Passive Components Blog
No Result
View All Result
  • Home
  • NewsFilter
    • All
    • Aerospace & Defence
    • Antenna
    • Applications
    • Automotive
    • Capacitors
    • Circuit Protection Devices
    • electro-mechanical news
    • Filters
    • Fuses
    • Inductors
    • Industrial
    • Integrated Passives
    • inter-connect news
    • Market & Supply Chain
    • Market Insights
    • Medical
    • Modelling and Simulation
    • New Materials & Supply
    • New Technologies
    • Non-linear Passives
    • Oscillators
    • Passive Sensors News
    • Resistors
    • RF & Microwave
    • Telecommunication
    • Weekly Digest

    Murata Releases First High-Frequency XBAR Filter for Next-Gen Networks

    Vishay NTC Immersion Thermistor Delivers Fast Response in Liquid Cooled Automotive Systems

    Wk 27 Electronics Supply Chain Digest

    VINATech Supercapacitors Enhance Automotive Safety with Reliable E-Latch Emergency Power

    Exxelia Unveils Advanced Components for the Medical Device Industry

    TDK Introduces High Current 80VDC Board-Mount EMI Filters

    Bourns Releases High Heat Tolerant TO-227 Thick Film Resistor

    TDK Increases Current Ratings of Automotive Thin-Film Power Inductors

    Sumida Announces New DC Common Mode Choke Coil Series

    Trending Tags

    • Ripple Current
    • RF
    • Leakage Current
    • Tantalum vs Ceramic
    • Snubber
    • Low ESR
    • Feedthrough
    • Derating
    • Dielectric Constant
    • New Products
    • Market Reports
  • VideoFilter
    • All
    • Antenna videos
    • Capacitor videos
    • Circuit Protection Video
    • Filter videos
    • Fuse videos
    • Inductor videos
    • Inter-Connect Video
    • Non-linear passives videos
    • Oscillator videos
    • Passive sensors videos
    • Resistor videos

    Accelerating Full Bridge LLC Resonant Converter Design with Frenetic AI

    Understanding Switched Capacitor Converters

    Coupled Inductors Circuit Model and Examples of its Applications

    Inductor Resonances and its Impact to EMI

    Highly Reliable Flex Rigid PCBs, Würth Elektronik Webinar

    Causes of Oscillations in Flyback Converters

    How to design a 60W Flyback Transformer

    Modeling and Simulation of Leakage Inductance

    Power Inductor Considerations for AI High Power Computing – Vishay Video

    Trending Tags

    • Capacitors explained
    • Inductors explained
    • Resistors explained
    • Filters explained
    • Application Video Guidelines
    • EMC
    • New Products
    • Ripple Current
    • Simulation
    • Tantalum vs Ceramic
  • Knowledge Blog
  • Suppliers
    • Who is Who
  • Events
  • Home
  • NewsFilter
    • All
    • Aerospace & Defence
    • Antenna
    • Applications
    • Automotive
    • Capacitors
    • Circuit Protection Devices
    • electro-mechanical news
    • Filters
    • Fuses
    • Inductors
    • Industrial
    • Integrated Passives
    • inter-connect news
    • Market & Supply Chain
    • Market Insights
    • Medical
    • Modelling and Simulation
    • New Materials & Supply
    • New Technologies
    • Non-linear Passives
    • Oscillators
    • Passive Sensors News
    • Resistors
    • RF & Microwave
    • Telecommunication
    • Weekly Digest

    Murata Releases First High-Frequency XBAR Filter for Next-Gen Networks

    Vishay NTC Immersion Thermistor Delivers Fast Response in Liquid Cooled Automotive Systems

    Wk 27 Electronics Supply Chain Digest

    VINATech Supercapacitors Enhance Automotive Safety with Reliable E-Latch Emergency Power

    Exxelia Unveils Advanced Components for the Medical Device Industry

    TDK Introduces High Current 80VDC Board-Mount EMI Filters

    Bourns Releases High Heat Tolerant TO-227 Thick Film Resistor

    TDK Increases Current Ratings of Automotive Thin-Film Power Inductors

    Sumida Announces New DC Common Mode Choke Coil Series

    Trending Tags

    • Ripple Current
    • RF
    • Leakage Current
    • Tantalum vs Ceramic
    • Snubber
    • Low ESR
    • Feedthrough
    • Derating
    • Dielectric Constant
    • New Products
    • Market Reports
  • VideoFilter
    • All
    • Antenna videos
    • Capacitor videos
    • Circuit Protection Video
    • Filter videos
    • Fuse videos
    • Inductor videos
    • Inter-Connect Video
    • Non-linear passives videos
    • Oscillator videos
    • Passive sensors videos
    • Resistor videos

    Accelerating Full Bridge LLC Resonant Converter Design with Frenetic AI

    Understanding Switched Capacitor Converters

    Coupled Inductors Circuit Model and Examples of its Applications

    Inductor Resonances and its Impact to EMI

    Highly Reliable Flex Rigid PCBs, Würth Elektronik Webinar

    Causes of Oscillations in Flyback Converters

    How to design a 60W Flyback Transformer

    Modeling and Simulation of Leakage Inductance

    Power Inductor Considerations for AI High Power Computing – Vishay Video

    Trending Tags

    • Capacitors explained
    • Inductors explained
    • Resistors explained
    • Filters explained
    • Application Video Guidelines
    • EMC
    • New Products
    • Ripple Current
    • Simulation
    • Tantalum vs Ceramic
  • Knowledge Blog
  • Suppliers
    • Who is Who
  • Events
No Result
View All Result
Passive Components Blog
No Result
View All Result

Tantalum Capacitors Reliability Prediction by Anode Characterization During Manufacturing Process

5.2.2025
Reading Time: 7 mins read
A A
Full paper pdf download

The purpose of the work is to propose a method for predicting the reliability of a capacitor by leakage currents (DCL), which allows predicting the behavior of DCL, already at the initial stages of anode manufacturing, based on the mechanical tests, which significantly reduces the time and cost at its manufacture.

The paper was presented by Vladimir Azbel, independent consultant, Israel at the 3rd PCNS 7-10th September 2021, Milano, Italy as paper No.1.6.

RelatedPosts

5th PCNS Conference Registration Now Open!

Enhanced Process Control in Tantalum Capacitor Anode Manufacturing Reduces Cost and Improves Reliability

Enhancing Effectiveness of Tantalum Capacitor Anode Control

METHODS TO CONTROL RELIABILITY OF TANTALUM CAPACITORS

Usually, deficiency of control methods in the early stages of manufacture of the product, with a multi-step process, leads to the search results of trial and error, which leads to a waste of time and money with a low probability of solving the problem. The reliability of the tantalum capacitor, its capacitance (CAP), and above all, the leakage currents, and their stability, are determined by the anode.

METHODS TO CONTROL RELIABILITY OF TANTALUM CAPACITORS FROM EARLY ANODE PRODUCTION STAGE

One of the ways to increase the reliability of the anode is the development of new effective control methods on the stage of its production. The anode is the heart of the tantalum capacitor.

Anode production – imagine how, as the two-stage process:

  • the first stage is getting a sintered pellet.
  • the second stage is getting anode, by the formation process of a sintered pellet. The CAP and DCL values of the anode, produced at the same powder, depend on choosing the parameters first and the second stage:
  • for sintered pellet, this choice of the pressing density, and temperature sintering
  • The only controlled parameter of the process is shrinkage. It should be noted that shrinkage depends on the temperature/time of sintering and does not depend on the change in the pressing density at the same sintering temperature
  • the second stage is the formation of the process of the sintered pellets and define of CAP and DCL.

Most of the tantalum capacitors manufacturers nowadays use for determining anode quality “wet-cell” tests (WC). The WC test is a good indicator of overall anode capacitance (CAP) and dissipation factor (DF) but insufficient to precise prognoses direct current leakage (DCL) on the final product and does not provide a direct connection to the structure of the sintered pellet.

The problem is that at present the quality assessment can be carried out only on the anode, and any deviation, in consisting of its components from the recipe process associated with the repetition of all stages of its manufacture.

Unfortunately, WC the test does not provide:

  • current control of the sintered pellet, which is currently controlled by shrinkage, which has its own   limitations / 1/.
  • control defects, at each technological stage
  • predicting risk degradation of the DCL in the final product.

Mechanical Test

Consider the possibility of estimate CAP and DCL of anode not by WC, but by mechanical tests, applied to porous materials.

The proposed method is based on recording the stress-strain curve of the material, which makes it possible to independently control, not only, changes in the porous structure, but and residual stress of the sintered pellet (at variations in the pressing density and sintering temperature), and the ability of the structure of the sintered pellet to resist the change, during the formation of an amorphous Ta2O5 film during the formation process.

The typical form of the CC curve and the parameters characterizing it are shown in Fig.1

Fig. 1 Stress-strain curve tensile (solid line)/ compression (red dash line) test, and parameters using for it des

The stress-strain curve provides information about the structure, which affects its parameters of yield strength (Ay), Young’s modulus (E), ultimate tensile stress (AUTS), exponential hardening factor (n), which is also true for porous materials.

The characteristics of the SS curve are widely used to assess the quality and reliability of the material, in particular powder porous materials, after various technological processes subjected to mechanical, thermal, and chemical treatment.

In the case of a composite material, which is an anode, the stability of its properties:

  1. first of all, will depend on the ability of its plastic matrix (sintered pellet) to withstand degradation caused by the formation process
  2. keep stability during exploitation.

An indicator, of the stability of anode properties, is the stability of its structure, after a reliability test, can be estimated by:

  • standard method determined CAP and DCL on the capacitor
  • suggested method / 5 /- Ay, E, and n determined from the SS curve of the anodes before and after heating in air, in the temperature/time range 400-450°C/20 – 60 min., should not exceed 10%.

HOW TO CONTROL FEATURES OF THE SINTERED PELLET

1.Press Density

Shrinkage value of pellets, pressed with different densities and sintered at the same temperature does not change and is not an indicator of changes in the porous structure. Currently, control of the sintered pellet, by volume shrinkage.  A higher in the press density pellet leads to an increase: E~ k1- decrease porosity sinter pellet and a decrease in the CV/g of anodes produced from these sintered pellets.

2.Sintering Temperature

The influence temperature sintering on Ay and k1 of sintered pellets and CV/g anode can be investigated. An increase in the sintering temperature, similar to an increase in the pressing density, leads to an increase in Ау, к1 and a decrease in CAP (CV/g) change.

3.Sintering Time

The influence time sintering on Ay and k1 of sintered pellets and CV/g, DCL/CV anode is another variable to consider. An increase in the sintering time leads to similar changes CV/g and DCL/CV as an increase in the pressing density and sintering temperature.

From our experimental results, it can be seen, that there is a correlation between the parameters Ay, k1 of the sintered pellet and CV/g, DCL/CV of the anode, depending on the variation of the pressing density, temperature, and sintering time. At the same time, to predict DCL, the Ay parameter is used, which is responsible for the size of the neck of the sintered pellet and the recipe for the formation of the anode.

4.Formation Process

The anode is a composite material, and unlike the test used to predict the stability of the DCL on the final anode, the mechanical test it possible to make such an estimate of the compatibility of the parameters Ау and the length of the plasticity region (Ls) of the sintered pellet and Av and Lv after formation (on the anode). The parameters Ay and the Ls of the sintered pellet, depend on powder, the press. density, temperature/time of sintering, and Av, Lv, from recipe formation (formation voltage and current, etc).

The scheme of the effect of formation voltage on the size neck, indicate an increase in the risk of overheating during formation.

5. Powder Vendors Benchmark

The different vendor powder, leads to significantly different DCL, it can be checked by standard powder parameters evaluation.

Comparison of the size of the neck obtained from the stress–strain curve, after sintering, allows predicting the acceptance of the powder in the early stages of production, significantly reduces the time and cost spent for powder conversion.

6. Powder Batch Acceptance Criteria

On sintered pellet from acceptable and problematic batches, SS- curves can be obtained and compared.

7. Using SS Curve to Monitor Anode Pellet Shape Influence on Ау and DCL

Pellets A and B were prepared at the same: grade powder, press density, temperature/time sintering, formation voltage have at the same shrinkage, and content oxygen. Anode, produce by sintered pellet B, has low values of Ау and burns out on formation.

SUMMARY & CONCLUSION

SUMMARY & CONCLUSION

The proposed method makes it possible to control the quality of the sinter and anode in comparison with their benchmark values ​​E and Ay (curve SS), for which acceptable electrical characteristics of the anode were obtained.

Using of mechanical test could help to:

  • Improve effectiveness of powder conversion. (since allow direct measurements and comparison of pellet with different powders at different manufacturing steps)
  • Control pelleting “process” to reduce lot-by-lot variation (for special products).
  • Reduce cost and increase effectiveness of new pellet developing. (achieving measurable data at early manufacturing steps)
  • Evaluate effectiveness and necessaries of different manufacturing steps/treatments.
  • Specific Ta pellets design optimization.

This article is shortened version of original paper available at the link below or pdf download.

Related

Source: EPCI

Recent Posts

VINATech Supercapacitors Enhance Automotive Safety with Reliable E-Latch Emergency Power

7.7.2025
15

Exxelia Unveils Advanced Components for the Medical Device Industry

7.7.2025
31

YAGEO Releases First to Market 750V Aluminum Capacitors

30.6.2025
49

Smolteks CNF-MIM Capacitors Meet Thermal and Voltage Stability Industry Requirements

30.6.2025
19

Learn How Supercapacitors Enhance Power System in Knowles eBook

30.6.2025
20

TDK Releases Industry First 1uF 100V X7R MLCCs in 1608 Case

27.6.2025
24

YAGEO Extends Lifetime of its Aluminum SMD Chip Capacitors to 5500hrs at 125C/Ur

27.6.2025
57

Murata Releases Worlds First 10µF/50V Automotive MLCC in 0805 Size

26.6.2025
56

Advancements and Applications of Switch Capacitor Power Converters

25.6.2025
37

Samsung Delivers Silicon Capacitors to Marwell AI Systems

24.6.2025
73

Upcoming Events

Jul 23
13:00 - 14:00 CEST

PCB design for a Smartwatch

Jul 29
16:00 - 17:00 CEST

Impact of Elevated Voltage and Temperature on Molded Power Inductors in DC/DC converters

View Calendar

Popular Posts

  • Buck Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Boost Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Flyback Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • What is a Dielectric Constant and DF of Plastic Materials?

    4 shares
    Share 4 Tweet 0
  • LLC Resonant Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Ripple Current and its Effects on the Performance of Capacitors

    3 shares
    Share 3 Tweet 0
  • How to Design an Inductor

    0 shares
    Share 0 Tweet 0
  • Dual Active Bridge (DAB) Topology Explained

    0 shares
    Share 0 Tweet 0
  • SEPIC Converter Design and Calculation

    0 shares
    Share 0 Tweet 0
  • Why Low ESR Matters in Capacitor Design

    0 shares
    Share 0 Tweet 0

Newsletter Subscription

 

Passive Components Blog

© EPCI - Leading Passive Components Educational and Information Site

  • Home
  • Privacy Policy
  • EPCI Membership & Advertisement
  • About

No Result
View All Result
  • Home
  • Knowledge Blog
  • Premium Suppliers

© EPCI - Leading Passive Components Educational and Information Site

This website uses cookies. By continuing to use this website you are giving consent to cookies being used. Visit our Privacy and Cookie Policy.
Go to mobile version