Table of Contents
Assignment background
In recent years, the cover glass bonding process has become a critical step in determining the optical performance and reliability of smart devices and in-vehicle cameras equipped with image sensors. In particular, adhesive application has presented the following challenges:
- The difficulty of applying ultra-fine lines in extremely narrow spaces
The space around the sensor was extremely narrow, and the existing equipment was unable to apply thin, stable lines, resulting in overflow of the liquid and uneven film thickness. - Effect of variations in adhesive thickness and width on optical performance
If the adhesive layer becomes too thick due to uneven application, it can affect the refraction and transmittance of light, potentially causing degradation of image quality and aberration in the image sensor. - Poor curing due to insufficient UV adhesive exposure
If the application was inaccurate, the curing light would reach the adhesive unevenly, which could lead to unstable adhesive strength and increased risk of peeling.
Benefits
The combination of the high-precision vision dispensing system “AXELIA” and the needle valve “SV59MD” that handles ultra-small amounts has resulted in the following benefits:
- Accurate position recognition and ultra-fine line application
The high-resolution camera and automatic correction function of AXELIA accurately captures the reference point and stabilizes the setting of the dispensing position, making it possible to accurately apply UV adhesive even to extremely small areas. - Stable micro-dispensing in units of 1 nanoliter
By controlling the volume of the two liquids separately and mixing them at a fixed ratio just before the nozzle, it is now possible to maintain the ideal mixture ratio without being affected by temperature or pressure. - Successfully achieving both optical performance and adhesive strength
This eliminates overflow of the liquid and uneven thickness, improving the efficiency of UV light irradiation, and as a result, the bonding quality between the sensor and cover glass and the optical performance are stabilized at the same time.
Introduced products
Needle valve for ultra-fine dispensing SV59MD
A high-precision valve capable of stable dispensing of ultra-small amounts of liquid.
- Stable discharge down to 1nL
- No dripping and high precision shutoff
- Equipped with calibration function

High-precision automatic vision dispensing system AXELIA
A fully automatic dispensing platform with excellent visibility and operability.
- Accurate position correction and reference point recognition function
- High repeatability of the discharge point position

