JP2001015645A - Resin-sealed semiconductor device and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] In a resin-encapsulated semiconductor device having a built-in heat sink, it is possible to prevent a short circuit between the heat sink and the lead frame while suppressing an increase in cost. SOLUTION: In a resin-sealed semiconductor device 100, a lead frame 20 on which an IC chip 10 is mounted is arranged on a heat sink 40 arranged in a mold, and a mold resin 50 is filled in the mold. Thus, the heat sink 40, the IC chip 10, and the lead frame 20 are sealed so as to surround them. Between the radiator plate 40 and the inner leads 22 of the lead frame 20, a spacer member 70 made of an insulator fixed by a mold resin 50 and installed by being dropped into a mold is interposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-encapsulated semiconductor device having a built-in heat sink, for example, a power semiconductor such as a driver IC or a power supply IC used in an engine control ECU, an ABS ECU, and the like in an automobile. It is suitable for use in an apparatus.

[0002]

2. Description of the Related Art Conventionally, a resin-encapsulated semiconductor device having a built-in heat sink (hereinafter referred to as a heat sink built-in package) is disclosed in, for example, JP-A-60-110145 and JP-A-61-194861. Gazette, JP-A-8-70016
Japanese Patent Application Laid-Open Publication No. H10-21078 and the like have been proposed. FIG. 3 shows a general schematic cross-sectional structure of the package with a built-in heat sink.

The IC chip 10 is mounted on an island portion 21 of a lead frame 20 and is connected to inner leads 22 of the lead frame 20 by bonding wires 30. Further, a heat sink (heat spreader) 40 independent of the lead frame 20 is provided below the lead frame 20.
As shown in FIG. 3, is sealed and integrated with a mold resin 50 made of, for example, epoxy resin or the like.

In this package with a built-in heat sink, the heat sink 40 is thrown into a mold (not shown) for molding before resin sealing, and then the lead frame 20 on which the IC chip 10 is mounted is mounted on the lead frame 20. It is manufactured by performing a series of resin sealing steps of disposing in a mold, filling the resin, and simultaneously sealing the resin. As described above, since the normal lead frame and the normal mold can be applied to the package with a built-in heat sink, there is an advantage that cost increase can be minimized and heat radiation can be improved.

[0005]

However, in the structure shown in FIG. 3, the lead frame 2 is not sealed when the resin is sealed.
When 0 is bent downward or when the heat radiation plate 40 has poor horizontality, there is a problem that the inner lead 22 of the lead frame 20 and the heat radiation plate 40 come into contact with each other and short-circuit is easily caused.

In order to solve such a problem, a package with a built-in heat sink having a structure as shown in FIG.
No. 10145) has been proposed. This structure aims at preventing the short circuit with the lead frame 20 by providing the insulating film J1 on the heat radiating plate 40 with the adhesive J2 interposed therebetween. Since a step of bonding to the substrate is required, there is a problem that the number of steps is increased and the cost is increased. In addition, there is an example in which such an insulating film is provided by applying and curing the heat sink, but the same problem occurs.

Accordingly, the present invention has been made in view of the above-described problems, and has been proposed in a package with a built-in heat sink while suppressing an increase in cost.
An object of the present invention is to realize prevention of a short circuit between a heat sink and a lead frame.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, in a package with a built-in radiator plate, the package is sealed with a sealing resin (50). A spacer member (70) made of an insulator for preventing a short circuit with the lead frame (20);
The spacer member is disposed between the heat radiating plate and the lead frame by being dropped into a mold, and is fixed by the resin.

As a result, the spacer member (70) is dropped onto the heat sink (40) disposed in the mold, and the lead frame (20) on which the semiconductor element (10) is mounted is disposed thereon. Then, by filling the resin (50) into the mold, a resin-sealed semiconductor device can be manufactured. Therefore, in a conventional series of resin sealing steps, it is possible to secure insulation by a simple method of dropping a spacer member into a mold, and to suppress a cost increase while maintaining a heat radiating plate and a lead frame. Can be prevented.

Further, when the spacer member (70) is formed by covering the surface of a material having excellent heat conductivity with an insulating material, the spacer member (70) can be formed between the heat sink and the lead frame. In addition to the effect of preventing short-circuiting, the effect that heat dissipation can be further improved is also added. Specifically, this can be achieved by employing a ceramic or metal surface such as alumina, aluminum nitride, or silicon carbide whose surface is insulated as the spacer member.

Further, the invention according to claim 3 relates to a method of manufacturing a package with a built-in heat sink, wherein a spacer member (70) made of an insulator is provided on a heat sink (40) arranged in a mold. ), The lead frame (20) on which the semiconductor element (10) is mounted.
Is arranged, and subsequently, the resin is filled in the mold. Thus, it is possible to prevent a short circuit between the heat sink and the lead frame while suppressing an increase in cost.

Incidentally, the reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. The embodiment described below is a modification of the resin-encapsulated semiconductor device shown in FIGS. 3 and 4, and the same parts as those in FIGS. 3 and 4 are denoted by the same reference numerals in the drawings. The description will be simplified. FIG. 1 shows a resin-sealed semiconductor device according to an embodiment of the present invention (a package with a built-in heat sink, hereinafter simply referred to as a semiconductor device).
100 shows a schematic cross section.

IC chip (semiconductor element in the present invention) 1
0 is A on the island portion 21 of the lead frame 20.
It is bonded via a die bonding agent 60 made of g paste, solder, or the like. The lead frame 20 includes an island portion 21 and leads 22 and 23 drawn out of the mold resin 50 from the periphery of the island portion 21. The leads 22 and 23 are made of the molding resin 5
The inner lead 22 is a portion located in the inner portion 0, and the outer lead 23 is a portion drawn out of the mold resin 50. Then, the IC chip 10 is connected to the wire 30
In addition, electric signals can be exchanged with the outside via the leads 22 and 23.

In the mold resin 50, the side opposite to the surface on which the IC chip 10 is mounted on the lead frame 20 (FIG. 1).
Heat sink (heat spreader) 40 located on the lower side in the middle
Is formed such that a step surface 41 protruding in the direction of the lead frame 20 is formed, and the step surface 41 contacts the island portion 21 on the opposite side of the IC chip 10.
The heat radiating plate 40 is provided to promote heat radiation of the IC chip 10, and is made of a material having excellent thermal conductivity such as copper (Cu) or aluminum (Al).

Further, the heat dissipation plate 40 needs to have a large surface area in order to improve heat dissipation.
, Almost the entire lower surface of the lead frame 20 is occupied. Therefore, the inner lead 22
Is deformed downward in the figure and the level of the heat radiating plate 40 is poor, so that the inner lead 22 and the heat radiating plate 40 may come into contact with each other and a short circuit may occur. A spacer member 70 made of an insulator is interposed between the lead 22 and the heat radiating plate 40 so that a short circuit can be prevented.

The spacer member 70 has an annular shape having a hollow portion 71 with a hollow central portion, and is formed of resin or ceramic which is an insulator. And
The spacer member 70 is fixed by the mold resin 50 between the inner lead 22 and the heat sink 40 with the step surface 41 of the heat sink 40 entering the hollow part 71.

Next, the semiconductor device 10 having such a configuration will be described.
0 will be described. The mold used in the present manufacturing method (the mold according to the present invention, not shown) includes, for example, a divided upper mold and a lower mold, and the outer periphery of the mold resin shown in FIG. It has a mold shape corresponding to the shape and has a gate for resin injection. First,
A heat sink 4 is placed on the lower mold of the mold heated to a predetermined temperature.
0 is dropped and installed, and the spacer member 70 is dropped and installed thereon. Here, the positioning of the spacer member 70 is performed by placing the heat sink 4 in the hollow portion 71 of the spacer member 70.
This is performed by inserting a step surface 41 protruding from zero.

Thereafter, the lead frame 20 on which the IC chip 10 is mounted and the bonding wire 30 is connected
Are set in the lower mold so that the spacer member 70 is interposed between the heat sink 40 and the inner lead 22 while the island portion 21 and the step surface 41 of the heat sink 40 are in contact with each other. Then, the upper mold of the mold is matched with the lower mold, and the resin is sealed by injecting and filling the mold resin 50 into the mold in a softened state. When the curing of the mold resin 50 is completed, the semiconductor device 100 shown in FIG. 1 is completed.

According to this embodiment, in the resin-encapsulated semiconductor device, the heat radiation plate 40 and the inner leads 22 of the lead frame 20 are utilized by utilizing the characteristic of fixing the internal components with the resin originally possessed. And a spacer member 70 interposed therebetween is fixed by a mold resin 50. Therefore, unlike the conventional insulating film described above, except for a series of resin sealing steps, another step for fixing the film to the heat sink (application, curing, adhesion, etc.) is not performed, and a series of resin similar to the conventional resin is used. In the sealing process, the heat sink 40 and the lead frame 20 are easily reduced while reducing the cost by a simple method of dropping the spacer member into the mold.
Can be prevented from short-circuiting.

(Other Embodiments) The spacer member 70
May be as shown in FIG.
The spacer member 70 is obtained by covering the surface of a main body 72 made of a material having excellent thermal conductivity with an insulating substance 73. Specifically, the main body 72 may be made of ceramic or metal such as alumina, aluminum nitride, silicon carbide, or the like, and the surface of the main body 72 may be insulated. As a result, the short-circuit prevention is realized, and the heat radiation plate 40 is further separated from the spacer member 70.
The heat can be dissipated to the leads 22 and 23 through the semiconductor device 100, so that the heat dissipation of the semiconductor device 100 can be further improved.

Further, the present invention provides a heat radiation plate provided with a semiconductor element mounted on a heat radiation plate disposed in a mold, and filling the mold with a resin so that the heat radiation plate, the semiconductor, In a resin-encapsulated semiconductor device formed by encapsulating an element and a lead frame, a spacer member for preventing a short circuit between the heat radiating plate and the lead frame is used as a main part. Semiconductor elements,
The parts such as the lead frame and the resin may be appropriately changed in design.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a resin-sealed semiconductor device according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a resin-sealed semiconductor device according to another embodiment of the present invention.

FIG. 3 is a schematic sectional view showing a conventional resin-encapsulated semiconductor device.

FIG. 4 is a schematic cross-sectional view showing another conventional resin-encapsulated semiconductor device.

[Explanation of symbols]

10 IC chip, 20 Lead frame, 40 Heat sink, 50 Mold resin, 70 Spacer member.

Claims (3)

[Claims] 1. A lead frame (20) on which a semiconductor element (10) is mounted is arranged on a heat sink (40) arranged in a mold, and a resin (50) is filled in the mold. Thereby, in the resin-encapsulated semiconductor device in which the heat sink, the semiconductor element and the lead frame are sealed so as to surround the same, the resin is sealed and the short circuit between the heat sink and the lead frame is prevented. A spacer member (70) made of an insulator for performing the above operation. The spacer member is disposed between the heat sink and the lead frame by being dropped into the mold,
And a resin-sealed semiconductor device fixed by the resin. 2. The resin-encapsulated semiconductor device according to claim 1, wherein the spacer member (70) is formed by coating a surface of a material having excellent thermal conductivity with an insulating material. 3. A lead frame (20) on which a semiconductor element (10) is mounted is disposed on a heat sink (40) disposed in a mold, and then a resin (50) is placed in the mold. A method of manufacturing a resin-encapsulated semiconductor device that is filled, comprising: disposing a spacer member (70) made of an insulator on the heat sink disposed in the mold by dropping the spacer member (70); By arranging the lead frame,
A method of manufacturing a resin-encapsulated semiconductor device, wherein the spacer member is interposed between the heat sink and the lead frame, and subsequently the resin is filled.