KR100726529B1 - Printed circuit board with easy discernment of connection and liquid crystal dispaly using the same - Google Patents

Abstract

The present invention relates to a printed circuit board and a liquid crystal display using the same. According to the present invention, An electrode pad region formed on the base substrate; A through hole formed in at least one of the pads forming the electrode pad region; And a transparent layer injected into the through hole. As a result, when the printed circuit board is connected using the anisotropic conductive film, the pressed state of the conductive particles located between the connection electrode pads can be easily confirmed.

A printed circuit board, a liquid crystal display, an anisotropic conductive film

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board and a liquid crystal display using the printed circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further the understanding of the technical idea of the invention, And should not be construed as limiting.

1 is a plan view showing a general LCD module.

2 is a cross-sectional view taken along the line II-II 'of FIG. 1;

3 is a cross-sectional view taken along line III-III 'of FIG.

4 is a plan view of a printed circuit board according to a preferred embodiment of the present invention.

5 is a sectional view showing a printed circuit board according to a preferred embodiment of the present invention.

6 is a cross-sectional view showing a printed circuit board according to another embodiment of the present invention.

7 is a perspective view schematically showing a liquid crystal display device according to another aspect of the present invention.

Description of the Related Art

100, 200 ... printed circuit board 130 ... substrate

140, 240 ... electrode 150, 250 ... through hole

160, 260 ... transparent layer 210 ... internal substrate

220 ... insulating adhesive layer 230 ... upper substrate

300 ... LCD panel 400 ... TCP

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board and a liquid crystal display using the same. More particularly, the present invention relates to a printed circuit board which can confirm the connection state of an anisotropic conductive film And a liquid crystal display using the same.

In general, an anisotropic conductive film (ACF) is a connecting material used when the material of the member to be connected is special or the pitch of the signal wiring is fine and the member and the member can not be attached in a soldering manner . Such anisotropic conductive film is typically used as a connection material for packaging an LCD panel, a printed circuit board (PCB), a driving IC, and the like in an LCD module.

In the LCD panel, a plurality of driving ICs are mounted to drive TFT (Thin Film Transistor) patterns. The driving ICs are largely mounted on the LCD panel through a chip carrier (COG) mounting method, which is a method of mounting the driver IC on the gate area and data area of the LCD panel, and a tape carrier package (TCP) And a TAB (Tape Automated Bonding) mounting method, which is a method of indirectly mounting a driving IC on the gate region and the data region of the TFT.

It is difficult to use means such as soldering because electrodes on the driving IC element side and electrodes on the LCD panel side are formed at minute pitch intervals. For this reason, an anisotropic conductive film is used to electrically connect electrodes on the driver IC side, electrodes on the panel side, and electrodes on the printed circuit board.

FIG. 1 is a plan view showing an LCD module according to a general TAB method, and FIG. 2 is a sectional view taken along the line II-II 'in FIG. 1 and 2, a source-side printed circuit board 10 for transferring an external signal to the LCD panel 20 is disposed in the row direction of the LCD panel 20, and a TCP (30) electrically connects the panel (20) and the printed circuit board (10). At this time, the anisotropic conductive film 40 is connected between the LCD panel 20 and the TCP 30 and between the TCP 30 and the printed circuit board 10.

The anisotropic conductive film 40 is formed by dispersing conductive particles in an insulating adhesive, and is interposed between the objects to be connected and thermocompression-bonded, so that the conductive particles come into contact with each other between the opposed terminals to make an electrical connection. That is, it is a connecting material that maintains its insulating property on the x-y plane and has conductivity on the z-axis. 3, which is a cross-sectional view taken along the line III-III 'in Fig. 1, the insulating adhesive component 41 and the insulating adhesive component 41 are provided between the TCP 30 and the printed circuit board 10 An anisotropic conductive film 40 including a plurality of dispersed conductive particles 42 is interposed. The electrodes 32 and 14 opposed to the conductive particles 42 interposed between the electrodes 32 of the TCP 30 and the electrodes 14 of the printed circuit board 10 are pressed against each other at a predetermined temperature and pressure, Respectively.

In order to confirm the electrical connection state by the anisotropic conductive film 40 as described above, it is most common to observe the breakage or the pressed shape of the conductive particles 42 with a microscope. Here, since the connecting portion between the LCD panel 20 and the TCP 30 is made of a transparent ITO electrode at the connecting portion of the panel, it is possible to observe the pressing of the conductive particles 42. However, direct observation was impossible because the connection portion between the printed circuit board 10 and the TCP 30 is an opaque metal electrode. Therefore, until now, when the anisotropic conductive film 40 is pressed by the compression tool bar, the depth or regularity of the crushing marks on the TCP 30 is observed by high-temperature and high-pressure compression to empirically judge the state of pressing the conductive particles .

However, this conventional method has a problem in that it causes a large defect in a process of a mass production system which is high-speed and large-sized because it is a defect detection method by empirical data.

SUMMARY OF THE INVENTION The present invention has been devised to solve the problems described above, and it is an object of the present invention to provide a printed circuit board capable of easily confirming the state of pressed conductive particles placed between connection electrode pads when connecting an printed circuit board using an anisotropic conductive film The purpose of that is to do.

Another object of the present invention is to provide a liquid crystal display device using such a printed circuit board.

According to an aspect of the present invention, there is provided a printed circuit board including: a base substrate; An electrode pad region formed on the base substrate; A through hole formed in at least one of the electrode pads forming the electrode pad region; And a transparent layer injected into the through hole.

According to another embodiment of the present invention, there is provided a plasma display panel comprising: an upper substrate having an electrode pad region; A plurality of inner substrates which are sequentially stacked on one side of the upper substrate and in which an inner layer circuit is formed; An insulating adhesive layer interposed between the upper substrate and the inner substrate or between layers of a plurality of inner substrates; A through hole penetrating through the upper substrate, the inner substrate, and the insulating adhesive layer from the surface of the electrode pad to at least one of the electrode pads forming the electrode pad region; And a transparent layer injected into the through hole.

The transparent layer may be made of a transparent resin.

According to another aspect of the present invention, there is provided an LCD panel including a TFT substrate and a color filter substrate attached to the TFT substrate through a liquid crystal; A printed circuit board comprising: a base substrate; and an electrode pad region formed on the base substrate; A through hole formed in at least one of the electrode pads forming the electrode pad region; A transparent layer injected into the through hole; And a driving IC for driving the LCD panel by electrically connecting the LCD panel and the printed circuit board.

According to another embodiment of the present invention, there is provided an LCD panel including a TFT substrate and a color filter substrate attached to the TFT substrate through a liquid crystal; And an insulating adhesive layer interposed between the upper substrate and the inner substrate or between the layers of the inner substrates, the upper substrate having an electrode pad area formed thereon, the inner substrate being laminated on one side of the upper substrate, A printed circuit board; A through hole penetrating through the upper substrate, the inner substrate, and the insulating adhesive layer from the surface of the electrode pad to at least one of the electrode pads forming the electrode pad region; A transparent layer injected into the through hole; And a driving IC for driving the LCD panel by electrically connecting the LCD panel and the printed circuit board.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

4 is a plan view showing a printed circuit board 100 according to a preferred embodiment of the present invention.

4, the printed circuit board 100 according to the present embodiment includes a base substrate 130, an electrode pad region 140 formed on the base substrate 130, an electrode pad 140 constituting an electrode pad region 140, And a transparent layer 160 filled in the through hole 150. The through hole 150 is formed in the through hole 150,

The base substrate 130 is a main body of the printed circuit board 100 and is generally formed by laminating a copper foil on a substrate made of an insulating material such as paper-phenol resin or glass-epoxy resin.

The electrode pad region 140 is formed at one end of the base substrate 130, and is electrically connected to an electronic component such as an LCD panel. Generally, the printed circuit board 100 and the driving IC or TCP provided on the LCD panel are connected as an anisotropic conductive film. On the electrode pads 141 constituting the electrode pad region 140, conductive particles existing in the anisotropic conductive film . As a result, each of the electrode pads 141 becomes a substantially electrical connection with an electronic component such as a driving IC.

The through holes 150 are formed in at least one of the electrode pads 141 constituting the electrode pad region 140. That is, the electrode pad 141 from the upper surface of the electrode pad 141 and the base substrate 130 which is in contact with the electrode pad 141.

In the through hole 150, a transparent layer 160 is formed. The transparent layer 160 may be made of a transparent resin. And can be formed by injecting a transparent resin into the through hole (150). Thus, even in a printed circuit board made of an opaque metal material, it is possible to confirm whether or not the conductive particles are sufficiently interposed, cracked, or pressed on the electrode pad 140 region through the transparent layer 160.

Fig. 5 is a cross-sectional view showing a state in which the printed circuit board 100 according to Fig. 4 is connected.

Referring to Fig. 5, the printed circuit board according to the present embodiment is connected to another connected member such as the TCP 30 and the anisotropic conductive film 40. Fig. The conductive particles 42 in the anisotropic conductive film 40 are interposed between the electrode pads 141 of the printed circuit board 130 and the electrodes 32 of the TCP 30 to electrically connect them. At this time, the inside of the anisotropic conductive film 40 can be confirmed through the transparent layer 160 formed on some of the electrode pads 141. Therefore, even if the printed circuit board 100 is entirely opaque, the portion of the electrode pad 141 that needs to be checked can be observed, and the connection state of the printed circuit board 100 can be easily confirmed.

6 is a cross-sectional view showing a state in which the printed circuit board 200 according to another embodiment of the present invention is connected to another member to be connected.

6, the printed circuit board 200 according to the present embodiment includes an upper substrate 230 having an electrode pad region 240, a plurality of internal substrates 210 mounted on one surface of the upper substrate 230, An insulating adhesive layer 220 interposed between the upper substrate 230 and the inner substrate 210 and at least one of the electrode pads 241 forming the electrode pad region 240 A through hole 250 provided in at least one of the through holes 250, and a transparent layer 260 formed in the through hole 250.

The upper substrate 230 is an actual base substrate and is directly connected to another connected member. This can be made of the same material as the base substrate 130 described above.

The electrode pad region 240 is formed on the upper substrate 230 and is electrically connected to an electronic component such as the TCP 30 provided on an LCD panel. In general, the print circuit board 200 and the driving IC or TCP 30 provided on the LCD panel are connected by the anisotropic conductive film 40. On the electrode pads 241 constituting the electrode pad area 240, Conductive particles 42 existing in the film 40 are interposed. As a result, each electrode pad 241 becomes a substantial electrical connection with an electronic component such as a driving IC or TCP 30. [

The inner substrate 210 has a substantially multilayer structure of the printed circuit board 200, and an internal circuit is formed on the upper surface and / or the lower surface thereof.

The insulating adhesive layer 220 is interposed between the upper substrate 230 and the inner substrate 210 or between the layers of the plurality of inner substrates 210 to insulate and adhere the substrates 210 and 230 to the printed circuit board 200 are formed in multiple layers.

The through holes 250 are formed on at least one of the electrode pads 241 and are formed on one surface of the upper substrate 230 and the upper substrate 230 on which the electrode pads 241 are formed on the upper surface of the electrode pads 241 And is penetrated through a plurality of inner substrates 210 and an insulating adhesive layer 220 formed in multiple layers.

A transparent layer 260 is formed in the through hole 250. The transparent layer 260 may be made of a transparent resin. And the transparent resin is injected into the through hole 250. [ Thus, it is possible to confirm whether the conductive particles 42 are sufficiently intervened, cracked or pressed on the electrode pad 241 through the transparent layer 260 in the printed circuit board 200 made of opaque metal.

7 is an exploded perspective view illustrating a liquid crystal display according to a preferred embodiment of the present invention.

7, the liquid crystal display according to the present embodiment includes an LCD panel 300, a printed circuit board 500 for transmitting an electrical signal to the LCD panel 300, an LCD panel 300 and a printed circuit board 500, And a TCP 400 for driving the LCD panel 300.

The LCD panel 300 receives an external electrical signal to display information. The LCD panel 300 includes a TFT substrate 310 and a color filter substrate 320 adhered to the TFT substrate 310. On the TFT substrate 310, a plurality of gate lines 311 are arranged along the width direction, and a plurality of data lines 312 are arranged along the length direction. Gate and data input pads 314 and 315 are arranged at one end of the gate and data lines 311 and 312.

The printed circuit board 500 includes a gate printed circuit board 510 connected to the gate input pad 315 via the TCP 400 and a source printed circuit board 510 connected to the data input pad 314 by the TCP 400. [ (520). The gate and source printed circuit board 500 is a single layer or multilayer printed circuit board 100, 200 having through holes formed in the electrode pad portions as described above and having a transparent layer. A duplicate description thereof will be omitted.

The TCP 400 includes a base film 410 and a driving IC 420 mounted on the base film 410 to drive the gate lines 311 and the data lines 312. An output lead 411 connected to the gate of the LCD panel 300 and the data input pads 314 and 315 and output leads 412 connected to the electrode pads of the printed circuit board 500 are formed on the base film 410, .

Although the driving IC 410 is installed in the TAB mode using the TCP 400, the driving IC 410 may be installed in the COG mode, which is directly mounted without using the TCP 400 Should be understood.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

As described above, according to the present invention, when the printed circuit board is connected by using the anisotropic conductive film, the pressed state of the conductive particles located between the connection electrode pads can be easily confirmed. As a result, it is possible to perform an easy crimping quality inspection in an adhering process of a printed circuit board which is roughly squeezed, thereby reducing process defects and quality defects over time, and securing stable quality of electronic equipment using a printed circuit board .

Claims (7)

A base substrate; An electrode pad region formed on the base substrate; At least one of the electrode pads forming the electrode pad region has a through hole penetrating from the surface of the electrode pad to the surface of the lower surface of the base substrate through the electrode pad and the base substrate; And And a transparent layer injected into the through hole. An upper substrate having an electrode pad region; A plurality of inner substrates which are sequentially stacked on one side of the upper substrate and in which an inner layer circuit is formed; An insulating adhesive layer interposed between the upper substrate and the inner substrate or between layers of a plurality of inner substrates; A through hole penetrating through the upper substrate, the inner substrate, and the insulating adhesive layer from the surface of the electrode pad to at least one of the electrode pads forming the electrode pad region; And And a transparent layer injected into the through hole. 3. The method according to claim 1 or 2, Wherein the transparent layer is made of a transparent resin. An LCD panel including a TFT substrate and a color filter substrate attached to the TFT substrate through a liquid crystal; A printed circuit board comprising: a base substrate; and an electrode pad region formed on the base substrate; At least one of the electrode pads forming the electrode pad region has a through hole penetrating from the surface of the electrode pad to the surface of the lower surface of the base substrate through the electrode pad and the base substrate; A transparent layer injected into the through hole; And And a driving IC electrically connecting the LCD panel and the printed circuit board to drive the LCD panel. An LCD panel including a TFT substrate and a color filter substrate attached to the TFT substrate through a liquid crystal; And an insulating adhesive layer interposed between the upper substrate and the inner substrate or between the layers of the inner substrates, the upper substrate having an electrode pad area formed thereon, the inner substrate being laminated on one side of the upper substrate, A printed circuit board; A through hole penetrating through the upper substrate, the inner substrate, and the insulating adhesive layer from the surface of the electrode pad to at least one of the electrode pads forming the electrode pad region; A transparent layer injected into the through hole; And And a driving IC electrically connecting the LCD panel and the printed circuit board to drive the LCD panel. The method according to claim 4 or 5, Wherein the driving IC circuit is mounted on the TCP to electrically connect the LCD panel and the printed circuit board. The method according to claim 4 or 5, Wherein the transparent layer is made of a transparent resin.

Images