JPS63149069A - Jet solder tank - Google Patents

Abstract

PURPOSE:To form the jet of a molten solder accompanied by an uniform rough wave of good quality with an inexpensive device by providing the loosely moving body extending long in the longitudinal direction inside the injection port of a molten solder and fitting a spring capable of adjusting its tension to the loosely moving body. CONSTITUTION:The roof shaped sqaure body B releasing its bottom and apex parts is composed of a pair of nozzle plates and a side plate 2 and an injection nozzle part A is formed by providing an injection port C extending long at the releasing end of the apex part. In this injection port C a circular columnar loose shaft 3, for instance, is arranged and projected to the external part from a hole 6, and the cover 5 storing the end part of the loose shaft 3 is provided at the outside of both side plates 2. A spring 4 capable of adjusting its tension is fitted to the loose shaft 3 inside this cover 5 and an adjusting screw 7 is connected thereto. When a molten solder bath is injected from the injection port C with this composition, the size of the wave added to the solder jet is varied by the strength of the upper and lower vibration of the loose shaft 3 and a soldering of good quality can be performed. Owing to the hole 6 being provided on the cover 5 no molten solder bath is collected and the deterioration of the spring 4 is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a jet solder bath for soldering printed circuit boards, particularly printed circuit boards mounted with chip components.

(Conventional technology) Conventional, pudding)! For temporary soldering, there is a method using, for example, a jet soldering bath. This method is a method in which the required parts of the printed circuit board are partially immersed in the bulges of the jet of molten solder and soldered. When immersed, the chip components are Soldering is a method to eliminate defects by allowing the solder to penetrate into the corners of the parts.

In such a type of jet solder bath, it is important to use a wave-making device as appropriate to wave the jetting molten solder in the solder bath so that rough waves are superimposed on the jet of molten solder.

(Problem to be solved by the invention) Regarding the structure of a jet solder bath used for soldering printed circuit boards mounted with chip components, many proposals have already been made, for example, just considering a wave-making device. Since there are sliding and rotating parts inside the solder bath, there are many failures, and the driving device for such a wave-making device needs to be installed separately outside the bath, making it very expensive. Moreover, they were unsatisfactory because the jet of molten solder was uneven and the ripples were not sufficient, making it impossible to achieve high-quality soldering.

The inventors of the present invention have repeatedly investigated a jet solder bath that can inexpensively apply rough waves to a jet of molten solder using a simple mechanism, and found that a spring is installed inside the spout of a jet nozzle portion immersed in a jet solder bath. We considered and attempted to provide a supported cylindrical floating body. See Utility Application No. 60-193624.

By immersing the cylindrical floating body whose both ends are supported by springs into the spout, the cylindrical floating body will move vertically and horizontally with the help of the spring's elasticity as the molten solder spouts out. The movement caused the molten solder to ripple, creating a solder jet with rough waves.

However, after further experiments, it was found that a wave-making device with such a structure did have some excellent effects.
Moreover, although it is inexpensive, it has been found that the spring is immersed in the molten solder bath, resulting in an uneven jet flow, and that the spring has a short lifespan and is prone to failure.

Therefore, an object of the present invention is to provide an inexpensive soldering method that can perform high-quality soldering of printed circuit boards mounted with chip components.
It is an object of the present invention to provide a jet solder bath with fewer failures.

A further object of the present invention is to improve the previously proposed jet solder bath and provide a jet solder bath that can stably form a jet flow entrained by rough waves even over a long period of time.

(Means for Solving the Problem) Therefore, in order to achieve the above object, the inventors of the present invention have conducted further studies to improve the support mechanism for the floating bodies in the jet soldering bath. , realized that the above-mentioned problems could be solved, and completed the present invention.

Here, the gist of the present invention is to provide a jet solder bath in which a jet nozzle portion having a long molten solder spout at the top is immersed in a molten solder bath, and a spout solder bath having a spouting nozzle portion provided with a long molten solder spout at the top thereof, and a spout solder bath having a spouting nozzle portion provided with a molten solder spout extending long at the top thereof. A floating body extending in the longitudinal direction is disposed at a position such that it is immersed in the molten solder bath, and is disposed so as to penetrate through the end faces of the molten solder spout which are spaced apart and opposed to each other in the longitudinal direction. It is a jet soldering bath.

There are many possible modifications to the manner in which the floating body is mounted at both ends of the floating body in the present invention, but according to one aspect, the floating body may be supported by tension springs at both ends, or may be supported by a stopper. These tension springs, which may be attached, may have their other ends fixed to an appropriate member, and in the case of a stopper, there are no particular restrictions on its specific structure as long as it can swingably support the floating body at both ends. Not done.

It is preferable that the widthwise position of such a floating body be kept as constant as possible during rocking motion, but when starting the operation of the jet soldering bath, it is preferable to make the widthwise position adjustable. preferable. This is because in many cases, it is preferable that the floating body be eccentric to the center of the jet, and the eccentric position also needs to be changed depending on the strength of the jet, the type of printed circuit board to be soldered, etc.

(Operation) Next, the present invention will be explained in more detail based on the accompanying drawings.

FIG. 1 is a schematic perspective view of a jet nozzle portion immersed in a jet solder bath according to the present invention, and in the figure, a jet nozzle portion A used in a jet solder bath according to the present invention has a pair of nozzle plates 1, 1. Side plates 2.
It is composed of 2. The nozzle plates 1 and 2 and the side plates 2.2 form a roof-like rectangular body B with an open bottom and an open bottom, and the solder flow flows inside this rectangular body from the bottom to the top, and the solder jet It flows out into the surroundings as a jet from the top that forms the outlet. This jetting nozzle portion A is immersed in a molten solder bath in a larger solder tank (not shown), and a circulating flow of molten solder is formed between the two. Note that the jet solder bath itself, which is a large solder bath, is already well known to those skilled in the art, and the present invention is not limited to a specific one. Omit disclosure.

A long elongated spout C is provided at the open end of the top of the quadrangular body B, and a floating shaft 3, which is, for example, a cylindrical floating body, is arranged at the center of the spout C. In the illustrated example, the top of the jet nozzle part A constitutes a rising part and is groove-shaped, and the idler shaft 3 is housed and arranged inside of the top part of the jet nozzle part A. ing. A cover 5 for accommodating the end of the floating shaft 3 is provided on the outside of the side plates 2.2. A spring 4 whose tension can be adjusted is attached to the floating shaft 3 extending inside the cover 5, and the other end of this spring 4 is connected to an adjusting screw 7, so that the floating shaft 3 is attached to the cover 5 at both ends. is supported by a spring 4 (hereinafter referred to as a "tension spring") at the opposite end of the spring.

Further, the adjustment screw 7 has a structure that allows the tension of the tension spring 4 to be adjusted as appropriate. Instead of this adjustment screw, it is also possible to adopt a structure in which the position of the spring is fixed with a pin.

When soldering is performed using a jet solder bath having the above-described structure according to the present invention, molten solder sent by a pump (not shown) is caused to flow upward inside the rectangular body B. The vertical vibration of the floating shaft 3 in the solder bath causes rough waves to be superimposed on the jet of molten solder flowing from below.

Also, during soldering, the magnitude of the wave applied to the solder jet can be changed depending on the strength of the vertical vibration of the floating shaft 3, so the tension spring 4 that supports the floating shaft 3 can be adjusted depending on the type of printed circuit board to be soldered. By adjusting the tension, the size of the waves can be adjusted. At this time, the position of the floating shaft 3 in the width direction is fixed as much as possible. In other words, when using the S7 pavers as described later, the play in the width direction is minimized as much as possible.

Most of the jet solder exits the spout C and flows out to the side, but a portion flows out from the aforementioned through hole 6 and flows down into the molten solder bath (not shown) on the outside. Since molten solder does not accumulate inside the cover 5, there is almost no chance that the molten solder comes into contact with the spring 4. Therefore, deterioration of the spring 4 due to the solder is minimized.

Note that the shape of the floating shaft 3 disposed in the jet portion at the top of the jet solder bath of the present invention is not limited to a cylindrical shape, and may be a flat plate, a prismatic shape, or any other suitable shape. The specific shape thereof is not limited to a specific shape, as long as it vibrates up and down by the jet of molten solder to give a kind of undulation to the jet.

The fixing mechanism of the floating shaft may be of a structure in which both ends are connected and supported by the cover by tension springs as shown in FIG. 1, but as a modification example, as shown in FIG. A hole is provided in the opposing wall of the side plate 2 and the box 5, and the floating shaft 3 is disposed through these through holes 6'' and 6°, and a stopper 8 is installed at the end of the floating shaft 3 from the outside of the cover 5 at both ends. may be attached and fixed.

The stopper 8 may be a screw having a head with a larger diameter than the through hole 6'', and if the screw is fixed to the floating shaft 3 from the outside of the box 5, there is no fear that it will fall out.

By the way, as already mentioned, the position of the floating shaft 3 is not particularly limited, but it is preferable to place it in the unrestricted flow region in order to promote vertical vibration.

Therefore, in another aspect of the present invention, the floating shaft 3 is provided at a position biased to either side from the center of the jet port C. In this case, the strength of the jet flow differs at the rear surface of the floating shaft 3, In addition to the vibration of the solder, is the movement of rough waves applied to the solder jet? It becomes U54t. Fourth
Examples of distribution in these cases will be briefly explained in the figure. In this case, it is preferable that the floating shaft 3 is provided biased toward the direction in which the printed circuit board enters (in the figure, the arrow indicates the direction in which the printed circuit board enters).The center of the ejection port C is indicated by a chain line.

If the floating shaft 3 is installed in a biased position,
The jet of molten solder does not flow symmetrically, but slopes upward along the direction of entry into the printed circuit board.
By forming such an inclined jet stream, it is possible to easily remove contaminants such as air from the surface when soldering a printed circuit board.

FIG. 5 is an assembled diagram of the ejection nozzle part A in the case of the above-mentioned example in which the structure is made eccentric by shifting the position of the cover 5, and the cover 5 supporting the floating shaft 3 is movable in the width direction. A flange 12 attached to the cover 5 is brought into contact with the side plate 2, and can be fixed in an appropriate position with a screw through an elongated part 10 provided on the flange 12. In this case, the groove hole 14 corresponding to the through hole 6 in FIG. 2 must also be formed eccentrically to correspond to the eccentric position of the floating shaft 3, or must be formed laterally long. In the example shown in FIG. 5, both ends of the floating shaft 3 are attached to a double force bar 5 via a tension spring 4.

(Effects of the Invention) According to the present invention, a jet of molten solder with good quality and uniform rough waves can be obtained by vertical vibration of a floating body installed in a jet solder bath, and a support mechanism for the floating body such as a spring can be obtained. A jet solder bath is obtained which has a jet nozzle portion that exhibits little deterioration, has an extremely simple structure, and has few failures. In particular, there is no need to separately provide a drive source for the floating body, and the present invention is also advantageous in terms of running costs.

Furthermore, according to the present invention, in the case of a floating body supported by a spring, by adjusting the spring tension according to the printed circuit board to be soldered, it is possible to generate a jet stream with an adjusted wave size. A profitable jet solder bath that allows high-quality soldering to be performed at low cost is obtained.

In addition, when the floating body is installed eccentrically within the jet nozzle,
A so-called inclined jet can be obtained, and the quality of soldering can be further improved.

Therefore, by using the jet solder bath according to the present invention, it is possible to improve the process efficiency and quality of soldering of printed circuit boards, etc., and the benefits thereof are very large.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing a jet solder bath according to the present invention; FIG. 2 is a partially enlarged sectional view showing the structure of a floating body support mechanism using a tension spring of a jet solder bath according to the present invention; FIG. 3 is a schematic partial cross-sectional view of another embodiment of the jet solder bath according to the present invention; FIG. 4 is a schematic explanation showing the floating shaft provided at the eccentric position of the jet nozzle and the state of the flow of the jet at that time. Figures 1 and 5 are assembly diagrams of further embodiments of the jet solder bath according to the present invention.

Claims (4)

[Claims] (1) A jet soldering bath in which a spouting nozzle portion with a long molten solder spout at the top is immersed in a molten solder bath, and a floating body extending longitudinally within the molten solder spout. 2. A jet solder tank, characterized in that the jet solder bath is disposed at a position such that it is immersed in the molten solder bath, and is disposed so as to penetrate through both end faces of the molten solder spout which are spaced apart and opposed to each other in the longitudinal direction. (2) The jet solder bath according to claim 1, wherein the floating body is supported by tension springs at both ends thereof. (3) The jet solder bath according to claim 1, wherein the floating body is supported with stoppers attached to both ends thereof. (4) The jet solder bath according to any one of claims 1 to 3, wherein the floating body is provided so that its position in the width direction can be freely adjusted.