Excellent heat resistance and weather resistance are ensured by
the use of metal glaze thick film.
・
Suitable for both flow and reflow solderings.
・
Products with lead free termination meet EU-RoHS requirements.
EU-RoHS regulation is not intended for Pb-glass contained in
electrode, resistor element and glass.
・
AEC-Q200 Tested (Exemption 1F).
■Dimensions
Type
（Inch Size Code）
1F
（01005）
1H
（0201）
1E
（0402）
1J 0603）
（
1J AT
（0603）
2A
（0805）
2A AT
（0805）
2B
（1206）
2B AT
（1206）
2E
（1210）
W2H
（2010）
※1
Dimensions（mm）
L
0.4±0.02
0.6±0.03
1.0
＋0.1
－0.05
1.6±0.2
2.0±0.2
3.2±0.2
5.0±0.2
6.3±0.2
W
0.2±0.02
0.3±0.03
0.5±0.05
0.8±0.1
1.25±0.1
1.6±0.2
2.6±0.2
2.5±0.2
3.1±0.2
0.5±0.3
c
0.10±0.03
0.1±0.05
0.2±0.1
0.3±0.1
0.35±0.15
0.4±0.2
0.45±0.25
0.5±0.3
0.55±0.35
d
0.11±0.03
0.15±0.05
0.25
＋0.05
－0.1
0.3±0.1
0.5±0.2
0.3
＋0.2
－0.1
0.6±0.2
0.4
＋0.2
－0.1
0.8±0.2
0.4
＋0.2
－0.1
0.65±0.15
0.6±0.1
t
0.13±0.02
0.23±0.03
0.35±0.05
0.45±0.1
0.5±0.1
0.55±0.10
Weight
（g）
（1000pcs）
0.04
0.14
0.68
2.14
4.54
9.14
15.5
24.3
37.1
■Reference Standards
IEC 60115-8
JIS C 5201-8
EIAJ RC-2134C
※1
W3A
（2512）
■Type Designation
Example
RK73B
Product
Code
2B
Power
Rating
Characteristic
T
Terminal
Surface Material
T：Sn
G：Au
※3
（L：Sn/Pb
※4
）
W3A2 2512）
（
※1
※1 RK73B 2H, 3A and 3A2 are also still available (different d”
“ dimensions=0.4
＋0.2
mm)
−0.1
TD
Taping
TX：4mm width-
1mm pitch plastic
embossed
TBL・TCM：
2mm pitch
press paper
TPL・TP：
2mm pitch
punch paper
TD：4mm pitch
punch paper
TE：4mm pitch
plastic
embossed
BK：Bulk
103
Nominal
Resistance
3 digits
J
Resistance
Tolerance
G：±2%
J：±5%
1F：0.03W
Nil：Standard
NEW
A：Heat shock
1H：0.05W
1E：0.1W
resistance
※2
1J ：0.1W
0.125Ｗ
2A：0.25Ｗ
2B：0.25W
2E：0.5W
W2H：0.75W
W3A：1W
W3A2：2W
※4
※2 With type A only T is available as the terminal surface material.
※3 Products with gold plated electrodes are also available with 1E, 1J and 2A types
（10Ω∼1MΩ） so please consult with us.
,
※4 With type 1F, 1H, W2H, W3A, W3A2 only T is available as the terminal surface material.
The terminal surface material lead free is standard.
Contact us when you have control request for environmental hazardous material other than the substance specified by EU-RoHS.
For further information on taping, please refer to APPENDIX C on the back pages.
■Ratings
Type
1F
1H
1E
1J
2A
2B
2E
W2H
W3A
W3A2
Power
Rating
0.03W
0.05W
0.1W
0.1W
0.125W
0.25W
0.25W
0.5W
0.75W
1.0W
2.0W
※5
Rated Ambient Rated Terminal
T.C.R.
Temp.
Part Temp. （×10
−6
/K）
70℃
70℃
70℃
70℃
70℃
70℃
70℃
70℃
70℃
70℃
70℃
—
125℃
125℃
125℃
125℃
125℃
125℃
125℃
125℃
125℃
95℃
±200
±250
0½＋300
±200
±400
±200
±200
±400
±200
±200
±400
±200
±400
±200
±400
±200
±400
±200
±400
±200
±400
Resistance Range（Ω）
G：±2%
J：±5%
E24
E24
100k½1M
100k½10M
10½91k
10½91k
1½9.1
1½9.1
10½10M
10½10M
—
1½9.1
1½10M
1.1k½10M
—
1½1k
1½1M
1.1M½10M
1½5.6M
6.2M½10M
10½5.6M
—
10½5.6M
—
10½5.6M
—
10½5.6M
—
1½10M
1.1k½10M
11M½22M
1½1k
1½1M
1.1M½10M
1½5.6M
6.2M½22M
1½5.6M
6.2M½10M
1½5.6M
6.2M½22M
1½5.6M
6.2M½22M
1½5.6M
6.2M½22M
75V
100V
Max. Working Max. Overload
Voltage
Voltage
20V
25V
30V
50V
Packaging & Q'ty/Reel（pcs）
TX
40,000
—
—
—
—
—
200V
400V
—
—
200V
200V
400V
400V
—
—
TBL
20,000
—
—
—
—
—
—
—
—
—
TCM
—
15,000
—
—
—
—
—
—
—
—
TPL・TP
—
—
TPL：20,000
TP ：10,000
TP ：10,000
TP ：10,000
—
—
—
—
—
TD
—
—
—
5,000
5,000
5,000
5,000
—
—
—
TE
—
—
—
—
4,000
※6
4,000
※6
4,000
※6
4,000
4,000
4,000
150V
200V
Operating Temperature Range :−55℃∼＋125℃
（1F）
、−55℃∼＋155℃
（1H・1E・1J・2A・2B・2E・W2H・W3A・W3A2）
Rated voltage＝
√￣￣￣￣￣￣￣￣￣￣￣
or Max. working voltage, whichever is lower.
Power Rating×Resistance value
For flat chip jumper resistor, please refer to RK73Z series.
※5 If you use at the rated power, please keep the condition that the terminal of the resistor is below the rated terminal part temperature. Please refer to the derating curves based on the terminal temperature of right side on the next
page.
※6 Standard packaging：TD(4mm pitch punch paper)
If any questions arise whether to use the Rated Ambient Temperature” the Rated Terminal Part Temperature” your usage conditions, please give priority to the Rated Terminal Part Temperature”
“
or “
in
“
.
For more details, please refer to Introduction of the derating curves based on the terminal part temperature” the beginning of our catalog.
“
on
While using under high power, the temperature of the product may increase depending on the condition of heat dissipation from PCB.
Be sure to check the terminal part temperature as well as precautions to use on delivery specifications before use.
Specifications given herein may be changed at any time without prior notice. Please confirm technical specifications before you order and/or use.
Specifications given herein may be changed at any time without prior notice. Please confirm technical specifications before you order and/or use.
Contact our sales representatives before you use our products for applications including automotives, medical equipment and aerospace equipment.
Contact our sales representatives before you use our products for applications including automotives, medical equipment and aerospace equipment.
Malfunction or failure of the products in such applications may cause loss of human life or serious damage.
Malfunction or failure of the products in such applications may cause loss of human life or serious damage.
Aug.
2021
Oct.
2021
www.koaglobal.com
■Derating Curve
Ambient temperature
100
Percent rated power ％）
（
80
60
40
20
0
-60 -40 -20
-55
0
20
40
60
80 100 120 140 160
125
155
1F
1H,1E,1J,2A,2B
2E,W2H,W3A
（1W）
,
W3A2 2W）
（
Flat Chip Resistors
Flat Chip Resistors
Terminal part temperature
100
Percent rated power ％）
（
80
60
40
20
0
-60 -40 -20
-55
0
20
40
60
80 100 120 140 160
125
155
1H,1E,1J,2A,2B,2E,
W2H,W3A
（1W）
Terminal part temperature
RK73B W3A2
100
Percent rated power ％）
（
80
60
40
20
0
-60 -40 -20
-55
0
20
40
60
80
100 120 140 160
155
70
Ambient temperature
（℃）
70
Terminal part temperature
（℃）
あ1
95
Terminal part temperature
（℃）
For resistors operated at an ambient temperature of 70℃ or higher,
the power shall be derated in accordance with the above derating
curve.
When the terminal part temperature of the resistor exceeds the rated terminal part temperature shown above, the power shall be derated
according to the derating curve.
※Please refer to Introduction of the derating curves based on the terminal part temperature” the beginning of our catalog before use.
“
あ1
on
■Temperature Rise
RK73B 1F-1J
60
1E
50
1J
RK73B 2A-2E
100
90
80
2E
2E
2B
2A
2B
2A
250
300
RK73B W2H-W3A2
W3A2
Temperature Rise
（℃）
Temperature Rise
（℃）
1E
40
1J
1H
1F
30
1H
1F
20
W3A2
Regarding the temperature rise, the
value of the temperature varies per
conditions and board for use since the
temperature is measured under our
measuring conditions.
70
60
50
40
30
20
10
Temperature Rise [℃]
200
W3A
150
W2H
W3A
100
W2H
Measurement condition
Room temperature: 25℃
PCB: FR-4t = 1.6mm
Cu foil thickness: 35µm
① Hot spot
：
10
50
0
0
25
50
75
100
0
Power Rating
（%）
0
Power Rating
（%）
25
50
75
100
0
② Terminal
：
0
Power Rating
（%）
25
50
75
100
■One-Pulse Limiting Electric Power
RK73B 1F-2A
One-Pulse Limiting Electric Power W）
（
100
RK73B 2B-W3A2
One-Pulse Limiting Electric Power W）
（
1000
10
2A
1
1J
1E
0.1
1H
1F
0.01
0.001
100
W3A/W3A2
2H/W2H
10
2E
2B
1
0.001
0.01
0.1
1
10
100
1000
0.01
0.1
1
10
100
1000
Pulse Duration
（ms）
Pulse Duration
（ms）
The maximum applicable voltage is equal to the max. overload voltage.
Please ask us about the resistance characteristic of continuous applied pulse.
The pulse endurance values are not assured values,so be sure to check the
products on actual equipment when you use them.
■Performance
Test Items
Resistance
T.C.R.
Overload（Short time）
Resistance to
soldering heat
Rapid change of
temperature
Moisture resistance
Endurance at 70℃ or rated
terminal part temperature
High temperature
exposure
Typical
—
—
1：1F
2
0.5：others
1：1F½W3A2
（10Ω≦R≦1MΩ） 0.5：1F½W3A2
（10Ω≦R≦1MΩ）
3：1F½W3A2
（R＜10Ω, R＞1MΩ） 1：1F½W3A2
（R＜10Ω, R＞1MΩ）
1：1F, Characteristic A」
「
0.5：1F, Characteristic A」
「
（Heat shock resistance）
（Heat shock resistance）
0.5：others
0.3：others
0.75：1J, 2A, 2B
2：1J, 2A, 2B
1.5：1F
3：others
1：others
2：1J, 2A, 2B
0.75：1J, 2A, 2B
3：others
1：others
0.5：1F
1
0.3：others
Performance Requirements
ΔR±（％＋0.1Ω）
Limit
Within specified tolerance
Within specified T.C.R.
Test Methods
25℃
＋25℃/－55℃ and ＋25/＋125℃
Rated voltage×2.5 for 5s 1E, 2B, W3A2：Rated voltage×2 for 5s）
（
260℃±5℃, 10s±1s
Characteristic
「Nil」
（Standard）ー55℃
：
（30min.）
/＋125℃(30min.）
100 cycles
Characteristic （Heat shock resistance）ー55℃
「A」
：
（30min.)/＋125℃
（30min.）
1000 cycles
40℃±2℃, 90%½95%RH, 1000h
1.5h ON/0.5h OFF cycle
70℃±2℃ or rated terminal part temperature ±2℃ 1000h
The substrate of chip resistors is alumina. Cracks may occur at the connection of solder (solder fillet portion) due to the difference of the coefficient of thermal
expansion from a mounting board when heat stress like heat cycle, etc. are repeatedly given to them. Care should be taken to the occurrence of the cracks when
the change in ambient temperature or ON/OFF of load is repeated, especially when large types of W2H/W3A/W3A2 which have large thermal expansion and
also self heating. By general temperature cycle test using glass-epoxy (FR-4) boards under the maximum/minimum temperatures of operating temperature range,
the crack does not occur easily in the types of 1F∼2E, but the crack tends to occur in the types of W2H/W3A/W3A2. The occurrence of the crack by heat
stress may be influenced by the size of a pad, solder volume, heat radiation of mounting board etc., so please pay careful attention to designing when a big change
in ambient temperature and conditions for use like ON/OFF of load can be assumed.
・
Care should be taken that RK73B1F may be damaged when static electricity occurs and is applied in the equipment assembly process.
Specifications given herein may be changed at any time without prior notice. Please confirm technical specifications before you order and/or use.
Specifications given herein may be changed at any time without prior notice. Please confirm technical specifications before you order and/or use.
Contact our sales representatives before you use our products for applications including automotives, medical equipment and aerospace equipment.
Contact our sales representatives before you use our products for applications including automotives, medical equipment and aerospace equipment.
Malfunction or failure of the products in such applications may cause loss of human life or serious damage.
Malfunction or failure of the products in such applications may cause loss of human life or serious damage.
