Metal Clad PCB Experience?

[asdf44]

I just read this nice thread but it's a few years old and closed (PS I don't see the value in closing threads like that):
https://www.edaboard.com/threads/263171/


Does anyone have more recent testimonials for metal clad PCB's. Fab houses? Turn times? Prices? I'm trying to wrap my head around the pros, cons and process in the context of a custom amplifier.

It seems like my design is a decent fit where I have mosfets that should be dissipating in the 2-8W range. So surface mount D-Packs with good board thermal conduction should work.


I'm not sure I need metal clad but from what I've gathered so far if I design the board with mostly surface mount components on the top side then I'll have a design which might easily transition to metal clad if needed? Does that sound right?

 

[BradtheRad]

I just read this nice thread but it's a few years old and closed (PS I don't see the value in closing threads like that)

Sorry, the system automatically closes a thread after six months inactive. Forum administrators decided to apply this as a general policy, even though it means closing discussions which could receive further replies as years go by.

Therefore it is a good idea to reference a previous thread, by providing a link to it as you have done in your post.

 

[marce]

Thermal PCB design is always an interesting problem. These days there are many solutions dependant on the circuit complexity and how many layers required to get the routes in. I recently did a 12 layer (all 2 ounce) flexi-rigid layout with numerous D pack and similar devices, lots of copper pours and thermal vias. The best use for metal clad is simple circuits preferably single layer routing where you have the lowest possible thermal resistance down to the metal. Generally for minimum cost simple LED boards on single sided layout offer the cheapest option, then you can get as complex as you like, but this does come at a cost, maybe thermal vias with an external heatsink attached would be a less costly option, lots of methods out there.
How complex is the circuit, what is the PCB size etc. all these factors can have an influence on your design choices...

 

[asdf44]

In your particular example with all that copper what was the rough thermal resistance and/or wattage that you were able to get out of your DPAKs? And what was the board thickness?

Like I said, I plan on going to a traditional PCB first, then see how that performs. But it's always nice to have a plan B. With space constrained if I run into thermal problems I'll have limited space for additional sinking. I've already chosen to split the control onto a separate board which leaves the power board relatively simple, perhaps 2 layers would be possible, which is one reason it seems like a reasonable fit for possible metal clad.

On the other hand it's not hard to move heat around a simple FR-4 board with copper and vias either.