Gideon Analytical Laboratories received two 153D8496G1 printed circuit boards (PCBs)for failure analysis. A PCB mechanically supports and electrically connects electronic components using conductive tracks, pads, and other features etched from copper sheets laminated onto a non-conductive substrate. Some of the electronic components that might appear on a PCB include semiconductors like diodes or transistors, discharge devices, power sources, resistors, and capacitors. The153D8496G1 circuit card assembly has 6 capacitors, 20 resistors, and 18 semiconductors all mounted to a printed wiring board.
Gideon Analytical Laboratories received several Bourns Trimpot Trimming Potentiometers for failure analysis. A Potentiometer (known as a pot) is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider. They are widely used for volume control in radio and television receivers. The Bourns Trimpot Trimming Potentiometer 3006P 203 has a standard resistance range of 10 to 5 megohms, the power rating of 400 volts maximum, and is ROHS compliant.
Gideon Analytical Laboratories performed thermal mechanical analysis TMA and differential thermal analysis (DSC) on two plastics which compose the encapsulation of Unity LEDs. TMA is a measurement of a change of a dimension or a mechanical property when it is subjected to a temperature regime. DSC is a technique for quantitatively analyzing the chemical composition of a substance by observing its thermal behavior while being heated. The samples were disassembled and separated into three items to analyze; the white casing, the clear resin, and the clear core material.
Gideon Analytical Laboratories received several contaminated lead screw assemblies. Also received were three insulin samples, one grease sample, and several new parts making up the lead screw assembly. Lead screws are designed to translate turning/rotary motion into linear motion. The contamination on the shaft of the assembly was primarily concentrated between the bearing and the ball seal. The goal was to identify and determine the cause of the contamination.
Gideon Analytical Laboratories primarily used FTIR and SEM-EDS analysis for diagnostics.
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.
Gideon Analytical Labs received a contaminated white translucent adhesive at the edge of a polyimide strip under a rubber keypad. Since most of the materials were organic, FTIR was the method of analysis first used to determine the foreign material.
The polyimide is a double-sided adhesive based flexible laminate (Kapton) film coated with adhesive on one or both and laminated to copper. There are two kinds of adhesive used in flex, epoxy, and acrylic.
Gideon Analytical Labs received several PCB that opened up on several of the I/O metal dome pads.
The three black circles are the time, status, and menu pads. The metal domes came out when the two switches were separated. These buttons are connected to an output. The insulator cavity (the black spots) provides space for the metal dome. The metal dome makes contact when pushed from the top switch circuitry to the bottom switch shown later.
Gideon Analytical Laboratories received three contaminated Buna-N diaphragms and several new ones for reference. These Buna-N diaphragms have a variety of applications, including in submersible level transmitters, actuary assemblies, air operated diaphragm pumps, and manual loading regulators. The goal was to identify the contamination and pinpoint its cause.
Upon examination under a stereo-zoom microscope, it was found that the surface of the sample contains a thick layer of a gel-like material.
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 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.
