Jeff Liebermann wrote in message
...
On Fri, 21 May 2010 10:51:48 -0500, Jeffrey D Angus
wrote:
Wild_Bill wrote:
What's taken place, I think, which I suspect was intentionally
forced upon most of us, is that manufacturers wanted to lower
everyone's expectations of quality.
I've been watching this "trend" since the '70s.
What happened before the 70's? It's not like designed obsolescence is
anything new. Auto manufacturers were doing that since WWII where you
were expected to buy a new car every two years.
My opinion is that we as consumers have brought this on
ourselves with the attitude of: "I don't care if it's
crap, I want it now, I want it cheap and I'll be bored
with it within a year anyway."
Yep. Blame the victims.
It's really a self fulfilling mechanism. Today's consumers simply
assume that everything they buy is junk and will blow up immediately
after the warranty expires. Why bother paying for quality when
literally everything falls apart or blows up overnight? The only
thing the vendors can compete on is price, resulting in very small
differences in price that can kill or make a product. That also
results in cutting every corner possible, including shoddy soldering,
bitter edge component selection, and designed to fail component
selection.
What seems to be happening is the demise of hand soldering. In the
distant past, it was somewhat traditional to solder mask the large
physical parts, which acted as a heat sink, during wave soldering, and
hand solder them in "touch-up". Component manufacturers have made
heroic attempts to design components that can be properly wave
soldered, but they tend to be expensive. So, to cut costs,
manufacturers seem to be running everything through wave soldering or
vapor reflow soldering machines, including parts that are really are
too massive. Touch-up is eliminated as is burn-in and QA. If it
blows up, by the time the customer returns it, the next generation of
products will be available. That actually worked with tin-lead
solder, but is failing with RoHS solder. The problem seems to be
(i.e. my opinion) that tin-silver solder has a narrower range of
working temperatures than tin-lead. The large physical components
that were previously soldered by hand, simply suck away too much heat
when soldered, resulting in a cold solder joint.
Although this isn't entirely new. You could be cheap or
shoddy merchandise for as long as they've been bartering
from stuff. It's just that the ability to mass produce
garbage has exceeded our wildest expectations.
Yeah, but you probably couldn't afford it if everything were quality
merchandise.
Anyway, cease complaining. Your test equipment collection is about
the same age as mine and belongs in a museum. It is possible to build
reliable and long life electronics. Just don't expect that from
consumer electronics.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
My suspicion it is more to do with tinpest rather than lead free solder. A
layer of 100 percent tin tinning of all leads. Often on removing failed
joints , by pulling, not desoldering, you can see the dusty grey surface of
presumably tinpest .
Then volume change (27 percent ?) to the tinpest allotrope of tin and its
insulation rather than conduction causes the electrical break. Mismatch
thermal expansion coefficients don't seem t be problematic
http://www.boulder.nist.gov/div853/l...1.html#%201.12.
etc on
http://www.boulder.nist.gov/div853/l...e/props01.html