JP2001125055A - Manufacturing method for liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of cracks on a surface hardened layer, to dispense with problems related to seal releasing and to efficiently lead terminal parts in the case a plastic substrate on which the surface hardened layer is formed is used for a transparent electrode substrate. SOLUTION: A first dummy substrate part 32 with a specified width is set between neighboring cell-forming regions 31 on a first mother substrate 30 side. A display part 31a and a terminal part 31b are formed on each of the cell-forming regions 31. Only a display part 41a is formed on each of cell- forming regions 41 on a second mother substrate 40 side and a second dummy substrate part 42 is set between respective neighboring cell-forming regions 41. Then, both of the mother substrates 30, 40 are pressed to stick together via a peripheral sealant 51 and a spacer sealant 52. Both of edges 32a, 32b of the first dummy substrate part 32, and an edge 42a of the second dummy substrate part 42 are fully cut respectively. The other edge 42b of the second dummy substrate part 42 is half cut and subsequently bending stress is applied to the cut groove part from the first dummy substrate part 32 side so as to divide the second dummy substrate part 42.

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 device, and more particularly to a technique for cutting a cell for a display device using a plastic substrate having a hardened surface layer as a transparent electrode substrate.

[0002]

2. Description of the Related Art In a liquid crystal display device, a pair of substrates having a transparent electrode formed on one surface is pressure-bonded with a peripheral sealing material interposed therebetween, with the transparent electrode forming surfaces facing each other. It is constituted by injecting a display active substance such as a liquid crystal into a cell gap between the substrates.

When actually manufacturing a liquid crystal display element, a plurality of display element cells are formed at a time on a so-called mother substrate (multi-substrate) in consideration of productivity, and then the mother substrate is mounted on the display element. Each of the display cells is divided along a column or a row into a stick substrate. After a display active substance is injected into each display element cell, individual liquid crystal display elements are cut out from the stick substrate.

When individual liquid crystal display elements are cut out from the stick substrate, so-called terminal portions are provided. In the case of a glass substrate, the following two methods are known for the terminal portions. In the first method, as shown in FIG. 3, a display section 1a and a terminal section 1b are formed for one cell formation area on one mother substrate 1 side, and a display section 1a and a terminal section 1b are formed on the other mother substrate 2 side. Display unit 2 per cell formation area
a is formed, and both substrates 1 and 2 are pressure-bonded via the peripheral sealing material 3. Then, after cutting the portion A to cut out individual liquid crystal display elements, the substrate portion (dummy portion) 2b of the other substrate facing the terminal portion 1b is cut off from the portion B.

In a second method, as shown in FIG. 4, a display section 1a and a terminal section 1 are provided on one mother substrate 1.
The first cell formation regions 11 having the “b” and the second cell formation regions 12 having only the display unit 1 a are alternately arranged. Similarly, for the other mother substrate 2, the first cell forming region 21 having the display unit 2 a and the terminal unit 2 b and the display unit 2
The second cell formation regions 22 having only a are alternately arranged.

Then, the first cell formation region 11 and the second cell formation region 22 are connected to each other, and the second cell formation region 12 and the first cell formation region
The two mother substrates 1 and 2 are pressure-bonded via the peripheral sealing material 3 such that the cell formation regions 21 face each other.
According to the second method, since the terminal portion 1b and the terminal portion 2b face each other, by cutting two portions of the portion C and the portion D, the terminal portion is simultaneously cut out of the liquid crystal display element. be able to. In addition, productivity is good because no discarded substrate portion occurs.

[0007]

When the substrate is a glass substrate, the glass substrate is fixed on a cutting table and cut or cut relatively easily by drawing a marking line with a carbide wheel cutter or the like. However, plastic substrates are more flexible than glass substrates, and
Due to the property that it is not easily broken easily, it is difficult to make the terminal portion by any of the first and second methods.

That is, for example, thermoplastic polyethylene terephthalate, polyether sulfone, polycarbonate, thermosetting acrylic or epoxy resin is used for a plastic substrate for a liquid crystal display element. For the purpose of improving chemical resistance, for example, an acrylic hard coat layer and a surface hardened layer composed of an oxygen barrier coat layer made of an organic or inorganic material for preventing permeation of oxygen and the like are formed, and for example, ITO (Indium Tin Oxide)
Is formed. This type of hardened layer is harder and easier to crack than a plastic substrate.

In the case where such a plastic substrate is provided with a terminal portion by the first method described with reference to FIG.
Can be completely cut (full cut) with a cutter or the like, but the remaining dummy portion 2b has only a gap of about 6 μm between the opposing terminal portion 1b, so that the terminal portion 1b is not damaged. , Its substrate part 2b
It is extremely difficult to fully cut

[0010] Therefore, conventionally, a cut groove (so-called half cut) having a predetermined depth is formed in the portion B, and the dummy portion 2b is torn by hand, so that a reduction in productivity cannot be denied. In addition, since it is a manual operation, when the dummy portion 2b is grasped, the terminal portion 1b is erroneously contacted with the terminal portion 1b to be scratched, and a cutting failure in appearance is likely to occur.

In the case where the terminal portion is formed by the second method described with reference to FIG. 4, a half cut is made in each of the C and D portions, and then a bending stress is applied to the portions to divide the portions. However, since a large amount of stress concentrates on the cross section of the terminal portions 1b and 2b, cracks occur in the hard coat layer and the oxygen barrier coat layer of the hardened surface layer, and the peripheral seal material 3 peels off considerably. Occurred frequently.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object the purpose of using a plastic substrate as a transparent electrode substrate to form cracks in the surface hardened layer and the like. It is an object of the present invention to provide a method of manufacturing a liquid crystal display element in which a terminal portion can be provided without causing the generation and without damaging the terminal portion.

In order to achieve the above object, the present invention provides a method of allocating a plurality of cell forming regions in a predetermined arrangement to each of a first mother substrate and a second mother substrate each formed of a plastic substrate having a hardened surface layer. On the first mother substrate side, a first dummy substrate portion having a predetermined width is set between adjacent cell forming regions, and a display portion and a terminal portion are formed in each of the cell forming regions. In each cell formation region, only a display portion is formed at a position corresponding to the display portion on the first mother substrate side, and a space between each adjacent cell formation region is used as a second dummy substrate portion. A peripheral sealing material is applied around the respective display portions on the mother substrate side, and a spacer sealing material is applied between the first dummy substrate portion and the second dummy substrate portion to seal both mother substrates. And a plurality of display element cells are simultaneously formed by pressure bonding via a spacer sealing material, and both ends of the first dummy substrate portion and one end of the second dummy substrate portion on the side not facing the terminal portion are completely cut off, respectively. (Full cut), a notch groove (half cut) having a predetermined depth is formed at the other end of the second dummy substrate portion facing the terminal portion, and then the notch groove is formed from the first dummy substrate portion side. The second dummy substrate portion is divided by applying a bending stress to the portion.

In this case, the width of the first dummy substrate portion is 3 to 1
It is preferably within a range of 0 mm, particularly 5 to 7 mm. If it is less than 3 mm, the width is too narrow, and it becomes difficult to divide the second dummy substrate portion. On the other hand, if the width of the first dummy substrate portion exceeds 10 mm, the rebound of the second dummy substrate portion becomes remarkable when the second dummy substrate portion is divided, which may cause damage to the terminal portion.

Further, in the present invention, the uncut amount of the cut groove portion is 3 to 40% of the substrate thickness, particularly 5 to 40%.
Preferably it is 20%. It is difficult to reduce the uncut portion to less than 3% in terms of accuracy. On the other hand, if the uncut portion exceeds 40%, stress at the time of cutting increases, and cracks occur in the surface hardened layer of the plastic substrate. It is not preferable because there is a possibility that the peripheral sealing material may peel off.

According to the present invention, the terminal portion is obtained by dividing and cutting a total of four positions at both ends of the first dummy substrate portion and both ends of the second dummy substrate portion. Two places at both ends of one dummy substrate part and one place at one end side of the second dummy substrate part) can be cut by full cutting.

The remaining one portion (one portion on the other end side of the second dummy substrate portion) is cut by half cutting. In the case of the present invention, a separating force is applied from the first dummy substrate portion side to the second dummy substrate portion. Since it can be added, the dividing operation can be performed efficiently. Further, it is possible to automate the dividing operation by the automatic dividing machine.

[0018]

Next, the present invention will be described more specifically with reference to the drawings.

FIG. 1 is a cross-sectional view of an essential part in a state where a pair of first and second mother substrates 30 and 40 are combined in a state in which a terminal portion is to be extended. Each mother board 3
Both 0 and 40 are made of, for example, a plastic substrate such as polycarbonate. Although not shown, each surface thereof is provided with, for example, an acrylic hard coat layer for improving chemical resistance, and for preventing permeation of oxygen and the like. A surface hardened layer composed of an oxygen barrier coat layer made of an organic or inorganic material is formed. As the plastic substrate for a liquid crystal display device, a substrate having a substrate thickness of about 0.1 to 0.4 mm is usually selected.

A plurality of cell forming regions 31 and 41 are allocated to each of the mother substrates 30 and 40 in a predetermined arrangement. According to this embodiment, the first mother substrate 3
On the 0 side, a first dummy substrate portion 32 having a predetermined width is set between adjacent cell formation regions 31, 31, and a display portion 31 a and a terminal portion 31 b are formed in each cell formation region 31.

Although not shown in detail, the display unit 31
A transparent electrode made of ITO is formed in a predetermined pattern at a, and an extraction electrode connected to the transparent electrode is formed at the terminal portion 31b. In the present invention, the first
The width of the dummy substrate portion 32 is 3 to 10 mm, particularly 5 to 7 mm.
mm.

On the other hand, each of the cell forming regions 41 of the second mother substrate 40 has a display portion 3 on the first mother substrate 30 side.
Only the display section 41a is formed at a position corresponding to 1a, and a second dummy substrate section 42 is formed between adjacent cell formation areas 41, 41.

The mother substrates 30 and 40 are pressure-bonded via a peripheral sealing material 51 applied around each display portion (31a or 41a) of one of the substrates. In this case, the first dummy substrate Part 32 and second dummy substrate part 42
A spacer sealing material 52 is also provided between them.
The peripheral sealing material 51 and the spacer sealing material 52 may be, for example, an epoxy resin-based adhesive that is commonly used.

In order to carry out the terminal section, on the first mother board 30 side, both ends 3 of the first dummy board section 32 are provided.
2a and 32b are completely cut (full cut). On the second mother substrate 40 side, one end 42a of the second dummy substrate portion 42 is fully cut. Note that this end portion 42a
Is an end on the side not overlapping with the terminal 31b, which overlaps with one end 32a of the first dummy substrate part 32 in position.

The other end of the second dummy substrate 42, that is, the end 42b facing the terminal 31b, is provided with a cut groove (half cut) by, for example, a carbide wheel cutter. The uncut amount of the cut groove portion is preferably 3 to 40%, particularly preferably 5 to 20% of the substrate thickness.

Then, as shown in FIG.
After being placed on the table 61 of the cutting machine with the mother board 40 side down, and firmly fixed with the holding bar 62, the cutting bar 63 is pressed from above the first dummy board unit 32,
A bending stress is applied to the cut groove portion formed at the end portion 42 b to separate the second dummy substrate portion 42 from the second mother substrate 40. Thus, the dummy portion can be divided without causing cracks in the hardened surface layer or the like formed on the plastic substrate.

The width of the first dummy substrate portion 32 is set to 2 to 1
Actually, the cutting was carried out by appropriately changing the distance within a range of 5 mm. When the cutting was less than 3 mm, the width was too narrow and the cutting operation could not be performed smoothly. On the other hand, if the width of the first dummy substrate portion 32 exceeds 10 mm, even if the depth of the cut groove is appropriate, the end portion 42b of the second dummy substrate portion 42 may rebound at the time of division and the terminal portion 31b may be damaged. . Therefore, it is appropriate that the width of the first dummy substrate portion 32 is 3 to 10 mm.

The width of the first dummy substrate portion 32 is 5 mm.
And the uncut amount of the cut groove is set to 1 to 6 of the substrate thickness.
The actual cutting was performed by appropriately changing it within the range of 0%. When the cutting was less than 3%, the uncut amount could not be managed. On the other hand, when the uncut amount exceeds 40%, the stress at the time of cutting is large, cracks are generated in the hardened surface layer, and seal peeling is scattered. Therefore, the appropriate range of the uncut amount is 3 to 40%.

[0029]

As described above, according to the present invention,
When a plastic substrate having a hardened layer such as a hard coat layer or an oxygen barrier coat layer is used as a transparent electrode substrate, without causing cracks in the hardened surface layer, and without any problem of peeling of the seal, the terminal portion can be exposed. It can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of a mother board on which a terminal portion is provided according to the present invention.

FIG. 2 is a schematic side view showing a divided state according to the present invention.

FIG. 3 is a schematic cross-sectional view for explaining a first conventional method of providing a terminal portion.

FIG. 4 is a schematic cross-sectional view for explaining a second conventional method for providing a terminal portion.

[Explanation of symbols]

 30, 40 Mother substrate 31, 41 Cell formation region 31a, 41a Display unit 31b Terminal unit 32 First dummy substrate unit 42 Second dummy substrate unit 51 Peripheral seal material 52 Spacer seal material

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H088 FA06 FA07 FA10 FA27 FA29 HA01 HA04 MA20 2H089 LA09 LA10 LA11 LA13 NA12 NA17 NA39 NA41 QA12 QA16 TA01 TA05 2H090 JA07 JA08 JB03 JC07 JC13 LA02 LA03

Claims (3)

[Claims] When allocating a plurality of cell formation regions with a predetermined arrangement to each of a first and a second mother substrate formed of a plastic substrate having a surface hardened layer, the first mother substrate is adjacent to the first mother substrate. A first dummy substrate portion having a predetermined width is set between each cell formation region, a display portion and a terminal portion are formed in each cell formation region, and a first dummy substrate portion is formed in each cell formation region on the second mother substrate side. Only the display portion is formed at a position corresponding to the display portion on the mother substrate side, and a space between each adjacent cell formation region is used as a second dummy substrate portion. A peripheral sealing material is applied to the periphery, and a spacer sealing material is applied between the first dummy substrate portion and the second dummy substrate portion, and both mother substrates are pressed through the peripheral sealing material and the spacer sealing material. And simultaneously forming a plurality of display element cells, and completely cutting both ends of the first dummy substrate portion and one end of the second dummy substrate portion which is not opposed to the terminal portion. At the other end on the side facing the terminal portion, a notch groove of a predetermined depth is formed, and then a bending stress is applied to the notch groove portion from the first dummy substrate portion side to divide the second dummy substrate portion. A method for manufacturing a liquid crystal display device, comprising: 2. The method according to claim 1, wherein the first dummy substrate has a width of 3 to 10 m.
2. The method for manufacturing a liquid crystal display device according to claim 1, wherein m is within a range of m. 3. The method for manufacturing a liquid crystal display element according to claim 1, wherein an uncut amount of the cut groove portion is 3 to 40% of a substrate thickness.