JP2578602B2 - Automatic soldering device and automatic soldering method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic soldering apparatus and an automatic soldering method, and more particularly to an insulation coating when an electronic component having a lead wire is soldered to a circuit board. The present invention relates to an automatic soldering apparatus and method suitable for automatically soldering a lead wire to a connection pattern of a circuit board.

B) Conventional technology Conventionally, when an electronic component having a lead wire, for example, a coil 1 formed into a cylindrical shape by winding an insulated conductor wire as shown in FIG. As shown in the figure, one lead wire 3 of the coil 1 is led out from the hollow portion 5 side of the coil 1 so that the lead wire 3
Is generally soldered to the connection pattern 9 of the circuit board 7 in the hollow portion 5 of FIG. Reference numeral 10 in FIG. 9 denotes a solder resist layer.

In order to solder the lead wire 3 to the connection pattern 9, it is difficult to adopt an automatic soldering method such as providing a circuit board 7 on the molten solder or jetting the molten solder on the circuit board 7. The lead wire 3 was soldered to the connection pattern 9 using a soldering iron after pre-treatment such as partially peeling off the insulating coating of the lead wire 3 and applying preliminary soldering to the peeled portion. .

C) Problems to be Solved by the Invention However, such an operation of partially soldering using a soldering iron is extremely inefficient and has the following problems.

That is, the soldering operation as described above requires extra and troublesome pretreatment such as partially peeling off the insulating coating of the lead wire 3 of the coil 1 and further applying preliminary soldering to the peeled portion. In addition, the number of man-hours is increased, and the production efficiency is easily reduced, and the price is hardly reduced.

Also, due to the rapid vaporization of the flux mixed in the solder at the time of soldering, solder balls are likely to be generated around the connection pattern 9 after soldering, and extra time is required for removing the solder balls. Was needed.

Furthermore, when the circuit board has a configuration in which a connection pattern is formed on a metal substrate via an insulating layer, and pressing the lever of the solder to the connection pattern 9, the insulating layer between the metal plate and the connection pattern is damaged. I was worried.

The present invention has been made in order to solve such a conventional drawback, automatic soldering to a partial area of the circuit board is easy, the pretreatment of the lead wire is unnecessary and solder balls are hardly generated, Provided are an automatic soldering apparatus and an automatic soldering method that do not cause damage to a circuit board.

D) Means for solving the problem In order to solve such a problem, the present invention, as shown in FIGS. 1 and 4 to 7, stores a molten solder 13 in a solder bath 11. A heat-resistant raw mask 19 having a protruding nozzle 17 is arranged so as to overlap the liquid surface of the molten solder 13, and the molten solder 13 is pressurized to raise the liquid surface of the mask 19 to increase the nozzle 17. It is provided with a pressurizing means for forming a hemispherical liquid surface 25 at the tip, and when at least a member to be soldered is brought close to the nozzle 17, it is formed at the tip of the nozzle 17 by pressurizing the molten solder 13. The hemispherical liquid surface 25 is soldered to the connection pattern 29 of the circuit board 27.

E) Function The present invention provided with such means provides a protruding nozzle
When a pressure is applied to the molten solder 13 using a mask 19 that has 17 and is arranged so as to overlap the liquid level of the molten solder 13, the liquid level rises and a hemispherical liquid level 25 is formed at the tip of the mask 19. If the connection pattern 29 of the circuit board 27 is overlaid on the hemispherical liquid surface 25, it is soldered to the connection pattern 29.

F) Examples Examples of the present invention will be described below.

FIG. 1 is a sectional view showing an embodiment of the automatic soldering apparatus according to the present invention.

In the figure, solder is stored in a molten state in a solder bath 11, and the melted solder 13 is heated to 400 ° C.
It is kept at about 50 ° C.

A cylindrical inner container 15 whose upper side is open is arranged in the solder tank 11, and communicates with the inside of the solder tank 11 so that the molten solder 13 also accumulates in the inner container 15.

The upper end of the inner container 15 protrudes from the liquid surface of the molten solder 13, and a mask 19 having a plurality of nozzles 17 projecting upward is superposed on the end of the inner container 15 as shown in FIG. I have.

FIG. 1 shows a mask 19 having one nozzle 17 for convenience. The inner diameter of the nozzle 17 is appropriately selected according to the area of the connection pattern (to be described later) 29 to be soldered, but usually about 2 to 3 mm is sufficient.

The mask 19 is formed by shaping a heat-resistant and corrosion-resistant material such as a stainless steel material or a titanium material, which is not corroded or deformed by the molten solder 13 or a flux at the time of soldering. Is coated with a ceramic coating by a thermal spraying technique using a material that does not melt in the molten solder 13 and is non-wetting.

A fan 21 for applying pressure to the melted solder 13 is disposed at a lower portion in the inner container 15, and the fan 21 is rotatable by a motor 23 from outside the solder bath 11.

When the fan 21 is rotated by the motor 23, pressure is applied to the molten solder 13 to raise the liquid level of the molten solder 13 in the inner container 15, and the outer periphery of the mask 19 is ceramic-coated with a non-wetting material. Therefore, at the tip of the nozzle 17 of the mask 19, as shown in FIG.

If the motor 23 is controlled so that the rotation speed of the fan 21 can be changed in a plurality of stages, the shape and height of the hemispherical liquid surface 25 formed at the tip of the nozzle 17 can be adjusted.

Such an automatic soldering apparatus of the present invention rotates the fan 21 to apply pressure to the molten solder 13, and forms a hemispherical liquid surface at the tip of the nozzle 17 of the mask 19 as shown in FIG. When the connection pattern 29 of the circuit board 27 is overlapped with the nozzle 17 at a small interval, the connection pattern 29 can be soldered.

Reference numeral 31 in FIG. 3 denotes a solder resist layer, and reference numeral 33 denotes a lead wire of the coil 35.

If the temperature of the molten solder 13 is set to a temperature at which the insulating coating of the lead wire 3 is melted, it is not necessary to peel off the insulating coating of the lead wire 33 in advance, and since there is no flux in the molten solder 13, the connection is made. Good soldering can be achieved simply by applying flux to the pattern 29.
Solder balls are less likely to form around the surface.

Further, since the circuit board 27 can be soldered by merely overlapping the tip of the nozzle 17 of the mask 19 at a small interval, no pressure is applied to the connection pattern 29, and the insulation layer between the connection pattern 29 and the circuit board 27 is damaged. Without, circuit boards 27 of various configurations
In this case, soldering becomes easy.

If at least the nozzle 17 of the mask 19 is ceramic-coated with a non-wetting material, a good hemispherical liquid surface 25 can be formed by melting solder.
If a titanium material is used as the material, it is not always necessary to perform ceramic coating with a non-wetting material.

Next, an example of use of the automatic soldering apparatus of the present invention will be described, and an automatic soldering method according to the present invention will also be described.

First, as shown in FIG. 4, when the solder bath 11 is heated and the molten solder 13 is stored therein, the liquid level of the molten solder 13 in the solder bath 11 including the inner container 15 is at the same level. Has become.

Next, as shown in FIG. 5, on a circuit board 27 having a connection pattern 29, a coil 35 formed into a cylindrical shape in the same manner as in FIG. 8 so that the connection pattern 29 is positioned in a hollow portion 37 thereof. After being fixed, the lead wire 33 extending into the hollow portion 37 is positioned above the automatic soldering apparatus of the present invention in a state of being led out onto the connection pattern 29.

On the other hand, the motor 23 is driven and the fan 21 is turned to rotate the inner container.
When a pressure is applied to the molten solder 13 in the inner container 15, the liquid level of the molten solder 13 in the inner container 15 rises, and a hemispherical liquid surface 25 of the molten solder is generated at the tip of the nozzle 17 of the mask 19.

In this state, as shown in FIG. 6, when the circuit board 27 is lowered and the connection pattern 29 is arranged so as to be slightly spaced from the nozzle 17, the semispherical liquid surface protruding from the nozzle 17 is obtained.
25 contacts the connection pattern 29 and the connection pattern 29 is soldered.

In this case, if the rotational speed of the fan 21 is increased and a stronger pressing force is applied to the molten solder 13 than in the state shown in FIG. 5, the hemispherical liquid surface 25 formed at the tip of the nozzle 17 projects higher and connects. Soldering to the pattern 29 becomes easier.

Then, as shown in FIG. 7, when the circuit board 27 is raised again, the lead wire 35 of the coil 35 is fixed in a state of being soldered to the connection pattern 29, and when the rotation of the fan 21 is stopped, the circuit board 27 is formed. The hemispherical liquid surface 25 falls down in the nozzle 17 and returns to the state shown in FIG.

In implementing the automatic soldering apparatus and the automatic soldering method of the present invention, since the solder bath 11 is heated at a high temperature in order to keep the solder in the solder bath 11 in a molten state, the surface of the molten solder 13 is oxidized. Oxides are easily generated, and oxides are less likely to be generated if the process is performed in an atmosphere such as nitrogen gas.

Further, in the embodiment of the present invention, a pressure is applied to the molten solder 13 in the solder bath 11 to apply a hemispherical liquid surface 25 to the tip of the nozzle 17.
Is formed, but as a pressing means applied to the molten solder 13,
In addition to the above-described fan 21 and motor 23, for example, even in a configuration in which the inner container 15 and the mask 19 in the above-described embodiment are lowered with respect to the solder tank 11, a hemispherical liquid surface 25 is formed at the tip of the nozzle 17. It is possible.

However, since the circuit board 27 to be soldered is also configured to be lowered with respect to the solder tank 11, the structure is likely to be complicated, and a means for applying a pressing force to the molten solder 13 in the solder tank 11 or the inner container 15 is employed. Would be better.

In implementing the present invention, when Sn-Pb solder is used, it is preferable to use a solder having both components of about 50% for the following reasons.

In other words, a general electric solder has a eutectic point temperature of about 183.
° C, 183 for solder with 63% Sn and 37% Pb
When the temperature is higher than ℃, it is liquefied, and when the temperature is lower than 183 ° C, it has the property of solidifying, and is unlikely to be semi-molten.

On the other hand, in the case of solder with both Sn and Pb components of about 50%, when the temperature is higher than 183 ° C, it liquefies through a semi-molten state, and the liquefaction temperature increases, and when the temperature decreases, it changes in the opposite state I do.

Therefore, when implementing the present invention, in the process of raising the circuit board 27 after the molten solder 13 melted at about 400 ° C. adheres to the connection pattern 29 and is soldered, the temperature of the solder adhered to the connection pattern 29 is raised. As a result, a semi-molten state is generated, so that it becomes difficult for solder to flow unnecessarily, and good soldering is achieved.

G) Effects of the Invention As described above, in the present invention, the projecting nozzle 17
A heat-resistant mask 19 having the following is superimposed on the molten solder 13 in the solder bath 11, and when at least the member to be soldered is brought close to the nozzle 17, the molten solder 13 is pressurized to melt the molten solder 13 in the mask 19. Is raised, and a hemispherical liquid surface 25 is formed at the tip of the nozzle 17, and soldering is performed at the hemispherical liquid surface 25. Can be soldered to the connection pattern 29 if they are arranged so as to overlap at a slight interval.

Therefore, it can be soldered very easily and automatically to a specific area of the circuit board 27, and the pre-treatment of peeling off the insulation coating of the lead wire 33 of the electronic component 35 and forming preliminary soldering on the peeled portion becomes unnecessary. , Solder balls are less likely to occur.

Further, since the connection pattern 29 of the circuit board 27 is not pressed, the circuit board 27 to be soldered is not damaged,
Is not limited.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the automatic soldering apparatus according to the present invention, FIG. 2 is a perspective view showing a mask in FIG. 1, and FIG. 3 is a hemisphere at the nozzle tip of the mask shown in FIG. 4 to 7 are sectional views showing the use of the automatic soldering apparatus in FIG. 1 together with the automatic soldering method of the present invention, and FIGS. FIG. 9 is a perspective view of an electronic component to be soldered, and FIG. 9 is a sectional view showing a state where the electronic component is soldered to a circuit board. 1,35 …… Electronic components (coils), 3,33 …… Lead wires 5,37…
… Hollow part, 7,27 …… circuit board, 9,29 …… connection pattern,
11 ... solder bath, 13 ... melting solder, 15 ... inner container, 17 ...
Nozzle, 19 Mask, 21 Pressurizing means (fan), 23
…… Pressurizing means (motor), 25… Hemispherical liquid level

Claims (2)

(57) [Claims] 1. A solder tank, a molten solder stored in the solder tank, a heat-resistant mask having a protruding nozzle and arranged to overlap the molten solder, and applying the molten solder. Pressurizing means for applying pressure to raise the liquid level of the melted solder in the mask portion to form a hemispherical liquid level at the tip of the nozzle. 2. A heat resistant mask having a protruding nozzle is superimposed on molten solder in a solder bath, and when at least a member to be soldered is brought close to the nozzle, the molten solder is pressurized to form the mask portion. Raising the liquid level of the molten solder in the nozzle to form a hemispherical liquid surface at the tip of the nozzle, and soldering to the member to be soldered at this hemispherical liquid surface portion. Characterized automatic soldering method.