Automotive overmolded connector sealing

[Joel_Lapointe]

Hi,

We have an automotive mechatronic actuator product that contains some overmolded electrical pins that forms a connector. This PBT enclosure must be IP67.
Despite the pins being overmolded, there is sealing issues. An example is that some automotive oil is running in electrical wires between the copper and the plastic sheath (capilarity).
Then, this oil gains access to the connector of the enclosure because the cable is connected to it. The oils seeps through the connector to go inside the enclosure (capilarity).
Our solution was to put urethane sealer in the connector cavity. Problem still present.

So I wonder if there is a supplier of overmoldable electrical pins that are coating their pins with a product that seals with the plastic PBT overmold?

Any other solution?

Thank you.

 

[3DDave]

One way to break the path is to use solder splices with adhesive lined heat shrink tubing, isolating the connector from the oil source.

You may also consider anti-capillary wire, though the ones I see are proofed against water, not oil.

If one is certain that oil will be present then adding a small nick to expose the copper wire inside and putting that nick at a low spot will allow oil to drip out; since it is oil the wire will remain protected against corrosion.

Since you are looking at the actuator, these adaptations could be made with a pig-tail/stub cable that plugs into your device. Or the device could have a small junction box that has weep holes added so that any oil that comes out of the connector drips into the box and not into the interior of the actuator. Since it is inside the junction box you can use solid wire to prevent further capillary action.

I know some recalls over cars spontaneously bursting into flames because always-on control units were getting filled with conductive liquid, but I don't know what the manufacturer did about that.