JP2005084420A - Manufacturing method for fly-eye lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a fly-eye lens proof against use under high temperature, maintaining the accuracy of each lens simple body, and prevented from causing a problem such as the dispersion of illuminance distribution. <P>SOLUTION: A lens group in which the lens simple bodies 1 coated with an adhesive are arranged crosswise is housed in a square holding frame 2 surrounding the periphery of the lens group, and tightening screws 3 of a number corresponding to the number of the lens matrix of the lens group disposed in the square holding frame 2 are tightened, whereby the lens group is firmly held in the square holding frame 2, and the lens simple bodies are heated and bonded by fusing in such a state. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a fly-eye lens, more specifically, a small convex lens (lens alone) used in a stepper (reduction projector), an exposure apparatus for a printed wiring board, or the like, which is a processing device for VLSI. It is related with the manufacturing method of the fly eye lens comprised.

  A fly-eye lens is an imaging element in which a large number of the same lens elements are arranged vertically and horizontally, producing multiple images of the number of lens elements constituting the same, and many point images can be obtained when the light source is a point. In order to improve and improve the optical characteristics of the illumination system, it is used in various exposure apparatuses and steppers.

  As a manufacturing method of a fly-eye lens, a single lens, which is a small convex lens, is manufactured one by one, and each lens unit is joined to form an assembly of convex surfaces and integrally molded using a mold. There is a method. In the former method, for example, in the case of a 5-row × 5-row fly-eye lens, first, five lens single bodies 31 are arranged in one row by applying an adhesive 32 on the side surface (FIG. 3A). Adhere and integrate in one row (FIG. 3B).

  The lens array 33 is created by bringing the side surfaces of the lens unit 31 applied with the adhesive 32 into close contact with each other and placing them in a heating furnace in this state. By heating in the heating furnace, the adhesive 32 is melted, and the lens units 31 are bonded to each other.

  In this way, five lenses are integrated into five rows, and the adhesive 32 similar to the above is applied to the longitudinal side surfaces thereof to bond the side surfaces to each other (FIG. 3C). A fly-eye lens that is an aggregate of × 5 rows of single lenses is finished (FIG. 3D).

  When joining the rows, use two fastening brackets 34 as shown in FIGS. 4 (A) and 4 (B), tighten the fastening screws 35, and pressurize the lens rows 33 from both ends while heating. Finish by welding.

  Since the use environment of the fly-eye lens is often high, an inorganic adhesive or a ceramic adhesive that can withstand high temperatures is used as the adhesive. However, in the case of these adhesives, since it is difficult to apply thinly and uniformly, the thickness of the adhesive layer becomes a problem. That is, if the thickness of the adhesive layer varies, each lens unit may be misaligned (see FIG. 5B), which causes variations in parallel light and illuminance distribution (focus). Further, due to variations in the adhesive layer, changes occur in the right angle and perpendicularity of the lens side surface, resulting in a difference in the amount of incident light and the amount of light at the output destination, resulting in poor uniformity.

In addition, as the manufacturing method of the fly-eye lens, the following is applied, but all of them are integrally molded from the beginning using a mold, and are different from the manufacturing method according to the present invention. Is.
JP-A-6-144842 JP 7-156284 A JP-A-8-26746 JP 2000-56101 A

  The present invention was made to eliminate the drawbacks in the above conventional fly-eye lens manufacturing method in which single lenses are joined vertically and horizontally to withstand the use at high temperatures, and the accuracy of each single lens is improved. It is an object of the present invention to provide a method for manufacturing a fly-eye lens that is maintained and does not cause problems such as variations in illuminance distribution.

  The invention according to claim 1 for solving the above-mentioned problem is that a lens group in which a single lens coated with an adhesive is arranged vertically and horizontally is accommodated in a rectangular holding frame that surrounds the lens group, and disposed in the holding frame. By tightening a number of tightening screws corresponding to the number of lens matrixes of the lens group, the lens group is firmly held in the holding frame, and in this state, the single lenses are heated and welded together. The fly eye lens manufacturing method.

  Further, the invention according to claim 2 for solving the above problem is characterized in that a holding frame made of the same material as that of the lens itself is used, and the invention according to claim 3 is characterized in that the holding The fastening screw of the frame is made of the same material as the holding frame.

  The invention according to claim 4 for solving the above-mentioned problem is characterized in that a reinforcing frame is fixed around a lens assembly formed by joining single lenses vertically and horizontally, and The invention according to claim 5 is that the reinforcing frame is made of the same material as that of the single lens.

  The invention according to claim 6 for solving the above-mentioned problem is characterized in that the adhesive is printed on the adhesive surface of the lens by a printing method such as a silk screen.

  According to the manufacturing method using the holding frame according to claim 1, even if the thickness of the adhesive layer between a large number of lens elements arranged side by side varies, the tightening degree of each tightening screw is adjusted. Therefore, it is possible to prevent the deviation of the single lens.

  According to the manufacturing method using the holding frame made of the same material as each lens unit to be bonded vertically and horizontally according to claim 2 and 3, the lens group to be joined and the holding frame surrounding the periphery thereof are the same material. Since the expansion coefficient is the same, there is no possibility that the lens is destroyed due to the difference in expansion coefficient during the heat treatment, and there is an effect that the accuracy after adjustment can be maintained.

  According to the fly-eye lens provided with the reinforcing frame around the lens array according to claim 4 and 5, since the peripheral portion is protected by the reinforcing frame, the end portion of the peripheral lens unit is prevented from being lost. Furthermore, in order to lower the transmittance, the fly-eye lens is often vapor-deposited. However, when the fly-eye lens is gripped during the process, it can have a reinforcing frame so that it can be gripped easily and stably. There is an effect that becomes possible.

  According to the manufacturing method in which the adhesive according to claim 6 is printed on the adhesive surface of the lens by a printing method such as silk screen, there is an effect that the thickness of the adhesive layer is not varied and a uniform adhesive layer can be obtained. .

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the first manufacturing method of a fly-eye lens according to the present invention, a lens group in which a single lens 1 coated with an adhesive is arranged vertically and horizontally is housed in a rectangular holding frame 2 surrounding the periphery of the lens group. By tightening the number of tightening screws 3 corresponding to the number of lens matrixes of the lens group, the lens group is firmly held in the holding frame 2, and the lens units 1 are heated and welded together in this state. That's it.

  In that case, it is preferable to use a holding frame 2 made of the same material as each lens unit 1 to be integrated. That is, the lens unit 1 is usually made of quartz glass (synthetic quartz glass), but the holding frame 2 is also made of the same quartz glass. The holding frame 2 has a quadrangular shape, and is provided with a number of tightening screws 3 corresponding to the number of rows of the lens unit 1 on two to four sides. More preferably, the tightening screw 3 is also made of the same material (usually quartz glass) as the holding frame 2.

  When a fly-eye lens is manufactured using the holding frame 2, the lens unit 1 and the holding frame 2 (and the fastening screw 3) are made of the same material and have the same thermal expansion coefficient during the heat treatment in the heating furnace. Therefore, there is no possibility that the lens unit 1 is excessively pressed and crushed due to the difference, or partially cracked due to overheating.

  The adhesive used in the present invention is preferably made of a heat melting glass powder generally called frit as a main raw material. The same applies to the following manufacturing methods.

  The second manufacturing method of the fly-eye lens according to the present invention includes a reinforcing frame 5 having an appropriate width around a lens assembly 4 formed by joining the lens unit 1 vertically and horizontally by the first method or the other method. It is characterized by fixing. The material of the reinforcing frame 5 is not particularly limited and may be made of metal, but is preferably made of the same material as that of the lens unit 1. The reinforcing frame 5 is preliminarily assembled into a quadrangle, and the lens assembly 4 may be fitted therein, or it may be disassembled and adhered to the periphery of the lens assembly 4 later. You may do.

  The fly-eye lens often does not use the outermost periphery when the number of constituent lenses is large. Therefore, even if the reinforcing frame 5 is present, the function as the fly-eye lens is not hindered. Further, since the peripheral portion is protected by the reinforcing frame 5, it is possible to prevent the end portion of the lens unit 1 at the peripheral portion from being lost. Further, in order to reduce the transmittance, the fly-eye lens is often subjected to vapor deposition processing. However, when the fly-eye lens is gripped during the processing, the reinforcing frame 5 can be gripped, so that it can be gripped easily and stably. Is possible.

  A third method for producing a fly-eye lens according to the present invention is characterized in that an adhesive is printed on the adhesion side surface of each lens unit 1 by a printing method such as a silk screen. In this case, the printing of the adhesive is performed in a state in which a large number of lens units 1 are raised with the adhesive side face up.

  According to this method, it is possible to provide the adhesive layer with a desired uniform thickness, thereby preventing the lens unit 1 from being misaligned due to the non-uniformity of the adhesive layer. This third method can be used in combination with the first and second methods.

It is a figure which shows the 1st method of the manufacturing method of the fly eye lens which concerns on this invention. It is a figure which shows the 2nd method of the manufacturing method of the fly eye lens which concerns on this invention. It is a figure which shows the manufacturing method of the conventional fly eye lens. It is a figure which shows the jig | tool used for the manufacturing method of the conventional fly eye lens. It is a figure which shows the center-alignment state of a lens single-piece | unit.

Explanation of symbols

1 Lens unit 2 Holding frame 3 Tightening screw 4 Lens assembly 5 Reinforcing frame

Claims (6)

  A lens group in which a single lens to which an adhesive is applied is arranged vertically and horizontally is housed in a rectangular holding frame that surrounds the lens group, and a number of tightenings corresponding to the number of lens matrixes of the lens group disposed in the holding frame A method of manufacturing a fly-eye lens, wherein the lens group is firmly held in the holding frame by tightening a screw, and the single lenses are heated and welded in this state.   The method for manufacturing a fly-eye lens according to claim 1, wherein the holding frame is made of the same material as the lens itself.   The method for manufacturing a fly-eye lens according to claim 2, wherein the fastening screw of the holding frame is made of the same material as the holding frame.   A method for manufacturing a fly-eye lens, comprising fixing a reinforcing frame around a lens assembly configured by joining a single lens vertically and horizontally.   The method for manufacturing a fly-eye lens according to claim 4, wherein the reinforcing frame is made of the same material as the lens itself.   A method for producing a fly-eye lens, characterized in that an adhesive is applied to a joint side surface of the lens unit by a printing method such as a silk screen.

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