JPH0511267A - Manufacture of liquid crystal display device - Google Patents

Abstract

PURPOSE:To facilitate the assembly and to improve the reliability of electric connections by inserting a pin into a hole for assembly formed in part of a pressure frame and a hole for assembly formed in a circuit board and relatively positioning a liquid crystal panel, the pressure frame, and the circuit board. CONSTITUTION:A liquid crystal panel 1 is fixed to a circuit board 3 with the pressure frame 2 and external electric power and simple signals are inputted to terminals on the circuit board 3 to make a display on the liquid crystal panel 1. The holes 20 and 30 for assembly are formed in the pressure frame 2 and circuit board 3 and when the pressure frame 2 is fixed to the circuit board 3, the pin is inserted into the assembly hole 20 of the pressure frame and the assembly hole 30 of the circuit board 3 to relatively position the circuit board 3 and pressure frame 2. The positions of those holes 20 and 30 and pin are so determined that the outer periphery of the liquid crystal panel 1 contacts the outer peripheries of the holes 20 and 30 and pin. Then the liquid crystal panel 1 is moved so that its outer periphery contacts the outer periphery of the pin inserted into the holes 20 and 30, and the legs 23 of the pressure frame 2 are twisted to fix the liquid crystal panel 1 and pressure frame 2 to the circuit board 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device.
Specifically, it relates to a liquid crystal display device in which a liquid crystal panel is integrated with a substrate on which a drive circuit is mounted.

Such a liquid crystal display device is used for a clock display and an alphanumeric (hereinafter abbreviated as αN) display for displaying numbers and characters. The present invention provides a liquid crystal display device that uses a film-shaped electrode connector and connects a liquid crystal panel and a circuit board, and that is highly reliable and easy to assemble.

[0003]

2. Description of the Related Art Conventionally, when assembling a liquid crystal panel, a circuit board, a holding frame, etc., for example, an alignment mark is formed on the circuit board side, and the mark and the liquid crystal panel or part of the holding frame are aligned. After that, the method of fixing and assembling was taken.

[0004]

However, the above-mentioned conventional techniques have problems that the mutual alignment is difficult and the working time is further increased.

Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a method of manufacturing a liquid crystal display device having a good assembling property. .

[0006]

According to a method of manufacturing a liquid crystal display device of the present invention, a liquid crystal panel, a circuit board on which a driving element for driving the liquid crystal panel is disposed, and the liquid crystal panel is fixed to the circuit board. In a method for manufacturing a liquid crystal display device, which comprises a holding frame for assembling each of them, a first assembling hole is formed in a part of the holding frame, and the first assembling hole is formed. A second assembly hole is formed in the circuit board so as to face each other, and a pin is inserted into the first assembly hole and the second assembly hole to form the liquid crystal panel and the circuit. The relative position of the substrate and the holding frame is matched.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal display device of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of an embodiment of the liquid crystal display device of the present invention. The liquid crystal panel 1 is fixed to the circuit board 3 by a holding frame 2, and a power source and other simple signals are externally input to terminals on the circuit board 3 to display (eg, “EPSON”) on the liquid crystal panel 1. ..

FIG. 2 shows a sectional view of FIG. 1, and FIG. 3 shows an exploded view.

The liquid crystal panel 1 shown in FIGS. 2 and 3 comprises at least two substrates made of glass plates or plastic films, and a liquid crystal material sandwiched between the substrates. When the liquid crystal panel 1 is a twisted nematic type (hereinafter abbreviated as TN type), the upper and lower polarizing plates and the reflection plate are fixed to the substrate by a silicon-based or acrylic pressure-sensitive adhesive or adhesive. When the liquid crystal panel 1 is a white-tailored guest-host type (hereinafter abbreviated as GH type), a UV filter is attached to the upper surface of the liquid crystal panel 1, and a reflector is attached to the lower surface.

At least a driving element 4 such as an IC for driving and displaying the liquid crystal panel 1 is mounted on the circuit board 3. As the substrate 3, a glass epoxy substrate, a paper epoxy substrate, a paper phenol substrate, a CC4 substrate (manufactured by Hitachi Chemical) or the like is used. The glass epoxy substrate has high reliability, such as high hardness, low heat shrinkage, and good environmental resistance. Paper epoxy boards, paper phenol boards, or CC4 boards are cheap. In particular, CC4 board has a simple manufacturing process,
The cost is low. The circuit board 3 needs to have a certain hardness, and an extremely soft material such as a flexible board is generally unsuitable. However, since the liquid crystal panel 1 and the circuit board 3 are connected by thermocompression bonding of the film-shaped electrode connector 5, the circuit board 3 may be softer than the conventional conductive rubber. On the circuit board 3, a metal pattern of the circuit board 3 is exposed at a connection portion (hereinafter, abbreviated as a board connector portion) 6 of the film electrode connector 5. The metal pattern is generally copper foil and has a thickness of 3 to 20 μm.
Those of m or less are preferable. The ordinary copper foil has a thickness of 39 μm, but the thickness of the copper foil of the board connector portion 31 of the circuit board 3 used in the liquid crystal display device of the present invention is within the range of 3 to 20 μm. .. A thin metal layer of 0.1 to 3 μm may be formed on the copper foil pattern by nickel plating, solder plating, gold plating, gold flash, electroless gold plating, silver plating, silver flash, or electroless silver plating. The thickness of the metal pattern of the board connector portion 31 is
When such a thin metal layer is formed, the thickness including the thin metal layer is within the range of 3 to 20 μm.
By forming a thin metal layer on a metal pattern such as copper foil, the electrical connection between the film-shaped electrode connector 5 and the circuit board 3 is improved, and the rust prevention of the metal pattern improves the reliability of the electrical connection. Further, the electric resistance of the connection portion is reduced, and when driving the liquid crystal panel, there is no sagging of the driving waveform due to the time constant of CR, so that the driving display characteristics are improved.
This advantage is particularly great when a thin metal layer is formed on the copper foil. Particularly in the field where reliability is required, gold plating by electrolysis is performed. If the terminal for electroplating cannot be taken out, electroless gold plating or gold flash is preferable.

An external terminal 32 for electrically connecting to the outside is provided at the end of the circuit board 3. This may have a connector attached. Mounting holes 30 formed by through holes are provided at four ends of the circuit board 3 so that the liquid crystal display device can be easily mounted on an external device. The holding frame 2 also has a through hole 20. The liquid crystal display device of the present embodiment is used by attaching it to an external device through the attachment holes 20 and 30 with bolts, nuts, screws and the like.

The film-shaped electrode connector 5 includes the circuit board 3
And the liquid crystal panel 1 are electrically connected to each other. The film-shaped electrode connector 5 has, for example, a conductive portion and an insulating portion formed on a polyester film having a thickness of 10 to 50 μm,
At least the insulating portion is composed of a hot-melt type adhesive, and the liquid crystal panel 1 and the circuit board 3 are thermocompression-bonded to each other for electrical and mechanical connection. The conductive pattern is printed in a predetermined pattern by mixing conductive powder such as silver powder, graphite powder, carbon black, etc. into an epoxy-based, rubber-based, or thermoplastic-based adhesive and screen-printing it. It Examples of such a material include a spot weld sealer 163M made by Cemedine KK and a conductive adhesive E202 made by Epotek. An insulating hot-melt type adhesive is formed between the conductive pattern portions by screen printing. An example of such an adhesive is “6500” manufactured by Cemedine KK. In addition, the conductive adhesive forming the conductive pattern is “6500” manufactured by Cemedine KK.
It is also possible to mix conductive powder such as silver powder, graphite and carbon black into a hot melt type adhesive as described above to have both hot melt property and conductivity. In addition, an insulating adhesive having no hot melt property, or a paint may be applied or screen-printed on a portion other than the terminal portion of the film electrode connector 5. This adhesive includes epoxy-based and thermoplastic-based adhesives and paints, such as "1565" and "181" manufactured by Cemedine KK. Other examples of such conductive adhesives, hot-melt type adhesives, insulating adhesives or coatings and film-like electrode connectors are described in detail in JP-A-55-60987. The film-shaped electrode connector 5 disclosed in JP-A-55-60987 is called a trade name "heat seal" (manufactured by Nippon Graphite KK). The film-shaped electrode connector is electrically and mechanically connected to a liquid crystal panel or a circuit board by heating and pressure bonding. The thermocompression bonding conditions are
For example, under a pressure of 5 kg / cm ² , 180 ° C. for about 10 seconds is sufficient.

The elastic body 6 is an elastic body made of sponge rubber, natural rubber, foamed urethane, silicone rubber, or the like, and is compressed when the liquid crystal panel 1 is fixed to the circuit board 3 by the holding frame 2. The film-shaped electrode connector 5 is formed into a size and utilizes the repulsive force generated by the size.
The connection part of the liquid crystal panel 1 and the circuit board 3 is pressed down. In addition to this, the elastic body 6 also has a function of a support for holding the liquid crystal panel 1 at a predetermined position. In the film-shaped electrode connector 5, the conductive pattern portion of the terminal connecting portion is mechanically coupled to the adherend of the liquid crystal panel 1 or the circuit board 3 by the hot-melt type insulating adhesive formed outside the conductive pattern portion. The elastic body 6 is brought into contact with the conductive terminal portion of the adherend by the force to obtain electrical continuity.
Presses the terminal portion, and in addition to bonding with a hot melt type adhesive, the force by pressing the elastic body 6 works,
The reliability of the connection is improved both mechanically and electrically. Even when the film-shaped electrode connector 5 is formed with a conductive hot-melt adhesive layer also in the conductive pattern portion of the terminal connection portion, it is more mechanical and electrical when the elastic body 6 presses. Improves connection reliability.

A double-sided adhesive member 61 may be formed on one surface or two surfaces of the elastic body 6. Double-sided adhesive member 61
May be a commercially available double-sided tape.

[0016] Further, this is because acrylic-based rubber-based or thermoplastic-based pressure-sensitive adhesive is sprayed, brushed,
It is formed on the surface of the elastic body 6 by screen printing or the like. This includes, for example, “840 by Cemedine KK
There is "0".

The holding frame 2 is a thin metal plate having a thickness of 0.
It is about 1 to 1.2 mm. Materials include iron, copper, bronze, brass, stainless steel, and aluminum plates. The thin metal plate used for the holding frame 2 has a constant thickness, and a rolled metal material such as a rolled steel plate is preferable. The iron material is the cheapest available. When an iron material is used, plating with nickel, chromium, etc. provides a rustproof effect. Also, if a stainless steel plate is used, it is strong against rust. Easy to process. It is tough. And so on. The holding frame 2 is formed by bending one metal plate into a predetermined shape with a press or the like and bending it.

Next, a method of assembling the liquid crystal display device of the present invention using the above parts will be described. First, the film-shaped electrode connector 5 is hot-pressed to the liquid crystal panel 1 by hot pressing. Next, the film electrode connector 5
The other terminal is connected to the circuit board 3 by hot pressing. Next, the elastic body 6 is installed below the terminals of the liquid crystal panel 1. Next, the holding frame 2 is set from above the liquid crystal panel 1 so that the legs 23 enter the holes 33 of the circuit board 3. Next, the foot 23 of the holding frame 2 protruding from the back surface of the hole 33 of the circuit board is twisted to fix the holding frame 2 and the liquid crystal panel 1 to the circuit board 3.

When assembling, the holding frame 2 and the circuit board 3
In addition, if the assembling holes 20 and 30 are provided, the workability is improved, the liquid crystal panel 1 is aligned, and a beautiful liquid crystal display device is assembled. This is an assembly hole 20 for the holding frame 2 when the holding frame 2 is fixed to the circuit board 3.
An elongated rod (hereinafter referred to as a pin) is inserted into each of the assembling holes 30 of the circuit board 3 and the relative positions of the circuit board 3 and the holding frame 2 are aligned by the pins. The positions of the holes 20, 30 and the pins are exactly the same as those of the holes 20, 3 on the outer periphery of the liquid crystal panel 1.
It comes in contact with 0 or the outer circumference of the pin. Next, the liquid crystal panel 1 is moved so that the outer circumference thereof contacts the outer circumferences of the pins inserted in the holes 20 and 30. Next, the legs 23 of the holding frame 2 are twisted to fix the liquid crystal panel 1 and the holding frame 2 to the circuit board 3.

FIG. 4 shows an example of the film electrode connector 5 used in the liquid crystal display device of this embodiment. Figure 4 (a)
Is a plan view and FIG. 4B is a sectional view. Reference numeral 51 is a base film made of a material such as polyester, polyethylene or cellulose acetate. On the base film 51, there are a conductive pattern portion on which a conductive member 52 is arranged and an insulating portion on which a hot-melt type insulating adhesive 53 is arranged, and an insulating member 54 is arranged outside the terminal portion. Has been done. The insulating member 54 does not have a hot-melt property and uses, for example, a thermosetting epoxy adhesive or a rubber adhesive. By arranging the insulating member 54 in this way, the on-film electrode connector 6 becomes tough and is less likely to tear, break, or break, and does not come into contact with the metal holding frame 2 or the like to cause a short circuit. And so on.

[0021]

As described above, according to the present invention, the pin is passed through the first assembling hole formed in a part of the holding frame and the second assembling hole formed in the circuit board. Since the relative positions of the liquid crystal panel, the circuit board and the press frame are aligned,
Very easy and accurate alignment is possible. Therefore, the assemblability of the liquid crystal display device is significantly improved.

[Brief description of drawings]

FIG. 1 is a schematic view of a liquid crystal display device according to the present invention.

FIG. 2 is a partial cross-sectional view of FIG.

FIG. 3 is an exploded view of the liquid crystal display device of the present invention.

FIG. 4 is a view showing a film electrode connector.

FIG. 5 is a view showing a film electrode connector.

[Explanation of symbols]

 1. Liquid crystal panel 2. Presser frame 3. Circuit board 5. Film electrode connector 6. Elastic body

Claims (1)

Claim: What is claimed is: 1. A liquid crystal panel, a circuit board on which a drive element for driving the liquid crystal panel is disposed, and a holding frame for fixing the liquid crystal panel to the circuit board. In a method for manufacturing a liquid crystal display device, the first assembling hole is formed in a part of the holding frame, and the circuit board is provided so as to face the first assembling hole. A second assembly hole is formed, a pin is passed through the first assembly hole and the second assembly hole, and the relative positions of the liquid crystal panel, the circuit board, and the holding frame are set. A method for manufacturing a liquid crystal display device, which is characterized by the following.