KEMET offers the design community many high-reliability capacitor solutions for applications such as communications, avionics, munitions, radars, lasers, and satellites. To support these markets/applications involves a clear understanding of existing requirements, which may have different levels of performance and reliability. KEMET offers multiple solutions that can meet the specified requirements. Depending on the program requirements, various solutions may be considered:
High-Reliability polymer tantalum capacitors are the preferred solution for today’s defense and aerospace segment requirements.
These solutions are supported by the Defense Logistics Agency (DLA) with three drawings, including Drawings 04051 and 04052 for the T540 and T541 series, and DLA drawing 13030 for the T550 hermetically sealed series. These series, along with the commercial up-screened T543 capacitors, offer exceptional performance in terms of reliability and electrical performance in power management applications, specifically due to the best-in-class ultra-low ESR offering.
Polymer tantalum technology is the preferred solution for filtering/decoupling in fast-switching DC/DC converters where efficiency is a critical parameter. In addition, polymer tantalum offers higher power levels and lower ESR capacitance solutions for medium to high levels of switching frequency domains.
KEMET responded to market demands by collaborating with the defense community to develop a new MILPRF-32700. This process was complex and significant and involved working closely with the DLA agency. The aim was to create a product that could withstand the rigorous demands of the defense and aerospace industries.
During the preparation of the new performance specification, manufacturers and end users must agree on the critical requirements, such as:
Figure 1 – Structure of MIL-PRF-32700 Performance Specification
KEMET underwent a lengthy qualification process after MIL-PRF-32700 was officially approved. The goal was to present the results to the DLA. KEMET has now introduced the first T581 capacitors that meet the requirements in Military Performance Specification Sheets MIL-PRF-32700/2. This release is significant because it marks the first time a polymer tantalum surface mount capacitor will meet these new specifications. This achievement reinforces the position of KEMET as a leader in the defense and aerospace high reliability application market.
KEMET is releasing the first group (Group 1) of 35V capacitors in an X case size (groups 2 and 3 will follow):
This will complement the already extensive high-reliability portfolio for the defense and aerospace market. In the table below, the most relevant details are shared to provide a clear understanding of the different capabilities and KEMET series:
| Tantalum MnO2 | Tantalum Polymer Technology | ||||||
| AUTO | HRA |
MIL-PRF-55365 |
AUTO | HRA (High Reliability Alternative) |
HRA (High Reliability Alternative) |
MIL - Poly | |
| KEMET SERIES | T491/T495/T498 /T499 |
T493/T495/T496 /T497/T513 |
T409/T419/T429 /T492 |
T591/T598/T599 | T543 | T540/T541 | T580/T581 |
| STYLE | CWR 11 | CWR11 (CWR09,19, and 29) | CWR09,19,29, and 11 | CWR11 | CWR11 | CWR11 | |
| Manufacturing location | Mexico | US/Mexico | US/Mexico | China | US/Mexico | US/Mexico | US/Mexico |
| Anode Design | Fixed design, for automotive grade requirements |
Fixed and conservative designs robustness driven | Fixed and conservative designs robustness driven | Fixed design, for automotive grade requirements | Fixed and conservative designs robustness driven | Fixed and conservative designs robustness driven | Fixed and conservative designs robustness driven |
| Standard Aging | Yes | Yes | yes | yes | yes | yes | yes |
| Surge Current Test (in process) | 4 Pulses @ Vr |
||||||
| Additional voltage aging | No | No | No | No | No | 100% @ 85°C, |
100% @ 85°C, |
| Surge Current Options | N/A | On request as per |
On request as per |
On request |
On request as per |
On request as per |
On request as per |
| Screening options available | N/A | Yes, as per customer request with C-SPEC | N/A | N/A | Yes, as per customer request with C-SPEC | Yes, as per customer request with C-SPEC | N/A |
| Reflow conditioning | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| 100% Electrical Screening | Capacitance / Dissipation factor / Leakage Current / ESR | ||||||
| Visual/Mechanical | Yes (100%) |
Yes (100%) |
Yes (100%) |
Yes (100%) |
Yes (100%) |
Yes (100%) |
Yes (100%) |
| Additional Screenings Tests | N/A | Yes, as per customer request with C-SPEC | N/A | N/A | Yes, as per customer request with C-SPEC | •3 Sigma screening (DCL and ESR) (2) After voltage aging
|
N/A |
| F-Tech & SBDS | N/A | YES | N/A | N/A | N/A | YES | YES |
| B, C, and D Failure rates grading | N/A | YES | YES | N/A | N/A | YES | YES |
| Group A Testing (100%) with data package | N/A | N/A | YES | N/A | N/A | YES | YES |
| Group C Testing (100%) with data package | N/A | N/A | YES | N/A | N/A | YES | YES |
Table 1 – Automotive, HRA, and MIL-qualified KEMET series for the defense and aerospace market.
KEMET is developing efforts to fully qualify the future QPL T580 and T581 series, according to the MIL-PRF-32700/1 and /2, which is expected to be finalized by the end of 2024. With the first group of 35V now available, this qualification will extend and support the polymer tantalum capacitor adoption in a market where performance and reliability are key factors. This is also the confirmation that polymer tantalum capacitors have achieved a mature stage and have been adopted in this demanding market space. This technology has been used in ground, airborne, and space devices for more than a decade.
