Sealing of an overmolded electrical connector pin

[MechDevEng]

Hi All,

I'm looking for best practices on sealing for overmolded electrical connector pins. I'm working on early concepts for electronics that will be subjected to 3bar of lightweight lube oil. The electronics will be submerged in oil with connector pins overmolded and running from the 3 bar wet environment to atmosphere. The environment is an under hood automotive application that will be subjected to typical automotive operating environment for exposed electronics. What if any sealing solutions have people used on small electrical pins for sealing in an overmolded plastic housing?

Maybe I'm over thinking this but from my experience with urea pumps I had an issue with urea wicking around an overmolded tube and crystals forming. I ended up solving that issue by adding an O-ring on the tube and overmoling that assembly. The rectangular cross section of the electrical pin makes an O-ring impractical. I know that urea is more difficult to seal against than other fluids due to the crystal formation. Maybe this is a non issue for oils.

Thanks,

 

[3DDave]

At that pressure you need a glass hermetic seals. Then put the o-ring around the glass. Otherwise I've mainly seen epoxy to adhere to the pins and the connector body.

 

[dgallup]

You need some form of seal otherwise the fluid will wick along the pins. I've seen designs with round pins and an o-ring on each pin. I've seen designs with the electronics encapsulated in various materials and the seals put around the encapsulation. There are may ways to skin this cat but the bottom line is you need seals.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[Brian Malone]

Hermetic sealing of wiring can be achieved for some applications without using glass seals or o-rings on each pin. Contact Pave Technologies to see if their tech can meet your requirements. I have no connection to Pave other than I have purchased feedthrus from them for a high vacuum application. You may find they can get a design put together for your application.

https://www.pavetechnologyco.com/

As 3DDave and dgallup note the encapsulation body still requires a seal, be it a radial or face configuration.

 

[waross]

Be aware that automotive lube oil may be subject to contamination and may become conductive.
I have seen this and have the anecdote to prove it.


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Ohm's law
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