JP4473566B2 - Jet soldering equipment - Google Patents

Description

  The present invention relates to a jet soldering apparatus having a plurality of nozzles.

A solder tank main body that accommodates molten solder is disposed below the work transfer line, and a primary nozzle and a secondary nozzle that jet molten solder at intervals in the work transfer direction are disposed inside the solder tank main body. There is a jet soldering device in place.
Japanese Examined Patent Publication No. 60-57946 (page 2-3, Fig. 4)

  Since this conventional jet soldering apparatus has a space between the primary nozzle and the secondary nozzle, when soldering a component mounting board as a workpiece, the board as shown by a thin line in FIG. Even if the lower surface temperature is increased to the allowable heat-resistant temperature (for example, about 250 ° C.) of the component mounted on the board, the lower surface temperature of the substrate decreases in the space, so that the upper surface temperature of the substrate is 200 as shown in FIG. It only rises to about ℃.

  For this reason, when using lead-free solder with a high solder melting point (about 217 to 227 ° C) and poor solder wettability, the upper surface of the board is included for the lead-free solder, although it is more environmentally friendly than conventional tin-lead solder. It is difficult to obtain a temperature profile in which the temperature of the entire substrate reaches a temperature at which the solder fluidity and wettability can be ensured. For example, problems such as insufficient solder rising in the through holes of the substrate have occurred.

  The present invention has been made in view of the above points, and solves the problems of the current soldering technology, which has a high solder melting point and does not increase the heat resistance of the component temperature, to lead-free solder having a high melting point in the entire workpiece. It is an object of the present invention to provide a jet soldering apparatus capable of obtaining a compatible temperature profile.

The invention according to claim 1 is a solder bath main body arranged below the work transfer line and containing molten solder, and a plurality of jets of molten solder arranged in the solder bath main body at intervals in the work transfer direction. Nozzles, an inter-nozzle plate that is provided between the plurality of nozzles and forms a molten solder pool between a plurality of jet waves jetted from the nozzles, and a flow-regulating flow that opens in the inter-nozzle plate A jet-type soldering device equipped with a port, and by providing an inter-nozzle plate between a plurality of nozzles and forming a molten solder pool between a plurality of jet waves, a long work immersion time over a plurality of nozzles. Large jet waves that can be secured are continuously formed. As a result, a temperature profile is obtained in which the temperature of the entire workpiece including not only the workpiece lower surface but also the workpiece upper surface reaches a sufficient temperature that can ensure solder fluidity and wettability. Therefore, even when lead-free solder having a high melting point and poor wettability is used, the solder rise in the through-hole of the work is kept good. Further, by opening a flow-regulating flow-down port in the inter-nozzle plate, the molten solder liquid pressure is lowered in the middle of a long dip distance, and a gas venting effect is obtained in which gas generated from the work is discharged from the lower surface of the work. In particular, in solder with poor solder wettability such as lead-free solder, a flux containing a large amount of solid content (resin component) that is easily gasified is used to ensure solder wettability, so this degassing effect is remarkable. Appear.

  The invention according to claim 2 is the jet soldering apparatus according to claim 1, comprising a plurality of pumps with adjustable flow rate and adjustable pressure respectively connected to the plurality of nozzles, and a workpiece conveying direction. A pump is connected to each of a plurality of nozzles arranged in the nozzle and the flow rate of each of these pumps is adjusted individually to adjust the wave height and immersion depth of the upstream and downstream workpiece transfer waves, and the jet flow The relative flow rate balance between the upstream and downstream sides of the workpiece conveyance is adjusted so that the oxide on the wave surface moves in the workpiece traveling direction to prevent poor adhesion of oxide to the workpiece. Adjust the flow rate to obtain the required solder pressure into the through hole. In addition, by adjusting the jet flow pressure from the nozzles on the upstream and downstream sides of the workpiece transfer, the angle of the workpiece transfer line is changed from the general upward inclined transfer to the horizontal transfer to reduce or eliminate the height difference before and after the soldering device. , To simplify the mechanism.

A third aspect of the invention is the jet soldering apparatus according to the first or second aspect, further comprising a discharge flow rate adjusting valve member capable of adjusting an opening degree of the flow-down port opened in the inter-nozzle plate. Yes, the discharge flow rate adjustment valve member adjusts the discharge flow rate of the molten solder discharged from the flow-down port opened in the inter-nozzle plate.

  According to a fourth aspect of the present invention, there is provided the jet-type soldering apparatus according to any one of the first to third aspects, wherein the jet flow is provided at a variable angle on the outlet side of the nozzle located on the downstream side of the workpiece conveyance and variably adjusts the jet waveform. The corrugated former and a weir plate provided at the tip of the jet corrugated former so that the vertical movement can be adjusted. The angle of the jet corrugated former is adjusted at the outlet side of the nozzle on the downstream side of the work transfer and the weir. By adjusting the vertical movement of the plate, the position and angle at which the workpiece is released from the jet solder surface can be adjusted to provide an appropriate workpiece removal environment, such as tsura and bridge that are likely to occur on the electrodes and leads of high heat capacity parts. Reduces soldering defects. In particular, lead-free solder, which has a high solder melting point and is easy to solidify at the working temperature, is prone to soldering defects such as wigs and bridges, but the workpiece is detached horizontally from the jet solder at the end of the jet waveform former. As described above, by adjusting the exit portion separation position and angle at which the workpiece is detached from the jet solder with the jet waveform former and the dam plate, the detaching direction of the glazing becomes the horizontal direction instead of the vertical direction, and no wiggling occurs. In addition, the angle adjustment of the jet waveform former on the outlet side also has the function of adjusting the work immersion time, and the weir plate that can adjust the vertical movement adjusts the flow rate of the molten solder to the solder surface in the solder bath body to oxidize Reduce the generation of things.

  According to a fifth aspect of the present invention, there is provided the jet soldering apparatus according to any one of the first to fourth aspects, wherein the plurality of molten solder ejection through holes are smaller than the upper openings provided in the upper openings of the plurality of nozzles, respectively. By providing a plurality of molten solder ejection holes smaller than these upper openings in the upper openings of a plurality of nozzles, respectively, the molten solder ejection flow rate is reduced in order to suppress the generation of oxides and to save energy. Even if this is reduced, the jet wave height necessary for soldering the workpiece is ensured, so that the non-wetting failure of the chip parts is eliminated and sufficient solder pressing pressure into the through hole of the workpiece is generated.

  According to a sixth aspect of the present invention, in the jet soldering apparatus according to the fifth aspect, the molten solder ejection through-hole provided on the nozzle on the downstream side of the workpiece conveyance is elongated and slit-shaped in a direction intersecting the workpiece conveyance direction. The wall of the jet wave ejected from the slit-shaped molten solder ejection through-hole is scraped like a squeegee so that the detaching direction of the tsura is not the vertical direction but the horizontal direction. Prevents the occurrence of wiggle.

According to the first aspect of the present invention, by providing the inter-nozzle plate between the plurality of nozzles and forming the molten solder pool between the plurality of jet waves, it is possible to ensure a long work immersion time over the plurality of nozzles. Since a jet wave can be continuously formed, a temperature profile is obtained in which the temperature of the entire workpiece including not only the lower surface of the workpiece but also the upper surface of the workpiece reaches a temperature sufficient to ensure solder fluidity and wettability. Even when lead-free solder having a high melting point and poor wettability is used, it is possible to maintain good solder rise in the through-hole of the workpiece. In addition, by opening a flow-regulating flow-down port in the inter-nozzle plate, the molten solder fluid pressure is lowered in the middle of a long dip distance, and a gas venting effect is obtained that discharges the gas generated from the work from the lower surface of the work Can do. In particular, in solder with poor solder wettability such as lead-free solder, a flux containing a large amount of solid content (resin component) that is easily gasified is used to ensure solder wettability, so this degassing effect is remarkable. Appear.

  According to invention of Claim 2, a pump is connected to the some nozzle arrange | positioned at the workpiece conveyance direction, respectively, and the flow volume of each of these pumps is adjusted separately, The workpiece conveyance upstream and downstream jets The wave height and immersion depth can be adjusted, and for example, the relative flow rate balance between the upstream side and the downstream side of the workpiece can be adjusted so that the oxide on the surface of the jet wave moves in the workpiece traveling direction. It is possible to prevent the oxide from adhering poorly, and to adjust the flow rate so as to obtain the necessary solder pressing pressure into the through hole in each nozzle. Furthermore, by adjusting the jet pressure from the nozzles on the upstream side and downstream side of the workpiece transfer, the angle of the workpiece transfer line can be changed from a general ascending and inclined transfer to a horizontal transfer. The mechanism can be simplified by reducing or eliminating it.

According to invention of Claim 3, the discharge flow rate of the molten solder discharged | emitted from the flow-down port opened to the plate between nozzles can be adjusted with the discharge flow rate adjustment valve member.

  According to the fourth aspect of the invention, the angle of the jet waveform former is adjusted at the outlet side of the nozzle on the downstream side of the workpiece conveyance, and the position at which the workpiece is detached from the jet solder surface by adjusting the vertical movement of the weir plate and By adjusting the angle, it is possible to obtain an appropriate work separation environment, and it is possible to reduce soldering defects such as icicles and bridges that are likely to occur on the electrodes and leads of high heat capacity components. In particular, lead-free solder, which has a high solder melting point and is easy to solidify at the working temperature, is prone to soldering defects such as wigs and bridges, but the workpiece is detached horizontally from the jet solder at the end of the jet waveform former. In this way, by adjusting the exit portion separation position and angle at which the workpiece is detached from the jet solder with the jet waveform former and the weir plate, the direction in which the workpiece is pulled away is set to the horizontal direction instead of the vertical direction, and the slurry can be eliminated. In addition, the angle adjustment of the jet waveform former on the outlet side also has the function of adjusting the work immersion time, and the weir plate that can adjust the vertical movement adjusts the flow rate of the molten solder to the solder surface in the solder bath body to oxidize Generation of objects can be reduced.

  According to the fifth aspect of the present invention, by providing a plurality of molten solder ejection through holes smaller than the upper openings in the upper openings of the plurality of nozzles, it is possible to suppress the generation of oxides and to perform the energy saving operation. Even when the solder ejection flow rate is reduced, the wave height necessary for soldering the workpiece can be ensured, so that non-wetting of the chip parts can be prevented and sufficient solder pressing pressure into the through hole of the workpiece can be secured.

  According to the sixth aspect of the present invention, the slit-shaped molten solder jet is formed by providing a slit-shaped molten solder jet through-hole formed elongated in a direction intersecting the workpiece transfer direction on the nozzle on the downstream side of the workpiece transfer. The wall of the jet wave ejected from the through-hole performs a scraping action like a squeegee, and the detaching direction of the glaring is changed to the horizontal direction instead of the vertical direction.

  Hereinafter, the present invention will be described in detail with reference to one embodiment shown in FIGS.

  As shown in FIG. 1, a solder bath main body 12 that accommodates the molten solder S is disposed below the work transport line 11 that transports the work W, that is, the component mounting board. A first nozzle 13 and a second nozzle 14 for jetting the solder S are arranged at an interval in the workpiece transfer direction.

  The upper openings of the first nozzle 13 and the second nozzle 14 are provided with a plurality of molten solder ejection through holes 15 and 16 smaller than these upper openings, respectively.

  As shown in FIG. 2, the molten solder ejection through hole 15 provided on the first nozzle 13 on the upstream side of the workpiece conveyance is a large number of small holes arranged in a staggered pattern in a direction crossing the workpiece conveyance direction. is there. The molten solder ejection through holes 16 provided on the second nozzle 14 on the downstream side of the workpiece conveyance are a large number of elongated holes that are elongated and formed in a slit shape in a direction intersecting the workpiece conveyance direction.

  Between the first nozzle 13 and the second nozzle 14, there is provided an inter-nozzle plate 17 for forming a molten solder pool Sp between a plurality of jet waves S1, S2 jetted from the nozzles 13, 14. ing.

  Connected to the first nozzle 13 and the second nozzle 14 are a first pump 18 and a second pump 19 that can adjust the flow rate and the pressure, respectively. As these pumps 18 and 19, an electromagnetic induction pump, an impeller pump or the like is used.

  At the center of the inter-nozzle plate 17, as shown in FIG. 2, a flow-regulating flow-down port 21 that is elongated in the direction perpendicular to the workpiece transfer direction is opened.

  A discharge flow rate adjusting valve member 22 having an inverted V-shaped cross section is vertically moved by a screw 24 or the like that is screwed to both ends of a support member 23 that supports the discharge flow rate adjustment valve member 22. The discharge port adjustment valve member 22 is vertically adjustable so that the opening degree of the flow-down port 21 can be adjusted.

  A jet waveform former 25 that variably adjusts the jet waveform is provided on the outlet side of the second nozzle 14 located on the downstream side of the work conveyance, and the angle of the jet waveform former 25 is variable around the hinge 26. Is bent downward, and a dam plate 28 is provided at its tip 27 so as to be adjustable in the vertical direction.

  The angle of the jet waveform former 25 can be adjusted by a structure in which a screw (not shown) screwed into the jet waveform former 25 is engaged with the second nozzle 14 and the vertical movement of the weir plate 28 is adjusted. This can be achieved by a structure in which the dam plate 28 is fixed to the distal end portion 27 of the jet corrugated former 25 with a set screw inserted through a long hole provided in the vertical direction of the dam plate 28.

  As shown in FIG. 3, in the workpiece W, the lead c of the component b mounted on the substrate a is inserted into the through hole d of the substrate a. As the component b, there is also a chip component bonded to the lower surface of the substrate a as shown in FIG.

  Next, the operation of this embodiment will be described.

  When the work W pre-heated with the flux applied in the previous stage is loaded onto the jet wave S1 ejected from the molten solder ejection through hole 15 of the first nozzle 13, the melt ejected from the molten solder ejection through hole 15 is carried out. The solder solders the land portion on the lower surface of the substrate a and the electrode or lead c of the component b, and the through hole d is raised by the solder pressing pressure from the pump 18 and supplied to the land portion on the upper surface of the substrate a. Is done.

  At this time, even if the workpiece W is a high-density mounting substrate, the turbulent molten solder ejected from the large number of small-hole molten solder ejection through holes 15 causes the flux gas generated on the lower surface of the substrate a to flow between the components. It is supplied to every corner between the parts so as to be expelled from the gap.

  The workpiece W soldered with the jet wave S1 is in contact with the molten solder pool Sp on the inter-nozzle plate 17 while the lower surface of the substrate a is in contact with the molten solder pool Sp. It is conveyed onto the nozzle 14. At this time, the flux gas on the lower surface of the substrate a transported horizontally is degassed downward together with the molten solder flowing down from the flow-down port 21 and exhausted to the outside.

  When the workpiece W is loaded onto the second nozzle 14, the solder indentation pressure of the jet wave S <b> 2 of the elongated elongated protrusion ejected from the elongated hole-shaped molten solder ejection through hole 16 is applied to the lower surface of the substrate a. Works. The position and angle at which the electrode and lead c of the mounting part b of the workpiece W are separated from the outlet side of the jet wave S2 are centered on the hinge 26 of the jet waveform former 25 as shown in FIGS. 3 (a) and 3 (b). The angle is adjusted by adjusting the vertical movement of the dam plate 28 relative to the jet waveform former 25.

  Next, the effect of this embodiment will be described.

  An inter-nozzle plate 17 is provided between the first nozzle 13 and the second nozzle 14, and a molten solder pool Sp is formed between the plurality of jet waves S 1, S 2. A large jet wave capable of ensuring a long workpiece immersion time over the two nozzles 14 can be continuously formed. As a result, as shown in FIG. 4, the temperature of the entire workpiece including the upper surface as well as the lower surface of the substrate a can be reduced. Therefore, even when lead-free solder with a high melting point and poor wettability is used, solder rise in the through-hole of the work W can be achieved. Can keep good.

  Pumps 18 and 19 are connected to the first nozzle 13 and the second nozzle 14 arranged in the workpiece conveyance direction, respectively, and the flow rate of each of these pumps 18 and 19 is adjusted individually, so that the workpiece conveyance upstream side and The wave height and immersion depth of the jet waves S1 and S2 on the downstream side can be adjusted. For example, the relative flow balance between the upstream side and the downstream side of the workpiece transfer so that the oxide on the jet wave surface moves in the workpiece traveling direction. Thus, it is possible to prevent the oxide from adhering to the work W and to adjust the flow rate so as to obtain the solder pressing pressure into the through hole d necessary for the nozzles 13 and 14. Furthermore, by adjusting the jet pressure from the nozzles 13 and 14 on the upstream side and downstream side of the workpiece transfer, the angle of the workpiece transfer line 11 can be changed from a general upward inclined transfer (about 5 °) to a horizontal transfer. The height difference between before and after the soldering apparatus can be reduced or eliminated to simplify the mechanism.

  Degassing effect that lowers the molten solder fluid pressure in the middle of a long dip distance and discharges the flux gas generated from the workpiece W from the lower surface of the workpiece W by opening the flow adjustment port 21 on the nozzle plate 17 Can be obtained. Especially for solders with poor solder wettability, such as lead-free solder, the solid content (resin component), which is easy to gasify, is larger than conventional products (10% or less) (12-15%) to ensure solder wettability. Since the flux contained in is applied to the lower surface of the component mounting board a, this degassing effect appears remarkably.

  By adjusting the angle of the jet waveform former 25 and adjusting the vertical movement of the weir plate 28 on the outlet side of the nozzle 14 on the downstream side of the work conveyance, the jet solder surface as shown in FIGS. 3 (a) and 3 (b). The position and angle at which the electrode and lead c of the mounting component b of the workpiece W are detached from the workpiece W can be adjusted to obtain an appropriate workpiece separation environment. Soldering defects can be reduced.

  In particular, lead-free solder, which has a high solder melting point and tends to solidify at the working temperature (about 250 to 260 ° C.), is liable to cause soldering defects such as icicles and bridges. As shown in FIG. By adjusting the exit position and angle at which the work W is detached from the jet solder at the end of the jet waveform former 25 by the jet waveform former 25 and the weir plate 28 so that the work W is detached from the jet solder in the horizontal direction. The direction of pulling apart the tiles is not the vertical direction as shown in FIG. 3A, but the horizontal direction as shown in FIG.

  In addition, the angle adjustment of the jet waveform former 25 on the outlet side also has the function of adjusting the work immersion time, and the dam plate 28 that can adjust the vertical movement adjusts the flow rate of the molten solder to the solder surface in the solder bath body 12 Thus, generation of oxide can be reduced. When the jet waveform former 25 is set at a high position, the separation position of the workpiece W can be adjusted by the weir plate 28.

  To suppress the generation of oxides and to save energy by providing a plurality of molten solder injection through holes 15 and 16 in the upper openings of the first nozzle 13 and the second nozzle 14 respectively. Even when the molten solder ejection flow rate is reduced, the wave heights of the jet waves S1 and S2 necessary for soldering the workpiece W can be secured, so that non-wetting defects such as chip parts can be prevented and the through hole d of the workpiece W can be prevented. A sufficient solder pressing pressure can be secured.

  By providing a slit-shaped molten solder ejection through hole 16 that is elongated in the direction intersecting the workpiece conveyance direction on the nozzle 14 on the downstream side of the workpiece conveyance, jet waves ejected from the slit-shaped molten solder ejection through hole 16 The wall of S2 scrapes like a squeegee and makes the detaching direction the horizontal direction instead of the vertical direction.

It is sectional drawing which shows one Embodiment of the jet type soldering apparatus which concerns on this invention. It is a top view which shows a part of plate between nozzles of a soldering apparatus same as the above. The operation of the jet waveform former of the soldering apparatus is shown in FIG. 2A. FIG. 4A is a cross-sectional view of the workpiece separation part in the jet waveform former lowered state, and FIG. . It is a graph which shows the temperature profile of the workpiece | work soldered by the soldering apparatus same as the above. It is a graph which shows the temperature profile of the workpiece | work soldered with the conventional jet-type soldering apparatus.

Explanation of symbols

11 Work transfer line
12 Solder bath body
13, 14 nozzles
15, 16 Molten solder ejection through hole
17 Nozzle plate
18, 19 pump
21 Downstream port
25 Jet waveform former
28 Weir plate S Molten solder
S1, S2 jet wave
Sp Molten solder pool

Claims (6)

A solder bath body which is disposed under the work transfer line and accommodates molten solder;
A plurality of nozzles arranged at intervals in the workpiece conveyance direction inside the solder bath body and jetting molten solder;
An inter-nozzle plate that forms a molten solder pool between a plurality of jet waves provided between the plurality of nozzles and jetted from each nozzle ;
A jet-type soldering apparatus comprising: a flow-regulating flow-down port opened in the inter-nozzle plate . The jet-type soldering apparatus according to claim 1, further comprising a plurality of pumps capable of adjusting a flow rate and capable of adjusting a pressure respectively connected to the plurality of nozzles. 3. The jet soldering apparatus according to claim 1, further comprising a discharge flow rate adjusting valve member capable of adjusting an opening degree of the flow-down port opened in the inter-nozzle plate . A jet waveform former that variably adjusts the jet waveform provided on the outlet side of the nozzle located on the downstream side of the workpiece conveyance;
The jet soldering apparatus according to any one of claims 1 to 3, further comprising a weir plate provided at a front end portion of the jet waveform former so as to be adjustable in vertical motion. 5. The jet soldering apparatus according to claim 1, further comprising a plurality of molten solder ejection through holes that are smaller than the upper openings provided in the upper openings of the plurality of nozzles, respectively. The jet soldering apparatus according to claim 5, wherein the molten solder ejection through hole provided on the nozzle on the downstream side of the workpiece conveyance is formed in a slit shape in a direction intersecting with the workpiece conveyance direction.

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