Analysis of the entire process of MLCC capacitor manufacturing: from ceramic powder to chip level packaging

Multilayer ceramic chip capacitors (MLCC) have become core components in the fields of consumer electronics and automotive electronics due to their small size, large capacity, and high reliability. This article takes Murata Manufacturing's process route as an example to deeply analyze the 18 key processes in MLCC manufacturing.

1、 Raw material preparation: The 'magic' of nanoscale ceramic powder

The performance of MLCC begins with the formulation design of ceramic powder. The mainstream materials include:

BaTiO Ⅲ - based ceramics: dielectric constant up to 3000~6000, but dielectric loss needs to be reduced by doping Nb, Co and other elements.

X7R/X5R medium: with stable temperature characteristics, suitable for environments ranging from -55 ℃ to 125 ℃, commonly used for power decoupling.

C0G/NP0 medium: ultra-low loss (tan δ ≤ 0.0005), used for high-frequency signal coupling.

The preparation of ceramic powder requires ball milling, spray granulation and other processes to control the particle diameter within the range of 200~500nm to ensure the uniformity of tape casting film.

2、 Casting and Printing: Building Nanoscale 'Sandwich' Structures

Casting film: Ceramic slurry is coated onto a PET carrier tape using a scraper to form a green film with a thickness of 1-3 μ m.

Internal electrode printing: Using thick film screen printing technology, silver palladium alloy paste (Ag/Pd=70/30) is printed on the green film with a line width controlled within 1.5 μ m.

Stacking and laminating: Hundreds of layers of green film are alternately stacked with electrodes and pressed together by isostatic pressing (200MPa) to form a capacitor body.

3、 High temperature sintering and end electrode formation

Gluing and roasting: Organic binders are removed at 450 ℃, followed by sintering at 1300 ℃ to densify ceramic particles.

Chamfering and End Sealing: Expose the inner electrode through mechanical grinding, then seal and sinter it with copper paste to form an electrical connection.

Nickel plating and tin plating: Nickel plating (to prevent copper migration) and tin plating (to improve weldability) are sequentially applied to the surface of the terminal electrode, with thicknesses controlled at 3 μ m and 5 μ m, respectively.

4、 Quality Control: From Microscopic Defects to Reliability Verification

Microscopic examination: Use SEM to observe the ceramic grain size (≤ 0.5 μ m) and electrode continuity.

Electrical performance testing: Use LCR tester to screen parameters such as capacity, loss, insulation resistance, etc., with tolerance control within ± 5%.

Life test: Load for 1000 hours at 125 ℃ and rated voltage, and monitor the capacity decay rate (≤ 10%).

5、 Future Trends of MLCC

Ultra miniaturization: The 01005 size (0.4 × 0.2mm) MLCC has achieved mass production with a capacity of 0.1 μ F.

High capacitance: By increasing the number of layers (up to 2000) and using high dielectric constant materials, the single capacitance value exceeds 100 μ F.

Vehicle grade certification: AEC-Q200 standard requires MLCC to pass 1000 hours of testing at -55 ℃~150 ℃ and 500V surge voltage.

Conclusion: The manufacturing of MLCC is a perfect combination of nanotechnology and precision engineering, and the birth of every capacitor requires strict control from micro materials to macro performance. With the rise of emerging markets such as 5G and AIoT, MLCC is accelerating its iteration towards higher capacity, lower loss, and smaller size, continuously empowering the innovative development of the electronics industry.