Electrolytic Capacitor Failures

Gideon Analytical Laboratories received two power supply boards with components. The supplies were thought to have contamination, possibly bromine, causing corrosion or failing the electrolytic capacitor. The term electrolytic capacitor in a generic term for three different capacitors, which include aluminum electrolytic capacitors, tantalum electrolytic capacitors, and niobium electrolytic capacitors. All electrolytic capacitors are polarized capacitors whose anode is made of a particular metal on which an insulating oxide layer forms by anodization, acting as the dielectric of the electrolytic capacitor.

Gideon Analytical Laboratories received three electrolytic capacitors that were failing in the field. A capacitor stores electrical energy. They have two terminals separated by some type of insulating material, known as a dielectric. Usually, these dialectics are metal plates and the dielectric is made of materials like ceramics, mylar, or glass. Electrolytic capacitors are a type of capacitor that uses an electrolyte as one of its plates to achieve a larger capacitance per unit volume.

Gideon Analytical Laboratories received a power supply with several bulging capacitors on the motherboard. A power supply is an electronic device that supplies electric energy to an electrical load. The primary function of a power supply is to convert one form of electrical energy to another and, as a result, power supplies are sometimes referred to as electric power converters. Some power supplies are discrete, stand-alone devices, whereas others are built into larger devices along with their loads.

Gideon Analytical Laboratories received five 25 volts (v) 120 microfarad (μF) electrolytic capacitors that were failing in the field. A capacitor stores electrical energy. They have two terminals separated by some type of insulating material, known as a dielectric. Usually, these dialectics are metal plates and the dielectric is made of materials like ceramics, mylar, or glass. Electrolytic capacitors are a type of capacitor that uses an electrolyte as one of its plates to achieve a larger capacitance per unit volume.

Gideon Analytical Laboratories received an Areovox Z26P6045M21 45uF 600V capacitor for failure analysis. Capacitors are passive two-terminal electrical components used to store electricity in an electric field. Inside most capacitors, there are two metal plates separated by a non-conducting substance (dielectric). Filter capacitors are used for filtering undesirable frequencies and removing voltage or signal spikes in electronic circuits. They are utilized in a variety of applications. Gideon Analytical Laboratories performed failure analysis the Areovox Z26P6045M21 45uF 600V capacitor.

Three lots of capacitors were submitted Gideon Analytical Labs for chloride and zinc contamination analysis on the terminal leads of the electrolytic capacitors. The analysis was performed using an SEM-EDS system giving elemental analysis in relation to the intensity of the element at a specific wavelength or energy level (Kev). Since Kev (energy levels) for specific elements do not change, these are used to identify the elements in the sample.

Gideon Analytical Laboratories performed failure analysis on several Bias BPS2-07001 failed power supplies. Several good units were submitted for comparison. These Bias BPS2-07001 are linear and switching power supplies 2W 14V, 5V DUAL 85-265V Std Temp and are ROHS compliant. They provide up to one-half, one, or two watts of output power (BPS0.5, BPS1, and BPS2) at 8 or 14 VDC (Vo) and an optional 3.3 or 5 VDC (Vr) output to power standby functions such as clocks, microprocessors, remote control sensors, and more.

Gideon Analytical Laboratories received a single capacitor for failure analysis. The capacitor had a capacitance of 22µF, a voltage rating of 400 V, was ROHS compliant and had a vented bottom and the wound was exposed. The goal was to determine the cause of the failure. The capacitor sleeve was not cracked and bulging was not apparent. This usually indicates the failure occurred during a minor period from onset of the pressure build up within the can.

Gideon Analytical Laboratories received electrolytic capacitors for chloride analysis according to a prior analysis technique for determining the presence of chloride. The chloride analysis technique was developed because chlorine is a known catalytic corrosive element on aluminum. The analysis was performed using an SEM-EDS system giving elemental analysis in relation to the intensity of the element at a specific wavelength or energy level (Kev). Since Kev (energy levels) for specific elements do not change, these are used to identify the elements in the sample.

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 ten failed microwave AC capacitors used in microwave applications. The capacitor used as a doubler failed in the circuit by shorting. The capacitors were Samwha vintage 2100VAC .65uF with 3 percent tolerance with a maximum temperature rating of 85°C. All the capacitors were tested for shorts or opens. The resistance of the integrated resistor (internal and immersed in the dielectric fluid) was measured also.