View Single Post
  #20   Report Post  
Posted to sci.electronics.design,sci.electronics.repair
n cook n cook is offline
external usenet poster
 
Posts: 1,220
Default So what's the truth about lead-free solder ?

Arfa Daily wrote in message
...

"Eeyore" wrote in message
...


Spurious Response wrote:

Eeyore wrote:
"Leeper" wrote:

t is really application and chip package specific,

Bull****. Lead based solder alloys are superior in damn near all
electronic realms, and there is no configuration where they would

not
be
other than high end commercial and military applications, and they
certainly do not include Tin.

Whilst I don't disagree with you, where's the hard comparative data ?

Considering the fact that we have 5 decade old circuit cards still
operating perfectly, and that we already know what alloys containing

Tin
which is not bound by Lead do over time and temperature cycling, I do

not
think that precise numerical analysis is even needed on such a

profoundly
lopsided issue.


Whilst I agree with you, bureacrats tend not to be very receptive to
anecdotal
comment. And make no mistake, the bureacrats are the ones in control of
this.

Graham



I have just this minute finished repairing a Panasonic DAB / FM radio

which
was dying as soon as it was switched on, with a "F76 Pdet" error in the
display. I took this to be "power detect", which seemed reasonable, given
the symptoms. When I took the main board out to have a look at the
underside, I found the power supply section riddled with poor and
'cracked-right-round' lead-free solder joints ( the board actually has
"PbF" silk-screened on it ). The poor joints were particularly well

defined
on the main free-air cooled regulator transistor, which is obviously

subject
to thermal cycling.

I reworked all the joints with lead-free, as that is what the RoHS
legislation legally charges me to do as a commercial repair outfit, but

boy,
the temptation was strong to just reach for the leaded solder, and do the
job 'properly' ...

Arfa



What was the chipcode dates on that DAB ?
No more than 2 years old no doubt.

If you had not repaired it than also no doubt it would have ended in
landfill taking with it ,perhaps not lead, but antimony, bismuth, tin,
copper, barium , phthalates etc

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/