Air-Vac DRS27, Руководство пользователя

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DRS27 User’s Guide Chapter 5: Process Development Guide/Engineering Training
0027.00.902 5-12
The following is a brief description of each stage (Event):
1. PREHEAT: Preheats the entire board to minimize the thermal differential between the reflow
site and the rest of the board. Preheat minimizes board warpage and reduces the amount of
component heating required to achieve reflow.
2. PRESOAK: Presoak is the period between preheat and soak.
3. SOAK: Flux is activated during the soak stage. Typically, significant voiding will occur without
proper soak.
4. RAMP: Quickly takes the solder joints from the end of soak to the beginning of reflow.
5. REFLOW 1: Time over liquidus until the heaters are shut off.
6. REFLOW 2: Time until the joints fall back below liquidus.
7. EVENT: Turns off the heaters.
The following are typical time/temperature targets for each stage (Event):
Tin/Lead Lead-Free
PREHEAT
- Topside Board Temp (
°
C) 90-120 130-150
avg=100 avg=140
PRESOAK
- Joint Temp (
°
C) 101-139 141-169
- Time (seconds) 20-45 20-45
SOAK (joint)
- Joint Temp (
°
C) 140-165 170-200
- Time (seconds) 45-75 45-75
RAMP (joint)
- Joint Temp (
°
C) 165-182 201-216
- Time (seconds) 15-30 20-35
REFLOW 1 (joint)
- Joint Temp (
°
C) 183-215 217-245
- Time (seconds) 30-50 35-55
REFLOW 2 (joint)
- Joint Temp (
°
C) 215-183 245-217
- Time (seconds) 15-25 10-20
EVENT Heaters Off
Typical solder liquidus temp (
°
C) 183 217
Typical max joint temp (
°
C) 210 245
Typical max package temp (
°
C) 250 260