A pressure sensing probe system

Abstract

The present invention belongs to the field of ultra-large-scale integrated circuits and semiconductor manufacturing technology, and specifically relates to a pressure sensing probe system, which integrates a slot-type photoelectric sensor, a probe and a digital signal module through a rigid-flex board design, and realizes the stable application of two-wire and four-wire flying probe tests. The system has a flexible probe configuration, and the number and layout of probes can be selected according to test requirements. It also supports unified test software and processes, and simplifies test operations. Through innovative test structure design, the present invention solves the problem of incompatibility between two-wire and four-wire test structures in the prior art, reduces system complexity, improves test accuracy and efficiency, and broadens application scenarios.

Description

Technical Field

[0001] The invention belongs to the technical field of ultra-large-scale integrated circuits and semiconductor manufacturing, and in particular relates to a pressure sensing probe system. Background Art

[0002] The pressure sensing probe system in the prior art is mostly used for flying probe testing, which is based on the principle of contacting the probe with the device under test to perform electrical performance testing. Traditional flying probe test systems mainly support one of the two-wire method or the four-wire method, and the system structure is relatively complex, including multiple components such as hard boards, probes, signal transmission and processing. These systems usually rely on mechanical structures and analog signal transmission to achieve probe positioning and test signal transmission.

[0003] The prior art has several significant defects in flying probe test applications. First, the two-wire method and the four-wire method test structures are incompatible, resulting in insufficient flexibility of the test equipment when facing different test requirements, requiring hardware replacement or complex adjustments. Secondly, the complex system structure not only increases the cost, but also reduces the reliability and stability of the system. In addition, the needle mark pressure control system is complex and expensive, which makes the test cost high. Finally, the application scenarios and functions of the prior art are relatively single, and it is difficult to meet the diverse needs in a multi-functional test environment. Therefore, there is an urgent need for a new type of pressure sensing probe system to solve the problems existing in the prior art. Summary of the invention

[0004] The purpose of the present invention is to provide a pressure sensing probe system to solve the problem that the flying probe test system in the prior art is insufficiently flexible when facing different test requirements, requires hardware replacement or complex adjustments, has high costs and limited reliability.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] The present invention proposes a pressure sensing probe system, the system comprising a rigid-flex board, a probe and a digital signal module;

[0007] The rigid-flex board includes a first rigid board portion for carrying a photoelectric sensor, a second rigid board portion having a sensor signal interface, a through-hole pad and a probe signal interface, and a flexible board portion for connecting the first rigid board portion and the second rigid board portion and for transmitting signals;

[0008] The probe is electrically connected to the digital signal module, and is electrically connected to the probe signal interface through an electrical connection point.

[0009] The digital signal module is electrically connected to the probe and the sensor signal interface, and is used to provide a test signal and process the test output signal based on a preset stroke control algorithm to generate a control signal to control the stroke of the probe.

[0010] Furthermore, the photoelectric sensor is specifically a slot-type photoelectric sensor having a U-shaped slot. During testing, the probe passes through the U-shaped slot and is connected to the device under test. The photoelectric sensor is used to sense the moving distance of the probe and output a corresponding photocurrent signal.

[0011] Further, the electrical connection point includes a first interface portion and a second interface portion, each of which is provided with a through-hole pad for signal transmission and / or single board fixing;

[0012] The electrical connection point is electrically connected to the probe through the conductive pad and the probe lead to implement the probe test mode preconfigured by the system.

[0013] Furthermore, the probe signal interface includes a probe signal input interface and a probe signal output interface, which are respectively used to receive the test output signal and send out the control signal.

[0014] Further, the probe test mode pre-configured by the system includes at least one of the following test configurations:

[0015] Single-probe two-wire test configuration: equipped with two rigid-flex boards, equipped with a conductive gasket 1 connected to the first interface part and the second interface part at the same time, a single probe is electrically connected to the conductive gasket 1 on the single rigid-flex board, one probe is used as an excitation input, and the other probe is used as a receiving output, forming a test loop;

[0016] Dual-probe four-wire test configuration: equipped with two rigid-flex boards, equipped with conductive gasket 2 respectively connected to the first interface part and the second interface part, two conductive gaskets 2 on a single rigid-flex board are electrically connected to two probes, two of which are used as excitation inputs, and the other two probes are used as receiving outputs, forming two independent test loops.

[0017] Furthermore, the digital signal module includes:

[0018] A signal source, used for providing a test signal, including a voltage and / or a current signal;

[0019] A signal processing submodule, used for filtering, amplifying and / or digitizing the test signal and the output signal;

[0020] The digital control submodule is used to process the test output signal based on a preset stroke control algorithm and generate a control signal to adjust the position and / or control the pressure of the probe.

[0021] Furthermore, the preset stroke control algorithm includes:

[0022] Set the initial position d1 of the probe relative to the reference point, set the initial voltage V1 at the initial position d1, define the maximum stroke d2, and determine the needle pressure stroke range |d1|+d2 of the probe;

[0023] According to the percentage of photocurrent output in the photocurrent signal output by the photoelectric sensor, and the output voltage V2, the moving distance of the probe is determined according to the preset formula , where 0.7 is a coefficient used to adjust the displacement calculation results;

[0024] When the moving distance of the probe reaches a preset value, the input and output switches of the probe are controlled to be turned on or off.

[0025] Furthermore, the rigid-flex board is distributed as a "hard-soft-hard" structure, which is used to adjust the structural position of the rigid-flex board to adapt to different probe cantilever structures.

[0026] Furthermore, the system also includes a host computer, which is communicatively connected to the digital signal module and is used for issuing instructions and processing data.

[0027] The beneficial effects of the present invention are:

[0028] The pressure sensing probe system provided by the present invention significantly improves the testing efficiency and accuracy in the field of ultra-large-scale integrated circuits and semiconductor manufacturing. Specifically, by adopting a rigid-flexible board design, digital control of the probe stroke and precise control of the needle mark are achieved, which not only supports two-wire and four-wire flying probe tests, but also has the ability of multi-scenario and multi-functional applications. Among them, the rigid-flexible board includes a hard board part for accurately sensing the moving distance of the probe to ensure that the needle mark is controlled while the needle is pierced, the soft board part is convenient for structural adjustment to adapt to different probe cantilever structures, and the interface hard board is used for signal transmission and connection with the digital control submodule. In addition, the system realizes precise control of the probe stroke through a preset stroke control algorithm, avoids the interference of digital signals on analog signals, thereby extending the service life of the probe and reducing power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the structure of a rigid-flex board in a pressure sensing probe system provided in an embodiment of the present application;

[0030] Figure 2 A schematic diagram of a structure of a conductive gasket in a pressure sensing probe system provided in an embodiment of the present application;

[0031] Figure 3 A schematic diagram of a two-wire method test in a pressure sensing probe system provided in an embodiment of the present application;

[0032] Figure 4 A schematic diagram of a four-wire test in a pressure sensing probe system provided in an embodiment of the present application;

[0033] Figure 5 A system block diagram of a two-wire method test in a pressure sensing probe system provided in an embodiment of the present application;

[0034] Figure 6 A system block diagram of a four-wire method test in a pressure sensing probe system provided in an embodiment of the present application;

[0035] Figure 7 This is a relationship diagram of "photocurrent output percentage-depth distance d" of the slot-type photoelectric sensor in the pressure sensing probe system provided in an embodiment of the present application.

[0036] Explanation of the reference numerals: 10, rigid-flex board; 20, probe; 30, digital signal module; 40, host computer; 50, conductive gasket; 101, first hard board part; 102, soft board part; 103, second hard board part; 104, photoelectric sensor; 105, sensor signal interface; 106, through-hole pad; 106a, first interface part; 106b, second interface part; 107, probe signal interface; 107a, probe signal input interface; 107b, probe signal output interface; 301, signal source; 302, signal processing submodule; 303, digital control submodule; 501, conductive sheet one; 502, conductive sheet two. DETAILED DESCRIPTION

[0037] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0038] Example 1

[0039] like Figure 1-3 As shown, this embodiment proposes a pressure sensing probe system, the system includes a rigid-flexible board 10, a probe 20 and a digital signal module 30; the rigid-flexible board 10 includes a first hard board part 101 for carrying a photoelectric sensor 104, a second hard board part 103 with a sensor signal interface 105, an electrical connection point 106 and a probe signal interface 107, and a soft board part 102 for connecting the first hard board part 101 and the second hard board part 103 and for transmitting signals; the probe 20 is electrically connected to the digital signal module 30, and is electrically connected to the probe signal interface 107 through the electrical connection point 106, the digital signal module 30 is electrically connected to the probe 20 and the sensor signal interface 105, and is used to provide a test signal and process the test output signal based on a preset stroke control algorithm, and generate a control signal to control the stroke of the probe 20.

[0040] In a preferred embodiment of the present invention, the system further includes a host computer 40, which is in communication connection with the digital signal module 30, and is used for issuing instructions and processing data.

[0041] In a preferred embodiment of the present invention, the photoelectric sensor 104 is specifically a slot-type photoelectric sensor having a U-shaped slot. During testing, the probe 20 passes through the U-shaped slot and is connected to the device under test. The photoelectric sensor 104 is used to sense the moving distance of the probe and output a corresponding photocurrent signal.

[0042] Specific as Figure 1 As shown, the rigid-flex board 10 in the present invention is distributed as "hard-soft-hard", that is, a hard board part - a first hard board part 101 for carrying a slot-type photoelectric sensor, wherein the derived pressure sensing signal passes through a soft board part - a soft board part 102, and is connected to a second hard board part 103 carrying a sensor signal interface 105, an electrical connection point 106 and a probe signal interface 107, the probe lead is connected to the electrical connection point 106 of the second hard board part 103, the interface of the pressure sensing signal (sensor signal interface 105) and the probe signal is connected to a back-end digital signal module 30 for logic control and signal processing of the test, and the digital signal module is finally connected to a host computer, and the host computer is used for command issuance and data processing.

[0043] Accordingly, the application principle of the slot photoelectric sensor in the present invention includes: when the probe is working, the structural part generates displacement inside the U-shaped slot of the slot photoelectric sensor. The photoelectric sensor 104 generates an output signal according to the displacement of the probe 20, which is transmitted to the sensor signal interface 105 on the second hard board part 103 through the soft board part 102 for output. The signal is used for input and output of pressure sensing signals and for controlling the probe stroke.

[0044] In a preferred embodiment of the present invention, the electrical connection point 106 includes a first interface portion 106a and a second interface portion 106b, each of which is provided with a through-hole pad for signal transmission and / or single board fixing; the through-hole pad is electrically connected to the probe 20 through a conductive gasket 50 and a probe lead to realize a probe test mode pre-configured by the system.

[0045] It should be noted that the main functions of the through-hole pads in the present invention include: signal transmission: they connect the probe signal input and output interface and the probe lead to realize the transmission of the probe signal; single board fixation: they can also serve as a single board fixation structure to provide mechanical support.

[0046] More specifically, the second hard board portion 103 is provided with an independent first interface portion 106 a and a second interface portion 106 b ; these two interfaces can be connected to probes respectively to implement a two-pin test.

[0047] In a preferred embodiment of the present invention, the probe signal interface 107 includes a probe signal input interface 107a and a probe signal output interface 107b, which are respectively used to receive a test output signal and send a control signal.

[0048] Specific combination Figure 5 and Figure 6 In the test system constructed in the present invention, Probe1, Probe2 and Probe1`, Probe2` are respectively connected to the two ends of the EUT (equipment under test) test point to establish a test loop. The test data is pre-processed by the digital signal module 30 and finally processed by the host computer 40, wherein the sensor signal interface 105 is used for stroke control, and the probe input and output are used to form a detection loop.

[0049] It should be noted that the specific Figure 2 The conductive gasket 50 in the present invention includes two types, such as conductive gasket 1 501 and conductive gasket 2 502 in the figure.

[0050] In a preferred embodiment of the present invention, the probe test mode pre-configured by the system includes at least one of the following test configurations:

[0051] Single-probe two-wire test configuration: two rigid-flex boards 10, a conductive pad 501 connected to the first interface portion 106a and the second interface portion 106b at the same time, a single probe 20 is electrically connected to the conductive pad 501 on the single rigid-flex board 10, one probe is used as an excitation input, and the other probe is used as a receiving output, forming a test loop;

[0052] Dual-probe four-wire test configuration: equipped with two rigid-flex boards 10, equipped with conductive gasket 2 502 respectively connected to the first interface part 106a and the second interface part 106b, the two conductive gaskets 2 502 on a single rigid-flex board 10 are electrically connected to two probes 20, two of which are used as excitation inputs, and the other two probes are used as receiving outputs, forming two independent test loops.

[0053] According to the above embodiment, in specific implementation, different testing methods can be implemented by selecting and connecting different conductive pads 50:

[0054] ① Two-needle four-thread method: specific combination Figure 6 , probe 1 and probe 2 are connected to the two ends of the EUT test point respectively, and two conductive pads 502 are connected to two through-hole pads to form a four-wire test loop for accurately measuring resistance.

[0055] ② Single needle two thread method: specific combination Figure 5 , the probe 1 is connected to one end of the EUT test point, and the conductive pad 501 is connected to two through-hole pads to form a two-wire test loop for measuring resistance or other electrical characteristics.

[0056] In a preferred embodiment of the present invention, the digital signal module 30 includes:

[0057] A signal source 301 is used to provide a test signal, including a voltage and / or current signal;

[0058] The signal processing submodule 302 is used to filter, amplify and / or digitize the test signal and the output signal;

[0059] The digital control submodule 303 is used to process the test output signal based on a preset stroke control algorithm and generate a control signal to adjust the position and / or control the pressure of the probe 20 .

[0060] In a preferred embodiment of the present invention, the preset stroke control algorithm includes:

[0061] The probe 20 is set at an initial position d1 relative to a reference point, an initial voltage V1 is set at the initial position d1, and a maximum stroke d2 is defined to determine the needle pressure stroke range |d1|+d2 of the probe 20;

[0062] According to the percentage of photocurrent output in the photocurrent signal output by the photoelectric sensor 104, and the output voltage V2, the moving distance of the probe is determined according to a preset formula Among them, 0.7 is the coefficient used to adjust the displacement calculation result, which is the coefficient calculated from the characteristic curve of the selected device;

[0063] When the moving distance of the probe 20 reaches a preset value, the input and output switches of the probe 20 are controlled to be turned on or off.

[0064] Exemplary, combined Figure 7 , which is a schematic diagram of the "photocurrent output percentage-depth distance d" of the sensor controlled by the probe stroke. In order to have better linearity, the initial position d1=-0.15, the initial voltage is V1, and the maximum stroke d2=0.15 are set. Therefore, the needle pressure stroke range is 0.3mm, the output voltage is V2, and the formula calculates the displacement , and finally the feedback digital control submodule 303 is used for stroke control.

[0065] like Figure 5 , Figure 6 As shown, it is specifically a test closed-loop system. During the probe insertion process, the sensor feeds back the insertion stroke to the digital control submodule through the above algorithm, which is used to control the opening and closing of the input and output switches of the probe. It can accurately ensure that the flying probe test is performed only after the probe is inserted and stabilized, thereby reducing power consumption and extending service life.

[0066] In a preferred embodiment of the present invention, the rigid-flex board 10 is distributed as a "hard-soft-hard" structure, which is used to adjust the structural position of the rigid-flex board 10 to adapt to different probe cantilever structures.

[0067] It can be understood that the present invention solves the problem of incompatibility between the two-wire method and the four-wire method test structures under flying probe testing in the following ways:

[0068] ①Flexible probe configuration:

[0069] The present invention designs a flexible probe configuration, which can select the number and layout of probes using the two-wire method or the four-wire method according to the test requirements. This design enables the flying probe tester to support both test methods at the same time without replacing hardware or making complex adjustments.

[0070] ② Unified testing software and process:

[0071] The present invention develops a unified test software, which can automatically identify the test requirements and configure the corresponding test methods and processes according to the requirements. Whether it is a two-wire method or a four-wire method, one-key testing can be achieved through the software, thereby simplifying the test process and improving the test efficiency.

[0072] ③Innovative test structure design:

[0073] The invention relates to an innovative test structure design, which can accommodate the test loops and line layouts of the two-wire method and the four-wire method at the same time. Through ingenious circuit design, the structure can achieve compatibility of the two test methods without sacrificing test accuracy.

[0074] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction 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 technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0075] In addition, each functional module 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.

[0076] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A pressure sensing probe system, characterized in that: The system comprises a rigid-flex board (10), a probe (20) and a digital signal module (30); The rigid-flex board (10) comprises a first rigid board portion (101) for carrying a photoelectric sensor (104), a second rigid board portion (103) having a sensor signal interface (105), an electrical connection point (106) and a probe signal interface (107), and a flexible board portion (102) for connecting the first rigid board portion (101) and the second rigid board portion (103) and for transmitting signals; The probe (20) is electrically connected to the digital signal module (30), and is electrically connected to the probe signal interface (107) via an electrical connection point (106), wherein the electrical connection point (106) comprises a first interface portion (106a) and a second interface portion (106b), each of which is provided with a through-hole pad for signal transmission and / or single board fixing; the electrical connection point (106) is electrically connected to the probe (20) via a conductive pad (50) and a probe lead, so as to realize a probe test mode pre-configured by the system; The system pre-configured probe test mode includes at least one of the following test configurations: Single-probe two-wire test configuration: having two rigid-flex boards (10), having a conductive gasket one (501) connected to both the first interface portion (106a) and the second interface portion (106b), the conductive gasket one (501) on the single rigid-flex board (10) being electrically connected to a single probe (20), wherein one probe is used as an excitation input and the other probe is used as a receiving output, thereby forming a test loop; A dual-probe four-wire test configuration: having two rigid-flex boards (10), having conductive gaskets (502) respectively connected to the first interface portion (106a) and the second interface portion (106b), two conductive gaskets (502) on a single rigid-flex board (10) being electrically connected to two probes (20), two of which are used as excitation inputs and the other two probes are used as receiving outputs, thereby forming two independent test loops; The digital signal module (30) is electrically connected to the probe (20) and the sensor signal interface (105), and is used to provide a test signal and process the test output signal based on a preset stroke control algorithm to generate a control signal to control the stroke of the probe (20).

2. A pressure sensing probe system according to claim 1, characterized in that: The photoelectric sensor (104) is specifically a slot-type photoelectric sensor having a U-shaped slot. During testing, the probe (20) passes through the U-shaped slot and is connected to the device to be tested. The photoelectric sensor (104) is used to sense the moving distance of the probe and output a corresponding photocurrent signal.

3. A pressure sensing probe system according to claim 1, characterized in that: The probe signal interface (107) comprises a probe signal input interface (107a) and a probe signal output interface (107b), which are respectively used to receive the test output signal and send out the control signal.

4. A pressure sensing probe system according to claim 1, characterized in that: The digital signal module (30) comprises: A signal source (301), used for providing a test signal, including a voltage and / or current signal; A signal processing submodule (302), used for filtering, amplifying and / or digitizing the test signal and the output signal; The digital control submodule (303) is used to process the test output signal based on a preset stroke control algorithm, and generate a control signal to adjust the position and / or control the pressure of the probe (20).

5. A pressure sensing probe system according to claim 4, characterized in that: The preset stroke control algorithm includes: Setting an initial position d1 of the probe (20) relative to a reference point, setting an initial voltage V1 at the initial position d1, and defining a maximum stroke d2 to determine a needle pressure stroke range |d1|+d2 of the probe (20); According to the photocurrent output percentage in the photocurrent signal output by the photoelectric sensor (104), and the output voltage V2, the moving distance D of the probe is determined according to a preset formula. , where 0.7 is a coefficient used to adjust the displacement calculation results; When the moving distance of the probe (20) reaches a preset value, the input and output switches of the probe (20) are controlled to be turned on or off.

6. A pressure sensing probe system according to claim 1, characterized in that: The rigid-flex board (10) is distributed as a "hard-soft-hard" structure, which is used to adjust the structural position of the rigid-flex board (10) to adapt to different probe cantilever structures.

7. A pressure sensing probe system according to claim 1, characterized in that: The system also includes a host computer (40) which is communicatively connected to the digital signal module (30) and is used for issuing instructions and processing data.

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