CN114488702A

CN114488702A - Light source device, illumination device, exposure device, irradiation device, and method for manufacturing article

Info

Publication number: CN114488702A
Application number: CN202111238372.4A
Authority: CN
Inventors: 大场森晓
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 2020-10-28
Filing date: 2021-10-25
Publication date: 2022-05-13
Also published as: KR20220056802A; TW202217188A; JP2022071584A

Abstract

The invention relates to a light source device, an illumination device, an exposure device, an irradiation device, and a method for manufacturing an article. The unevenness of the light emission distribution of the light emitted from the plurality of LED chips is reduced. Comprising: a substrate; light emitting elements arranged on the 1 st surface of the substrate; and an optical member disposed on the 1 st surface side of the substrate and forming a 1 st channel between the substrate and the optical member, wherein the optical member collects light emitted from the light emitting element, a direction in which the cooling medium flows through the 1 st channel is opposite to a direction in which the cooling medium flows through a 2 nd channel, and the 2 nd channel is formed on the 2 nd surface side of the substrate, which is a surface opposite to the 1 st surface.

Description

Light source device, illumination device, exposure device, irradiation device, and method for manufacturing article

Technical Field

The invention relates to a light source device, an illumination device, an exposure device, an irradiation device, and a method for manufacturing an article.

Background

In a photolithography process in manufacturing devices such as semiconductor devices and Flat Panel Displays (FPDs), an exposure apparatus is used which transfers a mask pattern onto a substrate. As the Light source of the exposure apparatus, for example, a mercury lamp is used, but in recent years, replacement with a Light Emitting Diode (LED) which is more energy-saving than the mercury lamp is expected. The LED has a long life because the time from when current flows through the circuit until the light output is stable is short and the LED does not need to emit light all the time as in a mercury lamp.

In the LED, there is a characteristic that the light emission efficiency and the peak wavelength change according to a change in temperature, and the light emission efficiency decreases with an increase in temperature of the LED, so that the LED needs to be cooled in order to suppress the increase in temperature of the LED. Patent document 1 discloses that flow paths are provided on both the front side and the back side of a substrate on which a plurality of LED chips are arranged, and the LED chips are efficiently cooled.

Documents of the prior art

Patent document 1: japanese patent laid-open publication No. 2005-079066

Disclosure of Invention

Problems to be solved by the invention

However, in the light source device having the configuration as in patent document 1, since the cooling efficiency differs depending on the position where the LED chips are arranged, the temperature of each LED chip differs. Since the LED chips have a characteristic that the light emission efficiency varies depending on the temperature, the light source device having the configuration as in patent document 1 may have unevenness in the light emission distribution of the plurality of LED chips.

Accordingly, an object of the present invention is to provide a light source device that is advantageous for reducing unevenness in light emission distribution of light emitted from a plurality of LED chips.

Means for solving the problems

In order to achieve the above object, a light source device according to one aspect of the present invention includes: a substrate; light emitting elements arranged on the 1 st surface of the substrate; and an optical member disposed on the 1 st surface side of the substrate and forming a 1 st channel between the substrate and the optical member, wherein the optical member collects light emitted from the light emitting element, a direction in which the cooling medium flows through the 1 st channel is opposite to a direction in which the cooling medium flows through a 2 nd channel, and the 2 nd channel is formed on the 2 nd surface side of the substrate, which is a surface facing the 1 st surface.

Further features of the invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).

Drawings

Fig. 1 is a schematic diagram showing a configuration of a light source device in embodiment 1.

Fig. 2 is a diagram for explaining a temperature distribution of the light source device in the comparative example.

Fig. 3 is a diagram for explaining a temperature distribution of the light source device in embodiment 1.

Fig. 4 is a diagram showing a structure for sealing the refrigerant in the light source device.

Fig. 5 is a diagram illustrating a configuration for adjusting the flow rate of the refrigerant in the light source device.

Fig. 6 is a diagram showing an arrangement of LED chips in the light source device.

Fig. 7 is a schematic diagram showing the structure of the light source device according to embodiment 2.

Fig. 8 is a schematic diagram showing the structure of a light source device according to embodiment 3.

Fig. 9 is a schematic diagram showing the configuration of the illumination optical system.

Fig. 10 is a schematic diagram showing the configuration of the exposure apparatus.

Fig. 11 is a schematic diagram showing the configuration of the irradiation device.

(symbol description)

1: a flow path (corresponding to the 1 st flow path); 2: a flow path (corresponding to the 2 nd flow path); 10: a light source device; 11: an LED chip; 12: a circuit substrate; 16: an optical component.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description thereof will be omitted.

< embodiment 1 >

A light source device 10 is explained with reference to fig. 1. Fig. 1 is a sectional view of a light source device 10 in the present embodiment. The light source device 10 includes a light source unit 13 including an LED chip 11 (light emitting element) and a circuit board 12 (substrate), and an optical member 16 including a condenser lens 14. In the present embodiment, an example in which a plurality of LED chips 11 are two-dimensionally arranged is described, but the present invention is not limited thereto, and the LED chips 11 may be one-dimensionally arranged. In the following description, the surface of the circuit board 12 on which the LED chips 11 are arranged is referred to as the 1 st surface of the circuit board 12, and the opposite surface thereof is referred to as the 2 nd surface of the circuit board 12.

On the circuit board 12, copper wiring is mounted on the LED chip 11, and a circuit for causing the LED chip 11 to emit light is formed. When a current flows through the circuit, light of a predetermined wavelength is output from the LED chip 11. The condenser lens 14 is disposed on the 1 st surface side of the circuit board 12 so as to match the position of the LED chip 11. The light collecting lens 14 is fixed to the flat plate 15 in matching with the position of the LED chip 11. Alternatively, the collective lenses 14 may be individually held by the frame. The structure in which the condenser lens 14 is held by the frame is preferable in terms of reducing the difficulty in processing the optical member 16, but as described later, it is necessary to prevent a gap from being generated between the frame and the condenser lens 14 through which a refrigerant passes.

As the LED chip 11 emits light, the LED chip 11 generates heat, and the temperature of the light source unit 13 rises. The configuration of the light source device 10 for cooling heat generated by light emission of the LED chip 11 will be described. In the present embodiment, the light source device 10 performs heat exchange between the refrigerant and the light source unit 13 by flowing the refrigerant therethrough. This heat exchange allows the light source unit 13 to be cooled. The heat-exchanged refrigerant is sent to the refrigerator and cooled. Then, the heat is again circulated through the light source device 10 so as to exchange heat with the light source unit 13. In order to improve the efficiency of the heat exchange, it is preferable to use a material having high thermal conductivity for the circuit board 12. As a material of the circuit board 12, for example, copper or aluminum having high thermal conductivity may be used. As the refrigerant, for example, a liquid containing water as a main component having an excellent cooling power and a liquid containing oil as a main component having an excellent electrical insulation property can be used. In the present embodiment, an example of cooling the light source unit 13 with a liquid is described, but the present invention is not limited to this, and for example, the light source unit 13 may be cooled with air cooling by blowing a gas having a low temperature.

In the present embodiment, in order to efficiently cool the light source unit 13, a cooling medium flows through both the 1 st surface side and the 2 nd surface side of the circuit board 12. A flow path 1 (1 st flow path) through which a refrigerant flows is formed between the circuit board 12 and the optical member 16. In the flow path 1, the 1 st surface of the circuit board 12 and the optical member 16 function as walls of the flow path 1 in order to prevent the refrigerant from leaking to the outside. A flow path 2 (2 nd flow path) through which a refrigerant flows is formed between the circuit board 12 and the flat plate 17. In the flow path 2, the 2 nd surface of the circuit board 12 and the flat plate 17 function as a wall of the flow path 2 in order to prevent the refrigerant from leaking to the outside.

The refrigerant flowing through the flow path 1 formed on the 1 st surface side of the circuit board 12 exchanges heat with the surface of the circuit board 12 and directly exchanges heat with the LED chip 11. The refrigerant flowing through the flow channel 2 formed on the 2 nd surface side of the circuit board 12 exchanges heat with the 2 nd surface of the circuit board 12. By performing heat exchange on both surfaces of the circuit board 12, the area of the circuit board 12 subjected to heat exchange increases, and the cooling efficiency of the light source unit 13 can be improved.

The LED chip 11 is a light source having relatively high directivity, but the light collection amount can be increased by disposing the condenser lens 14 as close as possible to the LED chip 11. Therefore, by disposing the condenser lens 14 itself as a member forming the flow path 1, the condenser lens 14 can be brought as close as possible to the LED chip 11. This is expected to increase the amount of light taken in and increase the illuminance as a light source.

The necessity of cooling the light source unit 13 will be described. As a characteristic of the LED chip, the amount of light emitted and the peak wavelength vary depending on the temperature of the LED chip. As an example, consider an LED chip with a peak wavelength of 365nm at a temperature of 25 ℃. When the maximum operating temperature of the LED chip is 85 ℃, the amount of light when the LED chip rises to 85 ℃ is reduced by about 18% compared to that at 25 ℃, and the peak wavelength is shifted to the long wavelength side by about 3 nm. That is, as the temperature of the LED chip increases, the amount of emitted light decreases, and the peak wavelength shifts to the longer wavelength side.

In view of such characteristics, in the case where the light source units 13 are two-dimensionally arrayed and formed on the circuit board 12 as in the present embodiment, it is desirable to keep the temperature low over the entire area of the array portion of the LED chips 11 to achieve light emission efficiency. Further, since a high resolution is required for a light source used in an exposure apparatus, for example, the peak wavelength of light emitted from the LED chip 11 can be suppressed from shifting to the long wavelength side by keeping the temperature low over the entire arrangement region of the LED chips 11.

(direction of refrigerant flow in comparative example)

In the present embodiment, a description is given of a case where the refrigerants flowing through the

flow paths

1 and 2 flow in opposite directions, but first, as a comparative example of the present embodiment, a description is given of a case where the refrigerants flowing through the

flow paths

1 and 2 flow in the same direction. Fig. 2 is a diagram for explaining the flow direction of the refrigerant in the comparative example. Fig. 2 (a) shows a direction in which a refrigerant circulating through the light source device 10 flows in the comparative example.

Here, when the amount of heat transmitted from the LED chip 11 to the refrigerant is Q [ W ], the temperature difference between the LED chip 11 and the refrigerant is Δ T [ K ], and the thermal resistance between the LED chip 11 and the refrigerant is R [ K/W ], the following formula (1) is satisfied.

Q＝ΔT/R…(1)

Further, the thermal conductivity is set to h [ W/m2K ]]The surface area of the circuit board 12 in contact with the refrigerant during heat exchange is defined as Am²]Then, the thermal resistance R [ K/W ] is obtained by the following formula (2)]。

R＝1/(h·A)…(2)

Since the thermal resistance R can be obtained from the thermal conductivity h and the surface area a according to the formula (2), it is understood that the thermal resistance R is determined by the material and the shape. A state in which the heat generated from the LED chip 11 and the heat Q transmitted from the LED chip 11 to the refrigerant are equal is referred to as a steady state. The steady state in the comparative example is as shown in fig. 2 (b) when the LED chips 11 are uniformly arranged without individual difference in the amount of heat generation. Fig. 2 (b) is a graph showing the temperatures of the LED chip 11 and the refrigerant at a position corresponding to fig. 2 (a). The horizontal axis of the graph is position and the vertical axis of the graph is temperature. In the comparative example, the refrigerant in the flow path 1 and the refrigerant in the flow path 2 tend to be the same.

As shown in fig. 2 b, the temperature of the refrigerant increases while the refrigerant flows from the upstream side to the downstream side of the flow path (broken line in fig. 2 b). Further, as the temperature of the cooling medium increases, the cooling power for cooling the LED chip 11 decreases, and therefore the temperature of the LED chip 11 on the downstream side is higher than that on the upstream side (solid line in fig. 2 (b)). Therefore, the LED chips 11 are in a stable state in a state where the temperatures of the upstream and downstream LED chips 11 are different from each other in the flow path, and a difference occurs in the light emission efficiency and the peak wavelength of light depending on the position where the LED chips 11 are arranged.

When the light source device 10 of the present embodiment is applied to, for example, a light source of an exposure apparatus using an LED module in which a large number of LED chips are integrated, a large amount of heat exchange between the cooling medium and the light emitting element is performed. As a result, the difference in temperature between the refrigerant on the upstream side and the refrigerant on the downstream side of the flow path becomes larger, and the difference in light emission efficiency and light peak wavelength of the LED chip 11 occurs more significantly.

(direction of refrigerant flow in the present embodiment)

Therefore, in the present embodiment, the refrigerants flowing through the

flow paths

1 and 2 circulate so as to flow in opposite directions. Fig. 3 is a diagram for explaining the direction in which the cooling medium flows in the present embodiment. Fig. 3 (a) shows a direction in which a refrigerant circulating through the light source device 10 flows in the present embodiment.

The steady state in the present embodiment is as shown in fig. 3 (b) when the LED chips 11 are uniformly arranged without individual difference in the amount of heat generation. Fig. 3 (b) is a graph showing the temperatures of the LED chip 11 and the cooling medium in the

flow paths

1 and 2 at the position corresponding to fig. 3 (a). The horizontal axis of the graph is position and the vertical axis of the graph is temperature.

As shown in fig. 3 (b), while the refrigerant flows from the upstream side to the downstream side of the

flow paths

1 and 2, the refrigerant temperature increases. The difference from fig. 2 (b) is that the directions in which the cooling medium flows through the

flow paths

1 and 2 are different, and therefore, a temperature difference is not easily generated depending on the position where the LED chip 11 is disposed. In particular, when the thermal resistances of the

flow paths

1 and 2 are equal, the temperature distribution is as shown in fig. 3 (b).

(example 1)

A specific example in this embodiment mode is explained with reference to fig. 4. Fig. 4 is a diagram illustrating a structure for sealing the refrigerant circulating through the light source device 10. The flow channel 1, the flow channel 2, the light source unit 13, the optical member 16, and the flat plate 17 are the same as those in fig. 1, and therefore, the description thereof is omitted. In the present embodiment, the light source device 10 further has a sealing member 18 and a member 19.

The sealing member 18 is disposed between the circuit board 12 and the optical member 16, and between the circuit board 12 and the flat plate 17, and seals the

flow paths

1 and 2 so as to prevent the refrigerant flowing therethrough from flowing to the outside of the flow paths. By using a member having a large elastic deformation amount as the sealing member 18, the refrigerant can be easily sealed. Further, since the sealing member 18 is irradiated with light emitted from the light source unit 13, it is desirable to use a material having high weather resistance such as Polytetrafluoroethylene (PTFE). On the other hand, when the amount of elastic deformation of the sealing member 18 is large, the distance between the light source section 13 and the optical member 16 (or the distance between the light source section 13 and the flat plate 17) is not constant. Thus, for example, the light quantity and angle at which the optical member 16 collects the light from the light source unit 13 are not constant, and therefore the light source device 10 cannot be used stably. Therefore, when the sealing member 18 having a large elastic deformation amount is used, the distance between the light source unit 13 and the optical member 16 (or the distance between the light source unit 13 and the flat plate 17) is constant by the combined use of the members 19, and the light source device 10 can be used stably.

The member 19 is a member having a small elastic deformation amount, and is disposed as shown in fig. 4 so that the distance between the light source unit 13 and the optical member 16 (or the distance between the light source unit 13 and the flat plate 17) becomes constant. The member 19 may be part of the light source unit 13 or the flat plate 17.

In the description of fig. 1, it is described that the material used for the circuit board 12 is preferably copper or aluminum having high thermal conductivity in order to improve the heat exchange efficiency between the cooling medium flowing through the

flow paths

1 and 2 and the circuit board 12. Similarly, a material having high thermal conductivity, such as copper or aluminum, is preferably used for the flat plate 17. When a material having high thermal conductivity is used for the flat plate 17, the heat of the 2 nd surface of the circuit board 12 is transferred to the flat plate 17 through the member 19, and therefore, the heat exchange efficiency is improved. The LED chip 11 can be directly cooled on the 1 st surface side of the circuit board 12, but the LED chip 11 cannot be directly cooled on the 2 nd surface side of the circuit board 12. Therefore, by improving the heat exchange efficiency of the 2 nd surface of the circuit board, the temperature distribution of the LED chip 11 as shown in fig. 3 (b) can be obtained on the 1 st surface side and the 2 nd surface side of the circuit board 12. It is desirable to decide a parameter that affects the heat flow rate of the structure including the flow path for each of the

flow paths

1 and 2 according to the difference between the cooled heat resistance of the flow path 1 and the cooled heat resistance of the flow path 2.

The parameters affecting the heat flow rate include, for example, the shape of the flow path, the material of a member functioning as a wall of the flow path, the type of the refrigerant, the initial temperature of the refrigerant, and the flow rate of the refrigerant per unit time. Here, setting of each parameter is explained.

By increasing the surface area of the circuit board 12 as the shape forming the flow path, the heat quantity of heat exchange between the refrigerant flowing through the flow path 1 and the flow path 2 and the circuit board 12 can be increased. Specifically, the surface area of the circuit board 12 can be increased by providing a plurality of fins (fin) on the circuit board 12. The fins provided on the circuit board 12 are desirably provided so as to extend in the direction in which the refrigerant flows without obstructing the flow of the refrigerant. The fins provided on the circuit board 12 may be integrated with the circuit board 12 or may be independent of the circuit board 12, and in the case of being independent of the circuit board, copper or aluminum having high thermal conductivity is preferably used as the material used for the circuit board 12. Further, as a means for improving the heat exchange efficiency without using fins, there is a method of narrowing the

flow paths

1 and 2. Even if the surface area of the surface for heat exchange is the same, the amount of movement of the refrigerant in the vicinity of the surface for heat exchange increases when the flow path is narrowed, and therefore, the heat exchange efficiency improves.

As described above, copper or aluminum is preferably used as the material of each member serving as the wall of the flow channel 2, and a material having excellent thermal conductivity such as iron or magnesium can be used in addition to copper or aluminum. In the flow channel 1, the optical member 16 functions as a wall of the flow channel 1, but the material of the optical member 16 is preferably selected in accordance with optical characteristics such as transparency and refractive index so as to prevent performance of the light source device 10 from being deteriorated, compared to when importance is attached to thermal conductivity. The optical member 16 may be made of a highly transparent resin such as synthetic quartz, glass, or acryl. The reason why the optical characteristics are prioritized over the thermal conductivity is that the amount of heat generated by the light source unit 13 itself can be suppressed by efficiently taking in the light emitted from the light source unit 13.

The type of the refrigerant is preferably a liquid having high non-corrosiveness, electrical insulation, and thermal conductivity with respect to a material serving as a wall of the flow path. The type of the refrigerant may be changed between the flow path 1 and the flow path 2, and the refrigerant to be supplied to the flow path 1 is preferably a highly transparent liquid so as not to block the light emitted from the light source unit 13. As the refrigerant flowing through the flow path 1, for example, a generally used heat medium such as a mixture of biphenyl and diphenyl ether can be used. By changing the kind of the refrigerant flowing through the

flow paths

1 and 2, the amount of heat exchanged between the 1 st surface side and the 2 nd surface side of the circuit board 12 can be adjusted by utilizing the difference in the thermal conductivity of the refrigerant.

As the essential condition, the initial temperature of the cooling medium is a temperature higher than the lower limit value of the operating temperature of the LED chip 11 and higher than the lower limit value of the use temperature of the cooling medium. The initial temperature here refers to the temperature of the refrigerant supplied to the light source device 10. In addition, from the viewpoint of heat exchange efficiency, the temperature of the refrigerant is desirably as low as possible. In setting the actual temperature of the refrigerant, for example, the initial temperature of the refrigerant may be set to about 20 ℃ to 25 ℃ so as to be approximately equal to the ambient temperature of the light source device 10. Further, the initial temperatures of the refrigerants flowing through the

flow paths

1 and 2 may be different from each other.

Since the heat transferred from the LED chip 11 to the refrigerant increases by increasing the flow rate of the refrigerant per unit time, a throttle valve capable of adjusting the flow rate may be provided in both or one of the

flow paths

1 and 2 to adjust the flow rate for changing the heat exchange efficiency of the

flow paths

1 and 2. Fig. 5 is a diagram showing the

flow paths

1 and 2 capable of independently adjusting the flow rates. A valve 3 is provided upstream of the flow path 1, and a valve 4 is provided upstream of the flow path 2. The valves 3 and 4 are connected to the control unit 5, and the amount of refrigerant flowing into the

flow paths

1 and 2 can be independently adjusted by controlling the amount of refrigerant flowing into the flow paths by the control unit 5 using the respective valves.

The

flow paths

1 and 2 are preferably flow paths that do not merge, because different types of refrigerants are used for the

flow paths

1 and 2, and the flow rates of the

flow paths

1 and 2 can be independently adjusted. However, the present invention is not limited to this, and for example, the refrigerant flowing from 1 flow channel may be a flow channel that branches into the flow channel 1 and the flow channel 2 before flowing into the portion where heat exchange with the light source unit 13 is performed, and then merges after flowing through the heat exchange portion. Alternatively, the flow path may be configured in series such that the flow passes through one of the

flow paths

1 and 2 and then the other. The flow path may be a circulating flow path or a non-circulating flow path.

As described above, the heat exchange efficiency of each flow path can be adjusted by appropriately setting the parameters of the

flow paths

1 and 2. This enables the light source unit 13 to be adjusted to an arbitrary temperature. That is, the wavelength can be finely adjusted to an arbitrary wavelength with a small difference in peak wavelength of the light emitted from the light source unit 13. For example, when a light source of a predetermined ideal single wavelength is required, such as an exposure apparatus using a band-pass filter, an effect is obtained that light emitted from the light source can be brought close to the predetermined single wavelength.

(example 2)

In example 1, the description has been given of adjusting the heat exchange efficiency between the light source unit 13 and the refrigerant by appropriately setting the parameters of the

flow paths

1 and 2. In example 2, an arrangement of the LED chips 11 for improving the heat exchange efficiency between the light source unit 13 and the refrigerant flowing through the flow path 1 will be described with reference to fig. 6.

Fig. 6 (a) is a diagram showing the arrangement of the LED chips 11 when the arrangement direction of the LED chips 11 coincides with the direction in which the refrigerant of the flow path 1 flows. When the arrangement direction of the LED chips 11 coincides with the direction in which the refrigerant of the flow path 1 flows, the LED chips 11 are arranged such that the downstream LED chip 11b is shielded by the upstream LED chip 11 a. When the flow velocities of the refrigerant at the point 20 and the point 21 in fig. 6 (a) are compared, the flow velocity of the refrigerant at the point 21 becomes larger. This is because the cooling medium flows between the LED chips 11, and therefore the cooling medium is less likely to flow into the space (near the point 20) on the downstream side of the LED chip 11 a. That is, in the arrangement of the LED chips 11 as in fig. 6 (a), heat exchange with the LED chips 11 is not actively performed, so that cooling efficiency is lowered.

Therefore, by arranging the LED chips 11 in a staggered manner as shown in fig. 6 (b), a decrease in cooling efficiency can be reduced. Fig. 6 (b) is a diagram showing the arrangement of the LED chips 11 when the arrangement direction of the LED chips 11 does not coincide with the direction in which the refrigerant flows through the flow path 1. In fig. 6 (b), for example, the LED chips 11c (1 st light emitting element) and 11d (2 nd light emitting element) are arranged such that the refrigerant flowing between the LED chips contacts the LED chip 11e (3 rd light emitting element) behind one row. That is, in the range between the LED chip 11c and the LED chip 11d aligned in the direction perpendicular to the flow direction of the refrigerant flowing through the flow path 1, the LED chip 11e is aligned on the downstream side of the refrigerant flowing through the flow path 1 with respect to the LED chip 11c and the LED chip 11 d.

In fig. 6 (b), the LED chips 11 are arranged in a staggered manner such that the refrigerant flowing between the

LED chips

11c and 11d contacts the center of the LED chip 11e behind one row, but the center may not be. For example, the flow line may be a stream line that meanders without coinciding with the overall flow direction of the refrigerant. The arrangement of the LED chips 11 is desired to reduce the number of portions where the cooling medium is less likely to move, such as stagnation points, as a whole.

As described above, by arranging the LED chips 11 in a staggered manner as shown in fig. 6 (b), the heat exchange efficiency of the refrigerant flowing through the flow path 1 can be improved. This enables the LED chip 11 to be cooled more efficiently, and a decrease in the light emission efficiency of the LED chip 11 can be suppressed.

As described above, in the present embodiment, the refrigerant formed in the

flow paths

1 and 2 of the light source device 10 flows in the opposite directions, so that the temperature unevenness of the plurality of LED chips 11 in the entire light source section 13 can be reduced. This can reduce the variation in the light emission distribution of the light emitted from the plurality of LED chips 11.

< embodiment 2 >

In embodiment 1, an example in which the 1 st surface of the light source unit 13 is cooled by the refrigerant of the flow path 1 and the 2 nd surface of the light source unit 13 is cooled by the refrigerant of the flow path 2 is described. In the present embodiment, an example will be described in which both the 1 st surface side and the 2 nd surface side of the light source unit 13 are cooled by the refrigerant flowing through the flow path 1, and the refrigerant flowing through the flow path 1 is cooled by the refrigerant flowing through the flow path 2. The basic configuration of the light source device 10 is the same as that of embodiment 1, and therefore, detailed description thereof is omitted. Note that matters not mentioned in the present embodiment are the same as those in embodiment 1.

Fig. 7 is a schematic diagram of the light source device 10 in the present embodiment. The light source device 10 in the present embodiment includes a light source section 13 including an LED chip 11 (light emitting element) and a circuit board 12, an optical member 16, a flat plate 17a (1 st flat plate), and a flat plate 17b (2 nd flat plate). In the flow channel 1 in the present embodiment, the optical member 16 and the flat plate 17a function as walls of the flow channel. The light source 13 is immersed in the refrigerant flowing through the flow channel 1, and both the 1 st surface side and the 2 nd surface side of the light source 13 are cooled by the refrigerant flowing through the flow channel 1.

In the flow channel 2 in the present embodiment, the flat plate 17a and the flat plate 17b function as walls of the flow channel. As with the flat plate 17 of embodiment 1, it is desirable to use copper or aluminum as a material having high thermal conductivity for the flat plate 17a of the present embodiment. In the case where the member 19 shown in fig. 4 is disposed in the present embodiment, it is desirable to use copper or aluminum as a material having high thermal conductivity for the flat plate 17b in the present embodiment as well.

The flow path 2 does not directly exchange heat with the light source unit 13, but exchanges heat with the flow path 1 via the flat plate 17 a. The flow direction of the refrigerant flowing through the

flow paths

1 and 2 is the opposite direction as in embodiment 1. The reason for this is that the flow path 1 plays a role of suppressing the temperature rise of the LED chip 11, and the flow path 2 reduces the temperature unevenness of the refrigerant in the flow path 1, and as a result, plays a role of reducing the temperature unevenness of the LED chip 11.

In the present embodiment, since the flow path 1 can be formed as a package enclosing the light source unit 13, the circuit board 12 does not need to have a structure for sealing the cooling medium, and therefore, the mechanical strength of the circuit board 12 may be reduced as compared with embodiment 1. Since the optical member 16 is used as a wall of the flow path in the same manner as in embodiment 1, the optical member 16 needs to be sealed with a refrigerant. The change of the parameters related to the

flow paths

1 and 2 described in example 1 of embodiment 1 and the arrangement of the LED chips 11 described in example 2 of embodiment 1 may be appropriately set in this embodiment.

As described above, in the present embodiment, the light source unit 13 is cooled by the refrigerant flowing through the flow path 1. Further, the refrigerant flowing through the flow path 1 is heat-exchanged with the refrigerant flowing through the flow path 1 via the flow path 2 flowing in the opposite direction, so that temperature unevenness of the plurality of LED chips 11 in the entire area of the light source unit 13 can be reduced. This can reduce the variation in the light emission distribution of the light emitted from the plurality of LED chips 11.

< embodiment 3 >

In embodiment 1 and embodiment 2, an example in which the light source unit 13 is two-dimensional is described. In the present embodiment, an example in which the light source unit 13 is not two-dimensional but cylindrical will be described with reference to fig. 8. The basic configuration of the light source device 10 is the same as that of embodiment 1, and therefore, detailed description thereof is omitted. Note that matters not mentioned in the present embodiment are the same as those in embodiment 1.

Fig. 8 (a) is a schematic diagram of the cylindrical light source device 10 in the present embodiment as viewed from the front direction, and fig. 8 (b) is a schematic diagram of a cross section of the cylindrical light source device 10 in the present embodiment as viewed from the side direction. The light source device 10 in the present embodiment includes a light source unit 43 including an LED chip 41 (light emitting element) and a circuit board 42, and an optical member 46. The circuit board 42 has a cylindrical shape, and the LED chips 41 are arranged to face the outside of the circuit board 42. In the present embodiment, the surface on the outside of the cylindrical shape of the circuit board 42 on which the LED chips 41 are arranged is referred to as the 1 st surface of the circuit board 42, and the surface on the inside of the cylindrical shape of the circuit board 42 on which the LED chips 41 are not arranged is referred to as the 2 nd surface of the circuit board 42.

The optical member 46 is arranged to have a diameter larger than that of the light source section 43 and the optical member 46 and the light source section 43 become concentric. The flow channel formed between the 1 st surface of the circuit board 42 and the optical member 46 is referred to as flow channel 1, and the flow channel formed on the 2 nd surface of the circuit board 42 is referred to as flow channel 2. The cooling medium flows through the

flow paths

1 and 2, thereby cooling both the 1 st surface and the 2 nd surface of the light source unit 13. As in embodiment 1 and embodiment 2, the directions of the flow of the cooling medium in the flow path 1 and the flow path 2 are opposite to each other. That is, the refrigerant flows into the

flow paths

1 and 2 from the opposite end. This can reduce the temperature unevenness of the entire light source section 13, as in embodiment 1.

In addition, the flow of the refrigerant may be provided with a guide portion that guides the direction in which the refrigerant flows so as to flow through the

flow paths

1 and 2 in a spiral shape, instead of flowing through one dimension. When the refrigerant flows spirally in the flow path, not only the temperature unevenness upstream and downstream of the flow can be reduced, but also the temperature unevenness in the circumferential direction of the cylindrical light source section can be reduced. In addition, in the spiral liquid feeding, as described in embodiment 2 of embodiment 1, a state in which the direction in which the LED chips 41 are arranged and the direction in which the refrigerant flows are different can be easily realized. This improves the cooling efficiency and can suppress a temperature rise of the LED chip 41.

In the present embodiment, the example in which the light source unit 43 and the optical member 46 are cylindrical has been described, but other shapes are also possible. For example, the light source unit 43 and the optical member 46 may have an angular tube shape, a curved tube shape, or the like, and the surface on which the LED chips 41 are arranged may be a flat surface or a curved surface. The change of the parameters related to the

flow paths

1 and 2 described in example 1 of embodiment 1 and the arrangement of the LED chips described in example 2 of embodiment 1 may be appropriately set in this embodiment as well.

As described above, in the present embodiment, temperature unevenness of the plurality of LED chips 41 arranged on the cylindrical circuit board 42 can be reduced. This can reduce the variation in the light amount distribution of the light emitted from the plurality of LED chips 41. The contents described in embodiments 1 to 3 may be combined and implemented.

< embodiment of Lighting device >

Next, an example of the illumination optical system will be described with reference to fig. 9. Fig. 9 is a schematic cross-sectional view of the illumination optical system 50. The illumination optical system 50 includes the light source device 10, a condenser lens 51, a condenser lens 52, an integrator optical system 53, a condenser lens 54, and an illumination surface 55. The light emitted from the light source device 10 passes through the condenser lens 51 and the condenser lens 52 to reach the integrator optical system 53. The collective lens 51 is a lens array having lenses provided corresponding to the positions of the LED chips of the light source device 10 (or collective lenses included in the optical components of the light source device 10).

The condenser lens 52 is designed such that the exit surface position of the light source device 10 and the entrance surface position of the integrator optical system 53 optically become conjugate surfaces of fourier conjugates. Such an illumination system is called kohler illumination. As for the condenser lens 52, a 1-piece plano-convex lens is illustrated in fig. 9, but in practice, it is often constituted by a plurality of lens groups. By using the integrator optical system 53, a plurality of secondary light source images conjugate with the emission surface of the light source unit 51 are formed at the emission surface position of the integrator optical system 53. The light emitted from the emission surface of the integrator optical system 53 reaches the illumination surface 55 via the condenser lens 54.

The integrator optical system 53 has a function of uniformizing the light intensity distribution. In the integrator optical system 53, an optical integrator lens or a rod lens is used to improve the illuminance uniformity of the irradiation surface 55.

The condenser lens 54 is designed such that the exit surface of the integrator optical system 53 and the illumination surface 55 optically become conjugate surfaces of fourier conjugates, and the exit surface of the integrator optical system 53 or the conjugate surface thereof becomes a pupil surface of the illumination optical system. As a result, a substantially uniform light intensity distribution can be produced on the illumination surface 55.

The light source device 10 and the illumination optical system 50 can be applied to various illumination devices, and can also be applied to a device for illuminating a photocurable resin, a device for inspecting an object by illuminating the object, a lithography device, and the like. For example, the present invention can be applied to an exposure apparatus that exposes a pattern of a mask to a substrate, a maskless exposure apparatus, an imprint apparatus that forms a pattern on a substrate using a mold, or a flat layer forming apparatus.

< embodiment of Exposure apparatus >

In the present embodiment, a case where the light source device 10 and the illumination optical system 50 are applied to an exposure apparatus will be described. Fig. 10 is a schematic diagram showing the configuration of the exposure apparatus 100. The exposure apparatus 100 is a lithography apparatus used in a lithography process as a manufacturing process of a semiconductor device or a liquid crystal display device, and forms a pattern on a substrate. The exposure apparatus 100 exposes a substrate through a mask, and transfers the pattern of the mask to the substrate. The exposure apparatus 100 is a step-and-scan type exposure apparatus in the present embodiment, a so-called scan type exposure apparatus, but a step-and-repeat type exposure apparatus or another exposure method may be employed.

The exposure apparatus 100 includes an illumination optical system 50 that illuminates a mask 101, and a projection optical system 103 that projects a pattern of the mask 101 onto a substrate 102. The projection optical system 103 may be a projection lens formed of a lens or a reflection type projection system using a mirror.

The illumination optical system 50 irradiates light from the light source device 1 to the mask 101. The mask 101 has a pattern corresponding to a pattern to be formed on the substrate 102. The mask 101 is held on the mask stage 104, and the substrate 102 is held on the substrate stage 105.

The mask 101 and the substrate 102 are disposed at positions substantially optically conjugate with each other with a projection optical system 103 interposed therebetween. The projection optical system 103 is an optical system that projects an object onto an image plane. In the projection optical system 103, a reflection system, a refraction system, and a catadioptric system can be applied. In the present embodiment, the projection optical system 103 has a predetermined projection magnification, and projects a pattern formed on the mask 101 onto the substrate 102. Then, the mask stage 104 and the substrate stage 105 are scanned in a direction parallel to the object plane of the projection optical system 103 at a speed ratio corresponding to the projection magnification of the projection optical system 103. This enables the pattern formed on the mask 101 to be transferred to the substrate 102.

< embodiment of irradiation apparatus >

In the present embodiment, a case where the light source device 10 and the illumination optical system 50 are applied to the illumination device 300 will be described. Fig. 11 is a schematic diagram showing the configuration of the irradiation device 300. The irradiation device 300 functions as an ultraviolet irradiation device that irradiates an irradiation object 301 with irradiation light 302 in a wavelength region of ultraviolet rays. The irradiation device 300 includes a light source device 10, an irradiation control device 303, and a control unit 304.

The irradiation target 301 is not particularly limited as long as it is an irradiation target that receives irradiation of ultraviolet rays. And may be solid, liquid, gas, or a combination thereof. The irradiation light 302 is ultraviolet light having wavelength characteristics that provide some action to the object 301. As the function of the irradiation light 302, sterilization treatment, surface treatment, and the like are considered.

The irradiation control device 303 is connected to a control unit 304 that controls the light source device 10, and communicates with the control unit 304. The irradiation control device 303 outputs an on/off (on off) signal of a current output, a command value of an output current, and the like to the control unit 304, thereby controlling the control unit 304. When the control unit 304 detects a failure of the LED chip, the control unit 304 outputs a failure detection signal to the irradiation control device 303.

< embodiment of treatment of article >

The method of manufacturing an article according to the embodiment of the present invention is suitable for manufacturing an FPD, for example. The method of manufacturing an article according to the present embodiment includes a step (exposure step) of forming a latent image pattern in a photosensitive agent applied to a substrate using the exposure apparatus, and a step (development) of developing the substrate on which the latent image pattern has been formed in the step. The above-mentioned manufacturing method includes other known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, adhesion, packaging, and the like). The method for manufacturing an article according to the present embodiment is more advantageous than conventional methods in at least 1 of the performance, quality, productivity, and production cost of the article.

While the preferred embodiments of the present invention have been described above, it is a matter of course that the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist thereof.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a light source device advantageous for reducing unevenness in light emission distribution of light emitted from a plurality of LED chips.

Claims

1. A light source device, comprising:

a substrate;

light emitting elements arranged on the 1 st surface of the substrate; and

an optical member disposed on the 1 st surface side of the substrate to form a 1 st channel between the substrate and the optical member, the optical member condensing light emitted from the light emitting element,

the direction in which the refrigerant flows through the 1 st flow path is opposite to the direction in which the refrigerant flows through the 2 nd flow path, and the 2 nd flow path is formed on the 2 nd surface side, which is a surface opposite to the 1 st surface, with respect to the substrate.

2. The light source device according to claim 1,

the 1 st channel is a channel formed between the substrate and the optical member.

3. The light source device according to claim 1,

the light source device has a flat plate forming the 2 nd flow path,

the 2 nd flow path is a flow path formed between the substrate and the flat plate.

4. The light source device according to claim 1,

the light source device has a 1 st plate forming the 1 st flow path,

the 1 st channel is a channel formed between the optical member and the 1 st plate.

5. The light source device according to claim 4,

the light source device has a 2 nd plate forming the 2 nd flow path,

the 2 nd flow path is a flow path formed between the 1 st plate and the 2 nd plate.

6. The light source device according to claim 1,

the light source device has a plurality of light emitting elements two-dimensionally arrayed on the substrate.

7. The light source device according to claim 6,

the plurality of light emitting elements are arranged on the substrate in a staggered manner.

8. The light source device according to claim 1,

the substrate and the optical member are cylindrical.

9. The light source device according to claim 1,

the light source device includes a sealing member disposed in the 1 st flow path and the 2 nd flow path, and sealing the 1 st flow path and the 2 nd flow path so that a refrigerant flowing through the 1 st flow path and the 2 nd flow path does not leak to the outside of the flow paths.

10. The light source device according to claim 1,

the optical component includes a lens.

11. The light source device according to claim 1,

the refrigerant flowing through the 2 nd flow path exchanges heat with the substrate.

12. The light source device according to claim 1,

the refrigerant flowing through the 2 nd flow path exchanges heat with the refrigerant flowing through the 1 st flow path.

13. The light source device according to claim 1,

the refrigerant flowing through the 1 st flow path is the same refrigerant as the refrigerant flowing through the 2 nd flow path.

14. The light source device according to claim 1,

the refrigerant flowing through the 1 st channel is different from the refrigerant flowing through the 2 nd channel.

15. The light source device according to claim 1,

the flow rate per unit time of the refrigerant flowing through the 1 st flow path is different from the flow rate per unit time of the refrigerant flowing through the 2 nd flow path.

16. The light source device according to claim 1,

the light source device includes a control unit that independently controls a flow rate per unit time of the refrigerant flowing through the 1 st flow path and a flow rate per unit time of the refrigerant flowing through the 2 nd flow path.

17. The light source device according to claim 16,

the light source device includes a valve that is controlled by the control unit and adjusts a flow rate per unit time of the refrigerant flowing through the 1 st flow path and a flow rate per unit time of the refrigerant flowing through the 2 nd flow path.

18. The light source device according to claim 1,

the light emitting element is an LED chip.

19. An illumination device, comprising:

the light source device of any one of claims 1 to 18;

a condenser lens; and

an optical integrator is provided, which is provided with a light source,

the illumination device causes the light intensity distribution from each of the plurality of light emitting elements to overlap in the incident surface of the optical integrator via the condenser lens.

20. A lighting device as recited in claim 19,

the optical integrator has a lens group.

21. An exposure apparatus, comprising:

an illumination optical system for illuminating the mask with the light from the illumination device according to claim 19; and

and an exposure unit that exposes the pattern of the mask to a substrate.

22. An irradiation apparatus for irradiating an irradiation object with light using the light source apparatus according to any one of claims 1 to 18,

the light performs at least one of sterilization and surface treatment of the irradiation target.

23. A method of manufacturing an article, comprising:

an exposure step of exposing a substrate by using the exposure apparatus according to claim 21; and

a developing step of developing the substrate exposed in the exposure step,

in the method for manufacturing an article, an article is manufactured from the substrate developed in the developing step.