Electronics > Manufacturing & Assembly

PCB is too tall for header connection to main PCB?

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Faringdon:
Hi,
Do you  think the attached PCB is too tall  to be supported by the 20 contact 2row header at its end?
These headers and their sockets seem a bit flimsy, and it makes you wonder whether the weight of this PCB will just be that bit too much ?

The PCB only comprises 0805 resistors, and SO8 chips etc, and one DPAK fet.

Header:
https://uk.farnell.com/multicomp/mc34775/header-2-row-r-angle-20way/dp/1593454

Socket housing (on other PCB):
https://uk.farnell.com/harwin/m20-7831046/socket-pcb-0-1-10-10way/dp/7992025?st=m20-783

evb149:
I assume it is a right angle header and the PCBA will stick up like a skyscraper?

I don't think it is a problem at all assuming the weight of the PCB will actually be adding pressure to mate the contacts, that's actually a good thing with respect to socket retention.

I wouldn't put it on a shake table that way, and I'd be careful of stray elbows / arms knocking into the board, but that's all.

If you are that worried about it you could always add a post or two or three for mechanical support of the board and maybe a shielding surface if you want to keep it more isolated from accidental contact.

Faringdon:

--- Quote ---I assume it is a right angle header and the PCBA will stick up like a skyscraper?
--- End quote ---
Thanks, yes thats right.

mariush:
You guys should work on that PCB a bit more, optimize it to lower height.  Looks like you can turn those SO8 chips 90 degrees to use the space better,  maybe consider resistor networks where possible instead of individual resistors.
Even the optocouplers on the right corner could be rotated 90 degrees to shorten those traces, C94 and C95 could be rotated to use shorter traces, and use that space around C97 and below the two capacitors C94 and C95 better ... in fact those two capacitors could be flipped horizontally so that the trace from the 5th pin in the header can go straight to the capacitors. 
If the header can be offset a bit, looks like you could make space on the right side to move that double optocoupler to the right of the header and save space, get that optocoupler to use the dead space there, especially if it's rotated 90 degrees.

The four traces on the left are a mess, could have the first trace go all way to left and to the top left and have the next 3 traces go straight up and then towards the left edge, without breaking the ground with vias right by the header, could use just one via pair to link that single trace to q34 instead of having 3 traces break the ground ... lots of wasted space around Q34 now. Lots of space to the left of U41 and U43 and U46...  Then that trace continues all the way to the top... that trace should be on the other side of the pcb, along the edge... use that empty space to put components there and shrink the height. The text can go on the top of the pcb or somewhere else, maybe the other side of the pcb which is empty of components.

Force 45 degree angle bends in traces, don't allow 90 degree traces, makes for better layout.

And can you guys really not make the board full SMD and have to use 4 through hole capacitors? Ask how much it costs to make the board have components on both sides

Faringdon:
Thanks, thats some great advice there, uch appreciated...ill work on that.

I must admit i did research on why 90 degree bends were bad, and came up with that in days gone by, etchant would get trapped in the 90 degree bend bit and thin the track there....but that nowadays, this isnt a problem?

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