JP2000047399A - Development processing method for resist film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the growth of an oxidized film on a surface to be etched on which a metallic film is exposed and to exactly etch the surface by removing the unnecessary portions of a resist film on the main surface of a metallic thin sheet, then heating the resist film in an inert gas atmosphere at the time of drying the film. SOLUTION: The metallic thin sheet 28 which is exposed with the surface to be etched by supplying a developer to the metallic sheet thin 28 formed with the resist film baked with prescribed patterns on the main surface to remove the unnecessary portions of the resist film is dried by heating. At this time, the metallic thin sheet 28 is heated up to about 200 deg.C in an inert gas, for example, gaseous nitrogen atmosphere while the metallic thin sheet 28 passes the inside of a burning chamber 48. Since the metallic thin sheet 28 is heated in the gaseous nitrogen atmosphere, the growth of the oxidized film on the surface to be etched on which the metallic surface is exposed by the removal of the resist film is suppressed. In such a case, the spacing between the inside wall surface of the chamber and the metallic thin sheet 28 is preferably as narrow as possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of processing a shadow mask for a color picture tube, an aperture grill for a trinitron tube (registered trademark of Sony Corporation), and the like by using a photoetching method to form a thin metal plate. The present invention relates to a resist film developing method for developing a resist film formed on a main surface of a metal substrate and having a predetermined pattern printed thereon in a series of manufacturing steps.

[0002]

2. Description of the Related Art For example, a shadow mask is generally manufactured by carrying out various processes on a thin metal sheet by a photo-etching method while conveying a long metal sheet in the longitudinal direction. More specifically, a cleaning step of cleaning a long metal sheet conveyed in the longitudinal direction, removing oil and the like attached to the main surface and washing with water, and applying a photosensitive method to the main surface of the cleaned metal sheet. Coating and drying a resist having a main surface of a thin metal plate, a coating process of forming a resist film on the main surface of the thin metal plate, a resist film formed on the main surface of the thin metal plate, a predetermined shape corresponding to an electron beam passage hole to be formed. A baking process for baking the pattern, a developing process for dissolving and removing unnecessary portions of the resist film on the main surface of the thin metal sheet according to the baked pattern, and a developing process for etching the etched surface where the resist film is removed and the metal surface is exposed. Through a number of processing steps such as an etching step to peel off the resist film from the main surface of the metal sheet,
After performing a predetermined processing on the metal sheet in each processing step, finally, by cutting the metal sheet in which a large number of through-holes to be electron beam passing holes are formed into a single-wafer form,
A shadow mask is manufactured.

[0003] In the developing process of the above series of manufacturing steps, for example, as disclosed in Japanese Patent Application Laid-Open No. 7-128866, first, hot water or the like is applied to the main surface of a metal sheet conveyed in the longitudinal direction. Spray and supply the developer
Unnecessary portions of the resist film formed on the main surface of the thin metal plate are dissolved and removed according to a predetermined pattern. Next, the thin metal plate is dipped in a hardening solution such as an aqueous solution of chromic anhydride to harden the resist film. Then, after supplying hot water or the like to the metal sheet and washing it, finally, the metal sheet is heated using an infrared heater or the like in a burning chamber to dry the resist film on the main surface of the metal sheet. Done.

[0004]

By the way, in the above-described developing step, when the metal sheet after resist removal, hardening and washing is heated in a burning chamber,
A phenomenon is observed in which the resist film is removed from the main surface of the thin metal plate and an extremely thin oxide film grows on the etched surface where the metal surface is exposed. in this way,
An oxide film grows on the surface to be etched of the main surface of the thin metal plate by heating during the drying process, and when a thick oxide film is formed on the surface to be etched, the surface to be etched can be accurately formed as desired in a subsequent etching step. The problem arises that etching cannot be performed at the same time.

The present invention has been made in view of the above circumstances, and removes an unnecessary portion of a resist film on a main surface of a metal thin plate according to a predetermined pattern, and then heats the metal thin plate to form a resist film. When the resist film is dried, the oxide film can be prevented from growing on the etched surface where the metal surface is exposed by removing the resist film, and the etched surface can be accurately etched in a later etching process to obtain a desired shape. It is an object of the present invention to provide a method for developing a resist film so that a product such as a shadow mask can be obtained.

[0006]

According to the present invention, a developing solution is supplied to a thin metal plate having a main surface on which a resist film having a predetermined pattern printed thereon is formed, and an unnecessary portion of the resist film is formed according to the predetermined pattern. A resist film developing method including a resist removing step of dissolving and removing, and a drying step of heating and drying a thin metal plate having an exposed surface to be etched which is to be etched in a subsequent etching step after the resist film is removed. In the drying step, the metal sheet is heated in an inert atmosphere.

According to the method for developing a resist film according to the present invention, when an unnecessary portion of the resist film on the main surface of the thin metal plate is removed according to a predetermined pattern, and then the resist film is dried, an oxidizing atmosphere is conventionally used. Since the metal sheet is heated not in the atmosphere but in an inert atmosphere, the growth of the oxide film on the etched surface where the resist film is removed and the metal surface is exposed is suppressed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIG.

FIG. 1 shows an example in which the present invention is applied to a manufacturing process of a shadow mask, and shows an overall configuration of a developing apparatus used for carrying out a resist film developing method according to the present invention. It is a schematic diagram which shows an example. This device has a long metal sheet (shadow mask material) supply unit 1
0, an accumulator 12, a resist removing unit 14, a hardening solution supply unit 16, a washing unit 18, a draining unit 20, a burning unit 22, and a metal sheet winding unit 24.

[0010] The thin metal sheet supply section 10 is provided with a thin metal sheet having a baking-completed resist film formed on the main surface thereof.
6 from the coil 26 to the sheet metal 28
Are fed out continuously. The metal sheet 28 fed from the metal sheet supply unit 10 is adjusted by the accumulator 12 so that the transport timing is adjusted and the tension is kept constant.
A developing tank 30 is provided in the resist removing section 14, and a thin metal plate 28 is introduced into the developing tank 30,
While the metal sheet 28 passes through the inside of the developing tank 30, a plurality of spray nozzles 32 arranged on both sides of the metal sheet 28 along a conveying path thereof apply hot water, for example, 40 mm, to both main surfaces of the metal sheet 28. ° C hot water is sprayed on the metal sheet 28
Unnecessary portions of the resist film on the main surface are removed according to a predetermined pattern. The hardening solution supply unit 16 is provided with a hardening solution tank 34 containing a hardening solution, for example, an aqueous solution of chromic anhydride 36. The metal sheet 28 is immersed. A pair of shower nozzles 38 are disposed above the hardening solution tank 34 on both sides of the transport path of the thin metal plate 28.
Prior to immersing the metal sheet 28 into the metal sheet 6, an aqueous solution of chromic anhydride is sprayed onto both main surfaces of the metal sheet 28 from a pair of shower nozzles 38. As a means for supplying the hardening liquid to the metal thin plate 28, in the illustrated example, the dipping method and the hanging coating method from the shower nozzle are used in combination. You may make it supply to the metal thin plate 28, and may make it use a spray system.

The washing section 18 is provided with a washing tank 40, in which a plurality of spray nozzles 42 are arranged on both sides of the metal sheet 28 along the conveying path. . Then, the thin metal sheet 28 is washed by being sprayed with hot water, for example, hot water of 40 ° C. from the plurality of spray nozzles 42 on both main surfaces while passing through the washing tank 40. At the outlet of the washing tank 40, a pair of squeezing rollers 44 and a pair of air knives 46 are provided in the transport direction.
Are sequentially arranged, and the draining section 20 drains the thin metal sheet 28 after washing. If the draining is not performed after the water washing, the distribution of the moisture in the resist film will not be uniform at the next burning process, so that a uniform hardening process cannot be performed, resulting in uneven etching during the subsequent etching process. It will be easier. Therefore, it is necessary to drain the water with the squeezing roller 44 and the air knife 46 before the burning treatment after the washing. As a means for draining, a method of squeegeeing the surface of a thin metal plate with a film or a rubber plate may be adopted.

The burning processing section 22 is constituted by arranging a number of infrared heaters 50 in a burning chamber 48 on both sides thereof along a conveying path of the thin metal plate 28. In addition, a gas supply pipe 52 connected to a supply source of an inert gas, for example, nitrogen gas, communicates with the inside of the burning chamber 48, and the inside of the burning chamber 48 is filled with nitrogen gas. While the metal sheet 28 passes through the burning chamber 48, the metal sheet 28 is heated to a temperature of about 200 ° C. in a nitrogen gas atmosphere. At this time, since the thin metal plate 28 is heated in a nitrogen gas atmosphere, growth of an oxide film on the etched surface where the resist film is removed and the metal surface is exposed is suppressed. In order to efficiently supply the inert gas to the main surface of the thin metal plate 28 in the burning chamber 48, it is desirable that the gap between the inner wall surface of the chamber and the thin metal plate 28 be as small as possible.
Further, hot air may be used to heat the metal sheet 28, or an induction heating method may be used.

The thin metal sheet 28 burned by the burning processing section 22 passes through a driving roller 54 and is wound in the form of a coil 56 by the thin metal winding section 24. Reference numeral 58 in the drawing denotes a roller for transporting a thin metal plate.

Using the developing apparatus having the above structure, the thin metal plate 28 having the resist film after baking formed on both main surfaces is removed from the resist removing section 14 and the hardening solution supply section 1.
6. The resist film formed on both main surfaces of the thin metal plate 28 is developed by carrying out the processing while sequentially transporting it to the rinsing unit 18, the draining unit 20, and the burning processing unit 22,
A metal sheet 28 having a resist film having a predetermined pattern formed on both main surfaces is obtained.

As the resist, besides milk casein, natural polymers such as fish glue, gelatin and egg white, or synthetic polymers such as PVA (polyvinyl alcohol) and polyacrylamide, as well as dichromates, diazonium salts, Generally, azide compounds are used as sensitizers.However, in order to improve the etching resistance of these resists and the adhesion to thin metal plates, the photosensitivity after removal of unnecessary portions of the resist film is improved. Diazonium salts such as chromic anhydride and dichromate, or tetrazonium salts, polydiazonium salts, para-formaldehyde condensates of p-diazophenylamine, and 4,4′-diazidostilbene-2,2 ′
The hardening treatment may be performed using a solution of a water-soluble bis azide compound such as sodium disulfonate.

In the above-described embodiment, an inert gas such as nitrogen gas is supplied into the burning chamber 48, and the metal sheet 2 is placed in the burning chamber 48 in an inert atmosphere.
8, the thin metal sheet 28 is heated and dried by a large number of infrared heaters 50. However, an inert gas, such as high temperature, heated against the main surface of the thin metal sheet conveyed in the longitudinal direction. Nitrogen gas may be supplied by an air knife method, and the metal sheet may be heated and dried in an inert atmosphere.

[0017]

According to the method for developing a resist film according to the present invention, when the unnecessary portion of the resist film on the main surface of the metal sheet is removed according to a predetermined pattern, the metal sheet is heated to dry the resist film. In addition, it is possible to suppress the growth of an oxide film on the etched surface where the resist film is removed and the metal surface is exposed, so that the etched surface is accurately etched in a later etching process,
Finally, a product such as a shadow mask having a desired shape is obtained. In addition, since the growth of the oxide film on the etched surface of the main surface of the thin metal plate is suppressed, the processing efficiency in the fining process performed before the etching process is improved.

[Brief description of the drawings]

FIG. 1 shows an example in which the present invention is applied to a manufacturing process of a shadow mask, and shows one example of an entire configuration of a developing apparatus used for performing a resist film developing method according to the present invention. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Metal thin plate supply part 12 Accumulator 14 Resist removal part 16 Hardening liquid supply part 18 Rinse part 20 Drain part 22 Burning processing part 24 Thin metal sheet winding part 28 Metal thin plate 30 Developing tank 32 Spray nozzle 34 Hardening liquid tank 36 Hardening solution (chromic anhydride solution) 38 Shower nozzle 40 Rinse tank 42 Spray nozzle 44 Squeeze roller 46 Air knife 48 Burning chamber 50 Infrared heater 52 Nitrogen gas supply pipe

Claims (1)

[Claims] A resist removing step of supplying a developing solution to a metal thin plate having a main surface on which a resist film having a predetermined pattern printed thereon is dissolved and removing unnecessary portions of the resist film in accordance with the predetermined pattern; A drying step of heating and drying a metal thin plate having an exposed surface to be etched in a later etching step after the resist film is removed, and a drying process of drying the metal thin plate. Is heated in an inert atmosphere.