JP3194250B2 - 2-axis laser processing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a two-axis laser beam machine.

[0002]

2. Description of the Related Art In the manufacture of a high-density multilayer printed circuit board, holes (via holes) such as inner vias and blind vias are formed in an insulating resin disposed between wiring patterns in order to perform interlayer connection of laminated wiring patterns. There is a need to.

[0003] In the past, via holes were formed by a mechanical drill or an exposure method (photolithography technique), but recently, in order to meet the demand for higher density, a via hole having a smaller diameter can be formed. Techniques using laser light have been used. And
In order to form a via hole more efficiently using a technique using laser light, a two-axis laser processing machine that uses a laser light from a laser oscillator by splitting it into two waves, an S wave and a P wave, has been developed. .

As shown in FIG. 2, a conventional two-axis laser beam machine includes a laser oscillator 21 for generating a laser beam, and a polarization splitter 22 for splitting the laser beam from the laser oscillator 21 into a P wave and an S wave. A mirror 23, and first and second galvanometer scanners 26, for scanning P and S waves on the surfaces of the first and second workpieces 24, 25, respectively.
27, and first and second fθ lenses 28, which cause the P wave and the S wave from each of the galvano scanners 26, 27 to be perpendicularly incident on the surfaces of the first and second workpieces 24, 25, respectively.
29.

[0005] The laser beam emitted from the laser oscillator 21 is split into two by a polarization splitter 22 into a P-wave and an S-wave. The P-wave is reflected by the polarization splitter 22, incident on a first galvano scanner 26, scanned, passes through a first fθ lens 28, and irradiates a first workpiece 24. The S-wave is transmitted through the polarization splitter 22, guided to a second galvano scanner 27 by a mirror 23, scanned, passed through a second fθ lens 29, and irradiated on a second workpiece 25. . Each workpiece 2
In Nos. 4 and 25, laser ablation is caused by the irradiation of the P wave or the S wave, and a via hole is formed.

[0006]

The conventional two-axis laser beam machine requires a fθ lens for each of the two branched laser beams, which is expensive.

[0007] Further, in the conventional two-axis laser beam machine, since two workpieces are arranged side by side, there is also a problem that the footprint is large.

An object of the present invention is to provide an inexpensive and compact two-axis laser beam machine.

[0009]

According to the present invention, a laser oscillator for generating a laser beam, a beam splitter for splitting the laser beam into two, and the laser beam split by the beam splitter are independently provided. First and second galvano scanners for scanning, fθ lenses for vertically irradiating the workpiece with laser light from the first and second galvano scanners, and the first and second galvanometers; Laser light from the galvano scanner
and a mixer for causing incident on θ lens, the amount
The two branched laser beams are different from each other on the workpiece.
A two-axis laser beam machine characterized by irradiating a position is obtained.

Here, the beam splitter includes:
A polarizing beam splitter that splits the laser light into a P wave and an S wave can be used. As the mixer, a polarizing mixer that guides both the P wave and the S wave to the fθ lens can be used.

[0011] Further, as the laser oscillator, CO ₂
A gas laser oscillator can be used.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a two-axis laser beam machine according to an embodiment of the present invention. The two-axis laser beam machine includes a CO ₂ gas laser oscillator 11 for generating a laser beam, and a polarizing beam splitter 12 for splitting the laser beam into a P wave and an S wave.
, Mirrors 13 and 14, a first galvano scanner 16 for scanning P-waves on the workpiece 15, and a second galvano scanner 1 for scanning S-waves on the workpiece 15.
7 and a polarization mixer 1 that transmits P waves and reflects S waves
8 and the laser light (P wave and S
Fθ to irradiate the workpiece 15 vertically to the workpiece 15
A lens 19.

Although not shown, an attenuator for attenuating the laser beam, a uniform optical system for uniformizing the intensity distribution of the laser beam, and a mask for limiting the beam diameter are provided as necessary. , Provided between the laser oscillator 11 and the polarization beam splitter 12.

Next, the operation of the two-axis laser beam machine will be described.

The CO ₂ gas laser oscillator 11 generates a laser beam in which a P wave and an S wave are mixed. The laser light emitted from the CO ₂ gas laser oscillator 11 is polarized by the polarization splitter 1.
2 is incident.

The polarization splitter 12 reflects a P-wave of the incident laser light. Also, the polarization splitter 12
Transmits an S-wave of the incident laser light. The P-wave reflected by the polarization splitter 12 enters the first galvano scanner 16. The S wave transmitted through the polarization splitter 12 is reflected by the mirrors 13 and 14 and enters the second galvano scanner 17.

The first galvano scanner 16 has two mirrors rotatably mounted on two axes orthogonal to each other, and scans the incident P wave on the surface of the workpiece 15. Thus, the traveling direction can be changed. The first galvano scanner 16 emits the P-wave so that the P-wave is applied to the first target position of the workpiece 15. Similarly, the second galvano scanner 17
It has two mirrors rotatably mounted on two axes orthogonal to each other, and can change its traveling direction so that the incident S wave is scanned on the surface of the workpiece 15. This second galvano scanner 17
The S-wave is emitted so that the S-wave is applied to the second target position of the workpiece 15. Here, the first galvano scanner 1
6 and the second galvano scanner 17 operate independently of each other, and the first target position and the second target position can be different from each other. The P wave from the first galvano scanner 16 and the S wave from the second galvano scanner 17 both enter the polarization mixer 18.

The polarization mixer 18 transmits the P wave from the first galvano scanner 16. Further, the polarization mixer 18 reflects the S wave from the second galvano scanner 17. Here, the first galvano scanner 16, the second galvano scanner 17, and the polarization mixer 18 have a scan range of the P wave transmitted through the polarization mixer 18 and a scan range of the S wave reflected by the polarization mixer 18. Are arranged to match.

The P wave transmitted through the polarization mixer 18 and the S wave reflected by the polarization mixer 18 are both the fθ lens 1
9 is incident. lens 19 changes the traveling direction so that the P wave and the S wave from the polarization mixer 18 are perpendicularly incident on the workpiece 15. The P wave and the S wave transmitted through the fθ lens 19 are irradiated on the workpiece 15.

As described above, according to the present embodiment, two laser beams of P-wave and S-wave are used for a single workpiece (processed area), and the laser light is independently controlled to form a via hole. Can be formed.

In this embodiment, a CO ₂ gas laser oscillator is used as the laser oscillator. However, another gas laser oscillator such as an excimer laser oscillator or a solid laser oscillator such as a YAG laser oscillator may be used.

[0023]

According to the present invention, a single laser beam 2 is branched to scan each independently by a so as to irradiate the workpiece through a single fθ lens, high-efficiency machining And an inexpensive and compact two-axis laser beam machine can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a two-axis laser beam machine according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a configuration of a conventional two-axis laser beam machine.

[Explanation of symbols]

REFERENCE SIGNS LIST 11 CO ₂ gas laser oscillator 12 polarizing beam splitter 13, 14 mirror 15 workpiece 16 first galvano scanner 17 second galvano scanner 18 polarization mixer 19 fθ lens 21 laser oscillator 22 polarization beam splitter 23 mirror 24 first processing Object 25 Second workpiece 26 First galvano scanner 27 Second galvano scanner 28 First fθ lens 29 Second fθ lens

Continued on the front page (51) Int.Cl. ⁷ Identification code FI // B23K 101: 42

Claims (3)

(57) [Claims] 1. A laser oscillator for generating a laser beam, a beam splitter for splitting the laser beam into two, and a laser beam split by the beam splitter.
First and second galvanometer scanners for independently scanning, an fθ lens for vertically irradiating a workpiece with laser light from the first and second galvanometer scanners, and the first and second galvanometers; and a mixer for causing incident on both the fθ lens of the laser beam from the second galvano-scanner, the object of the two laser beams the branched
A two-axis laser beam machine characterized by irradiating different positions on a workpiece. 2. The beam splitter according to claim 1, wherein the beam splitter is a polarizing beam splitter that splits the laser light into a P wave and an S wave, and the mixer guides both the P wave and the S wave to the fθ lens. The two-axis laser beam machine according to claim 1, which is a polarization mixer. 3. The two-axis laser beam machine according to claim 1, wherein said laser oscillator is a CO ₂ gas laser oscillator.