KR20080012538A - Apparatus for measuring sheet resistance - Google Patents

Abstract

An apparatus for measuring sheet resistance is provided to guarantee a space margin with respect to a sheet resistance measuring position by including a stage for mounting a mother substrate and a head including a plurality of probes arranged in a line. A mother substrate for a liquid crystal display is placed on a stage. A head(150) is disposed on the stage, including a plurality of probes(160) that are arranged in a line to measure sheet resistance. The head is capable of rotating to convert the arrangement direction of the probe. The mother substrate can be composed of a plurality of cells and a cell interval part between the cells, and the probe can come in contact with the cell interval part to measure sheet resistance.

Description

Sheet resistance measuring device {Apparatus for measuring sheet resistance}

1 is a flowchart illustrating a manufacturing process of a liquid crystal display according to an exemplary embodiment of the present invention.

2 is a perspective view showing a sheet resistance measuring apparatus according to an embodiment of the present invention.

3 is a bottom view illustrating a head of the sheet resistance measuring apparatus of FIG. 2.

4 is a plan view illustrating a positional relationship between a probe and a mother substrate of FIG. 3.

(Explanation of symbols for the main parts of the drawing)

100: sheet resistance measuring device 110: stage

120: mother substrate 122: cell

124: cell gap 130: alignment pin

140: drive unit 142: guide rail

150: head 160: probe

The present invention relates to a sheet resistance measuring apparatus, and more particularly to a sheet resistance measuring apparatus for measuring sheet resistance of a conductive film formed on a liquid crystal panel.

Cathode ray tube (CRT), which is one of the display devices that are generally used, is mainly used for monitors such as televisions, measuring devices, information terminal devices, etc., but due to its own weight and size, It could not actively respond to the demand for miniaturization and weight reduction.

In order to replace the cathode ray tube, it has advantages such as small size, light weight, low power consumption, and the like, and a liquid crystal display device that displays information by using the electrical and optical properties of the liquid crystal injected into the liquid crystal panel has been actively developed. Recently, it plays a role as a flat panel display device. In general, a liquid crystal display device is a display device having low power consumption, light weight, and small volume. The liquid crystal display device has been widely applied to a wide range of industries, for example, the computer industry, the electronics industry, and the information and communication industry due to such unique advantages. As a matter of fact, the liquid crystal display device having such advantages has been applied to various fields such as a display device of a portable computer, a monitor of a desktop computer, a monitor of a high-definition video device, and the like.

Such a liquid crystal display is formed by forming a thin film transistor array and a common electrode in cell units on two large mother substrates, and then bonding the mother substrates and cutting them in cell units. That is, the liquid crystal display includes a thin film transistor substrate on which a thin film transistor array is formed, a common electrode substrate on which a common electrode is formed, and a liquid crystal layer interposed therebetween.

In the process of forming a thin film transistor array or a common electrode on the mother substrate, a process of forming and patterning a conductive film on the mother substrate is performed. Here, after the conductive film is formed on the mother substrate, the sheet resistance of the conductive film is measured to check the electrical properties of the conductive film.

In general, the sheet resistance is measured by contacting four probes arranged in a line with the cell gap located between the cells, and the cell gap is reduced by arranging a plurality of cells in one mother substrate to reduce the manufacturing cost. The spatial margin for the measurement position of the sheet resistance is reduced. In addition, in the conventional sheet resistance measuring apparatus, a head having four probes only moves up and down on the mother substrate, and the cell layout in the mother substrate varies according to the type of liquid crystal display device. There is a problem that cannot be uniformly applied to various cell arrangements with a measuring device.

The technical problem to be achieved by the present invention is to provide a sheet resistance measuring apparatus that can secure a spatial margin for the sheet resistance measurement position and can be applied uniformly to various cell arrangements.

Technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, a sheet resistance measuring apparatus includes a stage on which a mother substrate for a liquid crystal display device is placed, and a plurality of probes disposed on the stage and arranged in a line for measuring sheet resistance. An installed head, the head includes a rotatable head for changing the arrangement direction of the probe.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

A liquid crystal display device according to the present invention includes a liquid crystal panel assembly including a liquid crystal panel for displaying image data using optical properties of liquid crystal, a printed circuit board having a driving circuit for driving the liquid crystal panel, and a backlight for supplying light for screen display. Assembly, and a storage container for fixing and receiving the liquid crystal panel assembly and the backlight assembly. Here, the liquid crystal panel includes a thin film transistor substrate on which a thin film transistor array is formed, a common electrode substrate on which a common electrode is formed, and a liquid crystal layer interposed between the thin film transistor substrate and the common electrode substrate.

Hereinafter, a process of manufacturing the liquid crystal display of the present invention will be described with reference to FIG. 1. 1 is a flowchart illustrating a manufacturing process of a liquid crystal display according to an exemplary embodiment of the present invention.

As shown in FIG. 1, the manufacturing process of the liquid crystal display includes a thin film transistor mother substrate manufacturing process (S10), a common electrode mother substrate manufacturing process (S20), a liquid crystal cell process (S30), and a module process (S40).

Here, the thin film transistor mother substrate manufacturing process (S10) is a process of manufacturing a thin film transistor mother substrate in which a thin film transistor array (TFT array) is formed on a large glass substrate (hereinafter referred to as a mother substrate) in units of cells, and a common electrode mother substrate manufacturing process S20 is a process of manufacturing a common electrode mother substrate in which a common electrode is formed in a cell unit on another mother substrate.

In the thin film transistor mother substrate manufacturing process S10, a conductive film is deposited and patterned on a substrate to form a gate line, a data line, or a pixel electrode.

The gate line is made of aluminum-based metal such as aluminum (Al) and aluminum alloy, silver-based metal such as silver (Ag) and silver alloy, copper-based metal such as copper (Cu) and copper alloy, molybdenum (Mo) and molybdenum alloy Molybdenum-based metals, such as chromium (Cr), titanium (Ti), tantalum (Ta) and the like. In addition, the gate line may have a multi-layer structure including two conductive layers (not shown) having different physical properties. One of the conductive films is made of a low resistivity metal such as an aluminum-based metal, a silver-based metal, or a copper-based metal so as to reduce the signal delay or voltage drop of the gate line. In contrast, the other conductive film is made of a material having excellent contact properties with other materials, particularly indium tin oxide (ITO) and indium zinc oxide (IZO), such as molybdenum-based metals, chromium, titanium, tantalum, and the like. A good example of such a combination is a chromium bottom film and an aluminum top film and an aluminum bottom film and a molybdenum top film. However, the present invention is not limited thereto, and the gate line may be made of various various metals and conductors.

The data line is preferably made of a refractory metal such as chromium, molybdenum-based metal, tantalum and titanium, and has a multi-layered structure consisting of a lower film (not shown) such as a refractory metal and an upper film (not shown) disposed thereon. Can have Examples of the multilayer film structure include a triple film of molybdenum film, aluminum film, and molybdenum film in addition to the above-described double film of chromium lower film and aluminum upper film or aluminum lower film and molybdenum upper film.

The pixel electrode is made of a transparent conductor such as indium tin oxide (ITO) or indium zinc oxide (IZO) or a reflective conductor such as aluminum.

In addition, in the common electrode mother substrate manufacturing process S20, there is a process of forming a common electrode by depositing and patterning a conductive film on a substrate.

The common electrode is made of a transparent conductor such as ITO or IZO.

The thin film transistor mother substrate and the common electrode mother substrate prepared by the thin film transistor mother substrate manufacturing process (S10) and the common electrode mother substrate manufacturing process (S20) are subjected to the liquid crystal cell process (S30), and the liquid crystal cell process (S30) is described above. An alignment layer and a seal line are formed on the mother substrate to partition a plurality of cells, drop the liquid crystal into the cells, bond two mother substrates, and cut each cell using various cutting tools to form a liquid crystal panel. Is fair.

Thereafter, a module process (S40) of attaching a driving circuit for supplying an electrical signal to the liquid crystal panel is performed. The module process (S40) is a process of mounting a driving IC on a liquid crystal panel, attaching a printed circuit board (PCB), and assembling a mold frame, a chassis, etc. together with a back light unit.

In the process of manufacturing the liquid crystal display, a process of forming and patterning a conductive film on the mother substrate is performed in the thin film transistor mother substrate manufacturing process S10 and the common electrode mother substrate manufacturing process S20. After forming the conductive film on the mother substrate and before patterning, the sheet resistance of the conductive film is measured to check the electrical properties of the conductive film.

Hereinafter, a process of measuring sheet resistance will be described in detail with reference to FIGS. 2 to 4. 2 is a perspective view illustrating a sheet resistance measuring apparatus according to an exemplary embodiment of the present invention, FIG. 3 is a bottom view illustrating a head of the sheet resistance measuring apparatus of FIG. 2, and FIG. 4 is a positional relationship between the probe of FIG. 3 and the mother substrate. It is a top view which shows.

2 and 3, the sheet resistance measuring apparatus 100 according to an embodiment of the present invention includes a stage 110 for supporting a mother substrate 120 made of glass or the like, and an upper portion of the stage 110. It includes a head (150) formed with four probes (160) for measuring the sheet resistance and a driving unit 140 for moving the head 150.

Here, the mother substrate 120 having the conductive film formed thereon is mounted on the upper surface of the stage 110, and the stage 110 is movable in the X-axis direction. The stage 110 has alignment pins 130 formed along edges of the mother substrate 120. The alignment pin 130 is a reference for determining the position of the mother substrate 120 by contacting at least one side of the mother substrate 120. The alignment pin 130 may be formed using a material having high abrasion resistance. The shape of the alignment pin 130 may be variously modified, such as a cylinder, a polygonal column.

The probe 160 of the head 150 descends from the upper portion of the mother substrate 120 positioned through the alignment pin 130 to contact the conductive film formed on the mother substrate 120 to measure the sheet resistance of the conductive film. The head 150 is provided with four probes 160 arranged in a line, and the distance between each probe 160 is about 1-1.2 mm. A current I flows between the outer two probes 160, and the sheet resistance is obtained by measuring the voltage V between the two inner probes 160.

The driving unit 140 is connected to the head 150 in which the probe 160 is installed to move the head 150 in the Z-axis direction. Therefore, the probe 160 is in contact with the mother substrate 120 by the Z-axis movement of the driving unit 140. In addition, the driving unit 140 may move along the guide rail 142 in the Y-axis direction. As mentioned above, since the stage 110 is movable in the X-axis direction and the driving unit 140 is movable in the Y-axis and Z-axis directions, the probe 160 may be moved at an arbitrary position on the mother substrate 120. The sheet resistance can be measured. In this embodiment, the stage 110 and the driving unit 140 are described as moving in a specific direction, respectively, but the present invention is not limited thereto and the probe 160 may measure sheet resistance at an arbitrary position on the mother substrate 120. The stage 110 and the driving unit 140 may move in any direction within the range.

2 and 3, a plurality of cells 122 are disposed on the mother substrate 120, and each cell 122 is later separated to form a thin film transistor substrate or a common electrode substrate constituting the liquid crystal display device. . Since the four probes 160 installed in the head 150 are arranged in a line, it is difficult to apply them collectively to the arrangement of the various cells 122. Therefore, the head 150 of the sheet resistance measuring apparatus 100 according to an embodiment of the present invention can rotate. That is, the direction in which four probes 160 installed in the head 150 are arranged may be switched. Since the arrangement direction of the probes 160 may be arbitrarily changed, one sheet resistance measuring apparatus 100 may be applied to various mother substrates 120 having different arrangements of the cells 122. Here, the driving unit 140 may use a motor method or a pneumatic method to rotate the head 150.

3 and 4, the cell gap 124 between the cells 122 and 122 is reduced in order to reduce manufacturing costs. In order to measure the sheet resistance of the conductive layer without damaging the cell 122, the probe 160 preferably contacts the cell spacer 124. As mentioned above, since each of the probes 160 is 1 to 1.2 mm apart, space of about 4 to 5 mm is required in the arrangement direction of the probes 160 in order for the four probes 160 to contact the conductive film. However, a smaller space is required in a direction perpendicular to the arrangement direction of the probe 160.

Therefore, as shown in FIG. 4, the rectangular cells 122 are arranged in a matrix form, and for example, the cell gaps 124 in the Y-axis direction are larger than the lengths of the cell gaps 124 in the X-axis direction. In the case where the length is longer, a spatial margin for the sheet resistance measurement position may be secured by arranging the probes 160 in the X-axis direction. If the length of the cell gap 124 in the Y-axis direction is shorter than the length of the cell gap 124 in the X-axis direction, as opposed to FIG. 4, it is preferable to arrange the probes 160 in the Y-axis direction. Since the head 150 is rotatable in this manner, even if the cell gap 124 is reduced, the probe 160 may be rotated and disposed in a direction in which a relatively large spatial margin is increased.

In addition, the probe 160 may rotate in all directions, but preferably, when the cell 122 is rectangular, the cell gap 124 is formed in the X-axis or Y-axis direction, as shown in FIG. 3. , Can rotate substantially 90 degrees.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

As described above, according to the sheet resistance measuring apparatus according to the present invention, a spatial margin with respect to the sheet resistance measuring position can be ensured and can be uniformly applied to various cell arrangements.

Claims (10)

A stage on which a mother substrate for a liquid crystal display device is placed; And And a head disposed on the stage and provided with a plurality of probes arranged in a row for measuring sheet resistance, the head including a head rotatable to change an arrangement direction of the probes. According to claim 1, And the head rotates substantially 90 degrees. According to claim 1, The mother substrate includes a plurality of cells and cell gaps between the cells, and the probe is in contact with the cell gaps to measure sheet resistance. According to claim 1, The sheet resistance measuring apparatus arranged in four in a row. According to claim 1, And a driving unit connected to the head to control vertical movement and rotational movement of the head. The method of claim 5, The driving unit is a sheet resistance measuring device for rotating the head using a motor method or a pneumatic method. The method of claim 5, And the stage moves forward and backward, and the driving unit moves left and right. According to claim 1, A sheet resistance measuring device having a conductive film formed on the mother substrate. The method of claim 8, And the mother substrate is a thin film transistor mother substrate, and the conductive layer forms a gate line, a data line, or a pixel electrode. The method of claim 8, The mother substrate is a common electrode mother substrate, the conductive film is a sheet resistance measuring device to form a common electrode.

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