14
NTC SMD Thermistors
With Nickel Barrier Termination NB 21
Types NB 21
IEC SIZE : 0603
Terminations Nickel Barrier
Marking On packaging only
Climatic category 40/125/56
Operating temperature -55°C to +150°C
Tolerance on Rn (25°C) ±5%, ±10%, ±20%
Maximum dissipation at 25°C 0.07 W
Thermal dissipation factor 1 mW/°C
Thermal time constant 4 s
Chip thermistors are high quality and low cost devices
especially developed for surface mounting applications. They
are widely used for temperature compensation but can also
achieve temperature control of printed circuits.
A nickel barrier metallization provides outstanding qualities of
solderability and enables this chip to meet the requirements
of the most severe soldering processes.
APPLICATIONS
• LCD compensation
• Battery packs
• Mobile phones
• CD players
• Heating systems
• Air-conditioning systems
• Temperature control of Switch Mode Power Supplies
• Compensation of pressure sensors
• Protection of power transistors in various electronic circuits
1.6 (.063) 0.2 (.008)
0.8 (.031)
±0.2 (.008)
0.8 (.031)
±0.2 (.008)
0.2 (.008) min 0.2 (.008) min
Resistance - Temperature characteristics: pages 36 to 40.
HOW TO ORDER
NB 21
Type
K 0
Material Code
K
(See tables page 15)
0103
Resistance
10,000 Ω
M
Tolerance
M (±20%)
J (±5%)
K (±10%)
BB
Suffix: Packaging
– –: Bulk
BB: Cardboard tape
(180mm diam. reel)
BF: Cardboard tape (1/2 reel)
BD: Cardboard tape
(330mm diam. reel)
DIMENSIONS:
millimeters (inches)
15
NTC SMD Thermistors
With Nickel Barrier Termination NB 21
TABLE OF VALUES
NB 21
IEC SIZE : 0603
Types Rn at 25°C Material B (K) ␣at 25°C
(Ω) Code (⌬B/B )(%/°C)
NB 21 KC 0 470 47
NB 21 KC 0 101 100 KC 3470 ± 5% – 3.9
NB 21 KC 0 471 470
NB 21 MC 0 102 1,000 MC 3910 ± 3% – 4.4
NB 21 J 0 0472 4,700 J 3480 ± 3% – 3.9
NB 21 J 5 0682 6,800 J5 3480 ± 3% – 3.9
NB 21 J 5 0103 10,000 3480 ± 3% – 3.9
NB 21 K 0 0103 10,000 K 3630 ± 3% – 4.0
NB 21 K 0 0153 15,000
NB 21 L 0 0223 22,000 L 3790 ± 3% – 4.2
NB 21 M 0 0333 33,000 M 3950 ± 3% – 4.4
NB 21 M 0 0473 47,000
NB 21 L 2 0683 68,000 L2 3805 ± 3% – 4.1
NB 21 N 0 0683 68,000 N 4080 ± 3% – 4.6
NB 21 N 5 0104 100,000 N5 4160 ± 3% – 4.7
NB 21 P 0 0154 150,000 P 4220 ± 3% – 4.7
NB 21 Q 0 0334 330,000 Q 4300 ± 3% – 4.7
NB 21 Q 0 0474 470,000
(1) ± 5%
(2) ± 3%
16
Packaging for Automatic Insertion
NTC Chip Thermistors / NC/NB Series
AUTOMATIC INSERTION
Super 8 Plastic Tape Packaging:
The mechanical and dimensional reel characteristics are in
accordance with the IEC publication 286-3.
R = 0.3 (.012) Max.
Max
3°
Max
3°
Max
3°
Max
3°
Cover Tape
30μ ± 5μ
T
K
A1
B1
B0
D0 P2
P0
W
Hole
F
E
A0
5.5 (.217)
±0.2 (.008)
Direction of
unreeling
+0.2 (.008)
-0
⭋1 (.039)
Designation Symbol Value Tolerance
Tape width W 8 ±0.2
Tape thickness T 0.4 max.
Pitch of the sprocket holes P0 4 ±0.1
Diameter of the sprocket holes D0 1.5 ±0.1
-0
Distance E 1.75 ±0.1
Distance (center to center) F 3.5 ±0.05
Distance (center to center) P2 2 ±0.1
Sizes of the NC 12 (0805) A0 1.5 ±0.1
cavities B0 2.4 ±0.1
K 1.4 max. K ±0.1
(size is adjustable)
(K = t1 +0.2)
NC 20 (1206) A0 1.95 ±0.1
B0 3.55 ±0.1
K 1.5 max. K ±0.1
(size is adjustable)
(K = t1 +0.2)
Bottom side
Reel
Upper side
Direction of unreeling
Reel
according to
ISO/DIS 3639-2
ø 12.75 (.502)
+ 0.15 (.006)
- 0
ø180 (7.09)
+ 0
- 2 (.079)
ø 20.5 (.087)
+ 0.5 (.020)
- 0
8.4 (.331)
+0.15 (.006)
14.4 (.567)
max.
ø 62 (2.44)
± 1.5 (.059)
QUANTITY PER REEL
Type Suffix Qty Per Reel
NC - NB 12 BA 4000
BE 2000
NC 20 - NB 20 BA 3000
BE 1500
17
Packaging for Automatic Insertion
NTC Chip Thermistors / NC/NB Series
AUTOMATIC INSERTION
8mm Paper Tape Packaging:
The mechanical and dimensional reel characteristics
are in accordance with the IEC publication 286-3.
P0
B0
P1
P2
D0
T
TOP
COVER
TAPE
BOTTOM
COVER
TAPE
CENTER LINES
OF CAVITY
CAVITY SIZE
SEE NOTE 1
10 PITCHES CUMULATIVE
TOLERANCE ON TAPE
0.20mm (0.008)
E1
F
G
User Direction of Feed
E2
W
T1
T1A0
Designation Symbol Value Tolerance
Tape width W 8 -.0.1/+0.3
Tape thickness T 1.1 max.
Pitch of the sprocket holes P04±0.1
Diameter of the sprocket holes D0
1.5 ±0.1
-0/+0.1
Distance E11.75 ±0.1
Distance (center to center) F 3.5 ±0.05
Distance (center to center) P22 ±0.05
Cover tape thickness T10.10 max.
Distance E26.25 min.
Distance G 0.75 min.
Component pitch 0805/0603 P1
4±0.1
0402 2 ±0.1
Bottom side
Reel
Upper side
Direction of unreeling
Reel
according to
ISO/DIS 3639-2
ø 12.75 (.502)
+ 0.15 (.006)
- 0
ø180 (7.09)
+ 0
- 2 (.079)
ø 20.5 (.087)
+ 0.5 (.020)
- 0
8.4 (.331)
+0.15 (.006)
14.4 (.567)
max.
ø 62 (2.44)
± 1.5 (.059)
QUANTITY PER REEL
Type Suffix Qty Per Reel
NB - NC 12 BB 4000
NB 21 BF 2000
STORAGE
Good solderability is maintained for at least twelve months,
provided the components are stored in their “as received”
packaging at less than 40°C and 70% RH.
SOLDERABILITY / LEACHING
Terminations to be well soldered after immersion in a 60/40
tin/lead solder bath at 235 ± 5°C for 2 ± 1 seconds.
Terminations will resist leaching for at least the immersion
times and conditions recommendations shown below.
NB products are compatible with a wide range of soldering
conditions consistent with good manufacturing practice for
surface mount components. This includes Pb free reflow
processes with peak temperatures up to 270ºC.
Recommended profiles for reflow and wave soldering are
shown below for reference.
NC products are recommended for lead soldering application
or gluing techniques.
Surface Mounting Guide
Chip Thermistor – Application Notes
REFLOW SOLDERING
WAVE SOLDERING
18
P/N Termination Solder Solder Immersion
Type Tin/Lead Temp ºC Time Seconds
NC AgPdPt 60/40 260 ± 5 15 max
NB Nickel Barrier 60/40 260 ± 5 30 ± 1
Case P/ND1D2D3D4D5
Size
0402 NB23 1.70 0.60 0.50 0.60 0.50
(.067) (.024) (.020) (.024) (.020)
0603 NB21 2.30 0.80 0.70 0.80 0.75
(.091) (.031) (.028) (0.31) (.030)
0805 NB12 3.00 1.00 1.00 1.00 1.25
(.118) (.039) (.039) (.039) (.049)
1206 NB20 4.00 1.00 2.00 1.00 2.50
(.157) (.039) (.079) (.039) (.098)
Case P/ND1D2D3D4D5
Size
0603 NB21 3.10 1.20 0.70 1.20 0.75
(.122) (.047) (.028) (.047) (.030)
0805 NB12 4.00 1.50 1.00 1.50 1.25
(.157) (.059) (.039) (.059) (.049)
1206 NB20 5.00 1.50 2.00 1.50 1.60
(.197) (.059) (.079) (.059) (.063)
Reflow
300
250
200
150
100
50
0
Solder Temp.
10 sec. max
1min
1min
(Minimize soldering time)
Natural
Cooling
220ºC
to
250ºC
Preheat
a) The visual standards used for evaluation of solder joints
will need to be modified as lead free joints are not as bright
as with tin-lead pastes and the fillet may not be as large.
b) Resin color may darken slightly due to the increase in
temperature required for the new pastes.
c) Lead-free solder pastes do not allow the same self align-
ment as lead containing systems. Standard mounting
pads are acceptable, but machine set up may need to be
modified.
300
250
200
150
100
50
00 50 100 150 200 250 300
• Pre-heating: 150°C ±15°C / 60-90s
• Max. Peak Gradient: 2.5°C/s
• Peak Temperature: 245°C ±5°C
• Time at >230°C: 40s Max.
Temperature °C
Time (s)
Wave
300
250
200
150
100
50
0
Solder Temp.
3 sec. max
1 to 2 min
(Preheat chips before soldering)
T/maximum 150°C
Preheat
Natural
Cooling
230ºC
to
250ºC
T
D1
D2
D3
D4
D5
RECOMMENDED
SOLDERING PAD
LAYOUT
Dimensions in
mm (inches)
