California Failure Anal

California Failure Analysis lab performed an electronic failure analysis on Pogo pin spring loaded contacts (Pogo connector pins) to determine the cause of intermittent open circuits. Electronic testing had detected that there were times when the spring loaded pin was depressed, the circuit would open and there would be an interruption of the signal. The cross section of a single Pogo (upper left) showed that the  the structure was entirely made of gold plated parts (pin, spring and outer
 case).  However, there was some concern that the inner wall of the case
was defective. For additional failure analysis, a sample case was split open (photo-micrograph on the right) and the inner surface was found to have horizontal machining marks,  not be plated, to be corroded and contaminated with plating salts. These plating defects indicate that the intermittent contact problem will worsen with time. These results are not surprising since the case is really a deep blind hole, and this makes it impossible to properly clean and plate  the interior. The vendor being analyzed is an overseas vendor that was to replace a reliable US supplier. These parts are unusable.

Rubber Failure Analysis: Rubber Seal Failure Analysis

A California failure expert witness was asked to determine the root cause of a rubber gasket leak. 

The molded rubber gasket seal was integrated into a hydraulic lift operating at 650 psi. Over time it had developed a very small hole and approximately 60 gallons of hydraulic oil escaped through this small leak. Read Consulting Failure Analysis Lab was asked to perform a detailed failure analysis to determine the cause of the leak.  The subject rubber seal failed as a result of a rubber molding defect. During the molding operation there was a region where the flowing rubber failed to re-bond properly. Over time the high pressure (650 psi) hydraulic oil created a hole in the weakened rubber and this resulted into a rubber failure and a hydraulic leak. Upper left is a 30X  photo-micrograph of the pinhole leak. The leak "protrudes" outward showing that the failure was created as a result of the hydraulic pressure. 

Device Patent Dispute: Automobile Rear View Mirrors

Read Consulting, a California failure analysis laboratory, often becomes involved with device patent disputes. In this case a patent dispute focused on external automobile rear view mirrors that had integral flashers showing through openings in the mirror. The assembly consisted of an array of LED lights that were behind the mirror, and these flashed through holes etched in the thin film chromium front surface mirror. Read Consulting had the electronic device expertise and thin film expertise to understand the various elements of the patent and to render an opinion in the patent dispute. Curiously, the same equipment that is used to perform failure analysis is also useful for examining elements in a patent dispute.

Construction Defect Analysis, Window Damage

California Failure Analysis Expert Witness performs a glass failure analysis on defective tempered glass windows installed in a public building. One of the construction defects was window scratching. Representative windows were removed and sent to the Read Consulting California failure analysis lab. This allowed a detailed investigation of the window defects. The failure analysis determined that the scratches were caused by post construction cleaning. Upper left is a macrophotograph of a typical set of scratches. Their parallel nature shows them to have been caused by a metal scraper. Upper right is a 40X photomicrograph of a scratched region. These scratches were in the glass. There was no coating on the scratched surface.  

Glass Failure Analysis of Tempered Glass Oven Door

California failure analysis expert witness analyzes a failed tempered glass toaster oven door to determine the cause of failure. The glass door remained intact, and this allowed the failure analysis to be performed. The origin is found to be in the center of a "butterfly" shaped region. There is a crush point that is the origin. The glass failure started at the crush region on the glass door surface and progressed inward till the residual stresses of the thermally tempered glass took over and caused the entire door to break into very small cubes. Upper left is an overview of the failed oven door. Upper right is a photomicrograph of the fracture surface at the origin.