Laser-assisted soldering device

Abstract

To provide a laser-assisted soldering apparatus which uses ball solder.SOLUTION: A soldering apparatus comprises: an application device (10) which has a laser duct (12) extending straight from a laser entry (16) to a laser exit (18) and a drop duct (14) that extends from a drop entry (20) to a drop exit (22); and a conveying device (34) which separately conveys solder bodies (2) to the drop entry (20). The laser and drop ducts (12) and (14) are interconnected over the entire lengths of the laser and drop ducts (12) and (14). The drop entry (20) and laser entry (16) are side by side and form a common entry. The drop exit (22) and laser exit (18) are spatially coincident and form a common exit that is smaller than the common entry. The application nozzle (24) is connected to the common exit.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a soldering body, in particular, a laser-assisted soldering device for separately applying a solder ball to a workpiece.

Background Art

[0002] A device for separately applying a connection material deposit is known from U.S. Patent No. 10,286,470. The device includes an application device and an application nozzle, and the connection material deposit is applied through the application nozzle. The application device has an application duct formed to extend straight through a lower housing portion, and a laser is irradiated through the application duct onto the connection material deposit held within the application nozzle. Further, the application device has a supply duct, which is formed obliquely separately from the application duct, through which the connection material deposit is conveyed to the application nozzle. Thus, the above device has the drawbacks that it is difficult to form the supply duct within the lower housing portion and the size or diameter of the connection material deposit is limited by the diameter of the supply duct.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Accordingly, an object of the present invention is to overcome the drawbacks of the prior art and provide an improved flexible laser-assisted soldering device for separately applying a soldering body. A further object of the present invention is to provide a laser-assisted soldering device that can be easily manufactured and can be flexibly adapted to various applications such as the application of a soldering body having a larger diameter.

Means for Solving the Problems

[0004] A soldering body according to the present invention, in particular a laser-assisted soldering device for separately applying a solder ball to a workpiece, is a coating device having a laser duct extending linearly from a laser inlet at the top of the coating device to a laser outlet at the bottom of the coating device, and a droplet duct extending from a droplet inlet at the top of the coating device to a droplet outlet at the bottom of the coating device. The device further comprises a conveying device configured to separately convey the soldering body to the droplet inlet, and a coating nozzle provided at the bottom of the coating device and configured to temporarily hold the soldering body exiting from the droplet outlet.

[0005] The laser duct and the droplet duct are formed so as to be interconnected over the entire length of the laser duct and the droplet duct from the top to the bottom of the coating device. In this regard, the term "interconnected" means that the laser duct and the droplet duct are not separated by side walls or other means, and both ducts are formed so as to obtain a single passage in the laser-assisted soldering device. The droplet inlet and the laser inlet are arranged side by side so as to form a common inlet opening, and the droplet outlet and the laser outlet are arranged in alignment so as to form a common outlet opening smaller than the common inlet opening. In other words, the laser duct and the droplet duct are formed such that the cross-sections of the laser duct and the droplet duct overlap each other from the top to the bottom of the coating device along the extension of the laser duct and the droplet duct, forming a common inlet opening at the top of the coating device and a common outlet opening at the bottom of the coating device. That is, the degree of overlap of the cross-sections of the laser duct and the droplet duct increases from a partial overlap at the top of the coating device to a complete overlap at the bottom. Further, the coating nozzle is connected to the common outlet opening.

[0006] According to one aspect of the present invention, the droplet inlet and the laser inlet form a common non-circular inlet opening, and the droplet outlet and the laser outlet form a common circular outlet opening. Thus, the common non-circular inlet opening and the common circular outlet opening can be easily formed by drilling the laser duct straight and then machining the droplet duct, for example using a ball cutter, so as to be interconnected with the laser duct.

[0007] Therefore, the laser duct and the droplet duct can be easily formed in the coating device. Further, since the laser duct can also be used to transfer the solder body to the coating nozzle, the diameter of the solder body is not limited to the diameter of the droplet duct. As a result, by using the laser-assisted soldering apparatus according to the present invention, a solder body having a large diameter can be applied.

[0008] In particular, the solder body is held at the tip of a coating nozzle having a diameter smaller than the diameter of the solder body. For this reason, the coating nozzle tapers from the common outlet opening towards the tip of the coating nozzle. When the solder body is held at the tip and closes the opening of the coating nozzle, pressure gas, particularly inert gas from a pressure gas source, particularly an inert gas source, is introduced into the coating nozzle. Then, a laser beam is irradiated onto the solder body in order to liquefy or melt the solder body. When the solder body held at the tip of the coating nozzle is sufficiently liquefied or melted, the solder body is ejected from the coating nozzle towards the workpiece.

[0009] Alternatively, the opening of the coating nozzle may be substantially the same as or slightly larger than the diameter of the solder body so that the solder body can exit the coating nozzle. Then, the solder body can be held at the tip of the coating nozzle spaced from the workpiece by less than the diameter of the solder body. Thus, the solder body is held between the coating nozzle and the workpiece. Then, a laser beam is irradiated onto the solder body to melt or liquefy the solder body so that a solder joint is obtained on the workpiece. Then, the coating nozzle is separated from the workpiece.

[0010] According to one aspect of the present invention, the solder body can have a diameter of 0.9 μm to 2 mm. In particular, the solder body can be a substantially circular solder ball. In this specification, a solder body having a diameter within the above range is referred to as a large solder body or a solder body having a large diameter. Therefore, the laser-assisted soldering apparatus can be used for applications that require a large amount of solder to form a strong and durable solder connection.

[0011] According to one aspect of the present invention, the droplet duct can extend along a curve from the top to the bottom of the application device. Thus, the solder body falls or rolls along the curve so that the solder body is properly transferred from the droplet inlet to the droplet outlet / common outlet opening and thus to the application nozzle.

[0012] According to one aspect of the present invention, the cross-section of the droplet duct may become narrower from the top to the bottom of the application device. As a result, the solder body can be easily dropped into the droplet inlet by the conveying device and properly transferred to the droplet outlet / common outlet opening.

[0013] According to one aspect of the present invention, the apparatus can further include a housing formed from an upper housing portion and a lower housing portion. The application device having the laser duct and the droplet duct can be integrated into the lower housing portion, and the conveying device can be positioned between the upper housing portion and the lower housing portion. Further, the upper housing portion and the lower housing portion can be separated by a spacer surrounding the conveying device. This modular configuration of the housing allows for quick replacement of the conveying device and / or the lower housing portion so that the apparatus according to the present invention can be easily adapted to another solder body, for example, having a larger diameter.

[0014] Furthermore, the upper housing part may form a guide duct configured to guide the solder bodies to the conveying device. In order to avoid a plurality of solder bodies from falling into the droplet duct, it is preferable that the guide duct and the droplet outlet of the droplet duct are spaced apart from each other. Thus, it should be noted that the conveying device needs to separately transfer the solder bodies from the guide duct to the droplet outlet. In particular, the guide duct and the droplet duct may be rotationally displaced relative to each other, and the conveying device may convey the solder bodies using a rotatable transfer element, such as a rotating disk. As described above, the conveying device, i.e., the transfer element, is surrounded by a spacer and moves, i.e., rotates, within the spacer. As a result, the solder bodies can be properly introduced into the conveying device through the guide duct.

[0015] According to another aspect of the present invention, the guide duct may extend along a straight line passing through the upper housing part. Thus, the solder bodies can be transferred to the conveying device without clogging.

[0016] According to an additional aspect of the present invention, the guide duct can be formed as an aspherical space, i.e., not spherical and not cylindrical, but as a tapered cross-sectional space passing through the upper housing part. The guide duct is formed to lift the solder body present within the guide duct. In particular, the aspherical space is slightly funnel-shaped. Additionally, the aspherical space may taper with respect to the moving direction of the conveying device, i.e., with respect to the rotational movement direction of the transfer element. Further, the radially outer wall portion of the guide duct can be formed tangentially with respect to the rotational movement direction of the transfer element, i.e., the rotating disk. Furthermore, the position of the radially outer wall portion is positioned outside the end of the transfer element, i.e., outside the radius of the rotating disk. Thus, the solder body present within the guide duct is also disposed on the spacer surrounding the transfer element, i.e., the rotating disk, and as a result, the solder body is further lifted. The radially inner wall portion of the guide duct may comprise an inclined wall portion inclined outwardly with respect to the guide duct at the top of the upper housing part. Therefore, the aspherical space further reduces the risk of the solder body clogging within the guide duct. It should be noted that the housing and the guide duct according to the above aspect can be implemented independently of the device having interconnected laser ducts and droplet ducts. Therefore, the applicant reserves the right to file one or more divisional applications directed to a laser-assisted soldering device comprising a housing and a guide duct according to one of the above aspects, i.e., not comprising interconnected laser ducts and droplet ducts.

[0017] According to one aspect of the present invention, the device may comprise a solder body reservoir configured to store a plurality of solder bodies and supply the solder bodies to a conveying device. In particular, the solder body can be supplied to the conveying device via a guide duct. Thus, the device can operate for a long time without the need to replenish new solder bodies.

[0018] According to an additional aspect of the present invention, the solder body reservoir may comprise a solder body tank and a line connecting the solder body tank and the guide duct. Thus, the apparatus and the solder body tank can be positioned in a separated state, and the solder body tank can be replenished without stopping the operation of the laser-assisted soldering apparatus. This is particularly beneficial for an apparatus operating with a large solder body.

[0019] According to a preferred aspect of the present invention, the line may be flexible. Thus, the solder body tank and the laser-assisted soldering apparatus can be separated from each other in terms of vibration. This is beneficial for a solder body tank that supports a heavy load due to storing a large number of solder bodies, particularly a large number of large solder bodies. It should be noted that the solder body reservoir according to the above aspect, i.e., the solder body tank and the line, can be implemented independently of an apparatus having interconnected laser ducts and droplet ducts. Therefore, the applicant reserves the right to file one or more divisional applications directed to a laser-assisted soldering apparatus comprising a solder body reservoir or a solder body tank according to one of the above aspects, i.e., not comprising interconnected laser ducts and droplet ducts.

[0020] According to one aspect of the present invention, the apparatus may further comprise a coating nozzle holder removably attached to the bottom of the coating device and configured to hold the coating nozzle replaceably. As a result, by simply changing the coating nozzle holder, the apparatus can be adapted to the desired coating. In particular, coating nozzle holders having different lengths can be attached. Thus, it is not necessary to use long coating nozzles made of ceramic materials such as SiN, SiC, Al2O3, WC. Such coating nozzles are expensive because they require a large amount of raw materials and a wide range of high manufacturing tolerances, and include a high risk of breakage during manufacture or attachment. Alternatively or additionally, the cavity of the coating nozzle holder can be adapted to the solder body used. The coating nozzle holder preferably tapers towards the opening of the coating nozzle. Thus, the outlet at the bottom of the coating device through which the solder body passes and is transferred to the coating nozzle holder, for example, a common outlet opening, a droplet outlet, or a laser outlet, can be designed to be large enough to apply a large solder body, and the apparatus can be adapted to a smaller solder body by installing a coating nozzle holder that provides sufficient taper towards the coating nozzle.

[0021] According to an additional aspect of the present invention, the coating nozzle holder may comprise a collet chuck portion configured to clamp the coating nozzle. As a result, the coating nozzle does not fall off when the coating nozzle is attached to the coating nozzle holder.

[0022] According to a further aspect of the present invention, the coating nozzle holder may comprise a bag nut configured to fasten the coating nozzle to the coating nozzle holder. As a result, the coating nozzle holder securely holds the coating nozzle. It should be noted that the coating nozzle holder according to the above aspect can be implemented independently of an apparatus having interconnected laser ducts and droplet ducts. Thus, the applicant reserves the right to file one or more divisional applications directed to a laser-assisted soldering apparatus comprising a coating nozzle holder according to one of the above aspects, i.e., not comprising interconnected laser ducts and droplet ducts.

[0023] According to one aspect of the present invention, the apparatus may further comprise a laser shield that surrounds the application nozzle with a lateral play. Thus, the laser shield can shield the soldering spot by positioning the laser shield around the spot such that the laser shield substantially contacts the workpiece. Preferably, the soldering spot can be preheated by using the laser beam of the laser-assisted soldering device, and the laser shield avoids the scattering of the laser beam to other parts of the workpiece. Also, the preheating is limited to the area inside the laser shield.

[0024] According to an additional aspect of the present invention, the laser shield can be detachably attached to the housing, particularly the lower housing part, or the application nozzle holder. For this purpose, the application nozzle holder may comprise a holding unit configured to hold the laser shield. For example, the flange of the laser shield can be fixed to the application nozzle holder, for example, by screws. Thus, the laser shield can be easily installed on an application nozzle holder having a holding unit such as a screw hole.

[0025] According to a preferred aspect of the present invention, the laser shield comprises an attachment part detachably attached to the application nozzle holder or the bottom of the application device, and a shield part held at the attachment part such that the shield part is movable relative to the attachment part to any position between a retracted position where the tip of the application nozzle is at the same height as the tip of the shield part and an extended position where the tip of the application nozzle is completely surrounded within the shield part. For example, the shield part can be biased towards the extended position by an elastic element such as a spring. Thus, when the laser shield is brought close to and contacts the workpiece, the shield part is moved towards the retracted position. As a result, damage to the workpiece can be avoided while efficiently shielding the soldering spot.

[0026] According to an advantageous aspect of the present invention, the laser shield may comprise a connection port configured to be connected to a vacuum source and / or an inert gas source. Additionally, the connection port can be connected and switched between a vacuum source and an inert gas source such that one can be applied after the other. Thus, a vacuum atmosphere or an inert gas atmosphere can be formed inside the laser shield. As a result, it can have a beneficial effect on the soldering process. In particular, the inert gas present inside the shield part can function as a pressure gas when ejecting the solder body from the capillary and can replace the inert gas introduced as a pressure gas. As a result, the amount of pressure gas that needs to be introduced into the coating nozzle is reduced. In particular, for a large solder body, due to the greater weight of the large solder body, less pressure gas is required to eject the large solder body from the coating nozzle. As a result, while having a beneficial effect on the soldering process, it is possible to avoid the scattering of the liquefied or melted solder body. It should be noted that the laser shield according to the above aspect can be implemented independently of an apparatus having interconnected laser ducts and droplet ducts. Therefore, the applicant reserves the right to file one or more divisional applications directed to a laser-assisted soldering apparatus comprising a laser shield according to one of the above aspects, i.e., not comprising interconnected laser ducts and droplet ducts.

[0027] According to one aspect of the present invention, the apparatus may comprise a laser coupling unit configured to couple a laser beam into a laser duct and comprising an optical window transparent to the laser beam. Thus, scattering of the solder material by the laser source emitting the laser beam can be avoided. Further, the laser source can be easily replaced or changed. It should be noted that the laser coupling unit according to the above aspect can be implemented independently of an apparatus having interconnected laser ducts and droplet ducts. Therefore, the applicant reserves the right to file one or more divisional applications directed to a laser-assisted soldering apparatus comprising a laser coupling unit according to the above aspect, i.e., not comprising interconnected laser ducts and droplet ducts.

[0028] According to one aspect of the present invention, the conveying device can be configured to carry or transfer the solder body from the guide duct to the droplet inlet. The conveying device can include a transfer element having at least one receiving hole, and the at least one receiving hole can be configured to receive the solder body and transfer the solder body from the guide duct to the droplet inlet along a predetermined movement path. An optical sensor can be provided along the movement path between the guide duct and the droplet inlet, and the optical sensor is configured to detect the presence or absence of the solder body inside the at least one receiving hole. Thus, the optical sensor can be used to detect whether the receiving hole is loaded with the solder body.

[0029] According to an additional aspect of the present invention, the apparatus can further include a control unit configured to control the movement of the conveying device, i.e., the transfer element, and to adjust the movement pattern of the conveying device when the optical sensor detects that there is no solder body inside the at least one receiving hole. As a result, the movement pattern can be adjusted to skip the receiving holes that are not filled with the solder body so as to increase the processing speed of the apparatus. It should be noted that the conveying device and the control unit according to the above aspect can be implemented independently of an apparatus having interconnected laser ducts and droplet ducts. Therefore, the applicant reserves the right to file one or more divisional applications directed to a laser-assisted soldering apparatus comprising the conveying device and the control unit according to one of the above aspects, i.e., not comprising interconnected laser ducts and droplet ducts.

[0030] According to one aspect of the present invention, the apparatus can include a laser source configured to couple a laser beam into the laser duct, and a control unit configured to operate the laser source to emit the laser beam in a pulse modulation mode. As a result, the laser beam can be emitted to appropriately melt the solder body held in the coating nozzle. The pulse modulation pattern needs to be adapted to particularly large solder bodies in order to achieve a sufficient degree of melting or liquefaction.

[0031] According to a preferred embodiment of the present invention, the control unit is configured to operate the laser source to emit a prepulse and, after the prepulse ends and a delay time has elapsed, emit a main pulse. Preferably, the prepulse includes a phase in which the output of the laser beam is gradually increased to a set output value and a phase in which the laser beam having the set output value is constantly irradiated. By applying the prepulse with a gradually increasing output, the solder body is gradually heated and liquefied so that the dynamics of the liquid solder material are reduced as compared with the case of immediately applying a pulse with a high constant output. As a result, a large solder body can be properly melted or liquefied using the apparatus. It should be noted that the laser source and the control unit according to the above embodiment can be implemented independently of an apparatus having interconnected laser ducts and droplet ducts. Therefore, the applicant reserves the right to file one or more divisional applications directed to a control unit according to the above embodiment and / or a laser-assisted soldering apparatus comprising the laser source and the control unit, i.e., not comprising interconnected laser ducts and droplet ducts.

[0032] According to one embodiment of the present invention, the apparatus may comprise a flux dispenser configured to administer flux to the solder body emerging from the application nozzle. In particular, the flux may be applied by a flux dispenser nozzle. The flux dispenser nozzle may be disposed inside the laser shield. Preferably, the flux is applied in the gas phase. This is achieved by introducing a pressurized gas through a pressurized gas line connected to a flux tank storing the liquid flux. As a result, the flux can be easily applied to the solder body so as to have a favorable effect on the soldering process. It should be noted that the flux dispenser according to the above embodiment can be implemented independently of an apparatus having interconnected laser ducts and droplet ducts. Therefore, the applicant reserves the right to file one or more divisional applications directed to a laser-assisted soldering apparatus comprising the flux dispenser according to the above embodiment, i.e., not comprising interconnected laser ducts and droplet ducts.

[0033] As a result, the present invention provides a laser-assisted soldering apparatus that can be easily formed and can be easily adapted to different applications. In particular, the laser-assisted soldering apparatus can be easily adapted to apply large solder bodies having diameters in the range of 0.9 μm to 2 mm.

[0034] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Brief Description of the Drawings

[0035]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0036] FIG. 1 shows an exploded view of a laser-assisted soldering apparatus 1 (hereinafter simply referred to as apparatus 1) according to the present embodiment, and FIG. 2 shows a cross-sectional view. In the present embodiment, the apparatus 1 is configured to separately apply a solder body 2 to a workpiece formed by an electronic component 4 including at least one lead 6 to be soldered to a land (not shown) of a circuit board 8. The workpiece is not limited to this, and the apparatus may be used for other workpieces that require soldering.

[0037] As shown in FIG. 2, the apparatus 1 includes an application device 10 having a laser duct 12 and a droplet duct 14. The laser duct 12 extends linearly from a laser inlet 16 at the top of the application device 10 to a laser outlet 18 at the bottom of the application device 10. In particular, the laser duct 12 is formed in a cylindrical shape. The droplet duct 14 extends from a droplet inlet 20 at the top of the application device 10 to a droplet outlet 22 at the bottom of the application device 10. In particular, the droplet duct 14 extends along a curve from the top to the bottom of the application device 10. Preferably, the cross-section of the droplet duct 14 becomes narrower from the top to the bottom of the application device 10.

[0038] As shown in FIG. 2, the laser duct 12 and the droplet duct 14 are formed to be interconnected from the top to the bottom of the coating device 10 over the entire length of the laser duct 12 and the droplet duct 14. Accordingly, the droplet inlet 20 and the laser inlet 16 form a common non-circular inlet opening, and the droplet outlet 22 and the laser outlet 18 form a common circular outlet opening. In other words, the laser duct 12 and the droplet duct 14 are formed such that the cross-sections of the laser duct 12 and the droplet duct 14 overlap each other from the top to the bottom of the coating device 10 along the extending portions of the laser duct 12 and the droplet duct 14, forming a common non-circular inlet opening at the top of the coating device 10 and a common circular outlet opening at the bottom of the coating device 10. It should be noted that the degree of overlap of the cross-sections of the laser duct 12 and the droplet duct 14 increases from a partial overlap at the top of the coating device 10 to a complete overlap at the bottom. Thus, the droplet inlet 20 and the laser inlet 16 are arranged side by side so as to form a common inlet opening, and the droplet outlet 22 and the laser outlet 18 are arranged in alignment so as to form a common outlet opening smaller than the common inlet opening.

[0039] The coating nozzle 24 is provided at the bottom of the coating device 10 and is configured to temporarily hold the solder body 2 exiting from the droplet outlet 22 (see FIG. 2), particularly the coating device 10. In particular, the coating nozzle 24 is connected to the common circular outlet opening formed by the droplet outlet 22 and the laser outlet 18. Preferably, the coating nozzle 24 is held by a coating nozzle holder 26 attached to the bottom of the coating device 10. Accordingly, the coating nozzle holder 26 connects the common circular outlet opening and the coating nozzle 24. Details of the coating nozzle holder 26 will be described later.

[0040] In this embodiment, the solder body 2 is held by a coating nozzle 24 whose tip opening diameter is smaller than the diameter of the solder body 2. To discharge the solder body 2 from the coating nozzle 24, pressure gas is introduced from a pressure gas source (not shown) to increase the pressure inside the coating nozzle 24, and the solder body 2 is melted or liquefied using a laser beam 46 described later. When the solder body 2 is sufficiently melted or liquefied, the solder body 2 is ejected toward the soldering spot on the workpiece by the pressure inside the coating nozzle 24.

[0041] However, this embodiment is not limited to this, and the opening of the coating nozzle 24 may be substantially the same as or slightly larger than the diameter of the solder body 2 so that the solder body 2 can exit the coating nozzle 24. Next, the solder body 2 can be held at the tip of the coating nozzle 24 where the coating nozzle 24 is less than the diameter of the solder body 2 and is separated from the workpiece. Thus, the solder body 2 is held between the coating nozzle 24 and the workpiece. Then, the laser beam 46 is irradiated onto the solder body 2 to melt or liquefy the solder body 2 so that a solder joint is obtained on the workpiece. Next, the coating nozzle 24 is separated from the workpiece.

[0042] As shown in FIGS. 1 and 2, the apparatus 1 includes a housing 28 formed by an upper housing portion 30 and a lower housing portion 32. A coating device 10 having a laser duct 12 and a droplet duct 14 is integrated with the lower housing portion 32. A transport device 34 configured to individually transport the solder body 2 to the droplet inlet 20 is positioned between the upper housing portion 30 and the lower housing portion 32.

[0043] Also, as shown in FIGS. 1 and 3, the upper housing portion 30 forms a guide duct 36 configured to guide the solder body 2 to the transport device 34. As shown in FIG. 2, the guide duct 36 extends along a straight line passing through the upper housing portion 30.

[0044] As shown in FIG. 1, the guide duct 36 and the droplet inlet 20 are rotationally displaced so as to avoid a plurality of solder bodies 2 from falling into the droplet duct 14. Thus, the transfer device 34 includes a transfer element 38 formed as a rotating disk in the present embodiment. The transfer element 38 in this embodiment is provided with receiving holes 40 arranged at equal intervals along a predetermined movement path, that is, a rotational movement path, configured to receive each solder body 2 and transfer the solder body 2 from the guide duct 36 to the droplet inlet 20. The transfer element 38 in the present embodiment is rotated in the clockwise direction (see FIG. 3) by a shaft 42 driven by an electric motor (not shown) operated by a control unit (not shown) of the apparatus 1. Thus, the control unit is configured to control the movement of the transfer element 38 and thus the transfer device 34.

[0045] As shown in FIG. 1, the transfer device 34 may include a spacer 44 surrounding the transfer element 38 in order to separate the upper housing portion 30 and the lower housing portion 32. Thus, the housing 28 of the apparatus 1 can be easily disassembled, and the transfer device 34 and the spacer 44, as well as the lower housing portion 32, can be replaced according to the diameter of the solder body 2 to be used. As a result, the apparatus 1 can be flexibly adapted to different applications, that is, solder bodies 2 having different diameters.

[0046] Furthermore, as shown again in FIGS. 1 and 3, the guide duct 36 is formed as an aspherical space, that is, not spherical and not cylindrical, but as a space having a tapered cross-section passing through the upper housing portion 30. The guide duct 36 is formed to lift the solder body 2 existing in the guide duct 36. As shown in FIG. 1, the aspherical space is slightly funnel-shaped. As shown in FIG. 3, the aspherical space tapers with respect to the moving direction of the conveying device 34, that is, with respect to the rotational moving direction of the transfer element 38, that is, the rotating disk. Further, the radially outer wall portion 37 of the guide duct 36 is formed tangentially with respect to the rotational moving direction of the transfer element 38. Further, the radially outer wall portion 37 is positioned outside the end of the transfer element 38, that is, outside the radius of the rotating disk. Thus, the solder body 2 existing in the guide duct 36 is also disposed on the spacer 44 surrounding the stationary, that is, non-moving transfer element 38, and as a result, the solder body 2 is further lifted. The inner wall portion 39 of the guide duct 36 includes an inclined wall portion 41 inclined outward with respect to the guide duct 36 at the top of the upper housing portion 30. By being formed in this way, the guide duct 36 avoids clogging when a plurality of solder bodies 2 are transferred to the conveying device 34.

[0047] As shown in FIG. 2, the apparatus 1 liquefies the solder body 2 held in the application nozzle 24 using a laser beam 46. Thus, the apparatus 1 includes a laser coupling unit 48 configured to couple the laser beam 46 into the laser duct 12. The laser coupling unit 48 further includes an optical window 50 that is transparent to the laser beam 46. The apparatus 1 also includes a laser source (not shown), and the laser source can be detachably attached to the laser coupling unit 48, for example, by using a screw connection, such that the laser beam 46 emitted by the laser source is coupled into the laser duct 12. The optical window 50 of the laser coupling unit 48 avoids the scattering of the solder of the molten or liquefied solder body 2 ejected toward the workpiece by the laser source.

[0048] As shown in FIGS. 4 and 5, the apparatus 1 preferably comprises a solder body reservoir 52 configured to store a plurality of solder bodies 2 and supply the solder bodies 2 to a conveying device 34 via a guide duct 36. The solder body reservoir 52 comprises a solder body tank 54 and a line 56 connecting the solder body tank 54 and the guide duct 36. The solder body tank 54 is separated from the housing 28 of the apparatus 1, and the line 56 is flexible so that separation in terms of vibration between the solder body tank 54 and the apparatus 1 is achieved. Preferably, the solder body tank 54 may comprise a transparent window 58 that enables easy monitoring of the filling level of the solder body tank 54. As a result, the solder body tank 54 can be monitored and refilled during operation of the apparatus 1 without the need to stop the operation of the apparatus 1.

[0049] As described above and as shown in FIGS. 2 and 6, the apparatus 1 further comprises a coating nozzle holder 26 detachably attached to the bottom of the coating device 10, i.e., the lower housing part 32. In particular, the coating nozzle holder 26 is fixed to the lower housing part 32 by screws 60. In order to align the coating nozzle holder 26 and the lower housing part 32, positioning pins 62 can be engaged with the coating nozzle holder 26 and the lower housing part 32. Thus, the coating nozzle holder 26 and the lower housing part 32 can be accurately arranged relative to each other, and as a result, there is no edge at the connection point between the coating nozzle holder 26 and the lower housing part 32 that could adversely affect the solder body 2 falling or rolling down the droplet duct 14.

[0050] The coating nozzle holder 26 is configured to hold the coating nozzle 24 in a replaceable manner. In the present embodiment, the coating nozzle holder 26 comprises a collet chuck part 64 configured to clamp the coating nozzle so that the coating nozzle 24 does not fall off during the mounting process. The coating nozzle holder 26 also comprises a bag nut 66 configured to fasten the coating nozzle 24 to the coating nozzle holder 26. As a result, the coating nozzle 24 is securely held by the coating nozzle holder 26 and can be accurately arranged in the coating direction.

[0051] As shown in FIG. 2, the common circular outlet opening formed by the laser outlet 18 and the droplet outlet 22 is significantly larger than the diameter of the application nozzle 24. The application nozzle holder 26 gradually tapers towards the application nozzle 24 without forming an edge. Thus, the diameter of the common circular outlet opening does not limit the usable size or diameter of the solder body 2. As a result, the apparatus 1 enables the use of large solder bodies 2. Further, the apparatus 1 can also be used for smaller diameters by attaching an application nozzle holder 26 having sufficient taper. Therefore, the apparatus 1 can be flexibly adapted to the use of solder bodies 2 having different diameters.

[0052] Examples of different application nozzle holders 26, 68 - 72 that can be attached to the lower housing part 32 are shown in FIG. 7. The lengths of the application nozzle holders 26, 68 - 72 can be easily adapted to the desired application without the need to stock a plurality of expensive application nozzles 24 having different lengths. Thus, by using different application nozzle holders 26, 68 - 72, it is possible to avoid the use of application nozzles 24 that require a large amount of raw materials and a wide range of high manufacturing tolerances and also have a high risk of breakage during manufacturing or attachment. Additionally or alternatively, the cavity of the application nozzle holder 26, such as the taper angle, can be adapted to the solder body 2 used for the desired application. Therefore, the apparatus 1 can be flexibly adapted to different applications.

[0053] As shown in FIGS. 8 and 9, the apparatus 1 further includes a laser shield 74 that surrounds the application nozzle 24 with a lateral play. Preferably, the laser shield 74 is removably attached to the application nozzle holder 26. For example, the flange of the laser shield 74 can be fixed to the application nozzle holder 26 using screws. Alternatively, the laser shield 74 can include an attachment portion 76 removably attached to the application nozzle holder 26, for example, by screws 78, and a shield portion 80 held by the attachment portion 76. It is also possible to preheat the soldering spot on the workpiece using the laser beam 46 or a special preheating laser beam (not shown), and it should be noted that the laser shield 74 effectively avoids the scattering of the laser beam 46 reaching the soldering spot. Furthermore, the thermal expansion on the workpiece can be locally limited. Alternatively, the laser shield 74 or the attachment portion 76 can be directly attached to the lower housing portion 32 or the bottom of the application device 10.

[0054] In particular, the shield portion 80 is held by the attachment portion 76 so as to be movable relative to the attachment portion 76 to any position between a retracted position where the tip of the application nozzle 24 is at the same height as the tip of the shield portion 80 and an extended position (see FIG. 9) where the tip of the application nozzle 24 is completely surrounded within the shield portion 80. For example, the shield portion 80 is biased toward the extended position by a spring 82. In particular, the flange 81 of the shield portion 80 is pushed by the spring 82 toward the protruding portion 83 of the attachment portion 76 to fix the shield portion 80 in the extended position. Thus, when the laser shield 74 is brought close to and contacted with the workpiece, for example, the circuit board 8 (see FIG. 1), the shield portion 80 is moved toward the retracted position. As a result, damage to the workpiece can be avoided while efficiently shielding the soldering spot.

[0055] The laser shield 74 may include a connection port 84 configured to be connected to a vacuum source or an inert gas source (not shown). As a result, particles inside the laser shield can be removed by vacuum suction. Further, an inert gas atmosphere can be created within the laser shield 74. Alternatively, the connection port 84 can be connected and switched between a vacuum source and an inert gas source, and one can be applied after the other. For example, the particles can be removed first, and then an inert gas atmosphere can be created. This can have a beneficial effect on the soldering process and can reduce the amount of inert gas that functions as a pressure gas for ejecting the solder body 2 from the application nozzle 24.

[0056] As described above, the transfer device 34 individually transfers the solder body 2 from the guide duct 36 to the droplet inlet 20 of the droplet duct 14 in order to supply the solder body 2 to the tip of the application nozzle 24. It may happen that the receiving hole 40 of the transfer element 38 is not loaded with the solder body 2. Therefore, the apparatus 1 includes an optical sensor 86 provided along the movement path between the guide duct 36 and the droplet inlet 20, and the optical sensor 86 is configured to detect the presence or absence of the solder body 2 inside each receiving hole 40. For example, as shown in FIG. 3, the optical sensor 86 can be screwed to the upper housing portion 30. Then, the above-described control unit of the apparatus 1 is configured to control the movement of the transfer device 34 and adjust the movement pattern of the transfer device 34 when the optical sensor 86 detects that there is no solder body 2 inside one receiving hole 40. In the present embodiment where the transfer element 38 is a rotating disk having a plurality of receiving holes 40, the control unit skips the receiving hole 40 not loaded with the solder body 2 by rotating the transfer element 38 to two positions instead of one. As a result, the processing speed of the apparatus 1 can be improved.

[0057] As described above, the apparatus 1 includes a laser source (not shown) configured to couple a laser beam 46 into the laser duct 12 via a laser coupling unit 48 in order to melt or liquefy the solder body 2 held at the tip of the application nozzle 24. The control unit of the apparatus 1 is configured to operate the laser source so as to emit the laser beam 46 in a pulse modulation mode. This is particularly necessary to appropriately melt or liquefy a large solder body 2.

[0058] FIG. 10 is a time diagram showing a laser pulse modulation pattern. During a first period (referred to as a cleaning pulse delay) between t0 and t1, the laser beam 46 is not irradiated. In a subsequent period t1 to t2 (referred to as a cleaning pulse period), a cleaning pulse 87 having an output in the range of 50 to 100 W, particularly 80 W, is applied without holding the solder body 2 in the application nozzle 24 in order to clean the spot to be soldered. Further, the cleaning pulse 87 may be applied during this period to preheat the spot to be soldered on the workpiece.

[0059] During a period (referred to as a solder body loading and detection time) between t2 and t3, which is about 100 ms, the laser beam 46 is not irradiated, and the solder body 2 is transferred from the solder body reservoir 52 to the application nozzle 24. In addition, proper loading of the application nozzle 24 is detected by using optical means or by detecting an increase in pressure inside the application nozzle 24 when applying a pressure gas for discharging the solder body 2.

[0060] Thereafter, from t3 to t4 (referred to as pre-pulse delay), the laser beam 46 is not irradiated onto the solder body 2 which is present inside the application nozzle 24 here. From t4 to t5, the laser beam 46 is irradiated onto the solder body 2 held in the application nozzle 24 with an output that gradually increases. The gradient of the output of the laser beam 46 is in the range of 0.5 W / ms to 1.5 W / ms, particularly 1 W / ms. At time t5, the output of the laser beam 46 at that time is 150 W to 250 W, particularly 200 W, and the laser beam 46 with this output is continuously irradiated until time t6. The time from t4 to t6 is also referred to as the pre-pulse period, and the pulse including the gradually increasing output and the constant output is referred to as the pre-pulse 88. Alternatively, a pre-pulse 88 having only a constant output may be applied. Nevertheless, by using the pre-pulse 88 having a phase in which the output gradually increases, the solder body 2 is gradually heated and melted, thereby avoiding the dynamics of the melted solder. As a result, the scattering of the melted solder can be avoided.

[0061] From t6 to t7 (referred to as intermediate pulse delay), the laser beam 46 is not irradiated onto the solder body 2. During this period, the heat generated by the application of the pre-pulse 88 on the outer surface of the solder body 2 expands toward the inside of the solder body 2. As a result, appropriate melting or liquefaction inside the solder body 2 can be achieved.

[0062] From t7 to t8 (referred to as main pulse period), in order to sufficiently liquefy the solder body 2, the laser beam 46 having an output in the range of 300 W to 400 W, particularly 320 W or 350 W, is irradiated onto the solder body 2. This pulse is referred to as the main pulse 90. Thereafter, between time t8 and t9 (referred to as post-pulse delay), the solder body 2 is applied, particularly ejected, toward the workpiece because the pressure inside the application nozzle 24 is increased and the solder body 2 is sufficiently melted or liquefied. Thereafter, the apparatus 1 repeats the soldering process starting from t0.

[0063] With the above laser pulse modulation pattern, in particular, the prepulse 88 applied during the period from t4 to t6, the intermediate pulse delay between t6 and t7, and the main pulse 90 applied from t7 to t8, the solder body 2 held in the application nozzle 24 is appropriately melted or liquefied. The prepulse 88, the intermediate pulse delay, and the main pulse 90 are particularly necessary to ensure sufficient liquefaction when applying a large solder body 2.

[0064] Flux is known to be able to have a good influence on the soldering process. However, when using a preformed solder body 2, it is usually necessary to apply flux to the spot to be soldered. As shown in FIG. 11, the apparatus 1 according to this embodiment includes a flux dispenser 92 that applies flux 94 in the gas phase to the solder body 2 exiting the application nozzle 24. In this way, the cumbersome application of flux to the spot to be soldered can be avoided.

[0065] The flux dispenser 92 includes a flux tank 96 that stores the liquid-phase flux 98. A pressure line 100 is connected to the flux tank 96 to generate an overpressure, whereby the liquid flux 98 is output as the gaseous flux 94 through the flux nozzle 102 to the solder body 2 exiting the application nozzle 24. As a result, the flux 94 is applied onto the solder body 2 so as to have a good influence on the soldering process. It should be noted that the tip of the flux nozzle 102 can also be positioned inside the laser shield 74. The application of the flux dispenser 92 is particularly beneficial when using a large solder body 2 because the large solder body 2 provides a larger surface area on which sufficient flux can adhere.

[0066] In summary, the laser-assisted soldering apparatus 1 according to the present invention can be easily formed and can be easily adapted to various applications. In particular, the apparatus 1 according to the present invention can be adapted to the use of a large solder body 2 having a diameter in the range of 0.9 μm to 2 mm.

[0067] This application discloses the following further embodiments 1-8.

[0068] Embodiment 1 A laser-assisted soldering apparatus according to Embodiment 1, particularly for separately applying a solder body, in particular a solder ball, to a workpiece, comprises a coating device having a laser duct extending linearly from a laser inlet at the top of the coating device to a laser outlet at the bottom of the coating device, and a droplet duct extending from a droplet inlet at the top of the coating device to a droplet outlet at the bottom of the coating device. The apparatus further comprises a conveying device configured to separately convey the solder body to the droplet inlet, and a coating nozzle provided at the bottom of the coating device and configured to temporarily hold the solder body exiting from the droplet outlet. The apparatus further comprises a housing formed by an upper housing part and a lower housing part.

[0069] The coating device having the laser duct and the droplet duct can be integrated into the lower housing part.

[0070] The conveying device can be positioned between the upper housing part and the lower housing part.

[0071] The upper housing part and the lower housing part can be separated by a spacer surrounding the conveying device.

[0072] The upper housing part can form a guide duct configured to guide the solder body to the conveying device.

[0073] The guide duct and the droplet outlet of the droplet duct can be spaced apart from each other.

[0074] The guide duct and the droplet duct can be rotationally displaced relative to each other, and the conveying device can convey the solder body using a rotatable transfer element such as a rotating disk.

[0075] The conveying device, i.e., the transfer element, can be surrounded by a spacer and move, i.e., rotate, within the spacer.

[0076] The guide duct can extend along a straight line passing through the upper housing part.

[0077] The guide duct can be formed as an aspherical space, i.e., a space that is neither spherical nor cylindrical.

[0078] The guide duct can have a tapered cross-section passing through the upper housing part.

[0079] The aspherical space may be slightly funnel-shaped.

[0080] The aspherical space may taper in the moving direction of the conveying device, i.e., in the rotational movement direction of the transfer element.

[0081] The radially outer wall portion of the guide duct can be formed tangentially with respect to the rotational movement direction of the transfer element, i.e., the rotating disk.

[0082] The position of the radially outer wall portion is positioned outside the end of the transfer element, i.e., outside the radius of the rotating disk, whereby the solder body present in the guide duct is also disposed on the spacer surrounding the transfer element, i.e., the rotating disk.

[0083] The radially inner wall portion of the guide duct can include an inclined wall portion inclined outward with respect to the guide duct at the top of the upper housing part.

[0084] Embodiment 2 According to Embodiment 2, a soldering body, in particular, a laser-assisted soldering device for separately applying a solder ball to a workpiece, is a coating device having a laser duct extending linearly from a laser inlet at the top of the coating device to a laser outlet at the bottom of the coating device, and a droplet duct extending from a droplet inlet at the top of the coating device to a droplet outlet at the bottom of the coating device. The device further includes a conveying device configured to separately convey the soldering body to the droplet inlet, and a coating nozzle provided at the bottom of the coating device and configured to temporarily hold the soldering body exiting the droplet outlet. The device further includes a soldering body reservoir configured to store a plurality of soldering bodies and supply the soldering bodies to the conveying device.

[0085] The soldering body reservoir may include a soldering body tank and a line connecting the soldering body tank and the conveying device.

[0086] The line may be flexible so that the soldering body tank and the laser-assisted soldering device can be separated from each other in the plane of vibration.

[0087] The soldering body tank may include a transparent window.

[0088] Embodiment 3 According to Embodiment 3, a soldering body, in particular, a laser-assisted soldering device for separately applying a solder ball to a workpiece, is a coating device having a laser duct extending linearly from a laser inlet at the top of the coating device to a laser outlet at the bottom of the coating device, and a droplet duct extending from a droplet inlet at the top of the coating device to a droplet outlet at the bottom of the coating device. The device further includes a conveying device configured to separately convey the soldering body to the droplet inlet, and a coating nozzle provided at the bottom of the coating device and configured to temporarily hold the soldering body exiting the droplet outlet. The device further includes a coating nozzle holder detachably attached to the bottom of the coating device and configured to hold the coating nozzle replaceably.

[0089] Coating nozzle holders having different lengths can be attached to the bottom of the coating device.

[0090] The cavity of the coating nozzle holder can be adapted to the solder body used.

[0091] The coating nozzle holder may taper towards the coating nozzle.

[0092] The coating nozzle holder may comprise a collet chuck portion configured to clamp the coating nozzle.

[0093] The coating nozzle holder may comprise a bag nut configured to fasten the coating nozzle to the coating nozzle holder.

[0094] Embodiment 4 A laser-assisted soldering device according to Embodiment 4 for separately applying a solder body, in particular solder balls, to a workpiece, is a coating device having a laser duct extending linearly along a straight line from a laser inlet at the top of the coating device to a laser outlet at the bottom of the coating device, and a droplet duct extending from a droplet inlet at the top of the coating device to a droplet outlet at the bottom of the coating device. The device further comprises a conveying device configured to separately convey the solder body to the droplet inlet, and a coating nozzle provided at the bottom of the coating device and configured to temporarily hold the solder body exiting the droplet outlet. The device further comprises a laser shield surrounding the coating nozzle with a lateral play.

[0095] The device may further comprise a coating nozzle holder detachably attached to the bottom of the coating device and configured to removably hold the coating nozzle.

[0096] The laser shield may be detachably attached to the bottom of the coating device or to the coating nozzle holder.

[0097] The coating nozzle holder or the coating device may comprise a holding unit configured to hold a laser shield.

[0098] The laser shield may comprise a flange configured to be fixed to a coating nozzle holder or a coating device having the holding unit.

[0099] The holding unit may be a threaded hole and the laser shield may be attached using a screw.

[0100] The laser shield may comprise an attachment part removably attached to the bottom of the coating nozzle holder or the coating device, and a shield part held at the attachment part such that the shield part is movable relative to the attachment part to any position between a retracted position where the tip of the coating nozzle is at the same height as the tip of the shield part and an extended position where the tip of the coating nozzle is completely surrounded within the shield part.

[0101] The shield part may be biased towards the extended position by an elastic element, in particular a spring.

[0102] The laser shield may comprise a connection port configured to be connected to a vacuum source and / or an inert gas source.

[0103] The connection port may be connected and switched between a vacuum source and an inert gas source such that one can be applied after the other.

[0104] Embodiment 5 A solder body, in particular a laser-assisted soldering device for separately applying solder balls to a workpiece according to another embodiment, comprises an application device having a laser duct extending linearly from a laser inlet at the top of the application device to a laser outlet at the bottom of the application device, and a droplet duct extending from a droplet inlet at the top of the application device to a droplet outlet at the bottom of the application device. The device further comprises a conveying device configured to separately convey the solder body to the droplet inlet, and an application nozzle provided at the bottom of the application device and configured to temporarily hold the solder body exiting from the droplet outlet. The device further comprises a laser coupling unit configured to couple a laser beam into the laser duct and comprising an optical window transparent to the laser beam.

[0105] A laser source configured to emit a laser beam can be removably attached to the laser coupling unit.

[0106] Embodiment 6 A solder body, in particular a laser-assisted soldering device for separately applying solder balls to a workpiece according to Embodiment 6, comprises an application device having a laser duct extending linearly from a laser inlet at the top of the application device to a laser outlet at the bottom of the application device, and a droplet duct extending from a droplet inlet at the top of the application device to a droplet outlet at the bottom of the application device. The device further comprises a conveying device configured to separately convey the solder body to the droplet inlet, and an application nozzle provided at the bottom of the application device and configured to temporarily hold the solder body exiting from the droplet outlet. The device further comprises a housing formed by an upper housing part and a lower housing part. The application device having the laser duct and the droplet duct is integrated into the lower housing part. The conveying device is positioned between the upper housing part and the lower housing part. The upper housing part forms a guide duct configured to guide the solder body to the conveying device. The guide duct and the droplet outlet of the droplet duct are spaced apart from each other.

[0107] The guide duct and the droplet duct can be rotationally displaced relative to each other.

[0108] The conveying device can be configured to carry or transfer the solder body from the guide duct to the droplet inlet.

[0109] The conveying device can include a transfer element having at least one receiving hole, and the at least one receiving hole can be configured to receive the solder body and transfer the solder body from the guide duct to the droplet inlet along a predetermined movement path.

[0110] The conveying device can convey the solder body using a rotatable transfer element such as a rotating disk.

[0111] An optical sensor can be provided along the movement path between the guide duct and the droplet inlet, and the optical sensor is configured to detect the presence or absence of the solder body inside at least one receiving hole.

[0112] The apparatus can further include a control unit configured to control the movement of the conveying device, i.e., the transfer element, and to adjust the movement pattern of the conveying device when the optical sensor detects that there is no solder body inside at least one receiving hole.

[0113] The transfer element can include a plurality of receiving holes, and the control unit can be configured to adjust the movement pattern such that the receiving holes determined to be not loaded with the solder body are skipped.

[0114] Embodiment 7 According to Embodiment 7, a soldering body, in particular, a laser-assisted soldering device for separately applying a solder ball to a workpiece, is a coating device that includes a laser duct extending linearly from a laser inlet at the top of the coating device to a laser outlet at the bottom of the coating device, and a droplet duct extending from a droplet inlet at the top of the coating device to a droplet outlet at the bottom of the coating device. The device further includes a conveying device configured to separately convey the soldering body to the droplet inlet, and a coating nozzle provided at the bottom of the coating device and configured to temporarily hold the soldering body exiting from the droplet outlet. The device also includes a laser source configured to couple a laser beam into the laser duct, and a control unit configured to operate the laser source to emit the laser beam in a pulse modulation mode.

[0115] The control unit may be configured to operate the laser source to emit a pre-pulse and, after the pre-pulse ends, emit a main pulse after a delay time has elapsed.

[0116] The pre-pulse may include a phase in which the output of the laser beam is gradually increased to a set output value, and a phase in which the laser beam having the set output value is constantly irradiated.

[0117] The main pulse may include a phase in which a laser beam having a constant output is irradiated.

[0118] The constant output of the laser beam of the main pulse may be greater than the output of the pre-pulse.

[0119] The control unit may be configured to operate the laser source to emit a cleaning pulse to clean and / or heat the soldering spot on the workpiece before the pre-pulse.

[0120] Embodiment 8 The solder body according to Embodiment 8, in particular, a laser-assisted soldering apparatus for separately applying a solder ball to a workpiece, is a coating device having a laser duct extending linearly from a laser inlet at the top of the coating device to a laser outlet at the bottom of the coating device, and a droplet duct extending from a droplet inlet at the top of the coating device to a droplet outlet at the bottom of the coating device. The apparatus further includes a transport device configured to separately transport the solder body to the droplet inlet, and a coating nozzle provided at the bottom of the coating device and configured to temporarily hold the solder body exiting the droplet outlet. The apparatus includes a flux dispenser configured to administer flux to the solder body exiting the coating nozzle.

[0121] The flux can be administered by a flux dispenser nozzle.

[0122] The apparatus may further include a laser shield surrounding the apparatus with a lateral play, and the flux dispenser nozzle may be disposed inside the laser shield.

[0123] The flux dispenser may include a flux tank for storing the flux in a liquid phase.

[0124] The pressure line may be connected to the flux tank and configured to generate an overpressure in the flux tank, whereby the liquid flux is output as a gaseous flux through the flux nozzle.

[0125] Each of the above specific further Embodiments 1 to 8 represents an individual basis for the claims of a divisional application (to be filed at a later date). Each divisional application may further include the specification and drawings of the present application.

Description of Reference Numerals

[0126] 1…Laser-assisted soldering device, 2…Solder body, 4…Electronic component, 6…Lead, 8…Circuit board, 10…Coating device, 12…Laser duct, 14…Droplet duct, 16…Laser inlet, 18…Laser outlet, 20…Droplet inlet, 22…Droplet outlet, 24…Coating nozzle, 26…Coating nozzle holder, 28…Housing, 30…Upper housing part, 32…Lower housing part, 34…Conveying device, 36…Guide duct, 37…Radial outer wall part, 38…Transfer element, 39…Radial inner wall part, 40…Receiving hole, 41…Inclined wall part, 42…Shaft, 44…Spacer, 46…Laser beam, 48…Laser coupling unit, 50…Optical window, 52…Solder body reservoir, 54…Solder body tank, 56…Line, 58…Transparent window, 60…Screw, 62…Positioning pin, 64…Collet chuck part, 66…Nut, 68…Coating nozzle holder, 70…Coating nozzle holder, 72…Coating nozzle holder, 74…Laser shield, 76…Mounting part, 78…Screw, 80…Shield part, 81…Flange, 82…Spring, 83…Protruding part, 84…Connection port, 86…Optical sensor, 87…Cleaning pulse, 88…Pre-pulse, 90…Main pulse, 92…Flux dispenser, 94…Gaseous flux, 96…Flux tank, 98…Liquid flux, 100…Pressure line, 102…Flux nozzle.

Claims

1. A solder body (2), in particular a laser-assisted soldering device (1) for separately applying a solder ball to a workpiece (4, 6, 8), wherein the device (1) has an application device (10) having a laser duct (12) extending linearly from a laser inlet (16) at the top of the application device (10) to a laser outlet (18) at the bottom of the application device (10), and a droplet duct (14) extending from a droplet inlet (20) at the top of the application device (10) to a droplet outlet (22) at the bottom of the application device (10), a conveying device (34) configured to separately convey the solder body (2) to the droplet inlet (20), a coating nozzle (24) provided at the bottom of the coating device (10) and configured to temporarily hold the solder body (2) exiting the droplet outlet (22), in the laser-assisted soldering device (1), the laser duct (12) and the droplet duct (14) are formed so as to be interconnected over the entire length of the laser duct (12) and the droplet duct (14) from the top to the bottom of the application device (10), the droplet inlet (20) and the laser inlet (16) are arranged side by side so as to form a common inlet opening, and the droplet outlet (22) and the laser outlet (18) are arranged to coincide so as to form a common outlet opening smaller than the common inlet opening, characterized in that the coating nozzle (24) is connected to the common outlet opening, laser-assisted soldering device (1).

2. The laser-assisted soldering device according to claim 1, wherein the common inlet opening is non-circular and the common outlet opening is circular.

3. The laser-assisted soldering device (1) according to claim 1, wherein the droplet duct (14) extends along a curve from the top to the bottom of the application device (10).

4. The laser-assisted soldering device (1) according to claim 1, wherein the cross-section of the droplet duct (14) narrows from the top to the bottom of the application device (10).

5. further comprising a housing (28) formed by an upper housing part (30) and a lower housing part (32), The coating device (10) having the laser duct (12) and the droplet duct (14) is integrated with the lower housing part (32), The conveying device (34) is positioned between the upper housing part (30) and the lower housing part (32), The upper housing part (30) forms a guide duct (36) for guiding the solder body (2) to the conveying device (34), The laser-assisted soldering device (1) according to claim 1.

6. The laser-assisted soldering device (1) according to claim 5, wherein the guide duct (36) extends through the upper housing part (30) toward the conveying device (34).

7. The laser-assisted soldering device (1) according to claim 5, wherein the guide duct (36) is formed as an aspherical space.

8. The laser-assisted soldering device (1) according to claim 5, further comprising a solder body reservoir (52) configured to store a plurality of solder bodies (2) and supply the solder bodies (2) to the conveying device (34).

9. The laser-assisted soldering device (1) according to claim 8, wherein the solder body reservoir (52) includes a solder body tank (54) and a line (56) connecting the solder body tank (54) and the guide duct (36).

10. The laser-assisted soldering device (1) according to claim 1, further comprising a coating nozzle holder (26) detachably attached to the bottom of the coating device (10) and configured to removably hold the coating nozzle (24).

11. The laser-assisted soldering device (1) according to claim 10, wherein the coating nozzle holder (26) includes a collet chuck part (64) configured to clamp the coating nozzle (24).

12. The laser-assisted soldering device (1) according to claim 11, wherein the coating nozzle holder (26) includes a bag nut (66) configured to fasten the coating nozzle (24) to the coating nozzle holder (26).

13. The laser-assisted soldering device (1) according to claim 10, further comprising a laser shield (74) surrounding the coating nozzle (24) with a lateral play.

14. The laser-assisted soldering device (1) according to claim 13, wherein the laser shield (74) is detachably attached to the coating nozzle holder (26).

15. The laser-assisted soldering device (1) according to claim 14, comprising: an attachment portion (76) to which the laser shield (74) is detachably attached to the coating nozzle holder (26) or the bottom portion of the coating device (10); and a shield portion (80) held at the attachment portion (76) so as to be movable relative to the attachment portion (76) to any position between a retracted position where the tip of the coating nozzle (24) is at the same height as the tip of the shield portion (80) and an extended position where the tip of the coating nozzle (24) is completely surrounded within the shield portion (80).

16. The laser-assisted soldering device (1) according to claim 15, wherein the laser shield (74) comprises a connection port (84) configured to be connected to a vacuum source and / or an inert gas source.

17. The laser-assisted soldering device (1) according to claim 1, further comprising a laser coupling unit (48) configured to couple a laser beam (46) into the laser duct (12) and comprising an optical window (50) transparent to the laser beam (46).

18. The conveying device (34) is configured to convey the solder body (2) from the guide duct (36) to the droplet inlet (20). The conveying device (34) comprises a transfer element (38) having at least one receiving hole (40). The at least one receiving hole (40) is configured to receive the solder body (2) and transfer the solder body (2) from the guide duct (36) to the droplet inlet (20) along a predetermined movement path. The device (1) further comprises an optical sensor (86) provided along the movement path between the guide duct (36) and the droplet inlet (20), and the optical sensor (86) is configured to detect the presence or absence of the solder body (2) inside the at least one receiving hole (40). The laser-assisted soldering device (1) according to claim 5.

19. A control unit is further provided, which is configured to control the movement of the transfer device (34) and adjust the movement pattern of the transfer device (34) when the optical sensor (86) detects that there is no solder body (2) inside the at least one receiving hole (40). The laser-assisted soldering apparatus (1) according to claim 18.

20. The laser-assisted soldering apparatus (1) according to claim 1, further comprising a laser source configured to couple a laser beam (46) into the laser duct (12), and a control unit configured to operate the laser source to emit the laser beam (46) in a pulse modulation mode.

21. The laser-assisted soldering apparatus (1) according to claim 1, further comprising a flux dispenser (92) configured to administer flux (94) to the solder body (2) emerging from the application nozzle (24).

Images