A method of cleaning a chip electronic fuse region

Abstract

The application relates to a cleaning method for a chip electronic fuse area. The method comprises the following steps: performing pre-cleaning treatment on a chip sample to remove large-particle contaminants and organic residues on the chip surface; adding a swelling agent drop by drop in an electronic fuse windowing area of the chip, so that the swelling agent droplet completely covers the fuse windowing area, and wetting pretreatment of the electronic fuse area is completed; uniformly laying a glue film on the wetted electronic fuse windowing area, so that the glue film is in full contact with the contaminated particles of the electronic fuse area; performing low-temperature heating treatment on the chip with the glue film, so that the swelling agent is fully volatilized, the glue film is solidified and forms stable adhesion with the contaminated particles; after the chip is cooled to room temperature, the glue film is uniformly torn off, and the contaminated particles of the electronic fuse area are removed together with the glue film. The method can realize efficient cleaning of the electronic fuse small windowing area of the chip, and the cleaning cost is low and the operation can be repeated.

Description

Technical Field

[0001] This application relates to the semiconductor field, and in particular to a method for cleaning the electronic fuse region of a chip. Background Technology

[0002] In integrated circuit failure analysis and reverse engineering, characterizing the burn-in state of the fuse region is a core step in determining chip configuration and locating the cause of failure. The fuse region is typically a small-sized windowed recessed structure on the chip. After the plastic encapsulation is opened, inorganic particulate contaminants from the encapsulation filler are easily left behind, covering the fuse surface and making it impossible to clearly observe its morphology, directly hindering subsequent analysis.

[0003] Current technologies generally employ conventional ultrasonic cleaning methods, involving sequential ultrasonic cleaning with acetone, alcohol, and deionized water followed by drying. However, this method has significant drawbacks for small-sized recessed areas: firstly, particles in the cleaning solution are easily re-adsorbed back into the windowed area during the drying process due to surface tension and capillary forces, resulting in extremely low cleaning efficiency; secondly, ultrasonic energy decays rapidly within the recessed space, failing to effectively target contaminant particles in deep areas; and thirdly, conventional organic solvents cannot dissolve inorganic particles, and liquid rinsing alone is insufficient to overcome the electrostatic adsorption force between particles and the fuse area surface, making it difficult to remove strongly adsorbed particles. These problems cause a large number of failed analytical samples to be unable to proceed due to inadequate cleaning, severely impacting analytical efficiency and delivery schedules. Summary of the Invention

[0004] Therefore, it is necessary to propose a cleaning method for the electronic fuse region of a chip to address the above-mentioned technical problems, including the following steps:

[0005] The chip samples are pre-cleaned to remove large particulate contaminants and organic residues from the chip surface.

[0006] A swelling agent is dropped into the electronic fuse window area of ​​the chip, so that the swelling agent droplets completely cover the electronic fuse window area, thus completing the wetting pretreatment of the electronic fuse area.

[0007] The adhesive film is laid flat on the wetted electronic fuse window area to ensure that the adhesive film is in full contact with the contamination particles in the electronic fuse area.

[0008] The chip covered with the adhesive film is subjected to low-temperature heating treatment to allow the swelling agent to fully evaporate, the adhesive film to solidify, and a stable adhesion to the contaminant particles.

[0009] After the chip cools to room temperature, the adhesive film is peeled off at a uniform speed, and the contaminant particles in the electronic fuse area are transferred and removed along with the adhesive film.

[0010] Furthermore, prior to the pre-cleaning process of the chip sample, the procedure also includes:

[0011] The plastic-encapsulated integrated circuit chip was subjected to acid boiling to remove the epoxy resin encapsulation material on the chip surface, resulting in a chip sample with the electronic fuse area exposed.

[0012] Furthermore, the acid boiling and opening process includes:

[0013] Place the molded chip face up in a polytetrafluoroethylene container, add corrosive acid and heat until the epoxy resin encapsulation material is completely removed and the chip surface is fully exposed.

[0014] After the chip has been acid-boiled, it is placed in deionized water and repeatedly soaked and rinsed to remove any residual acid from the chip surface, and then dried with nitrogen.

[0015] Furthermore, the swelling agent is analytical grade acetone, the film is polyvinyl butyral film, and the cut size of the film is larger than the size of the electronic fuse window area.

[0016] Furthermore, the pre-cleaning process for the chip sample includes: sequentially ultrasonically cleaning the chip with acetone, alcohol, and deionized water, and drying it with nitrogen gas after each cleaning.

[0017] Furthermore, after pre-cleaning the chip sample to remove large particulate contaminants and organic residues from the chip surface, the process also includes pre-inspecting the electronic fuse window area under an optical microscope to mark the location of the contaminated area to be cleaned.

[0018] Furthermore, during the application of the adhesive film, air bubbles between the adhesive film and the chip surface are removed to achieve complete contact without air bubbles.

[0019] Furthermore, in the low-temperature heating treatment of the chip covered with the adhesive film, the low-temperature heating treatment is carried out on a constant temperature hot table or oven, and the temperature is controlled during the heating process to ensure that the swelling agent fully evaporates and the adhesive film does not undergo excessive thermal shrinkage.

[0020] Furthermore, when tearing off the adhesive film, the edge area of ​​the adhesive film is held and the film is pulled up at a preset tearing angle at a uniform speed.

[0021] Furthermore, after the chip cools to room temperature, the adhesive film is peeled off at a uniform speed to transfer and remove the contaminant particles in the electronic fuse area along with the adhesive film. After this is completed, a re-inspection step is also included: the cleaning effect of the electronic fuse area is checked under an optical microscope. If there are still contaminant particles remaining, the cleaning of the electronic fuse area with the adhesive film is repeated until the cleaning requirements are met.

[0022] The cleaning method for the electronic fuse area of ​​the chip described above achieves the following beneficial effects:

[0023] 1. Breaking through the limitations of electrostatic adsorption force, achieving efficient cleaning of small window areas, this invention utilizes the mechanical adhesion force of poly (polyvinyl butyral) film to physically overcome the electrostatic adsorption force between contaminant particles and the surface of the electronic fuse, directly transferring particles to the film. The cleaning efficiency is far higher than that of traditional ultrasonic cleaning, and the cleaning effect is not limited by the size of the fuse window area.

[0024] 2. No chemical damage to the fuse area structure. The reagents and materials used in this invention are all inert materials that will not corrode the metal structure of the fuse area. The heating temperature is low, which will not change the burning state of the fuse area or cause material deterioration. Moreover, the operation is simple and does not require special equipment. The entire cleaning process only requires conventional laboratory equipment and does not require special equipment such as ultrasonic cleaners. Operators can master it after simple training, and the processing efficiency is high.

[0025] 3. It is repeatable and compatible with subsequent analysis. If the cleaning is not complete in one operation, it can be repeated. Repeating it multiple times will not damage the fuse area. The cleaned chip can still be used for other subsequent analysis processes. After cleaning, there is no residual organic matter on the surface of the fuse area. It will not cause gas pollution in the vacuum chamber of the scanning electron microscope, nor will it affect the contrast of the image. It is fully compatible with subsequent characterization analysis. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of an uncleaned electronic fuse area on a chip in one embodiment;

[0027] Figure 2 This is a flowchart illustrating a method for cleaning the electronic fuse area of ​​a chip in one embodiment;

[0028] Figure 3 This is a schematic diagram of the acetone wetting pretreatment process in one embodiment;

[0029] Figure 4 This is a schematic diagram of the film application process in one embodiment;

[0030] Figure 5 This is a schematic diagram of the operation of the adhesive film heating and curing process in one embodiment;

[0031] Figure 6 This is a schematic diagram of the film removal operation in one embodiment;

[0032] Figure 7 This is a schematic diagram of the structure of the chip electronic fuse area after cleaning in one embodiment;

[0033] Figure 8 This is a schematic diagram comparing the cleaning effects of existing technologies and this embodiment in one example. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0035] The cleaning method provided in this embodiment is primarily developed for removing strongly adsorbed contaminant particles from the fuse (electron fuse) window area during integrated circuit failure analysis. In actual failure analysis work, this type of cleaning requirement is very common, and for a long time, there has been no effective solution. After the plastic seal of many failure analysis samples is opened, varying degrees of contaminant particles remain in the fuse area, such as… Figure 1 In the exposed uncleaned fuse area, these particles are mostly inorganic components from the encapsulation filler, which are firmly bonded to the fuse metal surface through electrostatic adsorption, and conventional cleaning methods cannot effectively remove them.

[0036] In traditional fuse cleaning operations, ordinary industrial adhesive films are used for adhesion, but the results are very poor. Only a small number of large particles are removed, while most small particles remain on the fuse surface. Two problems exist: First, the fuse area itself has a concave structure, and the surface of the contaminant particles has microscopic unevenness. Ordinary adhesive films are too hard to achieve sufficient conformal contact with these microscopic uneven surfaces, so many small particles cannot make effective contact with the film and therefore cannot be adhered and transferred. Second, the adhesive force of ordinary films is insufficient to overcome the electrostatic attraction between the particles and the fuse surface. Even if some particles make contact with the film, they remain on the fuse surface when the film is removed. Furthermore, the fuse area itself has a concave structure, and the surface of the contaminant particles has a microscopic uneven morphology. Ordinary adhesive films have high hardness and cannot achieve sufficient conformal contact with these microscopic uneven surfaces. Many small particles cannot make effective contact with the adhesive film at all, and therefore cannot be adhered and transferred. On the other hand, the adhesive force of ordinary adhesive films is insufficient and cannot overcome the electrostatic adsorption force between the particles and the fuse surface. Even if some particles make contact with the adhesive film, they will still remain on the fuse surface when the adhesive film is removed.

[0037] In one embodiment, to solve the above problem, such as Figure 2 As shown, a cleaning method for the electronic fuse region of a chip is proposed, and the specific cleaning process is as follows:

[0038] S1: Pre-clean the chip sample to remove large particulate contaminants and organic residues from the chip surface;

[0039] S2: Add a swelling agent to the electronic fuse window area of ​​the chip, so that the swelling agent droplets completely cover the electronic fuse window area, thus completing the wetting pretreatment of the electronic fuse area;

[0040] S3: Lay the adhesive film flat on the wetted electronic fuse window area to ensure that the adhesive film is in full contact with the contamination particles in the electronic fuse area;

[0041] S4: The chip covered with the adhesive film is subjected to low-temperature heating treatment to allow the swelling agent to fully evaporate, the adhesive film to solidify and form a stable adhesion with the contaminant particles;

[0042] S5: After the chip cools to room temperature, peel off the adhesive film at a uniform speed to transfer and remove the contaminant particles in the electronic fuse area along with the adhesive film.

[0043] The entire cleaning process is explained in detail below:

[0044] The first step is acid boiling to deseal the chip. This is a pre-processing step in the entire cleaning process, aimed at removing the epoxy resin encapsulation from the chip's exterior and fully exposing the internal fuse area. In practice, the molded integrated circuit chip to be treated is first placed face up in a PTFE container. PTFE is a very suitable container material due to its excellent corrosion resistance; it will not be corroded by acid or contaminated by the chip. Then, the appropriate etching acid is added to the container, completely immersing the chip in the acid. The container is then placed on a heating device for etching at 90–120°C for 15–40 minutes. During the etching process, the chip's etching status needs to be observed periodically until the epoxy resin encapsulation on the chip surface is completely removed, and the chip's surface structure is fully and clearly exposed. Heating is then stopped, completing the acid boiling desealment process. In this step, controlling the degree of etching is crucial. If etching is insufficient, the encapsulant will not be completely removed, the fuse area will not be fully exposed, and subsequent cleaning work cannot be carried out. If etching is excessive, the acid will damage the internal structure of the chip, affecting the subsequent analysis results.

[0045] After the acid boiling and unpacking process is complete, the chips need to be rinsed immediately to remove any residual acid from the surface. Specifically, use tweezers to remove the chips from the acid solution and immediately immerse them in a container of deionized water. Repeat this process several times, changing the deionized water each time, to ensure that any residual acid on the chip surface is completely removed, preventing any acid residue from affecting subsequent cleaning processes or the chip itself. After rinsing, gently dry the chip surface with a nitrogen gun, completing the pretreatment after acid boiling and unpacking.

[0046] This step not only fully exposes the fuse area, preparing it for subsequent cleaning processes, but also removes most of the encapsulation material residue, reducing the burden on subsequent cleaning processes and improving overall cleaning efficiency.

[0047] The second step is the pre-cleaning of the chip. The purpose of this step is to remove large particulate contaminants and organic residues from the chip surface, preventing these contaminants from interfering with subsequent fine cleaning processes. Specifically, the process involves sequentially performing acetone ultrasonic cleaning (40kHz frequency, 3-5 min) → alcohol ultrasonic cleaning (3-5 min) → deionized water ultrasonic cleaning (3-5 min). After each solvent's ultrasonic cleaning, the chip surface is dried with a nitrogen gun before proceeding to the next solvent. After the final deionized water ultrasonic cleaning, the chip is thoroughly dried, completing the pre-cleaning process. This pre-cleaning step primarily targets large particulate contaminants and organic contaminants such as grease and residual encapsulation resin on the chip surface. These contaminants have relatively weak adhesion and can be effectively removed by conventional ultrasonic cleaning, eliminating the need for the adhesion transfer cleaning process of this invention. This significantly reduces the workload of subsequent fine cleaning and improves overall cleaning efficiency. Simultaneously, pre-cleaning also allows the contamination status of the fuse area to be more clearly presented, facilitating subsequent pre-inspection and calibration.

[0048] After pre-cleaning, the fuse area needs to be pre-inspected. In this process, the chip is placed on the stage of an optical microscope, the magnification of the microscope is adjusted, and the windowed area of ​​the fuse is observed comprehensively. The distribution location, approximate size range, and distribution density of the contaminant particles are recorded, and the target areas that need to be cleaned in detail are marked.

[0049] The third step, as Figure 3 The diagram illustrates the acetone wetting pretreatment process, specifically the acetone wetting pretreatment of the fuse area. This step is crucial for achieving conformal bonding of the adhesive film. In practice, the chip is first placed on a flat, anti-static worktable with the fuse area facing upwards, ensuring the chip is stable and won't slip. Then, a suitable amount of analytical-grade acetone is drawn up using a pipette and slowly released directly above the fuse window area. The acetone droplet is allowed to fall naturally into the fuse window area and spread naturally due to surface tension, eventually completely covering the entire fuse window area.

[0050] The acetone wetting process in this step serves a dual purpose: First, acetone is an excellent organic solvent that can dissolve and pre-clean residual organic contaminants in the fuse area, such as small encapsulation resin fragments and grease residues, further removing organic contaminants. Second, acetone can swell and soften the subsequently laid poly film, transforming it from a rigid state to a viscoelastic state. This allows the film to deform according to the microscopic morphology of the fuse area, achieving full conformal contact with the uneven surface of the contaminant particles, greatly increasing the actual contact area between the film and the contaminant particles, and providing a foundation for subsequent adhesion and transfer.

[0051] It is important to note that after acetone wetting, the subsequent film application process must be carried out immediately. The film should not be left to stand for too long, as acetone is highly volatile. If left for too long, the acetone will completely evaporate, failing to swell the film and significantly reducing the effectiveness of the wetting pretreatment. This is a key operational point summarized from extensive testing. Many operators who initially tried this method failed because they left the film for too long after wetting, causing the acetone to evaporate and resulting in unsatisfactory cleaning results. Mastering this operational rhythm is crucial for ensuring cleaning effectiveness.

[0052] This wetting pretreatment step fundamentally solves the problem that ordinary adhesive films cannot fully contact microscopic uneven surfaces. Through the swelling effect of acetone, the adhesive film can achieve conformal adhesion, which is one of the foundations for the high-efficiency cleaning achieved by this invention. Compared with ordinary direct adhesion methods, after acetone wetting pretreatment, the contact area between the adhesive film and the contaminant particles can be increased several times, the adhesion will be significantly improved accordingly, and the cleaning effect will naturally achieve a qualitative leap.

[0053] The fourth step is the poly film application process. (For example...) Figure 4The diagram illustrates the polyfilm deposition process. First, based on the dimensions of the fuse window area, cut a suitable size of polyfilm with a thickness of 0.1–0.3 mm and an area of ​​at least 5 mm × 5 mm (rectangular or circular). The size of the film should be slightly larger than the fuse window area to ensure complete coverage and prevent cleaning dead zones. In this embodiment, the polyfilm used is polyvinyl butyral film. This film swells moderately under the influence of acetone, exhibiting moderate adhesion and making it an ideal adhesion and transfer material. After cutting the film, use clean PTFE tweezers to hold the edges and gently place the film over the acetone-wetted fuse window area, allowing it to naturally adhere to the chip surface. After the adhesive film is applied, gently press the surface of the film with a clean tool to completely remove any air bubbles between the film and the chip surface. This ensures that the film makes complete, bubble-free contact with the fuse window area, preventing some areas from being unable to contact the contaminant particles and affecting the cleaning effect.

[0054] In this embodiment, after the adhesive film is laid, under the swelling effect of acetone, the bottom surface of the film gradually transforms into a viscoelastic state. In this state, the film has excellent deformation capability, allowing it to deform according to the microscopic morphological undulations of the fuse window area. This achieves full conformal adhesion with the uneven surface of each contaminant particle, forming a physical adhesion interface with maximum contact area between the film and the contaminant particles. This conformal adhesion effect is something that ordinary rigid adhesive films simply cannot achieve, and it is one of the reasons why this invention can effectively remove tiny contaminant particles.

[0055] The fifth step is the low-temperature heating and curing process. For example... Figure 5 The diagram illustrates the heating and curing process, a crucial step in ensuring stable adhesion between the adhesive film and contaminant particles. In practice, the chip coated with the poly adhesive film, along with the worktable, is placed on a constant-temperature heating table or oven for low-temperature heating for 1.5–3 minutes (optimal 2 minutes). During heating, a suitable temperature range is controlled to ensure sufficient acetone evaporation without causing excessive thermal shrinkage of the adhesive film. During heating, acetone gradually evaporates from the adhesive film and chip surface, and the adhesive film gradually transitions from a swollen viscoelastic state to a dry, cured state. During curing, the adhesive film undergoes moderate shrinkage, further tightly encapsulating the contaminant particles, forming a stable three-layer mechanical locking structure between the adhesive film, contaminant particles, and the fuse surface. This establishes sufficient interfacial energy to overcome the electrostatic attraction between the contaminant particles and the fuse surface, firmly adhering the contaminant particles to the adhesive film.

[0056] Temperature control in this step is crucial. If the temperature is too low (below 30°C), the acetone evaporation rate will be insufficient, the adhesive film will not fully cure, and the adhesion will be unstable. When the film is removed, many particles will remain on the fuse surface. If the temperature is too high (above 60°C), the adhesive film will undergo excessive thermal shrinkage, generating significant internal stress. When the film is removed, this stress concentration will pull on the metal wires in the fuse area, potentially causing them to break and resulting in irreversible damage. After repeated testing and optimization, 35–45°C was found to be the optimal range for balancing acetone evaporation rate and adhesive film curing quality. Within this temperature range, acetone can be fully evaporated, the adhesive film can be fully cured, and excessive internal stress can be avoided, thus preventing damage to the fuse structure. This balances cleaning effectiveness and operational safety.

[0057] This heating and curing step not only ensures stable adhesion between the adhesive film and contaminant particles but also guarantees the non-destructive nature of the entire cleaning process. The low-temperature heating method does not cause any thermal damage to the metal structure of the fuse, nor does it change the fuse's programming state. This is one of the key advantages of this invention compared to other cleaning solutions; the entire cleaning process is non-destructive and does not alter the chip's structure or state, fully meeting the requirements for failure analysis.

[0058] Step six: Adhesive film removal and re-inspection. (For example...) Figure 6 The diagram illustrates the adhesive film removal process. After heating and curing, the chip is removed from the heating device and allowed to cool at room temperature until it is completely cooled to room temperature before removing the adhesive film. Removing the film while the chip is still hot will make the film brittle and prone to breakage. Additionally, the adhesion is unstable at high temperatures, and some particles may detach and fall back, affecting the cleaning effect. Therefore, cooling to room temperature before removal is crucial for ensuring a good cleaning result. When removing the adhesive film, use clean tweezers to hold the edge of the film and then pull it off the chip surface at a suitable angle (greater than 90°, meaning the angle between the film removal direction and the chip surface normal is less than 90°, and the angle with the chip surface tangent is greater than 90°) at a uniform speed. Controlling the tearing angle is also very important. By determining a suitable tearing angle range, it is possible to ensure that the adhesive force of the film can effectively peel off the contaminant particles from the surface of the fuse, without causing excessive stress on the metal structure of the fuse and avoiding the risk of structural damage.

[0059] After the adhesive film is removed, the contaminant particles will be transferred and removed along with the film, completing the entire cleaning process. The cleaned fuse area will look like... Figure 7As shown, it can be seen that the pollutants and small particulate matter in the fuse area are relatively... Figure 1 The contamination has been completely removed, indicating a good cleaning effect. After cleaning, the fuse area needs to be re-inspected. The chip is placed under an optical microscope to observe the cleaning effect of the fuse area and compare it with the contamination state recorded during the pre-inspection to determine whether the cleaning effect meets the requirements. If a small amount of contaminant particles remain, the processes of acetone wetting, film application, heat curing, and film removal can be repeated until the cleaning effect meets the requirements for subsequent analysis. Figure 8 As can be seen from the cleaning effect diagrams of the fuse area compared to existing technologies and this embodiment, the cleaning effects of the two are significantly different.

[0060] This method supports repeated operations without causing any damage to the structure of the fuse area. Even after multiple operations, the metal structure of the fuse remains intact, and the burning state remains unchanged. This is very beneficial for heavily contaminated samples, as all contaminant particles can be gradually removed through multiple operations to achieve the desired cleaning effect.

[0061] The technical advantages of this invention are as follows: First, this method overcomes the limitations of electrostatic adsorption force, directly transferring contaminant particles from the fuse surface through mechanical adhesion, completely solving the problem that conventional ultrasonic cleaning cannot remove strongly adsorbed particles, resulting in a qualitative improvement in cleaning efficiency and effect. Second, the entire operation is very simple, requiring only standard laboratory equipment and no specialized equipment. Operators can master the process after simple training, greatly lowering the barrier to entry. Third, the entire cleaning process is completely non-destructive, without affecting the structure and state of the fuse area, fully meeting the requirements of failure analysis. Fourth, this method is fully compatible with subsequent scanning electron microscopy analysis. The cleaned fuse surface has no organic residue, will not generate gas contamination in the vacuum chamber of the scanning electron microscope, and will not affect the imaging contrast. After cleaning, scanning electron microscopy observation can be performed directly without additional post-processing steps.

[0062] Beyond the aforementioned application scenarios, this method can also be extended to other chip contaminant cleaning scenarios with small, recessed areas. It can be used to clean any strongly adsorbed contaminant particles, demonstrating strong versatility. For example, the cleaning needs of chip pads and sensor sensitive areas are very similar to those of fuse areas, both facing the challenge of cleaning small, strongly adsorbed particles. This method can effectively solve these cleaning problems, expanding its application scope. Furthermore, the cleaning method provided in this embodiment fundamentally solves the long-standing problem of cleaning strongly adsorbed particles from fuse areas, providing a highly efficient, non-destructive, and simple cleaning solution for failure analysis. This significantly improves the efficiency of failure analysis, reduces analysis costs, and has high practical value and promotional significance.

[0063] It should be understood that although the steps in the above embodiments are described sequentially, these steps are not necessarily executed in that order. Unless otherwise expressly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps described above may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but may be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0064] Those skilled in the art will understand that the structure of this application is merely a block diagram of a portion of the structure related to the solution of this application, and does not constitute a limitation on the device to which the solution of this application is applied. The specific device may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0065] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0066] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for cleaning the electronic fuse area of ​​a chip, characterized in that, Includes the following steps: The chip samples are pre-cleaned to remove large particulate contaminants and organic residues from the chip surface. A swelling agent is dropped into the electronic fuse window area of ​​the chip, so that the swelling agent droplets completely cover the electronic fuse window area, thus completing the wetting pretreatment of the electronic fuse area. The adhesive film is laid flat on the wetted electronic fuse window area to ensure that the adhesive film is in full contact with the contamination particles in the electronic fuse area. The chip covered with the adhesive film is subjected to low-temperature heating treatment to allow the swelling agent to fully evaporate, the adhesive film to solidify, and a stable adhesion to the contaminant particles. After the chip cools to room temperature, the adhesive film is peeled off at a uniform speed, and the contaminant particles in the electronic fuse area are transferred and removed along with the adhesive film.

2. The cleaning method for the electronic fuse area of ​​a chip according to claim 1, characterized in that, Before performing the pre-cleaning process on the chip sample, the method further includes: The plastic-encapsulated integrated circuit chip was subjected to acid boiling to remove the epoxy resin encapsulation material on the chip surface, resulting in a chip sample with the electronic fuse area exposed.

3. The cleaning method for the electronic fuse area of ​​a chip according to claim 2, characterized in that, The acid boiling and opening process includes: Place the molded chip face up in a polytetrafluoroethylene container, add corrosive acid and heat until the epoxy resin encapsulation material is completely removed and the chip surface is fully exposed. After the chip has been acid-boiled, it is placed in deionized water and repeatedly soaked and rinsed to remove any residual acid from the chip surface, and then dried with nitrogen.

4. The cleaning method for the electronic fuse area of ​​a chip according to claim 1, characterized in that, The swelling agent is analytical grade acetone, the film is polyvinyl butyral film, and the cut size of the film is larger than the size of the electronic fuse window area.

5. The cleaning method for the electronic fuse area of ​​a chip according to claim 1, characterized in that, The pre-cleaning process for the chip sample includes: ultrasonically cleaning the chip sequentially with acetone, alcohol, and deionized water, and then drying it with nitrogen gas after cleaning.

6. The cleaning method for the electronic fuse area of ​​a chip according to claim 1, characterized in that, The process of pre-cleaning the chip sample to remove large particulate contaminants and organic residues from the chip surface also includes pre-inspecting the electronic fuse window area under an optical microscope to mark the location of the contaminated area to be cleaned.

7. The cleaning method for the electronic fuse area of ​​a chip according to claim 1, characterized in that, When applying the adhesive film, air bubbles between the adhesive film and the chip surface are removed to achieve complete contact without air bubbles.

8. The cleaning method for the electronic fuse area of ​​a chip according to claim 1, characterized in that, In the low-temperature heating treatment of the chip covered with the adhesive film, the low-temperature heating treatment is carried out on a constant temperature hot table or oven. During the heating process, the temperature is controlled to ensure that the swelling agent fully evaporates and the adhesive film does not undergo excessive thermal shrinkage.

9. The cleaning method for the electronic fuse area of ​​a chip according to claim 1, characterized in that, When tearing off the adhesive film, hold the edge area of ​​the adhesive film and pull it up at a preset tearing angle at a uniform speed.

10. The method for cleaning the electronic fuse area of ​​a chip according to claim 1, characterized in that, After the chip cools to room temperature, the adhesive film is peeled off at a uniform speed to transfer and remove the contaminant particles in the electronic fuse area along with the adhesive film. After the removal is completed, a re-inspection step is also included: the cleaning effect of the electronic fuse area is checked under an optical microscope. If there are still contaminant particles remaining, the cleaning of the electronic fuse area with the adhesive film is repeated until the cleaning requirements are met.

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