JP2015131313A - Laser soldering head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve adjustment of a spot diameter of a laser beam to be projected on a soldering object, without relatively changing a distance between a soldering head and the soldering object, and without affecting imaging of the soldering object with a CCD camera.SOLUTION: An incident light lens 20 movable in an optical axis L1, a semi-transparent mirror 23 inclining by 45 degrees to the optical axis L1 and a condenser lens 22 fixed to a constant position are provided in a prescribed arrangement inside a housing 10, a CCD camera 5 for capturing an image of a soldering object 4 via the semi-transparent mirror 23 and the condenser lens 22 is attached to the inside of the housing 10, and the housing 10 is provided with a position adjustment mechanism 28 for adjusting a position of the incident light lens 20. The position of the incident light lens 20 is adjusted in the optical axis L1 using the position adjustment mechanism 28, so that a diameter of a spot S of the laser beam 3 projected on the soldering object 4 can be adjusted.

Description

  The present invention relates to a laser soldering head for performing soldering by projecting laser light onto a soldering target.

  Laser soldering heads for performing soldering by projecting laser light onto a soldering target in a spot shape have been conventionally known as disclosed in, for example, Patent Document 1 and Patent Document 2. This type of soldering head generally has one or more optical lenses inside the housing, and the optical lens collects the laser light in a spot shape and projects it onto the soldering object. It is configured. Since the lens is fixed at a fixed position in the housing, the position of the focal point is also determined.

  On the other hand, the diameter of the spot to be projected onto the soldering target is not always constant, and varies depending on the size of the soldering target, the thermal energy of the laser beam, etc. There are many cases that must be projected. In such a case, conventionally, in order to obtain a required spot diameter, the distance between the soldering head and a soldering target (for example, a substrate) is relatively changed, and thereby the spot diameter of the laser beam is adjusted to be large or small. I was trying to do it.

  However, the method of relatively changing the distance between the soldering head and the soldering target must be performed while confirming the spot diameter by visual observation or the like, and thus the operation is relatively troublesome. In addition, when a CCD camera that captures an image of a soldering object using the optical lens is attached to the soldering head, the optical lens can be changed by changing the distance between the soldering head and the soldering object. Since the distance between the soldering object and the soldering object changes, the imaging position of the CCD camera also shifts, and readjustment is necessary.

  On the other hand, Patent Document 3 discloses a laser processing apparatus that focuses on the upper surface of a workpiece by adjusting the position of a condenser lens in the optical axis direction. If this technique is used for a soldering head, It is not impossible to adjust the diameter of the laser beam spot projected onto the soldering target.

  However, since the technique disclosed in Patent Document 3 is for adjusting the position of the condenser lens, as described above, when the soldering head includes a CCD camera, the position of the condenser lens is described. If the spot diameter is changed by changing the focus of the condenser lens, the focus of the condenser lens does not coincide with the object to be soldered, and it may be difficult to image the object to be soldered by the CCD camera.

JP 2001-198670 A JP 2005-254299 A JP-A-6-190578

  An object of the present invention is to adjust the spot diameter of a laser beam projected onto a soldering object without relatively changing the distance between the soldering head and the soldering object, and to image the soldering object with a CCD camera. It is an object of the present invention to provide a soldering head having a simple and rational design structure that can be performed without affecting the operation.

  In order to achieve the above object, a laser soldering head according to the present invention includes a laser introducing portion for introducing a laser beam, and a laser projection port for projecting the laser beam onto a soldering target. A light incident lens movable along the optical axis, a semi-transparent mirror inclined at 45 degrees with respect to the optical axis, and a constant, in order from the laser introduction unit side toward the laser projection port side along the optical axis A condensing lens fixed at a position, and a CCD camera for picking up an image to be soldered via the semi-transparent mirror and the condensing lens is attached to the housing, and the light incident is attached to the housing. A position adjustment mechanism that adjusts the position of the lens is provided, and the position adjustment mechanism adjusts the position of the light incident lens along the optical axis, thereby projecting onto the soldering target. That is characterized in that the diameter of the laser beam spot was adjustable.

The position adjusting mechanism includes a screw shaft disposed in parallel with the optical axis, an electric motor that rotationally drives the screw shaft, and a screw shaft that is engaged with the screw shaft and rotates along the screw shaft. It is desirable that the nut member move and the lens holder for holding the light incident lens, and the lens holder and the nut member are connected to each other.
The position adjusting mechanism includes a guide shaft disposed in parallel to the screw shaft and a slider slidable along the guide shaft, and the slider is coupled to the lens holder. Is desirable.

  According to the present invention, the adjustment of the spot diameter of the laser beam projected onto the soldering object is performed by adjusting the position of the light incident lens along the optical axis, so that the soldering head and the soldering object can be adjusted as in the past. This can be done easily without relatively changing the distance. In addition, since the position of the condensing lens is adjusted among the incident lens on the laser introduction side and the condensing lens on the laser projection port side at that time, it affects the imaging of the soldering target by the CCD camera. Absent.

It is a longitudinal cross-sectional view which shows one Embodiment of the soldering head for lasers which concerns on this invention, and shows the state which has an incident lens in an origin position. It is a right view of FIG. It is sectional drawing which shows the state which adjusted the position of the said incident lens, and expanded the spot diameter, and the state which moved the solder nozzle to the position different from FIG. FIG. 4 is a right side view of FIG. 3.

  FIG. 1 shows an embodiment of a laser soldering head according to the present invention. This soldering head is used by being attached to an arm of a soldering robot, and a laser output from a laser oscillator (not shown). While having the projection part 1 for introduce | transducing the light 3 and projecting on the soldering object 4, and the imaging part 2 for imaging the said soldering object 4 with the CCD camera 5, it is linear on the said soldering object 4 A solder nozzle 6 for supplying solder 7 is provided.

  The projection unit 1 has a main housing 11 that extends straight up and down in the drawing along the optical axis L1 of the laser beam 3. The main housing 11 has a first housing part 11a, a second housing part 11b, and a third housing part 11c in order from the top to the bottom along the optical axis L1, and the first housing part. A laser introducing portion 13 for introducing laser light 3 from the laser oscillator through the optical fiber 14 is formed at the upper end portion of 11a, and a tapered projection nozzle 15 is connected to the lower end portion of the third housing portion 11c. A laser projection port 16 for projecting the laser beam 3 toward the soldering target 4 is formed at the tip of the projection nozzle 15. The optical axis L1 and the axis of the main housing 11 substantially coincide with each other. Accordingly, in the following description, the axis L is also denoted by reference numeral L1.

  The laser introduction part 13 is provided with a connector 17 for connecting the optical fiber 14, and the laser beam 3 is emitted in a pre-expanded state from the distal end part 14 a of the optical fiber 14 connected to the connector 17. It is like that. Accordingly, the distal end portion 14a of the optical fiber 14 substantially serves as a light source. Therefore, in the following description, the distal end portion 14a of the optical fiber 14 in the laser introducing portion 13 is referred to as a “light source”. Shall.

  Inside the first housing portion 11a of the main housing 11, there is a light incident lens 20 for converting the pre-expanded laser light 3 introduced from the laser introducing portion 13 into a circular parallel light or a shape close to parallel light. The laser beam 3 from the light incident lens 20 is collected inside the third housing portion 11c, and is held in a lens holder 21 that is movably provided along the optical axis L1. Then, a condenser lens 22 that projects in a spot shape from the laser projection port 16 onto the soldering object 4 is disposed in a fixed state on the third housing portion 11c at a fixed position near the laser projection port 16. The laser beam 3 from the light incident lens 20 toward the condenser lens 22 is transmitted through the second housing portion 11b. Semi-transparent mirror 23 the visible light 8 reflected incident through the condenser lens 22 are disposed in a posture inclined 45 degrees with respect to the optical axis L1.

On the other hand, the imaging unit 2 has a sub housing 12 branched from the second housing portion 11b of the main housing 11 and extending in parallel with the first housing portion 11a, and the CCD camera 5 is provided at the upper end of the sub housing 12. Is attached. Further, inside the sub-housing 12, a total reflection mirror 24 that reflects upward visible light 8 as parallel light reflected in the horizontal direction by the semi-transparent mirror 23, and a visible light reflected by the total reflection mirror 24. An imaging lens 25 that focuses the light 8 and forms an image on the CCD camera 5 is disposed along the imaging optical axis L2.
The main housing 11 and the sub-housing 12 constitute the housing 10 for the soldering head.

  An image of the soldering object 4 picked up by the CCD camera 5 is displayed on a monitor (not shown). For example, at the teaching stage before soldering, a laser beam is projected onto the soldering object 4 while viewing this image. It is used for positioning, and is used for monitoring whether or not the soldering is normally performed during soldering.

A position adjusting mechanism 28 for adjusting the position of the light incident lens 20 along the optical axis L1 is provided at a position of the first housing portion 11a in the main housing 11 adjacent to the light incident lens 20. It has been.
The position adjusting mechanism 28 has an upper support member 29a and a lower support member 29b attached to the outer side surface of the first housing portion 11a, and an upper support member 29a and a lower support member 29b. A screw shaft 30 rotatably supported and arranged in parallel with the optical axis L1, an electric motor 31 mounted on the upper support member 29a, and a rotating shaft 31a of the electric motor 31 are attached. A small-diameter driving gear 32, a large-diameter driven gear 33 that is attached to the screw shaft 30 and meshes with the driving gear 32, and is screwed into the screw shaft 30 and rotated by the screw shaft 30. 30, and a lens holder 21 that holds the light incident lens 20. The lens holder 21 and the nut member 34 include the first housing. They are connected to each other through a connecting arm 21a extending from the side elongated window hole 35 of the portion 11a.

  The position adjustment mechanism 28 includes a guide shaft 37 disposed in parallel to the screw shaft 30 by supporting an upper end and a lower end on the upper support member 29a and the lower support member 29b, The slider 38 is slidable along the guide shaft 37. The slider 38 is connected to the lens holder 21 or the nut member 34. The guide shaft 37 and the slider 38 move the light incident lens 20 up and down. It is comprised so that it may guide. Two guide shafts 37 may be provided at symmetrical positions on both sides of the screw shaft 30.

  The screw shaft 30, the nut member 34, the drive gear 32, the driven gear 33, the guide shaft 37, and the slider 38 are preferably covered with a cover 36 attached to the upper and lower support members 29a and 29b.

When the electric motor 31 is rotated in the forward and reverse directions, the screw shaft 30 is rotated in the normal and reverse directions, and accordingly, the nut member 34 and the lens holder 21 are moved up and down along the screw shaft 30. The position of the light incident lens 20 is adjusted in the vertical direction in the figure along the optical axis L1.
The electric motor 31 is preferably a pulse motor. Since this pulse motor can accurately control the rotation speed, rotation angle, and the like, the position of the light incident lens 20 can be accurately grasped and controlled. However, a position sensor that detects the position of the light incident lens 20 by an electromagnetic method, an optical method, or the like may be provided separately.

  The light incident lens 20 is normally held at the origin position A by the position adjusting mechanism 28 as shown in FIG. This origin position A is a position where the laser beam 3 spread from the laser introduction part 13, that is, the light source 14a is converted into parallel light parallel to the optical axis L1 by the light incident lens 20, When the light incident lens 20 is at the origin position A, the focal point of the light incident lens 20 coincides with the light source 14a. Further, the laser beam 3 incident on the condenser lens 22 in the state of parallel light is condensed at the focal position of the condenser lens 22.

  Therefore, if the soldering object 4 is placed at the focal point of the condenser lens 22 while the light incident lens 20 is held at the origin position A, the spot S projected onto the soldering object 4 When the soldering object 4 is disposed closer to the condenser lens 22 side than the focal position of the condenser lens 22, the diameter of the spot S is the same as that of the soldering object 4. Larger than when placed on the focal point.

  Now, when the soldering object 4 is disposed at the focal position of the condenser lens 22, the position of the light incident lens 20 is adjusted between the origin position A and the light source 14a, thereby the solder. The diameter of the spot S of the laser beam projected on the attachment target 4 can be adjusted to be large or small.

  That is, the screw shaft 30 is rotated forward by the electric motor 31, and the nut member 34 is moved upward along the screw shaft 30 as shown in FIGS. When the light source 20 is moved from the origin position A toward the light source 14a, the light source 14a is closer to the light incident lens 20 than the focal position of the light incident lens 20, so that the light enters the light source 14a in a divergent state. The laser beam 3 incident on the lens 20 is converted by the incident lens 20 into a magnified light state that is slightly larger than the parallel light. Then, the laser light 3 converted into the expanded light state passes through the semi-transparent mirror 23 as it is, enters the condenser lens 22, is converged by the condenser lens 22, and is focused from the focal point of the condenser lens 22. It will be condensed at a far position. For this reason, the diameter of the spot S of the laser beam 3 projected onto the soldering object 4 is larger than the diameter of the spot S when the light incident lens 20 is at the origin position A.

  On the contrary, from the state where the diameter of the spot S of the laser beam 3 is largely adjusted, the screw shaft 30 is reversely rotated by the electric motor 31 to move the nut member 34 along the screw shaft 30 downward in the figure. When the light incident lens 20 is brought closer to the origin position A, the light source 14a moves away from the light incident lens 20 and approaches the focal position, so that the laser light 3 emitted from the light incident lens 20 gradually becomes parallel. Approaching the light. For this reason, the condensing position of the laser light 3 by the condensing lens 22 gradually approaches the focal point of the condensing lens 22, and as a result, the spot S of the laser light 3 projected onto the soldering object 4. The diameter gradually decreases.

  Further, even when the soldering object 4 is arranged in advance at a position closer to the condenser lens 22 than the focal position of the condenser lens 22, by adjusting the position of the light incident lens 20, The diameter of the spot S of the laser beam projected onto the soldering object 4 can be adjusted. In this case, in the initial state, the diameter of the spot S projected onto the soldering target 4 is set larger than that when the soldering target 4 is at the focal point of the condenser lens 22. The diameter of the spot S can be adjusted small by displacing the optical lens 20 from the origin position A in a direction approaching the condenser lens 22 (a direction away from the light source 14a). In the illustrated embodiment, the origin position A of the light incident lens 20 is set near the lower end of the first housing portion 11a. However, as described above, the light incident lens 20 is moved from the origin position A to the collecting point. When it is configured to be displaced in a direction approaching the optical lens 22, the origin position A is set at a position where the movement is possible.

  Then, when the electric motor 31 is rotated in the reverse direction and the light incident lens 20 is moved in a direction approaching the condenser lens 22 from the origin position A, the light source 14a moves away from the focal point of the light incident lens 20. The laser light 3 incident on the light incident lens 20 in a state of spreading from the light source 14a is converted by the light incident lens 20 into a convergent light state that is slightly converged compared to parallel light. Then, the laser light 3 converted into the state of the convergent light passes through the semi-transparent mirror 23 as it is, enters the condenser lens 22, is further converged by the condenser lens 22, and is focused on the condenser lens 22. The light is condensed at a position closer to the front. For this reason, the diameter of the spot S of the laser beam 3 projected onto the soldering object 4 is reduced.

  In this way, by adjusting the position of the light incident lens 20 along the optical axis L1, the light is projected onto the soldering target 4 without relatively changing the distance between the soldering head and the soldering target 4. The diameter of the spot S of the emitted laser beam 3 can be adjusted.

  On the other hand, the soldering object 4 is always imaged by the CCD camera 5 through the semi-transparent mirror 23 and the condenser lens 22 and its state is monitored, but the adjustment of the diameter of the spot S of the laser beam 3 is adjusted. This is done by adjusting the position of the light incident lens 20, and the condenser lens 22 does not move while being fixed at a fixed position, so that the focal position of the condenser lens 22 does not change, For this reason, the imaging of the soldering object 4 by the CCD camera 5 is not affected.

  Further, the solder nozzle 6 supplies a linear solder 7 sent from a solder supply device (not shown) through a tube 6b to the soldering target 4 from the supply port 6a at the tip thereof in a necessary amount. 10 is attached so as to be rotatable around the housing 10 via a nozzle attachment mechanism 40 and is driven by a driving means 41.

The nozzle mounting mechanism 40 includes a rotating member 43 that is mounted on the outer periphery of the third housing portion 11c via a bearing 42 so as to be rotatable about the axis L1. An annular nozzle support member 47 that is rotatable around the third housing portion 11 c is connected to the rotating member 43 via an annular connecting member 48 that is fixed to the lower surface of the rotating member 43. A support rod 49 extending in the vertical direction is attached to one end of the nozzle support member 47 so that the position of the support rod 49 can be adjusted in the vertical direction by a screw 50, and the angle of the support rod 49 can be adjusted around the connecting shaft 49a. Thus, the nozzle fixture 51 is connected, and the solder nozzle 6 is connected to the nozzle fixture 51 so that the inclination angle can be adjusted around the connection shaft 51a.
At least one of the nozzle support member 47 and the connecting member 48 may have a shape other than the annular shape, for example, an arm shape.

  In the illustrated embodiment, the rotating member 43 is formed of a gear, and the driving means 41 is formed of an electric motor 44, and the electric motor 44 is fixed to the outer surface of the second housing portion 11b. A drive gear 46 placed on the support base 45 and attached to the drive shaft 44 a of the electric motor 44 meshes with the outer peripheral teeth of the rotating member 43. The electric motor 44 is preferably a pulse motor.

  The drive shaft 44 a of the electric motor 44, the drive gear 46, the rotating member 43, and the connecting member 48 are covered with a cover 52 attached to the housing 10.

  Then, by rotating the electric motor 44 at a necessary angle in the forward and reverse directions, the rotating member 43 is driven to rotate, and the nozzle supporting member 47 is rotated forward and backward following the rotation, whereby the nozzle supporting member As shown in FIGS. 1 and 4, the solder nozzle 6 supported by 47 rotates around the housing 10 at a necessary angle in the forward and reverse directions.

  The reason why the solder nozzle 6 is rotated around the housing 10 in this way is that when the soldering object 4 is soldered using the soldering head, the position and posture of the soldering head are soldered. In order to prevent the solder nozzle 6 from coming into contact with the electronic component or other components attached to the soldering apparatus, the electronic device is variously changed depending on the arrangement, shape, and the like of the electronic component that is the target 4. It is.

DESCRIPTION OF SYMBOLS 3 Laser beam 4 Solder object 5 CCD camera 10 Housing 13 Laser introduction part 16 Laser projection port 20 Incident lens 21 Lens holder 22 Condensing lens 23 Semi-transparent mirror 28 Position adjustment mechanism 30 Screw shaft 31 Electric motor 34 Nut member 35 Window hole 36 Cover L1 Optical axis (axis)
S spot

Claims (3)

Inside a housing having a laser introduction part for introducing laser light and a laser projection opening for projecting laser light onto a soldering object, from the laser introduction part side to the laser projection opening side along the optical axis of the laser light In turn, a light incident lens movable along the optical axis, a semi-transparent mirror inclined by 45 degrees with respect to the optical axis, and a condenser lens fixed at a fixed position, and A CCD camera that captures an image of a soldering target through the semi-transparent mirror and the condenser lens is attached to the housing,
The housing is provided with a position adjusting mechanism that adjusts the position of the light incident lens, and the position adjusting mechanism adjusts the position of the light incident lens along the optical axis, thereby being projected onto the soldering target. The laser beam spot diameter can be adjusted.
This is a laser soldering head.   The position adjusting mechanism includes a screw shaft disposed in parallel with the optical axis, an electric motor that rotationally drives the screw shaft, and a screw shaft that is engaged with the screw shaft and rotates along the screw shaft. The soldering head according to claim 1, further comprising: a nut member that moves and a lens holder that holds the light incident lens, wherein the lens holder and the nut member are connected to each other. .   The position adjusting mechanism includes a guide shaft disposed in parallel to the screw shaft and a slider slidable along the guide shaft, and the slider is coupled to the lens holder. The soldering head according to claim 2.

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