CN116146911A

CN116146911A - LED module, light irradiation device, and liquid crystal panel manufacturing device provided with same

Info

Publication number: CN116146911A
Application number: CN202310156160.4A
Authority: CN
Inventors: 井上智彦; 木下雅章
Original assignee: Phoenix Electric Co Ltd
Current assignee: Phoenix Electric Co Ltd
Priority date: 2022-03-01
Filing date: 2023-02-23
Publication date: 2023-05-23
Also published as: KR20230129302A; TW202336539A; JP2023127490A

Abstract

The invention provides an LED module capable of easily narrowing the width of a voltage value corresponding to a current value output from a light sensor even if the current value has a width. The LED module (10) is composed of a substrate (12), a plurality of LEDs (14) arranged on the substrate (12), an LED power supply circuit (16) formed on the substrate (12), a photosensor (18) arranged on the substrate (12), and a resistor connected in series with the photosensor (18). The resistance can also be adjusted in resistance.

Description

LED module, light irradiation device, and liquid crystal panel manufacturing device provided with same

Technical Field

The present invention relates to an LED module, a light irradiation device, and a liquid crystal panel manufacturing apparatus including the LED module and the light irradiation device, which are used for exposure when bonding 2 substrates or manufacturing semiconductors in manufacturing a liquid crystal panel.

Background

Conventionally, as a light source of an exposure apparatus for manufacturing semiconductors or the like, for example, a system using 1 or a plurality of large mercury lamps rated for 12kW has been adopted. However, when the number of mercury lamps used in 1 exposure apparatus is small, even if 1 mercury lamp is in a non-lighted state, the quantity of light is insufficient immediately, and the exposure apparatus must be stopped, so that there is a problem in terms of production continuity in an exposure apparatus using a large-sized mercury lamp.

For this reason, for example, a multi-lamp type exposure apparatus has been developed in most of exposure apparatuses used for producing color filters of liquid crystal panels (for example, patent document 1).

Further, at present, as each light source, an LED (light emitting diode) is widely used.

In addition, in the production of a liquid crystal panel, a light irradiation device using a plurality of LEDs is also used to attach 2 light-transmissive substrates by irradiating light to a light-curable sealing agent disposed between the light-transmissive substrates (for example, patent document 2).

However, in order to maintain a stable exposure process, the exposure surface illuminance is required to be uniform and constant for a long time. However, LEDs have characteristics that the light emission amount gradually decreases due to degradation when used for a long period of time.

In order to cope with such attenuation, when the light emission amount is reduced, the amount of power supplied to the LED is increased to adjust the light emission amount to be equal to the initial amount.

Specifically, in order to obtain the amount of light emitted from the LEDs, for example, an optical sensor is mounted on a substrate on which the LEDs are mounted, and the amount of power supplied to each LED is adjusted based on the amount of current (or voltage value) output by the optical sensor in accordance with the amount of light received (patent literature 3, as an example of an LED module on which the optical sensor is mounted).

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2020-43012

Patent document 2: japanese patent laid-open publication No. 2011-76033

Patent document 3: japanese patent application laid-open No. 2012-89601

Disclosure of Invention

Problems to be solved by the invention

However, the characteristics of the photosensors vary due to individual differences, and even if the same type of photosensors receive the same amount of light, the amount of current output by each photosensor has a problem of width.

For example, even when a plurality of photosensors (phototransistors) are arranged at [ collector-emitter voltage=5v, light source wavelength=560 nm, illuminance=0.01 mW/cm ² ]When the same light quantity is received, the output current from each photosensor is also deviated by 2.8 to 7.1 μa. Even in the case of grouping the photosensors whose characteristics are close to each other, there is a deviation of 4.5 μa to 7.1 μa.

If there is such a deviation in the output current from the photosensor, for example, in an LED module to which the photosensor having a tendency to have a small output current is attached, the amount of light emitted is higher than the expected amount of light emitted, and there is a possibility that an excessive amount of light may be caused. In contrast, in an LED module in which a photosensor having a tendency to output a large current is mounted, the light emission amount is lower than the expected light emission amount, and there is a possibility that a state in which the light amount is insufficient is caused.

For example, when a photosensor having an output current of 4.5 μa is used, and the voltage across the resistor connected in series with the photosensor is 1V when the illuminance is equal to 100mW, even if the same illuminance is equal to 100mW and the same resistance value is used, the voltage across the resistor is about 1.6V in a photosensor having an output current of 7.1 μa, and the illuminance is erroneously recognized as 160 mW.

If the identification is made by mistake in this way, the LED module is adjusted so that the amount of power supplied to the LED is reduced to a voltage of 1V at both ends. In this way, the actual illuminance was reduced to about 62.5mW (100 mW/1.6), and the light amount was insufficient.

Further, since one light irradiation device includes a plurality of LED modules, if the amounts of light emitted from the LED modules vary as described above, the uniformity of illuminance on the irradiation surface of the light emitted from the entire light irradiation device also becomes problematic.

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an LED module, a light irradiation device, and a liquid crystal panel manufacturing apparatus including the same, which can easily narrow the width of a voltage value corresponding to a current value output from a light sensor even when the current value has a width.

Means for solving the problems

According to one aspect of the present invention, there is provided an LED module including:

a substrate;

a plurality of LEDs arranged on the substrate;

an LED power supply circuit formed on the substrate;

a photosensor disposed on the substrate; and

with respect to the resistance of the series connection of the light sensors,

the resistor is capable of adjusting a resistance value.

Preferably, the method comprises the steps of,

the resistor has:

a fixed resistor;

a plurality of slave resistors connected in parallel with respect to the fixed resistor; and

and a plurality of switching units connected in series with respect to the respective slave resistors.

Preferably, the method comprises the steps of,

the LED module further includes an operational amplifier connected in parallel with the resistor, and measures a voltage across the resistor.

In accordance with a further aspect of the present invention,

provided is a light irradiation device provided with a plurality of the LED modules.

In accordance with a further aspect of the present invention,

provided is a liquid crystal panel manufacturing apparatus provided with the light irradiation apparatus.

Effects of the invention

According to the LED module, the light irradiation device, and the liquid crystal panel manufacturing apparatus of the present invention, since the resistor capable of adjusting the resistance value is connected in series with the photosensor, the resistance value is adjusted according to the output current from the photosensor, and thus the width of the voltage value corresponding to the current value can be made relatively small in a state where the output current has a relatively large width.

Drawings

Fig. 1 is a diagram showing an exposure apparatus 100 according to an embodiment to which the present invention is applied.

Fig. 2 is a diagram showing an LED module 10 according to an embodiment to which the present invention is applied.

Fig. 3 is a circuit diagram of the output adjustment unit 22 according to the embodiment.

Fig. 4 shows a view of the cover 26 according to the embodiment, in which (a) is a front view, (b) is a rear view, and (c) is an X-X cross-sectional view.

Fig. 5 is a cross-sectional view showing a state where the cover 26 is attached to the substrate 12.

Fig. 6 is a graph showing a current value output from the photosensor 18 and a voltage across the resistor detected from the current value.

Fig. 7 is a graph showing a current value output from the photosensor 18 and a voltage across the resistor detected from the current value.

Fig. 8 is a circuit diagram of the output adjustment unit 22 according to modification 2.

Fig. 9 is a circuit diagram of the output adjustment unit 22 according to modification 3.

Detailed Description

(Structure of Exposure apparatus 100)

The exposure apparatus 100 including the light irradiation apparatus 200 according to the embodiment of the present invention will be described below. As shown in fig. 1, an exposure apparatus 100 mainly used for manufacturing a liquid crystal panel and the like is generally provided with a light irradiation apparatus 200, an optical system member 102, a workpiece stage 104, and a workpiece conveying apparatus 106.

The light irradiation device 200 is a device for emitting light L for exposing a work X such as a liquid crystal panel, and is configured such that a plurality of LED modules 10 are arranged on the same plane.

As shown in fig. 2, each LED module 10 generally includes a substrate 12, LEDs 14, an LED power supply circuit 16, a photosensor 18, a photosensor circuit 20, an output adjustment unit 22, a photosensor connector 24, and a cover 26.

The substrate 12 is a member on the surface of which the LED14, the light sensor 18, and the like are mounted. The outer shape of the substrate 12 is not particularly limited, and may be rectangular as in the present embodiment, square, or the like.

The LED14 is an element that emits light of a predetermined wavelength by receiving power through the LED power supply circuit 16, and in the LED module 10 according to the present embodiment, 20 LEDs 14 are arranged in a checkered pattern on the substrate 12. The number of LEDs 14 arranged in one LED module 10 is not particularly limited, and the arrangement shape of the LEDs 14 is also not particularly limited.

As described above, the LED power supply circuit 16 has an effect of supplying power for lighting to the LEDs 14, and is formed on the surface of the substrate 12. In fig. 2, a part of the LED power supply circuit 16 is illustrated, and the remaining LED power supply circuit 16 is omitted.

The light sensor 18 is an element that receives light from the LED14 to obtain the amount of light emitted from the LED14, and outputs an amount of current corresponding to the amount of light received. In the present embodiment, a "phototransistor" serving as the photosensor 18 is disposed on the substrate 12 so as to receive light from the LED14 mounted at the center of the substrate 12 and at the lower part in the drawing. Further, as the light sensor 18, a "photodiode" may be used.

Specifically, as shown in fig. 3, the photosensor 18 (phototransistor) has a collector side connected to a power supply line and an emitter side connected to the output regulator 22.

Returning to fig. 2, the photosensor circuit 20 has a function of electrically connecting the photosensor 18, the output adjustment section 22, and the photosensor connector 24 to each other, and is formed on the surface of the substrate 12.

The output adjustment unit 22 has an effect of reducing the variation in the amount of output current due to the individual difference between the photosensors 18, and the amounts of light emitted from the LED modules 10 are different in width, and in this embodiment, as shown in fig. 3, has a fixed resistor 30 connected in series with the emitter side of the photosensor 18 (phototransistor), and a first subordinate resistor 32 and a second subordinate resistor 34 connected in parallel with the fixed resistor 30. The resistance value of the first slave resistor 32 is set to be larger than the resistance value of the second slave resistor 34. The number of the

slave resistors

32, 34 is not particularly limited, and may be 2 or more.

The first and

second slave resistors

32 and 34 are connected in series with a first switching unit 36 and a second switching unit 38, respectively. By this, the resistance value of the entire fixed resistor 30, the first subordinate resistor 32, and the second subordinate resistor 34 connected in parallel to each other can be adjusted by opening and closing the first opening and closing means 36 and the second opening and closing means 38, respectively.

In the present embodiment, the jumper wires are used to open and short the first and second opening/

closing units

36 and 38, but the jumper wires may be wires or the like, or solder on the substrate may be used. The switch is not limited to the jumper wire, and may be used as a dip switch or the like.

The output adjustment unit 22 according to the present embodiment further includes: a first capacitor 40 connected in series with the light sensor 18; and a second capacitor 42 connected in parallel with the light sensor 18, the fixed resistor 30, the first slave resistor 32, the second slave resistor 34, and the first capacitor 40.

The optical sensor connector 24 is a terminal to which a voltmeter (not shown) for measuring the voltages across the fixed resistor 30, the first slave resistor 32, and the second slave resistor 34 connected in parallel with each other is connected. In the present embodiment, the terminal No. 1 [3V terminal ] connected to the collector side of the photosensor 18 is provided in addition to the two ends (terminal No. 2 [ sensor output terminal ] and terminal No. 3 [ ground terminal ] in the drawing), but this terminal No. 1 is not an essential component.

Returning to fig. 2, the cover 26 is a member for guiding light from the LEDs 14 to the photosensor 18, and is attached to the surface of the substrate 12 so as to cover the photosensor 18 and one LED14 located in the vicinity of the photosensor 18.

As shown in fig. 4, the cover 26 according to the present embodiment includes a cover body 50, an LED housing space 52, an optical sensor housing space 53, a light guide slit 54, and a boss 56.

The cover main body 50 is a substantially rectangular thick plate-like member formed of a resin such as polycarbonate.

A through hole serving as an LED housing space 52 is formed in a surface (surface facing outward when mounted on the substrate 12) of the cover main body 50. The LED housing space 52 has a substantially circular cross section, and has a diameter that gradually increases as it goes toward the surface.

The cover main body 50 has a rear surface (a surface facing the substrate 12 when mounted on the substrate 12) formed with: a through hole which serves as the LED housing space 52; a recess serving as a photosensor housing space 53; and a light guide slit 54 as a groove that communicates the LED housing space 52 with the photosensor housing space 53. In the present embodiment, the cross section of the photosensor housing space 53 is formed in a substantially rectangular shape, but the cross section of the photosensor housing space 53 is not particularly limited.

Further, a pair of bosses 56 protrude from the back surface of the cover main body 50. In the present embodiment, each boss 56 is formed in a cylindrical shape, but may be prismatic.

A boss insertion hole 58 into which a pair of bosses 56 on the cover 26 are inserted is formed at a predetermined position on the substrate 12, and when the boss 56 is inserted into the boss insertion hole 58 to mount the cover 26 on the substrate 12, the photosensor 18 is accommodated in the photosensor accommodation space 53 and one LED14 is accommodated in the LED accommodation space 52.

Only the light emitted from the housed LED14 is received by the photosensor 18 through the light guide slit 54, and the amount of light received by the photosensor 18 is not affected by the light from the other LED14.

In the present embodiment, as shown in fig. 5, the boss insertion hole 58 is formed such that the diameter of the back surface of the substrate 12 is larger than the diameter of the surface, and the tip end portion of the boss 56 fitted into the boss insertion hole 58 is melted by a heated (e.g., 200 ℃) iron or the like so that the tip end of the boss 56 does not protrude from the back surface side of the substrate 12, thereby filling the boss insertion hole 58 on the back surface side of the substrate 12 (heat staking). Thereby, the cover 26 is not accidentally detached from the base plate 12.

Returning to fig. 1, the optical system member 102 has a function of guiding the light L emitted from the light irradiation device 200 to the irradiation surface on the workpiece stage 104, and generally includes a fly-eye lens 108, a shutter 110, a parallelizing mirror 112, and a reflecting mirror 114.

The fly-eye lens 108 is a member for receiving the light L from the light irradiation device 200 and homogenizing the light L irradiated to the irradiation surface on the workpiece stage 104 via the parallelizing mirror 112 or the like, and is configured by combining a plurality of lenses 109.

The shutter 110 is a device that controls the exposure time of the workpiece X by passing or blocking the light L emitted from the fly-eye lens 108.

The parallelizing mirror 112 is a member that has a function of converting the light L passing through the shutter 110 into parallel light.

The reflecting mirror 114 reflects the light L converted into parallel light by the parallelizing mirror 112 toward the irradiation surface on the workpiece stage 104.

The configuration of the optical system component 102 according to the present embodiment is merely an example, and the number of components constituting the optical system component 102 and the arrangement positions and arrangement order thereof are determined according to various conditions such as the layout of the entire exposure apparatus 100. For example, a mode in which the shutter 110 is not used in the optical system component 102 may be considered.

The workpiece stage 104 is a stage on which the workpiece X exposed by the light L is placed.

The workpiece transport apparatus 106 is an apparatus for moving the workpiece stage 104 and the workpiece X in a predetermined direction and distance, and uses a known actuator or the like.

(adjustment of light sensor 18 in LED Module 10)

Next, a description will be given of an adjustment step of making the width of the voltage value output based on the current value relatively small in a state where the current value output from each light sensor 18 in each LED module 10 has a relatively large width.

For example, as shown in fig. 6, it is assumed that the current value output from each light sensor 18 in each LED module 10 has a width of 3 μa to 7 μa. At this time, if only the fixed resistor 30 is provided in the output adjustment section 22, the voltage across the fixed resistor 30 detected from the current value becomes a width of 0.6V to 1.6V.

Therefore, the voltage across the fixed resistor 30 (i.e., the voltage between the No. 2 terminal and the No. 3 terminal in the optical sensor connector 24) is measured while the first slave resistor 32 of the output regulator 22 is connected in parallel to the fixed resistor 30 (i.e., the first switching element 36 is closed (short-circuited)), and the second slave resistor 34 is disconnected (i.e., the second switching element 38 is opened (open)). If the measured voltage value falls within a given range (e.g., from 0.8V to 1.2V as shown in fig. 7), no adjustment operation is required.

If the measured voltage value is slightly higher than the predetermined range (region a in the figure), the second slave resistor 34 is connected in parallel to the fixed resistor 30 (i.e., the second switching means 38 is closed (short-circuited)), and the first slave resistor 32 is disconnected from the fixed resistor 30 (i.e., the first switching means 36 is opened (open). Thus, since the measured voltage is within the predetermined range, the voltage value is measured again and confirmed.

When the measured voltage value is significantly higher than the predetermined range (region B in the figure), the state in which the first slave resistor 32 and the fixed resistor 30 are connected is maintained, and the second slave resistor 34 is connected in parallel to the fixed resistor 30 (that is, the second switching means 38 is closed (short-circuited)). Thus, since the measured voltage is within the predetermined range, the voltage value is measured again and confirmed.

When the measured voltage value is lower than the predetermined range (region C in the figure), the second slave resistor 34 is kept disconnected, and the first slave resistor 32 is disconnected from the fixed resistor 30 (i.e., the first switching element 36 is opened (opened)). Thus, since the measured voltage is within the predetermined range, the voltage value is measured again and confirmed.

As described above, according to the LED module 10 of the embodiment, since the resistor capable of adjusting the resistance value is connected in series with the photosensor 18, by adjusting the resistance value according to the output current from the photosensor 18, the width of the voltage value corresponding to the current value can be made relatively small in a state where the output current has a relatively large width.

Modification 1

In the above-described embodiment, the fixed resistor 30 and the plurality of

slave resistors

32 and 34 are used as the resistors of the output adjustment section 22, but other than these, a thermistor (a resistor body having a large change in resistance with respect to a change in temperature) may be used. The thermistor has a characteristic that the resistance value decreases when the temperature thereof increases, and the resistance value increases when the temperature thereof decreases. By connecting the thermistor in parallel with the fixed resistor 30 or the like, when the output current value from the photosensor 18 fluctuates due to a temperature change of the photosensor 18, the width of the voltage value corresponding to the fluctuation width of the current value can be made smaller.

Modification 2

In the output adjustment unit 22 of the above-described embodiment, the resistance value is adjusted by connecting/disconnecting a plurality of

slave resistors

32 and 34, but a volume resistor (variable resistor) 44 may be used instead of these

slave resistors

32 and 34 as shown in fig. 8.

Modification 3

In the output adjustment unit 22 of the above embodiment, the output current value from the optical sensor 18 is converted into the voltage value by measuring the voltage across the resistor, but instead, an operational amplifier may be used to convert the current value into the voltage value.

For example, as shown in fig. 9, the inverting input of the operational amplifier 300 is connected to the cathode side of the light sensor 302 (photodiode), and the non-inverting input is grounded. The fixed resistor 30 and the plurality of

slave resistors

32, 34 are connected in parallel with respect to the operational amplifier 300, that is, between the inverting input and the output of the operational amplifier 300.

In the case of modification 3, the optical sensor connector 24 has a terminal No. 1 [ ground terminal ] and a terminal No. 2 [ sensor output terminal ], and the voltage between these terminals is measured.

In the same manner as in the above embodiment, when the operational amplifier 300 is used, the first switching means 36 and the second switching means 38 connected in series to the plurality of

slave resistors

32 and 34 are also switched to adjust the resistance value.

Modification 4

In the above-described embodiment, the example in which the LED module 10 and the light irradiation device 200 according to the present invention are applied to the exposure device 100 has been described, but the LED module 10 and the light irradiation device 200 may be applied to a liquid crystal panel manufacturing apparatus.

The presently disclosed embodiments are considered in all respects to be illustrative and not restrictive. The scope of the present invention is shown by the claims, not by the above description, but by all changes within the meaning and range equivalent to the scope of the claims.

Description of the reference numerals

10 … LED modules; 12 … substrate; 14 … LED;16 … LED power supply; 18 … photosensor; 20 … photosensor circuit; 22 … output adjusting part; 24 … connector for light sensor; 26 … cover

30 … fixed resistor; 32 … first slave resistor; 34 … second slave resistor; 36 … first opening and closing unit; 38 … second opening and closing unit; 40 … first capacitor; 42 … second capacitor; 44 … volume resistor

A 50 … cover body; 52 … LED accommodation space; 53 … photosensor accommodation space; 54 … light directing slits; 56 … boss; 58 … boss embedding hole

100 … exposure device; 102 … optical system component; 104 … workpiece mounting table; 106 … workpiece conveying device; 108 … fly-eye lens; 109 … lenses; 110 … shutter; 112 … parallelizing mirrors; 114 … reflector

200 … light irradiation device

300 … operational amplifier; 302 … light sensor

X … workpiece; l … light.

Claims

1. An LED module, comprising:

a substrate;

a plurality of LEDs arranged on the substrate;

an LED power supply circuit formed on the substrate;

a photosensor disposed on the substrate; and

a resistor connected in series with respect to the light sensor,

the resistor is capable of adjusting a resistance value.

2. The LED module of claim 1, wherein,

the resistor has:

a fixed resistor;

and a plurality of switching units connected in series with each of the slave resistors.

3. The LED module of claim 1, wherein,

the LED module further includes an operational amplifier connected in parallel to the resistor, and configured to measure a voltage across the resistor.

4. A light irradiation device, wherein,

the light irradiation device is provided with a plurality of LED modules according to any one of claims 1 to 3.

5. A liquid crystal panel manufacturing apparatus, wherein,

the liquid crystal panel manufacturing apparatus includes the light irradiation apparatus according to claim 4.