Issue link: https://iconnect007.uberflip.com/i/1491409
54 SMT007 MAGAZINE I FEBRUARY 2023 Over seven years ago, I put pen to paper to enumerate the top challenges needing to be overcome for a successful BGA rework. With the continued advancement of BGA technol- ogy, it's time to apply a fresh coat of paint to that list. Read on to find out my revised take on today's top BGA rework challenges (in no par- ticular order). Challenge #1: Very Large BGAs As devices become more complex and com- puting power requirements increase, the max- imum physical size of BGA packages has con- tinued to increase. Currently, some devices in development are planned to be 125 mm x 125 mm in size. ese large package sizes present some very challenging scenarios for rework process technicians. Today, the placement systems for such large packages are limited by the split vision prism systems that align the components during placement. To successfully handle such large packages, BGA rework equipment vision sys- tems will need to be upgraded. Bottom heaters, which ensure that the board onto which the package is placed is uniformly heated, need to be upgraded to handle these large component package sizes. Undersized underside heating sources may cause an incon- sistent temperature gradient from the top of the component to the underlying area, thereby sending different areas of the component into reflow at different times. is results in com- ponent balls that are stretched or elongated; "cold peels" due to improper temperature pro- files can also damage BGA pads on the board. 2023's Top Challenges in BGA Rework Knocking Down the Bone Pile by Bob Wettermann, BEST INC.