WO2018152662A1 - Device and method for testing fingerprint sensor - Google Patents

Abstract

A device (100) and a method for testing a fingerprint sensor, being able to improve test precision. The device (100) comprises: at least one test head (110), each test head (110) comprising a simulated finger (101), a base (102), and a spring (103), the spring (103) being connected between the simulated finger (101) and the base (102) and configured to cushion a force applied by a first support portion (120) to the simulated finger (101); the first support portion (120), the base (102) of each test head (110) being connected to the first support portion (120); and a first driving device (130), configured to drive the first support portion (120), so that the simulated finger (101) of each test head (110) presses a fingerprint sensor corresponding to the position where said test head (110) is located.

Description

Apparatus and method for testing a fingerprint chip Technical field

The present application relates to the field of fingerprint chip testing, and more particularly to an apparatus and method for testing a fingerprint chip.

Background technique

With the advent of fingerprint recognition and mobile payment, capacitive fingerprint chips are experiencing explosive growth. In the process of applying capacitive fingerprint chips, in order to obtain good image quality, fingerprint chips must be tested to determine fingerprint chips. Is it good?

When the fingerprint chip is mass-produced, in consideration of the efficiency problem, it is necessary to simultaneously test a plurality of chips on the entire chip. At present, when the fingerprint sensing area of a plurality of chips is synchronously tested, there are two ways of coupling the analog finger and the plurality of chips: the discrete pressing and the entire conductive adhesive simultaneously contact the plurality of chips. Both of these methods have their shortcomings: 1. Discrete pressing, the pressure of each test head needs to be adjusted separately, and the warpage of the IC will also cause pressure changes; 2. The whole piece of pressing is basically impossible. Control the pressure of each position of the whole board IC and the deformation of the whole piece of conductive rubber. Ultimately, it affects test accuracy.

Summary of the invention

Embodiments of the present application provide an apparatus and method for testing a fingerprint chip, which can improve test accuracy.

In a first aspect, there is provided an apparatus for testing a fingerprint chip, comprising: at least one test head, each test head comprising a dummy finger, a base and a spring, the spring being coupled between the analog finger and the base for Buffering the force of the first support portion on the simulated finger;

The first support portion, the base in each test head is connected to the first support portion;

The first driving device is configured to drive the first supporting portion such that the analog finger in each test head applies pressure to the fingerprint chip corresponding to the position of the test head.

The device for testing a fingerprint chip of the embodiment of the present application can compensate for the pressure difference caused by the surface condition of the chip and the tolerance of the fixture by using a spring structure with a suitable spring coefficient, so that when the whole board fingerprint chip is tested for pressing The pressure on a single chip on the whole board fingerprint chip can meet the test pressure accuracy, which can improve the test accuracy. Moreover, the physical damage of the fingerprint chip can be avoided, and the requirement for the accuracy of the jig can be reduced.

In a possible implementation, the first driving device is a hydraulic or pneumatic device.

By using a hydraulic or pneumatically driven device instead of a conventional motor to push the test head out, the pressure between the analog finger and the fingerprint chip can be guaranteed to be within a certain range, which can avoid the cumbersome procedure of the motor mode that needs to be calibrated, and can also reduce Requirements for structural accuracy.

In a possible implementation, the spring constant of the spring in each test head satisfies the following formula at Kt:

Among them, F1 is the maximum pressure that the fingerprint chip can withstand when the test pressure accuracy is met, F2 is the minimum pressure that the fingerprint chip can withstand when the test pressure accuracy is met, and D is the test head and the bearing subjected to the minimum pressure. The stroke of the maximum pressure test head is in contact with the fingerprint chip.

In a possible implementation, the compression length l of the spring satisfies the following formula:

Wherein, the compression length l of the spring indicates the length at which the spring in the test head subjected to the pressure F1 is compressed under the requirement of the test accuracy.

In a possible implementation, the device may further include:

a second support portion, the first support portion and the second support portion are slidably connected;

a second driving device, configured to apply pressure to the second supporting portion, such that the simulated finger in each test head contacts the fingerprint chip corresponding to the position of the test head, and the simulated finger in each test head Stopping driving the second support portion when contacting the fingerprint chip corresponding to the position of the test head, wherein the first driving device contacts the dummy chip in each test head when contacting the fingerprint chip corresponding to the position of the test head The first support portion is driven such that the analog finger in each test head applies pressure to the fingerprint chip corresponding to the position of the test head.

In a possible implementation, the second drive device is a hydraulic or pneumatic device.

In a possible implementation, the first driving device is a cylinder.

In a possible implementation, the device may further include:

And a controller for controlling the first driving device and the second driving device to drive the first supporting portion and the second supporting portion, respectively.

In a possible implementation, the second drive device is a cylinder.

In a second aspect, a method of testing a fingerprint chip is provided, the method being applicable to any of the possible implementations of the first aspect or the first aspect, the method comprising: the first driving device targeting Pressing the first support portion, the first pressure being equal to a product of a standard pressure and a number of test heads included in the at least one test head;

Determining a pressure parameter corresponding to the fingerprint chip at the location of each test head, the pressure parameter being used to indicate the amount of pressure experienced by the fingerprint chip at the location of each test head.

The method for testing a fingerprint chip in the embodiment of the present application can compensate for the pressure difference caused by the surface condition of the chip and the tolerance of the fixture by using a spring structure with a suitable elastic modulus, thereby making a single chip on the whole fingerprint chip The pressure can withstand the test pressure accuracy, which can improve the test accuracy. Moreover, the physical damage of the fingerprint chip can be avoided, and the requirement for the accuracy of the jig can be reduced.

In a possible implementation, the first driving device is a hydraulic or pneumatic device.

In a possible implementation, the spring coefficient of the spring in each test head satisfies the following formula at Kt:

Among them, F1 is the maximum pressure that the fingerprint chip can withstand when the test pressure accuracy is met, F2 is the minimum pressure that the fingerprint chip can withstand when the test pressure accuracy is met, and D is the test head that bears the minimum pressure and withstands the test. The stroke of the maximum pressure test head is in contact with the fingerprint chip.

In a possible implementation, the compression length l of the spring satisfies the following formula:

Wherein, the compression length l of the spring indicates the length at which the spring in the test head subjected to the pressure F1 is compressed under the requirement of the test accuracy.

In a possible implementation manner, the method may further include: applying, by the second driving device, pressure to the second support portion by using a second pressure to drive the analog finger in each test head and corresponding to the test head The fingerprint chip of the position contacts, and stops driving the second support portion when the dummy finger in each test head comes into contact with the fingerprint chip corresponding to the position of the test head.

In a possible implementation, the second drive device is a hydraulic or pneumatic device.

By using a hydraulic or pneumatically driven second drive device instead of a conventional motor to push the test head out, the pressure between the analog finger and the fingerprint chip can be guaranteed to be within a certain range, and the cumbersome procedure in which the motor mode needs to be calibrated can be avoided. It also reduces the requirement for structural accuracy.

DRAWINGS

1 is a schematic block diagram of an apparatus for testing a fingerprint chip in accordance with one embodiment of the present application.

Figure 2 is a schematic diagram of the force of the chip under test.

Figure 3 is another schematic diagram of the force of the chip under test.

4 is a schematic block diagram of an apparatus for testing a fingerprint chip in accordance with another embodiment of the present application.

FIG. 5 is a schematic flow chart of a method for testing a fingerprint chip according to an embodiment of the present application.

detailed description

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.

FIG. 1 is a schematic block diagram of an apparatus 100 for testing a fingerprint chip according to an embodiment of the present application. It should be understood that the apparatus for testing the fingerprint chip shown in FIG. 1 is only an example, and the apparatus for testing the fingerprint chip of the embodiment of the present application may further include other modules or units, or include functions of the respective modules in FIG. Similar modules, or not all of the modules in Figure 1.

The device 100 includes at least one test head 110, a first support portion 120 and a first drive device 130.

Each test head includes a simulated finger 101, a base 102 and a spring 103. The spring 103 is coupled between the dummy finger 101 and the base 102 for buffering the force of the first support portion 120 on the dummy finger 101. The base 102 in each test head is coupled to the first support portion 120.

When testing the fingerprint chip, the first driving device 130 drives the first support portion 120 such that the analog finger 101 in each of the test heads applies pressure to the fingerprint chip corresponding to the position of the test head.

It should be understood that the test head 110 is detachable, and in use, the test head 110 can be mounted in a test head fixture (not shown) and coupled to the first support portion 120. The first support portion 120 can be part of the test head clamp or can be a separate component. When testing the fingerprint chip, the first driving device 130 drives the first supporting portion 120 to push the test head 110 out of the test head fixture, and simulates a finger to simulate a human hand pressing the fingerprint chip.

It should also be understood that the four test heads shown in FIG. 1 are merely illustrative and that the apparatus 100 may include more or fewer test heads as needed.

Since the fingerprint chip production package is strip-shaped, the warpage caused by the cooling after the completion of the fingerprint chip package cannot be completely avoided, and the warpage may make the heights of the fingerprint chips inconsistent at various positions. That is, the height of a single fingerprint chip is inconsistent. In addition, due to the tolerances of the production and installation of the simulated fingers, the general machining can be guaranteed within ±0.01 mm (mm), but the tolerances of the components due to the multiple components of the fixture will accumulate, and the tolerance of the rubber due to material problems is also very It is difficult to guarantee, so there may be the possibility of tilt and unevenness. These two factors will lead to inconsistent test pressure, which will affect the test accuracy, mistake the bad fingerprint chip for a good fingerprint chip or mistake the good fingerprint chip for a bad fingerprint chip.

Suppose that it is necessary to test the data when the fingerprint chip pressure is 9 N (N), that is, the standard pressure is 9N, and the test pressure accuracy is ±2N. Since there are 4 fingerprint chips in FIG. 1, the first driving device 130 acts on the first The pressure of the support portion 120 should be 36N.

Due to the warpage of the whole chip, as shown in (a) of FIG. 2, the pressures of the four fingerprint chips corresponding to the four test heads from left to right are 13N, 7N, 3N, and 1.7N, respectively. Further, as shown in (b) of FIG. 2, the pressures of the four chips corresponding to the four test heads from left to right are 15N, 5N, 5N, and 15N, respectively. It can be seen that the warpage of the chip causes a large difference in the pressure of the test. After being compensated by the spring, as shown in (c) of FIG. 2, the pressures of the four fingerprint chips corresponding to the four test heads from left to right are 9N, 11N, 11N, and 9N, respectively. Therefore, the pressure difference caused by the warpage of the chip can be compensated by using a spring.

As shown in (a) of FIG. 3, due to the tilt of the chip caused by the jig, the pressures of the four fingerprint chips corresponding to the four test heads from left to right are 3N, 7N, 13N, and 17N, respectively. Since the heights of the test heads are inconsistent, as shown in (b) of FIG. 3, the pressures of the four fingerprint chips corresponding to the four test heads from left to right are 15N, 5N, 15N, and 5N, respectively. It can be seen that the tolerances of the test head production and installation fixtures lead to a large difference in test pressure. After being compensated by the spring, as shown in (c) of FIG. 3, the pressures of the four fingerprint chips corresponding to the four test heads from left to right are 11N, 9N, 9N, and 11N, respectively. Therefore, by using a spring, it is possible to compensate for the pressure difference caused by the production of the test head and the tolerance of the mounting jig.

Therefore, the device for testing the fingerprint chip of the embodiment of the present application can compensate the pressure difference caused by the surface condition of the fingerprint chip and the tolerance of the fixture by using a spring structure with a suitable elastic modulus, thereby making the whole-plate fingerprint chip When the test is pressed, the pressure of a single chip on the whole fingerprint chip can meet the test pressure accuracy, thereby improving the test accuracy. Moreover, the physical damage of the fingerprint chip can be avoided, and the requirement for the accuracy of the jig can be reduced.

Optionally, in the embodiment of the present application, the spring constant Kt of the spring 103 satisfies the following formula:

Wherein F1 is the maximum pressure that the fingerprint chip can withstand when the test pressure accuracy is met, and F2 is the minimum pressure that the fingerprint chip can withstand when the test pressure accuracy is met. That is to say, when testing the fingerprint chip, if the actual pressure of the single fingerprint chip is less than F1 or greater than F2, the test result may be biased, which affects the test accuracy. D is the difference in stroke between the test head subjected to the minimum pressure and the test head subjected to the maximum pressure in contact with the fingerprint chip. The stroke difference is caused by the warpage of the fingerprint chip, the tolerance of the jig (for example, the test head, the test head jig), and the deformation of the jig after long-term use.

By selecting a spring that conforms to the elastic coefficient of formula (1), normal testing of each fingerprint chip under simulated finger pressing can be achieved to avoid damage of the fingerprint chip.

In addition, the compression length l of the spring satisfies the following formula:

It should be understood that the compression length of the spring refers to the length of the spring in the test head that is subjected to the maximum pressure that is compressed under the test accuracy requirements.

For example, the standard pressure of the fingerprint chip test is 90N, the test pressure accuracy is ±10N, then F1=100N, F2=80N. It is expected that the stroke difference between the spring in the test head subjected to the minimum pressure and the spring in the test head subjected to the maximum pressure is 2 mm due to the warpage of the structure and the chip itself, and the elastic coefficient Kt may be selected to be greater than or equal to 10000 N/ The spring of m, and the compression length l of the spring is at most 1 cm.

Alternatively, the first drive device 130 can be a hydraulic or pneumatic device. For example, the first drive device 130 can be a cylinder. In this way, by using a hydraulic or pneumatically driven drive device instead of a conventional motor to push the test head out, it is possible to ensure that the pressure is within a certain range and to avoid damage to the fingerprint chip caused by excessive pressure.

Optionally, the device 100 may further include a second support portion 140 and a second driving device 150. The second drive 150 can also be a hydraulic or pneumatic device. For example, the second drive 150 can be a cylinder similar to the first drive 130.

The second driving device 150 performs the reference acquisition during the fingerprint chip test by driving the second support portion 140. Specifically, the first support portion 130 and the second support portion 140 are slidably connected. a second driving device 150 for applying pressure to the second supporting portion 140 such that the analog finger 101 in each test head contacts the fingerprint chip corresponding to the position of the test head, and the simulated finger in each test head The driving of the second support portion 140 is stopped when the 101 contacts the fingerprint chip corresponding to the position of the test head 110. Wherein, the analog finger 101 of the first driving device 130 in each test head 110 corresponds to The first support portion 120 is driven when the fingerprint chip at the position where the test head 110 is in contact, so that the dummy finger 101 in each test head 110 applies pressure to the fingerprint chip corresponding to the position of the test head 110.

Optionally, the apparatus 100 may further include a controller 160 for controlling the first driving device 130 and the second driving device 150 to drive the first support portion 120 and the second support portion 140, respectively.

4 is a schematic block diagram of an apparatus 200 for testing a fingerprint chip in accordance with another embodiment of the present application. In FIG. 4, the cylinder 210 is a specific implementation of the first drive unit 130 shown in FIG. 1, and the cylinder 260 is a specific implementation of the second drive unit 150 shown in FIG.

When testing the fingerprint chip, it is divided into two phases. The first phase performs the benchmark acquisition, and the second phase starts the test procedure to collect the semaphore.

When the first stage is performed, the entire fingerprint chip 280 is moved to the corresponding position of the test head, and the cylinder 260 is activated. The cylinder 260 is pressurized, so that the entire fingerprint chip 280 to be tested is in contact with the test socket (SOCKET) for reference acquisition.

During the second-stage test, the cylinder 210 pressurizes and drives the slider 220 connected to the first support portion 240 to move upward along the slide rail 230 relative to the second support portion 250, and ejects the test head 110, so that the entire fingerprint chip is The sensor on the 280 surface touches the analog finger. At the same time, the test program is started, the semaphore is collected, and the test result is obtained by testing the internal operation of the program.

The conventional method is to control the pressure by using the motor to control the stroke of the spring after the test head contacts the fingerprint chip, but this method has certain requirements for the mechanical structure and the fingerprint chip warpage, and the device needs to be calibrated to ensure each time. Power is safe and meets testing needs. However, the device for testing the fingerprint chip of the embodiment of the present application can change the thrust of the cylinder by changing the air pressure and the area of the cylinder by using a driving device in the form of a cylinder, thereby eliminating the need for calibration. Moreover, there is no need to calibrate the device when changing the fingerprint chip model. If you change the number of chips tested at the same time, you only need to change the air pressure to change the pressure.

The device embodiments of the present application are described in detail above with reference to FIG. 1 to FIG. 4 . The method embodiments of the present application are described in detail below with reference to FIG. 5 . It should be understood that the method embodiments correspond to the device embodiments, and similar descriptions may be referred to. Device embodiment.

FIG. 5 shows a schematic flow chart of a method for testing a fingerprint chip according to an embodiment of the present application. It should be understood that the method illustrated in Figure 5 can utilize any of the device embodiments described above. As shown in FIG. 5, the method includes: S510, the first driving device drives the first supporting portion with a target pressure, the first pressure is equal to a standard pressure and a test head included in the at least one test head The product of the number.

For example, taking the fingerprint chip currently required to be tested as shown in FIG. 1 as an example, if it is necessary to test the data when the fingerprint chip pressure is 9N, that is, the standard pressure is 9N, the first driving device 130 needs to act on the first support. The pressure of the portion 120 should be 36N, that is, the target pressure is 36N.

S520. Determine a pressure parameter corresponding to the fingerprint chip at the location of each test head, where the pressure parameter is used to indicate the pressure of the fingerprint chip at the location of each test head.

Optionally, the pressure parameter may be a generated capacitance between the fingerprint chip and the corresponding analog finger.

By determining the pressure parameter corresponding to the fingerprint chip at the location of each test head, it can be determined whether the fingerprint chip satisfies a so-called good chip or a bad chip under the test accuracy requirement.

The method for testing a fingerprint chip in the embodiment of the present application can compensate for the pressure difference caused by the surface condition of the chip and the tolerance of the fixture by using a spring structure with a suitable elastic modulus, thereby making a single chip on the whole fingerprint chip The pressure can withstand the test pressure accuracy, which can improve the test accuracy. Moreover, the physical damage of the fingerprint chip can be avoided, and the requirement for the accuracy of the jig can be reduced.

Optionally, before the first driving device drives the first supporting portion with a target pressure, the method may further include:

The second driving device applies pressure to the second supporting portion with a second pressure, driving the analog finger in each test head to contact with a fingerprint chip corresponding to the position of the test head, and in each test head The analog finger stops driving the second support portion when it contacts the fingerprint chip corresponding to the position of the test head.

It should be understood that the second pressure may be a pressure of any magnitude, and generally, the second pressure is less than the first pressure.

Alternatively, the second drive means may be a hydraulic or pneumatic device.

By using a hydraulic or pneumatically driven second drive device instead of a conventional motor to push the test head out, the pressure between the analog finger and the fingerprint chip can be guaranteed to be within a certain range, and the cumbersome procedure in which the motor mode needs to be calibrated can be avoided. It also reduces the requirement for structural accuracy.

It should be understood that the term "and/or" herein is merely an association relationship describing an associated object, indicating that there may be three relationships, for example, A and/or B, which may indicate that A exists separately, and A and B exist simultaneously. There are three cases of B alone. In addition, the character "/" in this article generally indicates that the contextual object is an "or" relationship.

It should be understood that, in the various embodiments of the present application, the size of the sequence numbers of the foregoing processes does not mean the order of execution sequence, and the order of execution of each process should be determined by its function and internal logic, and should not be applied to the embodiment of the present application. The implementation process constitutes any limitation.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods to implement the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present application.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

The functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a separate fingerprint chip. Based on such understanding, the technical solution of the present application or the part contributing to the prior art or the part of the technical solution may be embodied in the form of a software fingerprint chip, which is stored in a storage medium. Including a number of instructions for causing a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the methods described in various embodiments of the present application. Step by step. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like. .

The foregoing is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application. It should be covered by the scope of protection of this application. Therefore, the scope of protection of the present application should be determined by the scope of the claims.

Claims (12)

An apparatus for testing a fingerprint chip, comprising: At least one test head, each test head including a dummy finger, a base and a spring, the spring being coupled between the dummy finger and the base for buffering a force of the first support portion on the simulated finger; The first support portion, the base in each of the test heads is connected to the first support portion; And a first driving device, configured to drive the first supporting portion such that the simulated finger in each of the test heads applies pressure to the fingerprint chip corresponding to the position of the test head. The device of claim 1 wherein said first drive means is a hydraulic or pneumatic device. The apparatus according to claim 1 or 2, wherein the spring constant of the spring in each of the test heads satisfies the following formula at Kt:

Wherein F1 is the maximum pressure that the fingerprint chip can withstand when the test pressure accuracy is met, F2 is the minimum pressure that the fingerprint chip can withstand when the test pressure accuracy is met, and D is the test head that bears the minimum pressure. The difference in stroke between the test head that is subjected to the maximum pressure and the fingerprint chip. The device according to claim 3, wherein the compression length l of the spring satisfies the following formula:

Wherein, the compression length l of the spring indicates the length at which the spring in the test head subjected to the pressure F1 is compressed under the requirement of the test accuracy. The device according to any one of claims 1 to 4, wherein the device further comprises: a second supporting portion, the first supporting portion and the second supporting portion are slidably connected; a second driving device, configured to apply pressure to the second supporting portion, so that the analog finger in each test head is in contact with a fingerprint chip corresponding to a position of the test head, and in each of the test heads Stopping driving the second support portion when the analog finger contacts the fingerprint chip corresponding to the position of the test head, wherein the simulated finger of the first driving device in each test head corresponds to the test head Driving the first support portion when the fingerprint chip of the position contacts, such that the The analog finger in each test head applies pressure to the fingerprint chip corresponding to the location of the test head. The device of claim 5 wherein said second drive means is a hydraulic or pneumatic device. Apparatus according to any one of claims 1 to 4 wherein said first drive means is a cylinder. A method for testing a fingerprint chip, the method being applied to a device for testing a fingerprint chip, the device for testing a fingerprint chip comprising at least one test head, each test head comprising a simulated finger, a base and a spring, the spring being coupled between the dummy finger and the base for buffering a force of the first support portion on the dummy finger, the first support portion, each of the test heads The base is connected to the first supporting portion, and the first driving device is configured to drive the first supporting portion, so that the simulated finger in each test head applies pressure to the fingerprint chip corresponding to the position of the test head , the method includes: The first driving device drives the first support portion at a target pressure, the first pressure being equal to a product of a standard pressure and a number of test heads included in the at least one test head; Determining a pressure parameter corresponding to the fingerprint chip at the location of each of the test heads, the pressure parameter being used to indicate the amount of pressure experienced by the fingerprint chip at the location of each test head. The method of claim 8 wherein said first drive means is a hydraulic or pneumatic device. The method according to claim 8 or 9, wherein the spring constant of the spring in each of the test heads satisfies the following formula at Kt:

Wherein F1 is the maximum pressure that the fingerprint chip can withstand when the test pressure accuracy is met, F2 is the minimum pressure that the fingerprint chip can withstand when the test pressure accuracy is met, and D is the test head that bears the minimum pressure. The difference in stroke between the test head that is subjected to the maximum pressure and the fingerprint chip. The method according to any one of claims 8 to 10, wherein the means for testing the fingerprint chip further comprises a second support portion, the first support portion and the second support portion being slidably connected a second driving device for applying pressure to the second support portion, The method further includes: before the first driving device drives the first support portion with a target pressure, the method further includes: The second driving device applies pressure to the second support portion at a second pressure to drive the each The analog finger in the test head is in contact with the fingerprint chip corresponding to the position of the test head, and stops driving when the analog finger in each test head contacts the fingerprint chip corresponding to the position of the test head Two support parts. The method of claim 11 wherein said second drive means is a hydraulic or pneumatic device.

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