User Manual

Beginning Programming 8-13
Valve-On Time
This parameter controls the time the valve is on while positioned over the dispensing
location. The time interval affects dot size. The longer the Valve-On Time, the larger the dot.
The units are in seconds. The typical value is 30 ms. However, the Valve-On time can be as
long as 6 seconds, depending on the desired dot size and fluid properties.
Dispense Gap
The Dispense Gap is the distance between the substrate you are dispensing on and the needle
tip during dispensing. This distance is one of the more common adjustments to optimize
dispensing programs. The units are in inches. Typically, the Dispense Gap is set to half the
dot diameter.
Number of Shots
This parameter controls how many shots of fluid will be dispensed at a single location.
When making larger dots, it is desirable to move the needle up between shots at the same
location. This parameter is set >1 for more than one dot at the same location, and the Multi-
shot Delta is the vertical retract distance of the needle between each shot. The units are in
shots. Typically, this is set to 1 unless you are dispensing as described above.
Multi-Shot Delta
This is the height that the dispensing head retracts between multiple shots at the same
location. It is used in conjunction with Number of Shots. The units are in inches. If using
with Number of Shots, a typical value is 0.010 inches.
Dwell Time
Dwell Time is how long the dispensing head stays at the final position of a move before
retracting. This gives the fluid a chance to attach to the substrate. Increasing the Dwell can
reduce “stringing” of material. The units are seconds. For most solder pastes and adhesives,
30 ms is sufficient. However, the Dwell can also be set as long as 6 seconds for very elastic
fluids.
Retract Distance
This is a vertical distance that the dispensing head moves after dispensing. The Retract
Distance must be within the Safe-Z Height defined in Initial Setup. The Retract Distance can
be reduced to increase dispensing speed. However, the dot quality will be affected in viscous
fluids. The units are inches. Typically, 100 mils (0.1 in) is sufficient.
Retract Speed
This is the speed of the dispensing head while moving the Retract Distance. This parameter
affects when the dispensing head moves to do the next dot. The units are in inches/second.
Typically, 2 in/sec is sufficient.
Retract Acceleration
This is the parameter that controls how fast the dispensing head comes up to the Retract
Speed. You may need to set this high for small dispensing moves. The units are
inches/second squared. Typically, 300 in/sec
2
is sufficient.