Abstract

This white paper presents a comprehensive technical and supply chain comparison between the two major options in HV bolt terminal ceramic capacitors — the industry incumbent TDK and the emerging high-performance alternative HVC. We evaluate core technical parameters, product reliability, dimensional compatibility, and supply chain cost. The data shows HVC holds significant advantages in voltage range (10-150KV, wider coverage), maximum capacitance (8000pF vs 2100pF), environmental compliance (lead-free N4700), and delivery lead time (60% reduction).

1. Introduction

High-voltage bolt terminal ceramic capacitors are a specialized type of HV ceramic capacitor widely used in medical imaging (CT, X-ray), power transformers, industrial NDT equipment, laser power supplies, and scientific instruments. These components must operate reliably at tens of thousands of volts while maintaining ultra-low dissipation factor, excellent temperature stability, and long-term reliability.

TDK has over 40 years of experience in this field, with products spanning the UHV, FHV, and FD series. However, constrained by its Class 2 ceramic material system (Y5S/Z5T) and traditional single-chip structure, TDK's voltage ceiling sits at 50KV with a maximum capacitance of just 2100pF. Additionally, the Y5S dielectric contains lead (though RoHS-exempted), posing a potential risk as global environmental regulations tighten.

This white paper presents detailed comparative data to demonstrate how HVC delivers a more resilient solution without compromising performance.

2. Technical Background: Why Ceramic Material and HV Design Matter

2.1 Ceramic Dielectric Classification

The core performance of HV ceramic capacitors depends on dielectric material selection:

• Class 1 Ceramics (e.g. N4700, NP0): Lower dielectric constant but excellent temperature stability (near-linear TCC) and ultra-low dissipation factor (D.F. < 0.002), suitable for high-frequency resonant and precision applications.
• Class 2 Ceramics (e.g. Y5S, Z5T, Y5P): Higher dielectric constant but poorer temperature stability, with dissipation factor varying significantly with temperature and voltage. Y5S and similar leaded formulations can approach N4700 D.F. levels but fall under RoHS exemptions, raising long-term compliance uncertainty.

2.2 Technology Route Comparison

• TDK: Y5S/Z5T Class 2 ceramic + silver electrode + single-chip structure. Mature performance but leaded formulation, constrained by 60mm package mold limits.
• HVC: N4700 Class 1 ceramic + copper electrode + dual-chip series/parallel structure. Through material upgrade and structural innovation, HVC achieves performance metrics exceeding TDK at industrial-grade cost.

3. Core Technical Parameter Comparison

Parameter	TDK Spec	HVC Spec	Assessment
Voltage Range	20KV ~ 50KV	10KV ~ 150KV	HVC covers 3x range
Max Capacitance (Standard)	2100pF (50KV)	8000pF (50KV)	HVC 3.8x larger
Ceramic Material Type	Y5S, Z5T, Y5P (Class 2)	N4700 (Class 1)	HVC Class 1 more stable
Lead Content	Y5S contains lead (RoHS exempt)	Lead-free	HVC fully RoHS compliant
Electrode Process	Silver plating	Copper electrode plating	HVC superior migration resistance
Internal Structure	Traditional single chip	Dual-chip series/parallel	HVC breaks physical limits
Standard Lead Time	12-16 weeks	4-6 weeks	HVC 3x faster
Cost Index	100% (baseline)	50-80%	HVC 20-50% lower

4. Complete Series Quick Selection Guide

The following tables cover all standard models across TDK's UHV, FHV, TSF and FD series — 53 models with corresponding HVC replacement models. HVC uses N4700 Class 1 ceramic (lead-free, lower dissipation factor) to upgrade TDK's original Y5S/Z5T/Y5P Class 2 materials.

TSF & FD Series (AC Rated)

TDK Model	Spec (Voltage/Cap)	TDK Material	HVC Replacement	HVC Material (Upgrade)
TSF-40C	20KVAC, 1080pF	Z5T	HVCT8G-20KVAC-DL40-1081K	N4700
TSF-30	20KVAC, 400pF	Z5T	HVCT8G-20KVAC-DL30-401K	N4700
FD-9A	10KVAC, 100pF	Y5P	HVCT8G-10KVAC-DL30-101K	N4700
FD-10A / FD-10AU	10KVAC, 250pF	Y5P	HVCT8G-10KVAC-DL30-251K	N4700
FD-11A / FD-11AU	10KVAC, 500pF	Y5P	HVCT8G-10KVAC-DL30-501K	N4700
FD-12A / FD-12AU	10KVAC, 1000pF	Y5P	HVCT8G-10KVAC-DL40-102K	N4700
FD-16A / FD-16AU	13KVAC, 250pF	Y5P	HVCT8G-13KVAC-DL30-251K	N4700
FD-18A / FD-18AU	13KVAC, 500pF	Y5P	HVCT8G-13KVAC-DL30-501K	N4700
FD-20A	13KVAC, 1000pF	Y5P	HVCT8G-13KVAC-DL50-102K	N4700
FD-22A	20KVAC, 250pF	Y5P	HVCT8G-20KVAC-DL30-251K	N4700
FD-24A	20KVAC, 500pF	Y5P	HVCT8G-20KVAC-DL40-501K	N4700
FD-33A	25KVAC, 250pF	Y5P	HVCT8G-25KVAC-DL30-251K	N4700
FD-36A	25KVAC, 500pF	Y5P	HVCT8G-25KVAC-DL50-501K	N4700

FHV Series (DC Molded)

TDK Model	Spec (Voltage/Cap)	TDK Material	HVC Replacement	HVC Material (Upgrade)
FHV-153AN	15KVDC, 7000pF	Y5S	HVCT8G-15KV-DL60-702K	N4700
FHV-1AN	20KVDC, 1700pF	Y5S	HVCT8G-20KV-DL40-172K	N4700
FHV-2AN	20KVDC, 3000pF	Y5S	HVCT8G-20KV-DL50-302K	N4700
FHV-3AN	20KVDC, 5200pF	Y5S	HVCT8G-20KV-DL60-522K	N4700
FHV-4AN	30KVDC, 1200pF	Y5S	HVCT8G-30KV-DL40-122K	N4700
FHV-5AN	30KVDC, 2100pF	Y5S	HVCT8G-30KV-DL50-212K	N4700
FHV-6AN	30KVDC, 3500pF	Y5S	HVCT8G-30KV-DL60-352K	N4700
FHV-7AN	40KVDC, 850pF	Y5S	HVCT8G-40KV-DL40-851K	N4700
FHV-8AN	40KVDC, 1500pF	Y5S	HVCT8G-40KV-DL50-152K	N4700
FHV-9AN	40KVDC, 2600pF	Y5S	HVCT8G-40KV-DL60-262K	N4700
FHV-10AN	50KVDC, 700pF	Y5S	HVCT8G-50KV-DL40-701K	N4700
FHV-11AN	50KVDC, 1300pF	Y5S	HVCT8G-50KV-DL50-132K	N4700
FHV-12AN	50KVDC, 2100pF	Y5S	HVCT8G-50KV-DL60-212K	N4700

UHV Series (Ultra-High Voltage Bolt Terminal)

TDK Model	Spec (Voltage/Cap)	TDK Material	HVC Replacement	HVC Material (Upgrade)
20KV Grade
UHV-221A	20KVDC, 200pF	Z5T	HVCT8G-20KV-DL30-201K	N4700
UHV-222A	20KVDC, 400pF	Z5T	HVCT8G-20KV-DL30-401K	N4700
UHV-223A	20KVDC, 700pF	Z5T	HVCT8G-20KV-DL30-701K	N4700
UHV-224A	20KVDC, 1000pF	Z5T	HVCT8G-20KV-DL30-102K	N4700
UHV-1A	20KVDC, 1400pF	Z5T	HVCT8G-20KV-DL40-142K	N4700
UHV-2A	20KVDC, 2500pF	Z5T	HVCT8G-20KV-DL50-252K	N4700
UHV-3A	20KVDC, 4000pF	Z5T	HVCT8G-20KV-DL60-402K	N4700
30KV Grade
UHV-231A	30KVDC, 200pF	Z5T	HVCT8G-30KV-DL30-201K	N4700
UHV-232A	30KVDC, 400pF	Z5T	HVCT8G-30KV-DL30-401K	N4700
UHV-233A	30KVDC, 700pF	Z5T	HVCT8G-30KV-DL30-701K	N4700
UHV-4A	30KVDC, 940pF	Z5T	HVCT8G-30KV-DL40-941K	N4700
UHV-5A	30KVDC, 1700pF	Z5T	HVCT8G-30KV-DL50-172K	N4700
UHV-6A	30KVDC, 2700pF	Z5T	HVCT8G-30KV-DL60-272K	N4700
40KV Grade
UHV-241A	40KVDC, 100pF	Z5T	HVCT8G-40KV-DL30-101K	N4700
UHV-242A	40KVDC, 200pF	Z5T	HVCT8G-40KV-DL30-201K	N4700
UHV-243A	40KVDC, 400pF	Z5T	HVCT8G-40KV-DL30-401K	N4700
UHV-7A	40KVDC, 700pF	Z5T	HVCT8G-40KV-DL40-701K	N4700
UHV-8A	40KVDC, 1300pF	Z5T	HVCT8G-40KV-DL50-132K	N4700
UHV-9A	40KVDC, 2000pF	Z5T	HVCT8G-40KV-DL60-202K	N4700
50KV Grade
UHV-251A	50KVDC, 100pF	Z5T	HVCT8G-50KV-DL30-101K	N4700
UHV-252A	50KVDC, 200pF	Z5T	HVCT8G-50KV-DL30-201K	N4700
UHV-253A	50KVDC, 400pF	Z5T	HVCT8G-50KV-DL40-401K	N4700
UHV-10A	50KVDC, 560pF	Z5T	HVCT8G-50KV-DL40-561K	N4700
UHV-11A	50KVDC, 1000pF	Z5T	HVCT8G-50KV-DL50-102K	N4700
UHV-12A	50KVDC, 1700pF	Z5T	HVCT8G-50KV-DL60-172K	N4700

5. HVC HVCT8G Part Number Decoder

HVCT8G-[Voltage]-[Size Code]-[Capacitance Code]

Field	Meaning	Example
HVCT8G	Doorknob capacitor series prefix	HVCT8G-20KV-DL30-201K
Voltage	20KV / 30KV / 40KV / 50KV / 20KVAC etc.	30KV
DL30-60	Diameter code: DL30=30mm, DL40=40mm, DL50=50mm, DL60=60mm	DL40
Capacitance Code	201=200pF, 102=1000pF, 702=7000pF	941K
K	Tolerance ±10%	K

6. Typical Replacement Cases

TDK P/N	HVC Replacement	Key Technology Upgrade
UHV-4A 30KV 940pF	HVCT8G-30KV-DL40-941K	Z5T→N4700 material upgrade, copper electrode
FHV-3AN 20KV 5200pF	HVCT8G-20KV-DL60-522K	Y5S(leaded)→N4700(lead-free) upgrade
FD-12A 10KVAC 1000pF	HVCT8G-10KVAC-DL40-102K	Y5P→N4700, superior HF performance

7. Reliability Test Data

Addressing the lifetime concerns critical to industrial and medical applications, HVC conducted rigorous testing per IEC 60384 standards:

7.1 Dielectric Withstanding Voltage Test

• Condition: 1.5x rated voltage applied for 60 seconds.
• Result: Sample n=100, HVC HVCT8G series 100% passed — no flashover or breakdown.

7.2 High-Temperature Aging Test (1000 hours)

• Condition: +85℃ ambient temperature, rated voltage applied.

Monitored Parameter	TDK Reference	HVC Measured	Standard Requirement
Capacitance Change (ΔC/C)	Typical ±8%	< ±5%	< ±10%
Insulation Resistance (IR)	> 1000MΩ	> 5000MΩ	> 1000MΩ
Appearance Integrity	No anomaly	No anomaly	No cracks / no flashover

7.3 Temperature Cycling Test

• Condition: -55℃ to +125℃, 100 cycles.
• Result: No mechanical damage, capacitance change < ±3%.

8. Mechanical Compatibility Verification

HVC HVCT8G series products are designed to strictly follow TDK UHV/FHV physical dimension standards, ensuring Form-Fit-Function (3F) level drop-in replacement.

Dimension	TDK Spec (UHV-4A)	HVC Spec (HVCT8G-30KV-DL40-941K)	Compatibility
Body Diameter	40mm	40mm (DL40)	Identical
Bolt Spacing	M6 standard	M6 standard	Fully compatible
Overall Height	60mm (typical)	60mm (typical)	Fully compatible
Mounting Type	Screw terminal	Screw terminal	Identical

9. Supply Chain & Business Value Analysis

Evaluation Dimension	TDK (Baseline)	HVC (Optimized)	Customer Benefit
Standard Lead Time	12-16 weeks	4-6 weeks	3x faster turnaround
Custom Lead Time	20-24 weeks	6-8 weeks	Significantly faster R&D iteration
Cost Index	100%	50-80%	20-50% BOM cost reduction
MOQ	100 pcs	50 pcs	Lower inventory capital commitment

10. Conclusion & Selection Recommendations

Based on technical performance, reliability data, and supply chain capability, the HVC HVCT8G series has demonstrated its viability and superiority as a replacement for TDK HV ceramic capacitors.

Selection Recommendations:

• Recommended HVC deployment: All medical, industrial, and power electronics projects pursuing supply chain security (dual-source strategy), cost optimization, and fast delivery.
• Material upgrade scenario: For existing TDK Y5S (leaded) designs, HVC N4700 provides a lead-free upgrade path.
• Performance breakthrough scenario: For applications requiring >50KV voltage or >2100pF capacitance, HVC is currently the only mature alternative solution.

Start Replacement Verification

HVC offers free samples and technical support, with specification confirmation available within 48 hours.

© HVC Capacitor Manufacturing Co., Ltd. TDK® is a registered trademark of TDK Corporation. This document is for technical comparison purposes only and does not imply affiliation with or endorsement by the trademark holder.