Re: У кого есть опыт снятия КП 3GS без отрыва пятаков
#8
На микросхеме маркировкой указан тип припоя. По документу
www.lgintl.com/pdf/JESD97.pdf тип используемого припоя
e4 - Precious metal (e.g., Ag, Au, NiPd, NiPdAu) (no Sn)
Для компонентов этого типа рекомендуемый алгоритм выпайки от TI выглядит так
Код:
Table 3. Pb-Free Solder Component Removal
1. Apply flux paste to component.
2. Align nozzle over part to be removed.
3. Maintain nozzle 0.050-in over device. Care must be taken to prevent over travel of the vacuum tip, which may damage the
part or vacuum tip when measuring this distance.
4. Preheat board to 90 ° C, nozzle warming up 20% air flow, 125 ° C.
5. Soak stage – 20% air flow, 225 ° C, 90 s
6. Ramp stage – 20% air flow, 335 ° C, 30 s
7. Reflow stage – 25% air flow, 370 ° C, 65 s
8. Enable vacuum at the end of the reflow cycle, lower vacuum nozzle, and remove part.
9. Cool down stage – 40% air flow, 25 ° C, 50 s
10. Turn off the vacuum and remove part from nozzle.
11. Using any metal tweezers or rough handling can damage the part, and render it unanalyzable
12. Do not reuse the part after it is removed.
ссылка на документ
www.ti.com/lit/an/slua271a/slua271a.pdf