JP2007201410A - Ultraviolet rays irradiating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultraviolet rays irradiating device capable of shortening a tact time of ultraviolet rays irradiation. <P>SOLUTION: The ultraviolet rays irradiating device comprises: a short arc type mercury vapor lamp; a lighting circuit which alternatively repeats a first period during which the lamp is processed in a flashing-up lighting and a second period during which the lamp is processed in a preparation lightning by maintaining electric discharge; a shutter mechanism which passes or intercepts the ultraviolet rays generated from the lamp; and an ultraviolet rays irradiating portion which irradiates a work with the ultraviolet rays having passed through this. An injection starting-up time of relatively large power in the lighting circuit and an opening starting time of the shutter mechanism are roughly coincident, and when a starting-up time of ultraviolet rays output by injecting the relatively large power in the first period is set to be t1, and a starting-up time of the ultraviolet rays output passing through the shutter mechanism from a closed state to an opened state of the shutter mechanism is set to be t2, the time t1 and the time t2 are formed so that they satisfy a formula of t2≥t1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultraviolet irradiation apparatus using a short arc type mercury lamp as an ultraviolet light source.

  Ultraviolet irradiation devices are used for various purposes such as semiconductor exposure and curing of ultraviolet curable resins. In such an ultraviolet irradiation device, a short arc type ultra-high pressure mercury lamp (hereinafter referred to as a short arc type mercury lamp) has been conventionally used as an ultraviolet light source. In this ultraviolet irradiation device, ultraviolet rays radiated from a short arc type mercury lamp are condensed by an elliptical reflecting mirror, led out to the outside through a light guide, and a desired amount of ultraviolet rays is obtained using a light control plate. There is a type that is configured so that it can be adjusted and can be irradiated with ultraviolet rays using a shutter plate.

  Conventionally, in semiconductor exposure equipment, the short arc type mercury lamp is reduced to less than the rated lamp power under continuous lighting for the purpose of shortening the exposure time and increasing the efficiency by increasing the illuminance of the short arc type mercury lamp by ultraviolet rays. There is known a pulse lighting system that waits for exposure at a rated lamp power or higher (see, for example, Patent Document 1).

  Therefore, it is conceivable to employ the pulse lighting method as a lighting method of the short arc type mercury lamp in the ultraviolet irradiation device. In this case, the following sequence is generally adopted. In other words, when trying to expose the workpiece with a stable UV illumination, the lamp is opened after the lamp power exceeding the rating is applied to the short arc type mercury lamp to raise the light level and the shutter is opened. This is a sequence for starting exposure to a workpiece from the beginning.

JP 60-059733 A

  However, shortening the tact time of ultraviolet irradiation on the workpiece in the ultraviolet irradiation device is extremely important for reducing the product cost of the workpiece. However, when the conventional technologies are combined as described above, stable ultraviolet irradiation is possible. Although a highly reliable ultraviolet irradiation device can be obtained, a sufficiently short tact time cannot be realized.

  An object of this invention is to provide the ultraviolet irradiation device which can shorten the tact time of ultraviolet irradiation.

    The ultraviolet irradiation apparatus of the present invention includes a short arc type mercury lamp; a first period in which a relatively large power is supplied to flash up the short arc type mercury lamp and a relatively small power is supplied, and a short arc type mercury is supplied. A lighting circuit that alternately repeats the second period of standby lighting while maintaining the discharge of the lamp; a shutter mechanism that performs an opening and closing operation to pass or block ultraviolet rays generated from the short arc mercury lamp; and a shutter mechanism An ultraviolet irradiating unit that irradiates the workpiece with ultraviolet light that has passed, and the start-up start time of the relatively large power in the lighting circuit substantially coincides with the start time of the opening of the shutter mechanism, and the relative in the first period The rise time of the UV output when large power is applied is t1, and the shutter from the closed state to the open state of the shutter mechanism When the rise time of the UV output to pass through the structure to the t2, it is characterized in that the time t1 and t2 are configured so as to satisfy a formula t2 ≧ t1.

  According to the present invention, the start of flash-up lighting of the short arc type mercury lamp and the start of opening of the shutter mechanism are performed almost simultaneously, so that the tact time of ultraviolet irradiation can be shortened and the ultraviolet output at the time of flash-up is stable. Since the ultraviolet irradiation can be started from the above, it is easy to perform the desired integrated amount of ultraviolet irradiation, and it is possible to provide a highly reliable ultraviolet irradiation apparatus by performing stable ultraviolet irradiation.

  In addition, if the rise time of the light amount in flash-up lighting is set to 0.2 to 2.0 seconds, excessive scattering of the electrode material is suppressed by avoiding a rapid increase in the anode temperature, and at the time of maintaining the ultraviolet light flux. It is possible to provide an ultraviolet irradiating device with improved.

  Furthermore, if it is configured to shift from flash-up lighting to standby lighting after the shutter is closed, it is possible to provide an ultraviolet irradiation device that can easily perform accurate control of the amount of ultraviolet irradiation.

  Furthermore, if it is configured to generate a confirmation signal for opening the shutter mechanism, it is possible to provide an ultraviolet irradiation device that can easily reduce the tact time of ultraviolet irradiation by controlling the flow of the workpiece using this confirmation signal. it can.

Furthermore, it houses at least a part of the short arc type mercury lamp, lighting circuit, shutter mechanism and ultraviolet irradiation part, and has a housing with a volume V (cm ³ ), which is lit with the relatively high power of the short arc type mercury lamp. When the lamp power at the time of W is W (W), if it is configured so as to satisfy the formula V / W ≦ 45, it is possible to provide an ultraviolet irradiation device that is downsized and consumes less power.

  Furthermore, when the visible light irradiation mode can be selected in order to check the ultraviolet irradiation position, the amount of energy irradiated to the visible light conversion filter is reduced by turning on the short arc mercury lamp in standby mode. And the ultraviolet irradiation device which suppressed deterioration of the said filter and prevented the shortening of the lifetime can be provided.

  Furthermore, by monitoring the power input to the short arc mercury lamp, we have enhanced an error check function that checks whether an error occurs when the specified lamp power is not actually applied when the flash is turned on. It is possible to provide an ultraviolet irradiation apparatus capable of confirming that predetermined ultraviolet irradiation is performed.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

    1 to 8 show a first embodiment for carrying out the ultraviolet irradiation device of the present invention, FIG. 1 is a front sectional view, FIG. 2 is a front view of a short arc type mercury lamp, and FIG. 3 is a lighting circuit. 4 is a waveform diagram of the lamp power, FIG. 5 is a front view of the shutter plate, FIG. 6 is an explanatory view showing an operation sequence of the ultraviolet irradiation device, and FIG. 7 is a front view of the light control plate.

  The ultraviolet irradiation apparatus of this embodiment includes a short arc type mercury lamp SHL, a lighting circuit OC, a shutter mechanism SP, and an ultraviolet irradiation unit UIR as main components.

  In addition, as other subsidiary components that can be arranged as desired in the present invention, the present embodiment includes an elliptical reflecting mirror ER, a mirror M1, a dimming mechanism DP, a housing H, and the like. .

  [About Short Arc Mercury Lamp SHL] As shown in FIG. 2, the short arc mercury lamp SHL includes a translucent airtight container 1, a pair of electrodes 2K, 2A, external lead structures 3, 4 and a discharge medium. Yes.

  The translucent airtight container 1 is formed of quartz glass having fire resistance or the like, and includes, for example, an enclosure portion 1a and a pair of sealing portions 1b and 1b. A discharge space 1c is formed in the enclosure 1a. The sealing portion 1b hermetically seals the translucent airtight container 1, and seals a pair of electrodes 2K and 2A described later in the discharge space 1c. More specifically, when the translucent airtight container 1 is made of quartz glass, for example, a sealing metal foil (not shown) is embedded in the sealing portion 1b in an airtight manner. The sealing metal foil is made of, for example, a molybdenum foil, and one sheet or a plurality of sheets are used in parallel in order to obtain a required current capacity.

  The pair of electrodes 2K, 2A is made of a fireproof and conductive metal, such as tungsten (W), rhenium (Re), or tungsten-rhenium alloy. And in the case of direct current lighting, it comprises a cathode 2K and an anode 2A. The pair of electrodes 2K and 2A are disposed so that the tips thereof are spaced apart from each other so that the distance between the electrodes is smaller than the inner diameter of the surrounding portion 1a, for example 2.8 mm.

  The discharge medium is mainly composed of mercury and a rare gas. In addition, mercury evaporates at the time of lighting and exhibits an ultra-high pressure mercury vapor state. The rare gas is made of, for example, argon gas, and acts as a starting gas and a buffer gas.

  The external lead structures 3 and 4 are means for receiving power by connecting the pair of electrodes 2K and 2A to a lighting circuit. Further, when the short arc mercury lamp SHL is mounted inside the ultraviolet irradiation device, the external lead structures 3 and 4 can be used as mounting means. In this case, the external lead structures 3 and 4 can adopt a base structure as shown in the drawing.

  In this embodiment, the short arc type mercury lamp SHL is placed inside the ultraviolet irradiation device by supporting the bolt portion 3b protruding from the base portion 3a of the external lead structure 3 to the right in FIG. 2 using a nut (not shown). Can be attached to. At the same time, it is configured to be connected to the negative side of the output end of the lighting circuit.

  On the other hand, the external lead structure 4 includes a flexible covered conductor 4b extending from the base portion 4a to the outside. In addition, the connection terminal 4c is arrange | positioned at the front-end | tip of the covering conductor 4b.

  Further, although not shown, the external lead structures 3 and 4 have one end extending into the sealing portions 1b and 1b and welded to the sealing metal foil.

  Thus, when the short arc mercury lamp SHL is lit, an ultrahigh pressure mercury vapor discharge is generated inside the translucent airtight container 1 to generate ultraviolet rays.

  In addition to the basic structure described above, the short arc mercury lamp SHL is allowed to have the following configuration as desired.

  1. (Cathode insulation film 5) The cathode insulation film 5 is means for keeping the cathode 2K warm in order to prevent mercury from adhering to the cathode 2K. And it consists of vapor deposition films, such as platinum mainly formed in the outer surface of the sealing part by the side of the cathode 2K, for example. In addition, when mercury adheres to the cathode 2K, it becomes easy to cause an excessive start-up voltage and a lighting failure.

  2. (Anode insulation film 6) The anode insulation film 6 is a means for speeding up the temperature rise of the airtight container 1. And it consists of vapor deposition films, such as platinum formed in the outer surface of the airtight container 1 facing the base end part mainly of the anode 2A, for example. Note that the rise of the luminous flux is accelerated by increasing the temperature rise of the hermetic container 1.

  3. (Regarding Trigger Wire 7) The trigger wire 7 is a means for increasing the potential gradient in the vicinity of the electrode at the time of starting to improve the startability of the short arc type mercury lamp SHL. For example, the base end is connected to the external lead assembly 3 on the cathode 2K side, the middle extends close to the outer surface of the surrounding portion 1a, and the tip is adjacent to the surrounding portion 1a of the sealing portion 1b on the anode 2A side. It is wrapped around the site.

  [On Lighting Circuit OC] The lighting circuit OC is circuit means for flashing up the short arc type mercury lamp SHL. The flash-up lighting means that the lamp power supplied to the short arc type mercury lamp SHL is intermittently supplied with a relatively large lamp power, preferably a power exceeding the rated lamp power for the first period, for example, 10 seconds. During the second period following the first period, the lamp power is relatively small, preferably less than the rated lamp power and sufficient to sustain the discharge. This is a pulse lighting system in which the period is repeatedly turned on.

  As shown in FIG. 4, in the pulse lighting operation, as one aspect, a first period T1 in which a relatively large power H is supplied under constant current control and a second period T2 in which a relatively small power L is supplied. Is performed by alternately repeating the above. In this case, in the second period T2, constant current control or a constant power control circuit may be used.

  In the case of the above aspect, the lighting circuit OC uses, as an example, a direct current constant current control circuit CCR for the lighting circuit OC in order to perform constant current control of the lamp power input during at least the first period T1. A constant current obtained from between the output terminals can be supplied to the short arc type mercury lamp SHL. When performing the constant power control circuit in the second period, in addition to the DC constant current control circuit CCR, constant power control circuits are arranged in parallel or in series, and these control circuits are connected to the respective periods T1, It can be configured to switch to T2 and connect to the short arc mercury lamp SHL.

  Furthermore, in order to supply DC power to the input terminal of the DC constant current control circuit CCR, the AC voltage obtained from the AC power supply AC is rectified using the rectifier circuit RC.

  Furthermore, the lighting circuit OC uses the control means CC to intermittently change the lamp power supplied to the short arc type mercury lamp SHL between a relatively large power H and a relatively small power L in flash lighting. Thus, the lamp current output from the DC constant current control circuit CCR is controlled so as to have a value necessary for each period. The intermittent fluctuation cycle can be set as appropriate depending on the target of ultraviolet irradiation. For example, the first and second periods can each be set to about 10 seconds.

  [Shutter Mechanism SP] The shutter mechanism SP is an ultraviolet control means for irradiating a workpiece (not shown) with ultraviolet rays or blocking the ultraviolet rays from being irradiated. In this embodiment, the shutter mechanism SP has the structure shown in FIGS. I have.

  That is, the shutter mechanism SP, as shown in FIG. 5, is a shutter plate P2 that rotates around the rotation center x2 and a moderation motion that drives the shutter plate P2 by a predetermined angle, that is, 45 ° in FIG. Rotation driving means SM2, for example, a stepping motor is provided as shown in FIG. The shutter plate P2 has no opening at the first rotational rotation position and blocks (turns off) the ultraviolet rays, and the shutter opening OP2 is formed at the second rotational rotation position to pass the ultraviolet rays (on). ).

  Further, the shutter mechanism SP constitutes a disk-shaped ultraviolet ray passage amount control mechanism UVC together with a light control mechanism DP described later.

  [Regarding Ultraviolet Irradiation Unit UIR] The ultraviolet irradiation unit UIR is disposed at the subsequent stage of the shutter mechanism SP and has a configuration that irradiates the workpiece with ultraviolet rays. And in this form, it is comprised by the light guide LG, the condensing lens unit LU, the mirror M2, and the irradiation port IRO. Note that a part of the ultraviolet irradiation unit UIR, that is, a part of the light guide LG in FIG. 1, can be accommodated in a housing H described later.

  The light guide LG is a means for guiding the ultraviolet light collected at a second focal point f2 of an elliptical reflecting mirror ER described later to a desired position such as an irradiation position. And various known light guides can be adopted. However, a structure in which a quartz glass rod having a total internal reflection structure is preferably protected with a suitable outer shell is preferable.

  In addition, the light guide LG receives ultraviolet light reflected from a mirror M1 described later from one end and exits from the other end. The ultraviolet rays emitted from the other end may be used as they are, or the irradiation direction of ultraviolet rays is changed using other optical means as will be described later, or the light is condensed or diffused as in this embodiment. It is permissible to set an appropriate usage form.

  The condensing lens unit LU is disposed at the other end of the light guide LG, and condenses the ultraviolet rays emitted from the light guide LG.

  The mirror M2 reflects the ultraviolet light collected by the condensing lens unit LU, changes its irradiation direction by 90 °, and turns it downward.

  The irradiation port IRO is an opening for irradiating the workpiece with the reflected ultraviolet light from the mirror M2.

  [Operation of Ultraviolet Irradiation Device in the Present Embodiment] In the present invention, when the relative large power from the lighting circuit OC is input to the short arc type mercury lamp SHL, when the input power rises and when the shutter mechanism starts to open Are configured to substantially match.

  The operation will be described below with reference to FIG. Graph (a) shows the UV output level from the short arc mercury lamp SHL that reaches the shutter mechanism before passing through the shutter mechanism SP, and is referred to as UV output A. Graph (b) shows the ultraviolet output level from the short arc type mercury lamp SHL that has passed through the shutter mechanism SP that reaches the workpiece side, and is called the ultraviolet output level B. Graph (c) illustrates the timing at which the work flows in the lighting timings of the first period T1 and the second period T2 of the short arc mercury lamp SHL. When the shutter mechanism SP is fully closed, the level of the ultraviolet output B on the workpiece side is zero. When the shutter mechanism SP is fully opened at the predetermined time t2, the ultraviolet output B level reaching the workpiece increases. When the shutter mechanism SP is fully opened, the level of ultraviolet rays reaching the workpiece is maximized. According to the graph (a), when the ultraviolet output A is at a low level, the second period T2 in FIG. 4 is shown, and the relative large power from the lighting circuit OC in FIG. 4 is input to the short arc mercury lamp SHL. It can be seen from the timing relationship with FIG. 7A that the timing and the opening start timing of the shutter mechanism SP in FIG. That is, the timing t1 in FIG. 7A is an enlarged view of the timing at which the relative high power for switching from the second period T2 to the first period T1 is applied to the short arc type mercury lamp SHL. On the other hand, the maximum ultraviolet irradiation level on the workpiece side reaches t2 when the shutter mechanism SP is fully opened.

  Therefore, according to the ultraviolet irradiation apparatus of the present invention, the operation is configured to satisfy the time t2 ≧ t1, so that the ultraviolet ray immediately after the ultraviolet output at the time of flash-up lighting of the short arc type mercury discharge lamp is stabilized. Irradiation can be started.

  Next, the operation of the optical system in this embodiment will be described. In FIG. 1, the ultraviolet rays radiated from the short arc mercury lamp SHL are emitted from the first focal point f1 in the elliptical reflector ER and reflected by the reflecting surface of the elliptical reflector ER. In FIG. The second focal point f2 is incident on the mirror M1, reflected, changed in direction to approximately 90 ° with respect to the first optical axis LX1, and further condensed and positioned near one end of the light guide LG. To converge.

  The ultraviolet rays converged on the second focal point f2 pass through the disk-like ultraviolet ray passage amount control mechanism UVC, that is, the light control mechanism DP or / and the shutter mechanism SP, and enter the light guide LG from one end thereof. Then, the light is guided through the light guide LG and emitted from the other end. The emitted ultraviolet light is condensed again by the condenser lens unit RU, reflected by the mirror M2, refracted downward in FIG. 1, and irradiated from the irradiation port IRO to the outside of the ultraviolet irradiation device.

  [Other Configurations] Next, subsidiary components in the present embodiment will be described.

  1. (Elliptic Reflector ER) The elliptical reflector ER has a first focal point f1 and a second focal point f2, and has a spheroidal shape with, for example, a reflective surface. Further, by arranging the light emission center of the short arc mercury lamp SHL at the first focal point f1, the ultraviolet rays radiated from the short arc mercury lamp SHL are reflected and condensed to the second focal point f2. To do.

  Further, the elliptical reflecting mirror ER may be preferably constructed by depositing an ultraviolet reflective / infrared transparent coating on the inner surface of a bowl-shaped glass substrate. And the light emission part of short arc type mercury lamp SHL is stored in an inside.

  2. (Regarding Mirror M1) The mirror M1 is an optical means that changes the traveling direction of the reflected ultraviolet light emitted from the elliptical reflecting mirror ER at an angle of approximately 90 °. A planar reflecting mirror can be used as the reflecting means. An angle adjusting means for finely adjusting the tilt angle of the mirror M1 can be added if desired.

  Further, the mirror M1 is disposed between the opening of the elliptical reflecting mirror ER and the second focal point f2, and is preferably disposed as close as possible to the second focal point f2.

  3. (Regarding the Dimming Mechanism DP) As shown in FIG. 6, the dimming mechanism DP is a dimming plate P1 that rotates about the rotation center x1 and a driving rotation for rotationally rotating the dimming plate P1 by a predetermined angle. This includes a rotational rotation driving means (not shown), for example, a stepping motor. The dimming plate P1 is digitally set with a plurality of stepping rotation positions (for example, 63 steps between 270 degrees around the rotation center x1), and the stepping movement is performed at each step to a predetermined step position. Each step position is composed of one or a plurality of through holes, and the opening area is sequentially changed according to the number of steps, and the passing ultraviolet ray amount is defined as 0 to 100%. The opening OP1 is annularly arranged.

  Thus, according to the light control mechanism DP in the present embodiment, the light control plate P1 is driven and rotated, and the number of steps and the opening area are set in a predetermined relationship in advance, as shown in FIG. It is possible to obtain dimming characteristics with excellent linearity.

  Further, the light control mechanism DP constitutes a disk-shaped ultraviolet light passage control mechanism UVC together with the shutter mechanism SP described above. Further, as shown in FIG. 1, the disk-shaped ultraviolet ray passing amount control mechanism UVC is perpendicular to the first optical axis LX1 connecting the elliptical reflecting mirror ER and the mirror M1, and the mirror M1 and the light guide LG. The rotation centers x1 and x2 are located on the opposite side of the reflecting mirror ER across the plane P including the second optical axis LX2 connecting the two. And the action part of disk part P1 or P2 is an optical control mechanism which interposes between the mirror M1 and the light guide LG, and controls the passage amount of an ultraviolet-ray.

  Therefore, according to the disk-shaped ultraviolet ray passage amount control mechanism UVC of this embodiment, the amount of ultraviolet rays emitted from the other end of the light guide LG can be controlled. The control of the ultraviolet rays can be configured such that either one or both of dimming and switching between passing and blocking (shutter operation) can be performed. A dimming mechanism DP is disposed when dimming, and a shutter mechanism SP is disposed when switching between pass and block (shutter operation) is performed. When both are performed, the light control plate P1 of the light control mechanism DP and the action portion of the shutter plate P2 of the shutter mechanism SP are disposed close to each other.

  4). (Exhaust Mechanism AS) The exhaust mechanism AS can be provided so that dust and the like are not diffused from the ultraviolet irradiation device to the outside. If the exhaust mechanism AS is connected to an exhaust duct (not shown), the inside of the ultraviolet irradiation device becomes a low pressure, and impurities such as dust are not diffused from the inside.

  5. (Regarding Light Source Position Fine Adjustment Mechanism LXR) The light source position fine adjustment mechanism LXR is a mechanism for finely adjusting the tube axis position of the short arc mercury lamp SHL. The short arc type mercury lamp SHL is suspended from the ceiling of the housing H described later.

  6). (Regarding the Housing H) The housing H houses the above-described means at predetermined positions inside.

  Hereinafter, other embodiments for implementing the ultraviolet irradiation device of the present invention will be described.

[Second form]
In the second mode, in the first mode, in flash-up lighting, the rising time t1 of the ultraviolet output in the first period due to the relatively large power input is set to 0.2 to 2 seconds.

  Thus, in this embodiment, by setting the rise time to 0.2 to 2 seconds, unwanted scattering of the electrode material is suppressed, so that the luminous flux maintenance factor is improved and the lamp is lit for a long time. However, it is possible to suppress a decrease in the ultraviolet illuminance.

  It is the 1st form shown in FIG.

Short arc mercury lamp Translucent airtight container: Inner diameter 20mm
Pair of electrodes: 2.8 mm distance between electrodes
Discharge medium: Mercury and Ar gas lighting circuit (performs flash-up lighting)
First period: 1000W
Second period: 700W
First and second periods: 10 seconds each Power rise time: 0.2 seconds

[Comparative Example 1]
Power rise time: 0.1 seconds Others are the same as in the example.

The relative maximum value (%) of ultraviolet illuminance at a wavelength of 365 nm was as shown in Table 1.

[Table 1]
Lighting time (hr) Example (%) Comparative example (%)
0 100 100
100 95 90
500 90 80
1000 85 75

As can be understood from Table 1, according to the example (the present invention), a decrease in the ultraviolet illuminance accompanying the progress of the life of the short arc type mercury lamp is remarkably suppressed as compared with the comparative example.

[Third embodiment]
In the first embodiment, when the internal volume V (cm ³ ) of the housing H in FIG. 1 and the lamp power of the relatively large power in flash-up lighting is W (W) in the first embodiment, the formula V / It is configured to satisfy W ≦ 45.

  Thus, in the present embodiment, by satisfying the above formula, it becomes possible to use a relatively small short arc type mercury lamp, and the casing can be miniaturized and power saving can be achieved. it can.

V / W = 36.3
Others are the same as Example 1.

[Comparative Example 2]
Lighting circuit: Circuit for continuously supplying lamp power of 800 W V / W = 45.4
Others are the same as Example 1.

The maximum value of ultraviolet illuminance at a wavelength of 365 nm (mW / cm ² ) was as shown in Table 2.

[Table 2]
Maximum UV illuminance (mW / cm ² )
Example 2 200
Comparative Example 2 160

As can be understood from Table 2, the ultraviolet illuminance is higher in Example 2 than in Comparative Example 2.

Next, in this embodiment, the maximum value (mW / cm ² ) of the ultraviolet illuminance when the lamp power W (W) was changed with the internal volume of the housing H being constant was as shown in Table 3.

[Table 3]
W (W) V / W Maximum UV illuminance (mW / cm ² )
700 51.8 120
800 45.4 160
1000 36.3 200
1200 30.3 240

As can be understood from Table 3, according to this embodiment, the maximum value of the ultraviolet illuminance is remarkably increased.

In Example 2 and Comparative Example 2, the evaluation results when the curing test of the ultraviolet curable resin A was performed while changing the exposure time of ultraviolet irradiation were as shown in Table 4. The ultraviolet curable resin A is cured when the ultraviolet illuminance at a wavelength of 365 nm is 200 mW / cm ² or more. In the table, ◯ indicates cured, and x indicates not cured.

[Table 4]
Exposure time (seconds) 0.5 1.0 1.5 2.0
Example 2 × × ○ ○
Comparative Example 2 × × × ×

As can be understood from Table 4, according to Example 2, in the case of the ultraviolet curable resin A, if the exposure time is 1.5 seconds or longer, the ultraviolet curable resin A can be practically used for curing. On the other hand, curing was not obtained in Comparative Example 2.

Furthermore, the evaluation results when the curing test of the ultraviolet curable resin B was performed in the same manner as described above were as shown in Table 5. In addition, the ultraviolet curable resin B is cured at an ultraviolet integrated light quantity of wavelength 365 nm of 320 mWs / cm ² .

[Table 5]
Exposure time (seconds) 0.5 1.0 1.4 1.6 1.8 2.0
Example 2 × × ○ ○ ○ ○
Comparative Example 2 × × × × × ○

As can be understood from Table 5, according to Example 2, when the exposure time is 1.4 seconds or more, the ultraviolet curable resin B can be used for practical use. On the other hand, in Comparative Example 2, curing could not be obtained in a time shorter than 2.0 seconds.

[Fourth form]
The fourth embodiment is a coil made of a thin wire of a refractory metal having a diameter of 0.3 mm or less, such as tungsten (W), on the outer peripheral surface of the shaft portion of at least one electrode of the short arc type mercury lamp, preferably a pair of electrodes. It is the structure which formed. The coil is preferably closely wound.

  And in this form, since the said coil acts as a sealing buffer part in the state embed | buried in the sealing part of a translucent airtight container, lamp power will be in an over-input state by flash-up lighting. In this case, the difference in thermal expansion coefficient between the electrode shaft and the surrounding quartz glass can be relaxed in the space formed by the coil having the above configuration. For this reason, the reliability of an electrode sealing part improves.

[Fifth embodiment]
In the fifth embodiment, a pair of electrodes of a short arc type mercury lamp is constituted by a cathode and an anode so as to perform direct current lighting, and a cooling means for cooling the anode from the outside of the translucent airtight container is provided. This is the configuration. The specific structure of the cooling means is not particularly limited, but an air blower is preferably used.

  In the present invention, since the short arc type mercury lamp is turned on in a flash-up manner, the temperature rise of the anode is particularly severe, and the sealing portion around the anode is exposed to strong thermal stress. As a result, there is a problem that the reliability of the short arc type mercury lamp is lowered.

  In this embodiment, since the sealing portion around the anode is cooled by the cooling means, the sealing portion around the anode is not exposed to strong thermal stress. For this reason, the reliability of the short arc type mercury lamp is improved.

[Sixth embodiment]
In the sixth embodiment, when the surrounding portion of the light-transmitting airtight container in the short arc type mercury lamp is GV (cm ³ ) and the lamp power at the time of flash-up is W (W), BV And W satisfy the formula 50 <W / GV <300.

  If BV and W are within the range, thermal strain during the lifetime caused by flash-up lighting is reduced as shown in FIG. In FIG. 8, the horizontal axis represents W / GV, and the vertical axis represents the strain amount (MPa).

  For this reason, it is possible to extend the life of the short arc type mercury lamp. Moreover, since the bursting of the light-transmitting hermetic container during its lifetime can be suppressed, the reliability of the short arc type mercury lamp is improved.

  However, the short arc type mercury lamp is not possible because the pressure in the enclosure is about 40-50 atm due to flash-up lighting, and if the W / GV is 50 or less, the short arc type mercury lamp tends to burst. is there. In addition, when W / GV is 300 or more, the rise characteristic of the light beam is deteriorated, which is not possible. This is because mercury vapor depends on the temperature of the light-transmitting hermetic container, and when the inner volume of the enclosure increases and the value of BV increases, the time required to increase the temperature of the light-transmitting hermetic container becomes longer. .

[Seventh form]
In the seventh embodiment, a heat insulating film (for example, a portion denoted by reference numeral 6 in FIG. 2) is provided on the outer surface of the surrounding portion of the translucent airtight container that surrounds at least one of the pair of electrodes in the short arc type mercury lamp. When forming, when the film thickness of the heat insulating film is L (mm), L satisfies the formula L <0.5. A preferable material for the heat insulating film is a platinum film or the like.

  Thus, in this embodiment, when the film thickness of the heat insulating film satisfies the above formula, the heat insulating performance is optimized, and the temperature rise of the translucent airtight container is accelerated. A short arc mercury lamp having the same is obtained.

[Eighth form]
In the eighth embodiment, Va (cm 3) is the inner volume of the light-transmitting hermetic container in the short arc type mercury lamp, and the outer surface of the surrounding part of the light-transmitting hermetic container surrounding at least one of the pair of electrodes is kept warm. In the case of forming a film (for example, a portion denoted by reference numeral 6 in FIG. 2), when the volume of the heat insulating film is Vb (cm ³ ), Va and Vb satisfy the formula Vb / Va <0.1. It is a configuration.

  Thus, in this embodiment, since Va and Vb satisfy the above formula, the heat retention performance is optimized and the temperature rise of the translucent airtight container is accelerated, so that the short circuit having stable operating characteristics is achieved. An arc-type mercury lamp is obtained.

[Ninth Embodiment]
The ninth form is a configuration in which a getter is disposed at a position where a discharge spot of the anode is not formed in a case where a pair of electrodes of a short arc type mercury lamp is configured to perform direct current lighting using a cathode and an anode. is there. The getter is formed, for example, by applying a coating solution containing a known metal powder such as tantalum (Ta), zirconium (Zr), zirconium-aluminum alloy or the like as a main component to the predetermined position by coating and drying. Can do.

  Thus, in this embodiment, it is possible to suppress the start-up failure, flickering of light emission, and decrease in ultraviolet illuminance during the initial and lifetime of the short arc type mercury lamp. In particular, when performing flash-up lighting, it is possible to ensure improved performance of the ultraviolet irradiation device, cost reduction, and improved reliability of the short arc type mercury lamp even when the input is excessive.

[Tenth embodiment]
In the tenth embodiment, in the case where direct current is performed using a pair of electrodes of a short arc type mercury lamp as a cathode and an anode, as shown in FIG. 9, the sealing portion on the cathode side of the translucent airtight container is When the length in the tube axis direction is L1, and the length of the portion facing the sealing portion of the base attached to the sealing portion is L2, L1 and L2 satisfy the formula 1.5 ≦ L1 / L2 ≦ 5. It is a satisfactory configuration. The base is made of metal. Also, in FIG. 9, the same parts as those in FIG.

  And in this aspect, by satisfy | filling the said numerical formula, after turning off a short arc type mercury lamp, mercury becomes difficult to adhere to the electrode surface. As a result, the dielectric breakdown voltage at the time of relighting is reduced, the discharge spot is stabilized, and the occurrence of problems such as poor startability can be suppressed. In addition, when mercury adheres to the electrode, it is possible to suppress the start voltage (Vs) rise and the start failure at the next lighting.

[Eleventh form]
In the eleventh embodiment, when the direct current is performed using a pair of electrodes of a short arc type mercury lamp as a cathode and an anode, the length of the heat insulating film 5 shown in FIG. 2 in the tube axis direction is L3 (mm). In this case, L3 satisfies the formula L3> 3. A preferable material for the heat insulating film is a platinum film or the like.

  And in this aspect, by satisfy | filling the said numerical formula, after turning off a short arc type mercury lamp, mercury becomes difficult to adhere to the electrode surface. As a result, the dielectric breakdown voltage at the time of relighting is reduced, the discharge spot is stabilized, and the occurrence of problems such as poor startability can be suppressed. In addition, when mercury adheres to the electrode, it is possible to suppress the start voltage (Vs) rise and the start failure at the next lighting.

[Twelfth embodiment]
In the twelfth embodiment, when a direct current is formed using a pair of electrodes of a short arc type mercury lamp as a cathode and an anode, as shown in a conceptual cross-sectional view of FIG. In this configuration, a heat insulating film is formed. A preferable material for the heat insulating film is a platinum film or the like. In FIG. 10, the same parts as those in FIG.

  (1) First from the position of the intersection of a straight line drawn perpendicularly to the tube axis from the point K1 1 mm away from the tip of the cathode toward the base and the outer surface of the enclosure to the end of the enclosure on the cathode side A heat insulating film 6a is formed in the outer surface region.

  (2) Second from the position of the intersection of the straight line drawn perpendicularly to the tube axis from the point K2 1 mm away from the tip of the anode toward the base and the outer surface of the enclosure to the enclosure end on the anode side A heat insulating film 6b is formed in the outer surface region.

  (3) A heat insulating film 6c is formed on the outer surface of the exhaust tip off portion 1a1 protruding from the side surface of the surrounding portion.

  (4) In FIG. 2, the heat insulating film 5 is formed on at least one of the pair of sealing portions 1b and 1b, for example, the sealing portion 1b on the cathode side.

  Thus, in this aspect, by providing the above-described configuration, the temperature rise of the translucent airtight container of the short arc type mercury lamp is accelerated, and a short arc type mercury lamp having stable operating characteristics is obtained. Can do.

[13th form]
The thirteenth mode is a short arc type mercury lamp, a first period in which the short arc type mercury lamp is supplied with relatively high power to flash up the short arc type mercury lamp, and a relatively small power is supplied to supply the short arc type mercury lamp. A lighting circuit that alternately repeats the second period of standby lighting while sustaining discharge, a shutter mechanism that opens and closes and passes or blocks ultraviolet rays generated from a short arc mercury lamp, and passes through the shutter mechanism An ultraviolet irradiation unit for irradiating the workpiece with ultraviolet rays. As shown in FIG. 11A, after the ultraviolet output A due to the input of a relatively large power in the first period rises, ), The shutter opening operation is started, and the irradiation of the ultraviolet output B is started as shown in FIG. 11B. That.

  Preferably, as shown in FIG. 11C, the work flows to the ultraviolet irradiation position after the ultraviolet rays passing through the shutter mechanism rise. In addition, the shutter mechanism is configured to be opened after the ultraviolet output from the relatively large power input is raised.

  Thus, in this embodiment, stable ultraviolet irradiation can always be performed. In the figure, the same parts as those in FIG.

[14th form]
The fourteenth embodiment is configured to select a visible light irradiation mode that irradiates visible light instead of ultraviolet irradiation, and is configured to turn on a short arc mercury lamp in the visible light irradiation mode. It is characterized by being.

  That is, when performing predetermined processing by performing ultraviolet irradiation, it is convenient to perform visible light irradiation instead of ultraviolet light when positioning the ultraviolet irradiation area with respect to the workpiece. In order to perform visible light irradiation, ultraviolet rays generated from a short arc type mercury lamp are converted into visible light. In order to do this, a visible light conversion filter is used.

  In the fourteenth embodiment, the short arc mercury lamp is lit on standby when performing visible light irradiation, so that the intensity of ultraviolet rays generated at this time can be relatively reduced. Then, the ultraviolet light generated using the visible light conversion filter is converted into visible light and then irradiated. If the visible light irradiation at this time is utilized, it becomes possible to determine the ultraviolet irradiation position with respect to a workpiece | work etc. by visual observation.

  Next, the fourteenth embodiment will be described in further detail with reference to FIGS.

    FIG. 12: is a front view which shows the light control board in the 14th form for implementing the ultraviolet irradiation device of this invention. The structure of the dimming plate P1 itself is substantially the same as that in FIG. 6, but the description of the part concerned in the fourteenth embodiment and the rotation position in each light irradiation mode is added.

  That is, the light control plate P1 has one or a plurality of openings OP1 arranged so that the aperture ratio changes at each rotational irradiation position in order to adjust the UV (ultraviolet) irradiation amount. As described above, one large opening is arranged at a position of the light control plate P1 in the UV irradiation mode of 100% UV indicated by an arrow, for example. Further, a plurality of openings OP1 are arranged at the same position of UV 50%, and the opening ratio at that position is 50%. On the other hand, no opening is arranged at the same position of UV 0%. For this reason, ultraviolet rays are completely blocked by the light control plate P1.

  On the other hand, the visible light irradiation position of the light control plate P1 is one large opening as in the UV 100% position. In addition, a visible light conversion filter F is attached to the opening. The visible light conversion filter F is configured to convert ultraviolet rays incident thereon into visible light, and a known filter of this kind can be used.

  Therefore, in the visible light irradiation mode, the light control plate P1 is rotated to a predetermined position by the stepping motor. At this time, the visible light irradiation position of the light control plate P1 is a position that intersects the second optical axis LX2 in FIG. For this reason, since the ultraviolet rays generated from the short arc mercury lamp SHL and condensed by the elliptical reflector ER enter the visible light conversion filter F, they are converted into visible light and emitted. The emitted visible light irradiates the position of the workpiece in the same manner as when ultraviolet rays are irradiated via the light guide LG and the mirror M2 in FIG.

  Next, the relationship between the light irradiation mode, the input power state, and the shutter state will be described with reference to FIG.

    FIG. 13 is an explanatory diagram showing the relationship between the light irradiation mode, the input power state, and the shutter state in the thirteenth embodiment of the present invention. In the figure, the light irradiation mode, the shutter state and the input power state are shown from the top to the bottom on the left side, and the respective light irradiation modes, that is, visible light, UV 100%, UV 50% and UV 0% are shown from the left to the right.

  First, the shutter state will be described. In each light irradiation mode, the shutter mechanism SP of FIG. That is, there are open time and closed time.

  Next, the input power state will be described. In each light irradiation mode, the input power is relatively high when the flash is turned on, and relatively low when the standby is lit.

  Accordingly, when UV is 100%, UV 50%, and UV 0%, flash-up lighting and standby lighting are alternately repeated, so that UV irradiation is intermittently performed during flash-up lighting. On the other hand, at the time of visible light irradiation, the input power is maintained in a standby lighting state at a low level.

  Thus, according to the fourteenth embodiment, since the standby lighting state is maintained at the time of visible light irradiation, the generation of the amount of ultraviolet rays is reduced, so that the degradation of the visible light conversion filter F that performs ultraviolet-visible light conversion is deteriorated. Can be suppressed.

[15th form]
The fifteenth aspect is characterized in that it has a monitor function for monitoring a change in power level when the short arc type mercury lamp is flashed up.

  In other words, when performing UV irradiation with flash-up lighting, UV irradiation is performed while repeating the increase / decrease control of lamp power during flash-up and standby lighting, so the required lamp power is not input at the time of flash-up due to some error When the state occurs, a defect occurs in the ultraviolet irradiation process for the workpiece. The occurrence of such a situation must be detected and dealt with promptly.

  In the fifteenth embodiment, as the monitoring function, the input of lamp power increases when the short arc type mercury lamp is lit up. Therefore, if the change is electrically monitored directly or indirectly, the flash-up lighting is properly performed. It can be detected. In order to directly monitor changes in lamp power, input power may be detected. Moreover, what is necessary is just to detect a voltage or an electric current, in order to monitor the change of lamp electric power indirectly. If the change pattern of the voltage or current when the lamp power changes as described above is examined in advance, the change to be detected of the lamp power can be known from the change pattern of the voltage or current.

  If a situation occurs in which the required lamp power is not turned on at the time of flash-up, it can be dealt with by the human system if it is detected quickly, but it is preferable to handle errors in the control circuit of the lighting circuit of the short arc mercury lamp. It is good to incorporate as a system. As error handling, error display, automatic stop of ultraviolet irradiation operation, and the like can be performed.

  Next, the fifteenth embodiment will be described in further detail with reference to FIGS.

    FIG. 14: is a front view which shows the control block in the 15th form for implementing the ultraviolet irradiation device of this invention. In the fifteenth embodiment of the present invention shown in FIG. 14, the control block is divided into the outside, the power supply unit, and the lamp house.

  The outside is a higher-order side of the control located outside the ultraviolet irradiation device, and is configured by a customer side device that employs the ultraviolet irradiation device. Accordingly, (1) a shutter command signal that is a command for starting the irradiation operation of the ultraviolet irradiation device is sent from the outside (note that the numbers given in front of the control signals are indicated by the numbers surrounded by circles in the figure). The same applies hereinafter.)

  With respect to the outside, the power supply unit and the lamp house constitute a part related to the control of the ultraviolet irradiation device of the present invention. The power supply unit is a lighting device for a short arc type mercury lamp, and includes an electronic ballast and a control circuit. The electronic ballast is a lighting circuit for lighting a lamp (short arc type mercury lamp) in a lamp house, and is mainly composed of an electronic circuit. The control circuit controls the entire ultraviolet irradiation apparatus, and therefore controls the electronic ballast and various devices arranged in the lamp house.

  The lamp house includes a lamp (short arc type mercury lamp SHL), an igniter, a shutter (shutter mechanism SP), a stepping motor, a close sensor, and an open sensor. In addition, in the above, the code | symbol is common in the 1st form shown in FIG.

  Thus, the control circuit performs “shutter opening / closing” for controlling the stepping motor to open / close the shutter, and “close detection” for receiving the detection signal from the closing sensor and the opening sensor for the actual shutter opening / closing. “Open detection” is performed, and “(2) close signal” and “(3) open signal” are sent to the customer side device. In addition, “(4) FU signal, which is a command signal for flash-up lighting to the electronic ballast” is transmitted, and “(5) FU monitor signal” which is a characteristic configuration in the fifteenth embodiment is transmitted from the electronic ballast. Receive.

  Next, the timing of each control described above will be described with reference to FIG.

    FIG. 15 is a control timing chart in the fifteenth embodiment for carrying out the ultraviolet irradiation device of the present invention.

  When the shutter opening (high level) “(1) shutter command signal” is input from the customer side device to the control circuit of the power supply unit, the control circuit operates the stepping motor to open the shutter.

  When the shutter starts to open at time t1 after the rise of “(1) Shutter command signal” and the close sensor is opened (OPEN), the control circuit sends “(2) Close signal” of the high-level shutter to the customer side device. Is done. Similarly, when the shutter is opened after time t2 and the open sensor is closed, a “(3) open signal” of the shutter is sent from the control circuit to the customer side device.

  On the other hand, the control circuit sends “(4) FU signal” to the electronic ballast at time t3 after “(1) shutter command signal” rises. As a result, the electronic ballast starts flash-up lighting of the short arc type mercury lamp.

  When flash-up lighting starts, the input power from the electronic ballast to the short arc type mercury lamp increases. As an example, 1000 W is turned on when the flash-up is turned on, and 700 W is turned on when the light is on standby.

  "(5) FU monitor signal" is output at time t6 after the input power to the short arc type mercury lamp starts to increase.

  The control circuit is configured to determine an error when “(5) FU monitor signal” is not input at a predetermined timing.

  Then, when “(1) shutter command signal” becomes low level and turns off, the shutter is closed and the flash-up lighting state is ended. At this time, “(4) FU signal” is turned off at time t7 after the shutter is completely closed and “(2) open signal” is transmitted.

  The present invention can be applied to processing performed by irradiating with ultraviolet rays, such as semiconductor exposure, curing of an ultraviolet curable resin, and light washing.

Front sectional drawing which shows the 1st form for implementing the ultraviolet irradiation device of this invention Similarly, front view of short arc mercury lamp Similarly, block circuit diagram of lighting circuit Similarly, lamp power waveform diagram Similarly front view of shutter plate Similarly front view of the light control plate Explanatory drawing which similarly shows the operation sequence of an ultraviolet irradiation device The graph which shows the relationship between W / GV and the thermal strain in the 6th form for implementing the ultraviolet irradiation device of this invention Schematic sectional view showing a short arc type mercury lamp in a tenth embodiment for carrying out the ultraviolet irradiation device of the present invention. A conceptual sectional view showing a short arc type mercury lamp in the 12th form for carrying out the ultraviolet irradiation device of the present invention. Explanatory drawing which shows the operation | movement sequence in the 13th form for implementing the ultraviolet irradiation device of this invention. The front view which shows the light control board in the 14th form for implementing the ultraviolet irradiation device of this invention Explanatory drawing which similarly shows the relationship between light irradiation mode, input power state, and shutter state The block diagram which shows the control in the 15th form for implementing the ultraviolet irradiation device of this invention Control timing chart

Explanation of symbols

  D: Diameter of the opening, DP: Dimming mechanism, ER: Elliptic reflector, L: Distance, LG: Light guide, LX1: First optical axis, LX2: Second optical axis, M1, M2: Mirror, P1 ... Light control plate, P2 ... Shutter plate, SHL ... Short arc type mercury lamp, SP ... Shutter mechanism, UVC ... Disc-shaped ultraviolet ray passage control mechanism

Claims (5)

A short arc mercury lamp;
A first period in which the short arc type mercury lamp is flashed up by supplying a relatively large electric power and a second period in which the short arc type mercury lamp is continuously discharged and supplied with a relatively small electric power. A lighting circuit that repeats alternately;
A shutter mechanism that opens and closes to pass or block ultraviolet rays generated from the short arc mercury lamp;
An ultraviolet irradiation unit that irradiates the workpiece with ultraviolet rays that have passed through the shutter mechanism;
And the start-up start time of the relatively large power in the lighting circuit substantially coincides with the start time of the opening of the shutter mechanism, and the rise time of the ultraviolet output by the relatively high power input in the first period is t1. The ultraviolet rays are characterized in that the times t1 and t2 satisfy the formula t2 ≧ t1, where t2 is the rising time of the ultraviolet output that passes through the shutter mechanism from the closed state to the open state of the shutter mechanism. Irradiation device.   2. The ultraviolet irradiation device according to claim 1, wherein the light amount rise time in flash-up lighting is set to 0.2 to 2.0 seconds.   3. The ultraviolet irradiation device according to claim 1, wherein the ultraviolet irradiation device is configured to shift from flash-up lighting to standby lighting after the shutter is closed.   4. The ultraviolet irradiation device according to claim 1, wherein the ultraviolet irradiation device is configured to generate a confirmation signal for opening the shutter mechanism. Housing a short arc mercury lamp, a lighting circuit, a shutter mechanism and at least a part of the ultraviolet irradiation section, and a housing having a volume V (cm ³ );
5. The formula V / W ≦ 45 is satisfied when the lamp power when the short arc mercury lamp is lit with a relatively large power is W (W). 5. UV irradiation device.

Images