Abstract: An automatic single / dual wave soldering machine with a three-phase asynchronous induction pump as a crest generator is developed to replace the mechanical pump wave soldering machine. It has no rotating parts, no wear, no maintenance and improves the reliability of the whole machine . Key words: Three-phase asynchronous induction pump wave soldering machine without rotating parts maintenance-free First, the situation at home and abroad Surface mount technology (SMT) in the dual wave soldering PCB and surface components (SMC) circuit board single wave soldering process, Need to apply liquid solder wave soldering technology and equipment. At present, the domestic peak pick-up technology are mechanical pump wave soldering machines, only one developed a single-phase induction electromagnetic pump wave soldering machine. Abroad, the wave soldering machine is also based on mechanical pump wave soldering machine, in the late 1980s, Switzerland, the United States produced a conductive electromagnetic pump wave soldering machine (patent US-3.797.724) discontinued due to unstable performance. China in the 90's developed the first generation of single-phase induction electromagnetic pump wave soldering machine (patent CNA.CN..3.), From the beginning, China's wave soldering technology walk in the forefront of the world, followed by the military The second generation of electromagnetic induction gun - three-phase asynchronous induction pump has been successfully developed (patent CN.9). Single / dual-wave automatic welders using a three-phase asynchronous induction pump as a crest generator have also been in mass production. Second, the development of three-phase asynchronous induction pump the need for the current electronic assembly production of most of the wave soldering machine mechanical pump wave soldering machine, mechanical pump blades at high temperatures (about 250 ℃) rotation, rapid wear and tear, on the one hand On the other hand, it is necessary to regularly repair and replace the worn blades and wearing parts to cause inconvenience to users. Furthermore, due to the rotation of the mechanical pump, the disturbance of the tin surface causes the increase of oxidation and the formation of large amount of dross . To solve the above problems, developed a conductive electromagnetic pump wave soldering machine, canceled the mechanical pump, without any rotating parts, no wear and tear, maintenance-free, reduced production of tin oxide slag, partially solved the problem of mechanical pump wave soldering , But the conductive electromagnetic pump because of its inherent structural instability, the problem of fluctuating peaks and downs and can not meet the production process requirements. In 1990s, domestic relevant units developed single-phase induction electromagnetic pump wave soldering machine to solve the above problems and solved the problem of wave instability without any rotating parts and maintenance-free, basically solving the problems of mechanical pump wave soldering machine. However, The machine in the production of wide-wave peak (300mm ~ 400mm peak width) and ultra-high peak (40mm height), appears to be insufficient strength. In view of the above problems, the three-phase asynchronous induction pump based on the theory of electromagnetic gun has been developed successively in our country with no rotating parts, no wear, no maintenance, smooth and smooth wave crest, tin surface smooth, Oxidized slag formation decreased significantly, due to high efficiency, can be prepared wide wave peak (400mm) and ultra-high peak (40mm) wave soldering machines, wave soldering machines basically meet the needs. Third, the technical principles 1, the principle of mechanical pump wave soldering machine Mechanical pump schematic diagram shown, the mechanical pump liquid tin feed pump rotating components, resulting in wave instability, must be added several times the pressure steady flow can be used , And due to the rotation of the tin surface caused by a large number of instability tin oxide slag, the welding costs rise, rotating at high temperatures, resulting in blade and seal wear failure, it must be discontinued and repaired on a regular basis. 2, the principle of conductive electromagnetic pump The principle of conductive electromagnetic pump shown in the figure, the principle of conductive electromagnetic pump is: the conductors in the magnetic field, through the current, the conductor will be the thrust of the magnetic field, the three directions perpendicular to each other, the size of the thrust F = I × B. Conductive electromagnetic pump without any rotating parts to solve the mechanical pump wear problems, the formation of maintenance-free welder. However, due to the liquid metal contact with the large current electrode to the liquid metal conduction current process, due to the oxide residue on the electrode attachment and shielding, resulting in wave instability, and even ups and downs, can not be stable, the domestic imports of Switzerland such models Nearly 50 basic have been disabled. 3, the principle of electromagnetic induction pump It uses the principle is the use of single-phase C-type opening electromagnet, due to the difference between the inner and outer ring and the inner and outer ring magnetic field phase difference, and then form the forward magnetic field component, that is from the leading phase to the lagging phase Forward magnetic field component. The liquid metal brazing filler metal in the forward magnetic field component cuts the flux lines and is therefore subjected to a forward force to pump the liquid metal brazing material. Due to the use of magnetic phase difference generated phase difference, the formation of the forward magnetic field component, the forward magnetic field component is very limited, most of the pulsation magnetic field does not produce forward thrust to produce as shown in Figure broad-wave peak (300mm ~ 400mm peak width) and Very high peak (40mm height) is very difficult. 4, three-phase asynchronous induction pump principle This is our country in the wave soldering machine obtained another patented technology, which not only solves the conductive electromagnetic pump conductive electromagnetic pump conductive current electrode due to the oxidation of the shading caused by unsteady wave , Without any rotating parts, no current transformer, maintenance-free, wear-free, and high efficiency, access to high and powerful peaks and wide peaks. Three-phase asynchronous induction pump principle is the use of three-phase power 120 ° phase difference between each other in space, forming their own magnetic field, the magnetic field synthesis is a forward magnetic field cutting magnetic lines, the induction current, the formation of forward electromagnetic force. As the direct use of the three-phase power of the inherent phase difference, and thus the basic synthesis of magnetic pulse-free magnetic field components, are the forward force of the resultant magnetic field, and electromagnetic guns completely the same principle, and therefore high efficiency, up to 70% from the three Wave induction welder with phase asynchronous induction pump in addition to all the advantages of inductive electromagnetic pump, such as audio perturbation vibration wave superimposed to enhance the ability to weld and crawl capacity, without any rotating parts, no wear and tear, maintenance-free, Simple structure, etc., but also has a high and powerful wave peak, available 40mm high peak and wide peak width of 300 ~ 400mm. Since the asynchronous induction pump produces a linear thrust, the liquid metal solder does not rotate and the tin bath is calm. As a result, a large amount of oxidized slag is produced, and the single shift of the oxidized slag is reduced by about 4KG. Only one year's worth of solder can be recovered with an investment of nearly 10% Million. Fourth, the application effect comparison Three-phase induction pump developed by the use of single / dual peak automatic welding machine, the use of comparison, we get the following results: As with a unique perturbation vibration wave superimposed, you can effectively get rid of SMT solder Due to the thermal decomposition of flux and adhesive produced by brazing brazing zone gas, eliminating the jump welding and SMC, SMD shadow area, to SMT soldering requirements, at the same time, as a result of the superimposition of perturbation wave wave soldering climb Significantly enhanced hole capabilities to improve weld reliability and yield. Smooth wave crestless rotation component, as a result of three-phase asynchronous induction electromagnetic pump produces a linear thrust instead of the mechanical pump blade rotation thrust, and thus crest smooth, tin bath surface disturbance is small, slight oxidation. Peak smooth, due to induction pump technology, combined with the voltage regulator principle, can reach the grid voltage fluctuations of 10%, the induction pump voltage fluctuations of nearly 3%, and thus the peak stability. efficient. Due to the absence of pulsating magnetic field components, the efficiency of the three-phase asynchronous induction electromagnetic pump is greatly improved. According to the developed prototype, the peak width is 400mm and the peak height is 40mm. The magnetizing current of the three-phase induction pump is only about 5A, so that the working conditions ensure that the three-phase asynchronous induction pump works in a state of low thermal load and low current load, ensuring the long-term reliability of life. No rotating parts, no wear, truly maintenance-free, eliminating the need for regular maintenance links. From the above principles and the use of prototype comparison we concluded that: wave soldering machine with three-phase asynchronous induction pump to solve the current process to solve most of the problems, to achieve maintenance-free, saving solder, reducing the amount of oxide slag, convenient With the application of depth, wave soldering machine with three-phase asynchronous induction electromagnetic pump is the future trend of development, it will be in the development of electronic packaging technology, play a role in promoting The role, especially in the SMT mixed technology, the formation of a good international and domestic application prospects. V. CONCLUSIONS: From the above principles and comparison of the results of prototype use, we conclude that the three-phase induction pump for wave soldering machines solves most of the problems to be solved in the current process, and realizes maintenance-free, solder saving, and reduces oxidation slag Output, easy access to wide-peak and ultra-high peak and other requirements, with the application of depth, wave soldering machine with three-phase asynchronous induction electromagnetic pump is the future trend of development, it will be in the process of electronic assembly process , Play a catalytic role, especially in the SMT mixed process, the formation of a good international and domestic application prospects.
