Rework necessities
◆ BGA Rework Station
◆ Job skills
◆ Tools and materials (hot air gun, soldering iron, soldering helping pen, tweezers, thin bamboo sticks, solder wick, flux, B-propanol)

Removal of BGA around residue adhesive

1、Glue rework board with adhesive tape and fixed on the table;
2、Temperature control and hot air heating, continuously heat the components surface up to 100 degrees Celsius with a hot air gun, the hot air gun can be set to 300 degrees C / 12 seconds and the distance between the hot air gun with the components is about 3-5 mm;
3、With a toothpick or small wooden stick to remove the residue that have been heated and softened around the components.

BGA cannibalize

      Heating components with a rework table: To ensure that the surface temperature of components at or over 217 degrees Celsius, with the repair liquid heated to above the table for some time (For, about 15 seconds); alternative: hot air gun heating components to ensure the component surface Temperatures at or over 217 degrees Celsius, with the hot air gun heating components surface (such as hot air gun can be adjusted to about 400 degrees Celsius) above the liquid so that it reaches a period of time (For, about 1 minute), cannibalize components with tweezers.
    Note: You can make a test using the reported fee board firstly, then do batch rework after understand the heating methods.

Residue processing

      Heating residue with the hot air gun (such as adjust to about 200 degrees Celsius), then can immediately clean up the residue: scrape the adhesive residue that left in the circuit board pad surface with a toothpick or pointed stick, dip the residual tin that left in the circuit board surface with a soldering iron and solder wick, clean up the circuit board pad with acetone or isopropanol.
Re-mount components
1、Roll tin: roll tin with wire and iron on the board pad;
      Note: This step must be to ensure that no loss and the circuit board pad to be cleaned, which can be used with a magnifying glass (more than 10 times).
2、Re-mount components: process after rework table positioning;
     Note: To prevent bad welding, it can be pre-coated smear flux in the circuit board pads with flux pen.

Re-mount BGA / CSP components, the underfill adhesives re-filling technology process

1、Be subject to the normal bottom filling and solidification process;
      Note: The empty hole problem, the bottom re-filling must ensure that the circuit dried, keep dry before smear the adhesive (For, can be in condition of 2 hours @ 125 degrees Celsius; or on the air 8 hours).

2、The process speed of re-filled underfill adhesives will be slower than normal ones, due to the circuit board turned poor after maintenance and its poor quality.