Electronics > Manufacturing & Assembly

Daughter PCB....make it like an SOIC8...(the legs)

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Faringdon:
If i may please ask....We are doing a 2kW SMPS. PFC then Half Bridge LLC.
The main board has the chunky components on it and is rather large for this initial prototype (500mm x 400mm).
Therefore, we dare not put SMD on this potentially ‘bendy’ board. Though we need the Gate drive components to be SMD for sake of reducing stray L. As such, do you think the attached method is good for doing the gate drive with SMD daughter boards?
Its basically making the daughter board into a little kind of SMD component. (As SMD, The daughter board will be easier to remove if we need to, during testing.)
BTW, the cheap Chinese PCB Fabs don’t seem to be doing >1.6mm thickness on the cheap rates for our main board size, so we must use 1.6mm thick main board.
The below is the only thing I can find so far, but we need the legs to come “out” so we can solder them to the mains board SMD pads…..

https://uk.farnell.com/wurth-elektronik/61000418221/header-2-54mm-pin-smt-4way/dp/2356209
Is there such “SMD header” as in the attached picture?  :-//
Basically we just want a header which will kind of put "legs" onto the daughter PCB.....to make it kind of like a SOIC8, type of thing...those kind of SMD "legs"

I mean, the below could kind of be hacked to do it..
https://uk.farnell.com/multicomp/mc34747/header-1-row-r-angle-3way/dp/1593427
....but its  going to be a bit "raised" compared to a SOIC, kind of thing.

T3sl4co1l:
Wowee!  Last time I saw a board that big, it was because it was stuffed full of TTL chips.  Don't think I even saw a power board that big, not at 2kW anyways, maybe close in the 10-20kW (induction heating) machines I've seen.  Or there was one that was full panel size (like 24 x 36") but that was more like 30kW, ooold ass SCR based unit, tons of free space on the board anyway, clearly they didn't care.

Granted, they were using even bulkier components than you, I almost guarantee... freaking unit was near 50kg, just the 10kW "tabletop" model even.  But yeh, no choice but to chassis mount components like that.

Tim

spostma:
I would make a daugterboard with all SMD components,
and solder it high above the motherboard with two straight pin headers,
using the entire pin length as flexible interconnects.
Place the two pin header not too far apart.

Faringdon:
Thanks, so  may i enquire.....you wouldnt use these..?

i could use this on the sub board....
[1]...
https://uk.farnell.com/multicomp/2213r-06g/header-2-row-r-angle-6way/dp/1593449?st=2213r-06g

...and then this socket on the main board...
[2]...
https://uk.farnell.com/harwin/m20-7830446/socket-pcb-0-1-4-4way/dp/7991991

.....because soldering PTH header pins in is going to be difficult if we have to remove it....though if you say soldering is essential due to the 250khz and high tr (<100ns), then we will solder it?

3roomlab:
you are talking about something like this?

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