Press Fit Connectors (Compliant Pin)
pin technology is a solder-free assembly process. The press
fit pins are inserted to a ˇ§compliantˇ¨ section of the
board that is slightly larger than the plated PCB hole.
When the pin is inserted, the compliant section is compressed
and this is what provides the connection between the PCB
and the pin.
Plated-through-hole diameters for
solderless press-fit connectors.
press-fit connectors for insertion into plated through holes
has become a new method of attaching connectors.
regarding the specified size of plated through-holes for
this process is listed below.
Connectors with compliant pins work with industry standard
hole tolerances of ˇÓ.003ˇ¨. Xmultiple provides the drill
hole size which is specified before plating in order to
center the finished hole size within the ˇÓ.003ˇ¨ tolerance.
As an example, to achieve a finished hole diameter of .040ˇÓ.003ˇ¨
the plating would reduce the hole diameter by .0035ˇ¨.
drill hole size for press fit connectors is important to
note before plating. A square, pent. or hex. press-fit design
uses the thickness of the copper in the plated through-hole
for the press-fit interference. The drill size should be
slightly larger than the diameter of the points of the press-fit
thickness in the holes is not critical to the press-fit
operation. The copper material of the printed circuit board
is soft enough to be displaced by the pins.
press fit connectors have barbs as their press-fit feature.
These are designed for pressing into molded housings or
drilled holes (not plated through) in circuit boards. Drilled
holes can be specified with a ˇÓ.001ˇ¨ tolerance.
the assembly process there are steps you should take. When
pressing gold plated pins into gold plated boards or tin
pins into tinned boards, there is ˇ§cold
weldingˇ¨ of the similar metals in contact. This gives rise
to extremely high insertion forces that could damage the
board or the connector. You must use a lubricant in the
holes during the press fit insertion operation to dramatically
reduce ˇ§cold weldingˇ¨. A contact lubricant such as OS-138
is recommended. After the insertion process the boards should
should be noted that "cold welding" can occur
even if lubricant is use so heat can be generated in the
holes during the insertion process. When the insertion process
is performed it would be at a slow rate to minimize heat
which can damage a printed circuit board.