JP2002083907A - Semiconductor device, board, liquid crystal display and plasma display using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constitution capable of displaying a sufficient radiation effect on heating of a semiconductor chip mounted on a circuit board in a COG(chip on glass) system. SOLUTION: Heat sinks 4c,..., 6c,... are provided on semiconductor chips 4b,..., 6b,... mounted on a glass array board 1 in a COG(chip on glass) system.

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 heat dissipation efficiency from a semiconductor chip in a chip-on-glass (COG) system in which a semiconductor chip is directly mounted on a glass substrate in a liquid crystal display or a plasma display. To improve the configuration.

[0002]

2. Description of the Related Art Liquid crystal displays and plasma displays are suitable for applications such as notebook personal computers that require small size and light weight. To meet the demand for small size and light weight, semiconductor chips (bare chips) are required. A COG mounting method in which a drive circuit is directly attached to a display panel is employed.

Here, a conventional liquid crystal display employing a COG mounting method will be described with reference to FIGS. FIG. 5 is a schematic plan view of a conventional liquid crystal display, and FIG. 6 is a schematic partial sectional view taken along line AA of FIG.

As shown in FIGS. 5 and 6, reference numeral 20 denotes glass,
An array substrate made of quartz or the like; an opposing substrate 21 is arranged so as to oppose the array substrate 20;
A liquid crystal material is sandwiched between 1 and the array substrate 20 to constitute a liquid crystal display.

A pixel region 28 is formed on the array substrate 20, and a scanning signal drive circuit 23 composed of a plurality of semiconductor chips 23b and an image composed of a plurality of semiconductor chips 25b are provided on the periphery of the pixel region 28. A signal drive circuit 25 is provided.

A bump (not shown) is provided on a semiconductor chip 23b constituting the scanning signal drive circuit 23.
The bump is connected via a scanning signal line 22 to a gate electrode (not shown) of a thin film transistor forming a pixel region. Also, a bump 29 is provided on the semiconductor chip 25b constituting the image signal drive circuit 25, and the bump 29 is connected to the source electrode of the thin film transistor constituting the pixel region via the image signal line 24. The semiconductor chips 23b... 25b.
And is protected by being covered with a protective resin film 27 made of epoxy resin or the like.

[0007]

However, when the conventional liquid crystal display device is operated, heat is generated in the drive circuit (semiconductor chip). When glass is used as the substrate, there is a problem that heat is localized in the driving circuit portion and the performance of the driving circuit is reduced because the glass substrate has poor thermal conductivity. Further, when heat is localized in the drive circuit portion, members around the drive circuit, such as a sealant and a liquid crystal material, are affected, and the display performance of the liquid crystal display device may be degraded.

Further, as shown in FIG. 6, the drive circuit is protected by covering the drive circuit with a protective resin film. However, heat from the drive circuit is unlikely to be radiated. This causes a further decrease in the performance of the circuit.

Further, in order to meet the demand for narrower frame panels and the demand for higher performance of liquid crystal display devices, it has become necessary to further integrate drive circuits. As a result, the amount of heat generated from the drive circuit may increase dramatically, and it is necessary to promote the release of heat from the drive circuit.

[0010] The present invention has been made to solve the above-mentioned problem, and has as its object to provide a configuration capable of efficiently dissipating heat from a semiconductor chip.

[0011]

In order to solve the above-mentioned problems, the invention according to claim 1 is a semiconductor device, comprising: a semiconductor chip mounted on a substrate by a COG (chip-on-glass) method; And a heat sink provided on the semiconductor chip.

With this configuration, heat generated from the semiconductor chip mounted on the circuit board by the COG method is transmitted to the heat radiating plate and released from the heat radiating plate to the atmosphere. No heat is localized. Accordingly, the characteristics of the chip do not deteriorate, so that the reliability of the semiconductor chip can be improved. Also, by providing the heat sink on a semiconductor chip,
The occupied area of the semiconductor device does not increase, and the space can be effectively used.

The invention described in claim 2 is the first invention.
Wherein the area of the heat sink is smaller than the area of the semiconductor chip.

According to the above configuration, even when the semiconductor chips are mounted at a high density, the heat sink does not become an obstacle, and the semiconductor chips can be mounted at a high density.

[0015] The invention described in claim 3 is based on claim 1.
Alternatively, the semiconductor device according to claim 2, wherein a surface of the heat sink has an uneven structure.

According to the above configuration, since the surface area of the heat radiating plate is effectively increased, the heat of the semiconductor chip can be further released from the heat radiating plate to the atmosphere, and the heat radiation efficiency is improved.

The invention described in claim 4 is the first invention.
4. The semiconductor device according to claim 3, wherein the radiator plate is bonded to the semiconductor chip with an adhesive having a thermal conductivity substantially equal to or higher than that of the radiator plate. 5. It is characterized by.

By bonding the heat sink to the semiconductor chip with an adhesive having a thermal conductivity substantially equal to or higher than that of the heat sink, heat of the semiconductor chip is easily conducted to the heat sink. Heat dissipation efficiency is improved.

According to a fifth aspect of the present invention, there is provided a substrate on which a plurality of semiconductor devices are mounted by a COG method, wherein the semiconductor device is the semiconductor device according to any one of the first to fourth aspects. In addition, these semiconductor devices are characterized in that at least a part of the heat sink is covered with a protective resin film and mounted.

By adopting a configuration in which the radiator plate is exposed from the protective resin film as in the above configuration, the semiconductor chip can be protected by the protective resin film, and the heat generated from the semiconductor chip can be reduced by the radiator plate. Can be released to the atmosphere.

According to a sixth aspect of the present invention, there is provided a liquid crystal display, wherein the substrate according to the fifth aspect is used.

According to a seventh aspect of the present invention, there is provided a plasma display, wherein the substrate according to the fifth aspect is used.

According to the above configuration, it is possible to provide a liquid crystal display or a plasma display having the features of the substrate described in claim 5 (ie, excellent in heat radiation characteristics).

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal display to which the semiconductor device of the present invention is applied will be described below with reference to FIGS. FIG. 1 is a schematic plan view of a liquid crystal display to which a semiconductor device according to an embodiment of the present invention is applied, and FIG.
Is a schematic partial cross-sectional view taken along the line BB of FIG. 1, and FIG. 3 is a perspective view of a heat sink provided on the semiconductor chip.

As shown in FIGS. 1 to 3, reference numeral 1 denotes an array substrate made of glass, quartz, or the like, and an opposing substrate 2 is arranged so as to oppose the array substrate 1. A pixel region 7 is formed on the array substrate 1, and a scanning signal driving circuit 4 and an image signal driving circuit 6 are mounted on the periphery of the pixel region 7 by a COG (chip-on-glass) method. The scanning signal driving circuit 4 and the image signal driving circuit 6
Each of the semiconductor devices 4a... 6a... Is formed by a semiconductor chip 4b and a heat sink 4c.
Is composed of a semiconductor chip 6b and a heat sink 6c.

More specifically, the semiconductor chips 4b... 6b are adhered on the array substrate 1 by an adhesive 8, and the semiconductor chips 6b.
The bumps 14 are connected to the source electrodes of the thin film transistors constituting the pixel region 7 via the image signal lines 5. Further, a bump (not shown) is also provided on the semiconductor chip 4b. The bump is connected to the gate electrode (not shown) of the thin film transistor forming the pixel region 7 via the scanning signal line 3. I have.

On the semiconductor chips 4b... 6b, heat radiating plates 4c... 6c made of a material having high thermal conductivity such as aluminum and copper are adhered by an adhesive material 10 having a high thermal conductivity. . The heat radiating plates 4c... 6c have an uneven structure on the surface.

The semiconductor chips 4b... 6b.
Are protected by a protective resin film 9 made of an epoxy resin or the like. The protective resin film 9 has an opening 9a, and at least one of the concave and convex structures of the heat radiating plates 4c. The part is exposed.

The manufacturing method of the mounting structure is as follows.
Heat sinks 4c 6c on semiconductor chips 4b 6b
6b are mounted on the array substrate 1 and then the semiconductor chips 4b... 6b.
The semiconductor chips 4b are covered with a protective resin film 9. When covering with the protective resin film 9, the whole of the heat sinks 4c... 6c is prevented from being covered with the protective resin film 9, and at least a part of the uneven structure is exposed.

Another manufacturing method is as follows.
The semiconductor chips 4b... 6b are mounted on the array substrate 1, and then the semiconductor chips 4b. Thereafter, an opening 9a is opened in the protective resin film 9 by a process such as etching, and the opening 9a is formed.
The heat sinks 4c... 6c... may be bonded onto the semiconductor chips 4b.

Thus, the semiconductor chips 4b.
The heat generated in the semiconductor chip 3b can be released to the atmosphere by the heat radiating plates 4c.
Heat is not localized in the driving circuits 4 and 6 composed of... 4b, and therefore, the reliability of the driving circuits 4 and 6 is improved.

The heat sinks 4c... 6c are provided on the semiconductor chips 4b... 6b so that the semiconductor chips 4b.
The semiconductor device 4a has a small area occupied by the semiconductor devices 4a, 6a,.... it can.

Further, as in the present embodiment, a semiconductor chip is mounted on the periphery of an array substrate constituting a liquid crystal display device.
In the case of mounting by the OG method, since the liquid crystal display device has a thin configuration, the heat radiation efficiency cannot be improved by increasing the thickness of the heat radiation plate. However, by configuring the radiator plate to have a concavo-convex structure, the surface area increases, and the heat generated by the drive circuit can be further released to the atmosphere through the radiator plate. Effective use of a narrow space can be achieved.

Further, when semiconductor chips (drive circuits) are mounted at a high density in order to respond to demands for further performance improvement of the liquid crystal display device, for example, high speed response and high definition,
Although the heat radiating plate becomes smaller corresponding to the high-density mounting, the effective surface area of the heat radiating plate does not become smaller due to the unevenness of the heat radiating plate. Therefore, even when the semiconductor chips are mounted at a high density, the heat radiation characteristics do not deteriorate and the reliability of the semiconductor chips does not deteriorate.

When the semiconductor chips 4b... 6b are covered with a protective resin film 9, the semiconductor chips 4b.
The heat radiation efficiency for releasing the heat generated in b ... decreases, but as shown in FIG.
6c are exposed from the protective resin film 9, thereby enabling protection without lowering the heat radiation efficiency.

(Other Matters) In the above embodiment, the heat radiating plate has a concave-convex structure. However, a structure without the concave-convex structure may be adopted. And even in such a case, it is of course possible to release the heat of the semiconductor chip from the heat sink.
Further, the shape of the uneven structure is not limited to the shape described in the above embodiment.

In the above embodiment, the heat radiating plate has an uneven structure. However, for example, a structure as shown in FIG. 4 can be adopted. FIG. 4 is a schematic sectional view showing another example of the embodiment of the present invention.

That is, the structure of the heat radiating plate 6d having an uneven structure on the upper part is the same as that described above.
The lower portion d (on the side of the semiconductor chip 6b) also has an uneven structure.

In such a configuration, the surface area of the lower part of the heat radiating plate 6d can be increased by the concave-convex structure of the lower part of the heat radiating plate 6d, and the bonding by the adhesive 10 for bonding the heat radiating plate 6d and the semiconductor chip 6b. Since heat dissipation is improved, heat generated from the semiconductor chip 4b is more easily transmitted to the heat radiating plate 6d, and the heat radiation efficiency is further improved.

In the above-described embodiment, an example is shown in which the semiconductor device is applied to a drive circuit portion of a liquid crystal display.
The present invention is not limited to this, and the semiconductor device can be applied to a plasma display. In that case, it is considered that the power consumption of the plasma display is large and the amount of heat generated in the driving circuit is large. However, the configuration of the present invention increases the heat radiation effect of the plasma display.

In the above embodiment, the semiconductor chip is covered with the protective resin film. However, the covering with the protective resin film is not always required.

[0042]

The present invention is embodied in the form described above and has the following effects.

That is, by providing a semiconductor device having a semiconductor chip and a heat radiating plate provided on the semiconductor chip, heat radiation efficiency from the semiconductor chip is improved.
Accordingly, there is an effect that the characteristics of the semiconductor chip do not deteriorate and the reliability of the semiconductor chip (semiconductor device) is improved. Such a semiconductor device can be applied to a driving circuit portion of a plasma display or a liquid crystal display, and the reliability of the liquid crystal display or the plasma display is improved.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a liquid crystal display to which a semiconductor device according to an embodiment of the present invention is applied.

FIG. 2 is a schematic partial sectional view taken along line BB of FIG.

FIG. 3 is a perspective view of a heat sink provided on a semiconductor chip.

FIG. 4 is a schematic sectional view showing another example of the embodiment of the present invention.

FIG. 5 is a schematic plan view of a conventional liquid crystal display.

FIG. 6 is a schematic partial sectional view taken along line AA of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Array substrate 2 Counter substrate 3 Scan signal line 4 Scan signal drive circuit 4a Semiconductor device 4b Semiconductor chip 4c Heat sink 5 Image signal line 6 Image signal drive circuit 6a Semiconductor device 6b Semiconductor chip 6c Heat sink 6d Heat sink 7 Pixel area 8 Adhesion Material 9 Protective resin film 10 Adhesive 14 Bump 20 Array substrate 21 Counter substrate 22 Scan signal line 23 Scan signal drive circuit 23b Semiconductor chip 24 Image signal line 25 Image signal drive circuit 25b Semiconductor chip 26 Adhesive 27 Protective resin film 28 Pixel area 29 Bump

Claims (7)

[Claims] 1. A semiconductor device comprising: a semiconductor chip mounted on a substrate by a COG (chip-on-glass) method; and a heat sink provided on the semiconductor chip. 2. The semiconductor device according to claim 1, wherein an area of the heat sink is smaller than an area of the semiconductor chip. 3. The semiconductor device according to claim 1, wherein the surface of the heat sink has an uneven structure. 4. The heat sink according to claim 1, wherein said heat sink is bonded to said semiconductor chip by an adhesive having a thermal conductivity substantially equal to or higher than that of said heat sink.
The semiconductor device according to claim 3. 5. A substrate on which a plurality of semiconductor devices are mounted by a COG method, wherein said semiconductor device is the semiconductor device according to claim 1, and said semiconductor device is characterized in that: A substrate which is mounted by being covered with a protective resin film so that at least a part of the plate is exposed. 6. A liquid crystal display using the substrate according to claim 5. 7. A plasma display using the substrate according to claim 5.