Question: Industrial optocouplers keep failing on-site, what thermal management products can solve this issue?

Question

The optocouplers on our production line control boards work under continuous high-temperature conditions and often suffer breakdowns or signal distortion failures. 
 
 Besides standard cooling fans, I&rsquo;m wondering what mature thermal management products, thermal conductive components or circuit design solutions are available to reduce high-temperature damage. 
 
 It would be much appreciated if anyone could share solutions that have been applied in industrial or automotive projects.

SensoredHacker0 · Answer

Auxiliary cooling is a hack for design out of spec. dont do that. Better lab testing should reveal such things before they happen. whether the component is in spec for the environmental conditions, will be defined in the datasheet. I test failure patterns on all the hardware we use, regardless of spec. To do that, some of the tools I use are small ovens, thermal cameras, oscilloscopes, function generators, and insulated boxes of various sizes. Everything will fail. You should know the conditions where the products you use fail. Maybe its heat. maybe its noise from some other device, maybe high ambient humidity does it. when your techs show up, after whatever unit fails, do the components seem to work? or is there permanent damage? Is there discoloration? smells? surface texture changes? I had these relays operate at max load for 24 hours per their rating. The plastic got kinda soft. thats a fail. Others caught fire. testing the spec isnt even abuse. Ill abuse the crap out of a device to make sure it works as expected every time. we had one last year when some panels installed on a roof in the sun reached 130+ degrees. nice, we didn't anticipate that. we fixed it by installing a little roof to cast some shade. Thats a hack. I wouldn't point to that install as a proud moment in controls engineering. I cant say to a customer, hey we normally install these in mechanical rooms, or basements, this whole roof top thing, .. we didn't test for that.

Question: Industrial optocouplers keep failing on-site, what thermal management products can solve this issue?

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