JPH0933938A - Conductive film inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the conductive film inspection device which does not require to use a contact probe and eliminates the need to pay attention to the wear state of the needle tip. SOLUTION: This device is equipped with a common electrode 2 which traces one end part of a conductive film pattern Pi sequentially with time, a 1st probe needle 3a which traces the other end part of the conductive film pattern Pi in timing with the common electrode, a voltage supply part 9 which supplies an inspection voltage VTP to the 1st probe needle 3a when two electrodes 2 and 3a are in contact with the conductive film pattern, and a decision part 11 which decides the open-circuit state of the conductive film pattern according to the electric signal Vo obtained from the common electrode part 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection device for inspecting a broken state and a short-circuited state of a conductive film, and in particular, a conductive film for inspecting the quality of a transparent conductive film pattern of an LCD (Liquid crystal display) substrate by a tracing method. Regarding inspection equipment.

[0002]

2. Description of the Related Art As a device for inspecting the quality of a conductive film pattern on an LCD substrate by a tracing method, for example, a conductive film inspection device disclosed in Japanese Patent Laid-Open No. 6-273468 has been proposed, and a conductive film having a bent end portion is proposed. It is used to judge the quality of the film pattern. FIG. 13 is a schematic view of this conductive film inspection apparatus, which shows conductive film patterns P _{1 to} P _1.
A probe needle T ₁ that traces _n in the orthogonal direction and a solid probe B that contacts the bent ends b of all the conductive film patterns all at once are shown. The solid probe B is used because the pattern pitch is different between the central portion a and the bent end portion b. Therefore, two probe needles are used to trace the central portion a and the bent end portion b in synchronization. Because you can't. In the apparatus of FIG. 13, the probe needle T ₁
The, this has been synchronized with the inspection voltage is supplied to a timing that is in contact with each conductive pattern P _i, depending on whether it detects the same voltage thereto from solid probe B of each conductive pattern P _i Inspecting for wire breakage. Further, in this conductive film inspection apparatus, separate probe needles T ₂ and T ₃ are provided in order to inspect a short-circuit state between adjacent conductive film patterns (P _i , P _{i + 1} ).
All the probe needles T _{1 to} T ₃ were tilted in the direction orthogonal to the conductive film pattern P _i . Then, the two probe needles T contacting the adjacent conductive film patterns.
The center distance Dist between ₁ and T ₃ was set to be the same as the pitch Pit of the conductive film pattern, as shown in FIGS.

[0003]

However, the above-mentioned solid probe B needs to be brought into uniform contact with the LCD substrate as a whole, so that there is a problem in that the working precision of the contact surface must be increased. . On the other hand, even if the contact surface of the solid probe B is precisely finished, when dust or the like is present on the LCD substrate, the contact surface has a considerable contact resistance due to its thickness and size. There is a problem, and therefore, it is necessary to press the solid probe B against the LCD substrate with a predetermined strength or more. Also,
In conventional devices, the probe needle center distance Di
Since st is set to be the same as the pitch Pit of the conductive film pattern (Dist = Pit), as the tip of the probe needle wears, the probe needle T
₃ will straddle the adjacent conductive film patterns P _i and P _{i + 1} (see FIG. 15). That is, if the tip of the needle is worn away, the probe needle T ₃ will short-circuit the conductive film patterns P _i and P _{i + 1} before the measurement operation is completed, and the normal conductive film pattern will be abnormal. It will be determined that there is. Moreover,
In this case, since each probe needle is inclined orthogonal to the conductive film pattern, there is a problem that the worn state of the needle tip cannot be seen. The present invention has been made in view of these problems, and it is an object of the present invention to provide a conductive film inspection apparatus that does not need to use a solid probe and that does not need to worry about the worn state of the needle tip. To aim.

[0004]

In order to achieve the above object, the invention according to claim 1 is an LCD according to a tracing system.
A conductive film inspecting apparatus for inspecting the quality of a conductive film pattern of a substrate, comprising: a first electrode that relatively moves between the conductive film patterns so as to come into contact with each conductive film pattern in time sequence;
A common electrode that moves relative to the conductive film pattern in the same manner as the first electrode while being in contact with a plurality of conductive film patterns including the conductive film pattern in contact with the first electrode, and the common electrode and the common electrode. A judgment that determines whether the conductive film pattern is good or not depending on whether or not the inspection signal applied from one electrode is obtained from the other electrode by operating when both the first electrode and the conductive film pattern are in contact with each other. And the common electrode is made of a material having excellent elasticity and conductivity, and an appropriate number of metal wheels are fixedly connected to the conductor rod to be connected in series, or a coil spring of a predetermined length is fixed to the conductor rod. With this configuration, when the common electrode is pressed against the LCD substrate, the metal ring or the coil spring is deformed in the radial direction,
The LCD substrate and the common electrode are in line contact with each other. Here, the “tracing” means that the first electrode and the conductive film pattern are relatively moved in a state where the first electrode is in contact with the conductive film pattern. Since it is sufficient that the first electrode and the conductive film pattern move relative to each other, the first electrode may be moved and the LCD substrate may be moved, but it is preferable to trace the conductive film pattern orthogonally. The present invention
The pitch of the conductive film pattern is different between the central part and the end part.
It is suitable for inspection of a CD substrate, and it is preferable to incline the first electrode in substantially the same direction as the conductive film pattern.

According to a second aspect of the present invention, the first electrode relatively moves between the conductive film pattern and the conductive film pattern so as to make time-sequential contact with the conductive film pattern, and the conductive film pattern in contact with the first electrode. A second electrode and a third electrode that move relatively to the conductive film pattern similar to the first electrode while being in contact with the conductive film pattern adjacent to the first electrode, the first electrode, the second electrode, and the third electrode. Are commonly operated to contact the conductive film pattern, the inspection signal applied from the first electrode is detected from the second electrode and the third electrode, and the conductive film pattern is detected based on the detected value. And a determination unit that identifies a short-circuited portion, wherein the first electrode, the second electrode, and the third electrode are inclined in substantially the same direction as the conductive film pattern, and the tracing direction of the first electrode and the other electrode. The gap is
It is set to be almost equal to the pattern pitch of the conductive film pattern.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on embodiments. FIG. 1 is a circuit block diagram of a conductive film inspection apparatus according to an embodiment of the present invention. The conductive film inspection apparatus 1 includes an annular common electrode 2 that expands and contracts in a radial direction, a probe needle 3a that traces a conductive film pattern of an LCD substrate in an orthogonal direction, and a motor that moves an LCD substrate fixed to a mounting table 4. 5 and motor 5
, A pulse generator 7 for generating a reference pulse BP, a timing pulse generator 8 for receiving the reference pulse BP and generating a timing pulse TP, and an inspection voltage for receiving the output of the timing pulse generator 8. A voltage generator 9 that generates V _TP , an amplifier 10 that receives the detection voltage V _O detected from the common electrode 2, and an amplifier 10
And a determination section 11 for identifying a defective portion of the conductive film pattern by receiving the output voltage of the above and the timing pulse TP.

Although only the first probe needle 3a for supplying the inspection voltage V _TP to the LCD substrate is shown in FIG. 1, the conductive film inspecting apparatus 1 includes a first probe needle 3a for inspecting a short circuit position of the conductive film pattern. 2 and the third probe needle 3b,
3c and circuits associated with these probe needles 3b and 3c are also provided. Then, all the probe needles 3a, 3b, 3c are configured to contact the conductive film pattern while being inclined in substantially the same direction as the conductive film pattern. The probe needles 3a, 3b, 3c are provided with an elevating mechanism so that they can be appropriately elevated and lowered as needed. The common electrode 2 is, as shown in FIG.
An appropriate number of metal wheels may be fixedly attached to the conductor rod 21 and connected in series, or
The coil spring 20 having a predetermined length is fixed to the conductor rod 21. Although the metal ring and the coil spring 20 are made of a material having excellent elasticity and conductivity, it is preferable to use, for example, stainless steel or platinum. The continuous pitch and the winding pitch are about 100 μm, and the length is about 10 mm, and they are adhered to the conductor rod 21 by using silver paste or solder 22. The metal ring and the coil spring 20 are slightly tilted in the axial direction from the state of FIG.
In that state, it is bonded to the conductor rod 21 (see FIG. 3).
(B)).

The common electrode 2 has a smooth surface,
It is used by lightly pressing the conductive film pattern P _i when inspecting the conductive film pattern P _i of the LCD substrate for the presence of disconnection. That is, the adjacent conductive film patterns P _i ,
The common electrode 2 is provided with an elevating mechanism (not shown) using an air cylinder or a motor so that the common electrode 2 can be moved up and down as needed because it is not used when inspecting a short-circuited state between P _{i + 1} . Next, the operation content of the conductive film inspection apparatus 1 having the above configuration will be described. The conductive film inspection apparatus 1 is capable of open measurement for inspecting the broken state of the conductive film pattern and short position measurement for detecting the position of the short circuit portion of the conductive film pattern.

[Open Measurement] At the time of open measurement, the common electrode 2 and the first probe needle 3a are lowered to the position of the LCD substrate, and the common electrode 2 is appropriately pressed against one end of the conductive film pattern. , The first probe needle 3a is appropriately pressed against the other end of the conductive film pattern. FIG. 4 is a plan view showing the state at the start of this operation, in which the common electrode 2 and the first probe needle 3a appropriately press the conductive film pattern P ₁ on the first row of the LCD substrate. It shows the state. LCD as shown
The conductive film pattern P _i of the substrate is formed in a bent shape having a maximum deviation D (= about 5 mm) at one end. However, the total length L of the common electrode 2 is 2 ×
Since it is about D and the outer peripheral portion is inclined in the axial direction,
As shown by the alternate long and short dash line in FIG. 4, even if the common electrode 2 and the first probe needle 3a are set at the same position, the common electrode 2 must surely contact one end of the conductive film pattern P _i. become. Moreover, since the common electrode 2 is made of a material that is soft and has excellent elasticity, the common electrode 2
When the coil spring 20 of is pressed against the LCD substrate,
The coil spring 20 is deformed by the tension as shown in FIG. 5B, and the coil spring 20 and the LCD substrate are in linear contact with each other over a predetermined length S. Therefore,
Contact resistance does not pose a problem between the common electrode 2 and the conductive film pattern.

In this state, the motor 5 is mounted on the mounting table 4
Since the LCD substrate of FIG. 4 is moved upward in FIG. 4, the common electrode 2 and the probe needle 3a are separated from each other by the conductive film pattern P _i.
You will trace in sequence. FIG. 6 shows the output of the pulse generator 7 in this operating state (reference pulse B
P) and the output of the timing pulse generator 8 (timing pulse TP). Motor 5 and voltage supply unit 9
Are the reference pulse BP and the timing pulse TP, respectively.
The motor 5 operates with the reference pulse BP.
While the mounting table 4 is moved in accordance with the above, the voltage supply unit 9 synchronizes with the timing pulse TP and the probe needle 3a.
The inspection voltage V _TP is supplied to FIG. 7 shows the relationship between the inspection voltage V _TP supplied to the probe needle 3 a and the detection voltage V _O obtained from the common electrode 2. If the conductive film pattern is not in a broken state, the probe needle 3a and the common electrode 2 are short-circuited, so that the common electrode 2 detects the same voltage V _O as the inspection voltage V _TP. If the film pattern is broken, no voltage can be obtained from the common electrode 2 (i in FIG. 7).
See the second pulse).

The determination unit 11 receives the detection voltage V _O and the timing pulse TP, counts the timing pulse TP, and determines whether or not the detection voltage V _O is obtained in synchronization with the timing pulse TP. ing. As described above, in this example, since the detection voltage V _O cannot be obtained in the state where the i-th timing pulse TP is counted,
From this, it can be detected that the i-th conductive film pattern is broken. As described above, in the present invention, the first probe needle 3a and the common electrode 2 are
Means tracing the conductive film pattern P _i in the orthogonal direction while being pressed against the LCD substrate. That is, unlike the conventional device, since the solid probe is not used, the contact resistance does not become a problem even if dust or the like is placed on the LCD substrate. In addition, the conductive film pattern P _i and the coil spring 2
Since the contact state with 0 is smooth, the common electrode 2 and LC
There is no fear that the conductive film pattern P _i or the like will be damaged by the friction with the D substrate.

[Short Position Measurement] Next, the short position measurement of the conductive film pattern will be described. In the short position measurement, the common electrode 2 is raised and the second and third electrodes are moved.
Then, the probe needles 3b and 3c are lowered and brought into contact with the conductive film pattern P _i of the LCD substrate. FIG. 8 is a plan view showing the state at the start of this operation, in which the probe needles 3a, 3b, 3c are the conductive film patterns P of the LCD substrate.
_It shows the state where ₁ and P ₂ are pressed appropriately. In this state, the motor 5 moves the LCD substrate of the mounting table 4 upward in FIG. 8, so that the probe needles 3a,
3b and 3c will trace the conductive film pattern P _i sequentially. Since the inspection voltage V _TP (constant voltage) is supplied to the first probe needle 3a in synchronization with the timing pulse TP, the second and third probes are provided only when the adjacent conductive film patterns are short-circuited. Needles 3b, 3c
Therefore, the detection currents I _b and I _c are detected. Now, suppose that the total length L of the central portion of the conductive film pattern is L and the distance from the right end of the conductive film pattern to the short circuit location G _S is X (FIG. 9).
), And the resistance value per unit length of the conductive film pattern is r, the relationship of r (L−X) I _c = rXI _b is established.
When this relationship is arranged, I _c / (I _b + I _c ) = X / L
Because ...... relational expression (equation 1) is satisfied, based on the detected current I _b, I _c from the probe needles 3b, 3c,
It is possible to specify the short-circuited portion G _S.

By the way, in the present invention, FIG.
As shown in (a), all probe needles 3a, 3a
b and 3c are inclined in the same direction as the conductive film pattern, and the gap Gap between the first probe needle 3a and the other probe needles 3b and 3c in the tracing direction is set to be substantially equal to the pattern pitch Pit (Gap ≒ Pit). Thus, in the present invention, the probe needle is inclined orthogonal to the tracing direction, and since the gap Gap between the probe needles is almost equal to the pattern pitch Pit, regardless of the degree of wear of the probe needle, the measurement is performed. There is no risk that the probe needle 3b will contact the adjacent conductive film pattern P _{i + 1} during operation. Further, since the wear of the probe needle does not become a problem, it is not necessary to make the tip of the probe needle sharp. FIG. 10B shows an example of the measurement of the short position between the conductive film patterns P _{i and} P _{i + 1} at the start of measurement (broken line part) and at the end of measurement (solid line part). Inside the probe needle 3b
Indicates that the film does not contact the conductive film pattern P _{i + 1} . The probe needle 3a contacts the conductive film pattern P _{i + 2} during the measurement operation, but has no effect on the measurement of the short position between the conductive film patterns P _i -P _{i + 1} .

FIG. 11 illustrates an LCD substrate having a conductive film pattern different from that of FIG. In the case of the LCD substrate having such a conductive film pattern, in the open measurement, the patterns PAT1 and PAT2 are traced in the vertical direction of FIG. 11, and after the LCD substrate is moved to the left, the patterns PAT3 and PAT4 are moved. After the trace inspection is performed, the LCD substrate is further moved to the left, and then the trace inspection is performed on the patterns PAT5 and PAT6. The short position measurement is the same, and the PAT is measured by the three probe needles 3a, 3b and 3c.
1-PAT2, PAT3-PAT4, PAT5-P
Trace the AT6. FIG. 12 illustrates an LCD substrate having another conductive film pattern. In the case of an LCD substrate having such a conductive film pattern, two common electrodes 2 are provided and the left and right conductive film patterns are inspected separately. Although the embodiments of the present invention have been described above, the present invention is not limited to those described in the embodiments and can be appropriately modified in design. For example, although the LCD substrate is moved in the embodiment, the LCD substrate may be fixed and the common electrode or the probe needle may be moved. Further, in the embodiment, only the short-circuited portion G _{S at the} central portion of the conductive film pattern is detected, but if the number of probe needles is increased, a short circuit at the bent end portion of the conductive film pattern can also be detected. Alternatively, a continuous voltage may be supplied to the first probe needle 3a so that the measurement operation is performed in synchronization with the timing pulse TP.

[0015]

As described above, the conductive film inspection apparatus according to the present invention is provided with the common electrode that relatively moves in synchronization with the first electrode, so that it is not necessary to use a solid probe. The electrodes other than the common electrode are inclined in the same direction as the conductive film pattern, and the gap between these electrodes is set to be substantially equal to the pattern pitch of the conductive film pattern. There is no need to worry about, and no need to sharpen the tip. Since the tip portion is inclined in substantially the same direction as the conductive film pattern, the state of the tip portion can always be visually checked.

[Brief description of drawings]

FIG. 1 is a block diagram of a conductive film inspection apparatus that is an embodiment of the present invention.

FIG. 2 is a perspective view of a common electrode.

FIG. 3 is a schematic diagram for explaining a manufacturing method of a common electrode.

FIG. 4 is a plan view showing the start of the open measurement operation.

FIG. 5 is a view showing a contact state between a common electrode and a conductive film pattern.

6 is a diagram showing waveforms of respective parts of the block diagram shown in FIG.

FIG. 7 illustrates waveforms at various parts of the block diagram shown in FIG.

FIG. 8 is a plan view showing the start of the operation of short-circuit position measurement.

FIG. 9 is a diagram illustrating an operation principle of short-circuit position measurement.

FIG. 10 is a diagram illustrating an arrangement state of probe needles.

FIG. 11 illustrates another example of the conductive film pattern of the LCD substrate.

FIG. 12 illustrates still another example of the conductive film pattern of the LCD substrate.

FIG. 13 is a schematic view showing a conventional conductive film inspection apparatus.

FIG. 14 is a diagram illustrating an arrangement state of probe needles.

FIG. 15 is a diagram illustrating an arrangement state of probe needles.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Conductive film inspection apparatus 2 Common electrode 3a 1st electrode (1st probe needle) 3b 2nd electrode (2nd probe needle) 3c 3rd electrode (3rd probe needle) 9 Signal supply part (voltage supply part) 11 Judgment part 20 Coil spring 21 Conductor bar P _i Conductive film pattern Pit Conductive film pattern pitch Dist Center distance between electrodes a Central part of conductive film pattern b End part of conductive film pattern V _TP inspection signal (inspection voltage)

Claims (2)

[Claims] 1. A conductive film inspecting apparatus for inspecting the quality of a conductive film pattern of an LCD substrate by a tracing method, which relatively moves between conductive film patterns so that the conductive film patterns come into contact with each conductive film pattern in time sequence. A first electrode, and a common electrode that is in relative contact with a plurality of conductive film patterns including a conductive film pattern in contact with the first electrode, and that relatively moves between the first electrode and the conductive film pattern. The common electrode and the first electrode are operated when both are in contact with the conductive film pattern, and whether the inspection signal applied from one electrode is obtained from the other electrode causes the conductive film pattern And a determination unit for determining pass / fail, the common electrode is made of a material having excellent elasticity and conductivity, and an appropriate number of metal wheels are fixedly attached to the conductor rods or continuously provided,
A coil spring having a predetermined length is fixed to a conductor rod. With this structure, when the common electrode is pressed against the LCD substrate, the metal ring or the coil spring is deformed in the radial direction to cause the LCD substrate and the common electrode to be deformed. A conductive film inspecting device, characterized in that it is in line contact with. 2. A conductive film inspecting apparatus for inspecting the quality of a conductive film pattern of an LCD substrate by a tracing method, comprising: relatively moving between conductive film patterns so as to make time-sequential contact with the conductive film pattern. The second electrode and the third electrode, which are in contact with the first electrode and the conductive film pattern adjacent to the conductive film pattern in contact with the first electrode, and relatively move between the first electrode and the conductive film pattern similarly to the first electrode. It operates when the electrode and the first electrode, the second electrode, and the third electrode are in common contact with the conductive film pattern, and an inspection signal applied from the first electrode is applied to the second electrode and the third electrode. A first electrode, a second electrode, and a third electrode in the same direction as the conductive film pattern. Inclined The tracing direction of the gap between the first electrode and the other electrode is a conductive film inspection apparatus characterized by being substantially equal to the pattern pitch of the conductive film pattern.