Hello,

I am currently working on a personal project which uses a group of surface mount power LEDs.

The LEDs are available in two packages; one which is a simple surface mount device, and another which is the same device pre-mounted onto a regular "star" type heatsink base.

The heatsink base option provides a convenient thermal connection point for a heatsink, but unfortunately the group of LEDs together take up too much space in this package. So I need to make a custom solution (using a custom PCB) and provide adequate heatsinking for the LEDs myself.

I am wondering about techniques for generating optimum thermal transfer from the top-side of the PCB, where the LED will be mounted, and the bottom side.
I was thinking about covering the LED connection pads in lots of tiny through-hole-plated vias to try and take the heat down to the bottom side of the PCB, where I will make a heatsink connection.
I haven't tried this yet, but before I do I thought I'd ask the group here if anyone has better ideas.

Thanks!

 

Welcome to AAC!

I was thinking about covering the LED connection pads in lots of tiny through-hole-plated vias to try and take the heat down to the bottom side of the PCB, where I will make a heatsink connection.

More typical to use the body of the device package for heat transfer.


EDIT: image upload problem fixed...

 

You can buy aluminium PCB heatsinks such as this one but i don't know where you can get them made to your own design.

Les.

 

The classic solution is to use a metal core printed circuit board.

In an early phase of design I made a prototype lamp using approx 0.02" thick copper clad FR-4, The interconnects for the LEDs are on the component side and all of the copper on the non-component side was left alone. The LEDs were soldered directly to the component side of the board. The non-component side of the circuit board was coated with a thin layer of Wakefield (or similar) heatsink compound and the board mounted on an aluminum heatsink. It worked pretty well.