Lga Rework/Repair Procedure - Motorola iDEN i930 Field Service Manual

MECHANICAL PARTS REWORK AND REPAIR: LGA REWORK/REPAIR PROCEDURE
9.6

LGA REWORK/REPAIR PROCEDURE

9.6.1 Removal Procedure
1. Set proper temperatures
2. With bottom heater ON, place the assembly on top of it to start pre-heating the PCB.
3. Place adequate Nozzle in the hand-piece of the Hot Air Machine.
4. Set desired air pressure.
5. Get the new component ready by placing it over a thin film of flux.
6. Protect any heat-sensitive component by placing appropriate Heat Shield over (If necessary)
7. Lower the nozzle and evenly apply heat until reflow of all solder joints is observed.
8. Immediately remove component before solder joints re-solidifies.
9. Release faulty component onto a heat resistant surface.
10. Check for component disturbance before proceed and fix it if necessary.
9.6.2 Land Preparation Procedure
11. Swing out the top heater and maintain the board over the bottom heater.
12. Pre-fill the lands by fluxing the targeted area and re-flowing solder wire with a soldering iron
over each pad. The quantity of solder applied is critical to achieving acceptable joints.
13. Clean lands of flux residue.
9.6.3 Installation Procedure
14. Pick the new component and place it over the lands as overlay or Pedro shows.
15. Swing in microscope to aid on component alignment.
16. Align component and swing microscope out.
17. Lower the nozzle and evenly apply heat until reflow is observed.
18. Raise nozzle and stop heat cycle.
19. Allow solder to re-solidify.
20. Cool off the PC board using bench fan.
21. Inspect solder joints and adjacent components under Microscope.
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