BOB ZenerDiodes for ESD/EOS Protection SBS...ESD Protecting Diode 3. Species of Zener Diodes 6....
Transcript of BOB ZenerDiodes for ESD/EOS Protection SBS...ESD Protecting Diode 3. Species of Zener Diodes 6....
BOBSBSTGS
Zener Diodes for ESD/EOS Protection
4. GaN-based LEDs need ESD/EOS Protection1. Basic Functions of Zener Diode
GaN Epi Structure ESD damaged LEDs ESD Endurance
Dead & Degraded LEDs by ESD StrikeESD/EOS : 38 %Fabrication : 26 %
Assembly : 14 %
Mobile Ion : 3 %Good : 4 %
Unknown: 15 %
10-3
10-2
10-1
RT 120 °C
Zener voltage (Vz )Leakage current (Ileak @ -4 V)ESD strength (> ±8 kV)Current drivability (>100 mA)Temperature coefficient (ΔVz/ΔT < a few mV/K)
Zener breakdown
- Tunneling probability(Θ)
- Tunneling current(Jn)
Jn=qvRn ΘvR: Richardson velocity
Key Device Parameters
⎟⎟⎟
⎠
⎞
⎜⎜⎜
⎝
⎛−=Θ
ε
23
*234exp gE
qmh
60
80
100
2. ESD/EOS Models and Standards 5. Configuration for LED Protection
-10 -8 -6 -4 -2 0 2 410-12
10-11
10-10
10-9
10-8
10-7
10-6
10-5
10-4 150 °C 180 °C
Cur
rent
(A)
Voltage (V)
Ileak
Tunneling
Rz
Vz
-10 -8 -6 -4 -2 0 2 4-100
-80
-60
-40
-20
0
20
40
60
Cur
rent
(mA
)
Voltage (V)
HBM
MM
IEC61000-4-2 : HBM + CDM
IEC61000-4-4 : EFT
Strong TransientVoltage(ESD, Surge, EFT) Weak
Clamped Voltage
Reverse
Forward
BypassExcessCurrent
Circuit/Deviceto protect
VP ~ ±8 kVVC <~ 20 V
Light emitting chip
ESD Protecting Diode
6. Effective Protection of GaN-based LEDs3. Species of Zener Diodes
IEC61000-4-5 : Lightning SurgeCDM
Single Chip DualPad Series Connection(Cathode to cathode)
LED
Zener
Single Chip DualPad Series Connection(Anode to Anode)
Zener
LED
Single Chip DualPad Parallel Connection
Zener
LED
GeneralConnection of ZenerDiode with LED chip
Zener
LED
6 Effective Protection of GaN based LEDs3 Species of Zener Diodes
Double Pad StructureSingle Pad Structure
N-Substrate
P+ P+
P-Substrate
N+ N+
N-Substrate
P+
P-Substrate
N+
Triple Pad Structure
Unidirectional
10-5
Room Temp. 10-1
ESD(HBM) Strength
LED only : ±0.3 ~±7 kV
LED+Zener : > ±8 kV
P-Substrate
N+ N+N+
N-Substrate
P+ P+P+
P-Substrate
P+
N-
N-Substrate
N+
P-
Triple Pad StructureBidirectional
0 1 2 3 4 5 6 7 8 910-9
10-8
10-7
10-6
Reverse Voltage 5 V 6 V 10 V
Rev
erse
Lea
kage
Cur
rent
(A)
ESD Voltage (kV)
BeforeESD Zap
with Zener diodeESD ±8kV, 5 times
without Zener diode
-20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0 2 410-9
10-8
10-7
10-6
10-5
10-4
10-3
10-2
25 °C 70 °C 110 °C
ESD : ± 8.0 kV, 5 times
Cur
rent
(A)
Voltage (V)
LED+ZenerLED only
Various Applications
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Various Applications