JP3054944B2 - Display device manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a portable device having a function such as pen input and a display device used for an electronic organizer.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal panel has an IC on a film substrate.
TCP (Tape Carrier Pack)
age) or COF (Chip On FPC)
They were connected by thermocompression bonding to the terminals of the liquid crystal panel with an anisotropic conductive film and mounted. TCP is similar in configuration to COF, except that T
CP is a semiconductor package, and COF is a circuit block in which an IC is mounted on a bare chip and further a resistor, a capacitor, and the like are mounted.

[0003] The TCP substrate is, for example, a pattern obtained by laminating a 18-micron Cu foil on a 75-micron polyimide film with an epoxy adhesive film of about 40 microns, patterning, resist coating, and plating. The IC on which the Au bumps are formed is thermocompression-bonded thereto, and the plating of TCP and the Au bumps of the IC are eutectic-metalized and connected. The connection is sealed with an epoxy adhesive to complete the TCP.

[0004] The film substrate used for COF is, for example, about 8 micron C film on a 25 micron polyimide film.
u is deposited, patterned, resist-coated, and plated. In this case, since the base film of the two-layer film is thinner than the TCP, it has high flexibility and can be bent basically at any point. Connection is C
The OF can be connected by thermocompression bonding of the IC on which the Au bump is formed and the COF plating and the Au bump of the IC can be connected by using a metal eutectic, or by using an anisotropic conductive film. In the case of a metal eutectic, an underfill is poured into the connection portion and sealed. Further, components such as resistors and capacitors are printed and mounted with cream solder and reflowed to complete the process.

The anisotropic conductive film used for connection to the liquid crystal panel is formed by forming a film obtained by dispersing and mixing conductive particles of 10 to 5 microns in a thermosetting adhesive. The conductive particles include, in addition to nickel and solder, plastics obtained by plating nickel and gold on a plastic. For connection, temporarily attach an anisotropic conductive film to the terminal of the liquid crystal panel, align COF and TCP,
The connection is made by thermocompression bonding from the COF or TCP side via a Teflon or silicon rubber sheet. The appropriate compression temperature depends on the material of the anisotropic conductive film, but is approximately 160 ° C at the film temperature.
From 20 to 30 kg per square centimeter at 190 ° C,
Crimping for about 20 seconds.

[0006]

However, for example, when the liquid crystal panel has two terminals on the X-axis side and the Y-axis side,
TCP and COF were connected to each. for that reason,
At least two ICs are required for each side and two ICs are required. Considering cost reduction, it is conceivable to use these ICs as one-chip ICs, for example. When the one-chip IC is mounted on a film substrate on a liquid crystal panel, the structure is as shown in FIG.
The liquid crystal panel 1 has a structure in which metal particles are dispersed in a seal for enclosing liquid crystal and all connection terminals are formed on a transparent substrate on one side. In such a structure, the size of the film substrate 3 increases, and the price of the film substrate 3 increases. In addition, the normal display device has a TCP or C
Since the OF is bent and arranged, the COF must be bent at least twice to arrange the COF on the back surface of the liquid crystal panel, and there is a problem that the thickness is further increased.

Therefore, it is most desirable to mount the device using a COF having the shape shown in FIG. The above thickness problem,
Although the cost can be reduced because the area of the COF can be reduced, the connection between the liquid crystal panel and the COF is difficult. In the case of this structure, the COF and the liquid crystal panel are first pressure-bonded to one side as in the related art. Next, the glass epoxy substrate is bonded to the back surface of the terminal to be connected, and this portion is bent and fixed with a jig. The fixing method is φ1.0mm on both ends of this glass epoxy board.
It is easy to do this by drilling a pin hole and inserting it into the jig with the pin up and fixing it. Further, the pins are designed to be dented by a spring. If the terminals of the liquid crystal panel are aligned with the film substrate and heated under pressure, the temporary attachment is easy.

Next, the liquid crystal panel and the COF are connected by the final compression, but in this case, the conventional compression cannot be performed. Therefore, there is no other way than to press the liquid crystal panel from the COF side through the glass epoxy substrate. Heating from the COF side does not easily raise the temperature. Also, the temperature is not uniform between the center and the end. When pressure bonding is performed from the glass side, there is no problem with the pressure bonding temperature, but the polarizing plate of the liquid crystal panel melts.

[0009] It is very difficult to attach the polarizing plate after the COF is pressure-bonded, because there are components such as ICs on the back surface. In addition, there is no heat-resistant polarizing plate , and lowering the curing temperature of the anisotropic conductive film has a reliability problem,
It is very difficult at present. Therefore, an object of the present invention is to solve the problem that the polarizing plate is melted in the pressing step.

[0010]

In order to solve the above-mentioned problems, the present invention provides a liquid crystal panel in which a liquid crystal is held between at least two transparent substrates and an optical film such as a polarizing plate is adhered to the transparent substrates. In the method of manufacturing a display device in which the film substrate and the film substrate are connected by pressure bonding with an anisotropic conductive film, a spacer made of glass epoxy or the like is attached to the back surface of the terminal connected to the liquid crystal panel of the film substrate with an adhesive, and the spacer is attached. Bend. An anisotropic conductive film is attached to a terminal of a liquid crystal panel or a terminal connected to the liquid crystal panel of the film substrate, and the terminals are aligned and temporarily attached. By disposing a heat sink on the optical film and connecting the film substrate and the liquid crystal panel by heating and pressing with a pressure bonding head from the terminal side of the liquid crystal panel, the problem of melting the polarizing plate was solved.

[0011]

Placed on the polarizing plate, for example aluminum plate when thermocompression bonding from PREFERRED EMBODIMENTS glass side, the aluminum may not be cooled by the thickness and shape. Larger and thicker is better. By applying heat and pressure with a pressure bonding head, the anisotropic conductive film
The polarizing plate can be cooled and does not melt because it has an aluminum plate. Therefore, the size of the film substrate can be reduced.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram of an embodiment of the display device of the present invention. The liquid crystal panel is an STN passive matrix type. The transparent substrate is a glass of 0.5 mm, on which a transparent electrode is formed, a liquid crystal is injected, and a polarizing plate 8 is attached. COF is C on 25 micron polyimide film.
The IC 2 is face-down bonded to a film substrate 3 on which u is deposited and patterned and Sn-plated.

The glass epoxy substrate 11 is bonded to the back surface of the terminal to be connected, and this portion is bent and fixed with a jig.
For bonding the glass epoxy substrate 11, a thermoplastic adhesive is better than a thermosetting adhesive. It is a reliability test
This is because in the case of the thermosetting adhesive, the difference in the coefficient of thermal expansion between the glass of the liquid crystal panel and the glass epoxy and the stress are greatly applied to the joint surface. The fixing method is as follows. A pin hole of φ1.0 mm is made in both ends of the glass epoxy substrate, and the glass epoxy substrate is fixed by inserting it into a jig having pins.
The terminals of the liquid crystal panel 1 to which are temporarily attached are aligned, and both sides of the terminals are heated from the glass side and temporarily fixed with a soldering iron.

Next, the final press bonding is performed. The liquid crystal panel 1 to which the COF is temporarily attached is placed on the stage 7 with the silicone rubber 9 placed thereon, and the terminal portion to be crimped is set. The silicon rubber 9 is for making the parallelism uniform. 1.5 m on the polarizing plate 8
m aluminum plate 10 is placed, and a Teflon sheet 6 is placed on the terminal portion to be crimped. The Teflon sheet 6 is for preventing the liquid crystal panel 1 from breaking in the event that foreign matter such as dust occurs. Next, the crimping head 5 heated to 260 ° C. is crimped to the terminal portion at 20 kg per square cm for about 20 seconds. The anisotropic conductive film 4 can be cured at temperature reached 180 ° C., polarized
The light plate 8 does not melt.

After the connection is completed, the exposed transparent electrode of the liquid crystal panel 1 is subjected to a moisture-proof coating with a long needle dispenser to complete the display device. The heat sink is not limited to an aluminum plate, but may be Fe, SUS, or the like, or may be a heat pump or any other heat sink. The method is not limited to COF, but may be TCP.

[0016]

As described above, according to the present invention, by placing a heat sink on the deflection plate, pressure bonding from the glass side becomes possible, and an inexpensive liquid crystal display device can be provided.

[Brief description of the drawings]

FIG. 1 is a side view of a final pressure bonding step of an embodiment according to the present invention.

FIG. 2 is a top view of a conventional liquid crystal display device.

FIG. 3 is a top view of a COF used for manufacturing the display device of the present invention.

FIG. 4 is a side view of the main bonding step of the prior art.

[Explanation of symbols]

Reference Signs List 1 liquid crystal panel 2 IC 3 film substrate 4 anisotropic conductive film 5 pressure bonding head 6 Teflon sheet 7 stage 8 polarizing plate 9 silicon rubber 10 aluminum plate 11 glass epoxy substrate

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1345

Claims (2)

(57) [Claims] 1. A liquid crystal sandwiched and held between two transparent substrates,
A liquid crystal panel with a polarizing optical film attached to the surface of the two transparent substrates and an anisotropic conductive film
In a method of manufacturing a display device by thermocompression bonding with a film , a step of bonding and fixing a spacer to the back surface of a terminal to which the film substrate is connected, and folding the film substrate based on the bonded and fixed spacer to invert the connection terminal surface Process and
A step of attaching an anisotropic conductive film to the terminals of the liquid crystal panel or the film substrate and aligning the terminals; and placing a heat sink on the optical film of the liquid crystal panel on the side of the thermocompression bonding head. method for producing Viewing device you characterized in that the panel and the terminal of the film substrate and a step of thermocompression bonding by thermocompression bonding head. 2. The display device according to claim 1, wherein in the step of thermocompression bonding the liquid crystal panel and the film substrate, thermocompression is performed from a transparent substrate side of the liquid crystal panel.
Method of manufacturing location.