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proper pc board soldering technique

Should the resistors, caps, diodes etc. be slightly off the board, or flush to it. I'm building a nixie tube clock. I've asked 3 people and got 4 different answers.  All advice and reasoning , meathodology appreciated.


astroboy9076 years ago
Idk, whatever you what, I guess. There is not real "right" way to this probably. Flush would give it a cleaner look (to me at least)
apparently, there is a right way! :) Loks like im getting some info 2
framistan6 years ago
Components that get HOT should be slightly off the surface. Components that might vibrate or wiggle such as LARGE capacitors should be mounted flush to reduce movement and vibration. I have seen some SMALL electrolytic capacitors that were mounted flush to the surface and if you touched them they would bend over and be destroyed. So at the factory, we started mounting THAT particular tiny electrolytic slightly off the board to help protect it from handling damage. In most cases mount components close to the board except when it causes problems such as overheating etc. If you are working on circuits that are RADIO frequencies, then length of component wires can affect the circuit alignment.
frollard6 years ago
Flush. All components should be aligned to the same vertical and/or horizontal orientation (including non-specific components like resistors) -- makes reading them easier.

they lay touching the board, since bending the leads to hold them down before soldering ...pulls them towards the pcb.

As for other components that naturally stand off, like transistors, the spec sheet will describe the minimum distance or bend radius. Generally it's "don't kink the legs" - shorter is generally better for conduction and resistance, not that a few mm makes a huge difference.

Capacitors I like fully inserted flush to the board so they have less play and can't 'work' the legs to fatigue break in a vibrating environment as easily.

some components like LED's have little stand-offs on the legs so they all mount a uniform depth. Nobody is stopping you from inserting the leds flush to the surface of the pcb though.