Dual-sided plastic encapsulated shield package structure and method of processing the same

Abstract

The application provides a double-side plastic-sealed shielding packaging structure and a processing method thereof. The double-side plastic-sealed shielding packaging structure comprises a single substrate, an upper-layer chip arranged on the upper surface of the single substrate, and a lower-layer chip arranged on the lower surface of the single substrate; a first plastic sealing layer is arranged on the upper surface of the single substrate, and a second plastic sealing layer is arranged on the lower surface of the single substrate; the first plastic sealing layer covers the upper-layer chip; and a first resin shielding film is arranged on the upper surface of the first plastic sealing layer and the side surface of the single substrate. The application can solve the problems of low processing efficiency and high manufacturing cost of the conventional double-side plastic-sealed shielding packaging structure.

Description

Technical Field

[0001] This invention relates to the field of device packaging technology, and more specifically, to a double-sided plastic-encapsulated shielding packaging structure and its processing method. Background Technology

[0002] With the advancement of technology, people have increasingly urgent demands for multifunctional electronic products and high integration of components. For electronic products such as mobile phones, it is necessary to maximize the integration of electronic products within a limited space. In the past, classified component packaging was used, but now it is gradually being replaced by high-density SiP integrated assembly technology. In electronic product packaging, double-sided SMT (surface mount technology) and molding technology (especially double-sided packaging) have been widely adopted in the industry.

[0003] Currently, the industry's (such as Samsung's) double-sided packaging process with EMI (electromagnetic interference) shielding typically involves first performing double-sided SMT on the entire substrate, then placing solder balls and molding the top and bottom surfaces of the substrate; next, strip grinding is used to expose the solder balls on the substrate; then, laser ablation and reflow soldering are performed to cut the substrate into individual package structures; then, a 100-200µm thick UV (ultraviolet-cured) protective tape is used to protect the solder balls on the bottom surface to prevent overplating, and sputtering is performed on the individual package structures to achieve the shielding function; finally, the UV protective tape is removed, and the process is complete.

[0004] However, the existing double-sided plastic encapsulation shielding process has the following technical drawbacks:

[0005] 1. Because vacuum sputtering is required for shielding and encapsulation, the UPH (production rate) is usually relatively low; and the surface thickness of the sputtered layer is usually set at around 6um, while the side thickness is usually 2-3um. This type of sputtered layer does not provide ideal shielding for low-frequency signals.

[0006] 2. To prevent the solder balls or pads on the lower surface from being over-plated, a certain distance needs to be reserved between the solder balls or pads on the lower surface and the edge of the package to prevent short circuits caused by sputtering; this design will affect the further reduction of package size.

[0007] 3. Because UV protective tape or polyimide film is required to cover the solder balls on the lower surface to prevent over-plating, and then the balls are cut into individual packaging structures, placed in the sputtering carrier, and sputtered, the entire production line requires a large investment, and the product handling and sputtering efficiency is relatively low, resulting in high costs.

[0008] 4. UV protective tape is usually quite thick, requiring a thickness greater than the height of the solder balls, thus increasing the cost. Each substrate costs approximately $7-8, significantly increasing Sputtering's auxiliary material costs.

[0009] 5. UV protective tape requires UV light irradiation, and the reaction rate of the material is difficult to control, so there is a quality risk of residual adhesive in the solder balls.

[0010] 6. In the sputtering process, because sputtering requires a certain aspect ratio, it can only be used for conformal shielding of products, and not for small, isolated comparative shielding.

[0011] 7. During the sputtering process, if the coating is thick, metal particles can easily adhere to the product. To avoid the risk of product failure, metal burrs (spurs) need to be removed. Obviously, this type of operation will further reduce work efficiency.

[0012] Based on the above technical problems, there is an urgent need for a double-sided plastic encapsulation shielding packaging method that can significantly improve work efficiency and reduce manufacturing costs. Summary of the Invention

[0013] In view of the above problems, the purpose of this invention is to provide a double-sided plastic-encapsulated shielding packaging structure and its processing method, so as to solve the problems of low processing efficiency and high manufacturing cost of traditional double-sided plastic-encapsulated shielding packaging structures.

[0014] The double-sided plastic-encapsulated shielding packaging structure provided in this embodiment of the invention includes a single substrate, an upper chip disposed on the upper surface of the single substrate, and a lower chip disposed on the lower surface of the single substrate. A first plastic encapsulation layer is disposed on the upper surface of the single substrate, and a second plastic encapsulation layer is disposed on the lower surface of the single substrate. The first plastic encapsulation layer covers the upper chip. Furthermore, a first resin shielding film is disposed on the upper surface of the first plastic encapsulation layer and on the side surface of the single substrate.

[0015] Furthermore, a preferred embodiment is that a slot corresponding to the grounding terminal position on the monomer substrate is formed within the first molding layer, and a second resin shielding film is disposed within the slot; wherein,

[0016] One end of the second resin shielding film is connected to the first resin shielding film, and the other end of the second resin shielding film is connected to the grounding terminal.

[0017] Furthermore, in a preferred embodiment, both the first resin shielding film and the second resin shielding film are set using a vacuum pressing and injection method; and...

[0018] The first resin shielding film is linked to the side of the monomer substrate to form a conformal shield, and the second resin shielding film is used to form a sectional shield.

[0019] Furthermore, a preferred embodiment is that both the first resin shielding film and the second resin shielding film are made of resin containing metal particles.

[0020] Furthermore, a preferred embodiment is that the surface of the lower chip is exposed outside the second molding layer or flush with the surface of the second molding layer.

[0021] Furthermore, a preferred embodiment is to provide solder balls on the lower surface of the monomer substrate, with the tops of the solder balls protruding beyond the second molding layer.

[0022] On the other hand, the present invention also provides a method for processing the aforementioned double-sided plastic-encapsulated shielding packaging structure, the method comprising:

[0023] The upper chip and the lower chip are respectively mounted at corresponding positions on the upper and lower surfaces of the overall substrate; and the upper and lower surfaces of the overall substrate are encapsulated to form a first encapsulation layer covering the upper chip and a second encapsulation layer covering the lower chip.

[0024] The encapsulated substrate is laser-cut to form a half-groove on the upper surface; wherein the half-groove on the upper surface is used to divide the substrate into at least two structural units, and two adjacent structural units are connected by a half-cut encapsulation portion.

[0025] A resin shielding film is pressed onto the upper surface of the first molding layer, the side surface of the integral substrate, and the inner wall of the half-groove on the upper surface to form the first resin shielding film.

[0026] The lower surface of the integral substrate is ground to remove the half-cut reserved plastic encapsulation portion, thereby separating the individual structural units.

[0027] Furthermore, a preferred embodiment is that the laser cutting process of the encapsulated integral substrate includes upper surface half-cutting and laser grooving; wherein, the upper surface half-cutting is used to form the upper surface half-cut groove, and the laser grooving is used to form a groove corresponding to the grounding terminal position on the substrate; and the processing method further includes:

[0028] A resin shielding film is pressed into the groove to form a second resin shielding film, wherein one end of the second resin shielding film is connected to the first resin shielding film, and the other end of the second resin shielding film is connected to the grounding terminal.

[0029] Furthermore, a preferred embodiment is that solder balls are also provided on the lower surface of the integral substrate; and during the grinding process of the lower surface of the integral substrate,

[0030] The top of the solder ball is exposed outside the second molding compound, and the surface of the lower chip is exposed outside the second molding compound or flush with the surface of the second molding compound.

[0031] Furthermore, a preferred embodiment includes, after grinding the lower surface of the integral substrate, the following steps:

[0032] The encapsulant on the edge of the solder ball is removed by laser.

[0033] As can be seen from the above technical solution, the double-sided plastic-encapsulated shielding packaging structure and its manufacturing method provided by the present invention adopt a new packaging structure, new packaging materials, and new processing technology. It mainly includes: after overall double-sided encapsulation, the entire board is cut using a half-cut method on the upper surface, and a thermosetting resin material with shielding properties (mainly containing conductive metal particles) is pressed and cured to form a shielding layer. Then, the lower surface is ground to form individual packaging structure units, exposing the solder balls. First, since the shielding layer is set using a simple pressing method, compression molding equipment can be used, significantly improving work efficiency and eliminating the need for sputtering processes and loading / unloading equipment. Furthermore, the pressing film can increase the thickness of the shielding layer on the packaging surface to 30-40µm, and simultaneously increase the thickness of the sidewall shielding layer to 4-5µm, thereby significantly improving the shielding effect. Additionally, by using laser cutting for half-cutting the upper surface and laser grooving, both inter-area shielding and conformal shielding can be formed simultaneously, greatly simplifying the inter-area shielding manufacturing process and reducing costs. In addition, because the lower surface is ground, it is less likely to generate quality risks such as sputtered metal particles.

[0034] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below and specifically pointed out in the claims. 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

[0035] 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:

[0036] Figure 1 This is a front cross-sectional view of a double-sided plastic-encapsulated shielding packaging structure provided according to an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the upper chip mounting process for a double-sided plastic-encapsulated shielded packaging structure according to an embodiment of the present invention.

[0038] Figure 3 This is a schematic diagram of the upper surface molding of a double-sided molded shielding encapsulation structure according to an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the lower-layer chip mounting in the processing method of the double-sided plastic-encapsulated shielded packaging structure according to an embodiment of the present invention;

[0040] Figure 5 This is a schematic diagram of the lower surface molding of a double-sided molded shielding encapsulation structure according to an embodiment of the present invention;

[0041] Figure 6 A schematic diagram of laser cutting for processing a double-sided plastic-encapsulated shielding packaging structure according to an embodiment of the present invention;

[0042] Figure 7 This is a schematic diagram of resin shielding film lamination in a processing method for a double-sided plastic-encapsulated shielding packaging structure according to an embodiment of the present invention;

[0043] Figure 8 This is a schematic diagram of the lower surface grinding process of the processing method of the double-sided plastic-encapsulated shielding packaging structure according to an embodiment of the present invention;

[0044] Figure 9 This is a schematic diagram of solder ball edge molding compound removal in a processing method for a double-sided molded shielding encapsulation structure according to an embodiment of the present invention.

[0045] Figure 10 This is a final single-unit product molding diagram of the processing method of the double-sided plastic-encapsulated shielding packaging structure according to an embodiment of the present invention;

[0046] The reference numerals in the figures include: 1. Monolithic substrate; 2. Upper chip; 3. First molding layer; 4. First resin shielding film; 5. Second resin shielding film; 6. Lower chip; 7. Second molding layer; 8. Solder ball; 9. Intermediate layer; 10. Groove; 11. Upper surface half-groove; 12. Positioning tape; 13. Overall substrate.

[0047] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0048] To describe in detail the structure of the double-sided plastic-encapsulated shielding packaging structure of the present invention, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] It should be noted that if the embodiments of the present invention involve descriptions such as "first" and "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, if the embodiments of the present invention involve terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," or "outer" indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, this is only for the convenience of describing the present invention and simplifying the description, and does not 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, it should not be construed as a limitation of the present invention.

[0050] In addition, the meaning of "and / or" in the text is that it includes three parallel options. Taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0051] Figure 1 The diagram shows a front cross-sectional view of a double-sided plastic-encapsulated shielding packaging structure according to an embodiment of the present invention. Figure 1 As shown, the double-sided plastic-encapsulated shielded packaging structure provided in this embodiment of the invention includes a single substrate 1, an upper chip 2 disposed on the upper surface of the single substrate 1, and a lower chip 6 disposed on the lower surface of the single substrate 1. The single substrate 1 can be a circuit board, such as a PCB (Printed Circuit Board, which is a support for electronic components), used to mount the upper chip 2 and the lower chip 6.

[0052] Furthermore, a first molding compound layer 3 is disposed on the upper surface of the single substrate 1, and a second molding compound layer 7 is disposed on the lower surface of the single substrate 1, adopting a double-sided molding compound structure to effectively protect the device and provide reliability. The first molding compound layer 3 covers the upper chip 2, serving to protect it. A first resin shielding film 4 is disposed on the upper surface of the first molding compound layer 3 and on the side surface of the single substrate 1, wherein the two locations of the first resin shielding films 4 are connected. It should be noted that the first resin shielding film 4 (and the second resin shielding film 5 described below) provided by this invention are both made of thermosetting resin material with shielding function. This thermosetting resin material can be directly pressed onto the molding compound layer or the single substrate 1 using a compression molding device, which, compared to the existing method of using sputtering plating, provides both work efficiency and cost savings.

[0053] Furthermore, a slot 10 corresponding to the grounding terminal position on the monomer substrate 1 is formed within the first molding layer 3, and a second resin shielding film 5 is pressed into the slot 10. One end of the second resin shielding film 5 is connected to the first resin shielding film 4, and the other end is connected to the grounding terminal. It should be noted that both the first resin shielding film 4 and the second resin shielding film 5 can be directly vacuum-pressed and cast into their corresponding positions using a compression molding machine. The first resin shielding film 4 on the first molding layer 3 and the first resin shielding film 4 on the side of the monomer substrate 1 together form a conformal shield. Since one end of the second resin shielding film 5 is connected to the first resin shielding film 4 and the other end is connected to the grounding terminal, the second resin shielding film 5 itself can form a zone shield, greatly simplifying the zone shielding manufacturing process and reducing costs. In addition, it should be emphasized that the slot 10 can be of any shape, as long as it meets the corresponding conductivity and zone shielding performance requirements.

[0054] Additionally, it should be noted that traditional thermosetting resin materials do not possess electrical conductivity, and therefore typically do not have corresponding shielding capabilities. To enable these thermosetting resin materials to have shielding capabilities, metal particles (such as Ag or Cu powder) need to be added. After adding the metal particles, the thermosetting resin material will possess the corresponding shielding capabilities while still retaining the corresponding resin properties. Therefore, this can be achieved through direct vacuum compression molding using a compression molding machine.

[0055] Furthermore, in actual use, since the lower chip 6 on the single substrate 1 is usually located on the inner side of the device casing, it is not easy to come into direct contact with external objects and thus avoid damage. Therefore, in the actual manufacturing process, the surface of the lower chip 6 can be exposed outside the second molding layer 7 or flush with the surface of the second molding layer 7, thereby enhancing the heat dissipation effect of the entire structure.

[0056] In one specific embodiment of the present invention, solder balls 8 can be provided on the lower surface of the single substrate 1, with the top of the solder balls 8 protruding beyond the second molding layer 7. By providing solder balls 8, pre-set terminals (such as I / O port terminals) on the single substrate can be directly led out, facilitating connection to external devices. Of course, for some terminals that require direct connection, the corresponding solder balls 8 can be directly connected through solder ball pads or the interposer layer 9.

[0057] Corresponding to the above-mentioned double-sided plastic encapsulation shielding packaging structure, the present invention also provides a processing method for a double-sided plastic encapsulation shielding packaging structure, through which the above-mentioned double-sided plastic encapsulation shielding packaging structure is processed and manufactured.

[0058] Specifically, Figures 2 to 10 The diagram illustrates the steps of the processing method. Figures 2 to 10 As shown in the figure, the processing method includes:

[0059] Surface mount technology (SMT) is used to mount the upper layer chip 2 and the lower layer chip 6 at corresponding positions on the upper and lower surfaces of the integral substrate 13 (which is a single substrate, cut into sections as described above, resembling a single substrate 1). The upper and lower surfaces of the integral substrate 13 are then encapsulated and cured to form a first encapsulation layer 3 covering the upper layer chip 2 and a second encapsulation layer 7 covering the lower layer chip 6 (corresponding to...). Figures 1 to 4 ).

[0060] Then, the encapsulated substrate 13 is laser-cut to form an upper surface half-groove 11 from the upper surface of the first encapsulation layer 3 to the middle position of the second encapsulation layer 7; wherein, the upper surface half-groove 11 is used to divide the substrate 13 into at least two structural units (when viewed from above the substrate 13), and the two adjacent structural units are connected by a half-cut reserved encapsulation portion (i.e., the reserved portion of the second encapsulation layer 7 below the upper surface half-groove 11).

[0061] Then, the resin shielding film is pressed and cured on the upper surface of the first molding layer 3, the side surface of the overall substrate 13 and the inner wall of the upper surface half groove 11 using a molding machine, so that the thermosetting resin material is fixedly covered in the corresponding position to form the first resin shielding film 4.

[0062] Finally, the upper surface of the overall substrate 13 is fixed on the positioning tape 12, and then the lower surface of the overall substrate 13 is ground and thinned. As the second molding layer 7 is thinned, the half-cut reserved molding portion is continuously removed. When the half-cut reserved molding portion is completely removed, each structural unit separates (corresponding to the separation of the substrate unit).

[0063] Furthermore, the laser cutting process for the encapsulated substrate 13 mainly includes two processes: upper surface half-cutting and laser grooving; wherein, upper surface half-cutting is used to form upper surface half-cut groove 11, and laser grooving is used to form groove 10 corresponding to the ground terminal position on the substrate; and the processing method also includes:

[0064] While the resin shielding film is pressed and cured on the upper surface of the first plastic seal 3, the side of the overall substrate 13 and the inner wall of the upper surface half groove 11 by the compression molding equipment, the resin shielding film is pressed in the groove 10 to form the second resin shielding film 5, wherein one end of the second resin shielding film 5 is connected to the first resin shielding film 4 and the other end of the second resin shielding film 5 is connected to the grounding terminal.

[0065] Specifically, solder balls 8 are also provided on the lower surface of the integral substrate 13; and during the grinding process of the lower surface of the integral substrate 13,

[0066] Alternatively, the top of the solder ball 8 can be exposed outside the second molding compound layer 7, and the surface of the underlying chip 6 can be exposed outside the second molding compound layer 7 or flush with the surface of the second molding compound layer 7. This design allows the underlying chip 6 to be exposed, enhancing heat dissipation. Furthermore, after grinding the lower surface of the overall substrate 13, the process also includes: removing the molding compound from the edges of the solder ball 8 using a laser to reduce the impact of the molding compound on the solder ball 8.

[0067] Once all the above steps are completed, several individual shielded encapsulated units can be formed. At this point, each unit can be picked up and packaged.

[0068] It should be noted that the double-sided plastic encapsulation shielding packaging structure and its processing method provided by the present invention can be used not only for double-sided plastic encapsulation structures, but also for single-sided plastic encapsulation structures. Simply cut the single-sided plastic encapsulation in half, then vacuum press-fit it, and finally separate it.

[0069] The double-sided plastic-encapsulated shielding packaging structure and its processing 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 double-sided plastic-encapsulated shielding packaging structure and its processing method according to the present invention 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 method for processing a dual-side plastic-encapsulated shield package structure, characterized in that, The processing method comprises: attaching an upper chip and a lower chip on corresponding positions of upper and lower surfaces of a whole substrate, respectively; and plastic packaging the upper and lower surfaces of the whole substrate to form a first plastic packaging layer covering the upper chip and a second plastic packaging layer covering the lower chip; laser cutting the whole substrate after plastic packaging to form an upper surface half-cut groove; wherein the upper surface half-cut groove is used to divide the whole substrate into at least two structural monomers, and two adjacent structural monomers are connected through a half-cut reserved plastic packaging part; performing resin shielding film pressing on the upper surface of the first plastic packaging layer, the side surface of the whole substrate and the inner wall of the upper surface half-cut groove to form a first resin shielding film; grinding the lower surface of the whole substrate to remove the half-cut reserved plastic packaging part to separate the structural monomers; wherein the process of laser cutting the whole substrate after plastic packaging comprises upper surface half-cutting and laser slotting; wherein the upper surface half-cutting is used to form the upper surface half-cut groove, and the laser slotting is used to form a slot corresponding to the position of a grounding end on the substrate; and the processing method further comprises: performing resin shielding film pressing in the slot at the same time when the first resin shielding film is formed to form a second resin shielding film, wherein one end of the second resin shielding film is connected with the first resin shielding film, and the other end of the second resin shielding film is connected with the grounding end.

2. The method of claim 1, wherein the method further comprises: soldering balls are arranged on the lower surface of the whole substrate; and during the process of grinding the lower surface of the whole substrate, the top of the soldering ball is exposed outside the second plastic packaging layer, and the surface of the lower chip is exposed outside the second plastic packaging layer or is flush with the surface of the second plastic packaging layer.

3. The method of claim 2, wherein the method further comprises: forming a first die attach film on the first die; and forming a second die attach film on the second die. after the grinding of the lower surface of the whole substrate, the process further comprises: removing plastic packaging material from the edge of the soldering ball by laser.

4. A shielded package structure for dual side plastic encapsulation, characterized in that, processed by the processing method of the double-sided plastic packaging shielding packaging structure according to any one of claims 1 to 3; the double-sided plastic packaging shielding packaging structure comprises a monomer substrate, an upper chip arranged on the upper surface of the monomer substrate and a lower chip arranged on the lower surface of the monomer substrate; a first plastic packaging layer is arranged on the upper surface of the monomer substrate, the first plastic packaging layer covers the upper chip, and a first resin shielding film is arranged on the side surface of the monomer substrate and the side of the first plastic packaging layer away from the upper chip; a slot corresponding to the position of a grounding end on the monomer substrate is arranged in the first plastic packaging layer, and a second resin shielding film is arranged in the slot, one end of the second resin shielding film is connected with the first resin shielding film, and the other end of the second resin shielding film is connected with the grounding end; wherein the first resin shielding film and the second resin shielding film are both arranged by vacuum pressing and filling of the whole substrate.

5. The double-sided plastic packaging shielding packaging structure according to claim 4, wherein The first resin shielding film links with the side surface of the single substrate to form a conformal shield, and the second resin shielding film is used to form an interval shield.

6. The double-sided plastic-encapsulated shield package structure of claim 5, wherein the first resin shielding film and the second resin shielding film are both made of resin containing metal particles inside. The first resin shielding film and the second resin shielding film are both made of resin containing metal particles inside.

7. The dual-side plastic-encapsulated shield package structure of claim 6, wherein, A second plastic-encapsulated layer is arranged on the lower surface of the single substrate, and The surface of the lower layer chip is exposed to the outside of the second plastic-encapsulated layer or is flush with the surface of the second plastic-encapsulated layer.

8. The double-sided plastic-encapsulated shield package structure of claim 7, wherein Solder balls are arranged on the lower surface of the single substrate, and the top of the solder balls is exposed to the outside of the second plastic-encapsulated layer.

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