Introduction
In modern electronics, automotive, and semiconductor manufacturing, precision dispensing is no longer a luxury — it’s a necessity. Whether applying adhesives, epoxy, or silicone, even a minor deviation in dispensing position can lead to product defects, rework, or yield loss.

So, how do high-end dispensing systems ensure such high accuracy?

The answer lies in vision positioning technology — a powerful integration of CCD imaging, mark point alignment, laser-based focus control, and post-dispensing inspection (AOI).

This article explains how vision technology works in dispensing equipment and why it's critical for industries that demand micro-level precision.

1. CCD Vision System: High-Resolution Target Recognition
Most advanced dispensing machines are equipped with industrial-grade CCD cameras that capture high-resolution images of the target area.

The system identifies key features like PCB pads, chip edges, or connector outlines.

Image processing algorithms analyze the captured frame to locate the exact point where adhesive needs to be dispensed.

🛠 Example:
In smartphone mainboard assembly, components are often placed within microns of each other. Manual or purely mechanical alignment simply isn't precise enough. With CCD vision, the machine detects the real-time position of every part and dynamically corrects the dispensing path.

2. Mark Point Recognition & XY Correction
Components are never perfectly placed — even in automated lines. Mark points (fiducials) are added to PCBs or parts to help systems align precisely.

The vision system quickly detects the mark points and calculates any XY deviation.

This allows the system to automatically adjust its path, compensating for mounting or fixturing errors.

📐 Example:
In flexible circuit (FPC) modules like camera assemblies, FPCs often shift slightly due to bending. The mark point helps realign the path even if the surface isn’t in the original program position.

3. Laser Focus & Z-Axis Adjustment: Consistent Height Control
Pointing glue too close or too far from the surface causes problems — from too much adhesive to messy stringing. A stable Z-axis distance is critical.

Laser sensors or autofocus modules scan the surface height in real-time.

The dispensing head automatically adjusts vertically (Z-axis) to maintain optimal gap.

🔍 Use case:
Power modules may have components at different heights. The vision system measures each area and ensures the needle adjusts accordingly — maintaining consistent bead thickness and shape.

4. Post-Dispensing Inspection (AOI): Closed-Loop Quality Assurance
Advanced systems don’t just dispense — they inspect. After dispensing, the vision system can perform AOI (Automated Optical Inspection) to detect:

Misaligned dispensing

Underfill or missing glue

Overfill or overflow

Glue shape irregularities (stringing, blob defects)

⚠️ Quality Assurance Example:
In LED strip production, missing glue on one module may lead to short circuits. AOI cameras detect such issues before curing, flagging the unit for review or rework — saving costs downstream.

5. Summary: Why Vision Positioning is a Must-Have
Integrating vision positioning into dispensing machines offers these major benefits:

✅ Precision within ±10μm, even on complex geometries
✅ Adapts to inconsistent part placement and heights
✅ Enables full automation and reduces need for operator intervention
✅ Supports high-throughput, error-free manufacturing

Final Thoughts
Vision positioning is no longer a luxury feature — it's a core requirement for any manufacturer dealing with fine-pitch PCBs, micro-electronics, or complex 3D surfaces. Whether you're building smartphones, LED modules, EV control boards, or medical devices, vision-enabled dispensing is your gateway to zero-defect production.