JP2002060927A - Mask for thin film pattern deposition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mask for thin film pattern deposition with which an excellent color filter where a desired thin film pattern is deposited particularly on a multiple printing color filter can be obtained. SOLUTION: In addition to the primary pattern openings in the mask for thin film pattern deposition, dummy openings are further provided to their peripheries. Moreover, the occupancy of the dummy openings in the mask ranges from 2 to 20%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a mask for forming a thin film pattern.

[0002]

2. Description of the Related Art A color liquid crystal display of a TFT type has a color filter at a position facing a liquid crystal layer. This color filter has an IT
A transparent conductive thin film such as an O film is formed. A sputtering method is generally used as the film forming method, and a masking sputtering method for forming and forming a desired thin film pattern on a color filter using a metal mask is known as a conventional technique.

[0003]

However, the substrate 1
When ITO, which is one of the transparent conductive films, is formed on a multi-colored color filter having a pattern of 6 or more per sheet using a conventional metal mask, the film is formed by thermal expansion of the metal mask. Since the mask is deformed inside and the adhesion to the color filter is deteriorated, the color filter after film formation has a film formation defect called pattern blur which makes the boundary portion of the ITO film unclear, and a desired thin film pattern is formed. Is not obtained. The film formation accuracy of the ITO film pattern is one of the important quality factors of the color filter. If the film formation accuracy is poor, a display defect of the liquid crystal display may be caused.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and in particular, a mask for forming a thin film pattern capable of forming a good color filter in which a desired thin film pattern is formed on a multi-cavity color filter as described above. The purpose is to provide.

[0005]

According to the mask for forming a thin film pattern according to the present invention, a dummy opening is provided around the original pattern opening in addition to the original pattern opening, and the occupancy of the dummy opening in the mask is 2%. -20%.

The dummy openings absorb the thermal expansion of the mask during thin film formation, maintain the adhesion between the mask and the color filter, and provide a color filter free from film formation defects.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is characterized in that a mask for forming a thin film pattern is provided with a dummy opening in addition to the original pattern opening. Further, the occupancy of the dummy opening in the mask is 2 to 20.
%.

The dummy opening is provided outside the portion of the substrate to be cut. Further, the mask area occupation ratio of the dummy opening is suitably 2 to 20%. If it is less than 2%, pattern blur occurs without fulfilling the role of absorbing thermal expansion, which is not preferable. On the other hand, if it exceeds 20%, the deposited film is likely to be deformed when the cleaning of the deposited film by blasting is repeated, and the flatness of the mask is impaired. More preferably, the mask area occupancy of the dummy opening is 9
１１11%.

The thin film formed in the dummy opening is a portion which is removed by a cutting process in a later step, so that there is no problem in a product.

The thin film forming mask according to the present invention is desirably made of a metal such as stainless steel or 42 alloy in consideration of handling properties and enabling multiple uses.

[0011]

Embodiment 1 Hereinafter, as an embodiment of the present invention, an example in which an ITO film, which is one of transparent conductive films, is formed on a 3.5 inch × 20 chamfered color filter will be described.

FIG. 1 is a configuration diagram of a mask for forming a thin film pattern according to an embodiment of the present invention before film formation, and FIG. 2 is a configuration diagram of FIG. 1 after film formation.

This color filter is formed after forming the ITO film.
It is cut into a size of 360 × 465 mm to 320 × 400 mm. Note that the color filter pattern of 320 × 400 mm is 360 × 465 mm before cutting.
Located at the center of the substrate.

First, the structure of the thin film pattern forming mask of the present invention will be described. As shown in FIG. 1, an original color filter pattern opening 2 is formed in a stainless steel plate having a length of 360 mm, a width of 470 mm and a thickness of 2 mm. Thereafter, a dummy opening 3 is formed therearound, and a mask 1 for forming a pattern for a thin film is manufactured.

At this time, the mask area occupancy of the color filter pattern opening 2 is about 50%, and the mask area occupancy of the dummy opening 3 is 10%.

Next, as shown in FIG. 2, a pattern made of an ITO film is formed on a 3.5 inch × 20 chamfered color filter substrate 4 using the mask 1. The method for forming the ITO film is a sputtering method. The film forming conditions are a pressure of 0.2 Pa, a temperature of 200 ° C., and a film thickness of about 140 nm.

As a result of inspecting the appearance after forming the ITO film, it was confirmed that all the film patterns were patterned at predetermined positions without film defects such as blur.

Using this mask, 200 color filters were formed, but no film formation defects such as blurring were observed.

After forming the ITO film, 360 × 4
A 65 mm substrate is cut into 320 × 400 mm. The dummy film-forming portion 7 formed through the dummy opening 3 of the mask 1 is designed so as to be removed at the time of the cutting process, so that there is no problem as a product at all.

Comparative Example 1 A mask for forming a thin film was formed on a stainless steel plate having the same size as in the example and only the pattern opening 2 was formed, and an ITO film was formed on the same color filter as in the example under the same conditions.
As a result of film formation on 100 sheets, film formation defects such as pattern blurring were observed in almost all of them. Many pattern blurs were observed especially at the center of the substrate.

Comparative Example 2 A pattern opening 1 was formed in a stainless steel plate having the same size as that of the embodiment.
Was formed, a mask provided with a dummy opening having a mask area occupancy of 21% was manufactured, and an ITO film was formed on the same color filter as in the example under the same conditions. As a result of film formation on 24 sheets, no pattern blurring was observed, but about half of the 11 sheets showed scratches due to contact with the mask. Since the mask area occupation ratio of the dummy opening was too large, the strength of the mask was reduced and the mask was deformed, so that the flatness was impaired, and the pattern edge was brought into contact with the substrate to cause a flaw.

[0022]

According to the present invention, a color filter can be formed without generating a film formation defect such as pattern blur at the time of forming a transparent conductive thin film, and the color filter is excellent in quality. A color filter can be obtained.
In particular, the effect is remarkable when a transparent conductive thin film is formed on a multi-colored color filter having six or more substrates per substrate.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a mask for forming a thin film pattern according to an embodiment of the present invention before film formation.

FIG. 2 is a configuration diagram after forming a thin film pattern forming mask according to an embodiment of the present invention.

[Explanation of symbols]

 1: Pattern forming mask 2: Pattern opening 3: Dummy opening 4: Substrate (mother) 5: Color filter (Pattern forming part) 6: Cutting line 7: Dummy forming part

Claims (1)

[Claims] In a mask for forming a thin film pattern, in addition to an original pattern opening, a dummy opening is further provided around the opening, and the occupancy of the dummy opening in the mask is within a range of 2 to 20%. A thin film pattern deposition mask, characterized in that: