Hello, We have four narrow rectangular LED PCB's, each one comprising three 1W LEDs. These are double sided PCB's with thermal vias to the bottom layer.
Each PCB is mounted on one of the four faces of a vertical, solid aluminium bar...so we have light shining North, East, South & West from the aluminium bar, so to speak.
Now, unfortunatley, the LED PCB's totally cover the vertical faces of the aluminium bar, so unfortunately the only bare metal surface of aluminium that can contribute to heat transfer by convection is the top 1 inch square part of this vertical aluminium bar.
As you can see, this big aluminium bar is mostly a waste of time, since most of its vertical sides are covered by the LED PCB's themselves....which impedes convection from the metal sides of the aluminium bar.
Anyway, do you believe that a better heatsinking solution would be to simply remove the solid , vertical aluminium bar, and have the four LED PCB's standing vertical, with their copper clad bottom layers providing the convection surface?(...i.e more metal surface area but far less metal volume)
(The bottom copper is obviously covered in solder-mask, as it must be to prevent oxidation of the copper......do you think that the solder mask layer will ruin the effective convection of heat from the bottom of these PCB's.?)
Is there any other material (other than solder mask) that we can cover the bottom copper layer with to aid convection more?....what about covering it with solder?, -eg as in some EMS's will cover bare copper pads with solder
(as in HASL = Hot Air Solder Layering).
Anyway, to summarize, for cooling LEDs, what do you choose.......A Big volume of metal, or much, much smaller volume of metal but more metal surface area?
Each PCB is mounted on one of the four faces of a vertical, solid aluminium bar...so we have light shining North, East, South & West from the aluminium bar, so to speak.
Now, unfortunatley, the LED PCB's totally cover the vertical faces of the aluminium bar, so unfortunately the only bare metal surface of aluminium that can contribute to heat transfer by convection is the top 1 inch square part of this vertical aluminium bar.
As you can see, this big aluminium bar is mostly a waste of time, since most of its vertical sides are covered by the LED PCB's themselves....which impedes convection from the metal sides of the aluminium bar.
Anyway, do you believe that a better heatsinking solution would be to simply remove the solid , vertical aluminium bar, and have the four LED PCB's standing vertical, with their copper clad bottom layers providing the convection surface?(...i.e more metal surface area but far less metal volume)
(The bottom copper is obviously covered in solder-mask, as it must be to prevent oxidation of the copper......do you think that the solder mask layer will ruin the effective convection of heat from the bottom of these PCB's.?)
Is there any other material (other than solder mask) that we can cover the bottom copper layer with to aid convection more?....what about covering it with solder?, -eg as in some EMS's will cover bare copper pads with solder
(as in HASL = Hot Air Solder Layering).
Anyway, to summarize, for cooling LEDs, what do you choose.......A Big volume of metal, or much, much smaller volume of metal but more metal surface area?
