JPH0936285A - Resin-sealed semiconductor device and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a resin-encapsulated semiconductor device that prevents invasion of a harmful medium from the outside and improves reliability. [Structure] The radiator 2 supporting the semiconductor chip 5 is
Surface 8 of package 8 in which semiconductor chip 5 is sealed with resin
It is arranged without touching its side surface 2C to A. As a result, even if the thermal expansion coefficients of the package 8 and the radiator 2 are different from each other, no gap is formed between the side surface 2C of the radiator 2 and the package 8 due to the temperature rise during operation.
Therefore, harmful media such as moisture and water do not enter from the outside through the gap.

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 and a method for manufacturing the same, and more particularly to a technique effective when applied to a resin-encapsulated semiconductor device that efficiently dissipates heat generated in a semiconductor chip. .

[0002]

2. Description of the Related Art In a resin-sealed semiconductor device having a package in which a highly integrated semiconductor chip is sealed with resin such as LSI, a large amount of heat is generated from the semiconductor chip during operation of the device. In order to stably operate the above, it is necessary to efficiently radiate the heat to the outside.

For such a purpose, a resin-sealed semiconductor device in which a semiconductor chip is supported by using a heat radiator having an excellent heat radiation property such as Cu and the heat radiator is exposed from a package is, for example, Published by Nikkei BP, "Nikkei Microdevice", November 1988 issue, P74-
P75.

The resin-encapsulated semiconductor device 21 disclosed herein, as shown in FIG. 6, has a back surface 22B of a radiator 22.
While fixing the plurality of leads 23 to the
The semiconductor chip 25 is fixed on the same surface of the radiator 22,
The wire 2 is provided between the electrode of the semiconductor chip 25 and the lead 23.
After bonding 7, the radiator 22, the lead 23, the semiconductor chip 25, and the bonding wire 27 are sealed by a package 28 made of resin. The surface 22A of the radiator 22 is exposed from the package 28. As a result, the heat generated in the semiconductor chip 25 is radiated to the outside air from the surface 22A which is the exposed surface of the radiator 22.

[0005]

The resin-encapsulated semiconductor device having the heat dissipation structure as described above is incorporated into various electronic devices by being mounted on a wiring board. Here, in the resin-encapsulated semiconductor device incorporated in various electronic devices, since the resin, which is the material of the package 28, and the radiator 22 have different thermal expansion coefficients, the temperature rises during operation. There is a problem that reliability is reduced due to the influence of.

That is, when the temperature rises, the side surface 22C of the heat radiator 22 and the package 28 which are in contact with each other are, as shown in FIG. 7, based on the difference in thermal expansion coefficient between the package 28 and the heat radiator 22. A gap 29 appears at the boundary as shown by an arrow. Then, with the passage of time, a harmful medium such as moisture or water enters from the outside through the gap 29, so that the semiconductor chip 25 deteriorates.

Further, in the conventional heat dissipation structure of the resin-sealed semiconductor device, when the resin is supplied by the transfer molding method or the like to form the package 28, the resin dissipates heat.
Since there is a possibility that it will go around from the side surface 22C to the front surface 22A, unnecessary resin will adhere to a part of the surface of the package 28, and will remain and be covered, and there is a possibility that a sufficient heat dissipation effect cannot be obtained.

An object of the present invention is to provide a resin-encapsulated semiconductor device which prevents intrusion of harmful medium from the outside and improves reliability.

Another object of the present invention is to provide a method of manufacturing a resin-encapsulated semiconductor device which prevents the surface of a radiator from being covered with unnecessary resin.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0011]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, typical ones are briefly described as follows.

(1) The resin-sealed semiconductor device of the present invention is
In a resin-sealed semiconductor device having a package in which a semiconductor chip supported by a radiator is sealed with resin,
The heat radiator is arranged such that the side surface does not contact either one of the front surface and the back surface of the package.

(2) In the method of manufacturing a resin-encapsulated semiconductor device of the present invention, the tip of each lead is fixed to one surface of the radiator by using a lead frame that integrally holds a plurality of leads. After fixing the semiconductor chip on the same surface of the heat radiator and bonding a wire between the electrode of the semiconductor chip and the tip of the lead, all the surfaces except one surface of the heat radiator were covered. In this state, the resin is supplied to form the package.

[0014]

According to the above-mentioned means (1), the resin-encapsulated semiconductor device of the present invention is a resin-encapsulated semiconductor device having a package in which a semiconductor chip supported by a radiator is encapsulated with resin. Since the side surface of the heat radiator is arranged without contacting either side of the front surface or the back surface of the package, a gap is not formed between the side surface of the heat radiator body and the package, which may be harmful to the outside. Intrusion of the medium can be prevented and reliability can be improved.

According to the above-mentioned means (2), the tip of each lead is fixed to one surface of the heat radiator by using a lead frame which integrally holds a plurality of leads, and the same surface of this heat radiator is secured. After fixing the semiconductor chip and bonding a wire between the electrode of the semiconductor chip and the tip of the lead, supply the resin while covering all the surfaces except one surface of the radiator. Since the package is formed in this manner, it is possible to prevent the surface of the radiator from being covered with unnecessary resin.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view showing a resin-sealed semiconductor device according to Embodiment 1 of the present invention. Example 1
The resin-encapsulated semiconductor device 1 according to the present invention has, for example, Fe-Ni on the back surface 2B of a plate-shaped radiator 2 having excellent heat dissipation such as Cu.
The tips of the plurality of leads 3 made of a system alloy material are fixed by an adhesive tape 4, and the semiconductor chip 5 is fixed on the same surface of the radiator 2 by a high thermal conductive adhesive 6 made of, for example, silicone rubber. There is. Wires 7 made of, for example, Au wires are bonded between the electrodes of the semiconductor chip 5 and the tips of the corresponding leads 3, and the tips of the leads 3, the semiconductor chip 5, and the bonding wires 7 are made of, for example, an epoxy resin package. It is sealed by 8.

Here, the back surface 2B of the heat radiator 2 is arranged in contact with the front surface 8A of the package 8, and the front surface 2A and the side surface 2C of the heat radiator 2 are exposed from the package 8, and especially the side surface 2C thereof is the same as the conventional one. As described above, the structure is not in contact with the package 8. As a result, the heat generated in the semiconductor chip 5 is radiated to the outside air through the high thermal conductive adhesive 6 from the surface 2A and the side surface 2C which are the exposed surfaces of the radiator 2. The radiator 2 and the package 8
In the drawings, the upper position is referred to as the front surface and the lower position is referred to as the back surface.

Next, a method of manufacturing the resin-sealed semiconductor device 1 according to the first embodiment will be described in the order of steps with reference to FIG.

First, as shown in FIG. 5A, for example, F
A lead frame 9 that integrally holds a plurality of leads 3 made of an e-Ni alloy material is prepared, and the tips of the leads 3 are fixed to the back surface 2B of the radiator 2 such as Cu with an adhesive tape 4. The lead frame 9 is pre-etched,
It is formed to have a lead shape of a desired pattern by a processing means such as a press.

Next, as shown in FIG. 5B, the semiconductor chip 5 is attached to the central portion of the back surface 2B of the radiator 2 surrounded by the tips of the leads 3 with a high thermal conductive adhesive made of, for example, silicone rubber. Fix by 6. As a result, the semiconductor chip 5 is supported by the radiator 6.

Subsequently, as shown in FIG. 5C, a wire 7 made of, for example, an Au wire is bonded between the electrode of the semiconductor chip 5 and the tip of each lead 3 corresponding thereto.

Next, as shown in FIG. 5D, the radiator 2
A cavity 13 for supporting the radiator 2 and the surface 9A of the lead frame 9 and forming a package 8 having a desired shape by using an upper mold 10 having a groove 11 having a shape covering the surface 2A and the side surface 2C of the The lower mold 12 having the gate 14 and the gate 14 is used to support the back surface 9B of the lead frame 9. Then, from the gate 14 of the lower mold 12 to the cavity 1
For example, epoxy resin is supplied to 3. As a result, the package 8 as shown in FIG. 1 is formed. Next, the frame portion of the lead frame 9 is cut, and each lead 3 is cut.
Each lead 3 is shaped and shaped into a gull wing shape as shown in FIG. 1, for example.

As shown in the step of FIG. 5D, the upper mold 1
The groove portion 11 of 0 allows the surface 2A and the side surface 2C of the radiator 2
By completely covering the resin, it is possible to prevent the resin from flowing into the upper mold 10 when the resin is supplied from the gate 14 of the lower mold 12. As a result, the surface 2 of the radiator 2
It is possible to prevent the resin from adhering to A or the side surface 2C.

According to the resin-encapsulated semiconductor device of Example 1, the following effects can be obtained.

Heat sink 2 supporting semiconductor chip 5
Is arranged without contacting the side surface 2C of the semiconductor chip 5 with the surface 8A of the package 8 sealed with a resin, even if the thermal expansion coefficient of the package 8 is different from that of the radiator 2. Side surface 2 of the radiator 2 due to the temperature rise of
No gap is formed between C and the package 8. Therefore, it is possible to prevent the harmful medium from entering from the outside and improve the reliability.

According to the method of manufacturing the resin-sealed semiconductor device of the first embodiment, the following effects can be obtained.

A surface 2A and a side surface 2C of the radiator 2 are attached to the upper mold 1
Since the resin is supplied only into the lower mold 12 to form the package 8 in a state of being covered with 0, the resin is prevented from wrapping around from the side surface 2C of the radiator 2 to the surface 2A. It is possible to prevent the surface 2 </ b> A of 2 from being covered with unnecessary resin.

FIG. 2 is a sectional view showing a resin-sealed semiconductor device according to a second embodiment of the present invention.
It shows a structure in which the area of the heat radiator 2 that supports the semiconductor chip 5 is larger than the area of the package 8 in which the semiconductor chip 5 is sealed with resin. This structure can be easily realized by first using the heat radiator 2 having an arbitrary area without depending on the step of supplying the resin to form the package 8.

According to the resin-encapsulated semiconductor device of the second embodiment, not only the same effects as those of the first embodiment can be obtained, but also the heat dissipation effect can be particularly enhanced. Further, when the same heat radiation effect as in the first embodiment is obtained, the heat radiator 2 can be made thinner.

FIG. 3 is a cross-sectional view showing a resin-sealed semiconductor device according to a third embodiment of the present invention. The heat radiator 2 supporting the semiconductor chip 5 is a back surface 8B of a package 8 in which the semiconductor chip 5 is sealed with resin. The structure arranged in FIG. This structure can be easily realized by selecting a bending direction opposite to that of the first embodiment when shaping the leads 3 immediately before obtaining the structure of the first embodiment.

The resin-encapsulated semiconductor device according to the third embodiment has the same structure as that of the first embodiment except that the bending direction of each lead 3 is different. It is possible to obtain various effects.

FIG. 4 is a sectional view showing a resin-sealed semiconductor device according to a fourth embodiment of the present invention. In the structure of the third embodiment,
It shows a structure in which the area of the heat radiator 2 that supports the semiconductor chip 5 is larger than the area of the package 8 in which the semiconductor chip 5 is sealed with resin. Similar to the second embodiment, this structure does not depend on the step of supplying the resin to form the package 8 and can be easily realized by first using the radiator 2 having an arbitrary area. .

According to the resin-sealed semiconductor device of the fourth embodiment, not only the same effects as those of the third embodiment can be obtained, but also the heat radiation effect can be particularly enhanced. Further, when the same heat radiation effect as in the third embodiment is obtained, the heat radiator 2 can be thinned.

As described above, the invention made by the present inventor is:
Although the present invention has been specifically described based on the above-mentioned embodiments, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the scope of the invention.

For example, although Cu has been described as an example of the material of the heat radiator 2 in the above-described embodiment, the material is not limited to Cu, and any material having excellent heat dissipation property such as Al or Al alloy may be used.
Other materials can be used as well.

Further, the shape of the radiator 2 is not limited to the plate shape. However, when marking or the like, it is desirable that this surface be flat.

Furthermore, the method of manufacturing a resin-sealed semiconductor device described in the text can be applied to a method of manufacturing a resin-sealed semiconductor device that does not use a heat radiator, and particularly, the package can be made thinner. It will be effective if.

In the above description, the case where the invention made by the present inventor is mainly applied to the manufacturing technology of the resin-encapsulated semiconductor device which is the field of application which is the background of the invention has been described, but the invention is not limited thereto. . The present invention can be applied to at least a resin-sealed semiconductor device under the condition of improving heat dissipation.

[0040]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

Even if the thermal expansion coefficient of the package is different from that of the radiator, a gap is not formed between the side surface of the radiator and the package due to the temperature rise during operation, so that harmful medium from the outside is prevented from entering. It can prevent and improve reliability.

Since the resin is supplied to cover the surface and the side surface of the radiator to form the package, the resin is prevented from wrapping around from the side surface to the surface of the radiator. It is possible to prevent the resin from being covered with unnecessary resin.

[Brief description of drawings]

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

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

FIG. 3 is a sectional view showing a resin-sealed semiconductor device according to a third embodiment of the invention.

FIG. 4 is a sectional view showing a resin-sealed semiconductor device according to a fourth embodiment of the invention.

FIG. 5 shows a method for manufacturing a resin-sealed semiconductor device according to a first embodiment of the present invention, in which (a) to (d) are sectional views.

FIG. 6 is a cross-sectional view showing a conventional resin-sealed semiconductor device.

FIG. 7 is a cross-sectional view illustrating a defect of a conventional resin-encapsulated semiconductor device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Resin-sealed semiconductor device, 2 ... Radiator, 2A ... Front of radiator, 2B ... Rear surface of radiator, 2C ... Side surface of radiator, 3
... Lead, 4 ... Adhesive tape, 5 ... Semiconductor chip, 6 ...
High thermal conductive adhesive, 7 ... Bonding wire, 8 ... Package, 8A ... Package front surface, 8B ... Package back surface, 9 ... Lead frame, 10 ... Upper mold, 11 ... Groove portion,
12 ... Lower mold, 13 ... Cavity, 14 ... Gate.

Claims (4)

[Claims] 1. In a resin-sealed semiconductor device having a package in which a semiconductor chip supported by a heat radiator is sealed with a resin, the heat radiator has a side surface on either side of a front surface or a back surface of the package. A resin-encapsulated semiconductor device, which is arranged without contact. 2. The resin-sealed semiconductor device according to claim 1, wherein the area of the radiator is larger than that of the package. 3. The resin-encapsulated semiconductor device according to claim 1, wherein a plurality of leads that are electrically connected to the electrodes of the semiconductor chip are adjacently drawn from the side surface of the package. 4. A lead frame for integrally holding a plurality of leads is used to fix the tips of the leads to one surface of a heat radiator, and a semiconductor chip is fixed to the same surface of the heat radiator. After the wire is bonded between the electrode of 1 and the tip of the lead, resin is supplied to form a package in a state where all the surfaces except one surface of the radiator are covered. And a method for manufacturing a resin-encapsulated semiconductor device.