[sdiy] IC socket reliability/0.100 headers?

[Colin Hinz]

On Mon, 21 Jan 2013, ASSI wrote:

> On Monday 21 January 2013, 10:39:06, Dave Kendall wrote:
>> I guess it's fair to say that MTA-type 0.100 style connectors can
>> suffer from many of the disadvantages of IC sockets? They do make life
>> easy and neat, but I guess a soldered connection to a PCB pin with
>> heastshrink for added mechanical strength is possibly the most
>> reliable.
>
> No, you veered into the _other_ lane now.  There is no reliable way to
> solder a flexible cable to a board if it can still move, so if you can't
> bring whatever is at the other end of that cable directly on board, you need
> a calbe-to-board connection.  That's what these are designed to do, the
> important difference to an IC socket is that the socket and the pin are
> mated.  If you really don't need the cable to be removable (usually on one
> side only) you could skip the socket by using press-fit pins crimped to the
> cable.

Stranded wires soldered to turret pins are pretty reliable. I first
discovered this construction technique decades ago when I had a bit
of a hobby dismantling old military gear, all built by the people who
wrote the book on reliability, so to speak. "Wire dress" is another
important part of the reliability, of course....

More recently, I've serviced guitar amplifiers where wire-to-board
connections are mechanically protected with a dab of RTV where the wire
meets the board. All kinds of failures in these amps, but not where
these wires are soldered in.

>> Any comments on that, or long-term 0.100 fail stories?
>
> As long as the cables are crimped correctly you'd need really adverse
> conditions to require moving up to even better connectors.  Make sure
> there's no mechanical strain on them and they should be fine.  The ones
> I've seen fail have mostly been mistreated during assembly or soldering
> or overloaded due to a short circuit.

Well, "crimped correctly" is essential. Good crimp tools are very
expensive, cheap crimp tools make unreliable connections and the
"crimp with pliers and solder" approach often leads to grief.

- Colin