CZ294717B6 - Device for inert protection during soldering - Google Patents

Abstract

In the present invention, there is disclosed an inert protection of a soldering device, particularly in cases when during soldering of flat parts large movement and whirl of solder and consequently increased oxidation of surface thereof take place. The invention is characterized in that an inert gas being preheated in an external heater or by heating a piping (8) directly in the soldering bath (1) is supplied through the piping (8) via a closing and reduction valves, flow meters and a system of nozzles (6) or rustfree diffusers to the soldering point. The device is provided with a bottom cover (5) that is disposed at utmost proximity of the level and an upper cover (7) sealing up the whole space above the main wave (3) and a chip wave (2). The upper cover (7) is provided on its sides with elastic, heat-resistant orifices (9) serving for reduction of gas escape and air turbulence above the soldering path level (1) but simultaneously enabling free passage of a conveyor belt (4) and boards with components wherein a refractory gas can be provided on top side thereof for checking the main wave (3), the chip wave (2), and the conveyor belt (4) with transported boards.

Description

Equipment for inert soldering protection

Technical field

BACKGROUND OF THE INVENTION The present invention relates to devices for inert soldering protection, in particular where solder of sheet metal parts causes great movement and turbulence of the solder, thereby increasing oxidation of its surface.

BACKGROUND OF THE INVENTION

When soldering flat parts, wave soldering equipment uses a wide variety of inert gas distribution systems as well as various types of enclosures designed to close the area above the solder to prevent oxidation.

In the patent application PV 2000 - 1650, for example, the protection of the soldering bath is provided by gas curtains, which greatly increase the consumption of inert gas, create secondary turbulence and thus further suction of residual oxygen. The solder bath kiytu design of EP 0 500 135, EP 0 626 226, EP 0 621 101 or US 5 297 724 protects the brazing area, but the inert gas distributors are only above the brazed plate so that the inert atmosphere does not reach the bath level. In addition, the cold gas introduced into the top portion is expelled by the hot gas from the bath surface. The gas distributor below the plate conveyor, as in WO 92/10323, feeds inert gas to the brazing point, but does not prevent leakage due to the flow caused by the different temperature of the supplied gas, the suction of the machine and the passage of the brazed plates. All of these systems for the distribution of inert gas to the brazing device do not sufficiently prevent leakage and suction of atmospheric oxygen. Existing systems also do not address the turbulence that results from the different temperature of the supplied gas and the brazing atmosphere. This temperature difference, which exceeds 200 ° C, further increases the undesirable flow and further suction of atmospheric oxygen.

SUMMARY OF THE INVENTION

These drawbacks are largely eliminated by the device for inert soldering protection, especially where the soldering of flat parts leads to a large movement and turbulence of the solder and thus an increased oxidation of its surface, which is caused by the fact that the supply piping from the shut-off, pressure reducing valves and the pre-heated inert gas flowmeters are stored directly in the brazing bath and terminated by a set of nozzles or stainless steel diffusers directly at the brazing point.

The inert soldering protection device according to the invention has a bottom cover as close as possible to the surface under the plate conveyor, sealing the whole space above the main wave and the chip wave is a top cover provided with flexible, heat-resistant screens to reduce gas leaks and air turbulence. soldering bath, but at the same time allowing free passage of the conveyor and plates with components.

The device according to the invention preferably has a top cover provided on the upper side with a refractory glass for controlling the main wave, the chip wave and the conveyor with passing plates.

For proper operation, it is advantageous that both covers are manufactured and installed in such a way that there is no need to interfere with the solder wave construction, and their design allows for smooth cleaning of the bath and the main and chip wave formers.

Furthermore, it is advantageous to enclose the solder bath space ideally with, for example, flexible screens, but which do not prevent the passage of the plates with the components, thereby avoiding secondary turbulences and

Atmospheric oxygen. This turbulence is also greatly eliminated by preheating the inert gas, the nozzle aperture design and the inner surface of the stainless steel diffusers being designed to provide a uniform and continuous flow of gas throughout the bath.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the apparatus of the present invention; FIG. 2 is a schematic cross-sectional side view of the apparatus; and FIG. 3 is a detail of the nozzles.

DETAILED DESCRIPTION OF THE INVENTION

The inert soldering protection device according to FIGS. 1 and 2 consists of a soldering bath 1 through which a pipe 8 with preheated inert gas is fed to the nozzles 6 under the lower covers 5. These lower covers 5, located just below the conveyor 4, are provided. shaped so that the inert gas is directed at both edges and between the main wave 3 and the chip wave 2. The entire space above the conveyor 4 is closed by a top cover 7, which is provided with flexible heat resistant screens 9, for example silicone rubber.

The nozzle orifices 6 are designed such that the gas flow is either narrowly directed, for example, through circular openings, or dispersed through the longitudinal openings over the entire length of the bath.

The manipulation with the soldering device according to the invention consists only in starting the melting of the soldering bath, thereby preheating the inert gas pipes and after setting the appropriate parameters of pressure, speed and quantity of supplied gas it is possible to start the whole soldering process.

Industrial applicability

The inert soldering protection device of the present invention reduces solder consumption, reduces flux consumption, reduces maintenance time and frequency. Significant reduction of oxides on the surface of the soldering bath also improves the quality of soldering and reduces the number of defects by up to 80% and thus also a considerable saving of production costs.

Claims (4)

Device for inert soldering protection, especially where the soldering of the components results in a large movement and swirling of the solder and thus an increased oxidation of its surface, characterized in that the supply line (8) from the shut-off valves, pressure regulators and flow meters in advance The heated inert gas is stored directly in the soldering bath (1) and is terminated by a set of nozzles (6) or stainless diffusers directly at the soldering point. The inert soldering protection device according to claim 1, characterized in that under the plate conveyor (4) the bottom cover (5) is as close as possible to the surface, sealing the entire space above the main wave (3) and the chip wave (2) being the top cover (7), which is provided with flexible, heat-resistant screens (9) on the sides, reducing gas leaks and air turbulence above the surface -2GB 294717 B6 solder bath (1), but at the same time allowing free passage of the conveyor (4) and component plates. An inert soldering protection device according to claims 1 and 2, characterized in that: 5, that the top cover (7) is provided with a refractory glass on the top side for controlling the main wave (3), the chip wave (2) and the conveyor (4) with passing plates.