Gideon Analytical Laboratories received four Spectrum Control Pi filters N49927 Bus A (capacitor components FL1, FL2, FL3, and FL4). Capacitor-input filters (also known as Pi filters) are a type of electronic filter used to remove unwanted frequencies from a signal. Pi filters are primarily constructed of two capacitors and an inductor. They are used in situations where the ripple of a signal or the AC and DC currents within the signal are found to interfere with each other.
Gideon Analytical Laboratories received several switches with cracked ceramic capacitors (MLCC) for failure analysis. In electrical engineering, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another. A ceramic capacitor is a fixed value capacitor in which ceramic material acts as the dielectric. It is constructed of two or more alternating layers of ceramic and a metal layer acting as the electrodes.
Gideon Analytical Laboratories received one failed multilayer ceramic capacitor (MLCC) on a printed circuit board (PCB). Multilayer ceramic capacitors are fixed value capacitors in which ceramic the material acting as the dielectric. It is made up of two or more alternating layers of ceramic and a metal layer acting as the electrodes. There are various types of materials that could function as the dielectric in a capacitor, for example, glass, porcelain, paper, or mica.
Gideon Analytical Laboratories received about 20 electrolytic capacitors which all had unacceptable leakage current. An electrolytic capacitor (also known as an e-cap) is a capacitor whose anode (+) consists of pure aluminum foil with an etched surface, covered with a uniformly very thin barrier layer of insulating aluminum oxide, which operates as a dielectric. The electrolyte, which covers the rough surface of the oxide layer, operates as the second electrode, the cathode (-).
Gideon Analytical Laboratories received one printed circuit board (PCB) with an open in the plated through hole (PTH). A printed circuit board mechanically supports and electrically connects electronic components using conductive tracks, pads and other features etched from copper sheets laminated onto a non-conductive substrate. Advanced PCBs may contain components - capacitors, resistors or active devices - embedded in the substrate. PCBs are used in all but the simplest electronic products.
Gideon Analytical Laboratories received a power supply with several bulging capacitors on the motherboard. A power supply is an electronic device that supplies electric energy to an electrical load. The primary function of a power supply is to convert one form of electrical energy to another and, as a result, power supplies are sometimes referred to as electric power converters. Some power supplies are discrete, stand-alone devices, whereas others are built into larger devices along with their loads.
Gideon Analytical Laboratories received two Fairchild transient voltage suppressors (TVS) SMBJ5V0CA. Both diodes were identified as having failed.Transient Voltage Suppressors (TVS’s) are devices used to protect vulnerable circuits from electrical overstress such as that caused by electrostatic discharge, inductive load switching, and induced lightning. Within the TVS, damaging voltage spikes are limited by clamping or avalanche action of a rugged silicon pn junction which reduces the amplitude of the transient to a nondestructive level.
Gideon Analytical Laboratories received two failed AUIRF7648M2 MOSFETs. These are rather new on the market and specifically designed for the automotive industry. Typically, when a MOSFET fails, all terminals short. It is the failure analyst’s job to discover how the MOSFET failed in the application by combining the schematics, clues found in the failure analysis, and clues found on the PCB to give a complete picture to help resolve the client’s problem.
Gideon Analytical Laboratories received two 144A9111 pulse transformers with the secondary wiring shorting. Transformers are devices that transfer electric energy from one circuit to another, usually with a change in voltage. Pulse transformers are transformers optimized for transmitting rectangular electrical pulses. Ideally, pulse transformer designers try to minimize voltage droop, rise time, and pulse distortion. Small versions called signal types are used in digital logic and telecommunications circuits, often for matching logic drivers to transmission lines.
Gideon Analytical Laboratories, Inc. received on Vishay ES2D rectifier on a PCB. The initial condition and observation were that the diode had a conformal coating on a small circuit board in which when tested on a curve tracer had excessive leakage current across the junction and caused the PCB to fail in the application.
Rectifiers are primarily used for conducting in one direction and blocking in the other. The Vishay ES2D is an ultra-fast rectifier, which means the reverse recovery time should be less than 100 ns.
