JPH06102539A - Liquid crystal display panel - Google Patents

Abstract

PURPOSE:To obtain the practical liquid crystal display panel which uses a thick film varistor as a nonlinear element connecting a pixel electrode and a signal line. CONSTITUTION:On a pixel electrode substrate 1, pixel electrodes 1c which are arranged in matrix, plural beltlike signal lines 1b which are arranged along pixel electrodes 1c in respective arrays in a specific direction Y1-Y2 (perpendicular to paper surface) among the respective pixel electrodes 1c and send signals to the pixel electrodes 1c in the respective arrays, and the nonlinear element 1d which connects the pixel electrodes 1c in the respective arrays and the signal lines are formed. A counter electrode substrate 2 which is arranged on the pixel electrode substrate 1 across liquid crystal has plural beltlike counter electrodes 2b opposite the pixel electrodes 1c in the respective arrays orthogonal to the specific direction among the pixel electrodes 1c in the matrix. The nonlinear element 1d is formed of the rectangular thick film varistor by a lift-off method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel, and more particularly to a liquid crystal display panel characterized by pixel driving elements.

[0002]

2. Description of the Related Art A liquid crystal display panel is a light receiving display device.
Since it is possible to display at low voltage and low power, and the display device has a simple structure and can be directly driven by an IC, downsizing of the device,
It is easy to make thin, and it has come to dominate the display elements of calculators and wristwatches. 2. Description of the Related Art In recent years, with the spread of information processing devices such as word processors and personal computers, portability, thinning, and downsizing of devices have been demanded, and liquid crystal display panels have begun to be adopted as display devices replacing CRTs. In such a case, since it is possible to display Chinese characters, the number of pixels will be much larger than in applications such as calculators and watches.
As a driving method of the liquid crystal display panel, a simple matrix display driving method in which electrodes are crossed in an XY shape is usually used. In this case, a constant voltage is applied to the adjacent pixels because the electrodes for each pixel are not individually independent, so that the adjacent pixels are not completely in the non-display state and so-called crosstalk occurs. There is.

In order to improve this crosstalk, an active matrix display driving method in which a non-linear element such as a diode or a thin film transistor is provided for each pixel is used. However, it is difficult to fabricate a diode, a thin film transistor, or the like for each pixel up to several thousands to several hundreds of thousands of pixels without any defect or to have the same characteristics, and there is little variation in characteristics, and it is possible to form a large area. Fabrication of nonlinear elements has been desired.

As a method for solving the above-mentioned problems, I
EEE TRANSACTION ON ELECTRO
N DEVICES, VOL. ED-26, NO. 8,
AUGUST 1979, p. As disclosed in 1123 to 1128, a liquid crystal display element using a varistor was proposed by GE Corporation of the United States, and its concrete configuration diagram and the possibility of matrix display by time division driving were shown. This method uses a ceramic varistor substrate as one of two substrates sandwiching a liquid crystal, and it has been impossible to construct a transmissive liquid crystal display panel. Therefore, a method disclosed in Japanese Patent Laid-Open No. 2-291528 has been proposed. That is, it is a liquid crystal display panel in which a pixel electrode formed on a substrate and a signal line for sending a signal to this pixel electrode are connected in a planar structure by a varistor produced by printing and firing a thick film varistor paste.

A varistor is generally used as a surge absorbing element, and as shown in FIG. 16, it has a large resistance below a certain voltage (hereinafter referred to as varistor threshold voltage (Va)) and practically almost no current flows. There is no voltage V
When it exceeds a, the resistance sharply decreases and the current flows.Therefore, the varistor voltage, current capacity, etc. can be arbitrarily controlled by controlling the distance between electrodes, the size of particles, etc. It is used in a wide range of areas such as electronic circuit protection and lightning rods.

[0006]

17 and 18 show a liquid crystal display panel using a varistor produced by printing and firing a conventional thick film varistor paste. 17 is a cross-sectional view of the liquid crystal display panel, FIG. 18 is an explanatory view of a pixel electrode substrate of the liquid crystal display panel, FIG. 18A is a lower substrate of the liquid crystal display panel, that is, an electrode configuration portion of the pixel electrode substrate, and FIG. 18 is an enlarged plan view of one pixel of the electrode structure portion, FIG.
C is a cross-sectional view of one pixel of the electrode configuration portion (see FIG. 18B).
XVIIIC-XVIIIC line sectional view). In FIG. 17, the liquid crystal display panel D includes a pixel electrode substrate 01 and a counter electrode substrate 0.
2 and spacers 03 for holding them at a constant interval. The pixel electrode substrate 01 and the counter electrode substrate 0
Polarizing plates 04 and 05 are provided on the outer surfaces of 2, respectively. A liquid crystal 06 is enclosed in a space surrounded by the pixel electrode substrate 01, the counter electrode substrate 02, and the spacer 03.

The pixel electrode substrate 01 has a transparent substrate body 01a made of glass. A signal line 01b extending in a direction perpendicular to the paper surface (Y1-Y2 direction, Y1 is a direction from the front surface side to the back surface side of the paper surface, Y2 is a direction from the back surface side to the front surface side of the paper surface) on the inner surface of the substrate body 01a. Are provided, and a plurality of pixel electrodes 01c are formed along each signal line 01b. Therefore, the pixel electrodes 01c are arranged in a matrix as a whole. Each of the plurality of pixel electrodes 01c arranged along each of the signal lines 01b and the signal line 01b are connected by a printed thick film varistor 01d. The counter electrode substrate 02 is the substrate body 02a.
And a strip-shaped counter electrode 02b extending in the X1-X2 direction (the left-right direction in FIG. 17) on the inner surface of the substrate body 02a.
Are arranged in a plurality of rows along the direction (Y1-Y2 direction) perpendicular to the paper surface. Then, each of the strip-shaped counter electrodes 02b is
It is arranged so as to face the plurality of pixel electrodes 01c for one column arranged along the -X2 direction.

When such a thick film varistor paste is used as a raw material and a method of forming the thick film varistor 01d by a printing method is used, the manufacturing method is simple as compared with the case of using a thin film forming technique such as sputtering or CVD. It is inexpensive and it is possible to fabricate a device in a large area at a time. However, the cross-sectional shape of the thick film varistor 01d formed by the printing method has a mountain shape as shown in FIG. 18C, and it is not easy to control the film thickness. The film thickness is at least 10 μm or more, and the film thickness variation is about ± 3 μm. Therefore, the liquid crystal 6
The thickness is at least 13 μm or more, which causes a decrease in the contrast of the liquid crystal. In addition, when the varistor paste is screen-printed, the spread due to the dripping of the paste is 40 on both sides outside the width of the opening of the screen.
˜50 μm. The formed thick film varistor 01d is also difficult to be finely processed by etching or the like. Therefore, it is extremely difficult to form the thick film varistor 01d finely and accurately by using a printing method. It cannot be applied to a liquid crystal display panel having a high pixel pitch.

Therefore, conventionally, it has been proposed to use a thick film varistor for the non-linear element 01d for connecting the pixel electrode 01c and the signal line 01b as shown in FIGS. 17 and 18, but it is only at the idea stage. It has not been put to practical use. The reason is probably as follows. That is, it was generally thought that a liquid crystal display panel having a large display area could not be produced practically without high-precision thin film technology. The present inventors initially thought that it would be impossible to put a large-area liquid crystal display panel using thick film technology into practical use. However, as a precaution, a liquid crystal display panel having a thick film varistor formed by the lift-off method was used. As a result of manufacturing it, it was found that a large-area liquid crystal display panel with sufficient practicality could be manufactured.

In view of the above-mentioned problems and research results, the present invention has an object to be described in the following (A11). (A11) To provide a practical liquid crystal display panel using a thick film varistor as a non-linear element that connects a pixel electrode and the signal line.

[0011]

The present invention devised to solve the above problems will now be described. The elements of the present invention are to facilitate correspondence with the elements of the embodiments described later. , The reference numerals of the elements in the embodiments are enclosed in parentheses. The reason why the present invention is described in association with the reference numerals of the embodiments described later is to facilitate the understanding of the present invention.
It is not intended to limit the scope of the invention to the examples.

In order to solve the above problems, the first of the present application
The liquid crystal display panel of the invention has the following requirements (A1) to (A3).
Liquid crystal display panel equipped with the following requirements (A4)
(A1) The pixel electrodes (1c) arranged in a matrix, and the pixel electrodes (1c) in each column in a predetermined direction among the pixel electrodes (1c) arranged in a matrix. ) Along with a plurality of strip-shaped signal lines (1b) for sending signals to the pixel electrodes (1c) in each column, and connecting the pixel electrodes (1c) in each column to the signal lines (1b). A pixel electrode substrate (1) on which a non-linear element (1d) is formed, (A2) faces the pixel electrode (1c) of each column in the matrix-shaped pixel electrode (1c) orthogonal to the predetermined direction. A counter electrode substrate (2) having a plurality of strip-shaped counter electrodes (2b), (A3) liquid crystal filled between the pixel electrode substrate (1) and the counter electrode substrate (2), (A4) the non-linear element (1d) ) Is formed by a rectangular thick film varistor (1d) formed by the lift-off method. It was.

The method of manufacturing a liquid crystal display panel according to the second invention of the present application is the same as the method of manufacturing a liquid crystal display panel having the following requirements (A1) to (A3).
To (A8), a method for manufacturing a liquid crystal display panel, (A1) pixel electrodes (1c) arranged in a matrix, and among the pixel electrodes (1c) arranged in this matrix A plurality of strip-shaped signal lines (1b) arranged along the pixel electrodes (1c) of each column in a predetermined direction and transmitting signals to the pixel electrodes (1c) of each column, and the pixel electrodes (1c) of each column And a pixel electrode substrate (1) on which a non-linear element (1d) connecting the signal line (1b) is formed,
A counter electrode substrate (2) having a plurality of strip-shaped counter electrodes (2b) facing the pixel electrodes (1c) in each column orthogonal to the predetermined direction in the matrix-shaped pixel electrodes (1c),
(A3) A liquid crystal filled between the pixel electrode substrate (1) and the counter electrode substrate (2), and (A5) a rectangular shape at a position on the pixel electrode substrate (1) where the nonlinear element (1d) is arranged. A non-linear element resist pattern forming step of forming a non-linear element forming resist pattern (RP2) having an opening (RP2a), (A6) wider than the opening area of the rectangular opening (RP2a), (R
P2a) thick film varistor paste filling step of filling the thick film varistor paste thicker than P2a), (A7) after drying the thick film varistor paste filled in the opening (RP2a), the non-linear element forming resist Removing the thick film varistor (1d) on the pattern (RP2) and removing the unfired thick film varistor (B) embedded in the opening (RP2a) so as to have the same thickness as the opening (RP2a). A step of shaping an unfired thick film varistor (B) into a rectangular shape by (A8) firing the shaped unfired thick film varistor (B) and simultaneously forming the nonlinear element forming resist pattern ( Firing process to burn off RP2).

[0014]

Next, the operation of the present invention having the above features will be described. In the liquid crystal display panel of the first invention of the present application having the above-mentioned characteristics, the pixel electrode substrate (1) has the pixel electrodes (1c) arranged in a matrix, and the pixel electrodes (1c) arranged in the matrix. ), A plurality of strip-shaped signal lines (1b) arranged along the pixel electrodes (1c) of the respective columns in the predetermined direction and sending signals to the pixel electrodes (1c) of the respective columns, and the pixels of the respective columns. It is composed of a non-linear element (1d) connecting the electrode (1c) and the signal line (1b). The non-linear element (1d) is formed by a rectangular thick film varistor (1d) formed by a lift-off method. The thick film varistor (1d) thus formed has a uniform shape and thickness, and has uniform characteristics. The counter electrode substrate (2) has a matrix of pixel electrodes (1
In each of the pixel electrodes (1
It has a plurality of strip-shaped counter electrodes (2b) opposed to c).

The liquid crystal driving principle when the liquid crystal display is performed using the pixel electrode substrate (1) and the counter electrode substrate (2) as described above is as follows. FIG. 14A shows a thick film varistor (1d) for one pixel, a pixel electrode (1c) and a counter electrode (2).
It is an equivalent circuit showing that the liquid crystal between b) and is connected in series. CLc is the resistance of the liquid crystal, Cvar is the capacitance of the thick film varistor, and generally Cvar is much smaller than CLc. If the symbol "<<" is used to represent the very small things, then Cvar << CLc. 14
(B) is a diagram showing an IV characteristic of the thick film varistor, in which Vb is a threshold voltage. FIG. 14C is a diagram showing the optical response of the liquid crystal, where Von is the ON voltage of the liquid crystal.
FIG. 14D is a diagram showing the optical response of the series circuit of the varistor and the liquid crystal shown in FIG. 14A.

When a voltage is gradually applied to the series circuit, no current flows in the varistor until the applied voltage Vapp reaches Vb, and the varistor is in the off state. When Vapp> Vb, the voltage of Vapp-Vb starts to be applied to the liquid crystal, and Vapp
When ≧ Vb + Von, the liquid crystal is turned on. Then Va
When pp is lowered, the varistor turns off, the charges injected into the liquid crystal are confined, and the liquid crystal remains on. The charges injected into the liquid crystal gradually flow out according to RLc, and eventually the liquid crystal is turned off. If the liquid crystal element is driven in a cycle shorter than the storage time, that is, the time from turning off the applied voltage to turning off the liquid crystal, continuous liquid crystal display is possible.

Next, driving when such series circuits of varistor and liquid crystal are arranged in a matrix will be described. FIG. 15 is a diagram showing an equivalent circuit in which a series circuit of a varistor and a liquid crystal is arranged in a matrix.
1, X2, X3, ... Corresponds to the signal line (1b) formed on the pixel electrode substrate (1), and the row electrodes (Y1, Y2, Y3,
...) corresponds to the counter electrode (2b). Now, (X2, Y
When only the pixel of 2) is selected, when the voltage Vapp ≧ Vb + Von is applied across the series circuit of the varistor and the liquid crystal, the liquid crystal of the pixel of (X2, Y2) is turned on. At that time, Vap is applied to other pixels around the (X2, Y2) pixel.
A voltage of p / 3 is applied, but Cvar
Is small, most of the voltage of Vapp / 3 is applied to the varistor, and since this voltage is smaller than the threshold voltage Vb of the varistor, no current flows through these pixels and the liquid crystal remains in the off state, which causes crosstalk. There is no occurrence.

If the shape and thickness of the thick film varistor (1d) are not uniform, the following problems will occur. As described above, according to the driving method of the liquid crystal display panel of the present invention, when Vapp is applied to the selected pixel and then Vapp is removed, the charge Q (= CLcVon) is injected into the liquid crystal, and the charge Q
It is designed to maintain the display state of the liquid crystal by the voltage generated by. As described above, since the capacitance Cvar (<< CLc) exists in the thick film varistor, the voltage applied to the liquid crystal after removing Vapp can be expressed by the following equation. (CLcVon) / (CLc + Cvar) ……… (1)

When the shape and thickness are not uniform like the conventional thick film varistor (01d) shown in FIGS.
Pixels cause variations in Cvar, which causes variations in the voltage applied to the liquid crystal after removal of Vapp, as well as the storage time, resulting in a flickering of the liquid crystal screen display (flicker). Occurs. Therefore, when the shape and thickness are not uniform like the conventional thick film varistor (01d), the screen display is very difficult to see due to flicker. On the other hand, in the liquid crystal display panel of the present invention, since the shape and thickness of the thick film varistor are uniform, the screen display is easy to see without flicker.

The method for producing a liquid crystal display panel of the second invention of the present application having the above-mentioned characteristics is the above requirements (A1) to (A3).
Since the non-linear element (1d) of the pixel electrode substrate (1) of the liquid crystal display panel provided with is formed by the steps (A5) to (A8), the non-linear element (1d) having uniform characteristics can be easily formed. can do. That is, according to the method for manufacturing a liquid crystal display panel of the second invention of the present application, the thick film varistor (1d) has a uniform rectangular cross-section and a film thickness of 3 to 3.
The thickness can be freely controlled within the range of 30 μm, and the thick film varistor (1d) having an arbitrary shape can be formed. The variation in the shape of the thick film varistor (1d) is within ± 3 μm, the variation in the film thickness of the thick film varistor (1d) is also within ± 1 μm, and the pitch density of the thick film varistor (1d) is 6
It is possible to form up to 00 DPI. Therefore, it is possible to manufacture a liquid crystal display panel having a high pixel pitch and a high contrast.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a side sectional view of a liquid crystal display panel of an embodiment of the present invention, FIG. 2 is a detailed explanatory view of a pixel electrode substrate of the embodiment, and FIG. 2A is a partial plan view of the pixel electrode substrate. FIG. 2B is a partially enlarged view of one pixel electrode shown in FIG. 2A, and FIG.
2C is a sectional view taken along the line IIC-IIC of FIG. 2B, and FIG.
FIG. 4 is a perspective view of one pixel electrode shown in FIG. 4, and FIGS. 4 to 13 are explanatory views of the method for manufacturing the pixel electrode substrate of the embodiment. In FIG. 1, the liquid crystal display panel D is a transmissive type, and has a pixel electrode substrate 1, a counter electrode substrate 2, and a spacer 3 that holds them at a predetermined interval. Polarizing plates 4 and 5 are adhered to the outer surfaces of the pixel electrode substrate 1 and the counter electrode substrate 2, respectively. The polarization direction of the polarizing plate 4 is the left-right direction (arrow X1
-X2 direction), and the polarization direction of the polarizing plate 5 is a direction perpendicular to the plane of the drawing (arrow Y1-Y2 direction). In the figure, a symbol with "x" in "○" means an arrow Y1 from the front side to the back side of the paper, and a symbol with "." It means an arrow Y2 from the back to the front. In the space surrounded by the pixel electrode substrate 1, the counter electrode substrate 2, and the spacer 3, TN (T
A liquid crystal 6 of the Wisted Nematic type is enclosed. The liquid crystal 6 is a DS (Dynamic).
ic Scattering mode type, ECB (E
electrically controllable bi
refrence) type, GH (Guest Ho)
st) type, STN (Super Twisted Ne)
type), FLC (Ferroelectric)
It is possible to employ various conventionally known liquid crystals such as Liquid Crystal type. The polarizing plates 4 and 5 (see FIG. 1) can be omitted depending on the type of liquid crystal.

Next, the pixel electrode substrate 1 will be described with reference to FIGS. The pixel electrode substrate 1 has a transparent substrate body 1a made of glass. A plurality of signal lines 1b extending in the Y1-Y2 direction are formed on the inner surface of the substrate body 1a, and a plurality of pixel electrodes 1c are formed along the respective signal lines 1b. Each of the plurality of pixel electrodes 1c arranged along each signal line 1b and the signal line 1b is a rectangular uniform thick film varistor 1 formed by a lift-off method.
Connected by d. Since a plurality of signal lines 1b extending in the Y1-Y2 direction are provided and a plurality of pixel electrodes 1c are formed along each signal line 1b as described above, the pixel electrodes 1c are arranged in a matrix as a whole. . Also,
In FIG. 1, the counter electrode substrate 2 has a substrate body 2a, and a plurality of strip-shaped counter electrodes 2b extending in the X1-X2 direction are provided on the inner surface of the substrate body 2a along the Y1-Y2 direction. . Then, each of the strip-shaped counter electrodes 2b has Y1-Y2
It is arranged so as to face the plurality of pixel electrodes 2c for one column arranged along the direction.

Next, an example of a method of manufacturing the pixel electrode substrate 1 of the liquid crystal display panel having the above-mentioned structure will be described. As a method of manufacturing the liquid crystal display panel other than the pixel electrode substrate 1, a conventionally known liquid crystal display panel manufacturing technique is adopted. First, in FIG. 4, a conductor film L to be the signal line 1b is formed on the substrate body 1a of the pixel electrode substrate 1 made of a glass material. Next, in FIG. 5, a photosensitive resist layer R1 is formed on the substrate body 1a on which the conductor film L is formed. Next, in FIG. 6, a photomask is overlaid on the photosensitive resist layer R1 formed in the above step, exposed, and developed with a developing solution. Then, the signal line forming resist pattern RP
Forming a one. Next, in FIG. 7, the conductor film L is etched using the signal line forming resist pattern RP1 as a mask to form the signal line 1b.

Next, in FIG. 8, the transparent pixel electrode 1c is formed by the same process as the manufacturing process of the signal line 1b described in FIGS. Next, referring to FIG. 9, the film thickness is 5 μm.
The photosensitive resist layer R2 having a thickness of about m to 30 μm is formed by, for example, a roll coater, a spin coater, or a dip. Next, in FIG. 10, by exposing using a photomask (not shown) and then developing,
A resist pattern RP2 for forming a non-linear element having a plurality of openings RP2a for forming the non-linear element is formed at a location where the thick film varistor 1d is provided. In this step, as the photosensitive resist layer R2, a resist which is usually used for manufacturing a hybrid IC may be used, but as an example, PMER N-HC6 manufactured by Tokyo Ohka Kogyo Co., Ltd.
00 (trade name) can be used. In addition, OFPR80 resist (trade name) can be used as a similar resist.

Next, in FIG. 11, a varistor paste is formed by screen printing on the opening RP2a for forming the non-linear element so as to be wider than the opening RP2a and thicker than the film thickness of the opening RP2a. After doing, 130
The unfired thick film varistor B is formed by drying at a temperature of about ° C. Next, referring to FIG. 12, the unfired thick film varistor B on the non-linear element forming resist pattern RP2 is removed, and at the same time, the unfired thick film varistor B embedded in the opening RP2a is replaced with the film thickness of the opening RP2a. Remove to be equal. That is, the upper surface of the unfired thick film varistor B is removed so that the surface of the non-linear element forming resist pattern RP2 and the surface of the unfired thick film varistor B are flush with each other. At this time, the unfired thick film varistor B is very soft because it is still in a dry state and unfired. Therefore, the unfired thick film varistor B can be easily removed by lapping the unfired thick film varistor B with a 2000 to 5000 lapping sheet (grinding sheet), and can be removed accurately without damaging the non-linear element forming resist pattern RP2. In this way, the unfired thick film varistor B and the nonlinear element forming resist pattern RP2 can be flattened.

Next, referring to FIG. 13, the unfired thick film varistor B flattened as described above is fired at a temperature of 500 to 800 ° C. to sinter the unfired thick film varistor B and, at the same time, nonlinearly. Resist pattern for element formation RP2
Is burned and vaporized. The thick film varistor 1d thus formed has a rectangular cross section. And, the variation in the shape of the thick film varistor 1d is ± 3.
Within 1 μm, the film thickness variation of the thick film varistor 1d is ± 1μ
A very small product within m was obtained. It was also confirmed that the pitch density (arrangement density) of the thick film varistor 1d can be formed up to 600 DPI.

Next, the operation of the liquid crystal display panel D will be described. Liquid crystal display panel D constructed as described above
Is a thick film varistor 1 which is a non-linear element of the pixel electrode substrate 1.
The shape and characteristics of d can be uniformly configured. That is, the non-linear element of the pixel electrode substrate 1 can be uniformly formed by the thick film technique. Since each of the non-linear elements 1d of the pixel electrode substrate 1 can have a uniform capacitance, the voltage applied to the liquid crystal is uniform after removal of Vapp expressed by the above equation (1), and is stable without flicker. Liquid crystal display is possible.

Although the embodiments of the liquid crystal panel according to the present invention have been described in detail above, the present invention is not limited to the above embodiments, and does not deviate from the present invention described in the claims. It is possible to make various design changes.

For example, the present invention can be applied to a reflective liquid crystal display panel instead of a transmissive liquid crystal display panel.

[0030]

In the liquid crystal display panel of the present invention described above, a thick film varistor having a uniform shape, thickness and characteristics can be obtained, so that display without flicker can be performed during active matrix driving. Further, in the present invention, the varistor threshold voltage of the varistor thin film can be arbitrarily set, so that a desired liquid crystal display format can be selected without giving much consideration to the withstand voltage of the nonlinear element. The liquid crystal display format includes, for example, a direct-view format using a transmissive type and a reflective type, and a projection format using a transmissive type. Further, the liquid crystal display panel of the present invention can be provided in a liquid crystal display panel that is simple and inexpensive to manufacture, has a large element size, and has a high pixel pitch and a high contrast. Further, in the above-described method for manufacturing a liquid crystal display panel of the present invention, the varistor has a uniform rectangular cross section,
The film thickness can be freely controlled within the range of 3 to 30 μm, and a varistor having an arbitrary shape can be formed. In addition, the variation in the shape of the varistor and the variation in the film thickness are very small,
The pixel pitch of the liquid crystal display panel can be increased and a high contrast liquid crystal display panel can be manufactured. Further, the method of manufacturing the liquid crystal display panel of the present invention uses a thick film technique for forming the varistor film, and thus the manufacturing method is simple and inexpensive as compared with the case of using a thin film forming technique such as sputtering or CVD. It is possible to fabricate a non-linear element in a large area at a time, and it is possible to form a stable varistor element with less variation in characteristics.

[Brief description of drawings]

FIG. 1 is a side sectional view of a liquid crystal display panel according to an embodiment of the present invention.

2 is a detailed explanatory view of the pixel electrode substrate of the embodiment, FIG. 2A is a partial plan view of the pixel electrode substrate, FIG. 2B is a partially enlarged view of one pixel electrode shown in FIG. 2A, 2C is a sectional view taken along line IIC-IIC of FIG. 2B.

FIG. 3 is a perspective view of one pixel electrode shown in FIG. 2C.

FIG. 4 is an explanatory diagram of a method of manufacturing the pixel electrode substrate of the same example.

FIG. 5 is an explanatory diagram of a method of manufacturing the pixel electrode substrate according to the embodiment, which is an explanatory diagram of a step subsequent to that of FIG.

FIG. 6 is an explanatory diagram of a method of manufacturing the pixel electrode substrate of the embodiment, which is an explanatory diagram of a step following the step of FIG. 5.

FIG. 7 is an explanatory diagram of the method of manufacturing the pixel electrode substrate according to the embodiment, which is an explanatory diagram of a step following the step of FIG. 6.

FIG. 8 is an explanatory diagram of a method of manufacturing the pixel electrode substrate of the embodiment, which is an explanatory diagram of a step subsequent to the step of FIG. 7.

FIG. 9 is an explanatory diagram of a method of manufacturing the pixel electrode substrate of the same example, which is an explanatory diagram of a step following the step of FIG. 8.

FIG. 10 is an explanatory diagram of the method of manufacturing the pixel electrode substrate according to the embodiment, which is an explanatory diagram of a step following the step of FIG. 9.

FIG. 11 is an explanatory diagram of a method of manufacturing the pixel electrode substrate of the same example, which is an explanatory diagram of a step following the step of FIG. 10.

FIG. 12 is an explanatory diagram of a method of manufacturing the pixel electrode substrate of the same example, which is an explanatory diagram of a step subsequent to that of FIG. 11.

FIG. 13 is an explanatory diagram of a method of manufacturing the pixel electrode substrate of the same example, which is an explanatory diagram of a step following the step of FIG. 12.

FIG. 14 is an operation explanatory view of a liquid crystal display panel using a thick film varistor, and FIG. 14 (A) shows a thick film varistor (1d) of one pixel, a pixel electrode (1c) and a counter electrode (2b). 14B is an equivalent circuit showing that liquid crystals between and are connected in series, FIG. 14B is a diagram showing IV characteristics of the thick film varistor, and FIG. 14C is an optical response of the liquid crystal. 14D is a diagram showing the optical response of the series circuit of the varistor and the liquid crystal shown in FIG. 14A.

FIG. 15 is an operation explanatory view of a liquid crystal display panel using a thick film varistor, showing an equivalent circuit in which series circuits of varistor and liquid crystal are arranged in a matrix.

FIG. 16 is a characteristic explanatory view of a varistor.

FIG. 17 is an explanatory diagram of a conventional liquid crystal display panel using a thick film varistor.

18 is a detailed explanatory view of a pixel electrode substrate of the conventional liquid crystal display panel shown in FIG. 17, FIG. 18A is a partial plan view of the pixel electrode substrate, and FIG. 18B is one of the pixel electrodes shown in FIG. 18A. 18C is a partially enlarged view of a portion of FIG.
FIG. 13 is a sectional view taken along line XVIIIC-XVIIIC of B.

[Explanation of symbols]

B ... Unfired thick film varistor, RP2 ... Non-linear element forming resist pattern, RP2a ... Opening (non-linear element forming opening, 1 ... Pixel electrode substrate, 1a ... Substrate body, 1b ... Signal line, 1c ... Pixel electrode, 1d ... Non-linear element (thick film varistor), 2 ... Counter electrode substrate, 2a ... Substrate body, 2b ... Counter electrode, 3 ... Spacer,

Claims (2)

[Claims] 1. A liquid crystal display panel having the following requirements (A1) to (A3), characterized in that it has the following requirements (A4), and (A1) arranged in a matrix. Pixel electrodes, a plurality of strip-shaped signal lines that are arranged along the pixel electrodes of each column in a predetermined direction among the pixel electrodes arranged in a matrix and that send signals to the pixel electrodes of each column, and A pixel electrode substrate on which a non-linear element that connects the pixel electrode of the column and the signal line is formed, (A
2) A counter electrode substrate having a plurality of strip-shaped counter electrodes facing the pixel electrodes in each column orthogonal to the predetermined direction in the matrix pixel electrodes, (A3) between the pixel electrode substrate and the counter electrode substrate Filled liquid crystal, (A4) The non-linear element is formed by a rectangular thick film varistor formed by a lift-off method. 2. A method of manufacturing a liquid crystal display panel having the following requirements (A1) to (A3), wherein the following requirements (A5)
To (A8) are provided, a method for manufacturing a liquid crystal display panel, (A1) pixel electrodes arranged in a matrix, and each column in a predetermined direction in each pixel electrode arranged in the matrix. Pixel electrode substrate formed with a plurality of strip-shaped signal lines arranged along the pixel electrodes and sending signals to the pixel electrodes in each column, and a non-linear element connecting the pixel electrodes in each column and the signal lines , (A2) a counter electrode substrate having a plurality of strip-shaped counter electrodes facing the pixel electrodes in each column orthogonal to the predetermined direction in the pixel electrodes in the matrix, (A3) the pixel electrode substrate and the counter electrode substrate A liquid crystal filled in between, (A5) a non-linear element resist pattern manufacturing step of forming a non-linear element forming resist pattern having a rectangular opening at a position where the non-linear element is arranged on the pixel electrode substrate, A6) A thick film varistor paste filling step of filling the rectangular opening with a thick film varistor paste wider than the opening area and thicker than the thickness of the opening, (A7) the thick film filled in the opening After drying the varistor paste, the thick film varistor on the nonlinear element forming resist pattern is removed and the unfired thick film varistor embedded in the opening is removed so as to have the same thickness as the opening. Unfired thick film varistor shaping step of shaping the unfired thick film varistor into a rectangular shape, (A8) A firing step of firing the shaped unfired thick film varistor and at the same time burning off the non-linear element forming resist pattern.