1. Foreword and Abstract

In the fields of power electronics and high-voltage engineering, the supply chain stability of passive components often determines the lifecycle of entire equipment. In 2018, Murata Manufacturing Co., Ltd., a global giant in passive components, officially announced the discontinuation of its High Voltage Ceramic Capacitors product line. This strategic adjustment primarily affected core series such as DHS, DHR, DHK, DHB, and DHC, covering a voltage range from 2kV to 50kV.

For global manufacturers of high-end medical imaging equipment (CT/X-Ray), industrial non-destructive testing (NDT), high-power lasers, and high-voltage power supplies, Murata's exit was undoubtedly a "grey rhino" event for the supply chain. Finding an alternative that achieves Pin-to-Pin compatibility in electrical performance, mechanical dimensions, safety certifications, and long-term reliability became an urgent priority for engineering and procurement departments.

• HVC Capacitor, with decades of deep expertise in high-voltage passive components, has launched a complete alternative solution for Murata's discontinued series. This white paper will detail how HVC Capacitors, utilizing independently developed N4700 (Class I) ceramic dielectric technology, not only fills the market gap left by Murata but also achieves technological superiority in voltage ratings (extended to 100kV) and high-frequency loss control, from the perspectives of material science, manufacturing processes, electrical characteristic benchmarking, and practical applications.

1. Industry Background: Murata Discontinuation and Supply Chain Restructuring

2.1 Market Logic Behind the Discontinuation

Murata's discontinuation was not a sudden event but based on a shift in its global strategic focus. With the explosion of the electric vehicle (EV) and 5G communication markets, the demand for MLCCs (Multilayer Ceramic Capacitors) has grown exponentially. In contrast, high-voltage through-hole ceramic capacitors, while technically demanding, have relatively vertical application areas (primarily concentrated in medical and industrial high-voltage sources), belonging to a typical "high-tech, low-turnover" market. To optimize its production capacity structure, Murata decided to divest this non-core business.

2.2 Key Application Areas Affected

This discontinuation primarily impacted manufacturers of the following long-lifecycle equipment:

• Medical Imaging Systems: CT machines and DR (Digital Radiography) equipment from brands like Philips, GE, and Siemens, whose high-voltage generators (HV Generator) heavily rely on Murata's DHS bolt-type capacitors in their voltage multiplier circuits.
• Semiconductor Manufacturing Equipment: High-voltage power modules in ion implanters and electron beam lithography machines.
• Industrial Inspection and Security: Airport security X-ray machines, industrial flaw detectors.
• Frontier Physics Research: Particle accelerators, strong magnetic field generators, and other scientific research devices.

These devices typically require stringent certifications such as FDA, UL, and CE. Replacing critical components means a lengthy re-validation cycle. Therefore, the "in-situ replacement capability" of alternatives is crucial.

1. HVC Capacitor: From "Replacer" to "Transcender"

Since 2018, HVC Capacitor has established a dedicated Replacement Engineering Dept to provide seamless solutions for global customers.

3.1 Core Material Breakthrough: In-depth Analysis of N4700 Ceramic Dielectric

In ceramic capacitors, the dielectric material determines the soul of the product. Murata's high-voltage products were classic because they used a special strontium titanate-based material. Many low-end alternatives on the market use inexpensive Y5T or Y5U (Class II) dielectrics, which, while capable of achieving high capacitance values, suffer from extremely high dielectric loss (Dissipation Factor) under high frequency and high voltage, easily leading to capacitor heating and breakdown.

HVC insists on using N4700 (Class I) ceramic formulation, which is equivalent to or even superior to Murata's. According to test data from HVC laboratories and third-party authoritative institutions, N4700 material offers three major physical advantages:

1. Extremely Low Dissipation Factor (tanδ):

• Common Y5T material: tanδ ≈ 1.0%
• HVC N4700 material: tanδ < 0.2%
• Engineering Value: In the high-frequency voltage multiplier circuits of X-ray machines (typically operating at 20kHz-100kHz), low loss means extremely low self-heating of the capacitor. This is crucial for capacitors encapsulated in sealed oil tanks filled with insulating oil, as the oil tank has limited heat dissipation capacity, and thermal runaway is a major cause of equipment downtime.

1. Excellent Voltage Coefficient of Capacitance:

• Class II dielectrics experience a significant drop in capacitance when a DC bias voltage is applied (DC Bias aging).
• N4700 dielectric exhibits minimal capacitance change rate across the full rated voltage, ensuring the stability of high-voltage power supply output waveforms.

1. No Piezoelectric Effect:

• N4700 belongs to paraelectric phase materials and does not exhibit a significant piezoelectric effect. This means that during high-frequency pulse operation, the capacitor will not generate mechanical vibrations or audible noise, thereby avoiding the generation of internal micro-cracks and significantly extending its service life.

3.2 Manufacturing Capability Leap: 100kV Technical Threshold

Murata's original product line typically topped out at 50kV. HVC, through special internal series construction and unique encapsulation processes, has successfully extended the voltage withstand boundary of ceramic capacitors to 100kV and even higher.

This capability allows HVC not only to replace Murata's existing 20kV, 30kV, 40kV products but also to provide technical support for next-generation ultra-high voltage industrial CT (160kV+) and pulsed power systems, a domain unattainable by the original manufacturer's products.

1. Alternative Solution Details and Process Specifics

HVC's alternative solutions cover two main categories: lead-type (DHR series) and bolt-type (DHS series), ensuring dual compatibility in mechanical dimensions and electrical performance.

4.1 Engineering-Grade Replacement for DHS Series (Bolt-type/Doorknob)

Murata's DHS series (e.g., DHS4E4G202KT2B) is a core component of medical CT machines. HVC adopts the same "doorknob" structural design.

• Terminal Process: HVC offers multiple thread options, including metric (M4/M5/M6) and imperial (UNF 10-32). The terminal material uses high-conductivity silver-plated copper, ensuring low contact resistance under high current.
• Encapsulation Material: High-density epoxy resin is used, applied through a vacuum potting process to eliminate air voids, ensuring no surface creepage occurs in high humidity or oil-immersed environments.
• Customized Dimensions: In addition to standard diameters of 20mm, 30mm, 38mm, and 60mm, HVC can customize special ultra-thin or elongated dimensions according to customers' narrow installation spaces.

4.2 General Replacement for DHR Series (Lead-type/Radial Lead)

Murata's DHR series is widely used in various small to medium power high-voltage modules.

• Lead Pitch: HVC offers various standard pitches such as 7.5mm, 9.5mm, 10mm, 12.5mm, perfectly matching the original PCB hole positions, eliminating the need for board redesign.
• Lead Forming: Provides various forming services, including straight leads, cut leads, and outward bent leads.

1. Detailed Model Cross Reference Guide

To facilitate quick selection for engineers, HVC has established a comprehensive database. Below is a selection of frequently replaced models:

5.1 Bolt-type (DHS Series) Replacement Cross Reference Table

• Main applications: CT machines, X-ray machines, high-power lasers

5.2 Lead-type (DHR Series) Replacement Cross Reference Table

• Main applications: Handheld flaw detectors, electrostatic spraying, negative ion generators

Note: In HVC models, DL stands for N4700 material, DP for Y5P material, and E for Z5U material; F value represents lead pitch.

1. Quality Control and Market Validation

6.1 Rigorous Testing Procedures

To ensure reliability after replacing Murata, HVC implements QA processes even more stringent than industry standards:

• Partial Discharge Test: Ensures no internal micro-discharges under high voltage, which is crucial for the lifespan of N4700 high-voltage capacitors.
• X-Ray Inspection: Checks the internal electrode structure and the bonding of the ceramic dielectric, eliminating hidden cracks.
• Oil Immersion Withstand Voltage Test: Simulates CT machine oil tank conditions, conducting long-duration aging tests at 1.5 times the rated voltage.

6.2 Endorsement from Top Global Customers

HVC's alternative solutions have been validated and mass-produced by numerous Fortune 500 companies worldwide:

• Medical Field: In CT and X-ray machine projects for GE Healthcare, Philips, Siemens Healthineers, and leading domestic medical imaging companies, HVC has become a qualified supplier for their high-voltage generator core components.
• Industrial Field: Japanese companies such as Nikon (industrial CT), Konica Minolta, and Shimadzu have also begun integrating HVC products into their supply chains to address the risks posed by Murata's discontinuation.
• Energy and Research: ABB's smart grid protection equipment and various university physics laboratories extensively use HVC's ultra-high voltage capacitors.

Most Inquiry Alternative Items

For Murata End-of-Life (EOL) items, inquiry for HVC's Part Number and datasheet/quotation/sample:

DHR Series Cross Reference

DHS Series Cross Reference

1. Conclusion

While the discontinuation of Murata's high-voltage ceramic capacitors brought short-term turbulence to the global supply chain, it also provided an opportunity for equipment manufacturers to review supply chain security and optimize component selection.

• HVC Capacitor, with its profound understanding of N4700 ceramic dielectric technology, 100kV+ manufacturing capability, and full range of Pin-to-Pin alternative solutions, has undeniably become the most authoritative successor in this field after Murata's discontinuation. We offer not just a capacitor, but a complete high-voltage engineering solution encompassing selection consultation, customized design, and failure analysis.

1. Contact and Technical Support

If you are looking for alternatives to Murata's discontinued series, or have any needs regarding high-voltage capacitor selection or customization, HVC's replacement engineering team is ready to provide support.

• Business Inquiry Email: sales@hv-caps.com">sales@hv-caps.com
• Official Website: www.hv-caps.com

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