Pop packaging structure and method based on mold separation film embedded ball

Abstract

This invention discloses a POP packaging structure and method based on a molded separation film with embedded solder balls. The invention relates to the field of semiconductor packaging technology and includes: a substrate; multiple chips stacked on the substrate; an adapter plate attached to the upper surface of the topmost chip, the adapter plate having pre-placed solder balls for PAD solder joints on its upper surface; and a separation film attached to the upper surface of the adapter plate, which embeds the pre-placed solder balls for PAD solder joints on the upper surface of the adapter plate into the film. During the molding process, the pre-placed solder balls for PAD solder joints on the upper surface of the adapter plate are not encapsulated by the molding compound. This invention does not use the TMV (Thin-Metal Veneer) process for opening holes. By setting a special separation film, it can ensure smooth demolding and protect the pre-placed solder balls for PAD solder joints on the adapter plate from being encapsulated during molding. This improves the POP soldering effect, increases operational efficiency, reduces operational costs, and shortens the packaging delivery time.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging technology, particularly to the field of product process development technology, specifically to a POP packaging structure and method based on Mold separation film ball embedding. Background Technology

[0002] Currently, in semiconductor packaging processes, "demolding" may seem like a simple step, but it directly determines the yield and reliability of chips. Traditional release materials such as PET, PTFE, and silicone films frequently encounter problems like demolding difficulties, chip damage, and residual contamination when facing the high temperatures, high precision, and multi-material synergy requirements of advanced packaging, hindering yield improvement. The emergence of ETFE ethylene-tetrafluoroethylene copolymer release film not only systematically solves the demolding problem but also, through the deep integration of material properties and processes, drives the upgrade of semiconductor packaging processes towards higher precision, higher efficiency, and higher reliability, achieving a leap from "passive adaptation" to "active reshaping." As the semiconductor industry accelerates its evolution towards high density, miniaturization, and multi-functionality, advanced packaging technologies, such as 2.5D / 3D packaging, fan-out packaging, and SiP system-in-package, have become core paths to overcome the limitations of Moore's Law. These technologies place unprecedentedly stringent requirements on the precision, stability, and compatibility of packaging materials. ETFE ethylene-tetrafluoroethylene copolymer release film, with its unique material properties, adapts to the needs of advanced packaging technologies while providing key support for industry breakthroughs through continuous innovative applications.

[0003] The fundamental difference between advanced packaging technology and traditional packaging lies in three dimensions: high-density integration (e.g., chip spacing less than 5μm in 3D stacking), complex process environments (e.g., high-temperature bonding), multi-material compatibility, and precise dimensional control (e.g., RDL wiring accuracy of 1μm in fan-out packaging). These factors present unique challenges to release films. With the increasing pursuit of miniaturization, thinness, and high performance in electronic products, their internal space is becoming increasingly compact, posing growing challenges to component mounting processes and structural layouts. Therefore, packaging technology must continuously advance to meet the demands of multi-pin, high-integration applications. As package sizes further shrink, traditional semiconductor die-bonding adhesive solutions face numerous challenges. These problems mainly include: stringent control of dispensing volume: adhesive used during die bonding often overflows around the chip, increasing the chip's footprint and potentially adversely affecting surrounding components. The rheological properties of the resin: to prevent adhesive from overflowing along the chip edges onto the upper surface or bonding area, the chip needs to maintain a certain thickness, adding extra difficulty to process control. Chip miniaturization and thinning: When the chip thickness is less than 100μm or even thinner, it becomes extremely difficult to directly pick up the chip without a mechanical support film using a die-loading nozzle, because even slight stress can cause the chip to deform or break. Process control requirements: The die-loading process requires extremely high precision in adhesive dispensing, necessitating not only precision equipment but also more time for process control.

[0004] POP (Package On Package) products combine two independent UFS and LPDDR products using a Package On Package (BOP) structure, allowing for greater flexibility in adapting to market capacity demands. Current industry POP soldering processes involve attaching an adapter board onto a multi-layer chip. The adapter board has pads on its surface for soldering. Solder balls are pre-soldered onto these pads, followed by encapsulation. Then, a TMV (Technical Method Instrumentation) process is used to create openings in the encapsulation, exposing the pads on the adapter board to allow for POP soldering of another BGA device. However, this method involves TMV opening of the adapter board's pads, resulting in a complex process and difficulties in quality control. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a POP packaging structure and method based on a molded separator membrane with embedded solder balls. This invention is applicable to applications that do not require TMV (Technical Microwave Oven) process for opening holes. During the molded process, the separator membrane uses an embedded solder ball process to protect the solder balls with PAD solder joints on the surface of the adapter board. After molding, the packaging process is completed by conventional printing, ball placement, and cutting.

[0006] To achieve the above objectives, the first technical solution adopted by the present invention is: a POP packaging structure based on a Mold release film with embedded solder balls, comprising: a substrate; multiple chips stacked on the substrate; an adapter plate attached to the upper surface of the topmost chip, the upper surface of the adapter plate having PAD solder points with pre-placed solder balls; and a release film attached to the upper surface of the adapter plate, through which the pre-placed solder balls of the PAD solder points on the upper surface of the adapter plate are embedded into the film body, so that during the molding process, the pre-placed solder balls of the PAD solder points on the upper surface of the adapter plate are not encapsulated by the molding compound.

[0007] Optionally, the separation membrane includes: a conventional separation membrane layer disposed on the outermost side of the separation membrane, the conventional separation membrane layer forming a contact surface with the inner wall of the molding die; an AS material layer adhered to the inner side of the conventional separation membrane layer, the AS material layer being an antistatic material; and a foam adhesive material layer adhered to the innermost side of the separation membrane, the separation membrane being embedded in the PAD solder joints on the upper surface of the adapter board via the foam adhesive material layer to pre-place solder balls.

[0008] Optionally, the distance between the surface of the foam adhesive layer of the separation membrane and the surface of the conversion plate is not less than a first predetermined distance.

[0009] Optionally, the distance between the surface of the foam adhesive material layer of the separation membrane and the surface of the conversion plate is not greater than the height of the pre-placed solder ball at the PAD soldering point on the upper surface of the conversion plate.

[0010] Optionally, the distance between the foam adhesive material layer of the separation membrane and the welding line on the conversion plate is not less than a second predetermined distance.

[0011] Optionally, the thickness of the foam adhesive material layer of the separation membrane is not less than the height of the pre-placed solder balls at the PAD solder joints on the upper surface of the adapter plate.

[0012] The second technical solution adopted in this invention is: a packaging method based on the POP packaging structure based on a Mold release film and embedded balls as described in any one of the first technical solutions, comprising the following steps: bonding multiple chips together with DAF and then stacking them sequentially in a staggered manner on a substrate, and connecting the chips to corresponding bonding wires on the substrate respectively; attaching an adapter board on the multi-layered chips, and soldering solder balls on the PAD solder points on the surface of the adapter board; attaching a release film to the outside of the adapter board, adjusting the gap between the release film and the adapter board so that the pre-placed solder balls on the surface of the adapter board are embedded in the release film; and performing a one-time compression molding and encapsulation of the structure using a mold.

[0013] Optionally, the step of attaching the separation membrane to the outside of the adapter plate and adjusting the distance between the separation membrane and the adapter plate to embed the pre-placed solder balls on the surface of the adapter plate into the separation membrane further includes: partially embedding the solder balls into the foam adhesive layer of the separation membrane, and maintaining a certain gap between the separation membrane, the adapter plate, and the pre-placed solder balls at the PAD solder joints of the adapter plate.

[0014] Optionally, the step of attaching the separation membrane to the outside of the adapter plate and adjusting the distance between the separation membrane and the adapter plate to embed the pre-placed solder balls on the surface of the adapter plate into the separation membrane further includes: sprinkling EMC epoxy resin molding compound on the foam adhesive layer of the separation membrane and filling the gap space between the separation membrane, the adapter plate and the pre-placed solder balls at the PAD solder joint of the adapter plate with EMC epoxy resin molding compound.

[0015] Optionally, the process of compressing and molding the structure using a mold further includes: separating the molded body from the mold, removing the separation film on the molded body, and exposing the portion of the pre-placed solder balls at the PAD solder joint of the adapter board embedded inside the separation film that protrudes from the molded body.

[0016] The beneficial effects of this invention are: This invention eliminates the need for TMV (Technical Microwave Oscillator) hole-opening technology by attaching an adapter board onto a multi-layer chip. The adapter board has PAD solder joints on its surface. Solder balls are pre-soldered on the PADs on the adapter board surface. During molding, the separation membrane uses an embedded solder ball process to protect the solder balls with PAD solder joints on the adapter board surface. After molding, the packaging process is completed by conventional printing, ball placement, and cutting.

[0017] By setting a special separation membrane, smooth demolding can be ensured, and the solder balls pre-placed at the PAD soldering points of the adapter board can be protected from being wrapped during the molding process. This improves the POP soldering effect, increases work efficiency, reduces work costs, and shortens the packaging delivery time. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the POP packaging structure based on the Mold separation membrane with embedded balls before molding of the present invention; Figure 2 This is a schematic diagram of the POP packaging structure based on the Mold separation membrane with embedded balls after molding. Figure 3 This is a schematic diagram of the conventional POP product packaging structure of the present invention; Figure 4 This is a schematic diagram of the separation membrane structure of the present invention.

[0019] Reference numerals: 1. Substrate; 2. Chip; 3. Bonding wire; 4. DAF film; 5. Adapter board; 6. Pre-placed solder balls at the PAD soldering point on the adapter board; 7. Separation membrane; 71. Conventional separation membrane layer; 72. AS material layer; 73. Foam adhesive material layer; 8. Encapsulation body. Detailed Implementation

[0020] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0021] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0022] This invention provides a POP packaging structure based on Mold-separated membrane ball embedding. This application relates to packaging technology; IC packaging is a technology that mounts and fixes semiconductor integrated circuit chips in a housing. Conductivity is achieved by connecting chip contacts to housing pins via wires. Its main functions include protecting the chip from corrosion, enhancing electrothermal performance, and forming an electronic connection between the chip and the PCB by the packaging substrate. As a downstream process in the integrated circuit industry chain, it encompasses packaging and testing, playing a crucial role in ensuring chip performance and quality. Common packaging forms include BGA, QFP, DIP, and PLCC, among which BGA uses bottom ball bumps to support over 200 pins, and QFP achieves high-density connections through gull-wing pins. Advanced packaging technologies such as flip-chip, wafer-level packaging, 2.5D / 3D packaging, and chiplets are gradually becoming mainstream and are applied in high-performance computing, 5G communication, and autonomous driving.

[0023] In one specific embodiment of this application, as follows: Figures 1-4As shown, the packaging structure includes: a chip 2, multiple chips 2 stacked on a substrate 1 with staggered alignment using DAF film 4, and each chip 2 connected to the substrate 1 via bonding wires 3. With increasing packaging performance requirements and advancements in packaging technology, chip 2 bonding technology is constantly being innovated. DAF is a high-performance adhesive film widely used in semiconductor packaging for connecting chip 2 and substrate 1, particularly excelling in thin-film stacking. Its advantages include: size adaptability: As the size of chip 2 shrinks, the DAF film can flexibly adapt to various sizes while maintaining excellent coating uniformity. Good interface contact: The DAF film forms a good interface contact with chip 2 and the packaging structure, ensuring efficient heat transfer. Reliability and durability: Under various temperature, humidity, and mechanical stress conditions, the DAF film maintains stable performance, ensuring the reliability and durability of chip 2 during long-term use. Semiconductor DAF films, with their excellent adhesion, packaging performance, and superior heat resistance, significantly improve the stability, shock resistance, and vibration resistance of chip 2, providing strong support for the continuous and stable operation of equipment. Using DAF allows for very small and constant thickness adjustments. DAF is not only used for bonding between chip 2 and substrate 1, but also widely used for bonding between chips 2 to form multi-wafer packages. Specifically, the DAF film 4 located at the bottom of chip 2 supports chip 2, while the dicing tape pulls the DAF underneath it with weak adhesive force. During bonding, after removing chip 2 and DAF film 4 from the dicing tape, the die is immediately placed on substrate 1, eliminating the need for epoxy resin and skipping the dispensing step. This simplifies the process and improves thickness uniformity, thereby reducing defect rates and increasing productivity.

[0024] In one specific embodiment of this application, the DAF film 4, or wafer bonding film, is a thin film material specifically designed for semiconductor chip 2 packaging. It mainly consists of a first adhesive surface, a second adhesive surface, an intermediate layer, and a high thermal conductivity resin layer. The first adhesive surface bonds to the chip 2, protecting the wafer from external environmental damage; the second adhesive surface bonds to the substrate 1, improving the wafer's conductivity; the intermediate layer, located between the first and second adhesive surfaces, provides support, filling, and protection for the circuitry; and the high thermal conductivity resin layer improves the wafer's heat dissipation. The DAF film possesses excellent isolation, thermal conductivity, and corrosion resistance, making it the preferred material for demanding semiconductor packaging processes. Currently, the DAF film is primarily used for stacking chips to achieve 3D packaging of flash memory devices. In memory chip packaging, the DAF film has become a commonly used process. Compared to adhesives, the DAF film allows for consistent thickness and thinner processes, and can be used not only for bonding the chip 2 to the substrate 1 but also primarily for bonding chips to each other, thereby forming multi-chip packages. For achieving high reliability, high performance, high speed, high device density, and smaller, thinner packages, DAF films have become a key technology. DAF films offer excellent adhesion to various leadframe surfaces and chip-2 sizes without resin leakage. Precise control of the adhesive layer thickness eliminates chip-2 tilting issues, enabling high-volume assembly. DAF films were created to address the problems associated with epoxy adhesives in multi-chip modules and other applications involving wafer-level and chip-size constraints.

[0025] In one specific embodiment of this application, the packaging structure includes an interposer 5, which is bonded and stacked with the chip 2. The surface of the interposer 5 has pre-placed solder balls 6 on its PAD solder joints. The interposer, also known as the interposer layer or interposer 5 in this application, is a core connection component in the packaging technology. It acts as a "bridge" between the chip and the substrate 1, establishing a vertical conductive channel through through-silicon via (TSV) technology to achieve efficient transmission of electrical signals and rapid data exchange. This structure not only supports the physical fixation of the chip but also reduces signal delay by optimizing wiring density, thereby improving the overall chip performance. Furthermore, the interposer allows chips from different process nodes to be integrated into the same package, enhancing the modularity and flexibility of the design. The interposer plays a crucial role in the chip 2; it is an interposer technology commonly used in distributed systems to facilitate information exchange between upper or lower layer nodes, particularly connecting two chips. The interposer typically uses microbumps and C4 bumps for electrical interconnection with the chip and the packaging substrate, enabling information exchange between them. Interposer is a middle layer technology used to connect chips. Its substrate is typically a silicon substrate, and it is related to the substrate. Interposers achieve electrical connections through wire bumps / TSVs and can be made of silicon and organic materials. In 2.5D packaging, chips are placed side by side on top of the interposer, and interconnection is achieved through microbumps on the chips and wiring in the interposer. The interposer connects the upper and lower layers through through-silicon vias (TSVs).

[0026] In one specific embodiment of this application, the packaging structure includes a separation membrane 7, which is arranged parallel to the adapter plate 5. The separation membrane 7 embeds the pre-placed solder balls 6 of the PAD solder joints of the adapter plate into the membrane body. During the molding process, the solder balls of the PAD solder joints on the surface of the adapter plate 5 are embedded in the separation membrane 7 and are not wrapped by the molding compound 8. The separation membrane 7 not only ensures smooth demolding during the semiconductor packaging process, but also protects the pre-placed solder balls 6 of the PAD solder joints of the adapter plate, preventing them from being wrapped during the packaging process. With its unique material design, the separation membrane 7 constructs a comprehensive "protective barrier" from three dimensions: physical protection, chemical isolation, and precision control, becoming a key material for ensuring chip integrity.

[0027] In one specific embodiment of this application, the separation membrane 7 includes a conventional separation membrane layer 71, disposed on the outermost side of the separation membrane 7, which forms a contact surface with the inner wall of the molding die. In the semiconductor packaging process, the "integrity" of the chip 2 is a core prerequisite for determining the final device performance and reliability—it requires not only that the chip's physical structure, such as the wafer, bonding points, and passivation layer, be intact, but also that electrical performance, such as conductivity and insulation, be unaffected, and that the surface be free of any contaminants, such as residual adhesive or metal ions. However, factors such as high temperature, mechanical stress, and chemical corrosion during the packaging process always pose a threat to chip integrity. Optimization of the material properties and process of the conventional separation membrane layer 71 can effectively avoid these problems.

[0028] In one specific embodiment of this application, the separation membrane 7 includes an AS material layer 72 disposed inside the conventional separation membrane layer 71. The AS material layer 72 is an antistatic material. AS material layer 72, i.e., injection-molded ESD material, is an important antistatic material with broad application prospects in the electronics manufacturing field. It possesses good conductivity and antistatic properties, effectively controlling and eliminating static electricity, protecting the safety of electronic components and equipment. ESD materials exhibit a good balance between processability and physical properties. They can meet the requirements of injection molding processes, ensuring product quality and production efficiency. ESD materials also possess high heat resistance, corrosion resistance, and mechanical properties, enabling them to operate stably in harsh environments for extended periods.

[0029] In one specific embodiment of this application, the separation membrane 7 includes a foam adhesive material layer 73 disposed on the innermost side of the separation membrane 7. The separation membrane 7 is embedded with pre-placed solder balls 6 at the PAD soldering points of the adapter plate through the foam adhesive material layer 73. Foam adhesive, a type of rubber, does not corrode foam molds and has the functions of shock absorption, heat insulation, and sound insulation. Its characteristics include non-corrosion of foam molds and a sponge-like porous structure of vulcanized rubber. It can be classified as open-cell, closed-cell, mixed-cell, and microporous, and can be made into soft or hard rubber products. It is lightweight, soft, elastic, and does not conduct heat well. It has functions such as shock absorption, shock absorption, heat insulation, and sound insulation. Those made of synthetic rubber also have characteristics such as oil resistance, aging resistance, and chemical resistance.

[0030] In one specific embodiment of this application, the distance between the foam adhesive material layer 73 of the separation membrane 7 and the conversion plate is not less than a first predetermined distance and not greater than the height of the pre-placed solder balls 6 at the PAD soldering points of the conversion plate. This ensures that the pre-placed solder balls 6 at the PAD soldering points of the conversion plate are partially embedded in the foam adhesive layer, leaving a solderable portion, while providing sufficient encapsulation space on the outside of the conversion plate.

[0031] In one specific embodiment of this application, the distance between the foam adhesive material layer 73 of the separation membrane 7 and the leads on the conversion plate is not less than a second predetermined distance. This ensures that the leads can be completely inserted into the molding compound during the encapsulation process.

[0032] In one specific embodiment of this application, the thickness of the foam adhesive material layer 73 of the separation membrane 7 is not less than the height of the pre-placed solder balls 6 at the PAD solder joint of the adapter board. This ensures that the pre-placed solder balls 6 at the PAD solder joint of the adapter board can be embedded as much as possible in the foam adhesive layer for protection.

[0033] In one specific embodiment of this application, the surface area of ​​the separation membrane 7 is not less than the area of ​​the substrate 1. This ensures that the separation membrane 7 can completely protect the solder balls on the adapter board 5, while also ensuring smooth demolding of the entire molding compound.

[0034] The present invention also provides a packaging method for a POP packaging structure based on a molded separator 7 with embedded solder balls, comprising the following steps: stacking multiple chips 2 and DAFs in parallel on a substrate 1 with staggered alignment, and soldering the chips 2 to the pins on the substrate 1 with wires; mounting an adapter board 5 on the multi-layered chips 2, and soldering solder balls to the PAD solder points on the surface of the adapter board 5; arranging the separator in parallel on the outside of the adapter board 5, adjusting the spacing between the separator and the adapter board 5 so that the solder balls 6 pre-placed at the PAD solder points of the adapter board are embedded in the separator; and performing a single compression molding encapsulation using a mold.

[0035] In one specific embodiment of this application, the separation membrane is arranged parallel to the outside of the adapter plate 5, and the distance between the separation membrane and the adapter plate 5 is adjusted so that the pre-placed solder balls 6 of the adapter plate PAD solder joints are embedded in the separation membrane; specifically, it also includes: partially embedding the pre-placed solder balls 6 of the adapter plate PAD solder joints into the foam adhesive material layer 73 of the separation membrane, and maintaining a certain gap space between the separation membrane, the adapter plate 5 and the pre-placed solder balls 6 of the adapter plate PAD solder joints. The gap space is used to fill the encapsulation material.

[0036] In one specific embodiment of this application, the separation membrane is arranged parallel to the outer side of the adapter plate 5, and the spacing between the separation membrane and the adapter plate 5 is adjusted to embed the solder balls into the separation membrane. Specifically, the process further includes: sprinkling EMC epoxy molding compound onto the foam adhesive layer 73 of the separation membrane 7, and filling the gap between the separation membrane 7, the adapter plate 5, and the pre-placed solder balls 6 at the PAD solder joints of the adapter plate with the EMC epoxy molding compound. This allows the epoxy molding compound to melt at high temperatures and fill the gap, achieving encapsulation.

[0037] In one specific embodiment of this application, a compression molding encapsulation process is performed, which further includes: separating the encapsulation body 8 from the mold, removing the separation film 7 from the encapsulation body, and exposing the pre-placed solder balls 6 at the PAD solder joints of the adapter board. Subsequent conventional printing, ball placement, and cutting complete the encapsulation process.

[0038] This invention does not use the TMV (Technical Microwave Ore) process for opening holes. During molding, the separation membrane employs an embedded solder ball process to protect the solder balls with PAD (Pad Injection Point) solder joints on the adapter board surface. After molding, conventional printing, ball placement, and cutting complete the packaging process. This improves POP soldering performance, increases operational efficiency, reduces operating costs, and shortens packaging lead time.

[0039] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A POP packaging structure based on Mold-separated membrane with embedded balls, characterized in that, include: substrate; Multiple chips, which are stacked on the substrate; An adapter board is attached to the upper surface of the topmost chip, and the upper surface of the adapter board has pre-placed solder balls at the adapter board PAD soldering points. A separation membrane is attached to the upper surface of the adapter plate. The separation membrane embeds the pre-placed solder balls of the PAD solder joints on the upper surface of the adapter plate into the membrane body. During the molding process, the pre-placed solder balls of the PAD solder joints on the upper surface of the adapter plate are not wrapped by the molding body.

2. The POP packaging structure based on Mold separation membrane with embedded balls according to claim 1, characterized in that, The separation membrane comprises: A conventional separation membrane layer is disposed on the outermost side of the separation membrane, and the conventional separation membrane layer forms a contact surface with the inner wall of the molding die. An AS material layer is attached to the inner side of the conventional separation membrane layer, and the AS material layer is an antistatic material. A foam adhesive material layer is attached to the innermost side of the separation membrane, and the separation membrane is embedded in the pre-placed solder balls of the PAD solder joint on the upper surface of the adapter plate through the foam adhesive material layer.

3. The POP packaging structure based on Mold separation membrane with embedded balls according to claim 1, characterized in that, The distance between the surface of the foam adhesive layer of the separation membrane and the surface of the conversion plate is not less than a first predetermined distance.

4. The POP packaging structure based on Mold separation membrane with embedded balls according to claim 1, characterized in that, The distance between the surface of the foam adhesive material layer of the separation membrane and the surface of the conversion plate is no greater than the height of the pre-placed solder ball at the PAD soldering point on the upper surface of the conversion plate.

5. The POP packaging structure based on Mold separation membrane with embedded balls according to claim 1, characterized in that, The distance between the foam adhesive layer of the separation membrane and the welding line on the conversion plate is not less than a second predetermined distance.

6. The POP packaging structure based on Mold separation membrane with embedded balls according to claim 1, characterized in that, The thickness of the foam adhesive material layer of the separation membrane is not less than the height of the pre-placed solder ball at the PAD soldering point on the upper surface of the adapter plate.

7. A packaging method based on the POP packaging structure based on the Mold separation film and embedded balls as described in any one of claims 1-6, characterized in that, Includes the following steps: Multiple chips are bonded together using DAF and then stacked on a substrate in a staggered manner, and the chips are connected to the corresponding bonding wires on the substrate. An adapter board is then mounted on the multi-layered chip, and solder balls are soldered onto the PAD solder joints on the surface of the adapter board. The separation membrane is attached to the outside of the adapter plate, and the distance between the separation membrane and the adapter plate is adjusted so that the pre-placed solder balls on the surface of the adapter plate are embedded in the separation membrane. The structure is compressed and molded in one step using a mold.

8. The POP packaging method based on Mold separation membrane with embedded balls according to claim 7, characterized in that, The step of attaching the separation membrane to the outside of the adapter plate and adjusting the distance between the separation membrane and the adapter plate to embed the pre-placed solder balls on the surface of the adapter plate into the separation membrane; further includes: The solder balls are partially embedded in the foam adhesive layer of the separation membrane, and a certain gap space is maintained between the pre-placed solder balls at the solder joints of the separation membrane, the adapter plate, and the adapter plate PAD.

9. The POP packaging method based on Mold separation membrane with embedded balls according to claim 8, characterized in that, The step of attaching the separation membrane to the outside of the adapter plate and adjusting the distance between the separation membrane and the adapter plate to embed the pre-placed solder balls on the surface of the adapter plate into the separation membrane also includes: EMC epoxy resin molding compound is sprinkled onto the foam adhesive layer of the separation membrane, and the gap between the separation membrane, the adapter plate, and the pre-placed solder balls at the PAD solder joint of the adapter plate is filled with EMC epoxy resin molding compound.

10. The POP packaging method based on Mold separation membrane ball embedding according to claim 7, characterized in that, The process of compressing and molding the structure using a mold in one step also includes: Separate the molding compound and the mold, remove the separation film on the molding compound, and expose the portion of the pre-placed solder balls at the PAD solder joint of the adapter board embedded inside the separation film.

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