MLCC Failure Analysis

Gideon Analytical Laboratories received several Murata Electronics GCM21BR70J106KE22L Multi-Layered Ceramic Capacitors (MLCCs) for failure analysis. An MLCC consists of a number of individual capacitors stacked together in parallel and contacted via the terminal surfaces. The starting material for all MLCC chips is a mixture of finely ground granules of paraelectric or ferroelectric raw materials, modified by accurately determined additives. The Murata Electronics GCM21BR70J106KE22L has a capacitance of 10 uF, a DC voltage rating of 6.

Gideon Analytical Laboratories received a printed circuit board (PCB) with suspected failing multi-layered ceramic capacitors (MLCC). Multilayer ceramic capacitors are fixed value capacitors in which ceramic the material acting as the dielectric. It is made up of two or more alternating layers of ceramic and a metal layer acting as the electrodes. There are various types of materials that could function as the dielectric in a capacitor, for example, glass, porcelain, paper, or mica.

Gideon Analytical Laboratories received two printed circuit board (PCB) assemblies, each of which had a single multilayer ceramic capacitor (MLCC) suspected of failing. These MLCCs are Johanson Dielectrics PN 500T15W103MV4E. 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. Components (e.g. capacitors, resistors or active devices) are generally soldered on the PCB. Advanced PCBs may contain components embedded in the substrate.

Gideon Analytical Laboratories received several Multi-Layered Ceramic Capacitors that had failed and two good MLCCs for comparison. The failure was occurring during the development cycle and it was thought this might be an issue with the manufacturing process. Multilayer ceramic capacitors are fixed value capacitors in which ceramic the material acting as the dielectric. It is made up of two or more alternating layers of ceramic and a metal layer acting as the electrodes.

Gideon Analytical Laboratories received several switches with cracked ceramic capacitors (MLCC) for failure analysis. In electrical engineering, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another. A ceramic capacitor is a fixed value capacitor in which ceramic material acts as the dielectric. It is constructed of two or more alternating layers of ceramic and a metal layer acting as the electrodes.

Gideon Analytical Laboratories received one failed multilayer ceramic capacitor (MLCC) on a printed circuit board (PCB). Multilayer ceramic capacitors are fixed value capacitors in which ceramic the material acting as the dielectric. It is made up of two or more alternating layers of ceramic and a metal layer acting as the electrodes. There are various types of materials that could function as the dielectric in a capacitor, for example, glass, porcelain, paper, or mica.

Gideon Analytical Laboratories received two multilayer ceramic capacitors (MLCCs)for failure analysis. Multilayer ceramic capacitors are fixed value capacitors in which the ceramic is acting as the dielectric material. It is made up of two or more alternating layers of ceramic and a metal layer acting as the electrodes. There are various types of materials that could function as the dielectric in a capacitor, for example, glass, porcelain, paper, or mica. They were not EU ROHS compliant.

Gideon Analytical Laboratories received three 1210 Multi-Layer Ceramic Capacitors (MLCC) for analysis. Multilayer ceramic capacitors are fixed value capacitors in which ceramic the material acting as the dielectric. It is made up of two or more alternating layers of ceramic and a metal layer acting as the electrodes. There are various types of materials that could function as the dielectric in a capacitor, for example, glass, porcelain, paper, or mica. The MLCCs were from a Time Hub printed circuit board (PCB).

Gideon Analytical Laboratories received one MLCC on a DC input noise filter PCB on which to perform failure analysis. MLCCs (Multi-Layered Ceramic Capacitors) are extremely ubiquitous in the electronics field; it was estimated that around 1000 billion are produced per year. The MLCC has severe thermal damage but was still intact to the pads via the termination solder connections. Analytical services were provided. The MLCC could not be cut from the PCB and the PCB could not be cut because of the fragile nature of the condition.

Gideon Analytical Laboratories received several Tusonix Pi filters that were failing in the field. Capacitor-input filters (also known as Pi filters) are a type of electronic filter used to remove unwanted frequencies from a signal. Pi filters are primarily constructed of two capacitors and an inductor and are used in situations where the ripple of a signal or the AC and DC currents within the signal are found to interfere with each other.

Gideon Analytical Laboratories received a single failed Spectrum Control Pi filter on which to perform failure analysis. Capacitor-input filters (also known as Pi filters) are a type of electronic filter used to remove unwanted frequencies from a signal. They are called “Pi” filters because of their resemblance to the Greek letter “Pi”. Pi filters are primarily constructed of two capacitors and an inductor and are used in situations where the ripple of a signal or the AC and DC currents within the signal are found to interfere with each other.

Gideon Analytical Laboratories received four 220 picofarad AVX capacitors for failure analysis. There are a variety of capacitors, including ceramic, aluminum, film, and tantalum, but all serve the same purpose, which is to store electrical charge. They are passive electrical components with at least two electrical conductors separated by an insulator (dielectric). The four220 picofarad AVX capacitors were giving low resistance readings. Failure analysis ensued. The four 220 picofarad AVX capacitors were inspected for mechanical cracks, which would propagate upon voltage; no cracks were found on the external ceramic.

Gideon Analytical Laboratories received 19 multilayered ceramic capacitors (MLCCs). MLCCs have a ceramic dielectric, a ceramic or lacquered coating, a metalized electrode, and connecting terminals. Ceramic capacitors, in particular, MLCCs, are ubiquitous in all kinds of electrical equipment. Some of the MLCCs Gideon received were to test quality control, some were to test process evaluation immediately after wave solder, and some were failures in the field. The objective was to determine where these failures were entering the product and the cause of the failures.

Gideon Analytical Laboratories received six MLCC on power cards. MLCC are multilayer ceramic capacitors. A ceramic capacitor is fixed value capacitor with the ceramic material acting as the dielectric. They have two or more alternating layers of ceramic and metal acting as electrodes. Two MLCCs were identified as failures and four MLCCs were to determine whether “flexiterm” terminations were used. All six capacitors were removed from the power boards and tested for capacitance, ESR, and leakage current.

Gideon Analytical Labs received one failed multilayer ceramic capacitor for failure analysis. The image below is from Wikipedia. It shows the standard metallurgy for MLCCs. The capacitor was mounted to the PCB and showed no signs of external damage. The capacitor was removed from the PCB and tested. The leakage current was too high for a capacitor of this size. The capacitor failure analysis revealed by a cross-section that the capacitor had thermal cracks extending from one side to the other.

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 Laboratories received several SVAA-3V25 relays for failure analysis. These solid state relays have a control voltage range between 100 VAC and 280 VAC, a load voltage rating of 330 V, and a load current rating of 25 A. Solid state relays are ideal for industrial and commercial ovens, injection molding machines, and induction furnaces, and many other applications. The goal was to find the cause of the failures.

Gideon Analytical Labs received two 0805 MLCC capacitors mounted on daughter boards and several good capacitors for comparison. One capacitor mounted on a PCB had multiple cracks. The pictures supplied indicated several horizontal cracks. The capacitor was cleaned and cut from the remainder of the PCB and mounted for horizontal to the PCB. After analysis the conclusion was a combined affect of terminal fracturing and poor soldering wetting lead to over heating which in turn caused thermal cracks that lead to the EOS.

Gideon Analytical Laboratories received a PCB with possible failed capacitors in several positions. PCBs are used to mechanically support and electrically connect electronic components. They are used in almost every all but the simplest electronic devices, from GPS systems to laptops, from cell phones to microwave ovens. Several MLCC capacitors on this PCB had failed, and the goal of Gideon Analytical Laboratories was to diagnose the cause of the failure.

Gideon Analytical Laboratories performed failure analysis on several SM Syfer SM MLC Capacitors (also known as MLCC failures). The goal was to determine the root cause of these failures. Pictured on top left is the failed capacitor; it had an 11.5 Kohm resistance short. The capacitors were cross sectioned. All cross sections of the new Syfer were in excellent quality. No voids, knit cracks, delamination, blow holes, or contamination was found.

Gideon Analytical Laboratories received 100 capacitors and directed to analyze them via cross-sectional analysis. Capacitors store charges and frequently appear on PCBs. There are many types of capacitors; electrolytic capacitors are tantalum capacitors are fairly common. The goal was to discover any abnormalities or determine if there were no abnormalities. Each capacitor was cross-sectioned and observed 15 to 20 times under 40-72x magnification during the sectioning process. At some point during the cross-sectioning process, pictures were taken to depict the internal quality of the ceramic structure and any cracks (mechanical, knit, Kirkendall voiding or other defects) that may be present.

Gideon Analytical Laboratories received two printed circuit boards (PCB) with the questionable failure of multilayer ceramic capacitors in the C4 position. Both these capacitors were removed from the PCB and the PCB was inspected for contamination for possible leakage current or electromigration that would account for conduction across the pad lands. The picture at the top left is the C4. During analysis, no contamination was found on either of the PCBs or on any of the four sides of each capacitor.