JP2009160603A - Soldering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately control the temperature of a soldering part. <P>SOLUTION: The soldering device 100 includes a laser component 101, optical systems 102, 103, 104, 105, 106, 107, a temperature detector 108, and laser beam control parts 109, 110, 111, 112. The laser component 101 outputs laser beam, and the optical systems 102, 103, 104, 105, 106, 107 converge laser beam and irradiate a soldering part 12 with it. The temperature detector 108 detects the temperature of the soldering part 12. The laser beam control parts 109, 110, 111, 112 control the laser beam outputted from the laser component 101 so that the temperature detected by the temperature detector 108 becomes a predetermined temperature which melts the solder 10 applied to the soldering part 12. By this configuration, the temperature of the soldering part 12 can be appropriately controlled. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a soldering apparatus.

  In recent years, with the miniaturization of components incorporated in various apparatuses, there are many scenes that require soldering in very complicated and narrow places. For example, as shown in FIG. 7, a plurality of suspensions for supporting the objective lens holder 1 with respect to a soldering location 12 on a substrate 20 provided on the side surface of the objective lens holder 1 provided in the optical pickup device. This is a case where one end of each wire 11 is soldered. Also, for example, when a focusing control or tracking control coil (not shown) is mounted in the objective lens holder 1 by soldering, the soldering is similarly difficult.

It is difficult to perform manual soldering to a narrow part such as the soldering part 12 shown in FIG. 7 with a soldering iron or the like. Even if manual soldering is performed, soldering is not possible. There is concern that the defect rate will increase. Therefore, a soldering apparatus has been proposed that performs non-contact and automatic soldering using a laser beam having coherency that can be condensed at one point by a condenser lens. Specifically, in a soldering apparatus using laser light, the laser light is condensed through a condensing lens onto an area corresponding to the soldering location to be a heat source for soldering. Further, soldering is performed after setting the intensity of the laser beam and the irradiation time to predetermined values at which the solder is appropriately dissolved (see, for example, Patent Document 1 shown below).
Japanese Patent Laid-Open No. 10-296434 (page 1-2, FIG. 1-4)

  By the way, it is very difficult to set the intensity of the laser beam and the irradiation time so that an appropriate melting temperature of the solder at the soldering point can be obtained. Even if an appropriate set value of the intensity and irradiation time of the laser beam under certain conditions is obtained by experiment, it is uncertain and difficult to predict, such as the state of the outside air temperature, heat dissipation to the periphery of the soldering location, etc. This is because there is a possibility that the amount of heat required to melt the solder may change greatly due to other external factors.

  If the intensity and irradiation time of the laser beam are not set appropriately due to external factors, phenomena such as insufficient melting of the solder at the soldering location or excessive heating of the soldering location may occur. . For this reason, the subject that uniform soldering becomes difficult will arise. Further, when the amount of solder changes due to external factors, for example, there arises a problem that an optimum setting of the intensity of laser light and the irradiation time according to the amount of solder must be made by trial and error.

  In order to solve the above-described problems, a main soldering apparatus according to the present invention includes a laser element that outputs laser light, an optical system that collects the laser light and irradiates the soldering portion, and the soldering portion. A temperature detector for detecting the temperature of the laser, and controlling the laser light output from the laser element so that the temperature detected by the temperature detector becomes a predetermined temperature for dissolving the solder applied to the soldering location And a laser light control unit for performing the above-described operation.

  Other features of the present invention will become apparent from the accompanying drawings and the description of this specification.

  ADVANTAGE OF THE INVENTION According to this invention, the soldering apparatus which controls appropriately the temperature in a soldering location can be provided.

  At least the following matters will become apparent from the description of this specification and the accompanying drawings.

[Example 1]
<< Configuration of soldering device >>
The configuration of the soldering apparatus 100 according to the first embodiment of the present invention will be described with reference to FIG. In the following, the soldering portion 12 that is one end of the suspension wire 11 of the pickup device shown in FIG. 7 will be described as an example of an object to be soldered by the soldering device 100. It is not limited to this.

  In the soldering apparatus 100, a solder 10 such as a cream solder material is preliminarily applied to the substrate 20 constituting the soldering target component disposed on the stage 30, and the substantially cream-like solder 10 is preliminarily applied. The applied soldering portion 12 is heated by a laser beam to melt and solidify the solder 10 to solder a component to be soldered.

  Further, in this soldering apparatus 100, for example, a solder 10 such as a substantially pad-shaped reflow solder material is placed on the substrate 20 in advance, and a soldering location 12 where the substantially pad-shaped solder 10 is placed in advance is irradiated with a laser beam. The solder 10 is melted and solidified by heating, and the soldering portion 12 is soldered.

  In addition, the soldering apparatus 100 preheats the soldering portion 12 to which the solder 10 has not yet been attached by heating with a laser beam in advance, and then the tip of the soldering portion 12 such as thread solder (not shown). The tip of a solder wire (not shown) is heated and melted and solidified to perform soldering on the soldering portion 12.

  The soldering apparatus 100 includes a stage 30 (workbench), a laser element (hereinafter referred to as LD (Laser Diode)) 101, a condensing lens 102 (first collimator lens) including an anamorphic lens 102a and a collimator lens 102b (first collimator lens). 1 lens), a beam splitter 103 (polarization member), a focusing lens 104, an optical fiber cable 105, another collimator lens 106 (second collimator lens), and another condenser lens 107 (second lens). , A temperature detector 108, a correction amount setting unit 109, an operational amplifier 110 (first amplifier), a laser output setting unit 111, and another operational amplifier 112 (second amplifier).

  The condensing lens 102, the beam splitter 103, the converging lens 104, the optical fiber cable 105, the collimator lens 106, and the condensing lens 107 constitute an “optical system” according to the claims of the present application. The correction amount setting unit 109, the first operational amplifier 110 (operation / amplification unit), the laser output setting unit 111, and the second operational amplifier 112 (operation / amplification unit) constitute a “laser light control unit” according to the claims of the present application. To do. The laser output setting unit 111 constitutes a “laser output setting unit” according to the claims of the present application, and the first operational amplifier 110 and the second operational amplifier 112 include the “laser element driving unit” according to the claims of the present application. It constitutes.

  The stage 30 is a workbench for placing and fixing the substrate 20 at a predetermined position so that a second laser beam described later outputted from the condenser lens 107 is irradiated to the soldering spot 12 on the substrate 20. is there.

  The LD 101 is driven by a laser output setting signal SI ′, which will be described later, and emits first laser light that is, for example, near infrared rays. Laser light emitted from the LD 101 travels while being enlarged. Further, the irradiation spot of the laser beam emitted from the LD 101 is formed in an approximately elliptical shape.

  The condensing lens 102 condenses the first laser light from the LD 101 and makes it incident on one end of the optical fiber cable 105 via the beam splitter 103 and the converging lens 104. Hereinafter, one end of the optical fiber cable 105 on which the first laser light is incident is referred to as a laser light incident end 105a, for example. The other end of the laser light incident end 105a of the optical fiber cable 105 is referred to as a laser light output end 105b, for example. In the present embodiment, the condensing lens 102 is composed of two (a pair / plurality) of lenses 102a and 102b to facilitate condensing the optical fiber cable 105 to the laser light incident end 105a. Although shown, for example, it may be constituted by one lens having a large refractive index.

  In the embodiment of the soldering apparatus in this specification, one lens 102a that is positioned between the LD 101 and the optical fiber cable 105 and that constitutes the first lens group 102X is substantially elliptical of the laser light emitted from the LD 101. The special lens 102a is used to make the irradiating spot a substantially circular spot. One lens 102a constituting the first lens group 102X is configured, for example, as an anamorphic lens 102a, a so-called anamorphic lens 102a. Further, one lens 102a constituting the first lens group 102X focuses the laser light emitted from the LD 101 and magnified, and makes the focused laser light that becomes a substantially circular irradiation spot enter the other lens 102b. .

  In addition, the other lens 102b constituting the first lens group 102X causes the focused laser beam emitted from the one lens 102a to be a substantially circular irradiation spot to be a substantially parallel light, and is irradiated with a substantially circular irradiation. The substantially parallel laser beam that has become a spot is incident on the beam splitter 103. The other lens 102b constituting the first lens group 102X is configured, for example, as a collimator lens 102b.

  Further, the other lens 104 constituting the first lens group 102X focuses the substantially parallel laser beam emitted from the beam splitter 103 and capable of forming a substantially circular irradiation spot, and converges the substantially circular irradiation. The spot laser beam is incident on the optical fiber cable 105. The other lens 104 constituting the first lens group 102X is configured as a focusing lens 104, for example.

  The anamorphic lens 102a, the collimator lens 102b, and the focusing lens 104 are, for example, three (plural) lenses 102a, 102b, and 104 that constitute the first lens group 102X. Thus, in the embodiment of the soldering apparatus in this specification, the first lens group 102X located on the laser light incident end 105a side of the optical fiber cable 105 includes one lens 102a, the other lens 102b, and the other A lens 104 is provided.

  The optical fiber cable 105 guides the first laser light incident from the laser light incident end 105 a toward the condenser lens 107. The optical fiber cable 105 guides the third laser light incident from the laser light output end 105 b toward the beam splitter 103. The third laser beam is a far infrared ray radiated from the soldering point 12 on the heated substrate 20 and has a property as a heat ray having an energy amount corresponding to the temperature of the soldering point 12. .

  The beam splitter 103 is provided between the condensing lens 102 and the laser light incident end 105a of the optical fiber cable 105, and transmits the first laser light (near infrared ray) incident on the beam splitter 103 from the condensing lens 102. . Further, the beam splitter 103 reflects the third laser light (far infrared rays) incident on the beam splitter 103 from the laser light incident end 105 a of the optical fiber cable 105 and makes it incident on the temperature detector 108.

  The collimator lens 106 collects with the laser light output end 105b of the optical fiber cable 105 in order to transform the first laser light expanded after passing through the optical fiber cable 105 into substantially parallel light and enter the condensing lens 107. It is provided between the optical lens 107. The condensing lens 107 uses the second laser light obtained by condensing the first laser light, which has become substantially parallel light by the collimator lens 106, as a heat source at the soldering location 12 on which the solder 10 is applied on the substrate 20. Irradiate. The collimator lens 106 and the condensing lens 107 also function as lenses for condensing the third laser light to be incident (guided) on the laser light output end 105b of the optical fiber cable 105.

  The collimator lens 106 and the condenser lens 107 are, for example, two (a pair / plurality) of lenses 106 and 107 constituting the second lens group 107X. As described above, the second lens group 107X located on the laser light emitting end 105b side of the optical fiber cable 105 includes one lens 106 and the other lens 107.

  The temperature detector 108 detects the temperature of the soldering point 12 or its surroundings. In the present embodiment, the temperature detector 108 includes an infrared sensor such as a thermopile provided at a position where the third laser light (far infrared light) reflected by the beam splitter 103 can be received, and the temperature of the soldering point 12 is determined. A temperature detection signal SO having a voltage level proportional to the amount of energy of the third laser beam corresponding to the output is output. In addition to the thermopile, a thermocouple or a pyroelectric infrared sensor may be used.

  The correction amount setting unit 109 outputs a correction signal ΔSO obtained by converting a correction amount to be added to the energy amount indicated by the temperature detection signal SO into a voltage level. For example, the correction amount setting unit 109 can be realized as a variable resistor or an electronic volume. The correction amount indicated by the correction signal ΔSO is set so that the amount of energy indicated by the temperature detection signal SO (detected temperature at the soldering location 12) can be accurately matched to the actual temperature at the soldering location 12. The

  As the first amplifier 110, for example, an operational amplifier 110 that is an amplifier having an arithmetic function is used. The first operational amplifier 110 adds the correction signal ΔSO output from the correction amount setting unit 109 to the temperature detection signal SO output from the temperature detector 108 and outputs the result as a corrected temperature detection signal SO ′.

  The laser output setting device 111 sets the light amount of the first laser beam output from the LD 101 in accordance with a predetermined temperature (hereinafter referred to as a melting temperature) suitable for dissolving the solder 10 applied to the soldering location 12. The amount of light is set. For example, the laser output setting device 111 can be realized as a variable resistor or an electronic volume. The laser output setting device 111 outputs a laser output setting signal SI having a voltage level proportional to the amount of light corresponding to the desired melting temperature of the solder 10.

  As the second amplifier 112, for example, an operational amplifier 112 that is an amplifier having an arithmetic function is used. In the second operational amplifier 112, the laser output setting signal SI is applied to the non-inverting input, the corrected temperature detection signal SO ′ is applied to the inverting input, and the resistance element R and the non-inverting input are connected to the feedback path from the output to the non-inverting input. An integrating circuit with a parallel connection of a capacitor C is connected. Then, the second operational amplifier 112 outputs a laser output setting signal SI ′ obtained by amplifying the difference between the laser output setting signal SI and the corrected temperature detection signal SO ′ with a time constant determined by the resistance element R and the capacitor C. . The LD 101 is driven by the laser output setting signal SI 'and outputs the first laser beam.

  As a result of the above configuration, due to an imaginary short between the inverting input and the non-inverting input of the second operational amplifier 112, the desired melting temperature of the solder 10 indicated by the laser output setting signal SI and the corrected temperature detection signal SO ′. The difference between the detected temperature at the soldering location 12 shown in FIG. 5 is gradually narrowed by a time constant determined by the resistance element R and the capacitor C. As a result, finally, the temperature of the solder 10 applied to the soldering location 12 can be matched with a desired melting temperature.

<< Setting of correction amount >>
2 to 4 are diagrams for explaining the correction amount set in the correction amount setting unit 109. FIG. 2 shows a flowchart for obtaining the correction amount, FIG. 3 shows a flowchart for the calibration trial shown in FIG. 2, and FIG. 4 shows the output characteristics of the temperature detector 108 obtained by the flowchart shown in FIG. FIG.

  First, a calibration trial step (S200) is performed in which calibration as a trial of the temperature detection signal SO output from the temperature detector 108 is performed based on the melting state of the solder 10. The overall flow of the calibration trial process is shown in the flowchart shown in FIG.

  As shown in FIG. 3, when the driving of the LD 101 is started and the first laser beam starts to be output (S300), the temperature detector 108 outputs the temperature in the process of gradually increasing the temperature of the soldering point 12. It is determined whether the current voltage level (variable T) of the detected temperature signal SO is higher than the previous voltage level (variable TM) (S301, S302). If the current voltage level (variable T) is higher than the previous voltage level (variable TM) (S302: YES), it is held as a comparison target (variable TM) with the next voltage level (variable T). (S303). The above flow from S301 to S303 is performed until a predetermined set time elapses (S304: NO), and when the predetermined set time elapses (S304: YES), the driving of the LD 101 is stopped (S305). .

  In the calibration trial process (S200), the temperature detection signal SO indicating the maximum voltage level is held in the variable TM until the drive of the LD 101 is started and stopped, and the melting state of the solder 10 at that time is also determined. It is verified whether or not it is appropriate (S201). If the melting state of the solder 10 is inappropriate (S201: NO), the calibration trial process (S200) is executed again. Note that the solder 10 is not properly dissolved when, for example, a part of the solder 10 is not dissolved or a solder failure such as solder crack or solder creep occurs. On the other hand, if the melting state of the solder 10 is appropriate (S201: YES), the temperature detection signal SO held in the variable TM at that time is used as the melting temperature PM (for example, predetermined by the conditions of the solder 10 to be used, for example). 360 ° C.) as the output of the temperature detector 108 (S202).

  Next, a default value TS which is an output of the temperature detector 108 corresponding to a predetermined initial temperature PS (for example, 25 ° C.) before starting the LD 101 is acquired (S203). Then, initial sample data (initial temperature PS, default value TS) and sample data (melting temperature PM, variable TM) obtained by the calibration trial process (S200) are obtained. The output characteristic of the temperature detector 108 shown in FIG. 4 is obtained by performing linear interpolation using (S204). The correction amount set by the correction amount setting unit 109 is set to correct the temperature detection signal SO output from the temperature detector 108 based on the output characteristics of the temperature detector 108 shown in FIG. S205).

  As described above, the soldering apparatus 100 appropriately performs soldering in consideration of the influence of uncertain and difficult external factors such as the state of the outside air such as temperature and the heat radiation to the peripheral part of the soldering location. Can be done.

  Further, by using a thermopile as the temperature detector 108 and providing the beam splitter 103, it is not necessary to arrange the temperature detector 108 around the soldering point 12. As a result, the wiring from the temperature detector 108 to the second operational amplifier 112 via the first operational amplifier 110 can be shortened, and the soldering apparatus 100 can be made compact.

  In addition, by providing the optical fiber cable 105 instead of the mirror or the like, it becomes possible to transmit the temperature information of the soldering point 12 to the temperature detector 108 with high accuracy.

  Further, by providing a correction amount setting unit 109 for setting a correction amount reflecting the preset output characteristic of the temperature detector 108, an energy amount (temperature) indicated by the temperature detection signal SO output from the temperature detector 108 is provided. ) Can be made to correspond to the actual temperature of the soldering point 12 with high accuracy.

  Also, the solder temperature indicated by the laser output setting signal SI is obtained by integrating the detected temperature at the soldering location 12 indicated by the corrected temperature detection signal SO ′ by the integrating circuit composed of the resistance element R and the capacitor C connected to the second operational amplifier 112. Control can be performed so that the temperature gradually approaches the melting temperature of 10 and finally matches. Note that the reason why the temperature of the soldering point 12 is gradually brought close to the melting temperature of the solder 10 is that when the temperature of the soldering point 12 rapidly increases, the solder 10 evaporates, scatters, cracks and flux sublimate, scatters, and the like. Because there is a risk of causing.

  The soldering apparatus 100 is also effective when so-called lead-free solder is used. This is because lead-free solder has a higher melting temperature than other solders, and therefore needs to be melted with fine temperature control so as not to exceed the heat resistance temperature of the soldering target.

[Example 2]
FIG. 5 is a diagram showing a configuration of a soldering apparatus 200 according to the second embodiment of the present invention.

  The soldering apparatus 200 includes functions of a correction amount setting unit 109, a first operational amplifier 110, a laser output setting unit 111, and a second operational amplifier 112 in the soldering apparatus 100 shown in FIG. The configuration is replaced with (FIG. 5). The MPU 120 (control unit) manages system control of the entire soldering apparatus 200. Note that, among the configurations of the soldering apparatus 200 shown in FIG. 5, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 6 is a flowchart showing the operation of the MPU 120. The MPU 120 sets the initial value of the laser output setting signal SI 'and outputs it to the LD 101 (S600). Then, the LD 101 outputs a first laser beam corresponding to the laser output setting signal SI ′, and the second laser beam corresponding to the first laser beam is irradiated on the soldering portion 12 on the substrate 20. Further, the temperature detector 108 receives the third laser beam corresponding to the temperature of the heated soldering spot 12 and outputs a temperature detection signal SO corresponding to the third laser beam.

When the temperature detection signal SO output from the temperature detector 108 is input, the MPU 120 determines the correction signal ΔSO based on the output characteristics of the temperature detector 108 shown in FIG. 4, and the temperature output from the temperature detector 108. The correction signal ΔSO is added to the detection signal SO. The MPU 120 determines whether or not the added value (= SO + ΔSO) matches the output of the temperature detector 108 corresponding to the melting temperature of the solder 10 (S602), and if it does not match (S602: NO), the laser A predetermined increment ΔSI ′ is added to the output setting signal SI ′ (S603). Further, the MPU 120 determines whether or not the preset time set as the irradiation time of the LD 101 has passed (S604). If the set time has not passed (S604: NO), the processing from S601 to S603 is performed. repeat.

  As described above, even in the case of the soldering apparatus 200 using the MPU 120, the same control as that of the soldering apparatus 100 is performed, so that the state of the outside air such as temperature and the heat radiation to the peripheral portion of the soldering point 12 are performed. It is possible to appropriately perform soldering in consideration of the influence of uncertain and difficult to predict external factors such as. Further, by using the MPU 120, the soldering apparatus 200 can be made compact.

  As mentioned above, although embodiment of this invention was described, embodiment mentioned above is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. The present invention can be changed / improved without departing from the gist thereof, and the present invention includes equivalents thereof.

It is the figure which showed the structure of the soldering apparatus which concerns on one Embodiment of this invention. It is the figure which showed the flowchart for calculating | requiring the corrected amount of the output of the temperature detector which concerns on one Embodiment of this invention. It is a flowchart which shows the flow of the calibration trial which concerns on one Embodiment of this invention. It is the figure which showed the output characteristic calculated | required by correction | amendment of the output of the temperature detector which concerns on one Embodiment of this invention. It is the figure which showed the structure of the soldering apparatus which concerns on other embodiment of this invention. It is a flowchart which shows operation | movement of the control part which concerns on other embodiment of this invention. It is the figure which showed the example of soldering of the suspension wire to the objective lens holder which an optical pick-up apparatus comprises.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Solder 12 Solder location 20 Board | substrate 30 Stage 100, 200 Soldering apparatus 101 Laser element 102, 107 Condensing lens 102a Anamorphic lens 102b, 106 Collimator lens 102X, 107X Lens group 103 Beam splitter 104 Focusing lens 105 Optical fiber cable 105a Laser Light incident end 105b Laser light emitting end 108 Temperature detector 109 Correction amount setting unit 110, 112 Operational amplifier 111 Laser output setting unit 120 MPU

Claims (5)

A laser element that outputs laser light;
An optical system for condensing the laser beam and irradiating the soldered portion;
A temperature detector for detecting the temperature of the soldering point;
A laser light control unit for controlling the laser light output from the laser element so that the temperature detected by the temperature detector is a predetermined temperature for dissolving the solder applied to the soldering portion;
A soldering apparatus comprising: The soldering apparatus according to claim 1,
The optical system includes a beam splitter that transmits the laser light output from the laser element toward the soldering portion and reflects heat rays emitted from the soldering portion irradiated with the transmitted laser light. Prepared,
The temperature detector is a thermopile that receives the heat ray reflected from the beam splitter and detects the temperature of the soldering location based on the heat ray. In the soldering apparatus according to claim 1 or 2,
The optical system includes an optical fiber cable that guides the laser light output from the laser element and transmitted through the beam splitter to the soldering portion, and guides the heat rays emitted from the soldering portion to the beam splitter. A soldering apparatus characterized by comprising: In the soldering apparatus of any one of Claims 1-3,
The laser light control unit corrects the output of the temperature detector based on a predetermined output characteristic of the temperature detector, and controls the laser light based on the corrected output of the temperature detector, Soldering device characterized by In the soldering device according to any one of claims 1 to 4,
The laser light control unit
A laser output setting unit for setting an output level of the laser beam according to the predetermined temperature;
A laser element driver for driving the laser element by amplifying the difference between the output level of the laser beam and the output level after correction of the temperature detector by a predetermined time constant;
A soldering apparatus comprising:

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