JP5051900B2 - Semiconductor laser welding equipment - Google Patents

Description

  The present invention relates to a semiconductor laser welding apparatus in which a material that is transparent to laser light and an absorptive material are brought into close contact with each other, and laser light is irradiated onto the contact portion to weld the close contact portion. It is about setting.

  As a means for welding and bonding resin materials, a resin material that transmits laser light and a resin material that absorbs laser light and generates heat are held in contact with each other, and a resin that transmits laser light such as a YAG laser. A part of the absorbent resin material is irradiated through the material, and the irradiated part of the absorbent resin material absorbs the light energy of the laser beam to generate heat and melt, and a part of the heat is irradiated. This is also applied to a part of the permeable resin material that is in contact with the melt, and the temperature of the part is raised to melt and fuse, and then the fused part is cooled and solidified to bond these resin materials. The method is known.

  This laser welding method requires appropriate control of the output of the laser beam, and is equipped with an external analog signal input unit, which enables laser beam control based on the analog signal input therefrom. The device is known. An invention relating to a laser welding apparatus and a laser welding method for controlling laser light in real time while measuring the transmittance of the laser light using such a laser welding apparatus is disclosed (for example, Patent Document 1).

FIG. 4 is a view for explaining this conventional laser welding apparatus and welding method.
In FIG. 4, 1 is a laser light source, 2 is an optical system for converging the laser light from the laser light source 1, 3 is a laser light that has passed through the optical system 2, and 4 is a resin that substantially transmits the laser light 3 that is a material to be processed. A transmitting material 5 made of a material is an absorbing material made of an opaque resin material that is in contact with the transmitting material and absorbs the laser beam 3.

  Reference numeral 6 denotes an arithmetic unit including a microcomputer that can control the output of the laser light source 1 in real time, 7 is an optical fiber cable that transmits laser light provided as needed, and 8 is a transmission This transmission is made close to a separate model (hereinafter referred to as a transmission material 4a) which is made of the same material as the material 4 and is supported at a position away from the work material by a necessary distance. A detector for measuring the amount of light transmitted through the material 4a, 9 is a measuring light source provided on the opposite side of the detector 8 with respect to the transmitting material 4a, and 10 is for focusing the light beam 11 emitted from the light source 9. And an optical system composed of a lens or the like that enters the detector 8 through the transmission material 4a.

Next, the operation of such a laser welding apparatus will be described.
Before the laser welding is performed, the light beam 11 from the measurement light source 9 is irradiated onto the transmission material 4a in advance, the amount of the light beam 11 transmitted through the transmission material 4a is measured by the detector 8, and the signal is sent to the arithmetic unit 6. By inputting, the transmittance of the transmissive material 4a (after all, the transmittance of the transmissive material 4) is calculated. Thereafter, laser welding is performed. First, an output corresponding to the magnitude of the transmittance calculated as a measurement result is set in the laser light source 1 by the arithmetic unit 6, and the laser light source 1 is passed through the optical system 2. Then, the laser beam 3 having the set intensity is irradiated to the workpiece material including the transmitting material 4 and the absorbing material 5. FIG. 5 is a diagram showing an example of the measured transmittance, and FIG. 6 is a diagram showing a laser beam output corresponding to the transmittance of FIG.

  As a result, the intensity of the laser beam 3 applied to the welded portion changes to a magnitude that immediately corresponds to the transmittance of the transmitting material 4 that is welded at that time. That is, when the transmittance is high, the intensity of the laser beam 3 is made relatively weak, while when the transmittance is low, the intensity of the laser beam 3 is increased so that the energy of the amount not excessive or insufficient is welded. Since the heat is applied to the surface of the absorbent material 5, an appropriate amount of heat is generated on the surface of the absorbent material 5. In addition, it is possible to prevent a trouble caused by a melted portion in the depth and perform high-quality laser welding.

The operation of the arithmetic device 6 will be described in detail.
In the arithmetic unit 6, in order to calculate the output of the laser light source 1 from the transmittance detected by the detector 8, the relationship between the transmittance of the transmissive material 4 and the output of the laser light source 1 is expressed by the transmittance x and the laser output W. Are defined in a form such as a functional expression W = f (x) and set in a memory in the arithmetic unit 6. Then, the transmittance of the transmissive material 4a is measured, and the obtained value is applied to this definition to calculate the optimum value of the output of the laser light source 1. Since a general laser welding apparatus has an analog voltage type input system, the laser light source 1 generates a laser output having a magnitude corresponding to a voltage input as a command value from the outside. Therefore, the output of the laser light source 1 can be changed by changing the voltage waveform of the command value. Regarding the output change pattern, it is also possible to perform multi-stage waveform control based on the result of measuring the change in transmittance over the entire circumference of the transmission material 4 along the line indicating the welding order.
JP 2004-243629 A

As described above, the transmittance is measured over the entire circumference of the transmission material, and the intensity of the laser output is controlled based on the measurement. Laser welding in the case where a transmission material with non-uniform transmittance is used for the workpiece However, it is useful in that stable quality welding is possible.
Then, as a more basic method, all the welded portions of the permeable material 4 to be actually welded are traced in advance, the in-plane distribution of transmittance is continuously measured, and this transmittance data is stored in the memory. It is also possible to perform laser welding later according to the transmittance data. When a large number of work materials having the same shape are repeatedly welded as in a normal welding process, first, the transmittance of the permeation material 4 of the work material is measured only once for the entire circumference of the welded portion. Since the output control of the laser light source 1 only needs to be repeated in the same pattern by the arithmetic unit 6 during the processing of the same lot, this method is the most efficient.

However, even when the data is stored in the memory in this way, since this data is the transmittance of the entire circumference of the welded portion, the arithmetic device 6 does not measure the transmittance of the permeation material of the same lot. The relationship between the transmittance of the transmission material 4 set in the memory in the arithmetic unit 6 and the output of the laser light source 1 is the optimum value of the output of the laser light source 1 corresponding to the transmittance from the relationship between the transmittance x and the laser output W. Since it is the same in that it is necessary to calculate, there is a disadvantage that it is not efficient in this respect.
In addition, the shape of the transmission material 4 of the workpiece material is complicated and the thickness is not uniform, or the distribution of crystals inside the material is not uniform, and the transmittance changes for each part of the workpiece material. In addition, there is a case where the distribution of the transmittance of the transmission material 4 cannot be stored in the memory and the output control cannot be routinely performed. In such a case, a system having excellent tact time and controllability is used. The transmittance of each part of the transmissive material 4 that changes with time is measured individually, and the output of the laser light source 1 must be controlled to change in real time according to the measurement result. .

  The present invention has been made in order to solve the above-described problems. The laser welding process is performed without separately storing the transmittance of the transmission material in the memory and the storage of the relationship between the transmittance and the laser output in the memory. The purpose of the present invention is to provide a laser welding apparatus that is easy to use by storing in a memory the relationship (hereinafter also referred to as a laser output profile) between the laser output suitable for the time and the changing transmittance in the memory. .

  The semiconductor laser welding apparatus according to the first aspect of the present invention includes an analog signal input unit that determines a laser output, and a light-transmitting material and a light-absorbing material are closely adhered to each other to overlap the light-transmitting material side. A semiconductor laser welding apparatus that welds both materials by irradiating laser light from the transmittance measuring means for measuring the light transmittance along the welded portion of the light transmissive material, and the transmittance measuring means An analog signal converting means for converting the obtained light transmittance into an analog signal by a predetermined procedure, and a storage means for receiving the analog signal from the analog signal converting means and storing the laser output profile of the welding process. Features.

  A semiconductor laser welding apparatus according to a second aspect of the present invention is characterized by comprising temperature measuring means for measuring the temperature of the welded part during the laser welding process in place of the transmittance measuring means.

  According to a third aspect of the present invention, there is provided a semiconductor laser welding apparatus comprising: a display means for displaying a laser output profile; an operation means for changing the laser output profile; And changing means for changing to a laser output profile changed based on an operation from the operating means.

  According to the first aspect of the present invention, since the laser output profile in one laser welding process can be set according to the transmittance of the transmission material, there is provided a laser welding apparatus suitable for repeated laser welding work of workpieces. be able to.

  According to the second aspect of the present invention, the laser output profile in one laser welding process can be set according to the temperature of the material to be processed in the laser welding process, so that laser welding can be performed in accordance with the melting characteristics of the material to be processed. Therefore, it is possible to provide a laser welding apparatus suitable for highly reliable laser welding work.

  According to the third aspect of the present invention, the laser output operation is performed with the laser output profile set to confirm the quality of the laser output profile, and the laser output profile can be corrected while confirming the welding condition. A good laser welding apparatus can be provided.

  The best mode of the present invention provides a laser welding apparatus having a function of controlling laser output in accordance with an analog signal from the outside, a table of correlation between the analog signal from the outside and the laser output, and an external in one laser welding process. This can be realized by providing a storage unit for storing a laser output profile corresponding to the analog signal. Next, the present invention will be specifically described with reference to three examples of the present invention.

FIG. 1 is a block diagram of a main part of one embodiment of a semiconductor laser welding apparatus according to the present invention.
The entire laser welding apparatus adopts the same configuration as the conventional example shown in FIG.
In FIG. 1, 60 is a laser welding power source corresponding to the arithmetic unit 6 of the conventional example, and 80 is a transmittance detector corresponding to the photodetector 8 of the conventional example.
The transmittance detector 80 irradiates the transmitting material 4a with the light beam 11 from the measuring light source 9 which is a transmittance measuring means, receives the transmitted light of the transmitting material 4a, and measures the transmittance, and an analog signal. An analog signal generating unit 82 that generates an analog signal (for example, an analog voltage signal of 0 to 10 V) required by the laser welding power source 60 from the transmittance from the transmittance measuring unit 81 serving as a conversion means.

  61 controls the entire laser welding power source 60. In this embodiment, in particular, a CPU that performs control to receive an analog signal from the outside and obtain a laser output corresponding to the analog signal, 62 is provided outside. An external signal that can be read by the CPU 61 as digital transmittance data after receiving an analog signal used as a laser output setting signal generated according to the transmittance of the transmission material 4a from the transmittance detector 80 and performing A / D conversion. A setting signal input unit 63 is a transmittance / laser output correspondence table that stores digital transmittance data from the external setting signal input unit 62 and laser output data determined in advance according to the transmittance in a table format.

  The CPU 61 reads the transmittance data of one laser welding process from the external setting signal input unit 62 by the CPU 61, reads the laser output corresponding to the transmittance data from the transmittance / laser output correspondence table 64, and outputs the laser output in the one laser welding process. A laser output profile table for storing a profile, 65 is a laser output profile setting unit for reading out the selected laser output profile from the laser output profile table 64 and setting it as a laser output profile, and 66 is a laser output from the laser output profile setting unit 65 It is a laser output control unit that receives a profile and controls so that a laser output according to the laser output profile is obtained. The CPU 61, the external setting signal input unit 62, the transmittance / laser output correspondence table 63, and the laser output profile table 64 constitute storage means for storing the laser output profile.

  Reference numeral 67 denotes an operation unit of a laser welding power source 60 including various operation keys (specifically described later) as operation means, 68 denotes a display unit which displays a laser output profile and the like as display means, and 69 denotes an external setting with the CPU 61. An address and data bus connecting the signal input unit 62 and the like. The laser output profile table 64 can store not only a laser output profile for one laser welding process but also profile data for a plurality of processes. The CPU 61, the operation unit 67, and the display unit 68 constitute a changing unit.

A drive current is supplied as a control parameter from the laser output controller 66 to the laser light source 1, and the output of the laser light source is determined. Then, a known method is used in which the drive current is detected by a current detection element and fed back to follow the laser output profile.
Next, the operation of such a laser welding apparatus will be described.

[Creation of transmittance / laser output correspondence table]
First, the transmittance / laser output correspondence table 63 of the laser welding power source 60 is completed. The amount of laser light reaching the absorbing material 5 varies depending on the transmittance of the transmitting material 4. Further, melting of the absorbing material 5 due to heat generated by the laser beam absorbed by the absorbing material 5 and the welding of the absorbing material 5 and the transmitting material 4 due to heat transfer melting to the transmitting material 4 accompanying with the melting time are the time during which the laser beam is irradiated. Varies depending on These relationships are obtained in advance experimentally, or the relationships obtained empirically are used to create the transmittance / laser output correspondence table 63 from the operation unit 67 according to the laser welding process to be executed. . As described above, when it is difficult to prepare the table by simultaneously considering the transmittance of the transmission material 4 and the irradiation time of the laser beam, a correspondence table for the transmittance and the laser output, and the irradiation time and the laser output is provided separately. It is also possible to read out necessary data from both tables at the time of generating the laser output profile.

  As described above, since the variation of the transmittance of the transmission material 4 in the laser welding process is used for setting the laser output profile, this transmittance / laser output correspondence table is an analog based on the variation of the transmittance of the transmission material 4 from the outside. There is a close relationship with the signal, and the creation of the transmittance / laser output correspondence table and the generation of the analog signal must be considered as one.

[Laser output profile settings]
Next, the laser output profile is set.
First, the transmittance of the transmissive material 4 is determined, and generation of a signal required by the laser welding power source 60 will be described based on the transmittance.
The entire laser welding apparatus is used to irradiate the transmission material 4 with a light beam for transmittance measurement according to the laser welding process, and the transmitted light is received by the transmitted light detector 80, so that the transmittance for each time of the laser welding process is obtained. Is measured by the transmittance measuring unit 81. FIG. 5 shows an example of the transmittance measured in this way, with the transmittance on the vertical axis and the progress time of the laser welding process on the horizontal axis. This transmittance is sent to the analog signal generation unit 82, where a signal required by the external setting signal input unit 62 of the laser welding power source 60 (for example, a voltage signal of 0 to 10 V) is generated and sent to the laser welding power source 60. It is done.

  The analog signal sent in this way is input to the external setting signal input unit 62 of the laser welding power source 60, where it is A / D converted and read into the CPU 61 every predetermined time, and the CPU 61 transmits data based on this data. Laser output data is read from the rate / laser output correspondence table 63, a laser output profile in the laser welding process is generated in the predetermined time unit, and stored in the laser output profile table 64.

[Welding work]
Next, the operation at the time of laser welding work will be described. First, the absorbent material 5 as the work material is placed on a predetermined placement table using a known conveyance and alignment means, and the transmission material 4 is stacked thereon.
Then, the irradiation position is moved while irradiating the laser beam from the laser light source 1 under the control of the laser welding power source 60. This irradiation position is also moved by a known means.

Since the laser light output at this time needs to be controlled by the laser output profile set as described above, the laser output profile table under the control of the CPU 61 is operated by operating the laser output profile designation key of the operation unit 67. The designated laser output profile is read from 64 and set in the laser output profile setting unit 65.
This laser output profile is sent to the laser output control unit 66, where a drive current of the laser light source is generated in accordance with the laser output profile to drive the laser light source. As for this drive current, a laser output based on a laser output profile is obtained by known feedback control, a desired laser output is obtained, and appropriate laser welding is performed.

In Example 1, laser welding is performed by paying attention to fluctuations in the transmittance of the transmission material, but in laser welding, the temperature of the welded portion in the laser welding process is a factor that determines whether the welding quality is good or bad. It is important to determine the laser output profile based on this temperature.
Therefore, in this embodiment, the temperature is detected instead of the transmittance.
Next, the present embodiment will be described focusing on this difference.

As the temperature detector, a radiation type thermometer capable of measuring the temperature of the target part in a non-contact manner as described in Patent Document 1 is used.
As described above, the present embodiment has an essential difference from the embodiment in the detection parameter. Therefore, the block diagram of FIG. 1 will be used and will be described in accordance with the present embodiment. Each device and each block adds “a” to the end of the corresponding code in order to clarify the difference from the first embodiment. In addition, even if it attaches | subjects and distinguishes by the code | symbol of this tail, description is abbreviate | omitted about the substantially same thing.

In FIG. 1, 60a is a laser welding power source, and 80a is a temperature detector.
The temperature detector 80 detects the infrared energy radiated according to the temperature of the laser irradiation part during laser welding, which is a temperature measurement means, and measures the temperature by measuring the temperature from the temperature data from the temperature measurement unit 81a and the temperature measurement unit 81a. An analog signal generator 82a that generates an analog signal (for example, an analog voltage signal of 0 to 10 V) required by the welding power source 60a.

  61a is a CPU, 62a is an analog signal used as a laser output setting signal generated according to the temperature of the laser irradiation part from the temperature detector 80 provided outside, and is A / D converted to digital temperature data. An external setting signal input unit that can be read by the CPU 61a, and a temperature / laser output correspondence table 63a that stores digital temperature data from the external setting signal input unit 62a and laser output data determined in advance according to the temperature in a table format. It is.

  In 64a, the CPU 61a reads the temperature data of one laser welding process from the external setting signal 62a, reads the laser output corresponding to the temperature data from the temperature / laser output correspondence table 63a, and stores it as a laser output profile in the one laser welding process. An output profile table, 65a is a laser output profile setting unit, and 66a is a laser output control unit.

[Creation of temperature / laser output correspondence table]
First, the temperature / laser output correspondence table of the laser welding power source 60a is completed. An appropriate melting temperature is determined by the combination of the permeable material 4 and the absorbent material 5 which are work materials. The reason why the melting temperature is controlled is due to the factors shown in the first embodiment. As in the first embodiment, the relationship between the temperature and the laser output is experimentally obtained in advance or empirically. The temperature / laser output correspondence table is created from the operation unit 67a in accordance with the laser welding process to be performed by using the relationship obtained in the above.

[Laser output profile settings]
Next, the laser output profile is set.
First, the generation of signals required by the laser welding power source 60a will be described based on the measurement of the temperature of each laser irradiation site in the actual laser welding process.
As shown in the laser welding process, the transmission material 4 is irradiated with a light beam for transmittance measurement (not shown), and the infrared energy emitted for each irradiated portion of the laser light at this time is received by the temperature detector 80a. Is measured by the temperature measuring unit 81a. This temperature is sent to the analog signal generator 82a, where a signal required by the external setting signal input unit 62a of the laser welding power source 60a is generated and sent to the laser welding power source 60a.

  The analog signal thus sent is input to the external setting signal input unit 62a of the laser welding power source 60a, where it is A / D converted into digital temperature data and read into the CPU 61a every predetermined time. Based on the data, the laser output data is read from the temperature / laser output correspondence table 63a, and the laser output profile in the laser welding process is stored in the laser output profile table 64a in the predetermined time unit.

[Welding work]
The laser welding operation is the same as that in the first embodiment.

  In both the first and second embodiments, a laser output profile is created based on an external signal, and the laser output is determined by controlling the drive current of the laser light source in accordance with the laser output profile data.

Even when the laser welding operation is executed in this way, there may be a case where it is actually desired to slightly modify the laser output profile. In this case, even if the laser output profile creation in the first or second embodiment is repeated, the laser output profile does not change in most cases.
In such a case, the laser welding operator may know from experience how the laser profile can be changed to achieve a more appropriate laser welding. It is this embodiment that makes this possible.
Next, the laser output profile change according to this manual will be described.

  FIG. 3 is a diagram showing a laser output profile before the change and a laser output profile after the change. (A1) indicated by a solid line is the laser output profile before the change, and (a2) indicated by a partly dotted line is the laser output profile after the change. Note that (b) and (c) are used to indicate the laser output (d) before the change of the time to be changed and the laser output (e) after the change in the laser output profile with the vertical and horizontal cursors.

  To change the laser output profile, the operator operates the setting change key of the operation unit 67 (67a) to set the laser welding power source 60 (60a) to the laser output profile change mode, and operates the laser output profile designation key. Specify the laser output profile you want to change. This operation is read by the CPU 61 (61a), and the CPU 61 (61a) displays the corresponding laser output profile and cursor on the display unit 68 (68a).

  Next, the operator operates a cursor movement key (not shown) of the operation unit 67 (67a) to move the displayed laser output profile to the laser output at the time to be changed. Since the laser output for the time to be changed is at the intersection of the vertical and horizontal cursors, the cursors (b) and (c) are first moved to match the laser output (d) before the change, and the confirmation is made here. Use the keys to confirm the laser output you want to change.

Next, if the operator wishes to change the laser output (d) at this time to the laser output (e), the cursor (c) is moved downward in FIG. 3 while viewing the display on the display unit 68 (68a). The movement key (not shown) to be operated is operated, and when the desired laser output (e) is reached, the operation of the movement key is stopped. Then, the changed laser output (e) is confirmed by operating the confirmation key.
The movement of the cursor (c) is executed under the control of the CPU 61 (61a) by reading the operation of the operation unit 67 (67a) by the CPU 61 (61a).

When the laser output (e) after the change is determined in this way, the CPU 61 (61a), based on the laser output (f) at time t7 around this time t8 and the laser output (g) at time t8. Change the laser output profile.
That is, the laser output (f) at time t7, the laser output (e) at time t8, the laser output (e) at time t8, and the laser output (g) at time t9 are connected by straight lines, respectively, and the time t7 and the time t8 are connected. And the laser output between time t8 and time t9 are obtained by linear interpolation, respectively. The changed laser output profile obtained in this way is indicated by a dotted line (a2).

  The changed laser output profile obtained in this way is stored in a form that can be rewritten in the laser output profile table 63 (63a), and is set in the laser output profile setting unit 65 (65a). The laser welding operation is executed by controlling the light source 1.

It is a principal part block diagram of the semiconductor laser welding apparatus which becomes this invention. It is an example of the laser output profile corresponding to the transmittance | permeability. It is a figure which shows the laser output profile before a change, and the laser output profile after a change. It is a figure explaining the conventional laser welding apparatus and the welding method. It is a figure which shows an example of the transmittance | permeability measured with the laser welding apparatus of FIG. It is an example of the laser output profile corresponding to the transmittance | permeability measured with the laser welding apparatus of FIG.

Explanation of symbols

60 Laser welding power supply 61 CPU
62 External setting signal input unit 63 Transmissivity / laser output correspondence table 64 Laser output profile table 65 Laser output profile setting unit 66 Laser output control unit 67 Operation unit 68 Display unit 80 Transmittance detector 81 Transmittance measurement unit 82 Analog signal generation Part

Claims (3)

A semiconductor laser with an analog signal input that determines laser output, a light-transmitting material and a light-absorbing material in close contact, and a laser beam irradiated from the light-transmitting material side to weld both materials A welding device,
A transmittance measuring means for measuring the light transmittance along the welded portion of the light transmissive material;
An analog signal converting means for converting the light transmittance obtained from the transmittance measuring means into an analog signal according to a predetermined procedure;
A semiconductor laser welding apparatus comprising: storage means for receiving an analog signal from the analog signal conversion means and storing a laser output profile of a welding process.   2. The semiconductor laser welding apparatus according to claim 1, further comprising temperature measuring means for measuring the temperature of the welded part in the laser welding process instead of the transmittance measuring means. A semiconductor laser welding apparatus in which a light-transmitting material and a light-absorbing material are adhered and overlapped, and laser light is irradiated from the light-transmitting material side to weld both materials,
Display means for displaying a laser output profile;
Operating means for changing the laser output profile;
Changing means for changing to a laser output profile changed based on the operation of the operating means;
The semiconductor laser welding apparatus according to claim 1, further comprising:

Images