JPS58200594A - Automatically soldering method and device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for automatic soldering, in which dip-type soldering can be applied to printed circuit boards without holes for lead wires by rippled the surface of molten solder. The present invention relates to a method and apparatus for automatic soldering of a printed circuit board that enables good soldering of one-side child components.

Conventionally, as shown in FIG. 1, in dip soldering, when soldering an electronic component 2 to a printed circuit board 1, a 1 m hole for a lead wire ZJl is drilled in the printed circuit board 1, and the electronic component 2 is is attached to the upper surface, the lead @ 2a is passed through the hole 1a, and the lower surface 1b KIIIt is applied, and a flux is applied to the lower surface 1b4C including the circuit portion 3 such as copper foil and the lead wire 2a using a flux coating device (not shown). After that, the lower surface 1 of the printed circuit board 1 is applied to the upper surface 4 m of the molten solder 4.
Soldering was performed by dipping b. In this case, the slack applied to the printed circuit board 1 comes into contact with the molten solder 4 and generates a large amount of 7 slack scum 5.
Since the 7 lux gas 5 escapes upward from the hole for the 5#-t lead wire 2a, the 7 lux gas 5 does not interfere with the contact between the soldering point and the molten solder 4, and the soldering can be performed well. It is something that

However, recently, in order to make the printed circuit board 1 thinner, lighter, and lower in cost, chip-type electronic components 2 without lead wires 2a have begun to be used.

This electronic component 211 without lead wire 2a, as shown in FIG.
Since the lead wire 2a is soldered directly to the printed circuit board 1, the hole 1a for the lead wire 2a is often not made in the printed circuit board 1.

Therefore, as shown in FIG. 2, in the same way as in FIG.
When attempting to solder the printed circuit board 1 with the circuit portion 3 and electronic components 2 facing down using dip soldering, a large amount of flux gas 5 is generated when the applied flux comes into contact with the molten solder 4. Since the printed circuit board 1 does not have a 1 m hole for the lead wire 2, the lead wire 2 either escapes horizontally by passing between the printed circuit board 1 and the upper surface 4a of the molten solder 4, or becomes stagnant with no place to escape. As a result, the flux gas 5 often interferes with the contact between the molten solder 4 and the location to be soldered, resulting in a disadvantage that there are often some areas where the solder does not attach.

In order to eliminate this drawback, wave soldering was adopted, in which soldering was performed while eliminating flux gas with solder waves, but in the case of this wave method,
Since the contact time between the part to be soldered and the molten solder is short, soldering has a disadvantage in that its performance is slightly inferior to that of dip soldering. In other words, the dip method has superior soldering performance because the printed circuit board is immersed in stationary molten solder for a long time, but conventional technology has the above-mentioned flux gas problem, so only the dip method is used. It has been practically impossible to solder a printed circuit board without holes for lead wires.

The present invention aims to eliminate the above-mentioned drawbacks of the prior art.
Dip soldering is a method and apparatus for soldering printed circuit boards by vibrating and undulating the surface of the solder near the point where the printed circuit board begins to come into contact with the molten solder. The purpose is to make it possible to remove the flux scum generated from the bottom surface to the outside, and also to make it possible to solder electronic components to one side of a printed circuit board without a hole for the lead wire piece. The goal is to make it possible to attach. Another purpose is to improve flux scum removal efficiency by making the waves on the surface of the molten solder as large as possible near the position where the printed circuit board starts contacting the molten solder.

In short, the method of the present invention is a dip-type soldering method in which a printed circuit board is conveyed from above to below, vibrates the surface of the molten solder in the vicinity of contact with the surface of the molten solder, and causes the molten solder to ripple. The device of the present invention is characterized in that flux gas is eliminated by waves of molten solder, and the device of the present invention is a dip-type soldering device that includes a vibration generator that generates vibrations at a predetermined frequency, and a vibration generator that generates vibrations at a predetermined frequency. A diaphragm connected to a vibrator, one end of which is immersed in molten solder in a solder bath, and vibrated by the vibration generator, and the surface of the molten solder is vibrated and rippled by the diaphragm. , is characterized in that the flux gas is removed by the waves of the molten solder.

The present invention will be explained below based on embodiments shown in the drawings. Third
In the first embodiment of the present invention shown in FIG. A diaphragm 7'Lfc diaphragm 9 with one end 9a immersed in molten solder 4 is attached to the vibrator. Further, the vibration generator 18 is connected to the power supply lO, and the vibration plate 9I/
'i It is designed to vibrate 200 to 500 times per second, with a single amplitude of about 5 snow. In this first embodiment, the diaphragm 9 vibrates in the same direction as the conveyance direction of the printed circuit board 1 as indicated by arrows A and H, and its width is equal to the width of the solder bath 7. Then melt the solder 4 by nuclear vibration etc.
The surface 4a of the molten solder is photographed to make waves)
K is configured to eliminate flux scum 5.

The present invention is constructed as described above, and its operation will be explained below. In Figures 3 and 4, when the vibration plate 9 vibrates in the molten solder 4 of the solder tank 7 by the vibration generator 8 as indicated by arrows A and l-S, the surface 4 of the molten solder 4
a is wavy, and waves 4W of the bath melted solder 4 are continuously formed n
As a result, the printed circuit board 1 descends diagonally as shown by the arrow C, and its lower surface 1b, circuit portion 3, and electronic component 2 are exposed to the molten solder 4.
The flux scum 5 generated when it comes into contact with is removed by the wave 4W as shown by the arrow. In addition, the wave 4W is almost attenuated and disappears at the position where the printed circuit board I is in a horizontal state, so complete soldering can be performed using the conventional dip method and the molten solder 4 between the circuit part 3 and the molten solder 4 due to the flux gas 5. Since the contact is not disturbed, good soldering can be achieved even when the printed circuit board 1 does not have a hole 1a for the lead wire 2a.

In the second embodiment of the present invention shown in FIG.
9 is formed so that the portion 19a is wide or narrow and bent downward.]
The portion 19b is extended horizontally, n1, and the portion 19C is bent upward, so that the portion 19c is formed to have a bottom width. Since the wave 4W is the largest at the position where the lower surface 1b of the printed circuit board 1 starts to come into contact with the molten solder 4, that is, at the position 1 where the most flux gas 5 is generated, the flux gas is most efficiently generated. 5 can be eliminated. In FIG. 5, the same parts as in the first embodiment are designated by the same reference numerals, and the explanation thereof will be omitted.

Next, in the M3 embodiment shown in FIG. 6, the vibration generator 8 is rubbed against the side edge 7b of the solder bath 7, and the vibration plate 29 is
The diaphragm 29 is designed to vibrate in the transverse direction with respect to the conveyance direction of the printed circuit board l (in the direction of arrow C), and the vibration plate 29 is formed in a comb shape, and the vibration plate 29 vibrates between the comb teeth 29a. The lead wire 2a protruding downward from the lower surface 1b passes through the diaphragm 29 so that the diaphragm 29 is brought as close as possible to the point where the printed circuit board 1 first contacts the molten solder 4. There is.

When the diaphragm 29 vibrates in the directions of arrows E and F, the surface 4a of the molten solder 4 is rippled by the diaphragm 29, causing the molten solder 4 to ripple f1.
In the transport direction of the printed circuit board 1 [.

A lateral wave 4W is formed by the wave button, and the flux gas 5 is expelled in the lateral direction of the printed circuit board 1.

Even if an electronic component 2 with a lead wire 2a is mounted together with a chip-type electronic component 2, there is no problem because the lead wire 2a passes between the comb teeth 29a of the diaphragm 29, and the diaphragm Since the wave 29 is formed into a comb-teeth shape and vibrates in the horizontal direction, the size of the wave 4W closest to the position where the most flux scum is generated increases, so that the flux scum 5 can be efficiently removed. can.

Since the present invention is constructed and operates as described above, dip-type soldering is a method and apparatus in which a printed circuit board comes into contact with molten solder and vibrates the surface of the solder in the vicinity where it begins to ripple. As a result, flux gas generated from the bottom surface of the printed circuit board can be expelled to the outside.This dip-type soldering can be applied to printed circuit boards that do not have holes for lead wires, even if the equipment is used. The effect is that electronic components can be soldered well on one side. Furthermore, since the waves on the surface of the molten solder are made larger near the position where the printed circuit board starts contacting the molten solder, an effect can be obtained in which flux scum can be efficiently removed.

[Brief explanation of the drawing]

Figures 1 and 2 show the conventional example tc*b, and Figure 1 shows the dip-type soldering of electronic components to a printed circuit board with holes for lead wires. A vertical cross-sectional view showing a state in which escape occurs through a hole,
Figure 2 is a side view showing how flux gas escapes in the horizontal direction when dip-type soldering is used to solder chip-type electronic components onto a printed circuit board that does not have holes for lead wires. , FIGS. 3 and 4 relate to the first embodiment of the present invention, and FIG. 3 shows how waves of molten solder are formed.
Vertical section showing the condition in which flux gas is removed.
1 side view, FIG. 4 is a perspective view of the landscape, FIG. 5 is a vertical cross-sectional view of the supporting part according to the second embodiment of the present invention, and FIG. 6 is a schematic plan view of the main part according to the third embodiment of the present invention. It is. 1 is a printed circuit board, 4 is molten solder, 4a is an interface, 4W wave, 5 is a fuse gas, 7 is a solder bath, 8 is a vibration generator, and 9, a 19.29 Fi diaphragm. Patent applicant: Asahi Kagaku Kenkyusho Co., Ltd. Patent attorney: 1) Kazuo

Claims (1)

[Claims] l Dip soldering is a method in which the printed circuit board is conveyed from above to below, and the surface of the molten solder is vibrated and rippled in the vicinity of contact with the surface of the molten solder;
The flux gas is removed by the waves of the molten solder.
Automatic soldering method featuring and. 2. Dip soldering uses a device that includes a vibration generator that generates vibrations at a predetermined frequency, and a device that is connected to a vibrator of the vibration generator and has one end immersed in molten solder in a solder bath.
and a diaphragm vibrated by the vibration generator,
An automatic soldering device characterized in that the surface of the molten solder is vibrated and rippled by the diaphragm, and the waves of the molten solder eliminate 7 lux gas.