VSMF Series (1206, 2010, 2512)
Vishay Foil Resistors
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The First High Precision Bulk Metal
®
Foil Surface-Mount
Chip Resistor with Flexible Terminations,
TCR of ±2 ppm/°C and Load Life Stability of ±0.01% (100 ppm)
FEATURES
• Temperature coefficient of resistance (TCR):
±2.0 ppm/°C typical (–55°C to +125°C, +25°C ref.)
(see Table 1)
• Resistance range: 10 Ω to 125 kΩ (for higher and lower
values, please contact Application Engineering)
• Resistance tolerance: to ±0.01%
• Power rating: to 400 mW at +70°C
• Load life stability: to ±0.01% at 70°C, 2000 h at
rated power
•
Strain relief construction by flexible terminations
• Vishay Foil resistors are not restricted to standard
values; specific “as required” values can be supplied at
no extra cost or delivery (e.g. 1K2345 vs. 1K)
• Thermal stabilization time < 1 s (nominal value achieved
within 10 ppm of steady state value)
• Electrostatic discharge (ESD): at least to 25 kV
• Thermal EMF: 0.05 μV/°C
• Non inductive, non capacitive design
• Rise time: 1 ns effectively no ringing
• Current noise: 0.010 µV
RMS
/V of applied voltage
(<–40 dB)
• Voltage coefficient <0.1 ppm/V
• Non inductive: <0.08 µH
• Non hot spot design
• Prototype quantities available in just 5 working days or
sooner. For more information, please contact us.
• Terminal finish: lead (Pb)-free or tin/lead alloy
*
Note:
*
Pb containing terminations are not RoHS compliant,
exemptions may apply.
Top View
INTRODUCTION
Vishay Foil Resistors’ new VSMF model is targeted for
applications that are prone to high thermal stress or
mechanical stress; it features low TCR, excellent load life
stability, tight tolerance, excellent shelf-life stability, low
current noise, high speed, and low voltage coefficient—all
in the same resistor.
It is well known that chips of 1206 dimensions and
larger can occasionally develop cracks and even fall off
the printed circuit board, especially when exposed to
temperature cycling. These instances are due to stress-
inducing mishandling of the PC board (e.g., bending during
assembly), excess thermal gradients, or thermal shock.
The latter two can be divided into two categories:
1. Thermal stress induced by changes in ambient
temperature. Here, different coefficients of expansion
induce mechanical stress as PCB compression
imposes tension on the resistor (or vice versa).
2. Thermal stress caused by internal heat generation
(load). Here, power dissipation within the resistor
generates temperature differentials between the
resistor and the PCB, resulting in variable stresses.
Stress cycling due to these two phenomena causes
material fatigue and cracks.
Vishay Foil Resistors’ new VSMF series of surface-mount
chip resistors feature flexible terminations to prevent
cracking of the body of the chip or delamination from the
board, especially in resistors with high length-to-width
aspect ratios.
For applications with high thermal stresses, designers
typically use molded resistors with flexible terminations.
These are larger than chip resistors and require more real
estate on the PCB. Vishay Foil Resistors has developed
and patented a solution which permits direct replacement
of standard chips by chips with flexible terminations.
The Vishay Foil Resistors’ application engineering
department is available to advise and make
recommendations.
For non-standard technical requirements and special
applications, please contact foil@vishaypg.com.
Document No.: 63177
Revision: 07-Nov-2011
TABLE 1—TOLERANCE AND TCR VS.
RESISTANCE VALUE
(1)
(-55°C to +125°C, +25°C Ref.)
RESISTANCE
VALUE (Ω)
250 to 125K
100 to <250
50 to <100
25 to <50
10 to <25
TOLERANCE
(%)
±0.01
±0.02
±0.05
±0.1
±0.25
TYPICAL TCR AND
MAX. SPREAD (ppm/°C)
±2 ±2
±2 ±3
±2 ±3
±2 ±4
±2 ±6
Note
(1)
For tighter performances and lower values, please contact
Application Engineering.
www.vishayfoilresistors.com
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For questions, contact
foil@vishaypg.com
VSMF Series (1206, 2010, 2512)
Vishay Foil Resistors
FIGURE 1—POWER DERATING CURVE
Percent of Rated Power
100
75
50
25
0
-75
TABLE 2—SPECIFICATIONS
CHIP SIZE
1206
2010
2512
RESISTANCE
RANGE (Ω)
10 to 25K
10 to 70K
10 to 125K
RATE POWER (mW)
AT +70°C
150
300
400
-55°C
+70°C
-50
-25
Ambient Temperature (°C)
0
+25
+50
+75
+100 +125 +150 +175
TABLE 3—PERFORMANCES
PARAMETERS
Working Temperature Range
Thermal Shock
Overload
Low Temp. Storage
PC board Flexion
Dielectric Withstanding Voltage
Insulation Resistance
Resistance to Soldering Heat
Moisture Resistance
Shock
Vibration, High Frequency
Storage Life
High Temperature Exposure
Load Life Stability
-65°C/30 min
⇔
+150°C/30 min, 5 cycles
Rated voltage x 2.5, 5 sec
-65°C, no load, 24 h → rated voltage, 45 min.
3 mm Bend, 60 sec
AC200 V, 1 min
DC100 V, 1 min
260°C, 10 sec
+65°C to -10°C, 90% RH to 98% RH, rated voltage,
10 cycles (240 h)
100 G, 6 ms, Sawthooth Wave, X, Y, Z, 10 shocks
20 G, 10 Hz to 2000 Hz to 10 Hz, 20 min., X, Y, Z,
each 2.5 h
15°C to 35°C, 15% RH to 75% RH, no load, 10000 h
150°C, no load, 100 h
70°C, rated power, 1.5 h ON, 0.5 h OFF, 2000 h
TEST CONDITIONS
MAXIMUM
±0.02% (200 ppm)
±0.02% (200 ppm)
±0.02% (200 ppm)
±0.01% (100 ppm)
±0.02% (200 ppm)
±0.02% (200 ppm)
±0.02% (200 ppm)
±0.02% (200 ppm)
±0.02% (200 ppm)
±0.005% (50 ppm)
±0.02% (200 ppm)
±0.02% (200 ppm)
TYPICAL
±0.005% (50 ppm)
±0.005% (50 ppm)
±0.005% (50 ppm)
±0.005% (50 ppm)
±0.005% (50 ppm)
±0.005% (50 ppm)
±0.01% (100 ppm)
±0.01% (100 ppm)
±0.01% (100 ppm)
±0.0025% (25 ppm)
±0.005% (50 ppm)
±0.01% (100 ppm)
-65°C to +150°C
Over 10,000 MΩ
FIGURE 2—TRIMMING TO VALUES*
(Conceptual Illustration)
FIGURE 3—TYPICAL RESISTANCE/
TEMPERATURE CURVE
+ 150
+ 100
R
(ppm)
Interloop Capacitance
Reduction in Series
Current Path
Before Trimming
Current Path
After Trimming
Trimming Process
Removes this Material
from Shorting Strip Area
Changing Current Path
and Increasing
Resistance
∆
R
+ 50
0
- 50
- 100
- 150
- 200
- 55 - 50
- 25
0
± 2 ppm/°C
+ 25
+ 50
+ 75 + 100 + 125
Mutual Inductance
Reduction due
to Change in
Current Direction
Note:
Foil shown in black, etched spaces in white
Ambient Temperature (°C)
* To acquire a precision resistance value, the Bulk Metal® Foil
chip is trimmed by selectively removing built-in “shorting bars.”
To increase the resistance in known increments, marked areas
are cut, producing progressively smaller increases in resistance.
This method eliminates “hot spots” and improves the long term
stability of the resistor.
www.vishayfoilresistors.com
2
For questions, contact
foil@vishaypg.com
Document No.: 63177
Revision: 07-Nov-2011
VSMF Series (1206, 2010, 2512)
Vishay Foil Resistors
TABLE 4—DIMENSIONS
in Inches (Millimeters)
Top View
L
W
D
CHIP
SIZE
1206
2010
2512
L
±0.005
(0.13)
0.126
(3.20)
0.198
(5.03)
0.249
(6.32)
W
±0.005
(0.13)
0.062
(1.57)
0.097
(2.46)
0.127
(3.23)
THICKNESS
MAXIMUM
0.025 (0.64)
0.025 (0.64)
0.025 (0.64)
D
±0.005
(0.13)
0.020
(0.51)
0.025
(0.64)
0.032
(0.81)
FIGURE 4—RECOMMENDED MOUNTING
T
1. IR and vapor phase reflow are recommended.
2. Avoid any cleaning agent that could attack epoxy
resins. Epoxy resins form an integral part of the resistor
construction.
3. Vacuum pick up is recommended for handling.
4. In case of using soldering iron, measurement precautions
should be taken to avoid damaging the resistor.
FIGURE 5—DEMONSTRATION OF FLEXIBLE TERMINATIONS
PCB Bending Test
The Effect of Bending on the Terminations
Standard SMD has been
cracked at solder connection
points or terminations
Vishay Foil Resistor—VSMF
has not been damaged due
to the unique flexible
terminations construction
Document No.: 63177
Revision: 07-Nov-2011
For questions, contact
foil@vishaypg.com
www.vishayfoilresistors.com
3
VSMF Series (1206, 2010, 2512)
Vishay Foil Resistors
FIGURE 6—THERMAL SHOCK
Thermal Shock
–65°C/30 min
+150°C/30 min,
300 cycle (5, 10, 50, 100, 200, 300), n=20
500
400
300
200
∆R (ppm)
100
0
–100 0
–200
–300
–400
–500
Number of Cycles
Average
50
100
150
200
250
300
FIGURE 7—LOAD LIFE
Load Life
70°C, Rated Power (0.3W), 1.5 hr/ON
0.5 hr/OFF, 2000 hr
Size 2010, 10 K ; n=30
200
150
100
∆R (ppm)
50
0
–50
–100
–150
–200
Time (hr)
Average
0
200
0
400
600
800
1000 1200 1400 1600 1800 2000
High Temperature Exposure
FIGURE 8—HIGH TEMPERATURE EXPOSURE
+150°C, No Load, 1000 hr, n=30
Size 2010, 10 K
250
200
150
100
50
0
0
–50
–100
–150
–200
–250
∆R (ppm)
100
200
300
400
500
600
700
800
900
1000
Time (hr)
Average
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4
For questions, contact
foil@vishaypg.com
Document No.: 63177
Revision: 07-Nov-2011
VSMF Series (1206, 2010, 2512)
Vishay Foil Resistors
TABLE 5—GLOBAL PART NUMBER INFORMATION
DENOTES PRECISION
Y
VALUE
R
=
K
=k
(1)
NEW GLOBAL PART NUMBER: Y161512K7560T0R (preferred part number format)
CHARACTERISTICS
0
= standard
9
= lead (Pb)-free
1 to 999
= custom
7
5
6
0
T
0
R
Y
1
6
1
5
1
2
K
PRODUCT CODE
1615
= VSMF1206
1616
= VSMF2010
1617
= VSMF2512
RESISTANCE TOLERANCE
T
= ±0.01%
Q
= ±0.02%
A
= ±0.05%
B
= ±0.10%
C
= ±0.25%
PACKAGING
R
= tape and reel
W
= waffle pack
FOR EXAMPLE: ABOVE GLOBAL ORDER Y1615 12K7560 T 0 R:
TYPE: VSMF1206
VALUES: 12.7560 k
ABSOLUTE TOLERANCE: 0.01%
TERMINATION: standard
PACKAGING: tape and reel
HISTORICAL PART NUMBER: VSMF1206 12K756 TCR2 T B T (will continue to be used)
VSMF1206
MODEL
VSMF1206
VSMF2010
VSMF2512
12K756
RESISTANCE
VALUE
12.756 k
TCR2
TCR
CHARACTERISTICS
T
TOLERANCE
T
= ±0.01%
Q
= ±0.02%
A
= ±0.05%
B
= ±0.10%
C
= ±0.25%
B
TERMINATION
S
= lead (Pb)-free
B
= tin/lead
T
PACKAGING
T
= tape and reel
W
= waffle pack
Note
(1 )
For non-standard requests, please contact application engineering.
Document No.: 63177
Revision: 07-Nov-2011
For questions, contact
foil@vishaypg.com
www.vishayfoilresistors.com
5
