JPH04326562A - Semiconductor device - Google Patents

Abstract

PURPOSE:To preserve the strength of a lead by equipping it with a metallic plate whereon an insulating film is made, and having a circuit pattern for electric connection between a semiconductor chip and an inner lead, which is made by lithography technology, in the periphery on the insulating film. CONSTITUTION:A circuit pattern 5, which is made on an insulating film using lithography, is used as the terminal of an inner lead 12. Accordingly, the distance between the side faces of the circuit pattern 5, that is, the extraction width can be made extremely small. Moreover, it is constituted such that a copper plate 3 high in thermal conductivity is bonded onto an island part 11, and that a semiconductor chip 2 is loaded on this. Hereby, it turns out that the heat generated in the semiconductor chip 2 is radiated to outside efficiently.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a resin-sealed semiconductor device.

0002

2. Description of the Related Art As shown in FIG. 2, a conventional semiconductor device has a semiconductor chip 2 mounted on an island portion 11 of a lead frame 1 having internal leads 12 and external leads 13. The package 6 was formed by connecting the bonding wire 7 and the internal lead 12, and then molding a sealing resin.

[0003] The pattern of the lead frame 1 is formed by pressing technology or etching technology. Further, the wire length of the bonding wire 7 needs to be approximately 3.5 mm at maximum in order to avoid problems such as deformation and cutting during resin sealing.

Therefore, the semiconductor chip 2 is small, and the number of terminals, that is, the number of bonding pads 2 is small.
If the number of 1's is large, it is necessary to design the pattern of the internal leads 12 of the lead frame 1 in accordance with the dimensions of the semiconductor chip 2 so that the line length of the bonding line 7 does not exceed 3.5 mm. In such a case, the internal lead 12
is formed long toward the center, and the center-to-center distance at its end, that is, the pitch, is very small, for example,
It becomes 0.15 mm or less. Further, the minimum width of the internal lead 12 necessary for bonding using the bonding wire 7 is about 0.1 mm.

[0005] On the other hand, in the current processing technology for patterning the lead frame 1, whether by pressing technology or etching technology, the distance between the side surfaces of the internal leads 12, that is, the punching width is about 70% of the plate thickness. For example, if the plate thickness is 0.15 mm, this becomes 0.105 mm. As mentioned above, if the pitch is 0.15 mm, taking into consideration this punching width of 0.105 mm, only 0.045 mm can be secured as the terminal width of the internal lead. With this dimension, bonding is impossible because it is smaller than the minimum bonding width of 0.1 mm.

[0006] Furthermore, as semiconductor devices become more sophisticated and highly integrated, there is a trend toward increased power consumption. For this reason, the semiconductor chip generates a large amount of heat, and it is necessary to appropriately design the heat dissipation.

[0007]

[Problems to be Solved by the Invention] In the conventional semiconductor device described above, when the semiconductor chip is small and has a large number of terminals,
Since the pitch at the end of the internal leads becomes very small, there is a drawback that there are restrictions on the minimum size of the semiconductor chip and the number of terminals. In addition, if the pitch at the end of the internal leads is designed to be small, the thickness of the internal leads must be reduced to reduce the width of the cutout in order to ensure the minimum bonding width, and the strength of the leads cannot be maintained and may break during processing. There were drawbacks. Furthermore, there is a drawback that it is difficult to efficiently dissipate heat from a semiconductor chip that consumes high power.

[0008]

[Means for Solving the Problems] A semiconductor device of the present invention includes:
An insulating film is formed on the upper surface, a semiconductor chip mounting part for mounting a semiconductor chip is provided in the center of the insulating film, and the semiconductor chip and internal leads of the lead frame are formed around the semiconductor chip mounting part by lithography technology. The metal plate has a circuit pattern for electrical connection.

[0009]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a semiconductor device according to the present invention, in which (A) is a partially cutaway plan view and (B) is a cross-sectional view taken along the line AB in (A).

As shown in FIG. 1, in the semiconductor device of this embodiment, a copper plate 3 is bonded to an island portion 11 of a lead frame 1 having an internal lead 12 and an external lead 13, and a distance of several μm is placed on the top surface of the copper plate 3. An insulating film 4 such as a silicon oxide film is formed to a thickness of The semiconductor chip 2 is mounted on the center part on the semiconductor chip 2, and the pads 21 on the semiconductor chip 2 and the circuit pattern 5 are connected by the bonding wire 8, and the bonding is performed between the circuit pattern 5 and the internal leads 12. After connecting through wires 7, a sealing resin is molded to form a package 6.

In this embodiment, since the circuit pattern 5 formed on the insulating film 4 using lithography technology is used as the termination of the internal lead 12, the distance between the sides of the circuit pattern 5, that is, the width of the cutout can be minimized. It can be made small, for example, about 0.01 mm. Therefore, even if the minimum bond width of 0.1 mm is secured as in the conventional example, the pitch of the circuit pattern 5 is reduced to 0.
．． It is possible to make it as small as 11 mm.

Furthermore, since the copper plate 3 with high thermal conductivity is bonded onto the island portion 11 of the lead frame 1 and the semiconductor chip 2 is mounted on this, the heat generated by the semiconductor chip 2 is efficiently dissipated. Heat is often radiated to the outside.

For example, if the semiconductor chip area is 25 square meters
m, the thickness of the lead frame is 0.15 mm, the thermal conductivity of the lead frame is 0.36 cal/cm/s/℃, the area of the copper plate is 225 square mm, the thickness of the copper plate is 1 mm, the thermal conductivity of the copper plate is 0.50 cal/cm/s/℃, the thermal conductivity of the resin is 0.0016 cal/cm/s/℃, the package dimensions are 40 x 40 x 4.2 mm, and the 296 pin quad flat package has the following improvements. be done. That is, while the conventional structure has a thermal resistance of 70° C./W, the structure of this embodiment has a thermal resistance of 45° C./W.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified in various ways.

For example, instead of mounting a copper plate with a circuit pattern formed on the island part and connecting the circuit pattern and internal leads with a bonding wire, the island part is omitted and the circuit pattern on the copper plate and the internal leads are directly connected by soldering, etc. It goes without saying that the method of adhesion can also be applied as long as it does not depart from the gist of the present invention.

[0017]

As explained above, the semiconductor device of the present invention includes a metal plate with an insulating film formed on the upper surface, and a semiconductor chip and internal leads formed on the surrounding area of the insulating film by lithography technology. By having a circuit pattern for electrical connection, restrictions on the minimum size of a semiconductor chip and the number of terminals can be significantly relaxed, and a semiconductor device that is small and has a large number of terminals can be provided. Further, even if the pitch at the end of the internal leads is reduced, the strength of the leads can be maintained and reliability can be increased. Furthermore, there is an effect that heat can be dissipated from a semiconductor chip with high power consumption with high efficiency.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway plan view and a sectional view showing an embodiment of a semiconductor device of the present invention.

FIG. 2 is a partially cutaway plan view and a cross-sectional view showing an example of a conventional semiconductor device.

[Explanation of symbols]

1 Lead frame 2 Semiconductor chip 3 Copper plate 4 Insulating film 5 Circuit pattern 6 Package 7, 8 Bonding wire 11 Island part 12 Internal lead 13 External lead 21 Pad

Claims (1)

[Claims] 1. An insulating film is formed on the upper surface, a semiconductor chip mounting part for mounting a semiconductor chip is provided in the center of the insulating film, and the semiconductor chip and leads are formed around the semiconductor chip mounting part by lithography technology. A semiconductor device comprising a metal plate having a circuit pattern for electrical connection with an internal lead of a frame.