AU2021206813B1

AU2021206813B1 - Method and system for testing mems acceleration sensor chips in batches

Info

Publication number: AU2021206813B1
Application number: AU2021206813A
Authority: AU
Inventors: Fangfang FENG; Zongwei LI; Jing Liu; Changchun YANG; Yongjian Zhou
Original assignee: Institute of Geology and Geophysics of CAS
Current assignee: Institute of Geology and Geophysics of CAS
Priority date: 2021-05-12
Filing date: 2021-05-19
Publication date: 2022-07-14
Also published as: CN113253095A; WO2022068217A1

Abstract

The application discloses a method and system for testing MEMS (Micro Electro Mechanical Systems) acceleration sensor chips in batches to solve the problem that a lot of 5 manpower is consumed and the testing workload is high when the MEMS acceleration sensor chips are tested. The system comprises a test clamp configured to place a plurality of to-be-tested MEMS acceleration sensor chips; a channel switching apparatus connected with the to-be-tested MEMS acceleration sensor chips, switching communication of each channel based on a first clock signal to switch test of the plurality of chips automatically and communicating first 10 electrode plates or third electrode plates of the to-be-tested MEMS acceleration sensor chips with a capacitance testing apparatus respectively; the capacitance testing apparatus configured to test a capacitance value between the first electrode plate and a second electrode plate and a capacitance value between the second electrode plate and the third electrode plate of each of the to-be-tested MEMS acceleration sensor chips; and a controller configured to determine 15 corresponding voltage-capacitance characteristic curves of the chips according to the tested capacitance values and control the channel switching apparatus to switch the corresponding channels.

Description

METHOD AND SYSTEM FOR TESTING MEMS ACCELERATION SENSOR CHIPS IN BATCHES

TECHNICAL FIELD The application relates to the technical field of sensor testing, in particular to a

method and system for testing MEMS acceleration sensor chips in batches.

BACKGROUND

MEMS (Micro Electro Mechanical Systems) achieve a micro mechanical

structure on a silicon wafer by means of a micro-nano machining technology, thereby

greatly decreasing the size of an apparatus, reducing the energy consumption and

improving the reliability. MEMS featuring in microminiaturization, integration, low

cost, low power consumption and the like are widely applied to the fields of consumer

electronics, automotive electronics, biomedicines and the like. An MEMS

acceleration sensor is one of applications.

MEMS acceleration sensor chips are prepared by an integrated circuit process

and can be produced in batches. It is needed to conduct preliminary test on the

performance of the MEMS acceleration sensor chips after the MEMS acceleration

sensor chips are machined, the chips which cannot work normally are excluded, and

the MEMS acceleration sensor chips with good performance are screened to be

packaged.

However, a lot of manpower is consumed and the testing workload is high when

the MEMS acceleration sensor chips produced in batches are tested.

SUMMARY

Embodiments of the application provides a method and system for testing

MEMS (Micro Electro Mechanical Systems) acceleration sensor chips in batches to solve the problem that a lot of manpower is consumed and the testing workload is high when a lot of MEMS acceleration sensor chips are tested.

On the one hand, an embodiment of the application provides a system for testing

MEMS acceleration sensor chips in batches, wherein each of the MEMS acceleration

sensor chips includes a first electrode plate, a second electrode plate and a third

electrode plate, and the system includes:

a test clamp configured to place a plurality of to-be-tested MEMS acceleration

sensor chips;

a channel switching apparatus connected with the plurality of to-be-tested

MEMS acceleration sensor chips and configured to control on or off state of switches

of corresponding channels of the to-be-tested MEMS acceleration sensor chips based

on a received first clock signal and to generate a second clock signal according to the

first clock signal and to communicate the first electrode plate or the third electrode

plate of each of the to-be-tested MEMS acceleration sensor chips with a capacitance

testing apparatus respectively based on the second clock signal;

the capacitance testing apparatus connected with the channel switching apparatus

and configured to test a capacitance value between the first electrode plate and the

second electrode plate and a capacitance value between the second electrode plate and

a third electrode plate of a currently communicating to-be-tested MEMS acceleration

sensor chip; and

a controller connected with the channel switching apparatus and the capacitance

testing apparatus and configured to determine a corresponding voltage-capacitance

characteristic curve according to the tested capacitance values and send the first clock

signal and the second clock signal to the channel switching apparatus to control the

channel switching apparatus to switch the channels correspondingly.

In a mode of execution of the application, the channel switching apparatus

includes a selective signal generation module configured to generate selective signals

corresponding to the plurality of to-be-tested MEMS acceleration sensor chips respectively according to the first clock signal to control on of switches of corresponding to-be-tested MEMS acceleration sensor chips respectively, wherein at the same moment, the switch corresponding to at most one to-be-tested MEMS acceleration sensor chip is in an on state.

In a mode of execution of the application, the channel switching apparatus

includes a channel switching module, a TOP port, a CTR port and a BOT port; the

channel switching module includes switches respectively corresponding to the first

electrode plate, the second electrode plate and the third electrode plate of each of the

plurality of to-be-tested MEMS acceleration sensor chips; and when the to-be-tested

MEMS acceleration sensor chip communicates, the first electrode plate is connected

with the TOP port through the corresponding switch, and the second electrode plate is

connected with the CTR port through the corresponding switch and the third electrode

plate is connected with the BOT port through the corresponding switch, such that the

to-be-tested MEMS acceleration sensor chip is connected with the capacitance testing

apparatus via the TOP port, the CRT port and the BOT port.

In a mode of execution of the application, the channel switching apparatus

includes a first test port and a second test port; the first test port is connected with the

second electrode plate of the currently communicating to-be-tested MEMS

acceleration sensor chip via the CTR port, such that the second electrode plate is

connected with the capacitance testing apparatus; and the second test port is

connected with the first electrode plate of the currently communicating to-be-tested

MEMS acceleration sensor chip via the TOP port or is connected with the third

electrode plate of the currently communicating to-be-tested MEMS acceleration

sensor chip via the BOT port, such that the first electrode plate or the third electrode

plate is connected with the capacitance testing apparatus to test corresponding

capacitance values respectively.

In a mode of execution of the application, the channel switching apparatus

generates a second clock signal with a second frequency that is several times of a first frequency according to the first frequency of the first clock signal and overturns the first clock signal via the second clock signal to switch communication between the first electrode plate or the third electrode plate of the currently communicating to-be tested MEMS acceleration sensor chip and the capacitance testing apparatus.

In a mode of execution of the application, the test clamp includes a plurality of

probes, a plurality of leads and a plurality of interfaces; the plurality of probes are

connected with the first electrode plates, the second electrode plates and the third

electrode plates of the plurality of to-be-tested MEMS acceleration sensor chips in a

one-to-one correspondence manner and the corresponding electrode plates are in

signal connection with the corresponding interfaces via the leads, such that the

plurality of to-be-tested MEMS acceleration sensor chips are connected with the

channel switching apparatus via the interfaces.

In a mode of execution of the application, the test clamp includes a shell and a

shell cover; the shell includes a plurality of first grooves for placing the to-be-tested

MEMS acceleration sensor chips and second grooves formed in opposite two sides of

the first grooves, the second grooves configured to pick and place the to-be-tested

MEMS acceleration sensor chips in an auxiliary manner; the shell includes a fixed

part and is riveted with the shell cover via the fixed part; and each of the probes

includes a fixed sleeve and an elastic probe head, the elastic probe head retracting in

the fixed sleeve based on a pressure to adjust the length of the probe.

On the other hand, an embodiment of the application further provides a method

for testing MEMS acceleration sensor chips in batches, wherein the method is applied

to any one system for testing MEMS acceleration sensor chips in batches, the method

including:

determining that a plurality of to-be-tested MEMS acceleration sensor chips are

connected with corresponding channels respectively; controlling communication of switches in the channels corresponding to the plurality of to-be-tested MEMS acceleration sensor chips successively via the first clock signal to achieve switching of the channels; determining that the second electrode plate of a currently communicating to-be tested MEMS acceleration sensor chip communicates with the capacitance testing apparatus, and controlling the first electrode plate or the third electrode plate of the currently communicating to-be-tested MEMS acceleration sensor chip to communicate with the capacitance testing apparatus via the second clock signal; testing the capacitance value between the first electrode plate and the second electrode plate and the capacitance value between the second electrode plate and the third electrode plate of the currently communicating to-be-tested MEMS acceleration sensor chip respectively; and determining voltage-capacitance characteristic curves corresponding to the to-be tested MEMS acceleration sensor chips according to the capacitance values.

In a mode of execution of the application, before switching of the

communication of channels via the first clock signal to control communication of the

switches corresponding to the plurality of to-be-tested MEMS acceleration sensor

chips successively, the method further includes: determining a clock period of the first

clock signal according to testing time of the capacitance values between the first

electrode plate and the second electrode plate and between the second electrode plate

and the third electrode plate of each of the to-be-tested MEMS acceleration sensor

chips to enable the testing time to be shorter than the clock period.

In a mode of execution of the application, controlling the switch corresponding

to the first electrode plate or the third electrode plate of the currently communicating

to-be-tested MEMS acceleration sensor chip to communicate via the second clock

signal specifically includes: determining that a second frequency of the second clock

signal is several times of the first frequency according to the first frequency of the

first clock signal; determining two corresponding second clock signals within one period of the first clock signal, wherein the 1st second clock signal controls the first electrode plate of the currently communicating to-be-tested MEMS acceleration sensor chip to communicate with the capacitance testing apparatus, and the rising edge of the 2nd second clock signal enables the first clock signal to overturn so as to control the third electrode plate of the currently communicating to-be-tested MEMS acceleration sensor chip to communicate with the capacitance testing apparatus.

The method and system for testing MEMS acceleration sensor chips in batches

provided by the embodiments of the application at least include the following

beneficial effects:

By arranging corresponding channels for the plurality of MEMS acceleration

sensor chips respectively, the selection of the channels is switched automatically by

using the first clock signal during test, such that capacitance tests can be conducted on

the plurality of MEMS acceleration sensor chips sequentially. Furthermore, when the

capacitance tests are conducted, the first electrode plate and the third electrode plate

are switched to be connected with the capacitance testing apparatus respectively by

using the second clock signal so as to conduct capacitance tests twice respectively.

Thus, automatic batched test of the MEMS acceleration sensor chips can be achieved,

so that the labor cost is lowered, the testing workload is saved, the testing time is

shortened and improvement of the testing efficiency is facilitated. In addition, the

system can avoid bringing extra capacitance interference by the selection of the

channels via a mechanical switch, and therefore, the testing accuracy and stability are

improved.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein for further understanding of the application

constitute a part of the application. The schematic embodiments and description

thereof are used for explaining the application and do not limit the application

improperly. In the drawings,

Fig. 1 is a simple structural schematic diagram of an MEMS acceleration sensor

chip provided by an embodiment of the application;

Fig. 2 is a structural schematic diagram of a system for testing MEMS

acceleration sensor chips in batches provided by an embodiment of the application;

Fig. 3 is a structural schematic diagram of a shell of a test clamp provided by an

embodiment of the application;

Fig. 4 is a top sectional view of a shell cover provided with probes in the test

clamp provided by an embodiment of the application;

Fig. 5 is a structural schematic diagram of probes provided by an embodiment of

the application;

Fig. 6 is a side sectional view of the shell cover provided with the probes in the

test clamp provided by an embodiment of the application;

Fig. 7 is a structural schematic diagram of a channel switching apparatus

provided by an embodiment of the application;

Fig. 8 (a) is a sequence diagram of a second clock signal provided by an

embodiment of the application;

Fig. 8 (b) is a sequence diagram of a first clock signal provided by an

embodiment of the application;

Fig. 8 (c) is a sequence diagram of a selective signal of a channel provided by an

embodiment of the application;

Fig. 9 is a flow diagram of a method for testing MEMS acceleration sensor chips

in batches provided by an embodiment of the application.

DETAILED DESCRIPTION

In order to make purposes, technical schemes and advantages of the application

clearer, clear and intact description will be made on the technical schemes of the

application below in combination with specific embodiments of the application and

corresponding drawings. Obviously, the described embodiments are merely a part of embodiments of the application and are not all the embodiments. On a basis of the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall into the scope of protection of the application.

Fig. 1 is a simple structural schematic diagram of an MEMS (Micro Electro

Mechanical Systems) acceleration sensor chip provided by an embodiment of the

application, wherein the MEMS acceleration sensor chip is comprised of a first

electrode plate, a second electrode plate and a third electrode plate. The first electrode

plate and the third electrode plate are fixed electrode plates and do not move under the

action of external forces. The second electrode plate is located in a position between

the first electrode plate and the third electrode plate, and the second electrode plate is

movable. A first surface of the second electrode plate and a first surface of the first

electrode plate form a plate capacitor with same areas of upper and lower electrode

plates, and the first surface of the second electrode plate and a first surface of the third

plates. The first surface of the second electrode plate and the first surface of the first

electrode plate are arranged oppositely, such that the second electrode plate and the

first electrode plate form a first capacitor, and a second surface of the second

electrode plate and the first surface of the third electrode plate are arranged oppositely,

such that the second electrode plate and the third electrode plate form a second

capacitor.

According to the method and system for testing the MEMS acceleration sensor

chips in batches provided by the embodiment of the application, under a circumstance

of placing a plurality of chips, by arranging corresponding channels for the plurality

of MEMS acceleration sensor chips respectively, communication of the chips is

switched automatically by using a first clock signal during test, such that capacitance

tests can be conducted on the plurality of MEMS acceleration sensor chips

sequentially. Furthermore, when the capacitance tests are conducted, the first electrode plate and the third electrode plate are switched to be connected with a capacitance testing apparatus respectively by using a second clock signal so as to conduct capacitance tests twice respectively. Thus, automatic batched test of the

MEMS acceleration sensor chips can be achieved. After one chip is tested, the system

will be switched to test the next chip automatically without manual monitoring and

placing, so that the labor cost is lowered, the testing workload is saved, the testing

time is shortened and improvement of the testing efficiency is facilitated. In addition,

the system can avoid bringing extra capacitance interference by the selection of the

improved. Furthermore, after voltage-capacitance characteristic curves of the chips

are determined subsequently, performance of the MEMS acceleration sensor chips can

be judged, so that chips which work normally can be screened for subsequent

packaging test, and thereby, the packaging cost can be saved greatly.

Further detailed description is made below.

Fig. 2 is a structural schematic diagram of a system for testing MEMS

acceleration sensor chips in batches provided by an embodiment of the application.

As shown in Fig. 2, the system includes a test clamp 1, a channel switching

apparatus 2, a capacitance testing apparatus 3 and a controller 4, wherein the test

clamp 1, the channel switching apparatus 2 and the capacitance testing apparatus 3 are

connected sequentially, and the controller 4 is connected with the channel switching

apparatus 2 and the capacitance testing apparatus 3 respectively.

Specifically, the test clamp 1 is configured to place a plurality of to-be-tested

MEMS acceleration sensor chips simultaneously to conduct batched tests. The

channel switching apparatus 2 is connected with the plurality of to-be-tested MEMS

acceleration sensor chips through corresponding channels respectively to switch on of

switches of the corresponding channels of the plurality of to-be-tested MEMS

acceleration sensor chips based on a received first clock signal and to generate a

second clock signal based on the received first clock signal and to switch a first electrode plate or a third electrode plate of a currently communicating to-be-tested

MEMS acceleration sensor chip to communicate with the capacitance testing

apparatus based on the second clock signal. The capacitance testing apparatus 3 is

configured to test a capacitance value between the first electrode plate and a second

electrode plate and a capacitance value between the second electrode plate and the

third electrode plate of the currently communicating to-be-tested MEMS acceleration

sensor chip. The controller 4 is configured to send the first clock signal to the channel

switching apparatus to control the channel switching apparatus to switch

correspondingly and determine voltage-capacitance characteristic curves

corresponding to the to-be-tested MEMS acceleration sensor chips according to the

capacitance values.

By arranging the channel switching apparatus, the system switches automatically

among the channels corresponding to the plurality of to-be-tested MEMS acceleration

sensor chips and switches automatically between the first electrode plate and the third

electrode plate of the currently communicating to-be-tested MEMS acceleration

sensor chip to test the plurality of to-be-tested MEMS acceleration sensor chips

respectively in sequence to obtain the capacitance values and the voltage-capacitance

characteristic curves corresponding to the to-be-tested MEMS acceleration sensor

chips so as to achieve batched test and detection of the MEMS acceleration sensor

chips, thereby saving a lot of testing workload and improving the testing efficiency.

Meanwhile, in a process of detecting performance of the chips preliminarily

subsequently, the chips with problems can be further excluded and MEMS chips with

good performance are screened to be packaged, so that the packaging cost can be

saved and the quality of the chips is controlled.

embodiment of the application. The test clamp includes a shell and a shell cover. The

shell is configured to place the to-be-tested MEMS acceleration sensor chips, and the shell cover covers the shell and is configured to protect and isolate the to-be-tested

MEMS acceleration sensor chips.

As shown in the Fig. 3, the test clamp includes first grooves 11, second grooves

12 and fixed parts 13. A plurality of first grooves 11 can be formed according to a size

of the shell and can be configured to place the MEMS acceleration sensor chips, and

sizes of the first grooves can be set according to sizes of to-be-tested MEMS

acceleration sensor bare chips. The second grooves 12 are formed in opposite two

sides of the first grooves 11, and are configured to assist test personnel to pick and

place the to-be-tested MEMS acceleration sensor chips from the first grooves 11. The

fixed parts 13 are arranged at two ends of the test clamp to fix the shell and the shell

cover, thereby improving the stability of the test clamp and preventing relative

movement between the shell and the shell cover in the testing process to avoid

affecting the testing result. The fixed parts can be protruding cylinders and the shell is

riveted with the shell cover via the cylinders.

The test clamp includes a plurality of probes corresponding to the first grooves,

and one groove correspond to three probes which are configured to be connected with

the first electrode plate, the second electrode plate and the third electrode plate of each

of the to-be-tested MEMS acceleration sensor chips in a one-to-one correspondence

manner respectively. The probes can be arranged on the shell or the shell cover. If the

probes are arranged on the shell, electrodes of the to-be-tested MEMS acceleration

sensor chips are placed facing the shell, such that the electrodes are in contact with the

probes on the shell. If the probes are arranged on the shell cover, the electrodes of the

to-be-tested MEMS acceleration sensor chips are placed facing the shell cover, such

that the electrodes are in contact with the probes on the shell cover.

Fig. 4 is a top sectional view of the shell cover provided with the probes in the

test clamp provided by an embodiment of the application. As shown in Fig. 4,

corresponding to the corresponding positions of the plurality of first grooves formed

in the shell, the shell cover of the test clamp is provided with a first probe 14 for connecting the first electrode plate of each of the to-be-tested MEMS acceleration sensor chips, a second probe 15 for connecting the second electrode plate of each of the to-be-tested MEMS acceleration sensor chips and a third probe 16 for connecting the third electrode plate of each of the to-be-tested MEMS acceleration sensor chips respectively. After the shell and the shell cover are closed, corresponding electrodes of the to-be-tested MEMS acceleration sensor chips placed in the shell are in contact with the corresponding probes on the shell cover respectively.

In an embodiment, the probes are retractable. As shown in Fig. 5, each probe

includes a fixed sleeve 124 and an elastic probe head 142. The elastic probe head 142

can move in the fixed sleeve 124 under the action of a spring, thereby adjusting the

length of the probe. In order to prevent the probe from not being in contact with the

electrode of one chip due to a machining or assembling error, the probe can be

arranged with a relatively great length. Meanwhile, in order to protect the chip, the

elastic probe head subjected to a pressure can retract in the fixed sleeve so as to

prevent the chip from being damaged. Thus, the flexibility of the probe is enhanced,

and meanwhile, the requirement on machining fineness is reduced.

test clamp provided by an embodiment of the application. As shown in Fig. 6, the test

clamp includes leads 17 and interfaces 18. The probes are connected with the

interfaces 18 via the leads 17 so as to export electrode plate signals of the

corresponding to-be-tested MEMS acceleration sensor chips to the interfaces 18 for

test. The lead led out from each probe shall be short to the great extent, for example,

according to a linear distance between the probe and the interface, the length of the

lead, which has a difference value not greater than a preset difference value with the

linear distance, is determined, thereby reducing stray capacitance caused by the lead

and improving the detecting accuracy on performance of the chip subsequently.

Furthermore, different leads shall be equal in length to the great extent to prevent

inconsistent testing conditions of the to-be-tested MEMS acceleration sensor chips as a result of difference influences of stray capacitance on different channels, thereby avoiding increasing the measuring error.

Fig. 7 is a structural schematic diagram of the channel switching apparatus

provided by an embodiment of the application. As shown in Fig. 7, the channel

switching apparatus includes a channel switching module 21, a TOP port, a CTR port,

a BOT port, a chip interface module 22, a capacitance measurement interface module

23 and a selective signal generation module 24. The chip interface module 22 is

connected with an interface in the test clamp, the first electrode plates 1-N, the

second electrode plates 1-N and the third electrode plates 1-N of the to-be-tested

MEMS acceleration sensor chips 1-N are connected with corresponding switches in

the channel switching module 21 respectively, and the capacitance measurement

interface module 23 includes a first test port and a second test port and is connected

with corresponding test ports in the capacitance testing apparatus.

The selective signal generation module 24 receives the first clock signal sent by

the controller to generate a plurality of selective signals SEL 1-N which correspond

to the plurality of (N) to-be-tested MEMS acceleration sensor chips, and each

selective signal controls communication of the switch corresponding to the

corresponding to-be-tested MEMS acceleration sensor chip. In Fig. 7, SEL 1 controls

communication of corresponding switches of the first electrode plate 1, the second

electrode plate 1 and the third electrode plate 1, SEL 2 controls communication of

corresponding switches of the first electrode plate 2, the second electrode plate 2 and

the third electrode plate 2, and by parity of reasoning, SEL N controls communication

of corresponding switches of the first electrode plate N, the second electrode plate N

and the third electrode plate N. When each of the to-be-tested MEMS acceleration

sensor chips communicates, the first electrode plate is connected with the TOP port

through the corresponding port, the second electrode plate is connected with the CTR

port through the corresponding port, and the third electrode plate is connected with

the BOT port through the corresponding port.

Specifically, as shown in Fig. 8(b) to Fig. 8(c), ©1 represents the first clock

signal, and the controller outputs the first clock signal to switch the selective signals.

the controller outputs one first clock signal each time, the selective signal generation

module generates the corresponding selective signal. Within a first clock period of the

first clock signal, the selective signal 1 is high level, the selective signals 2-N are low

level, and the first electrode plate 1, the second electrode plate 2 and the third

electrode plate 3 of the corresponding to-be-tested MEMS acceleration sensor chip are

connected with the TOP port, the CRT port and the BOT port sequentially. Within a

second clock period of the first clock signal, the selective signal 2 is high level, and

the rest of selective signals are low level, by parity of reasoning. At the same moment

in the testing process, the switch corresponding to at most one to-be-tested MEMS

acceleration sensor chip is in a communicating state, i.e., the system will test the to

be-tested MEMS acceleration sensor chips sequentially.

In an embodiment of the application, when each of the to-be-tested MEMS

acceleration sensor chips is tested, the capacitance value between the first electrode

plate and the second electrode plate and the capacitance value between the second

electrode plate and the third electrode plate are required to be tested. Therefore, the

TOP port (corresponding to the first electrode plate) or the BOT port (corresponding

to the third electrode plate) in the channel switching apparatus is controlled via the

second clock signal to be connected with the second test port respectively, i.e., the

TOP port or the BOT port is connected with the capacitance testing apparatus

separately.

As shown in Fig. 7, the first test port is connected with the second electrode plate

of the currently communicating to-be-tested MEMS acceleration sensor chip via the

CTR port, and the second test port is expressed as a selective switch which can be

MEMS acceleration sensor chip via the TOP port or can be connected with the third

electrode plate of the currently communicating to-be-tested MEMS acceleration sensor chip via the BOT port. As the first test port and the second test port are connected with corresponding ports in the channel switching apparatus, the capacitance testing apparatus can test the capacitance value between the first electrode plate and the second electrode plate and the capacitance value between the second electrode plate and the third electrode plate of each of the to-be-tested MEMS acceleration sensor chips respectively.

Further, as shown in Fig. 8(a), ©1 represents the second clock signal. The

channel switching apparatus can generate two second clock signals within one clock

period of the first clock signal when determining that the second frequency of the

second time clock is several times, for example two times,_ of the first frequency

according to the first frequency of the first clock signal, a rising edge of the 2nd

second clock signal can overturn the first clock signal to convert the first clock signal

from high level to low level so as to switch communication of the first electrode plate

or the third electrode plate of the currently communicating to-be-tested MEMS

acceleration sensor chip.

Specifically, the capacitance testing apparatus needs to test each of to-be-tested

MEMS acceleration sensor chips twice. When the first clock signal is high level, the

TOP port is connected with the second test port, the capacitance testing apparatus

tests the capacitance value between the first electrode plate and the second electrode

plate, and when the first clock signal is low level, the BOT port is connected with the

second test port, the capacitance testing apparatus tests the capacitance value between

the second electrode plate and the third electrode plate.

Further, after the currently communicating to-be-tested MEMS acceleration

sensor chip is tested, the second clock signal can overturn the first clock signal as well

via the rising edge, such that the first clock signal is converted from low level to high

level to test the next to-be-tested MEMS acceleration sensor chip.

In addition, the controller further includes a capacitance and voltage

characteristic testing module and a data storage and display module. The capacitance and voltage characteristic testing module is used for determining voltage-capacitance characteristic curves corresponding to the to-be-tested MEMS acceleration sensor chips according to the measured capacitance values. The data storage and display module is used for storing and displaying the tested voltage-capacitance characteristic curve and basic capacitance of the to-be-tested MEMS acceleration sensor chip of each channel. The controller can judge performance of the corresponding MEMS acceleration sensor chip via the tested capacitance and voltage curve and basic capacitance and screen the MEMS acceleration sensor chip with good performance for next packaging test.

It should be noted that besides detection of the voltage and capacitance

characteristics involved in the application, the scheme of the application for

conducting automatic batched tests by switching the channels of the to-be-tested

MEMS acceleration sensor chips further can be applied to detecting other related

electric characteristics of the MEMS acceleration sensor chips, for example, a transfer

function, a noise and the like, based on the same principle.

Based on a same inventive concept, an embodiment of the application further

provides a method for detecting MEMS acceleration sensor chips in batches, which

has a flow diagram as shown in Fig. 9.

Fig. 9 is a flow diagram of the method for testing the MEMS acceleration sensor

chips in batches provided by the embodiment of the application. The method includes

the following specific steps:

S901: a condition that a plurality of to-be-tested MEMS acceleration sensor chips

are connected with corresponding channels respectively is determined.

In the embodiment of the application, the plurality of to-be-tested MEMS

acceleration sensor chips are placed in a test clamp, such that each to-be-tested

MEMS acceleration sensor chip is connected with the corresponding channel in a

channel switching apparatus, i.e., the to-be-tested MEMS acceleration sensor chips in

the batch can be tested.

S902: a first clock signal controls on of switches in the channels corresponding

to the plurality of to-be-tested MEMS acceleration sensor chips successively to

achieve switching of communication of the corresponding channels.

The controller outputs the first clock signal to the channel switching apparatus,

such that a selective signal generation module in the channel switching apparatus

generates a plurality of corresponding selective signals. A channel switching module

in the channel switching apparatus includes switches corresponding to the to-be-tested

MEMS acceleration sensor chips respectively. The channel switching apparatus

enables the corresponding switches to communicate and other switches to be kept

disconnected according to the switches corresponding to the selective signals, such

that the to-be-tested MEMS acceleration sensor chips corresponding to the switches

communicate with the capacitance testing apparatus.

Each selective signal controls the switch corresponding to one to-be-tested

MEMS acceleration sensor chip, and other switches are kept disconnected when the

switch corresponding to one channel communicates.

In an embodiment of the application, the channel switching apparatus needs to

conduct switching to test the next to-be-tested MEMS acceleration sensor chip after

one to-be-tested MEMS acceleration sensor chip is tested. Thus, the controller can

determine a clock period of the first clock signal according to testing time of the

capacitance values between the first electrode plate and the second electrode plate and

between the second electrode plate and the third electrode plate of each of the to-be

tested MEMS acceleration sensor chips by the capacitance testing apparatus. When

the testing time is shorter than the clock period of the first clock signal, i.e., after test,

the channels are switched automatically according to output of next first clock signal.

S903: a condition that a second electrode plate of a currently communicating to

be-tested MEMS acceleration sensor chip communicates with the capacitance testing

apparatus is determined, and a first electrode plate or a third electrode plate of the currently communicating to-be-tested MEMS acceleration sensor chip is controlled to communicate with the capacitance testing apparatus via a second clock signal.

In the embodiment of the application, the capacitance testing apparatus needs to

test the capacitance value between the first electrode plate and the second electrode

plate and the capacitance value between the second electrode plate and the third

electrode plate of each of the to-be-tested MEMS acceleration sensor chips. Thus,

when the corresponding channel of one to-be-tested MEMS acceleration sensor chip

is in communication, the second electrode plate of the to-be-tested MEMS

acceleration sensor chip communicates with the capacitance testing apparatus all the

time via the CTR port of the channel switching apparatus, and the first electrode plate

and the third electrode plate of the to-be-tested MEMS acceleration sensor chip need

to be switched under the action of the second clock signal and communicate to the

capacitance testing apparatus in sequence.

Specifically, the channel switching apparatus can determine that a second

frequency of the second clock signal is several times, for example two times, of a first

frequency according to the first frequency of the first clock signal. There are two

second clock signals correspondingly within one period of the first clock signal

corresponding to the currently communicating to-be-tested MEMS acceleration sensor

chip. The 1st second clock signal controls the first electrode plate of the currently

communicating to-be-tested MEMS acceleration sensor chip to communicate with the

capacitance testing apparatus, and a rising edge of the 2nd second clock signal enables

the first clock signal to overturn so as to control the third electrode plate of the

currently communicating to-be-tested MEMS acceleration sensor chip to

communicate with the capacitance testing apparatus.

S904: a capacitance value between the first electrode plate and the second

sensor chip are tested respectively.

In the embodiment of the application, the capacitance testing apparatus can test

capacitance of each of the to-be-tested MEMS acceleration sensor chips twice. After

the capacitance of one to-be-tested MEMS acceleration sensor chip is tested, the

controller outputs the first clock signal in the next clock period and generates the

selective signal of the next channel, and the channel switching apparatus conducts

switching based on the selective signal to test the next to-be-tested MEMS

acceleration sensor chip.

S905: voltage-capacitance characteristic curves corresponding to the to-be-tested

MEMS acceleration sensor chips are determined according to the capacitance values.

In the embodiment of the application, the voltage-capacitance characteristic

curves corresponding to the to-be-tested MEMS acceleration sensor chips can be

determined according to the capacitance values, so that the performance of the to-be

tested MEMS acceleration sensor chips is determined.

It should be noted that the switches for selective connection of the channels in

the application are mechanical switches, and the mechanical switches can avoid

introducing extra capacitance interference, thereby improving the testing accuracy and

stability.

All the embodiments in the application are described progressively, reference is

made to same and similar parts of the embodiments, and each embodiment puts

emphasis on difference with other embodiments. In particular, as far as the

embodiment of the method is concerned, as the embodiment is substantially similar to

the embodiment of the system, the embodiment of the method is described simply.

The related part refers to description of the embodiment of the system.

It should be further noted that the terms "include", "comprise" or any other

variants are intended to cover non-excludable inclusions, such that a process, method,

commodity or apparatus including a series of elements not only include these

elements, but also further include other elements which are not listed expressly or

further include inhered elements of the process, method, commodity or apparatus.

Under a circumstance of no more limitations, for the elements defined by the term

"include one", a condition that there are additional same elements in the process,

method, commodity or apparatus including the elements is not excluded.

The above is merely the embodiments of the application and is not intended to

limit the application. For those skilled in the art, various alternations and changes can

be made on the application. Any modification, equivalent replacement, improvement,

etc., made within the spirit and principle of the application shall be included within

the scope of claims of the application.

Claims

1. A system for testing MEMS (Micro Electro Mechanical Systems) acceleration

sensor chips in batches, wherein an MEMS acceleration sensor chip comprises a first

electrode plate, a second electrode plate and a third electrode plate, and the system is

characterized by comprising:

a test clamp configured to place a plurality of to-be-tested MEMS acceleration

sensor chips;

a channel switching apparatus connected with the plurality of to-be-tested

on a received first clock signal, to generate a second clock signal according to the first

clock signal and to communicate the first electrode plate or the third electrode plate of

each of the to-be-tested MEMS acceleration sensor chips with a capacitance testing

apparatus respectively based on the second clock signal;

the third electrode plate of a currently communicating to-be-tested MEMS

acceleration sensor chip; and

a controller connected with the channel switching apparatus and the capacitance

testing apparatus and configured to determine corresponding voltage-capacitance

characteristic curves according to the tested capacitance values and send the first

clock signal to the channel switching apparatus to control the channel switching

apparatus to switch the corresponding channels.

2. The system for testing the MEMS acceleration sensor chips in batches

according to claim 1, characterized in that the channel switching apparatus comprises

a selective signal generation module; the selective signal generation module is configured to generate selective signals corresponding to the plurality of to-be-tested MEMS acceleration sensor chips respectively according to the first clock signal to control on of the switches of the corresponding to-be-tested MEMS acceleration sensor chips respectively, wherein at the same moment, the switch corresponding to at most one to-be tested MEMS acceleration sensor chip is in an on state.

3. The system for testing the MEMS acceleration sensor chips in batches

a channel switching module, a TOP port, a CTR port and a BOT port,

wherein the channel switching module comprises switches corresponding to the

first electrode plates, the second electrode plates and the third electrode plates of the

plurality of to-be-tested MEMS acceleration sensor chips; and

when one to-be-tested MEMS acceleration sensor chip is in communication, the

switch corresponding to the first electrode plate is connected with the TOP port, the

switch corresponding to the second electrode plate is connected with the CTR port

and the switch corresponding to the third electrode plate is connected with the BOT

port, such that the to-be-tested MEMS acceleration sensor chip is connected with the

capacitance testing apparatus via the TOP port, the CRT port and the BOT port.

4. The system for testing the MEMS acceleration sensor chips in batches

according to claim 3, characterized in that the channel switching apparatus comprises

a first test port and a second test port,

wherein the first test port is connected with the second electrode plate of the

currently communicating to-be-tested MEMS acceleration sensor chip via the CTR

port, such that the second electrode plate is connected with the capacitance testing

apparatus; and

wherein the second test port is connected with the first electrode plate of the

currently communicating to-be-tested MEMS acceleration sensor chip via the TOP

port or is connected with the third electrode plate of the currently communicating to- be-tested MEMS acceleration sensor chip via the BOT port, such that the first electrode plate or the third electrode plate is connected with the capacitance testing apparatus to test corresponding capacitance values respectively.

5. The system for testing the MEMS acceleration sensor chips in batches

according to claim 1, characterized in that the channel switching apparatus generates a

second clock signal with a second frequency that is several times of a first frequency

according to the first frequency of the first clock signal and overturns the first clock

signal via the second clock signal to switch communication between the first electrode

plate or the third electrode plate of the currently communicating to-be-tested MEMS

acceleration sensor chip and the capacitance testing apparatus.

6. The system for testing the MEMS acceleration sensor chips in batches

according to claim 1, characterized in that the test clamp comprises a plurality of

probes, leads and interfaces,

wherein the plurality of probes are connected with the first electrode plates, the

second electrode plates and the third electrode plates of the plurality of to-be-tested

MEMS acceleration sensor chips in a one-to-one correspondence manner and the

corresponding electrode plates are in signal connection with corresponding interfaces

via the leads, such that the plurality of to-be-tested MEMS acceleration sensor chips

are connected with the channel switching apparatus via the interfaces.

7. The system for testing the MEMS acceleration sensor chips in batches

according to claim 6, characterized in that the test clamp comprises a shell and a shell

cover,

wherein the shell comprises a plurality of first grooves for placing the to-be

tested MEMS acceleration sensor chips and second grooves formed in opposite two

sides of the first grooves, the second grooves configured to pick and place the to-be

tested MEMS acceleration sensor chips in an auxiliary manner;

the shell comprises fixed parts and is riveted with the shell cover via the fixed

parts; and each of the probes comprises a fixed sleeve and an elastic probe head, the elastic probe head retracting in the fixed sleeve based on a pressure to adjust a length of the probe.

8. A method for testing MEMS acceleration sensor chips in batches,

characterized in that the method is applied to the system for testing the MEMS

acceleration sensor chips in batches according to any one of claims 1-7, the method

comprising:

determining that a plurality of to-be-tested MEMS acceleration sensor chips are

connected with corresponding channels respectively;

controlling on or off state of switches in the channels corresponding to the

plurality of to-be-tested MEMS acceleration sensor chips successively via the first

clock signal to achieve switching of communication of the corresponding channels;

determining that the second electrode plate of a currently communicating to-be

tested MEMS acceleration sensor chip communicates with the capacitance testing

apparatus, and controlling the first electrode plate or the third electrode plate of the

currently communicating to-be-tested MEMS acceleration sensor chip to

communicate with the capacitance testing apparatus via the second clock signal;

testing the capacitance value between the first electrode plate and the second

electrode plate and the capacitance value between the second electrode plate and the

sensor chip respectively; and

determining voltage-capacitance characteristic curves corresponding to the to-be

tested MEMS acceleration sensor chips according to the capacitance values.

9. The method for testing the MEMS acceleration sensor chips in batches

according to claim 8, characterized in that before switching the communication of the

channels via the first clock signal to control communication of the switches

corresponding to the plurality of to-be-tested MEMS acceleration sensor chips

successively, the method further comprises: determining a clock period of the first clock signal according to testing time of the capacitance values between the first electrode plate and the second electrode plate and between the second electrode plate and the third electrode plate of the to-be-tested

MEMS acceleration sensor chip to enable the testing time to be shorter than the clock

period.

10. The method for testing the MEMS acceleration sensor chips in batches

according to claim 8, characterized in that controlling the first electrode plate or the

sensor chip to communicate with the capacitance testing apparatus via the second

clock signal specifically comprises:

determining that a second frequency of the second clock signal is several times

of the first frequency according to the first frequency of the first clock signal; and

determining two second corresponding clock signals within one period of the

first clock signal, wherein the 1st second clock signal controls the first electrode plate

of the currently communicating to-be-tested MEMS acceleration sensor chip to

communicate with the capacitance testing apparatus, and a rising edge of the 2nd

second clock signal enables the first clock signal to overturn so as to control the third

electrode plate of the currently communicating to-be-tested MEMS acceleration

sensor chip to communicate with the capacitance testing apparatus.