JP3100228B2 - Inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus.

[0002]

2. Description of the Related Art In general, an LCD (Liquid Crystal Display) using a TFT (Thin Film Transistor) has attracted attention as providing very excellent high image quality. In this type of LCD, for example, a TFT is formed on a plate-like glass substrate by a photolithography technique, and the TFT is formed, for example.
The pixel electrode electrically connected to the drain electrode of
A large number of pixel units arranged in such a manner are arranged with a gap between the FT and the pixel array. For example, several hundred thousand square pixel units each having a side of about several hundred μm are arranged. Then, a transparent electrode common to each pixel unit is arranged on such an LCD substrate with a gap interposed therebetween, and a liquid crystal is sealed in the gap to constitute an LCD.

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

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

A plurality of the electrode pads 8 are arranged outside the display surface 16 of the glass LCD substrate 14, for example, a pad group G including five electrode pads 8 is appropriately arranged for simplification in the illustrated example. It is provided by that. Then, the probing substrate 1 is moved along a guide mechanism 18 provided, for example, with a screw screw provided on the side of the LCD, and the contact is sequentially brought into contact with the electrode pad 8 to perform an inspection. . 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.
Although the size is very small, about mx 200 μm, on the other hand, large LCD boards of 450 mm × 450 mm have already appeared and tend to be larger in the future. To go. However, in the inspection method in which the probing substrate is brought into contact with the pad group G a plurality of times while sequentially moving the probing substrate with respect to the LCD substrate as described above, such a small pad 8
In order to accurately position the contact 4 in the pad 8 with respect to a pad group in which a large number of pads are arranged, in addition to the positional accuracy of the contact 4 of the probing substrate, the guide mechanism 1
Since the positioning of the probing substrate 8 with respect to the pad group and the mounting position of the probing substrate 1 with respect to the guide mechanism 18 are also required to be extremely high,
It is very difficult to accurately position the contact 4 so that the contact 4 contacts the electrode pads 8 distributed over a long range such that one side of the substrate is 450 mm.

It is also conceivable to inspect the pads collectively by enlarging the probing substrate, but in general, there is a difference between a place where the probing substrate 1 is manufactured and a place where the probing board 1 is used for inspection of the LCD. Therefore, the temperature difference between the time of manufacture and the time of use may cause a thermal expansion / contraction error in the accuracy of the probing substrate exceeding an allowable amount. For example, if one side of the LCD is 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 for a temperature difference of 10 ° C. There is also a problem that a case where the pad and the contact of the probing device cannot be brought into contact with each other due to misalignment. The present invention has been devised in view of the above problems and effectively solving them. An object of the present invention is to provide an inspection apparatus adapted to absorb the expansion and contraction due to temperature difference by expanding and contracting by the same thermal expansion and contraction amount of LCD substrate, for example.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a relatively simple construction in X, Y, Z, and θ directions.
A position adjustable retained electrode pads of the substrate to be inspected to a probing substrate by contacting the Secco held in the substrate inspecting the inspected substrate, the probing substrate
Inspection apparatus having a tester electrically connected to the
The substrate holding the contact is formed of a material having the same linear expansion coefficient as the material forming the substrate to be inspected, and the contact is formed on all the electrode pads of the substrate to be inspected.
And are provided so that they can be brought into contact all at once.

[0009]

According to the present invention, the substrate holding the contact is made of a material having the same linear expansion coefficient as the material of the substrate to be inspected. For example, when the substrate to be inspected is made of soda glass, the substrate holding the contactor is also made of a material having the same linear expansion coefficient, for example, soda glass. As a result, even if the surrounding environmental temperature during the inspection is changed, the substrate to be inspected and the substrate holding the contact expand and contract by the same amount, and as a result, the contact and the electrode pad to be inspected are excessively large. There is no displacement.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the inspection apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows the inspection according to the present invention.
FIG. 2 is a perspective view showing the apparatus , FIG. 2 is an explanatory view for explaining a state of formation of a contact made of a probe needle, and FIG. 3 is an enlarged view showing a portion of the contact in FIG. The same parts as those of the conventional device are denoted by the same reference numerals. As shown in the figure, the probing substrate 20 has a slightly larger area so as to cover the entire LCD 6 located below the probing substrate 20 at a time.
The LCD 6 is placed on the base 22, and its size is set to, for example, 450 mm × 450 mm. The LCD substrate 14 is formed of, for example, soda glass, and a portion corresponding to the long side of the outer peripheral portion of the display surface 16 is provided with, for example, several 100 μm × 100 μm drain electrode pads 8. 100 μm
The pad groups G formed by arranging, for example, 160 at intervals of 6 are arranged at appropriate intervals (only three groups are shown in the figure). Therefore, for example, 960 electrode pads 8 are formed on both long sides. Is done.

In addition, for example, 480 gate electrode pads 8 are formed at the same interval as described above on one short side of the outer peripheral portion of the display surface 16. Then, the probing substrate 2 for inspecting the LCD 6
No. 0 has an opening 24 in the center thereof having a size substantially the same as the size of the display surface 16 of the LCD, and a plurality of probing substrates 20 are provided along the edge of the opening 24. A probe needle 26 having a diameter of, for example, 100 μm, made of a cipher (trade name) made of, for example, tungsten or iron wire plated with gold as a probe, a substrate 28 for holding and positioning the probe needle 26, and mounting and supporting the substrate 28 It is mainly constituted by the support plate 30.

As shown in FIG. 2, a large number of the probe needles 26 are provided on the open end 30 of the substrate 28 along the longitudinal direction so as to correspond to the installation positions of the electrode pads 8 of the LCD. Have been. Each probe needle group G1
Represents 160 probe needles 2 in the same manner as the pad group G described above.
6, only five probe needles 26 are shown for simplicity in the illustrated example. In this embodiment, a substrate 28 for positioning and fixing these probe needles 26 is provided.
Are made of a material having the same linear expansion coefficient as the material forming 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, for example, soda glass having the same linear expansion coefficient.
When 4 is made of quartz glass, the substrate 28 is also made of, for example, quartz glass.

When mounting the probe needle 26, first, as shown in FIG.
An L-shaped groove 32 having a width L1 of, for example, about 110 μm is formed at a predetermined pitch in a corner of the zero by etching or the like.
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 that can completely accommodate the probe needle 26 in this groove. And the probe needle 26
Is protruded downward by, for example, about 250 μm to provide the probe needle 26 along each groove 32. 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. Thereby, the groove 32 facing the front side is formed as a guide hole 36, and guides the movement of the probe needle 26 when the probe needle 26 comes into contact with the electrode pad.

Further, above the substrate 28, as shown in FIG. 5, a vertical portion 26 of the probe needle 26 is provided in order to allow the probe needle 26 to escape when contacted.
An elastomer 38 made of, for example, an elastic member is provided over the entirety and is slightly displaced outwardly from above the portion a to absorb variations in the interval between the probe needle 26 and the electrode pad 8 at the time of contact. It is configured so that probing can be performed collectively with uniform pressure. Then, 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, for example, a pogo pin with a built-in spring (not shown), and each signal line 40 is connected to a tester 42. The LCD 6 can be inspected through the signal line 40. Further, as shown in FIG. 6, a base 22 on which the LCD 6 is mounted is mounted.
The upper, in order to adjust the Z (vertical direction), Ya screw shaft driven for example by a stepping motor for adjusting the vertically movably made a Z-axis adjustment mechanism 42, Y (vertical direction) direction Y-axis adjusting mechanism 44 having a nut or the like, X
The Y-axis adjustment mechanism 44 for adjusting the (lateral) direction
An X-axis adjustment mechanism 46 having the same configuration as that described above is sequentially provided.
A fixing plate 48 is provided on the X-axis adjustment mechanism 46. The fixed plate 48 is provided with a rotatable disk-shaped θ plate 50 for θ axis adjustment, and the LCD 6 is mounted and fixed on the θ plate 50.

As shown in FIG. 1, an alignment mark 52 formed, for example, in a cross shape is formed on the LCD substrate 14.
Are formed, and a viewing window 54 having a built-in CCD camera or microscope is formed in a portion corresponding to the mark 52 on the substrate 28 of the probing substrate 20.

Next, the operation of the present embodiment configured as described above will be described. First, the LCD 6 is moved from the base 22 to θ.
The probing substrate 20 provided on, for example, a lifting platform is lowered from above and fixed to the plate 50, and the tip of the probe needle 26 is brought into contact with each electrode pad 8 of the LCD 6. At the time of this contact, the X, Y, Z, and θ axes are adjusted by operating the respective adjustment mechanisms on the base 22 side while gazing at the mark 52 of the LCD 6 from the viewing window 54 of the probing substrate 20 with a CCD camera or the like. And gradually bring them into close contact. Then, the probe needle 2 is
A high frequency voltage of a predetermined frequency is applied to the electrode pad 8 of the LCD 6 via the LCD 6, and the inspection of the LCD is performed at once.

In this case, in this embodiment, the substrate 28 for positioning and fixing the probe needles 26 of the probing substrate 20 is made of a material constituting the LCD substrate 14, for example, a material having the same linear expansion coefficient as soda glass, for example, Since the same material is used for soda glass, for example, the temperature of the assembling place of the probing substrate 20 and the LCD
6 Even if there is a difference in the temperature of the place where the inspection is performed,
Both members will thermally 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, 450mm × 4
The probe needle can be brought into contact with the LCD substrate having a size of 50 mm or more at a time, and the alignment can be performed only once.

When the probe needle 26 comes into contact, the probe needle 26 is pushed upward by the electrode pad 8 as shown in FIG. 5, but since the upper part 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 accommodating it, so that the tip of the probe needle 26 is not displaced and does not come off the electrode pad 8. In particular,
When the substrate 28 for positioning the probe needle 26 is made of glass, it is particularly preferable in the LCD field where the tendency to miniaturization is remarkable because of the high insulation resistance value. In addition, since glass is a highly rigid material, its deformation strain can be suppressed significantly even with the stylus force at the time of contact compared to conventional materials such as aluminum and glass epoxy resin, and the flatness is also improved. Not only is it easy, but there is no deformation due to moisture absorption, and dimensional accuracy can be maintained even 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. For example, the elastomer 38 may be positioned above the vertical portion 26a of the probe needle 26 as shown in FIG. 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 when contacting the electrode pad 8, and as a result, the distal end of the probe needle 26 is positioned This means that it is in contact with the electrode pad 8 of the LCD without shifting.

Here, when the same glass material is combined with quartz glass and soda glass, for example, when the LCD substrate is soda glass and quartz glass is used as the positioning substrate for the probe needle, for example, the difference between the linear expansion coefficients of the two is as follows. , But 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 occurs by the following equation. 450 mm × 1 × 10 ⁻⁵ × 10 ° C. = 45 μm In such a situation, for example, when the probe needle 26 having a width L4 of 30 μm is brought into contact with the electrode pad 8 having a side L3 of 100 μm square as shown in FIG. Are 35 μm, respectively, and this value is equal to the above-mentioned error 45 μm.
Since the probe needle 26 is smaller than m, the probe needle 26 comes off the electrode pad 8 and the contact cannot be maintained. As described above, if the linear expansion coefficients are slightly different even in the same vitreous material, the combination is not proper.

In the above embodiment, the adjusting mechanism for adjusting the X, Y, Z and θ axes is provided on the base 22 on which the LCD 6 is mounted. 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 contact has been described. However, the present invention is not limited to this, and as shown in FIG. Child 6
It can also be applied to probing substrates having zero. That is, the contact 60 of the probing substrate 30
Is mounted on a circuit wiring formed by printing on a flexible film 62 having an area approximately equal to the area of the LCD so as to swell from the film.
It is formed so as to cover the entire range of the LCD 6 corresponding to the electrode pad 8 of the CD 6.

This film 62 is made of an LCD as described above.
A material having the same coefficient of linear expansion as the material forming the substrate 14,
For example, it is securely attached and fixed to a substrate 64 made of, for example, soda glass so as not to cause a relative displacement between the substrate 64 and the substrate 64. The substrate 64 is fixed to the support plate 30 via an elastic member, for example, an elastomer 66. The elastic action of the elastomer 66 causes the contact 60
When is pressed against the LCD substrate 14, variations in the distance between the contact 60 and the electrode pad 8 are absorbed, and they are brought into contact at a uniform pressure. The elastomer 66 may be formed in a single layer or a plurality of layers according to 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 size of expansion and contraction and the pressure may be adjusted by using.

In such a structure, 450 mm ×
Even a large-sized LCD substrate having a size of 450 mm or more can be brought into contact with the electrode pads at a time, and the inspection can be performed quickly. In addition, since only one alignment is required, the inspection efficiency as a whole can be improved. Further, since the shock at the time of contact can be absorbed by the elastomer 66, there is little damage to the LCD substrate, and there is no dust due to scratches as in the conventional inspection using a tungsten needle, and there is little contamination. Inspection can be performed.

In the embodiment described above, the structure in which the contact of the probing substrate and the electrode of the LCD substrate are brought into contact at once is described. However, the present invention is not limited to this. For example, FIG. The present invention can also be applied to a probing substrate that is not a batch contact type as shown,
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 constituting the LCD substrate, for example, a material having the same linear expansion coefficient as soda glass, for example, soda glass. I do. The present invention also relates to a rectangular LCD.
Although the substrate has been described, the present invention is not limited to this shape, and can be applied to various shapes of LCD substrates such as a triangle and a trapezoid. Furthermore, in order to make the coefficient of linear expansion the same, the substrate of the LCD substrate and the substrate of the probing substrate may be made of the same material as described above. Of course, a combination of

[0026]

As described above, according to the present invention,
The following excellent functions and effects can be exhibited. Contract
According to the invention of Motomeko 1, as a material of the substrate for positioning the Secco, because to use a material having the same linear expansion coefficient as of the substrate to be inspected materials, inspection even environmental temperature changes during test The substrate and the probing substrate expand and contract by the same amount, so that the contact can be brought into contact with the electrode pads of the substrate to be inspected with high positional accuracy. Ma
In addition, probing can be performed collectively. Claim
According to the invention of Item 2, the tip of the contactor at the time of contact with the electrode pad
The end portion can be prevented from being displaced. Claim
According to the invention of Item 3, the tip of the contactor at the time of contact with the electrode pad
Probing at uniform pressure as end escape
Can be

[Brief description of the 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 state in which a contact formed of a probe needle is formed.

FIG. 3 is an explanatory diagram for explaining attachment of a contact in FIG. 2;

FIG. 4 is a cross-sectional view for explaining a mounting state of a contact.

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

FIG. 6 is a cross-sectional view showing a probing substrate during inspection.

FIG. 7 is a sectional view showing the operation of a probe needle according to a modification 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 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 Contact 6 LCD 8 Electrode pad 10 Glass epoxy resin 12 Elastomer 14 LCD substrate 16 Display surface 20 Probing substrate 26 Probe needle (Contact) 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

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1343 G01R 31/26 G02F 1/13 101

Claims (3)

(57) [Claims] 1. Position adjustment relatively in X, Y, Z, θ directions
A probing substrate for inspecting the substrate to be inspected by bringing a contact held by the substrate into contact with an electrode pad of the substrate to be inspected held so as to be capable of being electrically connected to the probing substrate;
In the inspection device having a continuous tester, the substrate holding the contact is formed of a material having the same linear expansion coefficient as the material forming the substrate to be inspected, and the contact is
Collectively contact all electrode pads of the substrate to be inspected
An inspection device characterized by being provided so that it can be touched . 2. A tip portion of the contact is bent to form a vertical portion.
The vertical portion is formed at the time of contact with the electrode pad.
Make sure that it is housed in the guide hole to prevent misalignment.
The inspection apparatus according to claim 1, wherein: 3. The vertical portion is in contact with the electrode pad.
A structure that sometimes allows escape in the direction opposite to the contact direction
3. The inspection device according to claim 2, wherein
Place.