JP2007190576A - Laser type soldering apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser type soldering apparatus which can perform soldering at an adequate temperature by measuring and controlling the temperature of a soldering point, and can correctly project laser beams and feed a thread solder to the soldering point thereby providing enhanced soldering quality. <P>SOLUTION: The laser type soldering apparatus performs the soldering by projecting the laser beams B from a projecting head 1 to the soldering point 3a, wherein a temperature measurement instrument 7 receives a infrared light radiated from the soldering point 3a to control the laser beam output, the projecting time or the like, and every time when soldering a new similar object 3 to be soldered after the teaching, position correction between the laser beams B and the soldering point 3a and position correction of the fore end 6a of the thread solder 6 with respect to the soldering point 3a are performed by an image processor 20 based on the image data by a CCD camera 19 and the reference data set by the teaching. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laser soldering apparatus for precisely soldering electronic parts such as IC and LSI and other workpieces using a laser.

  The technique of soldering using a laser is already known. In this technology, a laser beam is projected from a projection head toward a soldering point on a printed circuit board, etc., and the solder is melted and soldered by the heat of this laser beam. There is an advantage that you can.

  By the way, generally the quality of soldering is greatly influenced by the heating temperature at the time of soldering, and the quality deteriorates even if the heating temperature is too high or too low. In addition, it is important to improve the quality of soldering by correctly projecting the laser beam to the soldering point and accurately feeding the thread solder to the soldering point.

  However, when performing soldering using a laser, since the laser is the amount of energy, it is difficult to know how many times the temperature of the soldering point is actually due to the projection of the laser beam. Also, when soldering multiple workpieces with the same shape one after another, usually, after performing teaching with the first workpiece and setting the reference, the subsequent workpieces are soldered one after another with that setting. In some cases, the set position with respect to the substrate is slightly shifted between the workpieces. In this case, the projection position of the laser beam relative to the soldering point and the supply position of the thread solder are shifted, resulting in defective solder.

On the other hand, in Patent Document 1, when welding a material to be welded using a laser, the temperature of the welded portion is detected by receiving infrared rays radiated from the vicinity of the welded portion, and the detected temperature time. Disclosed is a technique for determining whether welding is good or bad based on specific characteristics.
However, this technique cannot determine the welding temperature at an appropriate temperature only by determining the quality of the welding result based on the detected temperature. And since it is not a soldering apparatus, the mechanism for supplying the thread solder is not provided. Therefore, this technique cannot be applied to a soldering apparatus as it is.
JP-A-5-337762

  Accordingly, an object of the present invention is to measure and control the temperature of a soldering point in a laser type soldering apparatus so that soldering can be performed at an appropriate temperature, and at the same time, the laser beam to the soldering point is The aim is to improve the soldering quality by allowing the projection and the supply of the thread solder to be performed accurately.

  In order to achieve the above object, a soldering apparatus according to the present invention includes a laser oscillator that outputs a laser beam, a projection head that projects the laser beam output from the laser oscillator toward a soldering point, and a yarn that is applied to the soldering point. Based on the solder supply device for supplying the solder, the CCD camera attached to the projection head so that the laser beam and the optical axis coincide, the image data by the CCD camera and the reference setting by teaching, for each soldering object, An image processing apparatus that outputs a correction signal to the control device for correcting the position of the laser beam and the soldering point and correcting the position of the tip of the solder wire with respect to the soldering point, and radiating from the soldering point during soldering The soldering poi by receiving infrared rays A temperature measuring device for measuring the temperature of the solder, a laser controller for controlling the output and / or projection time of the laser oscillator based on the temperature measured by the temperature measuring device, and the whole soldering device for automatic soldering. And a control device.

  In the present invention, preferably, the temperature measuring device is configured to receive infrared rays emitted from the soldering point along the optical axis of the laser beam through the projection head.

In the present invention, there is a monitor for displaying an image of the soldering point imaged by the CCD camera, and an aiming point located on the optical axis of the laser beam is provided on the screen of the monitor. In addition, by performing the teaching while viewing this screen, the alignment of the aiming point and the soldering point and the positioning of the tip of the thread solder with respect to the soldering point may be performed. desirable.
In this case, at least the laser oscillator of the laser oscillator and the temperature measuring device has a test light source, and the test light can be irradiated from the light source to the soldering point along the optical axis of the laser beam during the teaching. You may be comprised so that it may become.

  Furthermore, in the present invention, it can be configured such that the quality of soldering can be determined based on the temperature measured by the temperature measuring device and the image data obtained by the CCD camera.

  According to the present invention, by measuring the temperature of the soldering point and controlling the output and projection time of the laser oscillator, the soldering point can be maintained at an appropriate temperature, and as a result, good quality soldering is achieved. It can be performed. Further, based on the image data by the CCD camera and the reference setting by teaching, the position correction of the laser beam and the soldering point and the position correction of the tip of the thread solder with respect to the soldering point are performed for each soldering object. Therefore, the quality of soldering can be improved also by this.

  FIG. 1 illustrates a preferred exemplary embodiment of a laser soldering apparatus according to the present invention. This soldering apparatus has a projection head 1 for mounting on a work arm of an articulated robot, and a laser. The laser beam B output from the oscillator 2 is projected onto the soldering point 3a of the soldering object (work) 3 through the projection head 1 and soldered.

  The soldering device also includes a laser controller 4 for controlling the laser oscillator 2, a solder supply device 5 for supplying the thread solder 6 to the soldering point 3 a, and the soldering point 3 a during soldering. A temperature measuring device 7 for measuring the temperature of the soldering point 3a by receiving the emitted infrared light and a control device 8 for controlling the entire robot are provided.

  The projection head 1 has a cylindrical casing 10 that is arranged in the vertical direction and has a projection port 10a at the lower end. A pair of upper and lower parts is disposed inside the casing 10 along the optical axis L of the laser beam B. Optical lenses 11a and 11b, and two half mirrors 12 and 13 disposed at positions above the optical lenses 11a and 11b so as to be inclined by 45 degrees with respect to the optical axis L, respectively. . The lower first half mirror 12 reflects the laser beam B but transmits visible light and infrared light, and the upper second half mirror 13 reflects infrared light but transmits visible light.

A tip of an optical fiber 15 leading to the laser oscillator 2 is connected to a position corresponding to the first half mirror 12 on the side surface of the casing 10, and a laser beam B is supplied to the first half mirror 12 through the optical fiber 15. It has come to be. The supplied laser beam B is reflected by the first half mirror 12, converted into parallel light by the upper first optical lens 11 a, and then condensed by the lower second optical lens 11 b to the soldering point 3 a. Projected, the solder wire 6 is melted and soldered.
The beam diameter of the laser beam B can be changed in size by passing through a shutter having a plurality of light guide holes having different diameters, but the illustration of the shutter is omitted. In addition, this shutter can be provided in the position corresponding to the said 1st half mirror 12 on the side surface of the said projection head 1, for example.

  A tip of an optical fiber 16 communicating with the temperature measuring device 7 is connected to a position corresponding to the second half mirror 13 on the side surface of the casing 10, and the infrared light is received through the optical fiber 16. ing. That is, infrared rays radiated from the solder melted mainly at the time of soldering are received along the optical axis L of the laser beam B through the projection head 1 and are passed through the two optical lenses 11a and 11b and the first half mirror 12. After being transmitted, it is reflected by the upper second half mirror 13 and sent to the temperature measuring device 7 through the optical fiber 15, whereby the temperature is measured by a temperature sensor built in the temperature measuring device 7.

The temperature measurement signal from the temperature measuring device 7 is sent to the laser controller 4 and the laser output from the laser oscillator 2 and the projection time are controlled based on the measured temperature so that optimum soldering is performed. The relationship between the output and projection time and the heating temperature is set in the laser controller 4 in advance, and necessary calculations are performed based on the setting data and the actual measurement temperature, and based on the calculation results. The laser oscillator 2 is controlled by selecting an appropriate output and / or projection time related to the measured temperature.
In this way, high-quality soldering is performed by measuring the actual temperature of the soldering point 3a during soldering and controlling the laser output and the projection time so that the soldering is performed at an appropriate temperature. Is possible.

  A CCD camera 19 is attached to the upper end of the projection head 1 so that the laser beam B and the optical axis L are aligned. The CCD camera 19 captures an image of the soldering point 3a through an optical system including the two optical lenses 11a and 11b and the two half mirrors 12 and 13, and the soldering image captured by the CCD camera 19 is used. The image of the point 3a is taken into the image processing apparatus 20 and is displayed on the screen 21a of the monitor 21.

On the screen 21a of the monitor 21, an aiming point 22 having a center on the optical axis L of the laser beam B is displayed. This aiming point 22 indirectly displays the position of the laser beam B as a beam spot, and is represented by a rectangular region surrounded by two lines 23a, 23a and 23b, 23b. The aiming point 22 can be changed in size according to the actual beam diameter of the laser beam B determined by the shutter or the like by changing the distance between the two lines 23a, 23a and 23b, 23b. The position on the screen can be moved.
However, the aiming point 22 does not need to be divided by two lines that intersect each other as described above, and may be surrounded by a circle or a rectangle.

  Then, at the time of teaching, as shown in FIG. 2, while observing the positional relationship between the aiming point 22 (beam spot), the soldering point 3 a and the tip of the thread solder 6 on the screen 21 a, the control device 8 projects the projection. By relatively displacing the head 1 and the table 26 on which the soldering object 3 is mounted, and controlling the solder supply device 5 to adjust the extension length and position of the thread solder 6, From the unadjusted state shown in FIG. 2A, the aiming point 22, the soldering point 3a, and the tip of the solder wire 6 are moved from the unadjusted state shown in FIG. Are aligned so as to overlap with each other at an appropriate ratio, and the tip 6a of the thread solder 6 is kept at an appropriate interval with respect to the soldering point 3a (and hence the aiming point 22). It is positioned.

  The teaching pattern can be confirmed on the screen 21a of the monitor 21. At this time, for easy understanding, the laser oscillator 2 is provided with a test light source 28 such as an LED. The test light 28a can be irradiated as a beam spot from the optical fiber 15 to the soldering point 3a through the optical system. Thus, it is safe because it is not necessary to actually project the laser beam B having a large energy during teaching. Note that the irradiation of the test light is stopped when the teaching is completed.

  On the other hand, in the temperature measuring device 7, since the center of the temperature detection region coincides with the optical axis L of the laser beam B, if the aiming point 22 and the soldering point 3a are aligned by the teaching, The temperature detection area is also always aligned with the soldering point 3a. For this reason, it is not necessary to check the situation on the monitor 21 in particular, but if necessary, the temperature measuring device 7 is also provided with a test light source 29 such as an LED, and the test light from the light source 29 is supplied to the test light. The soldering point 3a can be irradiated through the optical system.

  Thus, after the above teaching is performed on each soldering point 3a on the soldering object 3, the conditions necessary for automatic operation are set as the standard for the number, arrangement, distance, etc. of the soldering points 3a. When the soldering start button of the control device 8 is pressed, the laser beam B is projected from the projection head 1 and the thread solder 6 is fed out from the solder supply device 5 by a predetermined amount, and each soldering point 3a is successively moved. Soldered automatically. At this time, by injecting an inert gas such as nitrogen gas from the projection head 1, soldering can be performed in an atmosphere of the inert gas.

  When the soldering of one soldering object 3 is finished, the table 26 moves and the next new soldering object 3 is sent in, and the soldering is performed in the same manner. At this time, if the soldering object 3 has the same shape, it is possible to continue soldering without performing teaching again. However, in practice, when each soldering object 3 is set on the substrate, there may be a slight misalignment with each other. In this case, the positions of the aiming point 22 and the soldering point 3a are different. Or the position of the tip 6a of the thread solder 6 with respect to the soldering point 3a is displaced, resulting in defective solder.

  Therefore, before the new soldering object 3 is soldered, the image processing apparatus 20 corrects the position between the aiming point 22 and the soldering point 3a, and the yarn solder 6 with respect to the soldering point 3a. The position of the tip 6a is corrected. That is, the image processing apparatus 20 uses the teaching to determine the proper positional relationship between the beam spot and the soldering point 3a and the proper positional relationship of the tip 6a of the thread solder 6 with respect to the soldering point 3a. And necessary calculations are performed based on these reference data and the actual image data from the CCD camera 19, and a correction signal for correcting the positional deviation is output to the control device 8. Is done.

  Upon receiving this correction signal, the control device 8 corrects the positional relationship between the beam spot and the soldering point 3a by relatively displacing the projection head 1 and the table 26, and the solder supply device. 5 is controlled to correct the position of the tip of the thread solder 6. And the soldering mentioned above is performed after that.

  The image processing device 20 may have a function of determining whether soldering is good or not based on the temperature measured by the temperature measuring device 7 and the image data obtained by the CCD camera 19. That is, the quality of soldering is determined to some extent by the heating temperature at the time of soldering (the temperature of the molten solder), and from the image data by the CCD camera 19, the state of the soldering site and the presence or absence of unsolder can be observed. They can be detected by the image processing device 20 and output as a control signal or displayed on a display device.

Thus, the soldering apparatus measures the actual temperature of the soldering point 3a during soldering, and controls the laser output and the projection time so that the soldering is performed at an appropriate temperature. Good soldering can be performed.
Moreover, during teaching, the aiming point 22 and the soldering point 3a are aligned, the tip 6a of the thread solder 6 is positioned relative to the soldering point 3a, and a new soldering object 3 is soldered. Every time, based on the image data from the CCD camera 19 and the reference data set by teaching, the image processing device 20 corrects the position between the aiming point 22 and the soldering point 3a, and the soldering point. Since the position correction of the tip 6a of the thread solder 6 with respect to 3a is performed, it is possible to perform reliable and highly accurate soldering.

It is a block diagram of the soldering apparatus which concerns on this invention. (A) is a figure which shows the state before performing alignment of the beam spot (aiming point) with respect to a soldering point, and positioning of the thread solder front-end | tip. (B) is a figure which shows the state after performing alignment of the beam spot (sighting point) with respect to a soldering point, and positioning of the thread | solder tip.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Projection head 2 Laser oscillator 3a Soldering point 4 Laser controller 5 Solder supply apparatus 6 Yarn solder 6a Tip 7 Temperature measuring apparatus 8 Control apparatus 19 CCD camera 20 Image processing apparatus 21 Monitor 21a Screen 22 Aiming point 25 Control apparatus 28, 29 Light source B Laser beam L Optical axis

Claims (5)

A laser oscillator that outputs a laser beam,
A projection head that projects the laser beam output from the laser oscillator toward a soldering point;
A solder supply device for supplying thread solder to the soldering point,
CCD camera attached to the projection head with the laser beam and optical axis aligned,
Based on the image data by the CCD camera and the reference setting by teaching, the position correction of the laser beam and the soldering point and the position correction of the tip of the thread solder with respect to the soldering point are performed for each soldering object. An image processing device for outputting a correction signal to the control device,
A temperature measuring device that measures the temperature of the soldering point by receiving infrared rays emitted from the soldering point during soldering;
A laser controller for controlling the output and / or projection time of the laser oscillator based on the temperature measured by the temperature measuring device;
The above control device for controlling the entire soldering device for automatic soldering,
A laser soldering apparatus characterized by comprising:   2. The soldering apparatus according to claim 1, wherein the temperature measuring device is configured to receive infrared rays radiated from the soldering point along the optical axis of a laser beam through the projection head. .   The monitor has a monitor for displaying an image of the soldering point imaged by the CCD camera, and an aiming point located on the optical axis of the laser beam is provided on the screen of the monitor. The positioning of the sighting point and the soldering point and the positioning of the tip of the thread solder with respect to the soldering point are performed by performing the teaching while the teaching is performed. 2. The soldering apparatus according to 2.   At least the laser oscillator of the laser oscillator and the temperature measuring device has a test light source, and at the time of teaching, the test light can be irradiated from the light source along the optical axis of the laser beam to the soldering point. The soldering apparatus according to claim 3, wherein the soldering apparatus is configured.   5. The soldering apparatus according to claim 1, wherein the soldering apparatus is configured to determine whether soldering is good or not based on a temperature measured by the temperature measuring apparatus and image data obtained by a CCD camera. .

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