Unsealing method and unsealing device for packaging structure
By thinning and etching the plastic sealing layer of the packaging structure, forming grooves and cleaning, the problems of irregular opening and etching liquid overflow in the prior art are solved, and the efficiency, accurate opening and reliability of the packaging structure is achieved.
Patent Information
- Application Number
- CN202510154164.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-12
- Publication Date
- 2025-05-23
AI Technical Summary
In the process of opening the packaging structure, the gap between the tape and the packaging structure causes the etching liquid to overflow, causing the PCB board corrosion and difficult to clean the tape. The opening area is irregular, affecting the accuracy of subsequent tests.
By determining the area to be opened, the plastic sealing layer is thinned to form a first groove, and the etching liquid is dripped into the groove to remove the plastic sealing layer, forming a second groove, and then the groove is cleaned to expose the chip surface.
The packaging structure is uniformly opened, avoiding etching liquid overflow, reducing the residue of etching liquid, ensuring the accuracy of subsequent tests, and protecting the electrical functions of the packaging structure.
Smart Images
Figure CN120028673A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of semiconductor technology, and relates to but is not limited to a method and device for unsealing a packaging structure. Background Art
[0002] In failure analysis, unsealing the package structure is a common method to find the failure point. By partially unsealing the package structure, the test area of the chip can be exposed without affecting the electrical function of the chip in the package structure, so that the circuit of the test area can be edited and the node signal can be collected to determine whether there is a problem with the signal. Summary of the invention
[0003] In view of this, an embodiment of the present disclosure provides a method and a device for unsealing a packaging structure.
[0004] In a first aspect, an embodiment of the present disclosure provides a method for unsealing a package structure, wherein the package structure includes a chip and a plastic packaging layer covering the chip, and the method includes:
[0005] Determining a to-be-unsealed area in the packaging structure;
[0006] Thinning the plastic sealing layer located in the area to be unsealed to form a first groove;
[0007] dripping an etching liquid into the first groove, removing the thinned plastic sealing layer by the etching liquid, and forming a second groove;
[0008] The second groove is cleaned to expose the surface of the chip.
[0009] In some embodiments, the plastic sealing layer located in the area to be unsealed is thinned to form a first groove, including:
[0010] Measuring the thickness of the plastic sealing layer in the area to be unsealed;
[0011] The plastic sealing layer in the area to be unsealed is ground until the distance from the chip surface reaches a preset distance, and then the grinding stops to form the first groove.
[0012] In some embodiments, the grinding accuracy is ±5 microns;
[0013] The preset distance has a value range of 10±5 microns.
[0014] In some embodiments, after forming the second groove, the method further includes:
[0015] The etching solution after reaction in the second groove is absorbed.
[0016] In some embodiments, cleaning the second groove to expose the surface of the chip includes:
[0017] Pre-cleaning the second groove using a first cleaning liquid;
[0018] The second groove is rinsed with a second cleaning solution to expose the surface of the chip.
[0019] In some embodiments, pre-cleaning the second groove with a first cleaning solution includes:
[0020] dripping a first cleaning liquid into the second groove, and heating the packaging structure to a preset temperature;
[0021] After a preset time, the first cleaning liquid after the reaction is removed to complete the pre-cleaning of the second groove.
[0022] In some embodiments, flushing the second groove with a second cleaning liquid includes:
[0023] Under the action of ultrasonic waves, the second groove is rinsed with the second cleaning liquid.
[0024] In some embodiments, the etching solution is 98% fuming nitric acid;
[0025] The first cleaning solution is CU-7;
[0026] The second cleaning liquid is acetone.
[0027] In a second aspect, an embodiment of the present disclosure provides an unsealing device, comprising:
[0028] A determination module, used to determine a to-be-unsealed area in the packaging structure; the packaging structure comprises a chip and a plastic packaging layer covering the chip;
[0029] A thinning module, used for thinning the plastic sealing layer located in the area to be unsealed to form a first groove;
[0030] An unsealing module, used for dripping an etching liquid into the first groove, removing the thinned plastic sealing layer by the etching liquid, and forming a second groove;
[0031] A cleaning module is used to clean the second groove to expose the surface of the chip.
[0032] In some embodiments, the thinning module includes a grinding head having a diameter smaller than a preset diameter; and the grinding head is in a pointed shape.
[0033] The embodiment of the present disclosure provides a method and device for unsealing a package structure; wherein the package structure includes a chip and a plastic layer covering the chip; the method for unsealing a package structure includes: determining a region to be unsealed in the package structure; thinning the plastic layer located in the region to be unsealed to form a first groove; dripping an etching liquid into the first groove, removing the thinned plastic layer by the etching liquid to form a second groove; cleaning the second groove to expose the surface of the chip. On the one hand, since the plastic layer in the region to be unsealed is thinned, the first groove is formed in the region to be unsealed, which not only ensures that the size of the region to be unsealed is regular after unsealing, but also avoids overflow of the etching liquid and prevents the etching liquid from etching other regions; on the other hand, since the thickness of the thinned plastic layer is relatively thin, the thinned plastic layer (i.e., the bottom of the first groove) can be removed using a small amount of etching liquid and a short time, which not only reduces the etching of the side wall of the first groove by the etching liquid, ensures that the size of the second groove is the same as that of the design, but also reduces the residual etching liquid, and ensures the accuracy of the subsequent test structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Figures 1 to 4 A schematic diagram of the structure of the unsealing process of the packaging structure in the related art;
[0035] Figure 5 A schematic diagram of a process of unsealing a packaging structure provided by an embodiment of the present disclosure;
[0036] Figures 6 to 10 A schematic diagram of the unpacking process of the packaging structure in the embodiment of the present disclosure;
[0037] Fig.11 It is a schematic diagram of the structure of a grinding head provided in an embodiment of the present disclosure. DETAILED DESCRIPTION
[0038] The present disclosure is further described in detail below in conjunction with the accompanying drawings and embodiments.
[0039] It should be understood that the embodiments provided herein are only used to explain the present disclosure and are not intended to limit the present disclosure. In addition, the embodiments provided below are partial embodiments for implementing the present disclosure, rather than providing all embodiments for implementing the present disclosure. In the absence of conflict, the technical solutions recorded in the embodiments of the present disclosure can be implemented in any combination.
[0040] In the following description, the terms "first\second\..." are merely used to distinguish different objects, and do not imply that the objects are identical or related.
[0041] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element. The term "connected" includes both direct and indirect connections unless otherwise specified.
[0042] Before introducing the embodiments of the present disclosure, the three directions that may be used in the following embodiments to describe the three-dimensional structure are defined. Taking the Cartesian coordinate system as an example, the three directions may include the X-axis, Y-axis, and Z-axis directions. The X-axis direction and the Y-axis direction are located on the plane where the packaging structure is located and are perpendicular to each other; the Z-axis direction is perpendicular to the plane where the packaging structure is located.
[0043] Figures 1 to 4 The unsealing process of the package structure in the related art is shown. First, please refer to Figure 1 and Figure 2 , wrap the packaging structure 10 with the tape 11, and expose the unsealed area A; next, please refer to Figure 3 and Figure 4 , under the heating condition of the heating table 13, the etching liquid (such as 98% fuming nitric acid) is dripped into the unsealing area A through the dropper 12, and the plastic sealing material 14 in the unsealing area A is removed to expose the chip 15; finally, the tape 11 is removed, and the excess etching liquid and dirt are removed by ultrasonic cleaning. However, this method has the following disadvantages when unsealing:
[0044] 1) Since there is a gap between the tape 11 and the packaging structure 10, the etching solution can easily flow through the gap to the back of the packaging structure 10, causing the printed circuit board (PCB) on the back of the packaging structure 10 to corrode, resulting in failure of the electrical function of the packaging structure 10.
[0045] 2) Since it is difficult to completely clean the tape 11 on the surface of the package structure 10, when the package structure 10 is unpacked and tested, the uncleaned tape 11 on the test pins (ie, solder balls) may affect the test results.
[0046] 3) Since the plastic encapsulation material 14 on the surface of the chip 15 is relatively thick, a large amount of etching solution and a long etching time are required when removing the plastic encapsulation material 14 in the unsealed area A, which makes the unsealed area (such as Figure 4 The dotted area is irregular and exceeds the designed size.
[0047] 4) After etching with the etching solution, polymer residues are likely to remain on the surface of the chip 15, which will subsequently produce a serious charging effect under a microscope, thereby affecting the accuracy of circuit editing.
[0048] Based on this, the embodiment of the present disclosure provides a method for unsealing a packaging structure. Figure 5 A schematic diagram of a process for unsealing a packaging structure provided by an embodiment of the present disclosure, such as Figure 5 As shown, the method includes the following steps S110 to S140.
[0049] Step S110, determining a region to be unsealed in the packaging structure.
[0050] In the disclosed embodiment, the packaging structure includes a chip and a plastic layer covering the chip. The number of chips can be one or multiple chips (for example, 4) stacked together; the type of chip can be a dynamic random access memory (DRAM) chip, a static random access memory (SRAM) chip, a phase-change memory (PCM) chip, a NAND flash memory chip or a Nor Flash chip, etc. The plastic layer is used to protect and electromagnetically shield the chip; the material of the plastic layer may include a polyimide layer, a silicone layer, an epoxy resin layer or a curable resin-based material layer, etc.
[0051] In the disclosed embodiments, the area to be opened refers to: when performing chip testing, fault analysis, reverse engineering or repair operations on the chip in the package structure, it is necessary to remove part of the plastic sealing layer on the chip surface to expose the area to be operated on the chip. In addition, the size and position of the area to be opened are determined by the location of the circuit element to be operated on the chip, that is, the area to be opened at least includes the location of the circuit element.
[0052] Step S120, thinning the plastic sealing layer in the area to be unsealed to form a first groove.
[0053] In the disclosed embodiment, the plastic sealing layer in the area to be opened can be thinned by any suitable process, for example, mechanical grinding; specifically, the packaging structure can be fixed on a grinder, and then the plastic sealing layer in the area to be opened can be ground by controlling grinding parameters (such as grinding speed, pressure, etc.) to form the first groove.
[0054] It should be noted that in order to avoid damaging the circuit components on the chip during the thinning process, the thickness of the plastic packaging layer needs to be determined before the thinning process, so as to ensure the integrity and safety of the chip during the thinning process.
[0055] In the embodiment of the present disclosure, the plastic sealing layer of the area to be opened is thinned so that a first groove is formed in the area to be opened. This not only ensures that the size of the area to be opened is regular after opening, but also prevents the etching liquid from overflowing and preventing the etching liquid from etching other areas.
[0056] Step S130 , dripping an etching liquid into the first groove, removing the thinned plastic packaging layer with the etching liquid, and forming a second groove.
[0057] In the disclosed embodiment, the etching solution may be any solution that can remove the plastic sealing layer; for example, it may be fuming nitric acid with a concentration of 98%.
[0058] In the embodiment of the present disclosure, since the thickness of the thinned plastic sealing layer is relatively thin, the thinned plastic sealing layer (i.e., the bottom of the first groove) can be removed using a small amount of etching solution and a shorter time. This not only reduces the etching of the side wall of the first groove by the etching solution, thus ensuring that the second groove has the same size as designed, but also reduces the residual etching solution, thereby ensuring the accuracy of the subsequent test structure.
[0059] Step S140, cleaning the second groove to expose the surface of the chip.
[0060] In the embodiment of the present disclosure, since reacted polymer and etching solution are likely to remain in the second groove after the thinning process, the residual polymer and residual etching solution can be removed by cleaning the second groove, so that the exposed surface of the chip is cleaner, which is convenient for subsequent testing, repair or other operations.
[0061] Combine the following Figures 6 to 10 The unpacking method of the packaging structure provided by the embodiment of the present disclosure is described in detail.
[0062] First, please refer to Figure 6 , execute step S110 to determine the area B to be unsealed in the packaging structure 100.
[0063] Here, if Figure 6 As shown, the package structure 100 may include a PCB board 130, a plurality of chips 120 (four chips are shown) stacked on the PCB board 130, and a plastic packaging layer 110 covering the PCB board 130 and the chips 120. The plurality of chips 120 may be stacked in a step shape, and metal wires 121 are connected between the step surfaces of adjacent chips and between the bottom chip 120 and the PCB board 130; and solder balls 131 are provided on the back of the PCB board 130.
[0064] In the embodiment of the present disclosure, the area B to be opened is determined according to the purpose of opening the package structure 100 (such as chip testing, fault analysis, etc.); wherein, the scope of the area B to be opened needs to be as small as possible, and the circuit elements to be tested need to be fully exposed, so that the scope of damage to the package structure 100 can be reduced when opening. Specifically, the circuit elements of the chip 120 that need to be exposed (i.e., the surface of the chip 120 that needs to be exposed) can be determined by non-destructive testing technologies such as X-ray scanning and ultrasonic microscopy; then, the scope and shape of the area B to be opened are determined according to the position of the circuit elements.
[0065] Next, please refer to Figure 6 and Figure 7 , executing step S120, thinning the plastic sealing layer 110 located in the to-be-unsealed area B to form a first groove 111.
[0066] In some embodiments, step S120 includes: step S121 and step S122.
[0067] Step S121 , measuring the thickness of the plastic sealing layer 110 in the area B to be unsealed.
[0068] In the embodiments of this disclosure, please refer to Figure 6 , the thickness d1 of the plastic sealing layer 110 in the to-be-opened area B can be measured by using an appropriate technique such as an ultrasonic microscope. In this way, it is possible to avoid damaging the circuit components on the chip during the thinning process, thereby ensuring the integrity and safety of the chip during the thinning process.
[0069] Step S122 , grinding the plastic packaging layer 110 in the unsealed area B until the distance from the surface of the chip 120 reaches a preset distance, and then stopping to form a first groove 111 .
[0070] In the embodiments of this disclosure, please refer to Figure 7 The plastic sealing layer 110 of the unsealed area B can be thinned by any suitable process. For example, mechanical grinding; specifically, the packaging structure 100 can be fixed on a grinder (not shown), and then the plastic sealing layer 110 of the unsealed area B can be ground by controlling grinding parameters (such as grinding speed, pressure, etc.) to form the first groove 111.
[0071] In some embodiments, the grinding accuracy is ±5 microns, which makes the grinding accuracy higher, reduces the damage to the packaging structure 100, and improves the stability and reliability of subsequent processes.
[0072] In some embodiments, please refer to Figure 7The preset distance d2 has a value range of 10±5 micrometers. In this way, the distance between the surface of the chip 120 and the bottom of the first groove 111 is ensured to be within a reasonable range, which is beneficial to the stability and reliability of subsequent processes.
[0073] In the embodiment of the present disclosure, since the plastic sealing layer 110 of the area B to be opened is thinned, a first groove 111 is formed in the area B to be opened. This not only ensures that the size of the area B to be opened is regular after opening, but also prevents the etching liquid from overflowing and prevents the etching liquid from etching other areas.
[0074] Next, please refer to Figure 8 , executing step S130 , dripping an etching solution 113 into the first groove 111 , removing the thinned plastic layer 110 by the etching solution 113 , and forming a second groove 112 .
[0075] In the disclosed embodiment, the etching solution can be any solution that can remove the plastic sealing layer; for example, it can be 98% fuming nitric acid. Specifically, at room temperature, a syringe made of acid-proof material (such as polypropylene material) can be used to inject 98% fuming nitric acid into the first groove 111; in this way, overflow of the etching solution can be avoided, and the etching solution can be prevented from etching other areas.
[0076] In the disclosed embodiment, since the thickness of the thinned plastic sealing layer is relatively thin (10±5 microns), the thinned plastic sealing layer (i.e., the bottom of the first groove) can be removed using a small amount of etching solution and a shorter time. This not only reduces the etching of the side wall of the first groove by the etching solution, ensuring that the second groove has the same size as designed, but also reduces the residual etching solution, thereby ensuring the accuracy of the subsequent test structure.
[0077] In some embodiments, please refer to Fig. 9 After forming the second groove 112 , the unsealing method further includes: absorbing the reacted etching solution 113 in the second groove 112 .
[0078] Specifically, after the etching solution completely etches the thinned plastic sealing layer, the excess etching solution can be absorbed with an acid-absorbing cotton swab to reduce the contamination of the etching solution to other areas. Here, after the etching solution 113 is absorbed, the surface of the chip 120 located in the unsealed area B is exposed; however, at this time, the polymer produced by the reaction of the treatment solution 113 and the remaining etching solution 113 are still left on the surface of the chip 120.
[0079] Finally, please refer to Fig. 9 and Fig.10 , executing step S140 , cleaning the second groove 112 to expose the surface of the chip 120 .
[0080] In some embodiments, step S140 includes: step S141 and step S142.
[0081] Please refer to Fig. 9 , step S141, pre-cleaning the second groove 112 with a first cleaning solution.
[0082] In some embodiments, step S141 specifically includes: dripping a first cleaning liquid into the second groove 112 and heating the package structure 100 to a preset temperature; after a preset time, removing the reacted first cleaning liquid to complete pre-cleaning of the second groove 112 .
[0083] Here, the first cleaning solution can be any suitable solution, for example, CU-7 (polyimide resin solvent). The preset temperature can be any suitable temperature in the range of 60 degrees to 150 degrees; for example, the preset temperature is 150 degrees; wherein the preset temperature can be Fig. 9 The heating stage 140 shown is provided. The preset time is the time required to completely remove the polymer and the residual treatment liquid, for example, the preset time is 2 minutes.
[0084] Step S142 , washing the second groove 112 with a second cleaning solution to expose the surface of the chip 120 .
[0085] In some embodiments, step S142 specifically includes: flushing the second groove 112 with a second cleaning liquid under the action of ultrasound.
[0086] Here, the second cleaning liquid can be any suitable solution, for example, the second cleaning liquid is acetone.
[0087] It should be noted that the polymer and the residual treatment liquid may also be removed by other suitable methods, and the present disclosure is not limited thereto.
[0088] In the embodiment of the present disclosure, since reacted polymer and etching solution are likely to remain in the second groove after the thinning process, the residual polymer and residual etching solution can be removed by cleaning the second groove, so that the exposed surface of the chip is cleaner, which is convenient for subsequent testing, repair or other operations.
[0089] In summary, compared with the prior art, the embodiments of the present disclosure have the following advantages:
[0090] 1) Since there is no need to use tape to wrap the area outside the to-be-unsealed area B during the unsealing process of the packaging structure, it not only avoids acid seepage through the gap between the tape and the packaging structure, which may cause corrosion of the PCB board, but also avoids the problem of difficulty in cleaning the tape on the surface of the packaging structure after unsealing, so that the electrical function of the packaging structure after unsealing is better.
[0091] 2) The amount of etching solution during etching is small, and the etching solution will not overflow in the first groove, thereby preventing the etching solution from etching and contaminating other areas.
[0092] 3) Since the unsealed area is first thinned by grinding, and the grinding accuracy is high (micrometer level), the shape of the first groove is relatively regular and matches the designed size; further, since the plastic encapsulation layer 110 is thinner after thinning and less etching liquid is used, when the second groove is formed, even if the etching liquid etches the side wall of the second groove, there is only a slight side hollowing on the side wall of the second groove, that is, the exposed area of the chip basically matches the designed area (that is, the area to be unsealed B).
[0093] 4) The polymer can be completely removed by a first cleaning solution (such as CU-7) under heating conditions, thereby not affecting the subsequent imaging of the chip under a microscope and the accuracy of circuit editing.
[0094] In addition, the embodiment of the present disclosure further provides a decapsulation device for the package structure 100, including:
[0095] The determination module is used to determine the to-be-unsealed area A in the package structure 100 ; the package structure 100 includes a chip 120 and a plastic packaging layer 110 covering the chip 120 .
[0096] Here, the determination module may include equipment that can perform non-destructive testing, such as X-ray scanning equipment and ultrasonic microscopy equipment. Through these equipment, the circuit elements that need to be exposed in the chip 120 (i.e., the surface of the chip 120 that needs to be exposed) can be determined; then, according to the position of the circuit elements, the range and shape of the area to be unsealed B can be determined.
[0097] The thinning module is used to perform a thinning process on the plastic sealing layer 110 located in the to-be-unsealed area A to form a first groove 111 .
[0098] In some embodiments, the thinning module may include a device such as a grinder that can perform a thinning process. The packaging structure 100 may be fixed on a grinder (not shown), and then the plastic sealing layer 110 of the unsealed area B may be ground by controlling grinding parameters (such as grinding speed, pressure, etc.) to form the first groove 111.
[0099] In some embodiments, please refer to Fig.11 The thinning module (ie, the grinding machine) may include a grinding head 200 having a diameter smaller than a preset diameter; the grinding head 200 is in a pointed shape.
[0100] In the embodiment of the present disclosure, the material of the grinding head 200 can be a material that can be ground, such as diamond. The preset diameter can be less than 0.5 mm. In addition, please continue to refer to Fig.11The grinding head is pointed rather than flat. The pointed grinding head can cut into the material more easily when thinning the plastic packaging material, while avoiding damage to the chip caused by excessive local pressure.
[0101] The unsealing module is used to drip an etching solution into the first groove 111 to remove the thinned plastic sealing layer 110 and form a second groove 112 .
[0102] In the disclosed embodiment, the unsealing module may be a syringe made of acid-proof material (eg, polypropylene); thus, the etching solution (eg, 98% fuming nitric acid) is injected into the first groove 111 through the syringe.
[0103] The cleaning module is used to clean the second groove 112 and expose the surface of the chip 120 .
[0104] In the embodiment of the present disclosure, the cleaning module may include a heating platform 140 (such as Fig. 9 As shown in FIG. 1 , the speed of pre-cleaning can be accelerated by heating the platform 140. The cleaning module can also include an ultrasonic device, which can reduce the adhesion of pollutants such as polymers in the second groove (or on the chip surface).
[0105] The description of the above device embodiment is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment. For technical details not disclosed in the device embodiment of the present disclosure, please refer to the description of the method embodiment of the present disclosure for understanding.
[0106] The above description of the various embodiments tends to emphasize the differences between the various embodiments, and reference can be made to the same or similar aspects thereof.
[0107] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present disclosure. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present disclosure, the size of the serial number of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present disclosure. The serial numbers of the embodiments of the present disclosure are for description only and do not represent the advantages and disadvantages of the embodiments.
[0108] In the several embodiments provided in the present disclosure, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative.
[0109] The methods disclosed in several method embodiments provided in the present disclosure can be arbitrarily combined without conflict to obtain new method embodiments. The features disclosed in several method or device embodiments provided in the present disclosure can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.
[0110] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the protection scope of the present disclosure. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.
Claims
1. A method for unsealing a packaging structure, characterized in that: The packaging structure includes a chip and a plastic packaging layer covering the chip, and the method includes: Determining a to-be-unsealed area in the packaging structure; Thinning the plastic sealing layer located in the area to be unsealed to form a first groove; dripping an etching liquid into the first groove, removing the thinned plastic sealing layer by the etching liquid, and forming a second groove; The second groove is cleaned to expose the surface of the chip.
2. The method according to claim 1, characterized in that The plastic sealing layer located in the area to be unsealed is thinned to form a first groove, comprising: Measuring the thickness of the plastic sealing layer in the area to be unsealed; The plastic sealing layer in the area to be unsealed is ground until the distance from the chip surface reaches a preset distance, and then the grinding stops to form the first groove.
3. The method according to claim 2, characterized in that The grinding accuracy is ±5 microns; The preset distance has a value range of 10±5 microns.
4. The method according to claim 1, characterized in that: After forming the second groove, the method further includes: The etching solution after reaction in the second groove is absorbed.
5. The method according to claim 1, characterized in that Cleaning the second groove to expose the surface of the chip includes: Pre-cleaning the second groove using a first cleaning liquid; The second groove is rinsed with a second cleaning solution to expose the surface of the chip.
6. The method according to claim 5, characterized in that Pre-cleaning the second groove using a first cleaning liquid includes: dripping a first cleaning liquid into the second groove, and heating the packaging structure to a preset temperature; After a preset time, the first cleaning liquid after the reaction is removed to complete the pre-cleaning of the second groove.
7. The method according to claim 5, characterized in that Flushing the second groove with a second cleaning liquid includes: Under the action of ultrasonic waves, the second groove is rinsed with the second cleaning liquid.
8. The method according to claim 5, characterized in that The etching solution is 98% fuming nitric acid; The first cleaning solution is CU-7; The second cleaning liquid is acetone.
9. An unsealing device for a packaging structure, characterized in that: include: A determination module, used for determining a to-be-unsealed area in the packaging structure; The packaging structure includes a chip and a plastic packaging layer covering the chip; A thinning module, used for thinning the plastic sealing layer located in the area to be unsealed to form a first groove; An unsealing module, used for dripping an etching liquid into the first groove, removing the thinned plastic sealing layer by the etching liquid, and forming a second groove; A cleaning module is used to clean the second groove to expose the surface of the chip.
10. The unsealing device according to claim 9, characterized in that: The thinning module comprises a grinding head with a diameter smaller than a preset diameter; the grinding head is in a pointed shape.