By further refining a TDK specialty, namely process technology for low ... is the
MLG0402Q and MLG0603P series of multilayer chip inductors with high Q values
.
For High-frequency Circuits and Modules
Multilayer Chip Inductor
MLG0402Q/MLG0603P High-Precision Multilayering Technology Combines Small Size and High-Q Rating Mobile phones continue to shrink in size while offering an increasingly complex array of functions. Multilayer chip inductors for use in high-frequency circuits and modules of such phones therefore also need to be made even smaller in size while providing high Q ratings. By further refining a TDK specialty, namely process technology for low temperature co-fired ceramic (LTCC) multilayer substrates, extremely compact chips of size 0402 (0.4 x 0.2 mm) and size 0603 (0.6 x 0.3 mm) were created. Compared to existing products, the manufacturing process for the newly designed internal electrodes of the chip features even more accurate position control. The result is the MLG0402Q and MLG0603P series of multilayer chip inductors with high Q values.
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Multilayer Chip Inductors for High-frequency Circuits and Modules
From Simple Portable Phone to Multimedia Terminal Twenty years have passed since portable telephones first appeared
expected to reach 70 percent by 2011.
on the scene. Nowadays, the mobile phone has evolved into a
On a worldwide scale, the largest share is still held by 2G (second
complex product that goes beyond being a mere communication
generation) GSM phones, but in developed countries including
device. It has become a multimedia terminal encompassing
Japan, 3G (third generation) and 3.5G (3.5th generation) phones
elements and functions such as a camera, Internet connectivity,
have become the mainstream. In 2010, 3.9G (3.9th generation)
electronic money support, TV reception, video calls, and more.
services using the LTE (Long Term Evolution) standard will go
The number of mobile phone users in the world is estimated to
into operation. Work on standardization for 4G (fourth generation)
be around 5 billion. With increasing demand from developing and
mobile phones with ultra high communication speeds reaching 1
newly emerging countries, mobile phone market penetration is
Gbps is currently in progress.
□Progress history of mobile phones
1G 100M 10M 1M 100k 10k 1k
□Ratio of mobile phone subscribers by region (approximate)
Ultra high speed, high quality ubiquitous terminals
Communication speed bps Multimedia terminals featuring Internet connectivity and support for video calls
3.9G
Europe
Africa, Middle East
LTE etc.
3.5G HSDPA etc 3G (third generation)
From analog to digital
2.5G 2G (second generation)
Car phones
Number of mobile phone users worldwide estimated at about 5,000 million (as of 2010)
4G (fourth generation)
Latin America
UMITS/W-CDMA, cdma2000 etc.
North America
1G (first generation) PDC, cdmaOne, GSM etc. 1980
1990
2000
2010
Asia Pacific
2020 Year
Multilayer Chip Components Contribute to Miniaturization of Mobile Phones The precursor to the modern mobile phone was the shoulder phone
not quite as numerous as multilayer ceramic chip capacitors, various kinds
that appeared around 1985. Weighing as much as three kilograms and
of SMD (surface mounted device) type inductors are being used in the
more, this type of phone was carried using a shoulder belt. One factor
power supply, filter circuitry, and high-frequency circuitry of mobile phones.
that significantly contributed to the subsequent dramatic reduction in the
Categorized by the way they are manufactured, there are wire-wound
size and weight of mobile phones was the development of progressively
inductors, layered inductors, thin film inductors, and others. The two
smaller chip components. A mobile phone incorporates as many as 200
major categories by function type are power supply application and signal
multilayer ceramic chip capacitors. In the 1980s, most multilayer ceramic
application inductors. In the power supply section where high current flow
chip capacitors measured 3.2 x 1.6 mm, which is classified as size 3216.
conditions are encountered, wire-wound inductors using a ferrite drum
Currently a capacitor with the same capacitance rating can be as small as
core, as well as multilayer type power inductors are used extensively.
0.6 x 0.3 mm (size 0603) and 0.4 x 0.2 mm (size 0402).
By contrast, multilayer chip inductors are dominant in filtering and high-
Along with resistors and capacitors, inductors (coils) are the third major
frequency circuit applications, where very compact dimensions are
passive component category for electronic devices. While these parts are
essential.
□Main products and types of TDK multilayer chip inductors TDK multilayer chip inductors DC-DC converter applications
EMC control and decoupling applications Power supply line applications
MLP Series
Signal line applications
MLZ Series
RF circuit, LC circuit, choke applications Low frequency applications
High frequency applications
MLF Series
MLG Series
MLZ Series
MLK Series
High-Q
Low-RDC Power inductors
Ferrite inductors
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High-SRF Ceramic inductors
Multilayer Chip Inductors for High-frequency Circuits and Modules
Revolutionary Multilayer Process Creates a Coil without Windings □Structure and manufacturing process of multilayer chip inductor
Multilayer chip inductors are manufactured using thin sheets made of ferrite or special ceramics on which coil patterns are
Manufacturing process
printed with metallic paste (normally silver). By arranging these Ferrite (dielectric ceramics for RF applications)
sheets in multiple layers, a spiral-shaped internal electrode pattern is created. The multilayer technique creates the coil in a three-dimensional space without the need to wind wire on a
Source material preparation, blending, sheet forming
Terminal electrode contact area
core, which facilitates miniaturization and mass production. This revolutionary technique was developed by TDK and presented to
Via hole processing
Internal electrode (forms part of the printed coil pattern)
the world for the first time in 1980. When a current flows through the coil, a magnetic flux is created.
Internal electrode printing Layering Cutting
Via (for inter-layer connection)
The intensity of the flux (i.e. the number of magnetic field lines) is called the inductance (L).The inductance increases proportionally to the number of coil windings squared and proportionally to
Sintering Terminal electrode application
the cross section area. Using a material with high magnetic
Electroplating
permeability such as ferrite as a core results in higher
Measurement, packing
inductance. This is because the higher magnetic permeability of a core has the effect of concentrating the magnetic field lines.
Terminal electrode
Multilayer chip inductors for high-frequency circuit applications
Spiral-shaped layered internal electrode
use sheets made of dielectric ceramics instead of ferrite. This is because ferrite has higher losses in the frequency range of several hundred MHz and higher, making it difficult to achieve high Q values.
High-frequency Application Inductors Must Have Low Losses and High Q Values □Q value of a coil
"Q" stands for "Quality Factor". Coils easily pass direct current but act as a resistor to alternating current. This behavior is called inductive reactance. The higher the frequency of the
f: Frequency
alternating current, the higher the inductive reactance. However, although the coil is a conductor, the wire winding has certain resistance components (R).The ratio between
R: DC resistance component at high frequencies
Numeric value expressing the quality of a coil (Quality Factor)
the resistance components and the frequency-dependent inductance (R/2πf L) is called the loss factor, and its inverse
□Q value and frequency response of inductors with different substrate material
number is the Q value (Q=2πf L/R). Because f is the frequency of the current flowing through the coil, the Q value will differ according to the frequency.
60
In simple terms, a higher Q value means lower losses and
50
better suitability for use as a high frequency inductor.
40
mobile phones is linked to higher battery power consumption,
30
Q
Because the increasing number of functions incorporated in multilayer chip inductors used in the high-frequency circuitry
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should have low losses and high Q values.
10 0 0.01
Ceramic type inductor Ferrite type inductor
0.1
1
10 100 Frequency (MHz)
1000
10000
Q value changes depending on frequency and substrate material. In the frequency range of several hundred MHz and above, ferrite substrates cannot be used, and dielectric ceramics are used instead.
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Multilayer Chip Inductors for High-frequency Circuits and Modules
Influence of Distributed Capacitance on Inductors for High-frequency Applications Inductors to be used in the high-frequency circuitry of mobile
frequency and coil inductance is defined by the equation X
phones should have high Q values and small dimensions.
=2πf L. In the ideal inductor, if the inductance is constant, the
Unfortunately there is a tradeoff relationship between smaller
reactance is proportional to the frequency. Plotting frequency
sizes and higher Q ratings in multilayer chip inductors. If the
vs. reactance therefore should produce a straight line, but in
coil is reduced in size to allow for more compact dimensions,
reality, the reactance drops towards higher frequencies. This
the DC resistance rises, which leads to lower Q values. In
is due to the distributed capacitance of the coil, which forms
addition, at higher frequencies the influence of the distributed
a capacitor component that does not appear in the circuit
capacitance (parasitic capacitance) of the internal electrodes
diagram. In multilayer chip inductors, the coil patterns act
and other parts on Q becomes more significant.
like capacitor electrodes, resulting in distributed capacitance.
As shown above, the inductive reactance (X) of the coil acts
Similarly, distributed capacitance also occurs between the
as a resistor to AC current, and the relationship between
terminal electrodes and the coil patterns.
□Coil reactance X: Reactance (AC resistance of coil)
□Distributed capacitance between electrodes of a multilayer chip inductor Internal electrodes act like electrodes of a capacitor
Internal electrode Ideal coil
Distributed capacitance Terminal electrode Internal electrode
Actual coil
Dielectric ceramics f: Frequency
Terminal electrode
X=2πf L. In an ideal coil, the graph would be a straight line, but distributed capacitance of an actual coil causes a drop towards higher frequencies.
Distributed capacitance
Internal electrodes and terminal electrodes act like electrodes of a capacitor.
Reducing Distributed Capacitance Results in Higher Self-Resonant Frequency (SRF) The fact that multilayer chip inductors have distributed
Ideal inductor
Equivalent circuit of actual inductor
capacitance means that the equivalent of a parallel LC circuit
DC resistance (R: electrical resistance of internal electrode and terminal electrode)
(parallel connection of inductor and capacitor) is formed at high frequencies. As opposed to an inductor, a capacitor blocks DC current while acting more like a conductor for AC current the higher
Has only inductance (L)
the frequency becomes. Similar to a parallel LC element being used as a resonance circuit, the multilayer chip inductor with
Distributed capacitance (C: capacitor component between internal electrodes and between internal electrode and terminal electrode)
distributed capacitance has a resonance frequency. This is called the self-resonant frequency (SRF). At higher frequencies,
Frequency Insertion loss
when the self-resonant frequency is exceeded, the chip no longer acts as an inductor. The Q value also drops drastically, becoming zero at the self-resonant frequency. When selecting multilayer chip inductors for use in highfrequency circuits and modules, it therefore is not enough to
Large
simply consider the required inductance. The self-resonant frequency must also be sufficiently higher than the usage
Area where inductor function is dominant
Area where capacitor function due to distributed capacitance is dominant
Self-resonant frequency (SRF) 1/2π LC
frequency.
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Inductor to be used in high-frequency circuit should have high self-resonant frequency (SRF).
Therefore distributed capacitance of inductor must be kept as low as possible.
Multilayer Chip Inductors for High-frequency Circuits and Modules
New MLG Series Features Revolutionary Internal Electrode Design Inductors for high-frequency applications must also take the
to develop a highly advanced LTCC (low temperature co-fired
so-called skin effect into consideration. The term refers to a
ceramic) technique for manufacturing multilayer substrates. This
phenomenon where high-frequency current flowing in a conductor
process technology enables stable mass production of inductors
does not penetrate to the interior but tends to flow only on the
with extremely precise internal spiral conductors. The shape, layer
surface of the conductor. This drastically increases electrical
width, and layout of the internal conductors are designed so as to
resistance and therefore causes a drop in inductance.
keep distributed capacitance at negligible levels while achieving
As mobile phones incorporate more and more functions, an
high Q values. The result is the MLG0603Q series of multilayer chip
extremely large number of electronic components must be tightly
inductors. The new MLG0402Q series realizes the same High-Q
packed on the circuit boards. Multilayer chip inductors therefore
characteristics in the extremely small size 0402 form factor.
need to become even smaller and feature a low profile. Thin film chip
By redesigning coil patterns and layout from the ground up, TDK
inductors where the coil is formed using thin film process technology
engineers succeeded in minimizing the distributed capacitance
can be made very small and low-profile in shape, and maintaining
between terminal electrodes while largely maintaining the coil surface
high accuracy is possible, but it is difficult to realize high Q values.
area, resulting in excellent Q value characteristics.
As a consequence, multilayer chip inductors are the dominant
Even a slight shift in coil pattern will cause a drop in Q value. To
type used for high-frequency applications. However, as mentioned
prevent this, high-accuracy positioning control technology and other
above, a tradeoff relationship exists between achieving smaller
advanced measures were applied when developing the MLG0402Q
dimensions and higher Q values. There is a strong demand for high-
series. By further refining and perfecting these techniques, TDK
precision manufacturing techniques that help to minimize distributed
was able to add the MLG0603P series with newly designed internal
capacitance and the skin effect while enabling optimized design of
electrodes to the product lineup. The new series features outstanding
internal electrodes which is the key to realizing compact dimensions.
High-Q characteristics thanks to further reduced distributed
TDK has applied its accumulated expertise in fine layer technology
capacitance.
□MLG0402Q and new product MLG0603P combine ultra-small dimensions with high Q characteristics NEW ●New internal electrode design minimizes distributed capacitance Q value 20% higher than conventional products
esign
-Q d
High
MLG0603P
●Improved positioning accuracy during layering ●Optimized coil patterns for higher Q values
Extremely compact dimensions
MLG0603Q
Volume reduction: 70% Mounting footprint reduction: 54%
High-Q design
MLG0402Q
□Q vs. frequency characteristics of MLG0402Q MLG0402Q MLG0402S
10nH
40
40
30
30
20
20
MLG0603P MLG0603S
10
10 0 10
MLG0402S
□Q vs. frequency characteristics of MLG0603P
Q
Q
10nH
Q value 40% higher than conventional products
100 1000 Frequency（MHz）
0 10
10000
05
100 1000 Frequency（MHz）
10000
Multilayer Chip Inductors for High-frequency Circuits and Modules
Multilayer Chip Inductor Application Examples in Mobile Phones Multilayer chip inductors with compact dimensions and high Q
signal from being bounced back to the input, thereby increasing
characteristics are used extensively in the high-frequency circuitry
transmission losses.
of mobile phones. Applications include impedance matching in
TDK offers the MLG0402Q series (inductance ranging from 1 to 15
SAW filters and VCO circuits etc. and use as chokes. Impedance
nH) and the MLG0603P series (0.6 to 120 nH). Applications include
matching refers to matching the output impedance of a signal
not only mobile phones but also Bluetooth, W-LAN, UWB, digital
source to the input impedance of the signal destination. At high
TV tuners and other high-frequency circuits and modules, where
frequencies, impedance matching is important to prevent the
these multilayer chip inductors provide optimum performance.
□Main usage areas of multilayer chip inductors in mobile phone RF circuitry Flexible printed wiring board Ringer Microphone
LCD driver Logic circuitry
Power supply unit
high-frequency circuits
LCD panel
One seg module
Vibrator Card I/F
USB I/F
Camera unit
Sub panel
Wireless LAN/ Bluetooth module
Speaker Antenna
For choke For matching
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Multilayer Chip Inductors for High-frequency Circuits and Modules
□ Main Features MLG0402Q Series 1 Series lineup covers inductance range from 1 to 15 nH 2 Compared to existing compact size 0603 products, 70% smaller volume and 55% smaller effective
footprint of new series make it especially suitable for fine-pitch circuits
MLG0603P Series 1 Series lineup covers inductance range from 0.6 to 120 nH 2 Compared to conventional MLG0603S type products, optimized structural design results in signifi-
cantly higher Q, especially at 800 MHz and higher
3 Sintered complete monolithic construction using layers of ceramics and conductor material
optimized for high-frequency applications
□ Main Applications High-frequency circuits (PA, VCO, FEM etc.) in mobile phones, smartphones and similar, high-frequency circuitry in Bluetooth, W-LAN, UWB, tuners, and other mobile communication devices.
□ Dimensions and Shape MLG0402Q Series
MLG0603P Series 0.6±0.03 0.3±0.03
0.2±0.02
0.4±0.02
0.08 to 0.14
0.3±0.03
0.2±0.02
0.09±0.04
0.15±0.05
□ Major Specifications MLG0402Q Series
MLG0603P Series
Inductance
1 to 15 nH
0.6 to 120 nH
Temperature Range
-55 to +125℃
-55 to +125℃
DC Resistance
0.4 to 2.6Ω（max.）
0.06 to 5Ω（max.）
Rated Current
100 to 250mA
80 to 1,000mA
Dimensions
0.4×0.2×0.2mm
0.6×0.3×0.3mm
2011.3.10
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