TWI493596B - Fluorescent light - Google Patents

Description

Fluorescent light

The present invention relates to a fluorescent lamp that emits light in an ultraviolet region, and more particularly to a fluorescent lamp that emits light having a wavelength of around 200 to 250 nm.

The ultraviolet ray is used for recombination of various treatment objects or by a treatment using a photochemical reaction to produce a substance. Then, for example, ultraviolet light having a wavelength of about 200 nm is used in the curing treatment of a resin such as an ultraviolet-ray-based adhesive or the exposure treatment of a printed circuit board or the like.

Further, in the recent manufacturing process of semiconductors, ultraviolet light of the same wavelength band is used even in a process of improving the mechanical strength of a low dielectric constant film (low-k film).

In the production of a low dielectric constant film (low-k film) of the above-mentioned semiconductor, in recent years, the demand for fine wiring and multilayer wiring structure has been increased due to the high integration of the device, and the purpose is to increase the power consumption while reducing the power consumption. The processing speed, in order to reduce the interlayer capacitance, gradually use the low-k film material.

For this reason, it is impossible to ignore the decrease in the mechanical strength (elastic coefficient or EM) of the material with a decrease in the dielectric constant of the material, and the hardening treatment from the previous heat (annealing) is gradually changed to the purpose of increasing the mechanical strength and irradiating the ultraviolet rays. A hardening treatment is carried out to improve the strength reduction method.

Then, as the ultraviolet light used for the improvement of the strength of such a low-k film, as shown in Patent Document 1 (Japanese Laid-Open Patent Publication No. 2009-289996), Ultraviolet rays containing light having a wavelength of 200 nm are effective, and in particular, 200 to 260 nm, more preferably 220 to 250 nm, are required.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-289996

Conventionally, as a lamp that emits ultraviolet light in a wavelength band of about 200 nm, a long-arc type high-pressure mercury lamp in which mercury is sealed inside an arc tube is known.

However, such an ultraviolet ray lamp is a person in which mercury is sealed inside the arc tube. Of course, since the characteristics depend on the state in which the mercury is evaporated, there is a problem that the illuminating characteristics are unstable due to the slow rise in the ambient temperature condition of the lamp.

In addition, the high-pressure mercury lamp system mainly emits light in the range of 250 to 320 nm as a resonance line of mercury, and has a light output of 200 to 260 nm required for improvement of the strength of the low-k film, and an ideal light output of 220 to 250 nm is not sufficient. The problem.

Further, since the high-pressure mercury lamp has a structure in which an electrode is provided inside the arc tube, the life of the electrode is determined in accordance with the depletion state of the electrode included in the electrode. Therefore, the life of the high-pressure mercury lamp is usually within 10,000 hours, which causes a problem of high running cost.

According to this situation, it is required to develop a light source having a wavelength of 200 to 260 nm, preferably 220 to 250 nm, and a long life without using mercury.

In view of the above-described circumstances, the present invention provides a fluorescent lamp which does not use mercury as a discharge gas and has a high luminous intensity of ultraviolet rays having a wavelength of 200 to 260 nm, in other words, a conversion efficiency is high.

In order to solve the above problems, the fluorescent lamp of the present invention includes an arc tube formed of quartz glass and sealed with a discharge gas containing xenon, a pair of electrodes disposed outside the arc tube, and formed. The fluorescent lamp of the phosphor layer on the inner surface of the arc tube is characterized in that the phosphor layer is provided with a phosphor represented by (Y _1-X , Pr _X )Al ₃ B ₄ O ₁₂ . .

Further, it is characterized in that the fluorescent system x is in the range of 0.05 to 0.07.

Further, it is characterized in that a glass layer made of soft glass or hard glass is formed between the arc tube and the phosphor layer.

Further, it is characterized in that an ultraviolet reflecting film is formed on the inner surface of the arc tube.

Further, the ultraviolet reflecting film is characterized by comprising calcium pyrophosphate (Ca ₂ P ₂ O ₇ ), calcium phosphate (Ca ₃ (PO ₄ ) ₂ ), magnesium pyrophosphate (Mg ₂ P ₂ O ₇ ) or Ba-Na-Si. -O of any.

According to the fluorescent lamp of the present invention, an emission spectrum of about 200 nm is efficiently emitted, and the deterioration due to long-time lighting is small.

Further, by forming a glass layer between the arc tube and the phosphor layer, the phosphor layer is strongly bonded to the arc tube and does not peel off or fall off.

1 is a cross-sectional view of a fluorescent lamp according to a first embodiment of the present invention, (A) a cross-sectional view in the axial direction, and (B) a cross-sectional view in the radial direction. 2 is an enlarged cross-sectional view of FIG. 1(A).

As shown in Fig. 1, a pair of external electrodes 3 and 4 are disposed on the outer peripheral surface of the arc tube 2 made of quartz glass, and the external electrodes 3 and 4 are formed in a strip shape extending in the tube axis direction. The shape is formed, for example, from a silver paste in which silver (Ag) and powder glass are mixed, and a conductive film in which gold (Au) and powdered glass are mixed.

The wires W1 and W2 are connected to the external electrodes 3 and 4, respectively, and are connected to a power source 8 that generates a high-frequency voltage.

The arc tube 2 is made of quartz glass having a high ultraviolet transmittance for a band having a wavelength of 200 nm, and any of fused silica glass, synthetic quartz glass, and Ozone free (Ozone less) quartz glass may be used. However, in this case, in order to reduce the deterioration of ultraviolet rays, it is preferable to use quartz glass having an OH group concentration of 100 ppm or more.

Then, a rare gas is sealed as a discharge gas in the arc tube 2, but the rare gas system may be either helium or a mixed gas of helium and other rare gases.

As shown in detail in Fig. 2, on the inner surface of the arc tube 2, the glass layer 5 is formed to diffuse to almost the entire area. Then, to layer this glass The phosphor layer 6 is formed on the inner surface of the layer 5.

The glass layer 5 is used to adhere the phosphor layer 6 to the quartz glass constituting the arc tube 2. As the glass characteristics, the softening point is preferably in the range of the firing temperature (400 to 900 ° C) of the phosphor, specifically For the material, soft glass and hard glass are used. In particular, a hard glass excellent in thermal shock resistance is preferable.

By interposing such a glass layer 5 between the phosphor layer 6 and the arc tube 2, the following effects can be exhibited.

When the phosphor layer 6 is directly attached to the arc tube 2, the phosphor is applied to the inner surface of the arc tube 2, and then the firing temperature is raised to the vicinity of the temperature of the glass constituting the arc tube 2, and then fired. Engineering. However, when quartz glass is used as the arc tube material, the softening point is about 1600 ° C. When the phosphor is heated to such a high temperature band, the phosphor is deteriorated and the predetermined light cannot be obtained. On the other hand, when the temperature at which the firing temperature of the phosphor is lowered to a temperature band in which the luminescent property does not cause a problem, for example, at 900 ° C or lower, the quartz glass is not softened, and the phosphor layer 6 is removed from the tube. The discomfort of the wall peeling off. As a result, there is a problem that the desired light distribution cannot be obtained.

According to the fluorescent lamp of the present embodiment, since the glass layer 5 made of soft glass or hard glass having a softening point lower than that of quartz glass is formed on the inner surface of the arc tube 2, the firing temperature of the phosphor can be set. Set to be lower, the phosphor layer 6 can be stably held. Further, when the thickness of the glass layer 5 itself is about 3 to 30 μm, the phosphor layer 6 can be held, so that the transmittance of the glass layer 5 is not significantly lowered.

As a specific material of the glass layer 5, the condition of the hard glass is borosilicate glass (Si-BO glass, softening point: about 800 ° C), aluminum silicate glass (Si-Al-O glass, softening point: about It is preferable to add 900 ° C) or an alkali earth oxide or an alkali metal oxide or a metal oxide based on any of these compositions, and the hard glass may be used alone or in an appropriate ratio. Also. Further, it is preferable that the form of the glass is a powder.

The glass layer 5 is formed on the inner surface of the arc tube 2, and as described above, the phosphor layer 6 laminated on the glass layer 5 is strongly held by the arc tube 2, and peeling without the phosphor layer 6 or A high-reliability fluorescent lamp that falls off.

Further, since the quartz glass having a high ultraviolet transmittance is used as the material of the arc tube 2, the transmittance of ultraviolet light having a wavelength of about 200 nm (200 to 260 nm, preferably 220 to 250 nm) is good, and the ultraviolet light is highly efficient. Fluorescent light.

The fluorescent system constituting the phosphor layer 6 is irradiated with vacuum ultraviolet light of 146 nm or 172 nm emitted by excimer light emission of helium, and is excited to have a wavelength of about 200 nm, specifically, a wavelength of 200 to 260 nm. A phosphor having a good light-emitting property of preferably 220 to 250 nm is represented by the following general formula.

(Y _1-X ,Pr _X )Al ₃ B ₄ O ₁₂

Ideally x=0.05~0.07

By using the above-mentioned phosphor, it is possible to provide a maximum of light-emitting characteristics of 200 to 260 nm, preferably 220 to 250 nm, and the efficiency is extremely good. Fluorescent light.

In the present invention, various modifications can be made regarding the lamp structure, and several examples thereof are disclosed in FIG.

In Fig. 3(A), a portion of the circumference of the phosphor layer 6 is removed, and the portion is the aperture 10 for light extraction. With such a configuration, ultraviolet light of 200 to 260 nm generated inside the arc tube 2 is guided to the diaphragm portion by reflection of the surface of the phosphor layer 6, and ultraviolet light is efficiently emitted from the diaphragm 10.

Further, in Fig. 3(B), an ultraviolet reflecting film 7 is formed on the inner surface of the arc tube 2, and a portion of the circumference is cut away to form the diaphragm 10, and the glass layer 5 and the phosphor are laminated on the ultraviolet reflecting film 7. Body layer 6 people.

The ultraviolet reflecting film 7 includes calcium pyrophosphate (Ca ₂ P ₂ O ₇ ), calcium phosphate (Ca ₃ (PO ₄ ) ₂ ), magnesium pyrophosphate (Mg ₂ P ₂ O ₇ ), and Ba-Na-Si-. In any of the above, it is preferred that the total amount is included in the range of more than 50% in the film.

Accordingly, the ultraviolet ray generated in the arc tube 2 is reflected by the ultraviolet ray reflection film 7 in the arc tube, and is transmitted in the order of the phosphor layer 6 and the glass layer 5 of the aperture 10 to the illuminating tube 2. The outside is directional and radiates.

3(C) is an example of the aperture (10), and the aperture 10 is also formed on the phosphor layer 6. The ultraviolet light is efficiently transmitted to the light-emitting tube through the glass layer 5 only. 2 outside.

Hereinafter, an example of the production procedure of the present invention will be disclosed.

1. As a light-emitting tube material, a cylindrical stone made of fused silica glass is used. British tube.

2. Apply a glass powder slurry to the inner surface of the arc tube.

First, the glass powder of the low temperature zone is compared with the quartz glass, and the nitrocellulose and the butyl acetate solution are mixed at a predetermined ratio to prepare a suspension, and a glass powder slurry in which the glass powder is dispersed is prepared.

The glass used in the glass layer may be selected from the group consisting of borosilicate glass (Si-BO glass) and aluminum silicate glass (Si-Al-O glass), or an alkaline earth oxide is added based on any of the compositions. A glass of a substance or an alkali metal oxide or a metal oxide, for example, glass made by Nippon Electric Glass Co., Ltd., type BFK or BS, PS-94.

The slurry of the glass powder is applied to the inner surface of the arc tube made of quartz glass by an inflow method, a suction method, or the like.

3. Dry the layer of glass powder

After the slurry is fixed, a dry nitrogen gas (dry air may be passed) from one of the arc tubes to evaporate the butyl acetate contained in the glass slurry. As a result, a layer made of glass powder having a thickness of 3 to 10 μm can be obtained on the inner surface of the glass tube.

Further, as the distribution state of the dried glass layer, it is preferable to disperse it in an area ratio of 30 to 90%. Further, the thickness of the glass layer is preferably 3 to 10 μm, particularly preferably 3 to 6 μm.

As the formation ratio of the glass layer, when the concentration is low, when the fluorescent lamp is finally formed, the exposed surface of the quartz glass is too wide and it is difficult to protect the phosphor. hold. On the other hand, when it is more than 90%, the glass powder constituting the glass layer is formed in a state in which there is no gap therebetween, because the temperature change at the time of lamp production, and the thermal expansion caused by repeating the lamp lighting/eliminating, there is A state in which a gap is formed in the interface between the arc tube and the glass layer and the glass layer is peeled off.

4. Layers of fired glass powder

The layer made of the dried glass powder was baked in the air at 800 ° C for 1 hour. Further, as the most suitable firing temperature, it is preferred to use the above-described borosilicate glass or aluminum silicate glass at 600 to 900 °C. Further, when a glass such as an alkaline earth oxide, an alkali oxide or a metal oxide is added to the glass, it is preferably carried out at 500 to 800 °C.

The glass powder is partially bonded to each other by the firing process, and is fused to a glass tube made of quartz glass, and the glass layer is strongly bonded to the substrate.

5. Modulation of phosphor slurry

The fluorescent system is a phosphor formed of an activated aluminum borate compound, which is as follows in the conventional formula.

(Y _1-X ,Pr _X )Al ₃ B ₄ O ₁₂

Ideally x=0.05~0.07

6. Coating the phosphor slurry on the inner surface of the arc tube

The slurry phosphor slurry is applied to the arc tube 2. Coating method Inflow method, etc. are more suitable.

7. Drying the phosphor

The dry nitrogen gas (dry air may be passed) inside the glass tube to evaporate the butyl acetate contained in the phosphor slurry.

8. Burning the phosphor

The glass tube for the light-emitting tube was placed in a furnace and fired. The firing conditions are heated in an atmosphere of about 500 to 800 ° C for a period of 0.2 to 1 hour at a maximum temperature holding time. In this firing process, softening of the glass occurs at the interface between the phosphor layer 6 and the glass powder layer 5, and the phosphor is adhered to the glass powder layer 5, and as a result, a strong bonding state is obtained.

Finally, after cooling the arc tube after firing, the inside of the arc tube is evacuated, and the discharge gas is sealed and tip-off is performed to form an external electrode.

In the fluorescent lamp configured as described above, when a high-frequency voltage is applied to the pair of outer electrodes 3 and 4 by the power source 8, a dielectric (the upper and lower walls of the arc tube 2) is interposed between the electrodes 3 and 4. The discharge is caused by the emission of a discharge gas such as xenon (Xe) gas to generate ultraviolet light having a wavelength of 172 nm.

In the luminescence for excitation of the ultraviolet-based phosphor obtained here, the phosphor layer 6 is irradiated with ultraviolet light having a wavelength of 172 nm, and the phosphor is excited to obtain a wavelength of 200 to 260 nm, preferably 220 to 250 nm. Fluorescent light. Further, quartz glass can be used as a material of the arc tube, and a fluorescent lamp having excellent transmission characteristics of ultraviolet light of about 200 nm can be obtained.

<Experimental example>

Next, the composition of the phosphor was changed in the manner of the foregoing embodiment to constitute a fluorescent lamp, and the emission spectrum was measured by a spectral distribution meter (oxtail mechanism: USR40).

The fluorescent system is specifically an endowed active aluminum borate phosphor ((Y _1-X ,Pr _X )Al ₃ B ₄ O ₁₂ ), and the value of x is changed to 0, 0.005, 0.01, 0.03, 0.05. , 0.07 to the producer.

In addition, in any of the fluorescent lamps, the enclosed gas was set to helium gas, and the sealing pressure was set to 21 kPa (160 Torr). The lamp was applied to the lamp by applying a rectangular wave voltage of V _0-p = 1700 V to perform measurement.

Next, an example of the emission spectrum of the wavelength band (λ) of the above-mentioned respective fluorescent lamps in the range of 200 to 350 nm is disclosed in FIG.

Furthermore, in FIG. 4, in order to eliminate the overlap of the graphs of the emission spectra of the respective fluorescent lamps, the vertical axis is sequentially illuminated with the increase of the value of X based on the emission spectrum of the fluorescent lamp at x=0. The value of the intensity is added to "1" to shift the emission spectrum to eliminate the overlap.

It can be clearly seen from the same figure that any fluorescent lamp can obtain a good light-emitting state at a wavelength of 200 to 300 nm, but the luminous intensity greatly differs depending on the composition of the phosphor (the ratio of Y to Pr).

Further, the amount of integrated light in the wavelength range of 200 to 300 nm of all the lamps is divided by the lamp power, and the dependence on the luminous efficiency with respect to the ratio of x is examined. This result is disclosed in Figure 5.

The spectroscope is used in the self-illuminating tube using the oxtail electric mechanism USR-40D. The central distance is measured by a distance of 25 mm. At this time, the length of the input lamp to the lamp lighting power source 8 is 10 W/m per 1 m.

According to the same figure, the highest luminous efficiency can be obtained when x is 0.05. Then, when the luminous efficiency when x is 0.05 is 100%, it is understood that the luminous efficiency is 98% or more when X is 0.05 to 0.07, and a good fluorescent lamp can be obtained.

As described above, in the fluorescent lamp of the present invention, a phosphor represented by (Y _1-X , Pr _X )Al ₃ B ₄ O ₁₂ is provided on the inner surface of an arc tube made of quartz glass. Therefore, ultraviolet light having a wavelength of 200 to 260 nm, more preferably 220 to 250 nm, can be efficiently emitted, and a glass layer made of soft glass or hard glass is formed between the light-emitting tube and the phosphor layer. By embedding this, it is excellent in the highly reliable fluorescent lamp which can provide the fluorescent layer which is strongly hold|maintained in the light-emitting tube, and this phosphor layer does not peel and fall.

1‧‧‧ fluorescent light

2‧‧‧Light tube (quartz glass)

3,4‧‧‧External electrode

5‧‧‧ glass layer

6‧‧‧Fluorescent layer

7‧‧‧UV reflective film

10‧‧‧ aperture

W1, W2‧‧‧ wire

Fig. 1 is a cross-sectional view showing a fluorescent lamp of the present invention.

Fig. 2 is an enlarged cross-sectional view showing a portion P of Fig. 1.

Fig. 3 is a cross-sectional view showing another embodiment of the present invention.

Fig. 4 is a graph showing the emission spectrum of the fluorescent lamp of the present invention.

Fig. 5 is a graph showing the luminous efficiency (relative value) of the fluorescent lamp of the present invention.

1‧‧‧ fluorescent light

2‧‧‧Light tube (quartz glass)

3,4‧‧‧External electrode

5‧‧‧ glass layer

6‧‧‧Fluorescent layer

8‧‧‧Power supply

W1, W2‧‧‧ wire

Claims (4)

A fluorescent lamp comprising: an arc tube formed of quartz glass, in which a discharge gas containing xenon is sealed, a pair of electrodes disposed outside the arc tube, and a phosphor formed on an inner surface of the arc tube The fluorescent layer of the photo-layer layer is characterized in that the phosphor layer is provided with a phosphor represented by (Y _1-X , Pr _X )Al ₃ B ₄ O _{12 in the} ordinary formula; and the phosphor is x. It is in the range of 0.05 to 0.07. The fluorescent lamp according to claim 1, wherein a glass layer made of soft glass or hard glass is formed between the arc tube and the phosphor layer. The fluorescent lamp according to the first or second aspect of the invention, wherein the ultraviolet light reflecting film is formed on the inner surface of the arc tube. The fluorescent lamp according to claim 4, wherein the ultraviolet reflecting film comprises calcium pyrophosphate (Ca ₂ P ₂ O ₇ ), calcium phosphate (Ca ₃ (PO ₄ ) ₂ ), magnesium pyrophosphate Any of (Mg ₂ P ₂ O ₇ ) or Ba-Na-Si-O.