Preparation method of packaging structure

Abstract

According to the preparation method of the packaging structure, a supporting structure is provided with a first supporting part and a second supporting part, the first supporting part is located on one side of the second supporting part, and the orthographic projection area of the first supporting part is smaller than the orthographic projection area of the second supporting part in the direction perpendicular to the supporting structure; therefore, the supporting structure forms a step shape. And bonding the first support part with the interposer initial structure, and thinning the interposer initial structure by taking the support structure as a support to obtain the interposer structure. As the orthographic projection surface of the first support part is smaller than the orthographic projection area of the initial structure of the interposer on the projection surface perpendicular to the thickness direction of the support structure, de-bonding is easier when the support structure is removed, the interposer structure does not need to be annularly cut, and the process difficulty is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of integrated circuits, and in particular to a method for preparing a packaging structure. Background Art

[0002] In the traditional through glass via (TVS) process, glass is used as an interposer to replace the silicon interposer. When the glass interposer is used in the transfer process, a temporary glass carrier is required for transfer.

[0003] When debonding the glass interposer from the temporary glass carrier, due to the similar diameters of the two pieces of glass, glue overflow will occur during debonding, and the two pieces of glass cannot be untied. Therefore, the glass interposer needs to be ring-cut during this process. However, the glass interposer needs to be very hard as a cutting object, which increases the technical difficulty of the process. Summary of the invention

[0004] Based on this, the present application provides a method for preparing a packaging structure that is easier to debond and ring cut.

[0005] A method for preparing a packaging structure, comprising:

[0006] A support structure is provided, the support structure comprising a first support portion and a second support portion, the first support portion is located on one side of the second support portion, and on a projection plane perpendicular to a thickness direction of the support structure, an orthographic projection area of ​​the first support portion is smaller than an orthographic projection area of ​​the second support portion;

[0007] Providing an initial structure of the intermediate layer, wherein on a projection plane perpendicular to the thickness direction of the support structure, the orthographic projection area of ​​the first support portion is smaller than the orthographic projection area of ​​the initial structure of the intermediate layer;

[0008] bonding the initial structure of the interposer to the first support portion;

[0009] Using the support structure as support, thinning the side of the initial structure of the intermediate layer away from the support structure to form an intermediate layer structure;

[0010] The support structure is removed.

[0011] In one embodiment, the first supporting portion and the second supporting portion are an integral structure.

[0012] In one embodiment, providing a support structure comprises:

[0013] providing a supporting substrate;

[0014] A circular cut is performed on one side of the support substrate to form the first support portion and the second support portion to obtain the support structure.

[0015] In one embodiment, the first supporting portion and the second supporting portion are made of the same material.

[0016] In one embodiment, the first supporting portion and the second supporting portion are both made of silicon material.

[0017] In one embodiment, bonding one side of the initial structure of the interposer to the first support portion includes:

[0018] A first bonding layer is formed on one side of the initial structure of the intermediate layer, and the first supporting portion is connected through the first bonding layer.

[0019] In one embodiment, removing the support structure comprises:

[0020] The support structure is removed by laser lift-off technology.

[0021] In one embodiment, the interposer initial structure includes an interposer initial sheet, a first wiring layer, and a conductive initial structure, wherein the first wiring layer is located on one side of the interposer initial sheet. After providing an interposer initial structure, the method includes:

[0022] forming an insulating layer on a side of the first wiring layer away from the initial sheet of the interposer;

[0023] forming a through hole on the insulating layer, wherein the through hole exposes the first wiring layer;

[0024] A first bump is formed in the through hole.

[0025] In one embodiment, the step of thinning a side of the initial structure of the intermediate layer away from the support structure with the support structure as support to form the intermediate layer structure includes:

[0026] Performing physical grinding on a side of the initial structure of the interposer away from the first wiring layer;

[0027] A chemical mechanical polishing process is performed on a side of the interposer initial structure away from the first wiring layer, and the remaining interposer initial sheet forms an interposer substrate, and the remaining conductive initial structure forms a conductive structure, thereby obtaining the interposer structure.

[0028] In one embodiment, after forming the interposer structure, the method further comprises:

[0029] A second wiring layer is formed on a side of the interposer structure away from the first wiring layer.

[0030] In the preparation method of the packaging structure, the support structure is provided with a first support portion and a second support portion, and the first support portion is located on one side of the second support portion. Since the orthographic projection area of ​​the first support portion is smaller than the orthographic projection area of ​​the second support portion in the direction perpendicular to the support structure, the support structure forms a step shape. The first support portion is bonded to the initial structure of the intermediary layer, and then the initial structure of the intermediary layer is thinned with the support structure as support to obtain the intermediary layer structure. Since the orthographic projection surface of the first support portion is smaller than the orthographic projection area of ​​the initial structure of the intermediary layer in the projection surface perpendicular to the thickness of the support structure, it is easier to debond when removing the support structure, and there is no need to perform ring cutting on the intermediary layer structure, which reduces the process difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 is a flow chart of a method for preparing a packaging structure provided in an embodiment;

[0033] Figures 2 to 13 It is a schematic diagram of a partial cross-sectional structure of a packaging structure provided in one embodiment.

[0034] Explanation of the accompanying drawings: 01a-support substrate; 01-support structure; 011-first supporting part; 012-second supporting part; 02-initial structure of interposer; 021-initial sheet of interposer; 022-conductive initial structure; 023-first wiring layer; 024-blind hole; 0221-conductive material layer; 02a-interposer structure; 021a-interposer substrate; 022a-conductive structure; 03-insulating layer; 04-patterned photoresist; 05-through hole; 06-first bump; -08 second wiring layer; 07-first bonding layer. DETAILED DESCRIPTION

[0035] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0037] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers, doping types and / or parts, these elements, components, regions, layers, doping types and / or parts should not be limited by these terms. These terms are only used to distinguish an element, component, region, layer, doping type or part from another element, component, region, layer, doping type or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer, doping type or part discussed below can be represented as a second element, component, region, layer or part.

[0038] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientations shown in the figures, spatially relative terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0039] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, in this specification, the term "and / or" includes any and all combinations of the relevant listed items.

[0040] Based on the content in the background technology, glass materials have smaller warping than silicon materials, but as a cutting object, it requires a higher hardness and is more expensive. Ordinary circular cutting knives can generally only cut into the glass to a thickness of about 400um. If it is deeper, it will easily lead to knife breakage. When glass sheets are bonded to glass sheets for circular cutting, the cutting depth even for thinner glass needs to be cut to a depth of more than 600um, which puts a huge load on the knife itself.

[0041] Based on this, the present application provides a method for preparing a packaging structure to solve the above problems.

[0042] In one embodiment, see Figure 1 , a method for preparing a packaging structure is provided, comprising the following steps:

[0043] Step S10: Provide a support structure 01 (such as Figure 3 as shown).

[0044] Among them, the support structure 01 includes a first support part 011 and a second support part 012. The first support part 011 is located on one side of the second support part 012. On the projection plane perpendicular to the thickness direction of the support structure 01, the orthographic projection area of ​​the first support part 011 is smaller than the orthographic projection area of ​​the second support part 012.

[0045] The shapes of the first support portion 011 and the second support portion 012 are not specifically limited. In a direction perpendicular to the plane where the support structure 01 is located, the first support portion 011 is located on one side of the second support portion 012, and the orthographic projection area of ​​the first support portion 011 is smaller than the orthographic projection area of ​​the second support portion 012, so that the first support portion 011 and the second support portion 012 of the support structure 01 form a step structure.

[0046] Step S11: Providing an initial structure of an intermediate layer 02 (such as Fig. 9 as shown).

[0047] Among them, on the projection plane perpendicular to the thickness direction of the support structure 01, the orthographic projection area of ​​the first support portion 011 is smaller than the orthographic projection area of ​​the initial structure 02 of the intermediate layer (such as Fig.10 as shown).

[0048] The intermediary layer initial structure 02 may be a glass intermediary layer, and the intermediary layer initial sheet 021 may be made of glass material.

[0049] The orthographic projection area of ​​the first support portion 011 is smaller than the orthographic projection area of ​​the initial structure of the intermediate layer 02 , so that the contact area between the support structure 01 and the initial structure of the intermediate layer 02 can be reduced.

[0050] Step S12: Bonding the initial structure of the intermediate layer 02 to the first support portion 011 (eg Fig.10 as shown).

[0051] The first support portion 011 is bonded to a side of the initial structure 02 of the interposer layer where the first wiring layer 023 is disposed, and bonding may be performed by using bonding adhesive.

[0052] Step S13: With the support structure 01 as support, a thinning process is performed on a side of the initial structure 02 of the intermediate layer away from the support structure 01 to form an intermediate layer structure 02a (such as Fig.11 as shown).

[0053] The thinning process includes but is not limited to grinding. During the thinning process, the support structure 01 is used as a support to avoid damaging the intermediate layer structure 02a. After thinning, the intermediate layer structure 02a is obtained, wherein the intermediate layer initial sheet 021 after thinning is the intermediate layer substrate 021a, and the conductive initial structure 022 after thinning is the conductive structure 022a.

[0054] Step S14: Remove the support structure 01 (such as Fig.13 as shown).

[0055] By removing the support structure 01, the glass interposer can be obtained.

[0056] In this embodiment, the support structure 01 is provided with a first support portion 011 and a second support portion 012, and the first support portion 011 is located on one side of the second support portion 012. Since the orthographic projection area of ​​the first support portion 011 is smaller than the orthographic projection area of ​​the second support portion 012 in the direction perpendicular to the support structure 01, the support structure 01 forms a step shape. The first support portion 011 is bonded to the initial structure 02 of the intermediate layer, and then the initial structure 02 of the intermediate layer is thinned with the support structure 01 as the support to obtain the intermediate layer structure 02a. Since the orthographic projection surface of the first support portion 011 is smaller than the orthographic projection area of ​​the initial structure 02 of the intermediate layer in the projection surface perpendicular to the thickness of the support structure 01, it is easier to debond when removing the support structure 01, and there is no need to perform ring cutting on the intermediate layer structure 02a, which reduces the process difficulty.

[0057] In one embodiment, the first support portion 011 and the second support portion 012 are an integrated structure.

[0058] Specifically, when the first support portion 011 and the second support portion 012 are made of the same material, the first support portion 011 and the second support portion 012 can be integrally formed, thereby reducing the preparation process and saving costs.

[0059] In one embodiment, step S10 includes:

[0060] Step S101: Provide a supporting substrate 01a (such as Figure 2 as shown).

[0061] Step S102 : performing circular cutting on one side of the supporting substrate 01 a to form a first supporting portion 011 and a second supporting portion 012 , thereby obtaining a supporting structure 01 .

[0062] Specifically, when the first support portion 011 and the second support portion 012 are made of the same material, providing the support substrate 01a includes providing a silicon substrate. The support substrate 01a is then ring-cut so that the silicon at the edge of one side of the support substrate 01a is removed to form a ring-cut region. At this time, the first support portion 011 and the second support portion 012 can be prepared at the same time.

[0063] During the ring cutting, since the support substrate 01a is made of silicon, there are many blade models to choose from when cutting, which reduces the difficulty of preparation. At the same time, the price of silicon is also cheaper than glass.

[0064] At this time, the support structure 01 of the silicon material is taken as the ring cutting object, and the ring cutting is performed separately first to ensure the diameter difference between the intermediate layer structure 02a and the support structure 01, and then bonding is performed. It is easier to debond without cutting the intermediate layer structure 02a, which reduces the technical difficulty of the process.

[0065] In one embodiment, the first support portion 011 and the second support portion 012 are made of the same material.

[0066] Specifically, the materials of the first support portion 011 and the second support portion 012 may be the same. The same materials can make the preparation of the support mechanism easier and save costs.

[0067] In one embodiment, the materials of the first support portion 011 and the second support portion 012 are both silicon materials.

[0068] Specifically, the material of the first support part 011 and the material of the second support part 012 can both be silicon material. It should be noted that, in preparing the support structure 01 having the first support part 011 and the second support part 012 , silicon material is cheaper than glass material.

[0069] It should be noted that the materials of the first support part 011 and the second support part 012 may be different, for example, the material of the first support part 011 is glass material, and the material of the second support part 012 is silicon material. There is no specific limitation on this, and it can be set according to specific needs.

[0070] In one embodiment, Fig.10 As shown, step S12 includes:

[0071] Step S121 : forming a first bonding layer 07 on one side of the initial structure 02 of the interposer, and connecting the first supporting portion 011 through the first bonding layer 07 .

[0072] Specifically, the material of the first bonding layer 07 can be bonding glue, and the first bonding layer 07 is adhered to the surface of the first support portion 011 away from the second support portion 012. The initial structure of the intermediate layer 02 is connected to the first support portion 011 through the first bonding layer 07.

[0073] In this embodiment, the first bonding layer 07 can ensure the stability of the initial structure 02 of the intermediate layer and the supporting structure 01 , and provide a buffering effect to protect the initial structure 02 of the intermediate layer.

[0074] In one embodiment, step S14 includes:

[0075] Laser lift-off technology is used to remove support structures 01.

[0076] Specifically, removing the support structure 01 includes but is not limited to using laser stripping technology. It can also include cutting stripping, chemical corrosion stripping, or heating stripping, etc., which are not specifically limited. It should be noted that using laser stripping technology can improve the accuracy and speed of stripping.

[0077] In one embodiment, the interposer initial structure 02 includes an interposer initial sheet 021, a first wiring layer 023, and a conductive initial structure 022, wherein the first wiring layer 023 is located on one side of the interposer initial sheet 021. After step S12, the following steps are included:

[0078] Step S102: forming an insulating layer 03 (eg, Figure 8 as shown).

[0079] In this step, the insulating layer 03 can play a role of electrical isolation, preventing the first wiring layer 023 from short circuiting, ensuring signal integrity, and protecting the first wiring layer 023 from damage.

[0080] Step S112: forming a through hole 05 on the insulating layer 03, wherein the through hole 05 exposes the first wiring layer 023 (such as Figure 8 as shown).

[0081] It should be noted that, when forming the through hole 05 , a patterned photoresist 04 may be first formed on the insulating layer 03 , and the insulating layer 03 may be etched based on the patterned photoresist 04 to form the through hole 05 .

[0082] Step S122: forming a first bump 06 in the through hole 05 (such as Fig. 9 as shown).

[0083] Specifically, in the above steps, the initial structure 02 of the intermediate layer needs to be prepared first. When preparing the initial structure 02 of the intermediate layer, a glass substrate is first provided, and then a blind hole 024 is made on the glass substrate, and then the blind hole 024 is metallized to obtain an initial sheet 021 of the intermediate layer (such as Figure 4 as shown).

[0084] Then, a conductive material is filled on one side of the initial interposer sheet 021 having the blind hole 024 to form a conductive material layer 0221. The conductive material layer 0221 at least extends beyond the blind hole to ensure that the blind hole 024 is completely filled (e.g., Figure 5 Then, the conductive material is etched and chemically mechanically polished to obtain a conductive initial structure 022 (as shown in FIG. Figure 6 As shown). It should be noted that the conductive material may be a metal material such as copper. In the thickness direction of the initial intermediate layer sheet 021 , the height of the conductive initial structure 022 is less than the thickness of the initial intermediate layer sheet 021 .

[0085] Then, a first wiring layer 023 is formed on the side of the interposer initial sheet 021 where the conductive initial structure 022 is disposed. The first wiring layer 023 is in contact with the conductive initial structure 022 (eg, Figure 7 It should be noted that there may be multiple interconnected first wiring layers 023, which is not specifically limited and is only an example.

[0086] Then, an insulating layer 03 is disposed on the side of the first wiring layer 023 away from the initial interposer sheet 021, and then a through hole 05 is formed on the insulating layer 03 for disposing a first bump 06. The first bump 06 can connect the wiring or circuit elements between different layers to form an electrical path, which is more convenient for connecting with external signals.

[0087] In one embodiment, Fig.11 As shown, step S13 includes:

[0088] Step S131 : performing a physical grinding process on a side of the interposer initial structure 02 away from the first wiring layer 023 .

[0089] Step S132: chemically mechanically polishing the side of the interposer initial structure 02 away from the first wiring layer 023, the remaining interposer initial sheet 021 forms an interposer substrate 021a, and the remaining conductive initial structure 022 forms a conductive structure 022a, thereby obtaining an interposer structure 02a.

[0090] Specifically, the interposer structure 02a includes an interposer substrate 021a, a conductive structure 022a, and a first wiring layer 023. First, a physical grinding process is performed on the side of the interposer initial structure 02 away from the first wiring layer 023, which can increase the grinding speed and improve the preparation speed. Then, a chemical mechanical polishing process is performed to accurately obtain the required interposer structure 02a.

[0091] In this embodiment, physical grinding is performed first, followed by chemical mechanical polishing, which improves the preparation speed while ensuring the accuracy.

[0092] In one embodiment, after forming the interposer structure 02a, the following steps are included:

[0093] A second wiring layer 08 (eg, Fig.12 as shown).

[0094] Specifically, with the support structure 01 as support, the second wiring layer 08 is further formed on the side of the interposer structure 02a away from the first wiring layer 023. It should be noted that the second wiring layer 08 can be multi-layered, and there is no specific limitation. The figure is only an example. It should be noted that the material of the second wiring layer 08 can be copper material. In this embodiment, the second wiring layer 08 can ensure the transmission of signals.

[0095] Based on the above-mentioned preparation method of the packaging structure, compared with the existing preparation method, it is obvious that the preparation method in this application is easier to debond. In addition, since the temporary support structure 01 is cut in the ring, the ring cutting is easier and the difficulty of preparation is reduced.

[0096] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0097] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features of the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0098] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for preparing a packaging structure, characterized in that: include: A support structure is provided, the support structure comprising a first support portion and a second support portion, the first support portion is located on one side of the second support portion, and on a projection plane perpendicular to a thickness direction of the support structure, an orthographic projection area of ​​the first support portion is smaller than an orthographic projection area of ​​the second support portion; Providing an initial structure of the intermediate layer, wherein on a projection plane perpendicular to the thickness direction of the support structure, the orthographic projection area of ​​the first support portion is smaller than the orthographic projection area of ​​the initial structure of the intermediate layer; bonding the initial structure of the interposer to the first support portion; Using the support structure as support, thinning the side of the initial structure of the intermediate layer away from the support structure to form an intermediate layer structure; The support structure is removed.

2. The method for preparing a packaging structure according to claim 1, characterized in that: The first supporting portion and the second supporting portion are an integrated structure.

3. The method for preparing a packaging structure according to claim 2, characterized in that: The method provides a supporting structure, comprising: providing a supporting substrate; A circular cut is performed on one side of the support substrate to form the first support portion and the second support portion to obtain the support structure.

4. The method for preparing a packaging structure according to claim 1, characterized in that: The first supporting portion and the second supporting portion are made of the same material.

5. The method for preparing a packaging structure according to claim 4, characterized in that: The first supporting portion and the second supporting portion are both made of silicon material.

6. The method for preparing a packaging structure according to claim 1, characterized in that: The step of bonding the initial structure of the interposer to the first supporting portion comprises: A first bonding layer is formed on one side of the initial structure of the intermediate layer, and the first supporting portion is connected through the first bonding layer.

7. The method for preparing a packaging structure according to claim 1, characterized in that: The removing of the support structure comprises: The support structure is removed by laser lift-off technology.

8. The method for preparing a packaging structure according to claim 1, characterized in that: The interposer initial structure comprises an interposer initial sheet, a first wiring layer and a conductive initial structure, wherein the first wiring layer is located on one side of the interposer initial sheet. After providing an interposer initial structure, the method comprises: forming an insulating layer on a side of the first wiring layer away from the initial sheet of the interposer; forming a through hole on the insulating layer, wherein the through hole exposes the first wiring layer; A first bump is formed in the through hole.

9. The method for preparing a packaging structure according to claim 8, characterized in that: The method of using the support structure as support and performing a thinning process on a side of the initial structure of the intermediate layer away from the support structure to form an intermediate layer structure includes: Performing physical grinding on a side of the initial structure of the interposer away from the first wiring layer; A chemical mechanical polishing process is performed on a side of the interposer initial structure away from the first wiring layer, and the remaining interposer initial sheet forms an interposer substrate, and the remaining conductive initial structure forms a conductive structure, thereby obtaining the interposer structure.

10. The method for preparing a packaging structure according to claim 9, characterized in that: After the intermediate layer structure is formed, the method includes: A second wiring layer is formed on a side of the interposer structure away from the first wiring layer.

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