JP2000271770A - Excimer laser beam machining device and adjustment method of machining energy intensuty of excimer laser beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excimer laser beam machining device of high machining efficiency. SOLUTION: This machine 10 is provided with an oscillator 11 of an excimer laser beam and a mask 14 to regulate the excimer laser beam emitted from the oscillator to a prescribed pattern, and is an excimer laser beam machine to machine a work with the excimer laser beam pattern-regulated by the mask. Further, the device is provided with an angle adjustment jig 16 which holds the work, rotates the work so that a face to be machined of the work is set to a set angle for a radiation direction of the excimer laser beam and positions the face to be machined, and an optical attenuator 54 which is arranged between the oscillator 11 of an excimer laser beam and the mask and attenuates the excimer laser beam with a prescribed attenuation rate in accordance with the relation between an angle of the face to be machined with respect to the radiation direction of the excimer laser beam and a required energy of the excimer laser beam based on the set angle of the face to be machined for the radiation direction of the excimer laser beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excimer laser processing apparatus and a method for adjusting a processing energy intensity of an excimer laser beam, and more particularly, to a function of adjusting an excimer laser beam to an optimum processing energy intensity for a desired processing. And a method for automatically adjusting the processing energy intensity of the excimer laser beam to an optimum intensity for desired processing.

[0002]

2. Description of the Related Art Excimer laser light is composed of Ar, Kr, and Xe.
Is a laser beam which is discharged in a gas in which a rare gas such as a rare gas and a halogen gas such as F or Cl are mixed at a certain ratio, and is laser-oscillated by a discharge phenomenon, and has a high output having a short oscillation wavelength in an ultraviolet region. By emitting light as pulsed laser light, it is used in various fields.

An excimer laser beam processing apparatus is an apparatus for processing a workpiece using excimer laser light.
It is particularly suitable for performing fine processing on semiconductor devices and electronic / electrical components. For example, when a fine hole is formed in an orifice plate of an ink jet recording head, a through hole or a via hole is formed in a flexible printed circuit board. It is sometimes used or when fine processing is performed on a polymer material, and has a wide field of application. In particular, polyimide resin, polysulfone resin, polycarbonate resin,
Processing of polymer materials such as polyethylene terephthalate by excimer laser light is performed using a CO ₂ laser processing device, YA
Unlike a thermal melting process using a G laser device, it is based on an ablation process called a photochemical reaction, so that the heat effect is extremely small, so that high-quality processing can be performed.

[0004] Drilling methods using excimer laser light are roughly classified into a mask image method and a contact mask method. In the mask image method, as shown in FIG. 6, an excimer laser light beam emitted from an excimer laser light oscillator 60 is reflected by a reflection mirror 62, and then a mask 64 is formed.
To pass through the shape pattern of the opening 66 of the mask 64. The excimer laser light beam that has passed
8 is a method of irradiating the workpiece 70 with reduction.
FIG. 6 is a schematic diagram showing a configuration of an excimer laser processing apparatus using a mask image method.

In the processing method using excimer laser light in accordance with the mask image method, a through hole is formed in the workpiece in which the center line of the through hole is inclined at a predetermined angle with respect to the processing surface of the workpiece. In this case, it is necessary to irradiate the surface to be processed with the excimer laser beam at the same irradiation angle as the predetermined angle. In other words, the excimer laser light is applied to the work surface, for example, when the work surface is irradiated with the excimer laser light perpendicularly to open a through hole vertically penetrating the work surface in the work. As in the case of irradiating the processing surface perpendicularly, and when performing a processing method of irradiating an excimer laser beam obliquely to the processing surface and opening a through hole obliquely penetrating the processing surface in the processing object, There is a case where the surface to be processed is irradiated with the excimer laser light obliquely. Then, the present inventors, when irradiating the excimer laser light obliquely to the surface to be processed, compared to the case where the excimer laser light is irradiated perpendicularly to the surface to be processed, to perform accurate processing, a higher It is experimentally recognized through many experiments that the processing energy intensity is necessary.

When irradiating an excimer laser beam to a work surface at two fixed angles perpendicular and oblique to the work surface of the work, the excimer laser light is applied to the optical axis of each excimer laser light, or By attaching a mechanism for attenuating the amount of excimer laser light to only the optical axis of the excimer laser light in the vertical direction and attenuating the excimer laser light, it is possible to set optimum processing energy intensities.

[0007]

The required light quantity of the excimer laser light will be described by taking as an example a working operation for opening a large number of through holes having different center line angles of the through holes with respect to the surface to be processed. It is necessary to set the amount of excimer laser light each time a through-hole whose center line angle changes with respect to the surface to be processed is opened.
This is because of the following reasons. That is, if the amount of excimer laser light is small and the processing energy intensity is too low, for example, in the case of a polymer film, 0.5 to
1.0 J / cm ² or less, in the case of polyimide resin,
If it is less than 1.0 J / cm ² , the shape of the opening will not be stable when processed, and the roundness of the opened through hole will be poor. vice versa,
If the amount of excimer laser light is large and the processing energy intensity is too high, the edge shapes of the through holes on both the incident side and the exit side of the excimer laser light become rough due to the jet effect. Further, when an optical system for excimer laser light is configured by a telecentric optical system, if the amount of excimer laser light entering the objective lens is too large, the lens life becomes shorter than expected.

For this reason, in the conventional excimer laser processing apparatus, when performing a processing operation for opening a large number of through holes having different center line angles of the through holes with respect to the surface to be processed, when the through holes are formed with respect to the surface to be processed. Each time a through-hole having a different center line angle is opened, the work of adjusting the amount of excimer laser light is performed so that the amount of excimer laser light becomes optimal for processing. However, in the conventional excimer laser processing apparatus, there is a problem that each time the angle of the through-hole is changed, the amount of excimer laser light is adjusted, so that the adjustment requires time and the processing efficiency is reduced. In the above description, the problem of the conventional excimer laser processing apparatus has been described by giving an example in which a through hole that penetrates the workpiece is opened. However, this problem is not limited to the opening of the through hole, and the problem is not limited to the opening of the through hole. This is a universal problem when processing is performed by irradiating an excimer laser beam obliquely.

Accordingly, an object of the present invention is to provide an excimer laser processing apparatus with high processing efficiency and a method for adjusting the processing energy intensity of excimer laser light.

[0010]

The inventor of the present invention has changed the irradiation angle of excimer laser light on the surface of a workpiece to be processed, for example, such that the center line of the through hole is inclined at a predetermined angle to the surface to be processed. By implementing an excimer laser processing device that automatically sets and adjusts the amount of excimer laser light when opening a through hole in a workpiece, it is possible to realize an excimer laser processing device with high processing efficiency. With the idea and repeated experiments, the present invention was completed.

In order to achieve the above object, an excimer laser processing apparatus according to the present invention comprises: an excimer laser light oscillator; and a mask for regulating the excimer laser light emitted from the oscillator into a predetermined shape pattern. In an excimer laser processing apparatus that processes a workpiece with excimer laser light whose pattern is regulated by the pattern, the workpiece is held, and the processing surface of the workpiece is set at a set angle with respect to the irradiation direction of the excimer laser light. An angle adjusting jig for rotating the workpiece so as to position the workpiece surface, and being disposed between the excimer laser light oscillator and the mask, and the set angle of the workpiece surface with respect to the irradiation direction of the excimer laser light Specified in accordance with the relationship between the angle of the surface to be processed with respect to the irradiation direction of the excimer laser light and the required energy of the excimer laser light based on In the attenuation factor, it is characterized by comprising an optical attenuator for attenuating the excimer laser beam.

In the present invention, the relationship between the angle of the surface to be processed with respect to the irradiation direction of the excimer laser light and the required energy of the excimer laser light is determined in advance by experiments or the like. The workpiece is rotated to a predetermined angle by the angle adjustment jig, and the optical attenuator is automatically controlled to adjust the processing energy intensity. Therefore, the excimer laser beam is applied to the workpiece surface of the workpiece. By changing the irradiation angle, for example, automatically setting and adjusting the amount of excimer laser light even when opening a through hole in which the center line of the through hole is oblique at a predetermined angle to the surface to be processed, for example. Can be done.

In a preferred embodiment of the present invention, an XY stage supporting an angle adjusting jig and freely moving on an XY plane, and irradiating an excimer laser beam in a direction orthogonal to the XY stage. An optical system for excimer laser light to be provided, an angle adjustment jig, a rotation mechanism that holds and rotates the workpiece,
It has a drive mechanism for driving the rotation mechanism, an encoder for measuring the rotation angle of the workpiece, and a control mechanism for controlling the drive mechanism so that the rotation angle of the workpiece measured by the encoder becomes a predetermined angle.

In the method for adjusting the processing energy intensity of an excimer laser beam according to the present invention, when processing a workpiece by an excimer laser processing apparatus, a processing dimension and a processing shape to be performed on the workpiece are set, and a mask is selected. And moving the workpiece in the XY plane, positioning the processing location of the workpiece at the excimer laser beam irradiation position, rotating the workpiece, and moving the workpiece in the excimer laser beam irradiation direction. Setting the work surface at a predetermined angle, and based on the set angle, the excimer laser at a predetermined attenuation rate defined according to the relationship between the work surface angle with respect to the excimer laser light irradiation direction and the required energy of the excimer laser light. Controlling the optical attenuator to attenuate light.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments with reference to the accompanying drawings. This embodiment is an example of an embodiment of an excimer laser processing apparatus according to the present invention. FIG. 1 is a schematic view showing the configuration of an excimer laser processing apparatus according to this embodiment, and FIG. 2 (b) is a plan view, FIG. 3 is a cross-sectional view of the workpiece W, FIG. 4 (a) is a block diagram of a system for supplying air to the angle adjusting jig, And FIG.
(B) is a block diagram of a system for vacuum suctioning a vacuum chuck of the angle adjusting jig. The excimer laser processing apparatus 10 according to the present embodiment, when processing a workpiece with excimer laser light, the processing energy intensity of the excimer laser light according to the irradiation angle of the excimer laser light to the processing surface of the workpiece. Is an excimer laser processing apparatus provided with an automatic adjustment mechanism for automatically adjusting the temperature. As shown in FIG. 1, an excimer laser processing apparatus 10 supplies an excimer laser light oscillator 11 and a gas for forming a gas discharge space for causing laser oscillation to the excimer laser light oscillator 11 as a light source of the excimer laser light. And an optical system along the optical path of the excimer laser light.
In this order, a set of two reflecting mirrors 13, an optical attenuator 54, a mask 14, a reflecting mirror 18, and a processing lens 15 are sequentially provided.

The set of two reflecting mirrors 13 forms an optical path of excimer laser light having another optical axis parallel to the optical axis of the oscillator 11 for excimer laser light. The optical attenuator 54 attenuates the excimer laser light non-stepwise or stepwise. The mask 14 has a shape pattern for reduction projection of the shape pattern processing performed on the workpiece. Reflection mirror 1
8 changes the direction of the excimer laser light that has passed through the shape pattern of the mask 14 downward. Processing lens 15
Is a lens for reducing and projecting the excimer laser light passing through the shape pattern of the mask 14.

The excimer laser processing apparatus 10 serves as a mechanism for supporting the workpiece W by mounting the workpiece W and rotating the mounted workpiece W so that the excimer laser beam is emitted in the irradiation direction of the excimer laser beam. An angle adjusting jig 16 that can freely change the angle of the work surface, and an angle adjusting jig 16
And an XY table 17 that moves freely on the XY plane and positions the processing location of the workpiece W. In addition, the excimer laser processing apparatus 10
The control device 51 controls the attenuation of the excimer laser light by the optical attenuator 54 based on the angle of the surface to be processed. In the configuration of the present embodiment, the optical attenuator 54 is disposed between the reflection mirror 13 and the mask 14, but the excimer laser oscillator 11 and the reflection mirror 1
3 may be arranged.

The angle adjusting jig 16 is, as shown in FIG.
A pulse motor 22 and a vacuum chuck 27 are mounted on a base 29.
A rotating unit (not shown) for supporting the rotating unit, an air spindle 25 for supporting the rotating unit, a harmonic drive 23 and a coupling 24 for transmitting the rotating power of the pulse motor 22 to the rotating unit for rotation. ing. The vacuum chuck 27 is configured such that the upper surface of the workpiece 26 is
The workpiece W is held by vacuum suction so as to coincide with a plane including the rotation center axis of the rotating unit supported by the workpiece. The rotation angle of the rotating part supported by the air spindle 25, and thus of the workpiece 26, is determined by a rotary encoder 28,
It is detected by the photo sensor 21. Although not shown, the air spindle 25 is supplied with air.

[0019] In this example embodiment, an excimer laser processing apparatus 10, as shown in FIG. 3, a through hole W ₁ which passes through the workpiece perpendicularly to the work surface, perpendicular to the work surface opening a through hole W ₂ which passes through the workpiece at an inclined angle from the direction. Moreover, since the positions of the holes on the laser light emission side are close to each other, and the shape of the edge is regarded as important, it is necessary to optimize the processing energy.

As shown in FIG. 4A, the angle adjusting jig 16 supplies air from the air source 46 to the air spindle 25 supporting the rotating unit via the filter / regulator unit 44. As shown in FIG. 4 (b), the vacuum pump 4
1 is connected to a vacuum chuck 27 and vacuum suction is performed.

The angle adjusting jig 16 is further controlled by a controller 51 as shown in FIG. Further, the control device 51 includes a rotary encoder / controller 52 connected to the rotary encoder 28 of the angle adjusting jig 16, a pressure sensor 53 for monitoring the pressure of air supplied to the air spindle 25, and an optical attenuator 54. It is connected. The control device 51 includes:
An input button for setting the rotation angle of the angle adjustment jig 16 is provided, and the control device 51 controls the pulse motor 22 of the angle adjustment jig 16 according to the input value of the rotation angle.
A driving pulse is sent to a pulse motor (not shown) of the optical attenuator 54 to rotate each pulse motor by a predetermined angle. Although there are several types of optical attenuators, in this embodiment, the optical attenuator 5 is used.
As No. 4, an attenuator of a type in which two optical glass plates are opposed to each other and continuously rotated at the same angle to reduce the amount of light is used. The optical attenuator of another system may be used as long as the amount of light can be controlled by a pulse signal without being limited to this system.

As described above, in the excimer laser processing apparatus 10 of this embodiment, the mechanism for automatically adjusting the processing energy intensity of the excimer laser light includes the angle adjusting jig 16, the control device 51, And an optical attenuator 54. That is, it is a feature of the present invention that the angle setting by the angle adjusting jig 16 and the control of the processing energy intensity by the optical attenuator 54 are linked.

With reference to FIG. 5, an operation method for opening a through hole in a workpiece using the excimer laser processing apparatus 10 of this embodiment will be described. FIG. 5 is a flowchart showing a procedure for opening a through hole in a workpiece using the excimer laser processing apparatus 10. First, in step S _1, sets the hole diameter of the through hole opening to the workpiece. As a result, a required mask is selected, the mask of the excimer laser processing apparatus 10 is changed, and the shape projected on the surface to be processed is determined. Then, the process proceeds to step S _2, sets the position of the through hole opened to the workpiece, X-Y table 1
7 is moved to position the workpiece at a predetermined position.
The above settings are performed on an operation panel (not shown) of the excimer laser processing apparatus 10.

[0024] Subsequently, in step S _3, the setting of machining angles of the workpiece. The setting of the processing angle is performed by the control device 51 of the angle adjusting jig 16. The control device 51 controls the pulse motor 22 of the angle adjusting jig 16 so that the irradiation angle of the excimer laser beam becomes the processing angle set with respect to the surface to be processed.
The work surface of the work is rotated, and at the same time, the optical attenuator 54 is interlocked, and the attenuation rate of the excimer laser light is automatically set and controlled based on the set processing angle according to a preset relationship. I do. In the following procedure, a description will be given assuming that the setting range of the processing angle of the excimer laser processing apparatus 10 of this embodiment is a range from 0 ° to 45 °. The present invention is not particularly limited to the processing angle in this range, but is merely an example for explanation.

[0025] In Step S ₄ working angle of 0 ° or more 15 °
It is determined whether it is less than 0 ° and less than 15 °, and the processing energy intensity of the excimer laser beam is attenuated by the optical attenuator 54 at a preset attenuation rate, for example, 50%. The excimer laser processing apparatus 10 processes a workpiece with a processing energy intensity in which the energy of the excimer laser light emitted from the oscillator 11 is attenuated by 50%. When working angle is 15 ° or more, the process proceeds to step S _5. In step S _5, the processing angle is determined whether it is less than 30 °, 30
When it is less than °, with a preset attenuation rate,
For example, the processing energy of the excimer laser light is attenuated by the optical attenuator 54 at an attenuation rate of 25%.
The excimer laser processing apparatus 10 processes a workpiece with a processing energy intensity in which the energy of the excimer laser light emitted from the oscillator 11 is attenuated by 25%. Processing angle is 3
When it is 0 ° or more, the process proceeds to step S _6. In step S _6, it is determined whether the machining angle is 45 ° or less, when it is 45 ° or less, an attenuation factor that is set, for example 0% attenuation, pre-optical processing energy of the excimer laser beam The attenuator 54 attenuates, in other words, does not attenuate. The excimer laser processing apparatus 10 processes a workpiece with the processing energy intensity of the excimer laser light emitted from the oscillator 11.

Although not shown in FIG. 5, since the processing rate changes depending on the material of the workpiece, surface treatment, etc., the excimer laser beam is perpendicular to the workpiece surface prior to the actual laser processing. The processing rate at the time of irradiation is confirmed by trial processing. Further, in the present embodiment, the number of processing laser shots is not automatically set according to the angle, but as in the present embodiment in which the attenuation rate of the attenuator is changed according to the angle, the branching according to the processing angle is further finely set. If the number of processing shots is fed back, automation can be performed.

[0027]

According to the present invention, an angle adjustment jig for positioning a work surface by rotating the work so that the work surface of the work becomes a set angle with respect to the direction of irradiation of the excimer laser beam. And an optical attenuator that attenuates the excimer laser light at a predetermined attenuation rate defined according to the relationship between the angle of the processing surface with respect to the irradiation direction of the excimer laser light and the required energy of the excimer laser light, to the excimer laser processing apparatus. With this arrangement, the processing energy intensity of the excimer laser beam is automatically adjusted to the optimum intensity for the desired processing, and the processing efficiency can be improved.

More specifically, the following effects are obtained. 1) When performing opening processing with various hole diameters and various angles on the workpiece, setting the number of processing shots in advance based on the processing rate for each angle allows the processing angle of the through hole to change. In addition, the operation can be continued and the processing can be performed automatically without stopping the excimer laser processing apparatus for the setup change. 2) Since the intensity of the excimer laser beam is automatically adjusted to the optimum processing energy intensity for the processing angle,
There is no need to open a vertical hole with strong energy according to the oblique processing, and edge damage to the hole can be prevented. In addition, it is expected that the life of the reflecting mirror and the processing lens provided in the optical system of the excimer laser processing apparatus can be extended.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating a configuration of an excimer laser processing apparatus according to an embodiment.

FIG. 2A is a side view showing a configuration of an angle adjusting jig, and FIG. 2B is a plan view.

FIG. 3 is a sectional view of a workpiece W;

FIG. 4A is a block diagram of a system for supplying air to the angle adjusting jig, and FIG. 4B is a block diagram of a system for vacuum-sucking a vacuum chuck of the angle adjusting jig.

FIG. 5 is a flowchart showing a procedure for opening a through hole in a workpiece using the excimer laser processing apparatus of the embodiment.

FIG. 6 is a schematic diagram illustrating a configuration of an excimer laser processing apparatus that performs laser processing by a mask image method.

[Explanation of symbols]

10 Excimer laser processing apparatus of embodiment example, 11
... Excimer laser light oscillator, 12 ... Gas unit, 1
3 ... reflection mirror, 14 ... mask, 15 ... worked lens, 16 ... angle adjustment jig, 17 ... XY table,
18 ... Reflection mirror, 21 ... Photo sensor, 22 ...
... Pulse motor, 23 ... Harmonic drive, 24
... coupling, 25 ... air spindle, 27 ...
Vacuum chuck, 28 ... Rotary encoder, 29 ...
Base 41: vacuum pump, 42: vacuum regulator,
43 ... air tank, 44 ... filter regulator unit, 46 ... air source, 51 ... control device, 62
... Rotary encoder controller 53 Pressure sensor 54 Optical attenuator 60 Excimer laser light oscillator 62 Reflecting mirror 64 Mask 66 Opening of mask 68 Lens, 70 ...
... workpiece.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H01S 3/10 H01S 3/10 Z F Term (Reference) 4E068 AF00 CA01 CA05 CA14 CB05 CB08 CC00 CD10 CE04 5F072 AA06 JJ20 KK05 KK30

Claims (3)

[Claims] An oscillator for excimer laser light, and a mask for restricting the excimer laser light emitted from the oscillator into a predetermined shape pattern, wherein a workpiece is processed by the excimer laser light whose pattern is regulated by the mask. In the excimer laser processing equipment, the workpiece is held and the workpiece is rotated so that the processing surface of the workpiece is at a set angle with respect to the irradiation direction of the excimer laser light, and the workpiece surface is positioned. The jig for adjusting the angle and the oscillator for excimer laser light and the mask,
Based on the set angle of the surface to be processed with respect to the direction of irradiation of the excimer laser light, the excimer laser An excimer laser processing apparatus, comprising: an optical attenuator for attenuating a laser beam. 2. An XY stage supporting the angle adjusting jig and freely moving on an XY plane, and an optical system for excimer laser light for irradiating an excimer laser light in a direction orthogonal to the XY stage. A rotation mechanism that holds and rotates the workpiece, a driving mechanism that drives the rotation mechanism, an encoder that measures the rotation angle of the workpiece, and a workpiece that is measured by the encoder. The excimer laser processing apparatus according to claim 1, further comprising a control mechanism that controls a driving mechanism so that a rotation angle of the workpiece becomes a predetermined angle. 3. A step of setting a processing dimension and a processing shape to be performed on a workpiece and selecting a mask when processing the workpiece by an excimer laser processing apparatus, and moving the excimer laser on an XY plane. Positioning the processing position of the workpiece at the irradiation position of the laser light, rotating the workpiece, and setting the processing surface of the workpiece at a predetermined angle with respect to the irradiation direction of the excimer laser light; Controlling the optical attenuator to attenuate the excimer laser light at a predetermined attenuation rate defined according to a relationship between the angle of the processing surface with respect to the irradiation direction of the excimer laser light and the required energy of the excimer laser light based on the angle. A method for adjusting the processing energy intensity of excimer laser light, characterized by comprising: