Within a whisker of failure
 

heres a few facts and figures for you to highlight the utter madness behind
leadfree solders......

Over 95% of lead mined every year ends up in car batteries.

Over 95% of that lead in car batteries gets recycled anyway.

Electronics accounts for less than 5% comsumption of worldwide annual lead
production.

Lead is insoluble in water so leaded electronics dumped in landfill do not
leach lead into the water courses.

The lead-free solders fall into the following types.

Tin-Zinc Cheapest but prone to aqueous corrosion and has low melting point
and could be used by manufacturers who like cutting corners
Tin-Indium Most expensive but prone to aqueous corrosion and has low
melting point and is used on components that are temperature sensitive

Tin-silver-copper. has a higher melting point higher than tin-lead solder
so you have to upgrade reflow ovens and change your components to ones that
can withstand the higher reflow temperatures. European electronics firms
have switched to Tin-Silver-copper.

Tin-silver bismuth - same melting point as lead-tin and used as a drop in
replacement particularly for companies that do not want to upgrade their
reflow ovens or upgrade their componen stocks to higher temperature rated
ones. Most of Japan and Asia have switched to Tin-Silver-Bismuth

Also there is a serious problem if you have components that are plated with
tin-lead solder i.e old stock prior to ROHS and you use tin-silver bismuth
solder, a ternary lead-bismuth eutectic is formed during soldering which has
a melting point of 98ºC. You only need 0.5% lead and 0.1% bismuth in the
joint. this means the joint is brittle, porous, low melting point and has
very poor thermal creep properties

Also look up Tin Pest via google.......

Regards

Mallory

"Ivan" wrote in message
...
http://www.guardian.co.uk/technology/2008/apr/03/research.engineering?gusrc=rss&feed=science

Within a whisker of failure
 

Coming back to tin whiskers,

you can have four particular scenarios...

If the current is less than 30mA you get a stable short circuit

If the current is more than 30mA then you get a transient short circuit

If there are mechanical moving parts, the tin whiskers can fall off and
cause problems such as in MEMS (Micro engineered mechnical systems)

In certain conditions, a tin plasma can form and the electronics equipment
can explode violently...

See http://nepp.nasa.gov/WHISKER/background/index.htm for more detail

"Ivan" wrote in message
...
http://www.guardian.co.uk/technology/2008/apr/03/research.engineering?gusrc=rss&feed=science

Within a whisker of failure
 

I'd like to know if anybody's got a reference for the scientific basis
for the promotion of lead-free solder. I wouldn't be surprised if it
didn't exist at all.

It all strted with ROHS, Restriction of Substances Hazardous to Health,

it also affects chromium, bromine, mercury, Cadmium as well as Lead.....

There are certain exemptions such as x-ray machines and CRT's are allowed to
carry on using lead, fluorescent tubes can continue to use lead, and
components with a lead pitch of 0.65mm can carry on using lead.Computer
server room extuingiushers can still use bromine

Mallory

Within a whisker of failure
 

"Mallory" wrote in message
news:[email protected]
I'd like to know if anybody's got a reference for the scientific basis
for the promotion of lead-free solder. I wouldn't be surprised if it
didn't exist at all.

It all strted with ROHS, Restriction of Substances Hazardous to Health,

it also affects chromium, bromine, mercury, Cadmium as well as Lead.....

There are certain exemptions such as x-ray machines and CRT's are allowed
to carry on using lead, fluorescent tubes can continue to use lead,

What about church roofs?

--
Max Demian

Within a whisker of failure
 

church roofs are not electronics, and they are also exempt.

"Max Demian" wrote in message
...
"Mallory" wrote in message
news:[email protected]
I'd like to know if anybody's got a reference for the scientific basis
for the promotion of lead-free solder. I wouldn't be surprised if it
didn't exist at all.

It all strted with ROHS, Restriction of Substances Hazardous to Health,

it also affects chromium, bromine, mercury, Cadmium as well as Lead.....

There are certain exemptions such as x-ray machines and CRT's are allowed
to carry on using lead, fluorescent tubes can continue to use lead,

What about church roofs?

--
Max Demian

Within a whisker of failure
 

In message [email protected], Mallory
writes

"Max Demian" wrote in message
...
"Mallory" wrote in message
news:[email protected]
I'd like to know if anybody's got a reference for the scientific basis
for the promotion of lead-free solder. I wouldn't be surprised if it
didn't exist at all.

It all strted with ROHS, Restriction of Substances Hazardous to Health,

it also affects chromium, bromine, mercury, Cadmium as well as Lead.....

There are certain exemptions such as x-ray machines and CRT's are allowed
to carry on using lead, fluorescent tubes can continue to use lead,

What about church roofs?

--
Max Demian


church roofs are not electronics, and they are also exempt.

But church organs (the organ pipes) were not.
--
Ian

Within a whisker of failure
 

"Paul Ratcliffe" wrote in message
...
On Sun, 06 Apr 2008 11:19:43 +0100, charles

wrote:

This problem is well known. That is why products for medical or
military use may continue to use solder which contains lead.

So it's OK for them to bugger up the environment but not us?
The attitude is that the stuff the public pays for can be a bag of ****e.
It's the usual '******** to Joe Public'.

Really? Have you heard of anyone being able to get anything mended
recently?
If you think it's a common occurrence, you must be in cloud cuckoo land.
The ever increasing rate at which stuff is made and then junked absolutely
has to stop, but the opposite seems to be happening.

My friends in the TV repair business are all packing it in.

Bill

Within a whisker of failure
 

"Brian Gaff" wrote in message
...
Not a great deal of help or any contribution as to why my access software
thought it was in weird format though, that comment. Its like saying, I
have no trouble, must be a mistake.

Sorry if you were offended, not my intent.

I was merely trying to assist you by letting you know that there did not
appear to be a general problem with the page so that you could look to your
own setup to try and solve the problem.

As others don't know anything about what setup you have, they cannot be
expected to provide any advice as to what you may need to do to sort it.

Within a whisker of failure
 

"Bill Wright" wrote in message
...

"Paul Ratcliffe" wrote in message
...
snip

Really? Have you heard of anyone being able to get anything mended
recently?
If you think it's a common occurrence, you must be in cloud cuckoo
land.
The ever increasing rate at which stuff is made and then junked
absolutely
has to stop, but the opposite seems to be happening.

My friends in the TV repair business are all packing it in.


Indeed, the only two TV repair businesses in my local area have now
shut, one has become a pet shop and the other a hand car wash!

Within a whisker of failure
 

In article , Ivan wrote:
Well Charles I was in the trade for 50 years man and boy before I retired,*
I'd hate to imagine the amount of solder fumes I have inhaled in confined*
spaces over those years, how much asbestos inhaled from blowing out the dust*
from electric irons and other pieces of equipment when changing elements as*
an apprentice, and also the amount of blue asbestos I must have inhaled from*
broken pipe lagging when crawling through ducts in the boiler rooms of early*
1960's tower blocks were our (Rediffusion) distribution equipment used to be*
housed.
Although it has to be said that I still keep my fingers crossed, as I hear*
that these things can catch up with one more than 60 years after the event!

I don't know about lead, but asbestos definitely can. I watched my father die
from the effects of this and it wasn't pleasant. If you are diagnosed with
mesothelioma, you've probably got about a year and you should endeavour to get
your affairs in order during the first few months of this because you won't be
much use for the rest of it. They say it only takes one fibre of the stuff in the
wrong place, so the fact that I worked for a number of years in television
studios lined with it does not cheer me at all. If you've been working with
asbestos in any way that involves disturbing it enough to kick up dust, then,
seriously, I hope you turn out to be one of the lucky ones.

Rod.