Screw terminal blocks: SMT or through-hole reflow?

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Dear all,

I am looking to use some screw terminal blocks for a design.

The board consists entirely of SMT parts with (maybe) the exception of the screw terminal block for attaching wires to the thing.

True SMD terminal blocks seems to be few and far between - there is one from Weco, one from Phoenix Contacts and one from Amphenol.

To give myself a bit more choice, apparently some are designed for "through-hole reflow" where paste is pushed into the holes and are suitably melted during the SMT process and are thus are generally compatible with SMT processes.

So, does this process limit those who can assemble the boards? How can I easily identify which through-hole parts are reflow capable? Are there any other tricks that I should be aware of?

-- Damien

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Normally a board would be done in two passes- smt in the reflow oven, through hole using selective solder or wave. Through hole connectors would usually be mechanically stronger but have to be manually loaded.....swings and roundabouts. If you making zillions of boards, then cents here and there count, but for 100 boards, there's probably little difference. Speak to your assembler - they do this sort of stuff everyday.

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Dear Damien
Agree with you if you have 100% SMD parts normalt to have reflow terminal.
I do not know a lot of screw type but I use
Weidmuller LSF-SMT serie
try digikey:
http://www.digikey.no/product-se...
Thierry

Thierry Pottier

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Because I know from my own experience how our devices are treated by fitters, so I never think about using SMS terminals in a new projects. IMHO all external connections must be as strong as possible. But we make only several hundred plates for month. In bigger volume using the SMD connectors may be the only possible solution.

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I looked into this some time ago in exactly the same situation. As far as I could find, the only way to know which parts can be reflowed is to ask the manufacturer (or distributor, who will ask the manufacturer on your behalf). In my case, the reflowable version of the specific terminals I needed had lead times and minimum quantities that didn't fit my project, so I had to do them the old-fashioned way.

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Kartman wrote:
Speak to your assembler - they do this sort of stuff everyday.

Ummm... normally I'm a software guy and this is a holiday project for Dad's model train hobby/obsession (they'll need dozens, and I don't want to hand assemble that many). I haven't done my own full electronic design since Uni. Finding an assembler is something for another thread ...

-- Damien