Paul,
Power LEDs usually have serious thermal tabs to conduct heat to a PCB. PCB
color can have a big effect on surface emissivity.
I played with bare aluminum vs black painted aluminum once, someone was
trying to tell me that paint acts like a thermal insulators. I considered
that nonsense.
After painting a bare piece of aluminum sheet that had a power resistor
mounted, the temperature dropped by 10 degree C. I was floored.
So before you use white on a PCB with power LEDs you might consider black.
Maybe you want one side whit to help reflect light and the other side black
to dump some heat. A lot depends on areas, temps and LED lens systems.
Bob K.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Paul Reid
Sent: Monday, August 15, 2011 8:23 AM
To: [log in to unmask]
Subject: Re: [TN] LAMP LED PCB
I learned recently that white PCBs reflect some of the energy emitted by the
LEDs which reduces heat in the assembly. LEDs that are not internally
mounted in the PWB, can get as hot as 180°C.
The application proposed used a very white solder mask that resists
yellowing over time.
Sincerely,
Paul Reid
Program Coordinator
PWB Interconnect Solutions Inc.
235 Stafford Rd., West, Unit 103
Nepean, Ontario Canada, K2H 9C1
613 596 4244 ext. 229
Skype paul_reid_pwb
[log in to unmask]
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Juliano Ribeiro
Sent: August 15, 2011 8:06 AM
To: [log in to unmask]
Subject: [TN] LAMP LED PCB
Technetters,
We need design the PCB to LED LAMP and we verified that PCBs are white.
What the benefits of the White PCB for this application?
What attention in the process to white pcb?
Is cost higher than green pcb?
Thank you
Juliano Ribeiro
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