Gideon Analytical Laboratories received two printed circuit boards (PCB) with the questionable failure of multilayer ceramic capacitors in the C4 position. Both these capacitors were removed from the PCB and the PCB was inspected for contamination for possible leakage current or electromigration that would account for conduction across the pad lands.
The picture at the top left is the C4. During analysis, no contamination was found on either of the PCBs or on any of the four sides of each capacitor.
Gideon Analytical Laboratories performed failure analysis on several Sky CKC-1C-12VDC 12A/120V relays. These relays have a contact resistance of 100 Mohms and have a surge resistance of 1000V. The devices had a liquid on the inside surface and corrosion on several of the leads. The liquid and corrosion is pictured at the top left.
The drop was analyzed using FTIR. The liquid was thought to have come from the flux residue and, therefore, an organic analysis FTIR is required as opposed to inorganic (XRF).
Gideon Analytical Laboratories performed failure analysis on two printed circuit board assemblies (PCB) with fractured solder joints on the Hall Sensor interconnect. The assemblies were taken apart and the conformal coating was removed to reveal the solder joints of the Hall Sensor. Five out of six of the Hall Sensors were mounted flush against the Valox 457 mounting block.
A Hall Effect Device detects magnetic flux density and is used in both movement and position sensing.
Gideon Analytical Labs performed failure Analysis on a failed RJR26 Bourns Potentiometer. The application failure was noticed when a lower than expected resistance value and, eventually, open in the potentiometer.
A potentiometer (or pot) is a simple electromechanical transducer. It converts rotary or linear motion from the operator into a change of resistance, and this change is used to control the resistance within a circuit. The pot (also known as a rheostat) is essentially a variable wire wound resistor or a carbon or metal film with a swiper.
Gideon Analytical Laboratories received two surface mount T491C155M035AT Kemet tantalum capacitors with internal resistive shorts. These capacitors have standard capacitance tolerances of ±10% and ±20%, with an operational temperature -55°C to +85°C rated voltage and up to +125°C with voltage derating in applications utilizing recommended series resistance. They have low leakage and are ROHS compliant. The goal was to determine the reason for the failure.
There was no damage tothe external plastic encapsulation of the package to indicate mechanical stress, which would weaken the package integrity.
Gideon Analytical Laboratories performed failure analysis on several IXYS IGBT IXGH32N60B transistors, encased in TO-247 packages. These transistors are 60 amp 600V 2.3 Rds 200W. The concern was that the devices were not functioning as 600V but topped out at 480V in the application.
Displayed in the picture above is a defect near the guard ring. Further analysis revealed there are several metal posts contacting more than likely underlying diffusion for voltage termination.
Gideon Analytical Laboratories performed failure analysis on one Ansul IQ-396X, which was submitted for possible failure due to an electrical surge. These control units have two intelligent signaling line circuits (SLC), 396 intelligent device capacity (198 intelligent detectors and 198 monitors/control modules), four built-in output circuits, up to 64 internal output circuits/relays on optional modules in the unit, 99 programmable zone output relays, and manual sensitivity adjustment.
The CPU 400 unit was dissembled and the entire board and components were inspected under 40x to look for and evidence of EOS (electrical overstress) that may have affected the operation of the unit.
Gideon Analytical Laboratories received a PCB for failure analysis. The board was identified as having a short from the NET trace to the ground. The short measured about 10 ohms. One area of the board was abraded to reduce the thickness of the black solder mask. The board was received like this and we tried to change the refractive index to optically see through the solder mask. This was unsuccessful. The abraded area produces different optical characteristics, which prevent clear optical vision.
Gideon Analytical Laboratories received an Aerovox Z26P6045M21 45uF 600V for failure analysis. No data was given on the capacitor. The capacitor was tested and found open. It did not take a charge when a voltage was applied. The capacitor was also under gas pressure and this gas was carbon dioxide. The top portion of the capacitor after it was removed showed a phenolic insulator used for the registration of the terminal leads.
Gideon Analytical Laboratories performed failure analysis on a cold rolled steel plate that was received with what looked like tape prints, fingerprints, and black oil which all appear to interfere with the plating process.
Using one microliter of methylene chloride (ACS HPLC Grade) the surface of the cold rolled steel was collected in a glass vial. A portion was then evaporate onto a KCL wafer and analyzed on an FTIR to give spectra in the top picture.
