JP2005236066A - Soldering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide such a constitution that a solder adhesion in the state that hangs down like an icicle while caught by a support claw that keeps and transports a printed circuit board may be dropped and returned to a solder supply device without damaging a transportation means. <P>SOLUTION: A contact solder removing device 40 is constituted so that the solder adhesion part in the state that hangs down while caught by the support claw 4 may be dropped by contacting the solder adhesion part, while arranged over the upper part side position of the molten solder accommodated in the solder tub of the solder supply device, and in the vicinity of the lower passage position of the support claw 4 for supporting a printed circuit 1 in the course position where the printed circuit 1 is transported after the completion of soldering supply. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a soldering apparatus that transports a printed wiring board while being held by a holding means, supplies molten solder to the printed wiring board, and performs soldering. Such a soldering apparatus is generally Is called a flow soldering apparatus, and is classified as such and classified as a reflow soldering apparatus.

  The present invention includes a soldering apparatus that includes both a soldering apparatus that uses a flowing wave of molten solder and a soldering apparatus that uses stationary molten solder, and that performs soldering by supplying molten solder to a printed wiring board. The technical field.

  In a soldering apparatus that performs soldering by supplying molten solder to a printed wiring board, the printed wiring board is generally transported by a transport conveyor having holding means for the printed wiring board, and a large number of printed wiring boards are continuously connected. It is configured so that it can be soldered. This holding means is usually called a holding claw.

  FIG. 4 is a view for explaining a configuration example of a main part of this type of soldering apparatus, and is a view of the soldering apparatus as viewed from above. Soldering equipment that supplies solder by supplying molten solder is generally composed of each process in the order of flux application process, pre-heating process, soldering process, and cooling process, and further printing is performed sequentially in each process. A transport conveyor is provided to transport the wiring board.

  That is, a flux application device I, a preheating device II, a solder supply device III, and a cooling device IV are disposed corresponding to each process, and a transport conveyor 2 that transports the printed wiring board 1 to each device in order is provided. In addition, recently, there is a configuration in which the flux coating apparatus I is configured separately and is not provided in the soldering apparatus.

  As the transfer conveyor 2, a chain conveyor is generally used as the core of the transfer mechanism, and the printed wiring board 1 is held and transferred by the chain conveyor, that is, the holding claw 4 provided in the transfer chain 3 in FIG. Configuration is adopted. There is also a soldering apparatus that employs a configuration in which a handling robot including a holding claw 4 that holds the printed wiring board 1 is used and the printed wiring board 1 is conveyed by the robot, although the number is small.

  The conveyor 2 shown in FIG. 4 is the most commonly used conveyor, and a drive sprocket 5 and a driven sprocket 6 are provided at both ends of a conveyor frame 20 (shown in FIG. 5) provided in two parallel strips. The conveyor chain 3 is stretched between the drive sprocket 5 and the driven sprocket 6 for each conveyor frame, and the conveyor chain 3 is configured to rotate in the direction of arrow B along the conveyor frame.

  The conveyance chain 3 is provided with a holding claw 4 for holding the printed wiring board 1. The printed wiring board 1 carried in from the carry-in port 21 in the direction of arrow A is held by the holding claw 4, and the conveyance chain 3 travels. It is a mechanism that transports along the direction, that is, along the conveyor frame, and unloads at the unloading port 22.

  The drive sprocket 5 is driven at a target speed by a motor (not shown), and the driven sprocket 6 is configured to freely rotate. In addition, one conveyor frame 20 is generally configured to be movable relative to the other conveyor frame 20 so that the width for holding the printed wiring board 1 can be varied, and the width for holding the printed wiring board 1 is adjusted. It is configured to be able to. In the example of FIG. 4, the conveyor frame 20 located in the upper part of the figure is configured to be movable and adjustable in the direction of arrow C.

  FIG. 5 is a view of the transport conveyor 2 in a state where the printed wiring board 1 is held from the XX cross section of FIG. 4. The transport conveyor 2 is configured to sandwich and transport the printed wiring board 1 between the holding claws 4 and the pressing claws 7, and the detailed technique is disclosed in Patent Document 1.

  That is, the guide rail 8 for the conveyance chain 3 to run in the conveyor frame 20 is provided, and the holding claw 4 and the pressing claw 7 are provided on the conveyance chain 3 via the rod 9. The pressing claw 7 has its engaging hole 10 loosely fitted in the small diameter portion 9a of the rod 9, and the pressing claw 7 is normally opened in the direction of arrow E by the spring 11 in a compressed state. However, at a position above the preheating device II and the solder supply device III, the holding claw 4 is pressed in the direction of the arrow D by the pressing plate 12 provided on the conveyor frame 20, and printing is performed between the holding claw 4 and the pressing claw 7. In this mechanism, the wiring board 1 is sandwiched and conveyed.

  As shown in FIG. 5, the height position of the return path traveling from the carry-out port 22 to the carry-in port 21 is higher than the forward path from the carry-in port 21 to the carry-out port 22 with the printed wiring board 1 interposed therebetween. In the return path, the holding claws 4 are configured so as not to come into contact with the molten solder of the solder supply device III described later.

  The printed wiring board 1 held by the holding claws 4 in this way is transported to the solder supply device III to be supplied with molten solder, and solder is supplied to the soldered portion to be soldered. In the example of FIG. 4, a solder supply apparatus including a primary supply unit 31-1 and a secondary supply unit 31-2 for the molten solder 34 is illustrated.

  FIG. 6 is a view showing a longitudinal section of the solder supply apparatus III. In addition, the conveyance conveyor 2 arrange | positioned above the solder supply apparatus III is abbreviate | omitted and shown with the dashed-dotted line. That is, the molten solder 34 is accommodated in the solder tank 33, and the molten solder 34 is maintained at a predetermined temperature determined in advance by a heater, a temperature sensor, a temperature control device, and the like (not shown).

  On the other hand, the solder supply apparatus III includes a primary supply unit 31-1 and a secondary supply unit 31-2, and the molten solder 34 supplied by the pumps 35-1 and 35-2 is supplied to the primary outlet. So that the primary jet wave 38-1 and the secondary jet wave 38-2 are formed above the blow holes 37-1, 37-2. It is configured. In addition, the guide plates 39-1 and 39-2 provided on both sides of the air outlets 37-1 and 37-2 are members for adjusting the shapes of the jet waves 38-1 and 38-2.

  The printed wiring board 1 is conveyed at an elevation angle θ (usually 0 to 7 degrees) and comes into contact with the jet waves 38-1 and 38-2 of the molten solder 34. Solder is supplied to and soldered. In this case, the immersion depth of the printed wiring board 1 in the molten solder 34 is usually about ½ of the thickness of the printed wiring board 1.

  Therefore, there is a problem that the holding claws 4 of the conveyor 2 that holds the printed wiring board 1 are also immersed in the molten solder, and the solder adheres to the holding claws 4. FIG. 7 is a perspective view showing an example of the adhesion, and FIG. 7A shows an example in which solder adheres to the holding claws described in FIG. 5 to form a solder adhesion part 34a, and FIG. An example of a holding claw 4 of a mold in which a holding recess 4b is formed and the printed wiring board 1 is fitted and held in the holding recess 4b, and an example in which solder adheres to the holding claw 4 and a solder attachment portion 34a is formed. (C) shows an example of a holding nail 4 of a mold that holds the printed wiring board 1 by fitting it in a holding recess 4c bent in a “<” shape, and solder adheres to the holding nail 4 The example of the aspect in which the part 34a was formed is shown.

  Incidentally, in the conventional tin-lead solder, there is almost no corner 4a as illustrated in FIG. 7 in the attached solder, and the round ball-shaped solder is formed on the holding claws 4. In the case of lead-free solder, as shown in FIG. 7, the solder adheres like an ice column in a state of being caught by the holding claw 4 or hanging, thereby forming a corner 4 a.

  If solder adheres to the holding claws 4 and is solidified, it becomes an obstacle when the printed wiring board 1 is held, so that the printed wiring board 1 is transported. Further, there is a problem that expensive solder is taken out from the solder supply apparatus III without producing added value, and the production cost is increased.

Therefore, a technique for removing the solder attached to the holding claws 4 is used. For example, Patent Document 2 discloses a technique for removing the attached solder by heating or rubbing on a path in which the holding claw returns from the carry-out port to the carry-in port. A technique is disclosed in which a scraping member is fitted into the concave portion of the holding claw on the path from the inlet to the carry-in port, and the solder attached to the concave portion is scraped off.
Japanese Patent Laid-Open No. 1-133668 JP-A-11-150360 Japanese Patent Laid-Open No. 2001-1134

  When the conventional tin-lead solder is used, the melting point (about 183 ° C.) is low, so that the solder does not adhere to the holding claws 4 in all the holding claws 4. Moreover, the amount of solder adhering to one holding claw 4 was small.

  However, the melting point of lead-free solder is high, and the soldering temperature is about 250 ° C. (for example, the melting point is around 220 ° C. for tin-silver solder, tin-silver-copper solder, tin-copper solder) Since soldering is performed at the same temperature as that of the conventional tin-lead solder, solder adheres to almost all the holding claws 4, and the amount of solder attached to one holding claw 4 is also large. Therefore, a large amount of solder is taken out from the solder supply device III by the holding claws 4.

  That is, when the holding claws 4 having a low temperature are immersed in the molten solder 34 together with the printed wiring board 1, and the holding claws 4 are separated from the molten solder 34 and then come out, the molten claws squeezed by the holding claws 4. The solder is solidified before it completely flows down from the holding claws 4, and adheres in a state where it is caught or hung on the holding claws 4. In addition, the difference in the state where the solder adheres to the holding claws 4 (in the case of tin-lead solder, the solder is often attached in a ball shape, and in the case of lead-free solder, the corner 4a is generated in a state where the solder claws 4 are caught. Is often caused by the difference in melting point.

  In addition, the solder thus attached to the holding claws 4 and taken out from the solder supply device III does not contribute to production. On the other hand, the price of lead-free solder is much higher than conventional tin-lead solder. Therefore, in the soldering apparatus using techniques such as Patent Document 2 and Patent Document 3, the solder removed from the holding claws 4 is returned to the solder supply apparatus by an operator and reused.

  Further, the lead-free solder adhering to the holding claws 4 has a problem that it easily falls off while the conveyor 2 is running, that is, while the holding claws 4 are running. It drops off due to slight vibration of the conveyor 2, slight distortion when the sprockets 5 and 6 circulate, and sudden changes in the conveying direction.

  For this reason, the dropped solder is scattered in the soldering device (particularly around the cooling device IV and the drive sprocket 5) to contaminate the soldering device, and therefore a cleaning operation is also required. In particular, in a soldering apparatus that covers each step of the soldering apparatus shown in FIG. 4 with a tunnel-shaped chamber and supplies an inert gas such as nitrogen gas to perform soldering in an inert gas atmosphere having a low oxygen concentration, Solder that has fallen into the chamber is scattered and becomes dirty. Therefore, the cleaning operation, that is, the cleaning operation in the tunnel chamber, is difficult.

  Further, since the inside of the chamber is maintained in an inert gas atmosphere having a target oxygen concentration, a cleaning operation with the chamber opened cannot be performed at any time. That is, in order to maintain the inert gas atmosphere in the chamber, the raw material cost of the atmospheric gas is required, and if a predetermined time (for example, 30 minutes) has not passed since the supply of the inert gas has started, If the target oxygen concentration cannot be obtained and the cleaning operation is performed with the chamber opened unnecessarily, not only will the process cost increase, but also the downtime of the soldering operation, that is, the production operation will be increased, and the productivity will be increased. This is because there is a problem of lowering.

  The solder that falls off from the holding claws 4 during the running of the holding claws 4 cannot be removed and collected by the techniques of Patent Document 2 and Patent Document 3. In addition, since the holding claw 4 is configured to remove the solder attached to the holding claw 4 in a path where the printed wiring board 1 is not held, that is, a return path returning from the carry-out port 22 to the carry-in port 21, the holding claw 4 is moved forward. The action does not reach at all between the forward path from the solder supply device III to the return solder removal means disclosed in Patent Document 2 and Patent Document 3.

  An object of the present invention is to allow solder that easily adheres to the holding claws, such as lead-free solder, to be removed immediately after attachment in the solder supply device and returned to the solder supply device. It is intended to eliminate the troublesome cleaning work and the work of returning the collected solder. Moreover, in the soldering apparatus provided with the chamber, it is intended to prevent an increase in running cost without impairing the productivity.

  The present invention is configured such that the solder that is caught in a holding claw, hanging down and hanging down in an ice column shape is dropped into the solder supply device by touching the solder hanging down in the ice column shape and returned. Moreover, it is characterized in that it is constructed so as not to damage the conveying means.

(1) A lead-free solder is accommodated in a molten state in a solder bath, a solder supply device for using the molten solder for soldering a printed wiring board, and a side end portion of the printed wiring board being held by a holding means thereabove. The holding means is provided at a position above the molten solder accommodated in the solder tank of the solder supply apparatus, where a transport path for transporting the transport means is provided, and where the printed wiring board for which the solder supply is completed is transported In the vicinity of the lower position of the soldering device, there is provided a soldering device configured to provide touching means for contacting the solder that hangs down on the holding means and drops the hanged solder into the solder bath.

  That is, when the touching means comes into contact with the solder that is hanging from the holding means, the solder is attached in a state where it is caught. Can be dropped into. That is, it can be immediately collected in the solder supply device. Therefore, the solder is not scattered and contaminated in the soldering apparatus, and it does not become an obstacle when holding the printed wiring board carried into the conveying means.

(2) In the soldering apparatus according to (1), a flexible member is used as the touching means, and the degree of flexibility is determined when the touching means and the holding means are in contact with each other. Is a soldering device selected and configured to such an extent that it is not damaged.

  Since the holding means of the conveying means travels and moves along the conveying path of the conveying means, the touching means is provided near the lower part of the passing position, so that the solder that hangs down and adheres to the holding means is attached. Can abut. That is, the vicinity below the passing position is an extremely close position that does not contact the traveling holding means, and the traveling position varies depending on the dimensional error of the holding means itself, the mounting error in the conveying means, the accuracy of the conveying means, and the like.

  For this reason, the touching means may come into contact with the holding means. Therefore, a flexible member is used for the touching means, and the touching means is configured to be able to be retracted when the touching means and the holding means come into contact with each other. By selecting a degree of flexibility that does not cause damage, the soldering apparatus is not damaged. Note that the flexible member is not necessarily used for the entire touching means, and may be partially used within a range that realizes the purpose.

  As a result, it is possible to maintain the continuous operation of the soldering apparatus while reliably removing the solder adhering to the holding means.

(3) The soldering apparatus according to (1) and (2), wherein a surface on which the touching means can come into contact with the holding means is configured by an arcuate curved surface.

  By forming the surface on which the touching means can come into contact with the holding means with an arcuate curved surface, when the holding means and the touching means come into contact, the touching means can easily retreat, and the contact is maintained by this contact. As a result, the transport means is not easily damaged, and the reliability of operation of the soldering apparatus is further improved.

  As described above, according to the soldering apparatus of the present invention, it is possible to easily remove and drop the solder that easily adheres to the holding claws, such as lead-free solder, by touching the touching means. It can be removed immediately after attachment in the apparatus and returned to the solder supply apparatus.

  As a result, it is possible to eliminate the occurrence of dirt in the soldering apparatus from the beginning, and to eliminate the troublesome cleaning work and returning the collected solder. In addition, the soldering apparatus provided with the chamber eliminates the need to perform cleaning work, recovery work, etc. by wastefully discharging and discarding the expensive inert gas, thereby reducing the process cost due to wasteful consumption of the inert gas. No increase in production, no recombination of inert gas into the chamber after cleaning, and no need for leadcome (header) required to reach the target oxygen concentration. It will be possible to prevent the rise of.

  The soldering apparatus of the present invention can be realized by the following configuration, for example.

(1) Configuration FIG. 3 is a diagram for explaining a configuration example of a main part of a soldering apparatus, and is a view of the soldering apparatus as viewed from above. FIG. 3 is a view showing a mode in which a soldering device is provided in the soldering apparatus of FIG. FIG. 2 is a perspective view for explaining the entire solder contact device provided in the soldering apparatus. Moreover, FIG. 1 is a figure which shows the example of the aspect which provided the soldering apparatus in the conveyance conveyor, and is the figure seen from the YY cross section of FIG. 3 in the state in which the conveyance conveyor is holding the printed wiring board.

  In these drawings, the same components as those in FIGS. 4 to 7 are denoted by the same reference numerals, and reference numeral 40 denotes a solder drop device, and as shown in FIG. 3, a position where the solder drop device 40 is provided. Is the rear side of the secondary supply section 31-2 of the solder supply device III (position on the side where the solder supply is completed) when viewed in the transport direction of the transport conveyor 2, and above the molten solder 34 of the solder supply device III. Side position. As shown in FIG. 2, the solder contact device 40 has a rod 41 provided on a suspension 44 by a washer 42 and a screw 43, and a screw hole 45 provided in the suspension 44, as shown in FIG. In this configuration, the conveyor frame 20 is fixed with screws 46. The configuration of the transfer conveyor 2 shown in FIG. 1 is the same as that of the transfer conveyor shown in FIG.

  Further, as shown in FIG. 1, the vertical positional relationship between the solder contact device 40 and the conveyer 2 is such that the rod 41 of the solder contact device 40 has the tip of the holding claw 4, that is, both sides of the printed wiring board 1. It is provided at a position near the lower side of the portion holding the end. The vicinity in the vertical direction is a position where the rod 41 can contact the corner 4a of the solder attached to the holding claw 4 as shown in FIG. Therefore, the rod 41 may be provided to such an extent that the rod 41 contacts the tip portion of the holding claw 4.

  Further, when the solder adheres to other portions of the holding claws 4, another rod may be provided so that the rod 41 contacts the solder adhering portion of the portion. Alternatively, one rod may be configured to match the shape of the holding claw 4 and may be configured to contact the solder attached to a plurality of locations of the holding claw 4 with one rod.

  Since the lead-free solder is attached in a hooked state, the rod 41 of the soldering device 40 may be provided so as to contact the solder attached to the holding claws 4. May be configured to contact the holding claws 4. Therefore, even when the suspension 44 and the rod 41 of the solder contact device 40 are made of a flexible member such as spring steel and the rod 41 and the holding claw 4 come into contact with each other, the conveyance conveyor 2 and the holding are held by the contact. The degree of flexibility may be selected so that the nail 4 is not damaged functionally. That is, when the rod 41 and the holding claw 4 come into contact with each other, the rod 41 is configured to be deformed in a self-retreating manner.

  In the example of FIG. 2, the rod 41 is illustrated as a member that contacts the solder attached to the holding claws 4, but a belt-like member or a member of another shape may be used. However, it is better to form the surface with an arcuate curved surface. In other words, when the belt-like member or other shape member and the holding claw 4 come into contact with each other, the members are configured to easily retreat.

  In the example of FIG. 1, the solder contact device 40 is provided on the conveyor frame 20 of the transport conveyor 2, but this changes the type of the printed wiring board 1 to be soldered and changes the dimensions of the printed wiring board 1. In other words, even when the position of the conveyor frame 20 is moved in the direction of the arrow C, the positional relationship between the holding claws 4 and the rod 41 of the soldering device 40 is held in a fixed positional relationship. .

  When the printed wiring board 1 is transported by the handling robot, the solder contact device 40 may be provided in the solder tank 33 of the solder supply device III, its frame, or the like. And also in that case, the position where the solder contact device 40 is provided is the rear side (position where the solder supply is completed) as viewed from the conveying direction of the secondary supply unit 31-2 of the solder supply device III, This is the position above the molten solder 34 of the solder supply apparatus III.

  The vertical position relationship between the solder touch device 40 and the holding claw 4 of the printed wiring board 1 of the handling robot is such that the rod 41 of the solder touch device 40 is at the tip of the holding claw 4, that is, the printed wiring board 1. What is necessary is just to provide in the vicinity position of the downward side of the part holding both the edge parts. Similarly, the position in the vicinity in the vertical direction is a position where the rod 41 can contact the corner of the solder attached to the holding claw 4, that is, the solder attached portion 34 a, and therefore the rod 41 is the tip portion of the holding claw 4. You may provide so that it may contact.

  In the example described above, the solder contact device 40 is provided at a position above the molten solder 34 of the solder supply device III, but this upper position must be above the molten solder. is not. For example, when viewed from the conveying direction of the secondary supply unit 31-2 of the solder supply apparatus III, the direction is the rear stage side (the position on the side where the solder supply is completed), and a position slightly offset from the solder supply apparatus III. Also good. In this case, a falling solder guide plate having a slope like the cross-sectional shape of the funnel is provided, and the solder dropped from the holding claws 4 is slid down onto the molten solder liquid surface of the solder supply device III. What is necessary is just to comprise so that it may roll down.

(2) Operation When the printed wiring board 1 is carried in from the carry-in entrance 21 of the soldering apparatus, both side ends of the printed wiring board 1 are held by the holding claws 4 of the conveyor 2 in the direction of arrow B (FIG. 3). It is conveyed to. Then, the flux is applied to the printed wiring board 1 by the flux applying apparatus I, and the pre-heating of the printed wiring board 1 is performed by the preheating apparatus II to perform preactivation and drying of the flux.

  Subsequently, in the solder supply apparatus III, the molten solder is reliably supplied to the fine soldered portion of the printed wiring board 1 by the primary supply unit 31-1, and the solder bridge is removed by the secondary supply unit 31-2. Finishing of soldering is done by adjusting the fillet shape. Then, the printed wiring board 1 and the solder to be soldered are cooled by the cooling device IV, and the printed wiring board 1 having excellent soldering strength is soldered and mounted.

  In general, the printed wiring board 1 is soaked in molten solder about half of its thickness in the molten solder, that is, soldering is performed, so whether or not the printed wiring board 1 is held, All the holding claws 4 of the conveyor 2 are immersed in the molten solder 34 and then come out of the molten solder 34. Then, when the holding claws 4 come out of the molten solder 34, the molten solder is scooped up, solidified before the scooped-up solder completely flows down, and caught as if having an icicle-shaped corner. Adhere (see FIG. 7). This is noticeable with lead-free solder having a high melting point.

  However, in the present invention, since the solder contact device 40 is provided above the molten solder 34 of the solder supply device III, the above-mentioned icicle-shaped corners are formed by the transport operation of the transport conveyor 2 and the travel of the holding claws 4. The solder 41 attached to the holding claw 4 in contact with the holding claw 4 in a state of being caught by the holding claw 4 comes into contact with the rod 41 of the solder touch device 40, and the solder attached by this contact is easily detached from the holding claw 4 and soldered. It falls on the liquid surface of the molten solder 34 of the supply device III.

  Therefore, all of the solder adhering to the holding claws 4 of the transport conveyor 2 is removed in the soldering process, falls back to the solder supply device III, and does not contaminate the soldering device. Moreover, it is not necessary to perform the troublesome work of returning the removed solder to the solder supply device as in the prior art. Of course, since it returns to the carry-in entrance 21 in a state where no solder is attached to the holding claws 4, no trouble occurs when the printed wiring board 1 into which the holding claws 4 are carried is held.

  Further, by configuring a part or all of the solder contact device 40 with a flexible member or a member having an arcuate curved surface that can be retracted as described above, the solder contact device 40 is transported. Even if it contacts the holding claw 4 of the conveyor 2, the conveyance conveyor 2 including the holding claw 4 is not damaged, and the reliability as a means for removing the solder is extremely high.

  In the conventional technique, when the solder is removed from the holding claws 4 of the transport conveyor 2, the precondition is that the holding claws 4 do not hold the printed wiring board 1. However, in the technique of the present invention, regardless of whether the holding claws 4 hold the printed wiring board 1 or not, the solder can be easily detached from all the holding claws 4 on the molten solder liquid surface of the solder supply device III. It can be dropped.

  Electronic devices are daily necessities and infrastructure. And the soldering apparatus for manufacturing the electronic device is an essential apparatus today. Therefore, a technique for performing soldering by supplying molten solder to a soldered portion of a printed wiring board on which a large number of electronic components are mounted needs to be extremely reliable and capable of low-cost production.

  The technique of the present invention is to improve reliability and reduce production costs in a soldering apparatus that supplies solder by supplying such molten solder, particularly in a soldering apparatus that uses lead-free solder. Is an extremely important technology.

It is sectional drawing which shows the example of an aspect which provided the soldering contact apparatus of this invention in the conveyance conveyor. It is a perspective view which shows the solder touch-off apparatus of this invention. It is a top view which shows the whole picture of the soldering apparatus of this invention. It is a top view which shows the whole picture of the conventional soldering apparatus. It is sectional drawing by the XX line of FIG. It is an enlarged view of the solder supply apparatus of FIG. It is a perspective view which shows the aspect in which a solder adhesion part is formed in the holding nail | claw of the conventional soldering apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed circuit board 2 Conveyor 3 Conveying chain 4 Holding claw 31-1 Primary supply part 31-2 Secondary supply part 33 Solder tank 34 Molten solder 40 Solder drop apparatus 41 Rod 44 Suspension I Flux application apparatus II Preheating apparatus III Solder supply device IV Cooling device

Claims (3)

A lead-free solder is accommodated in a molten state in a solder tank, and the molten solder is used for soldering a printed wiring board, and conveyed while holding the side edge of the printed wiring board above by a holding means. A transport path for the transport means is provided,
Adhering to the holding means in the upper position of the molten solder accommodated in the solder tank of the solder supply apparatus and in the vicinity of the position below the passing position of the holding means in the path position where the printed wiring board for which the solder supply is completed is conveyed A soldering device is provided, wherein touching means is provided for contacting the solder that hangs down and dropping the solder that hangs down into the solder bath.   2. The soldering apparatus according to claim 1, wherein a flexible member is used as the touching means, and the degree of flexibility is damaged when the touching means and the holding means are in contact with each other. Soldering device characterized in that it is selected and configured so as not to receive.   3. The soldering apparatus according to claim 1, wherein a surface on which the touching means can come into contact with the holding means is formed by an arcuate curved surface.

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