Is this due to RoHS solder?

Fri Dec 09, 2011 12:37 am   

Took apart a Volvo 850 fuel pump relay. Cracks everywhere.

http://www.viatrack.ca/Misc/FP%20Relay/


Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca

void _-void-_ in the obvious place

Fri Dec 09, 2011 2:55 am   

On Dec 8, 3:37 pm, Boris Mohar <borism_vo...@sympatico.ca> wrote:

Possibly.
It could also be the plating on the leads reacting with the Pb free
solder and causing a boundry cracking. I have seen this type of
problem since the late '50s and usually with the cheaper solders like
50-50 but even on Tektronix and HP equipment where better quality was
the norm.

Neil S.

Fri Dec 09, 2011 6:30 am   

On 12/8/2011 3:37 PM, Boris Mohar wrote:

the solder. You would have to carefully cut one of the connections apart
across a break and see haw far it does go.

When was the part manufactured. RoHS was not required until July 1996.
There have been many different formulations of lead-free solder. Most
have problems of one type or another. This could be one of the solders
that was discontinued for just the reason you see.

Paul

Fri Dec 09, 2011 7:28 am   

Boris Mohar wrote:

Looks like cold solder connections to me. Considering that the item with
the bad solder connections is the relay it could be that either it was
not soldered in well in the first place or that vibration that caused
its solder joints to fail.

If you reheat the solder connections and add some flux does it turn
shiny again?

Other possibilities spring to mind - lead/tin solder tinned leads then
installed with RoHS solder can produce bad joints too.

John :-#)#

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Fri Dec 09, 2011 9:49 am   

Boris Mohar <borism_void__at_sympatico.ca> wrote in message
news:2ei2e75p1a6q0j3lkdb68h7ija4cfe7s5g_at_4ax.com...

RoHS came in with a vengence 2006, the earliest I've seen it in anything was
2001.
If you have some known tin+lead solder try adding it to a joint with a
soldering iron. If the surface goes white and the surface "freezes" almost
instantly then the original joint was likely PbF. If the original was
tin/lead then a near enough normal leaded solder joint will result. If you
have a temp settable soldering iron and set it low enough to still create a
leaded solder joint then you may find it takes an awful long time and
produce a pastey looking lump if you try the iron on a PbF solder joint with
a bit of flux to give it a decent chance of melting.
Just by appearance I would say you have PbF
This is a known PbF crack developing, in the body of a joint rather than
around a pin , a pic of mine
http://www.diverse.4mg.com/talk_crack.jpg

Fri Dec 09, 2011 3:11 pm   

"Boris Mohar" <borism_void__at_sympatico.ca> wrote in message
news:2ei2e75p1a6q0j3lkdb68h7ija4cfe7s5g_at_4ax.com...


I thought automotive was exempt - after all you wouldn't want the solder
falling off your FI relay half way through an overtake.

Fri Dec 09, 2011 3:24 pm   

On 09/12/2011 14:11, Ian Field wrote:

owners) long before lead free solder was required.

Ron (Volvo owner)

Fri Dec 09, 2011 3:31 pm   

"Ian Field" <gangprobing.alien_at_ntlworld.com> wrote in
news:JGoEq.112962$CC2.47430_at_newsfe20.ams2:


Honda fuel pump relays have the same solder problems,have had them for many
years.
my 1994 Integra had it,I resoldered the PCB and it worked fine for many
years afterwards. I saved at least $50 for a few minutes work.

the relay failure mode was that on a hot day,the car would start
briefly,then die,and only crank for 15-20 minutes(no fuel pressure),then
the car would start and run normally(after the car's interior cooled
down).No further problem until it got another heat soak.
In the mornings,the car would start and run normally.

I think the solder crystallizes with age,then thermal cycling cracks it.

the automotive environment is very tough,hard on electronics.
lots of thermal cycling,shock and vibration.

--
Jim Yanik
jyanik
at
localnet
dot com

Fri Dec 09, 2011 7:56 pm   

In article <2ei2e75p1a6q0j3lkdb68h7ija4cfe7s5g_at_4ax.com>,
borism_void__at_sympatico.ca says...

Well if they are tin/lead, they are some of the best (worse???) examples
of cold solder joints I've ever seen. It is most likely some Pb free
stuff. Being brittle is pretty much SOP with SAC and the like. That's
why things like avionics and telecom are exempt. I guess being stranded
on the side of the road in January, in Montana, out in the middle of no
where would only kill one or two people...

Fri Dec 09, 2011 11:14 pm   

N_Cook wrote:

I was just going to ask how to identify RoHS but this thread made it
unnecessary.

I am now looking at an Antec PSU with no date except "copyright 2004."



I will try it.



That's exactly the kind of test I was going to ask about! Thanks.


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..

Fri Dec 09, 2011 11:25 pm   

"Boris Mohar" wrote in message
news:2ei2e75p1a6q0j3lkdb68h7ija4cfe7s5g_at_4ax.com...


Took apart a Volvo 850 fuel pump relay. Cracks everywhere.


Some of the responses to your post are misleading. The dull, grainy look is
normal with lead-free solder.

The cracks are not necessarily a fault. Surface cracks that we can see,
often do not extend deep enough to cause problems.

In any case, soldered joints have indeed been compromised by the new
"improved" lead-free alloys!

Mixing politics and engineering will almost always yield bad decisions.


..

Sat Dec 10, 2011 2:17 pm   

On Fri, 09 Dec 2011 14:24:11 +0000, Ron <ron_at_lunevalleyaudio.com> wrote:


Indeed. I have resoldered and brought back to life many of the white ones.
They were not RoHS, nevertheless the solder failed around relay armature
pins.

--
Boris

Sat Dec 10, 2011 2:47 pm   

Tom Del Rosso <td_03_at_verizon.net.invalid> wrote in message
news:jbu18r$3j9$1_at_dont-email.me...

Ignoring potentially dangerous chemical test here is another physical test,
perhaps not so conclusive.
Find a stainless steel sewing needle, must be st/st not ordinary steel. Try
poking the needle in a soldering iron made , molten pool of leaded solder ,
pulling out, with a blob on the needle.
Pull off using just a fingernail usually.
Repeat using PbF and you will probably need 2 pairs of pliers to pull the
blob off the needle

Sat Dec 10, 2011 2:52 pm   

Charles <charlesschuler_at_comcast.net> wrote in message
news:jbu1sg$70e$1_at_dont-email.me...

This is why the likes of the aviation industry has a derogation to allow
continued use of leaded solder. Fuel pumps etc with PbF on a plane will soon
have them falling out of the sky.
They then have the problem of sourcing guaranteed PbF-free componentry ,
only single type production lines (PbF) around these days , generally
speaking , so insentive (serious mark-up) for a lot of fraudulent paperwork
and manifests etc , declaring the items are leaded when they are actually
PbF

Sat Dec 10, 2011 6:59 pm   

"Jim Yanik" <jyanik_at_abuse.gov> wrote in message
news:Xns9FB660FF0FA2Djyaniklocalnetcom_at_216.168.3.44...

Looking at the pictures, I think it is highly unlikely that the relay is
manufactured with lead-free solder. Although the joints have a somewhat
crystaline appearance, the surfaces of the individual 'grains' still appear
too shiny to be lead-free. Also, if you look at the shape of the joints,
they are much more conventional solder than lead-free solder. Whilst I would
agree that there is rather a lot of poor joints to be seen, again, I don't
see any that are typically consistent with a 'volcano' joint that you get
with lead-free. Annular cracks in the actual solder, rather than cracks
around the component lead where the solder has not taken to it, are far more
common with leaded solder. I would say that we are looking at a combination
of circumstances here, including age, temperature cycling and the generally
harsh automotive conditions that it lives in, relay hammer from the relay
operating many many thousands - if not millions - of times in its life so
far, and the possibility of the solder having been 'over-cooked' in the
first place. Smitty with his knowledge of production soldering may be able
to comment better than I on that.

Also, as Nigel says, the RoHS directive was not implemented with a vengeance
in most of Europe, until June 2006. That relay board is fully 10 years older
than that. Like him, I don't think that I have seen any electronic design
that old, that was implemented in lead-free solder.

Just as a matter of interest, I had a 1985 VW Passat for about 10 years. It
was the 2 litre version with the 5 cylinder Audi engine fitted. It had a
fuel pump actually inside the tank, and this was controlled by a relay on
the main board at the front of the car. Towards the end of the time I had
it, so probably around 1996, it started to suffer intermittent engine
stops - always in embarrassing places like four-way junctions, of course. It
would run for weeks without so much as a cough, then it would just die
without warning. Not too bad if you were tooling along on a big highway. It
just lost power and slowed down, giving you time to get off onto the side
shoulder, before you had no power at all, but worst was when you pulled away
from a stop light, and it just died ...

I discovered that you had to wait exactly four minutes - not a second less -
before turning the key and trying a restart. Invariably, it would then start
and run as though nothing had happened. It took me a long time to track the
problem down, but it eventually turned out to be bad joints in the fuel pump
relay. As I recall, it looked in pretty much the same state as the OP's one.

Arfa