How much more expensive is MCPCB than 0.8mm double sided FR4 PCB?

[treez]

Hello,

How much more expensive is MCPCB than 0.8mm double sided FR4 PCB?

I am referring to use with mounting of LEDs that dissipate 2W on average.

 

[swapna.b]

Hello,

How much more expensive is MCPCB than 0.8mm double sided FR4 PCB?

I am referring to use with mounting of LEDs that dissipate 2W on average.

Hi,

MCPCB is quite costly.But it is good to choose dissipate heat.
How many power LED, you are using in your design.

Regards
Swapna.B

 

[treez]

24 leds in parallel...3 strings of 8...one 10r res each string....150ma in each string

 

[keith1200rs]

It depends on if you need double sided or single sided MCPCB. I got some good pricing from Tate Circuits for double sided although I didn't go ahead as we decided we could get away with a thin FR4 PCB.

Keith

 

[swapna.b]

24 leds in parallel...3 strings of 8...one 10r res each string....150ma in each string

Actually the cost is double if compare to double side FR4.But MCPCB is a good choise to select for power LED's.It will dissipate heat properly and LED life will also improve.

Thank You,

Regards
Swapna.B

 

[D.A.(Tony)Stewart]

treez please answer the original Q. What is the total power dissipated? not just current.

Actually also need device p.n. or you tell us the case thermal resistance and layout device spacing and PCB area with exposed (not insulated) metal heat conductor.
More details are also needed later to compare temperature rise vs area vs cost.

 

[treez]

9.6W LED power with our amber LEDs

 

[mrflibble]

... although I didn't go ahead as we decided we could get away with a thin FR4 PCB.

How thick was the FR4 pcb you ended up using? Also, do you remember roughly how much dissipation per cm^2 you had?

 

[poorchava]

Everything depends on ration of total power dissipated to total PCB area (like Watts per square cm or something). It's also very important how is the whole arrangement going to be cooled (convection? heatsink? fan? others?).

MCPCB is good when you have a small device dissipating a lot of power and you need that heat to be efficiently and quickly transferred to something that will dissipate that heat. MCPCB is useless if you have (for example) whole pcb with LEDs encased in cast acryllic.

 

[treez]

whole pcb with LEDs encased in cast acryllic

you mean encased in plastic?.....

The below "securiled" product is encased in plastic and that uses mcpcb mounted leds......do you say that this is wrong?

**broken link removed**

 

[mrflibble]

In that case I wouldn't say the MCPCB is totally useless. It still helps in transporting heat from the led die to the metal surface of your MCPCB. But the acrylic sure doesn't help in getting the heat away from that metal surface. Unless they used super awesome acrylic with low thermal resistance.

@treez:
How much dissipation per cm^2 were you planning to do on your 0.8 mm double sided PCB? I assume you are using lots of thermal vias to get the heat away from the top side (with the leds) to the bottom side of the pcb...