—— Solving Stability and Lead Time Challenges in Precision Instruments

• Release Date: March 2026
• Publisher: HVC Company Technical Center
• Reading Time: 12 minutes

1. Executive Summary

In the fields of global high-voltage power electronics, medical imaging (X-ray/CT), and precision testing equipment, High Voltage Thick Film Resistors are core passive components determining system measurement accuracy and long-term stability. Swiss NICROM (Nicrom Electronic), as a well-known manufacturer of high-voltage thick film resistors, is renowned for its applications in SF6/oil-immersed environments. However, recent supply chain data indicates that due to limited European production bases and complex raw material supplies, NICROM products often face delivery challenges with lead times as long as 16-24 weeks when meeting global delivery demands.

This white paper aims to analyze the fundamental technical causes of high-voltage resistor failure under extreme conditions and introduce the HVR series solution developed by HVC Company based on European ruthenium-based thick film technology. Through comparative testing and application cases, we will demonstrate why the HVC HVR series (including HVR-GFP, HVR-GXP, HVR-PFS series) can achieve 100% compatible replacement for similar NICROM products, enhancing long-term system reliability and procurement cost-effectiveness.

2. Industry Challenges: The "Invisible Killer" of High Voltage Resistors

In practical applications, our technical team has received extensive feedback from customers in Asia-Pacific, Europe, and America, primarily focusing on three major technical and commercial bottlenecks encountered when using NICROM products:

2.1 Resistance Drift Under High Temperature Load

High-voltage resistors often operate in sealed, high-heat oil tanks or gas-filled cabinets (SF6). Test data shows that under continuous load conditions with ambient temperatures ≥125°C, the resistance drift rate of some standard thick film products exceeds ±1.5%.

• Consequence: For Voltage Dividers and precision sampling circuits, a 1.5% drift means incorrect output voltage readings, potentially leading to imaging artifacts in medical equipment or malfunction of grid protection devices.
• Industry Standard: The typical drift standard for industrial-grade high-voltage resistors should be controlled within ±0.5%.

2.2 Voltage Coefficient (VCR) Induced Nonlinear Errors

In high-voltage applications, resistance value is not constant but decreases slightly as voltage increases (Voltage Coefficient of Resistance, VCR). If VCR is too large (> -5 ppm/V), it leads to nonlinear errors in high-voltage measurements.

• Challenge: Traditional thick film resistors often have less than ideal VCR performance at high voltages, limiting their application in high-end precision instruments.

2.3 Supply Chain Rigidity and Service Gaps

Lead times of 16-20 weeks for standard products and over 24 weeks for custom products, combined with an after-sales system lacking localized technical support, often leave customers in a passive state when facing sudden quality issues or capacity ramp-ups.

3. Technical Origins: Material Science Advantages of HVC HVR Series

The ability of the HVC HVR series to solve the above problems is not accidental but stems from strict control over the underlying material science of thick film processes. HVC inherits mature European thick film resistor manufacturing processes, solving stability problems at the microstructural level.

3.1 96% Alumina Ceramic Substrate

Unlike low-purity ceramics used in ordinary resistors, the entire HVC series uses 96% alumina substrates with high thermal conductivity.

• Technical Advantage: Excellent thermal conductivity ensures that resistors can dissipate heat rapidly during high-power operation, reducing "hot spot" temperatures, thereby physically suppressing resistance drift caused by heat accumulation.

3.2 Ruthenium-based Paste and 850°C High-Temperature Sintering Process

The stability of the resistor film layer depends on the paste formula and sintering curve.

• Ruthenium-based Paste: Compared to cheap carbon-based pastes, ruthenium-based materials have extremely low Voltage Coefficients (VCR) and Temperature Coefficients (TCR).
• 850°C Sintering: HVC employs a special high-temperature sintering process, forming a dense network structure of conductive particles and glass phase at the microscopic level. This structure maintains extremely high chemical and physical stability even under 150°C high temperature or high-voltage impact.

3.3 Unique Laser Trimming Technology

HVC adopts advanced "L-cut" or "Serpentine-cut" laser trimming path designs, effectively reducing Electric Field Concentration under high voltage, thereby enhancing the resistor's voltage withstand capability and pulse load capacity.

3.4 Nano-scale Thick Film Paste and IP65 Coating

HVC employs nano-scale thick film paste technology combined with IP65 protective coating, specifically optimized for high-humidity medical environments, ensuring long-term reliability in demanding conditions such as SF6/oil immersion.

4. In-Depth Comparison: HVC HVR Series vs. NICROM

Based on laboratory comparative tests and customer on-site feedback, we have conducted a multi-dimensional comparison between the HVC HVR series and corresponding NICROM products:

4.1 Performance Parameter Comparison

Key Parameter	NICROM (Standard Thick Film Product)	HVC HVR Series (HVC Solution)	Technical Evaluation
Resistance Drift (1000h @ 150℃)	±1.0% ~ ±2.0%	≤ ±0.5%	HVC stability improved 2-4 times, suitable for precision medical and metrology equipment.
Voltage Coefficient (VCR)	< -5 ppm/V	< -1 ppm/V	HVC provides superior linearity, reducing high-voltage measurement errors.
Breakdown Voltage Test	~ 80% of Rated Value	≥ 98% of Rated Value	HVC provides higher safety margin, especially in SF6/oil environments.
TCR Stability	±15 ~ ±100 ppm/°C	±15 ~ ±50 ppm/°C	HVC temperature coefficient control is more precise.
High Frequency Loss	Standard	≤ 0.02%	HVC low inductance design, suitable for high-frequency applications.
Size Compatibility	Standard	1:1 Drop-in Replacement	No need to modify PCB layout or mounting brackets, true "Drop-in Replacement".

4.2 Specification and Actual Performance Comparison

Example of high-voltage applications in SF6/oil-immersed environments:

Application Scenario	NICROM Product	HVC HVR Series	Technical Advantage
SF6/Oil-Immersed Environment (DC)	30kV DC Rated	30kV DC and Above	HVC measured breakdown voltage ≥98% of rated value, far exceeding NICROM's 80% level.
Air Environment (DC)	EBG SGP52: 15kV DC	HVR-GFP: 15kV+ DC	Power density increased by 10%, zero thermal drift at 25°C continuous operation.

4.3 Commercial and Service Comparison

Dimension	NICROM (Swiss)	HVC Company	Customer Benefit
Standard Product Lead Time	16-24 weeks	7-10 days (In Stock)	Supply chain flexibility increased by 90%, significantly reducing inventory capital occupation.
Custom Product Response	> 24 weeks	≤ 4 weeks	R&D iteration speed significantly accelerated.
Minimum Order Quantity	High	100 pieces minimum	Lower trial production threshold, supporting small batch multiple varieties.
Standard Model Inventory	Limited	> 95% inventory rate	Ensuring continuous supply, avoiding stockout risk.
Procurement Cost	European Benchmark Price	Reduced by 20% - 30%	Significant BOM cost optimization while maintaining performance.
Technical Support	Slow Response	24 hours (Asia-Pacific/Americas)	Providing full-process parameter matching and troubleshooting guidance.

5. Cross Reference Guide

The HVC HVR series has successfully replaced NICROM models in multiple international projects. The following is a direct replacement list for common NICROM high-voltage thick-film resistors:

(Note: For the complete cross-reference table, please contact HVC technical support)

HVR-GFP Series (Flat/Chip High Voltage Resistor)

• Corresponding NICROM Products: NICROM Flat Type High Voltage Thick Film Resistors
• Power Range: 0.125W - 5W
• Voltage Range: 50V - 5000V (Chip/Radial/Axial)
• Applications: Compact high-voltage modules, PCB space-constrained applications, replacement for EBG SGP series
• Technical Advantages: Extremely high power density, 10% higher power capacity than standard products, zero thermal drift at 25°C continuous operation

HVR-GXP Series (Cylindrical High Voltage Resistor)

• Corresponding NICROM Products: NICROM Cylindrical High Voltage Thick Film Resistors
• Power Range: Medium to high power
• Voltage Range: 5kV - 100kV
• Applications: X-ray machine high-voltage generators, high-voltage power supplies, pulse load circuits
• Technical Advantages: Enhanced pulse load capacity, vacuum deposition process, compliant with IEC 60068-2-6 vibration/shock standards

HVR-PFS Series (Precision High Voltage Resistor)

• Corresponding NICROM Products: NICROM Precision High Voltage Thick Film Resistors
• Power Range: Precision measurement grade
• Voltage Range: 5kV - 100kV
• Applications: High-voltage dividers, precision measurement equipment, medical imaging equipment feedback circuits
• Technical Advantages: Extremely low TCR (±15 ppm/°C), excellent long-term stability (>20,000 hours trouble-free operation)

HVRBSP Series (Special High Voltage Resistor)

• Corresponding NICROM Products: NICROM Special Application High Voltage Resistors
• Applications: SF6/oil-immersed environments, high-humidity medical environments, extreme industrial environments
• Technical Advantages: IP65 coating protection, nano-scale thick film paste, designed specifically for harsh environments

6. Application Cases

Case 1: High Voltage Measurement in SF6/Oil-Immersed Environments

Challenge: A medical equipment manufacturer using NICROM 30kV DC resistors found that after long-term operation in SF6/oil-immersed environments, the breakdown voltage degraded to 80% of the rated value, posing safety risks.

Solution: Switched to HVC HVRBSP series with nano-scale thick film paste + IP65 coating.

Results:

• Breakdown voltage stabilized at ≥98% of rated value
• Trouble-free operation for >20,000 hours
• Lead time shortened from 20 weeks to 2 weeks

Case 2: High Voltage Power Supply Feedback Circuit

Challenge: An industrial power supply customer using NICROM precision resistors faced lead times exceeding 16 weeks and cost pressures.

Solution: Direct replacement with HVC HVR-PFS series.

Results:

• Lead time shortened to 7-10 days
• Procurement cost reduced by 25%
• Performance indicators fully met design requirements

HVC High Voltage Thick Film Resistor Coding Rules

HVR-[Series]-[Size]-[Resistance]-[Tolerance]-[Power]-[Voltage]

Code	Description	Example
HVR	High Voltage Resistor Prefix	HVR-GFP-102-10M-F-0.5-5
GFP	Flat Economy Series	GFP=Economy Flat
GXP	Flat Standard Series	GXP=Standard Flat
BSP	Barrel Style Series	BSP=Barrel Style
Size	Length×Width(mm)	101, 102, 103, 104, 210
Resistance	Resistance Value	10M=10MΩ, 100M=100MΩ, 1G=1GΩ
Tolerance	Precision	F=±1%, J=±5%, K=±10%
Power	Rated Power(W)	0.25, 0.5, 1, 2, 3.5
Voltage	Working Voltage(kV)	1.5, 5, 10, 15, 25

Ordering Example: Replace 10M-5kV/1% → HVR-GFP-102-10M-F-0.5-5

Detailed Model Cross Reference Table

High Voltage Thick Film Resistors (Chip/Lead Type)

90 Series:

Nicrom Model	Power(W)	Voltage(kV)	A(mm)	B(mm)	C(mm)	Thickness(mm)	HVC Model
Nicrom 90.1	0.8	7	20.32	3.81	17.78	2	HVRGXP4.20
Nicrom 90.2	1.0	11	25.40	3.81	22.86	2	HVRGXP4.25
Nicrom 90.3	1.5	20	38.10	3.81	35.56	2	HVRGXP4.38
Nicrom 90.4	2.0	30	50.80	5.08	48.26	2	HVRGXP5.30

100 Series:

Nicrom Model	Power(W)	Voltage(kV)	A(mm)	B(mm)	C(mm)	Thickness(mm)	HVC Model
Nicrom 100.1	1.0	7	20.32	5.08	17.78	2.5	HVRGXP5.20
Nicrom 100.2	1.3	11	25.40	5.08	22.86	2.5	HVRGXP5.25
Nicrom 100.3	2.0	20	38.10	5.08	35.56	2.5	HVRGXP5.38
Nicrom 100.4	3.0	30	50.80	6.35	48.26	2.5	HVRGXP6.51

200 Series:

Nicrom Model	Power(W)	Voltage(kV)	A(mm)	B(mm)	C(mm)	Thickness(mm)	HVC Model
Nicrom 200.1	1.0	5	12.70	5.08	10.16	2	HVRGXP5.13
Nicrom 200.2	2.0	11	25.40	7.62	22.86	2.5	HVRGXP8.25
Nicrom 200.3	3.0	20	38.10	12.70	35.56	2.5	HVRGXP13.20
Nicrom 200.4	4.5	30	50.80	15.24	48.26	2.5	HVRGXP15.51
Nicrom 200.5	6.5	45	76.20	15.24	73.66	3	HVRGXP15.76
Nicrom 200.7	9.0	60	101.6	15.24	99.06	3	HVRGXP15.102

High Voltage Barrel Resistors

400 Series:

Nicrom Model	Power(W)	Voltage(kV)	A(mm)	B(mm)	HVC Model
Nicrom 400.2 / 400.2E	3.8	15	27	8	HVRBSP27
Nicrom 400.3 / 400.3E	5.0	21	37	8	HVRBSP37
Nicrom 400.4	6.5	26	45	-	HVRBSP45
Nicrom 400.5 / 400.5E	7.5	30	52	-	HVRBSP52
Nicrom 400.7 / 400.7E	10.0	45	77	-	HVRBSP77
Nicrom 400.10/400.10E	13.5	60	102	-	HVRBSP102
Nicrom 400.12/400.12E	16.0	72	122	-	HVRBSP122
Nicrom 400.15/400.15E	20.0	90	152	-	HVRBSP152

425 Series：

Nicrom Model	Power(W)	Voltage(kV)	A(mm)	B(mm)	HVC Model
Nicrom 425.2	2.0	8	27	8	HVRBSP27
Nicrom 425.3	3.0	12	37	8	HVRBSP37
Nicrom 425.4	3.5	14	45	8	HVRBSP45
Nicrom 425.5	4.0	17	52	8	HVRBSP52
Nicrom 425.7	6.0	25	77	8	HVRBSP77
Nicrom 425.10	8.0	35	102	8.3	HVRBSP102
Nicrom 425.12	10.0	40	122	8.5	HVRBSP122
Nicrom 425.15	12.0	50	152	8.5	HVRBSP152

MS400 Series：

Nicrom Model	Power(W)	Voltage(kV)	A(mm)	B(mm)	HVC Model
Nicrom MS400.2	6.0	5	27	8	HVRBSP27
Nicrom MS400.3	8.0	7	37	8	HVRBSP37
Nicrom MS400.4	10.0	8	45	8	HVRBSP45
Nicrom MS400.5	12.5	10	52	8	HVRBSP52
Nicrom MS400.7	15.0	15	77	8	HVRBSP77
Nicrom MS400.10	20.0	20	102	8.3	HVRBSP102
Nicrom MS400.12	24.0	24	122	8.5	HVRBSP122
Nicrom MS400.15	30.0	30	152	8.5	HVRBSP152

Note: P400 Series corresponds exactly to 400 Series in size and voltage; 480 Series has one-to-one correspondence with 400 Series.

High Voltage Power Resistors

Nicrom Model	Power(W)	Voltage(kV)	L(mm)	B(mm)	D(mm)	Thread	HVC Model
Nicrom 500.10 / MS500.10 / P500.10	15/23/15	35/12/35	81	14	13.5	M4	HVRPFS81
Nicrom 500.20 / MS500.20 / P500.20	25/38/25	80/27/80	156	14	13.5	M4	HVRPFS156
Nicrom 500.50 / MS500.50 / P500.50	55/83/55	70/23/70	158	31.5	30.5	M8	HVRPFS158
Nicrom 500.70 / MS500.70 / P500.70	75/113/75	100/33/100	208	31.5	30.5	M8	HVRPFS208
Nicrom 500.100/ MS500.100/ P500.100	110/165/110	150/50/150	308	31.5	30.5	M8	HVRPFS308

Conclusion

In the current situation where NICROM faces dual challenges in delivery capability and credit rating, continuing to use it as a single-source supplier will bring uncontrollable systemic risks to equipment manufacturers.

HVC HVR Series not only provides perfect physical size compatibility, but more importantly, it brings electrical specifications back to real, safe, and verifiable industry mainstream standards. HVC does not act as a "magician" with parameters, but only as a "guardian" of high-voltage circuits. For engineers and procurement managers seeking long-term stability and supply chain security, HVC is currently the best engineering-grade choice to replace NICROM.

Contact & Technical Support

The HVC sales and engineering teams are on standby to provide you with NICROM Replacement Cross Reference List, Free Samples, and Technical Consultation.

We are committed to providing free sample testing and factory-level technical support for all replacement projects, jointly promoting the continuous development of high-voltage technology.

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Copyright Notice: This document is copyrighted by HVC Capacitor. Unauthorized reproduction or commercial use is prohibited.
Disclaimer: The technical parameters in this document are for reference only; specific specifications are subject to the latest datasheet. NICROM mentioned herein is a registered trademark of its respective owner and is used solely for technical compatibility description.