuration and a manufacturing method of a second embodiment of the present invention.

FIG. 5 is a configuration diagram of a third embodiment of the present invention.

6A and 6B are views for explaining the manufacturing method of FIG.

FIG. 7 is a configuration diagram of another embodiment of FIG.

FIG. 8 is a diagram for explaining a configuration and a manufacturing method of a fourth example of the present invention.

FIG. 9 is a configuration diagram of a fifth embodiment of the present invention.

FIG. 10 is a diagram for explaining the manufacturing method in FIG.

FIG. 11 is a cross-sectional view of a conventional semiconductor device.

[Explanation of symbols]

 1 Semiconductor Device 2 Lead Frame 3 Stage 4 Chip 6, 6a, 6b, 16 Heat Dissipation Block 7, 7a Adhesive 8 Sealing Resin 9a Upper Mold 9b Lower Mold 10a, 10b Adsorption Hole 15 Heat Transfer Block 17 Communication Hole

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Koji Saito 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor, Shoji Takenaka 1015, Kamiodanaka, Nakahara-ku, Kawasaki, Kanagawa Prefecture, Fujitsu Limited

Claims (8)

[Claims] 1. A stage (3) of a lead frame (2)
The chip (4) is mounted on the lead frame (2)
In a semiconductor device that is resin-molded after being connected to, a predetermined surface exposed on the front surface of the resin-molded package in at least one of the front surface direction of the chip (4) and the back surface direction of the stage (3). A semiconductor device comprising a plurality of heat radiation blocks (6, 6a, 6b, 16). 2. A fixing member (7a, 7b) is interposed between the heat dissipation block (6, 6b) and the back surface of the stage (3) or the front surface of the chip (4). 1. The semiconductor device according to 1. 3. The heat transfer member (15) is interposed between the heat dissipation block (6) located in the surface direction of the chip (4) and the chip (4).
The semiconductor device described. 4. The heat dissipation block (6a) located in the surface direction of the chip (4) is formed in a reverse convex shape in cross section for enlarging the exposed area of the package (8). The semiconductor device according to 1, 2, or 3. 5. A communication hole (17) for adsorbing and fixing the stage (3) at the time of manufacturing is formed in the heat dissipation block (16) provided on the back surface side of the stage (3). The semiconductor device according to claim 1. 6. The semiconductor device according to claim 5, wherein an external heat dissipation means is attached to the communication hole (17) formed in the heat dissipation block (16). 7. The stage (3) of the lead frame (2)
The chip (4) is mounted on the lead frame (2)
In a method of manufacturing a semiconductor device, which is resin-molded with a mold (9a, 9b) after connection with, a predetermined number of heat dissipation blocks (6, 6a, 6b) are provided in the surface direction of the chip (4) and the stage ( 3) A step of attaching to at least one of the back surface directions or arranging at a predetermined interval;
And a step of adsorbing and fixing via a suction hole (10a, 10b) formed in at least one of the lower die (9b) and the periphery of the chip (4) having the heat dissipation block (6, 6a, 6b) And a step of resin-molding the resin. A method of manufacturing a semiconductor device, comprising: 8. A communication hole (17) is formed in the heat dissipation block (16) arranged in the back surface direction of the stage (3) to adsorb and fix the stage (3). 7. The method for manufacturing a semiconductor device according to 7.