KR-20260064438-A - METHOD AND APPARATUS FOR PROCESSING WORKPIECE BY USING LASER

KR20260064438AKR 20260064438 AKR20260064438 AKR 20260064438AKR-20260064438-A

Abstract

When forming cavities, etc. by ablation processing, overprocessing is suppressed. A rectangular mask pattern (MP1)(MP2) is formed in a mask (M) used in a laser processing device (100). In the mask pattern (MP1)(MP2), a light-blocking portion (P1)(Q1) is installed along the edge of the pattern corresponding to the sub-scanning direction (Y direction), and a transmission portion (P2)(Q2) is formed in a partition. Due to the complementary pattern shape (geometry) of the light-blocking portion (P1)(Q1) and the transmission portion (P2)(Q2), the light intensity distribution of the laser beam near the edge portion (CR) of the processing area (AR) of the substrate (W) is averaged, thereby suppressing overprocessing into the processing area (AR).

Inventors

후나야마, 마사히코
야마가, 마사루
시미즈, 타이시
카와모토, 유타

Assignees

가부시키가이샤 오크세이사쿠쇼

Dates

Publication Date: 20260507
Application Date: 20250224
Priority Date: 20241030

Claims (9)

For a mask that has formed a mask pattern, a line-shaped laser beam is scanned, and A processing method for performing ablation processing by projecting a pattern beam that has passed through the mask onto a workpiece using a projection optical system, A laser processing method characterized in that, in the above mask pattern, a transmitting part and a light-blocking part, each having a pattern width or pattern size smaller than the resolution according to the wavelength of the line-shaped laser beam and the numerical aperture of the projection optical system, are formed corresponding to the pattern edge according to the main direction.
In paragraph 1, The light-blocking portion is a bar-shaped pattern extending along the edge of the pattern, and A laser processing method characterized in that the above-mentioned transparent portion is formed between the light-blocking portion of the above-mentioned bar-shaped pattern and the edge of the above-mentioned pattern.
In paragraph 2, A laser processing method characterized in that the width corresponding to the direction of the main beam of the light-blocking part is narrower than the width corresponding to the direction of the main beam of the transmission part.
In paragraph 1, A laser processing method characterized by the fact that the light-blocking part and the light-transmitting part each have a rectangular pattern and are alternately aligned along the edge of the pattern.
In paragraph 4, A laser processing method characterized by the light-blocking portion and the light-transmitting portion being in contact with the edge of the pattern.
In paragraph 4, A laser processing method characterized in that the pattern size of the light-blocking portion is smaller than the pattern size of the transmission portion.
In any one of paragraphs 1 through 6, A laser processing method characterized by performing an ablation process to form a cavity on a substrate, which is the workpiece.
A mask used in a laser processing apparatus that performs ablation processing by scanning a line-shaped laser beam and projecting a pattern beam transmitted through the mask onto a workpiece by means of a projection optical system, wherein, regarding the mask, a line-shaped laser beam is scanned and a pattern beam transmitted through the mask is projected onto a workpiece. Having a mask pattern, A mask characterized in that, in the above mask pattern, a transmitting portion and a light-blocking portion are formed along the pattern edge of the mask pattern, each having a pattern width or pattern size smaller than the resolution according to the wavelength of the line-shaped laser beam and the numerical aperture of the projection optical system.
A mask having the mask pattern described in claim 8, a mask stage capable of supporting the pattern edge of the mask pattern so as to follow the direction of the shareholder, and A line-shaped beam forming unit that forms a line-shaped beam based on a laser beam emitted from a light source, and An injection device for injecting the line-shaped beam onto the above mask, and A projection optical system that projects the above-mentioned line-shaped beam onto a workpiece, and A machining stage capable of supporting the above workpiece, A laser processing device characterized by having [ ]

Description

Laser processing method, laser processing apparatus and mask The present invention relates to a laser processing device, and in particular to a mask pattern and a processing method. With the miniaturization and high-density packaging of electronic devices, high-precision pattern formation is required for printed circuit boards and the like. For example, on stacked boards, it is necessary to form fine vias or trenches on the order of μm. As a method for performing micro-machining, ablation processing is performed. In this method, high-energy density laser light is projected onto a workpiece, such as a substrate, while scanning it against a mask. By instantaneously evaporating and removing the surface of the material according to the mask pattern, vias or wiring grooves can be formed on the substrate (for example, see Patent Document 1). When a cavity is formed by irradiating a substrate with a high-frequency laser beam, a problem arises in which the bottom surface of the corner portion is engraved more deeply than other surfaces due to wall reflection, impact caused by gasification, and high temperature of the gas. To prevent this, the irradiation area and irradiation time of the laser beam are varied, and the corner portion is formed into a stepped shape or an R shape (see Patent Document 2). By increasing the mechanical strength of the corner portion, crack formation is suppressed. FIG. 1 is a schematic diagram of a laser processing device according to the present embodiment. Figure 2 is a schematic block diagram of a laser processing device. Figure 3 is a drawing illustrating a mask pattern. Figure 4 is a diagram showing the cross-sectional intensity distribution of the optical image and the processing cross-section of the substrate when a line-shaped laser beam is irradiated onto the substrate. Figure 5 is a diagram showing the light intensity distribution by simulation. Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a laser processing device according to the present embodiment. FIG. 2 is a schematic block diagram of a laser processing device. A laser processing device (100) is a processing device capable of forming a pattern on a substrate (W) by ablation processing, and is equipped with a line beam forming unit (20), a projection optical system (30), a mask stage (40), and a processing stage (50). The line beam forming unit (20), the mask stage (40), and the processing stage (50) are mounted on a device body not shown and are movable relative to the device body. The mask (M) and the substrate (W) are mounted on the mask stage (40) and the processing stage (50), respectively. The substrate (W) is composed of a resin substrate, such as a printed circuit board, in this case. A laser (10) installed next to the main body of the device emits high-energy density laser light. Here, an excimer laser that pulses KrF excimer laser light with a wavelength of 248 nm is applied. The laser light emitted from the laser (10) reaches the line beam forming unit (20) through a correction optical system for adjusting the optical axis, which is not shown. The laser (10) may be configured as part of the laser processing device (100) or as a separate device. The line beam forming unit (20) is equipped with an optical system including a lens array (24), a line beam forming optical system (25) including a laser light cylindrical lens, and an angle-changing mirror (26). The lens array (24) adjusts the intensity distribution of the incident laser light. The line beam forming optical system (25) shapes the beam beam of the incident laser light into a line-shaped laser beam (LB). The line beam forming unit (20) accommodates an optical system, such as a line beam forming optical system (25), in its casing (20K), and the casing (20K) is supported by a scanning mechanism (60). The scanning mechanism (60) can move the line beam forming unit (20) at a predetermined speed along the main scanning direction (X direction), and can move the line-shaped laser beam (LB) relative to the mask (M) in the main scanning direction (X direction). An angle-switching mirror (21) installed in the line beam forming unit (20) shifts the irradiation position of the line-shaped laser beam (LB) on the mask (M) along the sub-scanning direction (Y direction) by switching its angle (position). That is, it is possible to switch the scanning area. Here, the angle-switching mirror (21) is installed in a co-position between the lens array (24) and the line beam forming optical system (25). The mask stage (40) can support the mask (M) and simultaneously move and rotate it in the main scanning direction (X direction) and the sub-scanning direction (Y direction) which is the scanning width direction of the line-shaped laser beam (LB). The mask stage moving mechanism (70) drives the mask stage (40) based on a signal output from an encoder for position detection not shown. The projecti