RE: [CAD_CAM_EDM_DRO] Re: microstepping drivers

This’ll get you.

I asked some producers in Italy about RoHs.

They said ‘EU law doesn’t really apply to us. Sure we’ll do something for
the first 6 months then forget about it.’

Damn I in England.

You can stop lead whiskers and tin crystallization oxidisation problems if
you lacquer the pcb’s, though my cheap source of laquer was also banned.

It is difficult to say how the Rohs will effect long term reliability.
Tektronix introduced lead free assembly of their test kit at the beginning
of the 90’s, massive quantities of this kit never made it to the end of the
90’s including my £15,000 DSO. On the second hand market, if it was made in
the 80’s it’s worth something, if it’s made in the 90’s no one wants it,
commonly from the mod it doesn’t even get to auction. This has really
effected the second hand kit market where ex mod kit kept many smaller
development and manufacturing companies going. HP and Lecroy aren’t as bad,
but often the MOD just crushes the lot. We hope Tek problems were due to a
flux wash they used with methylene chloride or something like that,
components just disintegrate, there are also tin whisker problems, but
information isn’t clear as to what the proportions are, we just know to keep
clear of the lead free stuff .

Also back in the 60’s some transistors used tin in the metal can, these also
grow whiskers and stop working. I have a friend that restores this stuff, he
manages to zap them and burn the whiskers off without destroying the
transistor.

Make your own conclusions. In the EU’s effort to help the environment, I
think we are going to turnover a heck of a lot more electronics. The other
stupid thing from the EU is they think you can take an electronics board and
simply recycle repair and resell it. The warranty risks just aren’t worth
it, despite the labour costs involved. It has even been suggested we can
pull chips off of pcb’s and reuse them. Cloud cooko land springs to mind.
However Xerox are apparently collecting old photocopiers and reusing some of
the PCB’s and motors, not sure I want second hand parts in a copier they
charge £5K to £10K for.



Dr. Mark Vaughan Ph'D. B.Eng. M0VAU

Managing Director

Vaughan Industries Ltd, reg in UK no 2561068

Water Care Technology Ltd, reg in UK no 4129351

Addr Unit3, Sydney House, Blackwater, Truro, Cornwall, TR4 8HH, UK.
Phone/Fax 44 1872 561288

RSGB DRM111(Cornwall)

_____

From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of ballendo
Sent: 29 April 2007 06:58
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: microstepping drivers

>In CCED, "jeffalanp" <xylotex@...> wrote:
>The RoHS restriction is what is wierd.

So true. Are we all going to have blown drives from tin whiskers in a
few years?

How serious is this threat? Should we who HAVE the choice in our DIY-
CNC's CHOOSE lead based assembly for the drives we buy?

Ballendo





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