Issue link: https://iconnect007.uberflip.com/i/1523387
JULY 2024 I SMT007 MAGAZINE 73 Current quality procedures in the industry do not allow for more than three attempts to re-ball BGAs. Consequently, limiting the number of repair cycles is crucial to ensure BGA component reliability and quality. Excessive thermal cycles and repeated cleaning of surface pads can damage the contact surface quality and reduce the overall reliability of the component in operation. e success rate of manual stencil large BGA re-balling is quite low compared to robotic ball placement and reflow. In addition, the robotic process ensures high-quality and precise re-balling of BGAs, with consistent repeatability. In the robotic ball placement with laser soldering process, a robot precisely places solder balls onto the BGA package. Aer placement, a laser is used to individually solder each ball to the package. e laser provides localized heat, which minimizes thermal stress on the compo- nent and surrounding areas, enhancing the reliability and preci- sion of the solder joints. However, a notable drawback of this process is its slower pace, as each ball is soldered in- dividually. is process is sensitive to material composition and requires special setup of laser parameters to support soldering of different materials. e robotic ball placement and subsequent reflow soldering process, developed and implemented by Essemtec, is an integrated process that takes place on a single machine, combining robotic dispensing of flux followed by robotic ball placement. Initially, flux is applied to the BGA pads, and then solder balls are placed from a feeder. e ball material and diameter are loaded using a dedicated feeder equipped with a reel tape. is system accommodates various ball sizes, ranging from small diameters of 250 µm to large diameter balls of 1 mm and above. Furthermore, this approach supports dif- ferent ball materials, including Pb or ROHS- compliant materials, as needed. Figure 3: Soldering ball on a reel.