52 DESIGN007 MAGAZINE I FEBRUARY 2023
because of the use of mixed technology boards
(SMT and through-hole).
ENTEK CU-106A: is is the most prevalent ver-
sion primarily due to the ability to survive
multiple thermal assembly operations. PCBs
that have multiple surface finishes can use the
CU-106A(X) finish.
Pros and Cons of OSP
Pros
• Inexpensive and typically used in
fine pitch surface mount designs
• Environmentally friendly
• Provides a coplanar surface
• Lead-free (Pb-free)
• Mixed metal applications
Cons
• Press fit pin insertion
• Handling sensitive
• Limited shelf life
• In-circuit test (ICT) difficulties
• Exposed copper aer assembly
• Multiple reflow cycles and solder paste
removal are problematic
Understanding the cost drivers in PCB fab-
rication and early engagement between the
designer and the fabricator are crucial ele-
ments that lead to cost-effective design suc-
cess. Following your fabricator's DFM guide-
lines is the first place to start. DESIGN007
Anaya Vardya is president
and CEO of American Standard
Circuits; co-author of The
Printed Circuit Designer's Guide
to… Fundamentals of RF/
Microwave PCBs and Flex and
Rigid-Flex Fundamentals; and
author of Thermal Management: A Fabricator's
Perspective. Visit I-007eBooks.com to download
these and other educational titles. He also
co-authored "Fundamentals of Printed Circuit
Board Technologies" and provides a discussion
of flex and rigid flex PCBs at RealTime with…
American Standard Circuits.
