In the SMT manufacturing process manual soldering, board repair and rework rework is an indispensable process.
With the further development of SMT, not only the components are getting smaller, but also many new packages of components, no Pb, no VOC and other requirements, making the assembly more and more difficult, while making the difficulty of the rework work also escalated. For high density, BGA, CSP, QN and other new packaging components, how to carry out rework, how to improve the success rate of rework, how to ensure the quality and reliability of rework, etc., is also the SMT manufacturing industry is extremely concerned about the issue. Then for the manual welding clock common error operation we come to an analysis, I hope that we can avoid these situations in the future welding:.
1. Too much pressure, there is no help for heat transfer, can only cause oxidation of the soldering iron head, produce dents, so that the pad warped.
2. The wrong size, shape, length of the soldering iron tip, will affect the heat capacity, affecting the contact area.
3. Too high a temperature and too long, will make the flux failure, increasing the thickness of intermetallic compounds.
4. Incorrect placement of the solder wire does not form a thermal bridge. The transfer of solder cannot transfer heat effectively.
5. Inappropriate use of flux, using too much flux can cause corrosion and electromigration
6. Unnecessary trimming and reworking will increase intermetallic compounds and affect the strength of the solder joint.
7. Transfer soldering technique will make the flux evaporate in advance, can not be used in the welding of through-hole components, welding SMD can be used.
Transfer welding method is to use the tip of the soldering iron in the solder wire melt a little solder, and then use the soldering iron tip welding method. This method is the traditional manual welding often used method is the wrong method. Because the soldering iron head temperature is very high, molten tin will make the flux in the solder wire in advance of the solder evaporated before welding, welding because it does not play the role of flux and affect the quality of the solder joint.
Manual welding in the daily SMD processing is an important link, many customers' products in the design phase did not fully take into account the SMD components and plug-in components of a processing process issues, including reflow oven temperature and wave soldering machine temperature differences, resulting in plug-in material and SMD material for temperature sensitivity, or material complete time, certain shaped parts also need to use manual welding. Customers in the inspection of the SMD processing plant will also generally be concerned about the actual capacity of the DIP plug-in line and manual welding support to in place.
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① Established in 2010, 200+ employees, 8000+ Sq.m. factory
② NeoDen products: Smart series PNP machine, NeoDen K1830, NeoDen4, NeoDen3V, NeoDen7, NeoDen6, TM220A, TM240A, TM245P, reflow oven IN6, IN12, Solder paste printer FP2636, PM3040
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