Holding an SMPS Former to PCB with fishing line?

[cupoftea]

Hi,
Doing prototype LLC 2Kw…ETD59 transformer. We want to experiment with different home-brew litz wires. So we need to be able to remove/replace the LLC transformer easily…as such, we have put pads outside the footprint, and will terminate pri/sec to them…..the main former pins will never be soldered in……but there are NPTHs dotted about the footprint, (1.5mm and 3mm diam) and we will use Nylon fishing line to tie down the ETD59 via these holes. Will this be OK?.....is there a high temperature equivalent of fishing line?

 

[d123]

Hi,



Teflon coated fibreglass thread might be an option (search entry blurb says 1,000°F for this brand).

Teflon (PTFE) Coated Fiberglass Thread (AKA Teflon Thread) | CS Hyde Company |

PTFE Coated Fiberglass Thread has maximum temperature of 1000F. Excellent chemical, ultraviolet & flame resistance.

catalog.cshyde.com

What about small cable ties instead, if not wider than 3mm? You might have a few of those in your parts bin, perhaps?

 

[d123]

Hi,

Also read that nylon is a thermoplastic material that is good for use up to 100°C, melting point 220°C. Something or other about 50°C for normal use. If nylon screws for PCB spacers are sold, and most stuff operates up to 150 - 175°C, by extension expectation is some designs have a PCB in enclosures that will get (very) hot, then fishing line shouldn't melt either, might get stretchy 'though, and wobble a bit. As you're fiddling ("cumbersome and iterative" step in design), and it's a brief use, presumably in open air, I wouldn't worry too much.

 

[barry]

how about using wire??

 

[cupoftea]

i worried it may cut into the enamelled copper wire etc