Packaging module and method of manufacturing

Abstract

The application provides a packaging module and a preparation method thereof. The packaging module comprises an electronic device and a packaging substrate for realizing the conduction between the electronic device and the outside world. At least two copper foil layers and at least one glass fiber layer are arranged in the packaging substrate. The glass fiber layer comprises glass fiber cloth and short glass fibers. The application can effectively improve the structural strength of the packaging substrate and prevent the deformation or fracture of the substrate at the position of external force pressing.

Description

Technical Field

[0001] This invention relates to the field of SIP packaging technology, and more specifically, to a packaging module and its manufacturing method. Background Technology

[0002] Currently, System-in-a-Package (SIP) packaging primarily integrates multiple functional wafers, including processor and memory wafers, into a single package based on factors such as application scenario and the number of substrate layers, thereby achieving a complete packaging solution for a single substrate. SIP packaging can be further divided into Selective Mold packaging and Full Mold packaging. Selective Mold packaging requires adding a mold pressing force area to the product, unlike Full Mold packaging where pressing only occurs in the non-product-effective area at the substrate edge.

[0003] However, in the existing selective mold packaging process, in order to ensure that the molding compound does not overflow into the non-molded area, a large pressure is usually used for pressing during the process. Since this packaging method requires strong pressing within the effective area of ​​the product, the strength requirements of the corresponding pressing area substrate are also high. If the substrate strength is insufficient, it is easy to cause damage to the inner layer circuit of the substrate and breakage of the core material, affecting the electrical performance of the product and the reliability of long-term use.

[0004] To enhance the structural strength of the substrate, the traditional approach is to place fiberglass cloth inside the substrate. However, the effect of fiberglass reinforcement is closely related to the interface bonding. The interface bonding area between the traditional fiberglass cloth and the substrate is limited, so the mechanical reinforcement effect is limited. In addition, the fiberglass cloth is anisotropic due to structural influences, which is not conducive to pressure dispersion and is prone to stress concentration at the direct pressing position, causing the fiberglass to reach the stress threshold and break, thus failing to achieve an effective mechanical reinforcement effect. Summary of the Invention

[0005] In view of the above problems, the purpose of this invention is to provide a packaging module and its preparation method to solve the problems of existing methods that use fiberglass cloth to enhance the strength of substrates, such as stress concentration at the pressing position, resulting in over-threshold fracture, and limited interface bonding area between traditional fiberglass cloth and substrate, which affects the mechanical reinforcement effect of the substrate.

[0006] The packaging module provided by the present invention includes an electronic device and a packaging substrate for enabling the electronic device to communicate with the outside world; wherein, at least two copper foil layers and at least one glass fiber layer are disposed in the packaging substrate; the glass fiber layer includes interspersed glass fiber cloth and short glass fibers.

[0007] In addition, an optional technical solution is that the diameter of the short glass fibers ranges from 4μm to 8μm; the length of the short glass fibers ranges from 30μm to 50μm; and the thickness of the glass fiber layer is not greater than 200μm.

[0008] Alternatively, a possible technical solution is to mix and cure short glass fibers and glass fiber cloth by impregnation with a resin solution.

[0009] Alternatively, an alternative technical solution is to press the copper foil layer and the fiberglass layer together to fix them in place.

[0010] Alternatively, an optional technical solution is to have strip-shaped mold pressing force-bearing areas distributed on the packaging substrate; and to have a fiberglass layer distributed within the packaging substrate below the mold pressing force-bearing areas.

[0011] In addition, an alternative technical solution is that the distribution area of ​​the glass fiber layer is larger than the area of ​​the mold pressing force zone; and the minimum distance between the boundary of the glass fiber layer and the mold pressing force zone is not less than 200μm.

[0012] In addition, an alternative technical solution is to distribute long glass fibers in the glass fiber cloth.

[0013] According to another aspect of the present invention, a method for preparing an encapsulation module is provided, for preparing an upper encapsulation module; wherein the method includes: stirring and mixing short glass fibers with a resin solution to form an impregnation mixture; immersing a glass fiber cloth in the impregnation mixture; curing the glass fiber cloth immersed in the impregnation mixture; repeating the above-described immersion and curing process until the short glass fibers in the resin solution are uniformly attached to the glass fiber cloth to form a composite reinforced substrate; cutting the composite reinforced substrate to obtain a glass fiber layer; and pressing the glass fiber layer and a copper foil layer together to form an encapsulation substrate.

[0014] In addition, an alternative technical solution is to have the volume percentage of short glass fibers in the impregnation mixture range from 20% to 30%.

[0015] In addition, an optional technical solution is that when the thickness of the composite reinforced substrate is greater than a preset value, it further includes: stacking two layers of glass fiber cloth on one side of the composite reinforced substrate; using the two layers of glass fiber cloth as the attachment substrate, immersing the two layers of glass fiber cloth in an impregnation mixture.

[0016] Using the above-described encapsulation module and preparation method, at least two copper foil layers and at least one glass fiber layer are disposed within the encapsulation substrate. The glass fiber layer further comprises interspersed glass fiber cloth and short glass fibers. The short glass fibers are uniformly distributed between the glass fiber cloth. The two work together to increase the specific surface area of ​​the glass fiber, resulting in more surface active groups and thus a larger area of ​​bonding with the substrate, achieving a better strength enhancement effect. In addition, based on the superior compressive strength of the glass fiber cloth, the short glass fibers can achieve a more uniform structural strength, resulting in better isotropy of the substrate, which is more conducive to pressure dispersion and can avoid stress concentration, ultimately achieving a better mechanical enhancement effect.

[0017] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to encompass all such aspects and their equivalents. Attached Figure Description

[0018] Other objects and results of the invention will become more apparent and readily understood with reference to the following description taken in conjunction with the accompanying drawings. In the drawings:

[0019] Figure 1 This is a schematic diagram of the overall product structure of the packaging module according to an embodiment of the present invention;

[0020] Figure 2 for Figure 1 A magnified view of part A in the middle;

[0021] Figure 3 This is a partial cross-sectional view of the packaging module according to an embodiment of the present invention;

[0022] Figure 4 This is a flowchart of a method for preparing a packaging module according to an embodiment of the present invention.

[0023] The reference numerals in the attached drawings include: 1. Fiberglass cloth; 2. Short fiberglass; 3. Encapsulation substrate; 4. Molded body; 5. Electronic device; 6. Mold pressing force zone B.

[0024] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0025] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details. In other instances, well-known structures and devices are shown in block diagram form for ease of description of one or more embodiments.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] To address the problems existing in current methods of reinforcing substrates with fiberglass cloth, such as stress concentration at the substrate bonding point leading to over-threshold fracture, and limited interfacial bonding area between traditional fiberglass cloth and the substrate affecting the mechanical reinforcement effect and failing to meet the requirements of selective mold packaging processes, this invention provides a packaging module and its preparation method. The module comprises at least two copper foil layers and at least one fiberglass layer within the packaging substrate. The fiberglass layer includes interspersed fiberglass cloth and short glass fibers. The combination of short glass fibers and fiberglass cloth results in a larger specific surface area and more surface-active groups compared to fiberglass cloth, allowing for a larger bonding area with the substrate and thus achieving a superior strength enhancement effect. Furthermore, based on the superior compressive strength of fiberglass cloth, the short glass fibers achieve a more uniform structural strength with better isotropy, which is more conducive to pressure dispersion, avoids stress concentration, increases the pressure threshold that the substrate can withstand, and achieves a better mechanical reinforcement effect.

[0028] To describe in detail the packaging module and its preparation method in this invention, specific embodiments of the invention will be described in detail below with reference to the accompanying drawings.

[0029] Figure 1 and Figure 2 The schematic structure of the entire product and the enlarged structure of a partial area A according to embodiments of the present invention are shown respectively.

[0030] like Figure 1 and Figure 2As shown in the figure, the complete product of this embodiment includes several regularly distributed packaging modules. The left side of the packaging module is the molding area, which covers the electronic device through the molding body 4. The right side of the packaging module is the exposed electronic device 5. The joint between the two forms the mold pressing force area B. The present invention will be specifically described below using a single packaging module as an example.

[0031] Figure 3 A partial cross-sectional schematic structure of the packaging module according to an embodiment of the present invention is shown.

[0032] Combination Figures 1 to 3 As shown in the figure, the packaging module of the present invention includes electronic devices and a packaging substrate 3 for enabling the electronic devices to communicate with the outside world. The electronic devices are mounted on the surface of the packaging substrate 3. At least two copper foil layers and at least one fiberglass layer are provided in the packaging substrate 3. The fiberglass layer further includes interspersed glass fiber cloth 1 and short glass fibers 2. The specific number of glass fiber layers and copper foil layers can be flexibly set according to the performance requirements of the packaging substrate 3.

[0033] To ensure that the encapsulation substrate 3 has good structural strength, in the encapsulation module of this embodiment, the diameter range of the short glass fiber 2 can be set to 4μm to 8μm, and the length range of the short glass fiber 2 can be set to 30μm to 50μm. In addition, in order to achieve a better mechanical reinforcement effect and avoid the agglomeration of the short glass fiber 2, the thickness of the glass fiber layer can be controlled within 200μm. If the thickness of the glass fiber layer needs to exceed 200μm, the thickness of the encapsulation substrate 3 can be controlled to 0.1-0.4mm. Glass fiber cloth 1 can be superimposed on the original glass fiber layer as the attachment substrate for the short glass fiber 2 to increase the thickness of the glass fiber layer.

[0034] In other words, to ensure the structural strength of the encapsulation substrate 3, a layer of glass fiber cloth 1 can be provided in the glass fiber layer by default, while multiple layers of glass fiber layer located in the encapsulation substrate 3 can be provided; or, multiple layers of glass fiber cloth 1 can be provided in the glass fiber layer, with short glass fibers 2 attached between each glass fiber cloth 1, etc. The thickness of the encapsulation substrate 3 can be controlled between 0.1mm and 0.4mm, and the structural strength is stable and reliable.

[0035] In one specific embodiment of the present invention, the short glass fibers 2 and the glass fiber cloth 1 can be mixed using an impregnation solution. Specifically, the short glass fibers 2 are attached to the glass fiber cloth 1 using the impregnation solution, and then cured after mixing to form a glass fiber layer structure. Furthermore, since the short glass fibers 2 are relatively short, to ensure their uniform distribution on the glass fiber cloth 1, the short glass fibers 2 can be first mixed with the impregnation solution to form an impregnation mixture. The glass fiber cloth 1 is then repeatedly immersed in this impregnation mixture to achieve an effective bond between the short glass fibers 2 and the glass fiber cloth 1.

[0036] Furthermore, after the glass fiber layer is formed, a copper foil layer can be laminated onto the glass fiber layer. When both the glass fiber layer and the copper foil layer are provided in multiple layers, the glass fiber layer and the copper foil layer can be interleaved. For example, a copper foil layer can be provided between two adjacent glass fiber layers, and a glass fiber layer can be provided between adjacent copper foil layers.

[0037] It should be noted that when the selective mold packaging process is used to process the packaging substrate 3, strip-shaped mold pressing stress areas will be distributed on the packaging substrate 3, such as... Figure 3 Region B and Figure 4 As shown in the dashed box area, considering the overall cost of the packaging substrate 3, the fiberglass layer can be set in the area below the mold pressing force area of ​​the packaging substrate 3, that is, the fiberglass layer is only set in the mold pressing force area. The range of the fiberglass layer can be slightly larger than the range of the mold pressing force area, so as to ensure that the packaging substrate 3 does not deform or break when subjected to greater external pressure.

[0038] Where the distribution area of ​​the fiberglass layer is greater than the area of ​​the mold pressing stress area, the minimum distance between the boundary of the fiberglass layer and the mold pressing stress area is not less than 200μm. That is, when projected in the direction perpendicular to the packaging substrate 3, the boundary of the fiberglass layer is at least 200μm greater than the boundary of the mold pressing stress area at the corresponding position, so as to ensure an effective structural reinforcement effect.

[0039] In another specific embodiment of the present invention, long glass fibers are distributed in the glass fiber cloth 1.

[0040] Corresponding to the above-mentioned packaging module, the present invention also provides a packaging module packaging method for packaging the above-mentioned packaging module.

[0041] Specifically, Figure 4 A flowchart illustrating a method for fabricating a packaging module according to an embodiment of the present invention is shown.

[0042] like Figure 4 As shown, the packaging module preparation method of this invention mainly includes the following steps:

[0043] S110: Short glass fibers are stirred and mixed with a resin solution to form an impregnation mixture;

[0044] S120: Immerse the fiberglass cloth in the impregnation mixture;

[0045] S130: Curing treatment of glass fiber cloth impregnated with impregnation mixture;

[0046] S140: Repeat the above immersion and fixation process (steps 120 and 130) until the short glass fibers in the resin solution are uniformly attached to the glass fiber cloth to form a composite reinforced substrate.

[0047] S150: Cut the composite reinforced substrate to obtain a glass fiber layer;

[0048] S160: The fiberglass layer and the copper foil layer are pressed together to form a packaging substrate.

[0049] Each time the glass fiber cloth is immersed in the impregnation solution, it can be baked to allow the resin solution to be initially cured, thereby fixing the attachment position of the short glass fibers. Then, it is immersed again to ensure that the short glass fibers in the resin solution can be uniformly attached to the glass fiber cloth, thus forming a composite reinforced substrate composed of short glass fibers and glass fiber cloth. The composite reinforced substrate is then cut to obtain a prepreg. Finally, a copper foil layer is covered on the prepreg and pressed together to form an encapsulation substrate.

[0050] To ensure a better structural reinforcement effect, the diameter of the short glass fibers can be controlled between 4μm and 50μm, the length of the short glass fibers can be set between 30μm and 50μm, and the volume ratio of the short glass fibers in the impregnation mixture is between 20% and 30%.

[0051] Furthermore, to achieve mechanical reinforcement of the encapsulation substrate and avoid agglomeration of short glass fibers, the thickness of the glass fiber layer should ideally be controlled within 200 μm. If it exceeds 200 μm, a second layer of glass fiber cloth should be added as a substrate for uniformly distributing the short glass fibers, and then the substrate should be immersed in the impregnation solution again. For example, when the thickness of the composite reinforced substrate exceeds a preset value, the above preparation method may further include: adding two layers of glass fiber cloth to one side of the composite reinforced substrate; using the two layers of glass fiber cloth as an attachment substrate, immersing the two layers of glass fiber cloth in the impregnation solution.

[0052] Specifically, the embodiments of the above-mentioned packaging module preparation method can be referred to the description in the above-mentioned packaging module device embodiments, and will not be repeated here.

[0053] According to the encapsulation module and preparation method of the present invention, a glass fiber cloth with long glass fibers is used as the substrate, and short glass fibers are interspersed in the gaps of the glass fiber cloth. A high-strength impregnation mixture can be prepared by mixing short glass fibers with a resin solution, and then the short glass fibers can be interspersed in the glass fiber cloth and uniformly combined by impregnation. In addition, the short glass fibers are short, which can increase the structural strength while achieving the thinning of the encapsulation substrate. The process is simple and easy to manufacture. It can make the short glass fibers uniformly attached to the glass fiber cloth substrate to form a uniform and stable composite reinforcement structure, avoiding the problems of poor reinforcement effect of glass fiber cloth and easy agglomeration of short glass fiber reinforcement.

[0054] The packaging module and its preparation method according to the present invention have been described above by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various modifications can be made to the packaging module and its preparation method described above without departing from the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the contents of the appended claims.

Claims

1. A packaging module, characterized in that, It includes electronic devices and a packaging substrate for enabling the electronic devices to communicate with the outside world; wherein, At least two copper foil layers and at least one glass fiber layer are disposed within the packaging substrate; The fiberglass layer comprises interspersed fiberglass cloth and short fiberglass; Multiple layers of glass fiber cloth are disposed in the glass fiber layer, and short glass fibers are interspersed between each glass fiber cloth, with the short glass fibers interspersed in the gaps of the glass fiber cloth; Strip-shaped mold pressing force areas are distributed on the packaging substrate, and the glass fiber layer is distributed in the packaging substrate below the mold pressing force areas; The distribution area of ​​the fiberglass layer is greater than the area of ​​the mold pressing force area; and the minimum distance between the boundary of the fiberglass layer and the mold pressing force area is not less than 200μm.

2. The packaging module as described in claim 1, characterized in that, The diameter of the short glass fibers ranges from 4 μm to 8 μm; The length of the short glass fiber ranges from 30μm to 50μm; The thickness of the fiberglass layer is no greater than 200 μm.

3. The packaging module as described in claim 1, characterized in that, The short glass fibers and the glass fiber cloth are mixed and cured together by impregnation with a resin mixture.

4. The packaging module as described in claim 1, characterized in that, The copper foil layer and the fiberglass layer are pressed together and fixed.

5. The packaging module as described in claim 1, characterized in that, Long glass fibers are distributed in the glass fiber cloth.

6. A method for preparing a packaging module, characterized in that, For preparing the packaging module as described in any one of claims 1 to 5; wherein, the method comprises: Short glass fibers are stirred and mixed with a resin solution to form an impregnation mixture; The fiberglass cloth is immersed in the impregnation mixture; The glass fiber cloth impregnated with the impregnation mixture is subjected to a curing treatment; Repeat the above immersion and fixation process until the short glass fibers in the resin solution are uniformly attached to the glass fiber cloth to form a composite reinforced substrate. The composite reinforced substrate is cut to obtain the glass fiber layer; The fiberglass layer and the copper foil layer are pressed together to form the encapsulation substrate.

7. The method for preparing the packaging module as described in claim 6, characterized in that, The short glass fibers account for 20% to 30% of the volume of the impregnation mixture.

8. The method for preparing the packaging module as described in claim 6, characterized in that, When the thickness of the composite reinforced substrate is greater than a preset value, the method further includes: Two layers of glass fiber cloth are superimposed on one side of the composite reinforced substrate; Using the two-layer glass fiber cloth as the attachment substrate, the impregnation mixture is immersed in the two-layer glass fiber cloth.

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