1996 Nov 15 1
Philips Components
Chip resistors General Introduction
INTRODUCTION
Data in data sheets is presented - whenever possible -
according to a ‘format’, in which the following chapters are
stated:
•TITLE
•FEATURES
•APPLICATIONS
•DESCRIPTION
•QUICK REFERENCE DATA
•ORDERING INFORMATION
•FUNCTIONAL DESCRIPTION
– Product characterization
– Limiting values
•MECHANICAL DATA
– Mass
– Marking
– Outlines
•TESTS AND REQUIREMENTS
The chapters listed above are explained in this section
“General Introduction Chip resi stors”
, with detailed
information in the relevant data sheet. Chapters
“Mounting” and “Packaging” are detailed in separate
sections.
DESCRIPTION
All types of chip resistors have a rectangular ceramic body.
The resistive element is a metal glaze film. The chips have
been trimmed to the required ohmic resistance by cutting
one or more grooves in the resistive layer. This process is
completely computer controlled and yields a high
reliability. The terminations are attached using either a
silver dipping method or by applying nickel terminations
which are covered with lead/tin.
The resistive layer is coated with a coloured protective
layer. This protective layer provides electrical, mechanical
and/or environmental protection - also against soldering
flux and cleaning solvents, in accordance with
“MIL-STD-202E”
, method 215 and
“IEC 68-2-45”
.
ORDERING INFORMATION
Resistors are ordered by their ordering code, a 12-digit
number. In general, the packaging method and resistance
code are integral parts of this number.
Exceptions to this rule are customer/application specific
resistors that are not included in our standard series, such
as higher ohmic values and non-standard values.
FUNCTIONAL DESCRIPTION
The functional description includes: nominal resistance
range and tolerance, limiting voltage, temperature
coefficient, absolute maximum dissipation, climatic
category and stability.
The limiting voltage (DC or RMS) is the maximum
voltage that may be continuously applied to the resistor
element, see
“IEC publications 115-8”.
The temperature rise in a resistor due to power dissipation,
is determined by the laws of heat - conduction, convection
and radiation. The maximum body temperature usually
occurs in the middle of the resistor and is called the
hot-spot temperature.
In the normal operating temperature range of chip
resistors the temperature rise at the hot-spot, ∆T, is
proportional to the power dissipated: ∆T=A×P. The
proportionally constant ‘A’ gives the temperature rise per
Watt of dissipated power and can be interpreted as a
thermal resistance in K/W. This thermal resistance is
dependent on the heat conductivity of the materials used
(including the PCB), the way of mounting and the
dimensions of the resistor. The sum of the temperature
rise and the ambient temperature is:
Tm=T
amb +∆T
where:
Tm= hot-spot temperature
Tamb = ambient temperature
∆T = temperature rise at hot-spot.
The stability of a chip resistor during endurance tests is
mainly determined by the hot-spot temperature and the
resistive materials used.
Summarizing
DESCRIPTION RELATIONSHIP
Dimensions, conductance of
materials and mounting determine heat resistance
Heat resistance ×dissipation gives temperature rise
Temperature rise + ambient
temperature give hot-spot
temperature
1996 Nov 15 2
Philips Components
Chip resistors General Introduction
Performance
When specifying the performance of a resistor, the
dissipation is given as a function of the hot-spot
temperature, with the ambient temperature as a
parameter.
From ∆T=A×P and Tm=T
amb +∆T it follows that:
If P is plotted against Tm for a constant value of A, parallel
straight lines are obtained for different values of the
ambient temperature. The slope of these lines,
is the reciprocal of the heat resistance and is the
characteristic for the resistor and its environment.
The temperature coefficient
The temperature coefficient of resistance is a ratio which
indicates the rate of increase (decrease) of resistance per
Kelvin (K) increase (decrease) of temperature within a
specified range, and is expressed in parts per million per K
(×10−6/K).
PTmTamb
–
A
---------------------------
=
dP
dTm
----------- I
A
----
=
EXAMPLE
If the temperature coefficient of a resistor of Rnom = 1 kΩ
between −55 °C and +155 °C is ±200 ×10−6/K, its
resistance will be,
at 25 °C:
1000 Ω (nominal = rated value)
at +155 °C:
1000 Ω±(130 ×200 ×10−6)×1000 Ω
= 1026 Ω or 974 Ω
at −55 °C:
1000 Ω±(80 ×200 ×10−6)×1000 Ω
= 1016 Ω or 984 Ω
If the temperature coefficient is specified as ≤200 ×10−6/K
the resistance will be within the shaded area as shown in
Fig.1.
Fig.1 Temperature coefficient.
handbook, full pagewidth
MGA208
Rnom
2.6%
1.6%
1.6%
2.6%
T ( C)
o
16 Ω
15525055
26 Ω
1996 Nov 15 3
Philips Components
Chip resistors General Introduction
Noise
Most resistors generate noise due to the passage of
current through the resistor. This noise is dependent on
the amount of current, the resistive material and the
physical construction of the resistor. The physical
construction is partly influenced by the laser trimming
process which cuts a groove in the resistive material.
Typical current noise levels are shown in Fig.2.
Frequency behaviour
Resistors in general are designed to function according to
ohmic laws. This is basically true of rectangular chip
resistors for frequencies up to 100 kHz. At higher
frequencies, the capacitance of the terminations and the
inductance of the resistive path length begin to have an
effect.
Fig.2 Typical noise levels as a function
of rated resistance.
handbook, halfpage
12
8
4
01 10 100 1k 1M
R (Ω)
MGA212
100k10k 10 M
noise
level
µV
V
spec. level
RC02
Basically, chip resistors can be represented by an ideal
resistor switched in series with a coil and both switched
parallel to a capacitor. The values of the capacitance and
inductance are mainly determined by the dimensions of
the terminations and the conductive path length. The
trimming pattern has a negligible influence on the
inductance as the path length is not influenced. Also, its
influence on the capacitance is negligible as the total
capacitance is largely determined by the terminations.
The environment surrounding chips (e.g. landing paths,
nearby tracks and the material of the printed-circuit board)
has a large influence on the behaviour of the chip on the
printed-circuit board.
Typical values of capacitance and inductance
QUANTITY
CHIP PROPERTIES
THIN FILM THICK FILM
1206
R<1kΩ1206 0805 0603
Capacitance 0.05 pF 0.05 pF 0.09 pF 0.05 pF
Inductance 2 nH 2 nH 1 nH 0.4 nH
Fig.3 Equivalent circuit.
MLB715
1996 Nov 15 4
Philips Components
Chip resistors General Introduction
handbook, full pagewidth
0
2.0
1010
MLB716
109
108
107
106
0.4
0.8
1.2
1.6
Z
R
f (Hz)
R = 1 MΩ
nR = 100 kΩ
nR = 10 kΩ
nR = 1 kΩ
n
R = 100 Ω
n
R = 10 Ω
n
R = 1 Ω
n
Fig.4 Impedance as a function of frequency for a chip resistor.
Size 0603
handbook, full pagewidth
100
100
1010
MLB717
109
108
107
106
60
20
20
60
f (Hz)
R = 1 MΩ
nR = 100 kΩ
nR = 10 kΩ
nR = 1 kΩ
n
R = 100 Ω
n
R = 10 Ω
n
R = 1 Ω
n
ϕ
(deg)
Fig.5 Phase shift as a function of frequency for a chip resistor.
Size 0603
1996 Nov 15 5
Philips Components
Chip resistors General Introduction
Fig.6 Impedance as a function of frequency for a chip resistor.
handbook, full pagewidth
0
2.0
1010
MLB718
109
108
107
106
0.4
0.8
1.2
1.6
Z
R
f (Hz)
R = 1 MΩ
nR = 100 kΩ
nR = 10 kΩ
nR = 1 kΩ
n
R = 100 Ω
n
R = 10 Ω
n
R = 1 Ω
n
Size 0805
Fig.7 Phase shift as a function of frequency for a chip resistor.
handbook, full pagewidth
100
100
1010
MLB719
109
108
107
106
60
20
20
60
f (Hz)
R = 1 MΩ
nR = 100 kΩ
nR = 10 kΩ
nR = 1 kΩ
n
R = 100 Ω
n
R = 10 Ω
n
R = 1 Ω
n
ϕ
(deg)
Size 0805
1996 Nov 15 6
Philips Components
Chip resistors General Introduction
Fig.8 Impedance as a function of frequency for a chip resistor.
handbook, full pagewidth
0
2.0
1010
MLB720
109
108
107
106
0.4
0.8
1.2
1.6
Z
R
f (Hz)
R = 1 MΩ
nR = 100 kΩ
nR = 10 kΩ
nR = 1 kΩ
n
R = 100 Ω
n
R = 10 Ω
n
R = 1 Ω
n
Size 1206
Fig.9 Phase shift as a function of frequency for a chip resistor.
handbook, full pagewidth
100
100
1010
MLB721
109
108
107
106
60
20
20
60
f (Hz)
R = 1 MΩ
nR = 100 kΩ
nR = 10 kΩ
nR = 1 kΩ
n
R = 100 Ω
n
R = 10 Ω
n
R = 1 Ω
n
ϕ
(deg)
Size 1206
1996 Nov 15 7
Philips Components
Chip resistors General Introduction
PULSE-LOAD BEHAVIOUR
The load, due to a single pulse at which chip resistors fail
by going open circuit, is determined by shape and time.
A standard way to establish pulse load limits is shown in
Table 1.
Table 1 Pulse load limits
PARAMETER VALUE UNIT
Exponential time constant 50 to 700 µs
Repetition time 12 to 25 s
Amount of pulses 5 to 10
With this test, it can be determined at which applied
voltage the resistive value changes about 0.5% of its
nominal value under the above mentioned pulse
conditions. Figure 10 shows test results for the RC02 chip
resistors. If applied regularly the load is destructive,
therefore the load must not be applied regularly during the
load life of the resistors. However, the magnitude of a
pulse at which failure occurs is of little practical value. The
maximum ‘single-pulse’ load that may be applied in a
regular way can be determined in a similar manner.
Fig.10 Maximum permissible peak pulse voltage without failing to ‘open circuit’
in accordance with DIN IEC 40 (CO) 533. V
ˆmax
()
RC02
handbook, full pagewidth
10 102103104105106107
MBD641
104
10
102
103
V
R (Ω)
n
1.2/50 µs
10/700 µs
max
(V)
1996 Nov 15 8
Philips Components
Chip resistors General Introduction
Fig.11 Pulse on a regular basis; maximum permissible peak pulse power as a function
of pulse duration for R ≤10 kΩ, single pulse and repetitive pulse tp/ti= 1000.
P
ˆmax
()
handbook, full pagewidth
10 6
MBC188
103
10 1
1
10
102
10 510 410 310 2110 1
Pmax
(W)
t (s)
i
t / t = 1000
pi
single pulse
repetitive pulse
RC02G
Fig.12 Pulse on a regular basis; maximum permissible peak pulse voltage as a function
of pulse duration (ti). V
ˆmax
()
RC02
handbook, full pagewidth
600
200
0
400
MBD586
10 11
10 2
10 3
10 4
10 5
10 6
Vmax
(V)
t (s)
i
1996 Nov 15 9
Philips Components
Chip resistors General Introduction
Definitions of pulses
SINGLE PULSE
The resistor is considered to be operating under single
pulse conditions if, during its life, it is loaded with a limited
number (approximately 1500) of pulses over long time
intervals (greater than one hour).
REPETITIVE PULSE
The resistor is operating under repetitive pulse conditions
if it is loaded by a continuous train of pulses of similar
power.
The dashed line in Fig.11 shows the observed maximum
load for the RC02G chip resistors under single-pulse
loading.
More usually, the resistor must withstand a continuous
train of pulses of repetition time ‘tp’ during which only a
small resistance change is acceptable. This resistance
change (∆R/R) is equal to the change permissible under
continuous load conditions. The continuous pulse train
and small permissible resistance change reduces the
maximum handling capability.
The continuous pulse train maximum handling capacity of
chip resistors has been determined experimentally.
Measurements have shown that the handling capacity
varies with the resistive value applied.
However, maximum peak pulse voltages as indicated in
Fig.12, should not be exceeded.
Determination of pulse-load
The graphs in Figs 11 and 12 may be used to determine
the maximum pulse-load for a resistor.
•For repetitive rectangular pulses:
– must be lower than the value of max given by
the solid lines of Fig.11 for the applicable value of ti
and duty cycle tp/ti.
–i must be lower than the value of max given in
Fig.12 for the applicable value of ti.
•For repetitive exponential pulses:
– As for rectangular pulses, except that ti= 0.5 τ.
•For single rectangular pulses:
– must be lower than the max given by the dashed
line of Fig.11 for the applicable value of ti.
–i must be lower than the value of max given in
Fig.12 for the applicable value of ti.
V
ˆi2
R
------- P
ˆ
V
ˆ
V
ˆ
V
ˆi2
R
------- P
ˆ
V
ˆ
V
ˆ
1996 Nov 15 10
Philips Components
Chip resistors General Introduction
Definition of symbols (see Figs 11, 12, 13 and 14)
Examples
Determine the stability of a typical resistor for operation
under the following pulse-load conditions.
CONTINUOUS PULSE TRAIN
A 100 Ω resistor is required to operate under the following
conditions: Vi= 10 V; ti=10
−5
s; tp=10
−2
s.
Therefore:
= = 1 W and
For ti = 10−5 s and Fig.11 gives max =2W
and Fig.12 gives max = 400 V. As the operating
conditions = 1 W and i= 10 V are lower than these
limiting values, this resistor may be safely used.
SINGLE PULSE
A 10 kΩ resistor is required to operate under the following
conditions: i= 250 V; ti=10
−5s.
Therefore:
max = = 6.25 W
The dashed curve of Fig.11 shows that at ti=10
−5s, the
permissible max = 10 W and Fig.12 shows a permissible
max of 400 V, so this resistor may be used.
SYMBOL DESCRIPTION
applied peak pulse power
maximum permissible peak pulse power
(Fig.11)
iapplied peak pulse voltage (Figs 13 and 14)
maximum permissible peak pulse voltage
(Fig.12)
Rnom nominal resistance value
tipulse duration (rectangular pulses)
tppulse repetition time
τtime constant (exponential pulses)
Tamb ambient temperature
Tm(max) maximum hot-spot temperature of the
resistor
P
ˆ
P
ˆmax
V
ˆ
V
ˆmax
P
ˆ102
100
---------- tp
ti
---- 10 2–
10 5–
----------- 1000==
t
p
t
i
---- 1000,=P
ˆ
V
ˆ
P
ˆ
V
ˆ
V
ˆ
P
ˆ2502
10000
----------------
P
ˆ
V
ˆ
handbook, halfpage
MGA206
ti
V
Vi
t
tp
Fig.13 Rectangular pulses.
handbook, halfpage
V
t
τ
MGA207
tp
Fig.14 Exponential pulses.
1996 Nov 15 11
Philips Components
Chip resistors General Introduction
MECHANICAL DATA
Outlines
Table 2 Chip resistor type; USA case size code; mass per 100 units and relevant physical dimensions; see Fig.15
TYPE USA
SIZE CODE L
(mm) W
(mm) T
(mm) MASS
(g)
RC0... 1206 3.2 1.6 0.6 1.0
RC1.. 0805 2.0 1.25 0.6 0.55
RC2.. 0603 1.6 0.8 0.45 0.25
RC3. 0402 1.0 0.5 0.35 0.052
Fig.15 Component outline.
handbook, full pagewidth
,,
,,
,,
,
,,
,,
,,
,
protective coat
resistor layer
inner electrode
end termination
ceramic substrate
protective coat
MBC695
T
W
L
For dimensions see Table 2.
Marking
Wherever possible chip resistors are provided with a
resistance code; see Table 3. The resistance code
includes the first two or three significant digits of the
resistance value (in ohms) followed by the number of zeros
to follow. Whether two or three significant values are
represented depends on the tolerance:
•±5% requires two digits
•±2% tolerance may be marked with two or three digits
•±1% and lower requires three digits.
Table 3 Resistance value indication
Note
1. R denotes the decimal point.
INDICATOR TOL. ≥±2% TOL. ≤±1%
0 0.0 Ω; jumper −
R(1) 1to91Ω1 to 976 Ω
1 100 to 910 Ω1 to 9.76 kΩ
2 1 to 9.1 kΩ10 to 97.6 kΩ
3 10to91kΩ100 to 976 kΩ
4 100 to 910 kΩ1MΩ
5 1 to 9.1 MΩ−
610MΩ−
1996 Nov 15 12
Philips Components
Chip resistors General Introduction
TESTS AND PROCEDURES
To guarantee zero defect production standards, Statistical
Process Control is an essential part of our production
processes. Furthermore, our production process is
operating in accordance with
“ISO 9000”
.
Essentially all tests on resistors are carried out in
accordance with the schedule of
“IEC publication 115-1”
in the specified climatic category and in accordance with
IEC publication 68,
“Recommended basic climatic and
mechanical robustness testing procedure for electronic
components”
. In some instances deviations from the IEC
recommendations are made.
Tests and their requirements are described in detail in the
datasheets.
Fig.16 Typical temperature coefficients between the lower and upper category temperatures.
handbook, halfpage
300
TC
(10 /K)
6
200
100
0
100
200
300 1 10 100 1k 1M
R (Ω)
MGA210
100k10k 10M
spec. level
spec. level
handbook, halfpage
100 1k 1M
R (Ω)
MGA211
100k10k
60
40
20
0
20
40
60
spec. level
spec. level
TC
(10 /K)
6
a. RC01. b. RC02G.
1996 Nov 15 13
Philips Components
Chip resistors General Introduction
Fig.17 Typical percentage change in resistance after soldering for 10 seconds at 260 °C, completely immersed.
a. RC01.
handbook, halfpage
1.2
0.8
0.4
0
0.4
0.8
1.21 10 100 1k 1M
R (Ω)
MGA214
100k10k 10M
spec. level
spec. level
(%)
R∆
R
handbook, halfpage
0.3
0.2
0.1
0
0.1
0.2
0.3100 1k 1M
R (Ω)
MGA215
100k10k
spec. level
spec. level
(%)
R∆
R
b. RC02G.
Fig.18 Typical noise level as a function of rated resistance measured using Quantech - equipment.
handbook, halfpage
12
8
4
0100 1k 1M
R (Ω)
MGA213
100k10k
noise
level
spec. level
µV
V
RC02G
1996 Nov 15 14
Philips Components
Chip resistors General Introduction
Fig.19 Typical percentage change in resistance after 56 days at 40 °C and
90 to 95% relative humidity loaded with Pnom.
a. RC01.
handbook, halfpage
2
1
0
1
2
1 10 100 1k 1M
R (Ω)
MGA216
100k10k 10M
spec. level
spec. level
(%)
R∆
R
handbook, halfpage
1.2
0.8
0.4
0
0.4
0.8
1.2100 1k 1M
R (Ω)
MGA217
100k10 k
spec. level
spec. level
(%)
R∆
R
b. RC02G.
Fig.20 Typical percentage change in resistance after 1000 hours
loaded with Pnom at 70 °C ambient temperature.
a. RC01.
handbook, halfpage
1.2
0.8
0.4
0
0.4
0.8
1.21 10 100 1k 1M
R (Ω)
MGA218
100k10k 10M
spec. level
spec. level
(%)
R∆
R
handbook, halfpage
0.6
0.4
0.2
0
0.2
0.4
0.6100 1k 1M
R (Ω)
MGA219
100k10 k
spec. level
spec. level
(%)
R∆
R
b. RC02G.
