JPH0559431U - Inspection head for liquid crystal display - Google Patents

Abstract

(57) [Abstract] [Purpose] Without touching the liquid crystal electrodes of the inspection head used for the inspection of the liquid crystal display device in which the number of liquid crystal electrodes is extremely high, with a highly accurate contact position to the electrodes. A highly reliable inspection head for a liquid crystal display device that can be implemented and can achieve low impedance. [Structure] A drive LSI 4 is provided on the main surface of an insulating circuit board 5, and a contact pattern 6 is provided at a corresponding position of a liquid crystal electrode 2.
L for connecting the contact pattern 6 and the drive LSI 4
SI connection pattern 7 and input pattern 8 to LSI 4
An inspection head for a liquid crystal display device, which further comprises a contact 10 made of conductive rubber on the contact pattern 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an inspection head for a liquid crystal display device, and more particularly to an inspection head that can cope with a liquid crystal display device having a high pixel density.

[0002]

[Prior Art]

 In recent years, liquid crystal display devices have been used for a wide range of display applications such as televisions, word processors, personal computers, workstations, and viewfinders, and it is expected that their application range will continue to expand in the future. The liquid crystal display devices used for these applications are required to have a sharper image, and the density of pixels and the number of pixels are increasing. Currently, the pitch of the liquid crystal electrodes drawn from each pixel is less than 100 μm. Therefore, the number of liquid crystal electrodes arranged on one side of the liquid crystal display device has reached the level of 2000. With the increase in the density of pixels and the increase in the number of pixels in such a liquid crystal display device, when performing an image inspection of the liquid crystal display device, it is necessary to increase the contact height between the liquid crystal electrode of the liquid crystal display device and the liquid crystal drive circuit. Inspection head structures that support density and multiple electrodes are becoming a major issue.

By the way, in the conventional inspection of a liquid crystal display device, as shown in FIG. 4, for example, a liquid crystal inspection device 54 having a video signal generation circuit 51, a control circuit 52, and a liquid crystal display device drive circuit 53 is connected and a liquid crystal The inspection head 30 having an intermediary function for electrically contacting the liquid crystal electrodes of the display device 1 and transmitting an electric signal from the liquid crystal inspection device 54 to the liquid crystal display device 1 has been used.

As shown in FIGS. 5A and 5B, such an inspection head 30 has a pin electrode 31 and a liquid crystal inspection device 54 at a position corresponding to the liquid crystal electrode 2 of the liquid crystal display device 1. 6 is formed by implanting a probe pin 34 made of a spring probe or a metal fine needle or the like on the pin electrode 31 constituting portion of the printed circuit board 33 on which the connection electrode 32 for connection of FIG. As shown in FIG. 3, a contact electrode 41 and a connecting electrode 42 for connecting the liquid crystal inspecting device 54 are formed at a position corresponding to the liquid crystal electrode 2 of the liquid crystal display device 1 by a subtractive method or the like polyester or polyimide. The flexible circuit board 43 made of the film base material, and the flexible circuit board 43 are held, and the liquid crystal electrode 2 and the contact electrode 41 of the liquid crystal display device 1 are completely connected. A pressure holding member 44 made of an elastic material for contacting the terminals with uniform pressure has been used.

[0005]

[Problems to be solved by the device]

 However, in the conventional inspection head for a liquid crystal display device as described above, as shown in FIG. 5, in the case of the inspection head 30 using the probe pin 34, a probe pin having a small diameter of less than 100 μm is used. 34 is difficult to obtain, and as a processing drill for drilling holes with multiple pins and fine pitch for implanting the probe pins 34 in the printed circuit board 33, the current drill size is 100 μm or less. It is difficult to manufacture the inspection head 30 corresponding to the liquid crystal electrodes 2 having a pitch of 200 μm or less because there is nothing. Furthermore, there is a problem that the number of processing steps is increased to perform the hole processing corresponding to the multi-terminal of the liquid crystal electrode 2, and the inspection head corresponding to the future high-density, multi-terminal liquid crystal display device 1 is configured. Had reached the limit above.

Further, since the probe pin 34 is made of metal, there is a problem that the liquid crystal electrode 2 is easily scratched when inspecting the liquid crystal display device 1 and a quality problem may occur.

Further, in the case of the inspection head 30 using the flexible circuit board 43 as shown in FIG. 6, circuits such as the contact electrode 41 and the connection electrode 42 are formed by a wet process using a material such as polyester or polyimide as a base material. In the flexible circuit board 43 on which the pattern is formed, it is difficult to form the circuit pattern with high density and high precision. Especially, in the flexible circuit board 43 having fine and multi-electrodes, the accumulated pattern accuracy is determined by the liquid crystal display device 1. It is difficult to manage the liquid crystal electrode 2 with high precision so as to be compatible with it. Furthermore, due to the characteristics such as the hygroscopicity and thermal expansion coefficient of the base material itself such as polyester and polyimide, it expands and contracts due to changes in environmental conditions such as humidity and temperature to stabilize the circuit pattern placement accuracy with high accuracy. There was a problem that it was difficult to keep.

In addition, as a problem that the above-described conventional techniques have in common, the contact between the liquid crystal electrode 2 and the inspection head 30, the connection between the inspection head 30 and the liquid crystal inspection device 54, the liquid crystal The number of connections and contacts such as the connection of the drive LSI is large, the connection path from the liquid crystal electrode 2 to the drive LSI of the liquid crystal inspection device 54 is long, the wiring impedance of the system is large, and the impedance between the electrodes is large. There are problems such as low reliability of the measurement system due to difficulty in balancing and poor inspection performance.

As described above, the structure of the inspection head 30 of the conventional liquid crystal display device 1 has many problems.

In order to solve the above problems in the prior art, an object of the present invention is to provide a liquid crystal electrode 2 with a pitch of 100 μm or less, a narrow pitch of 2000 terminals level, multiple electrodes, and even when the environment changes. On the other hand, it is possible to maintain a high position accuracy, and it is possible to form a contactor that does not scratch the liquid crystal electrode 2 due to contact during measurement. Provided is an inspection head for a liquid crystal display device 1, which can shorten a connection path length between an electrode 2 and a driving LSI, can achieve low impedance, and can obtain high measurement reliability. To do.

[0011]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention electrically connects with a liquid crystal electrode, which is drawn from a pixel of a liquid crystal display device and is provided to connect to a liquid crystal driving circuit, and receives an electric signal from a liquid crystal inspection device. In a test head for a liquid crystal display device for transmitting to a display device, a drive LSI for driving the liquid crystal, a contact pattern formed corresponding to the liquid crystal electrode, and the contact pattern on at least one main surface. A circuit board on which an LSI connection pattern for electrically connecting the electrodes of the drive LSI and an input pattern to the drive LSI are arranged, and the liquid crystal electrode formed on the contact pattern of the circuit board. And a conductive rubber contactor made of a conductive rubber for contacting with. In addition, in order to improve durability, it is preferable that the drive LSI connected to the LSI connection pattern and the input pattern to the drive LSI be sealed with a resin.

[0012]

[Action]

 According to the present invention, a conductive rubber contact is connected from a drive LSI provided in an inspection head through an LSI connection pattern and a contact pattern, and the liquid crystal electrode of a liquid crystal display device is connected through the conductive rubber contact. An electric signal is sent to each pixel by an electrical connection by contact with the pixel, and the anisotropy of the conductive rubber provided in relation to the holes formed in the organic film is utilized. By doing so, the reliability of the contact state between the conductive rubber contact and the liquid crystal electrode is improved, and it has various advantageous features such as low impedance due to the shortening of the circuit between the contact and the drive LSI. The inspection head configuration is obtained.

[0013]

【Example】

 Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows an outline of the configuration of a liquid crystal display device inspection mechanism to which the inspection head according to the present invention is applied. That is, the inspection head 3 of the present invention is equipped with a drive LSI 4 for driving the liquid crystal display device 1, as will be described later, whereas the liquid crystal inspection device 24 is provided with a video signal generation circuit 21 and A control circuit 22 is provided. Thus, the electric signal from the liquid crystal inspection device 24 is sent to the liquid crystal display device 1 through the inspection head 3 of the present invention for inspection, and the inspection head according to the present invention will be described below with reference to FIG. The configuration of No. 3 will be described in detail.

In FIG. 2, 5 is an insulative circuit board such as glass or ceramic which is rigid and has a smooth surface and is suitable for application of a metal thin film method or an additive plating forming method, and 6 is a circuit board 5 on the circuit board 5. A contact pattern formed at a position corresponding to the liquid crystal electrode 1 (see (B)) on the liquid crystal display device 1 side, and 7 is formed for electrically connecting the contact pattern 6 and the drive LSI 4 to each other. An LSI connection pattern 8 is an input pattern formed for supplying each signal and power from the liquid crystal inspection device 24 side to the drive LSI 4. The patterns 6, 7 and 8 are formed by forming a thin metal film of Cr / Cu / Au or the like and then forming the pattern by a photolithography method, an etching method or the like, or a known thin film forming method or Cu plating according to the pattern. The circuit pattern can be formed by an additive plating method or the like.

Reference numeral 9 is a thin plate-shaped organic film made of polyimide, polyester, epoxy resin containing glass cloth, or the like, and 10 is a conductive rubber contact. In this example, the organic film 9 is made of Ni, Fe, C, or Ni, Fe plated with Au in a position corresponding to each liquid crystal electrode 2 by drilling or etching in advance. Conductive rubber obtained by dispersing conductive particles or conductive short fibers in a binder such as silicone rubber or urethane rubber is filled and cured. The conductive rubber contact 10 is formed by the portion of the organic film 9 that is sufficiently filled with the conductive rubber in the thickness direction and protrudes toward the liquid crystal terminal 2 side. Then, the organic film 9 on which the conductive rubber contact 10 is formed is positioned with respect to the contact pattern 6, and then pressure-bonded by the organic adhesive 11.

As described above, the contact for connection to the liquid crystal electrode 2 of the liquid crystal display device 1 is obtained. Therefore, the drive LSI 4 is further die-bonded onto the circuit board 5 using a conductive paste or the like, and the electrode pads of the drive LSI 4 and the LSI connection pattern 7 and the input pattern 8 on the circuit board 5 are wire-bonded by Au wires 12 or the like. An electrical connection is made by a bonding method, and at least the input pattern 8 and the organic film 9 of the drive LSI 4 and the surfaces of the drive LSI 4 and the circuit board 5 are protected by an encapsulation resin 13 such as an epoxy resin for protection from the external environment. By sealing, the inspection head 3 for the liquid crystal display device 1 is obtained.

In the inspection head 3 thus configured, when the circuit board 5 is made of glass, the position of the liquid crystal electrode 2 can be directly seen from the side of the circuit board 5, so that the liquid crystal electrode 2 can be seen. The conductive rubber contact 10 and the conductive rubber contact 10 can be easily aligned with each other. Further, since the main constituent material of the liquid crystal display device 1 is glass, it is possible to follow the deformation of the liquid crystal display device 1 due to environmental changes, and the high positional accuracy between the liquid crystal electrode 2 and the conductive rubber contact 10 is provided. Can be kept.

In forming the conductive rubber contact 10, magnetic conductive particles or magnetic conductive short fibers made of Ni, Fe or Ni, Fe and plated with Au are dispersed in a binder such as silicone rubber or urethane rubber. The conductive rubber is filled in the holes of the organic film 9 and is hardened by applying a magnetic field in the thickness direction of the film, so that conductive particles are arrayed in the thickness direction to achieve anisotropic conductivity in the thickness direction. It is also possible to form the conductive rubber contact 10 exhibiting the property.

In the embodiment shown in FIG. 2, the drive LSI 4 is connected by wire bonding. However, as in the other embodiment shown in FIG. 3, the electrode pads of the drive LSI 4 are made of Au, Cu or Pb /. The metal protruding electrode 14 made of Sn or the like is formed in advance, and the drive LSI 4 is connected by adhesion or soldering using a conductive paste such as Ag paste, and then the drive LSI 4 and the circuit board 5 are connected. It is also possible to connect the drive LSI 4 to the LSI connection pattern 7 and the input pattern 8 of the circuit board 5 by a so-called flip chip connection method in which the space between them is sealed by the sealing resin 13 such as epoxy resin. Further, although not shown, in connection with the drive LSI 4, the drive LSI 4 is mounted in advance with TAB (Tape Automated Bonding), and the drive LSI 4 with the TAB mounted is connected to the circuit board 5 through the LSI connection pattern 7 It is needless to say that outer lead bonding can be performed on top of the above, and various other methods can be adopted for mounting the drive LSI 4.

Particularly recently, as a mounting method corresponding to the high pixel density of the liquid crystal display device 1, a so-called chip-on-glass mounting method in which the drive LSI 4 is directly mounted on the liquid crystal electrode 2 of the liquid crystal display device 1 is adopted. Is beginning to be. The conventional inspection head structure cannot cope with such a chip-on-glass mounting method because the density of the liquid crystal electrodes 2 is higher, but the inspection head 3 according to the present invention has a problem. By adopting this structure, the liquid crystal display device 1 adopting such a chip-on-glass mounting method can be sufficiently applied to the inspection.

[0022]

[Effect of the device]

 As described above, according to the present invention, the drive LSI for driving the liquid crystal, the contact pattern formed corresponding to the liquid crystal electrodes, and the contact pattern and the drive LSI are provided on at least one main surface. A circuit board on which an LSI connection pattern for electrically connecting the electrodes of the drive circuit and an input pattern to the drive LSI are arranged, and for contacting with the liquid crystal electrode formed on the contact pattern of the circuit board. Equipped with a conductive rubber contact made of conductive rubber, it is possible to form each pattern on the circuit board with high accuracy and to prevent displacement of the liquid crystal electrode due to deformation of the liquid crystal display device against environmental changes. Therefore, it is possible to prevent the occurrence of contact failure between the liquid crystal electrode and the conductive rubber contact.

Further, the contact position accuracy between the conductive rubber contacts does not deteriorate. Furthermore, since the contactor provided corresponding to the liquid crystal electrode is made of conductive rubber, the ITO pattern, which is the liquid crystal electrode, is not damaged.

Further, since the drive LSI is directly mounted on the circuit board, the contact between the liquid crystal electrode and the drive LSI and the number of connection points are the contact between the liquid crystal electrode and the conductive rubber contact and the drive LSI electrode pad of the LSI connection pattern. Connection, it is possible to achieve the smallest number of contacts, and the connection distance from the liquid crystal electrode to the drive LSI can be shortened, so that the impedance can be reduced and the impedance balance between the electrodes can be taken. Therefore, it is possible to obtain the effects in terms of high reliability of measurement and high accuracy of measurement.

An inspection head suitable for a liquid crystal display device having a liquid crystal electrode with a narrow pitch and multiple terminals such as a liquid crystal display device having a high pixel density and a liquid crystal display device for chip-on-glass mounting. Is.

[Brief description of drawings]

FIG. 1 is a block diagram showing a structure of a liquid crystal display device inspection mechanism using an inspection head according to the present invention.

FIG. 2 is an explanatory view showing a state at the time of inspection according to the present invention and its configuration by a plan view (A) and an AA sectional view (B) in (A).

FIG. 3 is a sectional view showing a structure according to another embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of an inspection mechanism of a liquid crystal display device using an inspection head according to a conventional technique.

FIG. 5 is an explanatory view showing a state at the time of inspection and a configuration thereof according to a conventional technique by plan views (A) and a sectional view (B) taken along line BB in (A).

FIG. 6 is a sectional view showing a configuration according to another conventional technique.

[Explanation of symbols]

 1 Liquid Crystal Display Device 2 Liquid Crystal Electrode 3 Inspection Head 4 Driving LSI 5 Circuit Board 6 Contact Pattern 7 LSI Connection Pattern 8 Input Pattern 9 Organic Film 10 Conductive Rubber Contact 13 Sealing Resin 14 Projection Electrode 22 Control Circuit 24 Liquid Crystal Inspection Device

Claims (2)

[Scope of utility model registration request] 1. A liquid crystal display device is electrically connected to a liquid crystal electrode provided for connecting to a liquid crystal drive circuit, which is drawn from a pixel of the liquid crystal display device, and transmits an electric signal from the liquid crystal inspection device to the liquid crystal display device. In a test head for a liquid crystal display device, a drive LSI for driving the liquid crystal is provided on at least one main surface.
And a contact pattern formed corresponding to the liquid crystal electrode, an LSI connection pattern for electrically connecting the contact pattern and an electrode of the drive LSI, and an input pattern to the drive LSI. An inspection head for a liquid crystal display device, comprising: a circuit board; and a conductive rubber contact made of a conductive rubber formed on the contact pattern of the circuit board to contact the liquid crystal electrode. 2. The circuit board has the contact pattern, LS
The inspection head for a liquid crystal display device according to claim 1, wherein the I connection pattern and the input pattern are formed by forming at least one or more thin films on an insulating substrate.