Method and apparatus for probe testing substrate

Details Method and apparatus for probe testing substrate Method and apparatus for probe testing substrate

1996-11-18

1998-04-21

Raevis, Robert

Electricity: measuring and testing

Fault detecting in electric circuits and of electric components

Of individual circuit component or element

G01R 104

Patent

active

057421730

DESCRIPTION:

BRIEF SUMMARY
TECHNICAL FIELD

The present invention relates to method for probe testing electrical characteristics of pattern circuits of substrate for liquid crystal display (LCD) or semiconductor wafer, and to apparatus for probe testing substrate.
A TFT (Thin-Film Transistor) LCD has an LCD substrate which comprises a glass substrate and electric circuits are provided for performing on-off control of pixels. The electric circuits have been formed by an apparatus such as a film forming apparatus. Pads are provided on the substrate, located near the respective electric circuits. They are used as electric contacts.
The LCD substrate is inspected to determine whether or not each electric circuit works as desired. The inspection cannot be started unless the LCD substrate is correctly positioned. To position the LCD substrate correctly, alignment marks, e.g., crosses, are provided on the corners of the substrate.
In an LCD prober, a substrate is aligned with a probe, and then a pad on the substrate is contacted with the tip portion of the probe to conduct, and a test signal is sent to the circuits to inspect electrical characteristics of the substrate.
A method of inspecting an LCD substrate is disclosed in Jpn. Pat. Appln. KOKOKU Publication No. 62-31825. In this method, an image of the entire substrate is obtained by a first TV camera, while an image of the probes is obtained by the second TV camera. Both images are displayed on the same monitor screen. The substrate is moved until the pads displayed on the screen are aligned with the probes displayed on the screen.
However, in such conventional inspecting method, when an inspection performed by abutting the probe against a pad P is repeated, particles can deposit on the tip portion of probe, thereby causing the tip portion of the probe not to be recognized. A profile contrast of the tip portion at picking up can be changed due to a dirt on the probe tip portion or an oxidation of the probe tip portion surface, thereby causing the to be hardly recognized. For this reason, an alignment accuracy of the probe is reduced, or a variation in alignment time occurs.
The probe testing apparatus generally is provided with a handling section for loading/unloading an LCD substrate with respect to a substrate mounting table, and an inspecting section for electrically inspecting the LCD substrate unloaded from the handling section. The handling section is configured such that it unloads one by one from, for example, twenty five LCD substrates housed in a cassette to perform handling. The handling section is provided with, for example, a cassette placing member for placing a cassette, and a transfer device for unloading one by one from LCD substrates in the cassette placed on the cassette placing member and transferring the substrate to the testing section. The inspecting section is provided with a substrate mounting table for holding the substrate unloaded from the transfer device of the handling section, an alignment mechanism for detecting alignment marks M.sub.1, M.sub.2 shown in FIG. 2 while illuminating the substrate placed on the substrate mounting table, and a probe means for performing electric inspection by being contacted with respective pads of the substrate after the alignment by the substrate mounting table driven on the basis of inspection results from the alignment mechanism.
The testing apparatus is provided with a CCD camera for picking up the alignment marks M.sub.1, M.sub.2 detected by the alignment mechanism, an image processing means for image processing a signal from the CCD camera, and a display device for receiving the signal after being image processed to display the alignment marks M.sub.1, M.sub.2 as images. The substrate mounting table has up/down pins on the inside of the placing face. The up/down pins are such that the pins, when protruding beyond the mount surface, receive the substrate and support it at points, and then retract from the placing face to allow the substrate to be landed softly on the mount surface. Formed on the surface of the mount surf

REFERENCES:
patent: 4131267 (1978-12-01), Ono et al.
patent: 5091692 (1992-02-01), Ohno et al.
patent: 5479108 (1995-12-01), Cheng

Affiliated with

Also associated with

Rating

Method and apparatus for probe testing substrate does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and apparatus for probe testing substrate, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for probe testing substrate will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2061322