I can see why people had so many problems with your Beta test. Select the
most correct answer? My answer would be "B" for the following reasons.
A. CAD systems do everything on a coordinated system, even if it's a
submillimeter, it uses an X-Y coordinate. So yes, CAD systems require it,
but this is not the BEST answer.
B. Design standards do require it. Your IPC-D-275, para. 5.1.2 and the old
MIL-STD-275, para. 4.3 require them. My feeling is that this is a
carryover from before CAD came along (and yes, there are still people who
use tape) and vendors needed to bombsight locations. Those locations
usually were located on .025 centers. This was before surface mount came
along. CAD has all locations located in electronic files, no matter what
the dimension.
C. It doe help the manufacturer, as long as it is a taped or manual layout,
or they have no CAD data and must measure.
D. Design standards do require measuring individual locations if they do
not fall on a grid system. The grid system, again by spec, is a multiple
of .005.
So in essence, all the questions are correct to some extent, and none are
technically wrong. To me this question is ambiguous, and I'm glad to see it
was dropped. What I would hope to see in a test is something that would
really show if you know your job, not to see if I could answer silly
questions which are all correct.
I am not trying to shoot down the certification process at all, I hope to
take it in the future. I am definitely waiting for a study guide to become
available before presenting my boss with a request to attend. I do hope the
other questions will be more beneficial than this example. If I were to ask
to attend the certification testing by showing my boss this first example, he
would laugh me out of his office.
I am looking forward to seeing other questions of the day. Hopefully, they
will be helpfull in getting myself and my other co-workers certified.
Sincerely,
Larry Campbell
Supervisor, P.W.B.
BFGoodrich Avionics Systems,
Jet Electronics & Technology, Inc.
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the following question is one that was provided by designers for the "A"
basic level exam. It is NOT included in the final published test and is
for reference only. The topic was Grid Systems.
101. Why are grid systems used for locating components, PTH's
conductor patterns and other features on printed boards and printed board
assemblies?
A. Because CAD systems require it.
B. Because design standards require it.
C. Because it helps in the manufacturing operations
D. Because it avoids having to dimension individual
locations.
Select the most correct answer
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Please send comments, constructive critique, or suggestions to Lisa
Williams at [log in to unmask]
Dieter Bergman
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