Industrial, medical, and military demand for high-quality, high-voltage multilayer ceramic capacitors (MLCCs) has been hit hard by production shifts from the world’s largest MLCC manufacturers to focus on a seemingly insatiable demand for smaller, lower voltages – in a way – a lower performing MLCC. This demand is driven by the global growth of 5G networks and the continued advancement of smartphones and mobile devices, which consume a significant increase in MLCC per device.
With major manufacturers moving away from the larger, high-voltage, high-Q (high-quality) MLCCs used by industry and the military, OEMs have had up to six months of delays in MLCCs. The magnitude of the supply shortage jeopardizes product release schedules, industrial market share, and possibly even military readiness.
“It’s a huge carrot hanging in front of the major MLCC manufacturers,” said Scott Horton, vice president of Johanson Technology, a 40-year-old supplier of high-voltage ceramic multilayer capacitors in Camarillo, California. “The current market demand for smaller, lower-power MLCCs is unprecedented when you consider that today’s high-end smartphones may require more MLCCs in a single device than similar phones a few years ago.”
Many OEMs and distributors have excess inventory as consumer demand for capacitors slows in 2019. As a result, these OEMs and distributors are hesitant to order additional inventory in 2020. Now, as the market grows, so does the demand for MLCCs despite very low capacitor inventories. This further exacerbates the shortage of large high-voltage, high-Q MLCCs, as some manufacturers have focused production on smaller/lower-voltage MLCCs during this period.
Both ends of the market are now scrambling to restock, including large electronics distributors. Mainly Asian MLCC manufacturing supports telecom and mobile equipment operations, which are also based in Asia, making it more urgent for Western markets to meet industrial MLCC supply needs.
“The knock-on effects on the industrial and military market sectors are not yet fully understood,” Horton said. “While shortages of electronics used to make consumer products such as smartphones and cars will be national news, the lack of greater, greater, lesser, lesser, lesser, lesser, lesser, lesser, lesser, and lesser potential for industrial and military applications. Higher voltage MLCC supply is generally undervalued. However, until the issue is resolved, it will continue to squeeze enterprise customers and ultimately end users.”
Multilayer Ceramic Components
MLCCs consist of a stack of specially formulated ceramic dielectric materials interspersed with a metal electrode system. The layered structure is then fired at high temperature to produce a sintered and volume efficient capacitive device. A conductive terminal barrier system is integrated on the exposed end of the chip to complete the connection.
The capacitance is mainly determined by three factors: the k of the ceramic material, the thickness of the dielectric layer, the overlap area, and the number of electrodes. A capacitor with a given dielectric constant can have more layers and wider electrode spacing or fewer layers and closer spacing to achieve the same capacitance.
Industrial, medical and military consumers of MLCCs rely on high voltage and high Q capacitors for power supplies, amplifiers, MRI coils, plasma generators, lasers and many other specialty applications. In circuits with higher currents, higher-Q MLCCs are preferred to reduce self-heating.
The Q factor expresses the efficiency of the capacitor’s energy loss rate. High-Q capacitors lose less energy, reducing the need to dissipate or cool heat, protecting circuit boards from damage and performance loss in sensitive and high-reliability applications.
Not all MLCCs are created equal, even in high-performance MLCCs, but ensuring a consistent level of performance is critical for high-reliability applications demanded by industrial and military end users.
“If the MLCC manufacturer didn’t strictly control the number of layers, they might provide a batch of 10 layers in one batch and then a 17-layer part in a subsequent batch,” Horton explained. “The two parts don’t behave the same at high frequencies.”
Increased domestic supply
Domestic sources of MLCC for industrial and military applications have been increasing capacity. Increased domestic MLCC supply means that industrial or military customers will not need to delay building and shipping their products due to capacitor delays.
For example, with a focus on high-Q and high-voltage MLCCs, Johanson has expanded its production capacity to fill some of the supply gap created by the market’s shift to smaller capacitors.
“We have been investing in expanding our capacity for several years, by modernizing our production facility and opening a second production line, which will essentially double our MLCC production,” Horton said. “We can improve that with more production shifts.”
At the time of writing, Johanson cites a 10-week fulfillment time for large-scale, high-pressure MLCC orders.
Ceramic is the material of choice
Increasing domestic supply of high-voltage MLCCs also means that customers do not need to go beyond ceramic capacitors to meet their needs. Due to long lead times, polymer or tantalum capacitors may be considered in place of MLCCs; however, the trade-off between performance and optimal operating conditions needs to be carefully considered.
The polymers in capacitors degrade under the influence of heat, which is a consideration for some applications. The dielectric layer of polymer capacitors is thinner, which means that the maximum voltage is lower than that of ceramic capacitors, so they are not suitable for high voltage products. Polymers also do not have the low capacitance values offered by ceramics.
Tantalum electrolytic capacitors consist of a porous tantalum metal sheet as the anode, covered by an insulating oxide layer to form the dielectric, surrounded by a liquid or solid electrolyte as the cathode. While considered a reliable and suitable replacement for MLCCs, tantalum capacitors are usually polarized, which means they can only be connected to a DC power source. Unfavorable failure modes can lead to thermal runaway and fire. Tantalum capacitors are also currently experiencing extended lead times for procurement.
“In your high-voltage, high-quality applications, there is no reason to give up ceramics,” says Johanson’s Horton. “There is now a growing supply of domestic MLCCs to meet our domestic demand.”
Changes in supply and demand in the overall MLCC market, which is estimated to grow to a $12 billion market by 2025, have resulted in severe supply shortages for industrial, medical, and military customers that require higher-quality, larger-gauge multilayer ceramic capacitors. As the largest MLCC manufacturers continue to compete for demand for MLCCs used in industries such as telecommunications, smartphones, and mobile devices, new domestic sources of supply are stepping in to meet the demand for reliable and timely supplies of high-performance MLCCs.