TW201834776A - Laser processing device and laser processing method - Google Patents

Abstract

To shorten a processing time when processing of a substrate is performed. A laser processing device having an acousto-optic modulator which branches a laser pulse output from a laser oscillator into a processing direction and a non-processing direction, comprises an acousto-optic modulator control part which outputs a branch operation control signal for controlling branch operation of the acousto-optic modulator. The acousto-optic modulator control part outputs the branch operation control signal which branches the laser pulse into the processing direction during a first specified period before a start of attenuation of the laser pulse and during a second specified period after the start of attenuation of the laser pulse.

Description

Laser processing device and laser processing method

The present invention relates to a laser processing apparatus and a laser processing method for performing processing on a substrate using a laser.

For example, in the case where drilling is performed on a substrate in which a metal layer is laminated on a resin layer, as disclosed in Patent Document 1, the metal layer is drilled by a laser pulse wave from a previous stage of the laser oscillator. Then, a method of drilling the resin layer under the metal layer that has been perforated by the laser pulse in the subsequent stage is performed. However, this method has the disadvantage of long processing time because individual laser pulses are used on the metal layer and the resin layer. In contrast, there is a method of taking out two laser pulses for processing a metal layer and a resin layer for processing one laser pulse from a laser oscillator, but the attenuation of the laser pulse is Before the start, two types of laser pulses for processing were taken out. With this method, it is necessary to lengthen the period before the laser pulse attenuation. This method must lengthen the period of the laser pulse in the characteristics of the laser oscillator. As a result, it has the disadvantage of longer processing time. [Antecedent technical documents] [Patent documents]

[Patent Document 1] Japanese Patent Laid-Open No. 2001-313471

[Problems to be Solved by the Invention]

It is an object of the present invention to reduce processing time when processing is performed on a substrate. [Means to solve the problem]

Among the inventions disclosed in this patent application, a representative laser processing device includes a laser oscillator that oscillates a laser pulse wave, and extracts a processing pulse based on the laser pulse wave output from the laser oscillator. The acousto-optic modulator of the wave is characterized in that a control section for controlling the acousto-optic modulator is provided to take out each of the continuous laser pulse waves, and take out different energy during the oscillation period of the laser pulse wave. For a plurality of processing pulses, one processing position is processed with the above-mentioned plurality of processing pulses taken from the same laser pulse.

Also, among the inventions disclosed in this patent application, a representative laser processing method is to input a laser pulse wave oscillated by a laser oscillator into an acousto-optic modulator, and take out the processing pulse wave with the acousto-optic modulator. It is characterized in that the acousto-optic modulator, for each continuous laser pulse, extracts a plurality of processing pulses with different energies during the oscillation period of the laser pulse. The above-mentioned plural processings for taking out the laser pulse wave are processed with a pulse wave. [Inventive effect]

According to the present invention, since a plurality of processing pulse waves are taken out from one laser pulse wave, the processing time can be shortened.

[Example]

FIG. 2 is a block diagram of a laser drilling device according to an embodiment of the present invention. In Fig. 2, the substrate 1 to be drilled is placed on a tabletop (not shown). 2 is a laser oscillator that oscillates the laser pulse wave L1. 3 is the acousto-optic modulator (hereinafter referred to as AOM) that divides the laser pulse wave L1 output from the laser oscillator 2 into the processing direction and the non-processing direction, 4 is the lightning that will be divided into the processing direction at AOM3 The pulse wave L2 irradiates a Galvano scanner at the drilling position of the substrate 1. The Galvano scanner 4 scans the laser pulse wave L2 by rotating. 5 is a damper that absorbs the laser pulse wave L3 that is diverged to the non-processing direction in AOM3.

6 is an overall control unit that controls the overall operation of the device. For example, it is realized by a program-controlled processing device, which includes several elements. 7 is a laser oscillation control unit that outputs a laser oscillation command signal S that indicates the oscillation of each laser pulse L1 in the laser oscillator 2, and 8 is an AOM control unit that outputs an AOM drive signal D that controls the branching operation of AOM3. 9 is a Galvano control section that outputs a Galvano motion control signal G that instructs the operation of the Galvano scanner 4. Some or all of these control sections may be provided separately from the entire control section 6. In addition, in FIG. 2, each constituent element or connection line is mainly shown in order to explain the necessity of the present embodiment, and the laser drilling device does not necessarily mean that all of them are shown.

FIG. 1 is a timing chart of the laser drilling device shown in FIG. 2. The Galvano motion control signal G is turned on each time the hole machining at a new position is performed, and the Galvano scanner 4 is rotated, and the Galvano scanner 4 is stopped when closed. Once the Galvano action control signal G is turned off, the laser shock command signal S is turned on for a predetermined time, and the laser pulse wave L1 from the laser oscillator 2 starts to rise. Once the laser shock command signal S is turned off, the laser shock Device 2 starts the attenuation of laser pulse L1. Once the laser oscillation command signal S is turned on, the AOM driving signal D is turned on for t2 time after the time t1 after being turned on, and once the laser oscillation command signal S is turned off, the AOM driving signal D is turned on after the time t3 after the turning off. Turn on t4 time. In the time period when the AOM drive signal D is on, the laser pulse wave L1 input to AOM3 is branched into the processing direction and given to the Galvano scanner 4 as the laser pulse wave L2. In the time zone when the AOM drive signal D is turned off, the laser pulse wave L1 input to the AOM3 is branched to the non-processing direction and given to the shutter 5 as the laser pulse wave L3.

That is, in the present embodiment, during the laser pulse wave L1 output from the laser oscillator 2 once for processing a hole, before the energy of the laser pulse wave L1 reaches a peak, that is, before the laser AOM drive signal for a specific time zone t2 before the pulse wave L1 begins to decay and the energy of the laser pulse wave L1 after a peak, that is, a specific time zone t4 after the laser pulse L1 begins to decay D is output back and forth. When the AOM drive signal D is turned off for the second time, the electrical operation control signal G is turned on. In order to perform hole processing at a new position, the Galvano scanner 4 starts to rotate.

FIG. 3 is a cross-sectional view for explaining a process performed when drilling is performed on a substrate on which a metal layer is laminated on a resin layer according to the laser drilling device described above. (a) indicates the state before processing, (b) indicates the state during processing, and (c) indicates the state after processing. In FIG. 3, 22 is a metal layer on the surface side of the substrate to be perforated, for example, a copper foil, 23 is a resin layer below the metal layer 22, and 24 is under the resin layer 23, for example A metal layer made of copper foil.

Once the above laser drilling position is used, as shown in the first figure, the laser pulse wave L2 with a large critical value of output energy at a specific time zone t2 during the period from the start of the attenuation of AOM3, therefore, As shown in FIG. 3 (b), the metal layer 22 having a high critical value of the processing energy located mainly on the surface side of the substrate 1 is processed. After that, as shown in FIG. 3 (c), at a specific time zone t4 during the next period after the start of the decay, the resin layer 23 having a low critical value of processing energy is processed, and finally the holes 25 reaching the metal layer 24 are processed. form.

According to the above embodiment, when drilling is performed on the substrate 1 on which the metal layer 22 is laminated on the resin layer 23, before the attenuation of the laser pulse wave L1 oscillated from the laser oscillator 2 is started, the The metal layer 22 is processed, and the resin layer 23 is processed during the period after the attenuation starts, so the period before the attenuation of the laser pulse L1 does not become particularly long, and only one laser pulse can be borrowed Both the metal layer 22 and the resin layer 23 are processed. In addition, on the resin layer 23 with a low critical value of the processing energy, the extracted laser pulse wave is used during the period when the energy after the attenuation is small, so the energy is too large, and the shape of the holes in the resin layer 23 is not caused. Worse. Therefore, high-speed and high-quality hole processing can be realized.

In the foregoing, the present invention has been described mainly by way of examples. The examples are for easy understanding of the examples of the present invention. Various modifications can be implemented by replacing the constituent elements in the embodiments or adding other elements. Therefore, the present invention is not limited to the examples.

For example, in the above embodiment, the AOM driving signal D is turned on only once during the period after the attenuation is started, but it is also possible to perform multiple-turn processing by turning on the AOM driving signal D twice during the period. This method can alleviate the impact on the resin layer 23 and can perform drilling of excellent quality in this area. It is also possible to suppress the impact on the metal layer 24. Also, in the above embodiments, the case where holes are performed on the substrates in which the respective metal layers 22 and 24 are laminated above and below the resin layer 23 is described, but it may be a laminated substrate of another material having a different critical value of processing energy. For example, a ceramic layer may be used instead of the resin layer 23.

1‧‧‧ substrate

2‧‧‧laser oscillator

3‧‧‧AOM

4‧‧‧Galvano scanner

5‧‧‧ Gate

6‧‧‧All control department

7‧‧‧laser shock control unit

8‧‧‧AOM Control Department

9‧‧‧ Galvano Control Department

22, 24‧‧‧ metal layer

23‧‧‧resin layer

25‧‧‧ Hole

D‧‧‧AOM drive signal

G‧‧‧Galvano motion control signal

L1 ~ L3‧‧‧‧Laser Pulse

S‧‧‧laser shock command signal

[Fig. 1] is a timing chart of a laser drilling device according to an embodiment of the present invention. [Fig. 2] A block diagram of a laser drilling device according to an embodiment of the present invention. [Figure 3] is a cross-sectional view for explaining the processing of a laser hole-opening device according to an embodiment of the present invention.

Claims (5)

A laser processing device includes a laser oscillator that oscillates a laser pulse wave, and an acousto-optic modulator that extracts a processing pulse wave based on the laser pulse wave output from the laser oscillator, and is characterized by: A control unit for controlling the acousto-optic modulator is provided for each continuous laser pulse, and during the oscillation period of the laser pulse, a plurality of processing pulses with different energy are taken out, and one processing position will Processing is performed by the above-mentioned plural processing pulses taken from the same laser pulse. The laser processing device according to item 1 of the scope of the patent application, wherein the plurality of processing pulses taken out by the acousto-optic modulator reduce the energy of the subsequent processing pulses compared to the preceding processing pulses. The energy is low. A laser processing method, in which a laser pulse oscillated by a laser oscillator is input to an acousto-optic modulator, and a processing pulse is taken out by the acousto-optic modulator, is characterized in that: the acousto-optic modulator is continuous for each In the above-mentioned laser pulse wave, a plurality of processing pulse waves with different energies are taken out during the oscillation period of the laser pulse wave, and a processing position is obtained by using the plurality of processing pulse waves obtained from the same laser pulse wave. machining. The laser processing method according to item 3 of the scope of patent application, wherein the plurality of processing pulses taken out by the acousto-optic modulator reduce the energy of subsequent processing pulses more than the preceding processing pulses. The energy is low. The laser processing method according to item 4 of the scope of patent application, wherein the preceding processing pulse wave among the plurality of processing pulse waves mainly processes the aforementioned metal layer of the substrate on which the metal layer is laminated on the resin layer, The subsequent processing pulse wave after the preceding processing pulse wave mainly processes the resin layer.