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KR-20260064437-A - METHOD AND APPARATUS FOR PROCESSING WORKPIECE BY USING LASER

KR20260064437AKR 20260064437 AKR20260064437 AKR 20260064437AKR-20260064437-A

Abstract

The present invention suppresses overprocessing when forming cavities, etc. by ablation processing. Ablation processing is performed using a rectangular first mask pattern (MP1) in a laser processing device (100). Then, ablation processing is performed using a rectangular second mask pattern (MP2). The width (B1) corresponding to the sub-scanning direction (Y direction) of the first mask pattern (MP1) and the width (B1) corresponding to the sub-scanning direction (Y direction) of the second mask pattern (MP2) are opposite, and the width is narrower by the amount of ringing (parts of light intensity change) that occur at both ends of the line-shaped laser beam (LB).

Inventors

  • 후나야마, 마사히코
  • 야마가, 마사루

Assignees

  • 가부시키가이샤 오크세이사쿠쇼

Dates

Publication Date
20260507
Application Date
20250224
Priority Date
20241030

Claims (11)

  1. Regarding the mask, 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 above mask onto a workpiece, For the above mask, a plurality of rectangular mask patterns with different widths corresponding to the auxiliary scanning direction are formed, and A laser processing method characterized by flattening the bottom surface of a processing pattern formed in a processing area by repeatedly processing a predetermined processing area of a workpiece using a plurality of rectangular mask patterns.
  2. In paragraph 1, A laser processing method characterized by forming a first mask pattern and a second mask pattern that is narrower than the first mask pattern only by an amount corresponding to the ringing of the line-shaped laser beam, with respect to the above mask.
  3. In paragraph 2, A laser processing method characterized by reducing the energy density of the line-shaped laser beam when processing the processing area using the second mask pattern compared to when processing the processing area using the first mask pattern.
  4. In paragraph 2, A laser processing method characterized by performing ablation processing on the above processing area using the first mask pattern to make it shallower than the target depth, and then performing ablation processing using the second mask pattern to reach the target depth.
  5. In paragraph 4, A laser processing method characterized by performing ablation processing on the processing area using the first mask pattern to reach a depth of 80% or more of the target depth.
  6. In paragraph 2, A laser processing method characterized by forming the first and second mask patterns on a single mask.
  7. In paragraph 6, A laser processing method characterized by regularly forming multiple first and second mask patterns in pairs for the single mask above.
  8. In any one of paragraphs 1 through 7, A laser processing method characterized by performing an ablation process to form a cavity on a substrate, which is the workpiece.
  9. Each has a first mask pattern and a second mask pattern that are rectangular and parallel along a predetermined direction, The lengths of the first and second mask patterns according to a predetermined direction are equal, and The width according to the direction perpendicular to the predetermined direction of the first and second mask patterns is superior, and A mask characterized in that the width corresponding to the direction perpendicular to a predetermined direction of the second mask pattern is narrower than the first mask pattern only to the extent that it corresponds to the ringing of a line-shaped laser beam.
  10. As a processing device that performs ablation processing by a laser beam, A line-shaped beam forming unit that forms a line-shaped laser beam from a laser beam emitted from a light source, and A mask stage capable of supporting a mask having a first rectangular mask pattern and a second rectangular mask pattern having a width narrower than the first mask pattern in the sub-scanning direction, only to the extent corresponding to the ringing of the line-shaped laser beam, and capable of moving the mask in the scanning direction and the sub-scanning direction; An injection device for injecting the above-mentioned line-shaped laser beam, and A projection optical system that projects a pattern beam transmitted through the above mask onto a workpiece, and A processing stage capable of moving the above workpiece in the injection direction and the auxiliary injection direction, and The apparatus comprises a control unit that controls the light source, the scanning mechanism, the mask stage, and the processing stage, and A laser processing device characterized by the above-described control unit controlling the light source, the scanning mechanism, the mask stage equipped with the mask, and the processing stage to flatten the bottom surface of a processing pattern formed in a processing area, and performing repetitive processing on the processing area using the first and second mask patterns.
  11. Regarding the mask, 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 above mask onto a workpiece, Regarding the above mask, a plurality of mask patterns are formed in which the widths of the pattern edges intersecting in directions corresponding to the auxiliary scanning direction are different from each other and are analogous to each other. A laser processing method characterized by flattening the bottom surface of a processing pattern formed in a processing area by repeatedly processing a predetermined processing area of a workpiece using the plurality of mask patterns.

Description

Laser processing apparatus, laser processing method and mask {METHOD AND APPARATUS FOR PROCESSING WORKPIECE BY USING LASER} 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 process, 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 in accordance with 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 a cross-section of a substrate during laser processing. Figure 5 is a diagram showing the cross-sectional intensity distribution of an optical image when a line-shaped laser beam is irradiated onto a substrate. Figure 6 is a diagram illustrating the flow of the ablation process. 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 equipped on a device body not shown and are movable relative to the device body. A mask (M) and a 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) passes through a correction optical system for adjusting the optical axis (not shown) and reaches a line beam forming unit (20). 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 switching mirror (26, 27). 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). For example, as a line-shaped laser beam (LB), it is possible to shape it into a rectangular beam with a length direction of 26 mm and a width direction of 0.1 mm on the mask surface. 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 scanning direction (X direction), and the line shape laser beam (LB) can move relative to the mask (M) in the 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) supports the mask (M) and can also move and rotate it in the scanning direction (X direction) and the sub-sc