JP2570290B2 - Mask upholstery - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mask covering for performing processing such as rubbing, printing, and exposure using a mask having a predetermined cutout pattern provided on a thin plate.

[Conventional technology]

2. Description of the Related Art Conventionally, in a liquid crystal display element (liquid crystal cell) in which a nematic liquid crystal is sealed between two transparent substrates arranged in parallel, a part of the liquid crystal display element has a twisted nematic arrangement, and the other part has a predetermined pattern. And a liquid crystal display element is arranged between polarizing plates.
A liquid crystal display device in which the pattern is a window that constantly transmits light is manufactured. The substrate of this liquid crystal display element is manufactured in the following steps.

(A) On the surface of a transparent substrate such as glass or plastic,
A thin conductive layer of a transparent and low-resistance metal oxide such as tin oxide or indium oxide is formed by a method such as vacuum deposition, spraying, or high-frequency sputtering. In this case, if necessary, a protective film is provided on the surface of the transparent substrate as an undercoating in order to prevent sodium or the like from dissolving into the liquid crystal from the transparent substrate and deteriorating the liquid crystal.

(B) Next, in order to use the liquid crystal as a display element, the conductive layer is photo-etched to form a display electrode pattern.

(C) A groove-like structure is formed on the surface of the substrate to align the liquid crystal molecules parallel to the substrate. For this purpose, first, a solution of polyvinyl alcohol or polyimide is printed or applied on the surface of the transparent substrate to form a thin alignment film. Next, rubbing is performed on the surface of the alignment film in a certain direction (alignment treatment). Rubbing is rubbed in one direction with a rubbing cloth made of a material such as rayon or cotton.

(D) A thin metal plate (mask) provided with a cutout of a predetermined pattern is superimposed on the surface of the rubbed alignment film,
Rubbing (hereinafter referred to as mask rubbing) in a direction deviated by a predetermined angle with respect to the one direction (for example, orthogonal direction).

This mask rubbing is performed by a polishing means such as a roller around which the polishing tool is wound in order to accurately set the direction. Also, in mask rubbing, in order to manufacture a precise product of the above pattern, the thickness of the mask must be thin, the flatness of the mask during rubbing must be ensured with high accuracy, and the mask overlapping position must be set accurately. It becomes important to do.

Similarly, in a mask used for screen printing or photo-etching, the flatness of the mask and the accuracy of mask positioning similarly determine the quality of the product.

[Problems to be solved by the invention]

However, conventional masks do not take sufficient care to maintain their flatness, and in particular, where the frictional force is applied to the mask as in the case of mask rubbing, the mask must be kept on a highly accurate flat surface for a long time. Was difficult. In addition, in order to increase the display density (integration degree) of information, extremely high precision is required for the formation position of the pattern in a liquid crystal display device which is mass-produced in recent years. Therefore, management of maintaining the flatness of the mask is an important issue.

An object of the present invention is to provide a mask covering which can maintain a good flatness of a mask for a long period of time in the mask rubbing and enables precise mask rubbing.

[Means for solving the problem]

In order to achieve the above object, the rubbing mask upholstery of the present invention is provided with a frame, a mask disposed in the frame, and stretched between an outer periphery of the mask and the frame, and A structure composed of a film body that is pulled with an appropriate tension is adopted.

As the film, a screen mesh or screen cloth made of stainless steel or polyester is used.

[Action and Effect of the Invention]

In the mask covering of the present invention, since the mask is pulled from the entire periphery by the film body with an appropriate tension, when the mask is used such as mask rubbing, the flatness of the mask is maintained with high precision for a long time, and the mask An accurate projection of the cut-out pattern can be given to the workpiece.

〔Example〕

Next, the present invention will be described with reference to the embodiment shown in FIG. 1 and FIG.

Reference numeral 1 denotes a mask covering for use in mask rubbing. A screen mesh 12 is provided on a rectangular frame 11 made of aluminum and having an outer dimension of 40 cm in length and 50 cm in width. It is formed with a mask 14 provided. The screen mesh 12 is a sieve made of a stainless steel net, and is a net woven material that can be used as a flat work plate. This mask upholstery 1
A single screen mesh 12 with a predetermined tension applied to the entire surface of the frame 11 is bonded with an adhesive, and then a mask 14 around which the adhesive has been removed is bonded to a predetermined position of the screen mesh 12. Thereafter, the screen mesh in a portion other than the adhesive portion overlapping the mask 14 is removed by cutting or the like. As this adhesive, a thermosetting adhesive such as an epoxy resin is preferably used. The mask 14 is made of a stainless steel plate having a thickness of 0.05 mm to 0.1 mm. The mask 11 receives an appropriate distribution of tension from the entire periphery by the screen mesh 12 and has good flatness.
Is held. It is important that the distribution of the tension by the screen mesh 12 is appropriately set according to the pattern of the cutout 13 provided on the mask 14 in order to ensure the flatness of the mask 14, and the setting of this tension distribution is calculated or It is done by trial and error.

3 to 6 show a mask rubbing process using the mask covering 1.

Reference numeral 2 denotes a substrate in a rubbed state. This substrate 2 is a glass plate having good flatness such as float glass.
A transparent electrode layer is attached to 21 by vacuum evaporation, a predetermined pattern electrode 22 is formed by photoetching the transparent electrode layer, and a polyimide resin layer 23 is printed on a glass plate 21 on which the pattern electrode 22 is provided. And a rubbing treatment is performed on the surface of the polyimide resin layer 23. A certain number of the substrates 2 are set in the storage cassette 20 and set near the mask rubbing device 30.

The mask rubbing device 30 includes a rectangular floor plate 31, a pair of rails 33 laid thereon in parallel in the longitudinal direction, and a substrate setting device 40 that is movably arranged on the rails and reciprocates horizontally. And a cubic fixed frame set 35 fixed to the center of the floor plate 31, and a rubbing roller device 50 fixed on the fixed frame set 35.

The substrate setting device 40 has a rectangular parallelepiped movable frame 41 mounted on the rail 33 and a work table attached to the inside of the movable frame 41 for sucking and fixing the substrate 2.
And a lifting device 43 for the worktable.
The upper frame material of the movable frame 41 is disposed above the work table 42, and serves as a frame 45 for installing the mask covering 1, and a window 44 through which the work table 42 can be inserted is provided. Is provided.

As shown in FIG. 6, the mask upholstery 1 is placed on the upper surface of the frame 45, and is fixed to the frame 45 by a clamp 46.
Further, the position outside the rectangular frame 11 is accurately managed by a dial gauge 47 attached to the frame base 45. By accurately setting the relative position of the mask 14 with respect to the frame 11 as described above, if the position of the frame 11 with respect to the frame base 45 is managed, the position of the pattern can be set precisely.

The roller device 50 includes a motor base 51 mounted on the fixed framework 35, and a motor 52 fixed on the motor base 51. On both lower surfaces of the motor base 51, roller support walls 53 are provided so as to face each other, and a roller shaft 54 is rotatably supported on the roller support walls 53. A roller 55 is coaxially mounted on the roller shaft 54, and a cotton cloth 56 is wound around the outer periphery of the roller 55. A belt-type transmission 57 transmits power between the roller shaft 54 and the motor 52.

 Next, the operation of the mask rubbing device 30 will be described.

(A) A cassette 20 for storing unprocessed substrates, in which a predetermined number of substrates 2 rubbed in one direction shown in FIG. 3 are set, is placed near the mask rubbing device 30.

(B) The substrate 2 is taken out from the storage cassette 20, is set at a fixed position on the work table 42, and is sucked by a vacuum suction device.

(C) The work table 42 is raised by the elevating device 43 so that the substrate 2 contacts the lower surface of the mask 14.

(D) While the roller device 50 is operated, the driving device (not shown) moves the substrate setting device 40 under the roller device 50 and moves it to the position indicated by the dashed line in FIG. At this time, the substrate 2 has a cutout 13 of the mask.
Is rubbed (mask rubbed) by a cotton cloth of a roller in a direction perpendicular to the one direction. After completion of the mask rubbing, the work table 42 is lowered, and the substrate 2 after the mask rubbing process is stored in the substrate storage cassette 20.

A liquid crystal display device using this substrate is manufactured in the following steps.

The substrate rubbed only in one direction and the mask rubbed substrate are liquid-tightly stacked via a frame-shaped spacer such that the rubbing surfaces are opposed to each other, and the gap is filled with nematic liquid crystal. As a result, between the two substrates, the portion where the rubbing directions are orthogonal to each other is in a homogeneous arrangement of nematic liquid crystal and twisted by 90 degrees in the direction between the substrates. In this case, a partially twisted nematic liquid crystal cell having a normal homogeneous alignment parallel to the above can be manufactured. Next, polarizing plates are stacked on both sides of the liquid crystal cell.

The mask covering of the present invention may be manufactured by a method in which the outer peripheral edge of the mask is bonded to a screen mesh and then fixed to a frame while applying an appropriate tensile force to the screen mesh. In this case, the removal of the overlapping portion other than the bonding portion between the screen mesh and the mask may be performed before or after the bonding of the two.

[Brief description of the drawings]

FIG. 1 is a front view of a mask upholstery of the present invention, and FIG.
-B sectional view, FIG. 3 is an enlarged view of a main part of the substrate, FIG. 4 is a schematic front view of a mask rubbing apparatus, FIG. 5 is a right side view thereof,
FIG. 6 shows a plan view of the substrate setting device. In the figure, 1 ... mask covering, 2 ... substrate, 11 ... frame, 12
…… Screen mesh (membrane), 13… Cutout, 14
… Mask, 30… Mask rubbing device, 40… Substrate setting device, 50… Roller device

 ────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-54-40652 (JP, A) JP-A-62-164316 (JP, A) JP-A-62-110924 (JP, A)

Claims (1)

(57) [Claims] 1. A rubbing mask stretcher comprising a frame, a mask disposed in the frame, and a film stretched between an outer periphery of the mask and the frame and pulling the mask with an appropriate tension. .