JPH06326454A - Jet nozzle structure of local soldering apparatus - Google Patents

Abstract

PURPOSE:To obtain a jet nozzle structure of a local soldering apparatus which prevents an oxide film inside a jet nozzle from being attached to a soldered part so as to realize soldering of high quality. CONSTITUTION:An oxide film attaching plate 25, to which an oxide film floating on the surface of molten solder 5 is attached with the rise of molten solder 5, is provided upright in a jet nozzle. Or, a jet nozzle structure is split into two pieces, a stationary jet nozzle and a movable jet nozzle, a hole may be provided to the side wall of the movable jet nozzle, and the hole is closed when the movable jet nozzle is made to slide downward to a point where it overlaps the side wall of the stationary jet nozzle when the movable jet nozzle is pressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jet nozzle structure of a small jet type soldering device used for local soldering of a printed wiring board.

[0002]

2. Description of the Related Art Connection of electronic parts to a printed wiring board is
The mainstream is electrical connection by soldering. on the other hand,
In recent years, along with downsizing of electric products, SMP (Surface Mount) different from the conventional lead wire insertion type parts
(Parts: surface mount components) has emerged, and the lightness, thinness, and shortness of substrates are being advanced by high-density mounting. Under such circumstances, although the double-sided reflow (solder melting) board on which such SMP is mounted is actually put into practical use, it is difficult to achieve 100% SMP, and there is no choice but to mix lead wire insertion type parts in some parts. The current situation is that there are none.

FIG. 5 is a work flow chart for explaining an assembly procedure of a double-sided reflow board on which SMP is mounted. To assemble a double-sided reflow board on which SMP is mounted, first, solder paste is printed on the SMP pad on the A side of the board (S1). Mount the SMP (S3), melt the solder paste in a reflow oven,
Soldering is performed (S5). Next, the solder paste is printed on the SMP pad on the B side of the substrate (S7). The SMP is mounted (S9), the solder paste is melted in a reflow furnace, and soldering is performed (S11). Next, in the steps (S3) and (S9) described above, the component determined to be unmountable and the lead wire insertion type component are manually soldered (S13), and the assembly work of the double-sided reflow board is completed. .

By the way, in the above-mentioned step (S13), when the lead wire insertion type component is manually soldered, a small jet type soldering device capable of solder dipping on the substrate local part in order to improve work efficiency. (Commercial item) is adopted.
FIG. 6 is a schematic view of a small jet type soldering device. A small jet type soldering device (soldering device) 1 is a device in which molten solder 5 is stored in a solder bath 3 and a molten solder 5 is blown up from a hole at the bottom of a jet nozzle 7 by a circulating device (not shown). The molten solder 5 thus formed overflows from the escape port 9 on the side wall of the jet nozzle as indicated by an arrow a in the figure and returns to the solder bath 3 again. FIG. 7 is an explanatory diagram of the usage status of the jet nozzle.
In the figure, reference numeral 11 denotes a printed wiring board, and both sides of the reflow have been completed based on the above-mentioned assembly procedure. In this printed wiring board 11, when it is necessary to mount a plurality of lead insertion type components 15 and 17 near the SMP 13, the jet nozzle 7 of the soldering device 1 is placed near the through hole of the printed wiring board 11 located near the SMP 13. Contact.
In this state, when the switch is turned on, the molten solder 5 blows up in the jet nozzle 7 and the adjacent SMP 13 is not covered with the molten solder 5, and the lead insertion type components 15, 17 are provided.
The through holes are locally soldered together.

[0005]

In order to perform good soldering using the soldering apparatus 1, it is necessary to supply sufficient solder into the through holes of the printed wiring board 11 and to apply an appropriate pressure. It is necessary to call. Further, since the solder oxide film 19 (see FIG. 7) is not formed on the surface of the molten solder, it is necessary to overflow the molten solder 5 from the jet nozzle 7. For these reasons, the conventional soldering device 1
Then, the molten solder 5 is ejected after the printed wiring board 11 is brought into contact with the jet nozzle 7. However, when the printed wiring board 11 is in contact with the jet nozzle 7,
The molten solder 5 that blows up in the jet nozzle 7 does not sufficiently overflow from the escape port 9, and the oxide film 19 floating on the surface of the molten solder in the jet nozzle 7 causes the lead insertion type component 15,
There was a risk that it would adhere to the soldered portion of 17. The present invention has been made in view of the above circumstances, and provides a jet nozzle structure of a local soldering device in which an oxide film in the jet nozzle does not adhere to a soldering portion of a lead insertion type component, and thus high quality The purpose is to achieve easy soldering.

[0006]

A jet nozzle structure of a local soldering apparatus according to the present invention for achieving the above object has a lower portion communicated with a solder tank for storing molten solder, and the molten resin is fed under pressure by a circulating means. In a jet nozzle structure of a local soldering device having a frame-shaped jet nozzle with an open top, where the solder is blown up from the bottom, an oxide film floating on the surface of the molten solder inside the jet nozzle The oxide film adhering plate to be adhered is erected in the jet nozzle. Further, in the jet nozzle structure, a frame-shaped fixed jet nozzle with an open top is provided in the solder bath, and a frame-shaped movable jet nozzle with an open top is slidably inserted in the fixed jet nozzle. Urging means for urging the movable jet nozzle in the upward direction is provided between the movable jet nozzle and the fixed jet nozzle, and when the movable jet nozzle is slid downward by being pressed, the side wall of the fixed jet nozzle A hole may be formed on the side wall of the movable jet nozzle so that the hole is moved to a position overlapping with and closed.

[0007]

[Function] With the jet nozzle structure in which the oxide film-adhering plate is erected in the jet nozzle, when the molten solder blows up inside the jet nozzle with a narrow ejection port area partitioned by the oxide film-adhering plate, it floats on the surface of the molten solder. The oxide film gradually adheres to the inner wall surface of the jet nozzle, and when the molten solder is blown up to the vicinity of the jet port, a good solder surface having no oxide film is obtained. Further, in the jet nozzle structure in which the fixed jet nozzle and the movable jet nozzle are divided, by overflowing the molten solder from the hole of the movable jet nozzle, the oxide film on the surface of the molten solder is discharged from the hole, and the solder in the movable jet nozzle is removed. It is always in a mirror state. At the time of soldering, the printed wiring board is pushed downward together with the movable jet nozzle to close the hole, and the molten solder blows up the movable jet nozzle, which enables good soldering.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a jet nozzle structure of a local soldering device according to the present invention will be described in detail below with reference to the drawings. The same members as those shown in FIGS. 6 and 7 are designated by the same reference numerals, and a duplicate description will be omitted. FIG. 1 is a schematic view of a jet nozzle structure of a local soldering device of the present invention. A rectangular frame-shaped jet nozzle 21 with an open top is provided in the solder bath 3.
Is provided, and the jet nozzle 21 projects upward from the solder bath 3. The side wall 21a of the jet nozzle 21 is formed with an escape port 23 having a notched upper end, and the molten solder 5 blown up from the hole at the bottom of the jet nozzle 21 overflows from the escape port 23. An oxide film adhering plate 25 made of a stainless steel plate or the like is erected inside the jet nozzle 21, and the oxide film adhering plate 25 is attached slightly lower than the upper end of the jet nozzle 21. Therefore, the inside of the jet nozzle 21 is
By being partitioned by the oxide film adhering plate 25, the area of the ejection port is narrowed. This is because the oxide film 19 (see FIG. 7) at the bottom of the jet nozzle having a small jet area uses the property of adhering to the inner wall surface of the jet nozzle at the same time when the molten solder is blown up.

The operation of the jet nozzle structure thus constructed will be described with reference to FIG. FIG. 2 is an explanatory diagram of the usage status of the jet nozzle. First, the jet nozzle 21 is set to the SMP13.
The printed wiring board 11 in the vicinity is brought into contact with the vicinity of the through hole. When the switch is turned on in this state, the molten solder 5 is blown up in the jet nozzle 21 having a narrow ejection port area partitioned by the oxide film adhering plate 25. The molten solder 5 is blown up by blowing up inside the jet nozzle 21 having a narrow ejection port area.
When the molten solder 5 is blown up to the vicinity of the ejection port, the oxide film 19 floating on the surface of the nozzle gradually adheres to the inner wall surface of the jet nozzle 21 and becomes a good solder surface having no oxide film 19.

According to the jet nozzle structure according to the above embodiment, the oxide film 19 on the bottom of the jet nozzle has a simple structure.
Can be prevented from approaching the printed wiring board 11,
Good soldering can be performed.

FIG. 3 is a schematic view of another embodiment of the jet nozzle structure of the present invention. A fixed frame nozzle 31 having a rectangular frame shape with an open top is provided in the solder bath 3.
1 projects upward from the solder bath 3. The fixed jet nozzle 31 has a rectangular frame-shaped movable jet nozzle 33 whose upper surface is open.
Is slidably inserted in the vertical direction (in a slidably inserted state), and the movable jet nozzle 33 has a shaft (biasing means) 35 and a spring (biasing means) 3 provided on both sides thereof.
Up and down movement is supported by the fixed jet nozzle 31 via 7. Holes 39 are formed in both side walls of the movable jet nozzle 33, and the molten solder 5 is drawn from the holes 39 by an arrow b.
It overflows in the direction and returns to the solder bath 3 again. The hole 39 is moved into the fixed jet nozzle 31 when the movable jet nozzle 33 is slid downward, and is closed by the side wall 31 a of the fixed jet nozzle 31. Therefore, when the hole 39 is closed, the molten solder 5 is blown up in the movable jet nozzle 33. An escape port 23 is formed at the upper end of the movable jet nozzle 33, and the molten solder 5 overflows from the escape port 23.

The operation of the jet nozzle structure according to another embodiment thus constructed will be described with reference to FIG. FIG. 4 is an explanatory diagram of the usage status of another embodiment. A recirculation device (not shown) is driven to cause the molten solder 5 to overflow from the hole 39 of the movable jet nozzle 33. As a result, the oxide film on the surface of the molten solder is discharged from the hole 39, and the movable jet nozzle 33
The inner surface of the solder is always kept in a mirror state.
In this state, the printed wiring board 11 to be soldered
Is placed on the movable jet nozzle 33, and the printed wiring board 11
Is pushed downward together with the movable jet nozzle 33. Then, the hole 39 of the movable jet nozzle 33 is changed to the fixed jet nozzle 3
1, the molten solder 5 blows up the movable jet nozzle 33, performs good soldering, and is then discharged from the escape port 23. When the soldering is completed and the pressing force of the printed wiring board 11 is weakened, the movable jet nozzle 33 is pushed upward by the urging force of the spring 37, the hole 39 is opened again, and the state of overflow is restored.

According to the jet nozzle structure according to this embodiment, the molten solder 5 in the movable jet nozzle 33 can be overflowed, so that the solder surface in the movable jet nozzle 33 is always in a mirror surface state without an oxide film. Therefore, good soldering is always possible.

[0014]

As described in detail above, according to the jet nozzle structure according to the present invention in which the oxide film-attached plate is erected in the jet nozzle, when the molten solder blows up in the jet nozzle,
Since the oxide film floating on the surface gradually adheres to the inner wall surface of the jet nozzle and a good solder surface without any oxide film can be obtained, the oxide film does not adhere to the soldered portion,
High quality soldering can be realized with a simple structure. Further, according to the jet nozzle structure according to the present invention in which the fixed jet nozzle and the movable jet nozzle are divided, the molten solder can be overflowed from the hole of the movable jet nozzle, so that the solder in the jet nozzle always has an oxide film. It can be maintained in a mirror-like state, and high-quality soldering can be realized.

[Brief description of drawings]

FIG. 1 is a schematic view of a jet nozzle structure of a local soldering device of the present invention.

FIG. 2 is an explanatory diagram of a usage state of a jet nozzle.

FIG. 3 is a schematic view of another embodiment of the jet nozzle structure of the present invention.

FIG. 4 is an explanatory diagram of a usage situation of another embodiment.

FIG. 5 is a work flowchart illustrating an assembly procedure of a double-sided reflow board on which SMP is mounted.

FIG. 6 is a schematic view of a small jet type soldering device.

FIG. 7 is an explanatory diagram of a usage state of a jet nozzle.

[Explanation of symbols]

 1 Local Soldering Device 3 Solder Tank 5 Molten Solder 19 Oxide Film 21 Jet Nozzle 25 Oxide Film Adhering Plate 31 Fixed Jet Nozzle 33 Movable Jet Nozzle 35 Shaft (Biasing Means) 37 Spring (Biasing Means) 39 Holes

Claims (2)

[Claims] 1. A local soldering apparatus having a frame-shaped jet nozzle having an upper opening, in which a lower portion communicates with a solder tank for storing molten solder, and the molten solder pumped by recirculation means is blown up from the lower portion. In the jet nozzle structure, an oxide film attachment plate, to which an oxide film floating on the surface of the molten solder in the jet nozzle adheres as the molten solder blows up, is provided upright in the jet nozzle. Jet nozzle structure for local soldering equipment. 2. A frame-shaped fixed jet nozzle having an open upper portion is provided in a solder bath, and a frame-shaped movable jet nozzle having an open upper portion is slidably fitted in the fixed jet nozzle in the vertical direction, and the movable jet nozzle is movable. An urging means for urging the jet nozzle upward is provided over the movable jet nozzle and the fixed jet nozzle, and when the movable jet nozzle is slid downward by being pressed, the fixed jet nozzle 2. A jet nozzle structure for a local soldering device, characterized in that a hole is formed in a side wall of the movable jet nozzle, the hole being moved to a position overlapping with a side wall of the movable jet nozzle and closed.