I. Overview
NHR-5400 Series 60-segment AI Temperature Controller was used to upgrade the temperature control system of the single crystal furnace, replacing the imported temperature controller. This renovation achieved:

Multi-segment program temperature rise accuracy reached ±0.5°C (up to 59 segments).

18 months of continuous operation with zero downtime.

30% cost reduction compared to the previous imported solution.

KKPCB provided key PCB redesign and system integration support to ensure seamless compatibility with existing thyristor modules and safety circuits.

II. Customer Challenges
Background:
The customer uses a CZ single crystal furnace for HgCdTe crystal growth, and its temperature stability directly affects the crystal quality. Problems faced by the existing controller:

Inflexible programming: limited to 20 curve segments, insufficient to cope with complex crystal growth curves.

Frequent calibration drift: manual adjustment is required every week.

High maintenance cost: imported spare parts with 8-week lead time.

KKPCB’s solution:

Recommended NHR-5400 with its 59-segment PID control and AI self-tuning functions.

Redesigned the thyristor interface PCB to make it compatible with the existing system.

III. Technical implementation

1. Hardware modification (KKPCB lead)

Thyristor interface circuit:

Added 1kΩ current-to-voltage converter (0-10mA → 0-10V) to be compatible with the MJYD-JL-75 module.

Used a 4-layer PCB with an isolated ground plane to reduce EMI by 15dB.

Protection circuit optimization:

Upgraded RC snubber (RSV) to withstand 450V/75A surge.

Replaced L1 fuse with a fast-blow PPTC device.

2. Software Configuration
   Process curve programming:

Plain text
SV01=25.0°C → TI01=60 minutes
SV02=255.0°C → TI02=120 minutes (hold)
…
SV12=355.0°C → TI12=600 minutes
AI-PID regulation:

Automatically adjust parameters during the temperature rise phase (e.g., 25°C→255°C).

Fix PID values ​​during the hold period (e.g., 825°C ±0.5°C for more than 6,000 minutes).

3. Key Performance Indicators
   Parameters Before Retrofit After Retrofit
   Temperature Stability ±2.0°C ±0.5°C
   Calibration Interval Weekly Never (AI Self-Tuning)
   Mean Time Between Failures (MTBF) 6 months >24 months
   IV. KKPCB’s Value Proposition
   Cost Effectiveness:

Import tariffs were eliminated, and unit cost was reduced from
1,200 to 850.

Rapid Deployment:

Turnkey solution delivered in 4 weeks (12 weeks for OEM replacement).

Future-proof Design:

RS-485/CAN ports are reserved for IIoT integration.

V. Customer Benefits
Crystal Yield Improvement: Defective rate reduced from 8% to 2.5%.

Energy Saving: Furnace power consumption reduced by 12% due to precise control.

Local Support: KKPCB provides 2-hour response time for technical issues.

Conclusion
The NHR-5400 retrofit demonstrates KKPCB’s capabilities to:

Modernize legacy industrial systems with AI-enhanced controllers.

Finish compatibility gaps between new electronics and existing power modules.

Achieve measurable ROI within 6 months of deployment.

Project Number: KKPCB-INDT-2024-MCF01
Contact: [email protected] | +86-177-4855-1367

“KKPCB’s redesign enabled us to upgrade the control system without replacing the entire power module infrastructure – a game changer for cost-sensitive crystal growth applications.”