JPH05113574A - Matrix type display device - Google Patents

Abstract

PURPOSE:To provide a display device whose display panel can be easily inspected and tested even in the case that the device is a chip-on glass packaging system display device. CONSTITUTION:The electrode wire groups of the panel are concentrically arranged on the lower surface of the mounting part of a semiconductor chip 21 and connected by a member 50 whose conductivity is changed by light or heat. When the panel is inspected or tested, the electrode wire groups are made to be electrically conductive by being irradiated with the light or the heat. Then, when such electrical conduction is interuppted thereafter, they are easily mutually insulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matrix display device, and more particularly to a matrix display device in which a plurality of semiconductor chips are directly connected to a substrate for driving.

[0002]

2. Description of the Related Art There are liquid crystal displays, electroluminescent displays, plasma displays and the like as so-called matrix display devices which display by applying voltages from row-side and column-side electrodes and by their interaction. In the embodiments of the present invention and the conventional example, an example of a thin film transistor (TFT) type liquid crystal display mounted with a chip-on-glass (COG) in which a semiconductor chip is directly mounted on a glass substrate will be described.

FIG. 3 shows a glass substrate before assembly of a TFT liquid crystal display. In FIG. 3, 1
Reference numeral 0 is a glass substrate on which electrode lines and TFTs are formed. Drain electrode lines Du and Dl are applied vertically and gate electrode lines G are applied horizontally. The thin film transistor (TFT) shown in the equivalent circuit of FIG. 4 is formed between the drain electrode lines Du and Dl and the gate electrode line G.
Then, after subjecting the glass substrate 10 to an appropriate orientation treatment, liquid crystal is sealed between the substrate 10 and a counter substrate 11 having a transparent electrode coated on the entire surface.

In FIG. 4, C is the electrode of the counter substrate, and the broken line is the liquid crystal layer LC. The TFT liquid crystal display applies a voltage between the gate electrode line G and the drain electrode lines Du and Dl,
Display is performed by exciting the liquid crystal layer LC. In the TFT liquid crystal display, since the drain electrode lines Du and Dl and the gate electrode line G are wired in a fine pattern and in multiple layers, a short circuit check between these lines and an inspection such as aging to stabilize the TFT characteristics are performed. Conducting a test is an important process for improving the yield of the display device and reducing the cost.

Therefore, in the TFT liquid crystal display, as shown by the hatched portion in FIG. 3, electrodes 15 to which the drain electrode lines Du and Dl and the gate electrode line G are commonly connected are provided on the upper and lower and side surfaces of the glass substrate. .. Then, after the above-described inspection and test, the substrate 10 is formed by these electrodes 15.
Is cut along the lines AA ', BB', and CC ', and then the display is assembled.

FIG. 5 shows a structural example of a TFT liquid crystal display for realizing this by chip-on-glass mounting. Reference numeral 21 denotes a semiconductor chip. Also, chip 2 of this
FIG. 6 shows an electrode pattern in the vicinity of the mounting portion of No. 1. In FIG. 6, the electrode terminals of the semiconductor chip 21 and the electrodes applied to the liquid crystal panel are connected at the P portion and driven by the control signal applied from the end portion of the liquid crystal panel.

[0007]

However, FIG. 5 and FIG.
In the conventional electrode configuration shown in (4), no consideration is given to the inspection and test described above. That is, in order to do this before mounting the semiconductor chip 21, for example, as shown in FIG.
It is conceivable that the hatched portion 41 of FIG. 1 is connected to each electrode by a conductive member in common, and then this conductive member is removed. However, if this method is carried out, it may cause contamination of the panel. In reality, there is a drawback that the above-mentioned inspection and test are difficult.

It is an object of the present invention to provide a matrix display device capable of easily inspecting and testing a display panel even with a chip-on-glass mounting type display device.

[0009]

In order to achieve the above object, panel electrode wires are intensively arranged on the lower surface of a semiconductor chip mounting portion, and these are electrically conducted only during inspection and testing of the panel. After that, these can be easily insulated from each other.

That is, according to the present invention, a matrix having a plurality of row and column electrode line groups on a substrate surface, the electrode terminals of the semiconductor chip being directly mounted on the terminals of the electrode line group and being displayed by the output of the semiconductor chip. In the display device, the electrode wire group terminals are extended and arranged concentratedly on the lower surface of the semiconductor chip, and the electrode wire group is connected by a member whose conductivity changes in response to a physical quantity on the lower surface of the semiconductor chip. It is characterized by that.

In the matrix display device, the member whose conductivity changes in response to a physical quantity is preferably a member whose conductivity changes in response to light, particularly amorphous silicon. The member whose electric conductivity changes in response to a physical quantity is preferably a member whose electric conductivity changes in response to heat, especially a thermistor.

Further, according to the present invention, a matrix having a plurality of row and column electrode wire groups on a substrate surface, the electrode terminals of the semiconductor chip being directly mounted on the terminals of the electrode wire group and being displayed by the output of the semiconductor chip. In the display device, the electrode wire group terminals are extended and arranged concentratedly on the lower surface of the semiconductor chip, and the electrode wire group is connected by an electronic switch on the lower surface of the semiconductor chip.

Further, the present invention is a matrix having a plurality of row and column electrode line groups on a substrate surface, the electrode terminals of the semiconductor chip being directly mounted on the terminals of the electrode line group and being displayed by the output of the semiconductor chip. In the display device, a MOSFET (metal-oxide-semiconductor field effect transistor) is formed on the lower surface of the semiconductor chip, the electrode line group terminal is extended, and the electrode line group is connected as a drain or source electrode of the MOSFET. The gate electrode is drawn out from the MOSFET.

Further, according to the present invention, a plurality of row and column electrode wire groups are provided on the surface of the substrate, the electrode terminals of the semiconductor chip are directly mounted on the terminals of the electrode wire group, and displayed by the output of the semiconductor chip. In the matrix display device, the electrode wire group terminals are extended to the lower surface of the semiconductor chip, and are concentrated and connected to at least a portion smaller than the area of the semiconductor chip, and then the concentrated connection portions are cut to electrically connect. It was made non-conductive.

[0015]

Function: The electrode wire of the display panel connected to the electrode terminal of the semiconductor chip is extended and wired on the lower surface of the chip mounting portion.
Then, these are connected by, for example, a photosensitive material whose resistivity decreases by irradiation of light, and the extraction electrode terminal connected to this is exposed. During inspection and testing,
The electrode lines of the display panel are electrically connected to each other by light irradiation, and the above-described inspection is performed using the electrode terminals. After the inspection, the photoconductor part is shielded from light by mounting the chip, so the electrodes of the display panel are not electrically connected to each other.
Normal operation is maintained as a display. Instead of the photoconductor material, for example, a material whose conductivity changes depending on temperature to obtain conduction and non-conduction may be used. Further, it is possible to adopt a structure in which the electrodes wired on the lower surface of the chip mounting portion are concentrated and electrically connected to one minute point, and mechanically or cut by a laser or the like after the above inspection and test are completed.

[0016]

FIG. 1 is an embodiment of the present invention showing an electrode arrangement in the vicinity of an IC chip of a TFT liquid crystal display mounted on a chip on glass. The display panel has the same configuration as the TFT liquid crystal display shown in FIG. 5, and the IC chip arrangement is also the same. Further, here, it is assumed that the gate electrode line and the drain electrode line can be driven by the same driving IC chip.

In FIG. 1, reference numeral 21 is a driving IC chip, which is connected face down with an input side electrode terminal portion 24 and an output side electrode terminal portion 23. Reference numeral 31 is an input side electrode wire for control, and 32 is an output side electrode wire. Output side electrode wire 32
Are the gate signal lines G and the upper and lower drain signal lines Du and Dl of the display panel. The output-side electrode wires 32 pass through the output-side electrode terminal portion 23 and are centrally wired in the central portion of the lower surface of the IC chip. These are provided on the photoconductive layer 50 formed of, for example, amorphous-silicon (a-Si). Connecting. From this a-Si photoconductive layer 50, electrode lines 411, 412, 413 for connection with other ICs or for extraction electrodes are drawn out.

FIG. 2 is a sectional view of FIG. The electrode terminal portion 26 of the IC chip 21 and the output-side electrode 32 are connected to each other via the conductive paste 27 applied to the protrusion portion 25 of the IC chip. The height of the protrusion 25 is about 10 to 20 μm, and the insulating film 29 is formed in the active region of the chip. As shown in the figure, the output side electrode 32 enters the lower surface of the IC chip 21 and is connected to the a-Si photoconductive layer 50. Since the photoconductive layer 50 can be formed to have a thickness of 1 to 2 μm or less, the active region of the chip does not come into contact with the photoconductive layer 50. This photoconductive layer 50 is a TF of the display panel.
If T is an a-Si semiconductor, it can be formed at the same time.

In order to inspect and test the display panel which is the object of the present invention, the extraction electrodes 411, 412, 413 are used.
Should be used. FIG. 7 shows an electrode configuration of the display panel according to the present invention. 411 is an IC for driving the upper drain electrode
The extraction electrode formed on the lower surface, 412, the extraction electrode formed on the lower surface of the lower drain electrode driving IC, and 413,
It is an extraction electrode formed on the lower surface of the gate electrode driving IC. Other reference numerals are the same as those in FIG. In FIG. 7, when the inspection and test are performed, the photoconductive layer portion 50 described above is used.
The photoconductive layer portion 5 is irradiated with light sufficient for electrical conduction to the
Make 0 conductive and inspect.

The short circuit between the drain electrodes is checked by measuring the resistance between the extraction electrodes 411 and 412, and the short circuit between the gate electrode and the drain electrode is checked.
13 and the extraction electrode 411 or the extraction electrode 412. Further, in order to prevent electrostatic breakdown during the manufacturing process, the extraction electrodes 411, 412, 413 are used.
All should be short-circuited and kept at a constant potential. Furthermore, in order to stabilize the characteristics of the TFT in the display section, the extraction electrode 4
This can be achieved by short-circuiting 11, 412 and applying a voltage between this and the extraction electrode 413.

After completion of the above inspection and test, the irradiation of light is stopped, and the IC chip 21 is aligned with the electrode pattern and mounted on the display panel by the method described with reference to FIG. As a result, the IC chip 21 acts as a light shield, and the photoconductive layer 50 becomes non-conductive, so that a normal display operation is ensured. On the other hand, the light source of the liquid crystal display is IC
It may be on the active region surface side of the chip 21, but this does not limit the effect of the present invention because it can be easily shielded from light by a light shielding sheet or the like.

In the above-mentioned first embodiment, the material of the lower surface of the driving IC is a photoconductor, but it may be a heat sensitive material such as a thermistor which is conductive or nonconductive depending on temperature. In this case, the only difference is that heat is applied to this material,
The electrode configuration of the display panel, the inspection method and the test method are exactly the same as those in the first embodiment.

FIGS. 8 and 9 show an embodiment in which a semiconductor switch element which is an electronic switch is used in place of the photoconductor and the heat sensitive member. FIG. 8 is a plan view thereof, and FIG. 9 is a sectional structural view. In FIG. 8, reference numeral 52 is a semiconductor switch element portion, and this portion has, for example, the structure shown in FIG.
Formed on 0. That is, the structure is exactly the same as that of the TFT formed on the display panel, and the gate electrode (C
r), an insulating film (SiN), an active layer (i), an ohmic layer (n +), and a source / drain electrode. Of these, the source and drain electrodes are the drain electrode line and the gate electrode line 32 themselves of the display panel. Therefore, in the connection diagram shown in FIG. 9, if a voltage Vg sufficient to conduct conduction between the source and drain electrodes is applied from the gate electrode, the drain electrode line and the gate electrode line 32 of the display panel are short-circuited to each other. The inspection and test described above are possible. After the inspection and the test, the gate voltage Vg is set to 0.
By doing so, the drain electrode line and the gate electrode line 32 of the display panel become non-conductive with each other. In this embodiment, since only the voltage is applied, there is an effect that the facilities such as the light source and the heat source as in the first and second embodiments are unnecessary.

FIG. 10 shows another embodiment. In this embodiment, the electrode wire group 32 is concentratedly connected to the central minute point electrode 51. In addition, the lead-out electrode wires 411, 412, 4
13 is also connected to this fine point. Since these are electrically connected in this state, light, heat, etc. are unnecessary in the inspection process. The inspection and test method is exactly the same as that of the first embodiment. In this embodiment, since it is necessary to insulate the electrode wires 32 from each other after the inspection is completed, since the electrodes are connected by the minute point electrodes 51, they can be easily cut by a laser or the like. This cutting method may be a mechanical notch or the like.

Although the TFT liquid crystal display has been described in the above embodiments, the present invention is not limited to this, and the present invention is a chip-on-glass mounting method and short-circuiting between electrodes of a simple matrix liquid crystal display panel in which upper and lower alternate electrodes are drawn out. It can be easily inferred from FIG. 7 that it can be applied to inspection and the like. Further, the present invention is as shown in FIG.
It goes without saying that the present invention can be applied to a short-circuit inspection between the Lu and Ll electrodes of a liquid crystal display panel which is divided into upper and lower parts.

[0026]

According to the present invention, the electrode inspection and the test of the chip-on-glass mounting type display panel can be easily performed, so that the yield of the display panel can be improved and the cost of the display can be reduced.

In addition, in the TFT display panel, it is possible to take measures against electrostatic breakdown during manufacturing, and
It can contribute to the improvement of the characteristics of T.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of an electrode wiring according to the present invention.

2 is a cross-sectional view of a connection portion of the embodiment of FIG.

FIG. 3 is an explanatory diagram of a conventional method for inspecting a TFT liquid crystal panel.

FIG. 4 is an equivalent circuit of a pixel section of a TFT liquid crystal panel.

FIG. 5 is a configuration diagram of a chip-on-glass-mounted TFT liquid crystal panel.

FIG. 6 is a plan view of a conventional example of chip-on-glass mounting electrode wiring.

FIG. 7 is an explanatory diagram of a method for inspecting and testing a TFT liquid crystal panel according to the present invention.

FIG. 8 is a plan view showing another embodiment of the present invention.

9 is a sectional view of the embodiment of FIG.

FIG. 10 is a plan view showing another embodiment of the present invention.

FIG. 11 is a plan view showing another embodiment of the display of the electrode wiring according to the present invention.

[Explanation of symbols]

 21 IC Chip 32 Drain / Gate Electrode Line 50 Photoreceptor (or Heat Sensitive Body) 51 Minute Point Electrode 52 Semiconductor Switch Element 411 Extraction Electrode 412 Extraction Electrode 413 Extraction Electrode

Claims (8)

[Claims] 1. A matrix display device having a plurality of row and column electrode line groups on a substrate surface, wherein electrode terminals of a semiconductor chip are directly mounted on the terminals of the electrode line group and displayed by the output of the semiconductor chip. , The electrode wire group terminals are extended and arranged centrally on the lower surface of the semiconductor chip, and the electrode wire group is connected by a member whose conductivity changes in response to a physical quantity on the lower surface of the semiconductor chip. Matrix display device. 2. The matrix display device according to claim 1, wherein the member whose conductivity changes in response to a physical quantity is a member whose conductivity changes in response to light. 3. The matrix display device according to claim 2, wherein the member whose conductivity changes in response to light is amorphous silicon. 4. The matrix display device according to claim 1, wherein the member whose electric conductivity changes in response to a physical quantity is a member whose electric conductivity changes in response to heat. 5. The matrix display device according to claim 2, wherein the member whose conductivity changes in response to heat is a thermistor. 6. A matrix display device having a plurality of row and column electrode line groups on a substrate surface, wherein electrode terminals of a semiconductor chip are directly mounted on terminals of the electrode line group and displayed by an output of the semiconductor chip. The matrix display device according to claim 1, wherein the electrode line group terminals are extended and concentrated on the lower surface of the semiconductor chip, and the electrode line group is connected by an electronic switch on the lower surface of the semiconductor chip. 7. A matrix display device having a plurality of row and column electrode line groups on a substrate surface, wherein electrode terminals of a semiconductor chip are directly mounted on the terminals of the electrode line group and displayed by the output of the semiconductor chip. , M on the lower surface of the semiconductor chip
An OSFET (metal-oxide-semiconductor field effect transistor) is formed, the electrode line group terminal is extended and the electrode line group is connected as a drain or source electrode of the MOSFET, and a gate electrode is drawn out from the MOSFET. A matrix display device characterized by the above. 8. A matrix display device having a plurality of row and column electrode line groups on a substrate surface, the electrode terminals of the semiconductor chip being directly mounted on the terminals of the electrode line group, and being displayed by the output of the semiconductor chip. In, the electrode wire group terminals are extended to the lower surface of the semiconductor chip and are concentrated and connected to at least a portion smaller than the area of the semiconductor chip, and then the concentrated connection portion is cut to electrically non-conduct. A matrix display device characterized by the above.