Gideon Analytical Labs receives many counterfeit parts come in from Asia and China. Constant testing and evaluation with radiography, cross-sectioning, and electrical measurements and microscopy provide the means to identify these components flooding our markets.
Tantalums capacitors are made of tantalum metal which acts as an anode, covered by a layer of oxide which acts as the dielectric, surrounded by a conductive cathode. The use of tantalum allows for a very thin dielectric layer.
Gideon Analytical Labs received Wamco Display Socket 4160001-1 for failure analysis. The device had a reported open diode on pin G.
This display socket is encapsulated in a plastic housing filled with a silicone rubber filler to stabilize movement of the diodes. The diodes are hermetically sealed in glass and position via plastic at one end and a socket located at the bifurcation line. The electrical data indicated the diode was open when initially measured but was intermittent when moved.
Gideon Analytical Labs received one M83421/01-5191S film capacitor with lower than expected capacitance for failure analysis. This device is a fixed metalized paper-plastic dielectric hermetically sealed capacitor in a metal can. Metalized film capacitors are made of two metalized films with plastic film as the dielectric. A very thin vacuum deposited aluminum, tin or zinc metallization is applied to one or both sides to serve as electrodes. This configuration has “self-healing” properties, in that dielectric breakdowns or short circuits electrodes do not necessarily lead to the destruction of the component.
Gideon Analytical Labs received several samples thought to a contain silicone contaminate that prevented adhesion on the metal substrate. The analysis was performed using micro-FTIR analysis for the presence of silicone in three samples.
The samples were first examined under a microscope to identify the FTIR.
The contaminate is a dimethyl siloxane preventing adhesion.
Gideon Analytical Labs can save your company by identifying the materials that cause problems. We have many analytical techniques, instruments and years of experience in the electronic and chemical industries.
Gideon Analytical Labs received two BSP 77 HITFET devices with resistive shorts. The HITFET is a highly integrated temperature protected FET low-side switch which provides protection from short circuits, overloads, voltage surges, open circuits, excessive temperature, and ESD. These low-side switches are versatile power transistors specially designed for automotive and industrial applications. Their built-in intelligence and protective features offer improved performance and reliability over discrete components.
The die is covered with a polyimide over glassivation on top of the trace lines.
Gideon Analytical Labs received three failed and three operating Sitronix ST7528 LCD controller/drivers mounted directly on glass and connected via a 24 pad polyimide flex circuit to an FRU controller card. The failed units had a date code 06114A*C3 on a white label, version 1.6.
These are the test point pads on NG1. These are output pads. There is an EOS (electrical overstress) under the glass just below the second rail.
Several screws were presented to Gideon Analytical Labs due to corrosion. The screws were analyzed with SEM-EDS. The micrograph indicates the spot where this screw was analyzed. Chloride was found on the spot where corrosion was found.
Gideon Analytical Labs can identify the source and cause of corrosion allowing the customer to implement the corrective action immediately.
Screw Micrograph Screw EDS of Contaminate
This is the same terminal where the EOS occurred. There are multiple cracks on the capacitor near the bottom. This is due to board flexing, however, the solder does not wet the terminal metal to form a continuous interface leaving a good connection.
The four arrows point toward cracks in the bottom margin area of the capacitor. The fourth arrow from the left, if one follows that crackdown, it ends where the solder first makes a continuous interface to the terminal metal and goes around the corner and ends at the first electrode, where the void is shown by the blue arrow.
Gideon Analytical Laboratories received several PCBs with MLCC capacitors mounted near the circuit board edge. The capacitors had a polyurethane conformal coating passing class 2 IPC-A-610 inspection. Several of the capacitors had less than 3000 ohms leakage current when measured on an IR meter. The coating was removed and the samples were potted and cross-sectioned for further analysis. The capacitor shown is typical of a lot of failures.
These are flex cracks caused by PCB flexing or bending.
Gideon Analytical Labs received contaminated rubber seals which prevented the rubber from functioning correctly.
The colorless liquid gave the spectra in Figure 1. This is very similar and matches very well with a spectrum of N-(heptyl-nonyl-undecyl) phthalate, which is shown in Figure 2. This is generically known as a “phthalate ester” which is a liquid similar in appearance to vegetable oil. Phthalates are used primarily in the manufacture of polyvinyl chloride products and used as a plasticizer to create softness and flexibility.
