HS50_advance_level 1_20200522_221201 (1) - 第557页
06/2002 Edition S tudent Gui de HS- 50 Advanced I 20 App endix 30 20. 4.5 .3 V acu um che ck b efo re pl ac emen t F ig. 20 .4 - 5 Vac uum ch eck be fo re pl ac eme nt 1. Anot her vacuum check is made bef ore p lacem ent…
Student Guide HS-50 Advanced I 06/2002 Edition
20 Appendix
29
5. The threshold for component acceptance is determined at this time. In this case we have an
open value of 700 mbar, and a closed value of 900 mbar. The calculation is shown below.
Threshold = (900(closed) - 700(open)) x 0.2 + 700(open)
= 200 x 0.2 + 700
= 740
20.4.5.2 Vacuum check after pick up
Fig. 20.4 - 4 Vacuum check after pick up
1. A vacuum check is made after pick up when the z axis is in the upper position.
2. The component is accepted if the result is within 80% of the nozzle open/closed result deter-
mined during reference.
3. The component is rejected if the result is within 20% of the nozzle open/closed result.
4. The component is immediately re-picked if the result is within 5 mbar of the open value (the
machine assumes no component present).
5. Otherwise the head is moved to the reject bin and the component rejected with air kiss.
-700
-720
-740
-760
-780
-800
-820
-840
-860
-880
-900
0
t
maximum vacuum
Vacuum nozzle closed
Vacuum nozzle open
Vacuum difference at
the last reference run
Environment pressure
Component is rejected at reject box
Component is accepted
at vacuum check
Comp. is rejected
Component immediately re-picked
5 mbar
20%
Pressure difference nozzle - inside -> environment
06/2002 Edition Student Guide HS-50 Advanced I
20 Appendix
30
20.4.5.3 Vacuum check before placement
Fig. 20.4 - 5 Vacuum check before placement
1. Another vacuum check is made before placement, this ensures the component is still at the
nozzle.
2. The same threshold values apply as during pick up. Any failed components will be rejected dur-
ing the next pick up cycle.
-700
-720
-740
-760
-780
-800
-820
-840
-860
-880
-900
0
t
maximum vacuum
Vacuum nozzle closed
Vacuum nozzle open
Vacuum difference at
the last reference run
Environment pressure
Component is rejected at reject box at the next pick up cycle
Component is accepted
at vacuum check
20%
Pressure difference nozzle - inside -> environment
Student Guide HS-50 Advanced I 06/2002 Edition
20 Appendix
31
20.4.5.4 Vacuum check “segment sealed” before pick up
Fig. 20.4 - 6 Vacuum check “segment sealed” before pick up
1. The quality of the segment seal is checked prior to each pick up.
2. This tests the quality of the seal given by the vacuum pluneer.
3. Normally the result should be within ± 20 mbar of the closed result determined during refer-
ence.
4. If a result is outside the tolerance, then the machine logs an error. If the error occurs 3 times
within 350 placements at the same segment, an error is reported "Leaky segment".
5. If this error occurs check the condition of the value plunger.
6. The values for 20 mbar, 3 errors and 350 placements are in the vacuum.MA file.
-700
-720
-740
-760
-780
-800
-820
-840
-860
-880
-900
0
t
-920
Threshold -20 mbar
Threshold +20 mbar
Vacuum difference
at reference run
1.Error on this
segment is logged
2. Error logged
3. Error on this
segment is displayed
Pressure difference nozzle - inside -> environment