Under bonnet temperatures 3

[82james82]

Hi,

I'm looking for information regarding the temperature under the bonnet of a car experienced by electronics.

Any help would be great

 

[MacGyverS2000]

Depends on where the electronics are located in relation to open areas as well as heat sources. If you're on top of the header, you're going to be a lot hotter than if you were under the battery.

 

[patprimmer]

Proximity of exhaust pipes and catalytic converter can have a profound effect.

Apart from being close to the exhaust, many areas allow the use of filled polypropylene components which would imply a bit over 100 deg C. some areas need nylon which implies long term temperatures between 100 and 130 deg C with short term spikes not going over about 150 to 160 deg C

Nylon fails close to the exhaust which implies 160 to 200 deg C for a moderate amount of time (maybe 100 hours exposure)

Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[82james82]

Thanks, do you know where I can get any more information from.

 

[amorrison]

Some nice drawings and info.

http://www.dupont.com/mcm/cer-automotive.html

Nice graph near bottom

http://www.electronics-cooling.com/html/2003_august_a3.html

 

[sreid]

For most integrated circuits the industrial temperature range is -40 to 85 degree C. And that spec is for free air. That's why most electronics is under the dash board.