JPH0459070B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an automatic soldering method and apparatus,
Approximately V that becomes gradually narrower especially in the direction of conveyance of the substrate
It is equipped with a letter-shaped nozzle, and starts soldering from the left and right sides of the board in the transport direction, and as the board is transported, the soldering point is gradually moved toward the center in the width direction, and finally the center part is moved. The present invention relates to an automatic soldering method and apparatus that can solder the soldering points of a downwardly warped board by soldering.

BACKGROUND TECHNOLOGY A conventional automatic soldering device is a jet type automatic soldering device that is equipped with a conveyance device that conveys a board and a nozzle that opens in a straight line at right angles to the direction of conveyance of the board. The device is in practical use. However, with this soldering device, the surface of the jet of molten solder that is ejected from the nozzle is linear, so the soldering points can only be soldered to planar boards, and for example, the soldering points may convex downward. It has not been possible to solder curved boards such as warped boards at all. On the other hand, as electronic application devices have become more complex in recent years, there has been an increasing demand for soldering curved boards, and it is expected that the demand for such boards will further increase in the future. An example of an electronic application device that requires a curved substrate is a keyboard designed from an ergonomic standpoint with emphasis on operability. Since the keys of the keyboard are arranged in an upwardly curved shape when in use to fit comfortably in the operator's hand, the board on which the electronic components are mounted must also have a curved shape. Since it was impossible to solder such boards at all using conventional equipment, the soldering had to be done manually, which was extremely inefficient. In addition, because the process was performed by humans, the quality of the product varied greatly and the product lacked reliability. Furthermore, as electronic application equipment continues to become smaller, the mounting density of boards is increasing, and in some boards with high mounting density, the distance between adjacent soldering points is about 0.2 mm.
It has been impossible to manually solder boards with such high packaging density.

In addition, in Japanese Utility Model Publication No. 61-13157, two solder jet devices are arranged facing each other at a predetermined angle on both sides of the passage under the component passage, and the solder jetted from these two solder jet devices forms a An automatic soldering device has been disclosed which is configured to perform soldering by passing the solder flow path surface through the above-mentioned components, but in this conventional example, two solder jet devices It is cut off in parts,
Since these are not continuous, the jet of molten solder becomes like a waterfall flowing into a valley, and the only thing that can be obtained is a jet of molten solder with no flat parts formed at all. As a result,
Whether it is a flat board or a board that is curved downward, it is certain that the soldering performance in the center part will be poor, and it is highly doubtful whether it can be put to practical use. In any case, the present invention is a different invention with a completely different structure.

Purpose The present invention has been made in order to eliminate the drawbacks of the prior art described above, and its purpose is to provide an approximately
Molten solder is squirted out from a continuous nozzle in the shape of a letter.
Soldering is started from the left and right sides in the transport direction of a board that is warped downward in the width direction, and as the board is transported, soldering is performed while moving the soldering points toward the center in the width direction. Finally, by soldering the central portion, it is possible to automatically solder a board that is curved downward in a soldered state, which has been impossible in the past.
Another object of the present invention is to automatically solder a downwardly warped board, thereby making it possible to perform soldering with high working efficiency and high reliability. Still another object is to enable soldering of curved substrates with extremely high packaging density, increase the degree of freedom in the shape of the substrate, and enable diversification of products.

Composition In short, the present invention (claim 1) jets molten solder from continuous nozzles in a substantially V-shape that gradually narrows in the direction of conveyance of the substrate, and conveys the substrate convexly curved downward in the width direction. Soldering is started from both left and right sides, and as the board is transported, soldering is performed while moving the soldering point toward the center in the width direction, and finally the center is soldered. It is characterized by:

The present invention (claim 2) also provides a substrate transport device that transports the board so that the board is held with the required soldering points facing downward while gradually rising with respect to the horizontal line as the board is transported; A jet-flow type solder bath is provided with a nozzle that spouts molten solder continuously in a substantially V-shape that gradually becomes narrower in the direction of conveyance of the substrate, and the substrate is curved in a downwardly convex manner and is conveyed by the substrate conveyance device. The contact between the soldering point and the jet of molten solder spouted upward from the substantially V-shaped nozzle starts from the left and right sides of the board in the transport direction, and gradually contacts the center part in the width direction as the board is transported. The device is characterized in that it is configured so that it can be moved toward.

The present invention will be explained below based on embodiments shown in the drawings. An automatic soldering device 1 according to the present invention includes a substrate transfer device 2 and a solder tank 4 provided with a substantially V-shaped nozzle 3.

In FIG. 1, the substrate conveying device 2 holds both ends 6a of the substrate 6 in the width direction using two chain conveyors 5 arranged in parallel, and conveys the substrate 6 in the direction of arrow A. The rotating shaft 9 of the motor 8 is the pulley 1
0 is fixed, and a belt 11 is wound around the pulley 10. The belt 11 is further wound around a pulley 12, and the rotation of the motor 8 is transmitted via a drive transmission mechanism (not shown) to a sprocket (not shown) that rotates around a shaft 13, thereby operating the chain conveyor 5. There is.

Referring also to FIGS. 2 to 5, the chain conveyor 5 is inclined at an angle α so as to face the conveying direction of the substrate 6 and rise with respect to the horizontal line,
The angle α is configured to be variable using a handle (not shown). The nozzle 3 is disposed in the solder tank 4 with a continuous opening 3a in a substantially V-shape that spouts molten solder 14 facing upward. Inside the approximately V-shape of the opening 3a, a generally rectangular first guide plate 3b is fixed in a V-shape, facing diagonally downward, in order to smoothly flow the molten solder 14 ejected from the opening into the solder bath 4. has been done. Further, inside the substantially V-shaped root portion 3h of the nozzle 3, a second guide plate 3c having a substantially semicircular opening shape is disposed at substantially the same height as the opening 3a. Further, on the outside of the approximately V-shape of the opening 3a, protrusions 3d, 3e, and 3f are provided on the outside of the bolt 1 to prevent the molten solder 14 spouted from the opening 3a from flowing out.
5, respectively.

The solder tank 4 stores molten solder 14, and is divided into an upper tank 4b and a lower tank 4c by a separation plate 4a. The separation plate 4a has an inflow hole 4d for the molten solder 14 and a hole 4e communicating with the nozzle 3. An electric heater 16 for melting the solder is disposed in a part of the solder tank 4, and a motor 18 is disposed in the other part via a mounting plate 19.
Pulley 21 fixed to rotating shaft 20 of motor 18
There are 22 belts wrapped around it. belt 22
is further wound around a pulley fixed to one end of a shaft 24 rotatably held in a bearing portion 23 fixed to the mounting plate 19, and an impeller 26 for pumping the molten solder 14 is attached to the other end of the shaft 24. is fixed. A heat dissipation fin 23a is formed in the bearing part 23 to prevent the bearing part 23 from becoming high temperature due to the heat of the molten solder 14.

In FIG. 1, an automatic soldering apparatus 1 includes a known fluxer 28, a preheater 29, and a substrate cooling fan 30, respectively, arranged at predetermined positions.

The method of the present invention (claim 1) is such that the molten solder 14 is ejected from the continuous nozzle 3 in a substantially V-shape that gradually becomes narrower in the conveying direction of the substrate 6, and the substrate 6 is warped downwardly in the width direction. 6. Soldering starts from the left and right sides 6a in the transport direction, and as the board 6 is transported, soldering is performed while moving the soldering points toward the center part 6b in the width direction, and finally the center part 6b is soldered. This is the method of attaching.

Effects The present invention is configured as described above, and its effects will be explained below. 1 to 5, when the power to the heater 16 is turned on, the solder in the solder tank 4 is melted by the heat generated by the heater 16, becomes molten solder 14, and is stored in the solder tank 4. When power is supplied to the motor 18 and the rotating shaft 20 of the motor starts rotating, the rotation is caused by the pulley 21, the belt 22, the pulley 25, and the shaft 24.
is transmitted to the impeller 26 via. impeller 2
6, the molten solder 14 flows from the upper tank 4b through the inflow hole 4d into the lower tank 4c in the direction of arrow B, but the flow rate in the lower tank 4c is lower than that of the inflow hole 4d.
Because the flow rate is much slower than the flow rate through the lower tank 4, its kinetic energy is mainly converted into pressure energy and
The pressure in c is increased. Melted solder 14 is indicated by arrow C
The solder flows slowly in the direction of the arrow D from the hole 4e, flows into the nozzle 3, is ejected from the opening 3a, and is guided by the first guide plate 3b and the second guide plate 3c into the solder bath 4. , and the circulation is repeated again by the action of the impeller 26.

On the other hand, when the chain conveyor 5 is driven by the motor 8, the board 6, which is held at both sides 6a in the width direction by the chain conveyor and is warped downward in a convex manner, moves along the arrow A.
The lower surface 6c of the substrate 6 is processed by the fluxer 28 and the preheater 29, and reaches the position of the solder bath 4. Here, as shown in FIGS. 4 and 5, the molten solder 14 spouted from the opening 3a of the nozzle 3 is approximately V-shaped and parallel to the horizontal line, while the substrate 6 is transported at a predetermined angle α. Therefore, the contact between the molten solder 14 spouting from the opening 3a and the lower surface 6c of the substrate 6 is at the approximately V-shaped opening end 3g.
Both sides 6 of the substrate 6 are formed by the wave crests 14a formed by
a, and as the substrate 6 is transported, the contact position gradually changes to the approximately V-shaped root portion 3h of the nozzle 3.
The soldering is performed while moving in the direction of , and in the direction of the center part 6b of the board 6, and finally the center part 6b of the board 6 is soldered by the wave crest 14b of the molten solder 14 formed at the root part 3h of the nozzle 3. The soldering of the soldered board 6, which is curved downward in a convex manner, is completed.

In the illustrated embodiment, the nozzle 3 has been described as being approximately V-shaped, but the fact that the optimal nozzle shape for soldering the board 6, which is often used in an arcuate downward convex manner, is a parabolic shape means that the nozzle 3 is cylindrical. It is clear from the shape of the cut end that is cut by tilting the nozzle by an angle α with respect to its axis.If the automatic soldering device 1 equipped with the nozzle 3 is used, the board 6 can be easily soldered even when soldering various boards 6 with different widths. The predetermined angle α in the conveyance of
can be kept constant.

Effects As described above, the present invention jets molten solder from a continuous nozzle in a substantially V-shape that gradually becomes narrower in the direction of conveyance of the substrate, and spreads the solder from side to side in the direction of conveyance of the substrate, which is curved convexly downward in the width direction. Soldering was started from both sides, and as the board was transported, the soldering points were moved toward the center in the width direction, and finally the center was soldered. It is possible to automatically solder a convexly curved board, which conventionally could only be soldered manually, and the work efficiency can be dramatically improved. Furthermore, since it is possible to prevent manual soldering errors, the reliability of the product is improved, and the number of man-hours for correcting defective soldering points can be reduced, which has a large economic effect. Furthermore, it is possible to automatically solder boards that are curved downward and are mounted at high density, which would be impossible to do manually, increasing the degree of freedom in the shape of the board and making it possible to diversify products. It has the effect of

[Brief explanation of the drawing]

The drawings relate to embodiments of the present invention; FIG. 1 is a plan view showing the entire automatic soldering device, FIG. 2 is an enlarged plan view showing the solder tank, and FIG. 3 is the configuration of the solder tank and the approximately V-shaped nozzle. and a perspective view showing the positional relationship between the board and the board.
Fig. 4 is a vertical sectional view taken in the direction of - arrow of Fig. 2 for explaining the soldering state on both sides of the board;
The figure is a vertical cross-sectional view taken along the - arrow in FIG. 2 for explaining the positional relationship between the nozzle and the substrate. 1 is an automatic soldering device, 2 is a board transfer device, 3
3c is a roughly V-shaped nozzle, 3c is a guide plate for molten solder,
3d, 3e, and 3f are protruding parts, 3h is a root part, 4 is a solder tank, 6 is a substrate, 6a is a side part, and 6b is a central part.

Claims (1)

[Claims] 1. Approximately V that gradually becomes narrower in the direction of conveyance of the substrate
Molten solder is squirted out from a continuous nozzle in the shape of a letter.
Soldering is started from both left and right sides in the transport direction of the board that is convexly curved downward in the width direction, and as the board is transported, soldering is continued while moving the soldering point toward the center in the width direction. An automatic soldering method characterized in that the central part is soldered at the end. 2. A board transport device that transports the board so that it gradually rises relative to the horizontal line as it is transported, while holding the board with the soldering points facing down;
Approximately V that gradually becomes narrower in the direction of conveyance of the substrate
A jet-flow type solder bath is provided with a nozzle that spouts molten solder continuously in a letter shape, and the soldering tank is provided with a jet solder tank that is provided with a nozzle that spouts molten solder in a continuous letter shape, and the solder tank is provided with a soldering tank that is convexly curved downward and is conveyed by the substrate conveyance device, and is connected upward from the approximately V-shaped nozzle. The contact with the jet of molten solder that is ejected from the substrate starts from the left and right sides of the board in the transport direction, and gradually moves toward the center in the width direction as the board is transported. Automatic soldering equipment. 3. A protrusion is formed on the outer upper surface of the substantially V-shaped nozzle to prevent the outflow of the jet of molten solder, and the protrusion is located at substantially the same height as the upper surface of the nozzle at the base of the substantially V-shape of the nozzle. Claim 2, characterized in that a guide plate for molten solder having a substantially semicircular opening is formed on the front side in the conveyance direction of the board.
The automatic soldering device described in section. 4. The automatic soldering apparatus according to claim 2, wherein the substantially V-shape is a parabolic shape.