JPS6222299Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a flux application device that can be used in either a foaming type or a flow type when applying flux to the soldering surface of a printed circuit board or the lead wire of an electrical component. It is something.

As is well known, when pre-soldering a printed circuit board, use a foam flux applicator to apply flux to the entire surface to be soldered, and also pre-solder the lead wires of electronic components to a predetermined length. At this time, a flow type flux applicator is used to apply flux to the soldering length.

On the other hand, when performing two types of soldering, preliminary soldering of electronic components and final soldering of printed circuit boards, two types of flux applicators, a foaming type and a flow type, are required to apply flux. Therefore, it is necessary to install two soldering machines, one equipped with a foam-type flux applicator and the other with a flow-type flux applicator, which requires a large space for installing the soldering equipment. However, it also had the drawback of requiring high equipment costs and other expenses.

By the way, if you use a foam-type flux applicator to apply flux when performing final soldering, excess flux will adhere to the entire printed circuit board, and the viscosity of the flux that has adhered to areas that do not require soldering will cause problems. This had the disadvantage that dirt easily adhered to it, causing it to become dirty, and as a result, the insulation properties of the printed circuit board deteriorated.

In addition, if you want to apply flux by dipping the lead wire of an electronic component into a flux liquid for a predetermined length, if you use a foam-type flux applicator to apply the flux, the tip of the lead wire will get stuck in the flux bubbles. Since the lead wire part that has entered the bubble comes into contact with the air in the bubble, the flux liquid may not adhere to this part, or if it is deeply immersed in the bubble, the entire lead wire or the electronic component body may be damaged. However, there was a drawback that flux liquid could adhere to it.

For this reason, when finishing soldering printed circuit boards or soldering lead wires of electronic components, flux was conventionally applied using the dip method, but with the dip method, the flux liquid is poured into a flux tank. Since the flux remains in the tank and there is no replenishment of new fluid, and there is no circulation of the flux within the flux tank, debris that has fallen from outside may float on the surface of the flux and adhere to the lead wires. Volatilization of volatile matter in the flux changes the surface concentration of the flux liquid, which changes the specific gravity, resulting in non-uniformity of the components of the flux liquid, which has the disadvantage of adversely affecting the adhesion of the solder melt.

This idea was made to eliminate the above-mentioned drawbacks, and the flux tank body has two parts, an outer tank and an inner tank.
A foam tube is formed in the tank, a foam tube is provided in the inner tank, and a communication hole is provided to communicate the inner tank and the outer tank.By attaching and removing a stopper that fits into this communication hole, two functions can be achieved: foaming type and flow type. The present invention provides a flux coating device having the following functions. This idea will be explained below.

FIG. 1 is a side sectional view showing an embodiment of this invention. 1 is a flux tank main body, which is formed by an outer tank 2 and an inner tank 3, and the inner tank 3 is isolated inside the outer tank 2. ing. 4 is a nut fixed integrally with the inner tank 3; 5 is a bolt rotatably screwed into the nut 4; the lower end thereof is in contact with the bottom of the outer tank 2; 6 is a tank that stores the flux F liquid and adjusts its components. 7 is a pump that supplies the flux F in the tank 6 to the flux tank body 1;
8 is a supply pipe that connects the outer tank 2 and the pump 7 and supplies the flux F liquid; 9 is a valve that controls the flow rate of the flux F liquid in the supply pipe 8; 10 is a valve inside the flux tank body 1; 11 is a valve that controls the flow rate of flux F in the reflux pipe 10; 12 is a porous pipe formed by bisque firing or the like at the bottom of the inner tank 3; As shown in FIG. 2, pressurized air is sent into the foaming tube 12 through a blowing pipe (not shown) and blown out from the holes 12a on the outer periphery to foam the flux F liquid. 13 is a communication hole formed in the center of the bottom of the inner tank 3; 14 is a stopper that is removably fitted into the communication hole 13 in order to block the flux F flowing into the communication hole 13, and is in close contact with the inner tank 3; A flange 15 is formed. 16 is the stopper 14
It is a through hole formed inside with a T-shaped cross section, and communicates directly with the supply pipe 8 when installed. Moreover, P is a printed circuit board.

Next, the operation will be explained.

First, when the flux tank body 1 is used as a foaming type flux applicator, the stopper 14 is removed from the communication hole 13 of the inner tank 3 as shown in FIG. Then, when the valve 11 of the reflux pipe 10 is closed and the valve 9 of the supply pipe 8 is opened to drive the pump 7, the liquid flux F in the tank 6 flows into the outer tank 2 through the pump 7 and the supply pipe 8. Furthermore, from the communication hole 13 to the inner tank 3
flows into. When the liquid level of flux F reaches a little above the foaming tube 12, the pump 7 is stopped and the valve 9 is closed. At this time, the liquid level of the flux F becomes the same in both the outer tank 2 and the inner tank 3. In this state, pressurized air is sent into the foaming tube 12, and the holes 12a on the outer periphery are
Blow out more to generate flux F bubbles,
A foam layer is formed on the surface of the flux F in the inner tank 3. Then, the foamed flux F overflows outward from around the upper side of the inner tank 3, enters the outer tank 2, becomes liquid, enters the inner tank 3 again through the communication hole 13, and circulates. In this way, foaming type flux application is performed.

Next, when the flux tank main body 1 is used as a flow type flux applicator, a stopper 14 is attached to the communication hole 13 of the inner tank 3 as shown in FIG. Then, when each valve 9, 11 is opened and the pump 7 is driven, the flux F liquid in the tank 6 passes through the pump 7 and the supply pipe 8 to the stopper 14.
It flows directly into the inner tank 3 through the internal conduction hole 16. Here, since the inner tank 3 and the outer tank 2 are blocked by the stopper 14, the liquid level of the flux F rises inside the inner tank 3, and then overflows from the upper periphery of the inner tank 3 to the outside. After falling into the tank 2, it flows back into the tank 6 through the reflux pipe 10. Therefore, since the liquid flux F circulates between the flux tank main body 1 and the tank 6, a new liquid level is always maintained on the upper surface of the inner tank 3. In this way, flow type flux application is performed.

As explained above, this idea consists of forming the flux tank body into two tanks, an outer tank and an inner tank, with the inner tank being isolated inside the outer tank, and the inner tank is provided with a foaming tube and communicated with the outer tank. By having a structure in which a stopper that fits into the communication hole and has a communication hole that communicates with the supply pipe can be attached and detached,
One flux coating device can be used in two ways: foaming type and flow type. Therefore, various types of soldering can be performed, such as preliminary soldering of printed circuit boards, final soldering, and soldering of lead wires of electronic components. Since there is no need to install two soldering devices equipped with flow-type flux application devices, the installation area for installing the soldering devices is small, and
It has the advantage of requiring less cost for soldering. In addition, when used as a foam-type flux applicator, it can be used as a conventional flux applicator, while when used as a flow-type flux applicator, new flux liquid with adjusted components is constantly replenished. Therefore, there is an advantage that the components and concentration of the flux liquid in the flux tank body are constant, and a clean and level liquid surface can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an embodiment of this invention.
Figure 2 is a side sectional view showing the main parts of the flux applicator shown in Figure 1 when used as a foaming type, and Figure 3 shows the main parts when the flux applicator shown in Figure 1 is used as a flow type. FIG. In the figure, 1 is the flux tank body, 2 is the outer tank, 3 is the inner tank, 4 is the nut, 5 is the bolt, 6 is the tank, and 7
is a pump, 8 is a supply pipe, 9 and 11 are valves,
10 is a reflux pipe, 12 is a foaming pipe, 12a is a hole,
13 is a communicating hole, 14 is a stopper, 15 is a flange, 16 is a conductive hole, F is a flux, and P is a printed circuit board.

Claims (1)

[Scope of utility model registration request] The flux tank main body is made up of an outer tank that stores the flux liquid supplied from the tank through the supply pipe and returns the flux liquid to the tank through the reflux pipe, and an inner tank that has a porous foam tube installed inside. the inner tank is provided isolated inside the outer tank, a communication hole is provided in the inner tank through which the flux liquid communicates between the outer tank and the inner tank, and a communication hole is provided in the inner tank, and the communication hole 1. A flux coating device, characterized in that a stopper is removably provided, the stopper having a conductive hole that fits therein and directly communicates with the supply pipe, and cuts off communication between the outer tank and the supply pipe.