JPS6199570A - Flux coating instrument - Google Patents

Abstract

PURPOSE:To make easy the invasion of a flux behind electric components and into the gap by spouting in a wave shape a flux by the jet part of a flux and by having the forming means of a turbulent wave forming the wave front of this wave in a turbulent condition. CONSTITUTION:A flux is jetted from the numerous jet ports 14, 14... formed on a turbulent wave forming plate 13 with operating an impeller. The flux is spouted in half-wave shape and becomes such a turbulent condition as forming several small crests on the wave front and the wave front is varied up and down to the right and left irregularly always due to the fluidity of the flux at the wave bottom part. When a printing substrate is touched with the wave of flux, it is made so as to flow to the electrodes of a soldering land and tip component. The escape route of gas or air is secured with the vertical and horizontal variation of the wave front and the flux can be well wetted at the escaped traces.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a flux coating device, and in particular, to better improve flux coating in the pre-process when printed circuit boards are transported at high speed and soldered. Concerning what was done.

2. Description of the Related Art In general, printed circuit boards are made by forming a copper foil circuit pattern on the surface of a laminate board, and soldering the circuit pattern so that electrical components such as resistors and capacitors can be attached to the lands. In this case, the circuit pattern is formed on the opposite side of the printed circuit board where the electrical components are attached and there is a soldering land on this side, and the circuit pattern is formed on the same side of the printed circuit board where the electrical components are attached. There is a so-called flat mount type that has a soldering land on the side.

For any type of soldering, flux is applied and preheated in the previous process. For example, if we consider the case of jet soldering, when soldering a printed circuit board, the lands and leads or electrodes of electrical components come into contact with molten solder that can reach temperatures of 250°C. This is to prevent air oxidation since it is unavoidable, and also to reduce the lands and the like once air oxidized during soldering so that molten solder can easily adhere to them.

This kind of flux is made by dissolving pine resin in alcohol to make a 5-50% solution, and adding a small amount of amine halide salt to this, but in order to apply it,
There are also methods in which the flux is ejected from a nozzle and the soldering part is brought into contact with the top of the flux, and another method is in which the flux is foamed and the bubbles are attached to the soldering part.

However, with the method of ejecting flux from a nozzle, for example, in the case of a flat-mounted electrical component, the flux tends to not be applied to areas that are shaded by the ends of the electrodes.

In particular, as shown in FIG. 12, the circuit pattern formed on the board body 1 is soldered to the lands 2.2...of leadless chip components 3a, 3b, 3c, 3d, 3.
When soldering e, between these chip parts''
When the packaging density increases, such as when the spacing E is close to 0.5 to 5IIIn, the flow of the jet flux is laminar in the shaded area in the diagram, and the arc length is larger than this spacing. In some cases, flux solvent gas or air accumulates in this gap, which tends to prevent the flux from being supplied, and when this happens, problems such as land oxidation occur during soldering, as described above. soldering will harm the performance.

In addition, the method of attaching flux bubbles to the soldering part can form a thin and uniform coating while the conveyance speed of the printed circuit board is low, but when this increases to a speed of 3 m/lll1n, for example, the flux bubbles become attached to the soldering part. The flux adheres to the part, and before it disappears, the next bubble overlaps and adheres, and this repeats, resulting in many layers of flux bubbles adhering to the printed circuit board, which are broken when preheated in the next process. It is easy to cause dripping. If this happens, the flux will not be applied unevenly and will not only stain the equipment, but the amount of flux bubbles will also be the same.
Bubbles that should be attached to a subsequent printed circuit board are likely to adhere to the previous printed circuit board, so that no flux is applied to the subsequent printed circuit board. This kind of thing is
The higher the conveyance speed of the printed circuit board, the more likely it is to occur.

However, reducing the conveyance speed of the printed circuit board to reduce the soldering speed in order to apply flux causes the problem that the productivity of soldering cannot be improved and production costs cannot be reduced.

Problems to be Solved by the Invention As mentioned above, with conventional flux applicators, the jet type cannot sufficiently supply flux to areas that are shaded by electrical components, and the flux foaming type cannot supply flux at high speed. There may be too many bubbles on the printed circuit board being transported.
As a result, there is a problem that some printed circuit boards lack bubbles, and an improvement has been desired.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a flux coating device that jets flux from a spouting section. The present invention provides a flux applicator characterized by having a turbulent wave forming means for forming a flow state.

Further, in a flux application device that jets flux from a spouting part, the nozzle includes a turbulent wave forming means that jets out the flux in a wave shape and forms the crest of the wave in a turbulent flow state, and a nozzle that has a turbulent wave forming means that jets out the flux in a wave shape and forms the wave crest of the wave in a turbulent flow state; The present invention provides a flux coating device characterized by having a laminar flow wave forming means or a plane dipping means.

Since the working flux is ejected from the nozzle in a turbulent flow, the flux can easily enter behind and into gaps of electrical components. Furthermore, since the supplied flux is not foam, there is no possibility of foam adhering to the flux.

Next, one embodiment of the present invention will be described based on FIGS. 1 and 2 with reference to FIG. 12.

11 is a flux storage tank, and this flux storage tank 11
is provided with a nozzle 12. This nozzle 12 is formed into a trapezoidal cross-section with its lower part widened, and a turbulent wave forming plate 13 is attached to the nozzle opening at the upper end. A large number of jet ports 14, 14, . . . are formed in this turbulent wave forming plate. The size of the nozzles is such that when the flux is ejected from these nozzles, the crests of the waves can penetrate into the gaps between adjacent electrical components. Although not shown, an impeller is provided so that the flux is ejected from the nozzle 12.

Next, the operation of this embodiment will be explained.

The impeller (not shown) is operated to send the flux to the spout 1.
4. Make it erupt from 14... The flux ejected in this case is as shown in Figure 2. The flux is ejected in a half-wave shape, and the wave crest becomes a turbulent state with several small peaks. It constantly fluctuates irregularly up and down and left and right due to the flow of flux at the bottom of the wave. The height of the wave crest, the number of peaks, and the degree of fluctuation vary depending on the flux ejection pressure by adjusting the impeller. In this way-
When the printed circuit board shown in Figure 12 is brought into contact with the generated flux waves, the wave crests of the flux waves enter the shaded areas of the chip component, and the turbulence of these wave crests causes gas or air trapped in the shaded areas to As the soldering flux is removed, the flux begins to wet the soldering lands and the electrodes of the chip components. Further, since the wave crest fluctuates vertically and horizontally, this fluctuation also ensures an escape path for the gas or air, so that the flux can wet the traces of the escape.

In the above embodiment, the turbulent wave forming plate 13 was provided at the upper end of the nozzle 12, but as shown in FIG.
may be provided below within a range of, for example, 30 mm from the edge of the nozzle opening, so that only the wave crest of the flux projects upward from the edge of the nozzle opening.

Further, as shown in FIG. 4, the turbulent wave forming plate 13' may be formed in a convex arc shape. Further, as shown in FIG. 5, a large number of cylindrical ejection tubes 15, 15 for forming turbulent waves may be provided, and the flux may be ejected through these.Furthermore, as shown in FIG. Wave plate 12 is attached to the nozzle shown in the figure.
a, 12'a may be provided.

In addition, the above turbulent wave forming plates are shown in Fig. 7 (a), (b), (
Turbulent wave forming plate 1 having a jet outlet shape as shown in c)
3a, 13b, and 13c may also be used.

Combinations of jet ports with different shapes tend to cause fluctuations in the flux waveform. In addition, by changing the arrangement and number of ejection ports, the thickness of the turbulent wave forming plate, and even the ejection pressure of flux, and by combining these, it is possible to change the pattern shape of printed circuit boards, the density of component leads, and the shape of leadless components. A desired flux turbulence wave can be obtained to perform flux application that is optimal for the packaging density and arrangement state.

In the above, the turbulent flow of flux is formed by the jet port or the jet tube, but as shown in FIGS. The nozzle opening of the 71 nozzle 12 may be provided with a bar 18 to divide the nozzle opening into two, or the nozzle opening of the nozzle 12 may be provided with a bar 19a in a V shape.
19b may be provided to divide the nozzle opening into three parts and divide the flux into three parts to form a turbulent flow. Note that the cross-sectional shape (ellipse, triangle, quadrangle, etc.), size, number, and arrangement of the bars can be selected as appropriate, and any combination thereof can be used.

Although the turbulent wave forming plate, jet tube, and bar are fixed, they may be made movable, for example, swingable back and forth, left and right, or back and forth.

Also, the above was a case where one nozzle was provided, but the first
As shown in FIG. 1, for example, the turbulence forming plate 13 shown in FIG.
and a turbulence forming plate 1 like this.
3 is used in combination with the nozzle 12 that does not have 3, the flux film formed by the turbulent waves formed on the printed circuit board is immersed in the flux produced by the laminar waves, and the film thickness is made uniform.
You may also do a side-by-side comparison. In this case, a turbulence forming plate may be provided in a part of one nozzle opening so that one nozzle has the functions of the above two nozzles. In addition, in these cases, the nozzle 12 may not be used, and a plane dipping device for dipping into the flux contained in a flux tank may be used.

As described in detail, according to the present invention, since the nozzle is provided with a turbulent wave forming means such as a jet port for forming a turbulent flow, the ejected flux is formed in a wave shape having unevenness. Therefore, when applying flux, it is possible to expel gas or air accumulated in the gaps between adjacent electrical components on the soldering body, for example, a printed circuit board, while supplying flux to the necessary locations in the gaps. Since the flux is not supplied in the form of bubbles, it follows the printed circuit board even when it is transported at high speed, and the amount of flux applied is just the right amount.

This makes soldering work more efficient and reduces production costs.

Furthermore, if a printed circuit board is brought into contact with this turbulent flux, for example, and then brought into contact with laminar flow flux or flux from a plane dipping device, the film thickness etc. will be made uniform and the finish will be improved. . ”

[Brief explanation of the drawing]

FIG. 1 shows an apparatus 1 of an embodiment of the first invention of the present invention.
2 is a perspective view showing the state of use, FIGS. 3 to 6, and 8 to 10 are perspective views showing the nozzle of the device of other embodiments, and FIG. (stomach),
(B) and (C) are explanatory diagrams showing other shapes of the ejection opening of the turbulent wave forming plate of the nozzle shown in FIGS. 1 and 3 to 6 above, and FIG. FIG. 12 is an explanatory cross-sectional view of an apparatus according to an embodiment of the invention, and FIG. 12 is an explanatory view showing a state in which parts of a printed circuit board are soldered. In the figure, 12.12" is the nozzle, 13.13', 13"
, 13a. 13b, 13C115,15"・, 17a ~ 17
b, 18, 19a, and 19b are a turbulent wave forming plate, an ejection tube, and a bar, respectively, as turbulent wave forming means. October 22, 1980 Third Country Figure 7 r Inorakuchi Nora Chang No Figure 1o Figure 11 Figure 12

Claims (2)

[Claims] (1) A flux applicator that jets flux from a jetting part, wherein the jetting part has a turbulent wave forming means that jets flux in a wave shape and forms the crest of the wave in a turbulent state. Coating device. (2) A flux coating device that jets flux from a spouting part, including a nozzle having a turbulent wave forming means that spouts the flux in a wave shape and forms the crest of the wave in a turbulent state, and a laminar flow wave of the flux. 1. A flux coating device comprising a laminar wave forming means or a plane dipping means for forming a flux.