JP2010085791A - Liquid crystal display and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that the sealing state depends on the cut state of the mother sapphire plate since its cut surface changes each time when cutting. <P>SOLUTION: The liquid crystal display elements are made by cutting the mother plate obtained by sealing the peripheries of a first rectangular SOS plate consisting of a sapphire R surface forming desired elements on a silicon surface and of a second transparent rectangular plate disposed facing the element formed surface of the first plate, while leaving the area to use as the liquid crystal filling hole, and by forming a number of liquid crystal display element areas between the two plates. Also, these liquid crystal display elements are made by dicing along the parting line on the surfaces of the first and second plates facing each other, then cutting and sealing them along the dicing line. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal display element and a method for manufacturing the same.

  As the size of televisions has increased, the image display area has grown to 40 inches, 50 inches, and 65 inches. Liquid crystal televisions have also been increased in size to meet demands, but as liquid crystal display elements have become larger, the manufacture of liquid crystal display elements has become difficult in various aspects, and liquid crystal televisions have become expensive.

  Projection televisions have been developed to avoid the increase in size of liquid crystal display elements and to increase the size of the display section. A small liquid crystal display element is enlarged by an optical lens and projected on a screen. The liquid crystal display element can achieve a display portion of 1 inch or less and 100 inches.

  In the liquid crystal display element, a large number of pixel electrodes are formed on one glass substrate of two glass substrates, a common electrode facing a large number of pixel electrode regions is formed on the other glass substrate, and the two glass substrates are formed into a liquid crystal layer. It is manufactured by sticking through.

  A small liquid crystal display element has a plurality of small liquid crystal display element regions formed on two mother substrates, a sealant is disposed on the outer periphery of each small liquid crystal display element region, the two mother substrates are bonded together, and then divided. Thus, it is formed in each empty small liquid crystal display element. Liquid crystal is injected into the empty small liquid crystal display element, and the injection port is sealed to complete the small liquid crystal display element.

  The materials for the two substrates are selected according to the application. In general, both substrates are made of glass and used as a transmissive liquid crystal display element. An upper substrate made of glass and a lower substrate made of single crystal silicon is used as a reflective liquid crystal display element. As special ones, plastic substrates, SOI substrates, SOS substrates and the like are also used.

  A small liquid crystal display element used for a projector or a projection television is irradiated with strong light for projection, and must be cooled to prevent the small liquid crystal display element from reaching a high temperature. Although various cooling methods have been developed, there are advantages and disadvantages. A heat sink for heat dissipation may be attached to a small liquid crystal display element, but attempts have been made to use a sapphire substrate with high heat dissipation for the substrate itself.

  There is a type in which a single crystal silicon film is formed over a sapphire substrate, a transistor or other circuit element and a pixel electrode are formed over the single crystal silicon substrate, and a liquid crystal display element is formed in combination with a sapphire substrate or a glass substrate. (See Patent Document 1)

  3 to 5 are views for explaining a method of manufacturing a small liquid crystal display element according to the present invention. FIG. 3 is a top view of the mother silicon substrate. This is a circular mother silicon substrate 2 (hereinafter referred to as a mother silicon substrate). 4 is an enlarged view of the small liquid crystal display element regions 6-1 and 6-2 in the hatched portion of FIG. 3, and FIG. 5 is a top view and a side view after division. A sealing agent 3 is formed on the periphery of a small liquid crystal display element region 6 (52 region in FIG. 3) formed on the mother silicon substrate 2, and an injection port 4 is formed in a part of the sealing agent 3. A small liquid crystal display element region 6 formed by the sealant 3 is formed at the center of the mother silicon substrate 2. A circular mother glass substrate (hereinafter referred to as “mother glass substrate”) 1 is positioned and bonded to the mother silicon substrate 2 to which the sealing agent 3 is applied.

  A, B, and C in FIG. 4 indicate the positions of the cutting lines. A is a dicing line of the mother silicon substrate 2, B is a scribe line of the mother glass substrate 1, and C is a line in which the dicing line A of the mother silicon substrate 2 and the scribe line B of the mother glass substrate 1 overlap. As shown in the side view, the dividing positions of the mother glass substrate 1 and the mother silicon substrate 2 are offset in the Y direction shown in FIG. 3, but coincide in the X direction. The sealant 3 at the tip of the injection port 4 in the small liquid crystal display element region 6-2 is applied to the cutting line C, and the tip 5 is in the adjacent small liquid crystal display element region 6-1. Reference numeral 7 denotes a connection terminal portion to an external circuit.

  The reason why the tip of the inlet is cut along the cutting line is that the cut surface and the inlet coincide with each other, so that the injection efficiency of the liquid crystal increases and the sealing of the inlet is improved.

  FIG. 6 is a cross-sectional view for explaining division when both substrates are made of glass. (A) shows a scribe position, and (B) shows a divided state. When the position indicated by ▲ is scribed and broken, the sealing agent 3 forming the injection port 4 is also finely divided, and the tip 5 of the sealing agent at the injection port 4 in the small liquid crystal display element region 6-2 is adjacent to the small liquid crystal. It is in the display element area 6-1.

  FIG. 7 is a cross-sectional view for explaining the division in the case of the mother glass substrate 1 and the mother silicon substrate 2. FIG. 7A shows the scribe position of the mother glass substrate 1 and the dicing position of the mother silicon substrate 2. ) Indicates a divided state. When the mother glass substrate 1 is scribed at the position indicated by ▲ and the mother silicon substrate 2 is diced and broken as shown in the figure, the sealing agent that forms the injection port 4 is also finely divided as in FIG. The front end portion 5 is in the adjacent small liquid crystal display element region 6-1.

JP 2000-193927 A

  When using a sapphire substrate with high thermal conductivity for projectors and projection televisions, the single crystal sapphire substrate has high hardness, and depending on the crystal plane, it has weak cleavage but there is no complete cleavage surface. In the cutting method, there is a problem that diamond points wear quickly, it is difficult to obtain a good fractured surface, and the production yield is poor. In dicing, if the processing speed (cutting speed) is increased, the grinding wheel wears quickly and chipping occurs on the cut surface. On the other hand, even if the processing speed is slowed down, grinding wheel wear is extremely reduced. However, there is a problem that the running cost is high and the productivity is lowered. Laser scribing is attracting attention as a technique for solving this problem.

  FIG. 8 is a cross-sectional view for explaining division when the silicon substrate is replaced with a sapphire substrate. FIG. 8A shows a scribe position of the mother glass substrate 1 and a laser scribe position of the mother sapphire substrate 12, and FIG. Indicates a divided state. FIG. 9 is a top view after dividing (the dividing line by the cutting line C describes only the sapphire substrate 12) and a side view.

  However, in the case of the same inlet shape and cutting line as in the prior art, the sealing agent 3 is not divided as shown in FIGS. 8 and 9, and the sapphire substrate 12 is also a small liquid crystal display as shown in FIGS. The convex portion 12A remains in the element region 6-2, and the cut portion 12B is generated in the small liquid crystal display element region 6-1, thereby adversely affecting both small liquid crystal display element regions. . In FIG. 8, the sealant tip 5 at the tip from the cutting line is attached to the sapphire substrate 12, but it may be attached to the glass substrate 1 in the adjacent small liquid crystal display element region 6-1. In such division, chipping occurs and the liquid crystal display element may have a cooling liquid during processing or water immersion after completion. Therefore, a margin must be provided in the outer shape, and the number of pieces taken from the mother sapphire substrate 12 Will decrease. In addition, since the shape of the injection port varies, the sealing is not stable and leakage occurs.

  Although the crystal axis direction is indicated by an arrow in FIG. 9, the crystal axis direction will be described with reference to FIG. FIG. 10 is a perspective view and a plan view for explaining a sapphire crystal. Sapphire has a hexagonal crystal system, the central axis of which is the C axis, and the plane perpendicular to this is the C plane and is represented by the Miller index (0001). The A axis (a1, a2, a3) extending radially from the C axis and the plane perpendicular thereto are the A plane (11-20). As shown in the figure, the R plane has a certain angle with the C axis. The sapphire used in the present invention has a circular plate shape whose main surface is an R-plane, and forms an orientation flat parallel to XX shown in the figure. The direction perpendicular to XX on the R plane is defined as the crystal axis direction.

  FIGS. 11A and 11B are diagrams illustrating a sapphire substrate cut shape by laser scribing, in which FIG. 11A shows a cutting line A, and FIG. 11B shows a cutting line C taking the hatched portion of FIG. (C) is a figure which shows the division | segmentation abnormality by the cutting line C at the time of dividing in order of the cutting line A and the cutting line C, and is each a top view.

  In laser scribing, a sapphire substrate is divided by irradiating a laser along a cutting line and rapidly cooling, but is divided first by a cutting line A perpendicular to the crystal axis direction and then by a cutting line C. (In actuality, the scribing is performed on the sapphire substrate 12)

  In the division by the cutting line C, the laser is divided by leaving the 12C and 12E convex portions at the entrance and exit portions of the laser. However, since the convex portion reaches 0.5 mm, there is no need to have a margin for the outer shape. In other words, the number of pieces taken from the mother sapphire substrate is reduced. The recesses 12D and 12F are recessed by the convex portions of 12C and 12E.

  An object of the present invention is to obtain a liquid crystal display element structure capable of accurately dividing a mother sapphire substrate of a liquid crystal display element using an SOS substrate.

  A SOS substrate composed of a sapphire R-plane on which a desired element is formed on a silicon surface, a rectangular first substrate, and a transparent member provided to face the surface of the first substrate on which the element is provided. A plurality of liquid crystal display element regions for forming a liquid crystal layer between the substrates by sealing the rectangular second substrate and the peripheral portions of the substrates, leaving a portion serving as a liquid crystal injection port. In the liquid crystal display element that divides the mother substrate into individual liquid crystal display element regions, the dividing line on the surface side facing the second substrate of the first substrate is diced and sealed, and then divided along the dicing line. A liquid crystal display element is obtained.

  At least one side of each of the rectangular substrates is divided by being offset vertically, and the injection port is a liquid crystal display element formed on the side where the cutting lines of both mother substrates are the same.

  The dicing is a liquid crystal display element that is performed only on the side where the inlet is located. Naturally, it is possible to dice the entire sapphire substrate cutting line, but it is desirable to minimize the line.

  The dicing is a liquid crystal display element using a diamond wheel.

  After irradiating a laser from the opposite surface of the dicing line formed on the first substrate, an impact is applied from the second substrate side to form a liquid crystal display element that divides the first substrate.

  The division is a liquid crystal display element in which a side parallel to the crystal axis direction is divided first, and then a side perpendicular to the crystal axis direction is divided.

  At least a step of forming a plurality of liquid crystal display element regions on the first substrate, a step of forming an electrode facing the liquid crystal display element region on the second substrate, and a surface of the first substrate facing the second substrate A step of dicing the dividing line, a step of applying a sealing material to the outer periphery of the liquid crystal display element region of the first substrate, a step of attaching the first substrate and the second substrate, and both substrates A method of manufacturing a liquid crystal display element includes a step of scribing along a dividing line and a step of dividing into individual liquid crystal display element regions.

  In the dividing step, an impact is applied from the second substrate side to form a liquid crystal display element manufacturing method in which the first substrate is divided.

  In the dividing step, a side parallel to the crystal axis direction is divided first, and then a side perpendicular to the crystal axis direction is divided.

  According to the first aspect of the present invention, since the recessed groove is formed by dicing on the dividing line of the surface of the mother sapphire substrate facing the mother transparent substrate, the sapphire can be easily cut, and the injection port can be cut cleanly, and the sealed state Is stable.

  According to the second aspect of the present invention, since the injection port is formed on the side where the cutting lines of both the mother substrates are the same in the upper and lower directions, the upper and lower dividing lines coincide with each other, so that the dividing can be prevented.

  According to the third aspect of the present invention, the minimum required dicing is sufficient, the dicing process can be shortened, and various expenses required for dicing can be reduced.

  According to the invention of claim 4, dicing can be performed even on a hard sapphire substrate.

  According to the invention of claim 5, since a deep V-groove can be provided in sapphire and the division becomes easy, the stress applied to the mother sapphire substrate and the peripheral sealing agent due to the impact applied at the time of the division can be reduced.

  According to the sixth aspect of the present invention, it is possible to prevent the convex portion from being generated at the corner portion and reduce the number of pieces taken from the mother sapphire substrate.

  According to the seventh aspect of the present invention, it is possible to prevent the sapphire substrate from being divided abnormally in the liquid crystal display element using the sapphire substrate, and to prevent the coolant from entering the liquid crystal display element due to chipping. Further, laser scribing that does not affect the adjacent liquid crystal display element region is possible, and a manufacturing method that can effectively use the mother sapphire substrate can be provided.

  According to the invention of claim 8, hard sapphire can be easily divided by impact.

  According to the ninth aspect of the present invention, it is possible to provide a manufacturing method capable of preventing the convex portion from being generated at the corner portion and preventing the number of pieces taken from the mother sapphire substrate from decreasing.

  A SOS substrate composed of a sapphire R-plane on which a desired element is formed on a silicon surface, a rectangular first substrate, and a transparent member provided to face the surface of the first substrate on which the element is provided. A plurality of liquid crystal display element regions for forming a liquid crystal layer between the substrates by sealing the rectangular second substrate and the peripheral portions of the substrates, leaving a portion serving as a liquid crystal injection port. In the liquid crystal display element that divides the mother substrate into individual liquid crystal display element regions, the dividing line on the surface side facing the second substrate of the first substrate is diced and sealed, and then divided along the dicing line. A liquid crystal display element is obtained.

  FIG. 1 is a top view of a mother sapphire substrate of the present invention, FIG. 2 is a part of a cross section obtained by bonding a mother sapphire substrate and a mother glass substrate through a sealing agent, (A) is before cutting, (B) Indicates after division. A dicing groove 12G is formed only in a direction parallel to the C crystal axis of sapphire in the dividing line of the surface of the mother sapphire substrate 12 facing the mother glass substrate 1. Next, the injection port 4 is formed as desired in this dividing line.

  The mother glass substrate 1 scribes the position indicated by ▲ and laser scribes the arrow line on the mother sapphire substrate. A dicing groove 12G is formed in the mother sapphire substrate, laser scribing the opposite surface of the dicing groove, an impact is applied from the dicing groove 12G side (mother glass substrate side) of the mother sapphire substrate 12, and the mother sapphire substrate 12 is divided. Then, as shown in FIG. 2B, the sealing agent 3 forming the injection port 4 (see FIG. 4) is also divided cleanly, and the tip 5 of the sealing agent 3 is adjacent to the adjacent small liquid crystal display element region 6-. Enter 1.

  Although it is possible to form the position of the inlet at the offset portion in the −Y axis direction of the liquid crystal display element, it is better not to form the tip portion 5 of the sealant 3.

Top view of the mother sapphire substrate of the present invention It is a part of the cross section where the mother sapphire substrate and the mother glass substrate are bonded via a sealant. (A) is before dividing, (B) is after dividing Top view of mother silicon substrate Enlarged view of hatched small liquid crystal display element regions 6-1 and 6-2 in FIG. Top view and side view after cutting Sectional drawing for demonstrating the division | segmentation in case both substrates are glass Sectional drawing for demonstrating the division | segmentation in the case of the mother glass substrate 1 and the mother silicon substrate 2 Sectional drawing for demonstrating the division | segmentation at the time of replacing a silicon substrate with a sapphire substrate Top view and side view after cutting Perspective view and plan view for explaining sapphire crystal Top view showing the shape of the sapphire substrate cut by laser scribing

Explanation of symbols

1 Mother glass substrate (glass substrate)
2 Mother silicon substrate (silicon substrate)
DESCRIPTION OF SYMBOLS 3 Sealant 4 Inlet 5 Tip part of sealant 6 Small liquid crystal display element area 6-1 Small liquid crystal display element area 6-2 Small liquid crystal display element area 7 Connection terminal part 12 Mother sapphire substrate (sapphire substrate)
12A Convex part 12B Concave part 12C Convex part 12D Concave part 12E Convex part 12F Concave part 12G Dicing groove

Claims (9)

  A SOS substrate composed of a sapphire R-plane on which a desired element is formed on a silicon surface, a rectangular first substrate, and a transparent member provided to face the surface of the first substrate on which the element is provided. A plurality of liquid crystal display element regions for forming a liquid crystal layer between the substrates by sealing the rectangular second substrate and the peripheral portions of the substrates, leaving a portion serving as a liquid crystal injection port. In the liquid crystal display element that divides the mother substrate into individual liquid crystal display element regions, the dividing line on the surface side of the first substrate facing the second substrate is diced, sealed, and then divided along the dicing line. The liquid crystal display element characterized by the above-mentioned.   2. The liquid crystal according to claim 1, wherein at least one side of both of the rectangular substrates is divided by being offset vertically, and the injection port is formed on the side where the cutting lines of both mother substrates are the same. Display element.   The liquid crystal display element according to claim 1, wherein the dicing is performed only on a side where the injection port is provided.   The liquid crystal display element according to claim 1, wherein the dicing uses a diamond wheel.   The laser beam is irradiated from the opposite surface of the dicing line formed on the first substrate, and then an impact is applied from the second substrate side to divide the first substrate. Liquid crystal display element.   6. The liquid crystal display element according to claim 1, wherein the dividing is performed by first dividing a side parallel to the crystal axis direction and then dividing a side perpendicular to the crystal axis direction. at least,
Forming a plurality of liquid crystal display element regions on the first substrate;
Forming an electrode facing the liquid crystal display element region on a second substrate;
Dicing a cutting line on a surface of the first substrate facing the second substrate;
Applying a sealing material to the outer periphery of the liquid crystal display element region of the first substrate;
Attaching the first substrate and the second substrate;
Scribing both substrates along the cutting line;
A method of manufacturing a liquid crystal display element, comprising a step of dividing the liquid crystal display element region into individual liquid crystal display element regions.   8. The method for manufacturing a liquid crystal display element according to claim 7, wherein in the dividing step, an impact is applied from the second substrate side to divide the first substrate.   9. The method for manufacturing a liquid crystal display element according to claim 7, wherein, in the dividing step, a side parallel to the crystal axis direction is divided first, and then a side perpendicular to the crystal axis direction is divided.

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