KR20080020841A - Apparatus and method for electrode connection of display panel - Google Patents

Abstract

An apparatus and a method for connecting electrodes of a display panel are provided to bond a driving chip and a flexible substrate to an LCD(Liquid Crystal Display) panel using a single anisotropic conductive film to reduce the number of steps of an anisotropic conductive film bonding process. An apparatus for connecting electrodes of a display panel(100) includes a driving chip(131), a flexible substrate(133) and a single conductive film member(120). The display panel includes upper and lower substrates(111,113), a liquid crystal layer interposed between the upper and lower substrates, a first electrode and a second electrode. The driving chip has a first bump connected to the first electrode. The flexible substrate includes a second bump connected to the second electrode. The single conductive film member is heated and attached to the electrodes and the bumps such that the driving chip and the flexible substrate are electrically connected to each other.

Description

Apparatus and method for Electrode connection of display panel

1 is a front view illustrating an electrode connection device of a conventional display panel.

2 is a side view of FIG. 1;

3 is a front view illustrating an electrode connection device of a display panel according to an exemplary embodiment of the present invention.

4 is a side cross-sectional view of FIG. 3.

5 is a view showing an example of the bandwidth of the anisotropic conductive film for COG / FOC according to the embodiment of the present invention.

6 is an illustration of an anisotropic conductive film.

7 is a diagram illustrating an electrode connection example of a display panel according to an exemplary embodiment of the present invention.

8 is a diagram illustrating an electrode connection method of a display panel according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100 liquid crystal panel 111 upper substrate

113: lower substrate 115: upper polarizing plate

117 lower polarizing plate 120 anisotropic conductive film

121: conductive particles 122: insulating adhesive

131: driving chip 133: flexible substrate

113a, 113b: electrode 132, 134: bump

The present invention relates to an electrode connection device of a display panel and a method thereof.

The coupling between the lead line of the semiconductor chip or the liquid crystal display and the connection portion of the driving circuit thereof forms a bump or uses a carrier tape. However, this method is inadequate to form more detailed connecting portions. Thus, an anisotropic conductive film capable of improving this has become widely used as a material for electrically connecting electronic components such as semiconductor devices and circuit boards.

The use of anisotropic conductive films is becoming more diversified in accordance with the trend toward thinner and shorter electronic components. In recent years, computer monitors as well as televisions have become thinner and thinner. A connection method using an anisotropic conductive film (ACF) is widely used. In addition, in particular, the use of ACF in LCD mounting technology is intensifying, and a method of directly mounting a semiconductor circuit on a film or a glass substrate by a COF (Chip On Film) or COG (Chip on Glass) method is also rapidly developing.

1 and 2 are a front view and a side cross-sectional view showing an electrode connection device of a conventional liquid crystal display module.

Referring to FIGS. 1 and 2, the LCD panel 10 includes a lower substrate 13 on which gate lines, data lines, thin film transistors, and pixel electrodes are formed, and a color filter and a common electrode are formed to face the lower substrate 13. Upper substrate 11 and a liquid crystal layer (not shown) filled between the upper and lower substrates. Upper and lower polarizers 15 and 17 may be attached to both surfaces of the upper and lower substrates 11 and 13.

In addition, the driving chip 23 is connected to the first electrode of the lower substrate 17 using a first anisotropic conductive film (ACF) 21, and the flexible substrate 27 has a lower end 29. The bump portion is connected to the second electrode of the lower substrate 17 by using the second anisotropic conductive film 25.

Here, the time, temperature, and pressure applied to the first and second anisotropic conductive films 21 and 25 respectively attached to the lower substrate 13 are appropriately supplied to the first and second anisotropy to the lower substrate 17. By heat-compressing the conductive films 21 and 25, respectively, the drive chip 23 and the flexible substrate 27 are connected to the lower substrate 13, respectively.

However, since two anisotropic conductive films 21 and 25 are attached to the conventional liquid crystal display module in order to mount the driving chip 23 and the flexible substrate 27, the manufacturing process of the liquid crystal display device is increased. there is a problem.

The present invention provides an electrode connecting device of a display panel and a method thereof.

The present invention provides an electrode connecting device for a display panel and a method thereof in which a driving chip and a flexible substrate can be connected to a liquid crystal panel using one anisotropic conductive film.

An electrode connection device of a display panel according to an exemplary embodiment of the present invention includes a display panel in which liquid crystal is filled between upper and lower substrates, and first and second electrodes are formed on one side thereof; A driving chip having a first bump connected to the first electrode; A flexible substrate having a second bump connected to the second electrode; And a single conductive film member that is heat-pressed between the electrode and the bump to electrically connect the driving chip and the flexible substrate.

An electrode connecting method of a display panel according to an exemplary embodiment of the present invention includes: cleaning a junction of a liquid crystal panel on which first and second electrodes are formed; Attaching an anisotropic conductive film to the bonding portion of the liquid crystal panel; Arranging bumps of a driving chip on a first electrode on the anisotropic conductive film and heating and compressing them under driving chip connection conditions; And aligning the bumps of the flexible substrate on the anisotropic conductive film to the second electrode and heat-compressing them under the flexible substrate connection conditions.

An electrode connection device of a display panel according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

3 is a front view illustrating an electrode connection device of a liquid crystal display according to an exemplary embodiment of the present invention, FIG. 4 is a side cross-sectional view of FIG. 3, and FIG. 5 is an example of allocating a band width of an anisotropic conductive film according to an exemplary embodiment of the present invention. 6 is a diagram illustrating an anisotropic conductive film, and FIG. 7 is a diagram illustrating an electrode connection example of a liquid crystal display according to an exemplary embodiment of the present invention.

3 and 4, a driver chip 131 for driving the panel and a flexible substrate (FPCB) 133 for interfacing with the outside are attached to the liquid crystal panel 100, and the backlight unit is attached to the liquid crystal panel 100. (Not shown) will be assembled.

The liquid crystal panel 100 includes a lower substrate 113 on which gate lines, data lines, thin film transistors, pixel electrodes, etc. are formed, and an upper substrate 111 facing the color filter, a common electrode, etc .; And a liquid crystal layer (not shown) that is filled between the upper and lower substrates 111 and 113. Upper and lower polarizers 115 and 117 may be attached to both surfaces of the upper and lower substrates 111 and 113.

In order to drive the liquid crystal panel 100, a driving chip 131 is mounted on one side of the lower substrate 113, and the driving chip 131 is used for an interface between the driving chip and the main substrate (not shown). On the outside, a flexible substrate 133 is mounted.

In this case, a single anisotropic conductive film (ACF) 120 is attached to the plurality of electrodes (ITO: Indium Tin Oxide) junctions formed on the lower substrate 113, and the driving chip 131 and the anisotropic conductive film 120 are disposed on the lower substrate 113. The flexible substrate 133 is mounted through heat compression.

The driving chip attaching process is referred to as a chip on glass (COG) process, and the flexible substrate attaching process is called a film on glass (FOG) process, and the driving chip 131 using a single anisotropic conductive film 120. And the flexible substrate 133 on the lower substrate 113.

As shown in FIG. 5, the width a of the anisotropic conductive film 120 is the driving chip 131 so that the driving chip 131 and the flexible substrate 133 may be attached to one anisotropic conductive film 120. And larger than the sum of the bump pad portions of the flexible substrate 133.

The band width b of the band width a of the anisotropic conductive film 120 to be used by the driving chip 131 is allocated based on the driving chip width, and the band width c of the flexible substrate 133 is to be used. The bump pad portion 135 may be allocated based on the width of the bump pad portion 135. For example, when a 3 mm band width is used as the anisotropic conductive film for the driving chip and a band width of the anisotropic conductive film for the flexible substrate is 1 mm, the mounting of the drive chip and the flexible substrate is performed with one anisotropic conductive film for the driving chip having a 4 mm band width. It becomes possible.

As shown in FIG. 6, the anisotropic conductive film 120 is a conductive material composed of a metal particle and a particle deformed by pressure in an insulating adhesive 122 having a resin component having an epoxy group and a resin component which helps film formation as a main component. It consists of particles 121. Here, the conductive particles 121 may be contained in the insulating adhesive in such a number that sufficient number of conductive particles may contribute to the connection between the bumps and the electrodes in order to obtain proper electrical conductivity between the bumps and the electrodes.

A peeling film 125 and a transparent film 124 are attached to both surfaces of the anisotropic conductive film 120 as a protective film, and are removed in the mounting process of the driving chip and the flexible substrate on the lower substrate.

This invention mounts a drive chip and a flexible board | substrate simultaneously using the anisotropic conductive film for drive chips, for example, makes it contain the conductive particle in the dispersion density of 20,000-50,000 piece / mm <^2> . Alternatively, the anisotropic conductive film may be formed at a dispersion density at which at least 5 to 6 conductive particles may be present in one bump pad. The size and number of conductive particles of the anisotropic conductive film for the driving chip may vary depending on the width of the driving chip bumper pad (eg, about 30 μm).

7 is a view illustrating an electrode connection device of a liquid crystal panel according to an exemplary embodiment of the present invention.

Referring to FIG. 7, the anisotropic conductive film 120 is attached to a junction where the first electrode 113a and the second electrode 113b of the lower substrate 113 are formed. In this case, the release film is removed and then bonded to the first electrode 113a and the second electrode 113b using an insulating adhesive of the anisotropic conductive film.

When the anisotropic conductive film 120 is attached, the driving chip 131 or the flexible substrate 133 is attached. In this case, the driving chip 131 may be mounted first, and then the flexible substrate 133 may be mounted later, and may be mounted in the reverse order or simultaneously.

After aligning the bumps 132 formed below the driving chip 131 to the first electrode position, the bumps 132 of the driving chips 131 by heat pressing the liquid crystal panel by a heat pressing device (not shown). The conductive particles 121 of the anisotropic conductive film 120 are connected to the first electrode 113a of the lower substrate 113.

Here, when the pressure of the liquid crystal panel is heat-compressed, if the pressure is too weak, the force for uniformly crushing the conductive particles 121 of the anisotropic conductive film 120 may be insufficient, and if the pressure is too high, the liquid crystal panel may be broken, and thus anisotropic The input condition of the heat compression equipment is adjusted in consideration of temperature, pressure, and time according to the physical condition of the conductive film 120.

At this time, as a connection condition of the driving chip 131, a pressure of 17 to 23 kgf / mm ² is supplied to the liquid crystal panel in a temperature range of 200 to 220 ° C. for 5 to 7 seconds, followed by heat compression, thereby The bump 132 is electrically connected to the first electrode 113a formed on the lower substrate 113.

After the bumps 134 formed below the flexible substrate 133 are aligned at the second electrode position, the liquid crystal panel is heat-compressed by a heat compression apparatus (not shown) to mount the flexible substrate 133. do.

At this time, as a connection condition of the flexible substrate, the bumps 134 of the flexible substrate 133 by supplying a pressure of 17 to 23 kgf / mm ² for 15 to 20 seconds in a temperature range of 170 to 190 ° C to the liquid crystal panel, followed by heat compression. ) Is connected to the second electrode 113b formed on the lower substrate 113.

8 is a flowchart illustrating an electrode connection method of a display panel according to an exemplary embodiment of the present invention.

Referring to FIG. 8, the first and second electrode junctions formed on the liquid crystal panel are cleaned (S101). After bonding the anisotropic conductive film to the electrode junction region of the liquid crystal panel (S103), the bumps of the driving chips are aligned with the corresponding first electrodes, and then heat-compression-bonded using a heat compression apparatus, and the driving chips are attached to the lower substrate. It is mounted (S105). At this time, by heat-compression-bonding with respect to the liquid crystal panel with a said drive chip, it is adhere | attached by the insulating adhesive of an anisotropic conductive film between the bump of the said drive chip, and the 1st electrode of a liquid crystal panel, and is electrically connected by electroconductive particle.

After the bumps of the flexible substrate are aligned with the corresponding second electrodes, the flexible substrates are heat-compressed using a heat compression apparatus to mount the flexible substrate on the lower substrate (S107). At this time, by heat-compression-bonding with respect to the liquid crystal panel with a said flexible substrate, it adhere | attaches with the insulating adhesive of an anisotropic conductive film between the bump of the said flexible substrate, and the 2nd electrode of a lower board | substrate, and is electrically connected by electroconductive particle.

In this way, the drive chip and the flexible substrate are mounted on the lower substrate by using one anisotropic conductive film, so that the process of attaching the anisotropic conductive film is reduced.

Although the present invention has been described above with reference to the embodiments, these are only examples and are not intended to limit the present invention, and those skilled in the art to which the present invention pertains may have an abnormality within the scope not departing from the essential characteristics of the present invention. It will be appreciated that various modifications and applications are not illustrated. For example, each component shown in detail in the embodiment of the present invention may be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

According to the electrode connection device and the method of the display panel according to the present invention, it is possible to shorten the attaching process of the anisotropic conductive film by allowing the driving chip and the flexible substrate to be bonded to the liquid crystal panel using one anisotropic conductive film. have.

Claims (11)

A display panel in which liquid crystal is filled between upper and lower substrates, and first and second electrodes are formed on one side; A driving chip having a first bump connected to the first electrode; A flexible substrate having a second bump connected to the second electrode; And a single conductive film member heated and pressed between the electrode and the bump to electrically connect the driving chip and the flexible substrate. The method of claim 1,  And the conductive film member comprises an anisotropic conductive film made of an insulating adhesive and conductive particles. The method of claim 2, The electrode connection device of a display panel, wherein the conductive particles are formed with a dispersion density of 20,000 to 50,000 pieces / mm ² . The method of claim 1, The electrode connecting device of the display panel for applying a pressure of 17 ~ 23kgf / mm ² for 5 seconds to 7 seconds in the temperature range of 200 ~ 220 ℃ to the drive chip for the connection of the driving chip. The method of claim 1, Electrode connection device of the display panel for applying a pressure of 17 ~ 23kgf / mm ² for 15 seconds in the temperature range of 170 ~ 190 ℃ to the display panel for the connection of the flexible substrate. Cleaning the junctions of the display panel on which the first and second electrodes are formed; Attaching an anisotropic conductive film to a junction portion of the display panel; Arranging bumps of a driving chip on a first electrode on the anisotropic conductive film and heating and compressing them under driving chip connection conditions; And arranging the bumps of the flexible substrate on the anisotropic conductive film to the second electrode and performing heat compression on the flexible substrate connection conditions. The method of claim 1,  And the anisotropic conductive film is larger than the sum of the width of the driving chip and the width of the panel bump pad. The method of claim 2, Electroconductive connection method of the display panel of which the electroconductive particle of the said anisotropic conductive film is formed by the dispersion density of 20,000-500,000 / mm <^2> . The method of claim 1, The connection condition of the driving chip is a electrode panel connecting method of the display panel heat-compression pressed at a pressure of 17 ~ 23kgf / mm ² for 5-7 seconds in the temperature range of 200 ~ 220 ℃. The method of claim 1, The connection condition of the flexible substrate is an electrode connection method of the display panel heat-compression pressed at a pressure of 17 ~ 23kgf / mm ² for 15 to 20 seconds in the temperature range of 170 ~ 190 ℃ with respect to the display panel. The method of claim 6, A method of connecting electrodes of a display panel in which a driving chip or a flexible substrate is first mounted after the anisotropic conductive film is attached.

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