JP2853007B2 - Laser processing method of work and its device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for laser processing a work capable of performing laser processing by confirming the position and degree of laser processing of the work each time the processing is performed.

[0002]

2. Description of the Related Art Conventionally, laser processing has been frequently used as a method of welding a work or engraving a character on a work surface. Conventional laser processing focuses the laser light on the processing position of the workpiece, irradiates the processing position with laser light, performs laser cutting, laser welding, or laser engraving, and other various processing. The method of moving to the next processing position and performing processing without confirming the processing state has been adopted. Therefore, when a plurality of processing positions are set on a work, if there is any processing failure even at one position, the entire work becomes a defective product, which causes a reduction in product yield. Most of the recent work is not a simple member but a complex structure with a high degree of processing.Therefore, the whole product becomes defective due to poor welding or engraving at one place. In this case, higher processing accuracy was required to improve the yield. Also, when performing welding by laser processing of a workpiece, it is important to keep the welded portions in contact. In other words, if laser processing is performed without contacting the work of the welded part, energy is deprived to the work to which the laser beam enters, and energy is not input to the work on the opposite side, and conversely without welding. A phenomenon occurs in which a hole is formed in the work, and there is also a problem that the work is made defective.

[0003]

The problem to be solved by the present invention is as follows.
The cutting state, welding state or engraved state by laser processing is checked again after processing, and if processing is defective, laser processing is performed again to eliminate processing errors and improve product yield, and prior to laser processing The point is to check the contact state of the work and prevent the laser processing error itself.

[0004]

According to a first aspect of the present invention, there is provided a laser processing method for a work, wherein a pattern of a work (2) is recognized by a pattern recognition device (1). Processing position from upper reference position (O)
(P) is calculated, and the work (2) or the laser irradiation device (3) is moved so that the processing position (P) matches the laser irradiation position (R). (P) is matched with the laser beam (4) at the processing position (P) of the work (2).
The laser processing of (2) is performed, and then the laser processing position is determined by the pattern recognition device (1).
Recognize the pattern of (P), compare it with the standard laser processing pattern previously input to the control device (5), and use the pattern recognition device (1) to capture the laser processing pattern captured by the control device (5) and the standard laser processing pattern. Compare the processing pattern with the laser processing pattern and if the laser processing pattern is within the standard, complete the laser processing at that position, move to the next laser processing position, and reverse the captured laser processing pattern to the standard laser processing pattern. If the pattern is out of the reference as compared with the pattern, the laser beam (4) is irradiated again until the value falls within the reference as compared with the reference laser processing pattern, and reprocessing is performed.

A work (2) is set, and a pattern recognition device is set.
Operate (1) to recognize the surface pattern of work (2),
The image is converted into a digital signal and taken into the control device (5). In the control device (5), the machining position with respect to the reference position (O)
(P) is determined by XY coordinates (of course, polar coordinates are also possible),
The work (2) or the laser irradiation device (3) is moved by activating some moving means (10) so that the laser irradiation position (R) matches the processing position (P).

When the laser irradiation position (R) coincides with the processing position (P), the laser generator (6) is operated to irradiate the laser beam (4) to accurately heat the processing position (P). A predetermined process such as welding, drilling or engraving is performed. When the processing by the laser beam (4) is completed, the pattern recognition device (1) is operated again, and the image of the processing position (P) of the work (2) and the reference laser processing pattern already input to the control device (5). Then, it is determined whether or not the recognized laser processing pattern substantially matches the reference laser processing pattern within an allowable range. If it is within the allowable range, the processing is completed, and the moving means (10) is operated to move to the next processing position, and if it is out of the allowable range, the laser generator (6) is operated again to restart the laser. Perform processing. As a result, the laser processing is repeated until the reprocessing completely falls within the standard, and the occurrence of processing failure is prevented beforehand, and a high yield rate can be obtained.

According to a second aspect of the present invention, "in the case of performing laser re-working, the power supply (7) of the laser generator (6) adjusts the output of the laser beam (4) according to a command from the controller (5)". It is characterized by things. As a result, an output suitable for the image is obtained, the re-processing accuracy is improved, and re-re-processing is prevented from being repeated.

[0008] Claim 3 of the present invention states, "When performing rework,
The laser irradiation position (R) is shifted from the previous processing position (P), and laser reprocessing is performed at a new laser processing position (P1). " As a result, rework can always be performed at a new position, pattern comparison can be performed more accurately, and quality of rework can be more accurately determined.

A fourth aspect of the present invention is a laser welding method for a workpiece (2) when the workpiece (2) is conductive.
(2) Conduct the continuity test of (2), and as a result of the continuity test both (2)
(2) Perform laser processing if conduction is established between them. " This makes it possible to check in advance whether there is a gap between the conductive works (2) and (2) .As a result, when there is a gap, the laser processing is stopped and the work (2) is inadvertently laser-processed. It is possible to prevent the occurrence of damage to the vehicle.

According to a fourth aspect of the present invention, there is provided a concrete apparatus for carrying out the method, comprising: a laser generator (6); and a laser beam (4) generated by the laser generator (6).
A laser irradiation device (3) for irradiating the processing position (P) of (2), a laser transfer member (8) connecting the laser generator (6) and the laser irradiation device (3), and a work (2) are mounted. A work table (9) to be placed, a moving means (10) for moving either the work table (9) or the laser irradiation device (3), and a pattern recognition device (1) for pattern recognition of the work (2).
Before the laser processing of the work (2), the pattern of the work (2) recognized through the pattern recognition device (1) is processed to calculate the distance from the reference position (0) to the processing position (P). And the laser irradiation position (R) and the work processing position via the moving means (10).
(P) and the laser beam (4)
Irradiate (P) to perform laser processing of the work (2), and when the laser processing is completed, the pattern recognition device (1) recognizes the processing pattern of the laser processing part again and inputs the standard laser processing that has been input in advance. It is characterized by comprising a control device (5) that compares the pattern and terminates the processing at that position if it is within the reference, and conversely performs laser processing again if it is outside the reference. Thus, the method of the present invention can be carried out.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a block circuit diagram of a laser processing apparatus (A) according to the present invention. A laser generator (6) includes a yag rod (YAG rod) (11) and shutters (12) and (13) installed on both sides thereof.
And an excitation lamp (14) for applying light to the YAG rod (11)
And a power supply (7) for applying an excitation lamp (14), and an excitation lamp
A cooler (16) for cooling a housing (15) containing the (14) and the YAG rod (11), and a He-Ne laser (1
7), a reflecting mirror (18) for changing the traveling direction of the light emitted from the He-Ne laser (17), and all the mirrors installed between the reflecting mirror (18) and the shutter (12) on the left side in the figure. Reflection mirror (19)
And an output mirror (20) arranged in front of the shutter (13). The laser light (4) is output by a method such as continuous oscillation, pulse oscillation, Q-switch pulse oscillation, and single mode. Also, the optical system (24)
For example, an appropriate lens such as a single lens, a doublelet lens, a triplelet lens, a plano-convex lens, and a cylindrical lens is used.

The pattern recognition device (1) analyzes an image on the surface of the work (2) like a CCD camera and converts it into a digital electric signal, and is connected to the CPU (27) in the control device (5). Work captured by the pattern recognition device (1)
The pattern (2) is converted into a digital electric signal and sent to the CPU (27). Reference numeral (21) denotes a light source for illuminating a work, and a coupler (2) is connected via an optical fiber cable (22).
The light input terminal (23) disposed adjacent to the light input terminal (5) is adapted to enter the laser irradiation device (3), and the incident light is transmitted through the transmission type total reflection mirror (26). The light passes through the optical system (24) through the light source and irradiates the work (2).

The laser irradiation device (3) is composed of an optical system (24) combining a convex lens and other various lens systems as described above, and is provided with a laser generator (6) via a coupler (25).
And the laser irradiation device (3) are connected by a laser transfer member (8), and the laser light (4) is input to the laser irradiation device (3). In this embodiment, the laser irradiation device
(3) and the pattern recognition device (1) are integrated, and in this embodiment, are installed on a moving means (10) described later.

(26) The optical system (24) of the laser irradiation device (3)
This is a transmission-type total reflection mirror built in the coupler (25).
The laser light (4) input into the laser irradiation device (3), the illumination light, and the laser light for optical axis alignment are totally reflected from the laser irradiation device (3), and the light input to the pattern recognition device (1) is further reflected. The optical axis matches. Therefore, if the pattern recognition device (1) accurately captures the laser irradiation position (R) of the laser light (4), that position is the processing position (P), and the laser light (4) is concentrated at that point. Can do things.

The moving means (10) is, for example, an XY table. When the work (2) is placed on a transfer device such as a belt conveyor and moves intermittently, the pattern recognition device (1) is used. ) And the laser irradiation device (3)
0), and moves in the XY directions (XYZ directions are also possible). Conversely, the work (2) is not set on the conveyor belt as described above,
In the case where the work table (9) is installed, the work table (9) may be installed on the moving means (10). Although the movable range and the pitch are not limited, when processing a semiconductor pattern or an electronic component, it is relatively small, for example, about 2 to 5 mm.

The control device (5) includes a CPU (27), a ROM (28),
RAM (29), drive (30), CRT (31) and keyboard
(32), and the ROM (28) has a laser processing device
All of the processing procedures in (A) are programmed. RA
Work taken in from M1 (29)
The signal of (2) is stored. Drive (3
Numeral 0) is for controlling the moving means (10), is connected to the CPU (27), and moves the moving means (10) under the command of the CPU (27). CRT (31) is a pattern recognition device (1)
This is for displaying the pattern of the work (2) captured by. The keyboard (32) is for the operator to manually input the condition settings of the CPU (27).

When engraving the work (2),
It is sufficient to simply irradiate the processing position (P) with the laser beam (4), but when performing welding, the processing positions (P) are overlapped and the processing positions (P) are in contact with each other and there is no gap between the workpieces (2) and (2) This is very important. If there is a gap between the works (2) and (2), as described above, the work (2) to which the laser beam (4) enters receives energy, and the work (2) on the opposite side No energy is input to the work, and a phenomenon that a hole is made in the work (2) on the light incident side without welding is caused, thereby making the work (2) defective.

Therefore, when the pair of works (2) and (2) are conductive bodies such as metal or semiconductor, as shown in FIG. 3, the works (2) and (2) are connected to conductive means such as stylus. (34) is brought into contact, the continuity between the two (2) and (2) at the processing position (P) is checked prior to laser processing, and the data is taken into the control device (5) as data. If the conduction state is within the allowable range, the laser processing is started, but if not, the operator is notified without performing the laser processing. In conducting the continuity test, the workpieces (2) and (2) may be pressurized by the pressing means (33) to forcibly establish continuity. For objects with poor conductivity, simply press the work (2)
(2) may be contacted to start laser processing.

Next, the operation of the present invention will be described. Set the work (2) on the work table (9), and if the work (2) is conductive, conduct a continuity test to confirm that the continuity is established, and then check the pattern recognition device (1) Activate Thus, the pattern on the surface of the work (2) is recognized by the pattern recognition device (1), and the image is converted into a digital signal and sent to the CPU (27). This electric signal is sent to the CRT (31) via the CPU (27), and a circuit pattern as shown in FIG. 5, for example, is displayed on the CRT (31). The pattern recognition device (1) transmits through the transmissive total reflection mirror (26) and observes the surface of the work (2) on which the pattern is drawn through the optical system (24).

The work shown in FIG. 5 projected on the CRT (31)
In the video of (2), a case where a certain position (for example, a processing position (P)) with respect to the reference position (O) is determined is shown, and the reference position (O)
And the processing position (P) corresponding thereto are determined and displayed on the XY coordinates. The moving means (10) such as an XY table moves in the XY directions by an amount equal to the distance calculated thereby to move the position of the work (2) or the laser irradiating device (3) to thereby irradiate the laser irradiating device (3). Laser irradiation position
(R) is matched with the processing position (P). The function of the present apparatus is not limited to positioning only. For example, it is also possible to calculate the distance and direction between two points as shown in FIG. 6, or to measure the distance at a plurality of points as shown in FIG.

When the laser irradiation position (R) coincides with the processing position (P), the laser generator (6) is operated to irradiate a laser beam (4). The laser light (4) enters the laser irradiation device (3) from one coupler (25) and the laser transfer member (8) through the other coupler (25), and is totally reflected by the transmissive total reflection mirror (26). After that, the light is condensed at the processing position (P) through the optical system (24) and accurately heats the processing position (P). In this case, by appropriately adjusting the input energy, the irradiation position can be heated and welded, cut, perforated, or stamped.

The irradiation time of the laser beam (4) is set in advance and is controlled by the CPU (27). Laser light
When the processing by (4) is completed, the pattern recognition device (1)
Is operated to collect information on the processing position (P) of the work (2). FIG. 8 is an image of the processing position (P) of the laser-processed work (2). An image as shown in FIG. 8 is taken into the CPU (27) through the pattern recognition device (1), and is compared with the reference laser processing pattern already input to the ROM (28). Recognized laser processing pattern and ROM (2
When the reference laser processing pattern stored in advance in 8) substantially matches within the allowable range, the processing is completed, and the moving means (10) is operated to move to the next processing position. Then, processing similar to the previous processing is performed here.

Conversely, when the processed laser processing pattern obtained by the pattern recognition device (1) is smaller than the standard laser processing pattern stored in the ROM (28) in advance, and the processing is insufficient ( Conversely, the same applies when the processing is excessive and the processing pattern is too large), and the collected laser processing pattern is compared with the standard pattern,
If it is out of the allowable range, the laser generator (6) is operated again to perform laser rework.

In this case, the same point as the previous processing location may be laser-processed again. However, the laser beam (S1) is slightly shifted from the previous processing position (P), and is shifted to the position (P1) adjacent to the processing position (P). Four)
May be irradiated. At this time, in the case of performing re-machining with the laser beam (4), the CPU (27) calculates the degree of insufficient machining (excess) by comparing the standard pattern and the sampled machining pattern, and calculates the insufficient quantity (excess quantity). It is, of course, possible to estimate the power and increase (or decrease) the output of the power supply (7) so as to control the reprocessing to an appropriate processing scale.

When the rework is completed, the pattern recognition device is again
In (1), the processing pattern of the reworked portion is collected, and the processing pattern of the work (2) is compared with the reference pattern in the CPU (27) in the same manner as described above. If the rework is within the standard, it moves to the next position as described above, but if it is defective, repeat the rework operation and repeat the laser processing until the rework is completely within the standard. Become. In addition, it is also possible to regulate the number of repetitions and, if the repetition is not less than the standard even after performing a certain number of repetitions, an alarm is issued to urge the operator to check the device.

In the above embodiment, the pattern recognizing device (1) and the laser irradiating device (3) are installed on the moving means (10), and the pattern recognizing device (1) and the laser irradiating device (3) are moved in the XY directions by the moving means ( 1
However, the laser irradiation device (3) and the pattern recognition device (1) were fixed, and the work table (9) on which the work (2) was placed was moved by moving means. Needless to say, the work (2) may be moved in the X and Y directions by setting it to (10). The former case has an advantage in that the work (2) can be continuously processed. If you want to change the setting conditions of laser processing, etc., use the keyboard (32)
The necessary data may be sent to the CPU (27) to rewrite the data.

In the adjustment, the optical axes of the laser light (4) of the pattern recognition device (1) and the laser generator (6) need to be matched, but the He-Ne laser (17 ) Is used. That is, the laser light (4) emitted from the He-Ne laser (17)
Is reflected by a reflection mirror (18), passes through a total reflection mirror (19), a shutter (12), a YAG rod (11), a shutter (13), and an output mirror (20), and is a transmissive total reflection mirror (26). Reflected on
It reaches the processing position (P) of the work (2) through the optical system (24).
Here, the laser light of the He-Ne laser (17) and the pattern recognition device
If the optical axis of (1) matches (in other words, the processing position
(P) coincides with the irradiation position of the laser beam of the He-Ne laser (17)), the optical axis of the laser beam (4) of the yag rod (11) matches the optical axis of the pattern recognition device (1). It will be.

FIG. 9 shows the case of seam welding, in which the spot welding shown in FIG. 8 is laser-processed while continuously moving by a very small distance. In this case, in the case of seam welding that generally requires airtightness, the nugget overlap is 80%
In the case of seam welding that does not require much airtightness, the nugget overlap is about 50%. Therefore, the nugget overlap reference pattern during seam welding is stored in ROM (2
8), comparing the seam welding pattern on the work (2) collected by the pattern recognition device (1) with the seam welding reference pattern stored in the ROM (28) in advance,
The degree of overlap of the nuggets is checked, and when the degree of overlap is substantially the same, it is determined that the seam welding has been successfully performed.

Conversely, the images are compared to determine whether the nugget overlap condition, bead width, and other conditions necessary for welding are provided. If the predetermined requirements are within the standard, welding is performed as described above. It is completed, and if it is out of the standard, rework will be performed as in the case of spot welding. The laser-processed portion is compared with the image one by one, and it is confirmed that the laser processing has been performed satisfactorily. Then, the portion is moved to the next welding position. Therefore, occurrence of poor welding can be prevented beforehand, and a high yield rate can be obtained. The laser processing is performed in an assist gas atmosphere by injecting an assist gas into a processing position (P) of the work (2). As the assist gas, for example, oxygen gas is used as an active gas, and nitrogen, argon gas or the like is generally used as an inert gas.

[0030]

According to the present invention, as described above, the cutting state, welding state, or engraved state by laser processing is checked again after processing, and if processing is defective, laser processing is performed again. Checks can be performed, and the occurrence of defects due to processing errors can be significantly reduced, and there is an advantage that the yield of products can be improved. Also,
By conducting a continuity test prior to laser processing, it is possible to prevent processing errors due to laser processing.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram of a laser processing apparatus according to the present invention.

FIG. 2 is a schematic perspective view showing a laser processing state of the work according to the present invention.

FIG. 3 is a laser irradiation apparatus used in the present invention.

FIG. 4 is a side view of FIG. 3;

FIG. 5 is an image drawing of a work recognized by a pattern recognition device according to the present invention and projected on a CRT.

FIG. 6 is another image drawing of the work recognized by the pattern recognition device according to the present invention and projected on a CRT.

FIG. 7 is another image drawing of the work recognized by the pattern recognition device according to the present invention and projected on a CRT.

FIG. 8 is an image drawing of spot processing by a laser according to the present invention.

FIG. 9 is an image drawing of seam processing by a laser according to the present invention.

[Explanation of symbols]

 (1)… Pattern recognition device (2)… Work (3)… Laser irradiation device (4)… Laser beam (5)… Control device (0)… Reference position on pattern (P)… Working position of work (R ) ... Laser irradiation position

Claims (5)

(57) [Claims] 1. A pattern recognizing device that recognizes a pattern of a work, calculates a processing position from a reference position on the pattern of the work, and calculates a processing position and a laser irradiation device so that the processing position matches the laser irradiation position. Is moved, and laser processing is performed by irradiating a laser beam to the processing position of the work at a place where the laser irradiation position and the processing position match, and then the pattern of the laser processing part is recognized by a pattern recognition device, and When the laser processing pattern is within the standard, compared with the standard laser processing pattern input to the controller and comparing the laser processing pattern captured by the pattern recognition device with the standard laser processing pattern Completes the laser processing at that position, moves to the next laser processing position, and reverses the captured laser processing pattern to the standard laser processing pattern. A laser processing method for a workpiece, characterized in that, when the laser beam is out of the standard compared with the reference laser processing, the laser is re-processed until the laser beam is within the standard compared with the reference laser processing pattern. 2. The laser processing method for a workpiece according to claim 1, wherein when performing laser reprocessing, a laser power is adjusted by a power supply of the laser generator in accordance with a command from a control device. 3. When laser reworking is performed, the laser irradiation position is shifted from the previous processing position, and laser reworking is performed at a new laser processing position.
Or the laser processing method for a workpiece according to any one of the above. 4. When the workpiece is conductive, prior to laser processing, a continuity test is performed on a pair of superposed conductive workpieces. 4. The laser processing method for a workpiece according to claim 1, wherein the laser processing is performed. 5. A laser generator, a laser irradiator for irradiating a laser beam generated by the laser generator to a processing position of a work, a laser transfer member connecting the laser generator and the laser irradiator, and a work mounted thereon. Work table, a moving means for moving either the work table or the laser irradiation device, a pattern recognition device for work pattern recognition, and a pattern of the work recognized through the pattern recognition device before the laser processing of the work. To calculate the distance from the reference position to the machining position,
The laser irradiation position and the work processing position are made to coincide with each other via the moving means, and then the laser light is irradiated to the laser processing position to perform laser processing on the work. When the laser processing is completed, the laser processing is performed again by the pattern recognition device. A control device that recognizes the processing pattern of the part, compares it with a standard laser processing pattern that has been input in advance, ends processing at that position if it is within the reference, and performs laser processing again if it is outside the reference A laser processing apparatus for a work, comprising: