JPH11170074A - Laser beam machining device and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser drilling device capable of drilling for sure conduction between close conductive layers by precisely detecting the drilled state of a workpiece and controlling the machining. SOLUTION: A part of the output laser beam 14 is reflected by a multilayer substrate 7, becoming a reflected laser beam 15, advancing in the opposite direction on a laser optical path 16, and entering a reflected light detector 10. Information concerning the intensity of the reflected light so detected is processed by an arithmetic processor 11, controlling the laser generator and the optical system based on comparison between the reflected light intensity and the reference value. As a result, the drilled state of a workpiece is precisely detected and, by controlling the machining, a laser beam machining device can be realized that is capable of drilling for sure conduction between close conductive layers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus, and more particularly to a laser processing apparatus suitable for drilling holes in a circuit board formed by laminating an insulating layer and a conductive layer, and a control method thereof. .

[0002]

2. Description of the Related Art As a conventional example, see, for example, Japanese Patent Application Laid-Open No. 2-924.
No. 82 publication.

According to this, when a workpiece is irradiated with laser light and a hole is drilled, direct irradiation light from a laser oscillator and reflected light from the workpiece are detected by different sensors, respectively. The reflected light amount ratio is calculated from the amount of light, and the control of the laser light is performed by comparison with the reference value.

More specifically, the oscillator is stopped when the reflected light amount ratio becomes larger than a preset reference value.

[0005] By performing such an operation, damage to the conductive layer due to laser light can be eliminated, and at the same time, the processing time is shortened.

[0006]

However, the above-mentioned prior art has the following problems.

When the laser beam passes through the condensing lens for processing, when the central part of the processing area is processed by the scanning mirror, the laser light is radiated vertically to the processing object, but is irradiated to the periphery. When processing the part, the laser light is not irradiated perpendicularly to the processing target, and the laser light reflected from the processing target protrudes from the optical system part in the middle or is irradiated to the optical part holding part. In addition, the laser light reflected from the object to be processed is interrupted on the way, and the reflected light does not reach the 100% reflected light detector. As a result, the reflected laser light cannot be completely detected, and as a result, the detection of the reflected light becomes incomplete, and the accuracy of the processing state determination of the processing hole is reduced.

Further, when the table on which the object to be processed is placed is tilted, the laser light reflected from the object to be processed does not return to the laser light detector 100% in the same manner as described above. And the precision of the inspection of the machined hole is reduced.

In view of the above, the present invention detects a laser beam reflected from an object to be processed by a detector, corrects an intensity signal of the detected laser beam, and corrects a laser beam reflected from the object to be processed. It is an object of the present invention to provide a laser processing apparatus that accurately calculates the strength of a hole, accurately detects a processing state of a processing hole, and performs high-quality hole processing, and a control method thereof.

[0010]

According to the present invention, there is provided a laser oscillator for emitting a laser beam, an optical system structure for guiding the laser beam to an object to be processed, and A reflected light detector for detecting a light intensity of reflected light from the processing object, comprising a control device for controlling a laser oscillator, and a reflected light from the processing object changing until reaching the reflected light detector. A reflected light distribution table in which a ratio of the reflected light is stored for each processing position of the processing object, and reflected light for calculating a reflected light intensity immediately after reflection from the processing object from the reflected light detector and the reflected light distribution table. An intensity calculator is provided, and the control device controls the laser oscillator based on a comparison between the reflected light intensity calculated by the reflected light intensity calculator and a reference value thereof.

According to a second aspect of the present invention, there is provided a laser oscillator for emitting a laser beam, an optical system structure for guiding the laser beam to an object to be processed, and a control device for controlling the laser oscillator. An incident light detector for detecting intensity;
The reflected light detector for detecting the light intensity of the reflected light from the processing object, and the rate at which the reflected light from the processing object changes until it reaches the reflected light detector, the processing of the processing object. A reflected light distribution table stored for each position, and a reflected light intensity calculation unit for calculating a reflected light intensity immediately after reflection from the processing object from the reflected light detector and the reflected light distribution table; The controller controls the laser oscillator based on a comparison between the relative reflected light intensity calculated from the incident light intensity detected by the detector and the reflected light intensity calculated by the reflected light intensity calculator and its reference value. is there.

According to a third aspect of the present invention, in the laser processing apparatus according to the second aspect, an arithmetic expression for calculating the relative reflected light intensity from the incident light intensity and the reflected light intensity is represented by (Equation 1). .

According to a fourth aspect of the present invention, there is provided a laser oscillator for emitting a laser beam, an optical system structure for guiding the laser beam to an object to be processed, and a control device for controlling the laser oscillator. An incident light detector for detecting intensity;
A fixed mirror installed at a position where the object to be processed is placed, a reflected light detector for detecting the light intensity of the reflected light from the fixed mirror, and a laser beam is irradiated at a processing coordinate position of the object to be processed. Reflection for calculating the ratio of the reflected light intensity at which the reflected light immediately after being reflected from the fixed mirror reaches the reflected light detector from the reflected light intensity detected by the reflected light detector and the incident light intensity detected by the incident detector. A light distribution calculator,
A reflected light distribution table for storing the calculation result of the reflected light distribution calculation unit is provided.

According to a fifth aspect of the present invention, in the laser processing apparatus according to any one of the first to fourth aspects, the data of the ratio of the reflected light reaching the reflection detector is stored in a position where the processing positions are equally spaced. On the other hand, it is stored in the reflected light distribution table.

According to a sixth aspect of the present invention, in the laser processing apparatus according to any one of the first to fourth aspects, the data of the ratio of the reflected light reaching the reflected light detector is roughly divided at the center of the processing area. The peripheral portion is subdivided and stored in the reflected light distribution table.

According to a seventh aspect of the present invention, there is provided a control method of a laser processing apparatus for processing a processing object by emitting a laser beam from a laser oscillator, wherein the laser intensity is reflected from the processing object. Detected by the photodetector, and based on the data of the reflected light distribution table stored for each processing position of the processing object, the rate at which the reflected light from the processing object changes until reaching the reflected light detector. Then, the reflected light intensity immediately after the reflection from the object to be processed is calculated, and the laser oscillator is controlled based on a comparison between the calculated reflected light intensity and a reference value.

According to an eighth aspect of the present invention, there is provided a control method of a laser processing apparatus for processing a processing object by emitting a laser beam from a laser oscillator, wherein the intensity of the laser beam is used as an incident light intensity. With the detector, the light intensity of the reflected light from the processing object is detected by the reflected light detector,
From the output of the reflected light detector and the data of the reflected light distribution table stored for each processing position of the processed object, the rate at which the reflected light from the processing object changes until it reaches the reflected light detector Calculating the reflected light intensity immediately after the reflection from the processing object, controlling the laser oscillator based on a comparison between the relative reflected light intensity calculated from the incident light intensity and the calculated reflected light intensity and its reference value. Take the way to.

According to a ninth aspect of the present invention, in the control method of the laser processing apparatus according to the eighth aspect, the arithmetic expression for calculating the relative reflected light intensity from the incident light intensity and the reflected light intensity is represented by (Equation 2).
The method shown in is used.

According to a tenth aspect of the present invention, there is provided a method of controlling a laser processing apparatus for processing a processing object by emitting a laser beam from a laser oscillator, wherein the intensity of the laser beam is used as an incident light intensity. While detecting with the detector, the light intensity of the reflected light from the fixed mirror installed at the position where the processing object is placed was detected by the reflected light detector, and the laser light was irradiated to a processing coordinate position where the processing object was located. From the reflected light intensity detected by the reflected light detector and the incident light intensity detected by the incident detector, the ratio of the reflected light intensity at which the reflected light immediately after being reflected from the fixed mirror reaches the reflected light detector is calculated. Then, a method of controlling the laser oscillator based on a comparison between the data of the reflected light distribution table storing the calculation result and the reference value is adopted.

The present invention described in claim 11 is the invention according to claim 7 to claim 1.
0, wherein the data of the ratio of the reflected light reaching the reflection detector is stored in the reflected light distribution table with respect to the positions where the processing positions are equally spaced.

The present invention according to claim 12 provides the invention according to claims 7 to 1
0, wherein the data of the ratio of the reflected light reaching the reflected light detector is roughly divided at the center of the processing area, and finely divided at the periphery of the reflected light distribution table. Take the method you remember.

[0022]

According to the laser processing apparatus and the control method thereof according to the first and seventh aspects, it is possible to accurately detect a processing state of a processing object, and thereafter to control a laser oscillator and an optical system structure. Thus, high-quality laser processing can be realized.

Further, according to the laser processing apparatus and the control method thereof according to the second and eighth aspects, the processing state of the processing object is accurately detected, and thereafter, the laser oscillator and the optical system structure are controlled, thereby achieving high performance. High quality laser processing can be realized.

Here, as described in claims 3 and 9,
An arithmetic expression for calculating the relative reflected light intensity shown in (Equation 1) or (Equation 2) allows the state of drilling of the processing object to be more accurately determined, and controls the laser oscillator and the optical system structure thereafter. Thus, laser processing that achieves high yield and high quality hole processing can be realized.

Further, according to the laser processing apparatus and the control method thereof according to the fourth and tenth aspects, the processing state of the processing object can be accurately detected, and high quality laser processing can be realized. Here, as described in claims 5 and 11, the data table of the correction value for the processing position of the processing object for estimating the reflected light intensity immediately after being reflected by the processing object is such that the processing position is at regular intervals. , Or as described in claims 6 and 12, the data table capacity in the central part of the processing area is made coarse and the data interval in the peripheral part is made small, thereby reducing the capacity of the data table. be able to.

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view of a laser processing apparatus according to the present embodiment. In FIG. 1, 1 is a pulse laser oscillator used as an example of a processing light source, 2 is a bend mirror, 3 is a beam splitter, 4 is a first scanning mirror, 5
Is a second scanning mirror, 6 is a condensing lens for processing, 12 is a control device for controlling the laser oscillator 1, the first scanning mirror 4, and the second scanning mirror, and includes a bend mirror 2, a beam splitter 3, and a second One scanning mirror 4, the second scanning mirror 5, and the optical path 6 for the condensing lens for processing constitute an optical system structure.

Here, as the pulse laser oscillator 1 used in the present embodiment, for example, a carbon dioxide laser is used.

Next, reference numeral 7 denotes a multi-layer substrate to be processed. The multi-layer substrate includes an insulating layer 8 and a conductive layer 9.

Reference numeral 10 denotes a reflected light detector for detecting reflected light from the multilayer substrate 7, reference numeral 18 denotes an amplifier for amplifying a signal from the reflected light detector 10, and reference numeral 19 denotes reflected light immediately after reflection of the object to be processed. The reflected light distribution table stores the ratio of the reflected light returning to the photodetector 10 corresponding to the processing position of the object to be processed. Reference numeral 20 denotes a reflected light distribution table, based on the processing position of the control device 12 and the output of the amplifier 18. This is a reflected light intensity calculation unit that corrects reflected light. Numeral 11 denotes an arithmetic processing unit for performing arithmetic operations using an output signal from the reflected light detector 10, and 12 denotes a pulse laser oscillator 1, a first scanning mirror 4, and a second scanning mirror 5.
Is a control device for controlling the movement of the multi-layer substrate 7 as a processing object.

Reference numeral 14 denotes a pulsed output laser beam emitted from the laser oscillator 1, and reference numeral 15 denotes a reflected laser beam obtained by reflecting the output laser beam 14 from the multilayer substrate 7 which is a processing object. The output laser light 14 on the optical path toward the optical path and the reflected laser light 15 on the optical path reflected by the multilayer substrate 7 and returning toward the laser oscillator 1 are combined with the beam splitter 3 via the scanning mirrors 4 and 5 and the condenser lens 6 to form a multilayer. The direction as shown by the laser light 16 is opposite to that of the substrate 7, but the light path is the same.

With the above configuration, the processing hole 17 is formed in the multilayer substrate 7. This operation will be described.

First, the output laser light 14 emitted from the pulse laser oscillator 1 is reflected by the bend mirror 2 and the beam splitter 3, respectively, and is constituted by a first scanning mirror 4 constituted by a galvano mirror and a galvano mirror similarly. The second scanning mirror 5 is sequentially reflected so as to be scannable according to a required processing mode.

Here, in the case of the present embodiment, the first scanning mirror 4 and the second scanning mirror 5 are configured to scan the output laser light 14 in directions orthogonal to each other.
As a result, the output laser light 14 is configured to be able to scan the multilayer substrate 7 two-dimensionally.

Next, the light is incident on the processing condensing lens 6 composed of an fθ lens, and while being condensed, is incident on the multi-layer substrate 7 installed on the processing object moving mechanism 13 and located at the processing position.

As described above, the processing for forming the processing hole 17 in the multilayer substrate 7 is performed by using the collected output laser light.

Then, a part of the output laser light 14 applied to the multilayer substrate 7 is reflected by the multilayer substrate 7 to become a reflected laser light 15.

The reflected laser light 15 is the output laser light 1
The laser beam 4 propagates in the opposite direction through the laser beam path, reaches the beam splitter 3 in the order of the condenser lens 6 and the scanning mirrors 5 and 4, passes through the beam splitter 3, and enters the reflected light detector 10. Will be done.

The detection signal relating to the light intensity of the reflected laser light 15 detected by the reflected light detector 10 is supplied to the amplifier 1
After being amplified by an arbitrary constant multiple in step 8, it is sent to the reflected light intensity calculation unit 20. The reflected light intensity calculator 20 reflects the position information 29 of the processing of the multilayer substrate from the controller 12 and the laser light emitted from the processed multilayer substrate from the reflected light distribution table 19 and reaches the reflected light detector. Is extracted. For example, the reflected light distribution table stores the ratio of reflected light returning to the reflected light detector at every 1 mm pitch in the processing position of the processing target. The processed position is X =
Assuming that 2.5 mm and Y = 1 mm, from the reflected light distribution table, the ratio of the reflected light return of X = 2 mm and Y = 1 mm, for example, 0.99, and the ratio of the reflected light return of X = 3 mm, Y = 1 mm, for example, 0 .97 and interpolate between two points.

For example, when proportional interpolation is performed, X = 2.5 mm,
The rate of return of the reflected light at Y = 1 mm is 0.98. Further, when the pulse amplitude of the output of the amplifier 18 is output as a voltage, for example, when the output value is 3 [V], the intensity of the reflected light immediately after being reflected from the multilayer substrate is 3 / 0.98 [V]. ] =
3.06 [V].

Next, this information is sent to the arithmetic processing unit 11 and subjected to arithmetic processing. The output signal of the arithmetic processing unit 11 is sent to the control unit 12, and the control unit 7 includes the laser oscillator 1, the scanning mirror 4 and 5 are controlled. here,
If the intensity of the reflected light is larger than a predetermined reference value, the machining of the hole is stopped, and if the intensity of the reflected light is smaller than the reference value, the hole is additionally machined.

Next, a method of controlling the laser oscillator 1 and the scanning mirrors 4 and 5 based on a detection signal regarding the light intensity of the reflected laser light 15 detected by the reflected light detector 10 will be described.

FIG. 2 shows a state where the processing hole 17 gradually becomes deeper. FIG. 2 (a) shows that the processing hole has not yet reached the conductive layer 9, and FIG. 2 (b) shows a part of the processing hole. Is the conductive layer 9
FIG. 2C is a schematic view showing a state where most of the processed holes have reached the conductive layer 9.

Since most of the reflection of the output laser beam 14 occurs in the insulating layer 9, the amount of the reflected laser beam 15 is
(A), (b), and (c) increase in this order.

A signal relating to the light intensity of the reflected laser beam 15 detected by the reflected light detector 10 is sent to the arithmetic processing unit 11 via the amplifier 18 and is set to a reference value preset in the arithmetic processing unit 11. It is determined whether the processing is completed or not completed, and the information is sent to the control device 12.

When the reference value is set to an intermediate value between the amount of reflected light from the state of the hole in FIG. 2B and the amount of reflected light from the state of the hole in FIG. Since the reflected light amount is smaller than the reference value, the arithmetic processing unit 11 determines that the processing has not been completed, and sends a command signal to the control unit 12 to further irradiate the laser beam 14.

On the other hand, since the amount of light reflected from the hole shown in FIG. 2C is larger than the reference value, the arithmetic processing unit 11 determines that the machining is completed, and the control unit 12 informs the control unit 12 about the position of the hole. A command signal for not performing the above laser irradiation is sent.

By performing the above-described processes, a process for surely obtaining conduction between adjacent conductive layers can be performed.
It can be performed accurately and reliably.

In the present embodiment, the signal is amplified using the amplifier 18. However, the magnitude of the signal sent from the laser beam detector 21 is sufficient for the arithmetic processing unit 11 to perform signal detection. If you have the size, amplifier 1
8 is not always required.

In this embodiment, the laser oscillator is a pulse laser oscillator. However, a laser oscillator that emits laser light continuously may be used in some cases in relation to the object to be processed.

In this embodiment, a galvano mirror is used as a scanning mirror. However, similar effects can be obtained by using a polygon mirror, an acousto-optic device, an electro-optic device, a hologram scanner, or the like.

In this embodiment, the fθ lens is used as the processing condensing lens 6, but the same effect can be obtained by using an optical system in which a single lens or a plurality of Fresnel lenses are combined. is there.

In the present embodiment, the reflected light return distribution correction unit 20 performs proportional interpolation on the ratio of reflected light returned from the reflected light return distribution table 19. However, exponential function interpolation, polynomial interpolation, spline interpolation, Logarithmic interpolation or the like may be used.

Further, in this embodiment, the reflected light return distribution table 19 stores the reflected light return ratio in a grid pattern at regular intervals, but stores the value of the returned ratio based on the reflected light return ratio width. Alternatively, the pitch of the central portion of the multi-layer substrate 7 which is the object to be processed may be coarse, and the pitch may be made denser along the peripheral portion to store the return ratio value of the reflected light.

Further, the reflected light return distribution table 19 may be prepared and applied every time the moving mechanism 13 operates.

(Embodiment 2) Hereinafter, Embodiment 2 of the present invention will be described in detail with reference to the drawings.

FIG. 3 is a schematic view of a laser processing apparatus according to the present embodiment. The configuration of the present embodiment shown in FIG.
Bend mirror 2 in the configuration of the first embodiment shown in FIG.
Is replaced by a beam splitter 26, and an incident light detector 27 is provided so as to detect a part of the output laser light 14 transmitted through the beam splitter 26, and the light intensity of the output laser light 14 detected by the incident light detector 27 is detected. The signal is amplified by an amplifier 28 to an arbitrary constant multiple, and then sent out to the arithmetic processing unit 11 for arithmetic processing. The multi-layer substrate 22 as a processing target includes the first conductive layer 23, the insulating layer 24,
The configuration is similar to that of the first embodiment shown in FIG.

That is, in the present embodiment, the basic function of detecting the reflected laser light and controlling the processing is the same as that of the first embodiment. It has a configuration that enhances the function of detection.

In the first embodiment, a signal related to the light intensity of the reflected laser light 15 is detected, and the processing is controlled based on the result of comparison with the reference value.

In the following, a specific description will be given with reference to figures. Ma
For simplicity, it is described in (Equation 1) and (Equation 2)
The value of the constant k is k × b _max= A_maxDetermine a value that satisfies
Keep it.

As a result, c _max = 1, and (Expression 1)
The equation shown in (Equation 2) is described as (Equation 3).

[0062]

(Equation 3)

First, consideration will be given to light reflected from an arbitrary hole A. When the hole A is continuously irradiated with the pulse laser light over time, the information about the peak value of the first pulse laser light is c ₁ = 0.1, and the information about the peak value of the N-th pulse laser light is c _N. = 0.7.

This means that the laser light reflected by the first conductive layer 23 is 0.1, 0.9 means that it is used for drilling holes, and that the laser light reflected from the first conductive layer 23 is 0.7 to 0.7 in the Nth pulse. 0.1
0.6 means that the light is reflected light from the inside of the hole.

At this time, the Nth relative reflected light intensity is found to be 0.667 from (Equation 3).

Next, the reflected light from an arbitrary hole B will be discussed. When the hole B is continuously irradiated with the pulse laser light over time, the information about the peak value of the first pulse laser light is c ₁ = 0.3, and the information about the peak value of the N-th pulse laser light is c _N. = 0.7.

This means that the laser beam reflected by the first conductive layer 23 is 0.3, 0.7 means that it is used for drilling, and that the N-th pulse has a value of 0.7 to 0.7. 0.3
0.4 means reflected light from the inside of the hole.

At this time, the Nth relative reflected light intensity is found to be 0.571 from (Equation 3).

Since the information on the peak value of the N-th pulse laser beam in both holes has the same value of 0.7,
If an attempt is made simply to determine whether or not to drill a hole only from the Nth information, an incorrect conclusion is drawn.

As described above, by examining how much light amount ratio returns as reflected light with respect to the light amount actually illuminated into the inside of the hole, it is possible to accurately determine whether or not the hole processing is successful. In addition, not only can the hole be formed so that conduction between the adjacent conductive layers can be reliably obtained, but also unnecessary oscillation of the output laser light can be avoided, and the processing throughput also increases. be able to.

In this embodiment, the description has been made assuming the peak value of the pulsed laser light as the value of the information on the laser light intensity used in the arithmetic expression. It is needless to say that the same effect can be obtained by using the laser beam intensity after a certain time has elapsed from the rise or fall of the signal as a trigger.

For the sake of simplicity, the constant k is set to k × b
_{Although the} description has been given as a value satisfying _max = _amax , any value may be used as long as the constant k is a real number.

Further, as a method of obtaining c _max , a method of using a gold mirror, a copper mirror, or the like instead of the object to be processed prior to the actual processing is preferable. It may be determined using data acquired during the process.

In the equations described in (Equation 1) and (Equation 2), c ₁ is a value obtained from the first incident laser light intensity and the first reflected light intensity. If the amount of reflected light from the bottom is almost zero, the first value does not need to be used.

[0075] Further, if the spatial variation when the incident laser beam intensity is in the state almost negligible, since a _n will be regarded as substantially constant regardless of the value of n,
It goes without saying that a similar effect can be obtained by using the arithmetic expression shown in (Equation 4) instead of (Equation 1) and (Equation 2).

[0076]

(Equation 4)

At this time, if it is known in advance that a ↓ n is substantially constant regardless of the value of n, it is obvious that the incident light detector 27 does not need to be set.

(Embodiment 3) Hereinafter, Embodiment 3 of the present invention will be described in detail with reference to the drawings.

FIG. 4 is a schematic view of a laser processing apparatus according to the present embodiment. The configuration of the present embodiment shown in FIG.
In the configuration of the first embodiment shown in FIG. 3, a table creation unit 21 is added, a reflected light return correction calculation unit is deleted, and a fixed mirror 30 is installed instead of the multilayer substrate.

With the above configuration, this operation will be described in more detail. First, the above-described operation is performed until the laser 14 emitted from the pulse laser oscillator 1 reaches the fixed mirror 30 and the reflected light 15 reaches the reflected light detector and is amplified to an arbitrary constant multiple of the amplifier 18. This is the same as in Embodiment 2.

The ratio of the output of the amplifier 18 to the output of the amplifier 28 is calculated from the position information from the control device 12 and the outputs of the amplifier 28 and the amplifier 18. This calculation is performed by setting the laser to the fixed mirror 3 only for the data corresponding to the laser irradiation position necessary for the reflected light return correction table for the entire processing area.
Irradiation is performed for 0, and the following calculation is performed for each laser irradiation position.

Return ratio of reflected light = (reflected light / incident light) / M
AX (reflected light / incident light) Next, the above calculation result is stored in the reflected light distribution table 19 with the reflected light return ratio corresponding to each laser irradiation position. Here, FIG. 5 is a specific example of the reflected light distribution table. The return ratio of the reflected light for each position in the processing area is stored as a table. As a result, the reflected light return distribution tables used in the first and second embodiments can be created.

The data to be stored in the reflected light distribution table is roughly divided at the center of the processing area so that the stored data divides the processing area equally and the change rate of the stored data is constant. Alternatively, the periphery of the processing area may be divided densely.

In the present embodiment, a gold mirror, a copper mirror, a dielectric multilayer mirror, or the like may be used as the fixed mirror in practical use.

[0085]

According to the present invention, by adopting the above-described configuration and method, the signal pulse amplitude of the reflected light output from the amplifier is corrected by the processing position, so that the signal pulse amplitude immediately after the reflection from the multi-layer substrate which is the processing object. The intensity of the reflected light can be estimated, and the drilling situation can be determined, and not only can the drilling be performed accurately and reliably, but also unnecessary oscillation of the output laser light can be avoided.

Further, the intensity of the reflected light immediately after the reflection from the multi-layer substrate, which is the object to be processed, is estimated from the detected reflected light, and the ratio of the amount of reflected light to the amount of light actually illuminated inside the hole is determined. By calculating whether the light returns as light, it is possible to determine the state of drilling, not only to perform drilling accurately and reliably, but also to avoid unnecessary oscillation of the output laser light.

Further, a laser is irradiated to the mirror at each processing position, the laser irradiated to the mirror and the laser light of the reflected light are detected, and the return ratio of the reflected light is stored in a table from the ratio and used. This makes it possible to accurately estimate the intensity of the reflected light immediately after the light is reflected from the object irradiated with the laser.

[Brief description of the drawings]

FIG. 1 is a schematic view of a laser processing apparatus showing a first embodiment of the present invention.

FIG. 2A is a schematic diagram showing a state in which a machined hole does not reach a conductive layer. FIG. 2B is a schematic diagram showing a state in which a part of the machined hole has reached a conductive layer. Schematic diagram showing the state of reaching the layer

FIG. 3 is a schematic diagram of a laser processing apparatus according to a second embodiment of the present invention.

FIG. 4 is a schematic view of a laser processing apparatus according to a fourth embodiment of the present invention.

FIG. 5 is a reflected light distribution table diagram of a laser processing apparatus according to a fourth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 pulse laser oscillator 2 bend mirror 3 beam splitter 4 first scanning mirror 5 second scanning mirror 6 processing condenser lens 7 multilayer substrate 8 insulating layer 9 conductive layer 10 reflected light detector 11 arithmetic processing unit 12 controller 13 Movement mechanism 14 Output laser light 15 Reflected laser light 16 Laser light 17 Processing hole 18 Amplifier 19 Reflected light return distribution table 20 Reflected light return correction calculation unit 21 Table creation unit 22 Multilayer substrate 23 First conductive layer 24 Insulating layer 25 Second Conductive layer 26 beam splitter 27 incident light detector 28 amplifier 29 positional information 30 fixed mirror

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Makoto Kato 3-10-1 Higashi-Mita, Tama-ku, Kawasaki-shi, Kanagawa Prefecture Matsushita Giken Co., Ltd.

Claims (12)

[Claims] 1. A laser oscillator for emitting a laser beam, an optical system structure for guiding the laser beam to an object to be processed, and a control device for controlling the laser oscillator, the light intensity of reflected light from the object to be processed. A reflected light detector that detects the reflected light distribution table that stores, for each processing position of the processing object, the rate at which the reflected light from the processing object changes until it reaches the reflected light detector, A reflected light intensity calculator is provided for calculating a reflected light intensity immediately after reflection from the processing object from the reflected light detector and the reflected light distribution table, and the reflected light intensity calculated by the reflected light intensity calculator and its reference A laser processing device for controlling the laser oscillator by the control device based on a comparison with a value. 2. An incident light detection device comprising: a laser oscillator for emitting a laser beam; an optical system structure for guiding the laser beam to an object to be processed; and a control device for controlling the laser oscillator, and detecting an intensity of the laser beam. The reflected light detector for detecting the light intensity of the reflected light from the processing object, and the ratio of the reflected light from the processing object changing until reaching the reflected light detector is the processing object. A reflected light distribution table stored for each processing position of the object, and a reflected light intensity calculation unit for calculating the reflected light intensity immediately after reflection from the processing target from the reflected light detector and the reflected light distribution table; The controller controls the laser oscillator based on a comparison between a relative reflected light intensity calculated from the incident light intensity detected by the incident light detector and the reflected light intensity calculated by the reflected light intensity calculation unit and a reference value thereof. Do Laser processing equipment. 3. The laser processing apparatus according to claim 2, wherein an arithmetic expression for calculating the relative reflected light intensity from the incident light intensity and the reflected light intensity is represented by (Equation 1). (Equation 1) 4. A laser oscillator for emitting a laser beam, an optical system structure for guiding the laser beam to an object to be processed, and a control device for controlling the laser oscillator, wherein incident light detection for detecting the intensity of the laser beam Vessel, a fixed mirror placed at a position where the processing object is placed, a reflected light detector for detecting the light intensity of the reflected light from the fixed mirror, and irradiating the laser light to a processing coordinate position where the processing object is located. From the reflected light intensity detected by the reflected light detector and the incident light intensity detected from the incident detector, the ratio of the reflected light intensity at which the reflected light immediately after being reflected from the fixed mirror reaches the reflected light detector is calculated. A laser processing apparatus provided with a reflected light distribution calculation unit to calculate and a reflected light distribution table for storing the calculation result of the reflected light distribution calculation unit. 5. The laser processing apparatus according to claim 1, wherein data of a ratio of the reflected light reaching the reflection detector is stored in a reflected light distribution table with respect to positions where processing positions are equally spaced. . 6. A method according to claim 1, wherein the data of the ratio of the reflected light reaching the reflected light detector is coarsely divided at the center of the processing area and finely divided at the peripheral part and stored in the reflected light distribution table. A laser processing apparatus according to any one of the above. 7. A control method of a laser processing apparatus for processing a processing object by emitting a laser beam from a laser oscillator, wherein a light intensity of light reflected from the processing object is detected by a reflected light detector, The rate at which the reflected light from the processing object changes until it reaches the reflected light detector is based on the data of the reflected light distribution table stored for each processing position of the processing object, from the processing object. A control method for a laser processing apparatus, which calculates reflected light intensity immediately after reflection and controls the laser oscillator based on a comparison between the calculated reflected light intensity and a reference value. 8. A control method of a laser processing apparatus for processing a processing object by emitting laser light from a laser oscillator, wherein the intensity of the laser light is detected as incident light intensity by an incident light detector, and The light intensity of the reflected light from the object to be processed is detected by a reflected light detector, and the rate at which the reflected light from the object to be processed reaches the reflected light detector is the processing position of the object to be processed. The reflected light intensity immediately after reflection from the object to be processed was calculated from the data of the reflected light distribution table stored for each and the output of the reflected light detector, and was calculated from the incident light intensity and the calculated reflected light intensity. A control method for a laser processing apparatus for controlling the laser oscillator based on a comparison between a relative reflected light intensity and a reference value thereof. 9. The control method for a laser processing apparatus according to claim 8, wherein an arithmetic expression for calculating the relative reflected light intensity from the incident light intensity and the reflected light intensity is represented by (Equation 2). (Equation 2) 10. A control method of a laser processing apparatus for processing a processing object by emitting laser light from a laser oscillator, wherein the intensity of the laser light is detected as incident light intensity by an incident light detector, and The reflected light detector detects the light intensity of the reflected light from the fixed mirror installed at the position where the object to be processed is placed, and irradiates the laser light to a processing coordinate position where the object is processed. From the reflected light intensity detected in step 2 and the incident light intensity detected from the incident detector, the ratio of the reflected light intensity at which the reflected light immediately after being reflected from the fixed mirror reaches the reflected light detector is calculated, and the calculation result is stored. A method of controlling a laser processing apparatus for controlling the laser oscillator based on a comparison between the data of the reflected light distribution table and a reference value. 11. The laser processing apparatus according to claim 7, wherein data of a ratio of the reflected light reaching the reflection detector is stored in a reflected light distribution table with respect to positions where processing positions are equally spaced. Control method. 12. A method according to claim 7, wherein the data of the ratio of the reflected light reaching the reflected light detector is roughly divided at the center of the processing area and finely divided at the peripheral part and stored in the reflected light distribution table. A method for controlling a laser processing apparatus according to any one of the above.