409-32048
Rev A
18
of 64
PARS-
FPPL is an abbreviation of “Percent Above Range S
ample -
Force Per Pin Limited”.
This force
condition uses a special algorithm that calculates the average force generated while pressing the
connector into the PCB.
The “Start” and “Distance” boxes in the middle of the screen def
ine the bounds
for the average. Thus, rather than pressing to a specific force, the actual force required is dynamically
calculated for each cycle and termination is based on this force. The “xx%” is an excess force, as a
percentage of the calculated average, which is added to the average to ensure the connector is fully
seated.
For example:
The “Start” height is entered as .030
in. and the “Distance” as 0.015 in.
. PARS-FPPL force
is invoked in the ‘Force (lbs)’column, row 6, and 25% is used from what is ente
red in the connector
database. As the connector is pressed, the force readings taken from .030 to .015 in. above the board are
averaged. The head continues to press until the force generated is 25% higher than this average.
—
Min F/Pin * #Pins -
This force is calculated by multiplying the number of pins in the particular connector
being pressed by the minimum required force per pin. Both the number of pins and the minimum force
per pin are entries in the connector database. This can be used to assure at least a minimum force is
generated during the pressing process.
—
Max F/Pin * #Pins -
This force is calculated by multiplying the number of pins in the particular connector
being pressed by the maximum allowable force per pin. Both the number of pins and the maximum
force per pin are entries in the connector database. This can be used to prevent excessive force from
being generated during the pressing process.
—
User F/Pin * #Pins -
This variable is provided for the flexibility of defining a force event variable other
than Max and Min force per pin.
Its use is up to the programmer’s discretion. For example, while
pressing to force it may be useful to terminate on “User F/Pin * #Pins” rather than “Max F/Pin * #Pins”.
The variable “Max F/Pin * #Pins” would
still be used to generate an error if the allowable force is
exceeded.
“Force Action”
-
This defines the action to be taken when the force at this step is reached. Actions are
selected from the drop down menu. The force actions are the same as the height actions. See Figure 18.
Figure 18
—
Next Step -
This directs the process to the next step below.
—
Go To -
This directs the process to continue at any step below. The step number is entered from the
keyboard.
—
Complete -
This signals that the pressing process is complete. The head will stop immediately and rise
to the next tool clearance height.
—
Error 1 - 8 -
These are user defined error messages. If the height is reached and the action is an error.
The pressing process is immediately halted and the error message is displayed on the screen. The
operator must acknowledge the error message to continue.
“Speed (in/sec)”
-
This is the speed target for the current step in the process. See Figure 19.
Figure 19
