JPH07122717B2 - Liquid crystal display manufacturing method - Google Patents

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 which uses a film-shaped electrode connector to connect a liquid crystal panel and a circuit board, and which has good reliability and assemblability.

[0003]

2. Description of the Related Art Conventionally, conductive rubber has been generally used for connecting a liquid crystal panel and a circuit board.

[0004]

However, it is difficult to align the conductive rubber. For electrical connection, the conductive rubber must be pressed with a constant force, which makes it difficult to adjust the force. Easy to hold unevenly. The circuit board is easily bent by the force of crushing the conductive rubber, which may impair the reliability.

An object of the present invention is to provide a liquid crystal display device which is easy to assemble.

Another object of the present invention is to provide a highly reliable liquid crystal display device.

[0007]

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. the method of manufacturing a liquid crystal display device comprising and a presser frame for the plastic to the liquid crystal panel
Based on the
After one terminal of the film-shaped electrode connectors disposed edges of the hot melt adhesive are connected by hot pressing, and the other terminal of the film-like electrode connector and the circuit board are connected by hot pressing, the Conductive putter
The conductive pattern excluding the terminal portion on the surface on the side where the pattern is formed.
The film-shaped electrode connector having an insulating member formed thereon
With the conductive pattern forming surface facing outward,
With one substrate of the liquid crystal panel sandwiching the liquid crystal between the substrates of
The extension is formed on the circuit board side and is extended from the one board.
The other substrate with the panel terminal part formed on the length forming part
Both the liquid crystal panel and the circuit board, and the connecting portion between the film electrode connector and the liquid crystal panel and the connecting portion between the film electrode connector and the circuit board so as to be on the side opposite to the path substrate. The elastic body is arranged so as to press, and one metal plate is bent and the front of the liquid crystal panel is
While pressing on the other substrate, front from the liquid crystal panel
Surround the side of the liquid crystal display device reaching the printed circuit board.
Then, the legs of the holding frame formed on the extended portion are inserted into the holes provided in the circuit board and twisted, so that the liquid crystal panel is fixed to the circuit board by crushing the elastic body. A display device is manufactured.

[0008]

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 the terminals on the circuit board 3 to display (eg, “EPSON”) on the liquid crystal panel 1. .

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

The liquid crystal panel 1 shown in FIGS. 2 and 3 is composed of at least two substrates made of glass plates or plastic films and a liquid crystal substance sandwiched between them. 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-based 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, high heat resistance, low heat shrinkage, and good environmental resistance. Paper epoxy board, paper phenol board, or CC4 board is cheap. In particular, CC4 substrate 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.
It should be m or less. 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 in 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 a copper foil, the electrical connection between the film 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 connected. 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 attached to an external device. The holding frame 2 also has a through hole 20. The liquid crystal display device according to the present embodiment is provided with bolts, nuts, screws, etc., and mounting holes 20, 3
It is used by attaching it to an external device via 0.

The film-shaped electrode connector 5 is a circuit board 3
And the liquid crystal panel 1 are electrically connected to each other. The film-like 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 to make electrical and mechanical connection. The conductive pattern portion is printed in a predetermined pattern by mixing conductive powder such as silver powder, graphite powder, carbon black or the like 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 manufactured by Cemedine KK and a conductive adhesive E202 manufactured by Epotek. An insulating hot-melt type adhesive is formed by screen printing between the conductive pattern portions. 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
A conductive powder such as silver powder, graphite, or carbon black may be mixed into the hot melt type adhesive as described above to have both hot melt property and conductivity. Further, an insulating adhesive having no hot-melt property, or a paint may be applied or screen-printed on portions other than the terminal portion of the film-shaped electrode connector 5. This adhesive may be an epoxy-based or thermoplastic-based adhesive or paint, such as "1565" or "181" manufactured by Cemedine KK. Other examples of such conductive adhesives, hot melt type adhesives or 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 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, 180 ° C. and about 10 seconds under a pressure of 5 kg / cm ² is sufficient.

The elastic body 6 is made of sponge rubber, natural rubber, urethane foam, 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 by taking advantage of the repulsive force generated by the size.
The connection part between 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 connection 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 has a conductive hot-melt adhesive layer formed on the conductive pattern portion of the terminal connection portion as well, it is more mechanical and electrical when the elastic body 6 holds the film. 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.

Also, this is because acrylic-based rubber-based or thermoplastic-based pressure-sensitive adhesive is sprayed or 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 resistant to 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 by a press or the like and bending the metal plate.

Next, a method of assembling the liquid crystal display device of the present invention using the above parts will be described. First, the film electrode connector 5 is heated on the liquid crystal panel 1 by hot pressing. Next, the other terminal of the film electrode connector 5 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.
Then the foot 23 pressing frame 2 from the top of the liquid crystal panel 1 is set to enter the hole 33 of the circuit board 3. Next, the foot 23 of the holding frame 2 protruding from the back surface of the circuit board is twisted to fix the holding frame 2 and the liquid crystal panel 1 to the circuit board 3. LCD display device
The following is a more detailed description of the manufacturing method of the device.
It In other words, the liquid crystal panel 1 is based on plastic
Insulating hot between conductive pattern parts formed on it
5 of film-like electrode connector with melt-type adhesive
One terminal is connected by hot pressing. And times
The path substrate 3 and the other terminal of the film electrode connector 5
Connect by hot pressing. Surface on conductive pattern formation side
An insulating member is placed on the conductive pattern excluding the above-mentioned terminals.
The film electrode connector 5 that has been formed is used as a conductive pattern.
It is arranged so that the surface on which the projection is formed faces outward. And one
One substrate of the liquid crystal panel 1 in which liquid crystal is sandwiched between a pair of substrates
The extension is formed on one side of the circuit board 3 and the extension is formed.
The other board having a panel terminal portion formed on the bottom is referred to as a circuit board 3.
Arrange to be on the opposite side. Liquid crystal panel 1 and circuit board
3 and the film-shaped electrode connector 5 and the liquid crystal panel
1 connection part and film-like electrode connector 5 and circuit board 3
The elastic body 6 is arranged so as to press both of the connecting portions with
It Then, one metal plate is bent and the other liquid crystal panel 1 is folded.
Press the other board and the liquid crystal panel 1 to the circuit board
Extending the liquid crystal display device up to 3 to surround the side part
The foot of the holding frame 2 made of a thin metal plate formed on the
By inserting it into the hole provided in the plate 3 and twisting it,
The liquid crystal panel 1 so that the elastic body 6 is crushed.
And fixed to the circuit board 3. LCD display in this way
Manufacture the device.

4 and 5 show an example of the film-like electrode connector 5 used in the liquid crystal display device of the present invention. Figure 4
(A), FIG. 5 (a) is a plan view, FIG. 4 (b), FIG. 5 (b)
Is a sectional view. 51 is polyester, polyethylene,
It is a base film made of a material such as cellulose acetate. A conductive pattern portion in which a conductive member 52 is arranged on the base film 51, and a hot-melt type insulating adhesive 5
3 is arranged, and a hot-melt type insulating adhesive 54 is arranged outside the terminal portion. 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 film-shaped electrode connector 6 becomes tough, and is less likely to be torn, broken, or broken, and the metal holding frame 2 or the like is prevented from being short-circuited. There are advantages.

FIG. 6 shows an application example of the liquid crystal display device of the present invention. It has substantially the same configuration as the above-described embodiment described with reference to FIGS. A cross-sectional view is shown to clarify the differences. The difference from the above-described embodiment is that the elastic body 6
Both sides-the point where the above-mentioned adhesive member 61 is provided on the surface on the liquid crystal panel 1 side and the surface on the circuit board 3 side.

In this way, (1) the terminal portion of the liquid crystal panel 1 to which the film-shaped electrode connector 5 is connected is fixed by the adhesive 61 and the film-shaped electrode connector 5
Since the terminal portion of the circuit board 3 to which is connected is fixed by the adhesive 61, the liquid crystal panel 1 can be fixed more reliably, and there is an effect that deviation or the like is less likely to occur.

FIG. 7 shows another application example of the present invention.
Similar to the above, only a sectional view is shown. The difference from the embodiment of the present invention shown in FIGS. 1 to 5 is that, as is clear from the drawings, the adhesive member 61 is arranged on the surface of the elastic body 6 on the circuit board 3 side.

In this way, (1) the elastic body 6 may be attached to the position on the circuit board 3 on which the liquid crystal panel 1 is arranged via the adhesive member 61 in advance. This has the effect of facilitating positioning with respect to 3.

[0025]

As described above, the present invention has the following effects.

(1) Since the elastic body holds down the connecting portion of the film-like electrode connector to the liquid crystal panel or the circuit board, both electrical and mechanical connection reliability is improved.
Electrically, since the conductive portion of the film-like electrode connector and the terminal portion of the liquid crystal panel or the circuit board are pressed by the elastic body, the electrical resistance of the connecting portion is reduced and the drivability of the liquid crystal panel 1 is also improved. There are also advantages. Also, mechanically,
Prevents peeling of the film electrode connector.

(2) The elastic body has a function of supporting the liquid crystal panel in the holding frame, in addition to the function of improving the reliability of connection between the film electrode connector and the liquid crystal panel or the circuit board. Since the liquid crystal panel is supported by the elastic body, when the impact force is applied, the impact force is absorbed by the elastic body and the liquid crystal panel is not damaged. Therefore, the liquid crystal display device of the present invention has a flexible structure that is not damaged by impact force.

(3) Since the liquid crystal panel and the circuit board are adhesively connected by the film electrode connector, the electric connection between the liquid crystal panel and the circuit board is easy and reliable. For example, if the liquid crystal panel and the circuit board are electrically connected using conductive rubber, it is difficult for the three members to be aligned with each other. Since it is electrically connected to the circuit board and the circuit board, the workability is easy and reliable, the terminal alignment and the conductive rubber connection are not displaced, and the workability is reliable and the workability is good.

(4) In the liquid crystal display device of the present invention, since the force for crushing the conductive rubber for electrical conduction is not applied when crushing the elastic body, the circuit board may be soft. It is possible to select from a wide variety of materials and those with a reasonable price. Furthermore, the film electrode connector is thin
Therefore, it is easy to break, and the pitch of the conductive pattern is small.
Electrical reliability such as easy short circuit
It is essential that the film-shaped electric
The connection part of the pole connector is thin because the terminal part is formed on the base.
When the structure is used and the elastic body is used for pressing, the terminals are thin.
To achieve a connection with extremely high electrical reliability.
Is possible. In addition, the film electrode connector is electrically conductive.
The pattern formation side is placed so that the surface faces outwards.
Since the outside of is surrounded by a holding frame made of a metal plate,
The liquid crystal display device is extremely easy to manufacture and the connection part is pressed down.
The structure is protected by the frame, but the base terminal is removed.
An insulating member was formed on the conductive pattern forming part.
Because you are, there is no electrical short circuit or the like, immediately to electrical reliability
The thin film electrode connector is torn during manufacturing.
It is difficult to do so. Furthermore, after manufacturing, use a liquid crystal display device
Liquid with good mechanical and electrical reliability due to vibration etc.
It becomes possible to manufacture a crystal display device. in this way,
The liquid crystal display device of the present invention described above has an extremely simple structure.
In addition, it is extremely easy to manufacture a highly reliable liquid crystal display device.
Can be built.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of a liquid crystal display device of 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.

FIG. 6 is a diagram showing an application example of the liquid crystal display device of the present invention.

FIG. 7 is a diagram showing another application example of the liquid crystal display device of the present invention.

[Explanation of symbols]

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

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-55-45088 (JP, A) JP-A-56-116011 (JP, A) Practical application Sho-57-24768 (JP, U)

Claims (1)

[Claims] 1. A method of manufacturing a liquid crystal display device comprising a liquid crystal panel, a circuit board on which a drive element for driving the liquid crystal panel is arranged, and a holding frame for fixing the liquid crystal panel to the circuit board. In the liquid crystal panel
Based on the
After one terminal of the film-shaped electrode connectors disposed edges of the hot melt adhesive are connected by hot pressing, and the other terminal of the film-like electrode connector and the circuit board are connected by hot pressing, the Conductive putter
The conductive pattern excluding the terminal portion on the surface on the side where the pattern is formed.
The film-shaped electrode connector having an insulating member formed thereon
With the conductive pattern forming surface facing outward,
With one substrate of the liquid crystal panel sandwiching the liquid crystal between the substrates of
The extension is formed on the circuit board side and is extended from the one board.
The other substrate with the panel terminal part formed on the length forming part
Both the connecting portion of the film electrode connector and the liquid crystal panel and the connecting portion of the film electrode connector and the circuit board between the liquid crystal panel and the circuit board so as to be on the side opposite to the path substrate. The elastic body is arranged so as to press, and one metal plate is bent and the front of the liquid crystal panel is
While pressing on the other substrate, front from the liquid crystal panel
Surround the side of the liquid crystal display device reaching the printed circuit board.
Then, the legs of the holding frame formed on the extended portion are inserted into the holes provided in the circuit board and twisted, so that the liquid crystal panel is fixed to the circuit board by crushing the elastic body. A method of manufacturing a liquid crystal display device, which comprises manufacturing a display device.