JP2002346750A - Welding method and welding equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent oil shortage of a driving ball screw of each shaft without adversely affecting the welding time, to ensure smooth movement of an optical axis aligning mechanism, to prevent any wear, and to maintain the light aligning function of high accuracy for a long time. SOLUTION: In a welding equipment comprising a positioning mechanism having the driving ball screw for moving a movable member and a rotation driving device capable of rotating the driving ball screw by small angle or over, a pair of welding electrodes with at least one of the welding electrodes supported by the positioning mechanism, a tray with works of the predetermined number placed thereon, a transfer means for transferring the works on the tray to the welding electrodes corresponding thereto according to the predetermined order, and a carrying means for carrying the tray, the driving ball screw is rotated by the set angle larger than the small angel at the predetermined point of time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding method and apparatus suitable for welding while performing optical axis alignment between a stem of an optical semiconductor device such as a laser diode and a cap with a lens.

[0002]

2. Description of the Related Art Light emitting diodes, photodiodes,
In the manufacturing process of laser diodes or optical devices combining these with optical fibers, resistance welding machines are often used. In the case of such an optical device, after the cap with the lens supported by the upper electrode and the stem mounted with the light emitting element supported by the lower electrode, the upper electrode or the lower electrode is moved and aligned. Then, a welding current is applied between these electrodes to weld the cap and the stem.
Examples of such a resistance welding machine that automatically performs position adjustment between a cap and a stem and perform resistance welding include Japanese Patent Publication No. 61-50712 or Japanese Patent Application Laid-Open No. H11-291059.
Is disclosed in Japanese Patent Application Laid-Open Publication No. HEI 9-203 (1995).

One example of a positioning mechanism of a conventional device described in Japanese Patent Publication No. 61-50712 will be described with reference to FIG. 5. An upper welding electrode 31 is formed on a paper surface by a sliding action of a movable portion 32 such as a bearing. A Y-axis movable member 33 movable in a Y-direction perpendicular to the X-axis movable member 33 engaged with the Y-axis movable member 33 via a movable portion 34 and movable in the X direction, which is the left-right direction of the paper surface. The member 35 can be moved to any position in the X direction and the Y direction by moving in the Y direction and the X direction by an external force, respectively. This structure will be described in more detail. An X-axis fine movement adjusting device 36 that drives the X-axis movable member 35 in the X direction is mounted on the Y-axis movable member 33, and the X-axis movable member 33 is rotated by rotating the driving ball screw 36a. The member 35 is driven in the X direction. Although a Y-axis fine adjustment device for moving the Y-axis movable member 33 in the Y direction is not shown, the electrode holder 3 on which the upper electrode main body 31, the Y-axis movable member 33, and the X-axis movable member 35 are mounted.
7, the Y-axis movable member 33 is moved in the Y-direction together with the X-axis movable member 35 by driving a drive ball screw of a Y-axis fine movement adjusting device (not shown) that drives the Y-axis movable member 33. The X-axis movable member 35 moves in the X-direction by driving the driving ball screw of the X-axis fine movement adjusting device 36. The electrode holder 37 moves the guide shaft 38 in the vertical direction, that is, the Z direction perpendicular to the X direction and the Y direction.
You can move in any direction.

Here, a cap 39 with a lens such as a laser diode is clamped and held by a taper nut 42 on the electrode chip 31 a of the upper electrode body 31, and a light emitting element is mounted on the lower electrode chip 40 a of the lower electrode body 40. A stem 41 is supported by a stem clamper 43. Therefore, the positioning of the cap 41 with the lens such as a laser diode and the stem 41 is performed by the X-axis fine adjustment device 36 and the Y-axis fine adjustment device (not shown) as described above. It is automatically driven by an X-axis driving device 42 such as a precision servomotor, and the Y-axis fine adjustment device is also automatically driven by a Y-axis driving device (not shown). However, optical elements such as laser diodes are often small, and in many cases, the optical axis can be aligned with a movement in the range of several μm to several tens of μm. If the optical element can be moved in the range in the Y direction, the optical axis alignment of almost all optical elements can be performed.

In another example of the positioning mechanism disclosed in Japanese Patent Application Laid-Open No. H11-291059, a lower electrode main body is attached to a positioning mechanism including an X-axis movable member and a Y-axis movable member as described above. The stem, which is supported and supported by the electrode tip of the lower electrode main body, is moved to perform alignment with the cap. In any of the conventional examples, the cap or the stem is slightly moved in the X direction or the Y direction by slightly moving the ball screw of the positioning mechanism forward or backward, thereby performing the positioning of the cap and the stem.

[0006]

[Problems to be solved by the invention] As described above,
Since the optical axis alignment of an optical element such as a laser diode can be performed in a very narrow range of motion, the ball screw 36a of the X-axis fine movement adjusting device 36 does not rotate once, that is, does not rotate one pitch in normal operation. , Ball screw 3
The same part of FIG. 6a is repeatedly moved at a slight angle. This is exactly the same for the ball screw of the Y-axis fine adjustment device (not shown). As described above, when the ball screw of the X-axis fine adjustment device 36 and the ball screw of the Y-axis fine adjustment device repeatedly move in a small angle range, the lubricating oil does not rotate and the portion runs out of oil, making it difficult to move or becoming significantly worn. Therefore, there is a problem that the accuracy of the device is reduced and the life is shortened.

This means that the Y-axis movable member 33 and the X-axis movable member 35 are constantly loaded with the upper electrode main body, and a pressing force is applied thereon during welding. It is difficult to reduce the weight of the Y-axis movable member 33 and the X-axis movable member 35 from the surface, and there is a limit in reducing the diameter of the ball screw in terms of mechanical strength.
Due to the fact that optical devices such as laser diodes are becoming smaller and smaller, it was unavoidable.

Accordingly, the present invention solves such a problem, prevents running out of oil in the drive ball screw of each axis without affecting welding tact, ensures smooth movement of the optical axis alignment mechanism, and reduces wear. It is an object of the present invention to prevent such a problem and maintain a high-precision optical alignment function for a long period of time.

[0009]

According to a first aspect of the present invention, there is provided a driving ball screw for moving a movable member, and a rotary driving device capable of rotating the driving ball screw by a small angle or more. A positioning mechanism, a pair of welding electrodes on which at least one welding electrode is supported by the positioning mechanism, a tray on which a predetermined number of workpieces are placed, and the workpiece on the tray are predetermined. In a method of welding using a welding device including a transfer means for transferring the welding balls to the corresponding welding electrodes in accordance with the order described above, and a transfer means for transferring the tray, at a predetermined point in time, the drive ball screw is moved to the minute position. A welding method for rotating a set angle larger than an angle is provided.

According to a second aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect, the predetermined point in time is determined after the welding of the work to be welded placed on the tray is completed. The welding method is provided for each replacement period for replacing the new tray with a new tray, or for each of a plurality of replacement periods.

According to a third aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect, the predetermined time point is determined every time when the workpiece to be welded placed on the tray is welded or when a predetermined number of the workpieces are welded. A welding method is provided for each welding of the workpiece.

According to a fourth aspect of the present invention, there is provided an alignment mechanism including a driving ball screw for moving a movable member and a rotation driving device capable of rotating the driving ball screw by a minute angle or more. A controller capable of controlling the operation of the positioning mechanism, a CPU for providing a command signal to the controller, a pair of welding electrodes having at least one welding electrode supported by the positioning mechanism, and a predetermined number of workpieces to be placed; A welding device comprising: a tray formed by the method, a transfer unit for transferring the workpiece to be welded on the tray to a corresponding one of the welding electrodes in a predetermined order, and a transfer unit for transferring the tray. After the last workpiece is transferred,
When the empty tray is replaced with a new tray on which a large number of workpieces are placed, the control device gives a command signal to the rotary driving device to rotate the driving ball screw by a predetermined angle or more. Provide a welding device.

According to a fifth aspect of the present invention, in order to solve the above problem, in the fourth aspect, the control device includes:
The present invention provides a welding device that gives a command signal to the rotary drive device and rotates the drive ball screw by a predetermined angle or more every time a new tray is replaced or for each of a plurality of predetermined trays.

According to a sixth aspect of the present invention, in order to solve the above problem, in the fourth aspect, the control device includes:
Each time the workpiece mounted on the tray is welded, or each time a predetermined number of workpieces are welded, a command signal is given to the rotary drive to rotate the drive ball screw by a predetermined angle or more. Provide a welding device to be performed.

According to a seventh aspect of the present invention, in order to solve the above-mentioned problem, in any one of the fourth to sixth aspects,
The rotary driving device provides the welding device, wherein the driving ball screw is rotated by a predetermined angle or more and then reversely rotated to return the driving ball screw to its midpoint position.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is basically described in Japanese Patent Publication No.
A positioning mechanism similar to that disclosed in Japanese Patent Publication No. 91059 is used, and each time a tray containing a large number of one workpiece such as a stem such as a laser diode is stored, or a tray is set to be replaced. By rotating the driving ball screw of the positioning mechanism by a set angle or more every time the number of rotations is increased, partial running out of the lubricating oil of the driving ball screw is prevented.

An embodiment of the present invention will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes an X-axis movable member as described in the conventional example, which can move in the left-right direction on the paper. X
Although not shown, a Y-axis movable member that is movable in a direction perpendicular to the paper surface is mounted on the shaft movable member 1, and supports an upper welding electrode or a lower welding electrode (not shown). Therefore, when the X-axis movable member 1 moves in the X direction and the Y-axis movable member moves in the Y direction, the upper welding electrode or the lower welding electrode moves, and the lens L of the cap C shown in FIG.
And the semiconductor laser diode D mounted on the stem S, that is, optical axis alignment is performed. An X-axis driving ball screw 2a of an X-axis fine adjustment driving device 2 is screwed into a ball screw nut portion 1a extending downward from a lower surface of the X-axis movable member 1, and the X-axis driving ball screw 2a is rotated by a coupling member 2b. It is connected to the shaft 2c. The rotation shaft 2c is an X-axis rotation driving device 3 such as a servomotor.
When the rotating shaft 2c rotates in the direction of arrow A, the coupling member 2b fixed to the rotating shaft 2c also rotates in the direction of arrow A, and the X-axis drive ball screw 2a rotates while rotating. Retreat in the direction of arrow B. Therefore, the X-axis movable member 1 moves in the direction of arrow B.

An optical sensor 4 such as a vidicon or a CCD (charge transfer device) detects a light beam emitted from the semiconductor laser element D mounted on the stem S and emitted through the lens L of the cap C. I do.
The normal image processing device 5 performs image processing by receiving light from the optical sensor 4. For example, the light beam emitted from the semiconductor laser element D mounted on the stem S and the center of the lens L of the cap C are +5 μm in X direction, -8 μm in Y direction
If it is deviated, the image processing device 5
, A signal indicating that there is a shift of +5 μm in the X direction and −8 μm in the Y direction. Upon receiving this signal, the controller 6 supplies control signals to the X-axis rotation drive 3 and the Y-axis rotation drive (not shown), respectively.
Rotates the rotating shaft 2c by an angle corresponding to -5 μm. Similarly, a Y-axis rotation driving device (not shown)
A rotating shaft (not shown) is rotated by an angle corresponding to 8 μm. By such an operation of the alignment mechanism, the alignment is performed so that the displacement between the semiconductor laser element D and the center of the lens L of the cap C becomes zero. In addition, cap C
The position of each drive ball screw corresponding to the center of the lens L is referred to as its center position. In the above case, the X-axis drive ball screw 2a rotates by -5 μm from the center position, and the Y-axis drive ball screw rotates by an angle equal to +8 μm from the center position. I do.

On the other hand, the storage device 7 stores software and data necessary for various teachings.
The PU 8 performs an arithmetic operation on detection signals from various sensors (not shown) and the data in the storage device 7 to give an instruction signal to the controller 6. In the present invention, each time a tray is replaced or a predetermined number of trays are replaced, the CP
U8 gives a command to the controller 6, and the controller 6 causes the X-axis rotation driving device 3 to rotate the X-axis driving ball screw 2a at a predetermined angle, preferably one or more rotations. The tray may be called a pallet or a tape, but is called a tray here.

Next, the operation of transporting a tray and the like will be described with reference to FIGS. 3 and 4. Reference numeral 10 denotes a welding box, the inside of which is replaced with nitrogen gas. Reference numeral 11 denotes a stem gas replacement box of the stem tray Ts provided on a part of the outside of the welding box 10, and the inside thereof is replaced with nitrogen gas. The stem gas replacement box 11 includes, for example, ten stem trays Ts
Can be stored. The tray for stem Ts will not be described in detail, but, for example, 10 and 10 regularly in the vertical and horizontal directions for a total of 100 or 10 and 20
A total of 200 stems S can be mounted. Reference numeral 12 denotes a first transfer robot that transfers the lowest one of the stacked trays Ts from the stem gas replacement box 11 to a predetermined position in the welding box 10. A shutter (not shown) is provided between the stem gas replacement box 11 and the welding box 10,
When the tray Ts for stem is carried from the gas replacement box for stem 11 into the welding box 10, the shutter is opened. Next, the stem tray Ts is transported to the position P2 by the second transport robot 13 at the position P1 indicated by the chain line.

On the other hand, on the opposite side of the welding box 10, there is provided a cap gas replacement box 14 for storing the cap tray Tc, so that, for example, ten loaded cap trays Tc can be stored. I have.
Reference numeral 15 denotes a third transfer robot for transferring the lowermost one of the loaded cap trays Tc from the cap gas replacement box 14 to a predetermined position in the welding box 10, similar to the second transfer robot 12. It is something. A shutter (not shown) is provided between the cap gas replacement box 14 and the welding box 10, and the shutter (not shown) opens when the cap tray Tc is carried into the welding box 10 from the cap gas replacement box 14. . Next, the cap tray Tc is transported by the fourth transport robot 16 from a position Q1 indicated by a chain line to a position Q2.

Next, the process of transporting the stems S one by one from the stem tray Ts stopped at the position P2 to the welding portion 17 by the transport robot 13 will be described with reference to FIG.
This will be described with reference to FIG. The welding portion 17 is provided with the alignment mechanism, optical sensor, and the like shown in FIG. 1 and the like, and also includes a lower welding electrode 19 supported by the alignment mechanism, an electrode tip 19A detachably attached thereto, and the like. After the alignment of stem S and cap C,
Welding is performed, but the welding process is not directly related to the present invention, and is therefore omitted here. As described above, the stems S are usually placed on all the placement positions regularly on the stem tray Ts. With the stem position at one predetermined corner of the stem tray Ts as the origin, a transfer robot (not shown) equipped with the suction nozzle 18 sequentially advances in the X direction from the origin, and when one row is completed, moves by one row in the Y direction. And
Go in the X direction in the reverse direction and move to the last stem position. At this time, the suction nozzle 18 sucks and holds each stem S and carries it to the lower welding electrode 19, and also sucks and holds a welded article in which the stem S and the cap C are welded from the lower welding electrode 19, that is, the semiconductor laser diode D. To return to the original stem position of the stem tray Ts. Regarding the order of transfer of the stem, that is, the operation of the transfer robot (not shown),
It is stored in advance in the storage device of FIG. 1 and can be arbitrarily set.

Here, the suction nozzle section 18 has two suction nozzles. When one of the suction nozzles holds the stem S and moves to the upper part of the lower welding electrode 19, the suction nozzle section 18 performs suction. The nozzle part 18 is rotated and the empty suction nozzle is lowered to face the lower welding electrode 19, sucks and holds the welded article and rises, and the suction nozzle part 18 rotates in the opposite direction to suck and hold the stem S again. The suction nozzle is lowered to face the lower welding electrode 19, opens the stem S, and transfers the stem S to the lower welding electrode 19. The transfer of the cap C from the cap tray Tc to the upper electrode (not shown) is almost the same as that of the stem, except that the suction nozzle portion has only one suction nozzle. It does not return to.

In this manner, when the stem S at the last stem position of the stem tray Ts is welded and the welded article is returned to the last stem position, the position P
The second stem tray Ts is moved to the fifth position by the transfer robot 13.
Is transferred to the position P3 of the transfer robot 20 of FIG.
At this time, at the same time, the transfer tray 13 moves the stem tray Ts waiting at the position P1 to the position P2.
Transported to At this time, the cap tray Tc at the position Q2 is transported to the position Q3, and the cap tray Tc waiting at the position Q1 is transported to the position Q2.

As described above, when the stem S at the last stem position of the stem tray Ts is welded and the welded article is returned to the last stem position, the controller 6 shown in FIG. At the same time that the robot 13 outputs a command signal to start the transport operation, a drive signal is given to the X-axis rotation driving device 3 and the Y-axis rotation driving device in FIG. The driving ball screw 2a and the Y-axis driving ball screw of the Y-axis fine-adjustment driving device (not shown) are rotated by a set angle sufficiently larger than a normal operation angle, preferably one or more rotations, and further rotated in reverse through the center position or the origin. To the center position. Here, the operation of rotating by a set angle that is sufficiently larger than the normal operation angle is not limited to one time, and each driving ball screw is first rotated within the time required for replacement of the stem tray Ts and the cap tray Tc. If it can return to the center position described above, it may be performed twice or more. By this operation, the lubricating oil of the other portion is applied to each driving ball screw portion within the minute angle that is normally operated, so that running out of oil can be prevented.

The tray Ts for the stem at the position P 3 in FIG. 3 is transported by the fifth transport robot 20 to the recovery box 21 for the stem provided outside the welding box 10 and collected. The shutter and the like between the welding box 10 and the stem gas replacement box 21 are the same as those of the stem gas replacement box 11. Also,
The cap tray Tc at the position Q3 is transported by the sixth transport robot 22 to the stem gas replacement box 21 provided outside the welding box 10 and collected. At this time, the cap tray Tc at the position Q3
Is transported by the transport robot 22 to the cap gas replacement box 23 provided outside the welding box 10 and collected. The shutter and the like between the welding box 10 and the cap gas replacement box 23 are the same as those of the cap gas replacement box 14.

In the embodiment described above, an example has been described in which each drive ball screw is operated at a set angle that is sufficiently larger than the minute angle that is normally operated, every time one stem tray Ts or cap tray Tc is replaced. Of course, each drive ball screw may be operated to prevent the oil from running out for every plurality of stem trays Ts or every two or three trays Tc. Although the above embodiment has been described in connection with the case where the welding tact is short, that is, the welding speed does not occur, the position P2 and the position Q
In the case where it takes a relatively long time to carry the stem S and the cap C from 2 to the lower electrode and the upper electrode and hold them at a predetermined level, the above operation is performed between each welding process, or for example, 50 times of welding. Each time the operation is performed, each drive ball screw may be caused to perform the operation for preventing the oil from running out.

Further, in the above-described embodiment, the case where the cap and the stem of the semiconductor laser diode are welded has been described. However, the welding is not necessarily performed for the semiconductor laser diode, and high-precision alignment is required. , Any image processing can be performed.

[0029]

As described above, according to the present invention, the drive ball screw of each axis is prevented from running out of oil without affecting the welding tact, the optical axis alignment mechanism is smoothly moved, and the wear is prevented. Thus, a highly accurate optical alignment function can be maintained for a long period of time.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an embodiment of a welding method and a welding apparatus according to the present invention.

FIG. 2 is a view showing an example of a workpiece.

FIG. 3 is a view for explaining an embodiment of a welding method and a welding apparatus according to the present invention.

FIG. 4 is a view for explaining a welding method according to the present invention.

FIG. 5 is a diagram showing an example of a conventional welding device.

[Explanation of symbols]

1. X-axis movable member 2. X-axis fine adjustment driving device 3. X-axis rotation driving device 4. Optical sensor 5. Image processing device 6. Controller 7. Storage device 8. CPU 10.・ Welding box 11 ・ ・ Gas replacement box for stem 12 ・ ・ First transfer robot 13 ・ ・ Second
Transfer robot 14. Gas replacement box for cap 15. Third
Fourth transfer robot 17 Fourth transfer robot 17 Welding part 18 Suction nozzle 19 Lower welding electrode 20 Fiveth transfer robot 21 Gas replacement box for stem 22 Sixth transfer Robot 23 ・ ・ Gas replacement box for cap Ts ・ Tray for stem Tc ・ ・ Cap tray

Claims (7)

[Claims] 1. A positioning mechanism comprising: a driving ball screw for moving a movable member; and a rotary driving device capable of rotating the driving ball screw by a small angle or more; and at least one welding electrode is supported by the positioning mechanism. A pair of welding electrodes, a tray on which a predetermined number of workpieces are placed, transfer means for transporting the workpieces of the tray to the corresponding welding electrodes in a predetermined order, and the tray. A welding method using a welding device provided with a transfer means for transferring the drive ball screw at a predetermined time, wherein the drive ball screw is rotated by a set angle larger than the minute angle. 2. The method according to claim 1, wherein the predetermined time is after each welding period for replacing the tray with a new tray after welding of the workpiece placed on the tray is completed, or at a plurality of times. A welding method characterized in that it is every replacement period. 3. The method according to claim 1, wherein the predetermined time point is each time when the work pieces placed on the tray are welded or when a predetermined number of the work pieces are welded. And welding method. 4. A positioning mechanism including a driving ball screw for moving a movable member and a rotation driving device capable of rotating the driving ball screw by a small angle or more, a controller capable of controlling the operation of the positioning mechanism, A CPU for providing a command signal to the controller, a pair of welding electrodes having at least one of the welding electrodes supported by the alignment mechanism, a tray on which a predetermined number of workpieces are placed, and In a welding apparatus including a transfer unit that transfers an object to a corresponding one of the welding electrodes in accordance with a predetermined order, and a transfer unit that transfers the tray, the last workpiece to be welded on the tray is transferred. Later, when the empty tray is replaced with a new tray on which a large number of workpieces are placed, the control device sends a command signal to the rotary drive device. Welding apparatus characterized by Ete rotate a predetermined angle or more with the driving ball screw. 5. The control device according to claim 4, wherein the control device gives a command signal to the rotary drive device every time the tray is replaced with a new tray or for each of a plurality of predetermined trays. A welding apparatus characterized in that it is rotated by a predetermined angle or more. 6. The control device according to claim 4, wherein the control device instructs the rotation drive device every time the work to be welded placed on the tray is welded or when a predetermined number of the work to be welded is welded. A welding apparatus, wherein a signal is given to rotate the driving ball screw by a predetermined angle or more. 7. The rotary driving device according to claim 4, wherein the rotation driving device rotates the driving ball screw more than a predetermined angle and then reversely rotates the driving ball screw to return to the midpoint position. A welding device characterized by the following.