CN207488356U - A kind of measuring circuit of wafer tube core on-state voltage drop - Google Patents
A kind of measuring circuit of wafer tube core on-state voltage drop Download PDFInfo
- Publication number
- CN207488356U CN207488356U CN201721650655.9U CN201721650655U CN207488356U CN 207488356 U CN207488356 U CN 207488356U CN 201721650655 U CN201721650655 U CN 201721650655U CN 207488356 U CN207488356 U CN 207488356U
- Authority
- CN
- China
- Prior art keywords
- tube core
- wafer
- voltmeter
- current source
- module
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Testing Or Measuring Of Semiconductors Or The Like (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The utility model embodiment discloses a kind of measuring circuit of wafer tube core on-state voltage drop, wherein, wafer to be measured includes more tube cores；The measuring circuit includes at least two current source modules, at least two voltmeter modules and suction cup of probe station；One current source module, a voltmeter module and a tube core correspond；The first end of more tube cores is connected, and the public electrode for passing through the back side of wafer to be measured is connected with suction cup of probe station；Each the second end connection of the corresponding tube core of the first end of current source module, the second end of current source module are connect with suction cup of probe station；Each the second end connection of the corresponding tube core of the first end of voltmeter module, the second end of voltmeter module are connect with suction cup of probe station；Each current source module includes a current source；Each voltmeter module includes a voltmeter.The utility model embodiment can improve the accuracy of wafer tube core on-state voltage drop measurement.
Description
Technical field
The utility model is related to the measurement electricity of integrated circuit testing field more particularly to a kind of wafer tube core on-state voltage drop
Road.
Background technology
Wafer refers to the silicon wafer used in silicon semiconductor production of integrated circuits, since its shape is circle, therefore referred to as wafer；
Various circuit component structures can be manufactured on silicon, and become the IC products for having specific electrical functionality.
Wafer test, the automatic test equipment and the special of placing wafer for needing to configure analog voltage/current source table are set
It is standby --- probe station.Include more tube cores in wafer, need to test the tube core on-state voltage drop of every tube core.The back side of wafer is
One public electrode, if wafer is Schottky wafer, which can be the cathode phase of all tube cores in inside wafer
Connect, and the public electrode for passing through the back side of wafer is drawn, the top surface of wafer draws the anode of each tube core respectively；If wafer is
MOSFET wafers, the public electrode can be in inside wafer, and the drain electrode of all tube cores is connected, and passes through the public affairs at the back side of wafer
Common electrode is drawn, and the top surface of wafer draws the source electrode of each tube core and grid respectively.To measure the tube core on-state of Schottky wafer
For pressure drop, in wafer test to be measured, vacuum slot is by wafer adsorption on suction cup of probe station so that the back side of wafer to be measured
Public electrode be connected with suction cup of probe station.Suction cup of probe station has good conductive characteristic.By the anode of voltmeter, Yi Ji electricity
The anode in stream source is connect with the anode of tube core, and the cathode of the cathode of voltmeter and current source is connected with suction cup of probe station
It connects.Using the measured value of voltmeter as the tube core pressure drop of tested tube core.Since the public electrode at the back side of wafer is inhaled with probe station
There are contact resistance between disk, between the public electrode and suction cup of probe station at the back side of the measured value including wafer for leading to voltmeter
There are the pressure drop on contact resistance, the actual die pressure drop of not tested tube core, therefore measurement error is larger.
Utility model content
The utility model embodiment provides a kind of measuring circuit of wafer tube core on-state voltage drop, to realize wafer tube core pressure drop
Accurate measurement.
The utility model embodiment provides a kind of measuring circuit of wafer tube core on-state voltage drop, which includes more
Tube core；
The measuring circuit includes at least two current source modules, at least two voltmeter modules and suction cup of probe station；
Each current source module is corresponding with a tube core；Each voltmeter module is corresponding with a tube core；
Tube core includes first end and second end；Wherein, the first end of more tube cores is connected, and passes through the back side of wafer to be measured
Public electrode be connected with suction cup of probe station；
The second end connection of the corresponding tube core of the first end of each current source module, the second end of current source module with
Suction cup of probe station connects；
The second end connection of the corresponding tube core of the first end of each voltmeter module, the second end of voltmeter module with
Suction cup of probe station connects；
Each current source module includes a current source；
Each voltmeter module includes a voltmeter.
Further, each current source module further includes a switch unit source-series with electric current；Each voltmeter mould
Block further includes the switch unit connected with voltmeter.
Further, tube core is diode or MOSFET pipes.
Further, the connection of the second end of the corresponding tube core of the first end of each voltmeter module connects for Kelvin
It connects；The second end of voltmeter module and the connection of suction cup of probe station are connected for Kelvin.
Further, suction cup of probe station surface gold-plating or nickel plating.
Further, further include vacuum slot, for by wafer adsorption to be measured in suction cup of probe station.
The technical solution of the utility model embodiment by the way that every tube core is controlled individually to be connected, obtains wafer to be measured one by one
The corresponding the first voltage value of every tube core；By the way that more tube cores is controlled to simultaneously turn on, corresponding second electricity of every tube core is obtained
Pressure value；According to the first voltage value and second voltage value, the practical on-state voltage drop of every tube core of wafer to be measured is determined, it can be to avoid
Due to the contact resistance that the contact of rule unchanged between wafer and suction cup of probe station generates, the measurement of tube core on-state voltage drop is caused
Value includes the pressure drop generated on contact resistance, so as to improve the accuracy of wafer tube core drop measurement.
Description of the drawings
Fig. 1 is a kind of structural representation of the measuring circuit for wafer tube core on-state voltage drop that the utility model embodiment provides
Figure；
Fig. 2 is the structural representation of the measuring circuit for another wafer tube core on-state voltage drop that the utility model embodiment provides
Figure；
Fig. 3 is the structural representation of the measuring circuit for another wafer tube core on-state voltage drop that the utility model embodiment provides
Figure；
Fig. 4 is a kind of measuring circuit provided based on the utility model any embodiment that the utility model embodiment provides
Wafer tube core on-state voltage drop measuring method flow chart；
Fig. 5 is another measurement electricity provided based on the utility model any embodiment that the utility model embodiment provides
The flow chart of the measuring method of the wafer tube core on-state voltage drop on road；
Fig. 6 is another measurement electricity provided based on the utility model any embodiment that the utility model embodiment provides
The flow chart of the measuring method of the wafer tube core on-state voltage drop on road.
Specific embodiment
The utility model is described in further detail with reference to the accompanying drawings and examples.It is understood that herein
Described specific embodiment is used only for explaining the utility model rather than the restriction to the utility model.It further needs exist for
It is bright, part relevant with the utility model rather than entire infrastructure are illustrated only for ease of description, in attached drawing.
Fig. 1 is the structural representation of the measuring circuit of a kind of wafer tube core on-state voltage drop that the utility model embodiment provides
Figure, as shown in Figure 1, the wafer 110 to be measured includes more tube cores 111；The measuring circuit includes at least two current source modules
120th, at least two voltmeter modules 130 and suction cup of probe station 140；Each current source module 120 is corresponding with a tube core 111；
Each voltmeter module 130 is corresponding with a tube core 111；Tube core 111 includes first end and second end；Wherein, more tube cores 111
First end be connected, and the public electrode for passing through the back side of wafer 110 to be measured is connected with suction cup of probe station 140；Each current source
The second end connection of the corresponding tube core 111 of the first end of module 120, second end and the probe station of current source module 120 are inhaled
Disk 140 connects；Each second end connection of the corresponding tube core 111 of the first end of voltmeter module 130, voltmeter module
130 second end is connect with suction cup of probe station 140；Each current source module 120 includes a current source 121；Each voltmeter mould
Block 130 includes a voltmeter 131.
Wherein, the first end of tube core is drawn from the front of wafer.The current source 121 output size of current can be 0 or
Pre-set current value (being not 0).It, will with the 121 corresponding tube core 111 of current source if the output current for setting current source 121 is 0
Cut-off if the output current of setting current source 121 is pre-set current value, will be led with the 121 corresponding tube core 111 of current source
It is logical.The break-make of tube core 111 is controlled by setting the output current of current source 121.By controlling every 111 corresponding electricity of tube core
The output current value in stream source 121 is pre-set current value, and every tube core 111 is controlled individually to be connected, obtains wafer 110 to be measured one by one
Every 111 corresponding the first voltage value of tube core；Output current value by controlling more 111 corresponding current sources 121 of tube core is same
When be pre-set current value, control more tube cores 111 simultaneously turn on, obtain every 111 corresponding second voltage value of tube core；According to
One voltage value and second voltage value determine the practical on-state voltage drop of every tube core 111 of wafer 110 to be measured, can to avoid due to
The contact resistance R that the contact of unchanged rule generates between wafer 110 and suction cup of probe station 140, causes tube core on-state voltage drop
Measured value includes the pressure drop generated on contact resistance, so as to improve the accuracy of wafer tube core drop measurement.
Optionally, as shown in Fig. 2, Fig. 2 is another wafer tube core on-state voltage drop that the utility model embodiment provides
The structure diagram of measuring circuit, on the basis of above-described embodiment, each current source module 120 further includes and current source 121
One switch unit 122 of series connection；Each voltmeter module 130 further includes the switch unit 132 connected with voltmeter 131.
Wherein it is possible to by controlling the closure of switch unit 122 connected with current source 121, current source 121 to be controlled to connect
Whether entering.By controlling the closure of switch unit 132 connected with voltmeter 131, come whether voltmeter 131 is controlled to access.With
The switch unit 122 that current source 121 is connected can be contact or the switching tube of relay.The switch list connected with voltmeter 131
Member 132 can be contact or the switching tube of relay.The measuring circuit of the wafer tube core on-state voltage drop further includes control module, uses
In closure and the disconnection of the current value and each switch unit of control for controlling each current source output.
Optionally, tube core is diode or MOSFET pipes.
Wherein, if tube core be diode, as depicted in figs. 1 and 2, then the first end of tube core be cathode, the second end of tube core
For anode.If tube core is managed for MOSFET, lead to as shown in figure 3, Fig. 3 is another wafer tube core that the utility model embodiment provides
The structure diagram of the measuring circuit of state pressure drop, then the first end of tube core is drain electrode, and the second end of tube core is source electrode, the source of tube core
Pole and grid are drawn from the front of wafer.As shown in figure 3, when tube core is MOSFET, which further includes at least two electricity
Potential source module 150, each voltage source module 150 is corresponding with a MOSFET tube core 111, and the first of the voltage source module 150
It holds and is connected with the grid of corresponding MOSFET tube cores 111, the second end of the voltage source module 150 and corresponding MOSFET tube cores
Source electrode connects.The voltage source module 150 includes a voltage source 151 and the switch unit 152 connected with the voltage source 151.
By controlling the closure of switch unit 152 connected with voltage source 151, come whether voltage source 151 is controlled to access.The voltage source
The voltage swing of 151 outputs can be 0 or preset voltage value (being not 0).If the output current for setting current source 121 is default electricity
Flow valuve, the output voltage of setting voltage source 151 is preset voltage value, and corresponding switch unit is closed, then with the electricity
121 corresponding MOSFET tube cores 111 of stream source will be connected, and otherwise, will end with the 121 corresponding MOSFET tube cores 111 of current source.
Optionally, the connection of the second end of the corresponding tube core 111 of the first end of each voltmeter module 130 is Kai Er
Text connection；The second end of voltmeter module 130 is connected with the connection of suction cup of probe station 140 for Kelvin.
Wherein, Kelvin's connection is also known as forced with detecting connection, for eliminating the voltage drop shadow generated on conducting wire in circuit
It rings.Each the connection of the second end of the corresponding tube core 111 of the first end of voltmeter module 130 is that Kelvin connects；Voltage
The second end of table module 130 is connected with the connection of suction cup of probe station 140 for Kelvin, the electricity that can be measured to avoid voltmeter module
Pressure further includes the pressure drop of All other routes impedance generation, and the accuracy measured is caused to reduce, so as to the electricity for measuring voltmeter module
Press the pressure on the contact resistance R between the public electrode and suction cup of probe station at the back side for only including tube core pressure drop and wafer to be measured
Drop.
Optionally, suction cup of probe station surface gold-plating or nickel plating.
Wherein, by suction cup of probe station surface gold-plating or nickel plating, making suction cup of probe station that there is good electric conductivity.
Optionally, further include vacuum slot, for by wafer adsorption to be measured in suction cup of probe station.
Fig. 4 is a kind of measuring circuit provided based on the utility model any embodiment that the utility model embodiment provides
Wafer tube core on-state voltage drop measuring method flow chart, as shown in figure 4, the measuring method can be arbitrary by the utility model
The measuring circuit for the wafer tube core on-state voltage drop that embodiment provides realizes that the measuring method specifically comprises the following steps：
Every step 210, control tube core are individually connected, and obtain the corresponding first voltage of every tube core of wafer to be measured one by one
Value.
Wherein, if wafer to be measured includes N tube core, by the way that every tube core is controlled individually to be connected, wafer to be measured is obtained one by one
The corresponding the first voltage value of every tube core, respectively V11, V12 ... V1N, then flow through wafer to be measured the back side it is public
The electric current of contact resistance R between electrode and suction cup of probe station is equal with the electric current I for flowing through individually conducting tube core.I-th tube core
The first voltage value for V1i, the practical on-state voltage drop of i-th tube core is VFi, the first voltage value V1i and reality of i-th tube core
The relationship of on-state voltage drop VFi is V1i=VFi+R*I, wherein i=1,2 ... N.
More step 220, control tube cores simultaneously turn on, and obtain the corresponding second voltage value of every tube core.
Wherein, more tube cores is controlled to simultaneously turn on, the corresponding second voltage value of every tube core of acquisition, respectively V21,
V22 ... V2N, the electric current for then flowing through the contact resistance between the public electrode and suction cup of probe station at the back side of wafer to be measured are
Flow through the sum of electric current of all conducting tube cores.The second voltage value of i-th tube core be V2i, the second voltage value of i-th tube core
The relationship of V2i and practical on-state voltage drop VFi is V2i=VFi+N*R*I, wherein i=1,2 ... N.
It should be noted that more tube cores (i.e. at least two tube cores) of control simultaneously turn on, can be control wafer to be measured
On part tube core simultaneously turn on or whole tube cores of wafer to be measured controlled to simultaneously turn on.Simultaneously turn on more
Tube core includes the tube core be individually connected in step 210, i.e., tested tube core.
Preferably, the current value phase flowed through in the tube core corresponding conducting tube core that individually conducting and more tube cores simultaneously turn on
Deng.
Wherein, the on-state voltage drop of each tube core on same wafer is related with the current value for flowing through tube core, when flowing through each tube core
Current value it is equal when, tube core on-state voltage drop difference very little, it is believed that approximately equal.It is individually connected and more tube cores in tube core
When simultaneously turning on, the output current value of the corresponding each current source of conducting tube core is equal.
Step 230, according to the first voltage value and second voltage value, determine the practical on-state pressure of every tube core of wafer to be measured
Drop.
The technical solution of the present embodiment is predetermined current by the output current value for controlling the corresponding current source of every tube core
Value, every tube core of control are individually connected, and obtain the corresponding the first voltage value of every tube core of wafer to be measured one by one；It is more by controlling
The output current value of the corresponding current source of tube core is simultaneously pre-set current value, and more tube cores of control simultaneously turn on, and obtain every
The corresponding second voltage value of tube core；According to the first voltage value and second voltage value, the reality of every tube core of wafer to be measured is determined
On-state voltage drop can be caused to avoid the contact resistance generated due to the contact of rule unchanged between wafer and suction cup of probe station
The measured value of tube core on-state voltage drop includes the pressure drop generated on contact resistance, so as to improve the accurate of wafer tube core drop measurement
Property.
Fig. 5 is another measurement electricity provided based on the utility model any embodiment that the utility model embodiment provides
The flow chart of the measuring method of the wafer tube core on-state voltage drop on road, as shown in figure 5, the present embodiment based on above-described embodiment into
Row optimization, specifically according to the first voltage value and second voltage value, determines the practical on-state voltage drop of every tube core of wafer to be measured
Including：According to the corresponding the first voltage value of same tube core and second voltage value, the public electrode at the back side of wafer to be measured is determined
Contact resistance between suction cup of probe station；According to the corresponding the first voltage value of every tube core and contact resistance or every tube core
Corresponding second voltage value and contact resistance determine the practical on-state voltage drop of every tube core of wafer to be measured.Correspondingly, this implementation
The method of example includes：
Every step 310, control tube core are individually connected, and obtain the corresponding first voltage of every tube core of wafer to be measured one by one
Value.
More step 320, control tube cores simultaneously turn on, and obtain the corresponding second voltage value of every tube core.
Step 330, according to the corresponding the first voltage value of same tube core and second voltage value, determine the back side of wafer to be measured
Public electrode and suction cup of probe station between contact resistance.
Wherein, with the corresponding the first voltage value of i-th tube core and second voltage value, determine wafer to be measured the back side it is public
For contact resistance between electrode and suction cup of probe station, by V1i=VFi+R*I and V2i=VFi+N*R*I, it is known that R=
(V2i-V1i)/NI.I-th tube core can be any one tube core in N tube core.
Step 340, according to the corresponding the first voltage value of every tube core and contact resistance or every tube core it is corresponding second electricity
Pressure value and contact resistance determine the practical on-state voltage drop of every tube core of wafer to be measured.
Wherein, for determining the practical on-state voltage drop of jth tube core of wafer to be measured, by V1j=VFj+R*I and R=
(V2i-V1i)/NI, it is known that VFj=V1j- (V2i-V1i)/N, wherein, j=1,2 ... N；Can also by V2j=VFj+R*I and
R=(V2i-V1i)/NI, it is known that VFj=V2j- (V2i-V1i)/N, wherein, j=1,2 ... N.If it is corresponded to according to every tube core
The first voltage value and contact resistance, determine the practical on-state voltage drop of every tube core of wafer to be measured, can only obtain a pipe
The second voltage value of core, without obtaining the second voltage value of other N-1 tube core.If according to the corresponding second voltage of every tube core
Value and contact resistance determine the practical on-state voltage drop of every tube core of wafer to be measured, can only obtain the first electricity of a tube core
Pressure value, without obtaining the first voltage value of other N-1 tube core.
Fig. 6 is another measurement electricity provided based on the utility model any embodiment that the utility model embodiment provides
The flow chart of the measuring method of the wafer tube core on-state voltage drop on road, as shown in fig. 6, the present embodiment based on above-described embodiment into
Row optimization, specifically according to the first voltage value and second voltage value, determines the practical on-state voltage drop of every tube core of wafer to be measured
Including：According to the corresponding the first voltage value of every tube core and second voltage value, determine that the reality of every tube core of wafer to be measured is led to
State pressure drop.Correspondingly, the method for the present embodiment includes：
Every step 410, control tube core are individually connected, and obtain the corresponding first voltage of every tube core of wafer to be measured one by one
Value.
More step 420, control tube cores simultaneously turn on, and obtain the corresponding second voltage value of every tube core.
Step 430, according to the corresponding the first voltage value of every tube core and second voltage value, determine every pipe of wafer to be measured
The practical on-state voltage drop of core.
Wherein, by taking i-th tube core as an example, by V1i=VFi+R*I and V2i=VFi+N*R*I, it is known that VFi=(N*V1i-
V2i)/(N-1), wherein i=1,2 ... N.
Note that it above are only the preferred embodiment of the utility model and institute's application technology principle.Those skilled in the art's meeting
Understand, the utility model is not limited to specific embodiment described here, can carry out for a person skilled in the art various bright
Aobvious variation is readjusted, be combined with each other and is substituted without departing from the scope of protection of the utility model.Therefore, although passing through
Above example is described in further detail the utility model, but the utility model be not limited only to more than implement
Example in the case where not departing from the utility model design, can also include other more equivalent embodiments, and the utility model
Range is determined by scope of the appended claims.
Claims (6)
1. a kind of measuring circuit of wafer tube core on-state voltage drop, which is characterized in that wafer to be measured includes more tube cores；
The measuring circuit includes at least two current source modules, at least two voltmeter modules and suction cup of probe station；
Each current source module is corresponding with a tube core；Each voltmeter module and a tube core pair
It should；
The tube core includes first end and second end；Wherein, the first end of the more tube cores is connected, and passes through the crystalline substance to be measured
The public electrode at the round back side is connected with the suction cup of probe station；
Each second end connection of the corresponding tube core of the first end of the current source module, the second of the current source module
End is connect with the suction cup of probe station；
Each second end connection of the corresponding tube core of the first end of the voltmeter module, the second of the voltmeter module
End is connect with the suction cup of probe station；
Each current source module includes a current source；
Each voltmeter module includes a voltmeter.
2. measuring circuit according to claim 1, which is characterized in that each current source module further includes and the electricity
Flow a source-series switch unit；Each voltmeter module further includes the switch unit connected with the voltmeter.
3. measuring circuit according to claim 1, which is characterized in that the tube core is diode or MOSFET pipes.
4. measuring circuit according to claim 1, which is characterized in that the first end of each voltmeter module is right with it
The connection of the second end for the tube core answered is connected for Kelvin；The second end of the voltmeter module and the company of the suction cup of probe station
It is connected in Kelvin's connection.
5. measuring circuit according to claim 1, which is characterized in that the suction cup of probe station surface gold-plating or nickel plating.
6. measuring circuit according to claim 1, which is characterized in that vacuum slot is further included, for by the crystalline substance to be measured
Circle absorption is on the suction cup of probe station.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721650655.9U CN207488356U (en) | 2017-12-01 | 2017-12-01 | A kind of measuring circuit of wafer tube core on-state voltage drop |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721650655.9U CN207488356U (en) | 2017-12-01 | 2017-12-01 | A kind of measuring circuit of wafer tube core on-state voltage drop |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207488356U true CN207488356U (en) | 2018-06-12 |
Family
ID=62458476
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201721650655.9U Active CN207488356U (en) | 2017-12-01 | 2017-12-01 | A kind of measuring circuit of wafer tube core on-state voltage drop |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207488356U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107843762A (en) * | 2017-12-01 | 2018-03-27 | 北京华峰测控技术有限公司 | A kind of measuring circuit and method of wafer tube core on-state voltage drop |
| CN108037432A (en) * | 2017-12-01 | 2018-05-15 | 北京华峰测控技术有限公司 | A kind of measuring method and device of wafer tube core on-state voltage drop |
-
2017
- 2017-12-01 CN CN201721650655.9U patent/CN207488356U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107843762A (en) * | 2017-12-01 | 2018-03-27 | 北京华峰测控技术有限公司 | A kind of measuring circuit and method of wafer tube core on-state voltage drop |
| CN108037432A (en) * | 2017-12-01 | 2018-05-15 | 北京华峰测控技术有限公司 | A kind of measuring method and device of wafer tube core on-state voltage drop |
| CN107843762B (en) * | 2017-12-01 | 2023-08-15 | 北京华峰测控技术有限公司 | Measuring circuit and method for on-state voltage drop of wafer die |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105021967B (en) | The precise measurement of voltage drop across thyristor | |
| CN207488356U (en) | A kind of measuring circuit of wafer tube core on-state voltage drop | |
| CN105445635A (en) | Metal oxide semiconductor field effect transistor on-resistance measuring method | |
| CN205353210U (en) | It is applicable in internal resistance of cell on -line monitoring device of multiple battery type | |
| CN204156226U (en) | A kind of smart jack | |
| CN102879722A (en) | Volt-ampere performance testing device and method for solar array | |
| CN103913695B (en) | Test system | |
| CN203444012U (en) | High accuracy and rapid speed measurement circuit of wide range current in power system | |
| CN109709423B (en) | Method for measuring stray parameters of current conversion loop of electrical device | |
| CN206583938U (en) | Test switching circuit for component capacitive equipment | |
| CN107957541B (en) | A kind of power semiconductor modular internal parallel cDNA microarray method and system | |
| CN102759696A (en) | Device for adjusting and sampling I-V characteristics of solar battery | |
| CN106533406B (en) | Metal-oxide-semiconductor parameter degradation circuit, test circuit and early warning circuit | |
| CN202710712U (en) | I-V characteristic adjusting and sampling device of solar cell | |
| CN107843762A (en) | A kind of measuring circuit and method of wafer tube core on-state voltage drop | |
| CN105334468B (en) | Solar cell capacitance waving map device and test method | |
| CN207149531U (en) | A kind of measuring circuit of wafer tube core on-state voltage drop | |
| CN108037432A (en) | A kind of measuring method and device of wafer tube core on-state voltage drop | |
| CN107703431B (en) | Device surface state trap measurement method based on changeable frequency pulse technique | |
| CN207380140U (en) | Power battery insulation resistance detection circuit | |
| CN206147057U (en) | Inconsistent time relay calibration equipment of three -phase | |
| CN102520753B (en) | Equivalent circuit with Schottky diode | |
| CN105974293B (en) | A kind of elimination field-effect tube avalanche test inductance error circuit and its test method | |
| CN204177927U (en) | A kind of permanent-magnet breaker characteristic test control circuit | |
| CN207780155U (en) | A kind of portable CT polarity testers based on pulse circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 100070 7 floor, No. 2, No. 1, Haiying Road, Fengtai District, Beijing Patentee after: Beijing Hua Feng measurement and control technology Limited by Share Ltd Address before: 100070 7 floor, No. 2, No. 1, Haiying Road, Fengtai District, Beijing Patentee before: BEIJING HUAFENG TEST & CONTROL TECHNOLOGY CO., LTD. |
|
| CP01 | Change in the name or title of a patent holder |