JPH0565473U - Automatic soldering equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] In an automatic soldering device that covers the upper part of a solder bath with a cover to create an inert atmosphere, to prevent outside air from entering the inside from below the cover. [Structure] The lower parts of the four sides of the cover that covers the upper part of the solder bath are immersed in the molten solder.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an automatic soldering device that covers a solder bath and performs soldering by placing the solder bath on an inert gas atmosphere such as nitrogen.

[0002]

[Prior Art]

 Generally, the soldering of a printed circuit board by an automatic soldering device is carried out through the steps of applying flux with a fluxer, preheating with a preheater, attaching solder in a solder bath, and cooling with a cooler.

By the way, when a large amount of flux residue remains on the printed circuit board after soldering, the flux residue absorbs moisture and dust or dust adheres to the flux residue to reduce the insulation resistance, resulting in the performance of electronic devices. May make things worse. Therefore, the printed circuit boards for precision electronic devices, such as communication devices and computers, which place great importance on reliability, have been cleaned of flux residues after soldering.

Since the flux residue contains pine resin as a main component and an activator added to it, it must be a fluorine-based solvent such as CFC that dissolves pine resin well or a chlorine-based solvent such as trichlene. I couldn't wash it.

However, the fluorine-based solvent destroys the ozone layer surrounding the earth, causes a large amount of harmful ultraviolet rays to reach the earth, and causes skin cancer in humans, and the chlorine-based solvent penetrates underground. Then, it contaminates groundwater and causes various cancers to humans who drink it. Therefore, the use of fluorine-based solvents and chlorine-based solvents has come to be regulated.

As described above, in the printed circuit board used for precision electronic equipment, since the flux residue cannot be removed by washing after soldering, the electronic industry does not need to wash the printed circuit board. Has come to be requested. This non-cleaning flux is a flux where no flux residue remains after soldering, or even if it remains, it is a trace amount that does not adversely affect the printed circuit board.

In other words, the non-cleaning flux does not contain pine resin or activator at all, and most of the components are volatilized during soldering, or the amount of pine resin or activator added is extremely small. is there

[0008] Such a non-cleaning flux does not contain pine resin or an activator, which greatly contributes to soldering, or has a very small amount even if it is added, so that good soldering can be performed in the atmosphere. could not. This is because when soldering in air using uncleaned flux, the flux activity is weak, so not only the oxide film and dirt on the soldered part cannot be removed, but also the oxide film and dirt on the solder flux can be removed. However, this is because the soldering part will be reoxidized by the heat generated during the soldering.

Therefore, the non-cleaning flux cannot perform good soldering unless it is in an oxygen-free state, that is, in an inert atmosphere. Therefore, recently, in order to use the non-cleaning flux, an automatic soldering device in an inert atmosphere, which covers the solder bath and is filled with nitrogen gas, has come to be used.

The conventional automatic soldering device in an inert atmosphere is a shutter system in which the entire solder bath or the upper part of the solder bath is hermetically sealed, the printed circuit board inlet / outlet is a double chamber, and a shutter is installed at each inlet / outlet. It was (Reference: JP-A-61-282965 and JP-A-62-1101372)

This shutter system has a feature that the amount of outside air entering the solder bath is very small and the oxygen concentration on the solder bath can be made extremely low.

[0012]

[Problems to be solved by the device]

However, the shutter method is very poor in productivity because it takes a lot of time to open and close the shutter and to wait in the auxiliary chamber. Therefore, in an automatic soldering device that performs soldering in an inert atmosphere, it is preferable to use a shutterless device that does not have a shutter and that can solder a printed circuit board continuously.

When the automatic soldering device is made shutterless, the outside air enters the part of the inert atmosphere on the solder bath through the entrance / exit, but the applicant of the present invention proposed the shutterless in Japanese Patent Application No. 3-82975. Adopting an outside air intrusion prevention device can prevent outside air from entering the solder bath.

However, in the shutterless automatic soldering device, since there is a transfer device for transferring the printed circuit board, even if the upper part of the transfer device is covered, the lower part of the transfer device is exposed, and outside air enters from here. Met. An object of the present invention is to provide an automatic soldering device which can completely shield the lower part of the conveying device from the outside air while being a shutterless automatic soldering device.

[0015]

[Means for Solving the Problems]

 The present inventors have completed the present invention by paying attention to the fact that when a part of the plate is immersed in the liquid, the contact portion between the plate and the liquid does not allow gas to pass through.

The present invention is characterized in that, in an automatic soldering device that covers a solder bath to make an upper part of the solder bath in an inert atmosphere, lower parts on four sides of the cover that covers the solder bath are immersed in the molten solder in the solder bath. It is an automatic soldering device.

As for the cover for covering the solder bath, the lower part of the transfer device for transferring the printed circuit board is made into a box-like shape, and the upper part of the transfer device is an extendable cover member proposed by the applicant of the present invention in Japanese Patent Application No. 3-82975. When it is set, the sealed state becomes even better.

[0018]

【Example】

 The present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of an automatic soldering apparatus of the present invention, FIG. 2 is a perspective view illustrating a state in which a lower portion of a box-shaped body which is a part of a cover is immersed in a solder bath, and FIG. 3 is XX of FIG. FIG. 4 is a perspective view of the box-shaped body, taken along the line.

Jet nozzles 2 and 2 are installed in a solder bath 1 of an automatic soldering apparatus, and molten solder S is jetted from here by a pump (not shown) rotated by a motor 3. ing.

A pair of rails 4 and 5 are installed above the solder bath 1. One rail 4 is a fixed rail, and the other rail 5 is a moving rail that is held by a frame 6 with a ball screw and moves in the direction of arrow A. A large number of claws 7 that hold and transfer the printed substrate run on the fixed rail 4 and the movable rail 5.

A cover is installed on the upper portion of the solder bath 1 so as to cover the upper portion of the solder bath and to make the inside an inert atmosphere. The cover is composed of a box-shaped body 8 and a lid member 9. The box-shaped body 8 has a box shape with no lid and no bottom, and flanges 10 are formed on both upper sides of the box-shaped body 8. The box-shaped body 8 is installed by screwing the flanges 10 on both sides of the upper part to the fixed rail 4 and the frame 6.

The lid member 9 is made of a stretchable heat-resistant material, is installed between the fixed rail 4 and the movable rail 5, and between the movable rail 5 and the frame 6, and can be freely opened and closed by the magnet 11 and the iron plate 12. (Arrow B), and the sealed state is maintained.

A flexible pipe 13 is attached to the lid member 9. The pipe is for supplying an inert gas, and allows the inert gas sent from a supply source (not shown) to flow into the cover. As the inert gas used in the present invention, nitrogen is inexpensive and convenient to use, but besides nitrogen, argon gas, carbon dioxide gas, or a mixed gas of hydrogen and nitrogen can be used.

Next, the installation of the cover on the automatic soldering device will be described. First, the solder bath 1 is lowered downward, and the flanges 10 and 10 of the box-shaped body 8 are fixed to the lower side of the fixed rail 4 and the frame 6 with screws. Then, the solder bath 1 is raised until the lower part of the box-shaped body 8 is slightly immersed in the molten solder S (dashed line in FIG. 4).

Then, the nozzles 2, 2 for contacting the solder with the printed circuit board at the time of soldering are surrounded by the box-shaped body 8, and the inside of the box-shaped body 8 is shielded from the molten solder S by the box-shaped body. Outside air does not enter through the lower part of the body.

Next, a retractable lid member 9 is installed between the pair of rails above the box-shaped body 8 and between the rails and the frame. If the magnets 11 are attached to both sides of the lid member 9 and the iron plate 12 is attached to the rail and the frame corresponding to the magnets, the magnet and the iron plate are sealed when the lid member is closed, and the lid member is closed. When opening, the magnet and iron plate can be separated easily.

As described above, when the cover is installed on the solder bath, the box-like body ensures the insulation from the outside air at the portion where the box-like body is immersed in the molten solder, and the lid member prevents the outside air between the rails or between the rail and the frame from being exposed to the outside air. Make sure to shut off.

[0028]

[Effect of the device]

 As described above, in the automatic soldering device of the present invention, the nozzle for actual soldering is covered with the cover, and the lower part of the cover is immersed in the molten solder. The outside air never enters. Therefore, the automatic soldering device of the present invention reduces the amount of oxygen inside the cover even if the consumption of the inert gas is reduced, and it is said that good soldering can be performed even with the non-cleaning flux. It is possible to achieve an excellent effect not found in

[Brief description of drawings]

FIG. 1 is a perspective view of a solder bath in an automatic soldering device according to the present invention.

FIG. 2 is a view for explaining a state in which the box-shaped body is immersed in the molten solder in the automatic soldering device of the present invention.

FIG. 3 is a sectional view taken along line XX of FIG.

FIG. 4 is a perspective view of a box-shaped body.

[Explanation of symbols]

 1 Solder bath 4 Fixed rail 5 Moving rail 6 Frame 8 Box-shaped body 9 Lid member 10 Flange of lid member

Claims (2)

[Scope of utility model registration request] 1. An automatic soldering device for covering an upper part of a solder bath with an inert atmosphere in the upper part of the solder bath,
An automatic soldering device characterized in that the lower parts of the four sides of the cover are immersed in the molten solder in a solder bath. 2. The automatic soldering device according to claim 1, wherein the cover is composed of a box-shaped body and a lid member.