JPH10260425A - Circuit board and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the liquid crystal display device which can securely be connected to only corresponding electrodes and is improved in yield. SOLUTION: A driving circuit part for driving the liquid crystal display panel of the liquid crystal display device consists of TCPs(tape carrier package) 2 which are arranged on the liquid crystal panel and a driving circuit board 3 which is connected to the TCPs 2. A driving circuit part 3 is constituted by mounting various electric components on a printed board 6 and providing beltlike lower electrodes 7 which are exposed in the external surface side by side. An insulating restriction part 8 is laminated and formed covering some of the lower electrodes 7. The TCPs 2 and driving circuit board 3 are pressed holding an anisotropic conductive film 9 containing conductive particles in between. Even if they shift in position when pressed, the restriction part 8 which projects to between lead parts 5 restricts their movement to hold the opposition state of the lower electrodes 7 and upper electrodes 5, and consequently secure connection is made to improve the yield.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board and a liquid crystal display device in which a pair of substrates having a plurality of electrodes are bonded and fixed with a thin film having conductive particles.

[0002]

2. Description of the Related Art Conventionally, as a liquid crystal display device, for example, FIG.
The configuration shown in FIG. 5 and the configuration shown in FIG. 6 are known. The liquid crystal display device shown in FIGS. 4 and 5 includes a display area having a plurality of display pixels on a glass substrate (not shown), and a flat liquid crystal display panel having a plurality of electrodes exposed on the periphery at the periphery. And a drive circuit section 1 for driving the liquid crystal display panel. The drive circuit unit 1 has a plurality of TCPs (Tape Carrier Packages) 2 mounted on the flexible tape 4 along with the periphery of the liquid crystal display panel by mounting electrical components such as LSIs by gang bonding. And a drive circuit board 3 which is a printed circuit board which is electrically and mechanically connected to and drives the TCP 2.

The electrodes of the liquid crystal display panel and the TC
An upper electrode 5 which is exposed on the outer surface of P2 and is a plurality of electrodes arranged side by side along the peripheral edge on one end side, and an upper electrode 5 and a drive circuit board 3 arranged on the other side along the peripheral edge on the other end side of TCP2. Lower electrode 7 which becomes a plurality of electrodes arranged in parallel along the periphery of
Is an anisotropic conductive film containing conductive particles
Conductive Film (ACF) 9 is used for bonding and electrically and mechanically connected.

[0006] In the liquid crystal display device shown in FIG. 6, an insulating protective film 10 is provided between the lower electrodes 7 of the drive circuit board 3 to prevent a short circuit between the upper electrode 5 and the lower electrode 7.

The connection between the liquid crystal display panel and the TCP 2 and the connection between the driving circuit board 3 and the TCP 2 are performed by making the corresponding electrodes and the upper electrode 5 and the upper and lower electrodes 5 and 7 face each other. The overlapping portions are positioned with the film 9 interposed therebetween, and the overlapping portions are pressurized while heating. By this heating and pressurizing, the adhesive of the anisotropic conductive film 9 is melted, and the opposing electrode and the upper electrode 5, respectively,
The conductive particles of the anisotropic conductive film 9 are interposed between the upper electrode 5 and the lower electrode 7 and are electrically connected to each other. Display panel and TCP2, drive circuit board 3 and TCP
2 is fixedly bonded.

[0006]

By the way, when the connection between the liquid crystal display panel and the drive circuit board 3 is performed by heating and pressurizing with the TCP2, the pressurizing and pressurizing are performed by using a heater tool as a heating jig. , to pressurize a normal 20 kg / cm ² or more, when crimping a plurality of TCP2 is 1
A pressure of 00 kgf or more is required. For this reason, the entire crimping device is distorted, and the heater tool rattles and the TCP
2 may be displaced, and the position of the electrode of the liquid crystal display panel and the corresponding upper electrode 5 of the TCP 2 or the position of the lower electrode 7 of the drive circuit board 3 and the corresponding upper electrode 5 of the TCP 2 may be shifted. .

Further, the anisotropic conductive film 9 interposed between the electrode and the upper electrode 5 or between the upper electrode 5 and the lower electrode 7 is melted by the heating at the time of pressing, and the TCP 2 and the liquid crystal display panel or the drive circuit board are melted. The interface with 3 is slippery,
There is a risk of displacement. Furthermore, the liquid crystal display panel and the drive circuit board 3 may be thermally expanded due to the heating at the time of pressure bonding, which may cause displacement. Due to these displacements, there is a problem that the yield that causes display defects may be reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a circuit board and a liquid crystal display device in which only corresponding electrodes are reliably connected and the yield is improved.

[0009]

SUMMARY OF THE INVENTION The present invention is directed to a pair of opposed substrates, electrodes provided on a plurality of opposed surfaces of the substrates, and opposed to each other with a gap therebetween, and at least one of the substrates is connected to the other substrate. A regulating portion having an insulating property protruding between the adjacent electrodes, and a thin film having conductive particles positioned between the substrates and electrically connecting the opposed electrodes, and adhesively fixing the substrate. It is provided with. Then, a plurality of opposing electrodes are provided on the opposing surface with a gap therebetween, and at least one of a pair of substrates adhered and fixed with a thin film having conductive particles electrically connecting only the opposing electrodes to the other, Since the regulating portion having an insulating property protrudes between the adjacent electrodes of the substrate, even if the substrate relatively moves when the thin film is bonded and fixed, the regulating portion abuts on the adjacent electrode of the other substrate. Stipulate movement.
The opposing state of the corresponding electrodes is maintained, the positional displacement of the electrodes is prevented, and the connection is ensured without the occurrence of a connection failure, thereby improving the yield.

The regulating portion is provided at a position where a pair of electrodes corresponding to an electrode adjacent to the opposing electrode of the other opposing substrate opposes. And, a regulating portion protruding between adjacent electrodes of the other substrate,
Since a pair of electrodes corresponding to the electrode adjacent to the opposing electrode of the other substrate are positioned so as to oppose each other, even if the position of the opposing electrode is shifted and regulated by the regulating unit, Since the facing state of the corresponding electrodes is maintained, the corresponding electrodes are securely connected and the yield is improved.

The present invention further includes a circuit board according to claims 1 and 2, and a liquid crystal display panel connected to the circuit board. Since the liquid crystal display panel is connected to the circuit board according to the first and second aspects of the present invention, the corresponding electrodes are reliably connected to each other, so that the liquid crystal display is reliably performed without causing a liquid crystal display defect.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the liquid crystal display device of the present invention will be described with reference to the drawings.

Parts corresponding to those in the conventional example shown in FIGS. 4 and 5 will be described with the same reference numerals.

As shown in FIG. 1, a drive circuit section 1 as a circuit board drives a liquid crystal display panel of a liquid crystal display device, for example, and a plurality of TCPs (Tape) arranged along the periphery of the liquid crystal display panel. Carrier Package) 2 and these T
And a drive circuit board 3 of a printed circuit board which is electrically and mechanically connected to the CP 2 and drives the TCP 2.

The TCP 2 is configured by mounting an electrical component such as an LSI on a flexible tape 4 such as a polyimide tape as a substrate by gang bonding. Further, the TCP 2 is provided with a plurality of band-shaped upper electrodes 5 as electrodes exposed on the outer surface in parallel along the periphery.

On the other hand, the drive circuit board 3 is configured by mounting various electric components on a printed board 6 as a board on which a pattern (not shown) is formed. The printed board 6 is provided with a plurality of strip-shaped lower electrodes 7 as electrodes exposed on the outer surface in parallel along the periphery. Also,
The printed circuit board 6 is provided with an insulating regulating portion 8 that covers the lower electrode 7 from one side in the longitudinal direction to a part of the upper surface.

Then, the TCP 2 and the drive circuit board 3
An anisotropic conductive film (ACF) 9 which is a thin film containing conductive particles (not shown) is bonded and fixed with an intervening film. The anisotropic conductive film 9 has a thickness of about 0.03 mm in which an adhesive contains metal particles such as nickel or conductive particles such as spherical plastic having a metal coating such as nickel on the surface. It is an optical thin film, sandwiched between a portion of the TCP 2 on which the upper electrode 5 is provided and a portion of the drive circuit board 3 on which the lower electrode 7 is provided, and is adhered and fixed by heating and pressing. The corresponding upper electrode 5 and lower electrode 7 are electrically connected to each other.

The upper electrode 5 and the lower electrode 7 are separated from each other by the conductive particles, for example, about 0.01 mm in diameter.
TCP2 that opposes via a gap of mm and opposes the regulating part 8
Project between the upper electrodes 5. And
The restricting portion 8 has a first contact portion 8a which can contact one side of the upper electrode 5 of the TCP 2 corresponding to the lower electrode 7 to be covered, and a first contact portion 8a which can contact the upper electrode 5 adjacent to the corresponding upper electrode 5. A second abutting portion 8b that abuts.

That is, the restricting portion 8 is partially formed on the surface side of the lower electrode 7 so as to protrude between the upper electrodes 5 and is formed so as to be thicker than the diameter of the conductive particles. Further, as shown in FIG. 2 and FIG. 3, when the first contact portion 8 a and the second contact portion 8 b contact the upper electrode 5, the regulating portion 8 moves between the TCP 2 and the drive circuit board 3. As shown in FIG. 3, when the second contact portion 8b contacts the upper electrode 5 adjacent to the opposing upper electrode 5, the upper electrode 5 and the lower electrode 7 oppose each other. The opposing area is formed so as to be an area necessary for connection by the conductive particles.

For example, the length dimension of the lower electrode 7 is 2
mm, the pitch of the lower electrode 7 is 0.6 mm, the width L of the upper electrode 5 is 0.3 mm, the length of the upper electrode 5 is 2 mm, and the upper electrode 5 necessary for connection by the anisotropic conductive film 9 is formed. Lower electrode 7
Is 0.2 mm ² . In this case, the width dimension I of the lower electrode 7 is 0.4 mm, and the interval K between the lower electrodes 7 is 0.2
mm, the overlapping amount H between the regulating portion 8 and the lower electrode 7 is 0.2 mm,
As shown in FIG. 2, when the first contact portion 8a of the regulating portion 8 contacts the upper electrode 5 facing the lower electrode 7, the facing width dimension L of the upper electrode 5 corresponding to the lower electrode 7 is zero. 3 mm, when the second contact portion 8b of the regulating portion 8 contacts the upper electrode 5 adjacent to the corresponding upper electrode 5 as shown in FIG. Opposing width dimension L is 0.1
The restricting portion 8 is formed so as to be mm.

In the state shown in FIG. 2, the facing width L of the upper electrode 5 corresponding to the lower electrode 7 is 0.3 mm, which is the width of the upper electrode 5, and the length is 2 mm.
The facing area between the upper electrode 5 and the lower electrode 7 is 0.6 mm ² , and the facing area 0.2 mm ² required for connection is secured. In the state shown in FIG. 3, if the opposing width dimension L of the upper electrode 5 corresponding to the lower electrode 7 is 0.1 mm or more, the length dimension is 2 mm.
An area of 0.2 mm ² facing the lower electrode 7 is secured.

Next, the operation of connecting the TCP 2 and the drive circuit board 3 of the above embodiment will be described.

A liquid crystal display panel (not shown) to which the TCP 2 is attached in advance and the drive circuit board 3 are respectively positioned and held on a jig such that the upper electrode 5 of the TCP 2 faces the lower electrode 7 of the drive circuit board 3. At the time of these positioning, the anisotropic conductive film 9 is interposed between the portion of the TCP 2 to be bonded and fixed where the upper electrode 5 is provided and the portion of the drive circuit board 3 where the lower electrode 7 is provided. deep.

Then, a portion of the TCP 2 where the upper electrode 5 is provided and a portion of the drive circuit board 3 where the lower electrode 7 is provided are heated and pressurized by a crimping device having a heater tool (not shown). Next, after heating for a predetermined time to melt the anisotropic conductive film 9, the anisotropic conductive film 9 is cooled while being pressurized to be solidified and adhered and fixed.

Next, the operation of the above-described embodiment when the TCP 2 is connected to the drive circuit board 3 will be described.

When the anisotropic conductive film 9 is melted by heating at the time of press-fitting connection between the portion of the TCP 2 where the upper electrode 5 is provided and the portion of the drive circuit board 3 where the lower electrode 7 is provided,
The TCP 2 and the drive circuit board 3 become slippery. And
In the pressurization at the time of the crimping connection, a pressure of 100 kgf or more is applied, so that the entire crimping device is distorted and the heater tool is apt to rattle. For this reason, there is a possibility that the positions of the TCP 2 and the drive circuit board 3 that are likely to slip due to rattling of the heater tool are shifted.

If the TCP 2 and the drive circuit board 3 are displaced to one side as shown in FIG. 2, if the TCP 2 and the drive circuit board 3 are displaced to one side, the first contact portion 8 a of the regulating portion 8 is attached to the lower electrode 7. Movement is restricted in a state where the lower electrode 7 and the corresponding upper electrode 5 are in contact with one side of the corresponding upper electrode 5 so as to face each other. FIG.
In the case where the second contact portion 8b is shifted to the opposite side as shown in FIG. 7, the second contact portion 8b of the regulating portion 8 contacts one side of the upper electrode 5 adjacent to the upper electrode 5 corresponding to the lower electrode 7 and corresponds to the lower electrode 7. The movement of the upper electrode 5 is regulated in a state where the upper electrode 5 faces in a facing width dimension necessary for connection.

Therefore, even if the TCP 2 and the drive circuit board 3 are displaced by the movement regulation shown in FIGS. 2 and 3, the corresponding lower electrode 7 and upper electrode 5
Area required for the connection of the liquid crystal display panel can be obtained, a reliable connection between the upper electrode 5 of the TCP 2 and the lower electrode 7 of the drive circuit board 3 can be obtained, and a display failure of the liquid crystal display panel due to a connection failure can be prevented, thereby improving the yield. it can.

Further, as shown in FIG. 3, even if the displacement occurs, the insulating regulating portion 8 does not short-circuit the lower electrode 7 with the corresponding upper electrode 5 adjacent to the corresponding upper electrode 5,
Reliable connection of only the predetermined lower electrode 7 and upper electrode 5 can be obtained, display defects of the liquid crystal display panel can be prevented, and the yield can be improved.

Since the regulating portion 8 is formed by laminating the lower electrode 7, a conventional general laminating method can be used, and the regulating portion 8 can be easily formed.

In the above embodiment, the connection structure between the drive circuit board 3 of the liquid crystal display device and the TCP 2 has been described.
In addition, a pair of substrates each provided with a plurality of electrodes,
The same effect can be obtained with any circuit board structure that is adhered and fixed with a thin film containing conductive particles.

In the above description, the regulating portion 8 is formed by lamination so as to cover a part of the lower electrode 7.
When the opposing substrate relatively moves, the restricting portion 8 is provided on the opposing substrate, such as a band-like shape formed so that the tip protrudes between the upper electrodes 5 like the lower electrode 7. Any formation method can be used in any shape in which the movement is regulated by abutting on the electrodes and the facing state of the predetermined electrodes is maintained.

[0033]

According to the present invention, a plurality of opposing electrodes are provided on an opposing surface with a gap therebetween, and a pair of electrodes which are adhered and fixed by a thin film having conductive particles electrically connecting only the opposing electrodes is provided. Since at least one of the substrates has a regulating portion having an insulating property protruding between adjacent electrodes of the other substrate, even when the substrate relatively moves when the thin film is adhered and fixed, the regulating portion is kept on the other side. The movement of the substrate is regulated by contacting the adjacent electrode of the substrate, and the position of the corresponding electrode can be prevented from being displaced by maintaining the facing state of the corresponding electrode.

Further, the restricting portion protruding between the adjacent electrodes on the other substrate is positioned so that a pair of electrodes corresponding to the electrodes adjacent to the electrodes adjacent to the opposite electrode on the other substrate face each other. Because of the provision, even if the position of the opposing electrode is shifted and the position is regulated by the regulating portion, the facing state of the corresponding electrode is maintained, so that the corresponding electrode can be securely connected and the yield can be improved.

Further, since the liquid crystal display panel connected to the circuit board according to the first and second aspects of the present invention is provided so that the corresponding electrodes can be reliably connected, the display can be performed reliably without causing a liquid crystal display defect, and the yield can be improved.

[Brief description of the drawings]

FIG. 1 is a partially cut-away cross-sectional view showing a drive circuit section of an embodiment of a liquid crystal display device of the present invention.

FIG. 2 is a partially cut-away cross-sectional view showing a situation where a deviation between a TCP and a driving circuit board has occurred.

FIG. 3 is a partially cut-away cross-sectional view showing a situation in which a deviation between a TCP and a drive circuit board has occurred.

FIG. 4 is a partially cutaway cross-sectional view showing a drive circuit section of a conventional liquid crystal display device.

FIG. 5 is a partially cutaway sectional view showing the driving circuit board;

FIG. 6 is a partially cutaway cross-sectional view showing a drive circuit board of another conventional liquid crystal display device.

[Description of Signs] 1 Driving circuit section as a circuit board 4 Flexible tape as a board 5 Upper electrode as an electrode 6 Printed board as a board 7 Lower electrode as an electrode 8 Regulator 8 A thin film anisotropic conductive film

Claims (3)

[Claims] 1. A pair of substrates facing each other, electrodes provided on a plurality of opposing surfaces of the substrates and facing each other via a gap, and at least one of the substrates protruding between the adjacent electrodes of the other substrate. A regulating portion having an insulating property provided; and a thin film having conductive particles positioned between the substrates and electrically connecting the opposed electrodes, and adhesively fixing the substrate. Circuit board. 2. The device according to claim 1, wherein the restricting portion is provided at a position where a pair of electrodes corresponding to an electrode adjacent to the opposing electrode of the other opposing substrate are opposed to each other. Circuit board. 3. A liquid crystal display device comprising: the circuit board according to claim 1; and a liquid crystal display panel connected to the circuit board.