WO2008153238A1

WO2008153238A1 - Probe unit and needle thereof

Info

Publication number: WO2008153238A1
Application number: PCT/KR2007/003242
Authority: WO
Inventors: Tea-Woon Jeon
Original assignee: Im Co., Ltd
Priority date: 2007-06-11
Filing date: 2007-07-04
Publication date: 2008-12-18
Also published as: KR20080108712A; KR100899978B1

Abstract

A probe unit and a needle thereof are disclosed. The needle of the probe unit includes: a beam fixedly coupled to a needle guide; a probe portion for electrically touching a pad formed on an LCD panel. The probe portion is located under the beam, spaced apart from the beam at a certain distance within which the rise in height of the probe portion is limited by the beam. The needle includes a connection portion formed such that the probe portion can be connected to the beam, for exerting an elastic restoring force on the probe portion when the probe portion rises. The needle does not undergo an excessive deformation, and a plurality of needles do not mutually interfere. The life span of the probe unit can be extended.

Description

PROBE UNIT AND NEEDLE THEREOF

Technical Field

[1] The present invention relates to a system for testing electronic parts, and more particularly to a probe unit and a needle thereof, which are used to test operations of electronic parts used in the display apparatus. Background Art

[2] Liquid crystal display (LCD) fabrication processes are classified into: a cell process where an LCD panel is produced; and a module assembly process where a driver, a backlight, a polarizer, and a light guide panel are assembled with the PCD panel.

[3] The LCD panel produced through the cell process undergoes a defect test to check for any manufacturing defects, such as point defect, line defect, or stain defect, etc. In particular, the defect test estimates the electrical and optical characteristics of LCD devices and sorts the LCD devices based on the estimation. A more precise defect test can reduce production costs and improve the quality of the product.

[4] To test electrical characteristics of an LCD panel including TFT's, an open/short test of gate and data lines formed on the LCD panel and a visual inspection test are performed.

[5] The visual inspection test tests whether alien substances exist in the liquid crystal material filling the gap between a TFT substrate and a color filter. The color filter substrate is combined with the TFT substrate on which TFT's as a switching device are arrayed to form pixels, and gate and data lines are formed.

[6] After forming gate and data lines formed on a TFT substrate, the open/short test is performed to test the lines, respectively. That is, the open/short test determines whether a gate line and a data line is opened or shorted in such a way that: a voltage is applied to both ends of the probes touching the gate line or the data line; a current flowing in the circuit is measured; and resistance is calculated.

[7] The above described test is performed by the probe station equipment for testing

LCD devices.

[8] The probe station equipment for testing LCD devices is configured to include: a probe unit composed of a plurality of probe needles through which test signals are applied to a plurality of electrodes placed on the edge of an LCD panel; a taped automated bonding integrated circuit (TAB IC) for transmitting electric signals to the probe needles of the probe unit; a pattern signal generator for generating signals to test the LCD panel; a source/gate printed circuit board (PCB) for transmitting the signals to the TAB IC, with dividing the signals into X-line signals and Y-line signals. [9] FlG. 1 is a cross-sectional side view depicting a needle of a probe unit for testing an

LCD panel, and a needle guide for guiding the needle, according to a prior art. [10] As shown in FlG. 1, a probe unit for testing an LCD panel is configured to include: a needle guide 10 having a needle hole 11 ; and a needle 12 inserted to and coupled to the needle hole 11. [11] The needle 12 is configured to form a probe portion 13, a connection portion 14, and a beam (not shown). [12] The needle guide 10 forms the needle hole 11 to which the needle 12 is inserted and coupled. [13] The probe portion 13 touches a pad (not shown) formed on an LCD panel and transmits an electric signal from the beam to the pad, thereby testing the LCD panel. [14] The connection portion 14 supports the probe portion 13 based on an elastic restoring force generated as the probe portion 13 undergoes an external force. [15] The beam is inserted to the needle hole 11, and then fixed thereto as an adhesive, such as an epoxy, is applied thereon, thereby entirely supporting the needle. The beam transmits an electric signal from the TAB IC to the pad of the LCD panel via the connection portion 14 and the probe portion 13. [16] To test an LCD panel, when the probe portion 13 of the probe unit as configured above touches the pad of the LCD panel, the connection portion 14 becomes deformed and thus generates an elastic restoring force. Therefore, the probe portion 13 can maintain contact with the pad of the LCD panel by the elastic restoring force. [17] However, since the probe portion 13 of the needle 12 is located inside the needle guide 10, it does not appear to the outside, causing it to be difficult to align the probe unit such that the probe portion 13 can touch the pad of the LCD panel. [18] When the probe portion 13 touches the pad, the connection portion 14 may become excessively deformed. That is, since the rise in height of the probe portion 13 is unlimited, the connection portion 14 undergoes serious stress. [19] To resolve these problems, the following has been proposed:

[20] FlG. 2 is a cross-sectional side view depicting a needle of a probe unit for testing an

LCD panel, and a needle guide according to another prior art. [21] As shown in FlG. 2, a probe unit for testing an LCD panel is configured to include: a needle guide 10' having a needle recess 11'; and a needle 12' inserted to and coupled to the needle recess 11'. [22] The needle guide 10' forms the needle recess 11' to which the needle 12' is inserted and coupled. [23] The needle 12' is configured to form a needle portion 13', a connection portion 14', and a beam (not shown). [24] When the needle 12' is inserted to and coupled to the needle recess 11' of the needle guide 10', one end portion of the needle portion 13' is protruded from the needle recess 11 ', thereby checking the position of the needle portion 13' easily. Therefore, the probe unit can be conveniently aligned such that the probe portion 13' can precisely touch the pad (not shown) of the LCD panel.

[25] The connection portion 14' supports the probe portion 13' based on an elastic restoring force generated as the probe portion 13 undergoes an external force.

[26] The beam is inserted to the needle recess 11', and then fixed thereto as an adhesive, such as an epoxy, is applied thereon, thereby entirely supporting the needle. The beam transmits an electric signal from the TAB IC to the pad of the LCD panel via the connection portion 14' and the probe portion 13'.

[27] To test an LCD panel, when the probe portion 13' of the probe unit as configured above touches the pad of the LCD panel, the connection portion 14' is deformed and thus generates an elastic restoring force such that the probe portion 13' can maintain contact with the pad of the LCD panel by the elastic restoring force. The needle recess 11 ' limits the rise h in height of the probe portion 13', thereby controlling an excessive deformation of the connection portion 14'.

[28] However, since the probe unit tests numerous LCD panels repeatedly, the probe portion 13' cannot help but touch the needle guide 10' frequently. Therefore, the needle guide 10', which is made of silicon or glass, may be damaged. To prevent the needle guide 10' from becoming damaged, the needle guide 10' is fabricated from ceramic materials. As a result, the connection portion 14' does not undergo an excessive deformation, and the damage to the needle guide 10' caused by its contact with the probe portion 13' is prevented.

[29] Although the ceramic material has exerted its property on the connection portion 14' and the needle guide 10' to prevent and reduce excessive deformation and damage, it has a low machining property, making machining of a slot difficult for example, which causes problems when fabricating and installing the needle guide, and is expensive. Disclosure of Invention Technical Problem

[30] Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a probe unit and a needle thereof, which are manufactured in such a way that the probe unit cannot undergo an deformation excessively, the needle cannot undergo a mutual interference with the adjacent needles, and the life span of the probe unit can be extended, and which can be easily fabricated. Technical Solution

[31] In accordance with an aspect of the present invention, there is provided a needle of a probe unit, which includes: a beam fixedly coupled to a needle guide; a probe portion for electrically touching a pad formed on an LCD panel, wherein the probe portion is located under the beam, spaced apart from the beam at a certain distance within which the rise in height of the probe portion is limited by the beam; and a connection portion formed such that the probe portion can be connected to the beam, for exerting an elastic restoring force on the probe portion when the probe portion rises. [32] In accordance with another aspect of the present invention, there is provided a probe unit including: a needle guide; and a plurality of needles fixedly coupled to the needle guide, in which the plurality of needles are guided by the needle guide. Here, each of the needles includes: a beam fixedly coupled to a needle recess formed in the needle guide; a probe portion for electrically touching a pad formed on an LCD panel, wherein the probe portion is located under the beam, spaced apart from the beam at a certain distance within which the rise in height of the probe portion is limited by the beam; and a connection portion formed such that the probe portion can be connected to the beam, for exerting an elastic restoring force on the probe portion when the probe portion rises.

Advantageous Effects

[33] As described above, according to the present invention, since the beam limits the rise in height of the probe portion when the probe portion touches the pad of the LCD panel above a predetermined pin pressure, the needle guide can be prevented from becoming damaged as the probe portion directly touches the needle guide, and the life span of the probe unit can therefore be extended. [34] In addition, since the beam does not allow the probe portion to touch the needle guide, the needle guide does not require additional ceramic machining to form a slit therein. Instead, the needle guide can be made of silicon, etc. Therefore, the production costs of the probe unit and manufacturing time can be reduced.

Brief Description of the Drawings [35] The above and other objects, features, and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: [36] FlG. 1 is a cross-sectional side view depicting a needle of a probe unit for testing an

LCD panel, and a needle guide for guiding the needle, according to a prior art; [37] FlG. 2 is a cross-sectional side view depicting a needle of a probe unit for testing an

LCD panel, and a needle guide for guiding the needle, according to another prior art; [38] FlG. 3 is a side view depicting a needle of a probe unit according to an embodiment of the present invention; [39] FlG. 4 is a cross-sectional side view depicting a probe unit according to an embodiment of the present invention; and [40] FlG. 5 is a perspective view depicting the probe unit of FlG. 4.

[41 ] <Brief Description of Symbols in the Drawings>

[42] 100: needle of a probe unit

[43] 200: needle guide

[44] 113: probe portion

[45] 114: connection portion

[46] 115: beam

Best Mode for Carrying Out the Invention

[47] Preferred embodiments according the present invention will be described in detail with reference to the accompanying drawings.

[48] FlG. 3 is a side view depicting a needle of a probe unit according to an embodiment of the present invention.

[49] As shown in FlG. 3, the needle of a probe unit for testing an LCD panel is configured to include: a beam 115 fixedly coupled to a needle guide (not shown); and a probe portion 113 for electrically touching a pad formed on the LCD panel. The probe portion 113 is located under the beam 115, spaced apart from the beam 115 at a certain distance h' within which the rise in height of the probe portion 113 is limited by the beam 115. The needle of a probe unit also includes a connection portion 114 formed such that the probe portion 113 can be connected to the beam 115. The connection portion 114 exerts an elastic restoring force on the probe portion 113 when the probe portion 113 rises.

[50] The beam 115 is fixed to the needle guide and entirely supports the needle. In particular, the beam 115 is inserted to a needle recess formed in the needle guide and is then fixed thereto as an adhesive, such as an epoxy, etc., is applied thereon. One end of the beam 115 is connected to a TAB IC substrate or a flexible printed circuit board (FPC) and inputs an electric signal from the probe station equipment (not shown). The beam 115 transmits the input electric signal to the pad of the LCD panel through the connection portion 114 and the probe portion 113.

[51] The probe portion 113 is positioned under the beam 115, spaced apart from the beam

115 at a certain height h' within which the rise in height of the probe portion 113 is limited by the beam 115. The probe portion 113 rises by a certain height when it is touched with the pad of the LDC panel. When the probe portion 113 rises, the beam 115 limits the upward rise in height of the probe portion 113 such that the connection portion 114 cannot become excessively deformed, and such that the probe portion 113 cannot touch the needle guide, which prevents damage of the needle guide.

[52] The connection portion 114 is formed onto the lower side of the beam 115. The interval h' between the probe portion 113 and the beam 115 can be adjusted when the needle is fabricated. In another embodiment of the present invention, the shape of the connection portion 114 can be modified in such a way that one side of the connection portion 114 is connected to the beam 115 and another side is spaced from the beam at a certain interval.

[53] The probe portion 113, connection portion 114, and beam 115 of the needle may be made of different materials, but it is preferable that they are made of the same material, for example, tungsten alloy.

[54] FlG. 4 is a cross-sectional side view depicting a probe unit according to an embodiment of the present invention, and FlG. 5 is a perspective view depicting the probe unit of FlG. 4.

[55] The probe unit for testing an LCD panel is configured to include: a needle guide 200; and a plurality of needles 100 fixedly coupled to the needle guide 200. The plurality of needles 100 are guided by the needle guide 200. Each of the needles 100 is configured to include: a beam 115 fixedly coupled to a needle recess 201 formed in the needle guide 200; a probe portion 113 for electrically touching a pad (not shown) formed on an LCD panel. The probe portion 113 is located under the beam 115, and is spaced apart from the beam 115 at a certain distance h' within which the rise in height of the probe portion 113 is limited by the beam 115. The needle also includes a connection portion 114 formed such that the probe portion 113 can be connected to the beam 115. The connection portion 114 exerts an elastic restoring force on the probe portion 113 when the probe portion 113 rises.

[56] The needle guide 200 may be made of silicon. The needle guide 200 forms a plurality of needle recesses 201 insertedly receiving a plurality of needles 100. If the needle guide 200 is made of silicon, the needle recesses 201 are formed by lithography, one of the semiconductor device manufacturing processes. After forming the needle recesses 201, the respective needles 100 are inserted thereinto and covered by an adhesive, such as an epoxy. Therefore, the needle guide 200 can guide the needles 100 stably.

[57] The beam 115 is fixedly coupled to the needle guide 200, and entirely supports the needle. In particular, the beam is inserted to the needle recess 201 formed in the needle guide 200 and then fixed thereto as an adhesive, such as an epoxy, etc., is applied thereon. One end of the beam 115 is connected to a TAB IC substrate or an FPC and inputs an electric signal from the probe station equipment (not shown). Therefore, the beam 115 transmits the electric signal to the pad of the LCD panel through the connection portion 114 and the probe portion 113.

[58] The probe portion 113 is located under the beam 115, spaced apart from the beam at a certain height h' within which the rise in height of the probe portion 113 is limited by the beam 115. The probe portion 113 touches the pad of the LCD panel with a certain pin pressure that results from the elasticity of the connection portion 114 (or, its shape- restoring force). The probe portion 113 rises by a certain height when it touches the pad of the LDC panel. When the probe portion 113 rises, the beam 115 limits the upward rise in height of the probe portion 113 such that the connection portion 114 cannot become excessively deformed, and the probe portion 113 cannot touch the needle guide, which prevents damage of the needle guide.

[59] The probe portion 113 is mounted on the needle recess 201 of the needle guide 200 such that one of its end portions protrudes from the needle recess 201, allowing it to align the probe unit easily.

[60] The probe portion 113 is not limited in shape, but it is preferable that the end of the probe portion 113 to touch a pad of electronic parts is as sharp as possible.

[61] As shown in FlG. 4, the connection portion 114 is formed onto the lower side of the beam 115, and thus the probe portion 113 is located under the beam 115. Accordingly, as described above, the probe portion 113 is limited, in its rise in height, by the beam 115. The interval h' between the beam and the probe portion 113 can be adjusted when the needle is fabricated. In another embodiment of the present invention, the shape of the connection portion 114 can be modified in such a way that one side of the connection portion 114 is connected to the beam 115 and another side is spaced from the beam at a certain interval.

[62] As described above, if the probe portion 113 touches the pad of the LCD panel above a predetermined pin pressure, it contacts the beam 115, which means that the beam 115 controls the rise in height of the probe portion 113. Therefore, the connection portion 114 does not deform excessively. Accordingly, the connection portion 114 also undergoes relatively little stress caused by the shape deformation.

[63] Such a structure according to the present invention can protect the needle guide 200 against damage caused as the probe portion 113 directly touches the needle guide 200, and thus extends the life span of the probe unit.

[64] Since the beam 115 prevents the probe portion 113 from touching the needle guide

200, it is not necessary to additionally machine a ceramic material to form a slit, or to insert it to the needle recess 201 of the needle guide 200. Therefore, the production costs and manufacturing time can be reduced.

[65] Although exemplary embodiments of the present invention have been described in detail hereinabove, it should be understood that many variations and modifications of the basic inventive concept herein described, which may appear to those skilled in the art, will still fall within the sprit and scope of the exemplary embodiments of the present invention as defined in the appended claims Industrial Applicability

[66] The present invetion can be widely applied to the test systems for testeing semi- conductor devices.

Claims

[ 1 ] A needle of a probe unit comprising : a beam fixedly coupled to a needle guide; a probe portion for electrically touching a pad formed on an LCD panel, wherein the probe portion is located under the beam, spaced apart from the beam at a certain distance within which the rise in height of the probe portion is limited by the beam; and a connection portion formed such that the probe portion can be connected to the beam, for exerting an elastic restoring force on the probe portion when the probe portion rises.

[2] A probe unit comprising: a needle guide; and a plurality of needles fixedly coupled to the needle guide, in which the plurality of needles are guided by the needle guide, wherein each of the plurality of needles comprises: a beam fixedly coupled to a needle recess formed in the needle guide; a probe portion for electrically touching a pad formed on an LCD panel, wherein the probe portion is located under the beam, spaced apart from the beam at a certain distance within which the rise in height of the probe portion is limited by the beam; and a connection portion formed such that the probe portion can be connected to the beam, for exerting an elastic restoring force on the probe portion when the probe portion rises.