MEGGITT SENSORS
HUMIDITY, POSITION
TEMPERATURE
LIQUID LEVEL
SURFACE MOUNT DEVICES
WIRE LEADS, PC PINS
Thermistors For Surface Mount
TYPE 3157 SERIES
Meggitt Electronic Components are pleased to offer this
innovative range of Micro Chip Thermistors in several
outline packages. These specialist surface mount N.T.C.
devices available in initial resistances between 40 ohms
and 500K ohms, with four tolerances. Two styles are
offered; Style B is suitable for standard soldering techniques
such as wave, reflow or vapour phase; Style A is a thermistor
chip for mounting directly to the bonding pads of Hybrid
substrates. Meggitt Electronics welcome your custom
enquiries for suitable volumes on this product.
MEGGITT SENSORS
KEY FEATURES
CHOICE OF STYLES 12.06 to 08.05 OUTLINES
SUITABLE FOR BONDING OR PICK AND PLACE
TEMP OP -40°C to +125°C
WIDE VALUE RANGE
ATTRACTIVELY PRICED
BULK PACKED OR ON EMBOSSED TAPE
STABLE ALUMINA SUBSTRATE
SOLVENT RESISTANT COATING
SPECIAL TYPES AVAILABLE (MIN 100K PIECES)
MEGGITT
ELECTRONIC
COMPONENTS
SALES ACTION DESK
TEL: (01793 611666)
FAX: (01793 611777)
EMAIL: sales@megelec.co.uk
WEB SITE: www.megelec.co.uk
LOG No FO444
ISSUE 4
2 Pages
04-01
SPECIFICATION
TYPICAL CHARACTERISTICS
PART NO.
3157-252-55010
3157-252-53006
3157-252-55029
3157-252-53015
3157-502-55007
3157-502-53002
3157-103-55001
3157-103-53007
3157-153-55007
3157-153-53002
3157-203-55009
3157-203-53004
3157-303-55006
3157-303-53001
RESISTANCE
(R25°C)
2.5k
Ω
± 5%
2.5k
Ω
± 10%
2.5k
Ω
± 5%
2.5k
Ω
± 10%
5k
Ω
± 5%
5k
Ω
± 10%
10k
Ω
± 5%
10k
Ω
± 10%
15k
Ω
± 5%
15k
Ω
± 10%
20k
Ω
± 5%
20k
Ω
± 10%
30k
Ω
± 5%
30k
Ω
± 10%
TYPE 3157 SERIES
Page 2 of 4
* THERMAL
DISSIPATION
CONST. (mW/°C)
3
3400 ±0 200
3400 ± 200
3
3
4100 ± 200
4100 ± 200
3
3500 ± 200
3
3500 ± 200
3
3750 ± 200
3
3750 ± 200
3
3950 ± 200
3
3950 ± 200
3
3
4000 ± 200
4000 ± 200
3
4000 ± 200
3
3
4000 ± 200
B-VALUE
R25/50(K)
OPERATING
TEMPERATURE
-40 to +125
-40 to +125
-40 to +125
-40 to +125
-40 to +125
-40 to +125
-40 to +125
-40 to +125
-40 to +125
-40 to +125
-40 to +125
-40 to +125
-40 to +125
-40 to +125
STOCK
ITEM
•
•
•
•
•
•
•
* With O 0.3 solder plated copper wire and measured in still air.
For B-Values on other resistor values/styles please enquire
TYPICAL R.T. CHARACTERISTICS
Operating Temperature Range:
Thermal Time Constant:
Thermal Dissipation Constant:
-40°C to +125°C
5 seconds
3mW/°C
ENVIRONMENTAL
Solderability:
Thermistors are completely immersed for 3 ± 1 seconds in moulten solder (JIS3282 H60A
equivalent) at a temperature of 230 ± 3°C
Termination area shall be at least
3
/
4
covered with a new solder coating.
Thermistors shall be subjected to 5 temperature cycles as shown below:
-40°C (30min.) room temperature (10 ~ 15 min.) 125°C (30 min.)
No mechanical damage or abnormality of appearance.
Zero power resistance R25 within ± 10% + 0.1 ohms.
Test temperature 60 ± 2°C. Relative humidity 90 ~ 95% RH.
Period 1000 hours.
Test temperature -125 ± 3°C
Period 1000 hours.
Test temperature -40 ± 3°C
Period 1000 hours.
Temperature Cycle:
Moisture Resistance:
High Temperature:
Low Temperature:
All measurments above shall be taken one hour and twenty four hours following test conditions with the thermistors at ambient temperature.
Operating Temperature Range:
Soldering Conditions.
Thermal time constant. Thermal dissipation constant.
-40°C to +125°C
3mW/°C
250°C max. 5 seconds
SPECIFICATION
DIMENSIONS
TYPE 3157 SERIES
Page 3 of 4
Electrode (Solder Plated)
For dimensions see HOW
TO ORDER code below.
STRUCTURE
TYPE A
TYPE B
PACKAGING (REEL)
Reel Quantity
3000 pieces
THERMISTOR SELECTION GUIDE
Common Part Resistance B-Constant
(K)
& Resistance
R25 (Ω)
Ω
-400-
40
2750
100
2750
-101-
500
3300
-501-
3300
-102-
1K0
3400
-152-
1K5
-202-
2K0
3400
2K0
4100
-202-
2K5
3400
-252-
4100
-252-
2K5
4100
-302-
3K0
-502-
5K0
3500
-103-
10K
3750
15K
3750
-153-
-153-
15K
3950
20K
4000
-203-
-303-
30K
4000
1
-
o
o
o
o
o
-
o
-
-
o
o
o
-
o
o
Structure/Size
4
-
-
o
o
o
o
o
o
o
o
o
o
o
o
o
o
5
o
o
o
o
o
o
o
o
o
o
o
o
-
o
o
o
Common Part Resistance B-Constant
(K)
& Resistance
R25 (Ω)
Ω
-503-
50K
4000
-104-
100K
4100
-154-
150K
4100
300K
4200
-304-
4200
-504-
500K
-800-
-151-
-801-
-172-
-172-
-272-
-272-
-472-
-473-
80
150
800
1K7
1K7
2K7
2K7
4K7
47K
2750
2800
3300
3400
4100
3400
4100
3500
4000
1
o
o
o
o
o
-
-
-
-
-
o
-
o
-
Structure/Size
4
o
o
-
-
-
-
-
o
o
o
o
o
o
o
5
o
o
o
-
-
o
o
o
o
o
o
o
o
o
B-Constant Tolerance: ±200(K) (at -25°C to 50°C)
Resistance Tolerance: ±5%, ±10% (25°C)
HOW TO ORDER
3157
PART
COMMON PART
252
RESISTANCE
RESISTANCE
Refer to availability
chart above and overleaf.
The first two digits are
significant figures of
resistance value and the
third one donates the
number of zeroes following
103
CHIP SIZE AND TERMINAL SIZE
CODE
1
4
5
STRUCTURE
See Above
1
4
5
A
(mm)
3.20±0.2
3.20±0.2
2.00±0.2
B
(mm)
160±0.2
160±0.2
125±0.2
C
(mm)
0.95±0.4
0.50±0.3
0.40±0.2
T
(mm)
1.2
1.4
1.3
5
TOLERANCE
xxx
IDENTIFIER
A tree digit
factory code
issued by MEC
Please enquire
3157
3 = ±10%
5 = ±5%
N.B. Structure Type A is designed for bonding to solder pads on ceranic. Structure Type B is suitable for normal soldering
APPLICATION NOTES
TYPE 3157 SERIES
Page 4 of 4
The temperature difference between solder (maximum temperature of moulten solder or tip of soldering iron) and preheating thermistor
chip shall be 150°C maximum.
FIGURE 1.
below.
The temperature difference between solvent and the thermistor chip during solvent immersion shall be 150°C maximum (room temperaure
air blow is permissable.)
USE OF SOLDERING IRON - STRUCTURE B CHIPS
Soldering without peheating thermistor chip is permissible as follows:
Wattage of soldering iron:
25 watts max.
Diameter of soldering tip:
O 2.5mm max.
Temperaure of soldering tip:
280°C max.
Solder:
Sn60%, pb40%
Soledring tip shall not be in contact with thermistor chip directly.
Use only rosin flux for soldering.
REFLOW SOLDERING - STRUCTURE B CHIPS
Recommended reflow soldering conditions (a profile of temperature on a printed board) are shown in
Figure 2.
below.
FIGURE ONE
STANDARD/NON STANDARD VALUES
N.B.
FIGURE TWO
The following resistor values are standard.
101, 102, 103, 104, 151, 152, 153, 154, 172, 202, 203, 252, 272, 302, 304, 400, 472, 473, 501, 502, 503, 504, 800, 801.
Special values require more than 100K pieces one order in deliveries of 30K pieces.
USE OF UNTREATED THERMISTOR CHIPS - STRUCTURE A CHIPS
These thermistors are dies wraparound terminations for mounting directly to the bonding pads of hybrid circuits. The use of low temperature
2% to 5% silver bearing solder past, or suitable conductive epoxy is suggested for mounting.
Meggitt Electronic Components Ltd. Ohmic House, Westmead Industrial Estate, Swindon, Wilts. SN5 7US
Telephone:(01793)487301 (Admin.) (01793)611666 (Sales) Email: sales@megelec.co.uk Fax:(01793) 611777
This publication is issued to provide outline information only and (unless specifically agreed to the contrary by the Company in writing) is not to form part of any order
or be regarded as a representation relating to the products or service concerned. We reserve the right to alter without notice the specification, design, price or conditions
of supply of any product or service. Whilst Meggitt Electronic Components products are of the very highest quality and reliability, all electronic components can
occasionally be subject to failure. Where failure of a Meggitt Electronic Components product could result in life threatening consequences, then the circuit and application
must be discussed with the Company. Such areas might include ECG, respiratory. and other medical and nuclear applications and any non fail safe applications circuit.