defect of the month
Component Pin Float Issues
When through-hole connectors move during soldering, damage to the nozzle ensues.
This month we look at through-hole connectors and component pin float. All connector pins should be held in place by the body molding and not move during soldering. The connector should not be used outside of its specification. Suppliers typically define the temperature and time the pins and body of the part are exposed to a specific peak temperature. It is the designer’s job to ensure the correct parts are defined for the process. It is the purchasing department’s job to ensure the correct parts are ordered.

In the images shown, the pins in the connector have floated down. This happens easily during soldering or rework. In an automated process, if the pins drop down 1 to 2mm below the board in selective or wave soldering, they can cause damage. Pins can contact the solder nozzle or wave former, which will jam the machine. Using low-temperature solder with a lower specification connector will work fine, but consider the rework temperatures if parts must be removed.

We have presented live process defect clinics at exhibitions all over the world. Many of our Defect of the Month videos are available online at youtube.com/user/mrbobwillis.

Connector pins floating down
Connector pins damaging soldering equipment from being too far down
Figure 1. Connector pins that “float down” too far can damage soldering equipment.
Bob Willis illustration
Bob Willis
is a process engineering consultant; bob@bobwillis.co.uk. His column appears monthly.