Probes and methods of making the same

Abstract

The present disclosure provides a probe and a manufacturing method thereof, wherein the probe comprises: a needle smooth region located at a tapered region of a needle of the probe and having an axial length of the probe selected from 10 microns to 15 microns for forming electrical contact with a test pad on a wafer; and an annular rough region adjacent to the needle smooth region and having a rough structure on a surface thereof for forming mechanical anchoring force with a surface of the test pad under contact pressure to resist lateral slip; wherein a surface roughness of the needle smooth region is less than or equal to 0.1 microns; the rough structure is a pit and / or a groove, and a surface roughness of the annular rough region is greater than or equal to 2 microns. By using the above technical solution, the contact reliability between the probe and the test pad can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of wafer testing technology, and in particular to a probe and a method for manufacturing the same. Background Technology

[0002] In the field of semiconductor wafer testing, wafer acceptance test (WAT) is a critical process after wafer fabrication. As a micron-level contact element connecting the test equipment and the wafer chip, the contact stability between the probe tip and the test pad directly affects the accuracy and repeatability of the test signal.

[0003] However, the tip surface of traditional probes is usually electroplated or polished, resulting in a relatively smooth surface. Due to factors such as the inherent slight vibrations of the testing equipment, thermal expansion caused by temperature changes, and the tendency of the test pad surface to form a high-hardness oxide layer, the smooth tip surface has a low coefficient of friction with the oxide layer under contact pressure, making it prone to lateral slippage.

[0004] Therefore, how to provide technical solutions to improve the contact reliability between the probe and the test pad has become an urgent technical problem to be solved. Summary of the Invention

[0005] In view of this, embodiments of the present disclosure provide a probe and a method for manufacturing the same, which can improve the contact reliability between the probe and the test pad.

[0006] This disclosure provides a probe, comprising: a smooth region located in the tapered region of the probe tip, with a length selected from 10 micrometers to 15 micrometers along the axial direction of the probe, for forming electrical contact with a test pad on a wafer; and an annular rough region adjacent to the smooth region, having a rough surface structure for forming a mechanical anchoring force with the surface of the test pad under contact pressure to resist lateral slippage; wherein the surface roughness of the smooth region is less than or equal to 0.1 μm; the rough structure is a pit and / or a groove, and the surface roughness of the annular rough region is greater than or equal to 2 μm.

[0007] Optionally, the rough structure is a regularly arranged pit and / or groove, the depth of the pit and / or groove is selected from 0.5 μm to 5 μm, the top opening width of the pit and / or groove is selected from 0.5 μm to 5 μm, and the spacing between adjacent pits and / or grooves is selected from 2 μm to 8 μm.

[0008] Optionally, the length of the annular rough region along the axial direction of the probe is greater than or equal to 10 micrometers.

[0009] Optionally, the probe surface is coated with a conductive coating, the material of which is one or a combination of boron-doped polycrystalline diamond, nanocrystalline nickel-cobalt alloy, or conductive silicon carbide.

[0010] Optionally, the rough structure is a groove, and the extension direction of the groove is parallel to the axial direction of the probe.

[0011] This disclosure also provides a probe manufacturing method, comprising: providing a probe substrate; forming a conductive plating layer on the surface of the probe substrate to obtain a smooth needle tip region; wherein the smooth needle tip region is located in the conical region of the needle tip of the probe substrate, and its length along the axial direction of the probe substrate is selected from 10 micrometers to 15 micrometers; roughening a ring-shaped region adjacent to the smooth needle tip region to form a rough structure in the ring-shaped region to obtain a ring-shaped rough region; wherein the surface roughness of the smooth needle tip region is less than or equal to 0.1 μm; the rough structure is a pit and / or a groove, and the surface roughness of the ring-shaped rough region is greater than or equal to 2 μm.

[0012] Optionally, the roughened structure is a pit and / or a groove; the roughening process includes: coating a protective layer on the surface of the probe substrate; processing the annular region by sputtering or wet etching to form pits and / or grooves; and removing the protective layer to obtain the smooth area of ​​the probe tip and the annular roughened area.

[0013] Optionally, the roughened structure is a pit and / or a groove; the roughening treatment method includes one or more combinations of mechanical imprinting, laser micromachining, electrical discharge machining or focused ion beam machining; wherein, the mechanical imprinting is to use a diamond mold with an opposite roughened structure to the roughened structure to imprint pits and / or grooves in the annular region to obtain the smooth area of ​​the needle tip and the annular roughened area.

[0014] Optionally, the conductive coating is made of one or more of the following materials: boron-doped polycrystalline diamond, nanocrystalline nickel-cobalt alloy, conductive silicon carbide, diamond-like carbon, titanium nitride, tungsten carbide, or nickel-phosphorus alloy; the probe substrate is made of one or more of the following materials: tungsten, rhenium-tungsten alloy, or beryllium-copper alloy.

[0015] Optionally, the rough structure is a groove, and the extension direction of the groove is parallel to the axial direction of the probe substrate.

[0016] Compared with the prior art, the technical solution of the present disclosure has the following advantages: The probe and its manufacturing method provided in this disclosure include: a smooth region located in the conical region of the probe tip, with a length selected from 10 micrometers to 15 micrometers along the axial direction of the probe, for forming electrical contact with a test pad on a wafer; and an annular rough region adjacent to the smooth region, having a rough surface structure for forming a mechanical anchoring force with the surface of the test pad under contact pressure to resist lateral slippage; wherein the surface roughness of the smooth region is less than or equal to 0.1 μm; the rough structure is a pit and / or a groove, and the surface roughness of the annular rough region is greater than or equal to 2 μm. The smooth area of ​​the probe tip, located within a conical region with a surface roughness not exceeding 0.1 μm, ensures a stable, low-resistance ohmic contact with the test pad surface when the probe is pressed down, guaranteeing the accuracy and repeatability of electrical signal acquisition. The annular rough area, arranged axially adjacent to the smooth area, has a surface roughness (pits and / or grooves) of at least 2 μm under contact pressure. This rough structure penetrates the oxide layer of the test pad surface and embeds into the pad body, generating a mechanical anchoring force to resist lateral slippage. The axial length of the smooth area (10 to 15 micrometers) ensures a reasonable distance between the electrical contact area and the anti-slip area, preventing interference and avoiding any impact of the rough structure on signal acquisition in the electrical contact area. Therefore, the probe improves the contact reliability between the probe and the test pad. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments disclosed in this specification, the drawings used in the description of the embodiments disclosed in this specification or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a probe according to an embodiment of the present disclosure; Figure 2 This is a partially enlarged schematic diagram of the rough structure of a probe in an embodiment of this disclosure; Figure 3 and Figure 4 This is a schematic diagram of another probe in an embodiment of this disclosure; Figure 5 This is a schematic flowchart of a probe manufacturing method according to an embodiment of the present disclosure. Detailed Implementation

[0019] The technical solutions described herein will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of this disclosure and are used to illustrate the concept of this disclosure. These descriptions are illustrative and exemplary and should not be construed as limiting the implementation methods or the scope of protection of this disclosure. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0020] It should be noted that the accompanying drawings in this embodiment are schematic diagrams used to illustrate the concept of this disclosure, and to schematically show the shape and interrelationship of each part. It should be understood that, in order to clearly show the structure of each component of this disclosure, the drawings are not drawn to the same scale, and the same reference numerals are used to indicate the same parts in the drawings.

[0021] As described in the background section, in the field of semiconductor wafer testing, wafer acceptance test (WAT) is a key process after wafer fabrication. As a micron-level contact element connecting the testing equipment and the wafer chip, the contact stability between the probe tip and the test pad directly affects the accuracy and repeatability of the test signal.

[0022] However, the tip surface of traditional probes is usually electroplated or polished, resulting in a relatively smooth surface. Due to factors such as the inherent slight vibrations of the testing equipment, thermal expansion caused by temperature changes, and the tendency of the test pad surface to form a high-hardness oxide layer, the smooth tip surface has a low coefficient of friction with the oxide layer under contact pressure, making it prone to lateral slippage.

[0023] Therefore, how to provide technical solutions to improve the contact reliability between the probe and the test pad has become an urgent technical problem to be solved.

[0024] The probe and its manufacturing method provided in this disclosure include: a smooth region located in the conical region of the probe tip, with a length selected from 10 micrometers to 15 micrometers along the axial direction of the probe, for forming electrical contact with a test pad on a wafer; and an annular rough region adjacent to the smooth region, having a rough surface structure for forming a mechanical anchoring force with the surface of the test pad under contact pressure to resist lateral slippage; wherein the surface roughness of the smooth region is less than or equal to 0.1 μm; the rough structure is a pit and / or a groove, and the surface roughness of the annular rough region is greater than or equal to 2 μm. The smooth area of ​​the probe tip, located within a conical region with a surface roughness not exceeding 0.1 μm, ensures a stable, low-resistance ohmic contact with the test pad surface when the probe is pressed down, guaranteeing the accuracy and repeatability of electrical signal acquisition. The annular rough area, arranged axially adjacent to the smooth area, has a surface roughness (pits and / or grooves) of at least 2 μm under contact pressure. This rough structure penetrates the oxide layer of the test pad surface and embeds into the pad body, generating a mechanical anchoring force to resist lateral slippage. The axial length of the smooth area (10 to 15 micrometers) ensures a reasonable distance between the electrical contact area and the anti-slip area, preventing interference and avoiding any impact of the rough structure on signal acquisition in the electrical contact area. Therefore, the probe improves the contact reliability between the probe and the test pad.

[0025] To make the above-described objects, features and advantages of this disclosure more apparent and understandable, the disclosure is illustrated below with reference to the accompanying drawings.

[0026] See Figure 1 , Figure 1 This is a schematic diagram of a probe according to an embodiment of the present disclosure.

[0027] like Figure 1 As shown, in this embodiment, the probe includes a smooth needle tip region 110.

[0028] The smooth area 110 of the probe tip is located in the tapered area of ​​the probe tip and has a length along the axial direction of the probe selected from 10 micrometers to 15 micrometers, for forming electrical contact with the test pads on the wafer.

[0029] Specifically, the length of the smooth area 110 along the axial direction of the probe is the distance extending axially from the tip of the probe towards the root of the probe. Figure 1 The dashed line F passes through the central axis of the probe, and the axial direction of the probe is... Figure 1 The direction indicated by the dashed line F. In this embodiment, the needle smoothing region 110 is located in the conical region of the probe tip, that is, the needle smoothing region 110 is disposed near the tip surface of the probe and extends axially from the tip surface towards the root.

[0030] The surface roughness of the smooth area 110 of the needle tip is less than or equal to 0.1 μm.

[0031] The surface roughness of the smooth area 110 of the probe tip is less than or equal to 0.1 μm, meaning that the smooth area 110 of the probe tip is a smooth surface. This smooth surface can be obtained through electroplating, polishing, or other surface leveling treatments. When the probe presses down to contact the test pad, the smooth area 110 of the probe tip can form a tight fit with the surface of the test pad, ensuring stable electrical contact, reducing contact resistance, and thus ensuring the accuracy and repeatability of the electrical signal acquisition.

[0032] The length of the smooth area 110 along the probe axis is selected from 10 micrometers to 15 micrometers, for example, it can be 10μm, 11μm, 12μm, 13μm, 14μm or 15μm. Limiting it to the range of 10μm to 15μm can ensure both stable electrical contact and effective anti-slip anchoring.

[0033] In some embodiments, the surface of the smooth area 110 of the needle tip is a polished conductive plating surface.

[0034] Specifically, the probe surface is coated with a conductive coating, the material of which is one or a combination of boron-doped polycrystalline diamond, nanocrystalline nickel-cobalt alloy, or conductive silicon carbide. By providing a conductive coating on the surface of the smooth area 110 of the probe tip, the conductivity and wear resistance of the probe can be further improved, and the service life of the probe can be extended.

[0035] See Figure 2 , Figure 2 This is a partially enlarged schematic diagram of the rough structure of a probe in an embodiment of this disclosure. Figure 2 The diagram within the dashed box is a magnified view of a localized area of ​​the rough structure. Figure 2 Taking a rough structure as an example, H in the figure refers to the groove depth, W refers to the groove width, and L refers to the distance between adjacent grooves.

[0036] See also Figure 1 and Figure 2 In this embodiment, the probe further includes an annular rough region 120.

[0037] The annular rough region 120 is adjacent to the smooth region 110 of the needle tip, and has a rough surface structure to form a mechanical anchoring force with the test pad surface under contact pressure to resist lateral slippage.

[0038] The rough structure is pits and / or grooves.

[0039] The surface roughness of the annular rough region 120 is greater than or equal to 2 μm.

[0040] Specifically, the annular roughened region 120 is disposed on the surface of the probe, adjacent to the smoothed region 110, and arranged circumferentially around the probe. The annular roughened region 120 can be located in the conical region of the probe tip or in the probe body region. The smoothed region 110 extends axially from the tip face towards the root, while the annular roughened region 120 continues axially towards the root from the end of the smoothed region 110 (i.e., the end near the probe root). Thus, the smoothed region 110 and the annular roughened region 120 are arranged sequentially along the probe's axial direction. This ensures that when the probe presses down to contact the test pad, the smoothed region 110 forms electrical contact with the test pad surface, while the annular roughened region 120, through its roughened surface structure, penetrates the test pad surface under contact pressure, generating a mechanical anchoring force, thereby effectively resisting lateral slippage of the probe in the horizontal direction.

[0041] The annular rough region 120 is arranged around the smooth region 110 of the probe tip. The mechanical anchoring force it provides is evenly distributed around the smooth region 110 of the probe tip in the circumference. It can form effective resistance regardless of the direction of the lateral force, thereby improving the contact reliability between the probe and the test pad.

[0042] The surface roughness of the annular rough region 120 is greater than or equal to 2 μm, meaning that the annular rough region 120 is a rough surface. This rough surface is obtained by roughening the surface of the conductive plating layer. The surface roughness of the annular rough region 120, being greater than or equal to 2 μm, ensures that the protruding portions of the rough structure have sufficient height difference to penetrate the oxide layer on the test pad surface and embed into the pad body under contact pressure, increasing friction and forming a reliable mechanical interlocking force, thus effectively suppressing lateral slippage.

[0043] In some embodiments, the rough structure is a regularly arranged pit and / or groove.

[0044] Figure 2 The explanation will be based on a rough structure, specifically a groove.

[0045] like Figure 2As shown, the grooves are regularly arranged on the surface of the annular rough region 120. The groove depth H is selected from 0.5 μm to 5 μm, for example, H can be 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm or 5 μm. The groove width W (i.e., the width of the top opening of the groove) is selected from 0.5 μm to 5 μm, for example, W can be 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm or 5 μm. The spacing L between adjacent grooves is selected from 2 μm to 8 μm, for example, L can be 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm or 8 μm. If the trench depth H is less than 0.5 μm, the trench is too shallow, making it difficult for the test pad material to fully embed into the trench, resulting in insufficient mechanical anchoring force. If the trench depth H is greater than 5 μm, the trench is too deep, which may lead to stress concentration and increase the risk of probe damage. If the trench width W is less than 0.5 μm, the opening is too narrow, making it difficult for the test pad material to enter the trench. If the trench width W is greater than 5 μm, the spacing between adjacent protrusions is too large, reducing the number of protrusions per unit area and decreasing the anchoring effect. If the spacing L between adjacent trenches is less than 2 μm, the protrusions are too dense, and the pressure borne by a single protrusion is insufficient to penetrate the oxide layer. If the spacing L is greater than 8 μm, the number of protrusions is too small, resulting in uneven distribution of mechanical anchoring force and insufficient anti-slip effect. Limiting the trench depth H, width W, and spacing L between adjacent trenches within the above ranges can achieve the optimal mechanical anchoring effect while avoiding damage to the probe.

[0046] When the rough structure is a pit, the depth of the pit, the diameter of the top opening, and the spacing between adjacent pits are also subject to the above numerical range.

[0047] In some embodiments, the annular roughened region 120 has an axial length greater than or equal to 10 micrometers along the probe, for example, it can be 10 μm, 12 μm, 15 μm, 18 μm, 20 μm or larger. The axial length of the annular roughened region 120 is the distance extending axially towards the root of the probe from the end of the smooth probe region 110 (i.e., the end near the probe root). This ensures that the annular roughened region 120 has sufficient axial extension length to provide adequate and reliable anti-slip anchoring when the probe contacts the test pad.

[0048] In some embodiments, the rough structure is a groove, and the groove extends in a direction parallel to the axial direction of the probe.

[0049] See also Figure 2The groove extends along the axial direction of the probe (i.e., the direction shown by the dashed line F in the figure). The extension of the groove along the axial direction of the probe enables the sidewalls of the groove to form an effective mechanical barrier against lateral slippage in the horizontal direction, thereby maximizing the mechanical anchoring force's resistance to lateral slippage.

[0050] In some embodiments, the surface of the annular rough region 120 is covered with a conductive coating, which is integral with the conductive coating on the surface of the smooth region 110 of the needle tip.

[0051] The conductive coating is made of one or more of the following materials: boron-doped polycrystalline diamond, nanocrystalline nickel-cobalt alloy, or conductive silicon carbide. The conductive coating ensures both the conductivity of the annular rough region 120 and provides sufficient hardness to maintain the morphological stability of the rough structure, preventing wear and failure after repeated contact.

[0052] See Figure 1 , Figure 3 and Figure 4 , Figure 3 and Figure 4 This is a schematic diagram of another probe in an embodiment of this disclosure. Figure 3 This illustrates a probe structure with a cylindrical tip. Figure 4 The diagram shows a probe structure with a pyramidal needle tip.

[0053] It should be noted that the "conical region" described in this embodiment does not limit the probe tip to a conical geometry. For example... Figure 1 and Figure 3 As shown, the needle can be cylindrical; as... Figure 4 As shown, the needle tip can also be pyramidal, prismal, etc. In the embodiments of this disclosure, the conical region refers to a portion of the needle tip extending within a predetermined micrometer range along the probe axis F from the tip surface; this region is the functional section where the probe directly contacts the test pad. The shape of the needle tip is not limited, including but not limited to cylindrical shapes (such as...). Figure 1 and Figure 3 As shown), pyramidal (such as) Figure 4 (As shown), conical or prismatic. The smooth area 110 of the needle tip is located within the conical area and extends axially for a predetermined length from the tip of the needle.

[0054] In some embodiments, the probe 100 has a cylindrical tip (see...). Figure 1 and Figure 3 The smooth area 110 of the needle tip extends axially from the tip of the needle.

[0055] In other embodiments, the probe has a prismatic shape (see [reference needed]). Figure 4The probe has multiple side edges and side planes. The smooth area 110 of the probe tip is located within a polygonal area on the tip surface of the probe. The annular rough area 120 is arranged in a ring shape that matches the outer periphery of the prism.

[0056] The annular rough region 120 surrounds the probe body and its shape corresponds to the cross-sectional shape of the probe body, and is continuously distributed along each side plane and outer peripheral surface of the probe body.

[0057] Similarly, the probe 100 has a conical tip shape, with a smooth tip area 110 located at the tip of the cone and an annular rough area 120 encircling the surface of the cone in a circular shape, the shape of which corresponds to the outer circumference of the cone.

[0058] It should be noted that the "annular rough region" referred to in this disclosure is not limited to the region being geometrically circular. For example... Figure 3 and Figure 4 As shown, the annular rough region 120 refers to the continuous region surrounding the probe body, and its specific shape corresponds to the shape of the probe body. When the cross-section of the probe body is circular, the annular rough region 120 is circular (e.g., ...). Figure 1 As shown); when the needle body cross-section is polygonal, the annular rough region 120 is annular in shape matching the outer periphery of the polygon (as shown). Figure 4 (as shown in the prism shape). Regardless of the shape of the outer periphery of the annular rough region 120, its essential characteristic is that the region continuously encircles the probe and is adjacent to the smooth region 110 of the needle tip.

[0059] The roughening structure is disposed on the surface of the annular roughened region 120, changing the microscopic morphology of the surface of the region, rather than changing the overall shape of the annular roughened region 120 or the shape of the probe. In other words, the roughening structure is a microscopic uneven structure (such as pits and / or grooves) formed by roughening the surface of the annular roughened region 120. This roughening structure does not change the macroscopic geometric contour (such as circle, polygon, etc.) of the annular roughened region 120, but forms a microscopic structure on the surface of the macroscopic contour to generate mechanical anchoring force.

[0060] Specifically, regardless of the shape of the probe body, a smooth area 110 and an annular rough area 120 surrounding the smooth area can be formed in the conical region of the probe tip. Thus, when the probe contacts the test pad, stable electrical contact can be achieved through the smooth area 110, and uniform mechanical anchoring force can be provided in all directions through the annular rough area 120 surrounding the probe, achieving an all-directional anti-lateral slippage effect.

[0061] Accordingly, this disclosure also provides a method for manufacturing a probe.

[0062] See Figure 5 , Figure 5 This is a schematic flowchart of a probe manufacturing method according to an embodiment of the present disclosure.

[0063] The method can be performed by steps S201 to S203.

[0064] Step S201: Provide probe substrate.

[0065] Step S202: A conductive plating layer is formed on the surface of the probe substrate to obtain a smooth needle tip area; wherein the smooth needle tip area is located in the conical region of the needle tip of the probe substrate, and the length along the axial direction of the probe substrate is selected from 10 micrometers to 15 micrometers.

[0066] Step S203: Roughen the annular region adjacent to the smooth area of ​​the needle tip to form a rough structure in the annular region, thereby obtaining an annular rough region; wherein the surface roughness of the smooth area of ​​the needle tip is less than or equal to 0.1 μm; the rough structure is a pit and / or a groove, and the surface roughness of the annular rough region is greater than or equal to 2 μm.

[0067] It is understandable that probe manufacturing methods may include more or fewer steps, and the order of the steps may be the same or different.

[0068] In step S201, a probe substrate is provided.

[0069] The probe substrate is used to form the main structure of the probe, providing the probe with mechanical strength and electrical conductivity.

[0070] The probe substrate is made of one or more of tungsten (W), rhenium-tungsten alloy (ReW), or beryllium-copper alloy (BeCu). Tungsten has high hardness, high melting point, and good electrical conductivity, making it suitable for testing scenarios requiring high wear resistance. Rhenium-tungsten alloy, with the addition of rhenium to tungsten, improves tungsten's brittleness, bending strength, and fatigue resistance, making it suitable for WAT testing under high stress and repeated contact. Beryllium-copper alloy has good electrical conductivity and elasticity, making it suitable for probe structures requiring a certain degree of elastic deformation capability.

[0071] The shape and size of the probe substrate are determined according to the type of the actual probe card and the testing requirements.

[0072] The probe substrate can be formed into the desired needle shape through processes such as drawing, wire EDM, precision grinding, or electroforming. The shape of the needle is not limited, and includes, but is not limited to, cylindrical, prismatic, pyramidal, or conical shapes. The length and diameter of the needle are determined according to the design specifications of the probe card, for example, but not limited to: the total length of the needle can be 5mm to 20mm, and the needle diameter can be 20μm to 100μm.

[0073] The probe substrate has a tapered region at the tip. The tapered region refers to the area of ​​the tip extending within a predetermined micrometer range along the axial direction of the probe substrate from the tip surface. This area is the working section for subsequently forming the smooth area and the annular rough area of ​​the tip.

[0074] In some embodiments, after providing the probe substrate, a pretreatment step of the probe substrate may be included. The pretreatment includes, but is not limited to: a cleaning step for removing oil, oxides, and particulate impurities from the surface of the probe substrate to ensure the adhesion between the subsequent coating and the substrate; and a surface activation step for activating the surface of the probe substrate by means of plasma treatment or acid pickling to enhance the adhesion between the coating and the substrate.

[0075] In step S202, a conductive plating layer is formed on the surface of the probe substrate to obtain a smooth needle tip region; wherein the smooth needle tip region is located in the tapered region of the needle tip of the probe substrate, and its length along the axial direction of the probe substrate is selected from 10 micrometers to 15 micrometers.

[0076] Specifically, the conductive coating is formed on the surface of the probe substrate, covering at least the conical region of the probe tip. The conductive coating serves both as a surface layer for the smooth area of ​​the probe tip and as a base layer for subsequent roughening treatment of the annular roughened area. The method of forming the conductive coating is selected according to the chosen material, including but not limited to chemical vapor deposition (CVD), physical vapor deposition (PVD) (such as magnetron sputtering, ion plating), electroplating, or electroless plating.

[0077] The conductive coating is made of one or more of the following materials: boron-doped polycrystalline diamond, nanocrystalline nickel-cobalt alloy, conductive silicon carbide, diamond-like carbon, titanium nitride, tungsten carbide, or nickel-phosphorus alloy.

[0078] Specifically, boron-doped polycrystalline diamond is formed on the probe substrate surface via hot filament chemical vapor deposition (HFCVD) or microwave plasma chemical vapor deposition (MPCVD), with the boron doping concentration controlled between 100 ppm and 50,000 ppm, giving the coating both high hardness and good conductivity. Boron-doped polycrystalline diamond coatings exhibit extremely high wear resistance and chemical inertness, significantly extending probe lifespan and making them suitable for high-frequency testing scenarios. Nanocrystalline nickel-cobalt alloys are formed on the probe substrate surface via pulse electrodeposition. Pulse electrodeposition yields a fine grain structure and a smooth coating surface, facilitating surface quality control in smooth areas of the probe tip. Nanocrystalline nickel-cobalt alloy coatings combine high hardness, good conductivity, and a mature process route, with relatively low cost, making them suitable for large-scale production. Conductive silicon carbide is formed on the probe substrate surface via chemical vapor deposition, achieving conductivity through vanadium or nitrogen doping, or employing a silicon carbide coating combined with surface metallization (such as depositing a nickel / titanium / aluminum composite layer) to ensure good ohmic contact. Conductive silicon carbide coatings possess extremely high hardness and high-temperature resistance, making them suitable for high-temperature testing environments. Diamond-like carbon (DLC) is formed on the probe substrate surface via plasma-enhanced chemical vapor deposition (PECVD) or magnetron sputtering, and its conductivity is improved through metal doping (such as titanium or tungsten doping) or nitrogen doping. DLC coatings exhibit a low coefficient of friction and high hardness, helping to reduce frictional damage between the probe and the test pads. Titanium nitride is formed on the probe substrate surface via magnetron sputtering or ion plating, possessing high hardness and good conductivity, and exhibiting excellent adhesion to substrate materials such as tungsten and rhenium-tungsten alloys.

[0079] The thickness of the conductive coating is selected from 0.5μm to 5μm, for example, 0.5μm, 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, or 5μm. This ensures that the coating has sufficient wear resistance life while avoiding process reliability and dimensional accuracy problems caused by excessive coating thickness.

[0080] In some embodiments, masking techniques are used to control the coverage area of ​​the conductive coating, so that the conductive coating is formed only in the needle-tip tapered region of the probe substrate, without covering other parts of the needle. Alternatively, the conductive coating may cover the entire surface of the probe substrate, or the coating in non-working areas may be removed through subsequent processing.

[0081] The surface roughness of the smooth area of ​​the needle tip is less than or equal to 0.1 μm. To achieve this surface roughness requirement, after the conductive plating layer is formed, the surface of the smooth area of ​​the needle tip can be smoothed by polishing. Polishing methods include, but are not limited to, mechanical polishing, chemical mechanical polishing (CMP), or electrolytic polishing. Polishing removes microscopic protrusions and defects from the plating surface, making the surface roughness Ra of the smooth area of ​​the needle tip less than 0.1 μm, thereby ensuring a tight fit between the smooth area of ​​the needle tip and the test pad, achieving a stable, low-resistance electrical contact.

[0082] In step S203, the annular region adjacent to the smooth area of ​​the needle tip is roughened to form a rough structure in the annular region, thus obtaining an annular rough region.

[0083] The surface roughness of the smooth area of ​​the needle tip is less than or equal to 0.1 μm; the rough structure is a pit and / or a groove, and the surface roughness of the annular rough area is greater than or equal to 2 μm.

[0084] Specifically, the roughening treatment involves machining the surface of the annular region to create a microscopic uneven structure (pits and / or trenches), thereby obtaining a rough surface. The roughening treatment targets the annular region adjacent to the smooth area of ​​the probe tip. The annular region can be the surface of a conductive plating layer or the surface of the probe substrate. After the roughening treatment, the surface roughness of the annular region is greater than or equal to 2 μm, ensuring that the raised portions of the rough structure have sufficient height to penetrate the oxide layer on the test pad surface under contact pressure and generate mechanical anchoring force.

[0085] In some embodiments, the rough structure is a pit and / or a groove.

[0086] The roughening process includes the following steps: A protective layer is coated on the surface of the probe substrate.

[0087] Specifically, the protective layer covers the smooth area of ​​the needle tip to protect its surface morphology from damage during subsequent roughening processes. The protective layer can be made of photoresist, a metal mask layer (such as a nickel or chromium plating), or other etching-resistant materials. When applying the protective layer, a photolithography process or a precision dot coating process is used to ensure that the protective layer only covers the smooth area of ​​the needle tip, while the annular area remains exposed.

[0088] The annular region is treated using sputtering or wet etching to form pits and / or trenches. Sputtering processes (such as ion beam sputtering or radio frequency sputtering) use high-energy particles to bombard the surface of the annular region, removing surface material through physical bombardment and forming an irregular uneven structure. Wet etching uses chemical etchants to selectively etch the surface of the annular region. The appropriate etchant is selected according to the coating material (e.g., nitric acid or hydrochloric acid-based etchants can be used for nickel-cobalt alloys, and oxygen plasma-assisted wet etching can be used for polycrystalline diamond). By controlling the etching time and temperature, the desired pit depth and morphology can be obtained.

[0089] Remove the protective layer to obtain a smooth area of ​​the needle tip and a rough annular area.

[0090] The method for removing the protective layer depends on the material of the protective layer. For example, photoresist can be removed by dissolving it with an organic solvent, while the metal mask layer can be removed by selective chemical stripping. After removing the protective layer, the smooth area of ​​the needle tip is exposed again, and its surface roughness remains less than or equal to 0.1 μm.

[0091] In some embodiments, the roughening structure is pits and / or grooves. The roughening process includes one or more combinations of mechanical imprinting, laser micromachining, electrical discharge machining, or focused ion beam machining. Mechanical imprinting involves using a diamond mold with an inverse roughening structure to imprint pits and / or grooves in an annular region, resulting in a smooth needle tip region and an annular roughened region.

[0092] Specifically, the steps of mechanical imprinting include: preparing a diamond mold with a reverse roughness structure on its surface (i.e., the protrusions on the mold surface correspond to the positions where pits will be formed, and the grooves on the mold surface correspond to the positions where protrusions will be formed); aligning the mold with the annular region; pressing the mold into the conductive plating surface of the annular region under certain pressure and temperature, causing plastic deformation of the plating surface to form pits and / or grooves corresponding to the reverse structure of the mold; and then demolding to obtain the annular roughness region. Before mechanical imprinting, the smooth area of ​​the needle tip also needs to be protected, or the mold design should be used so that the mold only contacts the annular region and not the smooth area of ​​the needle tip. Laser micromachining uses nanosecond or femtosecond lasers to ablate the surface of the annular region. By controlling the laser scanning path and energy density, regularly arranged pits and / or grooves are formed on the surface of the annular region. Electrical discharge machining uses the instantaneous high temperature generated by the discharge to melt or vaporize the surface material of the annular region, thereby forming a rough structure. Focused ion beam processing utilizes a focused high-energy ion beam to scan and bombard the surface of an annular region point by point, removing material through physical sputtering to form precise and controllable pits and / or trench structures. It offers the highest precision and is suitable for probe manufacturing scenarios requiring small batches and high precision. The various processing methods described above can be flexibly selected according to actual production needs (such as batch size, precision requirements, cost budget, etc.), and all can achieve the technical effects of the embodiments disclosed herein.

[0093] In some embodiments, the surface roughness of the smooth area of ​​the needle tip is still less than or equal to 0.1 μm, the surface roughness of the annular rough area is greater than or equal to 2 μm, and the rough structure is pits and / or grooves.

[0094] In some embodiments, by controlling the process parameters of the roughening process (such as sputtering time, etching time, laser power, imprinting depth, etc.), the depth, width and spacing of the pits and / or trenches can be further controlled to meet the following requirements: the depth is selected from 0.5 μm to 5 μm, the top opening width is selected from 0.5 μm to 5 μm, and the spacing between adjacent pits and / or trenches is selected from 2 μm to 8 μm.

[0095] In some embodiments, the rough structure is a groove, and the extension direction of the groove is parallel to the axial direction of the probe substrate.

[0096] Specifically, in wet etching, a mask layer with parallel line patterns can be coated on the surface of the annular region, allowing the etching solution to etch only the areas not covered by the mask, thus forming axially extending parallel trenches. In laser micromachining, the laser scanning path can be controlled to move along the axial direction of the probe substrate, ablating to form axially extending trenches. In mechanical imprinting, the reverse roughening structure on the diamond mold surface has axially extending ridges, which, after imprinting, form axially extending trenches in the annular region. The extension direction of the trenches is parallel to the axial direction of the probe substrate, ensuring that when the probe presses down to contact the test pad, the trench sidewalls effectively mechanically block lateral slippage in the horizontal direction, maximizing the anti-slip effect.

[0097] It is understood that the numbering of steps S201 to S203 is for ease of description only and does not constitute a limitation on the execution order of the method steps. In some embodiments, some operations in steps S202 and S203 can be combined or their order adjusted. For example, after forming a conductive coating on the entire surface of the probe substrate, a smooth region and annular rough region can be formed simultaneously in the conical region of the probe tip through selective roughening treatment. Alternatively, the annular region of the probe substrate can be pre-roughened before forming the conductive coating, allowing the conductive coating to inherit the rough morphology of the substrate. As long as the final probe tip has a smooth region and an annular rough region adjacent to the smooth region, and meets the corresponding surface roughness and structural feature requirements, it falls within the protection scope of this disclosure.

[0098] The foregoing describes several embodiments of the probe and its manufacturing method. The various optional methods described in each embodiment can be combined and cross-referenced without conflict, thereby extending to a variety of possible embodiments. These can all be considered as embodiments disclosed in this disclosure.

[0099] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article indicates that the preceding and following related objects have an "or" relationship.

[0100] In the embodiments of this application, "multiple" refers to two or more.

[0101] The descriptions of "first," "second," etc., appearing in the embodiments of this application are for illustrative purposes and to distinguish the objects being described. They have no order and do not indicate any special limitation on the number of objects in the embodiments of this application. They cannot constitute any limitation on the embodiments of this application.

[0102] While the embodiments disclosed herein are as described above, this disclosure is not limited thereto. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this disclosure; therefore, the scope of protection of this disclosure should be determined by the scope defined in the claims.

Claims

1. A probe, characterized in that, include: A smooth area of ​​the probe tip, located in the tapered region of the probe tip, and with a length selected from 10 μm to 15 μm along the axial direction of the probe, is used to form an electrical contact with the test pads on the wafer. An annular rough region, adjacent to the smooth region of the needle tip, and having a rough surface structure, is used to form a mechanical anchoring force with the surface of the test pad under contact pressure to resist lateral slippage; The surface roughness of the smooth area of ​​the needle tip is less than or equal to 0.1 μm; the rough structure is a pit and / or a groove, and the surface roughness of the annular rough area is greater than or equal to 2 μm.

2. The probe according to claim 1, characterized in that, The rough structure is a regularly arranged pit and / or groove, the depth of which is selected from 0.5 μm to 5 μm, the top opening width of which is selected from 0.5 μm to 5 μm, and the spacing between adjacent pits and / or grooves is selected from 2 μm to 8 μm.

3. The probe according to claim 1, characterized in that, The length of the annular rough region along the axial direction of the probe is greater than or equal to 10 micrometers.

4. The probe according to claim 1, characterized in that, The probe surface is covered with a conductive coating, the material of which is one or a combination of boron-doped polycrystalline diamond, nanocrystalline nickel-cobalt alloy, or conductive silicon carbide.

5. The probe according to claim 1, characterized in that, The rough structure is a groove, and the extension direction of the groove is parallel to the axial direction of the probe.

6. A method for manufacturing a probe, characterized in that, include: Provide probe matrix; A conductive plating layer is formed on the surface of the probe substrate to obtain a smooth needle tip region; wherein the smooth needle tip region is located in the tapered region of the needle tip of the probe substrate, and its length along the axial direction of the probe substrate is selected from 10 micrometers to 15 micrometers; The annular region adjacent to the smooth area of ​​the needle tip is roughened to form a rough structure, resulting in an annular rough region. The surface roughness of the smooth area of ​​the needle tip is less than or equal to 0.1 μm; the rough structure is a pit and / or a groove, and the surface roughness of the annular rough area is greater than or equal to 2 μm.

7. The manufacturing method according to claim 6, characterized in that, The rough structure is a pit and / or a groove; The roughening process includes the following steps: A protective layer is coated on the surface of the probe substrate; The annular region is processed by sputtering or wet etching to form pits and / or trenches; Remove the protective layer to obtain the smooth area of ​​the needle tip and the annular rough area.

8. The manufacturing method according to claim 6, characterized in that, The rough structure is a pit and / or a groove; The roughening process includes one or more of the following: mechanical embossing, laser micromachining, electrical discharge machining, or focused ion beam machining. The mechanical imprinting involves using a diamond mold with a reverse roughness structure to imprint pits and / or grooves in the annular region, thereby obtaining the smooth needle region and the annular rough region.

9. The manufacturing method according to claim 6, characterized in that, The conductive coating material is one or more of the following: boron-doped polycrystalline diamond, nanocrystalline nickel-cobalt alloy, conductive silicon carbide, diamond-like carbon, titanium nitride, tungsten carbide, or nickel-phosphorus alloy. The probe substrate is made of one or more of the following materials: tungsten, rhenium-tungsten alloy, or beryllium-copper alloy.

10. The manufacturing method according to claim 6, characterized in that, The rough structure is a groove, and the extension direction of the groove is parallel to the axial direction of the probe substrate.

Images