Instruction Manual

Advanced Programming 9-1
9 Advanced Programming
Overview
This chapter discusses and demonstrates some of the more advanced techniques for perfecting your
dispensing programs. You will perform two underfill tutorials, one L-shaped pattern and one U-shaped
pattern. You will learn how to increase throughput by using timers and skip marks and reusing fiducials
and height sense information.
?NOTE You should complete the preceding chapter, Beginning Programming, before
attempting the tutorials in this chapter.
Programming Tips
Below are several commonly used programming conventions that should help you perfect your
dispensing programs.
Order of Pattern Placement and Timers
The order that the patterns are dispensed is an important part of optimizing the whole workpiece
program.
For instance, in a U-shaped pattern, as shown in Figure 9-2, the first underfill line is dispensed at all
pattern locations on the workpiece. Then, the second underfill line is dispensed at all pattern locations.
Finally, the U-shaped seal pass is dispensed at all pattern locations. Timers are set for each of these steps
using the
Reset Multipass Timer and Await Multipass Timer commands in the Program Commands
Toolbar. This technique is demonstrated in the exercises later in this chapter.
Re-using 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 “Re-using Fiducials” and is enabled by selecting
Pass
Block
from the Pattern button 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.