datasheet
EEWORLDEEWORLDEEWORLD
Datasheet
Part Number

Keyword

Search
Keyword

Part Number

Search
Datasheet> All Categories > Passive components> The resistor> VSMP2512274R00TCR0.2BBT
PDF
Preview

VSMP2512274R00TCR0.2BBT

Description
Fixed Resistor, Metal Foil, 0.75W, 274ohm, 220V, 0.1% +/-Tol, -.2,.2ppm/Cel, 2512,
CategoryPassive components    The resistor   
File Size2MB，6 Pages
ManufacturerVishay
Websitehttp://www.vishay.com
Download Datasheet Parametric View All

VSMP2512274R00TCR0.2BBT Overview

Fixed Resistor, Metal Foil, 0.75W, 274ohm, 220V, 0.1% +/-Tol, -.2,.2ppm/Cel, 2512,

VSMP2512274R00TCR0.2BBT Parametric

Parameter NameAttribute value
Is it Rohs certified?incompatible
Objectid860388788
Reach Compliance Codenot_compliant
Country Of OriginIsrael
ECCN codeEAR99
YTEOL10
structureChip
Number of terminals2
Maximum operating temperature150 °C
Minimum operating temperature-55 °C
Package height0.64 mm
Package length6.32 mm
Package formSMT
Package width3.23 mm
method of packingTR
Rated power dissipation(P)0.75 W
resistance274 Ω
Resistor typeFIXED RESISTOR
seriesVSMP
size code2512
technologyMETAL FOIL
Temperature Coefficient0.2 ppm/°C
Terminal surfaceTIN LEAD SILVER OVER NICKEL
Tolerance0.1%
Operating Voltage220 V

VSMP2512274R00TCR0.2BBT Preview

VSMP Series (0603, 0805, 1206, 1506, 2010, 2018, 2512) (Z-Foil)
Vishay Foil Resistors
Ultra High Precision Foil Wraparound Surface Mount Chip Resistor
with TCR of ± 0.05 ppm/°C and Power Coefficient of 5 ppm at
Rated Power and Load Life Stability of ± 0.005 % (50 ppm)
FEATURES
Temperature coefficient of resistance (TCR):
0.05 ppm/°C typical (0 °C to + 60 °C)
0.2 ppm/°C typical (- 55 °C to + 125 °C, + 25 °C ref.)
Resistance tolerance: to ± 0.01 %
Power coefficient “R due to self heating”:
5 ppm at rated power
Power rating: to 750 mW at + 70 °C (see table 3)
Load life stability: to ± 0.005 % at 70 °C, 2000 h at rated
power
Resistance range: 5
to 125 k (for lower or higher
values, please contact us)
Vishay Foil resistors are not restricted to standard values,
we can supply specific “as required” values 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
Short time overload:
0.005 %
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
Terminal finishes available: lead (Pb)-free, tin/lead alloy
Matched sets are available on request
Prototype quantities available in just 5 working days
or sooner. For more information, please contact
foil@vishaypg.com
Top View
(for date code print specification please refer to table 2)
INTRODUCTION
VSMP Series is the industry’s first device to provide high
rated power and excellent load life stability along with
extremely low TCR — all in one resistor.
One of the most important parameters influencing stability is
the Temperature Coefficient of Resistance (TCR). Although
the TCR of foil resistors is considered extremely low, this
characteristic has been further refined over the years. The
VSMP Series utilizes ultra high precision Bulk Metal
®
Z-Foil.
The Z-Foil technology provides a significant reduction of the
resistive element’s sensitivity to ambient temperature
variations (TCR) and to self heating when power is applied
(Power Coefficient of Resistance, or PCR). Along with the
inherently low PCR and TCR, Z-Foil technology also
provides remarkably improved load life stability, low noise
and tight tolerances.
The VSMP resistor has a full wraparound termination which
assures secure contact during the manufacturing process,
as well as providing stability during multiple thermal cyclings.
Vishay Foil Resistors' (VFR) application engineering
department is available to advise and make
recommendations. For non-standard technical requirements
and special applications, please contact VFR using the
e-mail address in the footer below.
Percent of Rated Power
TABLE 1 - TOLERANCE AND TCR VS.
RESISTANCE VALUE
(1)
(- 55 °C to + 125 °C, + 25 °C Ref.)
RESISTANCE
VALUE
()
250to 125K
100to < 250
50to < 100
25to < 50
10to < 25
5 to < 10
TOLERANCE
(%)
± 0.01
± 0.02
± 0.05
± 0.1
± 0.25
± 0.5
TYPICAL TCR AND
MAX. SPREAD
(ppm/°C)
± 0.2 ± 1.8
± 0.2 ± 1.8
± 0.2 ± 2.8
± 0.2 ± 3.8
± 0.2 ± 3.8
± 0.2 ± 7.8
FIGURE 1 - POWER DERATING CURVE
- 55 °C
100
75
50
25
0
- 75
+ 70 °C
- 50
- 25
0
+ 25 + 50 + 75 + 100 + 125 + 150 + 175
Ambient Temperature (°C)
* Pb containing terminations are not RoHS compliant; exemptions
may apply
Note
(1)
For tighter performances and non-standard values lower than
5

and above 125K, please contact VFR’s application
engineering using the e-mail addresses in the footer below
Document Number: 63060
Revision: 29-Oct-2012
For any questions, contact:
foil@vishaypg.com
www.vishayfoilresistors.com
1
VSMP Series (0603, 0805, 1206, 1506, 2010, 2018, 2512) (Z-Foil)
Vishay Foil Resistors
FIGURE 2 - TRIMMING TO VALUES
(Conceptual Illustration)
FIGURE 3 - TYPICAL RESISTANCE/
TEMPERATURE CURVE
+ 400
+ 300
+ 200
+ 100
ΔR
0
R
(ppm)
- 100
- 200
- 300
- 400
- 500
- 55
- 25
0
+ 25
+ 60 + 75 + 100 + 125
Ambient Temperature (°C) and TCR Chord Slopes for
Different Temperature Ranges
- 0.16 ppm/°C
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
0.05 ppm/°C
- 0.1 ppm/°C
0.1 ppm/°C
0.14 ppm/°C
0.2 ppm/°C
Mutual Inductance
Reduction due
to Change in
Current Direction
Note:
Foil shown in black, etched spaces in white
Note
• The TCR values for < 100
are influenced by the termination
composition and result in deviation from this curve
TABLE 2 - DIMENSIONS AND LAND PATTERN
in Inches (Millimeters)
Top View
Date Code
2
(Year/Week)
T
D
CHIP
SIZE
0603
0805
1206
1506
2010
2018
2512
L
± 0.005 (0.13)
0.063 (1.60)
0.080 (2.03)
0.126 (3.20)
0.150 (3.81)
0.198 (5.03)
0.204 (5.18)
0.249 (6.32)
W
± 0.005 (0.13)
0.032 (0.81)
0.050 (1.27)
0.062 (1.57)
0.062 (1.57)
0.097 (2.46)
0.184 (4.67)
0.127 (3.23)
THICKNESS
MAXIMUM
0.025 (0.64)
0.025 (0.64)
0.025 (0.64)
0.025 (0.64)
0.025 (0.64)
0.025 (0.64)
0.025 (0.64)
D
± 0.005 (0.13)
0.011 (0.28)
0.015 (0.38)
0.020 (0.51)
0.020 (0.51)
0.025 (0.64)
0.018 (0.46)
0.032 (0.81)
Z
(1)
0.102 (2.59)
0.122 (3.10)
0.175 (4.45)
0.199 (5.05)
0.247 (6.27)
0.248 (6.3)
0.291 (7.39)
G
(1)
0.031 (0.78)
0.028 (0.71)
0.059 (1.50)
0.083 (2.11)
0.115 (2.92)
0.146 (3.71)
0.150 (3.81)
X
(1)
0.031(0.78)
0.050 (1.27)
0.071 (1.80)
0.071 (1.80)
0.103 (2.62)
0.184 (4.67)
0.127 (3.23)
Recommended Land Pattern
L
X
W
Z
G
Footprint
Note
(1)
Land Pattern Dimensions are per IPC-7351A
(2)
The date code printing applies to all resistor sizes except for 0603
TABLE 3 - SPECIFICATIONS
CHIP
SIZE
0603
0805
1206
1506
2010
2018
2512
RATED
POWER
(mW)
at + 70 °C
100
200
300
300
500
750
750
MAX.
WORKING
VOLTAGE
(
P
R
)
20 V
40 V
87 V
95 V
187 V
122 V
220 V
RESISTANCE
RANGE
()*
100 to 4K
5to 8K
5to 25K
5to 30K
5to 70K
5to 20K
5to 125K
MAXIMUM
WEIGHT
(mg)
3
6
11
12
27
40
40
TABLE 4 - LOAD LIFE STABILITY
(+ 70 °C for 2000 h)
CHIP SIZE
0603
0805
1206, 1506
2010
2018
2512
MAXIMUM
R
LIMITS
± 0.005 % at 50 mW
± 0.01 % at 100 mW
± 0.005 % at 100 mW
± 0.01 % at 200 mW
± 0.005 % at 150 mW
± 0.01 % at 300 mW
± 0.005 % at 200 mW
± 0.01 % at 500 mW
± 0.005 % at 500 mW
± 0.01 % at 750 mW
± 0.005 % at 500 mW
± 0.01 % at 750 mW
* For non standard values please contact VFR’s application
engineering using the e-mail addresses in the footer below.
www.vishayfoilresistors.com
2
For any questions, contact:
foil@vishaypg.com
Document Number: 63060
Revision: 29-Oct-2012
VSMP Series (0603, 0805, 1206, 1506, 2010, 2018, 2512) (Z-Foil)
Vishay Foil Resistors
TABLE 5 - PERFORMANCES
TEST OR CONDITIONS
Thermal Shock, 100 x (- 65 °C to + 150 °C)
Low Temperature Operation, - 65 °C, 45 min at P
nom
Short Time Overload, 6.25 x Rated Power, 5 s
High Temperature Exposure, + 150 °C, 100 h
Resistance to Soldering Heat
Moisture Resistance
Load Life Stability + 70 °C for 2000 h at Rated Power
MIL-PRF-55342
CHARACTERISTIC E
R
LIMITS
± 0.1 %
± 0.1 %
± 0.1 %
± 0.1 %
± 0.2 %
± 0.2 %
± 0.5 %
TYPICAL
R
LIMITS
± 0.005 % (50 ppm)
± 0.005 % (50 ppm)
± 0.005 % (50 ppm)
± 0.01 % (100 ppm)
± 0.005 % (50 ppm)
± 0.005 % (50 ppm)
± 0.005 % (50 ppm)
MAXIMUM
R
LIMITS
(1)
± 0.01 % (100 ppm)
± 0.01 % (100 ppm)
± 0.01 % (100 ppm)
± 0.02 % (200 ppm)
± 0.01 % (100 ppm)
± 0.02 % (200 ppm)
± 0.01 % (100 ppm)
Note
(1)
As shown + 0.01
to allow for measurement errors at low values
FIGURE 4 - RECOMMENDED MOUNTING
Notes
(1)
IR and vapor phase reflow are recommended.
(2)
Avoid the use of cleaning agents which could attack epoxy resins, which form part
of the resistor construction
(3)
Vacuum pick up is recommended for handling
(4)
If the use of a soldering iron becomes necessary, precautionary measures should
be taken to avoid any possible damage / overheating of the resistor
* Recommendation: The solder fillet profile should be such as to avoid running over
the top metallization
*
FIGURE 5 - VSMP0603 100 CYCLE
THERMAL SHOCK - 65 °C TO
150 °C, 10 UNITS EACH VALUE
100
80
60
FIGURE 6 - LOAD LIFE TEST FOR
10,000 HRS @0.3W, +70°C;
VSMP 1206, N=40
500
400
300
200
100
R
(ppm)
0
-100
10R
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
1K
12K
ΔR/R
(ppm)
40
20
0
- 20
-200
- 40
VSMP0603
100R
VSMP0603
1K
VSMP0603
5K
-300
-400
-500
Time (hrs)
CRYOGENIC TEST
Different expansion/contraction rates of composite materials
in resistors may induce discontinuities during temperature
excursions that are not evident at temperature extremes,
making an unreliable resistor appear normal. A good resistor
must also return to its initial value with no resistance drift. In
this demo, a VFR VSMP0805 precision resistor is monitored
through the range of +25°C, down to -196°C and back up to
+25°C. Results confirm the VSMP0805 exhibits only 5
ppm/°C TCR, experiences no discontinuities, and returns to
its exact same starting value, showing absolutely no change
in resistance (< 1 ppm measurement accuracy).
FIGURE 7 - PRECISION RESISTOR IN
CRYOGENIC CONDITIONS -
ONLY 5 PPM/
°
C
(PRODUCT DEMO)
Document Number: 63060
Revision: 29-Oct-2012
For any questions, contact:
foil@vishaypg.com
www.vishayfoilresistors.com
3
VSMP Series (0603, 0805, 1206, 1506, 2010, 2018, 2512) (Z-Foil)
Vishay Foil Resistors
PULSE TEST
TEST DESCRIPTION
All parts are baked at +125°C for 1 hour and allowed to cool
at room temperature for 1 hour, prior to testing. By using an
electrolytic 0.01µF capacitor charged to 1200 VDC, a single
pulse was performed on 30 units of 1206, 10 k of Surface
Mount Vishay Foil resistor and Thin Film resistor. The units
were allowed time to cool down, after which the resistance
measurements were taken and displayed in ppm deviation
from the initial reading.
TEST RESULTS
Catastrophic Damage
- occurs when the ESD event causes
the device to immediately stop functioning. This may occur
after one or a number of ESD events with diverse causes,
such as human body discharge or the mere presence of an
electrostatic field.
Latent Damage
- occurs when the ESD event causes
moderate damage to the device, which is not noticeable, as
the device appears to be functioning correctly. However, the
load life of the device has been dramatically reduced, and
further degradation caused by operating stresses may cause
the device to fail during service. Latent damage is the source
for greatest concern, since it is very difficult to detect by
re-measurement or by visual inspection, because damage
may have occurred under the external coating.
TEST DESCRIPTION
FIGURE 8 - PULSE TEST DESCRIPTION
2
"#

*+
!)
By using an electrolytic 500 pF capacitor charged up to 4500
V, pulses were performed on 10 units of 1206, 10 k of three
different Surface Mount Chip Resistors technologies, with an
initial voltage spike of 2500 V (Figure 10). The units were
allowed time to cool down, after which the resistance
measurements were taken and displayed in ppm deviation
from the initial readings. Readings were then taken in 500 V
increments up to 4500 V.
FIGURE 9 - PULSE TEST RESULTS AT
1200 VDC*
140000
120000
100000
Thin Film
ΔR (ppm)
80000
60000
40000
20000
0
0
-20000
5
10
15
Resistor #
20
25
30
Bulk Metal
®
Foil
FIGURE 10 - ESD TEST DESCRIPTION
2500 V to 4500 V
1 MΩ
500 pF
Size: 1206
Value: 10K
n = 30
Rx
Note:
Average of 30 units yielded deviation of 30 723 ppm of the Thin Film vs –14 ppm for the Bulk Metal
®
Foil
DMM
* Note: Average of 30 units yielded deviation of 30,723 ppm of the
Thin Film vs. -14 ppm for the Bulk Metal
®
Foil
ELECTROSTATIC DISCHARGE (ESD)
ESD can be categorized into three types of damages:
Parametric Failure
- occurs when the ESD event alters one
or more device parameters (resistance in the case of
resistors), causing it to shift from its required tolerance. This
failure does not directly pertain to functionality; thus a
parametric failure may be present while the device is still
functional.
TABLE 6 - ESD TEST RESULTS
(AVERAGE OF 10 UNITS)
VOLTS
2500
3000
3500
4000
4500
∆R
(%)
THICK FILM
-2.7
-4.2
-6.2
-7.4
-8.6
THIN FILM
97
366
OPEN
OPEN
OPEN
FOIL
<0.005
<0.005
<0.005
<0.005
<0.005
www.vishayfoilresistors.com
4
For any questions, contact:
foil@vishaypg.com
Document Number: 63060
Revision: 29-Oct-2012
VSMP Series (0603, 0805, 1206, 1506, 2010, 2018, 2512) (Z-Foil)
Vishay Foil Resistors
TABLE 7- GLOBAL PART NUMBER INFORMATION
(1)
NEW GLOBAL PART NUMBER: Y162612K7560T9R (preferred part number format)
DENOTES PRECISION
Y
VALUE
R
=

K
= k
CHARACTERISTICS
0
= standard
9
= lead (Pb)-free
1 to 999
= custom
Y
1
6
2
6
1
2
K
7
5
6
0
T
9
R
PRODUCT CODE
1636
= VSMP0603
1624
= VSMP0805
1625
= VSMP1206
1626
= VSMP1506
1627
= VSMP2010
1637
= VSMP2018
1628
= VSMP2512
RESISTANCE TOLERANCE
T
= ± 0.01 %
Q
= ± 0.02 %
A
= ± 0.05 %
B
= ± 0.10 %
C
= ± 0.25 %
D
= ± 0.5 %
F
= ± 1.0 %
PACKAGING
R
= tape and reel
W
= waffle pack
FOR EXAMPLE: ABOVE GLOBAL ORDER Y1626 12K7560 T 9 R:
TYPE: VSMP1506
VALUES: 12.7560 k
ABSOLUTE TOLERANCE: 0.01 %
TERMINATION: lead (Pb)-free
PACKAGING: tape and reel
HISTORICAL PART NUMBER: VSMP1506 12K756 TCR0.2 T S T (will continue to be used)
VSMP1506
MODEL
VSMP0603
VSMP0805
VSMP1206
VSMP1506
VSMP2010
VSMP2018
VSMP2512
12K756
RESISTANCE
VALUE
12.756 k
TCR0.2
TCR
CHARACTERISTICS
T
TOLERANCE
T
= ± 0.01 %
Q
= ± 0.02 %
A
= ± 0.05 %
B
= ± 0.10 %
C
= ± 0.25 %
D
= ± 0.5 %
F
= ± 1.0 %
S
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.
PRECISION CENTER
Precision centers are located around the world to provide local, short run, quick delivery of Vishay Bulk Metal
®
Foil resistors.
Unique to Vishay Foil Resistors (VFR) is the ability to provide any value to any tolerance. The precision centers can ship small
quantities in five days or less.
Why do we have authorized local manufacturing or precision centers?
Because we have no standard values and each resistor is trimmed to the precise value ordered. The unique chain of Precision
Centers brings these precise values as close as possible to the circuit designers in the shortest time possible.
For your local Precision Center please click
here.
Document Number: 63060
Revision: 29-Oct-2012
For any questions, contact:
foil@vishaypg.com
www.vishayfoilresistors.com
5
More (Only the first 5 pages are displayed. Please Download Datasheet to view the full content.) >

Recommended Resources

Using 14-bit 125MSPS four-channel ADC circuit diagram

Square wave oscillator

amplifier circuit diagram

TDA7233D audio IC circuit diagram

Commonly used peripherals for general-purpose inverters

Periodic timer using astable flip-flop

I have received a challenging PCB design task. Is there anyone interested in learning it together?
I am preparing to start designing a relatively complex PCB board. I have preliminarily determined that the following modules will be included: - Xilinx ZYNQ7000 FPGA - DDR - ADC (Linear Technology) - ...
rna2012 PCB Design
Looking for a 2812 assembly program template
I want a 2812 assembly program template. If anyone has one, please send it to me at 1501806575@qq.com . Thank you....
liubuwei8888 DSP and ARM Processors
Key points for technician paper writing and defense
Key points for technician paper writing and defense...
fighting Embedded System
There is a problem with my DXP, can you help me?
My DXP suddenly stopped starting and an error window popped up [[i] This post was last edited by liaolun on 2012-6-18 22:07 [/i]]...
liaolun Analog electronics
Can the EDB database on CE6.0 be synchronized with the server database?
As the title says, thank you for your guidance. If Microsoft does not have a synchronization function, how can it be synchronized with the database in the service?...
hd12 Embedded System
Read the LDO manual
To understand a chip, start by reading its manual.The first page of the TI manual basically covers the indicators that everyone is more concerned about, starting with the features on the first page. F...
xutong Analog electronics
Shortcut:   E0 E1 E2 E3 E4 E5 E6 E7 E8 E9 EA EB EC ED EE EF EG EH EI EJ EK EL EM EN EO EP EQ ER ES ET EU EV EW EX EY EZ F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 FA FB FC FD FE FF FG FH FI FJ FK FL FM FN FO FP FQ FR FS FT FU FV FW FX FY FZ G0 G1 G2 G3 G4 G5 G6 G7 G8 G9 GA GB GC GD GE GF GG GH GI GJ GK GL GM GN GO GP GQ GR GS GT GU GV GW GX GZ H0 H1 H2 H3 H4 H5 H6 H7 H8 HA HB HC HD HE HF HG HH HI HJ HK HL HM HN HO HP HQ HR HS HT HU HV HW HX HY HZ I1 I2 I3 I4 I5 I6 I7 IA IB IC ID IE IF IG IH II IK IL IM IN IO IP IQ IR IS IT IU IV IW IX J0 J1 J2 J6 J7 JA JB JC JD JE JF JG JH JJ JK JL JM JN JP JQ JR JS JT JV JW JX JZ K0 K1 K2 K3 K4 K5 K6 K7 K8 K9 KA KB KC KD KE KF KG KH KI KJ KK KL KM KN KO KP KQ KR KS KT KU KV KW KX KY KZ

Popular Components

  1. 801-009-07M7-25PA
  2. ACVX1220L-001.000MHZ-J-S1-N20-Q15
  3. ZZL-HC-1414-07P10E-H45
  4. 54122-812-14-1950RLF
  5. PFC-D1206LF-02-1502-1502-BB
  6. ASFL2FREQ-NC-T2
  7. R-0903N-A100KL-35KQ
  8. FS2SX21U2654MLF
  9. BC817-AU_FU_0001
  10. 1.5SMC30A_R1_10001
  11. P4SMAJ120A_R2_00001
  12. P4KE440CA_R2_00001

Popular Articles

  1. ARM coprocessor access instructions (Linux learning records)
  2. Development history and application fields of permanent magnet motors
  3. 12V automotive power surge protection solution for ISO7637
  4. How to use the megohmmeter
  5. HBM3 memory: a breakthrough towards higher bandwidth
  6. Solution to the problem that Siemens PLC cannot be programmed online with a laptop
  7. ARM cross-compilation environment installation record
  8. Keysight Technologies and Singapore University of Technology and Design Sign MoU on O-RAN and 6G Technologies
  9. Design of analog display drive system based on LPC2478 LCD controller
  10. 8.3 Brief Analysis of SPS Call Control in the System

Technical ResourceMore

  1. Static electricity protection operation methods
  2. PCF8591 Chinese Data Sheet
  3. STM32F10x software library, stm32f10xfwlib_V3.5.0
  4. Mud Pressure Pulse Signal Simulator Based on ATmega128
  5. Semiconductor Integrated Circuit Manufacturing Handbook
  6. Microwave Transmission Line Theory and Practical Technology 417 pages 14.8M pdf version
  7. Single chip fuzzy control system design and application examples 303 pages 6.4M.pdf
  8. Some information about robots
  9. Agilent Spectrum Analyzer User Manual
  10. Measure the noise figure using a spectrum analyzer

EEWorld
subscription
account

EEWorld
service
account

Automotive
development
circle

Robot
development
community

About Us Customer Service Contact Information Datasheet Sitemap LatestNews
Index Files: 981  903  609  1309  1865  20  19  13  27  38 
Datasheet   0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Room 1530, 15th Floor, Building B, No. 18 Zhongguancun Street, Haidian District, Beijing Telephone: (010) 82350740 Postal Code: 100190
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved 京ICP证060456号 京ICP备10001474号-1 电信业务审批[2006]字第258号函 京公网安备 11010802033920号