JP2014018800A - Laser joining method and laser joining system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser joining method and a laser joint system which can independently set respective physical quantities of first laser beam whose image is formed in a first part to be joined and second laser beam whose image is formed in a second part to be joined.SOLUTION: In a laser joining method and a laser joint system 10A for joining a circular terminal 300 and a rod terminal 308 positioned inside the circular terminal 300, a first image formation part I1 is formed by forming the image of first laser beam LB1 on an emission end surface of a first optical fiber 36 into a circular shape while matching the image of first laser beam LB1 to the circular terminal 300, and a second image formation part I2 is formed by forming an image of a second laser beam LB2 on an emission end surface of a second optical fiber 50 into a circular spot shape while matching the image of the second laser beam LB2 to the rod terminal 308.

Description

  The present invention relates to a laser bonding method and a laser bonding system for bonding an annular first bonded portion and a second bonded portion positioned inside the first bonded portion.

  Conventionally, laser light has been widely used for brazing of cooling fins of heat exchangers and fine parts of jewelry, etc., which makes it possible to perform fine joining to fine parts at low cost and at high speed. It has become. In recent years, it has been studied to use a laser beam for soldering an electronic component to a printed wiring board.

  When this type of laser bonding is performed, laser light having a minute circular spot shape (so-called center peak beam) is generally used. However, when the annular first bonded portion and the second bonded portion located inside the first bonded portion are bonded, either the first bonded portion or the second bonded portion is used. Since only one side is irradiated with the laser beam, the temperature of the first bonded portion and the second bonded portion is biased, and the filler material (solder material such as solder) flows only to the higher temperature side. Therefore, it is not easy to obtain a good joint.

  Although it is conceivable to increase the spot diameter of the laser beam and irradiate the laser beam to both the first bonded portion and the second bonded portion. Must be used.

  In addition, for example, when a rod-shaped terminal (second bonded portion) passed through a through hole of a printed wiring board and an annular terminal (first bonded portion, copper pattern) of the printed wiring board are soldered with the laser light. There is a concern that the electronic component may be damaged when the laser beam is irradiated onto the electronic component through the through hole.

  In order to solve such a problem, by irradiating an axicon lens having a central hole with one laser beam, an annular first laser beam transmitted through the axicon lens is imaged on an annular terminal. A technical idea for forming an image of a circular second laser beam that has passed through the center hole on a rod-shaped terminal is known (see, for example, Patent Document 1).

JP 2008-260035 A

  By the way, as for the workpiece | work used for brazing, such as soldering, the cyclic | annular 1st to-be-joined part and the 2nd to-be-joined part located inside this 1st to-be-joined part have a three-dimensional shape in many cases. In addition, there are various sizes and heat capacities of the first bonded portion and the second bonded portion.

  Therefore, each of the first laser beam and the second laser beam, the irradiation time of each of the first laser beam and the second laser beam, and the first laser beam formed in an annular image on the first bonded portion. The respective diameters (imaging diameters) of the second imaging unit formed by imaging the first imaging unit and the second laser beam formed in a circle on the second bonded part can be changed. desirable.

  However, in the conventional technique such as Patent Document 1 described above, the annular first laser beam and the circular second laser beam are simultaneously formed using a special axicon lens having a center hole. The light beam shape and the like depend on the structure of the axicon lens.

  That is, for example, it is possible to change the diameter of the first imaging unit by changing the distance between the condenser lens arranged on the laser beam incident side of the axicon lens and the axicon lens. The diameter of the second imaging unit cannot be changed. In addition, when such a method is used, the output balance of the first laser beam and the second laser beam changes, so that it is difficult to set the conditions of the first laser beam and the second laser beam, and the axicon lens The image of the first imaging unit may be blurred due to the influence of the aberration.

  That is, in such a conventional technique, each physical quantity (light quantity, irradiation time, image formation) of the first laser beam focused on the first bonded portion and the second laser beam focused on the second bonded portion. There is a possibility that the diameter, etc.) cannot be set independently.

  The present invention has been made in consideration of such a problem, and even when the annular first bonded portion and the second bonded portion located inside the first bonded portion are bonded. The physical quantity of each of the first laser beam imaged on the first bonded portion and the second laser beam imaged on the second bonded portion can be set independently. It is an object of the present invention to provide a laser bonding method and a laser bonding system that can be improved.

[1] A laser joining method according to the present invention is a laser joining method for joining an annular first joined portion and a second joined portion located inside the first joined portion, First laser light is propagated to the cladding of the first optical fiber, and an image of the first laser light on the exit end face of the first optical fiber is formed in an annular shape in accordance with the first bonded portion. An image forming unit is formed, a second laser beam having a wavelength different from the wavelength of the first laser beam is propagated to the core of the second optical fiber, and the second laser beam on the emission end face of the second optical fiber The second image-forming portion is formed by forming the image in a circular spot shape in accordance with the second bonded portion.

  According to the laser bonding method according to the present invention, the first imaging portion is formed by forming an image of the first laser beam on the emission end face of the first optical fiber in an annular shape in accordance with the first bonded portion, Since the second image forming portion is formed by forming an image of the second laser light on the emission end face of the second optical fiber into a circular spot shape in accordance with the second bonded portion, the first laser light and the Each physical quantity of the second laser light can be set independently. Thereby, the improvement of the joining quality of a 1st to-be-joined part and a 2nd to-be-joined part can be aimed at.

[2] In the laser bonding method, a ratio between the light amount of the first laser light and the light amount of the second laser light is set based on the heat capacities of the first bonded portion and the second bonded portion. May be.

  According to such a laser bonding method, since the ratio between the light amount of the first laser beam and the light amount of the second laser beam is set based on the heat capacities of the first bonded portion and the second bonded portion, Regardless of the heat capacities of the first and second bonded parts, it is possible to suitably raise the temperature of the first and second bonded parts. Therefore, it is possible to improve the bonding quality.

[3] In the above laser bonding method, at least one of a first drive current value of the first laser oscillator that oscillates the first laser light and a second drive current value of the second laser oscillator that oscillates the second laser light. By adjusting either one, the ratio of the light amount of the first laser light and the light amount of the second laser light may be set. In this case, the ratio between the light amount of the first laser light and the light amount of the second laser light can be easily set.

[4] In the laser bonding method described above, an interval between the first imaging unit and the second imaging unit may be set based on shapes of the first bonded unit and the second bonded unit. .

  According to such a laser bonding method, since the interval between the first image forming unit and the second image forming unit is set based on the shapes of the first bonded unit and the second bonded unit, the first bonded unit is used. The first laser beam can be reliably imaged on the first bonded portion and the second laser beam can be reliably imaged on the second bonded portion regardless of the shape of the portion and the second bonded portion. Can do. Therefore, it is possible to improve the bonding quality. Further, when laser soldering is performed, it is preferable to prevent the first laser beam or the second laser beam from being irradiated to the electronic component or the like through the gap between the first bonded portion and the second bonded portion. be able to.

[5] In the above laser joining method, by performing at least one of selection of a first optical fiber including a clad having a predetermined diameter and selection of a collimating lens having a predetermined focal length, An interval between the first imaging unit and the second imaging unit may be set. In this case, the interval between the first image forming unit and the second image forming unit can be easily set.

[6] In the laser bonding method described above, the ring width of the first imaging unit may be set based on the shape or heat capacity of the first bonded part.

  According to such a laser bonding method, since the ring width of the first imaging portion is set based on the shape or heat capacity of the first bonded portion, the ring width is set regardless of the shape or thermal stress of the first bonded portion. The temperature of the first bonded portion can be suitably raised. Therefore, it is possible to improve the bonding quality.

[7] In the above laser joining method, by performing at least one of selection of a first optical fiber including a clad having a predetermined diameter and selection of a collimating lens having a predetermined focal length, The ring width of the first imaging unit may be set. In this case, the ring width of the first image forming unit can be easily set.

[8] In the laser bonding method described above, the imaging position of the first laser beam and the second laser beam of the first laser beam are determined according to a dimensional difference in the height direction between the first bonded portion and the second bonded portion. At least one of the imaging positions may be set.

  According to such a laser bonding method, the imaging position of the first laser beam and the imaging position of the second laser beam are varied according to the dimensional difference in the height direction between the first bonded portion and the second bonded portion. Since at least one of them is set, the temperature of the first bonded portion and the second bonded portion is suitably raised regardless of the position in the height direction of the first bonded portion and the second bonded portion. Can do. Therefore, it is possible to improve the bonding quality.

[9] In the laser joining method described above, an imaging position of the first laser light is obtained by moving a collimating lens that collimates the first laser light emitted from the first optical fiber along the optical axis direction. May be set. In this case, the imaging position of the first laser light can be easily set.

[10] A laser joining system according to the present invention is a laser joining system for joining an annular first joined portion and a second joined portion located inside the first joined portion, A first optical fiber including a clad for propagating one laser beam, a second optical fiber including a core for propagating a second laser beam having a wavelength different from the wavelength of the first laser beam, and the first optical fiber. A first imaging portion is formed by forming an image of the first laser beam on the exit end face in a ring shape in conformity with the first joined portion, and the second laser light on the exit end face of the second optical fiber. Imaging means for forming a second imaging portion by forming the image in a circular spot shape in conformity with the second joined portion.

  According to the laser bonding system according to the present invention, the first imaging portion is formed by forming an image of the first laser light on the emission end face of the first optical fiber in an annular shape in accordance with the first bonded portion, The second laser beam can be formed by forming an image of the second laser beam on the emission end face of the second optical fiber into a circular spot shape in accordance with the second bonded portion. The physical quantities of the light and the second laser light can be set independently. Thereby, the improvement of the joining quality of a 1st to-be-joined part and a 2nd to-be-joined part can be aimed at.

[11] In the above laser joining system, the clad constituting the first optical fiber may be formed in a hollow shape.

  According to such a laser joining system, the first imaging portion can be formed into an annular shape by propagating the first laser light with the hollow clad.

[12] In the above laser bonding system, the first optical fiber includes a core, an annular cladding that covers the core, and an outer cladding that covers the cladding, and the cladding includes the core. You may have a refractive index larger than both the refractive index and the refractive index of the said outer clad.

  According to such a laser junction system, the first imaging portion is formed into an annular shape by propagating the first laser light through the clad having a refractive index larger than both the refractive index of the core and the refractive index of the outer clad. be able to.

[13] The laser bonding system may further include a first laser oscillator that oscillates the first laser light and a second laser oscillator that oscillates the second laser light.

  According to such a laser bonding system, since the first laser oscillator that oscillates the first laser light and the second laser oscillator that oscillates the second laser light are provided, the first drive current of the first laser oscillator is provided. By adjusting at least one of the value and the second drive current value of the second laser oscillator, the ratio of the light quantity of the first laser light and the light quantity of the second laser light can be easily set. In this case, the temperature of the first bonded portion and the second bonded portion can be suitably raised regardless of the heat capacities of the first bonded portion and the second bonded portion. Therefore, it is possible to improve the bonding quality. In addition, the irradiation time of the first laser beam to the first bonded portion and the irradiation time of the second laser beam to the second bonded portion can be easily set.

[14] In the above laser joining system, the imaging means includes a first collimating lens that collimates the first laser light emitted from the first optical fiber, and the light emitted from the second optical fiber. And a second collimating lens that collimates the second laser light, and further includes a lens displacement mechanism that can displace at least one of the first collimating lens and the second collimating lens along the optical axis direction. You may have.

  According to such a laser joining system, since the lens displacement mechanism capable of displacing at least one of the first collimating lens and the second collimating lens along the optical axis direction is provided, the first laser light is coupled. At least one of the image position and the image formation position of the second laser light can be easily set. Thereby, it is possible to suitably raise the temperature of the first bonded portion and the second bonded portion regardless of the positions in the height direction of the first bonded portion and the second bonded portion. Therefore, it is possible to improve the bonding quality.

[15] In the laser joining system, the imaging unit includes a first mirror that reflects the first laser light and a second mirror that reflects the second laser light, and the first mirror May be configured to transmit the second laser beam, or the second mirror may be configured to transmit the first laser beam.

  According to such a laser bonding system, the first mirror that reflects the first laser light is configured to be able to transmit the second laser light, or the second mirror that reflects the second laser light is the first laser light. Therefore, the first laser beam can be irradiated to the first bonded portion and the second laser beam can be irradiated to the second bonded portion with a simple configuration.

  As described above, according to the present invention, the first image forming portion is formed by forming an image of the first laser light on the emission end face of the first optical fiber in an annular shape in accordance with the first bonded portion. The second image forming portion is formed by forming an image of the second laser light on the emission end face of the second optical fiber into a circular spot shape in accordance with the second bonded portion, so that the first laser light and Each physical quantity of the second laser beam can be set independently, thereby improving the bonding quality of the first bonded portion and the second bonded portion.

It is a mimetic diagram showing a laser joining system concerning one embodiment of the present invention. FIG. 2A is a partially omitted longitudinal sectional view of the first optical fiber constituting the laser joining system, and FIG. 2B is a partially omitted longitudinal sectional view of the second optical fiber constituting the laser joining system. It is the block diagram which showed the principal part of the said laser joining system. It is a flowchart for demonstrating the joining method using the said laser joining system. It is plane explanatory drawing which shows the 1st image formation part and 2nd image formation part which were formed in the workpiece | work. FIG. 6 is a partially omitted vertical sectional view of a first optical fiber according to a modification of the laser bonding system. FIG. 7 is a cross-sectional explanatory view taken along line VII-VII in FIG. 6 for explaining a refractive index distribution of the first optical fiber. It is a schematic diagram which shows the laser joining system relevant to the laser joining system shown in FIG. It is the block diagram which showed the principal part of the laser joining system of FIG. It is a block diagram for demonstrating the modification of the laser joining system of FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a laser bonding method and a laser bonding system according to the present invention will be described in detail with reference to the accompanying drawings by giving preferred embodiments.

  A laser bonding system 10A according to an embodiment of the present invention is a laser soldering system that performs soldering by irradiating a workpiece W placed on a stage (not shown) with a first laser beam LB1 and a second laser beam LB2. It is configured.

  As shown in FIG. 1, the workpiece W includes a printed wiring board 302 on which an annular terminal (copper pattern, first bonded portion) 300 is formed, and an electronic component 304 mounted on the printed wiring board 302. The electronic component 304 includes an electronic component main body 306 and a rod-shaped terminal (columnar terminal, second joined portion) 308 connected to the electronic component main body 306, and the rod-shaped terminal 308 is connected to the printed wiring board 302. Positioning and holding are performed while the through hole 310 is inserted.

  The laser bonding system 10A includes a first LD power source 12, a first laser oscillator 14 that oscillates a first laser beam LB1 having a first wavelength based on a first drive current supplied from the first LD power source 12, and a first laser oscillator. The second laser beam LB2 having the second wavelength based on the first transmission unit 16 that transmits the first laser beam LB1 oscillated from 14, the second LD power source 18, and the second drive current supplied from the second LD power source 18. The second laser oscillator 20 that oscillates, the second transmission unit 22 that transmits the second laser light LB2 oscillated from the second laser oscillator 20, and the first transmission unit 16 and the second transmission unit 22 are connected to each other. The output unit 24, a solder supply unit 26 for supplying solder (thread solder) S, and a control unit 28 are provided.

  The first laser oscillator 14 is composed of, for example, an FC-LD (fiber coupling laser diode), and is configured by integrally coupling the first LD unit 30 and the first extraction optical fiber 32.

  The first LD unit 30 has one or a plurality of LD arrays, and is supplied (injected) with a required first driving current from the first LD power supply 12, for example, high power LD light of 1 W to 200 W is supplied to the first laser. Oscillates and outputs as light LB1. The first extraction optical fiber 32 is, for example, an SI-type optical fiber, extends to the first transmission unit 16, and emits the first laser light LB1 from its emission end face.

  The first transmission unit 16 includes a first incident portion 34 and a first optical fiber (spot shape deforming means) 36. The first incident portion 34 includes a collimator lens 38 that collimates the first laser beam LB1 emitted from the first extraction optical fiber 32 at a predetermined spread angle into parallel light, and a first laser beam of parallel light from the collimator lens 38. And a condenser lens 40 that squeezes the light LB1 and enters the first optical fiber 36.

  As shown in FIG. 2A, the first optical fiber 36 is configured to include a clad 42 that is formed in a hollow shape and propagates the first laser light LB1. The first optical fiber 36 terminates in the emission unit 24.

  Since the basic configuration of the second laser oscillator 20 is the same as that of the first laser oscillator 14 described above, detailed description thereof is omitted. That is, the second laser oscillator 20 includes a second LD unit 44 and a second extraction optical fiber 46.

  The second transmission unit 22 includes a second incident part 48 and a second optical fiber 50. The second incident part 48 has the same configuration as the first incident part 34 described above, and includes a collimating lens 52 and a condenser lens 54.

  As shown in FIG. 2B, the second optical fiber 50 is configured as an SI-type optical fiber or a GI-type optical fiber, and includes a core 56 made of pure quartz and, for example, fluorine covering the core 56 coaxially. And a clad 58 made of doped quartz glass. The second optical fiber 50 is terminated in the emission unit 24.

  As shown in FIG. 3, the emission unit 24 includes a first fiber holding unit 60 that holds the emission side end of the first optical fiber 36 and a second fiber holding that holds the emission side end of the second optical fiber 50. A unit 62 and an imaging optical system (imaging means) 64 are provided.

  The imaging optical system 64 forms a first imaging portion I1 by forming an image of the first laser beam LB1 on the emission side end face of the first optical fiber 36 in an annular shape in accordance with the annular terminal 300, and forming the first imaging portion I1. A second imaging portion I2 is formed by forming an image of the second laser beam LB2 on the emission end face of the two optical fiber 50 into a circular spot shape in accordance with the end face of the rod-shaped terminal 308 (see FIG. 5). ).

  Specifically, the imaging optical system 64 includes a collimating lens (first collimating lens) 66 that collimates the first laser light LB1 emitted from the first optical fiber 36 at a predetermined spread angle, and a second optical fiber. 50, a collimating lens (second collimating lens) 68 that collimates the second laser beam LB2 emitted at a predetermined spread angle, and the first laser beam LB1 collimated by the collimating lens 66 is directed to the annular terminal 300. In the optical path between the second mirror 72 and the work W, the second mirror 72 that reflects the second laser beam LB2 collimated by the collimating lens 68 toward the rod-shaped terminal 308 And a condensing lens 74 provided.

  The collimating lens 66 is supported by a lens displacement mechanism 76 that constitutes the emission unit 24. The lens displacement mechanism 76 is configured as a slider that can be displaced along the optical axis of the first laser beam LB1 emitted from the first optical fiber 36 while holding the collimator lens 66, for example. Thereby, the space | interval of the output end surface of the 1st optical fiber 36 and the collimating lens 66 can be changed. In the present embodiment, the position of the collimating lens 68 is fixed. In other words, the interval between the emission end face of the second optical fiber 50 and the collimating lens 68 is fixed.

  The reflective surface of the first mirror 70 is provided with a highly reflective coat (HR coat) for the first wavelength light. On the other hand, the reflection surface of the second mirror 72 is provided with a high reflection coat (HR coat) for light of the second wavelength and an antireflection coat (AR coat) for the first wavelength. The second mirror 72 reflects the second laser light LB2 and transmits the first laser light LB1 incident from the back side of the reflecting surface.

  In the present embodiment, the first mirror 70 and the second mirror 72 include the optical axis of the first laser beam LB1 reflected by the first mirror 70 and the second laser beam LB2 reflected by the second mirror 72. The optical axis is arranged so as to be coaxial.

  The condensing lens 74 condenses the first laser beam LB1 transmitted through the second mirror 72 on the surface of the annular terminal 300, and the second laser beam LB2 reflected by the second mirror 72 on the end surface of the rod-shaped terminal 308. Condensate.

  As can be understood from FIG. 3, the emission unit 24 is a camera unit 78 capable of photographing the shutter 77 provided in the optical path between the second mirror 72 and the condenser lens 74, the annular terminal 300, and the rod-shaped terminal 308. And further.

  The shutter 77 is configured to be switchable between an open state that allows passage of the first laser beam LB1 and the second laser beam LB2 and a closed state that blocks passage of the first laser beam LB1 and the second laser beam LB2. Yes. The camera unit 78 can photograph the joined state (soldered state) of the annular terminal 300 and the rod-shaped terminal 308, and the photographed information (image information or moving image information) is output to the control unit 28. The solder supply unit 26 is configured to be able to supply the solder S to the annular terminal 300 at a predetermined feed rate.

  The control unit 28 includes a first power supply control unit 82 that drives and controls the first LD power supply 12, a second power supply control unit 84 that drives and controls the second LD power supply 18, and a control unit main body 86 (see FIG. 1). The control unit main body 86 includes a storage unit 88, a collimating lens displacement control unit 90, a shutter control unit 92, a solder supply control unit 94, and a camera unit control unit 96.

  The storage unit 88 stores data on the shape, material, heat capacity, and the like of each of the annular terminal 300 and the rod-shaped terminal 308 to be soldered. Examples of the data relating to the shape include the diameter of the rod-shaped terminal 308, the size and diameter of the ring width w0 of the annular terminal 300, the distance d0 between the annular terminal 300 and the rod-shaped terminal 308, the end surface of the rod-shaped terminal 308 and the annular terminal 300. A dimensional difference h (see FIG. 3) along the height direction with respect to the surface can be mentioned (see FIG. 5).

  The collimating lens displacement control unit 90 controls driving of the lens displacement mechanism 76. The shutter control unit 92 controls opening and closing of the shutter 77. The solder supply control unit 94 drives and controls the solder supply unit 26 to supply the solder S to a predetermined position. The camera unit control unit 96 controls driving of the camera unit 78.

  Next, a procedure for soldering (joining) the annular terminal 300 and the rod-shaped terminal 308 using the laser joining system 10A configured as described above will be described with reference to FIGS. In the present embodiment, the shutter 77 is closed in the initial state.

  First, the annular terminal 300 and the rod-shaped terminal 308 of the workpiece W to be soldered are positioned with respect to the emission unit 24 (step S1 in FIG. 4). That is, the emission unit 24 is moved with respect to the workpiece W by a driving mechanism (not shown), the annular terminal 300 is positioned at the irradiation position of the first laser beam LB1, and the rod-shaped terminal 308 is positioned at the irradiation position of the second laser beam LB2. Let In this positioning step, a stage (not shown) on which the work W is placed may be moved with the emission unit 24 fixed.

  At this time, the solder supply unit 26 moves to a predetermined position in conjunction with the movement of the emission unit 24. That is, at this stage, the solder supply unit 26 is disposed at a position where the solder S can be supplied to the annular terminal 300. At this stage, the height position of the emission unit 24 with respect to the end surface of the rod-shaped terminal 308 is determined based on the imaging position (condensing position) of the first laser beam LB1.

  Subsequently, the physical quantities of the first laser beam LB1 and the second laser beam LB2 are set (step S2). Here, the physical quantity is, for example, a ratio between the light quantity of the first laser light LB1 and the light quantity of the second laser light LB2 (sometimes referred to as a light quantity ratio), the first laser light LB1 and the second laser light LB2. These are the irradiation times (sometimes referred to as laser irradiation times), the imaging position of the first laser beam LB1, and the like.

  In the present embodiment, an example in which any one of the light amount ratio, the laser irradiation time, and the imaging position is set in step S2 will be described. However, in step S2, two or more may be set in combination from the light amount ratio, the laser irradiation time, and the imaging position. Hereinafter, the setting of the physical quantity will be described in detail.

  The light quantity ratio is set based on the heat capacities of the annular terminal 300 and the rod-shaped terminal 308. Specifically, for example, the ring width w0 of the annular terminal 300 is formed larger than the diameter of the rod-shaped terminal 308 (the heat withdrawal of the annular terminal 300 is fast), and the heat capacity of the annular terminal 300 is larger than the heat capacity of the rod-shaped terminal 308. In this case, the light amount ratio is set so that the light amount of the first laser light LB1 is larger than the light amount of the second laser light LB2. Thus, the temperature of the annular terminal 300 and the rod-shaped terminal 308 can be suitably raised regardless of the heat capacity of each of the annular terminal 300 and the rod-shaped terminal 308. Therefore, it is possible to improve the bonding quality.

  The light quantity ratio is set by adjusting at least one of the first drive current value of the first LD unit 30 and the second drive current value of the second LD unit 44. In this case, the light quantity ratio can be easily set.

  The laser irradiation time is set based on the heat capacities of the annular terminal 300 and the rod-shaped terminal 308, respectively. Specifically, for example, when the ring terminal w 308 has a ring width w 0 larger than the diameter of the rod-shaped terminal 308, and the heat capacity of the ring-shaped terminal 300 is larger than the heat capacity of the rod-shaped terminal 308, the first laser beam. The irradiation time of LB1 is set longer than the irradiation time of the second laser beam LB2. Thus, the temperature of the annular terminal 300 and the rod-shaped terminal 308 can be suitably raised regardless of the heat capacity of each of the annular terminal 300 and the rod-shaped terminal 308. Therefore, it is possible to improve the bonding quality.

  The setting of the laser irradiation time is performed by adjusting at least one of the time for supplying the first drive current to the first LD unit 30 and the time for supplying the second drive current to the second LD unit 44. In this case, the laser irradiation time can be set easily.

  The imaging position is set based on the height dimension difference between the surface of the annular terminal 300 and the end face of the rod-shaped terminal 308. Specifically, when the end surface of the rod-shaped terminal 308 is positioned closer to the emission unit 24 than the surface of the annular terminal 300, the imaging position of the first laser beam LB1 is more than the imaging position of the second laser beam LB2. The imaging position is set so as to be far away. Thereby, the temperature of the annular terminal 300 and the rod-shaped terminal 308 can be suitably increased regardless of the position in the height direction between the surface of the annular terminal 300 and the end surface of the rod-shaped terminal 308. Therefore, it is possible to improve the bonding quality.

  The imaging position is set by displacing the collimator lens 66 by the lens displacement mechanism 76. Specifically, when the collimating lens 66 is displaced toward the emission end face of the first optical fiber 36 to shorten the distance between the collimating lens 66 and the emission end face, the imaging position of the first laser beam LB1 is far. Thus, when the collimating lens 66 is displaced toward the first mirror 70 to increase the distance between the collimating lens 66 and the emission end face of the first optical fiber 36, the imaging position of the first laser beam LB1 becomes closer. In this case, the imaging position can be easily set.

  When the process of step S2 is completed, the first power supply control unit 82 drives the first LD power supply 12 to supply the first drive current to the first LD unit 30, thereby oscillating the first laser light LB1 having the first wavelength. The second power supply controller 84 oscillates the second laser beam LB2 having the second wavelength by driving the second LD power supply 18 and supplying a second drive current to the second LD unit 44 (step S3).

  The first laser beam LB1 oscillated from the first LD unit 30 is emitted from the first extraction optical fiber 32, collimated by the collimator lens 38, and then collected by the condenser lens 40 on the clad 42 of the first optical fiber 36. It is incident and propagated (transmitted) to the output unit 24.

  The first laser beam LB1 emitted from the first optical fiber 36 is collimated by the collimator lens 66, reflected by the first mirror 70, and then transmitted through the second mirror 72 and applied to the shutter 77.

  On the other hand, the second laser beam LB2 oscillated from the second LD unit 44 is emitted from the second extraction optical fiber 46 and collimated by the collimator lens 52, and then the core of the second optical fiber 50 by the condenser lens 54. The light is incident on 56 and propagated (transmitted) to the output unit 24.

  The second laser beam LB2 emitted from the second optical fiber 50 is collimated by the collimating lens 68, then reflected by the second mirror 72, and applied to the shutter 77. At this time, the first laser beam LB1 transmitted through the second mirror 72 and the second laser beam LB2 reflected by the second mirror 72 are coaxial.

  Next, the shutter controller 92 opens the shutter 77 (step S4). When the shutter 77 is opened, the first laser beam LB1 is focused on the surface of the annular terminal 300 in a state where the first laser beam LB1 is focused on the focusing lens 74, and the second laser beam LB2 is focused on the focusing lens 74. Thus, the end surface of the rod-shaped terminal 308 is irradiated (step S5, see FIG. 5).

  That is, an image of the first laser beam LB1 on the emission end face of the first optical fiber 36 is formed in an annular shape in accordance with the annular terminal 300, thereby forming the first imaging portion I1, and the second optical fiber 50. An image of the second laser beam LB2 on the emission end face is formed into a circular spot shape in accordance with the rod-shaped terminal 308, thereby forming the second imaging portion I2.

  Thereby, the temperature of the annular terminal 300 that has absorbed the first laser beam LB1 is raised, and the temperature of the rod-shaped terminal 308 that has absorbed the second laser beam LB2 is raised.

  Further, the solder supply control unit 94 drives the solder supply unit 26 to supply the solder S to the annular terminal 300 (step S6). Then, the solder S supplied to the annular terminal 300 is melted and spreads in the circumferential direction of the rod-shaped terminal 308 so as to fill a gap between the rod-shaped terminal 308 and the annular terminal 300.

  At this time, the camera unit control unit 96 may control the camera unit 78 to photograph the solder S. In this case, it is possible to determine whether or not the soldering has been performed satisfactorily based on information photographed by the camera unit 78.

  Thereafter, the solder supply control unit 94 controls the solder supply unit 26 to stop supplying the solder S (step S7). Further, the first power control unit 82 controls the first LD power source 12 to stop the oscillation of the first laser beam LB1, and the second power source control unit 84 controls the second LD power source 18 to oscillate the second laser beam LB2. Is stopped (step S8). After step S8, the current soldering is completed (step S9).

  In the present embodiment, the first laser beam LB1 is propagated to the cladding 42 of the first optical fiber 36, and the image of the first laser beam LB1 on the emission end face of the first optical fiber 36 is aligned with the annular terminal 300 to form an annular shape. The first imaging portion I1 is formed by forming an image on the second laser beam LB2 having a wavelength different from the wavelength of the first laser beam LB1 and propagating to the core 56 of the second optical fiber 50. Since the second imaging portion I2 is formed by forming an image of the second laser beam LB2 on the emission end face of the two optical fibers 50 into a circular spot shape in accordance with the rod-shaped terminal 308, the first laser beam LB1 is formed. And the physical quantities of the second laser beam LB2 can be set independently. Thereby, the joint quality of the annular terminal 300 and the rod-shaped terminal 308 can be improved.

  In addition, since the first laser oscillator 14 that oscillates the first laser beam LB1 and the second laser oscillator 20 that oscillates the second laser beam LB2 are provided, the first LD unit 30 that constitutes the first laser oscillator 14 has the first LD. By adjusting at least one of the one drive current value and the second drive current value of the second LD unit 44 constituting the second laser oscillator 20, the light amount of the first laser light LB1 and the light amount of the second laser light LB2 are adjusted. The ratio can be easily set.

  In this case, the temperature of the annular terminal 300 and the rod-shaped terminal 308 can be suitably raised regardless of the heat capacity of each of the annular terminal 300 and the rod-shaped terminal 308. Therefore, it is possible to improve the bonding quality. Further, the irradiation time of the first laser beam LB1 to the annular terminal 300 and the irradiation time of the second laser beam LB2 to the rod-shaped terminal 308 can be easily set.

  Furthermore, according to the present embodiment, the lens displacement mechanism 76 capable of displacing the collimating lens 66 along the optical axis direction is provided, so that the imaging position of the first laser beam LB1 can be easily set. Thereby, it is possible to suitably raise the temperature of the annular terminal 300 and the rod-shaped terminal 308 regardless of the height positions of the surface of the annular terminal 300 and the end surface of the rod-shaped terminal 308. Therefore, it is possible to improve the bonding quality.

  Further, since the second mirror 72 that reflects the second laser beam LB2 is configured to be able to transmit the first laser beam LB1, the second laser is irradiated with the first laser beam LB1 on the annular terminal 300 with a simple configuration. The light terminal 308 can be irradiated with the light LB2.

  Laser joining system 10A concerning this embodiment is not limited to the form mentioned above. For example, in this embodiment, before performing the soldering step (step S1 described above), the interval d1 between the first image forming unit I1 and the second image forming unit I2 (image forming unit interval d1) may be referred to. ) And the ring width w1 of the first imaging unit I1 may be set to set the physical quantities of the first laser beam LB1 and the second laser beam LB2.

  The imaging portion interval d1 is set based on the shapes of the annular terminal 300 and the rod-shaped terminal 308. Specifically, the imaging portion interval d1 is set based on the interval d0 between the annular terminal 300 and the rod-shaped terminal 308. Accordingly, the first laser beam LB1 can be reliably imaged on the surface of the annular terminal 300 regardless of the shapes of the annular terminal 300 and the rod-shaped terminal 308, and the second laser beam LB2 can be formed on the end surface of the rod-shaped terminal 308. An image can be reliably formed. Therefore, it is possible to improve the bonding quality.

  In the laser bonding system 10A as in the present embodiment, the imaging unit interval d1 is set so that the interval between the first imaging unit I1 and the second imaging unit I2 is in the range of 0.1 mm to 0.7 mm. Preferably it is done. By doing so, it is possible to suitably suppress irradiation of the electronic component body 306 with the first laser beam LB1 or the second laser beam LB2 through the through hole 310.

  Further, the setting of the imaging portion interval d1 can be performed by changing the ring width w1 of the first imaging portion I1 or the diameter of the second imaging portion I2. Specifically, the imaging portion interval d1 is set by performing at least one of selection of the first optical fiber 36 having a predetermined diameter and selection of the collimating lens 66 having a predetermined focal length. The

  In the selection of the first optical fiber 36, the collimating lens 66 and the condensing lens 74 have the same imaging conditions, and the ratio of the inner diameter to the outer diameter of the cladding 42 of the first optical fiber 36 is kept constant. When the clad 42 is increased in the radial direction, the imaging portion interval d1 is increased and the ring width w1 of the first imaging portion I1 is increased.

  On the other hand, with the same imaging conditions for the collimating lens 66 and the condenser lens 74, the cladding 42 is made smaller in the radial direction with the ratio of the inner diameter and outer diameter of the cladding 42 of the first optical fiber 36 being constant. In this case, the imaging portion interval d1 becomes narrow and the ring width w1 of the first imaging portion I1 becomes narrow. Further, by arbitrarily selecting the ratio between the inner diameter and the outer diameter of the clad 42 constituting the first optical fiber 36, the diameter and the ring width w1 of the first imaging portion I1 can be easily adjusted.

  In the selection of the collimating lens 66, when the collimating lens 66 having a long focal length is selected while the focal length of the condenser lens 74 is fixed, the imaging portion interval d1 is reduced and the ring of the first imaging portion I1 is selected. When the collimating lens 66 having a short focal length is selected while the width w1 is narrowed and the focal length of the condenser lens 74 is fixed, the imaging portion interval d1 becomes wide and the ring width of the first imaging portion I1. w1 becomes wider.

  Thus, by performing at least one of the selection of the first optical fiber 36 and the selection of the collimating lens 66, the imaging portion interval d1 can be easily set.

  The ring width w1 is set based on the shape of the annular terminal 300 or the heat capacity. Specifically, when the ring width w0 of the annular terminal 300 is relatively large or when the heat capacity of the annular terminal 300 is relatively large, the ring width w1 of the first imaging unit I1 is set to be large. Thereby, the temperature of the annular terminal 300 can be suitably raised regardless of the shape and heat capacity of the annular terminal 300. Therefore, it is possible to improve the bonding quality.

  The ring width w1 is set by performing at least one of selection of the first optical fiber 36 having a predetermined diameter and selection of the collimating lens 66 having a predetermined focal length. That is, since the setting of the ring width w1 can be performed in the same manner as the setting of the imaging portion interval d1 described above, detailed description thereof is omitted. Thus, the ring width w1 can be easily set by performing at least one of the selection of the first optical fiber 36 and the selection of the collimating lens 66.

  In addition, for example, the laser bonding system 10A may include a first optical fiber 36a instead of the first optical fiber 36 described above. As shown in FIGS. 6 and 7, the first optical fiber 36 a includes a core 100, a first cladding 102 that covers the core 100 coaxially, and a second cladding (outer cladding) that covers the first cladding 102 coaxially. 104.

  The refractive index n2 of the first cladding 102 is set to be larger than both the refractive index n0 of the core 100 and the refractive index n1 of the second cladding 104 (see FIG. 7). In the present embodiment, the refractive index n0 of the core 100 is set to be smaller than the refractive index n1 of the second cladding 104 (n0 <n1). However, the refractive index n0 of the core 100 may be set larger than the refractive index n1 of the second cladding 104 (n0> n1), or may be the same (n0 = n1). In short, if the refractive index n2 of the first cladding 102 is larger than both the refractive index n0 of the core 100 and the refractive index n1 of the second cladding 104, the magnitude relationship between the refractive index n0 and the refractive index n1 can be freely selected. be able to.

  When a fiber-coupled semiconductor laser with NA <0.2 is used as the first laser oscillator 14, the refractive indexes n0 and n1 are set so that the incident NA of the first optical fiber 36a is 0.2. , N2 is preferably set.

  When such a first optical fiber 36a is used, when the first laser light LB1 is incident on the first cladding 102, the first laser light LB1 propagates through the first cladding 102. The image of the first laser beam LB1 on the emission end face 36a is formed in an annular shape in accordance with the annular terminal 300.

  In addition, with the same imaging conditions for the collimator lens 66 and the condenser lens 74, the diameters of the cores 100 of the first optical fiber 36 a and the ratios of the diameters of the first claddings 102 are kept constant. Can be increased, the imaging portion interval d1 and the ring width w1 of the first imaging unit I1 can be widened, and when the respective diameters are reduced, the imaging unit interval d1 and the first imaging unit. The ring width w1 of I1 can be reduced.

  Furthermore, in the first optical fiber 36a, the diameter and the ring width w1 of the first imaging portion I1 can be easily adjusted by arbitrarily selecting the ratio of the diameter of the core 100 and the diameter of the first cladding 102. .

  In the present embodiment, the lens displacement mechanism 76 can be configured to displace at least one of the collimating lens 66 and the collimating lens 68 along the optical axis direction. When the collimating lens 68 is displaced along the optical axis direction by the lens displacement mechanism 76, the imaging position of the second laser light LB2 can be easily set.

  In the present embodiment, the positions of the first optical fiber 36 and the second optical fiber 50 may be interchanged, and the positions of the first mirror 70 and the second mirror 72 may be interchanged. In this case, the first mirror 70 is configured to reflect the first laser beam LB1 and transmit the second laser beam LB2.

  Further, in the present embodiment, the first transmission unit 16 and the second transmission unit 22 may be deleted. In this case, the first extraction optical fiber 32 configuring the first laser oscillator 14 is configured as the above-described first optical fibers 36 and 36 a and is directly connected to the emission unit 24 to configure the second laser oscillator 20. The take-out optical fiber 46 may be configured as the second optical fiber 50 and connected directly to the emission unit 24. By omitting the first transmission unit 16 and the second transmission unit 22, the configuration of the laser bonding system 10A can be made compact.

  Next, a laser bonding system 10B related to the above-described laser bonding system 10A will be described with reference to FIGS. In the laser bonding system 10B, elements having the same or similar functions and effects as those of the laser bonding system 10A described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 8, in the laser bonding system 10 </ b> B, an LD power source 150, a laser oscillator 152 that oscillates a laser beam LB based on a drive current supplied from the LD power source 150, and a laser beam LB oscillated from the laser oscillator 152. Transmission unit 154, an emission unit 156 to which the transmission unit 154 is connected, a solder supply unit 26, and a control unit 158.

  The laser oscillator 152 is configured by integrally coupling the LD unit 160 and the extraction optical fiber 162, and the transmission unit 154 includes an incident portion 164 including a collimating lens 168 and a condensing lens 170, an optical fiber 166, and the like. Have Since the LD unit 160, the extraction optical fiber 162, and the incident portion 164 have the same configuration as the first LD unit 30, the first extraction optical fiber 32, and the first incident portion 34 described above, a detailed description thereof will be given. Omitted. The optical fiber 166 has the same configuration as the second optical fiber 50 described above.

  As shown in FIG. 9, the emission unit 156 parallelizes the fiber holding part 172 that holds the emission side end of the optical fiber 166 and the laser beam LB emitted from the optical fiber 166 at a predetermined spread angle into parallel light. A collimating lens 174, a laser beam splitting unit 176 that splits the laser beam LB collimated by the collimating lens 174 into a first laser beam LB1 and a second laser beam LB2, and a focusing lens 178. An optical fiber 180 on which the first laser beam LB1 is incident, a collimator lens 182 that collimates the first laser beam LB1 emitted from the optical fiber 180, a lens displacement mechanism 184 that can displace the position of the collimator lens 182, A polarization conversion unit 186 that converts the polarization state of the first laser beam LB1 collimated by the collimator lens 182 into linearly polarized light; A polarization beam splitter 188 that reflects the first laser beam LB 1 that has been linearly polarized by the polarization conversion unit 186 and transmits the second laser beam LB 2 that is guided from the laser beam splitting unit 176, and a beam that is guided from the polarization beam splitter 188. An irradiation optical system 190 for irradiating the workpiece W with the first laser beam LB1 and the second laser beam LB2 is provided.

  The laser beam splitting unit 176 is, for example, a rectangular mirror, and can be configured such that the transmittance (reflectance) of the laser beam LB varies depending on the position in the longitudinal direction. In the case of such a configuration, for example, by changing the incident position of the laser beam LB on the laser beam splitting unit 176 by displacing the laser beam splitting unit 176 with an actuator or the like, the light amount of the first laser beam LB1 The ratio with the light quantity of the laser beam LB2 can be easily changed.

  Note that a beam splitter may be used as the laser beam splitter 176. In this case, the ratio between the light amount of the first laser light LB1 and the light amount of the second laser light LB2 can be changed by exchanging with beam splitters having different transmittances.

  For example, the same optical fiber 180 as the first optical fibers 36 and 36a described above can be used. The lens displacement mechanism 184 has the same configuration as the lens displacement mechanism 76 described above. As the polarization conversion unit 186, for example, a Glan-Thompson prism or a polarizing plate can be used.

  The polarization beam splitter 188 is set so that the optical axis of the first laser beam LB1 and the optical axis of the second laser beam LB2 are coaxial.

  The irradiation optical system 190 reflects the first laser beam LB1 toward the annular terminal 300 and reflects the second laser beam LB2 toward the rod-shaped terminal 308, the first laser beam LB1 and the second laser beam LB2. And a condensing lens 74 for condensing the light. The control unit 158 includes a power supply control unit 194 that drives and controls the LD power supply 150 and a control unit main body 86.

  In the laser bonding system 10B configured as described above, the image of the first laser beam LB1 on the emission end face of the optical fiber 180 is formed in an annular shape in accordance with the annular terminal 300, and the second laser beam LB2 is formed into the rod-shaped terminal 308. An image is formed in a circular spot shape on the end face of the lens. Such a laser bonding system 10B also has the same effect as the laser bonding system 10A described above.

  The laser bonding system 10 </ b> B may include a laser beam splitting unit 176 a instead of the laser beam splitting unit 176. As shown in FIG. 10, the laser beam splitting unit 176a includes a movable prism 200 for splitting the laser beam LB into a first laser beam LB1 and a second laser beam LB2, and a first laser split by the movable prism 200. A fixed prism 202 for collimating the light LB1 into parallel light and a mirror 204 for guiding the first laser light LB1 collimated by the fixed prism 202 to the condenser lens 178 are provided.

  The movable prism 200 can be advanced and retracted with respect to the laser beam LB by an actuator or the like, for example. In this case, the ratio of the light quantity of the first laser light LB1 and the light quantity of the second laser light LB2 can be easily changed by changing the incident amount of the laser light LB to the movable prism 200.

  The present invention is not limited to the above-described embodiment, and it is naturally possible to adopt various configurations without departing from the gist of the present invention.

  For example, in the above-described embodiment, the camera unit 78 and the camera unit control unit 96 may be deleted. In this case, the emission units 24 and 156 can be reduced in size.

  The laser joining system according to the present invention is not limited to an example configured as a laser soldering system, and can be used for brazing or the like. In such a case, the work has an annular first joined portion and a second joined portion located inside the first joined portion, and the first laser beam having an annular spot shape is supplied as the first laser beam. By irradiating one bonded portion and irradiating the second bonded portion with a second laser beam having a circular spot shape, the brazing quality can be improved.

DESCRIPTION OF SYMBOLS 10A, 10B ... Laser joining system 14 ... 1st laser oscillator 20 ... 2nd laser oscillator 36, 36a ... 1st optical fiber 42 ... Cladding 66 ... Collimating lens (1st collimating lens)
64: Imaging optical system (imaging means)
68 ... Collimating lens (second collimating lens)
DESCRIPTION OF SYMBOLS 70 ... 1st mirror 72 ... 2nd mirror 76 ... Lens displacement mechanism 100 ... Core 102 ... 1st clad 104 ... 2nd clad (outside clad)
300 ... annular terminal (first joined portion) 308 ... rod-shaped terminal (second joined portion)
I1 ... First imaging unit I2 ... Second imaging unit LB ... Laser beam LB1 ... First laser beam LB2 ... Second laser beam W ... Workpiece

Claims (15)

A laser joining method for joining an annular first joined portion and a second joined portion located inside the first joined portion,
The first laser light is propagated to the cladding of the first optical fiber, and an image of the first laser light on the emission end face of the first optical fiber is formed in an annular shape in accordance with the first bonded portion. 1 imaging part is formed,
A second laser beam having a wavelength different from the wavelength of the first laser beam is propagated to the core of the second optical fiber, and an image of the second laser beam on the emission end face of the second optical fiber is transmitted to the second object. A laser joining method comprising: forming a second imaging portion by forming an image in a circular spot shape in accordance with the joining portion. The laser joining method according to claim 1,
A laser bonding method, wherein a ratio between the light amount of the first laser beam and the light amount of the second laser beam is set based on the heat capacities of the first bonded portion and the second bonded portion. . The laser bonding method according to claim 2, wherein
By adjusting at least one of a first drive current value of the first laser oscillator that oscillates the first laser light and a second drive current value of the second laser oscillator that oscillates the second laser light, A laser bonding method characterized by setting a ratio between a light amount of the first laser light and a light amount of the second laser light. In the laser joining method according to any one of claims 1 to 3,
A laser joining method, wherein an interval between the first imaging unit and the second imaging unit is set based on the shapes of the first and second joined parts. The laser bonding method according to claim 4, wherein
By performing at least one of selection of a first optical fiber including a clad having a predetermined diameter and selection of a collimating lens having a predetermined focal length, the first imaging unit and the second connection are performed. A laser bonding method characterized by setting an interval with an image portion. In the laser joining method according to any one of claims 1 to 5,
A laser joining method, wherein a ring width of the first imaging part is set based on a shape or heat capacity of the first joined part. The laser bonding method according to claim 6, wherein
The ring width of the first imaging unit is set by performing at least one of selection of a first optical fiber including a clad having a predetermined diameter and selection of a collimating lens having a predetermined focal length. And a laser bonding method. In the laser joining method according to any one of claims 1 to 7,
At least one of the imaging position of the first laser beam and the imaging position of the second laser beam according to a dimensional difference in the height direction between the first bonded portion and the second bonded portion. A laser bonding method characterized by comprising: setting. The laser bonding method according to claim 8, wherein
The laser joining is characterized in that the imaging position of the first laser light is set by moving a collimating lens for collimating the first laser light emitted from the first optical fiber along the optical axis direction. Method. A laser joining system for joining an annular first joined portion and a second joined portion located inside the first joined portion,
A first optical fiber including a cladding that propagates the first laser light;
A second optical fiber including a core for propagating a second laser beam having a wavelength different from the wavelength of the first laser beam;
A first imaging portion is formed by forming an image of the first laser beam on the emission end face of the first optical fiber in a ring shape in accordance with the first joined portion, and the emission end face of the second optical fiber. Imaging means for forming a second imaging portion by forming an image of the second laser light in a circular spot shape in accordance with the second joined portion;
A laser bonding system comprising: The laser bonding system according to claim 10, wherein
The clad constituting the first optical fiber is formed in a hollow shape. The laser bonding system according to claim 11, wherein
The first optical fiber includes a core;
The annular clad covering the core;
An outer clad covering the clad,
The laser junction system, wherein the cladding has a refractive index greater than both the refractive index of the core and the refractive index of the outer cladding. The laser bonding system according to any one of claims 10 to 12,
A first laser oscillator for oscillating the first laser beam;
And a second laser oscillator that oscillates the second laser light. In the laser joining system according to any one of claims 10 to 13,
The imaging means includes a first collimating lens that collimates the first laser light emitted from the first optical fiber;
A second collimating lens that collimates the second laser light emitted from the second optical fiber,
The laser joining system further comprising a lens displacement mechanism capable of displacing at least one of the first collimating lens and the second collimating lens along the optical axis direction. The laser bonding system according to any one of claims 10 to 14,
The imaging means includes a first mirror that reflects the first laser beam;
A second mirror that reflects the second laser light,
The laser joining system, wherein the first mirror is configured to transmit the second laser light, or the second mirror is configured to transmit the first laser light.

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