Technical Guide(1190KB)

Technical Guide
Electric Double Layer Capacitors
（Gold Capacitor）
2016.01 http://industrial.panasonic.com/ww/products/capacitors/edlc
E7.8
Contents
1.
Introduction
………1
2.
Principles and features of Gold capacitors
………2
………2
………3
………4
2-1
What are electric double layer capacitors?
2-2
Construction and principle of electric double layer capacitor
2-3
Equivalent circuit
2-4
Electrical characteristics of electric double layer capacitor
2-5
Features
3.
Product type & selecting method of Gold capacitors
3-1
Product system
3-2
Construction, features and applications of each type
3-3
Applications in typical sets and recommended series
3-4
Basic idea for product selection
4.
Operational technique of Gold capacitor
4-1
Life design
4-2
Notes in using Electric Double Layer Capacitors
4-3
When making an order
5.
Gold capacitors Characteristics data
………6
………8
………10
………10
………11
………14
………15
………16
………16
………18
………24
………25
E7.8
1. Introduction
Electric Double Layer Capacitors (Gold Capacitor) were developed by the Central Research Laboratory of
MATSUSHITA ELECTRIC INDUSTRIAL COMPANY in 1972, then marketed and sold on a worldwide basis in
1978. Because these capacitors function as a battery, they are ideally suited for applications requiring a
secondary power source such as a back-up energy source for microprocessors and solar battery.
This product specification manual summarizes the technical characteristics of Gold Capacitors for use in
electronic devices.
Panasonic Gold Capacitor products meet our strict technological standards.
reviewing this manual, please feel free to contact us with your opinions or questions.
1
Upon
E7.8
2. Principles and Features of Gold Capacitors
2-1 What are electric double layer capacitors?
Generally, capacitors have dielectric between two opposite electrodes. For example, Aluminum Electrolytic
Capacitors use an aluminum oxide film, and Tantalum Capacitors use a tantalum oxide film as dielectric.
However, the electric double layer capacitor does not have dielectric but uses a physical mechanism that
generates an electric double layer which performs the function of dielectric, hence, the name Electric Double
Layer Capacitor. The charge-discharge factor in the element of electric double layer capacitors is an ion
absorption layer which is formed on the surface of the positive and negative electrodes of activated carbon,
to utilize absorption-desorption reactions.
Positive electrode
activated carbon
Anion
Electric double layer Charge
Negative electrode
activated carbon
Cation
Discharge
(Fig.1)
In an electric double layer capacitor, there are two types of electrolyte systems used. One is water soluble
and the other is non-water soluble. The non-water soluble electrolyte can increase the withstand voltage per
one cell compared to water soluble electrolyte. Our Gold Capacitors are constructed with non-water soluble
electrolyte, and feature small size and light weight.
The capacitance range of Gold Capacitors is mid-range between aluminum electrolytic capacitors and a
secondary battery. For application, it is mainly used as a secondary battery.
Capacitance
[Farad]
10-6
10-4
10-2
100
102
104
Aluminum electrolytic capacitor
Gold capacitor
Secondary battery cell
2
106
E7.8
The benefits of Gold Capacitors are small size and high capacitance. Gold Capacitors are used to backup
the real-time clock or memory as substitutions for secondary batteries. The examples are RTC backup of
DVD, fax, telephone, DSC, mobile phone and stereo. Recently, Gold Capacitors are in the spotlight as a
hybrid power supply system by the combination with the solar cell.
2-2 Construction and principle of electric double layer capacitors
A cross-sectional drawing of a coin-shaped
Activated
carbon electrode
single cell Gold Capacitor is shown in Fig.2.
Top cover
The electrode within the cell is made from
activated
carbon.
The
electrode
is
Separator
then
impregnated with an electrolyte. A separator with
Packing
high insulating properties against ion penetration
is positioned between both electrodes to prevent
short circuiting. Sealing is completed by adding
Bottom case
packing between the top cover and bottom case.
(Fig.2)
An electric double layer is a state where a very
thin ionosphere is formed to the boundary of the electrolyte and the electrode (Shown in Fig.3.). Electric
charge can be charged by applying the voltage (shown in Fig.4.)
Liquid
(Electrolyte)
Solid
(Activated)
Activated
Carbon
Activated
Carbon
Electric double layer
(Fig.3)
(Fig.4)
The electric double layer acts as an insulator and does not allow current flow when an external DC voltage
is applied. However, as the voltage is increased, an avalanche point is reached and current will begin to flow.
The magnitude of this voltage is the “decomposition voltage”. Further increasing this voltage will cause the
electrolyte to decompose causing additional current flow. The withstand voltage of Gold Capacitors is
determined by the decomposition voltage. The decomposition voltage is decided with electrolyte and
electrode material that composes Gold Capacitors.
Gold capacitors use an activated carbon electrode (solid) and an organic electrolyte (liquid). Electric double
layer formed to the interface of the electrode and electrolyte is very thin like a molecule. The activated
carbon used for the electrode is a very large surface. Therefore, it becomes very high capacitance.
Panasonic uses high withstand voltage organic electrolyte and products can be miniaturized.
3
E7.8
2-3 Equivalent circuit
The same equivalent circuit used for conventional capacitors can also be applied to Gold Capacitors.
In an electric double layer capacitor, the electric double layer is formed on the surface of the activated
carbon that is in contact with the liquid electrolyte. This is shown in Fig.5.
Because activated carbon particles are used as electrodes, each carbon layers as in Fig.5 functions as an
electric double layer capacitor having a capacitance value of Cn. In order for the capacitance Cn to charge,
two resistances are needed and are described in Fig.6.
Current
collector
Electrolyte
Resistor to charge
Activated
carbon
Separator
Electric double
layer capacitor
Current
collector
Resistor to move ions
(Fig.5)
As can be seen in Fig.6, resistance R1 moves ions while resistance Rs
is the charging resistance. The double layers formed on the activated
carbon surfaces can be shown as parallel circuits.
The resistances values can increase or decrease depending on the
distance between the current collectors, speed of ions, contact
resistance between the activated carbons, etc.
Particle type
activated carbon
The equivalent circuit of an electric double layer capacitor is shown by
the parallel R-C combinations shown in Fig.7.
(Fig.6)
R1, R2 and Rn are the internal resistance
RL
(Insulation resistance)
of the activated carbons. C1, C2 and Cn
R1
are the capacitance of the activated
carbons having resistances R1, R2 and
C1
C2
R2
Rn.
Rn
(Fig.7)
4
Cn
E7.8
When applying a simple CR series circuit, the charging current (i) when the voltage (V) is applied decreases
according to formula-(1). The value of the charging current decreases at charging time(t) . However, the
actual charging current curve is exponential.
i = V exp( -t )
R
C R
C1
C2
Rs
Re1
Re2
R2
R1
C1, C2
Re1,Re2
R1,R2
Rs
(1)
: Electric double layer capacitance
: Electrode resistance
: Insulation resistance
: Separator resistance
(Fig.8)
(Fig.9)
If one considers the equivalent circuit of the electric double layer capacitor shown in Fig.8 as having many
small capacitors (Cn) with various internal resistances (Rn), then the current that flows through an individual
capacitor can be represented by formula-(2).
in =
V exp( -t )
Rn
Cn Rn
(2)
Therefore, the current(i) within the capacitor can be regarded as the sum(in) of the currents flowing
through each of the small capacitors. It also can be seen that if the CR value is small, the charging time will
be short. Conversely, if the CR value is large, the charging time will be long. The sum of the small capacitor
charging currents is shown in Fig.10.
It should be noted that if the charging time is limited
to only several minutes, or the charging source is
current limited, the Electric double layer capacitor
may not be sufficiently charged to provide the
required backup energy for the time needed. If the
capacitor is not sufficiently charged and is called upon
to discharge its energy into a load, the discharge
current will flow from a high voltage level to a low
voltage level thereby causing a low terminal voltage.
(Fig.10)
5
E7.8
These conditions are shown in Fig.11, 12.
I1
I2
I3
R1
C1
R2
C2
R3
C3
R4
C4
Just after charging
After discharging
V1 =V0
V2
V3
V4
V0 = V1 > V2 > V3 > V4
V0 > V1 = V2 = V3 = V4
(Fig.12)
(Fig.11)
2-4 Electrical characteristics of electric double layer capacitors
2-4-1 Capacitance
The capacitance of an electric double layer capacitor differs from the battery and is not influenced by the
measurement condition in theory. However, it is influenced by internal resistance and leakage currents.
Therefore, the electrical characteristics change depending on the measurement condition.
As previously stated, the electric double layer capacitor is comprised of many small capacitors having
various values of resistance. Therefore, in order to measure the capacitance, measurement parameters
such as charge voltage and charge time must be defined.
If the starting voltage is set slightly below the fully charged voltage value (V0), then the voltage down
condition shown in Fig.13 will occur at the start of measurement. This is due to the small capacitors that
have large internal resistance not being fully charged which results in a large voltage drop at the start of
measurement. With this condition, the measured capacitance value will be small.
However, by increasing the charging time, the small capacitors with high resistances will become charged
and the voltage lost during the voltage down condition will be small resulting in a high measured value of
capacitance. See Fig.13.
In addition, the capacitance is influenced also by the current. Therefore, we use 1mA/F as a standard of
the measurement current. (It is discharged by the constant current for each 1F of 1mA.)
E (V)
V0
IR drop
C=
IT
(V1 – V2)
(Farad)
(3)
V1
V2
Charging time
T
t (s)
(Fig.13) Electrostatic capacitance test
6
C : Capacitance(F)
I : Test current(A)
T : Test time(s)
V1  V2: Testing voltage range(V)
E7.8
2-4-2 Internal resistance
As previously described, the equivalent circuit of an electric double layer capacitor consists of many small
capacitors having various internal resistance values. Normally, the values of these resistors would be
expressed in DC values. However, so that a true picture may be established, we will use impedance
(1kHz) as the parameter and being that the DC resistance and Z value are not equal, we must consider
their relationship under current conditions.
2-4-3 Current
If current is measured 30 to 60 minutes after the application for rated voltage, quite a large current
(several 10A) will be present. This is due to the fact that the measured current is the sum of the charging
currents that is flowing within the many small capacitors shown in the equivalent circuit. As it is extremely
difficult to determine the leakage current of electric double layer capacitors, the current value specified as
the leakage current is somewhat meaningless. It takes a minimum of 10 hours to fully charge the capacitor
so that a meaningful leakage current value can be obtained.
2-4-4 Charging characteristics
The charging characteristics of an electric double
layer
capacitor
can
be
represented
by
the
equation(4) below:
-t )
V = V0{1  exp(
}
CR
(4)
Because of the many internal resistances within
the electric double layer capacitor, no external
current limiting resistor is needed.
(Fig.14)
2-4-5 Discharging characteristics
Self discharge characteristics
The self discharge characteristic of an electric double layer capacitor is shown in equation (5).
V = V0 exp( -t )
C RL
(5)
RL: Insulation resistance
This Fig.15 shows ideal self-discharge in the state
that
the
product
is
completely
charged.
The
self-discharge changes actually by the influence at
charging time.
(Fig.15)
7
E7.8
Characteristics of constant current and constant resistance discharging
The time required for the constant current and constant resistance discharging are respectively presented
by the equations (6) and (7) below
Discharging time (t) of constant current discharge
t=
C(V0 – V1)
I
(6)
Discharging time (t) of constant resistance discharge
t = C R ln(
V1
V0
)
(7)
t : Charging time
C : Capacitance
V0: Initial voltage
V1: Terminal voltage after t(s)
I : Constant current load
R : Constant resistance load
The above equations may not always be accurate, as the terminal down voltage must be considered after
the start of discharge if load resistance or load current is present.
Backup characteristics for IC
Also, if the capacitor is used to backup and IC, the V-I characteristics of the IC must also be considered. It
can therefore be said that if the voltage is low, the current is also low and the actual backup time will be
longer than that calculated. To be certain that the capacitor selected is of sufficient value to maintain the
necessary energy and time, it should be checked and measured under actual operating conditions.
2-5 Features
The capacitance of an electric double layer capacitor can be expressed by equation (8)
C 
S
d
(8)
d = thickness of electric double layer
s = area of an activated carbon
It should be noted that the area of an activated carbon is approximately 2500 m2/gram and the thickness of a
double layer is less than a molecule. From this, it can be readily seen that the capacitance of an electric or
double layer capacitor is several times greater than of an aluminum electrolytic capacitor.
The internal resistance of an electric double layer capacitor is quite high compared to an aluminum
electrolytic capacitor and because of this it should not be used as a filter in an AC application. These devices
are specifically designed for energy backup applications and secondary power sources.
8
E7.8
Wide range for each application
These are wide range of Gold Capacitors from the coin type which is primarily used as RTC backup to the
HW series which need large current.
Limited life
Gold Capacitors have a limited life .
However, they have a capability that can be fully used within the life of equipment when used under the
proper conditions. (Refer “The Life” in details)
Therefore, you don’t need to replace the battery. Also, in overseas, there are many regulations for batteries.
It can be said Gold Capacitors are the best source for use in overseas.
Wide operating temperature range
Compared to Gold Capacitors, batteries lose much of their energy with exposure to heat and are
susceptible to leakage with exposure to temperatures below 0C. Gold Capacitors are suitable where the
operating temperature conditions are need to be considered, such as automobile stereo set for import, etc.
No need of charge control
Secondary batteries generate heat for over-charge and discharge, which make the life shorter. A charge
control circuit is needed. However, Gold Capacitors have no limit for charge and discharge and do not need
a charge control.
Speed charge, repeated charge/discharge cycles
Speed charge is possible for Gold Capacitors. Repeated rapid charge and discharge cycles are acceptable
because there is no internal chemical reaction like batteries. It suits the circuit that repeats charge and
discharge for a short time, which can not take a long charge time.
Good for environmental as secondary source
There are no toxic materials such as cadmium, mercury in Gold Capacitors. Europe has recently restricted
the use of products containing toxic materials due to pollution, and this action will be expanded. Our Gold
Capacitors do not use cadmium and mercury. And LED lights using our Gold Capacitors are very popular for
clean energy applications in Europe. Thus, Gold Capacitors are suitable for Europe and America where the
restriction will be stricter.
9
E7.8
3. Product type & selecting method of Gold Capacitors
3-1 Product system
For µA
SD/SG/NF
-series
Rated voltage: 5.5V
-40,-25 to +70C
Standard
SE-series
Rated voltage: 5.5V
-40,-25 to +70C
Taping
F-series
Rated voltage: 5.5V
-40,-25 to +85C
High reliability
RF-series
Rated voltage: 5.5V
-40,-25 to +85C
High reliability, 2000hrs
RG-series
Rated voltage: 3.6V
-40,-25 to +85C
High reliability, 2000hrs
HW-series ｼ
Rated voltage: 2.3(2.1)V
-25 to +70(60)C
Gold Capacitor
For mA to A
HZ-series
Rated voltage: 2.5V
-25 to +70C
Miniaturized
HL-series
Rated voltage: 2.7V
-40 to +65C
Low ESR, 2000hrs
Capacitance range
Standard
Series
104 224 334 474 684 105 155 335 475 106 226 306 506 706 107
SD
O
SE
O
SG
Low ESR
High
Reliability
NF
F
O
O
RG
RF
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
HZ
O
O
O
HW
O
HL
O
O
O
Capacitance code: 104=0.1F, 105=1F, 106=10F
*HW706:2.1V
10
O
O
E7.8
3-2 Construction, features and applications of each type
3-2-1 Coin style cell
(Construction)
The structural drawing of Coin type Gold Capacitor
is shown in Fig.16.
The activated carbon used as the electrode is
solidified in powder activated carbon. This activated
carbon is connected with the cover and the case
through a conductive point. This separator functions
as an insulator but does not restrict the movement
of ions through it. Packing is added to seal the cover
and case.
(Features)
(Fig.16)
The physical appearance looks like a coin type
battery. Unlike the battery, Coin type Gold Capacitor does not need charge/discharge control circuit, and
it is good for the environment.
(Applications)
1. Memory backup during battery replacement of mobile phone, DSC and PDA.
2. Secondary power source for solar watches.
18
9
Coin type cell
(Fig.17)
11
E7.8
3-2-2 RF, F and NF series
(Construction)
The RF, F and NF series capacitor is constructed
with 2 or 3 coin style cells series, and connected
with a spring plate. (Fig.18)
(Features)
The maximum operating temperature of RF/F
series is 85C, and suitable for conditions at
relatively
high
temperatures
such
as
car
audio ,electronical formula meter etc. It can be
used for the set which needs long life because it
has over double long life compared to 70C
(Fig.18)
products(The RF series has five times or more
longevity for the guarantee products of 85℃2000 hour.)
We also have low profile product (70C guarantee) for NF series.
(Application)
RF/F series
1. Memory backup for equipment used at relatively high temperatures (car audio, industrial robot, etc.)
2. Memory backup, data backup for equipment requiring relatively long life (computer, office apparatus,
etc.)
NF series
Memory backup for equipment requiring low profile (DVD, audio)
3-2-3 RG, SG, SD and SE series
(Construction)
These series are constructed from two series connected cells in connector cup by laser and welded
terminals in it. It is the smallest construction in the series products. (Fig.19)
(Features)
Type SD series are designed for miniaturization. There are type H for low profile (Fig.20) and type V for
reduction of mount area (Fig.21). SE series (Fig.22) has a standard packaging format of tape and box for
automatic insertion. These products are small and light, can be used for general equipment with 3 series
including taping.
(Fig.19)
(Fig.20)
12
(Fig.21)
(Fig.22)
E7.8
(Applications)
Memory backup for general equipment (DVD, TV, Audio, etc.).
(RG-series (70C 2000h) can be used for the same usage as RF/F-series)
3-2-4 HW / HZ / HL series
(Construction)
Series HW /HZ / HL are constructed from activated
carbon particles which are mixed with a binder then
deposited on strips of aluminum foil. Then, lead wire
is connected, and these foil strips are wound together
with a separator and inserted into aluminum case.
Electrolyte is added, the case is then sealed with a
rubber packing and sleeved (Fig.23).
(Features)
These series are developed for use in applications
requiring large current, its internal resistance is less
than 1/100 of general products. Due to the
development of this product, application of Gold
capacitor expanded from memory backup to motor
driving. For example, the motor can work over 3
minutes with charging for a few seconds. Over 100
thousand times of charge/discharge is possible, so
that it is suitable for the applications such as toys and LED light.
(Applications)
1. Solar battery circuit (e.g. Road guidance flasher, LED light)
2. Toys (Motor-drive)
3. Server/Storage
13
(Fig.23)
E7.8
3-3 Applications in typical sets and recommended series
Application in typical sets and recommended series
Set
DVD/Blu-ray
Application
At the time of power failure and a power supply off,
recorder
For RTC and channel backup
Digital TV
At the time of power failure and a power supply off,
For RTC and channel backup
PC, Server, Storage,
Data center
Mobile phone
At the time of power failure and a power supply off,
For RTC and channel backup
At the time of power failure and a power supply off,
base station
For RTC and channel backup
Inkjet printer
At the time of power failure and a power supply off,
For the time of intact backup
Smart meter
At the time of power failure,
For RTC and data backup
Recommended
series
SD, SG
SD, SG, NF
RF, F, RG,
HW, HZ, HL
RF, F
HW, HZ,HL
SD, SE, SG, NF
RF, F, RG
At the time of power failure,
For sending data
LED light with solar
battery
Toy (Motor drive)
FA, Robot, IPC
For LED lighting in the night
(Charges by the solar cell in daytime)
For motor drive
At the time of power failure and a power supply off,
For RTC and data backup
Car audio (Memory)
Drive recorder
At the time of battery exchange. For RTC backup
At the time of traffic accident,
For data backup
14
HW, HZ
HW, HZ, HL
HW, HZ
RF, F
RF, F, RG
HW, HZ
E7.8
3-4 Basic idea for product selection
3-4-1 Estimated enough initial backup time
Backup time of Gold Capacitors decrease with use and time. Especially, where the applied current is
large or the operating condition is severe such as high temperature, backup time decreases a lot.
Therefore, initial backup time should be considered to have enough margins.
Avoid setting the minimum backup time. (Refer the life design in details)
3-4-2 Select the optimum Gold capacitor according to applied current
Where the applied current of Gold Capacitors is large, flash voltage drop (IR drop) may occur by the
applied current and internal resistance of Gold Capacitors when changing to backup mode. Therefore,
product should be selected according to operating applied current. The amount of applied current
(discharge current) has different resistance against product kind, so that we recommend the current shown
in chart below. (Please consult Panasonic when the applied current is used beyond recommendation
range.)
Maximum operating (discharge) Current
Series
0.1 to 0.33F
0.47 to 1.5F
3.3 to 4.7F
10F to 70F
SG, SD, SE, NF
300A
1mA


F
300A
1mA


RG(-40℃/-25℃)
300A / 1mA
1mA / 20mA
RF(-40℃/-25℃)
300A / 3mA
1mA / 20mA
－
－
HW/HZ


300mA
1A
HL



10A
15
E7.8
4. Operational technique of Gold Capacitor
4-1 Life design
4-1-1 Useful life
Gold Capacitors have a limited life the same as aluminum electrolytic capacitors. It is greatly different
depending on use conditions. Therefore, the useful life of Gold Capacitors can be considered the time that
is satisfied with backup time set by customers in their use conditions.
4-1-2 Example of expected life
Generally, the Arrhenius low (Double-speed acceleration at 10C) is applied to similar aluminum
electrolytic capacitor. The guaranteed life time of Gold Capacitors is
After 1000 hours at 70C (SD/SE/SG/NF)
Capacitance change: 30% of initial value
Internal resistance: 4 times or less of initial spec value
(Refer to the SPEC sheet or catalog for details)
When assuming that this capacitor is used at 30C, the expected life becomes following.
70 – 30
T30 = 1000 2 10
= 16000 [hours]
Please have the margin in initial capacitance, when you use Gold Capacitors. As a result, there is a
possibility to be able to back up even if the capacitance becomes over the minus 30%. In this case, please
refer to Chapter 5 in this book “Gold capacitor characteristic data” and Panasonic web for the reliability test
data for the typical value of the characteristic change of our Gold Capacitors.
Example of calculating backup time
The case to use the SG series Gold Capacitor EECS5R5V155 in the following conditions is calculated.
Applied voltage ; 5.5V
Cut-off voltage ; 2V
Current during backup ; 10uF
The backup time after 70℃2000 hour is forecast from data. (We think the item of the leakage current is
0.8uA in this case. )
The characteristic after 70℃2000 hour (reference to data of Chapter 5)
Capacitance change about -32%，Internal resistance 120Ω
The Initial capacitance 1.2[F] （1.5[F] about -20%）
t = CV/I
t: Backup time (s)
=C  (V0iｘRV1)/(I+ iL)
C: Capacitance of Gold capacitor (F)
= 1.2ｘ0.68  (5.50.00122)/((10+0.8)10 )
-6
16
V0: Applied voltage (V)
E7.8
=260000s
V1: Cut-off voltage (V)
=73hours
i: Current during back-up (A)
iL: Leakage current(A)
R: Internal resistance () at 1kHz
70℃2000 hour is converted by applied the Arrhenius low (Double-speed acceleration at 10C) and the
calculation shows the backup time to be 79 hours after 3.6 years.
Even if the endurance change rate is exceeded with room in initial capacitance on the real use, with room
in initial capacitance, Gold Capacitor can be still used (It is possible to backup). It seems that the life time is
postponed. However the characteristic change has not been decreased in this case and the life of the Gold
Capacitor has not been postponed. The circuit of each equipment will be designed on the condition that
can be used even if the life of the Gold Capacitor is exceeded.
Generally, to decrease the capacitance change in the Gold Capacitor please refer to the following.
① The use temperature (ambient temperature) is lowered
As for the characteristic change in the Gold Capacitor, the Arrhenius low (Double-speed
acceleration at 10C) is applied generally as previously mentioned. The expected life becomes
double by lowering the temperature at 10℃.
② The 85℃ guarantee products are used.
The expected life increases to about 2.8 times that of 70℃ guarantee products when using it at the
same temperature.
③ The applied voltage to the Gold Capacitor (charge voltage) is lowered.
The applied voltage influences the characteristic change in the Gold Capacitor. The acceleration
calculation like the temperature acceleration is not clear now.
However, in the case 5.5V products are used by 5.0V: about 1.3 times. In the case 5.5V product
are used by 3.3V: about 2.8 times. This kind of level can be expected. (The RF/F series is
excluded. )
④ The electrical charge and discharge is intermittent and the charging time is shortened.
The characteristic change of Gold Capacitor is not influenced from electrical charge and discharge
cycle number but from the time that the voltage is applied. Therefore, please design for the electrical
charge and discharge when it is necessary. The characteristic change can be suppressed at time
that is not charged.
The result that a very long term backup can be expected in calculation might be obtained by use
conditions. However, please consider checking regularly and exchanging it when using it for the set that
long-term reliability is basically demanded from the Gold Capacitor.
17
E7.8
4-2 Notes in using Electric Double Layer Capacitors
4-2-1 Circuit design
4-2-1.1 Product Life
Electric Double Layer Capacitors (Gold Capacitors, hereafter referred to as capacitors) have a
limited life.
The life of
an electric
double layer capacitor is limited. Its capacitance will decrease and its internal
resistance will increase over time.
The life of a capacitor greatly depends on the ambient temperature, humidity, applied voltage and
discharging currents. Capacitor life can be extended when these parameters are set well below the
ratings.
The guaranteed durability of electric double layer capacitors is between 500 hours at 60C and 2000
hours at 85C. Generally, it is 1000 hours at 70C. The life of the capacitor is guaranteed to be 16000
hours at a normal temperature (30C) by applying the acceleration double for every 10C.
If your application incorporates this capacitor over a long period of time then check it periodically and
replace it when necessary.
4-2-1.2 Polarity and voltage
Capacitors have polarities
Do not apply a reverse or AC voltage. If a reversed voltage is applied to a capacitor for a long period of
time, then its life will be reduced and critical failures such as electrolyte leakage may occur.
Do not apply an over-voltage (a voltage exceeding the rated voltage).
If voltage exceeding the rating is applied to the capacitor for a long time, then its life will be reduced and
critical failures such as electrolyte leakage or physical damage due to gas generated by electrochemical
reaction or explosion may occur.
4-2-1.3 Circuits through which ripple currents pass
When using a capacitor in a circuit through which ripple currents pass, monitor the allowable temperature
range.
The internal resistance of electric double layer capacitors is higher than that of electrolytic capacitors.
Electric double layer capacitors may generate heat due to ripple currents.
The allowable temperature rise due to ripple currents is 3C measured on the surface of the capacitor.
4-2-1.4 Ambient temperature and product life
Capacitor life is affected by usage temperatures. Generally speaking, capacitor life is approximately
doubled when the temperature is decreased by 10C. Therefore, lower the usage temperature as much
as possible.
Using capacitors beyond the guaranteed range may cause rapid deterioration of their characteristics and
cause them to break down.
The temperature referred to here includes the ambient temperature within the equipment, the heat
18
E7.8
produced by heat generating devices (power transistor, resistors, etc.), self-heating due to ripple currents,
etc. Take all of these factors into consideration when checking the capacitor’s temperature.
Do not place any heat generating devices on the back of the capacitors.
Life acceleration can be calculated with the following equation:
L2 = L1
2
T1 – T2
10
L1:Life at temperatureT1C(h)
L2:Life at temperatureT2C(h)
T1:Catregory’s upper limit temperature(C)
T2:Ambient temperature to calculate the life + heat
generation due to ripple current(C)
Humidity also affects the capacitor’s life. When using capacitors outside the following conditions, please
contact Panasonic.
A temperature at +55C and a relative humidity of 90% to 95% for 500 hours.
4-2-1.5 Voltage drop
Pay particular attention to the instantaneous working current and the voltage drop due to the capacitor’s
internal resistance when used in backup mode. The discharging current level is different depending on
the capacitor’s internal resistance. Use a capacitor below maximum discharging current. (Ref 3-4)
4-2-1.6 Series connection
When connecting capacitors in series, add a bleeder resistor in parallel with each capacitor by taking the
leak current into consideration so that the balanced of voltages is not disrupted.
4-2-1.7 Electrolyte is used in the products
Electrolyte is used in the capacitors. Therefore, misuse can result in rapid deterioration of characteristics
and functions of each product. Electrolyte leakage will damage printed circuit boards and can affect their
performance, characteristics, and functions.
4-2-1.8 External sleeve
The external sleeve is not electrical insulation, and thus capacitors should not be used in an environment
that requires electrical insulation.
4-2-2 Mounting
4-2-2.1 Heat stress due to soldering
When soldering a capacitor to a printed circuit board, excessive heat stress could cause the deterioration
of the capacitor’s electrical characteristics. For example, the integrity of the seal can be compromised
causing the electrolyte to leak, and short circuits could occur in addition to failure of appearance.
Please observe the following guidelines:
(1) Manual soldering
19
E7.8
Do not touch the capacitor body with a soldering iron. Solder the capacitor using a soldering tip
temperature of 350C or less for 4 seconds or less. Solder the capacitor three times or less at
intervals of 15 seconds or more.
(2) Flow soldering
1) Do not dip the body of the products into a soldering bath.
2) Keep the product’s surface temperature
Flow soldering
at or below 100C for no more than 60 seconds
(the peak 105C) when soldering.
Please refer to the chart at right to set soldering
conditions. It is recommended to check the product temperature before you use.
3) The terminals of the NF/F/RF type are
designed so the bottom of the product
floats from the PCB.
This is to protect against heat stress
during soldering. Do not touch the bottom
of the product directly to the PCB.
(3) Other heat stress
1) Keep the product’s surface
temperature at or below 100℃ for no more
than 60 seconds (the peak 105℃) when applying
heat to bake the PCB or fixing resin, etc.
The capacitor voltage must be 0.3V or less.
2) Do not use a product more than once after it has been mounted on the PCB. Excessive heat
stress is applied when detaching it from the PCB. Please observe “(1) Manual soldering” when
adjusting it.
3) Be sure that excessive heat stress is not applied to the Gold Capacitor when other parts in its
surroundings are detached or adjusted.
(4) Others
1) The lead wires and terminals are plated for solderability. Rasping lead wires or terminals may
damage the plating layer and degrade the solderability.
2) Do not apply a large mechanical force to the lead wires or terminals. Otherwise, they may break
or come off or the capacitor characteristics may be damaged.
4-2-2.2 Circuit Design
Do not set wiring pattern directly to the mounted capacitor, and pass between terminals. If the electrolyte
leaks, short circuit may occur and tracking or migrations are anticipated.
If a capacitor is directly touching a PCB, then the bottom of the capacitor and the circuit pattern may
short-circuit. On PCBs, blowing flux or solder may cause the capacitor’s external sleeve to break or
shrink, potentially affecting the internal structure.
20
E7.8
4-2-2.3 Residual voltage
Gold Capacitors can hold a large charge and could have residual voltage. Therefore, some electronic
components with a low withstand voltage, such as semi-conductors, may be damaged.
Since Gold Capacitors can hold great charge, there may be residual electric charge that could damage
other low-withstanding voltage parts such as semiconductors.
4-2-2.4 Circuit board cleaning
Apply the following conditions for flux cleaning after soldering. (Excepted for NF,F and RF series)
Temperature: 60C or less
Duration: 5minutes or less
Rinse sufficiently and dry the boards.
[Recommended cleaning solvents include]
Pine Alpha ST-100s, Sunelec B-12, DK be-clear CW-5790, Aqua Cleaner 210SEP, Cold Cleaner P3-375,
Cllear-th-ru 750H, Clean-thru 750L, Clean-thru 710M, Techno Cleaner219, Techno Care FRW-17,
Techno Care FRW-1, Techno Care FRV1
 Consult Panasonic if you are using a solvent other than any of those listed above.
 The use of ozone depleting cleaning agents is not recommended in the interest of protecting the
environment.
4-2-3 Precautions for using equipment
Avoid using mounting equipment in environments where:
(1) Capacitors are exposed to water, salt water or oil.
(2) Capacitors are exposed to direct sunlight.
(3) Capacitors are exposed to high temperature and humidity where water can condense on the
capacitor surface.
(4) Capacitors are subject to various active gases.
(5) Capacitors are exposed to acidic or alkaline environments.
(6) Capacitors are subject to high-frequency induction.
(7) Capacitors are subject to excessive vibrations or mechanical impact.
A brown excretion might be caused around the sealing, depending on the conditions of use. This
excretion is insulation and does not have influence on the electrical characteristics.
4-2-4 Maintenance Precautions
Periodically check capacitors used in industrial equipment. When checking and maintaining capacitors,
turn off the equipment and discharge the capacitors beforehand. Do not apply stress to the capacitor lead
terminals.
Periodically check the following items.
(1) Significant appearance abnormalities (deformation, electrolyte leakage, etc.)
21
E7.8
(2) Electrical characteristics (described in the catalog or delivery specifications)
If any abnormalities are found, then replace the capacitors or take appropriate actions.
4-2-5 Emergency procedures
If the capacitors generate heat, then smoke may come out of the exterior resin. Under these conditions
turn off the equipment immediately and stop using it.
Do not place your face or hands close to the capacitor, burns may be caused.
4-2-6 Storage
Do not store capacitors in a high-temperature or high-humidity environment. Store capacitors at a room
temperature of 5C to 35C and a relative humidity of 85% or less.
Store capacitors in their packaging as long as possible.
Avoid storing capacitors under the following conditions.
(1) Exposed to water, high temperatures or humidity, or when condensation can occurs.
(2) Exposed to oil or in environments filled with gaseous oil contents.
(3) Exposed to salt water or environments filled with saline substances.
(4) In environments filled with harmful gases (hydrogen disulfide, sulfurous acid, nitrous acid, chlorine,
bromine, bromomethane, etc.)
(5) In environments filled with harmful alkaline gases such as ammonia.
(6) Exposed to acid or alkaline solvents.
(7) Exposed to direct sunlight, ozone, ultraviolet or radial rays.
(8) Exposed to vibrations or mechanical impact.
4-2-7 Discarding
Dispose of capacitors as industrial waste. They are comprised of various metals and resin.
4-2-8 Others
4-2-8.1 The purpose of these specifications is to ensure the quality of components as individual
components. Before use, check and evaluate their operation when mounted on your products.
4-2-8.2 Do not use our components outside of the corresponding specifications.
4-2-8.3 When using this capacitor in a product where safety is critical
We take great care in the quality of this product. However, performance may deteriorate and
short-circuiting or open-circuiting may occur. If it will be used in transportation equipment (e.g. trains,
cars, traffic lights), airborne equipment, aerospace equipment, electric heating appliances,
combustion/gas equipment, rotating equipment, disaster/crime prevention equipment, or other
equipment where a defect in this component may cause the loss of human life or other significant
damage. Ensure that the target equipment has a failsafe design and is provided with the following
22
E7.8
systems to guarantee adequate safety.
(1) Ensure the safety of the whole system by installing a protection circuit and a protection
device.
(2) Redundant circuits, etc. to maintain the safety of the entire system so that a single
independent failure will not lead to unsafe conditions.
4-2-8.4 Conditions of use
This products is intended to be use in electronic equipment for general-purpose standard applications
and is not designed for use in any special environments. When this capacitor is used in a special
environment or under special conditions, its performance may be affected. Before use, verify the
performance and reliability of the capacitor.
The precautions for the use of Electric Double Layer Capacitors (Gold Capacitor ) follow the “Precautionary
guidelines for the use of fixed Electric Double Layer Capacitors for electronic equipment”, RCR-2380A issued
From EIAJ in July, 2008.
23
E7.8
4-3 When making an order
When ordering Gold Capacitors, please provide information on the items below,
Inquiry check list
Gold Capacitor / Check sheet
Application
Condition of Charging
Charging Voltage
Charging Time（Max. Min.）
Charging Current
（Balanced Resister, If any）
Condition of Discharging
Backup Current
（Max. Min. Typical.）
Minimum Holding Voltage
Required Backup Time
Backup for xxx
（RTC, SRAM etc.）
Operating Condition
Expected Life
Ambient Temperature
24
E7.8
5. Gold Capacitors Characteristics data
 Charging characteristics
 Self-discharging characteristics according to charging time
 Influence of ambient temperature on self-discharging characteristics
 Discharge characteristics
 Influence of ambient temperature on discharging characteristics
 Current characteristics
 Relations between applied voltage and capacitance change
 Relations between ambient temperature and capacitance change
 Reliability and temperature characteristics data
This data is typical data. It does not guarantee life time.
Before using the products, carefully check the effects on their quality and performance.
25
E7.8
Charging characteristics
5.5V 1.0F
Time (min)
26
E7.8
Self-discharging characteristics according to charging time
Charging condition: 5V
5.5V 1.0F
Time (h)
(Note) If charging time is brief, complete charge is not attained, and initial voltage due to internal charge is
increased.
Influence of ambient temperature on self-discharging characteristics
Charging condition: 5V, 24hours
5.5V 0.1F
Time (h)
(Note) In the self-discharge characteristics, the terminal voltage drop is affected by ambient temperature. This
means a self-discharge current becomes great as ambient temperature rises. In case where it is used with a
micro applied current of nano-ampere order, ambient temperature allows a difference to occur in backup time.
27
E7.8
Discharging characteristics
Constant resistance discharge: 1M
Charge voltage: 5V
Charge time: 24hours
Measurement temp: +20C
Time (h)
28
E7.8
Influence of ambient temperature on discharge characteristics
Constant resistance discharge: 250k
Charge time: 24hours
5.5V 0.1F
Time (h)
(Note) Voltage drop gets a little faster as ambient temperature rise. This occurs because the rise in ambient
temperature causes a self-discharge current added to applied current.
Time (h)
(Note) In low temperature area, ion movement for the formation of electric double layers becomes slow, and
time required for complete charge takes longer. Consequently, The voltage drop is large in the condition with
low temperature when there is no difference at charging time..
29
E7.8
Current characteristics
Initialization of test samples
The samples shall be measured after applying 5.5V for 2hours 300 resistance in the temperature (2010C,
6510% not being wetted with dew) and discharging in short circuit for 12 to 24hours.
Current (A)
(n =20)
Time (h)
30
E7.8
Relations between applied voltage and capacitance change
Test condition: +70C 5.5V
Applied voltage: 4, 5, 5.5V
Time (h)
(Note) Capacitance changes at the life test vary from applied voltage. The lower the voltage is, the
smaller it becomes. Almost no capacitance change due to no-load shelving.
Relations between ambient temperature and capacitance change
Test condition: +70, +60, +55C
Applied voltage: 5.5V
Time (h)
31
E7.8
Reliability and temperature characteristics data
Part number: EECRF0H684 (5.5V, 0.68F)
Endurance (at 85C, 5.5V applied)
120
0
Internal resistance()
Capacitance Change(%)
100
-20
-40
-60
80
60
40
20
-80
0
0
1000
2000
3000
0
4000
1000
2000
3000
4000
Time(h)
Time(h)
Shelf life (at 85C)
120
0
Internal resistance()
Capacitance Change(%)
100
-20
-40
-60
80
60
40
20
-80
0
0
500
1000
1500
2000
0
2500
500
1000
1500
2000
2500
Time(h)
Time(h)
Temperature characteristics
120
0
Internal resistance()
Capacitance Change(%)
100
-20
-40
80
60
40
-60
20
-80
0
-40
-20
0
20
40
60
80
-40
-20
Temperature(°C)
0
20
40
Temperature(°C)
(The discharge current shall be calculated by the capacitance value in a ratio of 1mA/F)
32
60
80
E7.8
Reliability and temperature characteristics data
Part number: EECRF0H104 (5.5V, 0.1F)
Endurance (at 85C, 5.5V applied)
0
300
Internal resistance()
Capacitance Change(%)
250
-20
-40
200
150
100
-60
50
-80
0
0
1000
2000
3000
4000
0
1000
2000
Time(h)
3000
4000
Time(h)
Shelf life (at 85C)
0
300.0
Internal resistance()
Capacitance Change(%)
250.0
-20
-40
-60
200.0
150.0
100.0
50.0
-80
0.0
0
500
1000
1500
2000
2500
0
500
1000
Time(h)
1500
2000
2500
Time(h)
Temperature characteristics
e
500.0
0
Internal resistance()
Capacitance Change(%)
400.0
-20
-40
-60
300.0
200.0
100.0
-80
0.0
-40
-20
0
20
40
60
80
-40
Temperature(°C)
-20
0
20
40
Temperature(°C)
(The discharge current shall be calculated by the capacitance value in a ratio of 1mA/F)
33
60
80
E7.8
Reliability and temperature characteristics data
Part number: EECF5R5H105 (5.5V, 1.0F)
Endurance (at 85C, 5.5V applied)
120
0
Internal resistance()
Capacitance Change(%)
100
-20
-40
-60
80
60
40
20
-80
0
0
500
1000
1500
2000
0
2500
500
1000
1500
2000
2500
2000
2500
Time(h)
Time(h)
Shelf life (at 85C)
120
0
Internal resistance()
Capacitance Change(%)
100
-20
-40
-60
80
60
40
20
-80
0
0
500
1000
1500
2000
0
2500
500
1000
1500
Time(h)
Time(h)
Temperature characteristics
e
120
20
100
Internal resistance()
Capacitance Change(%)
0
-20
-40
-60
80
60
40
20
-80
0
-40
-20
0
20
40
60
-40
80
-20
0
20
40
Temperature(°C)
Temperature(°C)
(The discharge current shall be calculated by the capacitance value in a ratio of 1mA/F)
34
60
80
E7.8
Reliability and temperature characteristics data
Part number: EECF5R5H104(5.5V, 0.1F)
Endurance (at 85C, 5.5V applied)
500
0
Internal resistance()
Capacitance Change(%)
400
-20
-40
-60
300
200
100
-80
0
0
500
1000
1500
2000
0
2500
500
1000
1500
2000
2500
2000
2500
Time(h)
Time(h)
Shelf life (at 85C)
500
0
Internal resistance()
Capacitance Change(%)
400
-20
-40
-60
300
200
100
-80
0
0
500
1000
1500
2000
0
2500
500
1000
1500
Time(h)
Time(h)
Temperature characteristics
500
0
Internal resistance()
Capacitance Change(%)
400
-20
-40
-60
300
200
100
-80
0
-40
-20
0
20
40
60
80
-40
-20
Temperature(°C)
0
20
40
Temperature(°C)
(The discharge current shall be calculated by the capacitance value in a ratio of 1mA/F)
35
60
80
E7.8
Reliability and temperature characteristics data
Part number: EECS5R5V155(5.5V, 1.5F)
0
200
-20
150
Internal resistance()
Capacitance Change(%)
Endurance (at 70C, 5.5V applied)
-40
-60
-80
100
50
0
0
500
1000
1500
2000
2500
0
500
1000
Time(h)
1500
2000
2500
2000
2500
Time(h)
0
200
-20
150
Internal resistance()
Capacitance Change(%)
Shelf life (at 70C)
-40
-60
-80
100
50
0
0
500
1000
1500
2000
2500
0
500
1000
Time(h)
1500
Time(h)
Temperature characteristics
200
Internal resistance()
Capacitance Change(%)
0
-20
-40
-60
-80
150
100
50
0
-40
-20
0
20
40
60
80
-40
-20
Temperature(°C)
0
20
40
Temperature(°C)
(The discharge current shall be calculated by the capacitance value in a ratio of 1mA/F)
36
60
80
E7.8
Reliability and temperature characteristics data
Part number: EECS0HD224V(5.5V, 0.22F)
Endurance (at 70C, 5.5V applied)
0
500
Internal resistance()
Capacitance Change(%)
400
-20
-40
-60
300
200
100
-80
0
0
500
1000
1500
2000
2500
0
500
1000
Time(h)
1500
2000
2500
2000
2500
Time(h)
Shelf life (at 70C)
0
500
Internal resistance()
Capacitance Change(%)
400
-20
-40
-60
300
200
100
-80
0
0
500
1000
1500
2000
2500
0
500
1000
Time(h)
1500
Time(h)
Temperature characteristics
500
0
Internal resistance()
Capacitance Change(%)
400
-20
-40
-60
300
200
100
-80
0
-40
-20
0
20
40
60
-40
80
-20
0
20
40
Temperature(°C)
Temperature(°C)
(The discharge current shall be calculated by the capacitance value in a ratio of 1mA/F)
37
60
80
E7.8
Reliability and temperature characteristics data
Part number: EECHW0D506(2.3V, 50F)
0
200
-20
150
Internal resistance(m)
Capacitance Change(%)
Endurance (at 60C, 2.3V applied)
-40
-60
-80
100
50
0
0
500
1000
1500
2000
2500
0
500
1000
Time(h)
1500
2000
2500
2000
2500
Time(h)
0
200
-20
150
Internal resistance(m)
Capacitance Change(%)
Shelf life (at 60C)
-40
-60
-80
100
50
0
0
500
1000
1500
2000
2500
0
500
1000
Time(h)
1500
Time(h)
Temperature characteristics
200
Internal resistance(m)
Capacitance Change(%)
0
-20
-40
-60
-80
150
100
50
0
-40
-20
0
20
40
60
80
-40
-20
0
20
40
Temperature(°C)
Temperature(°C)
(The discharge current shall be calculated by the capacitance value in a ratio of 1mA/F)
38
60
80
E7.8
Reliability and temperature characteristics data
Part number: EECHZ0E106(2.5V, 10F)
0
200
-20
150
Internal resistance(m)
Capacitance Change(%)
Endurance (at 70C, 2.5V applied)
-40
-60
-80
100
50
0
0
500
1000
1500
2000
2500
0
500
1000
Time(h)
1500
2000
2500
2000
2500
Time(h)
0
200
-20
150
Internal resistance(m)
Capacitance Change(%)
Shelf life (at 70C)
-40
-60
-80
100
50
0
0
500
1000
1500
2000
2500
0
500
1000
Time(h)
1500
Time(h)
Temperature characteristics
500
0
Internal resistance(m)
Capacitance Change(%)
400
-20
-40
-60
300
200
100
-80
0
-40
-20
0
20
40
60
80
-40
-20
0
20
40
Temperature(°C)
Temperature(°C)
(The discharge current shall be calculated by the capacitance value in a ratio of 1mA/F)
39
60
80
E7.8
Reliability and temperature characteristics data
Part number: EECHL0E107(2.7V, 100F)
Endurance (at 65C, 2.7V applied)
Shelf life (at 85C)
Temperature characteristics
(The discharge current shall be calculated by the capacitance value in a ratio of 1mA/F)
40
E7.8
<M E M O>
41
E7.8
Technical Guide of Electric Double Layer Capacitors
The first edition: October 1st 1994
The 7.8 edition: January 1st 2016
The details of this technical guide are effective until Dec. 2016 or
revised edition issued.
Issued by Device Solution Business Division
AIS Company
Panasonic Corporation
Tel: +81-774-31-7300
All rights reserved. No part of this publication may be reproduced or utilized in
any form or by any means, electronic or mechanical, including photocopying
and microfilm, without permission in writing from the publisher
TGGC-7.8