With a common existing accelerated qualification test providing
inaccurate information, representatives from a variety of compound
semiconductor companies are calling for input on a standard
replacement.
Reliability scientists from across the power amplifier
manufacturing industry are pushing for a universal qualification
testing specification for laminate GaAs modules.
GaAs modules after surface mount, die attach, and wire bond, prior to laminate overmolding and singulation. In these GSM PA modules, each laminate includes a larger CMOS power control chip and a high band and low band GaAs HBT PA die. Credit: TriQuint Semiconductor.
The members of JEDEC's JC-14.7 subcommittee for GaAs reliability
and quality standards are now calling for additional input on how
that test should look.
A first-draft standard will be discussed at CS Mantech, which will
be held in Tampa, Florida, from May 18-21.
“We're definitely interested in finding anybody who has an interest
in this,” said Bill Roesch, fellow for reliability science at PA
maker TriQuint Semiconductor and JC-14.7 member.
Existing qualification tests, which are performed on the majority
of laminate-overmolded PA modules to show that they are fit for
use, vary widely in format.
Of even greater concern is that the fastest tests – developed for
silicon – do not provide accurate information on GaAs components.
Representatives from RF Micro Devices, TriQuint, M/A-Com Technology
Solutions and other companies have agreed that this needs
resolving.
The commonly used Highly Accelerated Stress Test, or HAST, heats a
module to 130°C at 85 percent humidity under bias for 96 hours. “A
96 hour HAST test is actually much, much harder on our devices than
it is on a silicon device because of the different failure
mechanisms,” Roesch said.
As well as providing more accurate information, a widespread
standard would streamline GaAs manufacturers' qualification
processes, reducing testing costs.
There is a strong case to be made to PA buyers as well, as the
information emerging will be comparable across different suppliers'
product offerings.
The draft standard to be discussed in Tampa will specifically cover
accelerated qualification testing, RF testing and problems unique
to compound semiconductors.
If you have any suggestions to make about these issues prior to CS
Mantech, contact Bill Roesch at bill.roesch@tqs.com.
• Roesch and Peter Ersland, chairman of the JEDEC JC-14.7
subcommittee will talk about the case for a uniform qualification
standard in more detail in the April/May issue of Compound
Semiconductor magazine.
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