Understanding and Selecting the right MLCC (Multi-Layer Ceramic Capacitors)

For optimizing performance, reliability, cost of your electronic product designs.

Misaligned component choices in customer BOMs have been a recurring issue, such as using low-end MLCCs in electric vehicles (EVs) or selecting automotive-grade components for 5G, base stations. This often occurs when R&D teams focus on legacy parts, while supply chain teams prioritize cost and availability, leading to poor reliability or higher overall costs.

The article aims to help engineers, designers, and procurement teams make more informed decisions and outlines the key features and selection criteria for MLCCs, using CCTC (www.cctc.cc) MLCCs as a reference, providing valuable insights for R&D and sourcing teams.

1. Introduction

In today's fast-evolving electronics landscape, MLCCs are crucial components. Made from layered ceramic material and conductive electrodes, they provide high capacitance in a small formfactor. Since their development in the 1960s, MLCCs have gained popularity for their reliability, longevity, and ability to function in wide temperature ranges. Recent material and manufacturing advances have improved their voltage and frequency handling too. As demand for electronics grows, understanding MLCC selection and reliability is key to ensuring stable product performance and competitiveness.

2. Applications of MLCC

MLCCs are essential in applications like telecommunications, automotive, consumer electronics, and more. They have largely replaced older capacitor (Electrolytic, Film, Ceramic through hole) types, playing key roles in power management and noise reduction in devices like smartphones and TVs. In automotive, MLCCs are crucial for filtering and voltage regulation in ECUs, ADAS, and EVs. They stabilize power in 5G infrastructure and filter noise in industrial and medical systems. MLCCs are also great fit in RF, aerospace, green energy, and LED lighting. Their typical share in a BOM ranges from 1-10% in consumer electronics to 10-30% in high-frequency applications, with every vehicle today containing thousands of them.

3. Selection Criteria for MLCCs

Let me use CCTC’s part numbering as a reference

Typical Selection Sequence:

1/ Application Specific Series (if any), 2/Capacitance 3/ Rated Voltage, 4/ Tolerance 5/ Size? 6/ Temp Characteristics (dielectric).

Refer below where I share deeper insights that will assist you in your selection criteria: -

3.1?Temperature Characteristics (Dielectric Types):

The dielectric material in MLCCs determines their capacitance, voltage rating, temperature stability, and overall performance, making it crucial to select the right type for each application. Class I MLCCs, like C0G, offer the most stable electrical properties with minimal changes due to temperature, voltage, or time, ideal for high-stability circuits like filters and oscillators. Class II MLCCs have higher capacitance and semi-stable temperature characteristics, commonly used in applications like DC-blocking, decoupling, and bypassing. Class III MLCCs, such as Z5U and Y5V, provide very high capacitance but with lower stability and accuracy.

Dielectric Characteristics:

3.2 Application-specific Series:

Engineers should carefully select the appropriate MLCC series based on the specific requirements of their applications. Here are a few suggested examples:

a) General Purpose: e.g. CCTC’s Regular Series: suitable for low end or general purpose non-critical applications

b) High Reliability: e.g. CCTC High Reliability series: suitable for applications requiring higher reliability

c) High-Frequency: High-frequency MLCCs are designed to minimize power loss and signal distortion, high dielectric strength, and stable capacitance across varying frequencies. These MLCCs are essential in communication devices and high-speed computing

d) Automotive-Grade : Automotive-grade MLCCs meet strict standards for reliability, vibrations, shocks, and thermal cycling. They undergo rigorous testing to ensure compliance with AEC-Q200 and other automotive standards.

e) 5G Series 5G series MLCCs are optimized for GHz frequencies, offering stable capacitance at high speeds, and compact sizes for space-constrained applications. Their high Q factor minimizes energy losses, making them ideal for high-speed communications.

f) Applications requiring High Strength Material

S Series: The S series capacitor uses high-strength ceramic medium at the upper and lower cover to improve the mechanical strength of the product

N Series: The N series improves the uniformity of inner electrode distribution in ceramic body to increase the bending strength;

C/ F Series: Soft terminal C series use Copper terminal to improve the stress tolerance and increase the bending strength while, F Soft terminal series use silver terminal to improve the stress tolerance increase the bending strength. Soft Terminal is much higher cost compared (due to silver) with the Regular Series. It is ideal for Automotive applications as it offers better performance and reliability.

Z Series: Used in Industrial applications e.g. Motor Controls and Robotics or equipments that have vibrations

3.3 Rated Voltage and Capacitance

MLCCs offer a wide range of capacitance values, from picofarads (pF) to microfarads (μF), allowing designers to meet specific circuit needs. Voltage ratings range from 6.3V to 2000V, so selecting the right combination of capacitance and voltage is crucial to prevent dielectric breakdown. Capacitance levels vary by application, with low (1pF-10nF), medium (10nF-1μF), high (1μF-10μF), and very high (10μF+) options.

3.4 Size (Physical Dimensions or Form Factor)

MLCC size codes, like 0201, 0402, and 0603 and more, indicate the component's dimensions, with the first two digits representing length and the last two width (e.g., 0201 is 0.02 inches long and 0.01 inches wide). CCTC offers a wide range of sizes, making their MLCCs suitable for various applications, including space-constrained environments. The size selection impacts the capacitor's capacitance, voltage rating, and performance. Smaller MLCCs are ideal for portable electronics due to their compactness, while larger sizes are preferred in applications requiring higher power handling.

3.5?Tolerance

MLCC tolerance refers to the allowable variation between a capacitor's actual and nominal capacitance, expressed as a percentage. Common tolerance levels include ±5% (J tolerance) for precise applications, ±10% (K tolerance) for general use, ±20% (M tolerance) for less critical applications, and ±30% to -80% (Z tolerance). Tolerance is influenced by the dielectric material, with Class I dielectrics offering tighter tolerances than Class II/III, and by operating conditions like temperature and voltage.

4. Reliability factors in MLCC

MLCC reliability is affected by factors like aging, mechanical cracking, thermal stress, and voltage exposure, which can cause capacitance loss or failure. To reduce these risks, engineers should choose components carefully, apply derating, and use proper manufacturing techniques. Excessive heat speeds up aging, and operating near rated voltage raises the risk of breakdown. Humidity and mechanical stress, such as PCB flexing, can lead to corrosion or micro-cracks. For optimal performance, engineers should select MLCCs designed for harsh conditions, use correct mounting techniques, and protect against moisture and stress.

5. Industry Trends and Innovations in MLCC Technology

Recent advancements in materials science and manufacturing have significantly enhanced the performance and reliability of Multi-Layer Ceramic Capacitors (MLCCs). New dielectric materials enable higher capacitance in smaller packages, meeting the growing demand for miniaturized electronics. Key trends include increased miniaturization, pursuit for higher capacitance, e.g. CCTC targeting breakthroughs in 0805-100μF and 1206-220μF, and improved high-frequency capabilities through copper inner electrode technology. Additionally, the demand for high-reliability MLCCs and high-voltage capacitors (3–4kV) is expected to grow as power supply circuit designs evolve.

6. Conclusion:

Understanding the complexities of MLCCs is essential for optimizing their use in electronics. Engineers must focus on proper selection and reliability to meet application needs. Staying updated on industry trends, and following best practices in selecting right MLCC can help maximize your product performance. The demand for reliable MLCCs and it's significance will only grow as technologies and applications evolve

About CCTC (Chaozhou Three-Circle (Group) Co): www.cctc.cc

Established in 1974, with over 10,000 employees and 1,700 R&D personnel, CCTC is a global leader in the MLCC (Multi-Layer Ceramic Capacitor) industry. Over the past half century, CCTC has been adhering to the vision of "'Materials Plus' Builds Better Life", focusing on the "material", and taking "material + structure + function" as their development direction. Their products cover fields such as electronics, new energy, communications, semiconductors, and mobile smart terminals. CCTC’s success is driven by strong R&D capabilities, state-of-the-art manufacturing, and a focus on process optimization to deliver high-quality products. Offering a diverse range of capacitors, including high-frequency, high strength, high capacitance and automotive-grade options, CCTC meets various industry needs. With certifications like AEC-Q200 for automotive applications, they ensure reliable, high-performance products. Their efficient production, robust supply chain, and commitment to sustainability reinforce their global leadership in the MLCC market.

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Founded on January 1, 2024, by a Industry veteran, Focalpoint Consultants is a Singapore based Business Consultancy & Rep Services provider within the Electronics/ Electronic Components Industry, focusing on India and ASEAN markets. It comprises Team of Expert Consultants with each having 30+ years of Electronic Component market experience and success and understanding of diverse business aspects. These Consultants are located strategically at Singapore, Bangalore, Delhi, Pune who have come together to help companies as a bridge or Gateway to India market and WIN! Contact RD Pai to know more!