TheBackShed.com

Forum Index : Electronics : Inverter building using Wiseguys Power board and the Nano drive board

Page 37 of 37

Author

Message

KeepIS

Guru

Joined: 13/10/2014
Location: Australia
Posts: 2223

Posted: 05:59am 08 Aug 2026

Copy link to clipboard

Print this post

Remember this part of the New WG inverter build thread is for those builders new to electronics and inverter building.

Below: Some of the the FET hardware, like the bolt and white "top / shaft" insulator washers that we use here to centre the FET body correctly over the PCB while soldering.

Below: Try to have a gentle bend in the FET Legs, instead of a right angle, there are proven reasons to do this. I will not be discussing those here, look it up!!

Below: A view of the White insulating (locating as well) washer on one side of the FET.

Below: The washer on the other side of the PCB.

Below: Ready to solder, gate lead will be trimmed neatly later, flip the board over and start soldering the TOP side of the board first.

I mount 4 FETS at a time as they share a common copper track, and soldering four FETS in close proximity helps heats the wide track, when the TOP is done, flip the board over and finish the Bottom.

Someone asked how long it took to heat the solder pad for the first leg, I was incorrect, it only takes 4 seconds to have the solder flow over the pad and migrate down the FET leg through the board, each one is progressively faster as the whole track heats. If you are doing this in a freezing room, use a heat gun to GENTLY heat the board first, I did not and it's 19°c in the room.

As stated earlier, solder the FET leads on the TOP of the PCB first, flat tip on the pad first, when solder flows on the pad, move the tip against the FET lead for a second or two as you feed a little solder, this normally flows through to the pad on the other side, once you get used to it's very quick to solder each leg.

Edited 2026-08-08 16:14 by KeepIS

NANO:Inverter V 8.4ks - Linux AvrDude GUI script V4.1

analog8484
Senior Member

Joined: 11/11/2021
Location: United States
Posts: 207

Posted: 04:41pm 08 Aug 2026

Copy link to clipboard

Print this post

KeepIS said 70 watt temp controlled 480°, around 10 seconds to flow, you always solder the underside first, minimising heat transfer through the FET leads by heating the PCB first, before sliding the tip against the FET lead and allowing the solder to flow through, flip the board and heat the PCB next to the lead, solder melts quickly, minimising heat flow through the FET lead, have done this for every inverter board I have built.

"you always solder the underside first" is WRONG

SHOULD read always solder the TOP side (component and Terminal side) of the PCB first. when soldering the FETS.
:

Thanks for the tips.

Interesting ... I always soldered the underside first

Also, I must admit I never tried 480C because that's the limit of my 70W iron and it became uncomfortably warm to hold even at 380C after more than a few minutes.
Edited 2026-08-09 02:41 by analog8484

Page 37 of 37

Print this page

To reply to this topic, you need to log in.