PCB Tech - Processing risk of PCBA processing flux dosage

In PCBA processing, many engineers are trying to control the amount of flux used, but in order to obtain good soldering performance, sometimes a larger amount of flux is required. In the selective soldering process of PCBA processing, because engineers often care about the welding results, It does not care about flux residues.

Most flux systems use glue-dispensing devices to avoid stability risks. The flux selected for selective soldering should be inert when it is in an inactive state-that is, in an inactive state.

The application of a large amount of flux by the PCB factory will cause it to penetrate into the SMD area and produce a potential risk of residues. Some important parameters in the welding process will affect the stability. The key is: the flux penetrates into the SMD or other processes The temperature is low and the non-opening part is formed. Although it may not have a bad influence on welding during the process, when the product is in use, the combination of the unopened flux part and the humidity will produce electromigration, which will help The expansion performance of the flux has become a key parameter.

A new development trend in the use of flux for selective soldering is to increase the solid content of the flux, so that as long as a smaller amount of flux is applied, a higher solid PCBA content can be formed. Usually the soldering process requires 500-2000μg/ The flux solid content of in2, except that the flux dosage can be controlled by adjusting the parameters of the soldering equipment, the actual situation may be complicated. The expansion performance of the flux is important to its stability, because the total amount of solids after the flux is dried Will affect the quality of welding.

However, everything has both pros and cons. The advantages of PCBA OEM method are obvious, but there are also certain safety risks.

Because PCBA foundry manufacturers are responsible for the overall ordering of electronic components and PCBs, a PCB circuit board processing manufacturer may order some fake and shoddy materials in order to reduce manufacturing costs. In order to prevent this from happening, product services The demander can request the PCBA OEM manufacturer to give the original certificate of the original material to ensure the quality of the material.

In the entire processing cycle of PCBA foundry materials, the cycle of purchasing electronic components is the most unstable. Specifically, it is possible that the components used by customers are relatively scarce, and they are not common products or the demand for components is large. Manufacturers who have no inventory and need to take orders will affect the arrival of materials between chip factories and ultimately affect the normal production cycle. In order to avoid falling into a more passive situation, product service providers can require PCBA OEM manufacturers to schedule The progress of material procurement is given, and the arrival time of materials is tracked.

In the production process of PCBA OEM production, due to some factors, large quantities of products have quality problems, and batch repairs are required. If the PCBA OEM chip processing manufacturer does not have strong repair capabilities, it will lead to Product maintenance is difficult, and the maintenance cycle is prolonged, which will eventually affect the delivery time of the product and cause relatively large losses to customers.