Probe preparation method and probe

Abstract

The invention discloses a preparation method of a probe and the probe, and relates to the technical field of semiconductor manufacturing, and the preparation method of the probe comprises the steps that an alloy sheet is processed into a probe rough blank, the probe rough blank is subjected to pretreatment, and the pretreatment comprises polishing, oil removal and activation; and electroplating the probe rough blank after pretreatment so as to form a plating layer in the tip area of the probe, and carrying out post-treatment on the electroplated probe, the post-treatment comprising cleaning and drying. The probe prepared by the invention has good mechanical performance and electrical performance, and can meet increasingly strict high-precision test requirements.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to a method for preparing a probe and the probe itself. Background Technology

[0002] In the field of semiconductor testing, probes are the core tools for achieving electrical connections between chip pins and test equipment. Their mechanical properties (such as strength, wear resistance, and fatigue resistance) and electrical properties (such as conductivity and contact resistance stability) directly determine the accuracy and reliability of the test results.

[0003] However, the probes produced by traditional preparation methods still need improvement in terms of mechanical and electrical properties. Summary of the Invention

[0004] This application provides a method for preparing a probe, which can improve the mechanical and electrical properties of the probe.

[0005] To achieve the above objectives, in a first aspect, this application proposes a method for preparing a probe, the method comprising: The alloy sheet is processed into a probe blank; The probe blank is pretreated, wherein the pretreatment includes polishing, degreasing and activation; The pretreated probe blank is electroplated to form a coating in the tip region of the probe. The electroplated probe undergoes post-processing, which includes cleaning and drying.

[0006] Optionally, the alloy sheet is made of nickel-cobalt alloy material.

[0007] Optionally, the pretreatment of the probe preform includes: The probe blank is loaded into a polishing drum and polished in a polishing solution; The polished probe blank is immersed in a degreasing solution and then subjected to ultrasonic treatment. The degreased probe blank is then immersed in a sulfuric acid solution for activation treatment.

[0008] Optionally, the electroplating of the pretreated probe blank includes: A photosensitive film is coated on the surface of the pretreated probe blank, and the tip area is exposed. The processed probe is then placed in an electroplating solution to perform electroplating.

[0009] Optionally, the electroplating solution is a rhodium plating solution.

[0010] Optionally, the method further includes: Measure the coating thickness, hardness, and adhesion of the post-processed probe; If any of the coating thickness, hardness, and adhesion does not meet the preset conditions, the probe is polished and re-electroplated.

[0011] Optionally, the coating thickness is 1 to 1.5 micrometers.

[0012] Optionally, the post-processing of the electroplated probe includes: Clean the electroplated probe with deionized water or distilled water. Use photosensitive film cleaning solution to remove the dry film from the unexposed areas of the probe; The probe was washed with hot water and then dried.

[0013] In addition, to achieve the above objectives, in a second aspect, this application also proposes a probe, which is a probe prepared using the probe preparation method provided in the first aspect.

[0014] Optionally, the probe is a MEMS probe.

[0015] One or more technical solutions proposed in this application have at least the following technical effects: The probe blank is fabricated from alloy sheet and pretreated, including polishing, degreasing, and activation. Then, the pretreated blank is electroplated to form a coating on the probe tip region. Following this, the electroplated probe undergoes post-treatment, including cleaning and drying. The probe prepared in this application exhibits excellent mechanical and electrical properties, meeting the increasingly stringent requirements for high-precision testing. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, 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 flowchart illustrating an embodiment of the probe preparation method of this application. Detailed Implementation

[0019] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0020] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0021] This application provides a method for preparing a probe, referring to... Figure 1 , Figure 1 This is a schematic flowchart of an embodiment of the probe preparation method of this application.

[0022] In this embodiment, the probe preparation method includes steps S10 to S40: Step S10: The alloy sheet is processed into a probe blank.

[0023] In some implementations, the alloy sheet is made of a nickel-cobalt alloy. In practice, processing techniques are used to shape the nickel-cobalt alloy into a probe shape that meets design requirements, thus obtaining a probe blank. The size and shape of the probe are precisely designed according to the specific semiconductor testing application scenario to meet the testing needs of different chips and circuits.

[0024] As an example, nickel-cobalt alloy materials include 0–0.08 g / L carbon, 13.5–16 g / L cobalt, 24–27 g / L nickel, 1–1.5 g / L molybdenum, 1.75–2.3 g / L titanium, 0–0.4 g / L aluminum, 0–10 g / L silicon, 0–0.03 g / L phosphorus, and 0–0.02 g / L sulfur. Probes prepared using nickel-cobalt alloy materials possess excellent strength and corrosion resistance, easily withstanding high-frequency contact and testing operations. This allows the probes to maintain stable performance in various complex environments, extending their lifespan and reducing maintenance and replacement costs. Simultaneously, it ensures a stable electrical connection, enabling smooth current transmission between the probe and the chip under test, thereby improving the accuracy and stability of the test signal.

[0025] Step S20: Pretreatment of the probe blank, including polishing, degreasing and activation.

[0026] In some embodiments, the probe preform undergoes pretreatment, including: The probe blank is loaded into a polishing drum and polished in a polishing solution. The polished probe blank was immersed in a degreasing solution and then subjected to ultrasonic treatment. The degreased probe blank is immersed in an acid solution for activation treatment.

[0027] As an example, when polishing the probe blank, the polishing time can be controlled to be 10-15 minutes, the polishing fluid can be a water-based suspension containing 5%-15% alumina abrasive by mass, and the polishing drum speed can be 50-150 rpm.

[0028] As an example, when degreasing the probe blank, it is ultrasonically treated at an ultrasonic frequency of 20kHz-40kHz for 10-15 minutes; wherein the degreasing solution is an alkaline solution with a pH of 9-11, containing 2%-5% sodium hydroxide and 1%-3% sodium carbonate by mass.

[0029] As an example, when activating the probe preform, the activation time is controlled to be 2-3 minutes and the concentration of sulfuric acid solution is 5-15%.

[0030] Step S30: Electroplating is performed on the pretreated probe blank to form a coating in the tip region of the probe.

[0031] In some embodiments, the coating thickness is 1 to 1.5 micrometers.

[0032] In some implementations, the probe is electroplated using a rhodium plating solution. Exemplarily, the rhodium plating solution can be a sulfate-based, phosphate-based, citrate-based, or malonate-based solution. By plating a layer of rhodium onto the probe tip, the extremely high hardness of rhodium, far exceeding that of traditional metals, significantly improves the tip's wear resistance, making it less prone to wear when in contact with the chip, thereby extending the probe's lifespan. Simultaneously, rhodium also possesses excellent electrical conductivity; plating the tip does not negatively impact the probe's electrical performance but rather further optimizes current transmission, ensuring the integrity and accuracy of the test signal. Furthermore, rhodium exhibits exceptional corrosion resistance, remaining stable even in harsh chemical environments. During semiconductor testing, probes may be corroded by various chemicals, and the rhodium plating layer provides strong protection for the tip, preventing chemical corrosion from affecting probe performance and ensuring the probe maintains optimal working condition throughout long-term use.

[0033] In some embodiments, a photosensitive film is coated on the surface of the pretreated probe blank, exposing the tip area; then, the treated probe is placed in an electroplating solution to electroplat the probe.

[0034] As an example, an electroplating system can be used to electroplat probe blanks. This electroplating system includes an electroplating tank, a DC power supply, a probe fixing device, a heating and cooling system, a filtration system, and an automated control system. The electroplating tank contains the plating solution and is equipped with the heating and cooling system, the circulating filtration system, and an anode plate, which is connected to the DC power supply. The probe fixing device can be in the form of rollers or hangers; its function is to fix the probe, ensuring its stable position during the electroplating process and preventing shaking or displacement. The heating and cooling system controls the temperature of the electroplating solution, keeping it within a preset temperature range. The filtration system removes impurities from the electroplating solution, maintaining its purity and preventing impurities from affecting the plating quality. The automated control system monitors and adjusts electroplating parameters in real time, such as current density, voltage, and temperature, ensuring the electroplating process proceeds stably according to the preset parameters.

[0035] Further, step S30 above, which involves electroplating the pretreated probe blank to form a coating in the probe tip region, may include: The pre-treated probe blank is fixed by a probe fixing device, and the probe blank is then immersed in the electroplating tank. The current power supply is started, and the probe blank is electroplated in stages, which are divided into a pre-plating stage and a rapid deposition stage: Pre-plating stage: Connect the positive and negative terminals of the DC power supply to the input terminal of the pulse control module, connect the output terminal of the pulse control module to the anode and cathode of the plating tank, and adopt the pulse plating mode. The duty cycle of the pulse plating is within the preset duty cycle range, and the current density is within the preset first current density range. Rapid deposition stage: DC electroplating mode is adopted, the current density is within the preset second current density range and the voltage is constant.

[0036] Specifically, the DC power supply is adjusted by the pulse control module to output pulse current.

[0037] In some implementations, the electroplating time t1 in the pre-electroplating stage is 2 to 4 minutes, and the electroplating time t2 in the rapid deposition stage is 5 to 8 minutes.

[0038] As an example, the preset duty cycle range is 30%-70%. The first current density range is 0.05A / dm²~0.3A / dm², and the second current density range is 2A / dm²-5A / dm².

[0039] The core of electroplating is to form a dense, uniform, and low-roughness coating by electrochemical deposition on the probe tip area. In the initial stage of traditional DC electroplating, there are few and sparsely distributed crystal nuclei on the substrate surface, which easily form coarse columnar crystals (dendritic crystals), resulting in a rough coating with high porosity.

[0040] In this embodiment, the probe is first pre-plated using pulsed electroplating to control the deposition process through an "on-off" cycle. During the on-off period, a microcurrent drives the reduction of metal ions on the substrate surface. This microcurrent significantly increases the nucleation point density, suppressing abnormal dendrite growth (dendrites require greater driving force), allowing the main plating layer to grow epitaxially on the pre-plated layer and preventing columnar crystal coarsening. During the off-off period, metal ions in the solution diffuse to the crystal nucleus surface, replenishing consumed ions and eliminating concentration polarization, promoting uniform distribution of crystal nuclei. After pre-plating, a uniform conductive substrate is formed on the substrate surface. At this point, the process switches to DC electroplating mode, using a high current density to provide a greater electrochemical driving force. Metal ions are rapidly reduced on the island-like crystal nuclei of the pre-plated layer, rapidly increasing the plating thickness to ensure the target thickness is achieved.

[0041] Step S40: Post-processing of the electroplated probe, including cleaning and drying.

[0042] In some embodiments, post-processing of the electroplated probe includes: Clean the electroplated probe with deionized water or distilled water. Use photosensitive film cleaning solution to remove the dry film from the unexposed areas of the probe; A protective film is formed on the surface of the probe's coating; The probe was washed with hot water and then dried.

[0043] As an example, in the step of cleaning the electroplated probe with deionized water or distilled water, the rinsing process should last for a certain period of time, such as 5-10 minutes, to ensure that most of the electroplating solution residue, impurities, etc. on the probe surface are initially rinsed away.

[0044] As an example, in the step of removing the dry film from the unexposed areas of the probe using a photosensitive film cleaning solution, the soaking time should be determined based on the thickness and adhesion of the photosensitive film, for example, 10-20 minutes. During the soaking process, the cleaning solution can be gently stirred periodically to accelerate the dissolution of the photosensitive film. After soaking, remove the probe and observe it to check whether the dry film in the unexposed areas has been completely removed. If some dry film remains, the probe can be immersed in the cleaning solution again for a period of time, or the remaining areas can be gently brushed with a soft brush, taking care not to scratch the probe surface and coating.

[0045] As an example, the protective film solution can be evenly coated onto the probe's surface using methods such as spraying, dipping, or brushing. If using spraying, a dedicated spray gun should be used, and the spray pressure and atomization effect should be adjusted to ensure the protective film solution evenly covers the probe surface, forming a thin and uniform film. If using dipping, the probe is slowly immersed in the protective film solution for a certain period (e.g., 1-2 minutes), then slowly removed, allowing excess solution to drip off naturally. Brushing is suitable for probes with complex shapes or those requiring focused protection. A soft brush is used to apply the protective film solution gently to the probe surface.

[0046] As an example, place the probe, after the protective film has been cured, along with the cleaning rack into a hot water bath and soak for a certain period of time (e.g., 5-10 minutes). During soaking, the hot water can be stirred appropriately to enhance the cleaning effect. After soaking, remove the probe and gently wipe or blow dry the surface moisture with a clean cloth or compressed air. An oven or hot air circulating drying device can be used to dry the probe. The oven should have good temperature uniformity and ventilation performance to ensure that the probe is heated evenly and dried quickly.

[0047] In some embodiments, the probe preparation method further includes: The thickness, hardness, and adhesion of the coating on the post-processed probe are measured. If any of the coating thickness, hardness, or adhesion fails to meet the preset performance requirements, the probe will be polished and re-electroplated.

[0048] Specifically, based on the actual application requirements of the probe and relevant industry standards, the performance requirements for coating thickness, hardness, and adhesion are clearly defined. For example, when the coating thickness is in the range of 1 to 1.5 micrometers, it is considered to meet the thickness performance requirements.

[0049] If any of the coating thickness, hardness, or adhesion fails to meet the preset performance requirements, the probe will be reworked, i.e., the probe will be polished and re-electroplated. The specific rework steps are as follows: First, use a suitable polishing tool to polish the probe surface to remove the original unqualified coating and ensure that the probe surface is flat, clean, and free of impurities; then, re-electroplat the probe according to step S30 described above to form a coating that meets the quality requirements.

[0050] For example, the thickness of the probe coating can be detected by microscopic observation, X-ray fluorescence analysis or imaging measurement.

[0051] Microscopic observation method: This method involves directly observing the cross-section of the coating using a high-powered microscope to obtain information about the coating thickness. Strict adherence to the microscope's operating specifications is essential to ensure the accuracy of the observation results.

[0052] X-ray fluorescence analysis: This method uses an X-ray fluorescence analyzer to determine the coating thickness by measuring the intensity of X-ray fluorescence, and can also analyze the coating composition. The standard operating procedures of the instrument must be followed during the testing process to ensure the reliability of the data.

[0053] Image measurement method: This method uses image measurement equipment to acquire images of the probe. The acquired images are preprocessed, including grayscale correction and noise filtering, to improve image quality and measurement accuracy. Then, the contour of the object is extracted, and the upper and lower contour lines are identified. The vertical distance between the upper and lower contour lines is calculated, and this vertical distance represents the thickness of the coating.

[0054] For example, the hardness of the coating is tested by the following steps: Place the probe stably on the worktable of the hardness tester, ensuring the probe and hardness needle are perpendicular. Apply a preset force to the hardness tester, causing the hardness needle to contact the probe surface and form an indentation. Read the corresponding hardness value on the hardness tester based on the indentation depth. To improve the accuracy and reliability of the test results, hardness tests can be performed on multiple different locations on the same probe, and the average of the multiple test results can be taken as the final hardness value of the probe coating. Compare the obtained hardness value with the corresponding hardness grade; if the hardness value is lower than the preset hardness grade, it is determined that the hardness performance requirements are not met.

[0055] For example, the adhesion of the coating can be tested by the circular or cross-cut method: Scratch test: Prepare a sample with the same composition and process as the probe coating on tinplate. After the paint film is completely dry (fully dry), determine the adhesion under constant temperature and humidity (temperature (23 ± 2)℃, relative humidity (50 ± 5)%). First, check the needle of the scratch adhesion tester to ensure it remains sharp, and adjust the rotation radius to match the standard radius of 5.25mm. Fix the test sample, slowly move the lifting bar backward so that the tip of the rotating needle gently touches the paint film surface, and then shake the handle clockwise at a uniform speed of (80 - 100) r / min to form a circular line with a length of (7.5 ± 0.5) cm on the paint film surface. After the test, carefully remove paint debris from the scratch with a soft brush, observe the scratch under a 4x magnifying glass, and rate it according to relevant standards. If the adhesion grade is lower than the standard grade, it is judged as not meeting the adhesion performance requirements.

[0056] Cross-cut method: Place the sample stably on a hard and flat surface. Use a specialized cutting tool to make vertical cuts at 90° angles across the sample's coating surface, maintaining uniform force and speed during the cutting process to create a grid pattern with specified intervals (e.g., 1mm or 2mm) on the coating. After cutting, use a soft brush to gently brush back and forth several times along the diagonal of the grid to remove paint debris. Then, precisely place the center point of a 75mm long transparent pressure-sensitive tape on the grid, ensuring the tape direction is parallel to a set of cutting lines. Use your fingers to evenly flatten the tape on the grid, and rub the tape firmly with your fingertips to ensure good contact between the tape and the coating. Within 5 minutes, peel off the tape smoothly and quickly at an angle close to 60° within a preset time period (e.g., 0.5-1.0s), observe the coating peeling, and rate it according to relevant standards. If the adhesion grade is lower than the standard specified grade, it is judged as not meeting the adhesion performance requirements.

[0057] This application also provides a probe, which is a probe prepared using the probe preparation method described in the above embodiments.

[0058] Optionally, the probe is a MEMS probe.

[0059] The probe in this embodiment is made using the above-described probe preparation method. The prepared probe exhibits excellent mechanical properties, electrical properties, and corrosion resistance. It can not only significantly improve the probe's service life and testing performance, but also effectively meet the needs of high-precision electronic testing, providing a reliable solution for fields such as semiconductor manufacturing, microelectronic packaging, and microelectromechanical systems testing.

[0060] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A method for preparing a probe, characterized in that, include: The alloy sheet is processed into a probe blank; The probe blank is pretreated, wherein the pretreatment includes polishing, degreasing and activation; The pretreated probe blank is electroplated to form a coating in the tip region of the probe. The electroplated probe undergoes post-processing, which includes cleaning and drying.

2. The method for preparing the probe as described in claim 1, characterized in that, The alloy sheet is made of nickel-cobalt alloy material.

3. The method for preparing the probe as described in claim 1, characterized in that, The pretreatment of the probe preform includes: The probe blank is loaded into a polishing drum for polishing; The polished probe blank is immersed in a degreasing solution and then subjected to ultrasonic treatment. The degreased probe blank is then immersed in a sulfuric acid solution for activation treatment.

4. The method for preparing the probe as described in claim 1, characterized in that, The electroplating of the pretreated probe blank includes: A photosensitive film is coated on the surface of the pretreated probe blank, and the tip area is exposed. The processed probe is then placed in an electroplating solution to perform electroplating.

5. The method for preparing the probe as described in claim 4, characterized in that, The electroplating solution is a rhodium plating solution.

6. The method for preparing the probe as described in claim 1, characterized in that, The method further includes: The thickness, hardness, and adhesion of the coating on the post-processed probe are measured. If any of the coating thickness, hardness, and adhesion does not meet the preset performance requirements, the probe is polished and then re-electroplated.

7. The method for preparing the probe as described in claim 1, characterized in that, The coating thickness is 1 to 1.5 micrometers.

8. The method for preparing the probe as described in claim 1, characterized in that, The post-processing of the electroplated probe includes: Clean the electroplated probe with deionized water or distilled water. Use photosensitive film cleaning solution to remove the dry film from the unexposed areas of the probe; The probe was washed with hot water and then dried.

9. A probe, characterized in that, The probe is a probe prepared using the probe preparation method described in any one of claims 1 to 8.

10. The probe as claimed in claim 9, characterized in that, The probe is a MEMS probe.

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