Manual

Advanced Programming 7-13
Multipass Timer
You also have the option to set timers during the dispensing process. For example, you may want to
make sure the fluid flows completely underneath the chip before the sealant is dispensed.
• Await Multipass Timer - Await Multipass Timer should be the first command in every Pass
of a multipass pattern, except for the first pass. Await Multipass Timer works in conjunction
with Reset Multipass Timer.
• Wait Time - Enter the number of seconds you want to wait between passes. Take all fluid
characteristics into consideration when you set the Timer.
• Reset Multipass Timer – Reset Multipass Timer should be the last command in every Pass of
a multipass pattern, except for the last. When you select Reset Multipass Timer, the Timer is
set to 0 and a Reset Multipass Timer command is inserted directly into your program. If the
indicated wait time has not expired before FmNT is ready to begin the next pass, then the
Await Multipass Timer dialog box opens containing a timer and a message. The timer counts
down the remaining seconds before the next pass is executed.
Weight Control on Multiple Passes
Weight control lines are usually used for all lines in multiple pass programs. Different line styles are
sometimes defined for each line of the program. For instance, the first L-shaped line in an L-shaped
pattern usually is defined with a higher weight than the second L-shaped “seal pass”. This assumes that
the fluid will flow underneath the die to the opposite corner.
Reusing Fiducials and Height Sense Information
If your workpiece contains many parts, and the pattern to be dispensed is a two or three-part pattern such
as the L-shaped and U-shaped patterns, checking fiducials and the substrate height during every pass can
be time consuming. In many cases, it is unnecessary since the likelihood that the parts could move
before the timers expire is very low. Rather than finding fiducials and doing a height sense check during
every pass, fiducials and height sense checks are performed once for each part and the information is
stored and reused during the second pass. This is called “Reusing Fiducials” and is enabled by selecting
Pass Block from the Pattern button cascading menu on the Program Commands toolbar. This feature is
a significant timesaving option.
Fiducial Options
In Setup Vision on the Configuration menu, there is a Vision Parameter called “Fiducial Options” with
the choices
Pause after search, Skip and Prompt.
Activating Pause after search means that FmNT will pause after every fiducial search and display a
message box indicating the status of the fiducial. This can be helpful during programming sessions, but is
not recommended for production runs since it requires an operator response in order to continue. When
developing a dispensing program, pausing after a fiducial search to verify that the correct fiducial was
found is a good way to determine the best fiducial to use for an application.
Skip and Prompt can be used for production runs. Occasionally chips are placed skewed on a workpiece
or a defect interferes with a fiducial. In this case, if Skip is chosen, the program will automatically skip
the fiducial or part it is searching for and continue with the next step in the program. If Prompt is selected,
the operator is asked to either reteach the unfound location, or skip it and continue the run.