JP2008124332A - Soldering method, soldering system, and fluxing coating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the problem of a vaporized gas in a flux generated from a carrier in a soldering process, and eliminate wet defects in soldering so as to allow the carrier to be preheated by the closest temperature of the molten solder when the carrier contacts a jet stream, i.e. the molten solder in a soldering process. <P>SOLUTION: The soldering method provides a cleaning process 201 of the carrier 600 between a flux coating process 401 and a soldering process 403. In addition, a carrier heating process 202 for only the carrier 600 is provided before the process 403. Further, a printed circuit board 500 is held by the carrier 600 between the process 401 and the process 403, and the carrier 600 is cleaned and is heated in the condition, i.e. with the board 500 held by the carrier 600. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides a soldering method for performing soldering by supplying molten solder to a soldered portion of a printed wiring board (plate-like soldered workpiece) on which electronic components are mounted, and for realizing the soldering method. The present invention relates to a soldering system and a flux application system.

  FIG. 4 is a diagram illustrating a general configuration example of a soldering system for supplying molten solder to a soldered portion of a printed wiring board on which electronic components are mounted and performing soldering. The outline is shown in a view seen from the side with respect to the conveyance direction of the printed wiring board, and the control system is shown in a block diagram.

  As shown in FIG. 4, the general soldering system is configured in the order of a flux application process 401 → a preheating process 402 → a soldering process 403 → a cooling process 404. A heating device 420, a solder supply device 430, and a cooling device 440 are provided.

  Further, a transporting conveyor 405 for transporting a printed wiring board (plate-like soldered workpiece) 500 on which the electronic component 501 is mounted in the direction of arrow A along these steps is provided. When the printed wiring board 500 is transported, the transported wiring board 500 is directly held by the transporting conveyor 405 to transport the printed wiring board 500, and the carrier that holds and fixes the printed wiring board 500 as illustrated in FIG. (Holding tool) 600 may be transported by transport conveyor 405.

  In addition, since the structure conveyed by the conveyance conveyor 405 via the carrier 600 is a structure couple | bonded with the conveyance conveyor 405 via the carrier 600 corresponding to holding | maintenance of various printed wiring boards, the printed wiring board of soldering is carried out. Even if the type changes, it is possible to perform continuous soldering, and it is possible to continuously produce a wide variety of printed wiring boards.

  FIG. 5 is a perspective view illustrating the entire contents of the carrier 600 shown in FIG. 5A shows a carrier that supplies molten solder to the soldered surface of the printed wiring board 500 in a lump, and FIG. 5B shows only the soldered portion of the printed wiring board 500 and its vicinity. A carrier for supplying molten solder is shown.

  6 is a diagram for explaining the state of the printed wiring board 500 held by the carrier 600 shown in FIG. 5. FIG. 6 (a) is a diagram showing a II cross section of FIG. 5 (a). (B) is a figure which shows the II-II cross section of FIG.5 (b).

  The carrier 600a shown in FIGS. 5 (a) and 6 (a) is formed with a fitting recess 601 for fitting and holding the printed wiring board 500, and the end of the printed wiring board 500 is supported by the support piece 602. This is a mechanism for supporting the portion and holding it in the fitting recess 601.

  Note that a window 603 is provided inside the support piece 602, and the lower surface of the printed wiring board 500 is exposed to the lower side of the carrier 600.

  The carrier 600a is provided with a conveyor coupling piece 604 that is coupled to the transport conveyor 405. The arrangement position and the arrangement dimension of the coupling piece 604 are standardized, and the shape of the insertion recess 601 is different. Even if the type of the printed wiring board 500 to be held is different, it is a mechanism that can be continuously conveyed without adjusting the holding width or the like of the conveyor 405 each time.

  The carrier 600b shown in FIG. 5B and FIG. 6B has a window portion in accordance with the position of the lead terminal 502 of the lead-type electronic component 501 mounted on the printed wiring board 500, that is, the position of the soldered portion 503. In the configuration provided with 606, that is, the configuration provided with the mask portion 605, only the region of the window portion 606 is exposed to the lower side of the carrier 600b. This configuration is used when it is not desired to supply molten solder to a region other than the window portion 606, that is, for partial soldering. For example, it is used when there is an electronic component that has already been reflow soldered.

  4 is an apparatus for applying flux to the soldered surface of the printed wiring board 500, that is, the lower surface of the printed wiring board 500 shown in FIG. If the carrier 600b having the mask portion 605 as illustrated in b) is used, the flux is selectively applied not to the entire lower surface of the printed wiring board 500 but to the soldered portion 503 and the vicinity thereof. You can also.

  There are various types of coating devices as the flux coating device 410, but a spray-type coating device that sprays the flux supplied from the flux supply device 411 from the spray nozzle 412 and applies the mist-like flux 414 is common. In this configuration, the amount of flux applied to the printed wiring board is controlled by an application amount controller 413 that controls the amount of flux supplied to the nozzle 412. In addition to the above-described spraying type, a foaming type or liquid flow type flux applying device is also used as the flux applying device. Regardless of which flux applying device is used, the lower surface of the printed wiring board 500 and the carrier are used. Usually, flux is applied to both sides of the lower 600 side.

  The pre-heating device 420 heats the printed wiring board 500 to dry and pre-activate the previously applied flux, and the printed wiring board 500 is jetted or melted in the subsequent soldering process 403. It is a device for reducing heat shock when it comes into contact with solder, and is heated by infrared rays radiated from a heater 421, hot air supplied from a blower fan 423, or the like. Then, the heating amount control device 425 detects the surface temperature of the heater 421 by the temperature sensor 422 and controls the power supplied to the heater 421, and also controls the rotational speed of the motor 424 of the fan 423, that is, the amount of hot air blown. Thus, the heating amount of the printed wiring board 500 is controlled.

  The solder supply device 430 is a device that supplies molten solder to the soldered portion 503 of the printed wiring board 500 on which the electronic component 501 is mounted, and performs soldering. The carrier 600a illustrated in FIG. Molten solder is supplied all at once to the soldering surface of the wiring board 500, and in the carrier 600b illustrated in FIG. 5B, the molten solder is supplied only to the soldered portion 503 and the vicinity thereof.

  In the solder supply device 430, molten solder controlled to a predetermined temperature predetermined by a heater 432, a temperature sensor 433, and a temperature control device 434 is accommodated in a solder tank 431, and the molten solder is pumped by pumps 436 and 438. It is the structure which is supplied to the blowing body 437 and 439 and forms the jet waves 451 and 452. The jet flow control device 435 controls the flow rate of the jet waves 451 and 452 by controlling the amount of molten solder supplied to the blower bodies 437 and 439 and controlling the jet flow rate from the blower bodies 437 and 439. It is a mechanism to do.

  In addition, in the example shown in FIG. 4, it has the 1st pump 436, the 2nd pump 438, the 1st blowing body 437, and the 2nd blowing body 439, and the 1st jet wave 451 and the 2nd The example of a structure which supplies molten solder with the two jet waves of this jet wave 452 is shown. Generally, a jet wave having a high dynamic pressure is used for the first jet wave 451 in order to ensure wettability of the molten solder in the soldered portion, and a fillet of the soldered portion is used for the second jet wave 452. A gentle stream of jet waves is used to shape the shape.

  The cooling device 440 is a device that improves physical properties such as the soldering strength of the soldered portion 503 by cooling the printed wiring board 500 to which the molten solder is supplied, and thus the soldered portion 503, at a high speed. This is a mechanism for controlling the cooling rate by controlling the amount of cold air supplied from the cold air supply device 441 by the cooling amount control device 442.

As a technical example having the same configuration, a technical example disclosed in Patent Document 1 can be given.
JP-A-61-212469

  However, in the soldering system using the carrier as described above, solder wettability is likely to occur in the soldered portion of the printed wiring board located in the peripheral area of the window portion of the carrier. There was a problem that would reduce the quality.

  That is, in the flux application process, since the flux is also applied to the carrier, when the carrier and the printed wiring board come into contact with the jet wave, that is, the molten solder, the vaporized gas is also generated from the flux applied to the carrier. appear. The vaporization gas of the flux generated from other than this printed wiring board moves to the soldered portion of the printed wiring board located in the peripheral area of the window portion of the carrier and inhibits the supply of molten solder to the soldered portion, This is because poor wetting or the like is caused and soldering quality is deteriorated.

  In addition to this, in a soldering system using a carrier, there is a cause that a solder wettability is likely to occur in a soldered portion of a printed wiring board located in a peripheral region of a window portion of the carrier. Hereinafter, this cause will be specifically described.

  In the system, the heating temperature in the preheating step is usually around 120 ° C., and the temperature of the jet wave in the soldering step, that is, the temperature of the molten solder is usually around 250 ° C., but a carrier with a large heat capacity is used in the soldering step. The temperature rise is slower than that of the printed wiring board, so that the jet wave around the carrier, that is, the temperature of the molten solder is lowered. For this reason, the temperature of the molten solder supplied to the soldered portion of the printed wiring board in that portion is lowered, and wettability is likely to occur.

  Patent Document 1 discloses a technique for cleaning the flux attached to the carrier using a brush and a cleaning liquid, and a technique for cleaning the carrier by applying an ultrasonic wave when the cleaning liquid is stored in a cleaning tank. .

  However, since the technique of Patent Document 1 provides the above-described cleaning process after the supply of the molten solder to the printed wiring board is completed, that is, the post-process of the soldering process or the pre-process of the flux application process. In the process, the flux remains attached to the carrier. For this reason, the technique disclosed in Patent Document 1 cannot remove the vaporized gas generated from the flux applied to the carrier. In addition, the temperature drop of the molten solder caused by the carrier cannot be eliminated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to eliminate the problem of vaporization gas of the flux generated from the carrier in the soldering process, and the carrier is soldered. Good soldering quality with no solder wetting failure by configuring the carrier temperature to be preheated to a temperature close to the temperature of the molten solder when contacting the jet wave or molten solder in the process It is to provide a mechanism that enables soldered mounting of a simple printed wiring board.

  The present invention is characterized in that a carrier cleaning step is provided between the flux application step and the soldering step. Another feature is that a heating process for only the carrier is provided immediately before the soldering process. The printed wiring board is held by the carrier between the flux application process and the soldering process. In this state, that is, the printed wiring board is held by the carrier, the carrier is cleaned and the carrier is targeted. It is the structure which heats.

  Cleaning and heating for the carrier, i.e., the holder that holds the printed wiring board (plate-like workpiece to be soldered), is performed in a state where the holder holds the printed wiring board. The process is provided immediately before the soldering process, and is provided between the preheating process and the soldering process. Moreover, you may provide between a flux application | coating process and a preheating process, and in addition, you may provide in two places between a preheating process and a soldering process.

  In addition, when the flux application process and the preheating process are provided apart from each other, a process of providing a holder cleaning process after the flux application process and combining the flux application process and the cleaning process into one unit It may be formed.

  The cleaning of the holder performed in the state where the printed wiring board is held is performed by rinsing the cleaning liquid by bringing the cleaning liquid into contact with only the surface where the flux is attached to the holder, that is, the lower surface, or impregnating the cleaning liquid. A moving roller body or a blade body may be brought into contact. Moreover, you may make it this jet wave contact only the lower surface of a holder using the jet wave of molten solder. With such a configuration, the flux can be previously vaporized and removed, that is, washed. In addition, when the molten solder jet wave is used for cleaning the holder, heating can be selectively performed only on the holder.

  By configuring as described above, only the flux applied to the holder out of the fluxes applied to the printed wiring board and the holder is cleaned and removed, and the printed wiring board and the holder are subjected to a soldering process. In contact with the jet wave, that is, the molten solder, the molten solder is supplied to the part to be soldered. When the molten solder is supplied, the vaporization gas of the flux generated from the holder is eliminated, and therefore, this gas does not hinder the solder wettability at the soldered portion of the printed wiring board.

  In addition, if the jet wave of molten solder is used for cleaning the holder and this jet wave is brought into contact only with the lower surface of the holder, the flux applied to the holder is cleaned. It is possible to heat only this holder and heat it to a temperature close to the temperature of the molten solder, greatly exceeding the range of the heating temperature performed in the preheating step. This makes it possible to immediately raise the temperature of the holder to the temperature of the molten solder in the subsequent soldering process, and the holder having a larger heat capacity than the printed wiring board reduces the temperature of the molten solder. The conventional problem of inhibiting solder wettability at the soldered portion of the printed wiring board can be solved.

  In addition, when using molten solder jet waves for cleaning and heating the holder, the temperature of the molten solder is controlled so that the degree of cleaning of the holder (the degree of vaporization of the flux) and the holding are maintained. The heating temperature of the tool can be controlled. Thereby, the temperature of the holder when the printed wiring board and the holder are conveyed to the soldering process and start to contact with the molten solder can be set to the same temperature as the temperature of the supplied molten solder. Therefore, it is possible to solve the problem of deterioration in solderability caused by the temperature drift of the molten solder supplied to the printed wiring board.

  According to the present invention, the problem of the vaporized gas of the flux generated from the holder in the soldering process can be solved. Further, the temperature of the holder when the holder comes into contact with the jet wave, that is, the molten solder in the soldering step can be heated to a temperature close to the temperature of the molten solder.

  Therefore, the temperature of the molten solder supplied to the soldered part of the printed wiring board does not disturb the solder wettability in the soldered part of the printed wiring board due to the generation of an unnecessarily large amount of vaporized gas of the flux. However, the temperature does not drop below the target temperature and the solder wettability at the soldered portion is not hindered. As a result, the printed wiring board with good soldering quality without solder wettability can be soldered and mounted.

  The present invention is characterized in that a “cleaning process” for cleaning the carrier is provided between the flux application process 401 and the soldering process 403 shown in FIG. Further, there is a feature in that a “carrier heating process” for heating only the carrier is provided immediately before the soldering process 403.

[First Embodiment]
Hereinafter, with reference to FIG. 1A-FIG. 1C and FIG. 2, it demonstrates how the soldering method of this invention, a soldering system, and a flux application | coating system are realizable.

  1A to 1C are system configuration diagrams showing a cleaning process (also serving as a carrier heating process) and a soldering process in the soldering system according to the first embodiment of the present invention. The outline of the configuration is printed wiring. The control system is shown in a block diagram as viewed from the side with respect to the conveying direction of the plate.

  FIG. 2 is a system configuration diagram illustrating an example of the organization of all processes from the flux application process to the cooling process in the soldering system of the present invention, and an overview of the configuration is seen from the side with respect to the direction of conveyance of the printed wiring board. In the figure, the control system is shown in a block diagram. 1A to 1C and FIG. 2, the same components as those in FIGS. 4 to 6 are denoted by the same reference numerals.

  First, referring to FIG. 1A to FIG. 1C, a “cleaning step” provided between the flux application step 401 and the soldering step 403 shown in FIG. 4 and a “carrier heating step” provided immediately before the soldering step 403. Will be described.

  1A and 1B, reference numeral 100 denotes a cleaning device, which also serves as a carrier heating device (hereinafter referred to as “cleaning device (also called carrier heating device)”). As shown in FIG. And a step that also serves as a carrier heating step (hereinafter referred to as “cleaning step (also called carrier heating step)”) 202. Reference numeral 110 denotes a solder supply device, which is used in a soldering step 403 as shown in FIG.

  FIG. 1A is a diagram illustrating a state in which a jet of molten solder used in the cleaning apparatus 100 is in contact with only the carrier 600, that is, a state in which the carrier 600 is cleaned and heated. FIG. 1B is a diagram illustrating a state after the state of FIG. 1A and in which molten solder is supplied to the soldered portion 503 of the printed wiring board 500. Moreover, FIG. 1C is a figure explaining the example (an example of a structure different from FIG. 1A and FIG. 1B) by which the carrier washing | cleaning apparatus (cum-carrier heating apparatus) and the solder supply apparatus are comprised by one solder tank.

  In the configuration example shown in FIGS. 1A and 1B, the solder bath 101 responsible for the carrier cleaning step (or carrier heating step) 202 shown in FIG. 2 and the solder bath 111 in the soldering step 403 are provided separately, respectively. (105, 115), a temperature sensor (106, 116), and a temperature control device (107, 117) are provided.

  Further, the first solder bath 101 includes a first pump 102, a first blower body 103, and a jet flow rate control device 104 that controls the flow rate of the molten solder 108 that the pump 102 supplies per unit time. The wave height of the first jet wave 109 formed on the first blowing body 103 can be controlled.

  Similarly, the second solder tank 111 includes a second pump 112, a second blower body 113, and a jet flow rate control device 114 that controls the flow rate of the molten solder 118 supplied by the pump 112 per unit time. The height of the second jet wave 119 formed on the second blowing body 113 can be controlled.

  The second blower body 113 has a hybrid wave (second wave) that combines a jet wave 119a having a high dynamic pressure with emphasis on solder wettability and a gentle jet wave 119b with a focus on shaping the fillet shape. The jet wave 119) can be formed. Therefore, the contact of the molten solder to the printed wiring board is made only once, and the contact of the molten solder illustrated in FIG. 4 is configured to obtain the soldering quality equivalent to the soldering process of two times. That is, the means comprising the first solder bath 101 is the cleaning device (or heating device) 100, and the means comprising the second solder bath 101 is the solder supply device 110.

  On the other hand, the printed wiring board 500 is held by the carrier 600 as illustrated in FIGS. 5 and 6 and is conveyed in the direction of arrow A by the conveying conveyor 405. Then, as shown in FIGS. 1A and 1B, the wave height of the first jet wave 109 is adjusted to a wave height at which the jet wave 109 contacts only the lower surface of the carrier 600, and the wave height of the second jet wave 119 is adjusted. The wave height is adjusted so that molten solder can be brought into contact with the soldered portion 503 of the printed wiring board 500 and supplied.

  Therefore, the soldering operation proceeds as follows. That is, when the printed wiring board 500 held by the carrier 600 is conveyed in the direction of the arrow A, as shown in FIG. 1A, the first jet wave 109 first contacts only the lower surface of the carrier 600, and this The flux applied to the lower surface of the carrier 600 is vaporized and removed, that is, washed. In addition, only the carrier 600 is heated to the temperature of the molten solder or a temperature close to the temperature by the first jet wave 109.

  Subsequently, as shown in FIG. 1B, the second jet wave 119 having a wave height higher than that of the first jet wave 109 comes into contact with the printed wiring board 500 to supply the molten solder to the soldered portion 503 and solder. To do.

  When the second jet wave 119 is in contact with the printed wiring board 500, the carrier 600 is also in contact with the second jet wave 119, but the flux applied to the lower surface of the carrier 600 is the first. Since the jet wave 109 has already been removed, vaporized gas originating from the flux applied to the carrier 600 is not generated. Further, since the carrier 600 is heated by the first jet wave 109 to the temperature of the molten solder 108 in the first solder bath 101 or a temperature close thereto, this second carrier wave 119 is brought into contact with the second jet wave 119. The temperature of the molten solder forming the jet wave 119 is not lowered.

  Therefore, the solder vapor in the soldered portion 503 of the printed wiring board 500 is not hindered by the vaporized gas of the flux generated from the carrier 600, and the temperature of the molten solder supplied to the soldered portion 503 is determined by the carrier. Therefore, soldering with good solder wettability at the soldered portion 503 can be performed.

  The temperature of the molten solder 118 accommodated in the second solder bath 111 is adjusted and set to about 250 to 255 ° C. in the case of tin-silver-copper lead-free solder. By adjusting and setting the temperature of the accommodated molten solder 108 to a temperature higher by about 10 to 30 ° C. than this temperature, the temperature of the carrier 600 when the carrier 600 contacts the second jet wave 119 The temperature of the second jet wave 119 can be made uniform. Further, by adjusting the temperature of the molten solder 108 accommodated in the first solder bath 101, it is possible to adjust the degree of removal and cleaning by vaporization of the flux applied to the carrier 600. Note that the higher the temperature of the molten solder 108, the better the cleaning action.

  In this example, molten solder is used as a medium for cleaning the carrier 600. However, a cleaning liquid, for example, a solvent similar to the solvent of the flux is used as the cleaning liquid to form a jet wave, and the jet wave of this cleaning liquid is formed on the lower side of the carrier 600. You may comprise so that it may be made to contact only the surface of this and wash. When this cleaning liquid is used, the carrier 600 cannot be heated, but it is better to control the temperature of the cleaning liquid to a target temperature by the temperature control means so that the cleaning action is high.

  Next, although it is a structural example of FIG. 1C, it is a structural example which comprised the washing | cleaning apparatus (heating apparatus of a carrier) and the soldering apparatus by one solder tank. In addition, the same code | symbol is attached | subjected to the same thing as FIG. 1A and FIG. 1B.

  In FIG. 1C, reference numeral 120 denotes a device (hereinafter referred to as “cleaning device (heating carrier and carrier)” which constitutes the cleaning device (heating device for carrier) and the solder supply device shown in FIGS. Device) and a solder supply device).

  Reference numeral 124 denotes a jet flow control device, which is configured to separately control the flow rates of the molten solder supplied by the first pump 102 and the second pump 112 per unit time. In this example, the temperature of the jet wave 109 used for cleaning and heating of the carrier 600 and the temperature of the molten solder and the temperature of the jet wave 119 used for soldering the printed wiring board 500 and the temperature of the molten solder are the same. In addition, there is an advantage that the structure of the temperature control means of the molten solder 128 can be simplified (it also reduces the cost). That is, the temperature control means can be constituted by one heater 125, one temperature sensor 126, and one temperature control device 127.

  Also in the configuration example of FIG. 1C, the second blower body 113 configured in the same manner as in the examples of FIGS. 1A and 1B is used, and the second jet wave 119 employs a hybrid wave. The first jet wave 109 is adjusted and set to a wave height that contacts only the lower surface of the carrier 600, and the second jet wave 119 is supplied with molten solder to the soldered portion 503 of the printed wiring board 500. It is adjusted and set to the wave height. In the configuration example of FIG. 1C, the progress of the soldering operation of the printed wiring board 500 is the same as in the example of FIGS. 1A and 1B, but the heating of the carrier 600 is performed as in the example of FIGS. 1A and 1B. The temperature cannot be adjusted and set independently.

  The overall configuration of the soldering system of the present invention will be described below with reference to FIG.

  The configuration example of the soldering system 200 of the present invention shown in FIG. 2 is different from the configuration example of the conventional soldering system shown in FIG. 4 in that a carrier is provided between the flux application process 401 and the preheating process 402. The cleaning step 201 is provided, and the cleaning step (cum carrier heating step) 202 is provided between the preheating step 402 and the soldering step 403.

  In view of the structure of the soldering system, the cleaning process of the carrier 600 may be provided only on one of 201 and 202. However, as shown in FIG. 2, a cleaning process for the carrier 600 may be provided at two locations 201 and 202.

  A cleaning apparatus 210 provided between the flux application process 401 and the preheating process 402 is a cleaning apparatus having the same configuration as the cleaning apparatus (cum carrier heating apparatus) 100 illustrated in FIGS. 1A and 1B. In addition, the cleaning device (cum carrier heating device) and the soldering device 220 of the cleaning step (cum carrier heating step) 202 provided between the preheating step 402 and the soldering step 403 are the cleaning device illustrated in FIG. 1C. (Also, it may be a cleaning device having the same configuration as the cleaning device (cum carrier heating device) 100 illustrated in FIGS. 1A and 1B). Therefore, the wave height of the jet wave 109 of the cleaning devices 210 and 220 is adjusted and set to a wave height that contacts only the carrier 600 as in the example of FIG.

  As described above, the cleaning process may be provided only between the flux application process 401 and the preheating process 402. In this knitting system, immediately after the flux application in the flux application process 401, the lower surface of the carrier 600 is cleaned by the cleaning process 201, and after the preliminary heating in the preheating process 402, the soldering process 403 is performed on the printed wiring board 500 to be soldered. Molten solder is supplied to the attaching part 503. Of course, since flux cleaning is performed, when the molten solder is supplied to the soldered portion 503 of the printed wiring board 500, the vaporized gas of the flux is not generated from the carrier 600. The property is not hindered by the vaporized gas.

  Further, if a cleaning process (also called a carrier heating process) 202 is provided between the flux application process 401 and the preheating process 402 and between the preheating process 402 and the soldering process 403, the flux of the carrier 600 is further increased. It is completely removed, and generation of vaporized gas of flux generated from the carrier 600 in the soldering process 403 is more completely prevented. Furthermore, since the temperature of the carrier 600 conveyed to the soldering process 402 is also heated to the temperature of the second jet wave 119, that is, the temperature of the molten solder or the closest temperature, the soldered portion 503 of the printed wiring board 500 is heated. The temperature of the supplied molten solder does not decrease.

  On the other hand, when the soldering process from the flux application process 401 to the cooling process 404 is constructed, the flux application process 401 and the subsequent preheating process 402, the soldering process 403, and the cooling process 404 are separated and knitted. There is a case. This makes it easy to change or replace the configuration of each device such as the flux coating device 410, the preheating device 420, the solder supply device 110, the cooling device 440, etc., which constitutes each process, and the soldering process characteristics. This is because it is easy to change and adjust.

  As described above, in the knitting example in which the flux application process 401 is provided separately from other processes and the flux application apparatus 410 is provided independently, the flux application process 401 and the subsequent cleaning process 201 are combined into one. It is better to configure as a flux application system. That is, the flux application system 203 includes the flux application device 410 and the carrier cleaning device 210.

  As a result, the printed wiring board 500 and the carrier 600 that have been applied with the flux are immediately removed from the carrier 600, and the contamination of the carrier 600 due to the flux is removed before reaching the preheating step 402. This is because dirt is not brought into the step soldering system, and it is easy to maintain a clean process environment in the soldering system.

  In particular, when a water-soluble flux is used, it is desirable to use a flux coating system including a cleaning device 210 because the acidity of the flux is high. That is, the flux that causes corrosion in each device constituting the system can be removed early. Of course, the effect on the wettability of the solder is similarly retained.

  Further, in the conventional soldering system illustrated in FIG. 4, the cleaning device 100 including the first solder bath 101 illustrated in FIGS. 1A and 1B is provided between the preheating process 402 and the soldering process 403. After cleaning the carrier 600 in the cleaning process 202 by the cleaning apparatus 100, the molten solder may be supplied in the soldering process 403 including two jet waves.

  As described above, according to the present embodiment, the problem of the vaporized gas of the flux generated from the holder in the soldering process can be solved. Further, the temperature of the holder when the holder comes into contact with the jet wave, that is, the molten solder in the soldering step can be heated to a temperature close to the temperature of the molten solder.

  Therefore, the vaporized gas of the flux is generated unnecessarily in large quantities and does not hinder the solder wettability in the soldered part of the printed wiring board, and the temperature of the molten solder supplied to the soldered part of the printed wiring board However, the temperature does not drop below the target temperature and the solder wettability at the soldered portion is not hindered. As a result, it is possible to perform soldering mounting of a printed wiring board with good soldering quality without any solder wettability.

[Second Embodiment]
In the first embodiment described above, soldering is performed using a cleaning device that cleans the carrier 600 by bringing a jet wave of molten solder into contact with the surface of the carrier 600 on which the flux is adhered (that is, the lower surface). Although the system has been described, a cleaning device that removes the flux by cleaning the lower surface of the carrier 600 with a cleaning liquid may be used. The embodiment will be described below with reference to FIG.

  FIG. 3 is a diagram illustrating the configuration of the cleaning device in the soldering system according to the second embodiment of the present invention. FIG. 3A is a diagram showing an outline of the configuration as viewed from the side with respect to the conveyance direction of the printed wiring board, and a control system and an air circuit such as piping are shown in a block diagram. Moreover, FIG.3 (b) is a perspective view explaining the whole content of the porous body of Fig.3 (a). Furthermore, FIG.3 (c) is a figure which shows the longitudinal cross-section for demonstrating the internal structure of the porous body of Fig.3 (a).

  In FIG. 3, reference numeral 300 denotes a cleaning apparatus showing an example of this embodiment. This cleaning device 300 performs cleaning by contacting a rotating cylindrical porous body (sponge-like member or brush-like member) 301 impregnated with a cleaning liquid on the lower surface of the carrier 600 conveyed in the direction of arrow A. The cleaning liquid is supplied from the cleaning liquid intermittent supply device 308 via the pipe 309 to the tray 307, and the cleaning liquid is supplied from the tray 307 to the porous body 301.

  The porous body 301 is supported by a bearing (not shown) with an exhaust pipe 302 provided at the center axis thereof as a rotation axis so as to be rotatable, and drives the sprocket 305 provided on the exhaust pipe 302 and the conveyor 405. A sprocket (not shown) provided in the system is linked by a transmission chain 306 so as to rotate synchronously. In addition, you may comprise so that the porous body 301 may be rotationally driven with a dedicated motor.

  The exhaust pipe 302 is provided with a large number of holes 303, and the exhaust pump 315 supplies the porous body 301 from the cleaning liquid intermittent supply device 308 by exhausting the gas in the storage tank 310 through the pipe 316. The impregnated cleaning solution is sucked out, the flux is removed from the carrier 600, and the cleaning solution containing the flux is stored in the storage tank 310. The drain valve 311 is a means for discharging the dirty cleaning liquid (recovered liquid 313). On the other hand, the exhaust pipe 302 of the porous body 301 and the pipe 312 of the storage tank 310 are coupled to each other by a plug-in type universal joint 304 as illustrated in FIG.

  As the cleaning liquid, a solvent similar to the solvent of the flux or an alcohol-based one may be used, but other cleaning liquid may be used as long as it is excellent in removing the flux and does not affect the soldering.

  Further, instead of the cylindrical porous body 301, a blade body may be constituted by a porous member or a brush-like member, and the blade of this blade body may be configured to contact only the lower surface of the carrier. Good. If it is immediately after the flux application process 401, it is also effective to suck it with a vacuum cleaner. In addition, although the price of the apparatus is expensive, a structure may be provided in which a plasma cleaning apparatus is provided and cleaning is performed by irradiating only the carrier with plasma.

  By using the cleaning apparatus 300 as described above for the cleaning process 201 and / or 202 in FIG. 2, the problem of the vaporized gas of the flux generated from the holder (carrier) in the soldering process can be solved. become able to.

  Therefore, the vaporized gas of the flux is generated unnecessarily in large quantities and does not hinder the solder wettability in the soldered part of the printed wiring board. As a result, the soldering quality is good without any solder wettability. The printed wiring board can be soldered and mounted.

  It should be noted that the configuration and the contents shown in FIGS. 1 to 3 are not limited to this, and it is needless to say that the configurations and contents are configured according to applications and purposes.

  Although one embodiment has been described above, the present invention can take an embodiment as, for example, a system, apparatus, method, program, or storage medium, and specifically includes a plurality of devices. The present invention may be applied to a system including a single device.

  Furthermore, a configuration combining the above-described embodiments is also included in the present invention.

  For example, a cleaning apparatus that cleans the carrier 600 with a cleaning liquid like the cleaning apparatus 300 shown in the second embodiment is used in the cleaning process 201, and the cleaning apparatus shown in the first embodiment is used in the cleaning process (also serving as a carrier heating process) 202. A cleaning device that cleans the carrier 600 by a jet wave of molten solder, such as the (cum-carrier heating device) 100, or the cleaning device (cum-carrier heating device) and the solder supply device 120, may be used.

  As described above, the soldering system of the present invention is characterized in that a carrier cleaning step is provided between the flux application step and the soldering step. Another feature is that a heating process for only the carrier is provided immediately before the soldering process. Between the flux application process and the soldering process, the printed wiring board is held by the carrier. In this state, that is, the printed wiring board is held by the carrier, the carrier is washed and the carrier is targeted. It is the structure which heats.

  In the present invention, cleaning and heating for the carrier, that is, the holding tool for holding the printed wiring board, is performed in a state in which the holding tool holds the printed wiring board, and the cleaning process (also heating process) of the holding tool is performed. It is configured to be provided immediately before the soldering process and between the preheating process and the soldering process. Moreover, you may provide a washing | cleaning process between a flux application | coating process and a preheating process, and may provide in two places between a preheating process and a soldering process in addition.

  In addition, when the flux application process and the preheating process are provided apart from each other, a process of providing a holder cleaning process after the flux application process and combining the flux application process and the cleaning process into one unit It may be formed.

  The cleaning of the holder performed in a state where the printed wiring board is held is performed by using the jet wave of the molten solder only on the surface where the flux is attached to the holder, that is, the lower surface. You may make it contact only the surface below this. Alternatively, the cleaning liquid may be brought into contact with only the lower surface of the holder for cleaning, or a rotating roller body or blade body impregnated with the cleaning liquid may be contacted. Thus, the flux can be vaporized in advance and removed, that is, washed. In addition, when the molten solder jet wave is used for cleaning the holder, heating can be selectively performed only on the holder.

  By configuring as described above, only the flux applied to the holder out of the fluxes applied to the printed wiring board and the holder is cleaned and removed, and this printed wiring board and the holder are in the soldering process. When the molten solder is supplied to the part to be soldered in contact with the jet wave, that is, the molten solder, the problem of the vaporization gas of the flux generated from the holder is solved. It is possible to prevent the occurrence of a situation in which the wettability of the solder is hindered in the part to be soldered.

  In addition, cleaning of the flux applied to the holder is performed by using a jet wave of molten solder for cleaning the holder and bringing the jet wave into contact with only the lower surface of the holder. By heating only this holder, it becomes possible to heat it to a temperature close to the temperature of the molten solder, greatly exceeding the range of the heating temperature performed in the preheating process, and the temperature of the holder can be set in the subsequent soldering process. The temperature can be immediately raised to the temperature of the molten solder. This prevents the occurrence of a situation in which a holder having a larger heat capacity than the conventional printed wiring board reduces the temperature of the molten solder and hinders solder wettability at the soldered portion of the printed wiring board. be able to.

  In addition, when using molten solder jet waves for cleaning and heating the holder, the temperature of the molten solder is controlled so that the degree of cleaning of the holder (the degree of vaporization of the flux) and the holding are maintained. The heating temperature of the tool can be controlled. Then, the temperature of the holder when the printed wiring board and the holder are conveyed to the soldering process and start to contact with the molten solder can be set to the same temperature as the temperature of the supplied molten solder. Accordingly, it is possible to eliminate the decrease in solderability caused by the temperature drift of the molten solder supplied to the printed wiring board.

  Therefore, the problem of the vaporized gas of the flux generated from the carrier in the soldering process is solved (the generation of the vaporized gas of the flux is prevented), and the carrier is in contact with the jet wave, that is, the molten solder in the soldering process. In addition, by configuring the carrier temperature to be preheated to a temperature close to the temperature of the molten solder, it is possible to solder and mount a printed wiring board with good soldering quality without any solder wetting failure. There are effects such as.

  The soldering method, the soldering system, and the flux application system according to the present invention are applicable to all cases where the printed wiring board is held by a carrier and soldered, and various types of printed wiring boards are continuously soldered. Also when attaching, it becomes possible to perform soldering mounting with high soldering quality, and thereby the reliability of the electronic device produced can be greatly improved.

It is a system configuration figure showing a washing process (also serving as a carrier heating process) and a soldering process in the soldering system showing the first embodiment of the present invention. It is a system configuration figure showing a washing process (also serving as a carrier heating process) and a soldering process in the soldering system showing the first embodiment of the present invention. It is a system configuration figure showing a washing process (also serving as a carrier heating process) and a soldering process in the soldering system showing the first embodiment of the present invention. It is a system block diagram explaining the organization example of all the processes from the flux application | coating process to the cooling process in the soldering system of this invention. It is a figure explaining the structure of the washing | cleaning apparatus in the soldering system which shows 2nd Embodiment of this invention. It is a figure explaining the general structural example of the soldering system for supplying molten solder to the to-be-soldered part of the printed wiring board with which the electronic component is mounted, and performing soldering. FIG. 5 is a perspective view for explaining the entire contents of the carrier 600 shown in FIG. 4 and the usage state thereof. It is a figure explaining the mode of the printed wiring board 500 hold | maintained at the carrier 600 shown in FIG.

Explanation of symbols

401 Flux application process 201 Cleaning process 402 Preheating process 202 Cleaning process (also serving as a carrier heating process)
403 Soldering process 404 Cooling process 210 Cleaning device 220 Cleaning device (also carrier heating device) and solder supply device

Claims (16)

Hold the plate-shaped workpiece to be soldered with a holder and transport the holder with a conveying means to bring at least the soldered portion of the plate-shaped workpiece to be soldered into contact with the molten solder for soldering. When performing, first, the plate-shaped workpiece to be soldered is cleaned with the holder and then only the holder is cleaned, and then at least the soldered portion of the plate-shaped workpiece to be soldered is molten solder. Soldering in contact,
Soldering method characterized by A plate-shaped workpiece to be soldered is held by a holder, the holder is conveyed by a conveying means, and the plate-shaped workpiece to be soldered is preheated by a heating means, and at least its soldered portion When the solder is brought into contact with the molten solder, the plate-shaped workpiece to be soldered is pre-heated, and then the plate-shaped workpiece to be soldered is held by the holder and only the holder is held. Cleaning, and then performing soldering by contacting at least a soldered portion of the plate-like workpiece to be soldered with molten solder,
Soldering method characterized by A plate-shaped workpiece to be soldered is held by a holder, the holder is conveyed by a conveying means, and the plate-shaped workpiece to be soldered is preheated by a heating means, and at least its soldered portion When the solder is brought into contact with the molten solder, the plate-shaped workpiece to be soldered is first cleaned in a state where the workpiece is held by the holder, and then the plate-shaped workpiece to be soldered is then washed. Preheating, and then performing soldering by contacting at least a soldered portion of the plate-like workpiece to be soldered with molten solder,
Soldering method characterized by A plate-shaped workpiece to be soldered is held by a holder, the holder is conveyed by a conveying means, and the plate-shaped workpiece to be soldered is preheated by a heating means, and at least its soldered portion When the solder is brought into contact with the molten solder, the plate-shaped workpiece to be soldered is first cleaned in a state where the workpiece is held by the holder, and then the plate-shaped workpiece to be soldered is then washed. In the state where the plate-like workpiece to be soldered is further held by the holder, and then only the holder is cleaned, and then at least the soldered portion of the plate-like workpiece to be soldered Soldering by bringing it into contact with the molten solder,
Soldering method characterized by The soldering method according to any one of claims 1 to 4, wherein when a flux is applied to a plate-shaped workpiece to be soldered held by a holder, Having a step of cleaning only the holder in a state where the plate-like workpiece to be soldered is held by the holder in the subsequent stage;
Soldering method characterized by The soldering method according to any one of claims 1 to 5, wherein the solder is brought into contact only with the holder in a state where the plate-like workpiece to be soldered is held by the holder. Only soldering after cleaning and heating,
Soldering method characterized by The soldering method according to claim 6, wherein the soldering is performed by independently controlling the temperature of the molten solder used for cleaning the holder and the temperature of the molten solder used for soldering.
Soldering method characterized by Hold the plate-shaped workpiece to be soldered with a holder, transport this holder with the conveying means, and supply molten solder to the at least the soldered portion of the plate-shaped workpiece to be soldered with the molten solder supplying means. A soldering system for performing soldering,
Provided with a cleaning means for cleaning only the holding tool in a state where the plate-like workpiece to be soldered is held by a holding tool before the molten solder supply means;
Features a soldering system. A plate-shaped workpiece to be soldered is held by a holder, the holder is conveyed by a conveying means, and the plate-shaped workpiece to be soldered is preheated by a heating means, and at least its soldered portion A soldering system for performing soldering by supplying molten solder by means of molten solder supply means,
A cleaning means for cleaning only the holding tool in a state where the plate-like workpiece to be soldered is held by a holding tool at the subsequent stage of the heating means, and the molten solder supply means is provided at a subsequent stage of the cleaning means;
Features a soldering system. A plate-shaped workpiece to be soldered is held by a holder, the holder is conveyed by a conveying means, and the plate-shaped workpiece to be soldered is preheated by a heating means, and at least its soldered portion A soldering system for performing soldering by supplying molten solder by means of molten solder supply means,
Provided with a cleaning means for cleaning only the holder in a state where the plate-like soldered workpiece is held by a holder before the heating means, and provided with the molten solder supply means after the heating means,
Features a soldering system. A plate-shaped workpiece to be soldered is held by a holder, the holder is conveyed by a conveying means, and the plate-shaped workpiece to be soldered is preheated by a heating means, and at least its soldered portion A soldering system for performing soldering by supplying molten solder by means of molten solder supply means,
A cleaning means for cleaning only the holder in a state where the plate-like soldered workpiece is held by a holder before the heating means is provided, and the plate-like soldered workpiece is also provided after the heating means. Provided with a cleaning means for cleaning only the holding tool in a state of being held by the holding tool, and provided with the molten solder supply means at a subsequent stage of the subsequent cleaning means,
Features a soldering system. The soldering system according to any one of claims 8 to 11,
In the case where flux application means is provided with a step of applying flux to the plate-like workpiece to be soldered held by the holder, the plate-like workpiece to be soldered is provided at the subsequent stage of the flux application means. Provided with a cleaning means for cleaning only the holder in a state of being held by the holder;
Features a soldering system. The soldering system according to any one of claims 8 to 12,
The cleaning means is a means for cleaning and heating the holder by bringing the molten solder into contact only with the holder in a state where the plate-like workpiece to be soldered is held by the holder.
Features a soldering system. The soldering system of claim 13.
A solder bath for molten solder used for cleaning the holder and a solder bath for molten solder used for soldering are provided independently, and the temperature of the molten solder in each solder bath is controlled independently. Providing a control means;
Features a soldering system. This flux application means is provided when a flux application system is provided in which a flux application means is provided in a case different from the case of the soldering system and the flux is applied to a plate-like workpiece to be soldered held by a holder. In the subsequent stage, provided with a cleaning means for cleaning only the holder in a state where the plate-like workpiece to be soldered is held by the holder,
Flux application system characterized by 16. The flux application system according to claim 15, wherein the cleaning means contacts the molten solder only with the holder while the plate-like workpiece to be soldered is held by the holder and cleans and heats the holder. Being
Flux application system characterized by

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