JP3041551B2 - Processing method of photosensitive glass - Google Patents

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 Heretofore, there has been known a method of etching photosensitive glass and performing fine processing on a flow path substrate and the like of an ink jet printer head. This method includes an exposure step of exposing a desired portion of the photosensitive glass by irradiation with an ultraviolet lamp, a heat development step of heating the photosensitive glass to 500 to 700 ° C. to crystallize the exposed portion, This is a method comprising an etching step of dissolving and removing the portion with an etching solution (hydrofluoric acid solution). In addition,
As an ultraviolet lamp, a high-pressure mercury lamp or the like is used.

[0003]

As shown in FIG. 6, in a method using a conventional ultraviolet lamp (high-pressure mercury lamp) 100, in a photosensitive glass plate 101 having a thickness of about 10 mm or less, an ultraviolet light from the lamp 100 is used. When the photosensitive glass plate 101 is exposed through the mask 102 by the mask 100a, the front surface 101a of the photosensitive glass plate
When exposure is performed by penetrating up to b, and thermal development is performed, a crystal part 103 penetrating from the front surface 101a to the back surface 101b is formed. For this reason, since the crystal part 103 is dissolved by the etchant from the exposed surface side and the opposite surface side during etching, different shapes cannot be formed on the front and back of the photosensitive glass plate 101.

However, in application fields requiring fine processing such as a recent ink jet printer head and a micro machine, it is desired to form fine shapes that are different on the front and rear sides on a thin plate.

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

[0006]

In order to achieve the above object, a method for processing photosensitive glass according to the present invention comprises: an exposure step of exposing the photosensitive glass to a predetermined pattern by a laser; 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, wherein the laser is a pulse oscillation control type including a sensitivity wavelength region of the photosensitive glass as a laser. Irradiating the photosensitive glass plate with a plurality of laser pulses by lowering the energy intensity per pulse of the laser using the above laser, and the total exposure required to form a crystal part where the etching rate is faster than the non-crystal part Give the laser
Energy intensity per pulse is 1 mJ / cm ² to 50
It is characterized in that it is mJ / cm ^2.

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

The inventor of the present invention exposed the photosensitive glass with an excimer laser and, when thermally developed, formed a crystal part having a higher etching rate than a non-crystal part (hereinafter referred to as a predetermined crystal part). Have found that it depends on the energy intensity per pulse of the laser. That is, it has been found that the total exposure amount required to form a predetermined crystal part is larger when the energy intensity per pulse is low than when the energy intensity per pulse is high.

The experimental data leading to this conclusion is shown in FIG. 7, and when exposure is carried out with a XeCl excimer laser having an energy intensity per pulse of 1 mJ / cm ² , 160
Etching rate 1 with pulse (total exposure 160 mJ / cm ² )
When 0 μm / min is obtained and the energy intensity per pulse is 10 mJ / cm ² , 10 pulses (total exposure 100
mJ / cm ² ), an etching rate of 10 μm / min was obtained.
When the energy intensity per pulse 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. As described above, the smaller the energy intensity per pulse, 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, 308 nm of the sensitivity wavelength range of photosensitive glass
When a XeCl excimer laser having an oscillation wavelength of 1 mm is used, as shown in FIG. 8, the transmittance of the photosensitive glass is about 30% at a plate thickness of 1 mm. Therefore, since the total exposure amount reaching the rear surface of the photosensitive glass plate is about 30% of the front surface, when the total exposure amount of the front surface is 200 mJ / cm ² by the laser having an energy intensity of 1 mJ / cm ² per pulse, 7 is only 30% of 60 mJ / cm ² , and FIG.
As apparent from (A), the etching hardly proceeds, and the total exposure amount required for forming a predetermined crystal part on the back surface does not reach. On the other hand, when the total exposure on the front surface is exposed at 216 mJ / cm ^{2 using} a laser having an energy intensity per pulse of 72 mJ / cm ² , the total exposure on the back surface is 65 mJ / cm ² , as shown in FIG. As shown, it can be seen that the etching rate became 10 μm / min or more, and the total exposure required for forming a predetermined crystal part also on the back surface was reached. Furthermore, the energy intensity per pulse is 72 mJ /
In the case of cm ² , one pulse, that is, the total exposure amount is 72 mJ / cm.
Pattern of back exposure even ² appears. As described above, even when the total exposure amount on the front surface is almost the same, when the energy intensity per pulse is large, a predetermined crystal part is sufficiently formed on the back surface.

By controlling the energy intensity per pulse and the number of irradiation pulses (total exposure dose given to the surface) in this manner, the minimum total amount required to form a predetermined crystal part on the surface is obtained. Although the exposure amount is reached, the photosensitive glass can be exposed on the back surface so as not to reach the required total exposure amount. This makes it possible to independently expose different shapes on the front and back, and to form different shapes on the front and back by etching.

On the other hand, in the conventional high-pressure mercury lamp,
5 just to expose the glass surface to be etchable
Irradiation must be performed for about 15 minutes at a power of 00 W, and the total exposure amount is as large as 4.5 × 10 J / cm ^2. Naturally, an exposed portion that becomes a crystal part having a high etching rate not only on the front surface but also on the back surface. Is formed. FIG. 9 shows an emission spectrum of the ultra-high pressure mercury lamp USH-500D. As can be seen from FIG. 9, the wavelength of the high-pressure mercury lamp contains many wavelengths other than the sensitivity wavelength range of the photosensitive glass, so that there is much waste, and therefore, 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 having a high etching rate even on the surface.

[0013]

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

As the laser to be used, a pulse oscillation control type laser including a photosensitive 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 during this exposure is between 1 mJ / cm ² and 50 mJ / cm ² , preferably about 10 mJ / cm ² , and in this embodiment, it is 1 mJ / cm ^2. , About 200 pulses, and the total exposure amount was about 200 mJ / cm ² .

By this irradiation, the surface 1 of the photosensitive glass 1 is
In a, there are exposed portions 11, 11 corresponding to the exposure pattern 3a.
However, since the energy intensity per pulse is low, no exposed portion is 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 crystal part having a high etching rate from irradiation of 100 mJ / cm ^2, that is, 100 pulses, is exposed. Exposure that can be formed is started to be obtained, and the total exposure amount becomes 200 mJ / cm ² , and the crystal part becomes an exposed part that can be stably formed. In the case of photosensitive glass, the optical absorption at an oscillation wavelength of 308 nm of a XeCl excimer laser is about 30% at a plate thickness of 1 mm, and the total exposure of the surface is 200 mJ / cm.
² , the total exposure on the back side is about 60 mJ / cm ² ,
On the back side, there is no exposed portion that becomes a crystal portion having a high etching rate.

As shown in FIG. 2, in the second step, the photosensitive glass 1 is inverted and the excimer laser
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 at other portions. During this exposure, the XeCl excimer laser 1
The energy intensity per pulse is 1 mJ / cm ² and 200
Irradiation is performed for about a pulse so that the total exposure amount is about 200 mJ / cm ^2, and exposed portions 12 and 12 are formed on the back surface 1b. In this case, as in the case described above, no exposure can be obtained in which a crystal part having a high etching rate is formed on the opposite side, that is, on the surface 1a side.

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 for crystallizing the exposed portions 11 and 12 is performed.
a and 12a are formed.

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

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

In the ink jet printer head, ink is filled in the ink flow paths 5 and 6 from ink supply means (not shown), and when a voltage is applied to the piezoelectric elements 8, the diaphragm 7 moves inward. The ink in the flow path is deformed and pressurized, and the ink is ejected from an ink ejection port (not shown) to form a dot.

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

[0023]

As described above, according to the present invention, in order to expose the photosensitive glass, a pulse oscillation control type laser including the sensitivity wavelength range of the photosensitive glass is used, and the energy intensity and irradiation per pulse are controlled. Since the number of pulses to be controlled is controlled, it is possible to form a crystal part which is easily etched only on the exposed surface. For this reason, it is possible to process grooves having different shapes on the front and back sides of a thin photosensitive glass.

[Brief description of the 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 step of the above.

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

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

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

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

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

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

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

[Explanation of symbols]

1 photosensitive glass 2a laser 11a, 12a crystalline portion

Claims (2)

(57) [Claims] An exposure step of exposing the photosensitive glass to a predetermined pattern by a laser, a heat development step of crystallizing the exposed portion, and an etching step of removing the crystal portion.
A processing method for forming grooves corresponding to the pattern in the photosensitive glass, wherein a pulse oscillation control type laser including a sensitivity wavelength range of the photosensitive glass is used as the laser, the energy intensity and low irradiated with multiple pulses of the laser in the photosensitive glass, gives the total exposure required to etch rate to form a faster crystal portion than the non-crystal portion, one pulse per the laser Energy intensity is 1mJ /
method of processing photosensitive glass, which is a cm ² ~50mJ / cm ^2. 2. The method according to claim 1, wherein the laser is X
A method for processing photosensitive glass, which is an eCl excimer laser.