How are the micro-pores on the atomizing plate formed，Punching is one of the core processes in the production of atomizing sheets, focusing on high-precision micro-hole machining of piezoelectric ceramic substrates. The mainstream processes include laser drilling (the industry mainstream), ultrasonic drilling, and chemical etching. Among them, laser drilling has become the preferred choice for mass production of civilian/industrial atomizing sheets due to its advantages in precision, efficiency, and consistency. Different processes are suitable for different hole diameters, materials, and mass production requirements. The following are detailed principles, operational processes, and applicable scenarios for each process. Additionally, the core technical requirements for atomizing sheet punching are supplemented:
1. Mainstream process: laser drilling (adopted by over 90% of mass-produced atomizing chips)
The micropore diameter of atomizing plates typically ranges from 0.08 to 0.5mm (micrometer level). Laser drilling can achieve submicron-level precision and is compatible with composite materials consisting of piezoelectric ceramics (ceramic substrates) and metal electrodes, making it a core solution for mass production.
Core principle
Utilizing high-energy-density laser beams (commonly CO₂ lasers, ultraviolet UV lasers, and femtosecond lasers) focused on the surface of the atomized substrate, the ceramic/metal materials at the focal point are instantly melted, vaporized, or even directly peeled off through photothermal/photochemical effects, forming micropores. This process, coupled with a precision motion platform, enables automated drilling of arrayed micropores.
Key operational procedures
Substrate pretreatment: Clean and secure the polished piezoelectric ceramic substrate (with silver/gold electrodes plated) on a precision fixture table, ensuring no offset;
Parameter calibration: Based on the aperture size (e.g. 0.1mm), thickness (0.1~0.3mm), and material of the atomizing plate, adjust the laser power, focusing distance, drilling speed, and pulse frequency;
Array drilling: The laser head/worktable is controlled by a numerical control system to perform high-precision XY-axis movement, drilling point by point according to a preset micro-hole array (such as circular, honeycomb shape). Some equipment supports simultaneous drilling with multiple beams, enhancing mass production efficiency;
Post-processing: After drilling, remove the laser ablation residue on the substrate surface (by sandblasting or ultrasonic cleaning), and inspect the micropores for burrs and hole diameter deviations.
Segmentation types and adaptation
Ultraviolet (UV) laser: suitable for small apertures (≤0.2mm) in atomizing plates (such as electronic atomization and medical atomization), with minimal heat-affected zone, smooth edges of micro-holes, and no risk of ceramic cracking;
CO₂ laser: suitable for industrial atomizing discs with slightly larger apertures (0.2~0.5mm) (such as humidifiers and aromatherapy machines), with high drilling efficiency and low cost;
Femtosecond laser: compatible with ultra-high precision atomizing plates (such as precision medical atomization), with almost no thermal damage, and a hole diameter precision of up to ±0.005mm, exclusively for high-end customization scenarios.
II. Traditional Craftsmanship: Ultrasonic Drilling (Suitable for Thick Substrates / Low-Precision Mass Production)
It belongs to the category of mechanical processing, utilizing high-frequency vibration from ultrasonic waves to achieve micro-crushing of materials. It is suitable for atomizing sheets with a hole diameter of ≥0.3mm and thicker ceramic substrates. The cost is low, but the precision and efficiency are lower than those of laser drilling.
Core principle
The ultrasonic transducer converts electrical energy into high-frequency mechanical vibrations ranging from 15 to 60 kHz, which are transmitted to the drilling grinding head (embedded with diamond micro-powder). The grinding head performs feed motion while vibrating, gradually removing ceramic material through the impact and grinding of the diamond micro-powder, forming micro-holes.
Characteristics
Advantages: Low equipment cost, capable of processing thicker piezoelectric ceramic substrates (≥0.5mm), and no thermal damage;
Disadvantages: Micro-holes are prone to burrs at the edges, have low hole diameter accuracy (±0.02mm), slow drilling speed, and are not suitable for mass production of small-diameter arrays.