28 The PCB Magazine • April 2016
the process and the product, and it results in a
process control window that is capable of pro-
ducing the product.
One approach to troubleshooting that
quantifies improvement for reporting to man-
agement involves a capability assessment. IPC-
9191 discusses in greater detail the generation
of capability indices. This step promotes a clear
understanding of the process matrices, but it re-
quires time and resources.
PCB
References
1. Click here to access an IPC Standards Im-
provement Form.
Michael Carano is VP of technol-
ogy and business development for
RBP Chemical Technology. To reach
Carano, or read past columns, click
here.
a proCess engineer's guiDe to effeCtively troubleshooting pWb DefeCts
In early 2016, long-
time author, PCB ex-
pert, and industry
veteran Happy Hold-
en started writing a
25-chapter book, "25
Essential Skills for Engi-
neers." He initiated it
with an introductory ar-
ticle in the January issue
of The PCB magazine.
Since that time, we
have been publishing
chapters approximately
every three weeks in our
I-Connect007 Daily newsletter, as well as some of
our weekly newsletters.
now Happy as upped the ante. He has been
writing steadily and has asked to publish every two
weeks, so we said, why not? Watch for his chapters
to appear every other Wednesday in the PCB sec-
tion of the I-Connect007 Daily newsletter. Chap-
ter 4 is currently scheduled to appear on April 6.
It's free to subscribe, so don't miss out on this
highly informative and downright useful book. To
catch up on the chapters we've already run, check
out Happy's columnist page for a complete list of
titles and links.
We are fortunate to have a second highly-
valuable series, penned by veteran SmT and mi-
croelectronics designer, author, and expert Vern
Solberg. His six-part series, "Flex and Rigid-Flex
Circuit Design Princi-
ples" publishes in both
the InsideDesign and
Flex007 weekly newslet-
ters, as well as the daily
newsletter a day or so
later.
Vern's introduction
nicely summarizes the
crux of his series: "Flexi-
ble circuits represent an
advanced approach to
total electronics pack-
aging…maintain uni-
form electrical charac-
teristics, controlling noise, crosstalk, and imped-
ance…saving up to 75% on space and weight…
improve overall product reliability…[and] fur-
nish unlimited freedom of packaging geometry
while retaining the precision density and repeat-
ability of printed circuits."
In part 1, Vern describes the primary flex struc-
tures, design for operating environment and base
material selection. In part 2, he discusses supplier
assessment, planning the flex-circuit outline and
circuit routing principles, while part 3 goes into
detail on specifying base materials, copper foil
variations and fabrication documentation. Part 4,
just published the week of march 30, focuses on
rigid-flex construction, conductor routing and me-
chanical clearances. Part 5 is expected to publish
April 27—28. Don't miss it!
Solberg and Holden:
Two Valuable Series Available now at I-Connect007
Happy Holden Vern Solberg
