How does a BGA Rework Station work?
When faults occur with BGA packages, it can be a challenge to de-solder/solder these components. A specially designed system is needed, known as a BGA Rework Station. How does the BGA Rework Station work?
The basic principle of operation of the BGA rework station is that whilst being heated from above and below, a single SMD / BGA is subjected to a similar temperature/time profile during rework, as it experiences during reflow in the original production process.
In a BGA rework operation, the BGA component is put through a full ‘reflow’ procedure. The rework station normally uses a software-controlled multi-stage reflow process where all parameters such as temperature levels and ramp rates are precisely controllable, as recommended by board and component manufacturers.
A typical SMD / BGA rework station will be able to de-solder and remove the defective component but also, pick, place and solder a new device in the right place, with process control over materials (flux. solder paste), mechanical alignment/placement and finally, an accurate reflow soldering process.
Typical features for a good rework system will include the following: temperature-controlled PCB and component heating, XY table with fine adjustment to manipulate the PCB, component vacuum pick-up to allow accurate placement, split-beam prism alignment system to align the BGA component with the PCB site, CCTV cameras for alignment and also process observation to view the BGA being soldered, and finally, electronic / software control.
With an IR rework station, the heating technologies for component/PCB heating use infra-red to generate heat, either focused infra-red or medium-wave, dark IR. A hot-gas rework station uses heated gas through ducts and nozzles to heat the BGA component and also the PCB.
During de-soldering, a good BGA rework station will preheat the PCB, then heat the component to reflow temperature, at which point the solder is molten and the component can be removed.
To re-solder the new component, the BGA site will be prepared so that it is clean and flat. Flux or solder-paste will be added, the component aligned and then placed accurately. Now, the BGA rework system will preheat the PCB and take the BGA component to reflow temperature, where the solder joints form. After cooling, the BGA is now correctly soldered in place, the reworked BGA can be inspected, cleaned if necessary and the BGA Rework operation is complete.