particle impact noise detection (PIND) - SPECTRAL DYNAMICS - #1

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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