OT: a presentation on Lead-free solder

[N_Cook]

I'm constructing a talk/presentation on PbF for the local-to-me part of the
science cafe movement
http://www.cafescientifique.org/
Title something like
A 21 century plague: some reasons for failures/problems in electronic
equipment.

If anyone knows of a public domain published like-for-like test of
conventional between conventional and Pbf boards+components ?
I suspect accelerated aging via thermal +humidity cycling and vibration to
show something like a 3 to 1 advancement of aging before solder faults
emerge, but cannot find any such published results.

Anyone here familiar with automobile engine management / control electronics
issues with PbF, not in-car entertainment issues.

Anyone familiar with de-tinning of tin-tinned components / deballing
+reballing of BGA etc in the defense/aerospace/medical spheres?

My email address for anyone not wishing to be on public record ,
divZZZZZZerse9@oneZZZZZZtel.com,
minus the ZZZs. Small text only not pics or large files, I can relay a
non-internet account for that purpose , if necessary.

 

[Smitty Two]

In article <i0pbjt$el1$1@news.eternal-september.org>,
"N_Cook" <diverse@tcp.co.uk> wrote:

Anyone familiar with de-tinning of tin-tinned components / deballing
+reballing of BGA etc in the defense/aerospace/medical spheres?

Aren't those arenas exempt from RoHS?

 

[N_Cook]

Smitty Two <prestwhich@earthlink.net> wrote in message
newsrestwhich-C37DE4.07303204072010@mx01.eternal-september.org...

In article <i0pbjt$el1$1@news.eternal-september.org>,
"N_Cook" <diverse@tcp.co.uk> wrote:

Anyone familiar with de-tinning of tin-tinned components / deballing
+reballing of BGA etc in the defense/aerospace/medical spheres?

Aren't those arenas exempt from RoHS?

exactly the point - how many in those mission critical 4 areas have opted to
go with the new PbF stuff, they don't have to take up the derrogation and
stay with the old solder.

 

[hr(bob) hofmann@att.net]

On Jul 4, 11:00 am, "N_Cook" <dive...@tcp.co.uk> wrote:

Smitty Two <prestwh...@earthlink.net> wrote in message

newsrestwhich-C37DE4.07303204072010@mx01.eternal-september.org...

In article <i0pbjt$el...@news.eternal-september.org>,
 "N_Cook" <dive...@tcp.co.uk> wrote:

Anyone familiar with de-tinning of tin-tinned components / deballing
+reballing of BGA etc in the defense/aerospace/medical spheres?

Aren't those arenas exempt from RoHS?

exactly the point - how many in those mission critical 4 areas have opted to
go with the new PbF stuff, they don't have to take up the derrogation and
stay with the old solder.

I suspect some areas of the IEEE (in the USA) have investigated this.
Also some folks in the auto industry must have looked into the, as the
engine temps must accelerate failure modes.

 

[N_Cook]

Can anyone put age/years interpretation to the green/yellow/red solder-type
rankings in this publically available document?

http://teerm.nasa.gov/LFS%20Reliability/Solder%20Comparison%20by%20Component
%20Level%20Life_Use%20%20Analysis_Final.pdf

....
Unfortunately, this test data demonstrated that for some component types the
lead-free solders failed before the
SnPb control. References 1 & 2 stated that models for calculating the
actual field lifetime of lead-free solder joints
on certain component types will need to be developed due to their reduced
life capabilities relative to SnPb.

...

Vibration testing was conducted by Boeing Phantom Works (Seattle) for the
Joint Council on Aging Aircraft/Joint
Group on Pollution Prevention (JCAA/JGPP) Lead-Free Solder Project. The
JCAA/JG-PP Consortium is the first
group to test the reliability of leadfree solder joints against the
requirements of the aerospace/military community
(1,2).

Test vehicles were specially constructed circuit cards, capable of instant
detection of failure of all components.
Each test vehicle was 12.75 inches by 9 inches in size, 0.090 inches thick
and was populated with 55 components
consisting of ceramic leadless chip carriers (CLCC's), plastic leaded chip
carriers (PLCC's), TSOP's, TQFP's,
BGA's, and PDIP's. Sets of identical components were used in different
positions on the cards. The circuit cards were supported by WedgeLoks on
the two 9 inch edges. Thirty circuit cards were vibration tested.