In the manufacturing fields of semiconductor chips, display panels, optical devices, etc., a thin film with uniform thickness and stable performance is often the key to determining the success or failure of the product. The core equipment for achieving this critical step is the Spin Coater, known as the "film wizard". It uses precise control of centrifugal force to transform liquid photoresist, polymers, metal sol and other materials into high-quality thin films at the micrometer or even nanometer level, and is the core equipment in micro nano processing.

1、 Core working principle: "Thin film dance" under centrifugal force

The working principle of the glue homogenizer is based on classical fluid mechanics and centrifugal force effects, and the entire process can be summarized into four continuous and precise stages:

1. Dispensing: Drop a certain amount of liquid glue (such as photoresist) onto the central area of a high-speed rotating substrate (such as silicon wafer, glass). The key to this step lies in the amount and position of the glue, which directly affects the uniformity and edge effect of the final film.

2. Spin up: The substrate begins to rotate at a lower speed (usually 500-1000rpm). Centrifugal force causes the glue to slowly flow from the center to the edge, initially covering the entire surface of the substrate, in order to avoid splashing of the glue and insufficient glue in the central area during high-speed start-up.

3. Spin off: This is the core stage that determines the thickness of the film. The substrate is instantly raised to the set high speed (usually 1000-10000rpm) and maintained for a period of time. The strong centrifugal force "throws" excess glue out of the substrate, and at the same time, the solvent in the glue begins to evaporate. The final thickness of the film is mainly determined by the rotation speed and rotation time. The faster the speed and the longer the time, the thinner the film.

4. Drying: In the later stage of high-speed homogenization or a separate drying step, the substrate is maintained at a certain speed or stationary, allowing residual solvents in the film to fully evaporate, forming a structurally stable and uniformly thick solid film, which prepares for subsequent photolithography, etching, and other processes.

2、 Key technical indicator: a ruler for measuring the accuracy of 'magic'

To evaluate the performance of a glue homogenizer, the following core technical indicators should be considered:

-Speed range and accuracy: These are the core indicators. The speed range determines the thickness range of the thin film that can be prepared, and the speed accuracy (usually requiring ± 1rpm) directly determines the thickness uniformity of the thin film. The speed range of the glue homogenizer can cover from tens of revolutions to tens of thousands of revolutions.

-Uniformity of film thickness: The gold standard for measuring film quality, usually expressed as a percentage (such as ± 1%). It refers to the maximum deviation of film thickness measured at different positions on the same substrate. In semiconductor manufacturing, the requirements for this indicator are extremely strict.

-Substrate size compatibility: refers to the range of substrate diameters or sizes that the device can handle, from small substrates of a few millimeters to semiconductor wafers of 300 millimeters or even larger, with huge differences in requirements for different application scenarios.

-Control and automation level: Modern glue homogenizers are generally equipped with high-precision PLC or computer control systems, which can achieve precise programming and storage of parameters such as speed, time, and dispensing volume, support automated loading and unloading, and meet the requirements of large-scale production and process repeatability.

3、 Wide range of application areas: from chips to biomedicine

The application of glue homogenizers has already surpassed the traditional semiconductor industry and penetrated into multiple high-precision and cutting-edge fields:

-Semiconductors and Microelectronics: This is the main application area of the homogenizer, which is used to coat photoresist on silicon wafers. It is a key pre step in the photolithography process and directly determines the graphic accuracy of the chip.

-Flat Panel Display (FPD): Used in the manufacturing of display panels such as TFT-LCD and OLED to coat functional thin films such as alignment films, color filters, and organic light-emitting layers.

-Optical components: used to prepare anti reflective films, reflective films, filter films, etc. for optical lenses, to enhance the performance of optical components.

-MEMS and Sensors: Used in the manufacturing of microelectromechanical systems (MEMS) and various sensors such as pressure sensors and biosensors to construct microstructures and functionally sensitive layers.

-Biomedical: In the preparation of biochips and microfluidic chips, it is used to coat bioactive substances or functional polymer films, providing a platform for biological detection and analysis.

In summary, as a key equipment for converting "liquids" into "precision films", the technical level of the glue homogenizer directly restricts the development of downstream manufacturing industries. From the chips that drive Moore's Law to the screens we use on our phones in daily life, the precise control of this' film magician 'is indispensable behind everything.