JPH05341302A - Probing substrate - Google Patents

Abstract

PURPOSE:To absorb and offset the expansion and contraction by a temp. difference by expanding and contracting the probing substrate by as much as the same thermal expansion and contraction amts. of an LCD substrate. CONSTITUTION:The substrate 28 holding contactors 26 of the probing substrate which inspects the liquid crystal display substrate 14 by bringing the contactors 26 held on the substrate 28 into contact with electrode pads 8 of the liquid crystal display substrate is constituted of a material for example, soda line glass, having the same coefft. of linear expansion as the coefft. of linear expansion of material forming the LCD substrate 14. As a result, both members thermally expand and contract by as much as the same amts. even if the temp. difference arises at the time of assembling, for example, the device and at the time of inspecting the LCD and, therefore, the contactors 26 are brought into contact with the electrode pads 8 without mis-registration.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a probing substrate.

[0002]

2. Description of the Related Art Generally, an LCD (Liquid Crystal Display) using a TFT (Thin Film Transistor) has been attracting attention because it provides a very high image quality. In this type of LCD, for example, a TFT is formed on a plate-shaped glass substrate by a photolithography technique.
The pixel electrode electrically connected to the drain electrode of
A large number of pixel units arranged in such a manner as to be arranged with an FT through a gap are arranged. For example, hundreds of thousands of rectangular pixel units each having a side of several 100 μm are arranged. Then, on such an LCD substrate, transparent electrodes common to each pixel unit are arranged to face each other through a gap, and liquid crystal is sealed in the gap to form an LCD.

By the way, as the pattern on the LCD substrate becomes finer and the capacity becomes larger, due to fine particles in the manufacturing process, for example, an open short circuit between the gate and drain of a TFT, a wiring pattern and a pixel. Although a defect such as a short circuit with the electrode is likely to occur, repair cannot be performed even if a defect is found by inspection after encapsulating the liquid crystal. Therefore, each pixel unit of the LCD is inspected for operation confirmation before encapsulating the liquid crystal. ..

In this inspection, for example, an inspection electrode is provided on the back side of the glass substrate so as to face the pixel electrode, a voltage is applied to the gate electrode, and a current is supplied to the inspection electrode from a common terminal to change the drain current. The quality of each TFT is determined by detecting the flowing current. For example, as shown in FIGS. 10 and 11, the probing substrate 1 for performing this inspection has a large number of protruding contacts 4 on an FPC (flexible printed circuit) film 2 in which a circuit is pattern printed with copper on a flexible film. Are formed at the same intervals as the intervals of a large number of electrode pads 8 on the LCD 6 side, the film 2 is stretched over a glass epoxy resin 10, and the glass epoxy resin 10 is attached to an elastic material such as an elastomer 12. It is configured. In addition, a probe needle may be used as the contactor instead of the protruding contactor.

A plurality of electrode pads 8 are provided outside the display surface 16 of the LCD substrate 14 made of glass, for example, in the illustrated example, a pad group G consisting of five electrode pads 8 is appropriately arranged. It is provided by Then, the probing substrate 1 is moved along a guide mechanism 18 formed of, for example, a screw screw provided on a side portion of the LCD, and the contactor and the electrode pad 8 are sequentially brought into contact with each other to perform an inspection. .. It should be noted that such a probing substrate is provided in the X and Y directions of the LCD 6 or the LCD 6 itself is rotated by 90 degrees together with the base.

[0006]

The size of the electrode pad is 100 μm × 100 μm or 100 μm.
The size of the LCD substrate is very small, about m × 200 μm, but on the other hand, LCD substrates with a large size of 450 mm × 450 mm have already appeared, and there is a tendency for the size to further increase in the future, so the number of pads will increase accordingly. To go. However, in the inspection method in which the probing substrate is sequentially moved with respect to the LCD substrate and is brought into contact with the pad group G a plurality of times as described above, such a small pad 8 is used.
In order to accurately position the contactor 4 in the pad 8 for any pad group in which a large number of paddles are arranged, in addition to the positional accuracy of the contactor 4 of the probing substrate, the guide mechanism 1
The LCD 8 is positioned with a very high precision with respect to the pad group, and the mounting position of the probing substrate 1 with respect to the guide mechanism 18 is also required to have a very high precision.
It is very difficult to accurately position the contactor 4 so as to contact the electrode pads 8 distributed in a long range such that one side of the substrate is 450 mm.

It is also possible to increase the size of the probing substrate and inspect each pad at a time, but generally, the place where the probing substrate 1 is manufactured and the place where this is used for LCD inspection are different. Therefore, the temperature difference between the time of manufacture and the time of use may cause a thermal expansion and contraction error more than the allowable amount in the accuracy of the probing substrate. For example, if the LCD has a side of 450 mm and the probing substrate is made of glass epoxy resin, aluminum, or the like, a large positional error of 100 to 125 μm occurs with respect to a temperature difference of 10 ° C. However, there is a problem in that the pad and the contactor of the probing device are displaced and cannot be brought into contact with each other. The present invention has been made to pay attention to the above problems and to solve them effectively. An object of the present invention is to provide a probing substrate that absorbs expansion and contraction due to a temperature difference by expanding and contracting by the same thermal expansion and contraction amount as the LCD substrate.

[0008]

In order to solve the above problems, the present invention conducts inspection of the liquid crystal display substrate by contacting the electrode pads of the liquid crystal display substrate with contacts held on the substrate. In the probing substrate to be performed, the substrate holding the contactor is made of a material having the same linear expansion coefficient as that of the material forming the liquid crystal display substrate.

[0009]

Since the present invention is constructed as described above, the substrate holding the contacts is made of a material having the same linear expansion coefficient as that of the LCD substrate. For example, when the LCD substrate is made of soda glass, the substrate holding the contacts is also made of a material having the same linear expansion coefficient, for example, soda glass. As a result, even if the ambient temperature changes during LCD inspection, the LCD substrate and the substrate that holds the contact expands and contracts by the same amount, resulting in excessive misalignment between the contact and the electrode pad of the LCD. There is nothing to do.

[0010]

An embodiment of the probing substrate according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing a probing substrate according to the present invention, FIG. 2 is an explanatory view for explaining a formation state of a probe needle, and FIG. 3 is an enlarged view showing an enlarged portion of the contactor in FIG. Is. still,
The same parts as those of the conventional device are designated by the same reference numerals. As shown in the figure, the probing substrate 20 has a slightly larger area so that the entire LCD 6 located therebelow can be covered at one time. The LCD 6 is placed on the base 22 and its size is, for example, 450 mm × 450.
It is set to mm. The LCD substrate 14 is formed of, for example, soda glass, and the portion corresponding to the long side of the outer peripheral portion of the display surface 16 has, for example, 100 μm.
6 groups (only 3 groups are shown in the figure) of pad groups G, which are formed by arranging, for example, 160 electrode pads 8 for drain having a size of m × 100 μm, for example, at intervals of several 100 μm, are arranged. Therefore, for example, 960 electrode pads 8 are formed on both long sides.

Further, for example, 480 electrode pads 8 for gate are formed on the short side of one side of the peripheral portion outside the display surface 16 at the same intervals as described above. Then, the probing substrate 2 for inspecting the LCD 6
No. 0 has an opening 24 in the center thereof, which is approximately the same size as the display surface 16 of the LCD, and the probing substrate 20 has a large number of contacts arranged along the edge of the opening 24. As a child, for example, a probe needle 26 having a diameter of, for example, 100 μm made of cipher (trade name) or the like plated with tungsten or iron wire with gold, a substrate 28 for holding and positioning the probe needle 26, and mounting and supporting the substrate 28 for fixation. It is mainly configured by the support plate 30.

As shown in FIG. 2, the probe needles 26 are grouped along the lengthwise direction of the opening end 30 of the substrate 28 so as to correspond to the installation positions of the electrode pads 8 of the LCD. Has been. Each probe needle group G1
Is 160 probe needles 2 as in the pad group G described above.
6, the number of probe needles 26 is only five in the illustrated example for simplification. In the present embodiment, a substrate 28 for positioning and fixing these probe needles 26
Is made of a material having the same linear expansion coefficient as the material of the LCD substrate 14, for example, the same material.
Specifically, when the LCD substrate 14 is made of soda glass, the substrate 28 is made of soda glass having the same linear expansion coefficient, and the LCD substrate 1 is also used.
When 4 is made of quartz glass, the substrate 28 is also made of quartz glass, for example.

When the probe needle 26 is attached, as shown in FIG.
L-shaped grooves 32 having a width L1 of, for example, about 110 μm are formed at the corners of 0 by etching or the like at a predetermined pitch.
At this time, the interval L2 between the grooves 32 is set to, for example, about 80 μm, and the depth of each groove 32 is set to a depth at which the probe needle 26 can be completely accommodated in this groove. And the probe needle 26
The probe needle 26 is provided along the inside of each groove 32 by projecting the lower end of the probe downward by, for example, about 250 μm. Then, as shown in FIGS. 4 and 5, a pressing plate 34 made of the same material as the substrate 28 is stretched on the front side of each probe needle 26 along the longitudinal direction of the substrate 28. As a result, the groove 32 facing the front side is configured as a guide hole 36, and guides the movement of the probe needle 26 when the probe needle 26 contacts the electrode pad.

Further, above the substrate 28, as shown in FIG. 5, the vertical portion 26 of the probe needle 26 is allowed to allow the probe needle 26 to escape upward when the probe needle 26 contacts.
An elastomer 38, which is made of, for example, an elastic member, is provided over the entire body so as to be slightly outwardly displaced from above a, and absorbs the variation in the distance between the probe needle 26 and the electrode pad 8 at the time of contact. It is configured to be able to perform probing all at once with uniform pressure. The elastomer 38 is attached to the support plate 30 that supports the entire probing substrate. The substrate 28 may be directly attached to the support plate 30 without providing the elastomer 38.

The base of each probe needle 26 is connected to a signal line 40 (see FIG. 1) by a pogo pin (not shown) having a built-in spring, and the signal line 40 is connected to a tester 42. The LCD 6 can be inspected via the signal line 40. Further, as shown in FIG. 6, a base 22 on which the LCD 6 is mounted is mounted.
In the upper part of Z, a Z-axis adjusting mechanism 42 is arranged to be movable up and down in order to adjust Z (vertical direction), and a screw shaft and a nut driven by, for example, a stepping monitor in order to adjust Y (longitudinal direction). Y-axis adjusting mechanism 44, X having
The Y-axis adjusting mechanism 44 is used to adjust the (lateral) direction.
X-axis adjusting mechanism 46 configured in the same manner as
A fixed plate 48 is provided on the X-axis adjusting mechanism 46. The fixed plate 48 is provided with a rotatable disc-shaped θ plate 50 for θ axis adjustment, and the LCD 6 is mounted and fixed on the θ plate 50.

Further, as shown in FIG. 1, on the LCD substrate 14, for example, a positioning mark 52 formed in a cross shape.
Further, the substrate 28 of the probing substrate 20 is formed with a peep window 54 containing a CCD camera or a microscope at a portion corresponding to the mark 52.

Next, the operation of this embodiment configured as described above will be described. First, the LCD 6 is set to θ of the base 22.
It is attached and fixed to the plate 50, and the probing substrate 20 provided on, for example, an elevating table is lowered from above to bring the tip end portion of the probe needle 26 into contact with each electrode pad 8 of the LCD 6. At the time of this contact, while observing the mark 52 of the LCD 6 from the observation window 54 of the probing substrate 20 with a CCD camera or the like, each adjustment mechanism on the base 22 side is operated to adjust each axis of X, Y, Z, and θ. Then, gradually bring them closer to each other to make a contact. Then, from the tester 42, the probe needle 2
A high-frequency voltage of a predetermined frequency is applied to the electrode pad 8 of the LCD 6 via 6, and the LCDs are collectively inspected.

In this case, in the present embodiment, the substrate 28 for positioning and fixing the probe needles 26 of the probing substrate 20 is made of a material forming the LCD substrate 14, for example, a material having the same linear expansion coefficient as soda glass, for example, a soda glass. Since the soda glass, which is the same material, is used, the temperature of the assembly location of the probing substrate 20 and the LCD
Even if there is a difference in the temperature of the place where the inspection of 6 is performed,
Both members will expand and contract by the same length,
Therefore, the thermal expansion and contraction of both members are relatively offset, and as a result, the tip of the probe needle 26 comes into contact with the corresponding electrode pad 8 of the LCD 6 with almost no displacement. .. Therefore, 450 mm x 4
The probe needles can be collectively brought into contact with the LCD substrate having a size of 50 mm or more, and the alignment can be performed only once.

When the probe needle 26 contacts, the probe needle 26 is pushed upward by the electrode pad 8 as shown in FIG. 5, but since the upper portion of the probe needle 26 is open, the vertical portion of the probe needle 26 is opened. 26a is lifted vertically upward as it is along the guide hole 36 for accommodating it, and the tip portion of the probe needle 26 is not displaced and does not come off from the electrode pad 8. In particular,
When the substrate 28 for positioning the probe needles 26 is made of glass, it is particularly preferable in this LCD field where the miniaturization tendency is remarkable because of high insulation resistance. Moreover, since glass is a material with high rigidity, its deformation strain can be significantly suppressed even with stylus pressure at the time of contact compared with conventional materials such as aluminum and glass epoxy resin, and flatness is also achieved. Not only is it easy, but there is no deformation due to moisture absorption, and it is possible to maintain dimensional accuracy higher.

Further, in the above embodiment, as shown in FIG. 5, the upper portion of the vertical portion 26a of the probe needle 26 is opened to allow this bending at the time of contact.
The present invention is not limited to this, and the elastomer 38 may be positioned above the vertical portion 26a of the probe needle 26 as shown in FIG. 7, for example. In this case, the vertical portion 26a of the probe needle 26 bends in an arc shape in the guide hole 36 or the groove 32 at the time of contact with the electrode pad 8, and as a result, the tip portion of the probe needle 26 is positioned. It is in contact with the electrode pad 8 of the LCD without being displaced.

Considering a combination of quartz glass and soda glass even with the same glass material, for example, when the LCD substrate is soda glass and quartz glass is used as a probe needle positioning substrate, for example, the difference in linear expansion coefficient between the two is not found. , Only about 1 × 10 ^-5 , but one side is 450
Assuming that there is a temperature difference of 10 ° C. in the LCD substrate of mm, an error of about 45 μm will occur due to the following formula. 450 mm × 1 × 10 ⁻⁵ × 10 ° C. = 45 μm In such a situation, for example, as shown in FIG. 8, when a probe needle 26 having a width L4 of 30 μm is brought into contact with an electrode pad 8 having a side L3 of 100 μm square, both sides The allowable distance L5 of each is 35 μm, and this value is
Since it is smaller than m, the probe needle 26 comes off from the electrode pad 8 and the contact cannot be maintained. Thus, even with the same glass quality, if the linear expansion coefficient is slightly different, the combination will not be proper.

In the above embodiment, the adjusting mechanism for adjusting the X, Y, Z and θ axes is provided on the side of the base 22 on which the LCD 6 is mounted. However, these adjusting mechanisms are probing. It may be provided on the substrate 20 side. Further, in the above-described embodiment, the case where the probe needle 26 is used as the contactor has been described, but the present invention is not limited to this, and as shown in FIG. 9, a contact formed by a conductor such as copper in a protruding shape. Child 6
It can also be applied to a probing substrate having 0. That is, the contactor 60 of the probing substrate 30.
Is attached to the circuit wiring formed by printing on the flexible film 62 having an area substantially equal to that of the LCD so as to rise above this film, and L
It is formed so as to cover the entire area of the LCD 6 in correspondence with the electrode pad 8 of the CD 6.

This film 62 is used for the LCD as described above.
A material having the same linear expansion coefficient as the material forming the substrate 14,
For example, it is securely attached and fixed to a substrate 64 made of soda glass so as not to cause relative displacement between the substrate 64 and the substrate 64. The substrate 64 is attached and fixed to the support plate 30 via an elastic member such as an elastomer 66. Due to the elastic action of the elastomer 66, the armature 60
When is pressed against the LCD substrate 14, variations in the gap between the contact 60 and the electrode pad 8 are absorbed and they are brought into contact with each other at a uniform pressure. The elastomer 66 may be composed of a single layer or a plurality of layers depending on the size of the LCD substrate 14 or the distribution of the electrode pads 8. In the case of a plurality of layers, a fixed substrate is sandwiched between the elastomers. The amount of expansion and contraction and the pressure may be adjusted with.

Even in such a structure, 450 mm ×
Even a large-sized LCD substrate of 450 mm or more can be brought into contact with the electrode pads all at once, and the inspection can be performed quickly. Moreover, it is possible to improve the inspection efficiency as a whole because the alignment is performed only once. In addition, since the shock at the time of contact can be absorbed by the elastomer 66, the LCD substrate is less likely to be scratched, and dust is not generated due to scratches as in the case of the inspection with the conventional tungsten needle. It is possible to perform various inspections.

In the embodiment described above, the structure in which the contacts of the probing substrate and the electrodes of the LCD substrate are brought into contact with each other at a time has been described, but the present invention is not limited to this and, for example, FIG. The present invention can be applied to a probing substrate that is not the collective contact type as shown in the following.
In this case, the material of the substrate 10 to which the FPC film 2 is attached and fixed is not aluminum or glass epoxy resin but a material forming the LCD substrate, for example, a material having the same linear expansion coefficient as soda glass, for example, soda glass. To do. The present invention also provides a rectangular LCD.
Although the substrate has been described, the present invention is not limited to this shape and can be applied to LCD substrates having various shapes such as a triangle and a trapezoid. Further, in order to make the linear expansion coefficient the same, the LCD substrate and the probing substrate may be made of the same material as described above, but different materials may be used as long as they have the same linear expansion coefficient and insulation properties. Of course, a combination of

[0026]

As described above, according to the present invention,
The following excellent operational effects can be exhibited. Since the material of the substrate for positioning the contactor has the same linear expansion coefficient as the material of the LCD substrate, the LCD substrate and the probing substrate expand and contract by the same amount even if the environmental temperature at the time of inspection changes. Therefore, the contact can be brought into contact with the electrode pad of the LCD with high positional accuracy.

[Brief description of drawings]

FIG. 1 is a perspective view showing a probing substrate according to the present invention.

FIG. 2 is an explanatory diagram for explaining a formation state of a contact made of a probe needle.

3 is an explanatory diagram for explaining attachment of the armature in FIG. 2. FIG.

FIG. 4 is a cross-sectional view for explaining the attachment state of the armature.

FIG. 5 is an explanatory diagram for explaining a contact state of a contactor with an electrode pad.

FIG. 6 is a cross-sectional view showing a probing substrate at the time of inspection.

FIG. 7 is a cross-sectional view showing the operation of the probe needle of the modified example of the present invention.

FIG. 8 is an explanatory diagram for explaining a contact state between a probe needle and an electrode pad.

FIG. 9 is a sectional view showing another modification of the present invention.

FIG. 10 is a cross-sectional view showing a conventional probing substrate.

FIG. 11 is a plan view showing a conventional probing substrate.

[Explanation of symbols]

 2 FPC film 4 contactor 6 LCD 8 electrode pad 10 glass epoxy resin 12 elastomer 14 LCD substrate 16 display surface 20 probing substrate 26 probe needle (contactor) 28 substrate 32 groove 36 guide hole 38 elastomer 42 Z-axis adjusting mechanism 44 Y-axis Adjustment mechanism 46 X-axis adjustment mechanism 50 θ plate G pad group G1 probe needle group

Claims (2)

[Claims] 1. An electrode pad of a liquid crystal display substrate,
In a probing substrate for inspecting the liquid crystal display substrate by bringing a contact held on the substrate into contact, the substrate holding the contact is made of a material having the same linear expansion coefficient as that of the material forming the liquid crystal display substrate. A probing substrate characterized by being configured as follows. 2. The probing substrate according to claim 1, wherein both the liquid crystal display substrate and the substrate are made of soda glass.