IEC 61967-6:2002/AMD1:2008
(Amendment)Amendment 1 - Integrated circuits - Measurement of electromagnetic emissions, 150 kHz to 1 GHz - Part 6: Measurement of conducted emissions - Magnetic probe method
Amendment 1 - Integrated circuits - Measurement of electromagnetic emissions, 150 kHz to 1 GHz - Part 6: Measurement of conducted emissions - Magnetic probe method
Amendement 1 - Circuits intégrés - Mesure des émissions électromagnétiques, 150 kHz à 1 GHz - Partie 6: Mesure des émissions conduites - Méthode de la sonde magnétique
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IEC 61967-6
Edition 1.0 2008-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
AMENDMENT 1
AMENDEMENT 1
Integrated circuits – Measurement of electromagnetic emissions, 150 kHz to
1 GHz –
Part 6: Measurement of conducted emissions – Magnetic probe method
Circuits intégrés – Mesure des émissions électromagnétiques, 150 kHz à 1 GHz –
Partie 6: Mesure des émissions conduites – Méthode de la sonde magnétique
IEC 61967-6 A1:2008
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IEC 61967-6
Edition 1.0 2008-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
AMENDMENT 1
AMENDEMENT 1
Integrated circuits – Measurement of electromagnetic emissions, 150 kHz to
1 GHz –
Part 6: Measurement of conducted emissions – Magnetic probe method
Circuits intégrés – Mesure des émissions électromagnétiques, 150 kHz à 1 GHz –
Partie 6: Mesure des émissions conduites – Méthode de la sonde magnétique
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
R
CODE PRIX
ICS 31.200 ISBN 2-8318-9641-X
– 2 – 61967-6 Amend. 1 © IEC:2008
FOREWORD
This amendment has been prepared by subcommittee 47A: Integrated circuits, of IEC
technical committee 47: Semiconductor devices.
The text of this amendment is based on the following documents:
FDIS Report on voting
47A/781/FDIS 47A/784/RVD
Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this amendment and the base publication will
remain unchanged until the maintenance result date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
_____________
Page 49
Add the following new Annex E:
61967-6 Amend. 1 © IEC:2008 – 3 –
Annex E
(informative)
Advanced magnetic probe
E.1 General
The miniature magnetic probe (advanced magnetic probe) has a high spatial resolution, and it
enables accurate measurement of near magnetic fields of IC packages and dense PCBs. It
should be made of a low temperature co-fired ceramics (LTCC) board and its detecting part
(detecting loop) should be about 2 mm wide and 1 mm thick. The miniaturization may cause a
decrease of probe sensitivity of magnetic field, due to the reduction of loop size. The details
of probe design are shown in Figures E.1, E.2, E.3 and E.4. However, the lower sensitivity to
magnetic field is compensated by the decrease of necessary gain, resulting from the
possibility of placement of the new probe loop edge closer to the microstrip line than it was
before.
E.2 Advanced magnetic probe fixture
The previous model of magnetic field probe is a shielded loop probe, made by using
multilayer FR4-PCB. The loop part of the previous magnetic field probe cannot be made small
enough to measure current at short trace on PCB. The new model is made by precise glass
ceramic multi-layer board, enabling both compactness and high spatial resolution.
Figures E.1 and E.2 show an external view of the probe. The size of the magnetic detecting
loop is reduced to 2 mm width x 1 mm thickness. The advanced magnetic probe should be a
tri-plate strip line composed of a three-layer LTCC board. Recommended probe construction
details are shown in Figures E.3, E.4, E.5, E.6, E.7 and E.8. In all figures, braces ( ) indicate
that the enclosed values are examples. Other dimensions shall be within tolerances described
below. If the loop part does not fall within tolerance limits, measurement error will increase.
A semi-rigid cable can be attached at the junction area which is shown as Figures E.1 and E.2.
Junction for the connection should have characteristic impedance of 50 Ω up to 3 GHz. The
connection construction which is shown in the figures is one example of connection between
LTCC board and semi-rigid coaxial cable. Other constructions which provide good high-
frequency connectivity are acceptable.
In Figures E.4, E.5, E.6 and E.7, the relative dielectric constant of the board material is 7,1,
and the printed pattern on an LTCC board is formed with Ag-Pd paste. In these figures,
finished dimensions of printed pattern of loop portion may have a tolerance rating of ±2,5
percent. Dimensions with braces also may have a tolerance rating of ±10 percent. The
conductors are 15 μm thick with a tolerance of ±5 μm. The insulators (dielectric) are 120 μm
thick with a tolerance rating of ±10 percent. The ground pads on the first layer and the fifth
layer are coated with about 30 μm (thickness) of gold (Au) plating. Therefore the thickness of
the ground pad may be increased, so as to solder the pads to conductor case. Unless
otherwise specified, dimensions of printed pattern may have a tolerance rating of ±10 percent.
– 4 – 61967-6 Amend. 1 © IEC:2008
Shielded loop structure is used for detecting part for magnetic field. This part shall be
fabricated precisely using precise LTCC process. Figure E.3 shows the superimposed main
pattern of the magnetic field detector made by using a 5-layer glass ceramic board. The
second and forth layers are ground layers corresponding to the outer sheath of a coaxial
cable; the third layer is the signal layer, equivalent to the core conductor. The loop and lead
portion of the multilayer board of the new probe is symmetrical about the third layer except via
and signal pattern. The strip line was designed to have a characteristic impedance of 50 Ω, in
consideration of impedance matching with the measurement system. The end of the signal
line is passed through a via-hole and connected to ground.
The previous probe has apertures in the sides of the tri-plate strip line (lead portion), but both
sides of the ground pattern on the second layer are connected to the fourth layer by via-hole
as shown in Figure E.3. The via-hole shall be formed with a pitch of 0,25 mm or less. The loop
serving as the magnetic field detector is a rectangle 0,2 mm x 1 mm, and the spatial
resolution can be raised to 250 μm (typical) at the 6 dB degrading point. If the target of
measurement is a straight trace such as a microstrip line, the current calibration coefficient
can be used to convert measured magnetic field over a trace into current. About the pattern
on each layer of the LTCC board, the amount of deviation from perfect alignment shall be
within 10 μm. The performance of the probe will decrease when the alignment error increases,
because the characteristic impedance of the strip line of the probe deviates from 50 Ω. Taking
screening test by x-rays, nonconforming items where the alignment error exceeds 10 μm shall
be rejected. Furthermore, the front end face of the LTCC board shall be precisely cut and
polished flat.
The ground pads on the first layer and the fifth layer are shown in Figures E.4 and E.7. The
pad of the first layer is connected to the second layer by via-holes and the pad of the fifth
layer is connected to the fourth layer by enough number of vias, respectively. The ground pad
on the fifth layer is extended, when compared to that on the first layer. As shown in Figures
E.5 to E.6, the trace width is tapered down to a narrow trace. As shown in Figures E.4 and
E.7, the ground patterns are also tapered, because the second and fourth layer patterns are
tapered. Figure E.8 shows the configuration for connection of the LTCC board and the semi-
rigid coaxial cable. The joint construction consists of conductor case, step part of LTCC board
and semi-rigid coaxial cable. As shown in Figure E.8, the central conductor of the semi-rigid
coaxial cable is connected to the signal pad on the third layer of the LTCC board by solder.
LTCC board has a step, so the signal pattern on the third layer is exposed. The central
conductor of the semi-rigid cable can be mounted on signal pattern in parallel with signal
pattern. The outer conductor of the semi-rigid coaxial cable is contacted with the rear edge of
the LTCC board. Further, the conductor case (Cu) is connected to the ground pads on the
first and the fifth layers by solder so as to cover and surround a joint part of the central
conductor. The conductor case shall be connected to the outer conductor by solder. Here, the
ground pad, the outer conductor and the conductor case may preferably be solder-connected
to one another without any clearance. The shield performance of the joint section is enhanced
by the conductor case, so that electromagnetic interference of a sensor output signal with an
outcoming noise or another wiring signal can be suppressed. The characteristic impedance of
joint section including conductor case shall be designed by adjusting the dimensions of the
signal pads and the conductor case, a reflection loss due to impedance mismatching is
suppressed so that a high-frequency signal transmission characteristic can be made
satisfactory.
61967-6 Amend. 1 © IEC:2008 – 5 –
SMA connector
Semi-rigid coaxial cable
LTCC board
(magnetic loop)
A
Conductor case
(metal)
IEC 234/08
Figure E.1 – Illustration of the assembled advanced magnetic probe
(Solder metal case to outer sheath
Metal case
of the semi-rigid coaxial cable)
(Solder metal case to the ground
pad on first and fifth layer)
Semi-rigid
coaxial cable
LTCC board Ground pad
Solder joint
IEC 235/08
Figure E.2 – Enlarged view of part A of Figure E.1
(an example of connection construction)
– 6 – 61967-6 Amend. 1 © IEC:2008
Dimensions in millimetres
Outline of glass
ceramic board
Signal pattern on layer 3
Joint portion for
semi-rigid coaxial
cable, straight
connection is
Ground plane patterns
recommended
on layers 2 and 4
Blind via through
layers 2 and 4
(pitch is 0,25 or less)
Lead portion
50 Ω strip line
Loop portion
for magnetic
field detection
(2,0) (1,0)
Via through layers 2, 3, and 4
IEC 236/08
Figure E.3 – Main pattern (layer 2 to 4) of advanced magnetic probe
Dimensions in millimetres
Joint portion for
semi-rigid coaxial cable
0,6
Edge of the
LTCC board
(1,6)
Outline of glass
ceramic board
IEC 237/08
Figure E.4 – Layer 1 (ground pattern) of advanced magnetic probe
(5,0)
(5,0) (2,8) (0,2)
61967-6 Amend. 1 © IEC:2008 – 7 –
Dimensions in millimetres
Joint portion for
semi-rigid coaxial
cable
Blind via (pitch is
0,6
0,25 or less)
Center of the
loop aperture
Edge of the
LTCC board
Via
0,25
∅ 0,1
0,05
Gap width
0,3 0,3
1,0
1,6
Outline of glass
ceramic board
IEC 238/08
Figure E.5 – Layer 2 and 4 (ground pattern) of advanced magnetic probe
Dimensions in millimetres
This pad is soldered
to center conductor of
semi-rigid coaxial cable
0,05
(line width)
Center of line
0,05
(line width)
Center of line
Edge of the
0,25
LTCC board
Via 0,9
∅0,1
Outline of glass
ceramic board
IEC 239/08
Figure E.6 – Layer 3 (signal pattern) of advanced magnetic probe
0,8
0,2
0,15 0,15
0,3 0,3
Center of line
0,05
(line width)
Center of line
(7,3) (1,8) (0,05)
(0,2)
(2,8)
(5,0)
0,45
(0,2)
0,5
– 8 – 61967-6 Amend. 1 © IEC:2008
Dimensions in millimetres
Joint area for
semi-rigid
coaxial cable
0,6
Edge of the
LTCC board
(1,6)
Outline of glass
ceramic board
IEC 240/08
Figure E.7 – Layer 5 (ground pattern) of advanced magnetic probe
Dimensions in millimetres
A
Semi-rigid coaxial cable
Central conductor
of the semi-rigid
coaxial cable
Blind
via
Conductor case
Signal pad on third layer
First layer
(conductor thickness is about
Fifth layer (conductor
45 μm including plating)
thickness is 45 μm
including plating)
Second layer
(conductor thickness is 15 μm)
Fourth layer
(conductor thickness is 15 μm)
Third layer
(t ) t t (t )
2 1 1
(conductor thickness is 15 μm)
(1,0)
A’
Solder joint
(2,0)
t = 0,12 (Insulator thickness)
t = 0,38 (Insulator thickness)
2 IEC 241/08
(a) Top view (b) Section A-A’
Figure E.8 – Construction of advanced magnetic probe
(10)
(5,0) (4,8)
61967-6 Amend. 1 © IEC:2008 – 9 –
The output voltage of the magnetic probe (V ) depends on the distance (D ) between the loop
p m
center and the surface of the strip conductor under measurement. In Figure E.9, the strip
conductor width is 1,0 mm, when the insulator thickness of the test board is 0,6 mm. The
characteristic impedance is 50 Ω ± 5 Ω. The thickness of copper film (strip conductor) shall be
standardized. The film could be standardized to a thickness between 18 μm to 35 μm, while
35 μm is recommended. As shown in Figure E.10, the loop center is defined as the
rectangular aperture of the ground patterns on the second layer and the fourth layer. This
makes it very critical to maintain a 0,47 mm (470 μm) ± 20 μm distance between the strip
conductor and the center of the aperture of loop during the measurement. Therefore, a probe
spacing fixture should be used to maintain 0,07 mm spacing between the bottom of the
rectangular loop portion of the probe and the probe tip. The value of D is 0,47 mm.
m
Dimensions in millimetres
Conductor of
the second layer
Conductor of
the third layer
Conductor of
the fourth layer
Probe (LTCC board)
Edge of the
ground pattern
Center of aperture
Surface of
strip conductor
1,0
Ground (Resist coating
Strip
plane Dielectric is optional)
conductor
*D = Distance between strip conductor surface and center
m
of rectangular aperture of loop (loop center)
IEC 242/08
(a) Front view (b) Side view
Figure E.9 – Measurement set-up
Dimensions in millimetres
Ground pattern
(second and fourth layers)
Center of aperture
Rectangular aperture of the loop
IEC 243/08
Figure E.10 – Definition of loop center
0,6
0,4
0,1
0,1
D
m
(0,07)
(0,05)
– 10 – 61967-6 Amend. 1 © IEC:2008
Dimensions in millimetres
0,5
0,4
0,01 GHz
0,3
0,1 GHz
0,2
1,0 GHz
0,1
–0,1
–0,2
–0,3
–0,4
–0,5
0,44 0,45 0,46 0,47 0,48 0,49 0,50
Measurement distance D (mm)
m
IEC 244/08
Figure E.11 – Error graph of the measured voltage versus measurement distance
E.3 Spatial resolution of magnetic probe
The set-up for measuring of the magnetic field distribution across a microstrip line is shown in
Figure E.12. As seen in Figure E.13, it achieves high spatial resolutions. The spatial
resolution is 0,7 mm (−6 dB drop point), measured at D = 0,47 mm and f = 1 GHz. Therefore,
m
the magnetic field from an adjacent trace has little influence and can be neglected when the
probe is placed at the centre of the strip conductor. The test board is the same as that in
Figure E.9.
Dimensions in millimetres
Center of probe
(center of the conductor on the third layer)
Probe (LTCC board)
Strip conductor
(Resist coating
Center of aperture
is optional)
Surface of strip
x
Dielectric
conductor
ε = 4,7
r
Ground plane
x = 0
(0 dB)
1,0
IEC 245/08
Figure E.12 – Set-up for measuring magnetic field distribution
Normalized amplitude ΔV (dB)
p
0,6
0,47
61967-6 Amend. 1 © IEC:2008 – 11 –
–5
–10
–15
–20
–25
–30
–35
–40
–3 –2 –1 0 1 2 3
Position of center of probe (mm)
IEC 246/08
Figure E.13 – Magnetic field distribution across microstrip line (1 GHz)
E.4 Angle pattern of probe placement
The set-up for measuring a magnetic probe placement angle (ϕ) with respect to the direction
of a microstrip line is shown in Figure E.14.
ϕ
Strip conductor
Printed circuit
board
Probe (LTCC board)
IEC 247/08
Figure E.14 – Set-up for measuring an angle pattern of probe placement
The output voltage of the magnetic probe (V ) slightly depends on the probe placement angle
p
(ϕ ) to the direction of a microstrip line under measurement as seen in the following Figure
E.15. The microstrip line is the same as that shown in Figure E.9. The distance between the
strip conductor and the loop center (D ) is 0,47 mm.
m
Normalized amplitude (dB)
– 12 – 61967-6 Amend. 1 © IEC:2008
–0,5
–1,0
–1,5
–2,0
0 5 10 15 20 25 30 35 40
ϕ (°)
IEC 248/08
Figure E.15 – Probe output amplitude as function of angle ϕ
(D is 0,47 mm)
m
E.5 Calibration factor
The magnetic probe shall be placed at a distance above the surface of the line under test on
the test board described in Figure E.9. The output voltage of the magnetic probe (V ) is
p
measured by a spectrum analyzer or a measuring receiver as described in IEC 61967-1. RF
current (I_ ) is calculated from the measured value of V as corrected by the calibration
dB p
factor of the magnetic probe (C ) and the transfer constant (C ) by equation (E.1) for a typical
f h
example of the test board as described in Annex B.
I = V + C − C (dB A) (E.1)
_dB p_dB f_dB h_dB
where
V V value in dB (dB V ),
p_dB p
C C value in dB (dB S/m),
f_dB f
C C value in dB (dB 1/m).
h_dB h
Normalized amplitude (dB)
61967-6 Amend. 1 © IEC:2008 – 13 –
One method to obtain I is to determine C and C individually. C can be
_dB f_dB h_dB f_dB
measured by the microstrip line method under appropriate condition and C is calculated in
h_dB
Annex B. As led from equation (B.6), transfer function C is calculated from the ratio of the x-
h
component of magnetic field H to the current I of the microstrip line. In this case, the line
x
current model shown in Figure E.16(a) is used for the calculation of H in Annex B, because
x
the distance (D ) is large enough as shown in equation (B.6). However, for the advanced
m
magnetic probe, the x-component of average magnetic field in the loop area H shall be
x-ave
calculated from the distributed current model on the strip conductor of a microstrip line shown
in Figure E.16(b), because the measurement distance is closer compared to the line current
model shown in Figure E.16(a). The current model which is shown in Figure E.16(b) is the real
distributed current model on strip conductor (see bibliography [2-3]). If it is difficult to
determine the magnitude of current density distribution, the approximated uniform current
model can be used for calculating H , because of simplification of calculation (see
x-ave
bibliography [4]).
H is given as
x-ave
N
(A/m) (E.2)
H = []H ()i + H (− i ) dS
x−ave ∑ +x k −x k
∫
S
S
eq
eq
k =1
where H ( i ) and H ( -i ) are x-components of the magnetic field at segment k calculated by
x k x k
the distributed current of strip conductor i and image current −i . S is the equivalent loop
k k eq
area. (N i ) is equal to the total current I. The transfer constant from the distributed current
k
model (C ) is calculated from the ratio of H to current I as described in Annex B.
h_distributed x-ave
Equation (E.1) is rewritten as equation (E.3) by replacing C with C .
h h_distributed
I = V + (C − C ) (dB A) (E.3)
_dB p_dB f_dB h-distributed_dB
where
V is the voltage across the impedance in dB (dB V),
p_dB
C is the calibration factor for the magnetic field in dB (dB S/m),
f_dB
C is the transfer constant from distributed current model in dB (dB 1/m).
h-distributed_dB
Experimental results from the distributed current model are described in bibliography [2-5]. It
should be effective for obtaining C by calculation.
h-distributed_dB
varies when the dimension of the PCB varies. The worst case estimation (10 %
H
x-ave
deviation of dimensions of insulator thickness (h), resist thickness (t ), line width (W) and
r
conductor thickness (t ) ) is 0,89 dB and is accurate enough for this measurement.
s
– 14 – 61967-6 Amend. 1 © IEC:2008
Loop
H
x
Loop
H
x–ave
I
Strip conductor
I i
k
-i
k
-I
Ground
Image current
Image current
IEC 249/08
(a) Line current model where current is (b) Distributed current model considering
concentrated at centre of strip conductor edge effect
Figure E.16 – Current models of strip conductor of microstrip line
In equation (E.3), it is not necessary to obtain C separately by the complicated
h-distributed_dB
calculation described above, because the calibration objective is not to obtain the
intermediate parameter. It is practicable to obtain the current I directly without calculation
from equation (E.2). (C − C ) depends only on the parameters of the
f_dB h-distributed_dB
microstrip line under the conditions in Figure E.9, because the measurement distance is
constant (D = 0,47 mm). Method for seeking (C − C ) by measurement is
m
f_dB h-distributed_dB
described in Clause E.6.
61967-6 Amend. 1 © IEC:2008 – 15 –
W = 1,0
h = 0,6
h = thickness of insulator (mm)
h = 0,6
44 h = 0,5
h = 0,4
h = 0,3
h = 0,2
h = 0,1
0,2 0,4 0,6 0,8 1,0 1,2
W (mm)
IEC 250/08
Figure E.17 – Calibration factor for different board parameters
50,0
40,0
30,0
20,0
10,0
0,0
–10,0
0,01 0,1 1 10
Frequency (GHz)
IEC 251/08
Figure E.18 – Example of measured (C – C ) at microstrip line
f_dB h-distributed_dB
under the same condition (W=1,0 mm, h=0,6 mm) as shown in Figure E.9
C (dB 1/m)
Cf_dB - Ch-distributed_dB (dB S) h-distributed_dB
– 16 – 61967-6 Amend. 1 © IEC:2008
Figure E.17 shows the calculated C when the thickness of dielectric (h) and the
h-distributed_dB
width of strip conductor (W) are varied. It is obtained using the procedure for calculating the
ratio of H to current I. In this case, the measurement distance (D ) equals 0,47 mm.
x-ave m
When a microstrip line whose dimensions are different from those in Figure E.17 is used, the
calibration factor (C − C ) for the corresponding (W, h) shall be used.
f_dB h-distributed_dB
However, it is not efficient to repeat calibration using the procedure described in E.6. With a
test board having different thickness of dielectric (h) and width of strip conductor (W), the
value of current can be calculated with transfer constants C (W , h ) and C
h-distributed_dB cal cal h-
(W, h) by the following equations. C (W , h ) and C (W, h)
distributed_dB h-distributed cal cal h-distributed
can be read in Figure E.17. Current of non-50 Ω line is also obtained using the following
equations.
= V + (C − C (W , h )) +Δ C (dB A) (E.4)
I
_dB p_dB f_dB h-distributed_dB cal cal h
ΔC = C (W , h ) – C (W, h) (E.5)
h h-distributed_dB cal cal h-distributed_dB
E.6 Calibration for probe and microstrip line
E.6.1 General
The magnetic probe used for the measurement shall be calibrated in accordance with the
procedures described below. The calibration factor (C − C ) can be obtained
h-distributed_dB f_dB
by using the microstrip line method, which has the advantage in that the probe can be
calibrated under the normal operating conditions for the magnetic probe method.
The probe calibration for a reference microstrip line on a PCB is shown in Figure E.14. This
calibration can be performed with the same measurement set-up as a normal IC emission
measurement on a test board except for the measurement distance. This requires an accurate
space placement of the probe that definitely minimizes measuring errors and assures a highly
repeatable emission measurement.
E.6.2 Pre-amplifier
Use a pre-amplifier as specified in IEC 61967-1, if necessary.
E.6.3 Spectrum analyzer setup
Use manufacturer's recommended procedures for calibration of the spectrum analyzer. Set
attenuation at an appropriate level and video bandwidth at a minimum of three times the
resolution bandwidth to prevent video averaging of the signal.
E.6.4 Microstrip line
Use microstrip line structure to calibrate the probe; an example is shown in Figure E.20. The
characteristic impedance shall be 50 Ω ± 5 Ω. In that case, the strip conductor width (W) is
1,0 mm, when the insulator thickness (h) of the microstrip board is 0,6 mm. The ground plane
width (W ) of the microstrip line should be wide enough (for example 50 mm). The microstrip
g
line should be long enough to reduce the effect of connectors at both edges (for example
50 mm), and should have a sufficiently high frequency performance. In order to check the
characteristic impedance, RF measurement equipment such as a network analyzer or a TDR
oscilloscope should be used.
NOTE The power required to obtain a sufficient signal to noise (S/N) ratio may be determined in advance over
frequency range of interest.
61967-6 Amend. 1 © IEC:2008 – 17 –
Dimensions in millimetres
Strip
(metal)
W = 1,0
Ground
(metal)
Wg
IEC 252/08
Figure E.19 – Cross-sectional view of a microstrip line for calibration (example)
E.6.5 Calibration
a) Measure the gain or loss of the test setup. Include the pre-amplifier in this measurement,
if used.
b) Place the probe over the microstrip line so that the plane of the loop is perpendicular to
the ground plane and parallel to the longitudinal axis of the microstrip line. The centre of
the probe shall be located within ± 0,2 mm distance from the centre of the microstrip line,
or search for the position where the probe output voltage reaches a peak. The face angle
of the probe shall be within a 5 degree deviation from the axis of the microstrip line. The
distance from the microstrip line surface to the loop center shall be kept within 0,47 mm
± 20 μm. These restrictions on the probe placement shall be maintained to obtain
calibration factors as accurately as possible. The maximum error for calibration factors
under these restrictions is estimated to be within ± 1,6 dB.
Sensitivity deviations of the probes with the dimensions specified in this document are
regarded as less than ±1,0 dB. Further information about the dependency on these
placement factors is shown in E.2, E.3 and E.4.
c) Connect a signal generator to one end of the microstrip line while placing a 50 Ω
termination to the other end. Also, connect the cable from the magnetic probe connector to
a spectrum analyzer as shown in Figure E.20.
d) Establish a field excitation around the reference microstrip line by the signal generator at
one frequency within the frequency band of interest, and record the level of the RF signal
induced in the probe as measured with the spectrum analyzer.
e) Repeat the procedure above at other frequencies over the frequency range. This data can
be used to plot a calibration curve for the probe under test.
f) The calibration factor (C − C ) can be calculated by the following equation
h-distributed_dB f_dB
(E.6).
C − C = V – V – 20log 50 (dB S) (E.6)
f_dB h-distributed_dB s_dB p_dB
where
C is the calibration factor for the magnetic field (dB S/m),
f_dB
V is the output voltage of the magnetic probe (dB V),
p_dB
V is the output voltage of the signal generator (dB V).
s_dB
C is the transfer constant calculated from distributed current model in
h-distributed
dB (dB 1/m).
h = 0,6
– 18 – 61967-6 Amend. 1 © IEC:2008
NOTE The transmission loss of the microstrip line should be half the overall loss when the magnetic probe is
placed at the centre of the microstrip line.
Dimensions in millimetres
Spectrum
analyzer
Magnetic probe
+20 μm
0,47 mm
–20 μm
50 Ω termination
Signal
generator
Microstrip line
IEC 253/08
Figure E.20 – Measurement set-up for probe calibration
E.7 Test board
The test set-up requirements are described in IEC 61967-1.
The measurement set-up and circuit schematic of the magnetic probe measurement method
are described in Clause 7 of IEC 61967-6.
As described in Clause 7, the standardized IC test board shall be used. However, the IC test
board can be modified for the advanced magnetic probe, because the width of the probe is
reduced. An example of basic design of IC test board is shown in Figures E.21 and E.22. The
measurement line for V and ground plane are designed on the bottom layer. The extracted
DD
measurement line for V of the IC test board is shown in Figure E.22. Basic design of the
DD
measurement line is the same as that which is shown in Figure 9. The gap between the
measurement line and the ground plane is 2 mm. However, the gap shall be adjusted to the
size of the decoupling capacitors. If the length between both electrodes of a decoupling
capacitor is wide, the gap between the measurement line and the ground plane shall be
widened in the mounting area. The width of the line should be adjusted to the size of
decoupling capacitors, too. Vias through ground planes are placed with a pitch of about 1 mm.
The length of the measurement line can be reduced to 3 mm according to the miniaturization
of the magnetic probe. For detailed information on layer arrangement, layer thickness,
decoupling capacitors, I/O pin loading and other detail design of the IC test board, reference
should be made to the Figures 5, 6 and 10.
61967-6 Amend. 1 © IEC:2008 – 19 –
Dimensions in millimetres
Measurement
IC ground plane
pattern for V
DD2
C1
Ground plane
C1
101,6
Measurement pattern
for V , see Figure E.22
DD1
IEC 254/08
Figure E.21 – Example of IC test board – Bottom layer
Dimensions in millimetres
Via to V land
DD
∅0,8 mm
Power supply line for current measurement
width 1,0 (measurement line)
Gap
2,0
Via
∅0,8
Decoupling capacitors
(for example 0,1 μF)
Mounting area for
Decoupling capacitor decoupling capacitor
(for example 10 μF)
(Gap should be adjusted in size
of decoupling capacitors)
(2)
(2)
Power supply pattern
Ground plane (third layer)
(5)
* Measurement area
IEC 255/08
Figure E.22 – Example of measurement pattern of V
DD1
101,6
(5)
(2)
3*
(2)
– 20 – 61967-6 Amend. 1 © IEC:2008
Bibliography
[1] Norio MASUDA, Naoya TAMAKI, Takeshi WATANBE and Kazuyoshi ISHIZAKA: “A
Miniature High-Performance Magnetic-Field Probe for Measuring High-Frequency
Currents,” NEC Res. & Develop., Vol.42, No.2, pp.246-250, April, 2001.
[2] Naoya Tamaki, Norio Masuda, Toshihide Kuriyama, Jin-Ching Bu, Masahiro Yamaguchi,
and Ken-Ichi Arai: “A Miniature Thin-Film Shielded –Loop Probe with a Flip-Chip Bonding
for Magnetic Near Field Measurements,” Electronics and Communication in Japan, Part 2,
Vol.88, No.4, pp. 37- 45, 2005.
[3] N. ANDO, N. MASUDA, T. KURIYAMA, M. Saito, S. Saito, K. Kato, K. Ohashi, and M.
Yamaguchi: "Development of miniaturized thin-film magnetic field probes for on-chip
measurement," J. Magn. Soc. Jpn., 30, 429-434 (2006).
[4] Toshiki SHIMASAKI, Katsuji KOBAYASHI, Norio MASUDA and Naoya TAMAKI:
“Development of measurement method of high-frequency current for the wide microstrip
line”, Proceedings of JIEP Annual Meeting, Vol.18, pp.227-228, Japan Institute of
Electronics Packaging, Mar., 2004.
[5] Norio MASUDA, Naoya TAMAKI, Jin Chin BU, Masahiro YAMAGUCHI and Ken-Ichi ARAI :
“High Frequency Magnetic Near field Measurement on LSI chip using Planar Multi-layer
Shielded Loop Coil,” 2003 IEEE Symposium on Electromagnetic Compatibility, pp.80-85,
Aug., 2003.
⎯⎯⎯⎯⎯⎯⎯
– 22 – 61967-6 Amend. 1 © CEI:2008
AVANT-PROPOS
Le présent amendement a été établi par le sous-comité 47A:Circuits intérgrés, du comité
d'études 47 de la CEI: Dispositifs à semiconducteurs.
Le texte de cet amendement est issu des documents suivants:
FDIS Rapport de vote
47A/781/FDIS 47A/784/RVD
Le rapport de vote indiqué dans le tableau ci-dessus donne toute information sur le vote ayant
abouti à l'approbation de cet amendement.
Le comité a décidé que le contenu de cet amendement et de la publication de base ne sera
pas modifié avant la date de maintenance indiquée sur le site web de la CEI sous
"http://webstore.iec.ch" dans les données relatives à la publication recherchée. A cette date,
la publication sera
• reconduite,
• supprimée,
• remplacée par une édition révisée, ou
• amendée.
_____________
Page 48
Ajouter la nouvelle Annexe E suivante:
61967-6 Amend. 1 © CEI:2008 – 23 –
Annexe E
(informative)
Sonde magnétique améliorée
E.1 Généralités
La sonde magnétique miniature (sonde magnétique améliorée) comporte une résolution
spatiale élevée, et elle permet une mesure précise des champs magnétiques proches des
boîtiers CI et des cartes de circuit imprimé denses. Elle doit être constituée d’une carte en
céramique cocuite à basse température (LTCC, «low temperature co-fired ceramics») et il
convient que sa partie de détection (boucle de détection) soit d’environ 2 mm de large et de
1 mm d’épaisseur. La miniaturisation peut provoquer une diminution de la sensibilité de la
sonde de champ magnétique du fait de la réduction de la taille de la boucle. Les détails de la
conception de la sonde sont illustrés aux Figures E.1, E.2, E3 et E.4. Cependant, la
sensibilité plus faible au champ magnétique est compensée par la diminution du gain
nécessaire, résultant de la possibilité du placement du bord de la boucle de la nouvelle sonde
plus proche de la ligne à microruban qu’il ne l’était auparavant.
E.2 Fixation de la sonde magnétique améliorée
Le modèle précédent de sonde de champ magnétique est une sonde à boucle écrantée,
réalisée au moyen d’une carte de circuit imprimé multicouche en FR4. La partie boucle de la
sonde de champ magnétique ne peut être rendue suffisamment petite pour mesurer le courant
au niveau d’une piste courte sur la carte de circuit imprimé. Le nouveau modèle est constitué
par une carte multicouche en verre céramique précise, permettant à la fois la compacité et
une résolution spatiale élevée.
Les Figures E.1 et E.2 illustrent une vue extérieure de la sonde. La taille de la boucle de
détection magnétique est réduite à 2 mm de largeur x 1 mm d’épaisseur. Il convient que la
sonde magnétique améliorée soit une ligne triplaque composée d’une carte à trois couches en
céramique cocuite à basse température (LTCC). Les détails de la construction de la sonde
recommandés sont illustrés aux Figures E.3, E.4, E.5, E.6, E.7 et E.8. Dans toutes les
figures, les parenthèses ( ) indiquent que les valeurs contenues sont des exemples. Les
autres dimensions doivent respecter les tolérances décrites ci-dessous. Si la partie boucle ne
s’inscrit pas dans les limites de tolérance, l’erreur de mesure augmentera. Un câble semi-
rigide peut être fixé à la zone de jonction, ce qui est illustré aux Figures E.1 et E.2. Il convient
que la jonction pour la connexion comporte une impédance caractéristique de 50 Ω jusqu’à
3 GHz. La construction de la connexion représentée dans les figures constitue un exemple de
connexion entre la carte LTCC et le câble coaxial semi-rigide. D’autres constructions qui
fournissent une bonne connectivité à haute fréquence sont acceptables.
Dans les Figures E.4, E.5, E.6 et E.7, la constante diélectrique relative du matériau de carte
est 7,1, et la piste imprimée sur la carte LTCC est constituée de pâte à base de Ag-Pd. Dans
ces figures, les dimensions finies de la forme de piste imprimée de la portion de boucle
peuvent avoir une caractéristique de tolérance de ±2,5 pourcent. Les dimensions entre
parenthèses peuvent également avoir une caractéristique de tolérance de ±10 pourcent. Les
conducteurs ont une épaisseur de 15 µm avec une tolérance de ±5 µm. Les isolants
(diélectriques) ont une épaisseur de 120 µm avec une caractéristique de tolérance de ±10
pourcent. Les pastilles de masse sur la première couche et la cinquième couche sont
revêtues d’environ 30 µm (d’épaisseur) d'un placage d’or (Au). De ce fait, l’épaisseur de la
pastille de masse peut être augmentée, de manière à souder les pastilles au boîtier
conducteur. Sauf spécification contraire, les dimensions des pistes imprimées peuvent avoir
une tolérance de ±10 pourcent.
– 24 – 61967-6 Amend. 1 © CEI:2008
La structure de boucle écrantée est utilisée pour la partie détection concernant le champ
magnétique. Cette partie doit être fabriquée avec précision en utilisant le procédé LTCC. La
Figure E.3 illustre la forme principale superposée du détecteur de champ magnétique réalisé
en utilisant une carte à 5 couches en verre céramique. Les seconde et quatrième couches
sont des couches de masse correspondant à la gaine extérieure d'un câble coaxial; la
troisième couche est la couche pour signaux, équivalente au conducteur central. La portion
de boucle et de sortie de la carte multicouche de la nouvelle sonde est symétrique autour de
la troisième couche, à l’exception du trou de liaison et de la piste pour le signal. La ligne
triplaque a été conçue pour avoir une impédance caractéristique de 50 Ω, en tenant compte
de l’adaptation d’impédance avec le système de mesure. On fait passer l’extrémité de la ligne
de signal par le trou d’interconnexion et elle est reliée à la terre.
La sonde précédente comporte des ouvertures sur les côtés de la ligne triplaque (portion
sortie), mais les deux côtés du motif de mise à la masse sur la seconde couche sont
connectés à la quatrième couche par un trou d’interconnexion, comme l'illustre la Figure E.3.
Le trou d’interconnexion doit être formé au pas de 0,25 mm ou inférieur. La boucle servant de
détecteur de champ magnétique est un rectangle de 0,2 mm × 1 mm, et la résolution spatiale
peut être élevée à 250 µm (typique) au point de dégradation de 6 dB. Si la cible de mesure
est un ruban rectiligne telle qu’une ligne à microruban, le coefficient d’étalonnage du courant
peut être utilisé pour convertir en courant le champ magnétique mesuré sur un ruban. Autour
du motif de chaque carte en céramique cocuite à basse température (LTCC), la valeur de
divergence par rapport à l’alignement parfait doit se situer à 10 µm. La performance de la
sonde diminue lorsque l’erreur d’alignement augmente, parce que l’impédance caractéristique
de la ligne triplaque de la sonde diverge de 50 Ω. En prenant l’essai de sélection par rayons
X, les éléments non conformes pour lesquels l’erreur d’alignement dépasse 10 µm doivent
être rejetés. De plus, l’extrémité avant de la carte LTCC doit être précisément découpée et
polie plate.
Les pastilles de masse sur la première couche et la cinquième couche sont illustrées aux
Figures E.4 et E.7. La pastille de la première couche est connectée à la seconde couche par
des trous d’interconnexion et la pastille de la cinquième couche est connectée à la quatrième
couche par un nombre suffisant de trous de liaison, respectivement. La pastille de masse sur
la cinquième couche est étendue, en comparaison de celle située sur la première couche.
Comme l’illustrent les Figures E.5 à E.6, la largeur de ruban est décroissante pour devenir un
ruban étroit. Comme le montrent les Figures E.4 et E.7, les motifs de mise à la masse sont
également décroissants, parce que les formes de piste des seconde et quatrième couches
sont décroissantes. La Figure E.8 illustre la configuration pour la connexion de la carte LTCC
au câble coaxial semi-rigide. L’assemblage est constitué du boîtier conducteur, de la partie en
marche d’escalier de la carte LTCC et du câble coaxial semi-rigide. Comme l’illustre la Figure
E.8, le conducteur central du câble coaxial semi-rigide est connecté à la pastille de signal sur
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