Re: Cleaning Circuit Boards and "Static" rant

--- In CAD_CAM_EDM_DRO@egroups.com, "Wally K" <cnc4me@u...> wrote:

> --- In CAD_CAM_EDM_DRO@egroups.com, "Wally K" <cnc4me@u...> wrote:
> > To clean circuit boards i usally start with a air blast. Then

put

> > some rubbing alcohol in a spray bottle, spray board real good

with

> > alcohol and air blast again. Maybe repeat a few times. This
> methode
> > works ok and does leave streak marks on the board but its cheap,
> easy
> > and safe.
> >
> >
> > Wally K.
> >
>
> Wally K. replys.
>
> WARNING i do use this methode and it works ok for me...BUT i only

do

> it a few times a year and there is the possibility of building a
> static charge with an air blast.

Hi,

Theoretically static discharge may be a problem, but so was the Y2K
disaster we all were promised (does anyone remember that one?).

I have practised my craft for over 20 years and I cannot say I ever
saw a semiconductor damaged due to static discharge. In my opinion it
fits in the same catagory as any number of urban legends; fun and
frightening to recount, but short on factual specifics.

Modern circuitry that could be susceptible are now well protected
with intrinsic voltage clamping protection circuits. It is simply
impossible to damage them unintentionally.

I live and work in Southern California. The reason for telling you
that is we here are subject to occaisional climate condtitions that
result in relative humidity readings in the very low single digits.
Static charge buildup during these conditions is impressive, yet no
CMOS IC, MOSFET or other high input impedence device has ever died as
a result. No special handling precaution has ever taken.

Yet we get reels of 33 Ohm resistors carefully packaged in black
electrically conductive, anti-static bags. A direct lightning strike
would not damage these parts, but there they are in their protective
bags. Go figure.

This is a solution in search of a problem. It is an unecessary
precaution to the cautious and a ready excuse for the inept designer
to his customers excuse to his sorry work. "Yeah, it was static
discharge why the (fill in the blank) circuit died".

End of rant.

Mariss
Geckodrive Inc.