Is it fine to stick a pcb with holes aligned to the 4 terminals right into the isotop? Rubber washers can be used to prevent warping the board.

 

Dude, you're not making any sense. What is an "iso slot" What is an "isotop"? What is that thing in your drawing?

 

Dude, you're not making any sense. What is an "iso slot" What is an "isotop"? What is that thing in your drawing?

isotop: http://www.icbanq.com/icbank_data/semi_package/sot227_dim.pdf

Are you sure rubber washers will prevent warping? It seems at least as likely to exacerbate warping. If that is a real worry, use TH components near the attachment.

 

New one on me too. Here is a pic showing the captive nuts and screws to nail down ring terminals. Perhaps the OP is thinking of replacing wires with terminals with a PCB?

 

Would like a small thin board with a gate driver and a few filter caps but it doesen't seem this is ideal especially the emi which can come out of the package. Replacing wires doesent seem to be any option since their current handling needs to be high for such a package.

Another minus, can probably assume it is a fairly hot location for a lot of applications. Perhaps voltage sensing right at the terminals? Fault sensing? I dunno... Maybe the OP could say?

 

If the application has a current high enough that wires are not a choice then PCB traces are not likely to be adequate either. The very large problem with putting a circuit board under those flaps is that the flaps will be bent too sharply and develop stress breakage, which is a pain to have to deal with. I suggest reviewing the manufacturers application notes for mechanical connection to the device. They should be helpful.

 

If one considers a specific device such as this: http://gptechgroup.com/pdf/GCMS020A120S1-E1.pdf
The heat sink is isolated, so my assumption was that the TS intended to put the PCB on TOP of the contacts with a separate heat sink. Albeit, I would think that appropriate gauge wires and screw terminals would carry at least as much current as PCB traces.

 

I don't know if it is "proper" but it's the way I did it on the power board of my EDM project. By that, I mean the way jpanhalt said, the board goes on top of the tabs not between the tab and the nut. My traces on that part of the board were made the same size as the tab with a hole the size of the screw, using a 2 ounce copper board.

Pager48, the tabs are the actual current carrying part of that package not the embedded nuts. When you put the screws in and tighten them the nuts then come up to the bottom of the tab.

On my project to keep the board from being stressed I made a a frame that was screwed to the heat sink, an industrial type heat sink, not one of the small ones like are used on a PCB mounted device. The mosfets are mounted to the heat sink, and the PCB is then attached to the top of the frame by two screws. The frame is also on the same plane as the top of the mosfet tabs, to keep everything at the same level taking any strain out of the PCB. No rubber in any of the mounting.

This is what I mean by an industrial style heat sink -

 

Dude, you're not making any sense. What is an "iso slot" What is an "isotop"? What is that thing in your drawing?

That ISOTOP package is widely used in power mosfets, IGBTs and even some diodes. They use them in motor drives , welders , plasma cutters, etc. Stuff that need to pass a lot of power. The base is isolated from the electronic parts so it doesn't need to be insulated from the heat sink.

 

Rubber washers are a big No-No. The ISOTOP connection needs to nut tight or else you get this.
https://forum.allaboutcircuits.com/threads/board-burns.153544/