JPH05139784A - Working method for photosensitive glass - Google Patents

Abstract

PURPOSE:To provide the working method which forms grooves of different shapes on the front surface and rear surface of thin photosensitive glass. CONSTITUTION:An excimer laser oscillator 2 is disposed above the photosensitive glass 1 and the front surface 1a of the photosensitive glass is irradiated via an exposing mask with an XeCl excimer laser 2a. A laser of a pulse oscillation control type including the sensitivity wavelength region of the photosensitive glass is used for the laser. The energy intensity per pulse of the laser is specified to 1mJ/cm<2> and the glass is irradiated with about 200 pulses. The total exposure is specified to about 200mJ/cm<2>. As a result, exposed parts 11 are formed on the front surface 1a but the exposed parts are not formed on the rear surface 1b side. The photosensitive glass 1 is turned over and the rear surface 1b of the photosensitive glass is irradiated with the similar laser via the exposing mask 4, by which the exposed parts 12 are formed. The exposed parts are not formed on the front surface 1a either in such a case. The exposed parts 11, 12 are then subjected to a heating treatment and etching, by which the grooves are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing photosensitive glass by etching.

[0002]

2. Description of the Related Art Conventionally, there has been known a method of etching a photosensitive glass and finely processing a flow path substrate of an ink jet printer head. This method comprises an exposure step of exposing a desired portion of the photosensitive glass by irradiation of an ultraviolet lamp, a heat development step of heating the photosensitive glass to 500 to 700 ° C. to crystallize the exposed portion, and a crystallized exposure. It is a method comprising an etching step of dissolving and removing a part with an etching solution (hydrofluoric acid solution). In addition,
A high pressure mercury lamp or the like is used as the ultraviolet lamp.

[0003]

As shown in FIG. 6, in the method using the conventional ultraviolet lamp (high pressure mercury lamp) 100, in the case of the photosensitive glass plate 101 having a plate thickness of 10 mm or less, the ultraviolet light from the lamp 100 is used. When the photosensitive glass plate 101 is exposed through the mask 102 by 100a, the photosensitive glass plate 101 is exposed from the front surface 101a to the back surface 101a.
When it is exposed by penetrating to b and is thermally developed, a crystal part 103 penetrating from the front surface 101a to the back surface 101b is formed. For this reason, the crystal part 103 is dissolved by the etching solution from the exposed surface side and the opposite surface side during etching, so that different shapes cannot be formed on the front and back of the photosensitive glass plate 101.

However, in recent application fields such as ink jet printer heads and micromachines which require fine processing, it is desired to form a fine shape on a thin plate having different front and back sides.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method that enables processing of different shapes on the front and back of thin photosensitive glass.

[0006]

In order to achieve the above object, a method of processing a photosensitive glass of the present invention comprises an exposure step of exposing the photosensitive glass to a predetermined pattern with a laser and a heat for crystallizing an exposed portion. A processing method of forming a groove corresponding to the pattern in the photosensitive glass through a developing step and an etching step of removing a crystal part, which is a pulse oscillation control type including a sensitivity wavelength region of the photosensitive glass as a laser. The total exposure required to form a crystal part with a faster etching rate than the amorphous part by irradiating the photosensitive glass plate with multiple laser pulses by lowering the energy intensity per pulse of the laser. It is characterized by giving.

As the above laser, a XeCl excimer laser is preferably used.

Further energy intensity per pulse of the ^{laser, 1mJ / cm 2 ~50mJ / cm} 2 is preferred.

The inventor of the present invention exposes a photosensitive glass with an excimer laser and heat-develops it so that a total amount of exposure for forming a crystal part (hereinafter referred to as a predetermined crystal part) having an etching rate higher than that of an amorphous part is formed. , And found that it depends on the energy intensity per pulse of the laser. That is, it was discovered that the total amount of exposure required to form a predetermined crystal part is higher when the energy intensity per pulse is low than when the energy intensity per pulse is high.

Experimental data leading to this conclusion are shown in FIG. 7, in which the energy intensity per pulse is 1 mJ / cm ² of X.
When exposing with eCl excimer laser, the etching rate is 10 with 160 pulses (total exposure amount 160 mJ / cm ² ).
When μm / min is obtained and the energy intensity per pulse is 10 mJ / cm ² , 10 pulses (total exposure dose 100
mJ / cm ² ), an etching rate of 10 μm / min is obtained,
1 if the pulse per energy intensity of 72 mJ / cm ² can be seen to more etching rate 10 [mu] m / min per pulse (total exposure 72 mJ / cm ²⁾ is obtained. Thus, the smaller the energy intensity per pulse is, the larger the total exposure amount is required to form a predetermined crystal part.

FIG. 8 shows the transmittance and relative exposure sensitivity of the photosensitive glass. For example, the sensitivity wavelength range of photosensitive glass is 308 nm.
When the XeCl excimer laser having the oscillation wavelength of is used, the transmittance of the photosensitive glass is about 30% as can be seen from FIG. Therefore, the total exposure amount on the back surface of the photosensitive glass plate is about 30% of the front surface. Therefore, when the total exposure amount on the front surface is 200 mJ / cm ² with a laser having an energy intensity of 1 mJ / cm ² per pulse, The total exposure dose of 30% is 60 mJ / cm ^2, which is 30% of the total exposure amount, and as is clear from FIG. 7A, the etching hardly progresses and the total exposure required for forming a predetermined crystal part on the back surface. Not reach the amount. On the other hand, the total exposure of the surface is 216 mJ / with a laser having an energy intensity of 72 mJ / cm ² per pulse.
When exposed at cm ² , the total backside exposure is 65 mJ / cm ²
As shown in FIG. 7C, the etching rate is 10 μm / min or more, and it can be seen that the total exposure amount required to form a predetermined crystal part on the back surface is reached.
If more of the 1 pulse per energy intensity 72 mJ / cm ^2, the pulse that is the total exposure appears a pattern of back exposure even 72 mJ / cm ^2. Thus, even if the total amount of exposure on the front surface is almost the same, when the energy intensity per pulse is high, a predetermined crystal part is sufficiently formed on the rear surface.

In this way, by controlling the energy intensity per pulse and the number of pulses to be irradiated (total exposure amount given to the surface), the minimum total amount necessary to form a predetermined crystal part on the surface is controlled. It is possible to expose the photosensitive glass so that the exposure amount is reached but the required total exposure amount is not reached on the back surface. As a result, it becomes possible to expose different shapes independently on the front and back sides, and processing of different shapes on the front and back sides can be formed by etching.

On the other hand, in the conventional high pressure mercury lamp,
5 just to expose the glass surface so that it can be etched
It has to be irradiated with 00W for about 15 minutes, and the total exposure amount is as high as 4.5 × 10 J / cm ^2, and naturally, the exposed portion becomes a crystal portion with a high etching rate not only on the front surface but also on the back surface. Will be formed. FIG. 9 shows the emission spectrum of the ultra-high pressure mercury lamp USH-500D. As can be seen from FIG. 9, since the wavelength of the high-pressure mercury lamp includes many wavelengths other than the sensitivity wavelength range of the photosensitive glass, it is wasteful, and thus a large total exposure amount as described above is required. If the total exposure amount is smaller than this, it is impossible to form an exposed portion which becomes a crystal portion with a high etching rate even on the surface.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. First, a method for manufacturing a flow path substrate of an inkjet printer head by processing a photosensitive glass by the processing method according to the present invention will be described in order of steps with reference to FIGS. As shown in FIG. 1, in the first step, the plate thickness 1
The surface 1a and the back surface 1b of the 1 mm photosensitive glass 1 are polished, and the laser oscillator 2 is arranged above the laser 2a.
Is irradiated onto the surface 1a of the photosensitive glass through the exposure mask 3. The exposure mask 3 has an exposure pattern (aperture) 3 corresponding to a groove formed on the surface 1a of the photosensitive glass 1.
a and a light-shielding portion 3b in the other portion are formed.

As the laser used, a pulse oscillation control type laser having a sensitivity wavelength range of 150 to 400 nm of the photosensitive glass is selected. In this example, a XeCl excimer laser having an oscillation wavelength of 308 nm was used. The energy intensity per pulse of the XeCl excimer laser at the time of this exposure is between 1 mJ / cm ² and 50 mJ / cm ² , preferably about 10 mJ / cm ² , and in this embodiment, 1 mJ / cm ^2. Irradiation for about 200 pulses to give a total exposure of about 200 mJ / cm ² .

By this irradiation, the surface 1 of the photosensitive glass 1
a includes exposure units 11 and 11 corresponding to the exposure pattern 3a.
However, since the energy intensity per pulse is small, the exposed portion is not formed on the back surface 1b.

That is, as shown in FIG. 7 (A), when the energy intensity per pulse is 1 mJ / cm ² , the total exposure dose is 100 mJ / cm ^2, that is, a crystal part having a high etching rate from the irradiation of 100 pulses. Formable exposure begins to be obtained, and the total exposed dose becomes 200 mJ / cm ² , and this crystal part becomes an stably formed exposed part. In the case of photosensitive glass, the optical absorption of the XeCl excimer laser at the oscillation wavelength of 308 nm is about 30% at a plate thickness of 1 mm, and the total surface exposure is 200 mJ / cm 2.
If ^2, then the total exposure on the back side is about 60 mJ / cm ² ,
The exposed portion, which becomes a crystal portion having a high etching rate, is not formed on the back surface side.

As shown in FIG. 2, in the second step, the photosensitive glass 1 is inverted and the excimer laser oscillator 2 is operated to remove X.
The back surface 1b of the photosensitive glass is irradiated with the eCl excimer laser 2a through the exposure mask 4. The exposure mask 4 has an exposure pattern 4a of another shape formed on the back surface 1b of the photosensitive glass 1 and a light shielding portion 4b on the other portion. During this exposure, the XeCl excimer laser 1
The energy intensity per pulse is 1 mJ / cm ² and 200
Irradiation for about a pulse is performed to form the exposed portions 12, 12 on the back surface 1b with a total exposure amount of about 200 mJ / cm ² . Also in this case, similarly to the above, the exposure in which the crystal part having a high etching rate is formed on the opposite side, that is, the surface 1a side cannot be obtained.

As shown in FIG. 3, in the third step, the photosensitive glass 1 is heated to a high temperature of about 500 to 700 ° C., and thermal development is performed to crystallize the exposed portions 11 and 12, and the crystalline portion 11 is subjected.
a and 12a are formed.

Next, as shown in FIG. 4, in the fourth step, the photosensitive glass 1 is etched by showering it with an etching solution composed of a solution of hydrofluoric acid (HF) of 5 to 10% in a shower shape. Grooves 5 and 6 are formed by dissolving and removing the portions 11a and 12a. By this etching, the flow path substrate 10 of the ink jet printer head having the groove portions 5 and 6 which become the ink flow paths is formed.

In the ink jet printer head shown in FIG. 5, the vibrating plates 7 and 7 are attached to both front and back surfaces of the flow path substrate 10 made of the photosensitive glass formed as described above, and the vibrating plates 7 and 7 are attached at predetermined positions on the outer surface of the vibrating plate. The piezoelectric elements 8 are provided.

In this ink jet printer head, ink is filled in the ink flow paths 5 and 6 from an ink supply means (not shown), and when a voltage is applied to the piezoelectric elements 8 ... The ink is deformed to pressurize the ink in the flow path, and the ink is ejected from an ink ejection port (not shown) to form dots.

In the above embodiment, the X laser is used.
eCl excimer laser is used, but other X
eF (oscillation wavelength 351 nm), KrF (oscillation wavelength 248 n
m), ArF (oscillation wavelength 193 nm) excimer laser,
A N ₂ laser (oscillation wavelength 337 nm) may be used, and a fundamental oscillation wavelength of a laser in which Nd ⁺ and YAG (yttrium aluminum garnet) are mixed, a dye laser, a Kr ion laser, an Ar ion laser or a copper vapor laser. A laser in which light is converted into the ultraviolet region by a non-linear optical element or the like may be used.

[0024]

As described above, according to the present invention, a pulse oscillation control type laser including the sensitivity wavelength region of the photosensitive glass is used to expose the photosensitive glass, and the energy intensity per pulse and irradiation are increased. Since the number of pulses to be controlled is controlled, it is possible to form a crystal part that is susceptible to etching only on the exposed surface. Therefore, it is possible to form grooves having different shapes on the front surface and the back surface of the thin photosensitive glass.

[Brief description of drawings]

FIG. 1 is a front view showing a first exposure step of an embodiment of the present invention.

FIG. 2 is a front view showing a second exposure process of the same.

FIG. 3 is a front view of the photosensitive glass after the heat development step of the above.

FIG. 4 is a cross-sectional view of the photosensitive glass after the above etching process.

FIG. 5 is a cross-sectional view of an inkjet printer head using a photosensitive glass substrate manufactured by the above method.

FIG. 6 is a front view showing a conventional exposure process.

FIG. 7 is a diagram showing the relationship between the total exposure amount of photosensitive glass and the etching rate.

FIG. 8 is a characteristic diagram showing transmittance and relative exposure sensitivity of photosensitive glass.

FIG. 9 is an emission spectrum diagram of an ultra-high pressure mercury lamp.

[Explanation of symbols]

 1 Photosensitive glass plate 2a Laser 11a, 12a Crystal part

Claims (3)

[Claims] 1. An exposure step of exposing a photosensitive glass to a predetermined pattern by a laser, a heat development step of crystallizing an exposed portion, and an etching step of removing the crystal portion,
A method of forming a groove corresponding to the pattern on the photosensitive glass, wherein a pulse oscillation control type laser including the sensitivity wavelength region of the photosensitive glass is used as the laser, and Photosensitivity characterized by irradiating the photosensitive glass plate with a plurality of pulses of the laser at a low energy intensity to give a total exposure amount required to form a crystal part having an etching rate faster than that of the amorphous part. Glass processing method. 2. The laser according to claim 1, wherein the laser is X
A method for processing a photosensitive glass, which is an eCl excimer laser. 3. The energy intensity per pulse of the laser according to claim 1 or 2, which is 1 mJ / cm ^{2 to} 5
A method for processing a photosensitive glass, characterized in that it is 0 mJ / cm ² .