JPH10118569A - Filter for fine particle classification and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a piercing stage and to improve the yield of products and the accuracy of piercing by subjecting a film consisting of a high-polymer material, such as polyethylene terephthalate(PET) or polyether sulfone, to piercing by irradiation with a laser beam. SOLUTION: The high-polymer film 101 consisting of the high-polymer material, such as PET or polyether sulfone, attracted and fixed onto a processing stage is irradiated with the laser beam 202 which is formed by patterning the laser beam from a laser beam source by a mask and is emitted from an imaging lens. This laser beam 202 is so formed as to give rise to abrasion and to execute the piercing of a hole 12. A vapor deposited metallic film 23 is formed on the processing surface of the high-polymer film 101, i.e., the surface of the side irradiated with the laser beam and, further, a wear resistant film 22 is formed on the rear surface. As a result, the simplification of the hole 12 processing stage and the improvement in the yield and the processing accuracy of the hole 12 are made possible and the low-cost filter is embodies.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a filter for separating fine particles, particularly to a filter for classifying fine particles such as toner and a method for producing the same.

[0002]

2. Description of the Related Art A mesh weaving method, an electroforming method, and an etching method are known as conventional methods for producing a mesh for classifying powders. The net weaving method literally involves weaving a wire, and the electroforming method includes, for example, the step (a) in FIG.
(F). The etching method is based on, for example, steps (a) to (e) in FIG.

As a method of manufacturing a filter for separating fine particles by an electroforming method, a method of forming a mesh by forming a pattern by photolithography on a polished stainless steel plate, then performing electroforming and peeling an electrodeposited layer, Many are known.

For example, Japanese Patent Application Laid-Open No. Hei 3-232990 discloses that a plastic master having a concave portion is molded using a master, a conductor layer is formed only in the concave portion, and then the electrodeposited layer is formed on the conductor layer by electroforming. A method for producing an extremely fine mesh product by forming a mesh is described. Japanese Patent Application Laid-Open No. 4-118831 discloses a method of manufacturing a metal mesh by forming a mesh pattern by a reduced projection method and performing plating in two stages.

[0005]

However, in the above-mentioned net weaving method, it is difficult to form fine holes, and the hole diameter varies widely. In the electroforming method using photolithography and electroforming, there are disadvantages such as an inability to obtain a yield due to a large number of steps and a long processing time. In addition, since variations in the photolithographic pattern and variations in the thickness of the electroformed film appear as variations in the filter hole diameter, there has been a problem that fine holes cannot be formed with high precision. further,
In the etching method, there is a disadvantage that the accuracy of the hole processing is reduced because the variation in the etching rate greatly affects the hole diameter.

The present invention has been made in view of the above problems, and a first object of the present invention is to provide a method of manufacturing a filter for classifying fine particles capable of simplifying a drilling process, improving yield and improving drilling accuracy. Is to do. It is still another object of the present invention to provide a method for producing a filter which enables in-situ observation when classifying fine particles.

A second object of the present invention is to provide a method for producing a filter for classifying fine particles, which can freely control the hole diameter of the filter.

A third object of the present invention is to provide a method capable of manufacturing a filter having a large pattern area and high mechanical strength.

A fourth object of the present invention is to produce a filter which, when applied to a cage of a blow-off device, can electrostatically shield the entire cage and accurately grasp and protect the charge amount. .

[0010] A fifth object of the present invention is to produce a filter which is free from film peeling due to a residue of drilling or the like.

[0011] A sixth object of the present invention is to produce a filter which does not generate residues or the like generated by drilling.

[0012]

The method for producing a filter for classifying fine particles according to claim 1 is a method for producing a filter for PET (polyethylene terephthalate), PES (polyether sulfone), PC (polycarbonate), PI (polyimide).
And the like, characterized in that a film made of a polymer material such as is perforated by laser light irradiation.

According to a second aspect of the present invention, there is provided a method of manufacturing a filter for classifying fine particles, wherein the laser optical system for irradiating a laser beam is an imaging optical system.

It is preferable to use an excimer laser, a short pulse YAG laser, or a harmonic of the YAG laser as the laser light. In this method, since the resolution of the perforation process is high, a sharp processed shape (pattern hole) with high accuracy can be obtained.

According to a third aspect of the present invention, there is provided a method of manufacturing a filter for classifying fine particles, wherein a pattern is formed by a step-and-repeat method of a laser beam. In this case, it is preferable to provide a non-mesh forming area for each step, so that the mechanical strength of the filter can be increased.

According to a fourth aspect of the present invention, there is provided a method for producing a filter for classifying fine particles according to the first aspect, wherein the surface of the film processed after perforation (the surface on the side irradiated with the laser beam, that is, the surface on the side where the diameter of the perforated hole is large) It is characterized in that a metal such as Ni, W, Ti, or Al is deposited. Instead of this method, an abrasion-resistant film such as Ti, W, or Pt is deposited on the back surface of the processed film surface after drilling (the surface opposite to the laser beam irradiation side, that is, the surface with the smaller diameter of the drilled hole). Alternatively, the filter after perforation may be subjected to electroless plating of Ni, Co, or the like. According to these methods, it is possible to prevent the filter from being damaged due to the collision of fine particles at the time of classification.

The method for producing a filter for classifying fine particles according to claim 5 is characterized in that, in claim 1, a metal foil is formed on a film by vapor deposition or electrodeposition and then perforation is performed.

According to a sixth aspect of the present invention, in the method for producing a filter for classifying fine particles, the assist gas such as He, N ₂ , dry air or the like is blown onto the film processing surface and the assist gas is blown. And performing drilling while performing in parallel.

According to a seventh aspect of the present invention, there is provided a filter for classifying fine particles, which is manufactured by the manufacturing method according to any one of the first to sixth aspects.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 (according to claims 1 and 2) FIG. 1 is a schematic diagram showing a configuration of a laser processing apparatus. In this laser processing apparatus, a laser optical system for irradiating laser light is used as an imaging optical system, and a film such as PET is irradiated with laser light to perform a perforation process. In FIG. 1, 1 is a laser light source (excimer laser), 2 is a beam shaping optical system, 3 is a mask, 4 is a condenser lens, 5 is a plane mirror, 6 is an imaging lens, and 7 is a processing stage, that is, XY-.
It is a Z table. The film 101 to be perforated is disposed on the XYZ table 7.

In the above laser processing apparatus, the laser beam 201 oscillated from the light source 1 is made uniform by the beam shaping optical system 2 and irradiated on the mask 3. The laser beam 202 patterned by the mask 3 is imaged on the film 101 disposed on the processing stage 7 through the projection optical system 8 including the condenser lens 4 and the like.

It is considered that the boring process can be performed only by condensing the laser beam. However, it is preferable to use an image forming process for a laser beam having a relatively large irradiation beam such as an excimer laser. Is improved. Also,
The diameter of the processing hole can be controlled by adjusting the positional relationship among the mask 3, the imaging lens 6, and the processing stage 7.

Embodiment 2 When a fourth harmonic of YAG or a laser having a short wavelength such as a KrF excimer laser is used as a laser beam, the binding energy of the polymer material constituting the film can be directly cut off, so that a sharp The processed shape can be obtained. Further, even in the case of a YAG fundamental wave having a relatively long wavelength, by shortening the pulse, it is possible to perform a perforation process that suppresses the thermal effect.

Third Embodiment (Embodiment 3) In this embodiment, a pattern is formed by a step-and-repeat method of a laser beam, for example, as shown in FIG. This drawing is a schematic diagram in a case where a hole 12 has been drilled in a hexagonal area 11 in order to form a hole over a large area. By controlling the interval of the step feed at the time of processing, a non-mesh portion can be arranged on the film 101 for each step. FIG. 3 shows a processing cross section of the hole 12 when the laser beam 202 is irradiated from above, and the hole diameter on the irradiation side is formed somewhat larger in principle. Therefore, in order to avoid clogging at the time of classification, it is necessary to place fine particles on the small diameter side.

Fourth Embodiment FIG. 4 is a schematic perspective view showing a main structure of a classification device 31 provided with a filter 21 manufactured according to the present invention. The figure is partially broken. This classifier 31 is for classifying fine particles composed of two components. An air jet (spray nozzle) 33 is provided at one end of a cage 32, and the filter 21 of the present invention is fixedly provided at the other end. In this classification device 31, fine particles composed of two components are supplied into a cage 32, and the air jet 3
While stirring by blowing air from 3,
Separate with filter 21.

In the classifier 31 shown in FIG. 4, the cage 3
2 is made of metal, and it is necessary to measure the charge amount by electrically shielding the inside of the filter 21 by conducting the outside of the filter 21 with a metal. Reference numeral 34 denotes an electrometer (coulomb meter) for measuring a charge amount. Further, as shown in FIG. 5, the fine particles p stirred inside the cage 32 collide with the wall surface of the filter 21 (made of a polymer material), so that there is a concern that the filter 21 may be damaged. Therefore, it is effective to form the abrasion-resistant film 22 on the inner surface (small diameter side) of the filter to protect the film, and to form the metal deposition film 23 on the outer surface to make the filter conductive.

Embodiment 5 (According to Claim 5) In the present invention, it is preferable to perform laser processing after forming a metal foil on a film by vapor deposition or electrodeposition. In this method, the metal foil and the film are simultaneously punched and removed. When the metal foil is formed after the perforation process, it may be disadvantageous in handling the film or peeling off the film.

Embodiment 6 (according to claim 6) FIG. 6 is a schematic cross-sectional view showing the procedure of drilling. In this embodiment, the film 101
, An assist gas such as He, N ₂ , dry air, etc. is blown obliquely to the drilled surface, and laser processing is performed while sucking the blown assist gas. In this method, the product such as the ablated carbon is sucked into the exhaust port (not shown) by the assist gas, so that a problem such as the reattachment to the processing surface is eliminated. Further, merely changing the processing atmosphere (for example, when He gas is used) has an effect that the product can be discharged farther and the processed surface can be kept clean.

[0029]

Next, embodiments of the present invention will be described with reference to the drawings. Example 1 FIG. 7 is a sectional view showing a filter manufacturing method in the order of steps. In the processing apparatus shown in FIG. 1, a laser beam 201 is patterned by a mask 3, and a laser beam 202 from an imaging lens 6 is applied to a polymer film 101 adsorbed and fixed on a processing stage 7 [FIG.
(A)].

The laser beam 202 causes ablation as shown in FIG. 8 (FIG. 7B), and the hole 12 is drilled (FIG. 7C). The perforation rate depends on the wavelength / energy of the laser beam and the material of the film 101, but if KrF excimer is 1.0 J / cm ² ,
0.2 depth per pulse for polyimide film
μm can be dug down. After piercing, film 1
A metal deposited film 23 is formed on the processed surface of No. 01, that is, the surface on the laser beam irradiation side (FIG. 7D), and a wear-resistant film 22 is further formed on the back surface (FIG. 7E).

FIG. 8 is a sectional view showing the mechanism of excimer laser ablation processing. When a polymer film is irradiated with a laser beam, light absorption → breaking of intermolecular bonds by photon energy → decomposition / scattering occurs. According to the excimer laser ablation processing, fine holes having a sharper shape can be formed in the polymer film as compared with thermal processing using a CO ₂ laser or a YAG laser.

A Faraday cage provided with the filter of the present invention by excimer laser ablation processing (hole shape is almost a perfect circle) and a Faraday cage provided with a conventional stainless steel mesh (hole shape is almost a rectangle) are prepared. Using these, a classification test of a two-component developer was performed. As a result, in the conventional stainless steel mesh, clogging frequently occurred due to the carrier after classification, whereas in the filter according to the present invention, clogging hardly occurred, and the classified carrier was classified to the toner input side. .

Embodiment 2 FIG. 9 is a schematic perspective view showing the entire structure of a multi-stage classification device, and FIG. 10 is a schematic sectional view showing a classification state by this classification device. In this device, the filters are arranged in multiple stages, and the hole diameters of the filters 21a to 21c are sequentially reduced from the upper stage to the lower stage. Ultrasonic vibrations are applied to these filters and an air flow is supplied. Classify by

[0034]

As is apparent from the above description, claim 1
In the manufacturing method of the present invention, since the punching step is completed in a single step in order to perform direct drawing processing, simplification of the hole processing step, improvement of the yield and improvement of the hole processing accuracy are possible, and when classifying, A filter capable of performing field observation can be provided.

According to the manufacturing method of the second aspect, since the laser beam is image-formed, the diameter of the filter hole can be freely controlled by adjusting the optical system (the position of the mask pattern and the position of the imaging lens).

According to the manufacturing method of the third aspect, since the pattern is formed by the step-and-repeat method, the pattern area can be increased and a non-filter portion for reinforcement can be arranged.

According to the fourth aspect of the present invention, since the metal material is deposited on the hole processing surface (large diameter side) of the filter, when the filter is applied to the cage of the blow-off device, the entire cage is electrostatically shielded. In addition, the amount of charge can be accurately grasped.

According to the fifth aspect of the present invention, since a film is formed beforehand on the film and then the hole is formed, a filter free from film peeling due to a residue of the hole processing or the like can be obtained.

In the manufacturing method according to the sixth aspect, since the drilling is performed while blowing and exhausting the assist gas, there is no generation of drilling residue and the like, so that the yield is improved and post-processing is not required. A cost filter can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a configuration of a laser processing apparatus according to a first embodiment.

FIG. 2 is an explanatory diagram of a pattern processing example according to a third embodiment using a step-and-repeat method of laser light.

FIG. 3 is a cross-sectional view showing a shape of a hole formed by laser processing.

FIG. 4 is a schematic perspective view showing a main structure of a classification device according to a fourth embodiment.

FIG. 5 is a cross-sectional view showing a classifying action by the filter of the present invention.

FIG. 6 is a schematic cross-sectional view showing a procedure of laser processing using an assist gas according to a sixth embodiment.

FIG. 7 is a sectional view illustrating a filter manufacturing method according to the first embodiment in the order of steps.

FIG. 8 is a sectional view showing a mechanism of excimer laser ablation processing.

FIG. 9 is a schematic perspective view illustrating the entire structure of a classification device according to a second embodiment.

FIG. 10 is a schematic sectional view showing a classification state by the apparatus of FIG. 9;

FIG. 11 is a sectional view showing an example of a conventional mesh manufacturing method in the order of steps.

FIG. 12 is a sectional view showing another example of the conventional mesh manufacturing method in the order of steps.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser light source 2 Beam shaping optical system 3 Mask 4 Condenser lens 5 Plane mirror 6 Imaging lens 7 Processing stage 8 Projection optical system 11 Hexagonal area 12 Hole 21, 21a-21c Filter 22 Wear-resistant film 23 Metal deposition film 31 Classifier 32 Cage (Faraday cage) 33, 41 Injection nozzle 34 Electrometer 35 Compressor 36 Rotating device 37 Coulomb meter 38 Motor 39 Disk 101 Film 201 Laser beam 202 Laser beam p Particles

Continued on the front page (51) Int.Cl. ⁶ Identification code FI B23K 26/14 B23K 26/14 A

Claims (7)

[Claims] 1. A method for producing a filter for classifying fine particles, comprising irradiating a film made of a polymer material such as PET, PES, PC, PI or the like with a laser beam to perform perforation. 2. The method for producing a filter for classifying fine particles according to claim 1, wherein the laser optical system for laser beam irradiation is an imaging optical system. 3. The method for producing a filter for classifying fine particles according to claim 2, wherein a pattern is formed by a step-and-repeat method of laser light. 4. The filter for classifying fine particles according to claim 1, wherein a metal such as Ni, W, Ti, or Al is vapor-deposited on the film processing surface (surface on the laser beam irradiation side) after perforation. Production method. 5. The method for producing a filter for fine particle classification according to claim 1, wherein a perforation process is performed after forming a metal foil on the film by vapor deposition or electrodeposition. 6. The perforation process is performed while blowing assist gas such as He, N ₂ , dry air or the like onto a film processing surface and sucking the blown assist gas in parallel. 3. The method for producing a filter for fine particle classification according to item 1. 7. A filter for classifying fine particles, produced by the production method according to any one of claims 1 to 6.