[sdiy] 0.100 pin header reliability.

[Neil Johnson]

Hi,

David G. Dixon wrote:
> In my experience, aluminum repels solder, which forms droplets with acute
> contact angles when splashed onto aluminum.

While soldering aluminium is possible, see for example

http://www.aws.org/wj/2004/02/046/

the fluxes involved are pretty nasty.  Even just bolting aluminium
conductors to copper you need to use special jointing compounds to
stop joint failure from accelerated corrosion.

> For what it's worth, my crimping tool looks like a big pair of pliers, and
> those crimped joints ain't coming apart anytime soon!  The wire would break
> before those bad boys came loose, and in any case, there is no pulling
> stress on them, as I always leave some slack in the wire.

Ah, ok, the cheap $10 ones :)

Crimping is only guaranteed to work as stated by the manufacturer when
(a) you use the correct crimping tool, and (b) that tool is within
calibration (i.e., it needs regular checking and recalibration if
required).  If you spend $300 or more on a crimp tool then you're in
the right ballpark.

If you're patient enough you can find good ones on eBay.  A couple of
years ago I picked up a brand new large AMP crimp tool for not much,
although that starts at 6mm2 and goes up.

As far as reliability is concerned, something is only as reliable as
you are prepared to make it.  So its a cost/benefit issue.  If the
cost of failure is high, then you pay for good design, good assembly
people, good components and good tools (the defence/aerospace model).
If the cost of the product is the main factor, then you choose
low-cost design, cheap components, cheap tools, and either cheap
labour or design out manual assembly (the consumer product model).

If a connector is a crimp connector, and you are concerned about
reliability (including support from the connector manufacturer when
something goes wrong) you crimp it according to the manufacturer's
instructions.  Anything else and you have effectively voided the
manufacturer's warranty.

Same applies to soldered connections - don't try to crimp them.

Cheers,
Neil
-- 
http://www.njohnson.co.uk