JPH10274662A - Method for inspecting liquid crystal display panel and contact probe for inspection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surelt bring a contact lead into contact with a panel electrode with a simple alignment by forming a plurality of contact leads with a narrower width than the panel electrode of LCD and having elasticity in comb teeth shape in the width direction with a narrower gap than the electrode gaps. SOLUTION: At the end of a transparent electrode 21 of an LCD panel 1, the probe of a contact probe pushing to electrode pads 22 arranged in two rows with a gap of 100 μm in the front and back is constituted as follows. That is, on two folded stainless foils 12 and 14, contact leads 20 with a length of 0.3 mm and width of 15 μm are formed in a comb teeth shape with a 25 μm gap. When the contact lead groups of this probe are pushed along the arrangement direction of the panel electrode 21, one of the contact leads 20 is brought into contact with each electrode pad 22. Therefore, it is not necessary to strictly set the alignment in the width direction and the leads 20 made of stainless steel has proper elasticity and abrasion resistance so that repeated contact to the electrode 21 is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting a liquid crystal display panel and a contact probe used in the inspection process.

[0002]

2. Description of the Related Art In a liquid crystal display (LCD) panel, transparent electrodes are formed in stripes on two glass substrates, and both electrode surfaces face each other at an interval of about 10 μm so that the electrodes are orthogonal to each other. When a liquid crystal is injected into a gap between these two glass substrates and a voltage is applied between transparent electrodes orthogonal to each other, an intersection of the two electrodes serves as an optical switch to constitute a pixel. On the glass substrate, panel electrodes for inputting a signal voltage to the transparent electrode are arranged adjacent to a rectangular display unit. In the LCD panel inspection process, all lighting display inspection (solid image lighting inspection) is performed by inputting signals to panel electrodes arranged on the substrate at once.
It is also important to find defects before mounting a driver IC or a control board and to reduce manufacturing costs.

[0003] In such a full lighting display inspection, it is necessary to make an electrode of a contact probe for sending a display signal contact a panel electrode on a glass substrate. Conventionally, when performing a full lighting display inspection, as shown in FIG. 4 (a), a terminal array 81 patterned on an anisotropic conductive rubber or a flexible substrate (FLEXIBLE PRINT CIRCUIT: FPC) 80 is used as an LCD. The mainstream is to press the panel electrode 71 of the panel 1 to make contact. The probe card shown in FIG. 4B is obtained by soldering a fine core wire 91 made of tungsten or the like to a glass epoxy substrate 90 so as to be at the same pitch as the electrodes of the LCD panel 1. The free end of each wire core is finely polished, and a large number of wires 91 (referred to as a wire pin block) on which a conductive pattern is formed are pressed against the electrodes arranged on the LCD panel 1 to perform probing. is there. Probing using an FPC or a probe card is effective when the number of terminal rows is not increased and the pitch is not narrowed.

[0004]

However, as the liquid crystal display panel has a larger screen and higher definition, the number of electrodes arranged on the substrate has been greatly increased, and the panel electrodes have been reduced in size and pitch. (For example, electrode terminal width 50 μm,
(The electrode pitch is 100 μm). On the other hand, F
Conventional technologies, such as PCs and probe cards, use a one-to-one probing method in which terminal rows and core wires are in contact with electrodes arranged on the panel, so that LCD panels with larger screens and higher definition are progressing. It is difficult to align the front, back, left, and right of the contact probe for
It is becoming difficult to cope with the increase in the number of pins and the pitch of the electrodes of the D panel. Especially FP, which was the mainstream in the past
The contact probe that presses C has a problem that as the number of pins increases and the pitch becomes narrower, the contact resistance increases or a contact failure occurs, and the reliability of the contact decreases, which is not suitable for precise inspection. there were.

In a probe card in which a number of fine core wires are arranged at the same pitch as a panel electrode, a metal wire such as tungsten is polished at its free end in contact with the panel electrode, and is then formed on a narrow pitch electrode pad. Since they must be arranged in opposition on the order of microns, especially as the number of pins increases and the pitch decreases, advanced technology is required for their manufacture, and mass production is difficult. Therefore, there is a problem that the contact probe becomes expensive. Further, there is a drawback that a probe in which a large number of finely processed core wires are arranged is weak to an external force and the accuracy is easily destroyed, so that handling is difficult.

In addition, with the increase in the screen size and definition of the LCD, a so-called chip-on-glass (CHIP) in which an IC chip such as a driver is directly mounted on an electrode pad on a glass substrate.
(NGLASS: COG) mounting method is being adopted. In the COG mounting method, the electrode pads of the odd-numbered lines and the electrode pads of the even-numbered lines are usually arranged in a zigzag pattern at a very small pitch. It has been difficult to make sure and uniform contact while maintaining insulation between them.

[0007] The present invention has been made in view of such a problem, and an object of the present invention is to provide a large screen and high definition L.
It is an object of the present invention to provide an all-lighting inspection method corresponding to a CD and to provide a low-cost contact probe capable of reliably obtaining a contact with a simple alignment even with a panel electrode of a multi-pin, narrow-pitch LCD panel. It is another object of the present invention to provide a contact probe for full lighting display inspection of a COG mounting type LCD panel which also supports electrode pads arranged in a staggered manner.

[0008]

According to a first aspect of the present invention, there is provided a method for inspecting a liquid crystal display panel.
A liquid crystal display panel inspection method for simultaneously supplying voltages to a gate and a source having a plurality of electrodes arranged and arranged adjacent to a rectangular display portion on a substrate of the liquid crystal display panel and lighting the liquid crystal display panel, A plurality of contact leads having a width smaller than the width of the electrode and having elasticity are formed in a comb-like shape in a width direction at an interval smaller than the interval between the electrodes, and a conductor piece having one end of each contact lead connected in common is contacted. And pressing the contact to the plurality of electrodes so that the plurality of contact leads contact the plurality of electrodes at a predetermined angle of less than 90 ° with respect to the substrate to supply a voltage. I do. The present invention aims to contact a plurality of electrodes aligned on a substrate of an LCD panel by a group of fine contact leads formed on a conductor piece by pressing a contact having a plurality of contact leads. One electrode and one contact lead
Unlike the conventional technology in which one-to-one contact is made, there is no need to adjust delicate alignment in the electrode arrangement direction, and inspection can be performed without being affected by the pitch of a plurality of electrodes arranged on the substrate. . In addition, by pressing the contact lead having elasticity at a predetermined angle, it is possible to reliably contact the electrodes arranged on the substrate and supply the voltage collectively.

In the method for inspecting a liquid crystal display panel according to the present invention, a contact pressed by an electrode arranged adjacent to a rectangular display portion on a substrate is a single conductor piece having a plurality of contact leads formed thereon. May be composed of
The method of inspecting a liquid crystal display panel according to claim 2, wherein the conductor pieces each having a plurality of contact leads formed in a comb shape are overlapped with a plurality of layers by aligning the direction of the contact leads with a spacer made of an insulator interposed therebetween. The contact configured as described above is pressed against the plurality of electrodes to supply a voltage. By laminating a plurality of conductor pieces each having a contact lead formed in a comb-like shape, it is possible to more reliably make contact with electrodes arranged and arranged adjacent to a rectangular display portion on the substrate. In addition, an appropriate interval is provided between the conductor pieces by sandwiching a spacer made of an insulator therebetween, so that a voltage can be supplied collectively to each of the electrodes formed in a plurality of rows in a staggered manner, for example. .

According to a third aspect of the present invention, there is provided an inspection method for a liquid crystal display panel having a contact for pressing a plurality of electrodes arranged adjacent to a rectangular display portion on a substrate of the liquid crystal display panel. In the contact probe, the contact is formed such that a plurality of contact leads having a width smaller than the width of the electrode and having elasticity are formed in a comb shape in a width direction at an interval smaller than the interval between the electrodes, and One end is formed of a conductor piece commonly connected, and the contact lead is held so as to keep a predetermined angle of less than 90 ° with respect to the substrate. Here, the plurality of contact leads formed in a comb shape in the width direction are:
The ends opposite to the ends in contact with the electrodes arranged in parallel on the same plane and arranged on the substrate are commonly connected. Further, the contact lead has elasticity and is pressed at a predetermined angle with respect to the substrate, thereby making it possible to more reliably make contact with the electrodes arranged on the substrate and through the conductor piece. Voltage can be supplied collectively.

In such a contact, a comb-shaped contact lead may be formed by mechanically processing a conductor piece.
It is desirable to form the electrodes by etching in order to cope with multi-pin and narrow-pitch electrodes. At this time, the etching includes dry etching and chemical etching. Alternatively, a plurality of contact leads may be formed in a comb shape by laser beam or electric discharge machining. It is desirable that the material of the conductor piece used for the contactor has elasticity and is resistant to abrasion. For example, stainless steel or a nickel-cobalt (Ni-Co) alloy can be used. By configuring the contact in this way, unlike the prior art in which a large number of core wires are arranged, mass production can be performed in a short period of time, and a contact probe can be provided at a low manufacturing cost. Further, the contact probe can be provided which is easy to maintain because it has a simple structure and is not easily broken, and a conductor piece constituting the contact can be replaced.

The contact of the contact probe according to the present invention may be constituted by a single conductor piece on which a contact lead is formed. The present invention is characterized in that the above-mentioned conductor pieces having contact leads formed in a comb tooth shape are laminated in a plurality of layers with a spacer made of an insulator interposed therebetween. By laminating a plurality of conductor pieces each having a contact lead formed in a comb-like shape, it is possible to more reliably make contact with electrodes arranged and arranged adjacent to a rectangular display portion on the substrate. In addition, by providing an appropriate interval between the conductor pieces by sandwiching a spacer made of an insulator, a voltage is simultaneously supplied to the electrodes formed in a staggered manner on the COG mounting type substrate. be able to. Moreover, since the conductor piece is electrically insulated by the insulator, it goes without saying that the same signal is supplied to the electrodes arranged in a plurality of rows on the substrate.
It is also possible to supply a different voltage for each column.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a structure of a contact probe according to the present invention. The contact of the contact probe is composed of two stainless steel foils 12 and 14 stacked with a spacer 13 made of an insulator therebetween. At one end of each of the stainless steel foils 12 and 14, a plurality of contact leads having a width smaller than the width of a panel electrode (not shown in FIG. 1) of the LDC are smaller than the interval between the panel electrodes, as described later. It is formed in a comb shape at intervals and forms contact lead groups 12a and 14a. In this embodiment, the stainless steel foil 1 is used to make the contact leads have appropriate elasticity.
The thickness of 2, 14 is about 15 μm.

The two stainless steel foils 12 and 14 hold a spacer 13 therebetween and a contact lead group 1 formed by a resin probe holder 11 and a support plate 15.
2a and 14a are sandwiched and fixed so as to be exposed. The support plate 15 is fixed on the probe holder 16 by screws at an angle of R = 45 °, and the contact lead groups 12a and 14a of the stainless steel foils 12 and 14 exposed from the support plate 15 are fixed to the LCD panel substrate and a predetermined position. The panel electrode is pressed at an angle.

The support plate 15 is structured to be inserted into the connector 17 for a printed circuit board. A signal voltage is supplied to the stainless steel foils 12 and 14 from the external power supply (not shown in FIG. 1) through the terminals 17a and 17b. It is supposed to be. At this time, the support plate 1 is positioned opposite to the contact lead groups 12a and 14a.
5, the other end 1 of the stainless steel foils 12, 14 extending on
2b and 14b are printed circuit board connectors 17 respectively.
Are electrically connected to the terminals 17a and 17b provided on the terminal and function as lead wires.

A contact lead group 12a, 14a formed in a comb shape at one end of the stainless steel foils 12, 14 is
It is shown in FIG. 2 together with the panel electrodes of the D panel. FIG. 2 is a schematic diagram showing a state in which the above-mentioned contact is pressed against an electrode on a substrate. In FIG. 2, on a substrate 1 of an LCD panel, a plurality of transparent electrodes 21 made of ITO (Indium Tin Oxide: In2O3-SnO2) are formed in parallel at 50 μm intervals in the width direction. In the LCD panel, the transparent electrodes form an XY matrix by opposing two substrates so that the transparent electrodes formed in stripes cross each other. An electrode pad 22 having a width of 50 μm is formed at an end of the transparent electrode 21 at a position adjacent to a display unit (not shown in FIG. 2) of the panel substrate 1. These electrode pads 22 are arranged in a zigzag pattern so as to form two rows at an interval of 100 μm before and after.

On the other hand, the portions of the contact probes pressed by the panel substrate 1, that is, the contact lead groups 12a and 14a are, as shown in FIG.
2, 14 are formed by forming contact leads 20 having a length of 0.3 mm and a width of 15 μm in a comb shape at intervals of 25 μm (with a gap of 10 μm). Here, the contact leads 20 formed in a comb-like shape in the width direction of each of the stainless steel foils 12 and 14 are arranged in parallel on the same plane and are in contact with the electrodes arranged on the substrate 1. And the other end is commonly connected. The stainless steel foils 12 and 14 have a thickness of 15 μm.
The contact leads have appropriate elasticity and abrasion resistance. A large number of such contact leads 20 are formed in a comb shape, and the contact lead groups 12a and 14a are formed.
In order to form a, for example, the stainless steel foils 12 and 14 may be chemically etched. In order to further improve the wear resistance, hard gold plating may be performed after the formation of the contact leads.

According to the contact probe according to the present embodiment, such contact lead groups 12a and 14a
Is pressed in the direction in which the electrodes are arranged, so that one of the comb-shaped contact leads 20 comes into contact with each of the arranged electrode pads 22. Therefore, it is not necessary to strictly align in the width direction. In addition, since the contact lead made of stainless steel has appropriate elasticity and abrasion resistance, it is possible to reliably and repeatedly contact the electrode.

A spacer 13 not shown in FIG.
By appropriately selecting the thickness (see FIG. 1), the contact lead groups 12a and 14a formed on the two stainless steel pieces 12 and 14 are pressed onto the substrate at intervals of about 100 μm. Thus, when performing the full lighting inspection, it is possible to collectively supply the voltage to the electrodes arranged in a staggered manner. Further, the printed circuit board connector 7
By inputting different voltages through the terminals 17a and 17b (see FIG. 1) provided in the first and second terminals, it is also possible to input different signals for each row of the electrodes arranged in a staggered manner.

In this embodiment, an example in which stainless steel is used as the material of the contactor has been described, but a Ni—Co alloy may be used instead of stainless steel. In the present embodiment, the contact probe is a pair of stainless steel pieces 12 and 14 having comb-shaped contact leads.
Are arranged on top of each other with the spacer 13 interposed therebetween. A contact is formed by forming a contact lead group on a single piece of stainless steel foil in which contact leads are formed in a comb shape. Needless to say, it is good.

Next, as a second embodiment of the present invention, a method for inspecting an LCD panel using the above-described contact probe will be described with reference to FIG. LCD in FIG.
The display unit 31 of the panel 1 has transparent electrodes made of ITO formed in stripes on two glass substrates, and the two electrode surfaces face each other at an interval of about 10 μm so that the two electrodes are orthogonal to each other. Liquid crystal is injected into the gap between the glass substrates, and the intersections of the transparent electrodes orthogonal to each other constitute optical switches to form pixels in a matrix. A gate electrode 32 for inputting a signal voltage to a transparent electrode of the display unit 31 and two source electrodes 33 and 34 are formed on the substrate of the LCD panel 1 adjacent to the display unit 31. Here, the gate electrode 32 and the source electrodes 33, 34
As shown in FIG. 2, a large number of electrode pads electrically connected to the transparent electrode are arranged in a zigzag pattern.

In FIG. 3, three contact probes 4, 5, and 6 are made of two stainless steel foils each having a plurality of contact leads formed in a comb shape as shown in FIG. 2, and a spacer 13 as shown in FIG. Are provided so as to overlap with each other. However, in FIG.
The printed circuit board connector shown in FIG. Here, the width of each contact lead is the gate electrode 32, the source electrode 3
Smaller than the width of the individual electrode pads constituting
The pitch of the contact leads is formed to be narrower than the pitch of the electrode pads of each electrode. At this time, in order to make the gap between the two stainless steel foils constituting the contact correspond to the interval between the electrode pads arranged in a staggered manner,
The thickness of the spacer 13 (see FIG. 1) inserted between the two stainless steel foils as a spacer may be different between the gate contact probe and the source contact probe.

Although not shown in FIG. 3, the probe holders of the contact probes 2, 3 and 4 may be fixed to a frame surrounding the LCD panel 1. At this time, the width of the contacts of the contact probes 2, 3, and 4 is set to the gate electrode 1
1. By making the width sufficiently longer than the width of the source electrodes 12 and 13, alignment in the width direction, that is, the left-right direction can be omitted. Further, the probe holders 416, 516, and 616 of the contact probes 2, 3, and 4 may be fixed to the frame via a micrometer so that fine adjustment in the front-rear direction can be performed with the micrometer.

The three contact probes 4 shown in FIG.
In order to perform the full lighting display inspection of the LDC 1 using the steps 5 and 6, the following is performed. First, the contact probe 4 described above
The alignment of the contact lead groups 40, 50, 60 of 5, 6 is adjusted, and each panel electrode 3 on the LCD panel 1 is adjusted.
2, 33, 34. At this time, since the contact probes 4, 5, and 6 make contact with the electrode pads by the contact lead groups 40, 50, and 60 formed in a comb shape, it is necessary to strictly adjust the lateral (width) alignment. There is no. Note that one contact probe may be pressed against the source electrodes 33 and 34, but as shown in the present embodiment, if the two contact probes 5 and 6 are pressed independently, Even if the substrate of the LCD panel 1 is warped, the contact can be reliably established.

When the contact is pressed, a DC voltage is applied from an external power supply between the contact probe 4 for the gate electrode and the contact probes 5 and 6 for the source electrode. Specifically, the stainless steel foils 412a and 412b, 512a and 512b, 6 of the contact probes 4, 5, and 6
Contact lead groups 40, 5 via 12a and 612b
The input voltage is applied to the gate electrodes 32 at a time.
And a source electrode 33, 34 to supply a DC voltage,
The CD panel 1 is turned on for inspection. At this time, the full lighting test may be performed by supplying the same voltage to the two source electrode contact probes 3 and 4 at the same time. However, only one side of the LCD panel 1 is lit by inputting the voltage one by one. Needless to say, this is acceptable. Further, in this embodiment, a DC voltage is supplied between the gate electrode and the source electrode. However, this may be an AC voltage.

[0026]

According to the present invention, a plurality of resilient contact leads having a width smaller than the width of the electrodes arranged adjacent to the rectangular display portion on the substrate of the LCD panel and having elasticity are provided. Since a voltage is applied to the electrodes by pressing the conductor pieces formed in a comb-like shape in the width direction at smaller intervals as contacts, the electrodes can be reliably and easily contacted with electrodes having various pitches and sizes. be able to. In particular, since the contact leads make contact with the electrodes on the substrate, there is no need for lateral alignment, and the accuracy and efficiency of lighting inspection of an LCD panel with finer and narrower pitches can be improved.

In the contact probe according to the present invention, a comb-shaped contact lead group can be easily formed on a conductor piece by using a technique such as etching. As described above, since no advanced technology is required for manufacturing the contact, the manufacturing is simplified, and the unit price of the LCD panel inspection contact probe can be reduced. Further, a contact probe having a simple structure and being durable and easy to maintain can be provided.

According to the second or fourth aspect of the invention, a plurality of contact leads are formed in a comb-like shape by superposing a plurality of conductor pieces in a plurality of layers with a spacer made of an insulator interposed therebetween. Since the configured contact is pressed against the electrodes arranged on the substrate adjacent to the rectangular display unit,
For example, a voltage can be collectively supplied to electrodes arranged in a plurality of rows like a staggered pattern.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a contact probe according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a state in which a contact of the contact probe is pressed against an electrode on an LCD panel substrate.

FIG. 3 is a diagram for explaining an LCD panel inspection method according to a second embodiment of the present invention.

FIG. 4 is a diagram illustrating a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display (LCD) panel, 11 ... Probe holding, 12, 14 ... Stainless steel foil, 12a, 14a ... Contact lead group, 13 ... Spacer, 15 ... Support plate, 16 ... Probe holder, 17 ... Connector for printed circuit board, Reference numeral 20: contact lead, 21: transparent electrode, 2
2 ... electrode pad, 31 ... display part, 32 ... gate electrode, 3
3, 34: source electrode, 4, 5, 6: contact probe, 40, 50, 60: contact lead group, 412
a, 412b, 512a, 512b, 612a, 612
b: stainless steel foil, 416, 516, 616: probe holder.

Claims (4)

[Claims] 1. A liquid crystal display in which a voltage is collectively supplied to a gate and a source having a plurality of electrodes arranged and arranged adjacent to a rectangular display portion on a substrate of the liquid crystal display panel, and the liquid crystal display panel is turned on. In the panel inspection method, in the panel inspection method, a plurality of contact leads having a width smaller than the width of the electrode and having elasticity are formed in a comb-like shape in a width direction at an interval smaller than the interval between the electrodes, and one end of each contact lead is commonly connected. The plurality of contact leads are 90 ° with respect to the substrate.
A liquid crystal display panel inspection method, wherein a voltage is supplied by pressing the contact to the plurality of electrodes so as to contact the plurality of electrodes at a predetermined angle less than. 2. The method for inspecting a liquid crystal display panel according to claim 1, wherein the contact is formed by stacking the conductor pieces in a plurality of layers by aligning the direction of the contact lead with a spacer made of an insulator interposed therebetween. A method for inspecting a liquid crystal display panel, comprising: 3. A liquid crystal display panel inspection contact probe comprising a contact for pressing a plurality of electrodes arranged adjacent to a rectangular display portion on a substrate of the liquid crystal display panel, wherein the contact comprises: A plurality of contact leads having a width smaller than the width of the electrodes and having elasticity are formed in a comb-like shape in the width direction at intervals smaller than the interval between the electrodes, and one end of each contact lead is a conductor piece connected in common. A contact probe for inspecting a liquid crystal display panel, wherein the contact lead is held so as to keep a predetermined angle of less than 90 ° with respect to the substrate. 4. The contact probe for inspecting a liquid crystal display panel according to claim 3, wherein the contact is formed by stacking the conductor pieces in a plurality of layers by aligning the direction of the contact lead with a spacer made of an insulator interposed therebetween. A contact probe for inspecting a liquid crystal display panel, wherein the contact probe is configured in combination.