A method for chemically opening a chip

Abstract

A method for chemically opening a chip includes: obtaining a chip to be opened, the chip comprising a chip body and an underfill adhesive layer attached to the chip body; applying a first swelling agent to the underfill adhesive layer to soften the underfill adhesive layer; removing the softened underfill adhesive layer to obtain the chip body; applying a second swelling agent to the encapsulation layer of the chip body to remove the encapsulation layer; and cleaning the encapsulation layer to complete the opening. The chemical chip opening method provided in this application opens the chip using chemical reagents, easily removing the underfill adhesive layer without damaging the IC layer of the chip.

Description

Technical Field

[0001] This invention belongs to the field of chip opening technology, specifically relating to a method for chemically opening chips. Background Technology

[0002] Chips are frequently used components widely applied in various fields. When a chip malfunctions, the IC layer (Integrated Circuit layer) needs to be repaired and inspected. This requires exposing the IC layer, which is protected by a packaging layer. Therefore, the packaging layer must be removed before repair and inspection can proceed. However, during chip use, an underfill adhesive layer is often attached to the packaging layer. Currently, the method for removing the underfill adhesive layer and packaging layer involves direct acid etching. However, during the invention process, the applicant discovered that both the underfill adhesive layer and the packaging layer are organic materials and can be etched by nitric acid. The packaging layer etches faster than the underfill adhesive layer. Because the thickness of the underfill adhesive layer varies, the circuitry in areas not covered by the underfill adhesive layer is corroded, making repair and inspection impossible. Furthermore, when inspecting a chip, the presence of the packaging layer and underfill adhesive layer at the bottom obstructs the view of the IC layer. Therefore, it is necessary to remove the packaging layer and underfill adhesive layer without damaging the IC layer. Summary of the Invention

[0003] In view of the above problems, the present invention provides a chip chemical unlocking method to overcome or at least partially solve the above problems.

[0004] To address the aforementioned technical problems, embodiments of the present invention provide a method for chemically unlocking a chip, the method comprising:

[0005] A chip to be opened is obtained, the chip to be opened includes a chip body and a bottom filler layer attached to the chip body;

[0006] A first swelling agent is applied to the underfill adhesive layer to soften the underfill adhesive layer;

[0007] The softened bottom filler layer is removed to obtain the chip body;

[0008] A second swelling agent is applied to the encapsulation layer of the chip body to remove the encapsulation layer;

[0009] The encapsulation layer is cleaned to complete the unpacking process.

[0010] Optionally, applying the first swelling agent to the bottom filler layer includes:

[0011] The bottom filling adhesive layer is soaked in the first swelling agent;

[0012] The first swelling agent is held on the bottom filler layer for a first preset time.

[0013] Optionally, the first swelling agent is acetone.

[0014] Optionally, the first preset time is 20-40 minutes.

[0015] Optionally, the first preset time is 25-35 minutes.

[0016] Optionally, applying the second swelling agent to the encapsulation layer of the chip body includes:

[0017] The second swelling agent is dripped onto the encapsulation layer;

[0018] The second swelling agent is held on the encapsulation layer for a second preset time.

[0019] Optionally, the second swelling agent is at least one of nitric acid, dilute sulfuric acid, and hydrochloric acid.

[0020] Optionally, the second preset time is 20-40 minutes.

[0021] Optionally, the second preset time is 25-35 minutes.

[0022] Optionally, cleaning the encapsulation layer includes:

[0023] The surface from which the encapsulation layer has been removed is cleaned using a cleaning solution, which may include water, deionized water, or distilled water.

[0024] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0025] This invention provides a method for chemically unpacking a chip. When unpacking the chip, a first swelling agent is first applied to the bottom filler layer of the chip's topmost layer. The first swelling agent softens the bottom filler layer. Then, the bottom filler layer is removed, exposing the encapsulation layer. Next, a second swelling agent is applied to the encapsulation layer, dissolving it. Finally, debris on the encapsulation layer is cleaned, thereby exposing the chip's IC layer. This application achieves clean and convenient removal of the adhesive and encapsulation layer without damaging the IC layer, and allows for clear inspection of any damaged areas in the chip's circuitry after removal. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic flowchart of a chip chemical unlocking method provided in an embodiment of the present invention. Detailed Implementation

[0028] The present invention will be described in detail below with reference to specific embodiments and examples, thereby making the advantages and various effects of the present invention more clearly apparent. Those skilled in the art should understand that these specific embodiments and examples are for illustrative purposes only and are not intended to limit the present invention.

[0029] Throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any conflict, this specification shall prevail.

[0030] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0031] like Figure 1 In this application embodiment, the present invention provides a chip chemical unlocking method, the method comprising the steps of:

[0032] S1: Obtain a chip to be opened, the chip to be opened includes a chip body and a bottom filler layer attached to the chip body;

[0033] In this embodiment, the underfill adhesive used in the underfill layer is also called underfill adhesive, which is an epoxy sealant and is generally used in CSP or BGA underfill processes.

[0034] S2: Apply a first swelling agent to the underfill adhesive layer to soften the underfill adhesive layer;

[0035] As an optional implementation, the

[0036] Applying the first swelling agent to the bottom filler layer includes:

[0037] The bottom filling adhesive layer is soaked in the first swelling agent;

[0038] The first swelling agent is held on the bottom filler layer for a first preset time.

[0039] In this embodiment of the application, the first swelling agent can soften the bottom filling adhesive layer. After the first swelling agent is dripped onto the bottom filling adhesive layer and held for a first preset time, the first swelling agent can completely soften the bottom filling adhesive layer.

[0040] As an optional implementation, the first swelling agent is acetone.

[0041] Specifically, the underfill adhesive layer is generally composed of epoxy organic materials, including C (carbon), H (hydrogen), and O (oxygen) elements, while the encapsulation layer is composed of C (carbon), H (hydrogen), O (oxygen), and N (nitrogen) elements. Acetone can soften the underfill adhesive layer but will not soften the encapsulation layer, and it will not react with the underfill adhesive layer and the encapsulation layer, which is beneficial for the complete removal of the underfill adhesive layer in the future.

[0042] As an optional implementation, the first preset time is 20-40 minutes. Preferably, the first preset time is 25-35 minutes, and more preferably, the first preset time is 30 minutes. After being soaked in acetone for the first preset time, the bottom filler layer can be completely softened, which facilitates the subsequent complete removal of the bottom filler layer.

[0043] Preferably, in this embodiment, the bottom filler layer can be rinsed with liquid. After the first swelling agent softens the bottom filler layer, there may be too much of the first swelling agent, so it needs to be washed away. The washing solution can be water, deionized water, distilled water, etc.

[0044] S3: Remove the softened bottom filler layer to obtain the chip body;

[0045] In this embodiment, a removal tool is used to remove the bottom filler layer. The removal tool can be a knife, awl, or the like.

[0046] S4: Apply a second swelling agent to the encapsulation layer of the chip body to remove the encapsulation layer.

[0047] As an optional implementation, applying the second swelling agent to the encapsulation layer of the chip body includes:

[0048] The second swelling agent is dripped onto the encapsulation layer;

[0049] The second swelling agent is held on the encapsulation layer for a second preset time.

[0050] In this embodiment of the application, the second swelling agent can dissolve the encapsulation layer. After the second swelling agent is dropped onto the encapsulation layer and held for a second preset time, the second swelling agent can completely dissolve the encapsulation layer.

[0051] As an optional implementation, the second swelling agent is at least one of nitric acid, dilute sulfuric acid, and hydrochloric acid. Specifically, the encapsulation layer is generally composed of organic matter, including elements such as C (carbon), H (hydrogen), O (oxygen), and N (nitrogen), and nitric acid, dilute sulfuric acid, and hydrochloric acid can dissolve the encapsulation layer.

[0052] As an optional implementation, the second preset time is 20-40 minutes. Preferably, the second preset time is 25-35 minutes. The bottom filler layer can be completely dissolved after reacting with the second swelling agent, which facilitates the complete removal of the encapsulation layer subsequently.

[0053] S5: Clean the encapsulation layer to complete the unpacking.

[0054] In this embodiment of the application, after the second swelling agent dissolves the encapsulation layer, there may be too much second swelling agent or dirt on the surface. Therefore, it is necessary to clean the surface from which the encapsulation layer has been removed. The cleaning solution can be water, deionized water, distilled water, etc., but acetone and alcohol cannot be used.

[0055] Example 1

[0056] When unpacking the chip, acetone is first applied to the bottom filler layer on the topmost layer of the chip for 25 minutes. The acetone softens the bottom filler layer, thereby removing it and exposing the encapsulation layer. Then, nitric acid is applied to the encapsulation layer for 20 minutes. The nitric acid dissolves the encapsulation layer. At this point, the impurities on the encapsulation layer are cleaned to expose the IC layer of the chip.

[0057] Example 2

[0058] When unpacking the chip, acetone is first applied to the bottom filler layer on the topmost layer of the chip for 25 minutes. The acetone softens the bottom filler layer. Then, the bottom filler layer is cleaned with liquid. After that, the bottom filler layer is removed to expose the encapsulation layer. Then, hydrochloric acid is applied to the encapsulation layer for 35 minutes. The hydrochloric acid dissolves the encapsulation layer. At this time, the impurities on the encapsulation layer are cleaned to expose the IC layer of the chip.

[0059] Example 3

[0060] When unpacking the chip, acetone is first applied to the bottom filler layer on the top of the chip for 35 minutes. The acetone softens the bottom filler layer. Then, the bottom filler layer is cleaned with liquid. After that, the bottom filler layer is removed to expose the encapsulation layer. Then, dilute sulfuric acid is applied to the encapsulation layer for 25 minutes. The dilute sulfuric acid dissolves the encapsulation layer. At this time, the impurities on the encapsulation layer are cleaned to expose the IC layer of the chip.

[0061] Example 4

[0062] When unpacking the chip, acetone is first applied to the bottom filler layer on the topmost layer of the chip for 35 minutes. The acetone softens the bottom filler layer. Then, the bottom filler layer is cleaned with liquid. After that, the bottom filler layer is removed to expose the encapsulation layer. Then, nitric acid is applied to the encapsulation layer for 40 minutes. The nitric acid dissolves the encapsulation layer. At this point, the impurities on the encapsulation layer are cleaned to expose the IC layer of the chip.

[0063] The chip chemical unpacking method provided in this application uses chemical reagents to unpack the chip, which easily removes the bottom filler layer and does not damage the IC layer of the chip.

[0064] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The above descriptions are merely specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

[0065] In summary, the above description is merely a preferred embodiment of the technical solution of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for chemically opening a chip, characterized in that, The method includes: S1: Obtain the chip to be opened, the chip to be opened includes a chip body and a bottom filler layer attached to the chip body; S2: Apply a first swelling agent to the underfill adhesive layer to soften the underfill adhesive layer; S3: Remove the softened bottom filler layer to obtain the chip body; S4: Apply a second swelling agent to the encapsulation layer of the chip body to remove the encapsulation layer; S5: Clean the encapsulation layer to complete the unpacking; The application of the first swelling agent to the bottom filler layer includes: The bottom filling adhesive layer is soaked in the first swelling agent; The first swelling agent is held on the bottom filler layer for a first preset time; The first swelling agent is acetone, and the first preset time is 20min-40min; The step of applying the second swelling agent to the encapsulation layer of the chip body includes: The second swelling agent is dripped onto the encapsulation layer; The second swelling agent is held on the encapsulation layer for a second preset time; The second swelling agent is at least one of nitric acid, dilute sulfuric acid and hydrochloric acid, and the second preset time is 20 min-40 min; Acetone can soften the underfill layer, but it will not soften the encapsulation layer, and it will not react with either the underfill layer or the encapsulation layer.

2. The chip chemical unlocking method according to claim 1, characterized in that, The first preset time is 25min-35min.

3. The chip chemical unlocking method according to claim 1, characterized in that, The second preset time is 25min-35min.

4. The chip chemical unlocking method according to claim 1, characterized in that, The cleaning of the encapsulation layer includes: The surface from which the encapsulation layer has been removed is cleaned using a cleaning solution, which may include water, deionized water, or distilled water.

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