Exponent’s expertise in materials and packaging spans the range from small electronic components such as the integrated circuit, and large conductors, to materials used in large electric motors and generators.
At the IC level of electronics packaging, our focus is on the interaction between the materials used in electronics packaging, as well as environmental isolation properties and degradation. This includes stress and thermal analyses of packaging and electronics. Such analyses have been useful to our clients for thermal management and overheating of components, especially diodes and other temperature-sensitive semiconductor power components. In other components dealt with, polymer housings and their embedded flame-retardant chemicals can create issues for the metal electronics inside. Exponent has characterized corrosion issues and performed accelerated testing to understand exactly how these phenomena may impact our clients’ products. Exponent also has experience unraveling subtle failures due to problems in electrolytic, ceramic, film and tantalum capacitors.
Our experience further expands from electronic component materials to conductors and connectors providing power to our homes and workplaces. Exponent experience in materials degradation and analytical skills and can assist our clients in understanding the effects of high current heating in connectors that occurs over a long period of time. This mechanism creates an insidious failure mode where material oxidation, heating, and further oxidation lead to connection failure over a period of weeks or years. Other materials issues in power and wiring include analysis of arcing and melting in conductors, and alloying effects that can cause copper conductors to melt at depressed temperatures.
Exponent also has expertise in solid electric insulation materials, fluids or gases. Dielectric breakdown of an insulating material is often a precursor to arcing, electric shock, electrocution or a cause of fire. One of the most ubiquitous applications of solid insulation materials is the ever present circuit board, which sometimes fails and generates significant amounts of smoke in the process of failing and sometimes causes firs. Solid insulation materials are frequently used for cable insulation but also for support structures in breakers and switchgear. Liquid insulation materials are used in high voltage transformers and in most capacitors but are also found in old oil breakers. Gaseous insulation systems are found in high voltage equipment mostly for utility applications. However, most power lines are air insulted so air at atmospheric pressure is also an insulation medium.
Finally, at the largest size scale, another there are important material systems in electric generation and large motors. The laminations in these machines are needed to conduct magnetic flux through a generator or motor without conducting electricity. The insulation around the conductors (slot liners) is also of great importance in keeping the current where it is intended to be. The results of electric conduction through these materials can be catastrophic failure of the motor or generator. Typical failure modes include for example, arcing between conductors and metal melting in the generator stator core laminations. Materials work in this area has included examination of the insulating coating on the laminations to determine its thermal and mechanical breakdown characteristics, as well as electrical breakdown testing of the conductor insulation.