Method and system for cleaning pins on demand in chip test

Abstract

The invention discloses a method and a system for on-demand pin cleaning in a chip test. The method comprises the following steps: S101, collecting a defective product recovery rate value, a sensitive Bin value and a contact resistance value in real time; s102, judging whether a pin cleaning triggering condition is met or not; s103, if the pin cleaning triggering condition is met, executing pin cleaning operation; and if not, returning to the step S101. And ideal and appropriate needle cleaning according to needs is realized. In actual factory verification, the probe cleaning frequency can be reduced by 50%, the service life of the probe is prolonged by more than 40%, and good technical and economic benefits are brought.

Description

Technical Field

[0001] This invention relates to the field of testing technology, and in particular to a method and system for on-demand pin cleaning in chip testing. Background Technology

[0002] Semiconductor chip testing includes wafer testing (CP) and final product testing (FT). Both processes require the use of delicate probes (PINs) to connect the circuit board to the chip pins. The reliability of these probe connections (contact impedance, electrical performance, mechanical performance, etc.) plays a crucial role in test yield and efficiency. However, probe connections are susceptible to contamination, particulate matter, oxidation, and other issues. To mitigate this, the probe station and sorting machine typically employ a cleaning function during chip testing. This involves polishing the probe tips with cleaning sandpaper at a specific frequency, pressure, and number of passes to maintain good connection performance. However, this cleaning method is usually performed at a fixed frequency (e.g., once every 100 chips tested). To ensure test yield, this often results in over-cleaning, which cannot be adjusted based on the actual chip contact conditions. This leads to excessive wear and tear on the probes from the sandpaper, reducing their lifespan and increasing consumable costs. Previous studies have shown that approximately 50% of the lifespan of a probe over a length of 6-7 mil (0.1524 mm - 0.1778 mm) is consumed by frequent sandpaper cleaning. How to reduce the frequency of probe cleaning while extending probe lifespan, achieving ideal on-demand cleaning, is a pressing issue that needs to be addressed. Summary of the Invention

[0003] To address the aforementioned deficiencies, the present invention provides a method and system for on-demand pin cleaning in chip testing. This system monitors real-time test result technical indicators (including defective product recovery rate, sensitive bins, contact resistance values, etc.), sets pin cleaning trigger values, and when triggered, controls the equipment to perform pin cleaning operations through the Equipment Automation Platform (EAP), thus achieving ideal on-demand and appropriate pin cleaning.

[0004] The first aspect of this invention provides a method for on-demand pin cleaning during chip testing, comprising: S101: Real-time acquisition of defective product recovery rate, sensitive Bin, and contact resistance value; S102: Determining whether the pin cleaning trigger condition is met; S103: If the pin cleaning trigger condition is met, performing the pin cleaning operation; otherwise, returning to step S101.

[0005] According to an embodiment of the present invention, the real-time acquisition of defective product recovery rate, sensitive Bin, and contact impedance value in S101 includes: reading the defective product recovery rate, sensitive Bin, and contact impedance value based on the data acquired by the acquisition interface.

[0006] According to one embodiment of the present invention, determining whether the needle clearing trigger condition is met in S102 includes: three consecutive... The next step is to determine whether the defective product recovery rate is greater than a first threshold; whether the sensitive Bin is greater than a second threshold; and whether the average contact resistance is greater than a third threshold.

[0007] According to one embodiment of the present invention, determining whether the needle clearing trigger condition is met in S102 further includes: whether the failure rate of the test point contact impedance is greater than a fourth threshold.

[0008] According to one embodiment of the present invention, determining whether the needle clearing trigger condition is met in S102 further includes: whether the defective product recovery rate value of three consecutive tests increases continuously.

[0009] According to one embodiment of the present invention, in step S103, if the needle clearing trigger condition is met, a needle clearing operation is performed; if not, the process returns to step S101: if the needle clearing trigger condition in step S102 is met, a needle clearing command is sent to the device; otherwise, the process returns to step S101.

[0010] A second aspect of this invention provides a system for on-demand pin cleaning during chip testing, comprising: a data acquisition module for real-time acquisition of defective product recovery rate values, sensitive bins, and contact resistance values; a judgment module for determining whether pin cleaning trigger conditions are met; and a pin cleaning module for performing pin cleaning actions according to the pin cleaning trigger conditions. According to one embodiment of the present invention, the acquisition module includes: a first acquisition module for acquiring defective product recovery rate values; a second acquisition module for acquiring sensitive bin values; and a third acquisition module for acquiring contact impedance values.

[0011] According to one embodiment of the present invention, the judgment module includes: a first judgment unit, configured to judge three consecutive times whether the defective product recovery rate value is greater than a first threshold; a second judgment unit, configured to judge whether the sensitive Bin is greater than a second threshold; and a third judgment unit, configured to judge whether the average value of the contact resistance is greater than a third threshold.

[0012] According to one embodiment of the present invention, the judgment module further includes: a fourth judgment unit, used to judge whether the failure rate of the test point contact impedance is greater than a fourth threshold; and a fifth judgment unit, used to judge whether the defective product recovery rate value of three consecutive tests increases continuously.

[0013] A third aspect of the present invention provides an intelligent device, including a transmitter, a receiver, a memory, and a processor; the memory is used to store computer instructions; the processor is used to execute the computer instructions stored in the memory to implement the on-demand pin clearing method in the above chip testing.

[0014] A fourth aspect of the present invention provides a storage medium, comprising: a readable storage medium and computer instructions, wherein the computer instructions are stored in the readable storage medium; the computer instructions are used to implement the on-demand pin clearing method in the above chip testing.

[0015] The beneficial effects provided by this invention are as follows: Monitoring = real-time test results and technical indicators (including recovery rate, sensitive bin, contact resistance CR value, etc.), setting a needle cleaning trigger value, and when triggered, controlling the equipment to perform the needle cleaning operation through the Equipment Automation System Decision Platform (EAP), thus achieving ideal on-demand and moderate needle cleaning. In actual factory verification, it can reduce the needle cleaning frequency by 50% and increase probe life by more than 40%, bringing good technical and economic benefits. Attached Figure Description

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

[0017] Figure 1 This is a graph showing the trend of defective product recovery rate as a function of cleaning frequency, as disclosed in an embodiment of the present invention. Figure 2(a) is a test trajectory diagram of on-demand dynamic pin clearing in chip testing disclosed in an embodiment of the present invention; Figure 2(b) is a graph showing the trend of the sensitive Bin as a function of contact impedance in chip testing according to an embodiment of the present invention. Figure 3 This is a flowchart of the on-demand dynamic pin clearing method for chip testing disclosed in an embodiment of the present invention.

[0018] The accompanying drawings have illustrated specific embodiments of this disclosure, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this disclosure to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0019] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0020] During chip testing, probes may become less connected due to dirt, particulate matter, oxidation, etc., which can lead to a decrease in test yield and efficiency. Therefore, probe cleaning is a necessary means to maintain test quality.

[0021] Pin cleaning is the process of polishing the pin tip with sandpaper. Each pin cleaning will wear down the pin tip. The usable length of a pin is usually around 6mil (0.1524 mm - 0.1778 mm), and its lifespan is 300K-1000K contacts. Excessive pin cleaning will reduce the lifespan and increase the cost of consumables.

[0022] Currently, automated equipment in the industry, such as probe stations and sorting machines, can only be set to a fixed formula, that is, a fixed needle cleaning frequency, such as cleaning once every 100 particles. Although it can be set according to the product, the actual requirements for the needle cleaning frequency are not the same for different products and different batches. There is a lack of data support for manual adjustment according to the product each time.

[0023] In summary, to ensure the stability of testing, the current industry practice of cleaning pins is excessive. The ideal situation is moderate cleaning (i.e., cleaning is only performed when necessary and not when not needed).

[0024] In actual testing projects, extensive data analysis is used to determine the correlation between pin clearing frequency and relevant test metrics, such as... Figure 1 As shown, this includes: First, the recovery rate: as the needle cleaning frequency decreases ( Figure 1 (The yield rate decreased from 100 pieces / test to 300 pieces / test), resulting in a lower initial test yield and a higher defective product recovery rate.

[0025] Secondly, with the decrease in the frequency of needle cleaning, the number of sensitive defective bins in the product increases (e.g., Bin97 in Figure 2).

[0026] Furthermore, the contact resistance CR value: During the test, as the PIN becomes increasingly dirty, sticky with particles, oxidized, etc., the CR value gradually increases, and to a certain extent, it will cause the test to fail.

[0027] Figure 2(a) shows the test status of a certain test wafer. The arrows represent the test trajectory, and the numbers represent CR sampling points. The experimental process is as follows: (1) First, a normal test was performed. When the test reached a certain area, including the prototype area in the upper right corner of Figure 2(a), Bin97Overkill (over-cleaning needle) appeared. The main abnormalities were Site 1, 7, and 8 as shown in Figure 2(b). At this time, 5 sampling points were selected to measure the CR value. The measurement results are shown in the Sample1-Sample5 curve in Figure 2(b).

[0028] (2) Manually perform needle clearing and Bin97 Overkill to eliminate the problem. At this time, select one sampling point to measure the CR value. The measurement result is shown in the NeedleClean curve in Figure 2(b).

[0029] Comparing (1) and (2), it can be seen that the CR value is higher during Bin97 Overkill, and the Sites 1, 7, and 8 with higher CR values ​​match the Sites 1, 7, and 8 of Overkill. After cleaning the needle, the CR value decreases, and the Bin97 failure also disappears.

[0030] During chip testing, probes may become less connected due to dirt, particulate matter, oxidation, etc., which can lead to a decrease in test yield and efficiency. Therefore, probe cleaning is a necessary means to maintain test quality.

[0031] Pin cleaning is the process of polishing the pin tip with sandpaper. Each pin cleaning will wear down the pin tip. The usable length of a pin is usually around 6mil, and its lifespan is 300K-1000K contacts. Excessive pin cleaning will reduce the lifespan and increase the cost of consumables.

[0032] Currently, automated equipment in the industry, such as probe stations and sorting machines, can only be set to a fixed formula, that is, a fixed needle cleaning frequency, such as cleaning once every 100 particles. Although it can be set according to the product, the actual requirements for the needle cleaning frequency are not the same for different products and different batches. There is a lack of data support for manual adjustment according to the product each time.

[0033] In summary, to ensure the stability of testing, the current industry practice of cleaning pins is excessive. The ideal situation is moderate cleaning (i.e., cleaning is only performed when necessary and not when not needed).

[0034] This invention discloses a method for on-demand dynamic pin cleaning in chip testing, such as... Figure 3 As shown. S101: Real-time acquisition of defective product recovery rate, sensitive Bin, and contact resistance value. S102: Determine whether the needle clearing trigger condition is met. S103: If the needle clearing trigger condition is met, execute the needle clearing operation; if not, return to step S101.

[0035] This includes real-time acquisition of defective product recovery rate, sensitive Bin, and contact resistance values; determining whether the needle cleaning trigger condition is met; and executing the needle cleaning operation if the needle cleaning trigger condition is met.

[0036] EAP itself can communicate with the equipment, which typically reports key data periodically or in real time. Specifically, EAP can be used to obtain defect recovery rate values, sensitive bins, and contact resistance values. Taking the Advantest acquisition interface as an example, the defect recovery rate acquisition method reads the summary file after the test or exports it by adding user-defined variables to the T2000 test program. import pandas as pd df = pd.read_csv(" / ftp / result / summary_20240528.csv") recovery_rate = df['GoodDie'].sum() / df['TotalDie'].sum() Collect sensitive bins, including: reading the bin count after the test, identifying abnormally high bin counts (frequency, percentage), and automatically parsing the data exported from an STDF file or .csv file; specifically: bin_count = { "Bin1": 120, "Bin2": 300, "Bin97": 580# is significantly high. } sensitive_bin = max(bin_count, key=bin_count.get)# Return "Bin97" For contact impedance testing, an Open / Short Test is added to the test; most Advantest systems support sampling for each test pin, and the results are imported via Result Data or CSV after the test.

[0037] Determine the platform interface, receive test results, and upload the test results to the execution system. First, obtain the upload interface information, determine whether a key, username, or password is required, and determine the format and type of the data to be received.

[0038] The real-time acquisition of defective product recovery rate, sensitive Bin, and contact resistance value in S101 includes: reading the defective product recovery rate, sensitive Bin, and contact resistance value based on the data acquired by the acquisition interface.

[0039] Three consecutive checks are performed to determine whether the defective product recovery rate is greater than the first threshold; whether the sensitive Bin is greater than the second threshold; and whether the average contact resistance is greater than the third threshold. Finally, the test point contact resistance failure rate is checked to determine whether it is greater than the fourth threshold.

[0040] Does the defective product recovery rate increase continuously across three consecutive tests?

[0041] If the needle clearing trigger condition is met in step S103, the needle clearing operation is performed; otherwise, the process returns to step S101: if the needle clearing trigger condition in step S102 is met, a needle clearing command is sent to the device; otherwise, the process returns to step S101.

[0042] Specifically, for example, setting a trigger threshold: CLEAN_TRIGGER_FAIL_RATE = 5.0 # Defect rate exceeds 5% CLEAN_TRIGGER_OCR_THRESHOLD = 0.05# Contact resistance exceeds 0.05 Ω CLEAN_TRIGGER_OCR_COUNT = 3# The number of OCR errors exceeds 3. CLEAN_TRIGGER_SENSITIVE_BIN = 97# Sensitive Bin Number CLEAN_TRIGGER_SENSITIVE_BIN_COUNT = 100 # More than 100 is abnormal Determine if a needle clearing is triggered: def check_cleaning_needed(fail_rate, ocr_values, bin_counts, sensitive_bin): # Condition 1: High defect rate condition1 = fail_rate>CLEAN_TRIGGER_FAIL_RATE # Condition 2: OCR outlier exceeds the limit ocr_abnormal_count = sum(1 for v in ocr_values ​​if v>CLEAN_TRIGGER_OCR_THRESHOLD) condition2 = ocr_abnormal_count>= CLEAN_TRIGGER_OCR_COUNT # Condition 3: Accumulation of Sensitive Bins bin_count = bin_counts.get(sensitive_bin, 0) condition3 = bin_count>= CLEAN_TRIGGER_SENSITIVE_BIN_COUNT # Comprehensive Judgment trigger = condition1 or condition2 or condition3 return trigger, { "fail_rate_exceeded": condition1, "ocr_abnormal_exceeded": condition2, "sensitive_bin_triggered": condition3, "ocr_abnormal_count": ocr_abnormal_count, "sensitive_bin_count": bin_count } trigger, reasons = check_cleaning_needed( fail_rate=6.2, ocr_values=[0.04, 0.06, 0.05, 0.07, 0.03], bin_counts={1: 1700, 7: 150}, sensitive_bin=7 ) if trigger: print(" Needle clearing triggered! Trigger reason:") if reasons["fail_rate_exceeded"]: print("- Defect rate exceeds standard") if reasons["ocr_abnormal_exceeded"]: print(f"- Number of abnormal contact impedance values: {reasons['ocr_abnormal_count']}") if reasons["sensitive_bin_triggered"]: print(f"- Bin{CLEAN_TRIGGER_SENSITIVE_BIN} Count error: {reasons['sensitive_bin_count']} ") else: print("No need to clear the needle yet, status is normal.") Of course, the cleaning triggering logic can also be linked with the device through the cleaning device API interface documentation, such as the interface protocol, URL or address, request method, parameter requirements, return format and authentication method.

[0043] It can also include other functions, such as a retry mechanism that automatically retryes 3 times after a request fails to ensure reliable and stable triggering; and periodic heartbeat detection that checks whether the needle cleaning device is online every hour to ensure the reliability of the needle cleaning action.

[0044] A second aspect of this invention provides a system for on-demand pin cleaning during chip testing, comprising: a data acquisition module for real-time acquisition of defective product recovery rate values, sensitive bins, and contact resistance values; a judgment module for determining whether pin cleaning trigger conditions are met; and a pin cleaning module for performing pin cleaning actions according to the pin cleaning trigger conditions. According to one embodiment of the present invention, the acquisition module includes: a first acquisition module for acquiring defective product recovery rate values; a second acquisition module for acquiring sensitive bin values; and a third acquisition module for acquiring contact impedance values.

[0045] According to one embodiment of the present invention, the judgment module includes: a first judgment unit, configured to judge three consecutive times whether the defective product recovery rate value is greater than a first threshold; a second judgment unit, configured to judge whether the sensitive Bin is greater than a second threshold; and a third judgment unit, configured to judge whether the average value of the contact resistance is greater than a third threshold.

[0046] According to one embodiment of the present invention, the judgment module further includes: a fourth judgment unit, used to judge whether the failure rate of the test point contact impedance is greater than a fourth threshold; and a fifth judgment unit, used to judge whether the defective product recovery rate value of three consecutive tests increases continuously.

[0047] A third aspect of the present invention provides an intelligent device, including a transmitter, a receiver, a memory, and a processor; the memory is used to store computer instructions; the processor is used to execute the computer instructions stored in the memory to implement the on-demand pin clearing method in the above chip testing.

[0048] A fourth aspect of the present invention provides a storage medium, comprising: a readable storage medium and computer instructions, wherein the computer instructions are stored in the readable storage medium; the computer instructions are used to implement the on-demand pin clearing method in the above chip testing.

[0049] The beneficial effects achieved by this invention are: real-time monitoring of test results and technical indicators (including recovery rate, sensitive bin, contact resistance CR value, etc.), setting a needle cleaning trigger value, and when triggered, controlling the equipment to perform the needle cleaning operation through the Equipment Automation Platform (EAP), thus realizing ideal on-demand and appropriate needle cleaning. In actual factory verification, it can reduce the needle cleaning frequency by 50% and increase probe life by more than 40%, bringing good technical and economic benefits.

[0050] Obviously, the above specific implementation examples are merely illustrative of the application of this method and not intended to limit the implementation. Those skilled in the art can make other variations and modifications based on the above description to study other related issues. Therefore, the scope of protection of this invention should be limited to the scope of the claims.

[0051] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as ROM, RAM, magnetic disk, or optical disk.

[0052] The electronic devices and other embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0053] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, and are not intended to limit them. Although the embodiments of the present invention have 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

[0055] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0056] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method for on-demand needle cleaning in chip testing, characterized by, The method comprises: S101: collecting the defective product recovery rate value, the sensitive Bin and the contact impedance value in real time; S102: determining whether the needle cleaning trigger condition is met; S103: if the needle cleaning trigger condition is met, performing the needle cleaning operation; if not, returning to step S101.

2. The method of claim 1, wherein, The real-time collection of the defective product recovery rate value, the sensitive Bin and the contact impedance value in step S101 comprises: According to the data collected by the collection interface, the defective product recovery rate value, the sensitive Bin and the contact impedance value are read.

3. The method of claim 2, wherein, The determination of whether the needle cleaning trigger condition is met in step S102 comprises: The defective product recovery rate value is determined to be greater than a first threshold value for three times in succession; the sensitive Bin is determined to be greater than a second threshold value; and the average value of the contact impedance is determined to be greater than a third threshold value.

4. The method of claim 2, wherein, The determination of whether the needle cleaning trigger condition is met in step S102 further comprises: The test point contact impedance failure rate is determined to be greater than a fourth threshold value.

5. The method of claim 2, wherein, The determination of whether the needle cleaning trigger condition is met in step S102 further comprises: The defective product recovery rate value is determined to be continuously increasing in three consecutive detections.

6. The method of claim 5, wherein, If the needle cleaning trigger condition is met in step S103, the needle cleaning operation is performed; if not, returning to step S101: If the needle cleaning trigger condition in step S102 is met, a needle cleaning instruction is sent to the device; otherwise, returning to step S101.

7. A system for on-demand needle cleaning in chip testing, characterized by The system comprises: A collection module for collecting the defective product recovery rate value, the sensitive Bin and the contact impedance value in real time; A determination module for determining whether the needle cleaning trigger condition is met; A needle cleaning module for performing the needle cleaning operation according to the needle cleaning trigger condition.

8. The system of claim 7, wherein, The collection module comprises: A first collection module for collecting the defective product recovery rate value; A second collection module for collecting the sensitive Bin; A third collection module for collecting the contact impedance value.

9. The system of claim 8, wherein, The determination module comprises: A first determination unit for determining whether the defective product recovery rate value is greater than a first threshold value for three times in succession; A second determination unit for determining whether the sensitive Bin is greater than a second threshold value; A third determination unit for determining whether the average value of the contact impedance is greater than a third threshold value.

10. The system of claim 9, wherein, The determination module further comprises: A fourth determination unit for determining whether the test point contact impedance failure rate is greater than a fourth threshold value; A fifth determination unit for determining whether the defective product recovery rate value is continuously increasing in three consecutive detections.

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