Problem

A Russian medical device manufacturer producing continuous glucose monitoring (CGM) sensors needed reliable, repeatable coating of bio‑compatible fluids on sensor substrates. The process required fine linear deposits—0.3mm width with 3mm and 5mm lengths—to form protective hydrophilic/hydrophobic tracks and fluidic channels. Manual dispensing caused glue-width variation, inconsistent line mass, and occasional contamination, undermining sensor sensitivity and increasing lot rework.

Cause

Variability stemmed from operator-dependent dispensing, uncontrolled fluid temperature/viscosity, and limited motion resolution on legacy equipment. Small deviations in nozzle height or speed produced significant changes in line width and volume for micro-scale deposits. Lack of inline measurement and closed‑loop control prevented early detection of drift, leading to downstream electrical and biofunctional failures.

Solution: FS600A Inline Visual Dam & Fill Dispensing Machine

Mingseal deployed the FS600A configured for CGM coating using piezoelectric jet valves and an inline vision‑guided closed‑loop process. Key system selections and process controls included:

• Piezo valve micro‑dosing: Fast, repeatable pulses produced clean 0.3 mm line widths at both 3 mm and 5 mm lengths with minimal stringing and satellite droplets.
• High‑precision motion: ±10 μm repeatability and high acceleration motion ensured stable nozzle trajectory and consistent start/stop placement for micro‑lines.
• Real‑time vision metrology: Dual cameras measured line width and bead height immediately after dispense; automatic path correction adjusted XY/Z offsets to maintain geometry within tolerance.
• Thermal and fluid management: Syringe heating and environmental control stabilized viscosity for bio‑fluids sensitive to temperature, preserving dose consistency across multi‑hour runs.
• Closed‑loop weighing (optional): 0.1 mg resolution weighing verified deposited mass when required for traceability in medical production.
• Dam & Fill program adaptation: Although CGM coating is line-based rather than dam/fill, the FS600A’s inline measurement and path-correction algorithms used in Dam creation were adapted to control continuous micro‑tracks with KOZ protection and edge avoidance.

Integration and Process Flow

The FS600A was integrated into the customer’s cleanline with automated carriers and MES connectivity for recipe management and traceability. Typical cycle:

• Auto-load and fiducial recognition by dual cameras.
• Dynamic Z‑map compensation for carrier flatness and micro-warp.
• Piezo micro-dispense: programmed for 0.3×3 mm or 0.3×5 mm lines, using pulse width and frequency tuned to fluid rheology.
• Immediate vision AOI measures width and continuity; closed-loop feedback adjusts nozzle height, dispense pulse or robot speed for subsequent parts.
• Data logged to MES for SPC and batch release.

Results

• Line geometry control: Width variance reduced to ±5% and length tolerance met within ±0.1 mm, ensuring uniform fluidic channel behavior across lots.
• Mass consistency: With closed-loop metering and optional weighing, shot-to-shot mass variance dropped below 3%, supporting regulatory traceability.
• Yield improvement: First-pass yield increased significantly as defects from over‑apply, stringing, and misplacement were eliminated.
• Throughput: Dual‑valve operation and optimized motion profiles maintained production throughput without sacrificing precision.
• Contamination control: Enclosed, vision‑guided handling reduced particle deposition risk, crucial for medical sensor reliability.

Recommendations

1. Lock syringe temperature and piezo pulse recipes per fluid lot and store in MES to prevent drift.
2. Use vision AOI thresholds tied to functional testing (sensitivity/responsiveness) to close the quality loop.
3. Schedule predictive maintenance for piezo valves based on shot counts and weight-drift metrics.

Conclusion 

For Russian CGM sensor production, the FS600A provides an industry‑ready solution that converts manual micro‑dispense tasks into a controlled, traceable inline process. By combining piezo micro‑dosing, high‑precision motion, and closed‑loop vision metrology, FS600A meets stringent bio‑coating requirements for 0.3×3 mm and 0.3×5 mm lines—improving yield, consistency, and regulatory readiness. Contact Mingseal for pilot trials and process qualification tailored to your bio‑fluid formulations.