JANUARY 2023 I DESIGN007 MAGAZINE 67
cessing minimizes the pad orientation differ-
ence. HASL is not used for fine pitch compo-
nents. is is because it increases fabrication
and assembly rework for boards that have fine-
pitch SMT devices with lead centers below
0.020" and presents coplanarity issues.
Pros and Cons of HASL
Pros
• Economical and widely available
• Excellent solderability
• Can be reworked at the fabricator
• Presents a very flat solder deposit
Cons
• Limited assembly reflow cycles, as the
HASL process introduces a thermal
shock before it gets to assembly
• Not suited for fine pitch (due to uneven
surface height) or high aspect through-
holes
• Standard SnPb HASL is not RoHS
compliant
• Lead-free HASL requires different
assembly soldering parameters
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 The Printed Circuit
Designer's Guide to… Flex and Rigid-Flex
Fundamentals; and author of The Printed Circuit
Designer's Guide to… 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 Real
Time with… American Standard Circuits.
David N. Graves, 65, passed away December
22, 2022. He worked with several firms, starting
in 1974, and helped found UltraCAD Design Inc.
in 1992. Twenty years later he joined Monsoon
Solutions, Inc. where he spent the rest of his
career before retiring in 2021.
Dave was a superb designer, a patient mentor
to colleagues and customers alike, and was well
respected by everyone. He was inducted into
the Top Gun Hall of Fame in March 2001, during
the PCB Design Conference, West.
(Source: Douglas G. Brooks, PhD)
PCB Designer
Dave Graves
Passes Away
