Method for preparing sample by delaminating ceramic packaged chip

Abstract

The application provides a ceramic packaging chip delamination sample preparation method, which comprises the following steps: opening a metal cover of a target chip by grinding or mechanical means, wherein the target chip is packaged by a ceramic; encapsulating the target chip by using encapsulating epoxy glue to obtain an encapsulating epoxy glue sample; placing the encapsulating epoxy glue sample into an oven for hardening to obtain a hardening sample; cutting a ceramic shell of the hardening sample to obtain a cut sample, wherein the cut sample comprises a chip part and encapsulating epoxy glue located around the chip part; and polishing the ground sample to obtain a delaminated chip. The application can perform delamination treatment on a ceramic packaging chip to expose the circuit structure in the ceramic packaging chip and avoid damaging the circuit structure in the ceramic packaging chip.

Description

Technical Field

[0001] This application relates to the field of chip reverse engineering, and more specifically, to a method for preparing samples by removing layers from a ceramic packaged chip. Background Technology

[0002] In some scenarios, it is necessary to remove the layers of the packaged chip in order to analyze the circuit structure of the inner layers of the chip.

[0003] In existing chips, ceramic-packaged chips differ from plastic-packaged chips. Ceramic-packaged chips use the circuit structure of ceramic-packaged chips, while plastic-packaged chips use the internal structure of plastic-packaged chips. Therefore, the delamination methods used for plastic-packaged chips cannot be applied to the delamination of ceramic-packaged chips. Summary of the Invention

[0004] The purpose of this application is to provide a method for delamination of ceramic packaged chips, which is used to perform delamination processing on ceramic packaged chips to expose the circuit structure inside the ceramic packaged chips and avoid damaging the circuit structure inside the ceramic packaged chips.

[0005] Therefore, the first aspect of this application discloses a method for preparing a ceramic packaged chip by delamination, the method comprising:

[0006] The metal cap of the target chip is opened by grinding or mechanical means; the target chip is ceramic-encapsulated.

[0007] The target chip was encapsulated with encapsulating epoxy resin to obtain a sample of encapsulating epoxy resin;

[0008] The sample of the encapsulated epoxy resin was placed in an oven and baked to harden, resulting in a baked and hardened sample.

[0009] The ceramic shell of the baked and hardened sample is cut to obtain the cut sample, which includes a chip portion and an encapsulating epoxy resin around the chip portion.

[0010] The epoxy resin encapsulating the surface of the cut sample is laser-opened until the bonding wire of the cut sample is reached, and the opened sample is obtained.

[0011] The unsealed sample is ground with sandpaper until the passivation layer of the chip in the unsealed sample is reached, and the ground sample is obtained.

[0012] The ground sample is polished to obtain a chip with delamination.

[0013] In this application, the metal cap of a ceramic-encapsulated chip is opened by grinding or mechanical means, and then the target chip is encapsulated with encapsulating epoxy resin to obtain an encapsulating epoxy resin sample. On the other hand, by baking and hardening the encapsulating epoxy resin sample in an oven, a hardened sample is obtained. By cutting the ceramic shell of the hardened sample, a cut sample is obtained, which includes the chip portion and the encapsulating epoxy resin surrounding the chip portion. Furthermore, the encapsulating epoxy resin on the surface of the cut sample is laser-unsealed until the bonding wires of the cut sample are reached, resulting in an unsealed sample. Then, the unsealed sample is ground with sandpaper until the chip passivation layer is reached, resulting in a ground sample. Finally, the ground sample is polished to obtain the de-layered chip.

[0014] In this application, as an optional implementation, in the laser unsealing step of the epoxy resin encapsulating the surface of the cut sample, the power of the laser machine is 10-30KV.

[0015] In the embodiments of this application, the power of the laser machine is 10-30KV, which can quickly open the ceramic-packaged chip, with an opening time of about 1 minute. On the other hand, using a laser machine to open the ceramic-packaged chip can avoid the influence of acid-based opening methods, such as the disadvantage that the metal parts are prone to chemical reactions with acids.

[0016] In this application, as an optional implementation, in the step of grinding the opened sample with sandpaper, the mesh size of the sandpaper is between 6 and 30 micrometers.

[0017] In this optional embodiment, by setting the grit of the sandpaper between 6 and 30 micrometers, it is possible to avoid the sandpaper damaging the circuit structure in the sample after it has been opened.

[0018] In this application, as an optional embodiment, the polishing liquid used in the polishing step of the ground sample is a non-crystalline colloidal silica polishing suspension.

[0019] In this application, an amorphous colloidal silica polishing suspension is used as the polishing liquid, which enables fine polishing of the ground sample.

[0020] In this application, as an optional embodiment, the polishing cloth used in the polishing step of the ground sample is a soft, porous, chemically resistant synthetic cloth.

[0021] In this application, a soft, porous, chemically resistant synthetic cloth is used as the polishing cloth, which enables fine polishing of the ground sample.

[0022] In this application, as an optional embodiment, in the step of placing the encapsulated epoxy resin sample into an oven for baking and curing, the baking temperature of the oven is between 80 and 200°C.

[0023] In this optional embodiment, the baking temperature of the oven is set between 80 and 200°C, which allows the epoxy resin-encapsulated sample to fully harden.

[0024] In this application, as an optional embodiment, the baking temperature of the oven is 90°C.

[0025] In this optional embodiment, the baking temperature of the oven is set at 90°C, which allows the epoxy resin-encapsulated sample to harden sufficiently while avoiding the oven wasting electricity.

[0026] In this application, as an optional embodiment, after encapsulating the target chip with encapsulating epoxy resin and before placing the sample of the encapsulating epoxy resin in an oven for baking and curing, the method further includes:

[0027] The encapsulating epoxy resin is placed in the oven for preheating.

[0028] In this application, since the encapsulating epoxy is taken out of the refrigerator, it is easier to inject the encapsulating epoxy into the target chip by preheating it in the oven, so as to encapsulate the target chip.

[0029] In this application, as an optional implementation, the preheating temperature is 50-100°C. In this embodiment of the application, setting the preheating temperature to 50-100°C enables faster preheating.

[0030] In this application, as an optional implementation, the preheating temperature is 80°C. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 A schematic flowchart illustrating a method for preparing a ceramic packaged chip delamination sample according to an embodiment of this application;

[0033] Figure 2 This is a schematic diagram of the structure of a sample after baking and hardening, provided in an embodiment of this application. Detailed Implementation

[0034] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0035] Please see Figure 1 , Figure 1 This is a schematic flowchart of a ceramic package chip delamination and sample preparation method disclosed in an embodiment of this application. Figure 1 As shown, the ceramic package chip delamination sample preparation method of this application embodiment includes the following steps:

[0036] 101. The metal cap of the target chip is opened by grinding or mechanical means, wherein the target chip is ceramic packaged;

[0037] 102. The target chip is encapsulated with encapsulating epoxy resin to obtain a sample of encapsulating epoxy resin;

[0038] 103. Place the sample encapsulated with epoxy resin in an oven and bake it to harden, to obtain the hardened sample;

[0039] 104. Cut the ceramic shell of the baked and hardened sample to obtain the cut sample, the cut sample including the chip part and the encapsulating epoxy resin around the chip part;

[0040] 105. Laser-open the epoxy resin covering the surface of the cut sample until it reaches the bonding wire position of the cut sample, and obtain the opened sample.

[0041] 106. Use sandpaper to grind the opened sample until the passivation layer of the chip in the opened sample is reached, and the ground sample is obtained.

[0042] 107. Polish the ground sample to obtain a chip after delamination.

[0043] In the embodiments of this application, the sample after baking and hardening is as follows: Figure 2 As shown, Figure 2 In the diagram, the portion outside the dashed lines needs to be cut off, while the circuit structure within the dashed lines is preserved.

[0044] In this embodiment, the metal cap of the ceramic-encapsulated chip is opened by grinding or mechanical means, and then the target chip is encapsulated with encapsulating epoxy resin to obtain an encapsulating epoxy resin sample. On the other hand, by baking and hardening the encapsulating epoxy resin sample in an oven, a hardened sample is obtained. The ceramic shell of the hardened sample is then cut to obtain a cut sample, which includes the chip portion and the encapsulating epoxy resin surrounding the chip portion. Furthermore, the encapsulating epoxy resin on the surface of the cut sample is laser-unsealed until the bonding wires of the cut sample are reached, resulting in an unsealed sample. The unsealed sample is then ground with sandpaper until the chip passivation layer is reached, resulting in a ground sample. Finally, the ground sample is polished to obtain the de-layered chip.

[0045] In this embodiment of the application, as an optional implementation, in the laser unsealing step of the epoxy resin encapsulating the surface of the cut sample, the power of the laser machine is 10-30KV.

[0046] In this embodiment, the laser machine has a power of 10-30KV, enabling rapid decapsulation of ceramic-packaged chips, with an opening time of approximately one minute. Furthermore, using a laser machine to decapsulate ceramic-packaged chips avoids the drawbacks of acid-based methods, such as the tendency for metal components to react chemically with acids. In this embodiment, as an optional implementation, in the step of grinding the decapsulated sample with sandpaper, the mesh size of the sandpaper is between 6 and 30 micrometers.

[0047] In this optional embodiment, by setting the grit of the sandpaper between 6 and 30 micrometers, it is possible to avoid the sandpaper damaging the circuit structure in the sample after it has been opened.

[0048] In this embodiment of the application, as an optional implementation, the polishing liquid used in the polishing step of the ground sample is a non-crystalline colloidal silica polishing suspension.

[0049] In this embodiment, a non-crystalline colloidal silica polishing suspension is used as the polishing liquid, which enables fine polishing of the ground sample.

[0050] In this embodiment of the application, as an optional implementation, the polishing cloth used in the polishing step of the ground sample is a soft, porous, chemically resistant synthetic cloth.

[0051] In this embodiment, a soft, porous, chemically resistant synthetic cloth is used as the polishing cloth, which can perform fine polishing on the ground sample.

[0052] In this application, as an optional embodiment, in the step of placing the encapsulated epoxy resin sample into an oven for baking and curing, the baking temperature of the oven is between 80 and 200°C.

[0053] In this optional embodiment, the baking temperature of the oven is set between 80 and 200°C, which allows the epoxy resin-encapsulated sample to fully harden.

[0054] In this embodiment of the application, as an optional implementation, the baking temperature of the oven is 90°.

[0055] In this optional embodiment, setting the oven temperature to 90°C allows the epoxy resin-encapsulated sample to harden sufficiently while avoiding wasting electricity in the oven.

[0056] In this embodiment of the application, as an optional implementation, after encapsulating the target chip with encapsulating epoxy resin and before placing the sample of the encapsulating epoxy resin in an oven for baking and curing, the method of this embodiment of the application further includes the following:

[0057] The encapsulating epoxy resin is placed in the oven for preheating.

[0058] In this application, since the encapsulating epoxy is taken out of the refrigerator, it is easier to inject the encapsulating epoxy into the target chip by placing it in the oven for preheating, so as to encapsulate the target chip.

[0059] In this application, as an optional implementation, the preheating temperature is 50-100°C. In this embodiment of the application, setting the preheating temperature to 50-100°C enables faster preheating.

[0060] In this application, as an optional implementation, the preheating temperature is 80°C.

[0061] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0062] Furthermore, the units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0063] Furthermore, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0064] It should be noted that if the function is implemented as a software module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0065] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0066] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for preparing a ceramic packaged chip by removing layers, characterized in that, The method includes: The metal cap of the target chip, which is ceramic-encapsulated, is opened by grinding. The target chip was encapsulated with encapsulating epoxy resin to obtain a sample of encapsulating epoxy resin; The sample of the encapsulated epoxy resin was placed in an oven and baked to harden, resulting in a baked and hardened sample. The ceramic shell of the baked and hardened sample is cut to obtain the cut sample, which includes a chip portion and an encapsulating epoxy resin around the chip portion. The epoxy resin encapsulating the surface of the cut sample is laser-opened until the bonding wire of the cut sample is reached, and the opened sample is obtained. The unsealed sample is ground with sandpaper until the passivation layer of the chip in the unsealed sample is reached, and the ground sample is obtained. The ground sample is polished to obtain a chip with delamination.

2. The method as described in claim 1, characterized in that, In the laser unsealing step of the epoxy resin encapsulating the surface of the cut sample, the voltage of the laser machine is 10~30KV.

3. The method as described in claim 1, characterized in that, In the step of grinding the opened sample with sandpaper, the mesh size of the sandpaper is between 6 and 30 micrometers.

4. The method as described in claim 1, characterized in that, The polishing solution used in the polishing step of the ground sample is a non-crystalline colloidal silica polishing suspension.

5. The method as described in claim 1, characterized in that, The polishing cloth used in the polishing step of the ground sample is a soft, porous, chemically resistant synthetic cloth.

6. The method as described in claim 1, characterized in that, In the step of baking and curing the encapsulated epoxy resin sample in an oven, the baking temperature of the oven is between 80 and 200°C.

7. The method as described in claim 1, characterized in that, The baking temperature of the oven is 90℃.

8. The method as described in claim 1, characterized in that, After encapsulating the target chip with encapsulating epoxy resin and before placing the sample of the encapsulating epoxy resin in an oven for baking and curing, the method further includes: The encapsulating epoxy resin is placed in the oven for preheating.

9. The method as described in claim 8, characterized in that, The preheating temperature is 50~100℃.

10. The method as described in claim 8, characterized in that, The preheating temperature is 80°C.

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