Probe protection method based on flexible buffer layer

Abstract

This invention relates to the field of electronic component testing technology, specifically to a probe protection method based on a flexible buffer layer. The method includes: setting a flexible buffer layer with clearance holes on the surface of a test fixture base; the buffer layer being composed of a porous flexible material with resilience; placing the product to be tested above and positioning it on the buffer layer; applying test pressure through a pressing device to compress and deform the buffer layer, causing the probe to extend from the clearance holes for testing; after testing, the buffer layer automatically springs back to its original position, and the clearance holes tend to close, completely blocking the probe tip. This invention utilizes the porous structure to generate a purging effect to clean the test points during the compression stage, and utilizes negative pressure to generate an adsorption effect to collect dust and debris during the rebound stage. Simultaneously, the anti-static material dissipates static electricity. This method achieves three major functions simultaneously—probe scratch prevention, contact interface self-cleaning, and electrostatic protection—without changing the original testing process or adding a driving mechanism, making it suitable for batch online testing production lines.

Description

Technical Field

[0001] This invention relates to the field of electronic component testing technology, and specifically to a probe protection method based on a flexible buffer layer. Background Technology

[0002] In the field of electronic component manufacturing, probe contact testing is a core method for verifying whether the electrical performance of a product meets the standards. Taking flexible printed circuit boards (FPCs) as an example, in their production process, test probes need to form electrical contact with test points (pads) on the surface of the FPC to complete the detection of electrical parameters such as open circuit, short circuit, resistance, and capacitance.

[0003] However, probe-based contact testing has long faced the following technical challenges: 1. Test probes typically have sharp tips to ensure they can pierce the oxide layer or contaminants on the surface of the object under test (DUT) and form reliable electrical contact. However, after testing, when the probe is reset and retracted, the sharp tip remains partially exposed outside the probe hole. During the handling of the product under test, the tip can easily scratch the surface coating or insulation layer, and in severe cases, may even break the inner circuitry, directly rendering the product unusable. This problem is particularly prominent in thin, high-density cabling products such as FPCs.

[0004] Second, during the production process, the surface of the product under test inevitably retains tiny dust particles, fibers, or process residues. These contaminants tend to accumulate near the test points during testing, forming a physical barrier between the probe and the test point. This leads to increased contact resistance or unstable signal transmission, which in turn causes false tests or deviations in test results, increasing test uncertainty and defect rate.

[0005] Third, FPC and other products are extremely sensitive to static electricity. During testing, the contact and separation of probes and test points can easily generate static electricity. Static electricity accumulation may break down the internal circuitry of the product, causing hidden damage or even rendering it unusable. This is especially true for testing ultra-thin high-frequency FPCs, where electrostatic protection requirements are even more stringent.

[0006] To address the aforementioned issues, various improvement solutions have emerged in the existing technology. For example, one solution involves adding an overall protective cover to the surface of the fixture to isolate the probe area from the outside world after testing. However, this solution requires an additional opening and closing drive mechanism, which complicates the fixture structure, significantly increases manufacturing costs, and prolongs the testing cycle of a single product, making it difficult to adapt to the production pace of batch online testing. Summary of the Invention

[0007] The purpose of this invention is to provide a probe protection method based on a flexible buffer layer, which aims to solve the problems of probe tip scratching the surface of the product under test, poor contact caused by the accumulation of contaminants at the test point, and damage to the product due to static electricity accumulation during probe contact testing, while keeping the testing process unchanged and adapting to batch online testing production lines.

[0008] To achieve the above objectives, this application proposes a probe protection method based on a flexible buffer layer, comprising: Step S1: A flexible buffer layer is provided on the surface of the base of the test fixture facing the product to be tested. The flexible buffer layer has clearance holes that correspond one-to-one with the probe holes on the base. The diameter of the clearance holes is larger than the diameter of the test probes, and the clearance holes are coaxial with the probe holes. Step S2: Place the product to be tested on top of the flexible buffer layer, aligning the test points on the product to be tested with the clearance holes and probe holes in the vertical direction. Step S3: Apply test pressure toward the base to the product under test using the pressing device. The flexible buffer layer is compressed and deformed under the test pressure. The test probe extends out from the relief hole and forms electrical contact with the test point of the product under test to perform electrical testing. Step S4: After the test is completed, the test pressure is removed. The flexible buffer layer automatically rebounds and resets due to its own elasticity. The clearance hole tends to close again due to elastic contraction, completely blocking the tip of the test probe inside the clearance hole, thus isolating the tip from the surface of the product to be tested.

[0009] Furthermore, the flexible buffer layer is made of a porous flexible material with resilience, and its thickness is less than the working extension stroke of the test probe. The difference between the aperture of the relief hole and the diameter of the test probe is configured such that when the flexible buffer layer is in a natural rebound state, the relief hole tends to close due to the elastic contraction of the flexible buffer layer, sealing the tip of the test probe inside the relief hole.

[0010] Furthermore, in step S3, when the flexible buffer layer is compressed, the gas in its internal porous structure is discharged, forming an airflow purging effect that blows away loose pollutants around the test point.

[0011] Furthermore, in step S4, when the flexible buffer layer rebounds, a negative pressure is formed inside it, which generates an adsorption effect through the relief holes, drawing tiny dust and debris from the test point surface into the surface or internal pores of the flexible buffer layer.

[0012] Furthermore, the flexible buffer layer is detachably attached to the surface of the test fixture base via an adhesive backing layer, and the flexible buffer layer completely covers the entire surface of the test fixture base facing the product to be tested.

[0013] Furthermore, the flexible buffer layer is made of antistatic foam.

[0014] Furthermore, the thickness of the flexible buffer layer is 0.3–0.5 mm, the working extension stroke of the test probe is 0.5–0.8 mm, and the thickness of the flexible buffer layer is less than the working extension stroke of the test probe, with a difference range of 0.2–0.4 mm.

[0015] Furthermore, the edge of the clearance hole is provided with a guide structure, which is a chamfer or a rounded corner.

[0016] Furthermore, the flexible buffer layer is provided with positioning pin clearance holes for the positioning pins to pass through, and the positions of the positioning pin clearance holes correspond one-to-one with the positions of the positioning pins provided on the base.

[0017] Furthermore, the diameter of the clearance hole is 0.08 to 0.12 mm larger than the diameter of the test probe.

[0018] The advantages of the above technical solutions adopted in this invention compared with the prior art are as follows: 1. This invention utilizes the elastic contraction properties of a flexible buffer layer in its natural state to cause the clearance hole to tend to close when not in a testing state, completely sealing the probe tip within the clearance hole. During the handling of the product to be tested, even if accidental bumps occur, the product surface will only contact the upper surface of the flexible buffer layer, and will not come into contact with the probe tip blocked within the clearance hole. Compared to the existing technology that adds an overall protective cover, this invention achieves reliable automatic probe protection without any moving parts or driving mechanisms, fundamentally solving the problem of probes scratching the product surface.

[0019] 2. This invention fully utilizes the porous structure of the flexible buffer layer. During the compression test, gas is expelled from the porous structure, creating an outward airflow that pre-cleans loose contaminants around the test point. During the rebound test, a negative pressure is created inside the flexible buffer layer, generating an inward adsorption effect that draws tiny dust particles from the test point surface into the surface or internal pores of the flexible buffer layer. This "blow-then-suction" bidirectional airflow self-cleaning mechanism effectively maintains the cleanliness of the test point and significantly reduces contact defects and false test rates caused by dust.

[0020] 3. During the test, after the flexible buffer layer is compressed, its surface facing the product under test forms a tight fit with the area around the test point, forming a local sealed area around the probe. This effectively prevents contaminants from the external environment from entering the test point area during the test, further ensuring the cleanliness of the contact interface and the accuracy of the test results.

[0021] 4. This invention uses antistatic foam as a flexible buffer layer. Throughout the testing process, the flexible buffer layer remains in contact with the surface of the product under test, which can promptly discharge the static electricity generated by friction through the fixture base, avoiding static electricity accumulation that could damage the product. It is especially suitable for testing static-sensitive products such as ultra-thin high-frequency FPCs.

[0022] 5. The method of the present invention only requires adding a flexible buffer layer to the surface of the existing test fixture. It does not require any modification to the main structure of the fixture, nor does it require the addition of an extra drive mechanism or operating steps. It does not change the original test process and cycle time. It is low in cost and easy to promote and implement on existing production lines, and can well adapt to the production needs of batch online testing. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the fixture base structure; Figure 2 This is a schematic diagram of the structure of an elastic foam pad; Figure 3 This is a schematic diagram of the fixture cover plate structure; The components are: 1. Fixture base, 2. Probe hole, 3. Test probe, 4. Spring positioning pin hole, 5. Spring positioning pin, 6. Elastic foam pad, 7. Spring positioning pin clearance hole, 8. Probe extension hole, 9. Fixture cover plate, 10. Cover plate positioning hole. Detailed Implementation

[0024] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0025] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0026] In the description of this application, it should be understood that the terms "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0027] Example 1 This invention provides a probe protection method based on a flexible buffer layer, which is implemented through the following steps.

[0028] Step S1: As Figure 1 As shown, a test fixture base 1 is provided. The fixture base 1 is the supporting body of the test fixture, and has an overall plate-like structure, with its working surface facing the product to be tested. The fixture base 1 has several probe holes 2, which penetrate the thickness direction of the fixture base 1 to accommodate and guide test probes 3. The distribution of the probe holes 2 corresponds one-to-one with the test points on the FPC to be tested. The test probes 3 are inserted into the probe holes 2, with one end electrically connected to external testing equipment via a test lead, and the other end being a sharp needle used to form electrical contact with the test points of the FPC during testing. The working extension stroke of the test probe 3 is 0.6 mm.

[0029] The fixture base 1 is also provided with positioning pin holes 4, and positioning pins 5 are fixed in the positioning pin holes 4. The positioning pins 5 protrude upward perpendicularly to the working surface of the fixture base 1 and are used to pass through the positioning holes on the FPC to achieve precise positioning of the product to be tested. In this embodiment, there are four positioning pins 5, which are respectively set at the four corner positions of the working surface of the fixture base 1.

[0030] like Figure 2 As shown, a flexible buffer layer 6 is provided on the surface of the fixture base 1 facing the product to be tested. The flexible buffer layer 6 has a sheet-like structure, and its shape and size are adapted to the working surface of the fixture base 1, completely covering the entire surface of the fixture base 1 facing the product to be tested. The flexible buffer layer 6 is made of a resilient porous flexible material, preferably antistatic polyurethane foam. This foam has a sheet-like porous structure with uniformly distributed micropores inside. The pore size ranges from 0.01 to 0.1 mm, and the porosity is 30% to 50%. This microporous structure gives the flexible buffer layer 6 excellent resilience, buffering performance, and gas throughput capacity.

[0031] The thickness of the flexible buffer layer 6 is 0.4 mm, which is less than the working extension stroke of the test probe 3 (0.6 mm), with a difference range of 0.2 mm. This ensures that the test probe 3 can completely pass through the flexible buffer layer 6 and reliably contact the FPC test point during testing.

[0032] The flexible buffer layer 6 has relief holes 8 that correspond one-to-one with the probe holes 2. Each relief hole 8 is a through-hole extending through the thickness of the flexible buffer layer 6, and its diameter is larger than the diameter of the test probe 3. Specifically, the diameter of the relief hole 8 is 0.1 mm larger than the diameter of the test probe 3. This difference in diameter ensures that a small gap is maintained between the test probe 3 and the inner wall of the relief hole 8 during expansion and contraction. This not only does not affect the free expansion and contraction of the test probe 3, but also ensures that when the flexible buffer layer 6 is in a natural rebound state, the relief hole 8 tends to close due to the elastic contraction of the flexible buffer layer 6, sealing the tip of the test probe 3 within the relief hole 8.

[0033] To ensure smooth extension and accurate positioning of the test probe 3, the clearance hole 8 is coaxially arranged with the probe hole 2. The edge of the clearance hole 8 is provided with a guide structure, which is a chamfered structure (or a rounded corner structure), to prevent the edge of the hole wall from scratching and wearing the probe surface during the extension and retraction of the test probe 3, and at the same time to guide the extension and retraction of the probe.

[0034] The flexible buffer layer 6 is also provided with a positioning pin avoidance hole 7 for the positioning pin 5 to pass through. The position of the positioning pin avoidance hole 7 corresponds one-to-one with the position of the positioning pin 5, ensuring that the positioning pin 5 can pass smoothly through the flexible buffer layer 6 to position the product to be tested.

[0035] The flexible buffer layer 6 is detachably adhered to the surface of the fixture base 1 via an adhesive backing layer. The adhesive backing layer is an acrylic pressure-sensitive adhesive or a silicone pressure-sensitive adhesive, applied to the back of the flexible buffer layer 6. Release paper covers the outer side of the adhesive backing layer; after removing the release paper, the flexible buffer layer 6 can be adhered and fixed to the surface of the fixture base 1. The adhesive backing layer forms a uniform adhesive interface between the fixture base 1 and the flexible buffer layer 6, ensuring that the flexible buffer layer 6 will not shift or detach during repeated compression and rebound.

[0036] To ensure the accuracy of the pasting position, the mounting surface of the fixture base 1 is provided with positioning marks or positioning grooves, which are used for position reference when pasting the flexible buffer layer 6 to ensure the coaxiality of the clearance hole 8 and the probe hole 2, as well as the alignment accuracy of the positioning pin clearance hole 7 and the positioning pin 5.

[0037] Step S2: Place the FPC to be tested above the flexible buffer layer 6, aligning the positioning holes on the FPC with the positioning pins 5. The positioning pins 5 pass through the positioning holes on the FPC, achieving precise positioning of the FPC. At this time, the test points on the FPC are aligned vertically with the clearance holes 8 on the flexible buffer layer 6 and the probe holes 2 on the fixture base 1.

[0038] Step S3: As Figure 3As shown, a fixture cover plate 9 is provided as a pressing device. The fixture cover plate 9 is disposed above the fixture base 1 and is opposite to the fixture base 1. It can move up and down relative to the fixture base 1 under the drive of external force. The fixture cover plate 9 has a cover plate positioning hole 10 for the positioning pin 5 to pass through, and the position of the cover plate positioning hole 10 corresponds one-to-one with the position of the positioning pin 5.

[0039] During testing, external force drives the fixture cover plate 9 to move downwards, and the positioning pins 5 pass through the positioning pin avoidance holes 7 on the flexible buffer layer 6, the positioning holes on the FPC, and the cover plate positioning holes 10 on the fixture cover plate 9 in sequence, so as to achieve precise alignment of the fixture base 1, the FPC, and the fixture cover plate 9.

[0040] The fixture cover plate 9 continues to press down, applying test pressure to the FPC in the direction of the fixture base 1. Under this test pressure, the flexible buffer layer 6 is compressed, with a compression deformation of 50% of its initial thickness of 0.4 mm, i.e., a compression of 0.2 mm, resulting in a thickness of 0.2 mm after deformation. The test probe 3 extends from the probe hole 2, passes through the clearance hole 8 on the flexible buffer layer 6, and its tip protrudes from the surface of the flexible buffer layer 6 facing the product under test, forming electrical contact with the test point of the FPC. External testing equipment completes the electrical performance test of the FPC through the test probe 3.

[0041] During the compression of the flexible buffer layer 6, the gas in its porous structure is expelled, creating an airflow that blows away loose contaminants (such as fiber debris and dust particles) around the test point. Simultaneously, the surface of the flexible buffer layer 6 facing the product under pressure forms a tight seal with the area surrounding the test point, creating a localized sealed area around the probe, effectively preventing contaminants from the external environment from entering the test point area during the test.

[0042] In addition, throughout the entire test, the flexible buffer layer 6 (antistatic foam) remains in contact with the FPC surface, which can promptly discharge the static electricity generated by friction to the ground wire through the fixture base 1, thus preventing static electricity accumulation from damaging the FPC.

[0043] Step S4: After the test is completed, the external force drives the fixture cover plate 9 to move upward, removing the test pressure on the FPC and the flexible buffer layer 6. The flexible buffer layer 6 quickly rebounds and returns to its initial thickness of 0.4mm due to its own resilience.

[0044] During the rebound process of the flexible buffer layer 6, its internal porous structure expands, forming a negative pressure. Through the clearance pores 8, it generates an inward adsorption effect, sucking the tiny dust and debris on the surface of the test point into the surface or internal pores of the flexible buffer layer 6, thus achieving self-cleaning after the test is completed.

[0045] After the flexible buffer layer 6 fully rebounds, the clearance hole 8 tends to close again due to the elastic contraction of the flexible buffer layer 6, completely blocking the tip of the test probe 3 within the clearance hole 8, with the tip below the side of the flexible buffer layer 6 facing the product under test. At this time, when picking up or placing the FPC, even if there is an accidental bump, the FPC surface will only contact the upper surface of the flexible buffer layer 6, and will not come into contact with the probe tip blocked within the clearance hole 8, thus fundamentally avoiding the problem of the probe scratching the FPC surface cover film and inner layer circuitry.

[0046] At this point, the electrical testing of a single FPC is complete. Repeating steps S2 to S4 above will allow for batch continuous testing.

[0047] Example 2 The difference between this embodiment and Embodiment 1 lies in the material selection and structural parameters of the flexible buffer layer 6.

[0048] The flexible buffer layer 6 is made of antistatic polyethylene foam, with a thickness of 0.3 mm. The working extension stroke of the test probe 3 is 0.7 mm, and the difference between the thickness and the extension stroke is 0.4 mm. The aperture of the clearance hole 8 is 0.08 mm larger than the diameter of the test probe 3. The compression deformation of the flexible buffer layer 6 is 40% of its initial thickness, i.e., a compression of 0.12 mm, resulting in a thickness of 0.18 mm after deformation. The porosity of the flexible buffer layer 6 is 40%–60%, and the micropore diameter ranges from 0.02 to 0.15 mm.

[0049] In this embodiment, the flexible buffer layer 6 is thinner and has higher porosity, resulting in a larger gas throughput during compression and rebound, and a more significant effect on purging and adsorbing contaminants on the test point surface.

[0050] Example 3 The difference between this embodiment and Embodiment 1 lies in the structural design of the clearance hole 8.

[0051] The diameter of the clearance hole 8 is 0.12 mm larger than the diameter of the test probe 3. The guide structure at the edge of the clearance hole 8 is an arc-shaped rounded corner structure with a radius of 0.05 mm. This rounded corner structure can reduce friction and wear on the probe surface coating during the extension and retraction of the test probe 3, thus extending the probe's service life.

[0052] When the flexible buffer layer 6 is in a natural rebound state, the effective aperture of the relief hole 8 is about 0.8 times the diameter of the test probe 3, that is, the elastic contraction of the relief hole 8 is about 0.02mm (the aperture is 0.12mm larger than the probe diameter, and after rebound, the aperture shrinks to 0.02-0.04mm larger than the probe diameter). This ensures that the probe tip is reliably blocked, but also prevents the relief hole 8 from completely closing, which would prevent the probe from being able to pass through smoothly when it extends again.

[0053] Example 4 The difference between this embodiment and Embodiment 1 lies in the coverage area of ​​the flexible buffer layer 6.

[0054] The flexible buffer layer 6 does not completely cover the entire working surface of the fixture base 1, but only covers the area where the test probe 3 is located and a range extending 5-10 mm around it. This partial coverage method is suitable for scenarios where the fixture base 1 has a large area and the probes are concentrated. It can reduce the amount of material used in the flexible buffer layer 6 while ensuring the protective effect, thereby reducing the cost of consumables.

[0055] The flexible buffer layer 6 still has positioning pin avoidance holes 7 for the positioning pin 5 to pass through, ensuring that the positioning pin 5 can pass through smoothly.

[0056] Example 5 The difference between this embodiment and Embodiment 1 lies in the replacement cycle and maintenance method of the flexible buffer layer 6.

[0057] When the flexible buffer layer 6 shows signs of wear, decreased resilience, or excessive accumulation of surface contaminants after long-term use (usually 5,000 to 10,000 tests), it needs to be replaced.

[0058] The specific replacement method is as follows: Remove the old flexible buffer layer 6 from the fixture base 1. Clean the surface of the fixture base 1 with anhydrous ethanol or a lint-free cloth to remove any remaining adhesive and contaminants. After the surface is dry, remove the release paper from the back of the new flexible buffer layer 6. Align and paste the new flexible buffer layer 6 according to the positioning marks on the fixture base 1, ensuring that the clearance hole 8 is coaxial with the probe hole 2 and that the positioning pin clearance hole 7 is accurately aligned with the positioning pin 5. After pasting, use a roller to press evenly to ensure that the adhesive layer is fully bonded to the surface of the fixture base 1.

[0059] The core principle of this invention lies in utilizing the "compression-rebound" physical process of the flexible buffer layer 6 to achieve a triple function: (i) In its natural state, the flexible buffer layer 6, due to its elastic contraction properties, will cause the aperture of the relief hole 8 to tend to shrink (but still slightly larger than the probe diameter). When the test is completed and the test pressure is removed, the flexible buffer layer 6 returns to its natural state, and the relief hole 8 shrinks to its minimum aperture, sealing the probe tip inside the relief hole 8. Since the depth of the relief hole 8 (i.e., the thickness of the flexible buffer layer 6) is greater than the height of the probe tip protruding from the working surface of the fixture base 1, the tip is completely buried inside the relief hole 8 and will not be exposed.

[0060] (ii) The flexible buffer layer 6 has a connected porous structure. Compression stage: The porous structure is compressed, its volume decreases, and internal gas is expelled, generating a positive pressure purging effect. The airflow passes through the clearance holes 8 and micropores towards the test point, dispersing loose contaminants. Rebound stage: The porous structure recovers, its volume increases, and a negative pressure is formed internally, generating an adsorption effect. External airflow carrying tiny dust particles is drawn into the flexible buffer layer 6 through the clearance holes 8 and micropores. This "blow-then-suction" mechanism achieves bidirectional cleaning of the test point.

[0061] (iii) The flexible buffer layer 6 made of antistatic foam material has moderate conductivity (preferably with a surface resistivity of 10). 6 ~10 9 (Ω), which can prevent electrostatic discharge (ESD) damage while slowly dissipating static electricity generated by friction to the ground terminal, avoiding static electricity accumulation.

[0062] The probe protection method based on a flexible buffer layer provided by this invention achieves three major functions simultaneously: automatic probe protection, self-cleaning of test points, and electrostatic discharge by setting a flexible buffer layer with resilience, porosity, and antistatic properties between the test probe and the product under test. This method does not change the original testing process, requires no additional manual operation steps or driving mechanisms, and is low in cost. It can be widely applied to batch online testing production lines for electronic components such as FPCs, PCBs, and semiconductor packages, and has significant industrial practical and economic value.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions 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 this application.

Claims

1. A probe protection method based on a flexible buffer layer, characterized in that, Includes the following steps: Step S1: A flexible buffer layer is provided on the surface of the base of the test fixture facing the product to be tested. The flexible buffer layer has clearance holes that correspond one-to-one with the probe holes on the base. The diameter of the clearance holes is larger than the diameter of the test probes, and the clearance holes are coaxial with the probe holes. Step S2: Place the product to be tested on top of the flexible buffer layer, aligning the test points on the product to be tested with the clearance holes and probe holes in the vertical direction. Step S3: Apply test pressure toward the base to the product under test using the pressing device. The flexible buffer layer is compressed and deformed under the test pressure. The test probe extends out from the relief hole and forms electrical contact with the test point of the product under test to perform electrical testing. Step S4: After the test is completed, the test pressure is removed. The flexible buffer layer automatically rebounds and resets due to its own elasticity. The clearance hole tends to close again due to elastic contraction, completely blocking the tip of the test probe inside the clearance hole, thus isolating the tip from the surface of the product to be tested.

2. The probe protection method based on a flexible buffer layer according to claim 1, characterized in that: The flexible buffer layer is made of a porous flexible material with resilience, and its thickness is less than the working extension stroke of the test probe. The difference between the aperture of the relief hole and the diameter of the test probe is configured such that when the flexible buffer layer is in a natural rebound state, the relief hole tends to close due to the elastic contraction of the flexible buffer layer, sealing the tip of the test probe inside the relief hole.

3. The probe protection method based on a flexible buffer layer according to claim 1, characterized in that: In step S3, when the flexible buffer layer is compressed, the gas in its porous structure is discharged, forming an airflow purging effect that blows away loose pollutants around the test point.

4. The probe protection method based on a flexible buffer layer according to claim 1, characterized in that: In step S4, when the flexible buffer layer rebounds, a negative pressure is formed inside it, which generates an adsorption effect through the relief holes, drawing tiny dust and debris from the test point surface into the surface or internal pores of the flexible buffer layer.

5. The probe protection method based on a flexible buffer layer according to claim 1, characterized in that: The flexible buffer layer is detachably attached to the surface of the test fixture base via an adhesive backing layer, and the flexible buffer layer completely covers the entire surface of the test fixture base facing the product to be tested.

6. The probe protection method based on a flexible buffer layer according to claim 1, characterized in that: The flexible buffer layer is made of anti-static foam.

7. The probe protection method based on a flexible buffer layer according to claim 1, characterized in that: The thickness of the flexible buffer layer is 0.3 to 0.5 mm, the working extension stroke of the test probe is 0.5 to 0.8 mm, and the thickness of the flexible buffer layer is less than the working extension stroke of the test probe, with a difference range of 0.2 to 0.4 mm.

8. The probe protection method based on a flexible buffer layer according to claim 1, characterized in that: The edge of the clearance hole is provided with a guide structure, which is a chamfer or a rounded corner.

9. The probe protection method based on a flexible buffer layer according to claim 1, characterized in that: The flexible buffer layer is also provided with positioning pin avoidance holes for the positioning pins to pass through, and the positions of the positioning pin avoidance holes correspond one-to-one with the positions of the positioning pins on the base.

10. The probe protection method based on a flexible buffer layer according to claim 1, characterized in that: The diameter of the clearance hole is 0.08 to 0.12 mm larger than the diameter of the test probe.

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