This document discusses snap-in electrolytic capacitors for automotive applications. It describes the snap-in construction which uses grooves and optimized materials to provide fixation during high vibration. Test results show the snap-in capacitor passed 20G vibration testing at high frequencies, exceeding the 10G capability of standard snap-ins. Endurance testing at 600V and 85C also exceeded automotive standards, demonstrating suitability for electric vehicle fast charging applications.

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Snap-In High Vibration Products: AEC-Q200
Automotive for High Voltage Performance
Requirements
Rita Caeiro

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Let’s start…
• Snap-In Electrolytic capacitor introduction : Why use a Snap-In for
Automotive?
• Snap-In : A High Vibration, Reliable Construction for High voltage
products
• Achievements

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What is a Snap-In Capacitor?
Fixed Capacitors
Non-polarized
capacitors
Ceramics Films
Polarized
capacitors
Electrolytics
Aluminum
Non-solid
SMDs
Radial lead
terminals
Axial lead
terminals
Snap-In
Terminals
(radial)
Press Fit
Terminals
(radial)
Screw-
Terminals
Solid MnO2
Solid
Polymer
Hybrid
Tantalum Niobium
Super-
Capacitors

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Basic Snap-In structure

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• Motor Drives
• Motor Control
• UPS systems
• Inverters
• Rectifiers
• Switch Mode Power Supply
(SMPS)
• Traction
• Welding machines
• Solar Inverters
• Heating, Ventilation and Air
Conditioning (HVAC) systems
• Charging stations
• On-Board Chargers
Snap-In Applications

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Cycle or Trend?
EV & HV
0
2
4
6
8
10
12
14
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2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026
21% CAAGR
Prismark Partners LLC 01.18
Million Units

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• On-board single-phase battery charger.
Snap-In for Automotive On-Board Charger
applications
• Main purpose of the On-Board charger is to convert
AC supply into DC power to charge the battery.
1st stage 2nd stage
DC-Link voltage
~400V – 500V
• 1st stage – AC/DC converter that ensures a unity power factor
correction (PFC) by absorbing a sinusoidal current from the
grid with low current harmonics.
• 2nd stage – DC/DC converter that regulates the current
delivered to the battery according to its state of charge and
matches the difference between the DC-link and battery
voltages.
• DC-link capacitor (high power density electrolytic capacitor) to
connect 1st and 2nd stages whose main objective is energy
storage and voltage control. An electromagnetic interference
(EMI) filter is connected between the grid and the first stage.

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Why use Snap-In capacitors in On-Board
Charger applications?
• High vibration capability up to 20G
• Long life expectancy
• High ripple current capability
• High voltage up to 600V @ 85°C
• High voltage up to 500V @ 105ºC
• High power density capability
• Excellent surge voltage capability
• Insulation material UL recognized
Test Hours
250
500
1000
250
500
1000
250
500
1000
250
500
1000
External Visual
(MIL-STD-883 Method
2009)
N.A.
Physical Dimension (JESD22 Method JB-100) N.A.
Resistance to Solvents (MIL-STD-202 Method 215) N.A.
Mechanical Shock (MIL-STD-202 Method 213) N.A.
Vibration (MIL-STD-202 Method 204) N.A.
Resistance to Soldering
Heat
(MIL-STD-202 Method 210) N.A.
Solderability (J-STD-002) N.A.
Electrical
Characterization
(User Spec.) N.A.
Surge Voltage
(C 5101-1：2010 (IEC 60384-
1：2008)
N.A.
Test/Method
AEC-Q200 Main tests for Aluminum Electrolytic Capacitors
Biased Humidity (MIL-STD-202 Method 103)
Storage at High Temp (MIL-STD-202 Method 108)
Temperature Cycle (JESD22 Method JA-104)
Endurance Life Test (MIL-STD-202 Method 108)

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Standard Snap-In
Mechanical Construction and Vibration
capability
High Vibration Snap-In
Anti-Vibration Groove
10G maximum acceleration,
clamped by the body to a vibration
platform subjected to a simple
harmonic motion having a maximum
peak-to-peak amplitude of 1,5mm,
3 hours each axis at 10 – 500Hz
High Vibration
Reliability
Construction
20G maximum acceleration,
clamped by the body to a vibration
platform subjected to a simple
harmonic motion having a maximum
peak-to-peak amplitude of 1,5mm,
4 hours each axis at 10 – 2000Hz
Test condition D from MIL-STD-202
Method 204
Test condition A from MIL-STD-202
Method 204

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Mechanical Construction and Vibration
capability
Condition A
10G
Condition D & G
Condition E
MIL-STD-202 Method 204

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• Diameter maximization of the wound element
– maximum fit to can
Mechanical Construction and Vibration
capability
Anti-Vibration
groove
Post-Grooved
aluminum can
Wound Element Unrilled Aluminum Can Capacitor Assembly Capacitor with High
Vibration Reliability
Construction
• Post-grooved aluminum can – radial fixation
• Anti-vibration groove – radial fixation
• Optimized materials for excellent crush of
the wound element – axial and radial fixation
Tissue SEM
Crushfit
Y
X
Z

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Mechanical Construction and Vibration
capability
• Radial plane cross-section – X and Z
axis
Maximum fit to can of the wound element
showing terminal connection to the anode
and cathode foil
• Axial plane cross-section – Y axis
Observation of the cathode extension crush (bottom of
can) and tissue margin crush (terminal end)
• Computerized Tomography Scan analysis:
A B
A B
Legend:
A – High Vibration reliability Snap In
B – Standard Snap In

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• Bottom cross-section –
Radial plane
Base of aluminum can showing
cathode extension crush
Mechanical Construction and Vibration
capability
• Computerized Tomography Scan analysis:
• Upper cross-section – Radial
plane
Terminal connection side
showing maximum fit to can of
the wound element
• 3D image overview
Can groove and Anti-
Vibration groove observation

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Vibration Test results
• Electrical and visual measurements were taken before and after each axis test.
• Test components were stabilized for at least 2 hours at 20+/-1°C before electrical
measurements. The electrical measurements were recorded using a calibrated Agilent
4263b LCR meter.
• Capacitance measurements were collected at 100Hz and 20°C. The parts were visually
inspected for any signs of electrolyte leakage or visible physical damage.
Y axis X axis Z axis
Y
X
Z

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Vibration Test results
Variation 10G/1.5mm 3H
10-500Hz
(3 directions)
20G/1.5mm 4H 10-
2000Hz
(3 directions)
30G/1.5mm 4H
10-2000Hz
(3 directions)
Standard Snap-In –
35x50 mm
Ok Nok Nok
High Vibration Snap-
In – 35x50 mm
Ok Ok Ok(*)
• Standard Snap-In capacitors are
failing by open circuit under the 20G
condition.
• High Vibration Snap In
has successfully
passed 20G condition.
(*)An on-going
overstress test for 30G
is showing good
results.

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Endurance Test results for 600V 85ºC Snap In
• Determine the effects on electrical and mechanical characteristics resulting from exposure of
the capacitor, during operation, to an elevated, ambient temperature for a specified length of
time. We can observe the following results:
• All the submitted parts passed the test after 2000H which is beyond the AEC-Q200 standard of
1000 hours.

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Main Highlights
• A High Vibration mechanical construction for a Snap-In capacitor has
shown excellent results up to 20G high frequency testing, where
previously this technology was only able to widthstand 10G at low
frequency.
• 30G high frequency vibration capability appears feasible. Additional
testing on-going.
• Excellent Endurance test results were achieved on Snap-In capacitors
at 600V@85ºC. The very high voltage capability allows these
capacitors to be used in fast charging applications.

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