JP2001264794A - Method for manufacturing liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid crystal display device which can prevent a terminal short circuit caused by an electrically conductive foreign matter adhering to an exposed terminal part or an electrode part after connecting the terminal electrode of a liquid crystal display element and the connection terminal of a circuit board, and terminal corrosion caused by moisture adhering without lowering productivity in a liquid crystal display device electrically connected by superposing through an ACF the terminal electrode formed at the substrate constituting the liquid crystal display element and the connection terminal formed at the circuit boards (TCP or the like) to input a driving signal to the liquid crystal display element. SOLUTION: A slit 11 is formed in a base film 8 around a connection terminal 9 part exposed after connection of the terminal electrode 2 of the liquid crystal display element with the connection terminal 9 of the TCP 7, and then an insulating resin 15 is applied to the connection terminal 9 part of the side of rear surface through the slit 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display.

[0002]

2. Description of the Related Art A liquid crystal display element comprises a liquid crystal element formed by interposing a liquid crystal between a pair of translucent substrates each having a transparent electrode and an alignment film formed on opposing surfaces. It is constituted by being arranged in. Liquid crystal display elements are thinner, lighter, and have lower power consumption than CRTs, and are therefore used as display units of portable electronic devices and, more recently, as liquid crystal monitors. In the liquid crystal display element used in the above-described electronic devices, in view of the demand for further thinning and the reliability of connection with the drive circuit section, a form using a TCP system for connection with the drive circuit has become mainstream. I have.

FIG. 5 is a sectional view showing a conventional liquid crystal display device using a TCP system. In FIG. 1, reference numeral 1 denotes a first substrate formed of a light-transmitting substrate (a glass substrate or the like) on which pixel electrodes arranged in a matrix, transistors for driving the pixel electrodes, and metal wiring for supplying electric signals to the transistors are formed. Reference numeral 2 denotes a terminal electrode formed on the first substrate 1 so as to extend from the metal wiring. Reference numeral 3 denotes a second substrate formed of a light-transmitting substrate (a glass substrate or the like) on which the transparent electrode 4 and the like are formed. A seal that seals the first substrate 1 and the second substrate 3 with the surfaces on which the electrodes and the like are formed facing each other and seals the liquid crystal 6 sandwiched between the first substrate 1 and the second substrate 3 Material.

Reference numeral 7 denotes a connection terminal 9 formed on a flexible base film 8 made of polyimide or the like.
The connection terminals 9 are electrically connected to the terminal electrodes 2 of the first substrate 1 and the anisotropic conductive film (hereinafter, referred to as ACF) 12 on a flexible wiring board (TCP) on which the SI 10 is mounted. Connected. Reference numeral 13 denotes an insulating resin applied to a gap generated between an end of the TCP 7 connected to the terminal electrode 2 of the first substrate 1 via the ACF 12 and the second substrate 3.
Moisture adheres to a gap formed between the connection portion with the TCP 7 on the terminal electrode 2 and the second substrate 3, and between the terminal electrodes 2,
Alternatively, terminal corrosion caused by a short circuit between the terminal electrode 2 and the transparent electrode 4 formed on the second substrate 3 is prevented. As the insulating resin 12, a silicon RTV resin having characteristics such as adhesion to glass constituting the substrates 1 and 3, curability at room temperature, and solventless type is generally used.

Reference numeral 14 denotes an exposed portion of the connection terminal 9 formed on the TCP 7 (the terminal electrode 2 on the first substrate 1 and the ACF 1
A short circuit between the connection terminals 9 due to the adhesion of the conductive foreign matter is prevented by the solder resist applied to the portion not in contact with the substrate 2). In order to secure flatness when the connection terminal 9 of the TCP 7 and the terminal electrode 2 on the first substrate 1 are thermocompression-bonded with the ACF 12 interposed therebetween, the solder resist 14 is provided at the end of the connection portion with the terminal electrode 2. The insulating resin 15 is applied to the gap to protect the exposed connection terminals 9 because the coating is applied at an interval of about 1 mm.

[0006]

The conventional liquid crystal display device using the TCP system is configured as described above.
In the vicinity of the connection between P7 and the first substrate 1, the exposed portion other than the connection between the terminal electrode 2 of the first substrate 1 and the connection terminal 9 of the TCP 7 and the exposed portion of the transparent electrode 4 on the second substrate 3 Are applied to the first substrate 1 from the side on which the terminal electrodes 2 are formed, and the insulating resin 15 is applied from the side on which the connection terminals 9 of the TCP 7 are formed, that is, the connection is made. Since the first substrate 1 and the TCP 7, which are integrated, must be applied from both the front and back sides, it is necessary to provide a drying time for the resin after each application step, which makes the process complicated and reduces productivity. There was a problem.

Further, when applying the insulating resins 13 and 15, it is necessary to invert the liquid crystal display element to which the TCP 7 is connected, which is a problem in performing the automatic processing. Also, Japanese Patent Application Laid-Open No. 6-95137 proposes a method of attaching a coating tape which does not require a drying step, instead of applying a resin, but has a problem in the attaching accuracy and requires both-side and front-side treatment. This does not improve the automation and productivity.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a terminal electrode formed on a substrate constituting a liquid crystal display element and a circuit board (TCP) for inputting a drive signal to the liquid crystal display element. A) and the connection terminal formed in
In a liquid crystal display device connected by overlapping via a CF, after a terminal electrode of a liquid crystal display element is connected to a connection terminal of a circuit board, conductive foreign matter adheres to an exposed terminal portion or electrode portion. Terminal short circuit caused by
It is an object of the present invention to provide a method for manufacturing a liquid crystal display device, which can prevent terminal corrosion caused by adhesion of moisture without lowering productivity.

[0009]

According to a method of manufacturing a liquid crystal display device according to the present invention, a driving LSI for driving the liquid crystal display element is mounted on a terminal electrode formed on a substrate constituting the liquid crystal display element. In a method for manufacturing a liquid crystal display device in which connection terminals formed on a circuit board are electrically connected by overlapping via an anisotropic conductive film or the like, a liquid crystal display element connected and integrated with a circuit board To cover the terminal electrode portion and the connection terminal portion which are exposed after the connection of the terminal electrode and the connection terminal by applying an insulating resin from one side. The insulating resin applied to the terminal electrode portion and the connection terminal portion exposed after the connection between the terminal electrode and the connection terminal is the same, and is applied simultaneously or continuously.

In addition, a slit is formed in a base substrate constituting a circuit board on which a driving LSI is mounted, and an insulating resin applied to cover an exposed portion of a connection terminal formed on the circuit board is provided. This is to cover the connection terminal portion on the back side via the slit. Further, the base substrate constituting the circuit board on which the driving LSI is mounted is a flexible substrate.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a method for manufacturing a liquid crystal display device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a structure of a connection portion between a liquid crystal display element and a TCP in a liquid crystal display device according to a first embodiment of the present invention, and FIG. 2 is a partial plan view of the TCP shown in FIG. In the figure, 1 is a first substrate made of a light-transmitting substrate (a glass substrate or the like) constituting a liquid crystal display element, 2 is a terminal electrode formed on the first substrate 1, and 3 is a first substrate 1 A second substrate 4 which is a counter light-transmitting substrate (a glass substrate or the like) constituting a liquid crystal display element, 4 is a transparent electrode formed on the second substrate 3, and 5 is a Second substrate 3
With the electrodes and other surfaces facing each other and
It is a sealing material for enclosing the liquid crystal 6 held between the first substrate 1 and the second substrate 3.

Reference numeral 7 denotes a circuit board for inputting a drive signal to the liquid crystal display element. In the present embodiment, a connection terminal 9 is formed on a flexible base film 8 and a flexible board on which a drive LSI 10 is mounted. Wiring board (TCP), 11 is TCP7
A slit 12 provided in the base film 8, an anisotropic conductive film (hereinafter referred to as ACF) for electrically connecting the terminal electrode 2 on the first substrate 1 and the connection terminal 9 of the TCP 7,
Reference numeral 13 denotes an insulating resin applied to a gap formed between the end of the TCP 7 connected to the terminal electrode 2 of the first substrate 1 via the ACF 12 and the second substrate 3 and exposed to the gap. 2 parts of the terminal electrode and 4 parts of the transparent electrode.

Reference numeral 14 denotes an exposed portion of the connection terminal 9 formed on the TCP 7 (the terminal electrode 2 on the first substrate 1 and the ACF 7
The solder resist 15 applied to the portion where the connection terminal 9 is exposed on the first substrate 1 is not coated with the solder resist 14 around the connection portion with the terminal electrode 2. This is an applied insulating resin having moisture resistance. This portion is soldered to secure flatness when the connection terminals 9 of the TCP 7 and the terminal electrodes 2 on the first substrate 1 are thermocompressed with the ACF 12 interposed therebetween. The resist 14 has not been applied.

Next, a method for manufacturing TCP 7 used in the liquid crystal display device according to the present embodiment will be described. First, a device hole for mounting the driving LSI 10 and a slit 11 are formed in a flexible and insulating base film 8 such as polyimide or polyester having a thickness of about 75 μm by die punching or the like. The slit 11 is formed in a portion where the solder resist 14 is not applied around a connection portion between the connection terminal 9 of the TCP 7 and the terminal electrode 2 on the first substrate 1. Next, an adhesive resin made of epoxy is applied to the base film 8, a copper foil having a thickness of 15 to 35 μm is attached, and a connection terminal 9 is formed by patterning using a resist formed by a photoengraving method. For the purpose of preventing migration, a plating film made of tin, gold, solder or the like is formed to a thickness of about 0.2 μm.

Next, the electrodes of the driving LSI 10 are aligned and mounted on the connection terminals 9 at the center of the TCP 7, and then electrically connected by the gag bonding method. Next, TCP
The surroundings of the drive LSI 10 mounted on the chip 7 are covered with a potting resin to prevent entry of foreign matter and breakage of the electrodes of the drive LSI 10 and the connection terminals 9 due to thermal cycle stress. Finally, a solder resist 14 containing urethane, polyimide, or the like as a main component is applied to cover the connection terminals 9 other than the portion used for connection with the liquid crystal display element. The slit 11 formed in the TCP 7 is shown in FIG.
In the case where the connection terminals 9 are formed only between the connection terminals 9 as shown in FIG.
It is formed using an excimer laser or the like.

Next, the TCP formed by the above steps
A manufacturing process of a connection portion between the liquid crystal display device 7 and the liquid crystal display element will be described. First, conductive particles having a diameter of about 3 to 10 μm are dispersed between an insulating adhesive made of, for example, epoxy resin between the terminal electrodes 2 formed on the first substrate 1 of the liquid crystal display element and the connection terminals 9 of the TCP 7. The terminal electrode 2 and the connection terminal 9 are thermocompressed with the film-shaped ACF 12 sandwiched therebetween.
Are electrically connected and the TCP 7 is fixed to the first substrate 1. Next, an insulating resin 13 is applied to a gap generated between the end of the second substrate 3 and the end of the TCP 7. At this time, the exposed portion of the terminal electrode 2 on the first substrate 1 and the exposed portion of the transparent electrode 4 on the second substrate 3 are covered with the insulating resin 13.

Next, an insulating resin 15 is applied to the slits 11 formed in the base film 8 of the TCP 7. At this time, the insulating resin 15 is applied from the side of the base film 8 where the terminal electrodes 9 are not formed, but the connection terminals 9 are formed through the slits 11 formed in the base film 8.
The connection terminals 9 penetrate to the side and cover portions of the connection terminals 9 not covered with the solder resist 14. The insulating resin 15 is made of a silicon resin, a urethane resin, a fluorine resin, or the like. When a silicon resin is used, it needs to be left at room temperature for about two hours for curing. Insulating resin 1
In general, the application of No. 5 is performed by dispensing a dispenser filled with an insulating resin 15 while moving the dispenser along the slit 11 of the TCP 7. It is desirable to do.

Through the above steps, the TCP 7 for inputting a drive signal to the liquid crystal display element is electrically and mechanically connected, and the terminal exposed portions other than the connection portion are covered with the insulating resins 13 and 15.

According to the present embodiment, the connection terminal 9 of the TCP 7 is connected to the terminal electrode 2 of the first substrate 1 constituting the liquid crystal display element by overlapping the connection terminal 9 via the ACF 12 and then exposed. 2 terminal electrodes and transparent electrode 4
Insulating resins 13 and 15 applied for the purpose of covering the parts and the connection terminals 9 are connected to form an integrated liquid crystal display element with T
Since the liquid can be applied to the CP 7 from the same surface side, it is not necessary to invert the liquid crystal display element to which the TCP 7 is connected, and the productivity can be improved.

Embodiment 2 In the first embodiment, two kinds of insulating resins 13 and 15 are used for covering the exposed terminal electrode 2 part, the transparent electrode 4 part, and the connection terminal 9 part. However, as shown in FIG. End of second substrate 3 and TCP
Insulating resin 13 applied to the gap generated between the ends of 7
Is used as an insulating resin applied to the slits 11 formed in the base film 8, the same effects as those of the first embodiment can be obtained, the number of materials used and the number of steps can be reduced, and productivity can be reduced. Can be further improved. In addition, the gap between the end of the second substrate 3 and the end of the TCP 7 and the application of the insulating resin 13 to the slit 11 formed in the base film 8 are provided by providing two needles in a dispenser. It may be applied at the same time,
You may apply | coat sequentially with one needle.

In the first and second embodiments,
A case has been described where a flexible wiring board (TCP) on which a driving LSI is mounted is used as a circuit board for inputting a driving signal of a liquid crystal display element. Flexible wiring board (FP) as a circuit board for inputting a drive signal to the integrated LSI
C), when the connection terminal of the FPC is connected to the terminal electrode of the liquid crystal display element via the ACF,
A similar effect can be obtained by providing a slit in C.

[0022]

As described above, according to the present invention, the connection terminal of the circuit board for inputting the drive signal to the liquid crystal display element is provided on the terminal electrode formed on the substrate constituting the liquid crystal display element via the ACF. In a liquid crystal display device which is electrically connected by superimposing, after connecting the terminal electrode of the liquid crystal display element and the connection terminal of the circuit board, conductive foreign matter adheres to the exposed terminal portions and electrode portions. Of the insulating resin applied for the purpose of preventing the occurrence of terminal short-circuit due to the terminal and corrosion of the terminal due to the adhesion of moisture,
The insulating resin applied to the connection terminal exposed portion of the circuit board is connected to the terminal electrode exposed portion by applying the insulating resin to the connection terminal portion on the back side through a slit formed in the base substrate constituting the circuit board. A highly reliable liquid crystal that can apply two types of insulating resin applied for the purpose of covering the terminal exposed part to one side of the liquid crystal display element and circuit board that are connected and integrated. Productivity can be improved in manufacturing a display device.

Further, by using the insulating resin applied to cover the exposed portion of the terminal electrode of the liquid crystal display element as the insulating resin for covering the exposed portion of the connection terminal of the circuit board, a single coating process can be performed. With this, the insulating resin can be applied, and the productivity is further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a TCP used in the liquid crystal display device according to the first embodiment of the present invention.

FIG. 3 is a plan view showing another TCP used in the liquid crystal display device according to the first embodiment of the present invention.

FIG. 4 is a sectional view showing a liquid crystal display device according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a conventional liquid crystal display of this type.

[Explanation of symbols]

1 first substrate, 2 terminal electrodes, 3 second substrate, 4
Transparent electrode, 5 sealing material, 6 liquid crystal, 7 TCP, 8
Base film, 9 connection terminals, 10 driving LSI,
11 slit, 12 anisotropic conductive film (ACF), 13
Insulating resin, 14 solder resist, 15 insulating resin.

Claims (4)

[Claims] 1. A driving L for driving the liquid crystal display element on a terminal electrode formed on a substrate constituting the liquid crystal display element.
In a method of manufacturing a liquid crystal display device in which connection terminals formed on a circuit board on which an SI is mounted are electrically connected by overlapping via an anisotropic conductive film or the like, An insulating resin is applied to the liquid crystal display element and the circuit board from one surface side to cover the terminal electrode portion and the connection terminal portion exposed after the connection of the terminal electrode and the connection terminal. A method for manufacturing a liquid crystal display device, comprising the steps of: 2. An insulating resin applied to the terminal electrode portion and the connection terminal portion exposed after connection of the terminal electrode and the connection terminal is the same, and is applied simultaneously or continuously. The method for manufacturing a liquid crystal display device according to claim 1. 3. A slit is formed in a base substrate constituting a circuit board on which a driving LSI is mounted, and an insulating resin applied to cover an exposed portion of a connection terminal formed on the circuit board is provided. 3. The method for manufacturing a liquid crystal display device according to claim 1, wherein the connection terminal portion on the back surface is covered through the slit. 4. The method for manufacturing a liquid crystal display device according to claim 1, wherein the base substrate constituting the circuit board on which the driving LSI is mounted is a flexible substrate.