JP6792858B2 - Soldering equipment - Google Patents

Description

The present invention relates to a solder processing apparatus that heats and melts solder pieces.

In recent years, various devices have been equipped with electronic circuits in which electronic components are mounted. In the process of forming an electronic circuit, soldering using a soldering iron is performed for a process of joining lead wires to a wiring pattern (land) on a substrate. Further, in order to mechanically realize the soldering process, a soldering apparatus provided with a trowel tip is used.

In such a solder processing apparatus, for example, a solder piece (a piece obtained by cutting a thread solder) is supplied into a heated trowel tip, and the solder piece is heated and melted by using the heat of the trowel tip, thereby melting downward. It is configured to supply solder. As a result, it is possible to realize a soldering process for the substrate arranged below.

International Publication No. 2008/23461 Japanese Unexamined Patent Publication No. 09-108826 Japanese Unexamined Patent Publication No. 2011-056581 JP-A-2009-195938

When the solder piece is heated and melted by using the heat of the trowel tip as described above, it is important to surely bring the solder piece into contact with the inner wall of the trowel tip in order to surely transfer the heat of the trowel tip to the solder piece. However, for example, if the solder piece supplied from above into the trowel tip stands straight on the substrate or terminal arranged below, the solder piece may not come into contact with the inner wall of the trowel tip at all. In such a case, heat transfer from the tip of the trowel to the solder piece may be hindered, and the solder piece may not be melted properly.

Further, even when the solder piece comes into contact with the inner wall of the trowel tip and melts, the molten solder may spheroidize due to surface tension and may not flow out from the trowel tip.

In view of the above-mentioned problems, the present invention makes it possible to more reliably heat and melt the solder pieces by using the heat of the trowel tip, and to ensure that the molten solder flows out from the trowel tip. The purpose is to provide the device.

The solder processing apparatus according to the present invention has a substantially tubular trowel tip that can be heated and extends vertically, a solder piece supply unit that supplies a solder piece from above into the trowel tip, and a pressurized gas at the trowel tip. A solder processing device having a gas supply unit for supplying gas to the inside, melting the solder piece by using the heat of the trowel tip, and supplying the melted solder downward, and the inside of the trowel tip has a gas supply unit. A receiving portion for receiving the supplied solder piece is provided, and the solder piece is forcibly brought into contact with the inner wall of the trowel tip on the receiving portion to melt and pressurize from the gas supply portion. The structure is such that gas is supplied into the tip and the molten solder is extruded from the tip. According to this configuration, the solder pieces can be more reliably heated and melted by using the heat of the trowel tip, and the molten solder can be surely flowed out from the trowel tip.

More specifically, the control means includes a control means for controlling the pressure of the gas supplied from the gas supply unit, and the control means applies the molten solder after the molten solder moves from the receiving portion. The pressure of the pressure gas may be lower than the pressure immediately before the movement of the molten solder.

More specifically, as the above configuration, the detection means for detecting the movement of the molten solder from the receiving portion is further provided, and the movement of the molten solder from the receiving portion is detected by the detecting means. Then, the control means may be configured to make the pressure of the pressurized gas lower than the pressure immediately before the movement of the molten solder .

Further, more specifically, the configuration may be such that a hole penetrating the peripheral wall of the trowel tip is provided at a position below the receiving portion of the trowel tip. Further, more specifically, the structure may be such that a slit is provided in the peripheral wall of the trowel tip from a position below the receiving portion of the trowel tip to the lower end portion of the trowel tip.

According to the solder processing apparatus according to the present invention, the solder pieces can be more reliably heated and melted by using the heat of the trowel tip, and the melted solder can be surely flowed out from the trowel tip. ..

It is a perspective view of an example of the soldering apparatus which concerns on embodiment of this invention. It is sectional drawing which cut at the line II-II of the soldering apparatus shown in FIG. It is an exploded perspective view of a part of the drive mechanism provided in the soldering apparatus shown in FIG. It is explanatory drawing of the process which the solder piece is supplied into the trowel tip of 1st Embodiment. It is explanatory drawing of the state which the solder piece was supplied into the trowel tip of 1st Embodiment. It is explanatory drawing of the state in which the solder piece was melted in the trowel tip of 1st Embodiment. It is explanatory drawing of the state in which the molten solder flowed out from the inside of the trowel tip of 1st Embodiment. It is explanatory drawing of the state which the solder piece was supplied into the trowel tip of the 2nd Embodiment. It is explanatory drawing of the state in which the solder piece was melted in the trowel tip of the 2nd Embodiment. It is explanatory drawing of the state in which the molten solder flowed out from the inside of the trowel tip of the 2nd Embodiment. It is a control block diagram in 2nd Embodiment. It is a control flowchart in 3rd Embodiment. It is a perspective view of the trowel tip of the 4th embodiment. It is explanatory drawing of the state which the solder piece was supplied into the trowel tip of 4th Embodiment. It is explanatory drawing of the state in which the solder piece was melted in the trowel tip of 4th Embodiment. It is explanatory drawing of the state in which the molten solder flowed out from the inside of the trowel tip of 4th Embodiment. It is explanatory drawing of the state in which the molten solder flowed out from the inside of the trowel tip of the 5th embodiment. It is explanatory drawing of the state in which the molten solder flowed out from the inside of the trowel tip of the sixth embodiment. It is explanatory drawing of the gas opening hole of the trowel tip which concerns on 7th Embodiment. It is a perspective view of the trowel tip of the 8th embodiment. It is explanatory drawing of the state in which the molten solder flowed out from the inside of the trowel tip of the 8th embodiment. It is explanatory drawing of the state in which the molten solder flowed out from the inside of the trowel tip of the 9th embodiment. It is explanatory drawing of the gas opening slit of the trowel tip which concerns on 10th Embodiment. It is explanatory drawing about the other embodiment of the receiving part in a trowel tip.

Each of the first to tenth embodiments of the present invention will be described below with reference to the drawings. The contents of the present invention are not limited to these embodiments.

1. 1. 1st Embodiment [Overall configuration of soldering apparatus]
FIG. 1 is a perspective view of a soldering apparatus (one form of a soldering apparatus) according to the first embodiment, and FIG. 2 is a cross-sectional view of the soldering apparatus A shown in FIG. 1 cut along a line II-II. FIG. 3 is an exploded perspective view of a part of the drive mechanism provided in the soldering device A shown in FIG. In FIG. 1, a part of the housing and the support portion 1 is cut so that the inside of the soldering device A is displayed.

As shown in FIG. 1, the soldering apparatus A supplies the thread solder W from above, and utilizes the trowel tip 5 provided at the bottom to provide a wiring board Bd arranged below the trowel tip 5 and electronic components. It is a device for soldering with Ep. The thread solder W has a structure in which a flux layer is provided inside a tubular solder layer. Therefore, the solder piece Wh generated by cutting the thread solder W also has a structure in which a flux layer is provided inside the tubular solder layer (see FIG. 4). The soldering device A includes a support portion 1, a cutter unit 2, a drive mechanism 3, a heater unit 4, a trowel tip 5, and a solder feed mechanism 6. A combination of the heater unit 4 and the iron tip 5 constitutes a soldering iron portion.

The support portion 1 includes an erected flat plate-shaped wall body 11. In the following description, for convenience, as shown in FIG. 1, the horizontal direction along the wall body 11 is the X direction, the horizontal direction perpendicular to the wall body 11 is the Y direction, and the vertical direction along the wall body 11 is the Z direction ( Vertical direction). For example, as shown in FIG. 1, the wall body 11 has a ZX plane.

The soldering device A supplies molten solder to the wiring board Bd attached to the jig Gj and the terminal P of the electronic component Ep arranged on the wiring board Bd to fix the connection. When soldering, the jig Gj is moved in the X and Y directions to position the wiring board Bd with the land Ld. Further, the soldering device A is movable in the Z direction, and by moving in the Z direction after positioning, the tip of the trowel tip 5 can be brought into contact with the land Ld.

The support portion 1 includes a holding portion 12 provided at a position shifted upward from the lower end portion of the wall body 11 in the Z direction, and a sliding guide 13 fixed to an edge portion (lower portion) of the wall body 11 in the Z direction. And a heater unit fixing portion 14 provided at an end portion (lower end portion) of the wall body 11 in the Z direction.

The cutter unit 2 cuts the thread solder W sent by the solder feed mechanism 6 into solder pieces Wh having a predetermined length. The cutter unit 2 has a cutter lower blade 22 (fixed blade portion) fixed to the sliding guide 13 and a cutter upper blade 21 (movable) arranged above the cutter lower blade 22 and slidable in the X direction. A blade portion) and a pusher pin 23 (solder pressing portion) provided on the cutter upper blade 21 and sliding in a direction (Z direction) intersecting the sliding direction of the cutter upper blade 21 are provided. As shown in FIG. 1, the cutter upper blade 21 is restricted from moving in the Z direction by the sliding guide 13, and can slide in the X direction.

Here, the sliding guide 13 will be described in detail. The sliding guide 13 includes a pair of wall portions 131, 131 that come into contact with both ends of the cutter lower blade 22 in the Y direction, and the pair of wall portions 131 includes retaining portions 132, 132 that protrude toward the other. ing. In other words, the retaining portions 132 and 132 have an opening at the upper part of the sliding guide 13 so that the tips thereof do not come into contact with each other. The retaining portions 132, 132 restrict the movement of the cutter upper blade 21 in the Z direction.

As shown in FIG. 2, in the cutter upper blade 21, the upper blade hole 211, which is a through hole into which the thread solder W sent by the solder feeding mechanism 6 is inserted, and the rod portion 231 of the pusher pin 23 are inserted. It is provided with a pin hole 212 which is a through hole. The edge of the lower end of the upper blade hole 211 is formed in a cutting edge shape. The cutter lower blade 22 includes a lower blade hole 221 which is a through hole into which the thread solder W penetrating the upper blade hole 211 is inserted, and a gas inflow hole 222 through which gas passes. The edge of the upper end of the lower blade hole 221 is formed in a cutting edge shape. The upper blade hole 211 and the lower blade hole 221 are displaced in the direction intersecting the thread solder W with the thread solder W inserted, so that the thread solder W is cut by the mutual cutting blades. Further, the gas inflow hole 222 is connected to the vertical intermediate portion of the lower blade hole 221 to supply a pressurized gas such as nitrogen sent from the pressurizing pump 91 to the lower blade hole 221. The pressurized gas sent to the lower blade hole 221 is finally supplied to the solder hole 51 through the solder supply hole 422. The pressure of the pressurized gas supplied from the pressurizing pump 91 to the solder hole 51 via the lower blade hole 221 and the solder supply hole 422 is adjusted by the pressure regulator 92 controlled by the control unit 8. The gas supply unit 9 includes a pressurizing pump 91 and a pressure regulator 92.

The pusher pin 23 is a solder pushing portion, and pushes the solder piece Wh that is cut by the cutter upper blade 21 and the cutter lower blade 22 and remains in the lower blade hole 221 downward. The pusher pin 23 is wound around a rod portion 231 slidably supported by the pin hole 212, a head portion 232 provided at the end of the rod portion 231 and a rod portion 231 and is wound on the head portion 232 and the cutter. It is provided with a spring 233 arranged between the blade 21 and the blade 21. Further, the pusher pin 23 is provided with a retaining stopper at the end of the rod portion 231 opposite to the head portion 232 to prevent the rod portion 231 from coming off from the pin hole 212. The pusher pin 23 is always lifted upward by the elastic force of the spring 233, that is, on the side opposite to the cutter lower blade 22.

As shown in FIGS. 1 and 2, the drive mechanism 3 penetrates the air cylinder 31 held by the holding portion 12 and the through hole provided in the holding portion 12, and is slid driven in the Z direction by the air cylinder 31. The piston rod 32 is supported by both the holding portion 12 and the lower blade 22 of the cutter, and a columnar guide shaft 35 extending in the Z direction is provided. The drive mechanism 3 includes a cam member 33 slidably supported by the guide shaft 35 in the Z direction, and a slider portion 34 having a cam groove 340 with which a pin 332, which will be described later, is engaged with the cam member 33. It has.

The air cylinder 31 slides (expands and contracts) the piston rod 32 by the pressure of air supplied from the outside, and the air cylinder 31 and the piston rod 32 form an actuator of the drive mechanism 3. The piston rod 32 is provided parallel to the guide shaft 35 and reciprocates linearly along the guide shaft 35. The tip of the piston rod 32 is fixed to the cam member 33 and slides in the Z direction due to the expansion and contraction of the piston rod 32. The sliding of the cam member 33 is guided by the guide shaft 35.

As shown in FIG. 2, the lower end of the guide shaft 35 is fitted into a concave hole provided in the cutter lower blade 22, and is screwed and fixed to the cutter lower blade 22 with a screw 351. Further, the upper portion of the guide shaft 35 penetrates a hole provided in the holding portion 12, and movement is restricted by a pin 352. That is, the guide shaft 35 is fixed to the cutter lower blade 22 by the screw 351 and to the holding portion 12 by the pin 352.

As shown in FIGS. 2 and 3, the cam member 33 is a rectangular member, and is connected to a concave portion 330 having a part of a long side cut out in a rectangular shape and a cam member 33, and a guide shaft 35 penetrates therethrough. It is provided with a cylindrical support portion 331 having a through hole. A slider portion 34 is slidably arranged (in the X direction and the Z direction) in the recess 330. Further, the support portion 331 has a shape extending in a direction parallel to the pin 35, and is provided to suppress rattling of the cam member 33. That is, when the cam member 33 has a certain thickness and rattling is unlikely to occur, the cylindrical portion may be omitted and the support portion 331 may be formed only by the through hole.

The cam member 33 is supported by a columnar pin 332 provided in the intermediate portion of the recess 330 whose central axis is orthogonal to the guide shaft 35, and a pin pushing portion 333 that pushes the pusher pin 23 adjacent to the recess 330. It is provided with a bearing 334 arranged inside the hole 331. The pin 332 is inserted into a cam groove 340 provided in the slider portion 34, which will be described later. Further, the bearing 334 is a member that fits outside the guide shaft 35 and slides smoothly so that the cam member 33 does not rattle.

As shown in FIGS. 2 and 3, the slider portion 34 is a rectangular plate-shaped member, and is integrally formed with the cutter upper blade 21. The slider portion 34 includes a cam groove 340 that penetrates in the plate thickness direction and extends in the longitudinal direction. The cam groove 340 is provided with a first groove portion 341 extending parallel to the guide shaft 35 on the upper side and a second groove portion 342 extending parallel to the guide shaft 35 on the lower side. The first groove portion 341 and the second groove portion 342 are provided so as to be offset in the X direction, and the cam groove 340 includes a connection groove portion 343 that connects the first groove portion 341 and the second groove portion 342.

A pin 332 of the cam member 33 is inserted into the cam groove 340, and the pin 332 slides on the inner surface of the cam groove 340 as the cam member 33 moves along the guide shaft 35. When the pin 332 is located in the connecting groove 343 of the cam groove 340, it pushes the inner surface of the connecting groove 343. As a result, the cutter upper blade 21 integrally formed with the slider portion 34 and the slider portion 34 moves in the direction (X direction) intersecting the sliding direction (Z direction) of the cam member 33 (with respect to the cutter lower blade 22). Sliding).

As shown in FIG. 2, the heater unit 4 is a heating device for heating and melting the solder piece Wh, and is fixed to the heater unit fixing portion 14 provided at the lower end portion of the wall body 22. The heater unit 4 includes a heater 41 that generates heat by passing electricity, and a heater block 42 for attaching the heater 41. The heater 41 is wound around the outer peripheral surface of the cylindrical heater block 42.

The heater block 42 has a cylindrical shape, and has a recess 421 having a circular cross section for attaching the trowel tip 5 to the end in the axial direction, and a solder supply hole 422 penetrating from the center of the bottom of the recess 421 to the opposite side. And have. The heater block 42 is provided in contact with the cutter lower blade 22 so that the solder supply hole 422 and the lower blade hole 221 communicate with each other. By providing the heater block 42 in this way, the solder piece Wh moves from the lower blade hole 221 to the solder supply hole 422.

The trowel tip 5 is a cylindrical heatable member extending in the vertical direction, and has a solder hole 51 extending in the axial direction in a central portion. The trowel tip 5 is inserted into the recess 421 of the heater block 42, and is prevented from coming off by a member (not shown). Further, the solder hole 51 of the trowel tip 5 communicates with the solder supply hole 422 of the heater block 42, and the solder piece Wh is sent from the solder supply hole 422.

Heat from the heater 41 is transferred to the trowel tip 5, and the heat melts the solder piece Wh. Therefore, the trowel tip 5 is formed of a material having a high thermal conductivity, for example, a ceramic such as silicon carbide or aluminum nitride, or a metal such as tungsten. In the soldering apparatus A, the trowel tip 5 has a cylindrical shape, but the soldering device A is not limited to this, and a tubular shape having a polygonal cross section or an elliptical cross section may be used. It is also possible to prepare different shapes according to the shapes of the wiring board Bd to be soldered and / or the terminal P of the electronic component Ep.

As shown in FIGS. 1 and 2, the solder feed mechanism 6 supplies the thread solder W, and feeds the thread solder W to the feed roller pair 61 and feeds the thread solder W onto the cutter upper blade 21. It is provided with a guide tube 62 that guides the blade hole 211. The feed roller pair 61 is attached to the support portion 1, sandwiches the thread solder W, and rotates the thread solder W to feed the thread solder W downward. The guide tube 62 is an elastically deformable tube body, and the upper end thereof is arranged close to the portion where the thread solder W of the feed roller pair 61 is fed.

Further, the lower end of the guide tube 62 is provided so as to communicate with the upper blade hole 211 of the cutter upper blade 21. The lower end of the guide tube 62 moves following the sliding of the cutter upper blade 21, so that the guide tube 62 is not excessively pulled or stretched within the range in which the cutter upper blade 21 slides. It is provided. The feed roller pair 61 determines the length of the fed thread solder by the rotation angle (rotation speed).

When soldering is performed by the soldering apparatus A, the tip of the iron tip 5 is brought into contact with the land Ld of the wiring board Bd to be soldered, and the iron tip 5 surrounds the land Ld and the terminal P of the electronic component Ep. At this time, the heat from the heater 41 is transferred to the trowel tip 5, and when the trowel tip 5 comes into contact, the land Ld and the terminal P of the electronic component Ep are heated to a temperature suitable for soldering (preheat). ).

[Operation of soldering device]
Next, the operation of the soldering apparatus A will be described. As shown in FIG. 2, in the soldering device A, the piston rod 32 is housed inside the air cylinder 31 immediately before soldering, and the cam member 33 is in the upper portion (sliding range) in the Z direction. At the top of). At this time, the pin 332 is located in the first groove portion 341 of the cam groove 340, and the cutter upper blade 21 is located closest to the guide shaft 35. This position is the initial position. Further, in the soldering apparatus A, the cutter upper blade 21 and the cutter lower blade 22 are formed so that the upper blade hole 211 overlaps the lower blade hole 221 in the Z direction when it is in the initial position.

Then, the feed roller pair 61 is rotationally driven to feed the thread solder W. Since the upper blade hole 211 and the lower blade hole 221 are in a communicating state, the tip of the thread solder W moves to the inside of the lower blade hole 221. The rotation angle of the feed roller pair 61 is adjusted so that the length of the thread solder W entering the lower blade hole 221 is the length of the solder piece Wh. The length of the solder piece Wh is determined according to the size of the land Ld to be soldered, the terminal P of the electronic component Ep, and the like.

Then, the piston rod 32 is projected from the air cylinder 31 and the cam member 33 is moved downward along the guide shaft 35. Since the pin 332 is arranged in the cam groove 340, the pin 332 slides in the cam shaft 340. When the pin 332 is in the first groove portion 341, the slider 34 does not receive a force from the cam member 33 because the first groove portion 341 coincides with the moving direction of the pin 332 (the axial direction of the guide shaft 35), and the cam member 34 It is stationary. Then, when the pin 332 reaches the connection groove portion 343 from the first groove portion 341, the pin 332 pushes the inner surface of the connection groove portion 343. As a result, a force in the X direction is applied to the slider portion 34, and the cutter upper blade 21 integrally formed with the slider portion 34 and the slider portion 34 moves (slides) in the X direction.

When the cutter upper blade 21 slides, the upper blade hole 211 and the lower blade hole 221 are displaced in the X direction, and due to the displacement of these holes, the cutting edge formed on the edge of the end portion of the upper blade hole 211 The cutting edges formed on the edge of the end of the lower blade hole 221 intersect. As a result, the thread solder W is cut and a solder piece Wh is generated.

When the piston rod 32 further protrudes, the cam member 33 moves further downward, and the pin 332 moves from the connecting groove portion 343 to the second groove portion 342. Since the second groove portion 342 also extends parallel to the guide shaft 35, the pin 332 does not push the slider portion 34 even if the cam member 33 moves downward along the guide shaft 35. That is, the cam member 33 moves, but the cutter upper blade 21 and the slider portion 34 stop. The cutter upper blade 21 is located farthest from the guide shaft 35. When in this position, the cutter upper blade 21 and the cutter lower blade 22 are formed so that the pin hole 212 overlaps the lower blade hole 221 in the Z direction.

When the piston rod 32 further protrudes, the cam member 33 slides downward, and the pin pushing portion 333 of the cam member 33 pushes the head portion 232 of the pusher pin 23. As a result, the rod portion 231 of the pusher pin 23 is inserted into the lower blade hole 221. At this time, the solder piece Wh remaining in the lower blade hole 221 is pushed by the rod portion 231 and moves toward the trowel tip 5. The solder piece Wh may move downward due to its own weight at the time of cutting, but by using the pusher pin 23, the solder piece Wh can be reliably supplied to the solder hole 51 of the trowel tip 5.

FIG. 4 shows how the solder piece Wh is supplied into the trowel tip 5. As shown in this figure, the trowel tip 5 is provided with a rod-shaped member 5t inserted from the outer surface toward the inside. The rod-shaped member 5t reaches the inside of the trowel tip 5, and the tip portion of the rod-shaped member 5t is a rod-shaped protrusion protruding from the inner wall of the trowel tip 5. The rod-shaped member 5t is projected inward from the inner wall of the trowel tip 5 so that the distance between the tip portion of the rod-shaped member 5t and the inner wall of the trowel tip 5 facing the tip portion is smaller than the outer diameter of the solder piece Wh. .. The rod-shaped member 5t is located above the tip of the terminal P of the electronic component Ep, and serves as a receiving portion for receiving the solder piece Wh supplied into the trowel tip 5.

As shown in FIG. 4, the solder piece Wh that has fallen from above the trowel tip 5 is caught on the rod-shaped member 5t before reaching the terminal P of the electronic component Ep. As shown in FIG. 5, the solder piece Wh received by the rod-shaped member 5t is held so as to be inclined to the side opposite to the protruding portion of the rod-shaped member 5t. As a result, the lower end of the solder piece Wh comes into contact with the rod-shaped member 5t, and the upper end of the solder piece Wh comes into contact with the inner wall of the trowel tip 5. As described above, in the present embodiment, the solder piece Wh can be forcibly brought into contact with the inner wall of the trowel tip 5. Since the inner diameter of the solder hole 51 of the trowel tip 5 is set to a size slightly larger than the outer diameter of the solder piece Wh, even if the solder piece Wh is tilted in the trowel tip 5, FIG. As shown, since it is supported by the inner wall of the trowel tip 5, it always stands in the trowel tip 5.

Further, as is clear from FIG. 5, at least a part of the solder piece Wh supplied into the trowel tip 5 is always in contact with the inner wall of the trowel tip 5 (including the rod-shaped member 5t). If the rod-shaped member 5t (reception portion) is not provided, the solder piece Wh will stand straight on the terminal P of the electronic component Ep, and the solder piece Wh will not come into contact with any part of the inner wall of the tip 5. Can occur. From this, the rod-shaped member 5t avoids non-contact between the supplied solder piece Wh and the inner wall of the trowel tip 5 (in other words, the supplied solder piece Wh is forcibly brought into contact with the inner wall of the trowel tip 5). ) It can be said that it has a role.

The heat from the heater 41 is transferred to the trowel tip 5, and the solder piece Wh is heated by this heat. At this time, the solder piece Wh is held on the rod-shaped member 5t, and the solder piece Wh and the inner wall of the trowel tip 5 are always in contact with each other. Therefore, the solder piece Wh and the inner wall of the trowel tip 5 are not in contact with each other. Compared with the case, the heat of the trowel tip 5 can be transferred to the solder piece Wh more reliably.

Further, since the solder piece Wh is received by the rod-shaped member 5t, it does not come into contact with the terminal P of the electronic component Ep, and therefore the heat of the solder piece Wh is prevented from being taken away by the terminal P. Further, when the solder piece Wh is heated to some extent, a flux flows out from the inside of the solder piece Wh, and if this flux is interposed between the solder piece Wh and the inner wall of the trowel tip 5, the contact property between the two is further improved. .. For each of the above reasons, in the present embodiment, the solder piece Wh is efficiently heated, and problems such as insufficient heating and melting of the solder piece Wh are prevented as much as possible.

Normally, the molten solder flows to the land Ld below and the terminal P of the electronic component Ep. Then, by moving the soldering device A in the Z direction, the trowel tip 5 is separated from the land Ld. As a result, the solder is cooled by the outside air and solidified, so that the land Ld and the terminal P of the electronic component Ep are soldered.

Then, when the soldering is completed, the air cylinder 31 houses the piston rod 32 inside. As a result, the cam member 33 moves upward in the Z direction, and the pusher pin 23 is pushed upward by the elastic force of the spring 233. The rod portion 231 comes out of the lower blade hole 221. Even if the cutter upper blade 21 slides in this state, the pusher pin 23 is not damaged. Then, the pin 332 of the cam member 33 reaches the connecting groove portion 343 of the cam groove 340, and the slider portion 34 and the cutter upper blade 21 slide so as to approach the guide shaft 35. When the pin 332 reaches the first groove portion 341 of the cam groove 340, the soldering device A returns to the initial position.

By the way, as shown in FIG. 6, even when the solder piece Wh comes into contact with the inner wall of the trowel tip 5 and melts, it is possible that the molten solder spheroidizes due to surface tension and does not flow out from the inside of the trowel tip 5. .. Therefore, in the present invention, it is decided to supply a pressurized gas into the trowel tip 5 and extrude the molten solder from the trowel tip 5.

As shown in FIGS. 2 and 5, an exhaust hole 52 penetrating the peripheral wall of the solder hole 51 is formed at a position above the rod-shaped member 5t of the trowel tip 5. When the solder piece Wh is melted, nitrogen or the like is discharged from the pressurizing pump 91 into the solder hole 51 in order to suppress the oxidation of the solder in the solder hole 51 and discharge the flux fume (smoke) from the solder hole 51. An inert gas is supplied. The gas supplied to the solder hole 51 fills the periphery of the solder piece Wh and suppresses the oxidation of the solder, and the flux contained in the solder piece Wh is heated and melted and vaporized to generate a flux fume from the exhaust hole 52. It works to discharge from 5.

Further, as shown in FIG. 6, when the solder piece Wh is melted by heating from the trowel tip 5, and the molten solder is spheroidized by surface tension and stays in the rod-shaped member 5t, it is melted by the pressure of the pressurized gas. The solder is extruded from the tip 5 and flows out to the land Ld below and the terminal P of the electronic component Ep. As a result, as shown in FIG. 7, front fillets and back fillets are formed on the front surface and the back surface of the wiring board Bd through the through holes.

The pressure of the pressurized gas supplied to the trowel tip 5 may be changed depending on whether the purpose is to prevent the solder from oxidizing or to discharge the flux fume, or to extrude the molten solder from the trowel tip 5. desirable. That is, it is desirable to increase the gas pressure in the latter case than in the former case. This enables smooth extrusion of the molten solder from the trowel tip. As described above, the gas pressure supplied to the trowel tip 5 can be adjusted by the pressure regulator 92 controlled by the control means 8. Of course, the gas pressure supplied to the trowel tip 5 may be set as the pressure for extruding from the trowel tip of the molten solder from the beginning. Further, the pressurized gas may be continuously supplied before the solder piece Wh is supplied to the trowel tip 5, or may be supplied when the solder piece Wh is melted to become molten solder. Good. Further, the pressurized gas supply method may be continuous supply at a predetermined pressure or short-time periodic supply (pulse). Further, before supplying the pressurized gas to the molten solder, the inside of the trowel tip 5 may be temporarily put into a negative pressure state, and then the pressurized gas may be supplied. By momentarily applying a large pressure difference to the molten solder from a negative pressure to a positive pressure in this way, clogging at the receiving portion of the molten solder can be easily eliminated.

On the other hand, if the pressure of the pressurized gas supplied to the trowel tip 5 is too high, the molten solder is smoothly extruded from the trowel tip 5, but it flows excessively to the back surface side of the wiring board Bd through the through hole, which is normal. There is a possibility that fillets will not be formed, but in such a case, the exhaust holes 52 formed at the tip 5 act to release the gas pressure, and it is possible to reduce the pressure of the pressurized gas applied to the molten solder. is there.

(Second Embodiment)
Next, the second embodiment will be described. The second embodiment is basically the same as the first embodiment except for the portion related to the receiving portion that receives the solder piece Wh supplied into the trowel tip 5. In the following description, emphasis will be placed on the description of parts different from those of the first embodiment, and description of common parts may be omitted.

In the soldering apparatus A of the second embodiment, as shown in FIG. 8, a pair of rod-shaped members 5ta and 5tb are inserted into the trowel tip 5 from the outer surface toward the inside. The tips of the pair of rod-shaped members 5ta and 5tb protruding into the solder hole 51 of the trowel tip 5 face each other with a predetermined gap. The gap between the tips of the pair of rod-shaped members 5ta and 5tb is narrower than the outer diameter of the solder piece Wh, and the solder piece Wh supplied to the tip 5 is received by at least one of the rod-shaped members 5ta and 5tb. That is, the pair of rod-shaped members 5ta and 5tb function as receiving portions.

Further, the pair of rod-shaped members 5ta and 5tb have conductivity and also function as a detecting means for detecting a downward drop of the molten solder. That is, when the solder piece Wh is in contact between the pair of rod-shaped members 5ta and 5tb, when the molten solder is in contact, and when the solder piece Wh and the molten solder are not in contact, the pair of rod-shaped members Since the conduction resistance between the 5ta and 5tb changes, it is possible to detect the downward movement of the molten solder by measuring the conduction resistance between the pair of rod-shaped members 5ta and 5tb.

A specific processing example will be described. As shown in FIG. 8, a gas (inert gas such as nitrogen) set at a pressure P0 is supplied into the trowel tip 5, and a solder piece Wh is supplied into the trowel tip 5. When the solder piece Wh comes into contact with the pair of rod-shaped members 5ta and 5tb, conduction occurs between the pair of rod-shaped members 5ta and 5tb, and the arrival of the solder piece Wh in the trowel tip 5 is detected. Next, as shown in FIG. 9, when the solder piece Wh is melted by heating from the trowel tip 5, the conduction resistance between the pair of rod-shaped members 5ta and 5tb decreases. As a result, melting of the solder piece Wh is detected. When the melting of the solder piece Wh is detected, the pressure of the gas supplied to the iron tip 5 is set to a pressure P1 higher than the pressure P0. By increasing the gas pressure from P0 to P1, the molten solder can be smoothly pushed out from the inside of the trowel tip 5. Then, when all the molten solder falls from the pair of rod-shaped members 5ta and 5tb, the continuity between the pair of rod-shaped members 5ta and 5tb is lost. When a drop of the molten solder from the pair of rod-shaped members 5ta and 5tb is detected, the pressure of the gas supplied to the tip 5 is set to a pressure P2 lower than the pressure P1. By lowering the gas pressure from P1 to P2, it is possible to prevent the molten solder from excessively flowing to the back surface side of the wiring board Bd through the through holes, and as shown in FIG. 10, a normal fillet is formed. .. It is assumed that the pressure P2 includes zero.

FIG. 11 shows a control block diagram. The control unit 8 is configured to include logic circuits such as an MPU and a CPU. The control unit 8 controls the air cylinder 31 of the drive unit 3, the heater 41 of the heater unit 4, the feed roller 61 of the solder feed unit 6, the pressurizing pump 91 of the gas supply unit 9, and the pressure regulator 92. It is connected to each part so that signals can be transmitted and received. Further, the control unit 8 is connected to a temperature sensor (not shown), acquires the temperature of the heater block 42 measured by the temperature sensor, and controls the temperature of the heater 41. Further, the control unit 8 is also connected to a detection means (a pair of rod-shaped members 5ta, 5tb as check terminals) for detecting the melting of the solder piece Wh supplied to the supply hole 51 of the trowel tip 5, from the detection means. The molten state of the solder piece Wh and the drop from the detection means are determined by the signal of, and the pressure of the gas supplied into the tip 5 is controlled. Further, it is also connected to the storage unit 81 so that information can be exchanged with the storage unit 81. The storage unit 81 has a ROM capable of recalling information, a RAM capable of recalling and writing, a semiconductor memory such as a detachable flash memory, a hard disk, and the like.

(Third Embodiment)
The third embodiment will be described. The third embodiment is basically the same as the first embodiment except for the portion related to the control of the supply of the pressurized gas into the trowel tip 5. In the following description, emphasis will be placed on the description of the portion related to the supply control of the pressurized gas into the trowel tip 5, which is different from the first embodiment, and the description of the common portion may be omitted.

FIG. 12 shows a flowchart showing an example of supply control of the pressurized gas to the trowel tip 5. First, a gas having a set pressure P0 (an inert gas such as nitrogen) is supplied into the tip 5 (step S1). Then, the thread solder W is cut into solder pieces Wh and supplied to the trowel tip 5 (step S2). At this time, the timer T is set to zero (step S3) and then started (step S4). Then, when the timer T reaches the T1 time (step S5), it is determined that the solder piece Wh has melted, and the pressure of the gas supplied to the trowel tip 5 is changed from the pressure P0 to a pressure P1 higher than that (step S6). ). As a result, the molten solder is pushed out from the inside of the trowel tip 5. Next, when the timer T reaches T2 hours (step S7), it is determined that all the molten solder has fallen downward from the receiving portion, and the pressure of the gas supplied to the trowel tip 5 is set to a pressure P2 lower than the pressure P1. (Step S8). As a result, it is possible to prevent the molten solder from excessively flowing to the back surface side of the wiring board Bd through the through holes, and it is possible to form a normal fillet. Next, it is determined whether or not to end the soldering process (step S9), and if the soldering process is to be continued, the process returns to step S1 and a series of soldering processes is performed. On the other hand, when the soldering process is completed (step S9), the gas supply is stopped, the gas pressure is set to zero, and the control is terminated.

(Fourth Embodiment)
Next, the fourth embodiment will be described. The fourth embodiment is basically the same as the first embodiment except for a part related to a mechanism for reducing the gas pressure applied to the molten solder dropped from the receiving portion. In the following description, emphasis will be placed on the description of parts different from those of the first embodiment, and description of common parts may be omitted.

FIG. 13 shows a perspective view of the trowel tip according to the fourth embodiment, and FIG. 14 shows a vertical sectional view. In the soldering apparatus A of the fourth embodiment, as shown in FIGS. 13 and 14, a rod-shaped member 5t is inserted into the trowel tip 5 from the outer surface toward the inside, and protrudes into the solder hole 51 of the trowel tip 5. The gap between the tip of the rod-shaped member 5t and the inner wall of the solder hole 51 facing the tip is set to be smaller than the outer diameter of the solder piece Wh. As a result, the solder piece Wh supplied to the trowel tip 5 is received by the rod-shaped member 5t. That is, the rod-shaped member 5t functions as a receiving portion. A gas opening hole 53 penetrating the peripheral wall of the trowel tip is formed at a position below the mounting position of the rod-shaped member 5t of the trowel tip 5.

As shown in FIG. 15, when the solder piece Wh is melted by heating from the trowel tip 5, the pressurized gas is sent to the trowel tip so that the melted solder piece Wh does not spheroidize due to surface tension and stay in the rod-shaped member 5t. It is supplied to 5. At this time, if the pressure of the pressurized gas supplied to the iron tip 5 is too high, the molten solder is smoothly extruded from the iron tip, but excessively flows to the back surface side of the wiring board Bd through the through hole, which is normal. There is a possibility that a fillet is not formed, but in the tip 5 of this embodiment, since the gas opening hole 53 is formed at a position below the rod-shaped member 5t, the molten solder falls from the rod-shaped member 5t and the solder of the gas opening hole 53 is formed. When the communication portion with the hole 51 is exceeded, a part of the pressurized gas flows out of the iron tip 5 through the gas opening hole 53. As a result, the gas pressure applied to the molten solder flowing out to the land Ld below and the terminal P of the electronic component Ep is reduced, and as shown in FIG. 16, the front surface and the back surface of the wiring board Bd are fronted through the through holes. Fillets and back fillets will be formed.

(Fifth Embodiment)
FIG. 17 shows a vertical cross-sectional view of the trowel tip according to the fifth embodiment. The fifth embodiment is basically the same as the fourth embodiment except that an exhaust hole 52 penetrating the peripheral wall of the solder hole 51 is provided at a position above the rod-shaped member 5t of the trowel tip 5.

As described above, the exhaust hole 52 has a function of discharging the flux fume generated by heating and melting the flux contained in the solder piece Wh to the outside from the tip 5 when the solder piece Wh is melted. At the same time, when a pressurized gas is supplied to the tip 5 in order to push out the molten solder from the tip 5, the gas pressure applied to the molten solder is reduced. As a result, normal front fillets and back fillets are formed on the front surface and the back surface of the wiring board Bd through the through holes.

(Sixth Embodiment)
FIG. 18 shows a vertical cross-sectional view of the trowel tip according to the sixth embodiment. The sixth embodiment is basically a fifth embodiment except that two gas opening holes 53a and 53b penetrating the peripheral wall of the solder hole 51 are provided below the rod-shaped member 5t of the trowel tip 5. Is similar to.

Since the two gas opening holes 53a and 53b are provided in the trowel tip 5, the outflow of the pressurized gas to the outside of the trowel tip 5 becomes smoother than in the case where the gas opening hole 53 is one. The number of gas opening holes 53 formed is not limited and may be 3 or more. Further, when two or more gas opening holes 53 are provided, the formation position of the gas opening holes is not particularly limited, and the gas opening holes may be provided at different positions in the circumferential direction at the same height position or at different positions in the height direction. You may.

(7th Embodiment)
FIG. 19 shows a vertical cross-sectional view of the trowel tip according to the seventh embodiment. The seventh embodiment is basically the same as the fifth embodiment except for the shapes of the gas opening holes 53c and 53d provided below the mounting position of the rod-shaped member 5t of the trowel tip 5.

When the soldering process is performed, the flux contained in the solder is melted and vaporized by heating, and the vaporization and expansion of the flux may cause a small amount of molten solder to become balls (solder balls) and scatter. Since the trowel tip used in the present invention has a substantially tubular shape and the solder piece is heated and melted in the trowel tip, the solder ball does not scatter from the trowel tip 5 to the outside in principle.

However, in the trowel tip shown in the fifth embodiment and the sixth embodiment, since the gas opening hole 53 is provided below the trowel tip, the solder ball passes through the gas opening hole 53 to the outside of the trowel tip 5. The probability of popping out is low, but it can happen. Therefore, the trowel tip according to the present embodiment is configured to prevent the solder balls generated in the trowel tip 5 from jumping out of the trowel tip through the gas opening hole 53. That is, in the trowel tip shown in FIG. 19A, the gas opening hole 53c is assumed to have an angle inclined upward from the inside to the outside of the trowel tip 5. Further, in the trowel tip 5 shown in FIG. 19B, the shape of the gas opening hole 53d formed in the trowel tip 5 is V-shaped in a cross-sectional view. The shape of the gas opening hole 53d is not limited to a V shape, and may be, for example, a shape having a bend in the middle of the gas opening hole 53d. Even if the solder balls generated in the solder holes 51 enter the gas opening holes 53c and 53d by inclining the gas opening holes 53c in the horizontal direction or forming a shape having a bend in the middle portion in this way. , It is suppressed that the gas comes into contact with the inner walls of the gas opening holes 53c and 53d and stalls and goes out from the tip 5.

(8th Embodiment)
Next, the eighth embodiment will be described. The eighth embodiment is basically the same as the first embodiment except for a part related to a mechanism for reducing the gas pressure applied to the molten solder dropped from the receiving portion. In the following description, emphasis will be placed on the description of parts different from those of the first embodiment, and description of common parts may be omitted.

FIG. 20 shows a perspective view of the trowel tip according to the eighth embodiment, and FIG. 21 shows a vertical sectional view. As shown in FIGS. 20 and 21, in the trowel tip according to the eighth embodiment, a gas release slit 54 is formed on the peripheral wall of the trowel tip from a position lower than the mounting position of the rod-shaped member 5t as a receiving portion to the lower end portion. Has been done.

As shown in FIG. 21, when the solder piece Wh is melted by heating from the trowel tip 5, the pressurized gas is applied to the trowel tip so that the melted solder piece Wh does not spheroidize due to surface tension and stay in the rod-shaped member 5t. It is supplied to 5. At this time, if the pressure of the pressurized gas supplied to the iron tip 5 is too high, the molten solder is smoothly extruded from the iron tip, but excessively flows to the back surface side of the wiring board Bd through the through hole, which is normal. There is a possibility that a fillet will not be formed, but since the gas opening slit 54 from the lower position to the lower end of the rod-shaped member 5t is formed in the tip 5 of this embodiment, the molten solder falls from the rod-shaped member 5t and the gas When the region of the open slit 54 is reached, a part of the pressurized gas flows out of the tip 5 through the gas open slit 54. As a result, the gas pressure applied to the molten solder flowing out to the land Ld below and the terminal P of the electronic component Ep is reduced, and the front fillet and the back fillet are normally formed on the front and back surfaces of the wiring board Bd through the through holes. It will be formed. The length of the gas release slit 54 in the vertical direction is not particularly limited as long as the upper end of the gas release slit 54 is lower than the mounting position of the rod-shaped member 5t as the receiving portion, and the shape of the object to be soldered. It may be decided appropriately in consideration of the above. Further, the opening width of the gas opening slit 54 is preferably 1.2 mm or less from the viewpoint of suppressing scattering of the solder balls from the tip of the solder ball to the outside.

(9th Embodiment)
FIG. 22 shows a vertical cross-sectional view of the trowel tip according to the ninth embodiment. The ninth embodiment is basically the same as the eighth embodiment except that two gas opening slits 54a and 54b extending to the lower end of the trowel tip are provided below the rod-shaped member 5t of the trowel tip 5. The same is true.

By providing the two gas opening slits 54a and 54b on the trowel tip 5, the outflow of the pressurized gas to the outside of the trowel tip 5 becomes smoother than in the case where there is only one gas opening slit. The number of gas opening slits 54 formed is not limited and may be 3 or more. When two or more gas release slits 54 are provided, the positions where the gas release slits are formed in the circumferential direction are not particularly limited, but they are preferably provided at opposite positions.

(10th Embodiment)
FIG. 23 shows a bottom view of the trowel tip according to the tenth embodiment. The tenth embodiment is basically the same as the eighth embodiment except for the shape of the gas opening slit 54 provided below the mounting position of the rod-shaped member 5t of the trowel tip 5. In the following description, emphasis will be placed on the description of parts different from those of the eighth embodiment, and the description of common parts may be omitted.

As described in the seventh embodiment (see FIG. 19), when the soldering process is performed, the flux contained in the solder is melted and vaporized by heating, and the vaporization and expansion of the flux causes the solder balls to be formed. It may scatter outside from the tip 5. In the trowel tip of the embodiment shown in FIG. 23 (a), the gas opening slit 54c provided in the trowel tip 5 is V-shaped when viewed from the bottom. By forming the gas opening slit 54c in such a shape, even if the solder ball enters the gas opening slit 54c, it is prevented from coming into contact with the inner wall of the gas opening slit 54c and stalling and going out from the iron tip 5. The shape of the gas opening slit is not limited to a V shape when viewed from the bottom surface, and may be, for example, a shape having a bend in the middle of the gas opening slit. FIG. 23B is an example thereof, and the gas opening slit 54d shown in this figure has a wavy shape in bottom view.

[About the form of the receiving part in the trowel]
As for the form of the receiving portion provided in the trowel tip 5, another form may be adopted as long as the solder piece Wh supplied from above can be reliably received. Hereinafter, other forms will be described with reference to specific examples.

FIG. 24 shows an example in which a step portion 5s is formed in the middle portion in the vertical direction of the solder hole 51 of the trowel tip 5. The inner diameter of the step portion 5s is slightly smaller than the outer diameter of the solder piece Wh, and the solder piece Wh can be reliably received by the step portion 5s.

Summary In the soldering device A of each embodiment described above, a vertically extending tubular trowel tip 5 that can be heated and a solder piece supply unit (solder) that supplies the solder piece Wh from above into the trowel tip 5 It has a feed mechanism 6 and a cutter unit 2), and uses the heat of the trowel tip 5 to melt the solder piece Wh, and supplies the melted solder downward. Further, the soldering apparatus A is configured to forcibly bring the supplied solder piece Wh into contact with the inner wall of the tip 5. Therefore, according to the soldering apparatus A, it is possible to more reliably heat and melt the solder piece Wh by using the heat of the trowel tip 5. Further, the gas supply unit 9 is configured to supply the pressurized gas into the trowel tip 5. Therefore, according to the soldering apparatus A, it is possible to extrude the molten solder from the tip 5.

Although the embodiments of the present invention have been described above, the present invention is not limited to this content. Further, the embodiments of the present invention can be modified in various ways without departing from the spirit of the invention.

A Soldering equipment (soldering equipment)
1 Support member 11 Wall body 12 Holding part 13 Sliding guide 14 Heater unit fixing part 15 Actuator holding part 16 Spring holding part 2 Cutter unit 21 Cutter upper blade 211 Upper blade hole 212 Pin hole 22 Cutter lower blade 221 Lower blade hole 222 Gas Inflow hole 23 Pusher pin 231 Rod part 232 Head part 233 Spring 3 Drive mechanism 31 Air cylinder 32 Piston rod 33 Cam member 330 Recess 331 Support hole 332 Pin 333 Pin push part 334 Bearing 34 Slider part 340 Cam groove 341 First groove part 342 First 2 Groove 343 Connection groove 35 Guide shaft 4 Heater unit 41 Heater 42 Heater block 421 Recess 422 Solder supply hole 5 Iron tip 5t Rod-shaped member 5s Step 51 Solder hole 52 Exhaust hole 53 Gas opening hole 54 Gas opening slit 6 Soldering mechanism 61 Feed Roller vs. 62 Guide Tube 9 Gas Supply Unit 91 Pressurizing Pump 92 Pressure Regulator P Terminal W Thread Solder Wh Solder Piece Bd Wiring Board Ep Electronic Parts Ld Land

Claims (5)

A trowel tip in the shape of a cylinder that can be heated up and down,
A solder piece supply unit that supplies solder pieces from above into the trowel tip,
A gas supply unit that supplies pressurized gas into the trowel tip is provided.
A solder processing device that melts the solder pieces using the heat of the trowel tip and supplies the melted solder downward.
A receiving portion for receiving the supplied solder piece is provided in the trowel tip.
The solder piece is forcibly brought into contact with the inner wall of the trowel tip on the receiving portion to be melted.
Wherein from the gas supply unit pressurized gas is supplied into the soldering tip, and pushed out the molten solder from the soldering tip,
Further provided with a control means for controlling the pressure of the gas supplied from the gas supply unit,
The control means
A solder processing apparatus characterized in that after the molten solder has moved from the receiving portion, the pressure of the pressurized gas is made lower than the pressure immediately before the movement of the molten solder. Further provided with a detecting means for detecting the movement of the molten solder from the receiving portion,
When the detection means detects the movement of the molten solder from the receiving portion,
The control means
The solder processing apparatus according to claim 1, wherein the pressure of the pressurized gas is made lower than the pressure immediately before the movement of the molten solder. A trowel tip in the shape of a cylinder that can be heated up and down,
A solder piece supply unit that supplies solder pieces from above into the trowel tip,
A gas supply unit that supplies pressurized gas into the trowel tip is provided.
A solder processing device that melts the solder pieces using the heat of the trowel tip and supplies the melted solder downward.
A receiving portion for receiving the supplied solder piece is provided in the trowel tip.
A hole penetrating the peripheral wall of the trowel tip is provided at a position below the receiving portion of the trowel tip.
The solder piece is forcibly brought into contact with the inner wall of the trowel tip on the receiving portion to be melted.
A solder processing apparatus characterized in that a pressurized gas is supplied from the gas supply unit into the trowel tip and the molten solder is extruded from the trowel tip. A trowel tip in the shape of a cylinder that can be heated up and down,
A solder piece supply unit that supplies solder pieces from above into the trowel tip,
A gas supply unit that supplies pressurized gas into the trowel tip is provided.
A solder processing device that melts the solder pieces using the heat of the trowel tip and supplies the melted solder downward.
A receiving portion for receiving the supplied solder piece is provided in the trowel tip.
A slit is provided in the peripheral wall of the trowel tip from a position below the receiving portion of the trowel tip to the lower end portion of the trowel tip.
The solder piece is forcibly brought into contact with the inner wall of the trowel tip on the receiving portion to be melted.
A solder processing apparatus characterized in that a pressurized gas is supplied from the gas supply unit into the trowel tip and the molten solder is extruded from the trowel tip. Further provided with a control means for controlling the pressure of the gas supplied from the gas supply unit,
The control means
The solder processing apparatus according to claim 3 or 4, wherein after the molten solder has moved from the receiving portion, the pressure of the pressurized gas is made lower than the pressure immediately before the movement of the molten solder.