The YAGEO KEMET HRA Z‑Level series extends high‑reliability multilayer ceramic capacitors (MLCCs) beyond traditional MIL‑SPEC capacitance limits, while aligning its screening and process controls with MIL‑PRF‑32535 T‑Level expectations.
These YAGEO KEMET high‑reliability MLCC capacitors target demanding defense, aerospace, and space electronics where higher capacitance density, controlled reliability, and full lot traceability are required in compact SMD formats.
Building on the previously introduced HRA X‑Level platform, the new Z‑Level variant offers enhanced in‑process inspection and testing, leveraging base metal electrode (BME) technology to achieve significantly higher capacitance in standard EIA 0402–2220 case sizes. This makes the HRA series a practical bridge between commercial/automotive MLCCs and fully qualified MIL parts for designers who need more capacitance without losing reliability controls.
Key features and benefits
- High‑capacitance MLCC platform for mission‑critical electronics
- Capacitance range from 39 pF to 22 µF in standard SMD case sizes.
- Up to 5× the capacitance of comparable MIL‑PRF‑32535‑qualified devices, enabling downsizing and fewer components on the PCB.
- Extended high‑reliability screening levels
- HRA X‑Level: aligned with MIL‑PRF‑32535 M‑Level in‑process inspection and testing for limited mission applications.
- HRA Z‑Level: expanded screening and process controls more closely aligned with MIL‑PRF‑32535 T‑Level expectations, addressing longer or more critical missions.
- Robust construction versus automotive/COTS MLCCs
- Designs and process controls aimed at higher reliability than standard automotive or COTS parts.
- Defined screening and acceptance criteria including voltage conditioning and post‑electrical testing.
- Wide operating and voltage range
- Operating temperature: −55 °C to +125 °C, suitable for many defense, avionic, and space subsystems.
- DC voltage ratings: 6.3 V to 100 V, covering low‑voltage logic rails through typical 28 V and 48 V class systems.
- Flexible termination options for mechanical robustness
- Standard and flexible termination constructions available.
- Flexible termination uses a conductive silver epoxy layer to absorb board flex and mitigate MLCC flex cracking, especially important on large case sizes and stiff boards.
- Plating options for diverse assembly flows
- Termination finishes: 100% Sn, SnPb, and Au to support different soldering profiles and high‑reliability assembly requirements.
- Quality and traceability controls
- 100% electrical testing and full lot traceability.
- Optional Single Lot Date Code (SLDC) for programs that require tight configuration and batch control.
- Lot release testing and voltage conditioning per MIL‑PRF‑32535 (including 5% PDA) to screen early failures.
Typical applications
The HRA Z‑Level series targets systems where capacitance density, predictable reliability, and documentation/traceability are critical, but full MIL qualification may be either unnecessary or too restrictive in terms of available CV values.
Typical use cases include:
- Defense and aerospace electronics
- Avionics control units and flight computers.
- Mission computers and data‑processing modules.
- Guidance, navigation, and control electronics.
- Space and high‑altitude platforms
- Satellite subsystems where higher capacitance is required beyond many traditional MIL‑spec MLCC offerings.
- Payload electronics and communication modules that demand defined screening but also compact, high‑CV solutions.
- High‑reliability power management
- Decoupling of FPGAs, DSPs, and microprocessors in critical systems.
- Bypass capacitors on regulated power rails.
- Filtering elements in EMI/EMC networks.
- Transient voltage suppression support, where MLCC banks are used to absorb fast surges and edges alongside TVS or other protection devices.
- Long‑life industrial and specialty applications
- High‑end industrial control, measurement, or radar/lidar systems that adopt aerospace‑style qualification flows.
- Any design where enhanced screening, controllable process quality, and documentation are needed but classical MIL parts do not offer sufficient capacitance in the available footprints.
Technical highlights
The table below summarizes the key technical parameters of the HRA Z‑Level series according to the manufacturer information and product brief.
| Parameter | HRA Series (X & Z Levels) – overview* |
|---|---|
| Capacitance range | 39 pF to 22 µF (application‑specific) |
| Case sizes | EIA 0402 to 2220 |
| DC voltage range | 6.3 V to 100 V |
| Operating temperature range | −55 °C to +125 °C |
| Construction options | Standard and flexible termination |
| Electrode system | Patented Base Metal Electrode (BME) |
| Screening levels | X‑Level (M‑Level aligned), Z‑Level (T‑Level aligned) |
| Termination plating | 100% Sn, SnPb, Au |
| Screening steps | Voltage conditioning and post‑electrical testing per MIL‑PRF‑32535 |
*Exact value combinations by case size, voltage and dielectric should be confirmed in the manufacturer datasheet and product tables.
Base Metal Electrode (BME) technology
The HRA series uses patented BME technology to achieve higher capacitance per volume than many noble‑metal electrode solutions in similar case sizes. For designers, this means:
- The possibility to replace banks of smaller MLCCs with fewer high‑CV parts, simplifying layouts and inventory.
- Potential board area reduction or margin in routing in dense boards such as RF front‑ends, payload electronics, or advanced power modules.
- A path to higher CV values while still maintaining screening practices aligned to MIL‑PRF‑32535 expectations for high‑reliability programs.
Screening and reliability controls
The X‑Level and Z‑Level definitions provide a structured way to select screening intensity:
- X‑Level (M‑Level aligned)
Suitable for limited mission or medium‑criticality applications where enhanced screening above standard COTS/automotive is required, but mission duration or risk profile is relatively constrained. - Z‑Level (T‑Level aligned)
Aimed at applications more closely aligned with T‑Level expectations of MIL‑PRF‑32535, with extended in‑process inspection and testing. This is relevant for longer missions, more critical functions, or where program requirements drive higher assurance.
Both levels include voltage conditioning and post‑electrical testing with defined percent defective allowed (PDA) criteria, which help to remove early‑life failures before parts reach assembly. For designers, this reduces the risk of infant mortality and strengthens confidence during qualification and early field deployment.
Flexible termination for mechanical robustness
Flexible termination variants integrate a conductive silver epoxy layer between the ceramic body and outer plating. In practice this:
- Helps absorb PCB flexing and thermal cycling stresses, which are common causes of MLCC cracking.
- Is especially useful in larger case sizes (e.g., 1210 and above) or stiff boards like thick backplanes or modules with heavy components.
- Supports improved board‑level reliability in environments with vibration, shock, or repeated thermal excursions such as airborne or space platforms.
Source
This article is based on the official YAGEO Group / KEMET information about the HRA Series Z‑Level high‑reliability MLCC portfolio, including the published HRA Series product brief and related online resources, adapted and commented from the perspective of an independent technical editor.
