The working principle of BGA rework stations varies slightly among different manufacturers, but they generally share similar concepts. Let’s first introduce the concept of temperature profiles. The solder balls on BGAs are divided into two types: leaded and lead-free. Leaded solder balls have a melting point between 183°C and 220°C, while lead-free solder balls have a melting point between 235°C and 245°C.
The soldering process can be roughly divided into four stages: preheating, soaking, reflow, and cooling (although specific Stations de reprise de BGA may have variations). Whether it’s leaded or lead-free soldering, the stage where the solder balls melt is during reflow, with the difference being the temperature. The stages before reflow can be seen as a gradual heating and soaking process. Understanding this basic principle allows for the adaptation of any BGA rework station.
Next comes the issue of temperature control. Simply heating without following the temperature profile makes it difficult to solder BGAs properly. The key is to heat the BGA according to the temperature profile. This is where the crucial difference lies between using a BGA rework station and a hot air gun for BGA rework. A BGA rework station can perform rework directly by setting the temperature, while using a hot air gun requires more skill because it’s challenging to visually observe the real-time temperature. As a result, overheating can easily damage the BGA.
The working principle of an optical BGA rework station involves using a combination of hot air and infrared heating, along with automated optical alignment technology, to achieve integrated BGA chip removal, placement, and soldering. The ultimate core of our successful BGA rework revolves around controlling the rework temperature and minimizing board deformation, which are crucial technical issues.
