What are soft and flexible termination capacitors?

Soft termination capacitors, pivotal in modern electronics, offer flexibility and reliability. They're vital for stability in circuits, especially in high-speed communication and storage. Despite challenges like cost and miniaturization, they promise a bright future, powering innovations in wearable tech.

 

I. Introduction to Terminal Capacitors

A. Definition of Terminal Capacitors

Capacitors, usually abbreviated as capacitance, denoted by the letter C.

Definition 1: Capacitors, as the name suggests, are "containers for electricity," devices that store charge. Capacitors are one of the widely used electronic components in electronic devices, extensively employed in circuits for rectification, coupling, bypass, filtering, tuning, energy conversion, control, etc.

Definition 2: Capacitors, any two insulated conductors (including wires) separated by a small distance constitute a capacitor. Capacitance is different from a capacitor. Capacitance is a fundamental physical quantity, symbolized by C, with the unit F (farad).

 

General formula: C = Q/U

Parallel plate capacitor specific formula: Plate-to-plate electric field intensity E = U/d, capacitor capacitance determination formula C = εS/4πkd

With the rapid advancement of electronic information technology, the replacement cycle of digital electronic products is increasing. The continuous growth in production and sales of consumer electronic products such as flat-panel TVs (LCD and PDP), laptops, digital cameras, etc., has driven the growth of the capacitor industry.

 

B. Importance in Electronic Circuits

The basic characteristics of capacitors find extensive applications in electronic circuits, playing crucial roles in filtering circuits, tuning circuits, coupling circuits, bypass circuits, delay circuits, shaping circuits, and other circuits.

 

II. Soft Termination Capacitors

 

A. What are Soft Termination Capacitors?

They feature soft leads, convenient for surface mounting processes. The flexible leads of soft terminators shorten the distance between electrical components on the circuit board, enhancing circuit stability and reliability. Soft termination capacitors come in various capacities and sizes, adaptable to different electronic device applications. They are commonly used in high-speed communication, storage, and some high-end electronic products requiring small size and stable performance.

 

B. Characteristics and Properties

- Reduces PCB bending faults

- High reliability and stability

- Low ESR and ESL

- Low leakage current

- Excellent mechanical stress and thermal shock resistance

- Various sizes available

- Wide range of capacitance values

- High-temperature-resistant series available

- Series products compliant with AEC-Q200 automotive standards available

 

C. Applications and Use Cases

- Used in general digital circuits

- Used as power bypass capacitors

- Used in consumer electronics products

- Used in telecommunications

- Used in automotive electronics

- Safety design for battery lines

- Countermeasures against engineering substrate bending

- Corresponding products for welding cracks caused by thermal shock

 

D. Advantages and Benefits

In circuits with strict quality requirements, such as automotive electronics, high-temperature environments, power lines, TFT-LED inverters, conventional MLCCs have poor bend resistance. During surface-mounting processes, through wave soldering or reflow soldering, the electronic circuit board deforms, subjecting MLCCs to thermal shock and mechanical deformation stress, leading to cracks. "Soft terminators," namely flexible outer electrode MLCCs, are the optimal solution for addressing MLCC stress fractures.

 

E. Challenges and Limitations

Although MLCCs are mature and widely used electronic components, some manufacturing technologies still face challenges and difficulties:

Miniaturization: With the trend of electronic device miniaturization, MLCCs also need to continuously reduce in size, requiring high-precision processing equipment and process control.

High Capacitance: To meet current and future applications, MLCCs need to provide higher capacitance values, requiring innovative materials and structural designs.

High Voltage: Some applications require MLCCs to withstand high voltages, necessitating improvements in ceramic dielectric insulation strength and electrode electric field distribution design.

Reliability: MLCCs are sensitive to environmental factors such as temperature, humidity, and vibration, requiring higher reliability design and testing.

Cost: Competitive costs are required for mass production of MLCCs.

 

III. Flexible Termination Capacitors

A. Understanding Flexible Termination Capacitors

Flexible termination MLCCs are a special type of chip capacitor with flexible connection terminals among multilayer ceramic capacitors. Traditional chip capacitors use rigid terminals, while flexible termination capacitors use flexible materials with conductivity as connection terminals, providing better mechanical reliability and vibration resistance for capacitors.

 

B. Key Features and Specifications

Soft-headed capacitors, also known as low-voltage drop capacitors, have a different production process from ordinary capacitors. The end electrode production of soft-headed capacitors is coated with a layer of flexible end electrode paste on the copper layer of the capacitor ceramic body. Therefore, compared with ordinary capacitors, soft-headed capacitors have better mechanical stress and impact resistance. They can maintain their performance and quality even under bending, flexing, and deformation, protecting capacitors from damage.

 

C. Practical Applications

Conventional MLCCs have poor bend resistance. During surface mounting processes, electronic circuit board deformation due to wave soldering or reflow soldering subjects MLCCs to thermal shock and mechanical deformation stress, causing cracks. Soft-headed MLCCs are the optimal solution for addressing MLCC stress fractures. Their special high reliability, good anti-mechanical stress, and thermal shock resistance can effectively prevent cracks caused by vibration, suitable for electronic circuits with high mechanical stress and intense vibration, thereby mainly used in high-security and high-reliability design circuits.

D. Comparison with Traditional Capacitors

Traditional capacitors typically use rigid materials as terminals, while flexible termination capacitors use flexible materials such as polymers or elastic materials. This design makes flexible termination capacitors more resilient in dealing with thermal expansion and mechanical stress, thereby improving reliability and durability. Flexible termination capacitors also help reduce stress concentration, contributing to lower failure rates. However, compared to traditional capacitors, flexible termination capacitors typically have higher costs and may have performance limitations in high-frequency or high-power applications. When choosing capacitors, it is necessary to weigh their advantages and disadvantages based on specific application requirements.

 

E. Future Trends and Developments

Stretchable supercapacitors have high mechanical flexibility, maintaining structural integrity and high conductivity even under complex mechanical deformations such as bending and stretching. They can serve as energy storage devices for new wearable electronic devices and flexible bionic devices. With the outbreak of flexible electronic products, new types of supercapacitors have significant market potential, and related companies are expected to benefit.

The distribution network has a wide area, diverse users, complex loads, insufficient reactive power compensation in the distribution network, high failure rate of reactive power compensation devices, difficult maintenance, large active losses, and large switching surge currents. Strengthening and improving the reactive power compensation status of the distribution network is of great significance for reducing losses and improving voltage quality.