Application Background
In chip encapsulation processes, dispensing height directly affects bonding strength, heat dissipation, and reliability. Traditional contact measurement can damage the glue surface and cannot adapt to high-speed production lines. The ST-P series laser displacement sensor uses laser triangulation for non-contact measurement, enabling real-time detection of dispensing height and glue path profile, suitable for semiconductor packaging, wafer processing, and more.
Product Principle and Selection
The ST-P series laser displacement sensor operates on the laser triangulation principle, calculating displacement by detecting the position change of the reflected light spot on a CMOS or PSD receiver. For dispensing height detection, select the model based on installation distance and accuracy requirements:
- ST-P25: Reference distance 25mm, measurement range ±1mm, repeatability 0.05μm, linearity error < ±0.6μm, suitable for micro glue dot height detection.
- ST-P30: Reference distance 30mm, measurement range ±5mm, repeatability 0.15μm, linearity error < ±3μm, suitable for standard dispensing height.
- ST-P50: Reference distance 50mm, measurement range ±10mm, repeatability 0.25μm, linearity error < ±4μm, balancing accuracy and range.
- ST-P80: Reference distance 80mm, measurement range ±15mm, repeatability 0.5μm, linearity error < ±6μm, ideal for larger glue path profiles.
- ST-P150: Reference distance 150mm, measurement range ±40mm, repeatability 1.2μm, linearity error < ±16μm, for long-distance detection.
Maximum sampling frequency up to 160kHz, supporting Ethernet, RS485, analog, and IO outputs, compatible with PLC or host computer.
Solution Recommendations
It is recommended to mount the sensor vertically behind or beside the dispensing needle to measure glue height. For transparent or highly reflective glue, adjust the installation angle or use a polarizing filter. Sample testing is advised to verify measurement stability.
Installation and Debugging Tips
- Ensure the sensor is perpendicular to the measurement surface to avoid tilt-induced errors.
- Secure the sensor to minimize vibration effects.
- Adjust laser power or exposure time based on glue color and transparency.
- Use Ethernet or RS485 for real-time data transmission; analog output can be connected to PLC for closed-loop control.
Common Issues
- Unstable measurement with transparent glue? Try tilting the sensor or adding a background light, or select a model from the ST-P series suitable for transparent materials (requires testing).
- Insufficient sampling in high-speed lines? The ST-P series offers up to 160kHz sampling rate to meet high-speed needs, but controller processing capability must be confirmed.
- Temperature drift affecting accuracy? The sensor has temperature compensation, but extreme environments may require additional calibration.
Summary
The ST-P series laser displacement sensor provides a non-contact, high-precision solution for chip encapsulation glue dispensing height detection. Selection should be based on specific installation distance, glue characteristics, and accuracy requirements, with sample testing recommended. Manual review is required to verify product models, parameters, application scenarios, and SEO information.