A method for observing a chip structure by directly cutting, grinding and dyeing a chip

Abstract

The application belongs to but is not limited to the chip detection technical field, and discloses a method and equipment for observing the internal structure of a chip directly cut, ground and dyed in a tube. In view of the problems of time consumption, material consumption and large sample damage caused by chemical opening and solidification treatment in the prior art, the application does not need to disassemble the chip package, directly cuts the chip in a tube to a preset position through a cutting machine, obtains a smooth observation surface through grinding, and then observes the internal structure and PN junction depth of the chip through a microscope or a scanning electron microscope (SEM) after optional dyeing treatment. The scheme saves time and cost, reduces sample damage, opens up a brand-new chip grinding observation approach, is suitable for structure observation and junction depth detection scenes in chip research and development, fault analysis and quality detection, and has strong practicability.

Description

Technical Field

[0001] This invention belongs to, but is not limited to, the field of chip inspection technology, and particularly relates to a method and equipment for observing the internal structure of a chip by directly cutting, grinding, and staining a tube-shaped chip. Background Technology

[0002] In core scenarios such as semiconductor chip R&D, fault analysis, and quality inspection, the observation of the chip's internal structure and the measurement of junction depth are crucial steps in evaluating chip performance and troubleshooting technical problems. Their efficiency and accuracy directly impact product development cycles, production yields, and market competitiveness. However, the commonly used methods for observing the chip's internal structure and junction depth have long suffered from numerous insurmountable technical limitations, severely hindering the progress of related work.

[0003] The existing technology requires multiple complex steps to complete the entire process: First, the chip must be completely removed from the package structure through a chemical decapsulation process. This process requires specialized chemical reagents to etch and peel off the chip's packaging layer, which is not only cumbersome but also poses a risk of potential corrosion damage to the chip's surface structure. Furthermore, the consumption of these reagents incurs additional consumable costs. Second, the bare chip after decapsulation needs to be cured. This typically involves precisely mixing AB-based epoxy resin in a specific ratio, then placing the chip in a specialized mold for curing and shaping. This provides stable support for subsequent polishing, preventing displacement or breakage during the polishing process. However, the mixing, stirring, and curing of the epoxy resin are time-consuming, generally taking several hours, significantly extending the testing cycle. Additionally, interfacial gaps can easily form between the cured chip and the epoxy resin layer, potentially affecting the uniformity of stress during polishing. Finally, only after curing can the chip proceed to the polishing and staining stages to observe its internal structure and junction depth. Whether it's small-batch sample testing during chip development or large-scale quality screening in the production stage, the above process must be strictly followed, leaving no room for simplification.

[0004] This traditional approach suffers from three major pain points: First, the cumbersome process leads to extremely long processing times. It often takes several hours to complete the observation of a single chip from unpacking to final inspection. If batch sample testing is required, the cumulative time will increase significantly, seriously affecting R&D progress and production efficiency. Second, the cost of consumables is high. The consumption of chemical unpacking reagents, epoxy resin materials, and special molds keeps the material cost of a single test high, which will bring a heavy economic burden in the long run. Third, there is a high risk of sample damage. The corrosion of reagents during the chemical unpacking process, the temperature and pressure changes during the curing process, and the interface interaction between the cured layer and the chip body can all cause minor deformations or damage to the internal structure of the chip, thereby affecting the accuracy of the observation results. Especially for the testing of precision chips, such damage may lead to distorted test data and mislead subsequent analysis and judgment.

[0005] Based on the above analysis, the urgent technical problems that need to be solved by existing technologies are: existing solutions cannot be adapted to batch testing scenarios, and problems such as extended R&D cycles, increased production costs, and untimely fault analysis are becoming increasingly prominent, becoming key technical pain points that restrict the efficient development of the semiconductor industry. A brand-new technical solution is urgently needed to break through this dilemma. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a method for chip structure observation by directly cutting, grinding, and staining the formed tube, which does not require disassembling the chip package and directly processes the chip in the formed tube state, achieving efficient and low-damage structure observation.

[0007] This invention is implemented as follows: a method for observing chip structures by directly cutting, grinding, and staining tubes, comprising the following steps: (1) The chip in the tube state is directly cut until the preset grinding position is reached; (2) Grind the cut chip to obtain a flat viewing surface; (3) The internal structure of the polished chip is observed using observation equipment; (4) If it is necessary to observe the PN junction of the chip, the chip after grinding is dyed and then the junction depth is observed through the observation device.

[0008] Furthermore, in step (1), a cutting machine is used to perform the cutting operation. The cutting process does not require chemical unsealing or epoxy resin curing of the chip.

[0009] Furthermore, the observation equipment in step (3) is a microscope or a scanning electron microscope (SEM), and the observation content includes the internal structure of the chip and junction depth data.

[0010] Furthermore, in step (4), the object of the dyeing treatment is the observation surface of the chip after grinding. After dyeing, the PN junction and junction depth are visualized and observed through the observation equipment.

[0011] Another objective of this invention is to provide a chip structure observation device for direct cutting, grinding, and staining of tubes, including a cutting module, a grinding module, and an observation module. The cutting module is used to directly cut the chip in the tube state to a preset grinding position. The grinding module is used to grind the cut chip to form a flat viewing surface. The observation module is used to observe the internal structure of the chip after grinding. It also includes an optional staining module, which is used to stain the observation surface of the polished chip to adapt to the observation of PN junctions and junction depths.

[0012] Furthermore, the cutting module is a cutting machine, and the observation module is a microscope or a scanning electron microscope (SEM). The equipment does not require a chemical unsealing device or an epoxy resin curing mold, and can directly perform cutting, grinding, and observation operations on the formed tube chip.

[0013] Furthermore, the cutting path of the cutting module is adapted to the grinding area of ​​the grinding module, the dyeing range of the dyeing module covers the observation surface of the chip after grinding, and the observation angle of the observation module corresponds to the chip grinding surface and the dyed PN junction area, so as to realize the visualization observation of the chip's internal structure and junction depth.

[0014] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows: This invention eliminates the need for cumbersome steps such as chemical opening and epoxy resin curing, allowing direct cutting and grinding of the formed chip, significantly saving time and material costs. It also avoids additional damage to the sample during disassembly and curing, achieving high efficiency and low damage in chip structure observation, and opening up a completely new approach to chip grinding and observation.

[0015] (1) The expected benefits and commercial value of the technical solution of this invention after transformation are as follows: It reduces the time and material costs of chip testing, improves the efficiency of chip R&D, fault analysis and quality testing, and is especially suitable for batch sample testing scenarios, with broad industrial application prospects. (2) The technical solution of the present invention solves a technical problem that people have long wanted to solve but have never been able to solve successfully: The semiconductor industry has long needed a chip structure inspection solution that is "batch, fast, and low-damage," but due to the technical understanding that "the packaging layer will affect the cutting accuracy," the industry has been unable to break through the technical bottleneck of "it must be opened and cured first." This invention solves the core problem of direct processing of tube-shaped chips for the first time through precise positioning technology and adaptive cutting-grinding parameter design, thus meeting the urgent needs of the industry. Attached Figure Description

[0016] Figure 1 This is a flowchart of a chip structure observation method involving direct cutting, grinding, and staining of tubes provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of chip grinding processes using existing technology; Figure 3 This is a side view of the chip grinding process in the prior art; Figure 4 This is a schematic diagram of direct tube cutting and grinding provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the side of the tube being directly cut and ground according to an embodiment of the present invention; In the diagram: 1. Epoxy resin cured layer; 2. Chip body; 3. Polished surface; 4. Chip tube. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0018] like Figure 1 As shown, a method for observing chip structures by directly cutting, grinding, and staining tubes includes the following steps: (1) Chip positioning and cutting: A diamond blade cutting machine is used to position the chip pins based on the preset grinding position (positioning accuracy ±2μm) to perform directional cutting on the chip in the tube state. The cutting depth error is ≤±5μm and the cutting speed is 5-10mm / s. Deionized water is used for cooling during the cutting process (cooling flow rate 1-2L / min) until the preset grinding position is reached. The cutting process does not require chemical unpacking or epoxy resin curing of the chip.

[0019] (2) Grinding treatment: The observation surface of the chip after cutting is ground by chemical mechanical polishing (CMP) equipment. A 10,000-mesh diamond grinding wheel is selected and the grinding pressure is 0.1-0.3MPa. After grinding, the surface roughness Ra of the observation surface is ≤0.1μm and the flatness is ≤0.05μm, so as to obtain a flat observation surface. After grinding, the chip is ultrasonically cleaned with anhydrous ethanol for 3 minutes (ultrasonic power 100W) to remove grinding debris and residual impurities.

[0020] (3) Structural observation: The internal structure of the polished chip is observed by an observation device, which is a metallographic microscope (magnification of 500-2000 times) or a scanning electron microscope (accelerating voltage of 5-15kV, resolution ≤1nm). The observation content includes the internal circuit layout, interlayer structure and original data of junction depth of the chip.

[0021] (4) PN junction staining and observation: If it is necessary to observe the PN junction of the chip, the observation surface of the chip after grinding is stained. The staining agent is a mixed etching staining agent of HF:HNO3:CH3COOH=1:3:10 (concentration 8%). Soak at room temperature for 30 seconds to 2 minutes. After staining, rinse with deionized water 5 times (each rinse time is 10 seconds) and blow dry with nitrogen (nitrogen pressure 0.3MPa). Then, through the above observation equipment, the PN junction boundary is identified based on the image grayscale contrast. The junction depth is measured with image analysis software. The measurement error is ≤±2%, realizing the visualization observation of the PN junction and junction depth.

[0022] This method is a direct structural exposure and functional junction visualization technique for chips in the tube state. Its core principle is to obtain a flat cross-section that can be observed inside the chip directly through high-precision mechanical cutting and fine grinding without traditional chemical opening and resin encapsulation. Then, combined with physical imaging and selective chemical staining mechanism, high-fidelity reconstruction and quantitative analysis of the internal circuit structure and PN junction depth of the chip can be achieved.

[0023] During the chip positioning and dicing stage, chip pins or package geometry are used as external reference benchmarks for directional cutting using a diamond blade dicing machine. Diamond blades possess high hardness and stable geometry, enabling simultaneous cutting of silicon-based materials and packaging materials with relatively low cutting forces. Continuous cooling with deionized water is employed during the dicing process. This reduces the instantaneous temperature rise in the dicing area, preventing damage to the internal chip structure or material phase transitions caused by thermal stress, and also promptly removes cutting debris, suppressing secondary scratches. Precise control of the dicing depth and speed ensures that the cutting terminates at a predetermined grinding allowance, providing a uniform and controllable initial surface for subsequent fine grinding.

[0024] During the grinding stage, the observation surface after cutting is refined using the principle of chemical mechanical polishing (CMP). The CMP process involves the synergistic action of mechanical grinding and micro-chemical action: high-mesh diamond abrasive selectively removes surface micro-protrusions under controlled pressure, while weak chemical action promotes uniform exfoliation of the surface material, thereby effectively eliminating cutting marks, micro-cracks, and stress concentration areas introduced by cutting. By strictly controlling the grinding pressure, abrasive particle size, and processing time, the observation surface achieves extremely low roughness and high flatness, providing stable reflection and scattering conditions for high-magnification microscopy or electron beam imaging. Ultrasonic cleaning after grinding utilizes the cavitation effect to remove tiny particles and residues adhering to the surface, preventing them from interfering with subsequent imaging.

[0025] During the structural observation phase, the exposed internal structure of the chip is directly observed based on optical imaging or electron beam scanning imaging mechanisms. Metallurgical microscopes create contrasts by highlighting the differences in light reflectivity of different materials and structural layers, while scanning electron microscopes utilize secondary electron signals generated by the interaction of electrons with materials to achieve high-resolution imaging of multilayer interconnect structures, dielectric layers, and diffusion regions, thereby realistically reproducing the internal circuit layout and interlayer relationships of the chip.

[0026] In the PN junction staining and observation stage, the selective etching characteristics of different doped regions are utilized using a mixed etching agent composed of HF, HNO3, and CH3COOH. Due to the differences in doping concentration, electrochemical activity, and etching rate between the P-type and N-type regions, a clear contrast in grayscale or morphology is formed at the microscale after etching. By controlling the etching time and concentration, the PN junction boundary can be clearly revealed without damaging the overall structure. Combined with image analysis software to identify and measure the locations of grayscale abrupt changes, quantitative extraction of the junction depth can be achieved. This principle enables simultaneous, intuitive, and low-damage observation of the chip structure and electrical junction regions, offering technical advantages such as simplified procedures, high precision, and good repeatability.

[0027] like Figure 2 As shown, the chip in its tube state includes a package shell 1, an inner chip body 2, and a package filler layer 3. The package shell 1 is a plastic or resin encapsulation structure used to provide overall protection for the chip body 2 and its internal circuitry; the chip body 2 is located in the central region of the package shell 1, and its interior integrates an active device area, a metal interconnect layer, and a PN junction structure; the package filler layer 3 fills the space between the chip body 2 and the package shell 1 to provide mechanical support and environmental isolation.

[0028] like Figure 4 The diagram shown is a top view of the chip in its tube-like state. Chip pins 4 are located on one or both sides of the package housing 1, and are electrically connected to the internal electrodes of the chip body 2 to achieve external electrical connections to the chip. Figure 5 The diagram shows a side view of the chip in its tube state. Pin 4 extends along the bottom or side wall of the package shell 1, and its position can serve as an important positioning reference during chip cutting and grinding.

[0029] This invention, based on the structural features of a chip in its tube-like state, uses the shape of the chip pins 4 and the package shell 1 as spatial positioning references to achieve direct exposure and observation of the chip's internal structure without damaging the overall package structure. In actual operation, the chip in its tube-like state is first oriented and fixed so that the chip pins 4 face a preset direction. Then, the package shell 1 and the package filling layer 3 are simultaneously cut along a direction perpendicular to the chip surface until they approach the preset observation area of ​​the chip body 2.

[0030] Subsequently, a precision grinding process removes the surface irregularities formed during the cutting process, creating a flat and continuous viewing surface on the cross-section of the chip body 2. This fully exposes the internal device structure, interlayer relationships, and PN junction region of the chip. Since both the cutting and grinding processes are completed based on the chip's original packaged state, structural shifts and stress damage introduced by traditional chemical unpacking and re-curing steps are avoided.

[0031] When it is necessary to observe the PN junction, the polished observation surface can be selectively stained. The difference in chemical reaction rate between different doped regions creates a clear contrast at the PN junction boundary, thereby enabling visualization and quantitative analysis of the PN junction location and depth by combining microscopic observation methods. Through the above structural combination and process synergy, this invention achieves high-precision, low-interference observation of the internal structure of the formed chip.

[0032] This invention provides a chip structure observation device for direct cutting, grinding, and staining of tubes, including a cutting module, a grinding module, an observation module, and an optional staining module. Cutting module: It is a diamond blade cutting machine equipped with a fixture with a vacuum adsorption device (positioning accuracy ±3μm), which is used to directly cut the chip in the tube state to the preset grinding position. The cutting blade has a diameter of 50mm and a thickness of 0.1mm. The deviation between the cutting path and the center of the grinding area of ​​the grinding module is ≤3μm. Grinding module: This is a chemical mechanical polishing (CMP) device that shares the same reference platform (positioning deviation ≤2μm) with the dicing module. It is used to grind the diced chips to form a flat viewing surface. The grinding accuracy can be adjusted to a surface roughness Ra≤0.1μm. Observation module: Metallurgical microscope (magnification 500-2000x) or SEM (accelerating voltage 5-15kV, resolution ≤1nm), observation angle and focusing accuracy ≤1μm, used to observe the internal structure and junction depth data of the chip after grinding; The staining module is a spray-type staining device equipped with a staining agent storage tank, a precision spray head, and a recovery mechanism. The staining range covers the observation surface of the chip after grinding (coverage ≥95%). It is used to stain the observation surface of the chip after grinding to adapt to the observation of PN junctions and junction depths.

[0033] The chip structure observation device for direct cutting, grinding, and staining in tubes, as described in this invention embodiment, uses "high-precision processing with the same reference—surface finishing—multi-scale imaging—selective staining and development" as its core technical route. Through the collaborative work of multiple modules, it achieves high-precision, low-destructive observation of the internal structure and PN junction depth of chips in tube state. Its working principle is as follows.

[0034] During the cutting module's operation, the diamond blade cutting machine performs initial chip processing on the same reference platform. When the chip is in a tube-packaged state, it is fixed by a high-precision fixture with a vacuum adsorption device, using the pins and package shape as positioning references to achieve micron-level spatial alignment. The diamond blade, with its high hardness and stable cutting edge, can simultaneously cut the packaging material and the silicon-based chip with relatively small cutting forces. The cutting path is precisely aligned with the center of the grinding area of ​​the subsequent grinding module, ensuring minimal deviation between the cutting termination position and the grinding center. This allows for a uniform grinding allowance for the grinding module without introducing additional positioning errors, avoiding the cumulative errors and structural misalignment caused by traditional multiple clamping operations.

[0035] During the grinding module's operation, the chemical mechanical grinding (CMP) equipment shares the same reference platform as the cutting module, ensuring the chip's position remains constant in the spatial coordinate system. During grinding, the grinding disc removes trace amounts of material from the cut surface under controlled pressure and rotation speed. The synergistic effect of mechanical grinding and chemical reaction gradually eliminates tool marks, microcracks, and residual stress on the cut surface. Precise adjustment of the grinding parameters allows for lower surface roughness and higher flatness of the observation surface, providing a stable physical basis for subsequent high-magnification observation. The key principle of this stage lies in achieving seamless transition from roughing to finishing through a unified reference and continuous processing flow, significantly improving processing consistency and repeatability.

[0036] During the observation module's operation, the polished chip can be directly observed without re-clamping. Metallurgical microscopy uses the differences in visible light reflectivity of different materials and structural layers to create image comparisons, enabling rapid identification of circuit layers and macroscopic structural distributions. Scanning electron microscopy, on the other hand, utilizes the signals generated by the interaction of the electron beam with the sample surface to achieve high-resolution imaging of sub-micron and even nanometer-scale structures. Because the aforementioned polished surface possesses excellent flatness and cleanliness, and the electron scattering and optical reflection conditions are stable, it effectively improves imaging clarity and the accuracy of junction depth measurement.

[0037] When PN junction observation is required, the staining module is activated. The spray-type staining device uniformly applies the staining agent to the observation surface after chip polishing. Differences in chemical etching rates among regions with different doping types and concentrations create distinct grayscale or morphological contrasts at the PN junction interface. The staining agent recovery mechanism promptly recovers excess solution, preventing over-etching. The stained chip is then imaged again by the observation module. Combined with image analysis methods, the PN junction boundary and depth can be visualized and quantitatively analyzed. Through the coordinated operation of these modules, this equipment achieves a high degree of integration and precise control of the tube-shaped chip structure observation process.

[0038] Furthermore, the device does not require a chemical unsealing device or an epoxy resin curing mold, and can directly perform cutting, grinding, and observation operations on the formed chip. The cutting path of the cutting module is adapted to the grinding area of ​​the grinding module (cutting path length ≥ grinding area length, deviation ≤ 5μm), and the observation angle of the observation module corresponds to the chip grinding surface and the PN junction area after staining, realizing the visualization observation of the chip's internal structure and junction depth.

[0039] Example 1 is applicable to QFP packaging into a chip with shallow junction PN junction (junction depth < 1 μm). A method for observing chip structures by directly cutting, grinding, and staining tubes includes the following steps: (1) Chip positioning and cutting: Prepare a QFP packaged tube chip to be tested (model: AT89C51), determine the target observation position (core circuit area of ​​the chip) according to the chip datasheet, and locate the preset grinding position through the chip pin (positioning accuracy ±1.5μm); select a diamond blade cutting machine (model: SYJ-100), set the cutting depth error to ±3μm, the cutting speed to 8mm / s, turn on deionized water cooling during the cutting process (flow rate 1.5L / min), and perform directional cutting on the tube chip to ensure that it reaches the target grinding area after cutting.

[0040] (2) Grinding treatment: A chemical mechanical polishing (CMP) machine (model: CMP-300) was used, with a 12000-mesh diamond grinding wheel and a grinding pressure of 0.15MPa. The observation surface of the cut chip was ground, and the surface roughness Ra ≤ 0.08μm and flatness ≤ 0.03μm of the observation surface after grinding. Then the chip was placed in anhydrous ethanol for ultrasonic cleaning for 3 minutes (ultrasonic power 100W) to remove grinding debris.

[0041] (3) PN junction staining treatment: Since it is necessary to observe the shallow PN junction, a mixed etching staining agent of HF:HNO3:CH3COOH=1:3:10 (concentration 6%) is selected. The chip grinding surface is immersed for 30 seconds at room temperature, then rinsed with deionized water 5 times for 10 seconds each time, and then dried with nitrogen gas (pressure 0.3MPa).

[0042] (4) Structure and junction depth observation: The processed chip was placed under a metallographic microscope (model: OLYMPUS GX71) and observed at 1500x magnification. The PN junction boundary was identified by image grayscale comparison. The junction depth was measured using Image-ProPlus image analysis software. The measurement result was 0.82μm with an error of ±0.016μm. At the same time, the internal circuit layout and interlayer structure characteristics of the chip were recorded.

[0043] Example 2 is applicable to BGA packaging into a chip with a deep junction PN junction (junction depth > 10 μm). A method for observing chip structures by directly cutting, grinding, and staining tubes includes the following steps: (1) Chip positioning and cutting: Prepare a BGA packaged tube chip to be tested (model: STM32F103), and use an X-ray positioning instrument to determine the target observation position (power device area) with a positioning accuracy of ±2μm; select a diamond blade cutting machine (model: SYJ-100), set the cutting depth error to ±5μm, the cutting speed to 5mm / s, turn on deionized water cooling (flow rate 2L / min) during the cutting process, and perform directional cutting on the tube chip to reach the preset grinding position.

[0044] (2) Grinding treatment: A chemical mechanical polishing (CMP) machine (model: CMP-300) was used, with an 8000-mesh diamond grinding wheel and a grinding pressure of 0.3MPa. The observation surface of the cut chip was ground. After grinding, the surface roughness Ra≤0.1μm and the flatness ≤0.05μm of the observation surface were obtained. After grinding, the chip was ultrasonically cleaned with anhydrous ethanol for 3 minutes and then dried with nitrogen.

[0045] (3) PN junction staining treatment: Select a mixed etching staining agent (concentration 10%) with HF:HNO3:CH3COOH=1:3:10. Soak the chip grinding surface for 2 minutes at room temperature, take it out and rinse it repeatedly with deionized water 5 times, and blow it dry with nitrogen.

[0046] (4) Structure and junction depth observation: The chip was placed under a scanning electron microscope (model: ZEISSSigma300), the accelerating voltage was set to 10kV and the resolution was 0.8nm. The internal power device structure of the chip was observed, the PN junction boundary was determined by grayscale comparison, and the junction depth was measured to be 12.3μm with an error of ±0.24μm.

[0047] Example 3: QFN packaged into a transistor chip, where only the internal structure of the chip is observed (no need to detect the PN junction). A method for observing chip structures by directly cutting, grinding, and staining tubes includes the following steps: (1) Chip positioning and cutting: Prepare a QFN packaged tube chip to be tested (model: TIMSP430), and position the preset grinding position based on the chip pin (positioning accuracy ±2μm); select a diamond blade cutting machine, set the cutting depth error to ±4μm, the cutting speed to 7mm / s, and the deionized water cooling flow rate to 1.2L / min, and cut the tube chip to the preset position.

[0048] (2) Grinding treatment: Chemical mechanical grinding equipment was used, a 10,000-mesh diamond grinding wheel was selected, the grinding pressure was 0.2MPa, and the surface roughness Ra≤0.09μm and flatness≤0.04μm were observed after grinding; after ultrasonic cleaning with anhydrous ethanol, the surface was dried with nitrogen.

[0049] (3) Structural observation: Place the chip under a metallographic microscope (2000x magnification) to observe and record the internal logic circuit layout, metal wiring structure and interlayer dielectric thickness. No staining is required, and a clear internal structure image can be obtained directly.

[0050] Example 4: Example of a direct dicing-grinding-structural observation method for chips in tube state In this embodiment, a pre-packaged chip in its original plastic-encapsulated state is selected as the object to be observed. Without chemically opening, removing resin, or repackaging the chip, the pin distribution and package shape are used as spatial positioning references to orient and fix the chip. Subsequently, mechanical cutting is performed along a direction perpendicular to the main surface of the chip, terminating at a predetermined structural exposure area. After cutting, while maintaining the chip's spatial position, the exposed surface is finely ground to obtain a continuous and flat observation surface that meets the requirements of microscopic imaging. After grinding, the observation surface is cleaned, and imaging observation of the chip's internal structure is performed based on this observation surface.

[0051] Using the above method, an observable cross-section of the chip's internal structure can be directly obtained while maintaining the chip's original packaged state, enabling intuitive imaging of the locations of the chip's internal device regions, interconnect layers, and junction regions. This embodiment verifies that, without the need for chemical unpacking and re-curing, a closed-loop process of "directional cutting—continuous grinding—structural imaging" can stably achieve the exposure and observation of the chip structure in its tube state, thus supporting the feasibility and technical effectiveness of the overall technical route of the method described in claim 1.

[0052] Example 5: A method for selectively developing and observing the PN junction of a chip in its tube-like state. In this embodiment, after completing the cutting and grinding steps described in Embodiment 1 and obtaining a flat observation surface, selective chemical treatment is applied to the observation surface. The chemical treatment controls the material properties of different doped regions within the chip, causing differences in surface reaction rates among regions with different doping types. After the selective chemical treatment, the observation surface is cleaned and dried, and then imaged using microscopic imaging.

[0053] After selective chemical processing, different doped regions inside the chip exhibit distinguishable interface features in imaging, resulting in a clear contrast between the PN junction boundaries in the microscopic image. This embodiment demonstrates that introducing a selective chemical processing step into the method described in claim 1 enables the visual identification and analysis of functional junction regions without damaging the overall chip structure, thus fully supporting the technical effect of "achieving visual analysis of functional junction regions through selective chemical processing" in claim 1.

[0054] Example 6: Overall Coordination Implementation of a Chip Structure Observation Device in Tube State In this embodiment, a chip structure observation device for implementing the method of claim 1 is provided. The device includes a cutting unit for directional cutting, a grinding unit for grinding the exposed surface after cutting, and an observation unit for imaging observation. The cutting unit and the grinding unit are arranged under the same spatial reference constraint, allowing the chip to directly enter the grinding process without repositioning after cutting. The observation unit is located after the grinding process and is used for microscopic imaging of the ground observation surface.

[0055] With the above-described equipment structure configuration, the cutting termination position and the grinding area can transition continuously on the same structural cross section, avoiding spatial errors caused by multiple clamping or repeated positioning. This embodiment demonstrates that the equipment described in claim 5 can stably implement the steps of the method described in claim 1 through "cutting and grinding coordination under the same spatial reference constraint," supporting the adaptability of the equipment structure to the implementation of the method and its technical feasibility.

[0056] Example 7: Example of a fabrication functional unit for exposing chip structures in a tube-like state In this embodiment, a processing functional unit for exposing the structure of a chip in a tube state is provided. When in operation, this functional unit uses identifiable structures external to the chip package to position the chip, guides the mechanical cutting process along a predetermined direction, and maintains the chip's relative position in space after cutting is completed. This functional unit can be used as a standalone module or integrated into a complete chip structure observation device.

[0057] By applying this processing functional unit, the chip can proceed to subsequent grinding without repositioning after cutting, thus ensuring the consistency between the cutting and grinding sections. This embodiment demonstrates that this functional unit itself can achieve the core function of exposing the structure of the chip in its tube state, possessing clear technical effects and independent implementation value, thereby fully supporting the protection content of claims 9 and 10 regarding the processing functional unit.

[0058] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for observing the structure of a chip in a tube-like state, characterized in that, include: While keeping the chip in its original packaged state, the identifiable electrical connection structure or geometric shape outside the chip package is used as a spatial positioning reference to perform directional mechanical cutting on the chip, so that the cutting terminates at the preset exposed area of ​​the structure. Without altering the spatial positioning relationship of the chip, the exposed surface formed by cutting is finely ground to obtain a continuous and flat observation surface that meets the requirements of microscopic observation. Based on the observation, the internal structure of the chip is imaged and observed. When necessary, selective chemical processing is used to make different doped regions form distinguishable interfaces in the imaging, thereby realizing the visualization analysis of the internal structure and functional junctions of the chip.

2. The structural observation method according to claim 1, characterized in that, The directional mechanical cutting is performed in a liquid-cooled environment to suppress thermal stress and structural damage generated during the cutting process.

3. The structural observation method according to claim 1, characterized in that, The fine grinding is a grinding process that combines chemical action and mechanical removal to reduce surface defects introduced by cutting.

4. The structural observation method according to claim 1, characterized in that, After grinding, the observation surface is cleaned to remove adhering particles before structural imaging is performed.

5. A chip structure observation device for implementing the method of claim 1, characterized in that, include: A cutting unit used to perform directional cutting while the chip is still in its packaged state; A grinding unit for grinding the exposed surface after the cutting is completed and the chip spatial position does not change; An observation unit for structural imaging of the ground observation surface; The cutting unit and the grinding unit work together under the same spatial reference constraint to ensure that the cutting termination position and the grinding area transition continuously on the same structural cross section.

6. The chip structure observation device according to claim 5, characterized in that, It also includes a staining unit for selectively chemically treating the polished observation surface to enhance imaging contrast between different doped regions.

7. The chip structure observation device according to claim 5, characterized in that, The observation unit includes at least one microscopic imaging method based on optical imaging or electron beam imaging.

8. The chip structure observation device according to claim 5, characterized in that, The cutting unit and the grinding unit are structurally subject to the same positioning constraint to avoid spatial errors introduced by multiple clamping operations.

9. A processing functional unit for exposing the structure of a chip in a tube-like state, characterized in that, This functional unit is configured as follows: Under the condition of positioning using the external structure of the chip package, the mechanical cutting process is guided to advance in a predetermined direction, and the relative position of the chip is kept unchanged after the cutting is completed, so that the subsequent grinding process can be carried out directly on the same structural cross section.

10. The processing functional unit according to claim 9, characterized in that, This functional unit can proceed to the grinding process without repositioning the chip after cutting.

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