KR20080087629A - Optical source device and exposure device using the same - Google Patents

Abstract

An optical source device and an exposure device using the same are provided to irradiate continuously light for a long time by forming uniformly the illumination of the light. A lamp unit(18) includes a reflector formed in each of discharge lamps to reflect the light irradiated from each discharge lamp to the same direction, and an abnormal state determination unit(28) for measuring a voltage applied to each discharge lamp, determining an abnormal state of each discharge lamp on the basis of the measured voltage, and outputting an abnormal signal(S3) according to the abnormal state of each discharge lamp. A control unit(22) turns on/off each discharge lamp, interrupts the power applied to the discharge lamp of the abnormal state on the basis of the abnormal signal, and applies the power to an auxiliary discharge lamp.

Description

Optical source device and exposure device using the same

The present invention relates to a light source device having a discharge lamp and capable of emitting light of uniform illuminance over a long period of time, and an exposure apparatus using such a light source device.

Light source devices using discharge lamps are actively used in industrial processes in which objects are processed using light, such as the exposure process of photoresist in a semiconductor manufacturing process or a printed circuit board making process. The light source device used in such an industrial process is especially required to be able to emit light of uniform illuminance over a long period of time, but the discharge lamp used in the light source device deteriorates due to deterioration of the illumination time. It was not easy to meet these demands.

Therefore, from the past, research for meeting this demand has been conducted, and as a result, the light source device of Patent Document 1 is known. The light source device constitutes a light source device using a plurality of discharge lamps. When the light source device is a new one, the required illuminance is ensured by lighting fewer discharge lamps than the total number, and when the use time of the light source device has elapsed for a predetermined time. Each remaining discharge lamp is additionally lit to compensate for the decrease in illuminance caused by deterioration of the discharge lamp.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2005-227465

Since there is an "individual difference" in each of the discharge lamps, it is possible to completely eliminate the possibility that mixed discharge lamps, such as the use of electrodes, are very fast or the sealing container is broken at an extremely early time, causing "rays of light". There is no number. For this reason, as in the prior art (Patent Document 1), when the discharge lamp is additionally lit every predetermined time while ignoring the possibility of mixing of the bad discharge lamp, excessive shortage of illuminance easily occurs, and there is a limit in increasing the uniformity of illuminance. In short, even if some defective discharge lamps produce "low illuminance" or "real light" at an early time, additional lighting of the discharge lamp cannot be performed until a predetermined time has elapsed, and the illuminance of the light emitted from the light source device There is a shortage in On the contrary, there is a problem that the illuminance of the light emitted from the light source device becomes excessive when the discharge lamp is further turned on when the light source device emits light of sufficient illuminance even after a predetermined use time.

The present invention has been developed in view of the problems of the prior art. Therefore, the main subject of this invention is providing the light source apparatus which can continuously emit the light of uniform illuminance for a long time, and the exposure apparatus using the same.

The invention described in claim 1 is an exposure apparatus 12 "characterized in being formed in each of the plurality of discharge lamps 30 and the discharge lamps 30".

According to the present invention, since light of uniform illuminance is continuously emitted from the light source device 10 over a long period of time, a cycle time for irradiating light from the light source device 10 to the exposure object X, that is, The time required for exposure of the exposure target object X can be made constant over a long period of time. Therefore, the timing of loading the exposure object X on the support 14 or the timing of conveying it to the next processing step can be kept constant, thereby minimizing the occurrence probability of waiting time and delay in the steps before and after the exposure step. have.

According to the present invention, it is possible to provide a light source device capable of continuously emitting light of uniform illuminance over a long period of time. In addition, it is possible to provide an exposure apparatus in which the exposure time of the exposure object is constant over a long time.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated according to drawing. 1 is a view showing an outline of an exposure apparatus 12 in which a light source device 10 according to the present invention is incorporated. This exposure apparatus 12 is for exposing the resist layer X as a "exposure object" formed on the printed board P. The resist layer X together with the light source device 10 and the printed board P is provided. It consists of an optical system 16 which irradiates the resist layer X with the support stand 14 which supports this, and the light radiate | emitted from the light source apparatus 10 as parallel light.

The light source device 10 is for emitting light (ultraviolet light or visible light close to ultraviolet light) required for exposure at a predetermined illuminance, and the lamp unit 18, the illuminometer 20, and the lighting control device 22 are emitted. Equipped.

In addition, in this specification, "illuminance" means the light energy [mW / cm <2>] received for 1 second in the area of 1 cm <2>.

As shown in FIG. 2, the lamp unit 18 includes a plurality of lamp devices 24, a power supply device 26, and abnormal determination means 28. Moreover, the lamp unit 18 is provided with the block holder 29 which hold | maintains the several lamp apparatus 24 in order to emit the light from several lamp apparatus 24 to the same direction.

The lamp device 24 is comprised by the discharge lamp 30 and the reflector 31 which reflects the light radiate | emitted from the discharge lamp 30 toward a predetermined direction, respectively.

As shown in FIG. 3, the discharge lamp 30 is a direct-current short arc high-pressure lamp, and is formed by a shrink seal method at a spherical light emitting portion 30a and both ends thereof. A seal body 30c having a sealing portion 30b, an electrode rod 30d, a molybdenum foil 30e embedded in the sealing portion 30b, a lead rod 30f welded to the molybdenum foil 30e, and Mercury and other necessary seals enclosed in the light emitting portion 30a are provided.

The inside of each sealing part 30b in the sealing container 30c includes one end electrode 30d protruding into the light emitting part 30a and one end protruding outward of the lead rod 30f and the electrode bar 30d. The molybdenum foil 30e which electrically connects the other end and the other end of the lead rod 30f is arrange | positioned, The anode 30h and the cathode 30i which comprise a pair of electrode 30g at one end of each electrode rod 30d are arranged. ) Are connected at predetermined intervals (hereinafter referred to as "inter-electrode distance L").

As shown in FIG. 2, the power supply device 26 is a ballast for supplying a current required for supplying constant power to the discharge lamp 30 constituting the lamp device 24, and the ballast power unit ( 32) and the ballast control part 33 is roughly comprised. In addition, the lamp unit 18 has the same number of power supply devices 26 as the lamp device 24.

When the ballast power unit 32 receives the energization signal S1 from the lighting control device 22, the ballast power unit 32 performs a switching operation in accordance with the pulse width signal from the ballast control unit 33, and thus the power required for lighting the discharge lamp 30. Is supplied to the discharge lamp 30, or when the energization cutoff signal S2 is received from the lighting control device 22, the power supply to the discharge lamp 30 is stopped.

In addition, the ballast controller 33 may supply a current required to supply a constant power to the discharge lamp 30 in consideration of a voltage difference or a voltage change over time. 32).

The abnormality determination means 28 is a means for determining the presence or absence of abnormalities in the individual discharge lamps 30, and the measuring circuit 34 and the measurement circuit for measuring the voltage value supplied from the power supply device 26 to the discharge lamp 30. The comparison circuit 36 outputs the abnormal signal S3 when the measured voltage value is greater than the reference voltage V1 by comparing the voltage value measured at 34 with the preset reference voltage V1. In addition, the lamp unit 18 has the same number of abnormality determination means 28 as the lamp device 24.

As shown in FIG. 1, the illuminance meter 20 faces the lamp unit 18 on the rear surface of the reflector 54 constituting the optical system 16 on the emission axis of the light by the light source device 10. The illuminance of the light emitted from the light source device 10 is measured. The actual illuminance measured by the illuminometer 20 is output to the lighting controller 22 as the illuminance value S4.

The lighting control device 22 is a device for energizing or discharging the discharge lamp 30 individually, and as shown in FIG. 4, an integrated photometer 38 and a sequencer 40 (programmable logic controller (PLC)). ) And a computer processing unit 42 are provided.

The integrated light quantity meter 38 integrates the determination circuit 44 for determining the presence or absence of abnormality based on the illuminance value S4 output from the illuminometer 20 and the integrated circuit 46 for calculating the amount of light by integrating the illuminance value S4. Has

In addition, in this specification, "light quantity" means the light energy [mJ / cm <2>] which the area of 1 cm <2> received within the predetermined time.

The judging circuit 44 determines whether the illuminance value S4 sent from the illuminometer 20 is higher or lower than the preset appropriate illuminance value, and the illuminance of the light emitted from one discharge lamp 30 by the difference between the illuminance value S4 and the appropriate illuminance value. Determine whether or not When the illuminance value S4 sent from the illuminometer 20 is higher than the appropriate illuminance value, and the difference between the illuminance value S4 and the appropriate illuminance value is about the same as the illuminance of the light emitted from one discharge lamp 30, the determination circuit 44 ) Transmits the illuminance abnormality high signal S5 to the sequencer 40, on the contrary, the illuminance value S4 sent from the illuminometer 20 is lower than the appropriate illuminance value, and the illuminance value S4 and the appropriate illuminance When the difference in values is about the same as the illuminance emitted from one discharge lamp 30, the judging circuit 44 outputs the illuminance abnormality low signal S6 to the sequencer 40 (PLC).

The integrating circuit 46 is a circuit which receives the illuminance value S4 from the illuminometer 20 and integrates the illuminance value S4 to calculate the amount of light, and when the integration start signal S7 is received from the sequencer 40. The integrated value is reset and integration of the illuminance value S4 is started. When the amount of light reaches a predetermined value, the integration circuit 46 finishes integration of the illuminance value S4 and outputs an integration end signal S8 to the sequencer 40.

The sequencer 40 is an illuminance abnormality high signal S5 or illuminance output from the abnormality signal S3 output from the comparison circuit 36 of the abnormality determination means 28 and the determination circuit 44 of the integration photometer 38. The abnormal low signal S6, the integration end signal S8 output from the integration circuit 46, and the illuminance abnormality high signal S12 or the illuminance abnormality low signal S13 output from the computer processing unit 42 are received. The control unit 40a outputting the energization signal S1 or the energization cutoff signal S2 to each power supply device 26 and the discharge lamp 30 until the illuminance is stabilized after starting the lighting. It is possible to store a preset standby time set as time, a lamp device use setting set in advance, etc., which lamp device 24 is turned on when the light source device 10 is started, and which lamp device 24 is turned off. A storage section 40b and a timer 40c for counting time are provided.

That is, when the abnormal signal S3 is given to the sequencer 40 from the comparison circuit 36 included in the abnormal determination means 28 of the lamp unit 18, the sequencer 40 corresponds to the abnormal determination means 28. The energization cutoff signal S2 is sent to the power supply device 26, and the energization signal S1 is sent to the power supply device 26 corresponding to the preliminary discharge lamp 30 that has been turned off.

In addition, when the illuminance abnormality high signal S5 is given to the sequencer 40 from the determination circuit 44 of the integration photometer 38, the sequencer 40 has one discharge lamp 30 from among the discharge lamps 30 being lit. Select and transmit an energization cutoff signal S2 to the power supply device 26 corresponding to the discharge lamp 30. On the other hand, when the illuminance abnormality low signal S6 is given to the sequencer 40, the sequencer 40 selects one discharge lamp 30 from among the discharge lamps 30 which are extinguished, and the electric power corresponding to the selected discharge lamp 30 is performed. The energization signal S1 is sent to the supply device 26.

In addition, since the sequencer 40 exposes the resist layer X at an appropriate amount of light, the sequencer 40 outputs an open signal S10 or a closed signal S11 to the exposure control shutter 50 included in the optical system 16. .

In addition, when the sequencer 40 outputs the open signal S10 to the exposure control shutter 50, the integration signal 46 is transmitted to the integration circuit 46 while the timer 40c counts the time. To start. When the sequencer 40 receives the integration end signal S8 from the integration circuit 46, the sequencer 40 outputs the closing signal S11 to the exposure control shutter 50, and at the same time, the timer 40c. Ends the count of hours. In short, the timer 40c counts the exposure time of the resist layer X. FIG. The sequencer 40 outputs the exposure time value S9 counted from the transmission of the integration start signal S7 to the reception of the integration end signal S8 to the computer processing unit 42, and at the same time the timer 40c is turned on. Reset the count.

The computer processing unit 42 compares the exposure time value S9 received from the sequencer 40 with the appropriate exposure time set in advance, and determines the presence or absence of a problem in the exposure time value S9; It is comprised by the memory | storage part 42b which stores the exposure time value S9. When the exposure time value S9 is shorter than the appropriate exposure time, the computer processing apparatus 42 outputs the illuminance abnormality high signal S12 to the sequencer 40. On the contrary, when the exposure time value S9 is longer than the appropriate exposure time, the computer processing apparatus 42 transmits the low illuminance abnormality low signal S13 to the sequencer 40.

In addition, the exposure time data stored in the storage unit 42b is accumulated as data representing the operation history of the exposure apparatus 12. By accumulating the exposure time data in this way, if exposure failure occurs, the operation status of the exposure apparatus 12 can be analyzed by referring to the past exposure time data, and the cause of the failure can be traced.

As shown in FIG. 1, the support stand 14 supports the printed board P, and it is possible to employ | adopt a well-known structure suitably so far.

The optical system 16 is used to guide the light emitted from the light source device 10 as parallel light to the resist layer X of the printed circuit board P supported by the support 14, and output from the light source device 10. The integrator 52 (fly-eye lens) and the integrator 52 are made to have uniform distribution of illuminance of the emitted light, that is, light which does not cause unevenness of illuminance on the irradiated surface when the plane is irradiated. Of the light passing through the exposure control shutter 50 and the exposure control shutter 50 for controlling the opening and closing of the output light path of the light emitted from the light source device 10 (light after passing through the integrator 52 in this embodiment). The reflector 54 which refracts the optical path and the concave mirror 56 which guides the light reflected by the reflector 54 to the support stand 14 as parallel light are comprised. In addition, a through hole 58 is formed at a substantially central portion of the reflector 54, and the illuminometer 20 is mounted at a position where the light passing through the through hole 58 can be received at the rear surface of the reflector 54. have. Therefore, the illuminance meter 20 is able to take out a part of the light emitted from the light source device 10 and pass through the integrator 52 and the illuminance distribution becomes uniform, and measure the illuminance.

In addition, the structure of the optical system 16 disclosed here is an example, and is not limited to the structure of a present Example. For example, the light emitted from the light source device 10 may be reflected by the reflector 54 and then incident on the integrator 52. The configuration may be appropriately selected according to the intended optical path. It is possible to change. In addition, the type of the exposure control shutter 50 is formed of a material that does not allow light to pass, in addition to a louver system as shown in FIG. 1, and forms a hole through which light emitted from the light source device 10 passes. The rotating disk (not shown) which has a certain rotation control apparatus, etc. can be used.

When the lighting control device 22 is activated, the energization signal S1 is transmitted from the sequencer 40 to the predetermined number of power supply devices 26 so that the lamp device 24 lights up and exits from the lamp device 24. The light (mainly ultraviolet light in the present embodiment) is emitted toward the front. The illuminance required by the exposure apparatus 12 according to the present embodiment is an amount that can be provided by the light emitted from the three lamp apparatuses 24. Therefore, of the five lamp devices 24 included in the light source device 10, three lamp devices 24 may be turned on at the same time in principle, and the remaining two lamp devices 24 maintain an unlit state as a reserve. .

The light emitted from the light source device 10 passes through the integrator 52, so that the illuminance distribution is uniform. When the preset waiting time set in the storage unit 40b of the sequencer 40 elapses from when the discharge lamp 30 starts to turn on and the amount of light stabilizes, the sequencer 40 generates an integrated light meter ( The integration start signal S7 is output to the integration circuit 46 of 38, and the open signal S10 is transmitted to the exposure control shutter 50 to open the exposure control shutter 50. At the same time, the timer 40c starts counting the time.

And the light from the integrator 52 passes through the exposure control shutter 50 which received the open signal S10 from the sequencer 40, and opened. The light passing through the exposure control shutter 50 is reflected toward the concave mirror 56 by the reflecting mirror 54.

At this time, a part of the light directed to the reflector 54 passes through the through hole 58 formed in the reflector 54 to irradiate the illuminometer 20. The illuminometer 20 measures illuminance based on the light passing through the through-hole 58, and outputs the measured illuminance value S4 to the integrated photometer 38 of the lighting control device 22. In addition, the output illuminance value S4 is determined by the determination circuit 44 of the integration photometer 38, and is integrated in the integration circuit 46 at the same time.

The light reflected by the reflector 54 toward the concave mirror 56 becomes parallel light in the concave mirror 56 and is reflected toward the support 14. The light reflected toward the support 14 is irradiated to the resist layer X of the printed board P mounted on the support 14 via the mask M on which the circuit pattern is formed.

When the light quantity value accumulated in the integration circuit 46 reaches a preset value, the integration circuit 46 transmits an integration end signal S8 to the sequencer 40. The sequencer 40 receiving the integration end signal S8 outputs the closing signal S11 to the exposure control shutter 150 to close the exposure control shutter 50 to block light irradiating the resist layer X. The exposure time value S9 counted by the timer 40c is transmitted to the computer processing device 42 from the time when the integration start signal S7 is transmitted until the integration end signal S8 is received. The computer processing apparatus 42 which has received the exposure time value S9 determines whether the exposure time value S9 is within a preset appropriate exposure time, and simultaneously stores the exposure time value S9 as the exposure time data. 42b).

In this way, when exposure to one resist layer X is complete | finished, it exposes so that the printed board P under the mask M may be exchanged with an unprocessed material.

If the abnormality determination means 28 for measuring the voltage value supplied to the discharge lamp 30 being lit while the resist layer X is exposed detects the abnormality of the discharge lamp 30, the abnormality determination means 28 Outputs an abnormal signal S3 to the sequencer 40. The sequencer 40 which received this abnormal signal S3 sends the energization cutoff signal S2 to the power supply device 26 which supplies electric power to the discharge lamp 30 in which the abnormality occurred, and the spare discharge lamp 30 which was extinguished. The energization signal S1 is sent to the power supply 26 corresponding to). Thereby, since the discharge lamp 30 which generate | occur | produced abnormality turns off, and the new discharge lamp 30 turns on, when looking at the light source device 10 as a whole, the number of the discharge lamps 30 which emit light does not change. In addition, the discharge lamp 30 in which an abnormality has occurred is replaced by a worker at an appropriate time, and the replaced discharge lamp 30 is a spare discharge lamp 30, and is turned off until an abnormality arises in another discharge lamp 30 next. Keep it.

In the abnormality determination means 28, as described above, the abnormality of the discharge lamp 30 is determined based on the voltage value supplied from the power supply device 26 to the discharge lamp 30 of the lamp device 24. That is, as shown in FIG. 5A, the voltage value supplied to the discharge lamp 30 rises with the passage of the use time immediately after the use of the discharge lamp 30 begins, but after that the use time has elapsed. In accordance with this, the convergence is smoothly performed at a predetermined voltage value (this voltage value is called a convergence voltage value). This phenomenon occurs because when the discharge lamp 30 is used for a long time, the electrode 30g is consumed, the distance L between the electrodes becomes long, and the voltage value necessary for maintaining the discharge state becomes large.

By the way, among the many discharge lamps 30, there exists a defective discharge lamp 30 in which the sealing container 30c is broken and a real light is consumed at the time when electrode consumption is very fast or extremely early. In the relationship between the voltage value and the use time in the defective discharge lamp 30, as shown in FIG. 5B, a sudden increase in the voltage value is observed in a short time.

Therefore, a voltage value larger than the convergent voltage value is set as the reference voltage V1, and the measured voltage value is compared with the magnitude of the reference voltage V1. As a result of the comparison, when the measured voltage value is large, it is determined that the discharge lamp 30 has already been blinded or is likely to be blinded soon, and therefore is "abnormal."

As described above, in the light source device 10 according to the present embodiment, abnormalities are individually determined for the individual discharge lamps 30, the energization of the discharge lamps 30 determined to be abnormal is cut off, and the spare discharge lamps 30 are provided. Since the light is energized, there is no fear that the light source device 10 will continue to operate without noticing that the illuminance of the light emitted from the light source device 10 is lowered. On the contrary, there is a lack of illuminance of the light emitted from the light source device 10. Under normal lighting that does not occur, the automatic additional lighting of the discharge lamp 30 is not performed after a predetermined time elapses, so that there is no excessive shortage in the amount of light emitted from the light source device 10.

Therefore, in the light source device 10 according to the present embodiment, light of uniform illuminance can be continuously emitted for a long time.

Further, it is detected that the illuminance value S4 emitted from the light source device 10 is larger than the appropriate illuminance value, and that the difference between the illuminance value S4 and the appropriate illuminance value is about the same as the illuminance of the light emitted from one discharge lamp 30. The determination circuit 44 of the integrated photometer 38 outputs the illuminance abnormality high signal S5 to the sequencer 40. The sequencer 40 which has received the illuminance abnormality high signal S5 from the determination circuit 44 selects one discharge lamp 30 from among the discharge lamps 30 which are lit, and the power supply device corresponding to the discharge lamp 30 ( 26, the energization cutoff signal S2 is output. As a result, the number of discharge lamps 30 to be turned on decreases, so that the illuminance of the light emitted from the light source device 10 decreases, and the excessive illuminance enters an appropriate light quantity value. On the contrary, it is detected that the illuminance value S4 irradiated from the light source device 10 is smaller than the appropriate illuminance value, and the difference between the illuminance value S4 and the appropriate illuminance value is about the same as the illuminance of the light emitted from one discharge lamp 30. One determination circuit 44 outputs an illuminance abnormality low signal S6 to the sequencer 40. The sequencer 40 receiving the illuminance abnormality low signal S6 from the determination circuit 44 selects one discharge lamp 30 from among the discharge lamps 30 being extinguished, and the power supply device corresponding to the discharge lamp 30 ( 26, the energization signal S1 is outputted. As a result, the number of discharge lamps 30 to be turned on increases, so that the illuminance of the light irradiated from the light source device 10 increases, and the illuminance that is too small enters an appropriate light quantity value.

Thereby, the abnormality of each discharge lamp 30 can be grasped | ascertained by a voltage value, it is not only possible to light a predetermined number of discharge lamps 30 but also to illuminate the illuminance itself of the light radiate | emitted from the light source device 10 by itself. By measuring, the optimum number of discharge lamps 30 can be turned on.

In addition, since the light intensity received by the illuminometer 20 is the illuminance distribution uniformized by the integrator 52, the installation position of the illuminometer 20 is set to "the central axis of the light of the light source device 10, for example." If the illuminometer 20 is a position where the light from the light source device 10 can be received, the same illuminance can be measured wherever the illuminometer 20 is provided. That is, the position adjustment of the illuminometer 20 can be simplified.

The computer processing unit 42 that detects that the exposure time value S9 output from the sequencer 40 is longer than the appropriate exposure time (in other words, the illuminance of the light emitted from the light source device 10) is determined by the sequencer. The illuminance abnormality low signal S13 is output to 40. The sequencer 40 receiving the illuminance abnormality low signal S13 from the computer processing unit 42 selects one discharge lamp 30 from among the discharge lamps 30 being extinguished, and the power supply device corresponding to the discharge lamp 30. The energization signal S1 is output to (26). As a result, the number of discharge lamps 30 to be turned on increases and the illuminance of the light emitted from the light source device 10 increases, so that the time until the amount of light accumulated in the integration circuit 46 reaches a preset value is shortened. Therefore, exposure time value S9 falls within an appropriate exposure time. On the contrary, the computer processing device 42 which detects that the exposure time value S9 is shorter than the appropriate exposure time (in other words, the light intensity emitted from the light source device 10) is higher than the illuminance with respect to the sequencer 40. Outputs a high signal (S12). The sequencer 40 receiving the illuminance abnormality high signal S12 from the computer processing unit 42 selects one discharge lamp 30 from among the discharge lamps 30 being lit, and the power supply device corresponding to the discharge lamp 30. The energization cutoff signal S2 is output to (26). As a result, the number of discharge lamps 30 to be turned on decreases and the illuminance of the light emitted from the light source device 10 decreases, so that the time until the amount of light accumulated in the integration circuit 46 reaches a preset value is long. Since it loses, exposure time value S9 falls within an appropriate exposure time.

Thereby, the validity of the illuminance of the light emitted from the light source device 10 can be judged based on the exposure time, and the optimal number of lamp devices 24 can be turned on.

As described above, according to the exposure apparatus 12 according to the present embodiment, since light of uniform illuminance is continuously emitted from the light source apparatus 10 for a long time, the exposure target object X is exposed from the light source apparatus 10. A cycle time for irradiating light, that is, a time required for photosensitive exposure object X can be made constant. Therefore, the timing at which the exposure target object X is placed on the support base 14 or the timing for conveying it to the next processing step can be made constant to minimize the waiting time and the occurrence probability of delay in the steps before and after the exposure step.

In addition, although the discharge lamp 30 shown in FIG. 3 is a double-end type | mold DC lamp type | mold lamp, you may use an alternating current type lamp or a single-end type lamp instead. . The discharge lamp 30 is not limited to a short arc discharge lamp in which mercury is enclosed in the sealed container 30c, and a metal halide lamp in which a metal halide such as sodium or scandium is encapsulated as a light emitting material ( UV light or visible light may be emitted using a metal halide lamp). As the material of the sealed container 30c, quartz glass or light transmitting ceramics may be used.

In addition, in this embodiment, when the measured voltage value supplied to the discharge lamp 30 is larger than the reference voltage V1 set higher than the convergence voltage value, it is determined that the discharge lamp 30 is "ideal", but the discharge lamp 30 The determination method of this "abnormal" is not limited to this, but based on the voltage value ("original voltage value") when the discharge lamp 30 is first turned on, it increases from the original voltage value by a predetermined number of volts. There are a method of making the value the reference voltage V1 and a method of making the value increased by a predetermined ratio from the original voltage value as the reference voltage V1. The difference between the present measured voltage value and the measured voltage value measured a predetermined time from the present time is calculated so that the difference is larger than the predetermined value (that is, the voltage value is increased sharply) or the difference is negative ( In other words, the discharge lamp 30 may be judged to be "ideal" with the passage of the use time and the voltage value decrease. By using this determination method, it is possible to detect the case where the voltage value of the discharge lamp 30 makes a movement as shown in Fig. 5C. In other words, in the discharge lamp 30, the sealed container 30c may expand due to heat during use, and when such expansion occurs, the voltage value decreases only for a certain period of time, and then the discharge lamp 30 is blinded. The voltage is zero. Therefore, by calculating the difference between the current measured voltage value and the measured voltage value after a predetermined time has elapsed, not only the "abnormal" type of which the voltage value rises sharply but also the "abnormal" type of the voltage value decreases can be detected. .

In addition, it is determined whether the illuminance value S4 sent from the illuminometer 20 is higher or lower than a predetermined appropriate illuminance value, and the illuminance of the light emitted from the light source device 10 is constant by controlling the number of discharge lamps 30 to be turned on. However, when the illuminance value S4 sent from the illuminometer 20 is higher than the preset appropriate illuminance value, the amount of power supplied to the discharge lamp 30 is made smaller, and conversely, the illuminance value S4 is lower than the preset appropriate illuminance value. In this case, the illuminance of the light emitted from the light source device 10 may be made constant by increasing the amount of power supplied to the discharge lamp 30. In addition, the control of the number of discharge lamps 30 to be lit and the amount of power supplied to the discharge lamps 30 may be combined.

In addition, although the illuminometer 20 is arrange | positioned on the back surface of the reflector 54 which comprises the optical system 16, only while replacing the exposure-finished printed board P with a new printed board P, the mask M Another illuminometer 20 is placed directly on the upper side of the) and the illuminance of the light irradiated onto the mask M is measured to correct the illuminance measured by the illuminometer 20 on the rear side of the reflector 54 based on the illuminance. good. In this way, based on the illuminance in the vicinity of the resist layer X which is the actual exposure object, the illuminance measuring system of the illuminometer 20 arranged on the rear surface of the reflector 54 is increased to perform more accurate exposure time management. Can be.

In addition, although the function which the lighting control apparatus 22 has is shared between the integrated light quantity meter 38, the sequencer 40, and the computer processing apparatus 42, respectively, all the functions required for the lighting control apparatus 22 are one apparatus. The functions may be distributed to more devices than the present embodiment. The lighting control device 22 may be configured to bear the function of the abnormality determining means 28.

In addition, although the optical axis of the lamp device 24 passes through the center of the integrator 52 by adjusting the angle with respect to the holder 29 for every lamp device 24, as shown in FIG. The optical axis R of each lamp device 24 is focused using the light guiding unit 64 provided with the total reflection mirror 60 and the half reflection mirror 62 (half mirror) corresponding to the lamp device 24, The focused optical axis R may pass through the center of the integrator 52.

In addition, although the light source apparatus 10 which concerns on this invention is used for the exposure apparatus 12, the light source apparatus 10 which can output the uniform amount of light over a long time can be applied to all the industrial processes which use light. have.

1 is a view showing an exposure apparatus according to the present invention.

2 shows a light source unit.

3 is a view showing a discharge lamp.

4 is a diagram showing a lighting control device;

5 is a diagram showing a relationship between a voltage value supplied to a discharge lamp and a use time of the discharge lamp.

6 shows another embodiment relating to a plurality of lamps, integrators and positions;

Explanation of symbols on the main parts of the drawings

10: light source device

12: exposure apparatus

14: support

16: optical system

18 lamp unit

20: illuminometer

22: lighting control device

24: lamp device

26: power supply device

28: abnormal determination means

30: discharge lamp

38: accumulated photometer

40: programmable logic controller (PLC)

42: computer processing apparatus

50: shutter for exposure control (shutter)

52: Integrator

54 reflector

56: concave mirror

Claims (3)

A plurality of discharge lamps, reflectors formed on each of the discharge lamps and reflecting light emitted from each of the discharge lamps in the same direction, and an abnormality of the discharge lamp based on the voltages by separately measuring the voltage applied to the discharge lamps. And a lamp unit having an abnormality determining means for outputting an abnormal signal when it is judged to be abnormal and determining abnormality, and a function of energizing or discharging the discharge lamp individually, and at least one preliminary discharge lamp at start-up. A lighting control device which energizes the other discharge lamp in the state of interrupting the power supply of the lamp and cuts off electricity of the discharge lamp that is determined to be abnormal based on the abnormal signal, and energizes the preliminary discharge lamp of which the electricity supply has been cut off so far. Light source device characterized in that it comprises. The light source apparatus according to claim 1, wherein said abnormality determining means determines that said discharge lamp is abnormal when the measured voltage which measured the voltage applied to said discharge lamp separately is larger than the reference voltage set higher than the convergence voltage value. A light source device according to claim 1 or 2; A support for supporting an exposure object exposed by the light emitted from the light source device; And And an optical system for guiding the light emitted from the light source device to the exposure object supported by the support.

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