JP2002020513A - Method for etching - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for etching a resin film, by which the resin film can be etched in a short time anisotropically to the thickness direction of the resin film in a beautifully and uniformly arranged etching shape. SOLUTION: This method for etching the resin film, characterized by irradiating laser light before the etching and/or during the etching.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for etching a resin film used for a wiring board.

[0002]

2. Description of the Related Art Conventionally, as a method of etching a resin such as polyimide, a method of wet etching using a solution containing hydrazine as a main component has been disclosed (JP-A-3-101228, JP-A-5-101228). 2022
No. 06), and another etching method using potassium hydroxide is disclosed (Japanese Patent Application Laid-Open No. 5-301981).

However, in the usual wet etching method, there are materials that require a very long time for etching, and in some cases, materials that cannot be wet-etched. For example, it takes a very long time to wet-etch a polyimide "Upirex S" manufactured by Ube Industries, Ltd., a polyamide "Mictron" manufactured by Toray Industries, Inc., and a liquid crystal polymer "Vectra" manufactured by Polyplastics Co., Ltd. Was not realistic. Even in a material that can be easily wet-etched, unevenness often occurs in the etching. Especially when etching is performed on a large area or continuously, it is difficult to etch the entire surface in a clean shape. In addition, generally, the finer the pattern, the longer the etching time and the problem that the variation in the etching increases. Furthermore, since the lateral direction and the thickness direction of the film to be etched are usually etched only to the same extent, it is difficult to etch a fine pattern as the film to be etched becomes thicker.

[0004]

SUMMARY OF THE INVENTION In view of the background of the prior art, the present invention enables anisotropic etching in a thickness direction of a film to be etched in a short time and has an etched shape. It is an object of the present invention to provide an etching method capable of performing a clean and uniform etching.

[0005]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the etching method of the present invention is characterized in that when etching a resin film, a laser is irradiated before and / or during the etching.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has been made to solve the above-mentioned problem, that is, it is possible to anisotropically etch a film to be etched in a short time in a short time and to obtain a clean etching shape. We studied the etching method that can perform uniform and uniform etching, and conducted laser irradiation before and during etching, and surprisingly found that this problem could be solved all at once. is there.

The laser irradiation of the present invention can be performed before etching, during etching, or both. Irradiation before etching is effective mainly for modifying the surface of the film to be etched. By modifying the surface, the resin film can be etched anisotropically in the thickness direction, and the etching time can be reduced. It also leads to shortening. When the irradiation is performed during the etching, it is mainly effective in improving the etching efficiency, the etching can be performed in a short time, and the etching can be completed before the unnecessary etching of the resin film occurs in the lateral direction. Can be etched anisotropically in the thickness direction of the resin film. If both effects are desired, both irradiation methods may be used in combination.

The types of lasers used in the present invention include a carbon dioxide laser (wavelength 10.6 μm), a YAG laser (wavelength 1.06 μm), a second harmonic YAG laser (wavelength 532 nm), and a third harmonic YAG laser. (Wavelength 355 nm), fourth harmonic YAG laser (wavelength 26
6 nm), KrF excimer laser (248 nm), A
rF excimer laser (193 nm), XeCl excimer laser (308 nm), XeF excimer laser (351 nm), F ₂ excimer laser (wavelength 157 n)
m), a copper vapor laser (578 nm, 511 nm), a wavelength-converted copper vapor laser (255 nm), or the like, but is not limited thereto.

The output of the laser depends on the type of the resin film to be etched.
If the output is too large, it is not preferable because the resin film is greatly damaged and the etching mask may be damaged. On the other hand, if the output is too small, the etching efficiency will deteriorate. From these points, the laser power is 0.0
01 to 1000 W is preferable, and more preferably 0.01 to 1000 W
~ 500W.

In the present invention, the laser irradiation time at the time of etching is not particularly limited, but when irradiation is performed before etching, a surface modification time suitable for each resin film is selected. When the irradiation is performed during the etching, the irradiation is preferably performed intermittently, that is, it is preferable that the laser irradiation time and the laser non-irradiation time are alternately provided during the etching. By performing laser irradiation intermittently,
Etching can be performed more uniformly than simple laser irradiation. That is, although the etching efficiency is improved by laser irradiation, it is difficult to control the etching rate, but by providing a time during which laser irradiation is not performed, the entire variation can be suppressed, and as a result, the uniformity can be improved. The method of irradiating the laser or the case of not irradiating the laser is optional, and it is optional depending on the type of the film to be etched. When such etching is performed a plurality of times, the type of laser may be the same or may be changed each time. When using ultrasonic waves together, the frequency of the ultrasonic waves may be appropriately changed. Further, the etching temperature may be appropriately changed. Further, it is optional to add another step such as washing in the middle. Specific examples of intermittent etching include, for example, first etching for 1 to 10 minutes while irradiating laser, then stopping laser irradiation, etching for 1 to 10 minutes, and etching again for 1 to 10 minutes while irradiating laser. Method. In this case, the laser output may be constant, but the laser output may be gradually reduced.

The method of irradiating a laser beam may be such that the sample is directly illuminated with a laser beam, or may be condensed by a lens or reflected by a mirror.

According to the present invention, the resin film can be etched in a short time, without variation, uniformly and in a clean shape, and can be etched anisotropically. Since the resin film can be etched in a short time, work efficiency is remarkably improved, and it is very effective especially when a strip-shaped resin film is continuously etched. In addition, since etching can be performed uniformly without variation, a large-area resin film can be etched at a time, etching can be performed with uniform quality, and work efficiency can be improved. Further, since etching can be performed with a clean shape, not only is it advantageous in forming a fine pattern, but also steps such as plating after etching are facilitated. Being able to perform anisotropic etching is advantageous for forming fine patterns.

The resin film to be etched according to the present invention is, for example, polyimide (for example, “Kapton” manufactured by Toray DuPont, Ube Industries, Ltd. “Upilex”, Kanebuchi Chemical Industry Co., Ltd.) Co., Ltd., "Apical", polyamide (for example, "Mictron", manufactured by Toray Industries, Inc.), PPS (polyphenylene sulfide), PET (polyethylene terephthalate, for example, "Lumirror", manufactured by Toray Industries, Inc.), liquid crystal polymer (for example, "Siveras" manufactured by Toray Industries, Polyplastics Co., Ltd.
"Vectra" manufactured by Nippon Petrochemical Co., Ltd., etc.) are used, but are not limited thereto. The above resins may be used alone, or two or more kinds may be blended or bonded. Further, various additives may be added to the resin film. Examples of such additives include, but are not limited to, fillers such as flame retardants, glass cloth, and the like. Among these, a resin film made of polyimide, polyamide or liquid crystal polymer is particularly preferably used.

The resin film may be cut into an appropriate size or may be a strip. Further, the support may be attached to another material or may be adhered. In this case, as a support, metal, resin, glass, wood,
Paper, silicon wafers and the like can be used.

[0015] The thickness of the resin film is not particularly limited, and a thickness suitable for the use can be selected, but is preferably 500 µm or less, more preferably 100 µm or less.

As the etching of the present invention, a wet etching method mainly using an etching solution is preferably used. As such an etchant, an etchant suitable for the resin film to be etched is selected.

That is, a polyimide film or a polyamide film,
When etching a resin film such as a liquid crystal polymer,
Hydrazine-based solutions, such as ethylenediamine, ethanolamine, diethanolamine, aliphatic amine-based solutions such as hexamethylenediamine, such as benzylamine,
p-phenylenediamine, m-phenylenediamine, 3
-Acrylylenediamine, aromatic amine-based solutions such as 4-xylylenediamine, solutions containing alkali metal compounds such as potassium hydroxide and sodium hydroxide, and alkaline solutions in which these are used, and the like. Not limited. The above-mentioned etching solution may be either non-aqueous or aqueous, and an alcohol-based compound may be added to improve the uniformity of the solution. In some cases, a non-uniform combination may be used.

The following combinations are preferred as specific combinations of the etching liquids, but are not limited thereto.

(1) Combination of potassium hydroxide / water / amine / alcohol (for example, potassium hydroxide / water / ethylenediamine / ethylene glycol, potassium hydroxide /
Water / ethanolamine / ethylene glycol, potassium hydroxide / water / ethylenediamine / ethanol, potassium hydroxide / water / ethanolamine / ethanol, potassium hydroxide / water / ethylenediamine / glycerin, potassium hydroxide / water / ethanolamine / glycerin, Potassium hydroxide / water / benzylamine / ethylene glycol),
(2) Combinations of sodium hydroxide / water / amine / alcohol (for example, sodium hydroxide / water / ethylenediamine / ethylene glycol, sodium hydroxide / water / ethanolamine / ethylene glycol, sodium hydroxide / water / ethylenediamine / ethanol, water Sodium oxide / water / aeranolamine / ethanol, sodium hydroxide / water / ethylenediamine / glycerin, sodium hydroxide / water / ethanolamine / glycerin, sodium hydroxide / water / p-phenylenediamine / ethanol), (3) water Combinations of potassium oxide / water / amine (eg, potassium hydroxide / water / ethanolamine, potassium hydroxide / water / diethanolamine); (4) Combinations of sodium hydroxide / water / amine (eg, sodium hydroxide / water / ethanol) Ruamin, sodium hydroxide /
(5) combinations of potassium hydroxide / amine / alcohol (eg, potassium hydroxide / ethylenediamine / ethanol, potassium hydroxide / ethanolamine / ethanol, potassium hydroxide / ethylenediamine / ethylene glycol, potassium hydroxide / ethanol) Amine / ethylene glycol), (6) combinations of sodium hydroxide / amine / alcohol (eg, sodium hydroxide / ethylenediamine / ethanol, sodium hydroxide / ethanolamine / ethanol, sodium hydroxide / ethylenediamine / ethylene glycol, sodium hydroxide / (Ethanolamine / ethylene glycol).

The temperature of the etching solution depends largely on the properties of the film to be etched, and in particular, in the case of wet etching, it depends on the etching solution. Is 40
９０90 ° C. If the temperature is too high, the composition of the etching solution changes during the etching. Conversely, if the temperature is too low, the efficiency of the etching decreases, so that the above range is preferable.

The etching method of the present invention includes a method of immersing a film to be etched in an etching solution, a method of spraying the etching solution on the film to be etched, and the like. When immersing in an etching solution, a method of further irradiating ultrasonic waves is effective. A well-known vibrator is generally used for generating the ultrasonic waves. The frequency of these vibrators is not particularly limited, but is preferably 10 to 1000 kHz.
z, more preferably 20 to 600 kHz. These vibrators may be used alone or in combination.

The ultrasonic wave may be applied in the thickness direction of the film to be etched, in the lateral direction or oblique direction of the etched film, but more preferably in the thickness direction of the film to be etched. Better.

In the case of spraying an etching solution, a method is generally used in which a spray nozzle is attached to the tip of a blowout port and blown out by pressure. The shape of the spray nozzle is not particularly limited. For example, a mini mist, a round mist, an air injection nozzle, a descaling nozzle, a QC nozzle, a flat spray nozzle, a wide flat nozzle, an oblong nozzle, an oblique nozzle manufactured by Kyoritsu Gosei Co., Ltd. Flat nozzle, side spray nozzle, side spray nozzle, full cone nozzle, square nozzle, elliptical nozzle,
Spiral nozzles, hollow cone nozzles, cleaning nozzles, needle jet nozzles, and the like are used, but are not limited thereto. A single nozzle or a plurality of nozzles may be used, or different types of nozzles may be used in combination.

The pressure to be blown out also varies greatly depending on the type and thickness of the film to be etched.
Preferably, means for jetting at a pressure of 9000 to 10000000 Pa is employed. The jetting direction may be jetted from the thickness direction of the film to be etched, or from the lateral direction or oblique direction of the etching film, but more preferably the thickness direction of the film to be etched.

Next, a series of procedures of the etching method according to the present invention will be described, but the present invention is not limited to this method.

First, an etching mask (a copper mask, a stainless steel mask, a resist mask, etc.) is formed on the resin film. Examples of the mask forming method include a method of bonding the resin film to the resin film via an adhesive, a method of directly forming the mask on the resin film by sputtering or plating, and a method of adhering to the resin film. The mask may have a pattern formed in advance, or may be patterned after being formed on the resin film. Examples of the pattern formation of the mask include a method using a resist, a laser processing method, and the like.

After a patterned mask is formed on the resin film, an appropriate etchant is supplied from the mask side while irradiating laser to perform etching. Alternatively, a laser is first irradiated in advance, and then an etching solution is supplied from the mask side to perform etching. Examples of the method for supplying the etchant include a method in which the resin film is immersed in the etchant, a method using a spray, and the like. Since etching is usually performed only from one side, it is preferable to protect the side of the resin film where the mask is not formed with an appropriate material. Examples of the protective material include copper, stainless steel, and resist.

The resin film treated by the etching method according to the present invention has through holes according to the etching pattern. By embedding a metal (such as copper or aluminum) for conduction in the through-hole, conduction on both sides of the resin film can be achieved. Further, by providing wiring on both surfaces of the resin film, a wiring board of two-layer wiring in which both surfaces are electrically connected can be obtained.

According to the present invention, since holes for conducting can be finely formed in a good shape, the area which can be used for wiring increases accordingly, and as a result, a high-density wiring board can be formed. High-density wiring boards can be used in a wide range of applications from large substrates such as motherboards for personal computers to small substrates such as interposers for CSP (chip scale package).

[0030]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 and Comparative Example 1 A polyimide film “Kapton EN”, “Upilex S”, “Apical NPI”, a polyamide film “Mictron”, and a liquid crystal polymer film “Vectra CX” were cut into a size of 50 mm × 50 mm. . These resins were subjected to chromium sputtering, copper sputtering, and copper plating to form copper foils having a thickness of 8 μm on both surfaces. On both sides of this copper foil, a positive type photoresist “AZ P40” manufactured by Hoechst Co., Ltd.
"00" was applied by a spin coater and dried on a hot plate at 100 ° C. for 3 minutes. The dry film thickness was 10 μm.

Next, holes of 300 μmφ are formed every 2 mm.
One side was exposed at 300 mJ / cm ² with a g-line stepper using masks arranged in a grid of 4 × 24 pieces.
The Z400K developer was developed for 3 minutes using a developer diluted 5 times with water to form a 300 μmφ pattern suitable for the mask in a grid pattern.

Using the patterned photoresist as a copper etching mask, an aqueous solution of iron chloride at 40 ° C. as an etching solution, and a pressure of 196 from a full cone nozzle (model number 1/4 KSFHS0665) manufactured by Kyoritsu Alloys Co., Ltd.
An aqueous solution of iron chloride was sprayed at 133 Pa to perform etching for 5 minutes.

After completion of the etching of the copper, the photoresist is removed.
g, ethylene glycol 44 g, ethylene diamine 22
g and 68 g of water at 70 ° C. for immersion, etching while irradiating with a carbon dioxide laser manufactured by Mitsubishi Electric Corporation at an output of 10 W, and observing the time until the holes penetrate.

For comparison, the same etching was performed without irradiating a laser.

The results are as shown in Table 1. By irradiating a laser, any material from a thick resin to a thin resin could be etched in a short time. Without laser irradiation, "Upilex S", "Mictron", and "Vectra CX" could not be etched, and "Kapton EN" and "Apical NPI" also required a long time for etching.

[0037]

[Table 1]

Example 2 and Comparative Example 2 A 504 mm wide roll-shaped sample of polyimide film "Kapton EN", "Upilex S", "Apical NPI", polyamide film "Miktron", liquid crystal polymer film "Vectra CX" was used. First, a copper mask was formed in the same manner as in Example 1.

After forming the copper mask, 33 g of potassium hydroxide,
22 g of ethylene glycol, 11 g of ethylene diamine,
Using an etching solution composed of 66 g of water at 70 ° C., immersing while irradiating ultrasonic waves at 38 kHz from the copper mask side, etching while irradiating with a KrF excimer laser manufactured by Lambda Physic at an output of 0.1 W, and the holes were etched. The time until penetration, the etching shape, and the variation in etching were observed.

For comparison, the same etching was performed without irradiating a laser.

The etching time in Example 2 and Comparative Example 2 was 504 mm × 504 m, which is the size of the mask.
Assuming that m is one unit, the etching of one unit is completed and the etching of the next unit is continued, and the etching is continuously performed for 20 hours. The average of the etching time required for one unit is defined as the etching time.

The results are as shown in Table 2. By irradiating a laser, any material, from a thick resin to a thin resin, could be uniformly etched in a short time in a good shape.

However, when laser irradiation is not performed, “Upilex S”, “Mictron”, “Vectra CX”
In this case, etching could not be performed, and “Kapton EN” and “Apical NPI” also had poor shapes, and there were many variations depending on locations.

[0044]

[Table 2]

Example 3 A 5 cm square piece of a metal royal film (a material in which a 25 μm thick polyimide film “Kapton EN” and a 8 μm thick copper film formed on both surfaces) was cut off by Toyo Metallizing Co., Ltd. . Copper etching was performed in the same manner as in Example 1 except that a mask constituted of a circular pattern of 40 to 150 μmφ was used.

After the etching of the copper, the photoresist is removed.
g, ethylene glycol 22 g, ethylene diamine 11
g and 34 g of water at 60 ° C. using a hollow cone nozzle (model number KSC005) manufactured by Kyoritsu Gosei Seisakusho Co., Ltd. at a pressure of 490332.5 Pa.
Then, the etching solution was sprayed in the thickness direction of the film, and the etching was performed while changing the time while irradiating at 1 W using a YAG (third harmonic) laser manufactured by Mitsubishi Electric Corporation.

After completion of the polyimide etching, copper was removed using an aqueous solution of iron chloride, and the shape of the etched polyimide was observed. The results are as shown in Table 3, and good etching was performed in a short time.

The "anisotropic in the thickness direction with respect to the horizontal direction" indicates the ratio of how much the film is etched in the horizontal direction as compared with the thickness of the etched film.

In Table 3, for example, when the mask setting pattern diameter is 15
In the case of 0 μm, the difference between the polyimide pattern diameter on the resist side and the polyimide pattern diameter on the bottom side is 30 μm. In the case of the horizontal direction, the etching is performed not in one direction but in two directions, so that the etching is 15 μm in the horizontal direction. Since the thickness of the etched polyimide film is 25 μm, in this case, 25 ÷ 15 = 1.7 (times) becomes anisotropic.

[0050]

[Table 3]

Example 4 A metal royal film manufactured by Toyo Metallizing Co., Ltd. (a material in which a copper film having a thickness of 8 μm was formed on both sides of a polyimide film “Kapton EN” having a thickness of 50 μm) was used as a copper etching solution. Example 3 except that an aqueous copper solution was used.
, And copper was etched.

After the completion of the etching of copper, the photoresist is removed.
g, monoethanolamine 22 g, ethylenediamine 1
OXFORD using an etching solution for polyimide composed of 1 g and 34 g of water at 50 ° C. while irradiating ultrasonic waves from the copper mask side at 950 kHz to the etching solution.
Output 0.01W using LASERS copper vapor laser
Etching was performed while changing the time while irradiating with.

After the completion of the polyimide etching, copper was removed using an aqueous solution of copper chloride, and the shape of the etched polyimide was observed. The results are as shown in Table 4, and good etching was performed in a short time.

[0054]

[Table 4]

Example 5 Chromium and copper were sputtered on one side of a 25 μm thick polyamide film “MICRON” in this order, and then 8 μm thick copper films were formed on both sides by electrolytic plating. Using this material, copper was etched in the same manner as in Example 3.

After the etching of the copper, the photoresist is removed. This time, using copper as a mask, potassium hydroxide 10
g, 43 g of monoethanolamine, 1 ethylenediamine
Using an etching solution for polyamide composed of 1 g and 36 g of water at 80 ° C., immersing in an etching solution while irradiating ultrasonic waves at 100 kHz from the copper mask side, and irradiating with an output of 1 W using an XeCl excimer laser manufactured by Lambda Physics. The etching was performed while changing the time.

After the completion of the polyamide etching, copper was removed using an aqueous iron chloride solution, and the shape of the etched polyamide was observed. The results are as shown in Table 5, and good etching was performed in a short time.

[0058]

[Table 5]

Example 6 A liquid crystal polymer film "VECTRA CX" having a thickness of 50 μm.
Was sputtered with chromium and copper in this order, and then a copper film having a thickness of 8 μm was formed on both surfaces by electrolytic plating. Using this material, copper was etched in the same manner as in Example 3.

After completion of the etching of copper, the photoresist is removed.
g, 43 g of monoethanolamine, 1 ethylenediamine
Using an etching solution for liquid crystal polymer composed of 1 g and 26 g of water at 80 ° C., immersing it in the etching solution while irradiating ultrasonic waves from the copper mask side at 200 kHz, YAG manufactured by Hyper Photon System Co., Ltd. (Harmonic) Etching was performed using laser at an output of 10 W while changing the time.

After completion of the liquid crystal polymer etching, copper was removed using an aqueous solution of iron chloride, and the shape of the etched liquid crystal polymer was observed. The results are as shown in Table 6, and good etching was performed in a short time.

[0062]

[Table 6]

Example 7 The sample obtained by etching copper in Example 3 was used.
After the copper etching was completed, the photoresist was removed. Then, using a carbon dioxide laser manufactured by Sumitomo Heavy Industries, Ltd., a laser having an output of 0.02 W was irradiated from the patterned copper side for 2 minutes. After laser irradiation, this time using copper as a mask, the polyimide etchant used in
Using 0 ° C., ultrasonic waves were irradiated from the copper mask side at 200 kHz, immersed in an etching solution, and etched while changing the time while irradiating with a carbon dioxide laser manufactured by Mitsubishi Electric Corporation of Example 1 at an output of 10 W.

After the completion of the polyimide etching, copper was removed using an aqueous solution of iron chloride, and the shape of the etched polyimide was observed. The results are as shown in Table 7, and good etching was performed in a short time.

Example 8 The sample obtained by etching copper in Example 5 was used.
After the copper etching was completed, the photoresist was removed. Then, using a Lambda Physic ArF excimer laser, a laser having an output of 0.02 W was irradiated from the patterned copper side for 2 minutes. After the laser irradiation, using a copper mask as a mask, the etching solution for polyamide used in Example 5 was used at 80 ° C., and ultrasonic waves were irradiated from the copper mask side at 38 kHz to be immersed in the etching solution. Etching was performed while changing the time while irradiating with a carbon dioxide laser manufactured by Denki Co., Ltd. at an output of 10 W.

After the polyamide etching was completed, copper was removed using an aqueous solution of iron chloride, and the shape of the etched polyamide was observed. The results are as shown in Table 7, and good etching was performed in a short time.

[0067]

[Table 7]

Comparative Example 3 Example 3 was carried out in the same manner as in Example 3 except that the laser was not irradiated during the etching of the polyimide. The etching required a longer time than in Example 1, and the etching was distorted and had many variations.

Comparative Example 4 The procedure of Example 4 was repeated, except that the laser was not irradiated during the etching of the polyimide. It took a longer time for etching compared to Example 2, and the etching was distorted and had many variations.

Comparative Example 5 The procedure of Example 5 was repeated, except that the laser was not irradiated during the etching of the polyamide. A longer time was required for etching than in Example 3, and etching could not be performed.

Comparative Example 6 The procedure of Example 6 was repeated, except that the laser was not irradiated during the etching of the liquid crystal polymer. A longer time was required for etching than in Example 4, and the etching could not be performed. Example 9 The sample obtained by etching copper in Example 3 was used.
After the etching of copper, the photoresist is removed, and this time using copper as a mask, an etching solution for polyimide composed of 33 g of potassium hydroxide, 22 g of ethylene glycol, 11 g of ethylenediamine, and 34 g of water is used at 70 ° C.
Hollow cone nozzle (KSC)
005), an etching solution is sprayed in the thickness direction of the film at a pressure of 490332.5 Pa, and Hyper Photon Co., Ltd.
Etching was performed for 120 seconds using a system YAG (second harmonic) laser while irradiating in the thickness direction at an output of 0.01 W.

Next, laser irradiation was stopped and the same etching was performed for 120 seconds.

After completion of the polyimide etching, copper was removed using an aqueous solution of iron chloride, and the shape of the etched polyimide was observed. The results are as shown in Table 8, and good etching was performed in a short time.

Example 10 The same procedure as in Example 9 was carried out except that the polyimide was etched for 120 seconds without laser irradiation, and then etched for 120 seconds with laser irradiation. To etch the polyimide.

After the completion of the polyimide etching, the copper was removed using an aqueous solution of iron chloride, and the shape of the etched polyimide was observed. The results are as shown in Table 8, and good etching was performed in a short time.

[0076]

[Table 8]

Example 11 The sample obtained by etching copper in Example 5 was used.
After the etching of the copper, the photoresist is removed. This time, using copper as a mask, potassium hydroxide 33 having the following composition is used.
g, monoethanolamine 22 g, ethylenediamine 1
Using an etching solution for polyamide consisting of 1 g and 34 g of water at 70 ° C., immersing in an etching solution while irradiating ultrasonic waves from the copper mask side at 100 kHz, the KrF excimer laser manufactured by Lambda Physic of Example 2 was used. 1
Etching was performed for 80 seconds while irradiating with W in the thickness direction.

Next, laser irradiation was stopped and the same etching was performed for 80 seconds. Thereafter, the same etching was performed for 80 seconds while performing laser irradiation again. After the end of polyamide etching, copper is removed using an aqueous copper chloride solution,
The shape of the etched polyamide was observed. The results are as shown in Table 9, and good etching was performed in a short time.

Example 12 In Example 11, when the polyamide was etched, etching was first performed for 80 seconds without laser irradiation, then etching was performed for 80 seconds while irradiating laser, and then again for 80 seconds without laser irradiation. The polyamide was etched in the same manner as in Example 11 except that etching was performed. After the end of the polyamide etching, copper was removed using an aqueous solution of iron chloride, and the shape of the etched polyamide was observed. The results are as shown in Table 9, and good etching was performed in a short time.

[0080]

[Table 9]

[0081]

According to the present invention, the resin film used for the wiring board can be anisotropically etched in the thickness direction in a short time.

Claims (5)

[Claims] 1. An etching method, comprising: irradiating a laser beam before and / or during etching of a resin film. 2. The etching method according to claim 1, wherein said etching is performed by a wet etching method using an etching solution. 3. The etching method according to claim 1, wherein the resin film is at least one selected from the group consisting of polyimide, polyamide, polyphenylene sulfide, polyethylene terephthalate, and liquid crystal polymer. 4. The laser according to claim 1, wherein said laser is a carbon dioxide gas laser, YAG.
4. The etching method according to claim 1, wherein the etching method is at least one selected from a laser, an excimer laser, and a copper vapor laser. 5. The etching method according to claim 1, wherein the method of irradiating the laser during the etching is a method of performing the irradiation intermittently.