JP2000302488A - Fine holing of glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hole a fine hole having a complicated crosssectional shape, a high quality and a high aspect ratio on a glass material. SOLUTION: A fine hole 3 is bored through a glass substrate 3 by laser processing or ultrasonic processing. Both sides of the glass substrate are ground in a state in which the fine hole is packed with a filler 6 such as a resin material or a hot-melt material. Then the filler is removed from the fine hole to form a fine through-hole. Further, at least one peripheral part of the through- hole is subjected to a microblast processing or etching processing to form a tapered part on the opening part or to process the opening part to a fixed crosssectional shape. A practical processing method capable of removing strain, crack, surface roughness, dross, etc., obtaining excellent shape accuracy and forming a fine hole having a complicated crosssectional shape, a high quality and a high aspect ratio is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a method for processing fine holes having a complicated cross-sectional shape in a glass material, and more particularly, to a nozzle plate for an ink-jet printer having a large number of fine holes formed in a thin glass plate, and the like. , TFT
It is used to form a micro lens used for a substrate of a liquid crystal display device (LCD).

[0002]

2. Description of the Related Art Conventionally, not only a straight hole having a constant cross-section in a glass material but also a complicated cross-sectional shape in which, for example, an opening portion of the hole is tapered, or an aperture or an enlarged portion is provided in the center of the hole. In order to machine micro holes, there is generally a mechanical method such as a grinding method using a rotary grindstone, a drill, an ultrasonic wave or a micro blast method for injecting abrasive grains, and a chemical method such as a wet etching using a solution. Has been adopted. Recently, energy beam processing for irradiating an electron beam, an ion beam, or a laser beam has been widely used.

For example, in a method of forming a microlens for a TFT type LCD described in Japanese Patent Application No. 9-101401, a single crystal silicon film having strong adhesion to glass and excellent physical strength is used as a mask. By performing the wet etching, a substantially spherical microlens surface is formed on the glass substrate. Also, Japanese Patent Application No. 10-357245 (Title of Invention:
"Methods for manufacturing semiconductor chips and semiconductor devices") include:
When anisotropic etching is performed after a through hole is formed in a silicon single crystal substrate having a (100) orientation plane by laser processing,
It is described that by stopping the etching on the (111) plane, a through-hole having a cross-sectional shape in which the central portion of the through-hole is enlarged can be formed.

Regarding laser processing, a paper by Junichi Ikeno et al., “Crack-free three-dimensional laser processing of crystallized glass” (Journal of the Japan Society of Precision Engineering, Vol. 64, No. 7, 1998, No. 1062-
On page 1062), a pigment is applied to the surface of crystallized glass, which is considered difficult to finely process with a YAG laser, and the surface is irradiated with a YAG laser to form a processing hole and irradiate the molten layer at the tip of the glass. Change the direction by 90 degrees and YAG
It has been reported that by irradiating a laser and growing a processing hole in the incident direction, a crack-free three-dimensional drilling processing has been enabled.

[0005]

However, the above-mentioned conventional processing method has the following problems. First, the mechanical processing method is relatively easy to process a hole with a three-dimensional cross-sectional shape, but there is a limit to the miniaturization of the processed hole,
In addition, there is a concern that quality problems may occur such as chipping, that is, minute chipping or cracking is likely to occur around the opening of the machined hole. For example, a nozzle plate for an inkjet printer is formed by punching a stainless steel plate having a thickness of about 100 μm with a tool, thereby forming an ink ejection hole including a tapered portion near an opening and a straight portion ahead of the opening. Tools are easily damaged, which reduces work efficiency,
Not only is there a problem of increased processing cost, but it is practically difficult to perform such a punching process on a thin glass plate.

[0006] On the other hand, wet etching can process high quality holes without the risk of chipping or chipping.
It is difficult to control the shape with high precision, and it is particularly difficult to machine fine holes having a high aspect ratio. In addition, a processing device such as an electron beam or an ion beam is generally expensive and has a very low processing speed.

[0007] In laser processing, fine holes having a high aspect ratio can be processed at a relatively high speed. However, it is generally difficult to process an arbitrary cross-sectional shape with high precision. Further, in the case of laser processing, there is a problem that the glass material itself is damaged due to high heat of the laser due to thermal distortion, alteration, or the like, or the ejected dross adheres to the vicinity of the opening of the processing hole, and cracks are easily generated. .

Accordingly, an object of the present invention is to provide a practical method for forming a fine hole in a glass, which is capable of forming a high-quality, high-aspect-ratio fine hole at a relatively high speed with little damage, cracks and chipping to a glass material. To provide.

It is a further object of the present invention to provide a method for processing fine holes in a glass material capable of forming high-quality, high-aspect-ratio fine holes having a complicated cross-sectional shape in a glass material.

Another object of the present invention is to provide a method for forming a fine hole having a complicated cross section in a glass substrate, which can be used particularly for a nozzle plate for an ink jet printer.

[0011]

According to the present invention, there is provided a method for forming a fine hole in a glass, comprising the steps of: forming a fine hole in a workpiece made of glass; Polishing the surface of the workpiece to be opened. The micro holes can be formed by laser processing or ultrasonic processing.

The glass material is liable to cause various distortions and cracks due to mechanical stress and thermal stress during processing, particularly near the opening and the tip of the fine hole, and the surface is roughened by the removal of the material and the removed material is re-attached. Tends to occur. Generally, the shape of the opening and the tip of the hole is not constant. According to the present invention, by polishing and removing the surface layer of the workpiece,
These distortions, cracks, surface roughness, dross, etc. can be removed, and at the same time, straight fine holes with excellent shape accuracy where the inner wall surface of the hole and the surface of the workpiece are linearly crossed at the hole opening. be able to.

In one embodiment, the fine hole is formed so as to penetrate a workpiece. In this case, it is possible to polish both surfaces of the workpiece in which both ends of the fine holes are opened, or only one surface in some cases. In another embodiment, the fine holes can be formed so as not to penetrate the workpiece. In this case, by polishing not only the opening side of the holes but also the surface of the workpiece on the tip side thereof, The through hole can be formed by opening the tip of the closed hole.

Before polishing the surface of the workpiece,
Preventing chipping that is likely to occur around the opening of the processing hole during polishing, further including the step of filling the filling such as resin material or hot melt material and the step of removing the filling from the fine hole after polishing the workpiece surface This is convenient. When the filler is a resin material, it can be removed by a chemical that does not adversely affect the glass material, and when it is a hot melt material, it can be removed by heating or a solvent.

Further, according to the present invention, after the surface of the workpiece is polished, at least one peripheral edge of the opening of the fine hole penetrating the workpiece is subjected to microblasting to thereby taper the opening. be able to. If only one opening of the fine hole is machined, a through hole consisting of a tapered portion and a straight portion is obtained. If both openings are machined, a diaphragm can be provided at the center of the hole.

Further, according to the present invention, after polishing the surface of the workpiece, the peripheral portion of the opening of the fine hole is etched, whereby the opening can be processed into a desired shape. More specifically, the surface of the polished workpiece and the inner surface of the fine hole are coated with a corrosion-resistant coating, a photoresist is adhered on the corrosion-resistant coating, and the photoresist at the opening peripheral portion of the fine hole and the lower portion thereof By removing the corrosion-resistant coating on the side and performing wet etching, the glass material is removed centering on the periphery of the exposed fine hole opening.For example, in the case of isotropic etching, the hole opening is processed into a semicircular cross section. You.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings using preferred embodiments. FIG.
3A to 3D show a process of forming fine holes in a glass substrate by the method of the first embodiment of the present invention in the order of steps. In this embodiment, a Q-switch pulse oscillation YAG laser having a short pulse width and a small thermal effect is used, and a laser beam B is condensed by a condensing lens 1 as shown in FIG. Irradiating with a diameter of several tens μm as shown in FIG.
A minute through hole 3 having a diameter of m is formed. On the surface of the glass substrate 2, the molten material scattered during processing, that is, the dross 4 and 5, reattach to the periphery of the openings at both ends of the through hole 3 and solidify, and the surface is roughened or distorted due to the high heat of the laser. In addition, the opening on the incident side of the through hole 3 is somewhat flared.

Next, as shown in FIG.
Is filled with a hot melt material 6. As the hot melt material, a hot-melt plastic, wax or the like can be used. In this state, both surfaces of the glass substrate 2 are polished to a predetermined depth indicated by imaginary lines 7 and 8 by a known method such as lapping or grinding. The polishing amounts D1 and D2 are set so that the difference Δφ between the diameters φ1 and φ2 of the through holes 3 at the depths thereof is substantially zero or small in accordance with the requirements such as use conditions, and the dross 4 and 5 are reduced. The thickness is set based on the thickness T of the glass substrate to be finally obtained so that the surface layer of the glass substrate 2 having the attached, roughened or distorted surface is removed.

By filling the hot melt material in this way, it is possible to prevent chipping which is likely to occur around the opening of the through hole 3 due to polishing. In another embodiment, instead of a hot melt material, a resin material that can be dissolved with a predetermined chemical agent can be used as well.

The hot-melt material 6 remaining in the through-hole 3 is removed by heating the glass substrate 2 after polishing shown in FIG. As a result, a straight through-hole having a higher quality and a higher aspect ratio, which is excellent in shape accuracy and in which the glass substrate surface and the inner wall surface of the hole intersect linearly as shown in FIG. Naturally, the steps of filling and removing the hot melt material can be omitted, and both surfaces of the glass substrate shown in FIG. 1 (b) can be polished as they are.
Apart from the problem of chipping due to polishing, a straight through hole of high quality and high aspect ratio as shown in FIG.

In another embodiment, laser light of normal pulse oscillation or continuous oscillation other than Q switch pulse oscillation, ultrasonic machining, or various other known drilling methods is used.
As in the case of FIG. 1B, a through hole can be formed in the glass substrate. The through hole formed by ultrasonic processing causes surface roughness around the opening, but by polishing the surface to be processed of the glass substrate in the same manner as in the above embodiment, a straight through hole of high quality and a high aspect ratio is formed. Obtainable.

FIG. 2 shows a process of forming micro holes by the method according to the second embodiment of the present invention. In the second embodiment, the first
Similarly, a glass substrate 9 thicker than the glass substrate 2 of the embodiment is irradiated with a pulsed YAG laser beam B to form a fine hole (FIG. 2A). Therefore, the processed fine hole 1
No. 0 does not penetrate the glass substrate 9 as shown in FIG. 2B, and its growth is stopped halfway. The opening of the fine hole 10 spreads like a flare, and the dross 11 adheres to the periphery thereof as in the case of the first embodiment, causing surface roughness and distortion due to laser irradiation. A glass melt 12 solidifies and adheres to the tapered tip portion of the fine hole 10, and its peripheral portion is transformed into a molten layer by the high heat of the laser.

Next, also in this embodiment, the glass substrate 9
Are polished to a predetermined depth indicated by imaginary lines 13 and 14, and the surface layer is removed to form a through hole 15 as shown in FIG. 2 (c). The polishing amounts D1 and D2 are
As in the first embodiment, the diameters φ1, φ1
2 is set based on the final thickness T of the glass substrate so that the difference Δφ becomes substantially zero or becomes smaller in accordance with requirements such as use conditions. Particularly, the polishing amount D2 at the tip side of the fine hole 10
Is determined so that at least the melt 12 and the deteriorated layer are removed and a good quality inner wall surface is obtained. As a result, a straight through hole 15 having a high quality and a high aspect ratio is obtained.

The polishing of the glass substrate 9 can be performed in a state where an appropriate filler such as a hot-melt material is filled in the fine holes 10, as in the first embodiment. Can be prevented from being chipped in the vicinity of the openings at both ends. In addition to the laser processing, the fine holes 10 can be formed by using laser light of normal pulse oscillation or continuous oscillation other than the Q-switch pulse oscillation, ultrasonic processing, or various other drilling methods.

Further, according to the present invention, a fine hole having a complicated cross-sectional shape can be formed by removing the material around the opening of the through hole obtained in the first embodiment. FIG. 3 shows a process of tapering the openings at both ends of the through hole using microblasting. In this embodiment, a microblasting method in which fine abrasive grains are sprayed using a gas such as air, nitrogen, or carbon dioxide as an acceleration medium is used.

As shown in FIG. 3A, the nozzle 16 of the microblasting device is arranged at the opening position of the through hole 3 so that the tip of the nozzle 16 contacts the surface of the glass substrate 2. The inner diameter of the nozzle 16 is selected according to the inlet diameter of the tapered portion 17 to be formed. In this state, a solid-gas two-layer jet 19 containing fine abrasive grains 18 is jetted from the nozzle 16 toward the surface of the glass substrate 2. Since there is no escape of the abrasive particles injected between the tip of the nozzle and the surface of the glass substrate, the diameter of the inlet of the through hole 3 is substantially the same as the inner diameter of the nozzle 16 as shown in FIG. The tapered portion 17 is formed. Thereby, the through hole 20 including the tapered portion and the straight portion is obtained.

Further, in this embodiment, as shown in FIG. 3 (c), the glass substrate 2 is arranged upside down, and the nozzle 21 of the micro blast device is placed at the opening on the opposite side of the through hole 3, and the tip of the nozzle 21 A two-layer solid-gas jet 19 containing fine abrasive grains 18 is injected so as to be in contact with the surface of the glass substrate 2.
The inner diameter of the nozzle 21 is selected according to the inlet diameter of the tapered portion 22 to be formed on the opposite side of the through-hole 3, and is changed as necessary even if it is the same as the nozzle 16 in FIG. Is also good. In this way, a through hole 23 shown in FIG. 3D in which both ends are tapered and a stop is provided at the center is obtained.

The removed material, that is, the processing wastes 24 and 25 and the used abrasive grains 18 pass through the through-hole together with the carrier gas contained in the jet and are discharged from the opening at the tip thereof. It can be processed efficiently. Each taper portion 17,
The depth 22, the position of the iris, and the shape accuracy can be adjusted by appropriately setting the processing conditions such as the particle size of the abrasive grains and the pressure of the carrier gas.

FIG. 4 shows the process of forming the opening of the through hole obtained by the first embodiment in a semicircular cross section by using photolithography and wet etching. First, a hydrofluoric acid-resistant corrosion-resistant film 26 such as chromium or gold is formed on the inner wall surface of the through hole 3 and the entire surface of the glass substrate 2 (FIG. 4A). Next, as shown in FIG. 4B, a photoresist 27 is applied on the corrosion-resistant coating 26 to a substantially constant thickness, a mask 28 is provided above the glass substrate 2, and the circular pattern is concentric with the through hole 3. Expose it by placing it at the position.
The size of the circular pattern of the mask 28 is set slightly larger than the hole diameter of the through hole 3, for example, about several μm. As a result, an annular narrow gap 29 as shown in FIG. 4C is formed in the photoresist 27 so as to match the peripheral edge of the opening of the through hole.

Next, the corrosion-resistant coating 2 exposed in the gap 29
6 is removed by dry etching such as ion milling or any other suitable method to expose the glass substrate around the opening of the through hole 3 (FIG. 4D). On this glass substrate 2,
Wet etching is performed by using a hydrofluoric acid diameter etchant such as hydrogen fluoride (HF) or boron hydrogen fluoride (BHF). Thereby, isotropic etching proceeds with the gap 29 as a center, and a recess 30 having a semicircular cross section is formed in the opening of the through hole 3 as shown in FIG.

Finally, when the remaining photoresist 27 and corrosion-resistant coating 26 are removed, the through-hole 31 shown in FIG.
Is obtained. Such a glass substrate can be used, for example, for a nozzle plate of a head for an inkjet printer.

Although the present invention has been described in detail with reference to the preferred embodiments, the present invention can be implemented by adding various modifications and changes to the above embodiments within the technical scope thereof.

[0033]

Since the present invention is configured as described above, it has the following effects. According to the method for processing fine holes in glass of the present invention, by removing the surface layer of the workpiece by polishing after the formation of the fine holes, distortion and cracks generated near the opening and the tip thereof when forming the fine holes, High quality and high aspect ratio fine holes can be formed at high speed because surface roughness, dross, etc. can be removed, and excellent shape accuracy where the inner wall surface of the hole and the workpiece surface intersect linearly is obtained. can do.

Further, according to the present invention, by removing the peripheral portion of the opening of the fine hole by micro blasting or etching, it can be used for various practical uses such as a nozzle plate for an ink jet printer. High-quality and high-aspect-ratio fine holes having a complicated cross-sectional shape can be processed.

[Brief description of the drawings]

FIGS. 1A to 1E are schematic cross-sectional views showing a process of forming fine holes in a glass substrate by a method according to a first embodiment of the present invention in the order of steps.

FIGS. 2A to 2C are schematic cross-sectional views showing a process of forming a fine hole by a method according to a second embodiment of the present invention, similarly to FIGS.

FIGS. 3A to 3D are schematic cross-sectional views showing a process of tapering an opening of a fine hole by a method according to a third embodiment of the present invention.

FIGS. 4A to 4E are schematic cross-sectional views showing a process of forming an opening of a fine hole into a semicircular cross-section by the method of the fourth embodiment of the present invention, and FIG. It is a sectional perspective view of a fine hole.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Condensing lens 2 Glass substrate 3 Through hole 4, 5 dross 6 Hot melt material 7, 8 Imaginary line 9 Glass substrate 10 Micro hole 11 Dross 12 Melt 13, 14 Imaginary line 15 Through hole 16 Nozzle 17 Tapered portion 18 Fine grinding Particles 19 Solid-gas two-layer jet 20 Through hole 21 Nozzle 22 Tapered portion 23 Through hole 24, 25 Processing waste 26 Corrosion resistant coating 27 Photoresist 28 Mask 29 Gap 30 Concave portion 31 Through hole

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Nobuo Shimizu 3-5-5 Yamato, Suwa City, Nagano Prefecture Seiko Epson Corporation F-term (reference) 2C057 AF24 AF93 AG07 AP02 AP13 AP33 4E067 AA17 AB11 BA01 BF03 BH01 DA06 4E068 AA04 AF00 AF02 DA14 DB13 4G059 AA01 AA11 AB03 AC30

Claims (11)

[Claims] 1. A method for processing fine holes in glass, comprising the steps of forming fine holes in a glass workpiece and polishing the surface of the workpiece on which the fine holes are opened. . 2. The method according to claim 1, wherein the fine holes are formed by laser processing. 3. The method according to claim 1, wherein the fine holes are formed by ultrasonic processing. 4. The method according to claim 1, wherein the fine holes are formed so as to penetrate the workpiece. 5. The processing by forming the fine hole so as not to penetrate the workpiece and polishing not only the opening side of the fine hole but also the surface of the workpiece at the tip end side. 2. A through hole is formed in an object.
4. The method for processing a fine hole in glass according to any one of claims 1 to 3. 6. The method according to claim 6, further comprising: filling the fine holes with the filler before polishing the surface of the workpiece; and removing the filler from the fine holes after polishing the surface of the workpiece. The method for processing a fine hole in a glass according to any one of claims 1 to 5, wherein: 7. The method according to claim 6, wherein the filler is a resin material. 8. The method according to claim 6, wherein the filler is a hot melt material. 9. The method according to claim 4, wherein, after polishing the surface of the workpiece, at least one peripheral edge of the opening of the fine hole is microblasted. 10. The method according to claim 1, further comprising, after polishing the surface of the workpiece, etching the periphery of the opening of the fine hole. 11. The surface of the polished workpiece and the inner surface of the fine hole are coated with a corrosion-resistant film, and a photoresist is adhered on the corrosion-resistant film. 11. The method according to claim 10, wherein the corrosion-resistant coating on the lower side of the opening is removed, and the peripheral edge of the opening of the minute hole exposed thereby is wet-etched.