JP4189354B2 - Exposure equipment - Google Patents

Description

  The present invention relates to an exposure apparatus that exposes a substrate through a mask, and more particularly to an exposure apparatus that has a function of preventing the performance of an optical system from being deteriorated.

In general, a substrate on which an electronic circuit such as a printed wiring board is formed is required to have a multi-layered structure and a high density in accordance with the multi-function and high speed of an electronic device using the substrate. Therefore, electronic circuits tend to be refined and thinned. Therefore, in order to satisfy such a requirement, an exposure apparatus that exposes a photosensitive resin layer provided on a substrate surface has been improved from an exposure apparatus that uses scattered light to an exposure apparatus that uses parallel light. The exposure apparatus using the parallel light includes a cold mirror (plane mirror) that reflects the light emitted from the lamp, a fly-eye lens that is disposed in the optical path of the light reflected by the cold mirror, and passes through the fly-eye lens. An optical system including a collimation mirror (concave mirror) that irradiates the workpiece with parallel light as a work (see, for example, Patent Document 1). The surfaces of these optical systems are coated with a reflective film or the like in order to improve the performance.
JP 2001-296666 A (paragraphs 0011 to 0012, FIG. 1)

  However, since the reflective film that coats the surface of the optical system is inferior in heat resistance, if it is used under high temperature and high humidity, it tends to deteriorate and floats floating in the exposure apparatus are likely to adhere. Then, the reflectance of the reflective film to which the suspended matter is attached decreases.

  The photosensitive resin layer provided on the substrate surface undergoes a chemical change when exposed to light and volatilizes silicon dioxide, siloxane, or the like as a volatile substance. These volatile substances are known to adhere to the optical system and reduce the reflectance of the optical system. Note that this decrease in the reflectance of the optical system is significant in a collimation mirror (concave mirror) disposed immediately above the mounting table on which the substrate is mounted.

  Therefore, the present invention deteriorates due to the problem that the reflectance decreases due to adhesion of volatile substances that volatilize from the photosensitive resin layer to the concave mirror, and that the reflective film that coats the surface of the concave mirror is used under high temperature and high humidity. It is an object of the present invention to provide an exposure apparatus capable of solving the above-described problems and forming a precise and thin electronic circuit.

In order to solve the above-described problem, an exposure apparatus according to claim 1 includes a light source that emits light including ultraviolet rays having a predetermined wavelength, a plane mirror that reflects light from the light source along a preset optical path, and an optical path. A fly-eye lens disposed in the light source chamber, a concave mirror that reflects light from the light source along a preset optical path, a mask frame that supports a mask installed below the concave mirror, and the mask in an exposure apparatus provided in the exposure chamber and a mount table for mounting a substrate disposed so as to face the mask frame, a blowing port for blowing air along the concave surface of the formed concave mirror in the exposure chamber, an air purifying filter provided in the path of the blast, and an exhaust hole for discharging the air out of the exposure chamber which is blown along the concave surface of the concave mirror provided on the floor surface to place the mount table, the concave mirror The wall of the exposure chamber facing the blower opening and was configured to include a curved air guide plate for guiding air that is blown along the concave surface of the concave mirror to the exhaust hole.

In the exposure apparatus configured as described above, clean air that has passed through the air purification filter from the air blowing port flows along the concave surface of the concave mirror. The air discharges the suspended matter, such volatiles and dust and dust drifting in the exposure chamber such as silicon dioxide and siloxane volatilized from the photosensitive resin layer, from the exhaust hole provided in the floor surface to place the mount table . Further, in the exposure apparatus, by providing the air guide plate, air sent along the concave surface of the concave mirror from the air blowing port can be smoothly guided to the exhaust hole.

The exposure apparatus according to a second aspect is configured such that the air outlet is connected to an air conditioner disposed outside the exposure chamber .

In the exposure apparatus configured in this way, air whose temperature and humidity are controlled flows from the blower opening along the concave surface of the concave mirror. This temperature and humidity controlled air keeps the temperature and humidity in the vicinity of the concave mirror constant, and the reflective film that coats the surface of the concave mirror is exposed to volatile substances such as silicon dioxide and siloxane that are volatilized from the photosensitive resin layer and the exposure chamber. It is possible to prevent the floating matter such as dust and dust floating inside from being easily attached.

  According to such an exposure apparatus according to the present invention, it is possible to prevent a decrease in the reflectance of the concave mirror and a deterioration of the reflective film that coats the surface of the concave mirror with a simple structure. Therefore, it is possible to maintain the performance of the concave mirror, and it is possible to form a precise and thin electronic circuit on the substrate. Further, since maintenance on the concave mirror can be reduced, it is possible to extend the continuous working time of the exposure apparatus.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is a perspective view of a state in which the exposure apparatus of the present invention is broken, and FIG. 2 is a sectional view showing the flow of air of the present invention.

As shown in FIG. 1, the exposure apparatus 1 includes a light source 10, an optical system 20, a mounting table 30, a blower port 40, and an exhaust hole 60 in a housing 5, and the housing 5 is a light source. It is partitioned into a chamber 3 and an exposure chamber 4. Further, the exposure apparatus 1 includes an air conditioner 2 that supplies air to the air blowing port 40 outside the housing 5. Incidentally, the exposure apparatus 1 is provided with a baffle plate 50 into the exposure chamber 4.

  The light source 10 includes, for example, a mercury short arc lamp 11 and a condenser mirror 12. The mercury short arc lamp 11 irradiates light containing ultraviolet rays having a predetermined wavelength, and always lights during the exposure operation. The condensing mirror 12 reflects the light irradiated from the mercury short arc lamp 11 and condenses it toward the first flat mirror 21 side described later.

  Here, the optical system 20 includes a first plane mirror 21, a fly-eye lens 22, a second plane mirror 23, and a concave mirror 24, and each is installed in a preset optical path. The first plane mirror 21 is a plate-like mirror, for example, a cold mirror. The first plane mirror 21 is disposed immediately above the light source 10 so as to reflect light from the light source 10 in a predetermined direction.

  The fly-eye lens 22 is formed by arranging a plurality of convex lenses vertically and horizontally, and the first plane mirror 21 and the second plane mirror 21 irradiate the light reflected by the first plane mirror 21 to the second plane mirror 23 with a uniform illuminance distribution. It is arranged in the optical path between the plane mirror 23. On the first plane mirror 21 side of the fly-eye lens 22, a shutter 25 that blocks light reflected by the first plane mirror 21 and controls irradiation to the workpiece (substrate) W is disposed.

  The concave mirror 24 is a mirror whose surface shape is a paraboloid, and reflects the reflected light from the second plane mirror 23 to the mask M as parallel light, and is, for example, a collimation mirror. The concave mirror 24 is disposed immediately above the mounting table 30 to be described later in a state facing the mask M so that the light reflected by the second plane mirror 23 is irradiated as parallel light to the mask M to be described later. In the optical system 20 described above, the first plane mirror 21 and the fly-eye lens 22 are installed in the light source chamber 3. The second plane mirror 23 and the concave mirror 24 are installed in the exposure chamber 4.

  The mounting table 30 has a function of moving the workpiece W in alignment, can move in the parallel direction on the mounting surface, can rotate around the vertical axis, and can move the workpiece W in contact with the mask M in the vertical direction. It is configured to be able to move to. A mask frame 31 that supports a mask M on which a desired circuit pattern is formed is disposed immediately above the mounting table 30.

  In the air conditioner 2, the air conditioner 2 and the air outlet 40 are connected by a duct 41 so as to supply air whose temperature and humidity are controlled to an air outlet 40 described later.

  The air blowing port 40 is disposed in the vicinity of the concave mirror 24 so as to blow the air whose temperature and humidity are controlled by the air conditioner 2 along the concave surface of the concave mirror 24. In order to supply clean air along the concave surface of the concave mirror 24, an air purification filter 42 is provided in the air flow path. The air purification filter 42 is preferably a paper filter that adsorbs and removes suspended matters such as dust and dust, and preferably an HEPA filter that adsorbs and removes fine particles or volatile substances such as silicon dioxide and siloxane. Or it is a medium performance filter. Here, the air purification filter 42 is provided on the opening surface of the air blowing port 40. Further, the air outlet 40 has a predetermined angle so that it can be installed near the concave mirror 24 without overlapping the optical path of the light reflected from the second plane mirror 23 toward the concave mirror 24.

  The air guide plate 50 is a curved plate, and the concave mirror 24 is configured so that the air that is blown from the blower opening 40 and passes through the concave surface of the concave mirror 24 is exhausted from the exposure hole 4 described later to the outside of the exposure chamber 4. Is provided on the wall surface of the exposure chamber 4 located on the so-called leeward side facing the air outlet 40 through the concave mirror 24. In addition to mounting the air guide plate 50 on the wall surface of the exposure chamber 4 as shown in FIG. 1, the wall surface of the exposure chamber 4 may be formed in a curved surface so that the air flow is smooth (FIG. 3). (See (a) of FIG. 3 and (b) of FIG. 3).

  A plurality of exhaust holes 60 are provided on the floor surface on which the mounting table 30 is installed so that the air guided to the floor surface on which the mounting table 30 is installed by the air guide plate 50 is discharged out of the exposure chamber 4. It has been. In addition to providing the plurality of exhaust holes 60 on the floor surface on which the mounting table 30 is installed as in the present embodiment, the floor surface on which the mounting table 30 is installed may be formed in a net shape.

  Each component described above is installed in a housing 5 partitioned into a light source chamber 3 and an exposure chamber 4. The light source chamber 3 is a sealed box-shaped space. The exposure chamber 4 is a box-shaped space having an exhaust hole 60 on the floor surface and a work W carry-in / out port (not shown) for carrying in and out the work W on the side surface. In addition, the opening area of the exhaust hole 60 is set wider than the work W carry-in / out area. Therefore, the air supplied into the exposure chamber 4 from the blower port 40 flows in the direction represented by the arrow shown in FIG.

  In the exposure apparatus 1 configured as described above, the air whose temperature and humidity are controlled by the air conditioner 2 passes through the duct 41 from the air conditioner 2, passes through the air purification filter 42 from the blower port 40, and enters the exposure chamber 4. (See FIG. 2). This air flows along the concave surface of the concave mirror 24, is guided to the floor surface provided with the exhaust holes 60 by the baffle plate 50 located on the leeward side, and is discharged out of the exposure chamber 4 through the exhaust holes 60. It should be noted that the blowing speed of the air blown from the blower opening 40 is preferably such that turbulent flow is not generated in the exposure chamber 4. Here, as an example, the blower opening 40 has a speed of 1.5 m / sec. At 50 passes, the speed is 1.2 m / sec. Moreover, control of wind speed etc. is performed with the control valve which is not shown in figure. Note that the air blowing into the exposure chamber 4 is always performed during the operation of the exposure apparatus.

  Since air flows as shown in FIG. 2, volatile substances such as silicon dioxide and siloxane volatilized from the photosensitive resin layer and floating substances such as dust and dust floating in the exposure chamber 4 are pushed by the air to form the concave surface of the concave mirror 24. Then, the air flows along the air guide plate 50 and is discharged out of the exposure chamber 4 through an exhaust hole 60 provided in the floor surface on which the mounting table 30 is installed. Therefore, volatile substances such as silicon dioxide and siloxane that volatilize from the photosensitive resin layer and floating substances such as dust and dust floating in the exposure chamber 4 can be prevented from adhering to the concave surface of the concave mirror 24.

  In addition, since the air purification filter 42 is provided in the air flow path, the air blowing port 40 can blow clean air that has passed through the air purification filter 42 along the concave surface of the concave mirror 24, so that dust or dust is formed on the concave surface of the concave mirror 24. It is possible to more effectively prevent floating substances such as Further, by supplying air whose temperature and humidity are controlled by the air conditioner 2 into the exposure chamber 4, the temperature and humidity around the concave mirror 24 are kept constant, and the surface of the concave mirror 24 is coated. It is possible to prevent deterioration of the reflecting film. Here, the air conditioner 2 supplies air whose temperature is controlled at 22 to 23 ° C. and humidity at 55 to 60%.

  Furthermore, by providing the air guide plate 50, it is possible to prevent air that has passed through the concave surface of the concave mirror 24 from colliding with the wall surface of the exposure chamber 4 and generating turbulent flow in the exposure chamber 4. Further, it is possible to prevent the occurrence of snowdrift in the exposure chamber 4. Thus, by smoothing the air flow, volatile substances and the like can be efficiently discharged from the exposure chamber 4 and the temperature and humidity in the exposure chamber 4 can be efficiently maintained.

It is a perspective view of the state where the exposure apparatus of the present invention was fractured. It is sectional drawing which showed the flow of the air of this invention. (A) is a perspective view of embodiment which provided the baffle plate in the wall surface of the exposure chamber, (b) is the sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 2 Air conditioner 3 Light source room 4 Exposure room 5 Case 10 Light source 11 Mercury short arc lamp 12 Condensing mirror 20 Optical system 21 1st plane mirror 22 Fly eye lens 23 2nd plane mirror 24 Concave mirror 25 Shutter 30 Mounting table 31 Mask frame 40 Air outlet 41 Duct 42 Air purification filter 50 Air guide plate 60 Exhaust hole M Mask W Workpiece

Claims (2)

The light source chamber includes a light source that irradiates light including ultraviolet rays of a predetermined wavelength, a plane mirror that reflects light from the light source along a preset optical path, and a fly-eye lens disposed in the optical path , A concave mirror that reflects light from the light source along a preset optical path, a mask frame that supports a mask installed below the concave mirror, and a substrate that is arranged to face the mask of the mask frame. in the exposure apparatus and a mount table for mounting in the exposure chamber,
A blower port for blowing air along the concave surface of the concave mirror provided in the exposure chamber,
An air purification filter provided in the air flow path;
An exhaust hole for discharging the air that is blown along the concave surface of the concave mirror provided on the floor surface to place the said placing table outside of the exposure chamber,
An exposure apparatus comprising: a curved air guide plate that guides air blown along the concave surface of the concave mirror to the exhaust hole on a wall surface of the exposure chamber facing the air outlet through the concave mirror . The exposure apparatus according to claim 1, wherein the air blowing port is connected to an air conditioner disposed outside the exposure chamber .

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