■ PRECAUTIONS
Precautions on the use of Multilayer chip Inductors, Multilayer chip inductors for high frequency, Multilayer chip bead Inductors
1. Circuit Design
◆Verification of operating environment, electrical rating and performance
1. A malfunction in medical equipment, spacecraft, nuclear reactors, etc. may cause serious harm to human life or have severe social ramifications.
As such, any inductors to be used in such equipment may require higher safety and/or reliability considerations and should be clearly differentiated from
Precautions
components used in general purpose applications.
◆Operating Current（Verification of Rated current）
1. The operating current for inductors must always be lower than their rated values.
2. Do not apply current in excess of the rated value because the inductance may be reduced due to the magnetic saturation effect.
2. PCB Design
◆Pattern configuration（s Design of Land-patterns）
1. When inductors are mounted on a PCB, the size of land patterns and the amount of solder used（size of fillet）can directly affect inductor performance.
Therefore, the following items must be carefully considered in the design of solder land patterns:
（1）The amount of solder applied can affect the ability of chips to withstand mechanical stresses which may lead to breaking or cracking. Therefore, when
designing land-patterns it is necessary to consider the appropriate size and configuration of the solder pads which in turn determines the amount of
solder necessary to form the fillets.
（2）When more than one part is jointly soldered onto the same land or pad, the pad must be designed so that each component's soldering point is separated
Precautions
by solder-resist.
（3）The larger size of land patterns and amount of solder, the smaller Q value after mounting on PCB. It makes higher the Q value to design land patterns
smaller than terminal electrode of chips.
◆Pattern configuration（s Inductor layout on panelized［breakaway］PC boards）
1. After inductors have been mounted on the boards, chips can be subjected to mechanical stresses in subsequent manufacturing processes（PCB cutting,
board inspection, mounting of additional parts, assembly into the chassis, wave soldering the reflow soldered boards etc.）For this reason, planning pattern
configurations and the position of SMD inductors should be carefully performed to minimize stress.
◆Pattern configuration（s Design of Land-patterns）
1. The following diagrams and tables show some examples of recommended patterns to prevent excessive solder amount（s larger fillets which extend above
the component end terminations）. Examples of improper pattern designs are also shown.
（1）Recommended land dimensions for a typical chip inductor land patterns for PCBs
Recommended land dimensions for wave-soldering
Recommended land dimensions for reflow-soldering
Type
L
1608
1.6
2125
2.0
3216
3.2
Type
L
0402
0.4
0603
0.6
1005
1.0
105
1.0
0.6
1608
1.6
2012
2.0
2125
2.0
2016
2.0
3216
3.2
2520
2.5
W
A
0.8
1.25
1.6
W
A
0.2
0.3
0.5
0.8
1.25
1.25
1.6
1.6
2.0
0.8～1.0 1.0～1.4 1.8～2.5
0.5～0.8 0.8～1.5 0.8～1.7
0.6～0.8 0.9～1.2 1.2～1.6
（Unit：mm）
0.15～0.25 0.20～0.30 0.45～0.55 0.50～0.55 0.8～1.0 0.8～1.2 0.8～1.2 0.8～1.2 1.8～2.5 1.0～1.4
0.10～0.20 0.20～0.30 0.40～0.50 0.30～0.40 0.6～0.8 0.8～1.2 0.8～1.2 0.8～1.2 0.6～1.5 0.6～1.0
0.15～0.30 0.25～0.40 0.45～0.55 0.60～0.70 0.6～0.8 0.9～1.6 0.9～1.6 1.2～2.0 1.2～2.0 1.8～2.2
（Unit：mm）
B
B
C
C
Excess solder can affect the ability of chips to withstand mechanical stresses. Therefore, please take proper precautions when designing land-patterns.
Recommended land dimension for Reflow-soldering
Type
L
3216
3.2
2010
2.0
W
a
1.6
1.0
0.7～0.9 0.5～0.6
0.8～1.0 0.5～0.6
0.4～0.5 0.2～0.3
Technical
consider-
ations
b
c
d
0.8
0.5
（Unit：mm）
（2）Examples of good and bad solder application
Item
Not recommended
Recommended
Mixed mounting of SMD
and leaded components
Component placement
close to the chassis
Hand-soldering of leaded
components near mounted
components
Horizontal component
placement
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＊This catalog contains the typical specification only due to the limitation of space. When you consider the purchase of our products, please check our specification.
For details of each product (characteristics graph, reliability information, precautions for use, and so on), see our Web site (http://www.ty-top.com/) or CD catalogs.
mlci0109_reli_e-01
mlci0109_reli-PRP13
TAIYO YUDEN [ TAIYO YUDEN (U.S.A.), INC ]
