TE Connectivity CBP-5T Mk II Customer's Manual page 35

Explanation
The insertion process starts at row 1, and proceeds from there. Each row can be one of three different
types: "Move to Height or Force", "Delay", and "Retract". The "Move to Height or Force" type is the most
commonly used step type. This step type has a "Height" and a "Force" condition. As the press head
travels down, the program continuously monitors these conditions and acts on whichever condition is met
first. The Height condition is checked first so it takes priority in the case that both occur simultaneously.
The "Delay" step type can be used to delay the pressing profile by a specified amount of time in
milliseconds before continuing with the remainder of the profile. The "Retract" step type can be used to
raise the press head a specified distance before continuing with the remainder of the profile. Each
condition ("Height", "Force", "Delay", or "Retract") has an "action", which either continues the pressing
process at another step or generates an error. These events and actions are used to:
●detect and announce unexpected contact
●detect unacceptably high or low force generated during pressing
●detect a missing connector condition
●press to/verify the proper seated height
●repress a connector that has already been partially pressed
●pause for a fixed time period before proceeding
●retract the head a small distance to momentarily relieve force before proceeding
There are four basic methods of pressing, and each requires a unique profile.
 FIXED FORCE PER PIN - A connector can be pressed with a force proportional to the number of pins,
such as 30 pounds per pin. This is slightly better than the simplest method of pressing to a single fixed
total force because it recognizes that the force applied should be proportional to the number of pins
being pressed. It cannot compensate for normal variations in required force per pin for different
connectors, in different positions, in different boards.
 PERCENT ABOVE RANGE SAMPLE (PARS) - A connector can be pressed with seating force that is
proportional to the actual pin resisting force detected during the pressing cycle. This is called "Percent
Above Range Sample", or PARS. In this technique, the connector's pin resisting force while pressing
is sampled and averaged over a distance Range before final seating to the board surface. The final
force exerted on the connector is limited to a user-programmed Percent Above the Range Sample
force. This percent added assures complete seating of the connector against the PCB. This is the most
widely used technique because it limits the stress to the assembly, does not require accurate board
thickness measurement and automatically adjusts for small variations in connector and PCB thickness.
 PRESS TO HEIGHT - A connector can be pressed to within a programmed distance short of seating
on the board surface. This is the gentlest process possible because it exerts only enough force to
press the pins into the plated holes in the board. No excess force is pressed into the connector plastic
or the board. This sophisticated technique is made possible by the control available using an electric
servo press head and a rigid press structure. In order for press to height to be accurate, the board
thickness must be precisely known. This can be done using the thickness measurement probe and
sequence provided.
 FORCE GRADIENT - Monitors the rate of change of force to distance. This method is used for robust
connectors that need to be seated against the board surface. Generally, the force vs. distance plot will
make a sudden steep upturn as the connector contacts the board surface. The connector stops moving
so the force rises quickly. A minimum slope is specified for the upturn which corresponds to how solidly
the connector is pressed against the board. Note that the slope is calculated using the ratio of the
change in force (ΔForce) over the change in distance (ΔDistance) specified by the user in the profile or
in the connector part.
A "standard" profile template for each of the techniques above is provided with the press. They use
variables whose values come from the Connector and Tool databases rather than discrete numbers.
Since each connector requires the same basic steps, one profile with variables can be used for many
different connectors.
The standard profiles are named "standard_force_CDB", "standard_pars_CDB", "standard_HGT" and
"standard_FG_CDB". Example #1 below is the "standard_pars" profile.
Rev C
409-35001
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