Solder

BGA Rework Processes

Develop Process  Develop Profile  Part Removal  Site Preparation  Placement Reflow Inspection


rework-process BGA / LGA Rework Processes The following describes the general BGA rework process covering the development and criteria for establishing profiles for BGA removal and replacement. The materials required for such an operation are outlined below. Critical elements of the BGA / LGA rework operation including paste pattern printing and rework profile development are described in great detail in this BGA rework process outline. There are several technologies which can be used as the heat source in removal of a BGA including but not limited to hot air and IR. The BGA rework process described herein is generic in nature to the type of heating system used. The experience BEST has gained in reworking thousands of BGAs on hundreds of different customer PCBs has shaped the information found in this process description. BEST has expertise on stacked package (PoP) rework as well.

Material Required
  • Solder paste flux
  • BGA and LGA Rework System including computer-controlled heating source on the part area, PCB preheater capable of heating underneath entire board area, calibrated vision system, automatic vacuum pick up system and data logging functionality
  • XRAY System
  • Endoscope or other optical inspection system
  • Squeegee
  • Stencil
  • Kapton Tape
  • Hand held soldering system
  • Reflow oven
  • Solder wick or solder extraction tool
  • Stereo microscope

The BGA rework process can be methodically worked out by following these process guidelines though difference in printed circuit boards, devices populated on those boards. Years of experience, the correct equipment and a robust BGA rework process all help to insure high expected yields. Whileseveral skills can be trained including but not limited to BGA rework profiling, site preparation and process troubleshooting, having the “real world” experience of hundreds of different boards and part configurations make this a skill which is supported by experiences. By having the right equipment the BGA rework process will go much easier. For example some of the packages and board combinations are better-suited for hot air rework systems while other combinations are better-suited for infrared rework heat sources. Hot air non-contact excavation source are better-suited for sensitive boards susceptible to lifter pads or damages solder mask while robust printed circuit boards can have the solder wicking approach for site preparation be more appropriate and cost-effective for the BGA rework process.