Preventing connectors from corroding with silicone?

[treez]

Hello,
We have used 1 Amp rated connectors with 880mA in them because we can't fit bigger connectors on the PCB. The danger is that they will corrode prematurely due to overheating and become intermittent connections...(making and breaking repetitively).
Can we prolong the life of the connectors buy dousing them and covering them with silicone at assembly time, so that they are not in contact with air?

They are molex picoblade 1.25mm connectors....
https://www.molex.com/molex/product...oducts&chanName=family&pageTitle=Introduction

 

[D.A.(Tony)Stewart]

Depending on the number of adjacent pins carrying the same current, temperature rise will certainly exceed the allowed 30'C for 1 pin at rated current.

The plating is only 0.914μm tin over Phosphor Bronze, making it an easy target for rapid loss of plating if wet contact , or "hot insertion" is performed. Could be a poor choice.

How often is mating performed? Is it tested after assembly with vibration?

no, silicone RTV won't help, in fact may cause more temperature rise.

 

[treez]

Mating is performed just once.....we don't vibration test them....there must be something we can squirt over them so that they are less likely to corrode?...what about kind of potting them?

 

[D.A.(Tony)Stewart]

How many pins carry his current?

Does the friction lock work?

What is the new contact temperature rise?

Gold plated contacts are designed for low corrosion <2A

You can seal the shells after mating with RTV but not the contacts, then removal is hard. how well this performs, only your TE support Eng would know better.

Are these sharing current? Ohoh.

 

[treez]

yes they are sharing current.....its the 3.5 Amps load current which goes through four connector blades paralleled...each blade (ie wire) carries 880mA...and its a 10 way picoblade molex 1.25mm smt connector...the other two get used for a signal thermistor connection.

the friction lock is ok, though a more definite snap fit would be better...but we cant find anything this small like that

 

[D.A.(Tony)Stewart]

Try to measure contact temp. Rise. When one contact fails the others get hotter and fail faster.

 

[treez]

by a "failed" connector , you mean one that has rusted away ?......ive never seen connectors anywhere go like that......im just wondering if we douse the whole connector in thermal paste?...surely that will help keep it cooler?