SAMSUNG ELECTRO-MECHANICS

SAMSUNG Characteristics of MLCC [1] Basic [2] IR, BDV, [3] TCC, Aging [4] DC-Bias, AC Voltage, IZI

SAMSUNG Characteristics of MLCC, Basic MLCC Structure and Capacitance Design -Capacitance: Proportional to an internal electrode(A) area, Inversely proportional to distance between internal electrodes(t) 왼쪽 그림 - Ctotal=C1+C2+C3+C4+C5, Inner Electrode(Ni), Dielectric, External Termination(Cu-Ni-Sn), Inner Electrode(Ni), Dielectric 오른쪽 그림 - Ctotal=ε0εr(n-1)A/t, ε0: Vacuum Permittivity(8.854X10-12F/m), εr: Dielectric Constant, t: Thickness, A: Active area, n: Layer number, Dielectric, Internal Electrode, Active Area ↑, Dielectric, Internal Electrode, Distance ↓

SAMSUNG Characteristics of MLCC, Basic The electrical characteristics of MLCC - The MLCC characteristics changed according to the environment and conditions of use List - Temperature (TCC), Description - Capacitance change in operating temperature range → Design considering Deivce/Circuit usage temperature List - DC-bias, AC Voltage, Description - Capacitance change by applied DC-Bias & AC Voltage List - Aging, Description - Reduced capacitance over time List - Rated Voltage, Description - Maximum applicable voltage List - Insulation Resistance (IR), Description - Leakage current flow through MLCC List - Dissipation Factor (DF), Description - Energy Loss in MLCC (=ESR/Reactance) List - Breakdown Voltage (BDV), Description - Insulation breakdown by an applied voltage rise List - Ripple current, Description - Rise in surface temperature by ripple current List - Impedence (Z) & ESR, Description - Change in Impedance and ESR by frequency change

SAMSUNG Characteristics of MLCC, Basic The effect of electrical characteristics of MLCC on ECU - Ac voltage ripple, efficiency and reliability of the ECU represent MLCC electrical characteristics List - TCC, DC_Bias, AC Voltage, Aging / MLCC - Control Factor - Capacitance (C) / MLCC - Effect - Impedance (Z), C 10% ↓ → Z 10% ↑ / Vehicle ECU - Control Factor - AC Voltage Ripple (V AC), Z 10% ↑ → V AC 10% ↑ (V AC=I AC x Z) / Vehicle ECU - Effect - A significant increase in ac voltage can cause malfunction List - ESR / MLCC - Control Factor - ESR at SRF / MLCC - Effect - Impedance (Z), C 10% ↓ → Z 10% ↑ / Vehicle ECU - Control Factor - AC Voltage Ripple (V AC), Z 10% ↑ → V AC 10% ↑ (V AC=I AC x Z) / Vehicle ECU - Effect - A significant increase in ac voltage can cause malfunction List - ESR/DF / MLCC - Control Factor - Below SRF / MLCC - Effect - Thermal (Power Loss) / Vehicle ECU - Control Factor - Efficiency / Vehicle ECU - Effect - If the standard specifications are met, few malfunction will occur on ECU List - IR / MLCC - Control Factor - Insulation / MLCC - Effect - Leakage Current / Vehicle ECU - Control Factor - Efficiency / Vehicle ECU - Effect - If the standard specifications are met, few malfunction will occur on ECU List - BDV / MLCC - Control Factor - Voltage immunity / MLCC - Effect - ESD / Vehicle ECU - Control Factor - Reliability / Vehicle ECU - Effect - If the standard specifications are met, few malfunction will occur on ECU

SAMSUNG Characteristics of MLCC, IR, BDV IR and BDV characteristics of MLCC IR and BDV are determined by dielectric material and MLCC structure [IR] Spec. 10,000MΩ or 100MΩ÷C[㎌] Whichever is smaller Test Condition, Rated Voltage, 25℃, 60~120 sec. charging less than 50mA Ex) 10㎌, IR, ILk, 100MΩ÷10㎌ → 10MΩ, 5V/10MΩ → 0.1㎂ or less [BDV] Test Condition Spec., 250% of rated voltage Judgement No dielectric breakdown or mechanical breakdown

SAMSUNG Characteristics of MLCC, TCC, Aging Temperature and Aging characteristics of MLCC - Capacitance of MLCC decreases in over time and high temperature operating conditions ※ Reduced capacitance by long-term storage will be recovered to original capacity when soldering [TCC], [Aging] X5R (%ΔC ±15%, Temperature Range -55~85℃) X7R (±15%, -55~125℃), Y5V (=22/-82%, -30~85℃) Ct=Capacitance value, t hours after the start of aging C0=Initial capacitance value, k=Aging constant, t=Aging time

SAMSUNG Characteristics of MLCC, DC-Bias, Ac Voltage Voltage Bias characteristics of MLCC - The effective capacitance of the MLCC is changed according to the applied voltage condition [DC-Bias] An increase the applied DC Voltage to the MLCC → Dipoles to be aligned in the direction of the DC field → A decrease in the polarization change rate in the AC field → A decrease in capacitance [AC Voltage] An increase the applied AC voltage to the MLCC → An increase the polarization change rate in the AC field → An increase capacitance

SAMSUNG Characteristics of MLCC, IZI Impedance(Z) characteristics of MLCC - Output voltage ripple is proportional to impedance and inversely proportional to capacitance Z=-j/2πf·C+ESR+j2πf·ESL j/2πf = Xc, j2πf·ESL=Xesl Impedance graph by the capacitance, Output voltage ripple by the capacitance

SAMSUNG [Attachment]Characteristics of MLCC Capacitance is generated by dipole that formed by spontaneous polarization - Heat treatment (125℃ ↑) changes the tetragonal structure at 125℃ ↓ → Ti 4 + Spontaneous polarization(Dipole formation) occurs → dielectric constant increases (capacitance ↑) [Cubic] Centered Ti4+ → No Dipole [Tetragonal] Off-centered Ti4+, (+), (-) centers are changed as Ti4+ is biased to one side → Dipole formation (Spontaneous Polarization) → Permittivity ↑ Fig1. MLCC Grid Structure and Polarization phenomenon of BaTiO3

SAMSUNG [Attachment] DC-Bias of MLCC When DC voltage is applied to MLCC, capacitance is reduced - DC voltage is applied to MLCC → Dipoles are aligned in the direction of the dc field → the polarization change rate decreases in the AC field → Capacitance decreases (permittivity ↓) No dc bias, With a small dc bias, With a large dc bias Fig2. Number of dipoles responding to ac-field decreases with increasing DC bias leading to lower capacitance loss

[Attachment] Aging of MLCC The aging of MLCC(BaTiO3) is a process to relieve mechanical stress Structure of BaTiO3 - Tetragonal: a=b"<"c, (="" treatment]="" heat="" [after="" -="" batio3="" of="" effect="" aging="" ↑="" permittivity="" →="" dipole="" center)="" @="" energy="" ti4+(unstable="" off-centered="">150℃), degree of freedom of dipole ↓, [After Aging], 90' dipole formation to relieve mechanical stress(c">"a), degree of freedom of dipole ↓, Cap. ↓ - Variation of capacitance by aging time