Subject:                              Time:  11:11 AM
  OFFICE MEMO         RE>FAB:AOI DATABASE TERMS AND DEFS    Date:  3/22/96

All of you  ----  please be very careful when you develop terms and
definitions, and if you do need to develop a new term to communicate and
describe a different/new condition please think it out, even consider using a
standard dictionary or technical dictionary for an appropriate term.

I'm writing this on behalf of and as a member of the IPC's Terms and
Definitions committee.

Those of you who are familiar with industry documents, know that industry is
loaded with unsuitable jargon -- which may have been appropriate at the time,
but the original requirements and definition has been changed over the years. 
And once a term gets in-grained in the industry it's difficult/impossible to
change -- even when completely inappropriate.  I agree with George Murray, let
the appropriate technical personnel who have to live/use the terms and
definitions have a major voice in the selection of new terms and definitions, 
and if at all possible communicate with you peers to see if they have
discovered the same condition and have termed it.  

A few examples:

Printed Boards / Printed Circuit Boards / Printed Wiring Boards -- How about
the printed board industry itself, we're very inconsistent.  Many of us still
use and misapply the terms and  definitions for printed boards, printed
circuit and printed wiring.  How many of us use "printed wiring" when the
product being discussed is a "printed circuit".  

Measling -- this medical condition is mostly an easily identifiable (red
colored) surface condition, and is not a variation in the color of light due
to refractance of light due to a local separation of the cells in a human body
between layers of human tissue at the cellular intersections.  Most of us
assume that the term for printed board (PB) measles was based on one of our
predecessor's observing a similar pattern of visual condtions between an
offspring having a case of red spots and a PB with whitish spots.

Crazing -- before the PB industry was around, crazing was an array of surface
cracks in materials.  But not for PB's where it is actually a lack of bonding
or separation in/along the fibers in the reinforcement material and may
include fracturers (cracks?) of the resin between adjacent yarns.

Silver Streaks / Railroad Tracks / Tunnel Voids  --  and the list could go on
and on.

Pinholes / Blow Holes /  Voids  -- Now (to me) pinholes and blow holes are
subsets of voids and they resemble the term that describes them.

Mouse bites and "nibbles" indicate how the big of a mouthful the rodent took -
which was a function of hungryness -- but wait! - there are no teeth marks,
the edges are too smooth, perhaps it looks more like a leaf munching
caterpillar bite.  (;-)

In conclusion, two final suggestions:

1)  Document you term and definition with a illustration/photograph of the
condition and supply it to the IPC's appropriate technical and terms and
definitions committees, unless you can contain the use of the term to your
facility.

2) -- please give the selection of terms and definitions some very serious
though to determine if a term exists in another technology that resembles the
condition.  If you don't, all of us may eventually have to live with them,
including our successors -- who may comment in meetings with their peers --
"who were the dummies who came up with this term for this condition".  

Ralph Hersey