JP2000024923A - Fine hole.groove machining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form the fine hole and groove on a work piece with high accuracy or to finely cut the work piece by forming a prepared machining hole smaller than a diameter of a through hole or a width of a groove on a predetermined position in advance, and forming the through hole or the groove on the basis of the prepared machining hole. SOLUTION: The laser beam is irradiated to a surface of a work piece 21 to form a prepared through hole 23. The prepared machining through hole 23 is formed on a position corresponding to a central position of a fine hole 24 to be formed in a state that a spot diameter of the laser beam is adjusted so that a diameter of the prework through hole 23 is smaller than a diameter of the fine hole. Then the fine hole 24 is formed by the blasting process. A nozzle 25 is arranged on an upper part of the work piece 21 corresponding to a position of the fine hole 24 to be formed, and the solid and liquid two- layered jet 27 including the fine abrasive grain 26 is injected toward a surface of the work piece 21. Whereby a hole 28 is formed on the work piece 21 by removing a material by the collision of the abrasive grain 26, and the desired through hole 24 can be finally formed with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming fine through-holes and grooves in a workpiece made of various materials such as a metal material, a non-metal material such as glass, ceramics, silicon, and plastic, and a composite material. Alternatively, the present invention relates to a processing method for cutting a workpiece.

[0002]

2. Description of the Related Art Conventionally, techniques such as blasting, electric discharge machining, laser machining, and ultrasonic machining have been generally used to perform machining such as drilling, grooving, or cutting on workpieces of various materials described above. Has been adopted.

In blasting, as shown in FIG. 5A, solid particles, that is, abrasive grains 3 are jetted from a nozzle 1 onto a surface of a workpiece 2 at a high speed using a gas such as compressed air or a liquid such as water. In this way, drilling and grooving are performed by removing the material. By changing the particle size of the abrasive grains used, formation of fine holes and grooves and fine cutting can be performed.
No. 1774 discloses solid-air 2 containing such fine abrasive grains.
An apparatus for forming a micro through hole in a workpiece by injecting a laminar jet from above a mask is disclosed.

In electric discharge machining, generally, an arc discharge is generated in a narrow gap between a machining electrode and a workpiece in an insulating machining fluid, thereby removing material from a facing surface of the workpiece and transferring an electrode shape. Then, a desired shape is processed. Recently, as shown in FIG. 6A, a so-called creation electric discharge machining method has been developed in which the workpiece 2 is machined in a layered manner from the surface thereof to a predetermined depth by using electric discharge from the bottom surface portion of the pipe electrode 4. According to this processing method, it is reported that a fine hole or groove having a minimum hole diameter of about 5 μm can be processed by reducing the diameter of the pipe electrode.

[0005] Laser processing is generally performed using a YAG (yttrium aluminum garnet) laser or CO ₂
Using a (carbon dioxide) laser, laser light is condensed and radiated onto the surface of the workpiece, and drilling, grooving, cutting, and the like are performed for melting and removing the material. Laser processing is particularly advantageous for processing hard and brittle materials such as ceramics because external force does not directly act on the workpiece. In addition, by focusing laser light to a small spot diameter of about several μm, A groove can be formed or cut.

In the case of laser processing, a molten portion of a workpiece formed by irradiation with laser light evaporates or blows out to grow a hole, and the melt scattered from the hole is reattached to the vicinity of the opening of the hole. -There is a problem that the hole is solidified to make the shape and appearance of the hole dirty. To solve this problem, FIG.
As shown in, for example, as described in Japanese Patent Application Laid-Open No. 63-115761, the workpiece 2 is arranged in a liquid 5 such as water or a processing liquid, and a laser beam 7 is irradiated from the outside through a processing window 6. A submerged laser processing method is known.

[0007]

However, in the conventional micro-hole / groove machining or micro-cutting, since the entire process from the start of machining to the completion of machining is performed by one machining method as described above, the following problems occur. was there.

That is, in the blasting process, in FIGS. 5A and 5B, the abrasive grains 3 ejected from the nozzle 1
There is a risk that the abrasive grains that are subsequently injected will collide with and bounce off of the inner surface of the workpiece, and this will hinder the abrasive grains from colliding with the surface of the workpiece, thereby reducing the processing speed. . Further, since the gas 9 as the medium for accelerating the abrasive grains stays in the hole 8 during machining, the abrasive grains are not sufficiently accelerated, and there is a possibility that machining efficiency is reduced. In particular, when deep holes or grooves are machined, these problems become remarkable. In order to solve these problems, when the pressure of the carrier gas is increased and the injection speed of the abrasive grains is increased, the processing part and / or its peripheral part is damaged more than necessary, and finally the processing diameter of the through hole 10 is reduced. Is larger than the desired hole 10 ', or the surface is roughened, thereby deteriorating the quality.

In the case of electric discharge machining, as shown in FIG. 6A, machining dust 11 is not discharged from the hole 12 during machining and tends to accumulate at the bottom, which may cause a decrease in machining efficiency and quality. . Therefore, as shown in FIG. 6B, it is necessary to forcibly discharge the machining waste from the hole and circulate the machining fluid 13 by periodically raising and lowering the electrode 4 in and out of the hole 12 in the process of machining. However, there is a problem that the control of the electrodes is complicated and troublesome, the processing time is lengthened, and the processing efficiency is reduced.

In the submerged laser processing, as shown in FIG. 7A, the irradiation of the laser beam 6 generates bubbles 15 and processing chips 16 in the hole 14 being processed, and these scatter or block the laser beam. As a result, there is a problem that the processing accuracy is reduced and dirt near the processed portion is generated. In particular, in the processing of a deep hole or a deep groove, the balance between the processing in the hole diameter direction and the processing in the hole depth direction is deteriorated due to scattering of laser light and heat conduction to the periphery of the hole 14, and the finally obtained through hole The shape of 17 has a problem in that the processing accuracy is low, such as a tapered shape having a large processing diameter on the inlet side with respect to a desired hole 17 ′ as shown in FIG. is there.

Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to form a fine hole or groove in a workpiece with high precision or to process the workpiece. An object of the present invention is to provide a highly efficient processing method capable of finely cutting an object, increasing a processing speed without reducing quality, shortening a processing time, and reducing costs.

[0012]

According to the present invention, when a fine through hole or groove is formed in a workpiece, the workpiece penetrates the workpiece and has a diameter equal to the diameter of the through hole or the diameter of the groove. A fine processing hole having a width smaller than the width is previously formed at a position where the through hole or the groove is to be formed in the workpiece, and the through hole or the groove is formed in alignment with the processing hole. A hole / grooving method is provided.

[0013] With this, machining chips and the like generated when forming the intended through hole or groove are discharged from the back side of the workpiece through the machining hole, thereby improving machining efficiency and machining accuracy. It is possible to form and cut fine holes and grooves.

Since the hole to be machined disappears by being used for forming a target through hole or groove, it is sufficient if the hole penetrates the workpiece within the range of the size and position of the through hole. Because it does not require high quality and processing accuracy, various known processing methods such as micro blasting, drilling,
It can be formed by grinding or electric discharge machining. In particular, it is convenient to form by laser processing, which can be applied to various processing materials by high-power and non-contact processing and is easy to control during processing.

The through holes or grooves can be formed by blasting by appropriately selecting the particle size of the abrasive grains to be used. In this case, the processing chips and the used abrasive grains are transferred together with the carrier gas. Since it is discharged from the opposite side through the machining hole, the conventional collision between the abrasive grains, gas stagnation is eliminated or at least greatly reduced, and the machining efficiency is improved without increasing the pressure of the carrier gas. be able to. Therefore, high-precision processing becomes possible, and the shape of the processed part is greatly improved as compared with the conventional case.

In another embodiment, the through holes or grooves can be formed by electric discharge machining by appropriately selecting electrodes.
The generated machining waste is easily discharged from the opposite side through the machining hole without raising and lowering the electrode, and fresh machining fluid is supplied to the machining part, so that machining efficiency and quality are improved, The operation and control of the electrodes becomes easy.

In still another embodiment, the through holes or grooves can be formed by laser processing. Processing dust (melt) generated by laser irradiation and bubbles in the case of submerged laser processing are discharged to the back side through the processing target hole, so that scattering and interruption of laser light can be reduced, and processing Efficiency and processing accuracy can be improved, and the laser output can be reduced.

Further, according to the present invention, the quality can be improved if the etching step of finishing the processed surface with, for example, hydrofluoric acid after forming the through hole or groove is further included, which is more convenient. . In this case, it is more convenient to provide a corrosion resistant film against acid with a resist or the like on the surface that is not etched.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a process of forming a fine hole in a workpiece according to an embodiment of the present invention; In this embodiment, first, as shown in FIG. 1, the surface of the workpiece 21 is irradiated with a laser beam 22 from a laser oscillator (not shown) to penetrate the hole to be machined 23. The machining destination hole 23 is formed by adjusting the spot diameter of the laser beam so that the diameter thereof is smaller than the diameter of the fine hole, and preferably matching the center position of the fine hole 24 to be formed.

In this embodiment, a YAG laser capable of obtaining a high output by pulse oscillation is used for laser irradiation, and a hole to be machined is formed efficiently in a short time. As will be described later, the machining hole 23 only needs to penetrate the workpiece 21 within the range of the size and position of the minute hole 24 to be formed, and therefore does not require particularly high machining accuracy and quality. In another embodiment, continuous oscillation or another solid-state laser, or a gas laser such as a CO ₂ laser or an excimer laser can be used depending on the processing conditions such as the material of the workpiece and the processing dimensions. In still another embodiment, other than laser processing, various other material removal processing methods such as microblast processing using fine abrasive grains, drill processing, grinding stone processing, and electric discharge processing can be used.

Next, the fine holes 24 are formed by blasting. In the embodiment of FIG. 2, a processing device of a microblasting system using a gas such as air, nitrogen, carbon dioxide or the like as an acceleration medium is used. As shown in FIG. 2A, a nozzle 25 is disposed above the workpiece 21 in accordance with the position of the microhole 24 to be formed, and a solid-gas two-layer jet 27 containing fine abrasive grains 26 is applied to the surface of the workpiece 21. Inject toward

Generally, the tip of the nozzle 25 and the workpiece 21
Is larger than the inner diameter of the nozzle, and the size depends on the distance between the nozzle and the surface of the workpiece. On the other hand, when the nozzle tip is substantially in contact with the surface of the workpiece, the diameter of the hole to be processed is substantially the same as the nozzle diameter. Further, the shape of the hole to be machined is adjusted by adjusting the machining time, that is, the machining speed, so that the hole diameter on the inlet side is a forward tapered shape larger than the hole diameter on the outlet side, the straight shape in which both hole diameters are substantially equal, or the inlet shape. It can be formed in a reverse tapered shape in which the hole diameter on the outlet side is larger than that on the side.

The material is removed from the workpiece 21 by the collision of the abrasive grains 26 to form a hole 28. At this time, the removed material, that is, the processing waste and the used abrasive grains 29 are discharged to the outside from the lower end thereof through the processing destination hole 23 together with the gas contained in the jet flow. As a result, collision between abrasive grains and stagnation of gas as in the prior art are eliminated or at least greatly reduced, so that processing can proceed efficiently without increasing the pressure of the carrier gas, as shown in FIG. 2B. Thus, the desired through hole 24 is finally processed with high precision.

As described above, according to the present invention, although the shape of the processed portion is greatly improved as compared with the prior art,
Finishing can be performed by forming a corrosion-resistant film only on the front surface and the back surface of the substrate 1 with a resist or the like, and selectively treating the through-holes 24 with hydrofluoric acid or the like.

In the second embodiment shown in FIG.
Micro holes are machined by electric discharge machining using 0. The workpiece 21 in which the machining hole 23 is formed in advance is fixed in the insulating working fluid 32 of the container 31. The workpiece 21 is arranged on a horizontal support plate 33 provided in the container 31 so that the fine hole 24 to be machined is located within the range of the central opening 34 thereof. Similarly, the electrode 30 is disposed in the working liquid 32 close to the workpiece 21 with a slight gap in accordance with the position of the fine hole 24 to be formed. The electrode 30 and the workpiece 21 are connected to a DC power supply 35, and a short-time arc discharge is repeatedly generated between the gaps.

The material is removed by this discharge, and a circular hole 36 is formed in the workpiece 21. The holes 36 grow in layers from the surface of the workpiece 21 by gradually lowering the electrode 30 while generating arc discharge. The processing waste 37 from the material removal passes through the processing destination hole 23 from the bottom of the hole 36 by gravity and is easily discharged into the container 31 from the lower end thereof. Therefore, there is no need to move the electrode 30 up and down to remove the processing waste 37 as in the related art, and the operation and control of the electrode are greatly facilitated as compared with the related art, and the machining efficiency and quality are improved.

In this embodiment, a working fluid circulation mechanism including a pump 38 is provided in the container 31, and its discharge port 39 and suction port 40 are opened on the upper surface side and the lower surface side of the workpiece 21, respectively. At the same time as the processing of the hole 36, the pump 38 is operated to suck the processing liquid 32 from the lower surface side of the workpiece 21 and discharge it to the upper surface side. The inside of the container 31 is the workpiece 21
And the upper and lower surfaces of the workpiece 21 produce a pressure difference between the upper surface and the lower surface of the workpiece 21. A flow of the working fluid to the lower end opening occurs. Accordingly, the processing waste 37 is more smoothly and reliably discharged, and fresh processing liquid is forcibly supplied to the processing portion, thereby further improving the processing efficiency. In this way, the desired through hole 24 is finally machined with high precision, similarly to the embodiment of FIG. Also, in this case, the central opening 3 of the support plate
4 is preferably as small as possible in accordance with the fine holes 24 so as not to cause bending or deformation due to the pressure difference particularly when the workpiece 21 is a thin plate.

In the third embodiment shown in FIG. 4, fine holes are formed by submerged laser processing. The workpiece 21 in which the machining hole 23 is formed in advance is arranged in a container 42 containing a machining fluid 41 so as to irradiate a laser beam 44 from a lateral direction through a machining window 43 provided on one side wall thereof. I do. The workpiece 21 is
It is fixed to a vertical support plate 45 provided in the container 42 by using a suitable mounting means (not shown) so that the fine hole 24 to be machined is located within the range of the central opening 46 thereof. In addition to pure water, for example, a KOH solution can be used as the working liquid 41 so that the working can be further facilitated by using a chemical action in combination with the heat action of the laser beam.

Laser light 44 from a laser oscillator (not shown)
Is irradiated onto the workpiece 21 in accordance with the center position of the micro hole 24 to be formed, that is, in accordance with the position of the processing destination hole 23. In this embodiment, a pulse oscillation YAG laser output from the same laser oscillator as used for processing the processing hole 23 is used. Naturally, continuous wave lasers, other solid-state lasers, CO2
A gas laser such as a _two laser or an excimer laser can be used. The laser light 44 causes the focal position to be more distant from the workpiece 21 in the optical axis direction than when the processing destination hole 23 is processed, and increases the spot diameter in accordance with the size of the fine hole 24.

The container 42 is similarly provided with a working fluid circulation mechanism comprising a pump 47, and its discharge port 48 and suction port 49 are opened on the front side and the back side of the workpiece 21, respectively. The pump 47 is operated at the same time as the formation of the hole 50 by the irradiation of the laser beam, and the processing liquid 41 is sucked from the back side of the workpiece 21 and discharged to the front side. Since the inside of the container 42 is partitioned by the workpiece 21 and the support plate 45, a pressure difference occurs in which the front side of the workpiece 21 is higher than the back side, and the pressure difference between the hole 50 and the processing destination hole 23 communicating therewith is generated. The flow of the working liquid from the front opening to the rear opening occurs at the same time.

Due to the flow of the processing liquid, the bubbles 51 and the chips 52 generated by the laser processing are discharged from the inside of the hole 50 to the back side through the processing destination hole 23. Further, the bubble 51 in the hole 50 is compressed by the pressure difference, and its diameter becomes smaller. As described above, according to the present embodiment, the scattering and blocking of the laser beam 44 can be reduced by discharging the bubbles and the processing dust to the back side and compressing the bubbles, so that the processing efficiency is improved, and the hole size is improved as compared with the related art. Fine holes with good shape and good appearance can be machined with high precision. In addition, since the laser output can be reduced by improving the processing efficiency, the cost can be reduced,
Quality is improved by reducing surface roughness.

In this embodiment, laser processing in liquid is used, but the same effect can be obtained by laser processing in gas (dry type). In this case, no bubbles are generated due to the laser irradiation. Therefore, it is convenient to arrange the processing hole vertically so that the processing waste (melt) can pass downward from the processing hole.

In any of the above-mentioned embodiments, since the processing hole 23 disappears due to the processing of the target fine hole,
It suffices to penetrate the workpiece 21 within the range of the size and position of the fine hole to be formed.
It can be seen that it is only necessary to efficiently process in a short time without requiring quality.

In the above embodiment, a case where a through hole is formed in a workpiece has been described. However, according to the present invention, a target hole is similarly formed by using a processing tip hole previously penetrated in the workpiece. Processing and fine cutting of fine through grooves can be performed.
In this case, processing of the groove is started in accordance with the position of the processing destination hole, and the workpiece, the nozzle of the blast processing apparatus, the discharge electrode, and the laser beam are scanned. Then, the workpiece can be cut by connecting the start point and the end point of the processing groove.

Further, the present invention can be implemented by adding various modifications and changes to the above embodiment within the technical scope thereof. For example, in the above-mentioned blasting and electric discharge machining, the cross-sectional shape and electrode shape of the nozzle tip are variously formed, and in the blasting and laser machining, by disposing an appropriate mask means in front of the workpiece, the The hole or groove having a desired shape and size, such as a polygon other than a circle, a polygon such as a triangle or a rectangle, a star or a gear-shaped uneven shape, etc., can be machined as required.

[0036]

Since the present invention is configured as described above, it has the following effects. ADVANTAGE OF THE INVENTION According to the fine hole / groove processing method of the present invention, the processing efficiency and the processing are achieved by discharging processing waste generated at the time of processing the target through hole / groove from the back side of the workpiece through the processing destination hole. Accuracy and quality can be improved, and fine holes and grooves of various shapes can be formed and cut, and the processing time and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a process of forming a machining hole in a workpiece in an embodiment of the present invention.

FIGS. 2A and 2B are schematic cross-sectional views showing a process of performing blast processing on a workpiece having a processing destination hole formed therein, and a through hole after the processing is completed.

FIG. 3 is a schematic cross-sectional view showing a process of performing electric discharge machining on a workpiece having a machining hole formed therein.

FIG. 4 is a schematic cross-sectional view showing a process of performing laser processing in a liquid on a workpiece on which a processing destination hole is formed.

FIGS. 5A and 5B are schematic cross-sectional views respectively showing a process of a conventional blasting process and a through hole after the completion of the process.

FIGS. 6A and 6B are schematic cross-sectional views respectively showing a process of machining by a conventional electric discharge machining and discharge of machining chips by pulling up an electrode.

7A and 7B are schematic cross-sectional views respectively showing a process of processing by conventional laser processing in liquid and a through hole after processing is completed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle 2 Workpiece 3 Abrasive 4 Electrode 5 Liquid 6 Processing window 7 Laser beam 8 Hole 9 Gas 10 Through hole 10 'hole 11 Processing chips 12 Hole 13 Processing liquid 14 Hole 15 Bubbles 16 Processing chips 17 Through hole 17' Hole DESCRIPTION OF SYMBOLS 21 Workpiece 22 Laser beam 23 Processing tip hole 24 Microhole 25 Nozzle 26 Fine abrasive grain 27 Solid-liquid two-layer jet 28 Hole 29 Abrasive grain 30 Electrode 31 Container 32 Processing fluid 33 Support plate 34 Central opening 35 DC power supply 36 Hole 37 Processing waste 38 Pump 39 Discharge port 40 Suction port 41 Processing liquid 42 Container 43 Processing window 44 Laser beam 45 Support plate 46 Center opening 47 Pump 48 Discharge port 49 Suction port 50 hole 51 Bubbles 52 Processing debris

Claims (7)

[Claims] 1. A fine hole / groove processing method for forming a fine through hole or groove in a workpiece, wherein the processing target penetrates the workpiece and has a diameter smaller than the diameter of the through hole or the width of the groove. Forming a through hole or groove in the workpiece in advance at a position where the through hole or groove is to be formed, and forming the through hole or groove in alignment with the processing destination hole; Method. 2. The method according to claim 1, wherein the processing hole is formed by laser processing. 3. The method according to claim 1, wherein the machining hole is formed by microblasting, drilling, grinding, or electric discharge machining. 4. The method according to claim 1, wherein the through hole or the groove is formed by blasting. 5. The method according to claim 1, wherein the through hole or the groove is formed by electric discharge machining. 6. The method according to claim 1, wherein the through holes or grooves are formed by laser processing. 7. The method according to claim 1, further comprising the step of finishing the inner surface of the through hole or the groove.