The continued upswing in the electronic markets has been fueled by new options in connectivity, sensing and the powering of devices. Influenced by new technology like the Internet of Things (IoT) and Artificial Intelligence (AI), there has been a dramatic rise in demand and plurality in terms of input and output devices, primarily the human machine interfaces. As consumption keeps apace, there is a troubling shortage on some of the most common and widely produced components – namely resistors and Multilayer Ceramic Capacitors (MLCC).
While cheap and easy to manufacture, MLCCs have recently gone into allocation with no clear resolution on the horizon. Procurement departments now have to embargo MLCC usage in BOMs, putting hardware developers in a tough spot.
The bigger MLCCs with high CV values will be affected most. Bigger case sizes are a legacy product for MLCC suppliers and the price erosion ensured that nobody wanted to expand capacity further in this area. MLCCs are also popular for many reasons despite their shortcomings like volumetric efficiency, piezo noise issues, reliability and now availability. In high frequency applications, MLCCs are the best bet if you’re working above 500 kHz. They also have very low ESR and ESL characteristics, and are indifferent to ripple current. MLCCs are not easy to eliminate but require changing the circuits because the bigger ones will go extinct. Package forms 0402 and 0201 are being encouraged for replacing packages bigger than 0605. However, the heating characteristics and special layered PCBs required for these smaller packages open a much bigger bag of tricks.
In this area, other technology options exist – Tantalum, Niobium and Polymer come to mind. Polymer is the youngest and most diverse option due to form factor, dielectric options and better characteristics in terms of ESR/ ESL and frequency responses. Given Panasonic’s broad Polymer portfolio, we have witnessed a lot of replacement activity in the last year. Not all MLCCs should and can be replaced, but we have been helping customers make the leap from endangered MLCCs to Polymers when applicable (i.e. high CV values, package form 0805 and bigger, smoothing capacitors close to the LSI, or “platform” capacitors)
Drop-in replacement scenarios are rare, as MLCC land-pattern is pretty much unique. Also, MLCCs have hardy properties like voltages above 100V with nF or pF capacitance with indifference to reverse polarity (no protection circuitry), which makes them the single dielectric option in these cases. However, you get the most value when Polymer capacitors are used to replace multiple MLCCs – offsetting the size and cost performance that made MLCCs the viable option in the first place. Here, we list two of these use-cases.
Automotive Applications
The MLCC shortage will challenge the automotive sector due to its high demand and reliability aspects, leaving very few options of experienced suppliers to source from. The automotive sector must also realize its inability to switch in the short-term, and have also made arrangements with certain suppliers to satiate their demand.
As the automotive market figures out the finer points of functional safety, the switch to 48V battery systems and need for redundancy circuits will concentrate their demand on 25V, 50V and 100V parts while miniaturization and height constraints stave off replacement with electrolytics. Despite the ability to overcome the load dump and surge tests with MLCCs, the designers are restricted by the need for redundancy options given by OEMs for different dielectric options, which inflates the voltage (due to obvious MLCC derating requirements).
From Panasonic’s portfolio, an obvious option is the Conductive Polymer Hybrid Aluminum Electrolytic Capacitors, due to the AECQ-200 compliance. This class of polymer capacitor, due to its combination with electrolyte, offers high reliance of the electrolytic with the miniaturization, low ESR and the higher ripple of the Polymer dielectric.
As Panasonic does not make MLCCs, it might be difficult to make these comparisons between your Polymer option and the MLCCs you are currently using. The MLCC manufacturer (such as Murata’s SimSurf or Kemet’s K-Sim) usually has a characteristic viewer which will show the parameters of the capacitor in terms of different temperatures and frequency. Panasonic offers a similar tool called Characteristic Viewer (link below), which can be used for comparison. Another solution would be to export the data from both sources (as Excel files in CSV format) and then superimpose the plots on a single graph giving you a good comparison.
Dependent on the mission profile for your application, one may choose variation from the ZA Series (105 °C rated), the ZC Series (125 °C rated) or higher like the ZE Series (145 °C). Although one might be tempted to decide in favor of the 125 °C components from Polymer Hybrid alternatives, it is important to remember that if the ambient temperature and the ripple current for your applications are not that high, there is no need to inflate your costs and limit your options with the higher temperature. Your X7R MLCC is rated at 125 °C, but it is primarily your insurance for the improvement on the FIT rate compared to X5R MLCCs, especially if your application is scaling around 95 °C.