A composition for wafer encapsulation, a fan-out package structure comprising the composition, and a method of manufacturing the same

Abstract

The application discloses a composition for wafer packaging, a fan-out packaging structure containing the composition and a preparation method thereof, and the composition comprises, in terms of mass fraction, 75-83 parts of first spherical silica, 5.5-11 parts of first resin, 8.5-13 parts of first curing agent, 0.1-2 parts of first diluent and 0.05-1.15 parts of first accelerator, wherein the D50 of the first spherical silica is 3-6 mu m, the transmittance of the first resin to visible light is not less than 35%, the first resin is selected from an epoxy resin, has the characteristics of good light transmittance, low thermal expansion coefficient and low water absorption rate, can be applied to a wafer-level packaging process to fill the gap between two adjacent convex electric columns, can improve the precision of bonding of a cut wafer to a base carrier, effectively reduces the product failure rate, and improves the stability and reliability of the conductive column.

Description

Technical Field

[0001] This application relates to the field of semiconductor packaging technology, specifically to a composition for wafer packaging, a fan-out packaging structure containing the composition, and a method for preparing the same. Background Technology

[0002] With the rapid development of the semiconductor industry, chips are constantly evolving towards thinner, lighter, higher-performance, lower-power, and more multifunctional designs, thus continuously increasing the demands on wafer-level packaging technology. In recent years, chip feature sizes have approached their physical limits, and advanced packaging technology has become an important way to continue Moore's Law. A series of new packaging technologies have emerged, among which fan-out wafer-level packaging has become one of the most popular new packaging forms due to its advantages such as low cost and high integration. It is widely used in wireless communication, automotive electronics, medical electronics, artificial intelligence, and military electronics, and will provide solid and powerful support for the next generation of compact, high-performance electronic devices.

[0003] Fan-out wafer-level packaging (FLP) technology uses a redistributed layer (RDL) to fan out the circuitry from the conductive pillars of the chip unit to the metal pads of the printed circuit board (PCB), with a portion of the redistributed layer extending beyond the chip edge. FLP employs a wiring design that places I / O contacts outside the chip's dimensions, increasing the number of I / O contacts. The RDL process further expands the usable wiring area of ​​the chip, maximizing its effective area and reducing costs. Furthermore, after solder ball connection, FLP technology allows direct soldering to the PCB without a package carrier, shortening signal transmission distances and improving electrical performance.

[0004] Currently, in fan-out wafer-level packaging, polyimide (PI) is typically used to fill the gap between two adjacent conductive pillars to achieve initial encapsulation. However, PI has a high coefficient of thermal expansion and high water absorption, which can lead to excessive corrosion of the conductive pillars, thereby compromising their stability. For example, the conductive pillars may deform or collapse due to excessive corrosion. Therefore, it is necessary to develop a composition with a low coefficient of thermal expansion and low water absorption that can be used to encapsulate the gap between two adjacent conductive pillars. Summary of the Invention

[0005] This application provides a composition for wafer packaging, a fan-out packaging structure containing the composition, and a method for preparing the same, to provide a composition with a low coefficient of thermal expansion and low water absorption, which can be used to encapsulate the gap between two adjacent conductive pillars.

[0006] In a first aspect, this application provides a composition for wafer packaging, wherein, by weight parts, the composition comprises: 75 to 83 parts of first spherical silicon dioxide, 5.5 to 11 parts of first resin, 8.5 to 13 parts of first curing agent, 0.1 to 2 parts of first diluent, and 0.05 to 1.15 parts of first accelerator;

[0007] The first spherical silica has a D50 of 3μm to 6μm, the first resin has a transmittance of visible light of not less than 35%, and the first resin is selected from epoxy resin.

[0008] Optionally, the viscosity of the first resin is 0.9 Pa·s to 20 Pa·s; and / or

[0009] The viscosity of the composition is 100 Pa·s to 200 Pa·s.

[0010] Optionally, the first resin is selected from one or more of bisphenol A type diglycidyl ether, P-(2,3-epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline, and bisphenol F type epoxy resin ZLF-160U; and / or

[0011] The first curing agent is selected from acid anhydride curing agents; and / or

[0012] The first diluent is selected from one or more of γ-glycidyl oxypropyltrimethoxysilane and C12-14 alkyl glycidyl ethers; and / or

[0013] The first accelerator is selected from latent accelerators.

[0014] Optionally, the first curing agent is selected from one or more of methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and methylnadic anhydride; and / or

[0015] The latency promoter is selected from 2,4,6-tris(dimethylaminomethyl)phenol.

[0016] Secondly, this application provides a fan-out package structure, including:

[0017] Substrate plate;

[0018] Multiple spaced-apart chip units are disposed on one side of the substrate.

[0019] A first packaging section is disposed on one side of the substrate and encapsulates the chip unit; and

[0020] A redistribution layer is electrically connected to the chip unit.

[0021] Each of the chip units includes:

[0022] Bare crystal;

[0023] Multiple spaced-apart conductive pillars are disposed on one side of the bare die; and

[0024] A second encapsulation portion is located on the side of the bare die where the conductive pillar is provided, and the conductive pillar is embedded in the second encapsulation portion. The material of the second encapsulation portion comprises any of the compositions described in the first aspect.

[0025] Optionally, the gap between any two adjacent conductive pillars is 8 μm to 10 μm; and / or

[0026] The height of the conductive pillar is 10μm to 30μm.

[0027] Optionally, the material of the first encapsulation portion is a resin composition, calculated by weight, wherein the resin composition comprises: 86 to 89 parts of second spherical silica, 6 to 7.6 parts of second resin, 4.2 to 6.3 parts of second curing agent, 0.3 to 0.8 parts of second diluent, 0.4 to 1 part of second accelerator, and 0.1 to 0.5 parts of carbon black;

[0028] The second resin is selected from epoxy resin, and the average particle size of the second spherical silica is greater than the average particle size of the first spherical silica.

[0029] Optionally, the D99 of the second spherical silica is 73 μm to 76 μm; and / or

[0030] The second resin is selected from one or more of 1,4-cyclohexanediethanol diglycidyl ether and alicyclic epoxy resin Syna-Epoxy28; and / or

[0031] The second curing agent is selected from one or more of acid anhydride curing agents and amine curing agents; optionally, the second curing agent is selected from one or more of dimethylthiotoluenediamine and methylnadic anhydride; and / or

[0032] The second diluent is selected from terminal epoxy allyl polyether; and / or

[0033] The second accelerator includes adhesion accelerator XY-23-4 and latent accelerator SocoSci SC10208E, wherein the mass ratio of latent accelerator SocoSci SC10208E to adhesion accelerator XY-23-4 is 1:(0.6~3.5).

[0034] Thirdly, this application also provides a method for fabricating a fan-out packaging structure, used to fabricate a fan-out packaging structure as described in any of the second aspects, the method comprising the following steps:

[0035] (1) A prefabricated device is provided, the prefabricated device comprising a wafer and a plurality of conductive pillars, the plurality of conductive pillars being disposed at intervals on one side of the wafer;

[0036] (2) Apply the composition as described in any one of the first aspects to the side of the wafer near the conductive pillar, and fill the space between any two adjacent conductive pillars with the composition as described in any one of the first aspects, and cure to obtain a second encapsulation portion;

[0037] (3) Cut the prefabricated device on which the second encapsulation portion is formed on the surface to obtain multiple chip units;

[0038] (4) Provide a substrate carrier, and bond each of the chip cells to a predefined area of ​​the substrate carrier, wherein any two adjacent chip cells have a gap;

[0039] (5) The chip unit is encapsulated with a resin composition, and the gap between any two adjacent chip units is filled with the resin composition to obtain a first encapsulation portion;

[0040] (6) A plurality of openings are formed in the first encapsulation portion, and the side of each conductive post away from the substrate is respectively exposed to one of the openings; and

[0041] (7) Wiring is performed at the location of each of the openings to obtain a redistribution layer, the redistribution layer being electrically connected to the side of the conductive post away from the substrate.

[0042] Optionally, the prefabricated device further includes a connection layer disposed between the wafer and the conductive pillar; wherein the connection layer includes a plurality of spaced metal sub-units, the wafer and the metal sub-units are electrically connected, the conductive pillars and the metal sub-units are electrically connected, and any two adjacent metal sub-units are filled with passivation material.

[0043] This application provides a composition for wafer packaging, a fan-out packaging structure containing the composition, and a method for preparing the same, which has the following advantages:

[0044] The composition of this application possesses excellent light transmittance, a low coefficient of thermal expansion, and low water absorption, making it applicable to wafer-level packaging processes, such as fan-out wafer-level packaging. The composition can be used to fill the gap between two adjacent convex posts. Firstly, in fan-out wafer-level packaging, it facilitates positioning during the packaging process, thereby improving the accuracy of bonding the diced wafer to the substrate and effectively reducing the product defect rate. Secondly, the composition's low coefficient of thermal expansion reduces warpage to protect components, thus improving the stability of the conductive posts. Thirdly, the composition's low water absorption mitigates corrosion problems of the conductive posts, further enhancing their stability.

[0045] In the preparation method of the fan-out packaging structure of this application, on the one hand, the composition is used to fill the gap between two adjacent conductive pillars to improve the stability and reliability of the conductive pillars and improve the accuracy of bonding the diced wafer to the substrate, which is beneficial to reducing the defect rate of the product; on the other hand, another resin composition is used to encapsulate the chip unit on the substrate, which effectively reduces warpage, thereby improving the stability and encapsulation effect of the fan-out packaging structure. Attached Figure Description

[0046] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0047] Figure 1 This is a schematic diagram of a fan-out packaging structure provided in an embodiment of this application;

[0048] Figure 2 This is a schematic diagram of the prefabricated device in step S10 of a method for fabricating a fan-out packaging structure provided in an embodiment of this application;

[0049] Figure 3 This is a schematic diagram of the structure obtained after step S20 in the fabrication method of a fan-out packaging structure provided in this application embodiment;

[0050] Figure 4 This is a schematic diagram of the structure obtained after step S30 in the fabrication method of a fan-out packaging structure provided in this application embodiment;

[0051] Figure 5 This is a schematic diagram of the structure obtained after step S40 in the fabrication method of a fan-out packaging structure provided in this application embodiment;

[0052] Figure 6 This is a schematic diagram of the structure obtained after step S50 in the fabrication method of a fan-out packaging structure provided in this application embodiment;

[0053] Figure 7 This is a schematic diagram of the structure obtained after step S60 in the fabrication method of a fan-out packaging structure provided in this application embodiment;

[0054] Figure 8 This is a schematic diagram of the chip cell obtained after completing step S70 in a method for fabricating a fan-out packaging structure according to an embodiment of this application.

[0055] The attached figures are labeled as follows:

[0056] 1: Fan-out package structure; 10: Pre-fabricated device; 11: Substrate; 12: Chip unit; 13: First package section; 14: Redistribution layer; 120: Wafer; 121: Bare die; 122: Conductive pillar; 123: Second package section; 124: Connector layer; 1241: Metal sub-unit; 101: Passivation material; 102: Composition; 103: Resin composition; 104: Opening; 105: Circuit. Detailed Implementation

[0057] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0059] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of embodiments. Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0060] As used in this application, the term "comprising" means "including but not limited to".

[0061] As used in this application, "multiple", "various" or similar expressions refer to two (kinds) or more.

[0062] As used in this application, the selection range of "and / or" includes any one of two or more related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" includes three parallel solutions: A, B, and A+B. As another example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (i.e., all connected by "logical OR"), as well as any and all combinations of A, B, C, and D, i.e., combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (i.e., all connected by "logical AND").

[0063] As used in this application, "D50" refers to the particle size corresponding to the cumulative particle size distribution percentage of the first spherical silica reaching 50%, representing the average particle size of the first spherical silica.

[0064] As used in this application, "D99" refers to the particle size at which the cumulative particle size distribution percentage of the second spherical silica reaches 99%.

[0065] The applicant discovered that in fan-out wafer-level packaging, to improve the stability of conductive pillars, the composition used to encapsulate the gap between two adjacent conductive pillars should possess good light transmittance, a low coefficient of thermal expansion, and low water absorption. Specifically, after dicing, the wafer needs to be bonded to a substrate. To improve bonding accuracy, the composition used to encapsulate the gap between two adjacent conductive pillars should have good light transmittance to facilitate positioning; to reduce warpage and protect components, the composition used to encapsulate the gap between two adjacent conductive pillars should have a low coefficient of thermal expansion; and to mitigate corrosion of the conductive pillars and improve their stability, the composition used to encapsulate the gap between two adjacent conductive pillars should have low water absorption.

[0066] Based on this, embodiments of this application provide a composition for wafer packaging, which can be used to encapsulate the gap between two adjacent conductive pillars. The composition comprises, by weight parts: 75 to 83 parts of first spherical silicon dioxide, 5.5 to 11 parts of first resin, 8.5 to 13 parts of first curing agent, 0.1 to 2 parts of first diluent, and 0.05 to 1.15 parts of first accelerator.

[0067] In the compositions of this application embodiment, the mass fraction of the first spherical silica can be, for example, 75 parts, 76 parts, 77 parts, 78 parts, 79 parts, 80 parts, 81 parts, 82 parts, 83 parts, or any value between any two of the aforementioned mass fractions. The D50 of the first spherical silica is 3 μm to 6 μm, for example, 3 μm, 4 μm, 5 μm, 6 μm, or any value between any two of the aforementioned values.

[0068] It should be noted that the first spherical silica acts as a filler in the composition, reducing the coefficient of thermal expansion and thus lowering the water absorption rate. When the average particle size of the first spherical silica is at a specific value, a higher content of the first spherical silica in the composition is more beneficial for reducing the coefficient of thermal expansion. Furthermore, given a specific content of the first spherical silica in the composition, a smaller particle size results in greater opacity and poorer light transmittance.

[0069] In the compositions of this application embodiment, the first resin is the main compound of the composition. The mass fraction of the first resin can be, for example, 5.5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, or any value between any two of the aforementioned values. The transmittance of the first resin to visible light is one of the key factors affecting the light transmittance of the composition. In the embodiments of this application, the transmittance of the first resin to visible light is not less than 35%, for example, not less than 40%, not less than 50%, not less than 60%, not less than 70%, not less than 80%, not less than 90%, or not less than 95%. The first resin is selected from epoxy resin.

[0070] To further improve the reliability of the composition, in some embodiments of this application, the viscosity of the composition is 100 Pa·s to 200 Pa·s, for example, 100 Pa·s, 120 Pa·s, 150 Pa·s, 180 Pa·s, 200 Pa·s, and any two of the aforementioned values, so as to improve the fluidity of the composition, thereby reducing the printing push required to cover the wafer in wafer packaging, and improving the problem of conductive pillar deformation and collapse caused by excessive printing push.

[0071] It should be noted that the viscosity of the composition should not be too low to avoid jetting during high-temperature (e.g., 110°C) printing. The content of the first spherical silica, the content of the first diluent, and the viscosity of the first resin are all key factors affecting the viscosity of the composition. When the types and contents of other components in the composition, except for the first diluent, remain constant, a higher content of the first diluent is more beneficial for reducing the viscosity of the composition. When the types and contents of other components in the composition, except for the first resin, remain constant, and the content of the first resin remains constant, a lower viscosity of the first resin is more beneficial for reducing the viscosity of the composition. When the types and contents of other components in the composition, except for the first spherical silica, remain constant, and the content of the first spherical silica remains constant, a smaller particle size of the first spherical silica results in a higher filling density of the first spherical silica, which is more beneficial for increasing the viscosity of the composition.

[0072] In order to reduce the viscosity of the composition, in some embodiments of this application, the viscosity of the first resin is 0.9 Pa·s to 20 Pa·s, for example, 0.9 Pa·s, 1 Pa·s, 3 Pa·s, 5 Pa·s, 8 Pa·s, 10 Pa·s, 13 Pa·s, 15 Pa·s, 18 Pa·s, 20 Pa·s, and any two of the aforementioned values.

[0073] As an example, the first resin is selected from one or more of bisphenol A type diglycidyl ether, P-(2,3-epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline, and bisphenol F type epoxy resin ZLF-160U. The bisphenol A type diglycidyl ether can be Dow DER332 or Phoenix Epoxy Resin E-51 (Jinan Qingtian Chemical Co., Ltd.); the bisphenol F type epoxy resin ZLF-160U can be purchased from Zhilun Ultrapure Epoxy Resin (Xi'an) Co., Ltd.

[0074] In the compositions of this application, the first curing agent can react with the first resin to cure the first resin. The mass fraction of the first curing agent can be, for example, 8.5 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, or any value between any two of the aforementioned values. In some embodiments of this application, the first curing agent is selected from anhydride curing agents, including but not limited to one or more of methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and methylnadic anhydride.

[0075] In the compositions of this application embodiment, a first diluent is used to adjust the viscosity of the composition to facilitate further processing and to promote compatibility between the first spherical silica and the first resin. The mass fraction of the first diluent can be, for example, 0.1 parts, 0.5 parts, 1 part, 1.3 parts, 1.5 parts, 1.8 parts, 2 parts, and any two of the aforementioned values. As an example, the first diluent is selected from one or more of γ-glycidoxypropyltrimethoxysilane (CAS No. 2530-83-8) and C12-14 alkyl glycidyl ether (CAS No. 68609-97-2), wherein γ-glycidoxypropyltrimethoxysilane is, for example, KH-560, Dow Corning Z6040, or Shin-Etsu KBM403.

[0076] In the compositions of this application, the first accelerator is used to promote the reaction between the first curing agent and the first resin, thereby increasing the reaction rate. The mass fraction of the first accelerator can be, for example, 0.05 parts, 0.1 parts, 0.5 parts, 0.8 parts, 1 part, 1.15 parts, or any value between any two of the aforementioned values. To ensure good room temperature storage properties of the composition, in some embodiments of this application, the first accelerator is selected from latent accelerators, such as 2,4,6-tris(dimethylaminomethyl)phenol, which is available from Anhui Chuzhou Huisheng Electronic Materials Co., Ltd. (corresponding model K-54).

[0077] In some embodiments of this application, the composition for wafer packaging, by weight, consists of 75 to 83 parts of first spherical silicon dioxide, 5.5 to 11 parts of first resin, 8.5 to 13 parts of first curing agent, 0.1 to 2 parts of first diluent, and 0.05 to 1.15 parts of first accelerator.

[0078] The composition of this application embodiment possesses excellent light transmittance, a low coefficient of thermal expansion, and low water absorption, making it applicable to wafer-level packaging processes, such as fan-out wafer-level packaging. The composition can be used to fill the gap between two adjacent convex posts. In fan-out wafer-level packaging, it facilitates positioning during the packaging process, thereby improving the accuracy of bonding the diced wafer to the substrate and effectively reducing product defect rates. The composition's low coefficient of thermal expansion reduces warpage to protect components, thus improving the stability of the conductive posts. Furthermore, the composition's low water absorption mitigates corrosion problems of the conductive posts, further enhancing their stability.

[0079] This application also provides a method for preparing a composition, which can be used to prepare any of the aforementioned compositions. The preparation method includes the following steps:

[0080] S1. Take 75 to 83 parts of the first spherical silica, 5.5 to 11 parts of the first resin, 8.5 to 13 parts of the first curing agent and 0.1 to 2 parts of the first diluent and place them in a centrifugal mixer. Stir until the system is initially mixed and uniform to obtain the first mixed system.

[0081] S2. The first mixture obtained in step S1 is added to a three-roll mill for dispersion treatment, and then 0.05 to 1.15 parts of the first accelerator are added and mixed to obtain the second mixture.

[0082] S3. The second mixture obtained in step S2 is subjected to vacuum degassing using a centrifugal mixer to obtain the composition.

[0083] Specifically, in step S1, the centrifugal mixer rotates at 1000 r / min and revolves at 1400 r / min, and the mixing time is, for example, 120 s to 240 s.

[0084] In step S2, the feed gap of the three rollers is 40μm to 70μm, and the discharge gap is 20μm to 40μm.

[0085] In step S3, the vacuum degassing treatment time is 60s to 120s, the vacuum degree is, for example, 0.05MPa to 0.08MPa, the centrifugal stirrer rotates at 200r / min and revolves at 1400r / min.

[0086] This application also provides a fan-out packaging structure, such as... Figure 1 As shown, the fan-out package structure 1 includes a substrate 11, a plurality of spaced chip units 12, a first package 13, and a redistribution layer 14. The plurality of spaced chip units 12 are disposed on one side of the substrate 11, and the redistribution layer 14 is electrically connected to the chip units 12.

[0087] Continue to refer to Figure 1 Each chip unit 12 includes a bare die 121, a plurality of spaced-apart conductive pillars 122, and a second encapsulation portion 123. The plurality of spaced-apart conductive pillars 122 are disposed on one side of the bare die 121, and the second encapsulation portion 123 is located on the side of the bare die 121 where the conductive pillars 122 are disposed, and the conductive pillars 122 are embedded in the second encapsulation portion 123. The material of the second encapsulation portion 123 includes any of the aforementioned compositions. It should be noted that using a composition with good light transmittance, low coefficient of thermal expansion, low water absorption, and low viscosity as the material of the second encapsulation portion 123 can reduce warpage and improve the stability of the conductive pillars 122, and is also beneficial for observing the positioning of the chip unit 12.

[0088] Specifically, a bare die 121 is a wafer formed by dicing a wafer; a bare die 121 is a small piece on the wafer. A bare die 121 is a small, irregularly shaped crystal that makes up a polycrystalline material, and each bare die 121 sometimes consists of several subgrains with slightly different orientations. The average diameter of a bare die 121 is, for example, 0.015 mm to 0.25 mm.

[0089] The conductive post 122 is electrically connected to the redistribution layer and also electrically connected to the bare die 121. The conductive post 122 is made of metal, for example, copper.

[0090] In order to balance saving space and ensuring good fan-out packaging effect, in some embodiments of this application, the gap between any two adjacent conductive posts 122 is 8μm to 10μm, for example, 8μm, 9μm, 10μm and any two of the aforementioned values; and / or, the height of the conductive post is 10μm to 30μm, for example, 10μm, 20μm, 30μm and any two of the aforementioned values.

[0091] In some embodiments of this application, see further reference. Figure 1 The chip unit 12 also includes a connection layer 124, which is disposed between the bare die 121 and the conductive pillar 122. The bare die 121 and the connection layer 124 are electrically connected, and the conductive pillar 122 and the connection layer 124 are also electrically connected. The connection layer 124 includes a plurality of spaced metal sub-units 1241. A passivation material 101 is filled between any two adjacent metal sub-units 1241 to reduce stress, which can effectively improve the stress on the package structure, thereby further reducing warpage and further improving the reliability of the package. The passivation material 101 includes, but is not limited to, one or more of silicon oxide, silicon nitride, and silicon oxynitride. As an example, the passivation material 101 is Si3N4.

[0092] The first encapsulation portion 13 is used to encapsulate the chip unit 12 onto the substrate 11. Compared to the material of the second encapsulation portion 123, the material of the first encapsulation portion 13 has lower requirements for visible light transmittance and viscosity, but higher requirements for warpage resistance. In order to reduce the manufacturing cost and coefficient of thermal expansion of the material of the first encapsulation portion 13, in some embodiments of this application, the material of the first encapsulation portion 13 is a resin composition by weight. The resin composition includes 86 to 89 parts of second spherical silica, 6 to 7.6 parts of second resin, 4.2 to 6.3 parts of second curing agent, 0.3 to 0.8 parts of second diluent, 0.4 to 1 part of second accelerator, and 0.1 to 0.5 parts of carbon black, wherein the second resin is selected from epoxy resin, and the average particle size of the second spherical silica is larger than the average particle size of the first spherical silica.

[0093] Specifically, the second spherical silica serves as a filler in the resin compound. In the resin composition, the mass fraction of the second spherical silica can be, for example, 86 parts, 87 parts, 88 parts, 89 parts, or any value between any two of the aforementioned values. In some embodiments of this application, the D99 of the second spherical silica is 73 μm to 76 μm, for example, 73 μm, 74 μm, 75 μm, 76 μm, or any value between any two of the aforementioned values.

[0094] In the resin composition, the second resin is selected from one or more of 1,4-cyclohexanediethanol diglycidyl ether (CAS No. 14228-73-0) and alicyclic epoxy resin Syna-Epoxy28, wherein 1,4-cyclohexanediethanol diglycidyl ether is available from Shanghai Ruhong New Material Technology Co., Ltd. (model REP-111), and alicyclic epoxy resin Syna-Epoxy28 is available from Nantong Xinnaxi Material Co., Ltd. (model Syna-Epoxy28).

[0095] In the resin composition, the second curing agent can react with the second resin to cure the second resin. The mass fraction of the second curing agent can be, for example, 4.2 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.3 parts, or any value between any two of the aforementioned values. In some embodiments of this application, the second curing agent is selected from one or more of acid anhydride curing agents and amine curing agents, such as dimethylthiotoluene diamine and methylnadic anhydride.

[0096] In the resin composition, the second diluent is used to adjust the viscosity of the resin composition to facilitate further processing and to promote compatibility between the second spherical silica and the second resin. The mass fraction of the second diluent can be, for example, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, and any value between any two of the aforementioned values. As an example, the second diluent is selected from terminal epoxy-based allyl polyether (Klone KL-11B).

[0097] In the resin composition, the second accelerator is used to promote the reaction between the second curing agent and the second resin, thereby increasing the reaction rate. The mass fraction of the second accelerator can be, for example, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, or any value between any two of the aforementioned values.

[0098] To ensure good room temperature storage properties of the resin composition, in some embodiments of this application, the second accelerator comprises a latent accelerator, such as a microencapsulated modified imidazole epoxy composition (Sokol SC10208E). In the resin composition, the latent accelerator Sokol SC10208E is, for example, 0.2 to 0.3 parts by mass.

[0099] To ensure good adhesion of the resin composition, in some embodiments of this application, the second accelerator comprises an adhesion promoter, such as XY-23-4 from Guangzhou Silicon Fiber New Material Technology Co., Ltd. The amount of adhesion promoter XY-23-4 in the resin composition is, for example, 0.2 to 0.7 parts by weight.

[0100] When the resin composition includes adhesion promoter XY-23-4 and latent promoter Soco SC10208E, the mass ratio of latent promoter Soco SC10208E to adhesion promoter XY-23-4 is 1:(0.6 to 3.5), for example, 1:0.6, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, and any value between any two of the aforementioned ratios.

[0101] In the resin composition, carbon black is used as a colorant. The mass fraction of carbon black can be, for example, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, or any value between any two of the aforementioned values.

[0102] In some embodiments of this application, the resin composition, calculated by weight, comprises 75 to 83 parts of first spherical silica, 5.5 to 11 parts of first resin, 8.5 to 13 parts of first curing agent, 0.1 to 2 parts of first diluent, 0.1 to 0.5 parts of carbon black, and 0.05 to 1.15 parts of first accelerator. It should be noted that the resin composition is prepared using the same method as described above.

[0103] This application also provides a method for fabricating a fan-out packaging structure, which can be used to fabricate any of the aforementioned fan-out packaging structures, such as... Figures 2 to 8 As shown, it includes the following steps:

[0104] S10. Provide a prefabricated device, the prefabricated device including a wafer and a plurality of conductive pillars, the plurality of conductive pillars being spaced apart on one side of the wafer;

[0105] S20. Apply any one of the compositions described above to the side of the wafer near the conductive pillar, and fill the space between any two adjacent conductive pillars with the composition, then cure to obtain a second encapsulation portion.

[0106] S30. Cut the prefabricated device with the second encapsulation portion formed on its surface to obtain multiple chip units;

[0107] S40. Provide a substrate carrier, and bond each chip cell to a predefined area of ​​the substrate carrier, with any two adjacent chip cells having a gap.

[0108] S50. A chip unit is encapsulated using any of the resin compositions described above, and the gap between any two adjacent chip units is filled with the resin composition to obtain a first encapsulation portion.

[0109] S60. A plurality of openings are formed in the first encapsulation portion, and the side of each conductive post away from the substrate is exposed to one opening respectively.

[0110] S70. Wiring is performed at each opening location to obtain a redistribution layer, which is electrically connected to the side of the conductive post away from the substrate.

[0111] In step S10, the structure of the prefabricated device is as follows: Figure 2 As shown. In some embodiments of this application, see further details. Figure 2 The prefabricated device 10 also includes a connection layer 124, which is disposed between the wafer 120 and the conductive pillar 122. The wafer 120 and the connection layer 124 are electrically connected, and the conductive pillar 122 and the connection layer 124 are electrically connected. The connection layer 124 includes a plurality of spaced metal sub-units 1241, and any two adjacent metal sub-units 1241 are filled with a passivation material 101 to reduce stress.

[0112] In step S20, the composition 102 can be first dotted onto the center of the wafer 120, and then the composition 102 can be filled into the gap between any two adjacent conductive pillars 122 by a hot pressing process (temperature, for example, 115°C), and then pressed together to obtain the desired shape. Figure 3 The structure shown.

[0113] In step S30, a cutting wheel can be used to cut the prefabricated device with the second encapsulation portion formed on its surface, or conventional techniques in the art can be used for cutting to obtain... Figure 4 The structure shown is illustrated. It should be noted that in step S30, the low-warpage composition can improve the uniformity of cutting. If the warpage of the composition is too high, the cut chip unit will be deformed and damaged, and it will be impossible to accurately position it in subsequent processes.

[0114] In step S40, the structure obtained after the chip unit 12 is bonded to the substrate 11 is as follows: Figure 5 As shown, the key factor in the precise bonding of each chip unit 12 to the predefined area of ​​the substrate 11 is that the composition has good light transmittance.

[0115] In step S50, a printing process can be used to encapsulate the chip unit 12 with the resin composition. The structure obtained after completing step S50 is as follows: Figure 6As shown, the resin composition 103 can fully fill the gap between two adjacent chip units 12 and the gap between the chip unit 12 and the substrate 11.

[0116] In step S60, conventional methods such as etching and polishing can be used to form multiple openings in the first encapsulation portion, that is, polishing or etching the cured adhesive layer until the side of the conductive pillar away from the substrate is exposed. The structure obtained after completing step S60 is as follows. Figure 7 As shown, the side of each conductive post 122 that is away from the substrate 11 is exposed to an opening 104.

[0117] In step S70, as Figure 8 As shown, for each chip cell 12, a line 105 can be arranged on the side of each conductive post 122 exposed to the opening 104. It should be noted that... Figure 8 The diagram only shows the side of a single conductive post 122 exposed to the opening 104 with a line 105. In reality, a line 105 is provided on the side of each conductive post 122 exposed to the opening 104.

[0118] The properties of the resin composition and the functional membrane made from the resin composition in this application will be described in detail below with reference to specific embodiments, comparative examples and experimental examples.

[0119] Composition Example 1

[0120] This embodiment provides a composition and its preparation method for wafer packaging, which can be used to fill the gap between any two adjacent conductive pillars in a fan-out packaging structure. The formulation of the composition in this embodiment is detailed in Table 1 below:

[0121] Table 1 Formulation of the composition in this embodiment

[0122]

[0123] The preparation method of the composition in this embodiment includes the following steps:

[0124] S1.1 Weigh the first spherical silica, the first resin, the first curing agent and the first diluent according to the formula, place the weighed components in a centrifugal mixer and stir for 240s at a rotation speed of 1000r / min and a revolution speed of 1400r / min to obtain the first mixed system.

[0125] S1.2 Add the first mixed system obtained in step S1.1 into a three-roll mill for dispersion treatment, and then add the first accelerator according to the formula. The feed gap is 60μm and the discharge gap is 30μm to obtain the second mixed system.

[0126] S1.3. The second mixture obtained in step S1.2 is subjected to vacuum degassing treatment using a centrifugal mixer. The process parameters for vacuum degassing treatment are: rotation speed of 200 r / min, revolution speed of 1400 r / min, and treatment time of 100 s to obtain the composition.

[0127] Composition Example 2

[0128] This embodiment provides a composition for wafer packaging and a method for preparing the same, which can be used to fill the gap between any two adjacent conductive pillars in a fan-out packaging structure. Compared with the composition in Composition Example 1, the only difference in this embodiment is that the first resin is replaced with "bisphenol A type diglycidyl ether (Dow DER332)".

[0129] The preparation method of the composition in this embodiment is the same as that in Composition Example 1.

[0130] Composition Example 3

[0131] This embodiment provides a composition for wafer packaging and its preparation method, which can be used to fill the gap between any two adjacent conductive pillars in a fan-out packaging structure. Compared with the composition in Composition Example 1, the only difference in this embodiment is that the first resin is replaced with "bisphenol F type epoxy resin ZLF-160U (purchased from Zhilun Ultrapure Epoxy Resin (Xi'an) Co., Ltd)".

[0132] The preparation method of the composition in this embodiment is the same as that in Composition Example 1.

[0133] Composition Example 4

[0134] This embodiment provides a composition for wafer packaging and a method for preparing the same, which can be used to fill the gap between any two adjacent conductive pillars in a fan-out packaging structure. Compared with the composition in Composition Example 1, the only difference in this embodiment is that the first spherical silicon dioxide is replaced with "spherical silicon dioxide with a D50 of 6 μm".

[0135] The preparation method of the composition in this embodiment is the same as that in Composition Example 1.

[0136] Composition Example 5

[0137] This embodiment provides a composition for wafer packaging and its preparation method, which can be used to fill the gap between any two adjacent conductive pillars in a fan-out packaging structure. Compared with the composition in Composition Example 1, the only difference in this embodiment is that the compounding ratio of each component is different. Calculated by mass parts, the formulation of the composition in this embodiment is: 83 parts of first spherical silica (D50 is 3μm), 5.7 parts of first resin (same as Composition Example 1), 9.6 parts of first curing agent (methylnadic anhydride), 1.6 parts of first diluent (carbon 12-14 alkyl glycidyl ether), and 0.1 parts of first accelerator (2,4,6-tris(dimethylaminomethyl)phenol). The specific types of each component are the same as in Composition Example 1.

[0138] The preparation method of the composition in this embodiment is the same as that in Composition Example 1.

[0139] Composition Example 6

[0140] This embodiment provides a composition for wafer packaging and its preparation method, which can be used to fill the gap between any two adjacent conductive pillars in a fan-out packaging structure. Compared with the composition in Composition Example 1, the only difference in this embodiment is that the compounding ratio of each component is different. Calculated by mass parts, the formulation of the composition in this embodiment is: 83 parts of first spherical silica (D50 is 3μm), 6.1 parts of first resin (same as Composition Example 1), 10.2 parts of first curing agent (methylnadic anhydride), 0.6 parts of first diluent (carbon 12-14 alkyl glycidyl ether), and 0.1 parts of first accelerator (2,4,6-tris(dimethylaminomethyl)phenol). The specific types of each component are the same as in Composition Example 1.

[0141] The preparation method of the composition in this embodiment is the same as that in Composition Example 1.

[0142] Composition Example 7

[0143] This embodiment provides a composition for wafer packaging and its preparation method, which can be used to fill the gap between any two adjacent conductive pillars in a fan-out packaging structure. Compared with the composition in Composition Example 1, the only difference in this embodiment is that the compounding ratio of each component is different. Calculated by mass parts, the formulation of the composition in this embodiment is: 75 parts of first spherical silica (D50 is 3μm), 11 parts of first resin (same as Composition Example 1), 13 parts of first curing agent (methylnadic anhydride), 0.9 parts of first diluent (carbon 12-14 alkyl glycidyl ether), and 0.1 parts of first accelerator (2,4,6-tris(dimethylaminomethyl)phenol). The specific types of each component are the same as in Composition Example 1.

[0144] The preparation method of the composition in this embodiment is the same as that in Composition Example 1.

[0145] Composition Example 8

[0146] This embodiment provides a composition for wafer packaging and its preparation method, which can be used to fill the gap between any two adjacent conductive pillars in a fan-out packaging structure. Compared with the composition in Composition Example 1, the only difference in this embodiment is that the compounding ratio of each component is different. Calculated by mass parts, the formulation of the composition in this embodiment is: 79 parts of first spherical silica (D50 is 3μm), 9 parts of first resin (same as Composition Example 1), 10.6 parts of first curing agent (methylnadic anhydride), 1.3 parts of first diluent (carbon 12-14 alkyl glycidyl ether), and 0.1 parts of first accelerator (2,4,6-tris(dimethylaminomethyl)phenol). The specific types of each component are the same as in Composition Example 1.

[0147] The preparation method of the composition in this embodiment is the same as that in Composition Example 1.

[0148] Comparative Example 1

[0149] This comparative example provides a composition for wafer packaging and a method for preparing the same, which can be used to fill the gap between any two adjacent conductive pillars in a fan-out packaging structure. The only difference between this comparative example and the composition in Example 1 is that the first spherical silicon dioxide is replaced with "spherical silicon dioxide with a D50 of 1 μm".

[0150] The preparation method of the composition in this comparative example is the same as that in Composition Example 1.

[0151] Comparative Example 2

[0152] This comparative example provides a composition for wafer packaging and a method for preparing the same, which can be used to fill the gap between any two adjacent conductive pillars in a fan-out packaging structure. The only difference between this comparative example and the composition in Example 1 is that the first resin is replaced with "E44 epoxy resin (purchased from Guangzhou Kaixin New Material Technology Co., Ltd., product model E44)".

[0153] The preparation method of the composition in this comparative example is the same as that in Composition Example 1.

[0154] Resin Composition Example 1

[0155] This embodiment provides a resin composition capable of encapsulating chip cells on a substrate and filling the gap between any two adjacent chip cells. The formulation of the resin composition in this embodiment is detailed in Table 1 below:

[0156] Table 2 Formulation of the resin composition in this embodiment

[0157]

[0158]

[0159] The preparation method of the resin composition in this embodiment is the same as that of the composition in Composition Example 1.

[0160] Resin Composition Example 2

[0161] This embodiment provides a resin composition that can be used to encapsulate chip cells on a substrate and fill the gap between any two adjacent chip cells. Compared to the resin composition in Resin Composition Example 1, the only difference in this embodiment is that the second spherical silicon dioxide is replaced with "spherical silicon dioxide with a D99 of 73 μm".

[0162] The preparation method of the resin composition in this embodiment is the same as that of the composition in Composition Example 1.

[0163] Resin Composition Example 3

[0164] This embodiment provides a resin composition that can be used to encapsulate chip cells on a substrate and fill the gap between any two adjacent chip cells. Compared to the resin composition in Resin Composition Example 1, the only difference in this embodiment is that the second spherical silicon dioxide is replaced with "spherical silicon dioxide with a D99 of 65 μm".

[0165] The preparation method of the resin composition in this embodiment is the same as that of the composition in Composition Example 1.

[0166] Resin Composition Example 4

[0167] This embodiment provides a resin composition capable of encapsulating chip cells on a substrate and filling the gap between any two adjacent chip cells. The only difference between this embodiment and the resin composition in Resin Composition Example 1 is that the second spherical silica is replaced with "spherical silica with a D99 of 85 μm".

[0168] The preparation method of the resin composition in this embodiment is the same as that of the composition in Composition Example 1.

[0169] Resin Composition Example 5

[0170] This embodiment provides a resin composition that can be used to encapsulate chip cells on a substrate and fill the gap between any two adjacent chip cells. Compared to the resin composition in Resin Composition Example 1, the only difference in this embodiment is that the second resin is replaced with "1,4-cyclohexanediethanol diglycidyl ether (purchased from Shanghai Ruhong New Material Technology Co., Ltd., product model REP-111)".

[0171] The preparation method of the resin composition in this embodiment is the same as that of the composition in Composition Example 1.

[0172] Resin Composition Example 6

[0173] This embodiment provides a resin composition capable of encapsulating chip cells on a substrate and filling the gap between any two adjacent chip cells. Compared to the resin composition in Example 1, the only difference in this embodiment is the mixing ratio of the components. Based on mass parts, the formulation of this embodiment is: 86 parts of second spherical silica (D99 is 76 μm), 7.1 parts of second resin (alicyclic epoxy resin Syna-Epoxy28), 5.2 parts of second curing agent (methylnadic anhydride), 0.61 parts of second diluent (terminated epoxy allyl polyether), 0.62 parts of adhesion promoter XY-23-4, 0.27 parts of latent accelerator Soc SC10208E, and 0.2 parts of carbon black. The specific types of each component are the same as in Example 1.

[0174] The preparation method of the resin composition in this embodiment is the same as that of the composition in Composition Example 1.

[0175] Resin Composition Example 7

[0176] This embodiment provides a resin composition capable of encapsulating chip cells on a substrate and filling the gap between any two adjacent chip cells. The only difference between this resin composition and the one in Resin Composition Example 1 is that the latent accelerator is replaced with "dimethylthiotoluene diamine".

[0177] The preparation method of the resin composition in this embodiment is the same as that of the composition in Composition Example 1.

[0178] Experimental Example 1

[0179] The compositions in Composition Examples 1 to 8 and Comparative Examples 1 to 3 were subjected to performance tests. The performance tests included viscosity, thixotropy, warpage, visible light transmittance, water absorption, and thermomechanical properties.

[0180] The viscosity test method is as follows: adjust the circulating condensate of the viscometer to 25°C, place the composition in the sleeve of the viscometer and install it in the detection position of the viscometer, insert the thermocouple, adjust the speed of the viscometer to 20 r / min, and read the viscosity (Pa.s) value after 4 minutes.

[0181] The test method for thixotropy is as follows: for the same viscosity, read the viscosity value at a viscometer speed of 0.5 r / min and the viscosity value at a viscometer speed of 5 r / min, and record it as the TI value.

[0182] The warpage test method is as follows: a glass slide with a thickness of 1 mm is placed on a hot plate at a temperature of 90°C. Then, a composition is coated on the side of the glass slide away from the hot plate to form a film layer with a thickness of 1 mm. The glass slide containing the film layer is then placed in an oven at 130°C and baked for 1 hour. After cooling to room temperature, the warpage value of the glass slide is read using a 0.5 mm ruler.

[0183] The test method for visible light transmittance is as follows: the composition is coated onto one side of a release film using a doctor blade to form a film layer with a thickness of 60 μm, then placed in an oven at 115°C for 10 min, the release film is removed, and the obtained cured film is placed in a transmittance meter for visible light transmittance testing.

[0184] The method for testing water absorption rate is as follows: The composition is cured to obtain a cured sample; then, a mass of cured sample M1 (fixed value) is weighed and placed on a clean polytetrafluoroethylene (PTFE) film; next, the cured sample, along with the PTFE film, is placed in a high-temperature cooking apparatus for treatment. The process parameters are: 130℃, 85% humidity, and treatment for 96 hours; finally, the cured sample is removed, the surface water is wiped dry, and the mass is weighed again, recorded as M2. The formula for calculating the water absorption rate is (M2 - M1) / M1 × 100%.

[0185] The thermomechanical property testing method is as follows: The composition is uniformly dripped onto a polytetrafluoroethylene mold (10cm long × 1cm wide × 2mm high), then baked in an oven at 130℃ for 1 hour. A sample block measuring 1cm long × 1cm wide is then cut and sanded to ensure uniform thickness. Subsequently, the coefficient of thermal expansion (CTE) at low temperatures is measured using a thermomechanical analyzer (TMA). L ppm / ℃), coefficient of thermal expansion in the high-temperature range (CTE) H The CTE (parts per 100 ppm / ℃) and the glass transition temperature of TMA (Tg, ℃). L The detection temperature range is 40℃~60℃, CTE H The detection temperature range is 180℃~200℃. It should be noted that during the detection process, the thermomechanical analyzer's heating program is three-stage: Stage 1: heating from room temperature to 220℃ at a rate of 10℃ / min; Stage 2: cooling from 220℃ to 40℃ at a rate of 10℃ / min; Stage 3: heating from 40℃ to 220℃ at a rate of 10℃ / min. A thermal expansion coefficient-temperature characteristic curve is plotted for each stage. The average thermal expansion coefficient within the 40℃~60℃ detection temperature range of the third stage curve is recorded as CTE. L And read the average value of the coefficient of thermal expansion in the detection temperature range of 180℃~200℃ and record it as CTE. H .

[0186] The performance test results of each composition are detailed in Table 3 below:

[0187] Table 3. Performance test results of the compositions in Examples 1 to 8 and Comparative Examples 1 to 3.

[0188]

[0189] As shown in Table 3, compared to the compositions in Comparative Examples 1 to 2, the compositions in Examples 1 to 8 exhibit superior overall performance. Specifically, the compositions in Examples 1 to 8 demonstrate good light transmittance, a low coefficient of thermal expansion, and low water absorption, with the compositions in Examples 5 to 8 showing even better overall performance. Applying the compositions in Examples 1 to 8 to fill the gap between two adjacent convex pillars can improve the accuracy of bonding the diced wafer to the substrate, reduce warpage, and enhance the stability and reliability of the conductive pillars, thereby helping to reduce the product defect rate.

[0190] Experimental Example 2

[0191] The resin compositions in Examples 1 to 7 were subjected to performance tests. The performance tests included viscosity, thixotropy, warpage, thermomechanical properties, and silicon wafer adhesion. The testing methods for viscosity, thixotropy, warpage, and thermomechanical properties were the same as those in Example 1.

[0192] The test method for silicon wafer adhesion is as follows: Take a clean first silicon wafer, and use Teflon tape to make a square frame with a size of 2mm×2mm on the first silicon wafer. Then, apply the composition evenly inside the frame, and cover the composition inside the frame with a clean second silicon wafer to form a "sandwich" structure. Use clamps to clamp and fix the first and second silicon wafers to obtain a structural component. Then, place the structural component in an oven at 150℃ and bake for 1 hour. After that, take out the structural component and let it cool naturally. After the structural component has cooled to room temperature, put the structural component into a tensile testing machine to test the tensile force required for the adhesive layer to separate from the silicon wafer.

[0193] The performance test results of each resin composition are detailed in Table 4 below:

[0194] Table 4 Performance test results of the resin compositions in Examples 1 to 7 of resin compositions

[0195]

[0196] As shown in Tables 3 and 4, compared with the compositions in Composition Examples 1 to 8, the resin compositions in Composition Examples 1 to 8 have a lower coefficient of thermal expansion, resulting in lower warpage. This is because: in fan-out wafer packaging, the composition is used to fill the gap between two adjacent conductive pillars. Based on the stability requirements of the conductive pillars and the positioning accuracy requirements in subsequent processes, the composition needs to have good light transmittance, low viscosity, low coefficient of thermal expansion, and low water absorption. The resin composition is used to encapsulate the chip unit on the substrate, and its requirements for visible light transmittance and viscosity are lower, but its requirements for warpage are higher.

[0197] Furthermore, as shown in Table 3, using the compositions in Composition Examples 5 to 8 to fill the gap between two adjacent conductive pillars, and as shown in Table 4, using the resin compositions in Resin Composition Examples 1, 3, 4, and 8 to encapsulate the chip unit, is beneficial to improving the stability and encapsulation effect of the fan-out packaging structure.

[0198] The foregoing has provided a detailed description of a composition for wafer packaging, a fan-out packaging structure comprising the composition, and a method for preparing the same, as provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A composition for wafer packaging, characterized in that, The composition comprises, by weight parts: 75 to 83 parts of first spherical silica, 5.5 to 11 parts of first resin, 8.5 to 13 parts of first curing agent, 0.1 to 2 parts of first diluent, and 0.05 to 1.15 parts of first accelerator; Wherein, the first spherical silica has a D50 of 4 μm to 6 μm, the first resin has a transmittance of visible light of not less than 35%, the first resin is selected from epoxy resin, and the viscosity of the composition is 110 Pa.s to 190 Pa.s; The composition is used to fill the gap between two adjacent conductive pillars, wherein the gap between any two adjacent conductive pillars is 8 μm to 10 μm.

2. The composition according to claim 1, characterized in that, The viscosity of the first resin is 0.9 Pa·s to 20 Pa·s.

3. The composition according to claim 1 or 2, characterized in that, The first resin is selected from one or more of bisphenol A type diglycidyl ether, P-(2,3-epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline, and bisphenol F type epoxy resin ZLF-160U; and / or The first curing agent is selected from acid anhydride curing agents; and / or The first diluent is selected from one or more of γ-glycidyl oxypropyltrimethoxysilane and C12-14 alkyl glycidyl ethers; and / or The first accelerator is selected from latent accelerators.

4. The composition according to claim 3, characterized in that, The first curing agent is selected from one or more of methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and methylnadic anhydride; and / or The latency promoter is selected from 2,4,6-tris(dimethylaminomethyl)phenol.

5. A fan-out type packaging structure, characterized in that, include: Substrate plate; Multiple spaced-apart chip units are disposed on one side of the substrate. A first packaging section is disposed on one side of the substrate and encapsulates the chip unit; as well as A redistribution layer is electrically connected to the chip unit. Each of the chip units includes: Bare crystal; Multiple spaced-apart conductive pillars are disposed on one side of the bare die; and A second encapsulation portion is located on the side of the bare die where the conductive pillar is provided, and the conductive pillar is embedded in the second encapsulation portion, wherein the material of the second encapsulation portion comprises the composition as described in any one of claims 1 to 4.

6. The fan-out packaging structure according to claim 5, characterized in that, The height of the conductive pillar is 10 μm to 30 μm.

7. The fan-out packaging structure according to claim 5, characterized in that, The material of the first encapsulation part, calculated by weight, is a resin composition comprising: 86 to 89 parts of second spherical silica, 6 to 7.6 parts of second resin, 4.2 to 6.3 parts of second curing agent, 0.3 to 0.8 parts of second diluent, 0.4 to 1 part of second accelerator, and 0.1 to 0.5 parts of carbon black; The second resin is selected from epoxy resin, and the average particle size of the second spherical silica is greater than the average particle size of the first spherical silica.

8. The fan-out packaging structure according to claim 7, characterized in that, The second spherical silica has a D99 of 73 μm to 76 μm; and / or The second resin is selected from one or more of 1,4-cyclohexanediethanol diglycidyl ether and alicyclic epoxy resin Syna-Epoxy28; and / or The second curing agent is selected from one or more of acid anhydride curing agents and amine curing agents; optionally, the second curing agent is selected from one or more of dimethylthiotoluenediamine and methylnadic anhydride; and / or The second diluent is selected from terminal epoxy allyl polyether; and / or The second accelerator includes adhesion accelerator XY-23-4 and latent accelerator SocoSci SC10208E, wherein the mass ratio of latent accelerator SocoSci SC10208E to adhesion accelerator XY-23-4 is 1:(0.6~3.5).

9. A method for fabricating a fan-out type packaging structure, characterized in that, The method for preparing the fan-out package structure as described in any one of claims 5 to 8 comprises the following steps: (1) A prefabricated device is provided, the prefabricated device comprising a wafer and a plurality of conductive pillars, the plurality of conductive pillars being disposed at intervals on one side of the wafer; (2) Apply the composition as described in any one of claims 1 to 4 to the side of the wafer near the conductive pillar, and fill the space between any two adjacent conductive pillars with the composition as described in any one of claims 1 to 4, then cure to obtain a second encapsulation portion; (3) Cut the prefabricated device on which the second encapsulation portion is formed to obtain multiple chip units; (4) Provide a substrate carrier, and bond each of the chip cells to a predefined area of ​​the substrate carrier, wherein any two adjacent chip cells have a gap; (5) The chip unit is encapsulated with a resin composition, and the gap between any two adjacent chip units is filled with the resin composition to obtain a first encapsulation portion; (6) A plurality of openings are formed in the first encapsulation portion, and the side of each conductive post away from the substrate is respectively exposed to one of the openings; as well as (7) Wiring is performed at the location of each of the openings to obtain a redistribution layer, the redistribution layer being electrically connected to the side of the conductive post away from the substrate.

10. The preparation method according to claim 9, characterized in that, The prefabricated device further includes a connection layer disposed between the wafer and the conductive pillar; wherein the connection layer includes a plurality of spaced metal sub-units, the wafer and the metal sub-units are electrically connected, the conductive pillars and the metal sub-units are electrically connected, and any two adjacent metal sub-units are filled with passivation material.

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