Soldering device for soldering with laser beam and robot apparatus provided with soldering device

A soldering device includes a laser head for outputting a laser beam and a solder feeder for feeding a thread solder to a path of the laser beam. The soldering device includes a solder receiving member for receiving solder melted by the laser beam and a pouring member for pouring molten solder into a workpiece. The solder receiving member includes a recess part having a shape for retaining the molten solder. The pouring member has a groove part communicating with the recess part and allowing the solder to flow therein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a new U.S. Patent Application that claims benefit of Japanese Patent Application No. 2019-100500, dated May 29, 2019, the disclosure of this application is being incorporated herein by reference in its entirety for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a soldering device for soldering with a laser beam and a robot apparatus provided with the soldering device.

2. Description of the Related Art

Parts are fixed to each other and electrically connected to an electric circuit by soldering operation. For example, soldering can be performed when an electronic part is fixed to a board such as a printed circuit board. By performing soldering, an electronic part can be fixed to a board and the electronic part can be connected to an electric circuit formed on the board. In the case of soldering, solder is heated to melt. The molten solder is fed to portions for fixing the electronic parts, for example, the leads or terminals of the electronic parts. Thereafter, the solder hardens as the solder decreases in temperature.

In the related art, it is known that a laser beam is irradiated to solder in order to heat and melt the solder (for example, Japanese Unexamined Patent Publication No. 2011-216503, Japanese Unexamined Patent Publication No. 2010-89159, and Japanese Unexamined Patent Publication No. 8-8284). By using the laser beam for melting the solder, the solder can be melted in a short time, whereby an operation time for soldering can be shorten.

SUMMARY OF THE INVENTION

In a soldering device for melting solder with a laser beam, the solder is placed on the portion of the lead of DIP (Dual Inline Package) part or the terminal of surface-mount part before the solder is melted. A laser beam is then irradiated to the solder, so that the solder is melted and fed to the portion at which the lead or the terminal is arranged.

In a soldering operation, for example, the leads of electronic part are inserted into through holes formed on a printed circuit board. Subsequently, the solder is placed on the portions at which the leads are arranged from the back side of the printed circuit board. The solder is melted by irradiation of the laser beam so as to fix the leads arranged in the through holes onto the board.

In such a soldering operation, a laser beam may be reflected on the surface of the lead of the electronic part. The reflected laser beam may reach a portion around the through hole of the printed circuit board. For example, a laser beam may be reflected on the end of the lead and burn a portion around the through hole of the printed circuit board. Alternatively, a laser beam may be reflected on the tip of the lead and reach an electronic part disposed around an electronic part to be soldered. Thus, the electronic part may be burned by the laser beam.

The tips of the leads of the electronic parts may have various shapes, especially if the leads of the electronic parts do not have cylindrical shapes. For example, the leads may have shape like plate and the electronic part may be temporarily fixed in the through hole by the elasticity of the lead. A laser beam is reflected in various directions by the end part of the lead and thus may burn the printed circuit board or surrounding electronic part.

Alternatively, a laser beam may pass through the printed circuit board from a gap between the lead and the through hole and reach the main body of the electronic part. Thus, the laser beam may be irradiated to a mold covering an element and burn the main body. In particular, when the lead has a shape other than cylindrical shape, there is a large space between the lead and the through hole, and thus a laser beam easily reaches the main body of the electronic part.

The reliability of some electronic parts may decrease with increase in temperature. When the solder is melted by a laser beam, the electronic part may instantly rise in temperature, depending on the output of the laser beam, and the reliability of the electronic part may be reduced.

As described above, when the soldering operation is performed with a laser beam, the quality of the printed circuit board may be deteriorated. For example, also in an electric circuit operating normally during manufacturing, the printed circuit board or the electronic part may be burned and thereby reduce durability. Especially in the case of a device such as a machine controller that needs to operate normally over an extended period, there is the problem that the printed circuit board and the electronic part may be burned during the manufacturing of the printed circuit board.

A designer of a printed circuit board designs the printed circuit board so as to prevent damage to the printed circuit board or electronic parts during soldering with a laser beam. For example, a printed circuit board is designed with a small-diameter through hole so as to prevent a laser beam from passing through the through hole. However, when the through hole having small diameter is employed, the failure in insertion is liable to occur in an operation for inserting the lead of electronic part through the through hole. Alternatively, when the electronic part having low heat resistance is used, the range in which heat generated by the laser beam spreads is examined in the design of the printed circuit board. Moreover, an element arranged in the electronic part may be damaged by the irradiation of the laser beam. Thus, electronic parts having heat resistance are selected. Furthermore, an appropriate layout of the electronic parts is determined.

As described above, in the case of soldering with a laser beam, a special workpiece design is necessary in order to suppress damage to the workpiece such as a printed circuit board or damage to parts fixed to the workpiece. Hence, there is the problem that a considerable effort is required of the designer in a design of the workpiece.

A soldering device according to an aspect of the present disclosure feeds solder melted by a laser beam to a workpiece. The soldering device includes a laser beam emitting member for outputting a laser beam and a solder feeder for feeding the solder to the path of the laser beam. The soldering device includes a solder receiving member for receiving the solder melted by the laser beam and a pouring member for pouring molten solder into the workpiece. The solder receiving member includes a reception part having a shape for retaining the molten solder. The pouring member is fixed to the solder receiving member and has a solder channel communicating with the reception part and allowing the solder to flow therein.

A robot apparatus according to the aspect of the present disclosure includes the above soldering device and an articulated robot for changing the position and orientation of the soldering device. The robot apparatus includes a controller for controlling the articulated robot. The controller performs control in which the soldering device is tilted so as to feed the molten solder from the reception part to the workpiece through the solder channel. The controller performs control in which the laser beam is irradiated so as to feed the solder to the workpiece while the soldering device is tilted.

DETAILED DESCRIPTION

Referring toFIGS. 1 to 13, a soldering device and a robot apparatus provided with the soldering device according to an embodiment will be described below. The soldering device of the present embodiment melts solder with layer light and feeds molten solder to a workpiece.

FIG. 1is a schematic perspective view of the robot apparatus according to the present embodiment. A robot apparatus5includes an operation tool and a robot1that moves the operation tool. The operation tool of the present embodiment is a soldering device2. The soldering device2is connected to the robot1. The robot apparatus5changes the position and orientation of the soldering device2and feeds molten solder to a predetermined position of the workpiece.

The robot1of the present embodiment is an articulated robot including a plurality of joints. The robot1includes a base part14and a rotation base13supported by the base part14. The base part14is fixed to an installation surface. The rotation base13is formed so as to rotate relative to the base part14. The robot1includes an upper arm11and a lower arm12. The lower arm12is pivotally supported by the rotation base13via the joint. The upper arm11is pivotally supported by the lower arm12via the joint. The upper arm11rotates about a rotary axis parallel to a direction along with the upper arm11extends.

The robot1includes a wrist15connected to one end of the upper arm11. The wrist15is pivotally supported by the upper arm11via the joint. The wrist15includes a flange16that is formed to be rotatable. The robot1of the present embodiment includes six drive axes, but the embodiment is not limited to this. Any robot capable of changing the position and orientation of the soldering device2may be used.

The robot apparatus5of the present embodiment has an automatic tool changer (ATC) that can automatically change the operation tool. The automatic tool changer includes a robot-side plate71attached to the flange16of the robot1and a tool-side plate72attached to the soldering device2. The tool-side plate72is formed so as to be connected and released to and from the robot-side plate71. The robot apparatus5can automatically change the operation tool. The soldering device2may be fixed to the flange16without the automatic tool changer.

FIG. 2is a perspective view of the soldering device viewed from one side according to the present embodiment.FIG. 3is a perspective view of the soldering device viewed from the other side according to the present embodiment. Referring toFIGS. 2 and 3, the soldering device2includes a support member20fixed to the tool-side plate72of the automatic tool changer and a heat insulation member21fixed to the support member20. The heat insulation member21can be formed as a member having low thermal conductivity. For example, the heat insulation member21can be made of materials such as zirconia and steatite that are fine ceramics having excellent heat insulating properties.

The soldering device2includes a laser head31acting as a laser beam emitting member for outputting a laser beam. The laser head31is supported by the support member20and the heat insulation member21. To the laser head31of the present embodiment, a laser beam30is supplied through an optical fiber32. The soldering device2includes a solder feeder34for feeding the solder to the path of the laser beam30. The solder feeder34of the present embodiment feeds a thread solder35. The solder feeder34includes a delivery machine for feeding the thread solder35and a solder feed pipe36for guiding the thread solder35to a predetermined position. The delivery machine has a mechanism of a roller or the like and feeds the thread solder35into the solder feed pipe36. The delivery machine is attached to, for example, the robot1. The solder feed pipe36is fixed to the heat insulation member21. The thread solder35projects out of the tip of the solder feed pipe36. The laser beam30is irradiated from the laser head31to the thread solder35fed from the solder feed pipe36.

The solder feeder34of the present embodiment feeds the thread solder. The configuration is not limited to this embodiment. The solder feeder can feed solder in any form. For example, the solder feeder may feed solder paste or solder balls. The solder feeder can feed solder paste or solder balls to the path of the laser beam.

FIG. 4is an enlarged perspective view of a part where a laser beam is irradiated to the thread solder. Referring toFIGS. 2 to 4, the soldering device2includes a solder receiving member23for receiving solder melted by the laser beam30. The solder receiving member23is fixed to the heat insulation member21. The solder receiving member23is made of heat-resistant material. Furthermore, the solder receiving member23can be made of material having high thermal conductivity. For example, the solder receiving member23can be made of material such as silicon carbide or aluminum nitride that are fine ceramics having excellent thermal conductivity.

The solder receiving member23includes a recess part23aserving as a reception part to which the solder melted by the laser beam30drops. The reception part is shaped to retain the molten solder. The reception part in which the solder drops is not limited to the recess part, but may have any shape as long as liquid solder is temporarily retained. For example, a wall may be formed around the region in which the solder drops so as to intercept the molten solder.

The solder receiving member23of the present embodiment is L-shaped in side view. A part of the solder receiving member23is arranged on the path of the laser beam30. When viewed from the laser head31, the solder receiving member23is disposed behind the thread solder35. If the solder feeder34does not feed the thread solder35, the laser beam30reaches the solder receiving member23. In the present embodiment, if the solder feeder34does not feed the thread solder35, the laser beam30reaches the recess part23a.

The soldering device2includes a pouring member25for pouring the solder received in the solder receiving member23into a workpiece. The pouring member25can be made of the same material as the solder receiving member23. The pouring member25is fixed to the solder receiving member23. The pouring member25has a groove part25athat communicates with the recess part23aof the solder receiving member23and serves as a solder channel that allows the molten solder to flow therein.

In the present embodiment, the groove part of the pouring member is formed as a solder channel. The configuration is not limited to this embodiment. The solder channel may have any configuration in which the molten solder flows. For example, the pouring member may be formed by a pipe and formed so that the solder flows in the pipe.

FIG. 5is an enlarged cross-sectional view of the recess part of the solder receiving member and the groove part of the pouring member according to the present embodiment. The bottom surface of the groove part25ais tilted relative to the bottom surface of the recess part23a. In the present embodiment, the bottom surface of the recess part23ais formed at the same height as the end of the bottom surface of the groove part25a. In other words, any step is not formed at the boundary part between the bottom surface of the recess part23aand the bottom surface of the groove part25a.

Referring toFIGS. 4 and 5, when the solder feeder34is driven, the thread solder35projects out of the tip of the solder feed pipe36. As indicated by an arrow91, the thread solder35is melted by the irradiation of the laser beam30. The thread solder35is fed by the solder feeder34while being melted. The thread solder35is melted above the recess part23a. The molten solder drops into the recess part23aas indicated by an arrow92. Thereafter, as indicated by an arrow93, the molten solder passes through the groove part25aof the pouring member25and then drops from the tip of the groove part25a. The tip of the groove part25ais placed above a part to be soldered, thereby feeding the molten solder to the part to be soldered.

In this way, the solder dropped into the recess part23aimmediately passes through the groove part25aand is fed to the workpiece. The soldering device2of the present embodiment feeds the molten solder to the workpiece in a short time, thereby suppressing oxidation of the solder.

FIG. 6is an enlarged cross-sectional view of the recess part of the solder receiving member and the groove part of the pouring member according to a modification. In the example ofFIG. 5, any step is not formed at the boundary between the bottom surface of the recess part23aand the bottom surface of the groove part25a. The configuration is not limited to this embodiment. A step may be formed at the boundary between the bottom surface of the recess part23aand the bottom surface of the groove part25a. In the example ofFIG. 6, the recess part23ais formed deeper than the bottom surface of the end of the groove part25a. A step is formed at the boundary between the bottom surface of the recess part23aand the bottom surface of the groove part25a. Also in this case, the solder melted by a laser beam drops into the recess part23aas indicated by the arrow92. The solder then passes through the groove part25aas indicated by the arrow93. Thereafter, the solder is fed to the workpiece from the tip of the groove part25a.

FIG. 7is an enlarged perspective view of the soldering device viewed from the side opposite to the side on which the laser head is arranged according to the present embodiment. Referring toFIGS. 3, 4, and 7, the soldering device2of the present embodiment includes heaters26a,26b, and26cmounted in the solder receiving member23. The heaters26a,26b, and26cof the present embodiment are plate-like micro ceramic heaters. The heaters26a,26b, and26care embedded in the solder receiving member23.

The heaters26a,26b, and26care formed so as to keep the temperatures of the solder receiving member23and the pouring member25higher than the melting point of used solder. The solder receiving member23and the pouring member25are kept at high temperatures by driving the heaters26a,26b, and26c. The heaters26a,26b, and26cof the present embodiment can keep the temperatures of the solder receiving member23and the pouring member25within a temperature range according to the melting point of the solder. The melting point of lead-free solder is, for example, about 220° C. In this case, the heaters26a,26b, and26ccan keep the temperatures of the solder receiving member23and the pouring member25in the range of 250° C. to 350° C. In the case of eutectic solder, the melting point is, for example, about 180° C. In this case, the heaters26a,26b, and26ccan keep the temperatures of the solder receiving member23and the pouring member25in the range of 220° C. to 280° C.

The heaters26a,26b, and26cin the solder receiving member23can suppress decrease in temperature of the solder when the solder passes through the recess part23aand the groove part25a. The solder can be suppressed from hardening before the solder is fed to a workpiece. The heaters26cof the present embodiment, in particular, are disposed near a part where the recess part23ais formed and the pouring member25. Thus, the recess part23aand the pouring member25can be kept effectively at high temperatures. Note that the solder receiving member may not include the heaters. In this case, the solder receiving member can be heated in advance by a heating device that is different from the soldering device. For example, the solder receiving member can be heated by the heating device each time the solder is fed.

In the soldering device2of the present embodiment, the laser beam30is outputted toward the solder receiving member23. The solder receiving member23is disposed behind the solder when viewed from the laser head31. This configuration can suppress the reflection of a laser beam from a workpiece or a part mounted on the workpiece, reducing burning of the workpiece, the part mounted on the workpiece, or a part fixed to the workpiece. The soldering device of the present embodiment can suppress damage caused by a laser beam to a workpiece or a part fixed to the workpiece.

The soldering device2of the present embodiment is formed so as to eject high temperature air to a workpiece. The soldering device2includes an air feeder28that feeds air to the solder receiving member23. The air feeder28of the present embodiment includes a compressor for compressing air, air feed pipes27for feeding air, and connection members29connecting the air feed pipes27to the solder receiving member23. The compressor for compressing air is attached to, for example, the robot1.

The solder receiving member23has holes23bthat serve as air passages. The holes23bare formed in the solder receiving member23and are connected to the air feeder28. The solder receiving member23has an exhaust port23cformed on one end of the hole23b. The hole23bof the present embodiment extends from one end face to the other end face in the longitudinal direction of the solder receiving member23. The air feed pipe27is connected to the hole23bvia the connection member29.

A plurality of the heaters26aare placed in a line along the longitudinal direction of the solder receiving member23. A plurality of the heaters26bare also placed in a line along the longitudinal direction of the solder receiving member23. The holes23bare formed in a region between the line of the heaters26aand the line of the heaters26b.

The air feeder28feeds compressed air into the air feed pipes27. The air fed into the air feed pipes27is heated through the holes23b. The heated air is ejected from the exhaust ports23cas indicated by arrows94. The soldering device2of the present embodiment can preheat a workpiece with high temperature air ejected from the holes23b. The soldering device2is disposed with the exhaust ports23copposed to a part to be soldered, so that a workpiece can be preheated.

In the solder receiving member23of the present embodiment, the holes23bare formed in a region between the line of the heaters26aand the line of the heaters26b, thereby efficiently heating air. The hole23bof the present embodiment has a linear shape, but the embodiment is not limited to this. The air passage may have a curved portion. By adopting this configuration, the passage for heating air is extended so as to more effectively heat air.

In the soldering operation, a preheat operation in which a part to be soldered is heated is performed before the molten solder is fed. By performing the preheat operation, solder wettability is improved, thereby properly spreading the solder. In the device for soldering with a laser beam, a part to be soldered can be preheated by irradiating the laser beam directly. However, when a part having a large thermal capacity is soldered, a high-power laser oscillator is necessary. As opposed to this, the soldering device2of the present embodiment can extend a time for spraying high temperature air when a part having a larger thermal capacity is soldered. By adopting this control, the preheat operation of the workpiece can be performed easily. The need for the laser oscillator for oscillating a high-power laser beam is eliminated, so that the soldering device can have a simple configuration.

The heaters26a,26b, and26cof the present embodiment are embedded in the solder receiving member23, but the configuration is not limited to this embodiment. The solder receiving member can be heated by any heaters. For example, hot wires for heating the solder receiving member may be wound around the solder receiving member.

Referring toFIG. 3, the soldering device2of the present embodiment includes a vibrator37that vibrates the solder receiving member23. The vibrator37of the present embodiment is fixed to the support member20. The vibrator37may be any mechanism for generating vibration. For example, the vibrator37has a structure including an eccentric weight attached to the output shaft of a motor. The vibrator37can generate vibrations by rotating the eccentric weight.

The vibrator37has the function of vibrating the solder receiving member23and the pouring member25when the molten solder is fed. The molten metal is viscous and thus may not smoothly flow from the recess part23aalong the groove part25aof the pouring member25. When the solder is fed, the solder receiving member23and the pouring member25are vibrated so that the solder flows smoothly. Note that the vibrator37may not be disposed.

FIG. 8is a block diagram of the robot apparatus according to the present embodiment. Referring toFIGS. 1 to 3 and 8, the robot1includes a robot drive device that changes the position and posture of the robot1. The robot drive device includes a plurality of robot drive motors17that drive components such as an arm and a wrist. The robot drive motors17are disposed for the respective components. By driving the robot drive motors17, the orientations of the respective components are changed.

The robot apparatus5includes a controller4that controls the robot apparatus5. The controller4includes an arithmetic processing device (computer) having a CPU (Central Processing Unit) as a processor. The arithmetic processing device includes RAM (Random Access Memory), ROM (Read Only Memory), and the like that are connected to the CPU via a bus. A motion program41for controlling the robot1and the soldering device2is inputted to the controller4. Alternatively, the controller4generates the motion program41according to a teaching operation by an operator.

The controller4includes a storage unit42that stores information on the control of the robot apparatus5. The storage unit42may include a storage medium capable of storing information, such as a volatile memory, nonvolatile memory, or a hard disk. A processor acting as a motion control unit43is formed so as to read information stored in the storage unit42. The motion program41is stored in the storage unit42. The controller4of the present embodiment controls the robot1and the soldering device2based on the motion program41.

The command controller4includes the motion control unit43that transmits a motion command. The motion control unit43is equivalent to the processor driven according to the motion program41. The processor reads the motion program41and performs control as defined in the motion program41, so that the processor acts as the motion control unit43. The motion control unit43transmits a motion command for driving the robot1, based on the motion program41, to a robot drive unit45. The robot drive unit45includes an electric circuit that drives the robot drive motor17. The robot drive unit45supplies electricity to the robot drive motors17, based on the motion command.

The robot1includes a status detector that detects the position and posture of the robot1. The status detector of the present embodiment includes position detector18that is attached to the robot drive motor17. The controller4detects the position and posture of the robot1, based on the outputs of the position detectors18.

The motion control unit43transmits a motion command for driving the soldering device2, based on the motion program41, to an operation-tool drive unit44. The operation-tool drive unit44includes an electric circuit that drives the drive device of the soldering device2. The operation-tool drive unit44supplies electricity to the controller of the laser head31, the vibrator37, and the heaters26a,26b, and26cbased on the motion command. The operation-tool drive unit44also supplies electricity to the air feeder28and the solder feeder34based on the motion command.

The robot apparatus5includes a laser oscillator7that oscillates a laser beam. The laser oscillator7includes a laser controller that controls the oscillation of a laser beam. The laser controller is formed so as to communicate with the controller4. The laser controller includes an arithmetic processing device (computer) including a CPU as a processor and RAM. The motion control unit43transmits a command for outputting a laser beam, to the laser controller. The laser controller oscillates a laser beam based on the motion command. The laser oscillator7is controlled based on the motion program41. The laser oscillator7includes a light source that oscillates a laser beam. The light source of the present embodiment is a semiconductor laser. The laser oscillator7may include any light source capable of melting solder.

In the following example, the soldering operation is performed in the robot apparatus according to the present embodiment.FIG. 9is a perspective view of the robot apparatus in a first step of the soldering operation. Referring toFIGS. 2, 3, 7, 8, and 9, a printed circuit board74serving as a workpiece of the present embodiment is fixed to a pedestal76. In the present embodiment, an electronic part such as a DIP part is fixed to the printed circuit board74. The soldering device2feeds the solder to the back side of the printed circuit board74.

The controller4energizes the heaters26a,26b, and26c. During a soldering period, heating by the heaters26a,26b, and26cis maintained. The solder receiving member23and the pouring member25are kept at temperatures higher than the melting point of the solder.

Subsequently, a part to be soldered on the printed circuit board74is preheated. The controller4changes the position and posture of the robot1. The controller4places the soldering device2such that the exhaust ports23cof the solder receiving member23are opposed to the part to be soldered on the printed circuit board74. The exhaust ports23cthen approach the part to be soldered on the printed circuit board74.

The controller4drives the air feeder28so as to feed air into the holes23bof the solder receiving member23. The high temperature air is ejected from the exhaust ports23cof the solder receiving member23. The high temperature air then collides with the part to be soldered, thereby heating the part to be soldered.

The soldering device of the present embodiment has the function of preheating the workpiece, but the embodiment is not limited to this. A workpiece may be preheated by other devices. For example, an operation tool for preheating a workpiece can be prepared in advance. An operation tool for preheating may be connected to the robot so as to preheat a workpiece. Alternatively, a workpiece preheated in advance may be placed on the pedestal.

Subsequently, control for feeding the solder to the printed circuit board74is performed.FIG. 10is a perspective view of the robot apparatus in a second step of the soldering operation.FIG. 11is an enlarged perspective view of the recess part of the solder receiving member and the pouring member during the soldering operation. Referring toFIGS. 10 and 11, in this example, the printed circuit board74has through holes74a. Leads75of the electronic parts project from the through holes74a. The robot apparatus5feeds the molten solder into the through holes74a.

The controller4preheats the printed circuit board74and then changes the position and posture of the robot1based on the motion program41. The robot1tilts the soldering device2so that the molten solder flows from the recess part23ato the through hole74athrough the groove part25aof the pouring member25. In the present embodiment, the orientation of the soldering device2is changed so as to tilt the bottom surface of the recess part23awith respect to the horizontal direction. In other words, the orientation of the soldering device2is changed so as to direct the solder that drops in the recess part23ato the groove part25aby gravitation. Moreover, the soldering device2is disposed so as to place the tip of the groove part25aabove the through hole74a.

Subsequently, the thread solder35is melted by the laser beam30while the soldering device2is tilted. The controller4drives the vibrator37in a period during which the laser beam30is irradiated and the solder is fed. The laser oscillator7oscillates the laser beam30. The solder feeder34feeds a predetermined amount of the thread solder35based on the motion program41. The solder feeder34feeds an amount of the solder that corresponds to one soldering operation when the solder is melted by the laser beam30. In other words, the molten solder is not retained in the recess part23a, but a required amount of solder is melted for each time of the soldering operation immediately before the solder is fed. By adopting this control, the solder is prevented from being left in the recess part23aand oxidized.

When the predetermined amount of the solder is melted, the controller4stops the feeding of the thread solder35and the oscillation of the laser beam30. In the solder feeder34of the present embodiment, the feed rate of the thread solder35is kept constant and thus the thread solder35is fed in a predetermined time.

The molten solder drops into the recess part23a. The solder passes through the groove part25aand flows into the through hole74a. The solder is fed to the printed circuit board74without being retained in the recess part23a. In the present embodiment, the solder is melted while the soldering device2is tilted, so that the molten solder is quickly fed to the printed circuit board74. This control can suppress the oxidation of the solder during the soldering operation.

In the foregoing embodiment, the solder is melted after the soldering device is tilted. The embodiment is not limited to this. The soldering device may be tilted after the solder is melted. Alternatively, the solder may be fed without tilting the soldering device. For example, the solder may be fed while the soldering device is placed so that the bottom surface of the recess part in the solder receiving member extends in the horizontal direction.

In the soldering device2of the present embodiment, the laser beam30outputted from the laser head31is directed to the solder. When the solder is not fed, the laser beam30is directed to the solder receiving member23. Accordingly, the reflection of a laser beam from the lead of an electronic part is minimized, whereby the board can be prevented from being burned and an electronic part disposed around an electronic part to be soldered can also be prevented from being burned. Furthermore, the laser beam is prevented from traveling in a space between the lead and the through hole of the board, whereby the body of an electronic part can be prevented from being burned.

As described above, the soldering device of the present embodiment can prevent damage to the board or damage to the electronic part. The reliability of the electric circuit formed on a board such as a printed circuit board can be improved. The soldering device of the present embodiment is particularly suitable for manufacturing devices that need to maintain reliability over the long term.

Since the soldering device of the present embodiment can minimize damage to the board or the part fixed to the board, the need for a special board design for soldering with the laser beam is eliminated, and thus the amount of effort required of an operator designing the board can be reduced. For example, the design for a board soldered without a laser beam can be used without changing the basic design. In other words, a board in the related art can be used without changing the basic design.

FIG. 12is an enlarged perspective view of another soldering device according to the present embodiment. Another soldering device9of the present embodiment includes a wall member38surrounding the laser beam30outputted from the laser head31.

The wall member38can be formed so as to surround a part where the laser beam30collides with the thread solder35. The wall member38can be made of a heat-resistant material having a higher melting point than the solder. For example, the wall member38can be made of a fine ceramic, a metal, a resin having a higher melting point than the solder, or the like. By adopting this configuration, the wall member38acts as a dispersion preventing wall for preventing the molten solder from dispersing out of the soldering device9.

When the laser beam30is irradiated to the solder, a phenomenon in which small solder particles disperse may occur. In other words, spattering may occur, especially when the laser beam30rapidly raises the temperature of the solder. Short-circuiting may occur in the electric circuit formed on the board by the dispersion of the solder particles. For example, if the solder particles adhere to a board on which leads or through holes are placed with small pitches, an electric circuit may be short-circuited.

The dispersion of the solder due to spattering can be prevented by arranging the wall member38acting as a dispersion preventing wall. Moreover, when the solder rises in temperature, flux included in the solder may be broken and dispersed. A dispersion preventing wall can prevent the dispersion of flux.

The wall member38of the present embodiment can be formed so as to surround a part where the laser beam30reaches the solder receiving member23. In the present embodiment, the wall member38is formed so as to surround the recess part23aof the solder receiving member23. The wall member38can be made of material that prevents the transmission of the laser beam30. For example, the wall member38can be made of a metal or a fine ceramic. By adopting this configuration, the wall member38acts as a laser beam barrier wall for preventing the laser beam30reflected on the solder receiving member23from leaking out of the soldering device9.

The laser beam30outputted from the laser head31may reach the solder receiving member23. For example, when the feeding of the thread solder35is terminated, the laser beam30may reach the recess part23a. The laser beam30may be then reflected on the surface of the solder receiving member23and leak out of the soldering device2. The laser beam having leaked out of the soldering device2may reach a member such as the board or the electronic part, and burn the member. By arranging a wall member38which prevents transmission of the laser beam30, the laser beam30is prevented from reaching a member such as the board or the electronic part after reflection.

The wall member38of the present embodiment surrounds the entire outputted laser beam30. Moreover, the wall member38is formed around a region from the part in which the recess part23ais formed to the tip of the laser head31. Furthermore, the wall member38is made of heat-resistant material that prevents the transmission of the laser beam. Thus, the wall member38of the present embodiment acts as the dispersion preventing wall and the laser beam barrier wall.

In the robot apparatus of the present embodiment, the soldering device is supported by the articulated robot. The robot apparatus can perform the soldering operation using the soldering device in various orientations at various positions. For example, the soldering operation can be performed while avoiding a specific part. Alternatively, the solder can be fed from various angles during the soldering operation. Thus, by using the articulated robot as a device for moving the soldering device, various parts can be soldered.

FIG. 13is a schematic side view of a soldering system including the soldering device of the present embodiment. In the above embodiment, the soldering device is supported by the articulated robot. The configuration is not limited to this embodiment. The soldering device can be placed in various devices or systems.

A soldering system8includes a bed51serving as a pedestal and a column52raised from the bed51. On the top surface of the bed51, an X-axis guide rail56extending in the X-axis direction is disposed. On the X-axis guide rail56, a saddle53is disposed. The saddle53is formed so as to move along the X-axis guide rail56as indicated by an arrow95. On the top surface of the saddle53, Y-axis guide rails57extending in the Y-axis direction are disposed. On the Y-axis guide rails57, a table54is disposed. The table54is formed so as to move along the Y-axis guide rails57. The printed circuit board74as a workpiece is fixed to the table54via a board holder77.

The column52has a Z-axis guide rail58extending in the Z-axis direction. A movement member59is engaged with the Z-axis guide rail58. The soldering device2is fixed to the movement member59. The movement member59is formed so as to move along the Z-axis guide rail58as indicated by an arrow96.

The soldering system8of the present embodiment is a numerically controlled system. The soldering system8includes a movement device that moves at least one of the soldering device2and the printed circuit board74along a feed axis. The soldering system8includes a controller6that controls the soldering system8. The controller6controls the movement device. The controller6includes an arithmetic processing device (computer) including a CPU as a processor, RAM, and the like. The movement device includes a motor disposed for each feed axis. In the soldering system8of the present embodiment, the movement member59, the saddle53, and the table54are moved by the motors. The controller6drives the motor corresponding to the feed axis based on the motion program.

The soldering system8includes the laser oscillator7that oscillates a laser beam. The laser beam oscillated by the laser oscillator7is fed to the soldering device2through the optical fiber32. The laser oscillator7includes a laser controller that includes an arithmetic processing device (computer) having a CPU as a processor. The laser controller and the soldering device2are controlled by the controller6.

In the soldering system8of the present embodiment, the position of the soldering device2can be changed relative to the printed circuit board74. The controller6moves the printed circuit board74in the X-axis direction and the Y-axis direction such that a part to be soldered on the printed circuit board74is placed at a predetermined position based on the motion program. Moreover, the controller6moves the movement member59in the Z-axis direction so as to place the soldering device2at a predetermined distance from the printed circuit board74.

In this way, the soldering device2is moved relative to the printed circuit board74, so that various parts on the printed circuit board74can be preheated and the solder can be fed to the parts.

The soldering system8does not include a mechanism for tilting the soldering device2. The embodiment is not limited to this. The soldering system8may have a mechanism for tilting the soldering device2. For example, the movement member59may include a mechanism for rotating the soldering device2.

In the soldering system8, the printed circuit board74is moved in the X-axis direction and the Y-axis direction, whereas the soldering device2is moved in the Z-axis direction. The embodiment is not limited to this. The position of the soldering device can be changed relative to a workpiece by any mechanism.

In the present embodiment, the soldering operation is performed in order to fix the electronic part to the printed circuit board, but the embodiment is not limited to this. The soldering device of the present embodiment is applicable to any device for feeding the molten solder to a workpiece. For example, the soldering device of the present embodiment is applicable to a device for connecting conductive wires by the solder.

An aspect of the present disclosure can provide the soldering device that suppresses damage caused by a laser beam to a workpiece or a part fixed to the workpiece, and the robot apparatus including the soldering device.

The foregoing embodiment can be optionally combined with another. In the drawings, the same or equivalent parts are indicated by the same reference numerals. The foregoing embodiment is merely exemplary and does not limit the invention. The embodiments include the modifications described in the claims.