particle impact noise detection (PIND)0 pages

PARTICLE IMPACT NOISE DETECTION (PIND) COMBINES
VIBRATION, SHOCK, AND ACOUSTICS FOR DETERMINING
RELIABILITY OF ELECTRONIC COMPONENTS
Stewart J. Slykhous
Spectral Dynamics, INC. - PIND Products Group
804 N Twin Oaks Valley Rd., Ste. 116 , San Marcos, CA 92069
(760) 761-0440 FAX (760) 761-0533
Abstract: Particle Impact Noise Detection (P.I.N.D.) is a reliability screening technique that
employs vibration, shock, and acoustics. As a requirement for MIL-STD883E, MIL-STD750,
and MIL-STD39016, this test has helped the manufacturers of hermetically sealed
electronic components greatly increase the reliability of their product by eliminating
contaminants within the cavity over the past thirty years. Recent advancements in
packaging methods have created significantly larger packages with increased weight and
require improvements to the test equipment including advancements to the closed loop
control of vibration, increased dynamic range of closed loop control of shock, and the
addition of multiple crystal acoustic detection sensors. This paper will describe these
advancements and their effects in helping the test systems to better handle the challenge
presented by multi-chip modules (MCM), and Systems on Chip (SOC), and today’s’ larger
hybrids circuits.
INTRODUCTION
Small contaminants inside of electronic packages that contain a cavity will move in a dynamic
environment and locate into a position, typical the bond wires, which could short out the part for a brief
time during usage. Such a failure is critical for high dynamic stress environments and can pose a
significant integrity problem in high reliability electronics applications. As early as 1960, government
space organizations, electronic component manufacturers and end users employed PIND testing as a
nondestructive test to determine the integrity of electronic components.
For the past thirty years, the PIND test with its series of mechanical shocks and vibrations has been
employed by component manufacturers to screen electronic components. A significant trend in the
modern manufacture of these components is to build larger and larger packages resulting in changing
requirements for the venerable PIND test equipment.
DEFINITION OF PIND
Particle Impact Noise Detection (PIND) is used to determine the integrity of electronic components by
“listening” for the acoustic signals generated by impacts created by loose particles inside the cavities of
electronic components such as transistors, integrated circuits, hybrids, diodes, relays, and switches.
The PIND test simulates dynamic environments such as aircraft landings and aerospace launchings by
administering a series of mechanical shocks and vibrations to the device under test. These shocks and
vibrations free particles adhering to the component cavity walls. The high frequency acoustic noise from
the resulting impacts between the particles and the package interior are detected by a transducer on
which the test component is mounted.
ALTERNATE TESTS FOR LOOSE PARTICLE DETECTION
Vibration Testing