Air-Vac DRS27, Руководство пользователя

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DRS27 User’s Guide Chapter 5: Process Development Guide/Engineering Training
0027.00.902 5-4
5.0.1 Overview
The DRS27 Process Development Guide is designed to allow novice users to create and run new pro-
cesses. There are five (5) steps to creating and running a new process:
1. Physical Setup
2. Profile Tutor
3. Thermal Profile Analysis
4. Auto Profile Build
5. Program Execution
Each of the five steps is documented in detail in this Process Development Guide. Please contact Air-
Vac with any questions (203-888-9900; request DRS27 Process Assistance).
5.0.2 Physical Setup
IR Sensor
The IR Sensor measures and monitors board temperature during the rework process. Its main function
is to insure that the board is at the same starting temperature during each rework cycle. The IR Sensor
is connected to its own internal TC port. If you did not purchase the optional IR Sensor, contact Air-Vac
for further instructions. Position the IR Sensor on an open area of the board 2-3 inches away from the
rework site.
TC#1: Joints
Slide a TC underneath the BGA and plug into channel #1. If possible, slide two additional TC’s under-
neath the BGA for additional data. For large components, 3 thermocouples will provide a good set of
data to insure accurate profiling. Erroneous TC’s can be removed while running the profile tutor. Air-
Vac uses .003” gauge K-type TC’s (1-888-TC-OMEGA, Part #5 SRTC-TT-K-40-36).
Apply Kapton tape to hold the TC’s in place. If desired, x-ray will show the exact positioning of the TC
head, however this is not critical. Studies have shown that TC’s underneath the BGA that are not in di-
rect contact with a solder joint are typically within –5 to 0 degrees of the joint temperature.
The major advantage of this approach is that it is non-destructive yet still highly accurate.
If the standoff height or ball density does not allow a TC to be slid underneath it, a scrap board should
be drilled from the bottom, TC’s installed into the joints are then epoxied in place.