Manual

Beginning Programming 6-27
Line Parameters
Line Parameters offer greater control over line thickness and ensure cleanly dispensed lines. Line
Parameters are divided into three categories according to when each parameter is implemented during the
dispensing process. The categories are:
Pre-Dispense
During Dispense
Post Dispense
You may define up to ten different line styles in FmNT. Each style may have different parameters. You
may set line parameters for lines, weight control lines, arcs, circles, rectangles, and area fills.
Pre-Dispense Line Parameters
Pre-Move Delay Factor
Some fluids have a high viscosity which means that they do not dispense as quickly as lower viscosity
fluids. The Pre-Move Delay Factor increases the time that the Dispensing Head is parked with the valve
ON, prior to a programmed move. The delay at the beginning position insures that a full line is
dispensed. The units are seconds. Typically, 50 ms (0.050 sec) is sufficient for most underfill fluids.
Down Speed
The Down Speed is how fast the Dispensing Head lowers to dispense. Low viscosity fluids tend to drip
and you may want to set this parameter higher. The units are inches/second. Typically, 2 in/sec
is sufficient.
Down Acceleration
This is the parameter that controls how fast the Dispensing Head accelerates to the Down Speed. The
units are inches/second
2
. Typically, 300 in/sec
2
is sufficient.
During-Dispense Line Parameters
Dispense Gap
The Dispense Gap is the distance between the needle tip and the substrate during dispensing operations.
This distance is one of the more common adjustments made to optimize dispensing programs. The units
are in inches. Typically 15-20 mils (0.015-0.020 in) is sufficient.
Speed
Speed refers to how fast the Dispensing Head moves during dispensing. This parameter is actually not
used for weight control lines, but basic lines where the speed of the Dispensing Head affects the amount
of fluid dispensed. The units are inches/second.
Shut-Off Distance
Shut-Off Distance controls where dispensing is discontinued at the end of a move. Low viscosity fluids
require that you stop dispensing prior to the end of the move so that the fluid does not exceed the pattern
limits. The Shut-Off Distance is the point where the valve stops dispensing before the end of the move.
The units are in inches. Typically, 30 mils (0.030 in) is sufficient.