Method for forming a package structure

Abstract

A method for forming a packaging structure, after providing a dry film, a plurality of through holes are formed in the dry film by a drilling operation, the through holes penetrating the upper and lower surfaces of the dry film; a first substrate is provided, the upper and lower surfaces of the first substrate have first pads and second pads respectively, and the first substrate has a first circuit electrically connecting the first pads and the second pads; the dry film with the through holes is attached to the upper surface of the first substrate, and the through holes expose the surfaces of the corresponding first pads; a metal column filling the through holes is formed; the dry film is removed; a first chip is provided and attached to the upper surface of the first substrate on the side of the metal column, the first chip is electrically connected to part of the first pads; and a first plastic encapsulation layer covering the surface of the first chip, the side wall and the top surface of the metal column, and the upper surface of the first substrate is formed. The height of the formed metal column is higher and the side wall morphology is better, and the pitch and size can be smaller.

Description

Technical Field

[0001] This application relates to the semiconductor field, and more particularly to a method for forming a packaging structure. Background Technology

[0002] With the increasing demand for applications such as smartphones, smart wearables, smart manufacturing, automotive and motor vehicle driver assistance systems, and AIoT, end products need to maintain higher performance while keeping their size and power consumption small. Besides chip manufacturers focusing on System-on-Chips (SoCs) based on advanced silicon technology nodes, packaging and testing companies focusing on System-in-Package (SiP) based on advanced packaging technologies are also highly competitive due to their low cost, flexibility, and high yield. As integration density increases, SiP is also evolving from early 2D packaging forms (such as Multi-Chip Modules) towards 2.5D and 3D.

[0003] As a type of 3D packaging, PoP (Package on Package) stacked packaging typically consists of an upper substrate and a lower substrate stacked one on top of the other, on which corresponding semiconductor chips are mounted. Common connection methods between the upper and lower substrates include metal pillar connections. However, existing metal pillars formed using photoresist masking and electroplating processes suffer from limitations in spacing, height, and sidewall morphology, as well as cost and contamination issues. Summary of the Invention

[0004] Some embodiments of this application provide a method for forming an encapsulation structure, including:

[0005] Provide dry film;

[0006] A number of through holes penetrating the upper and lower surfaces of the dry film are formed in the dry film by drilling.

[0007] A first substrate is provided, wherein the upper and lower surfaces of the first substrate have a first pad and a second pad respectively, and the first substrate has a first line that electrically connects the first pad and the second pad.

[0008] The dry film with through holes is attached to the upper surface of the first substrate, and the through holes expose the surface of the corresponding first pads.

[0009] A metal pillar is formed that fills the through-hole;

[0010] Remove the dry film;

[0011] A first chip is provided and mounted on the upper surface of a first substrate between metal pillars, wherein the first chip is electrically connected to a portion of the first pad.

[0012] A first molding compound is formed covering the surface of the first chip, the sidewalls and top surface of the metal pillar, and the upper surface of the first substrate.

[0013] In some embodiments, the drilling operation is performed using a drill bit or a laser.

[0014] In some embodiments, the thickness of the dry film is 20 micrometers to 1000 micrometers, the depth of the via is 20 micrometers to 1000 micrometers, the height of the metal pillar is 20 micrometers to 1000 micrometers, and the diameter of the metal pillar is greater than 25 micrometers.

[0015] In some embodiments, the dry membrane is a single-layer structure or comprises multiple discrete sub-dry membranes.

[0016] In some embodiments, when the dry film comprises a plurality of discrete sub-dry films, a plurality of sub-through holes penetrating the upper and lower surfaces of each sub-dry film are formed in each sub-dry film by drilling. The plurality of sub-dry films are then stacked and attached to the upper surface of the first substrate in a direction perpendicular to the upper surface of the first substrate. The plurality of stacked sub-dry films constitute the dry film, and the plurality of corresponding sub-through holes in the plurality of sub-dry films are interconnected vertically to form the through holes.

[0017] In some embodiments, the upper and lower surfaces of the dry film, or the upper and lower surfaces of each sub-dry film, have a protective film; the protective film is removed after drilling and before attachment.

[0018] In some embodiments, a metal pillar is formed in the through hole by an electroplating process.

[0019] In some embodiments, the first molding layer is planarized by a chemical mechanical polishing process to expose the top surface of the metal pillar, or the first molding layer is etched by an etching process to form an opening in the first molding layer that exposes the top surface of the metal pillar.

[0020] In some embodiments, a second package is provided; the second package is stacked on top of the first molding layer, and the second package is connected to the exposed metal pillar.

[0021] In some embodiments, the second package includes a second substrate, a second chip mounted on an upper surface of the second substrate, and a solder bump located on a lower surface of the second substrate, the solder bump being electrically connected to the exposed metal pillar.

[0022] The method for forming the packaging structure in some of the foregoing embodiments of this application involves providing a dry film, then forming a plurality of through-holes penetrating the upper and lower surfaces of the dry film through a drilling operation; providing a first substrate, the upper and lower surfaces of the first substrate respectively having a first pad and a second pad, and the first substrate having a first line electrically connecting the first pad and the second pad; attaching the dry film with through-holes to the upper surface of the first substrate, the through-holes exposing the surfaces of the corresponding first pads; forming metal pillars filling the through-holes; removing the dry film; providing a first chip, attaching the first chip to the upper surface of the first substrate on one side of the metal pillars, the first chip being electrically connected to a portion of the first pads; and forming a first molding compound covering the surface of the first chip, the sidewalls and top surface of the metal pillars, and the upper surface of the first substrate. When through-holes are formed in the dry film through a drilling operation, the formed through-holes can have a deeper depth and a better sidewall morphology (and can also have a smaller spacing and size), thus the metal pillars formed in the through-holes can also have a higher height and a better sidewall morphology (and can also have a smaller spacing and size), improving the electrical performance of the formed metal pillars. Furthermore, when forming metal pillars, the dry film does not require exposure and development, which saves costs and avoids contamination problems.

[0023] Furthermore, in some embodiments, the dry film includes a plurality of discrete sub-dry films. A plurality of sub-through holes penetrating the upper and lower surfaces of each sub-dry film are formed in each sub-dry film by drilling. Then, the plurality of sub-dry films are sequentially stacked and attached to the upper surface of the first substrate in a direction perpendicular to the upper surface of the first substrate. The plurality of stacked sub-dry films constitute the dry film. The plurality of corresponding sub-through holes in the plurality of sub-dry films are interconnected vertically to form the through holes, and metal pillars are formed in the through holes. Therefore, a thicker dry film can be formed by multi-layered sub-dry films, and a taller metal pillar can be formed in the dry film. Furthermore, since several sub-through holes penetrating the upper and lower surfaces of each sub-dry film are formed by drilling, the sidewalls of the sub-through holes can maintain a good morphology, and the process difficulty of forming deep through holes is reduced. After several sub-dry films are stacked on the first substrate to form a dry film, the through holes composed of multiple sub-through holes in the dry film also have a good sidewall morphology, so that the taller metal pillars formed in the through holes can have a good sidewall morphology. Moreover, the aforementioned method can also make the aforementioned taller metal pillars maintain a small spacing and size at the same time. Attached Figure Description

[0024] Figures 1-14 This is a schematic diagram of the formation process of the semiconductor structure in some embodiments of this application. Detailed Implementation

[0025] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. In describing the embodiments of this application in detail, for ease of explanation, the schematic diagrams may be partially enlarged without adhering to the general scale, and the schematic diagrams are merely examples and should not limit the scope of protection of this application. Furthermore, in actual manufacturing, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0026] This application provides a method for forming an encapsulation structure in some embodiments, which will be described in detail below with reference to the accompanying drawings.

[0027] refer to Figure 1 Dry film 101 is provided.

[0028] The dry film 101 serves as a mask for the subsequent electroplating process to form metal pillars. The dry film 101 is made of an adhesive resin, which can be a photosensitive resin or a non-photosensitive resin. In a specific embodiment, since the subsequent process involves drilling (rather than exposure and development) to form through-holes in the dry film 101 penetrating its upper and lower surfaces, a non-photosensitive resin is used in this embodiment to save on the cost of the dry film. This non-photosensitive resin can be a non-photosensitive epoxy resin, a non-photosensitive polyimide resin, a non-photosensitive benzocyclobutene resin, or a non-photosensitive polybenzoxazole resin.

[0029] The thickness of the dry film 101 is approximately equal to or slightly greater than the height of the metal pillar to be formed subsequently. The thickness of the dry film 101 is greater than the thickness or height of the first chip to be mounted subsequently.

[0030] In this application, a plurality of through holes penetrating the upper and lower surfaces of the dry film 101 are subsequently formed through drilling. When forming through holes through drilling, through holes with great depth and good sidewall morphology can be formed, and through holes with reduced spacing and smaller size can be formed. Thus, metal pillars with great height and good sidewall morphology can be formed in the through holes, and metal pillars with reduced spacing and smaller size can be formed, which improves the electrical performance of the metal pillars. (In contrast, when forming through holes in the photoresist layer or photosensitive dry film formed on the substrate through exposure and development processes, the depth of the through holes formed in the photoresist layer or photosensitive dry film is limited due to material and process limitations. When the depth is greater, the sidewall morphology of the through holes will be worse, and the spacing and size of the through holes will also be limited. Correspondingly, the height of the metal pillars formed in the through holes is also limited. When the height is higher, the sidewall morphology of the metal pillars will be worse, and the spacing and size of the metal pillars will also be limited, affecting the electrical performance of the metal pillars.) Therefore, the thickness of the dry film 101 described in this application can be very large, and the height of the subsequently formed metal pillars can be very high. In some embodiments, the thickness range of the dry film 101 (or the depth range of the vias formed in the subsequent dry film 101) is 20 micrometers to 1000 micrometers, and can be 30 micrometers, 40 micrometers, 50 micrometers, 80 micrometers, 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers, 300 micrometers, 350 micrometers, 400 micrometers, 500 micrometers, 600 micrometers, 700 micrometers, 800 micrometers, 900 micrometers, or 950 micrometers. The corresponding height range of the metal pillars formed in the subsequent vias can also be 20 micrometers to 1000 micrometers.

[0031] In some embodiments, the dry film 101 has a single-layer structure, and both its upper and lower surfaces have protective films 102. The protective films 102 protect the dry film 101 from damage and / or contamination during subsequent drilling operations and before it is attached to the upper surface of the first substrate. In some embodiments, the protective film 102 is made of a hard passivating material. The hard passivating material is an organic material, and the protective film 102 will be drilled through during subsequent drilling operations.

[0032] In another embodiment, reference Figure 2The dry film includes multiple discrete sub-dry films (e.g., 101a, 101b). Subsequently, through a drilling operation, several sub-through holes penetrating the upper and lower surfaces of each sub-dry film are formed in each sub-dry film. Then, the multiple sub-dry films are sequentially stacked and attached to the upper surface of the first substrate in a direction perpendicular to the upper surface of the first substrate. The multiple stacked sub-dry films constitute the dry film. The multiple corresponding sub-through holes in the multiple sub-dry films are connected vertically to form the through holes, and metal pillars are formed in the through holes. Therefore, a thicker dry film (e.g., greater than 100 micrometers, or even greater than 500 micrometers but less than 1000 micrometers) can be formed by multilayer sub-dry films (e.g., 101a, 101b). Consequently, taller metal pillars (e.g., greater than 100 micrometers, or even greater than 500 micrometers but less than 1000 micrometers) can be formed within the dry film. Furthermore, since several sub-through holes penetrating the upper and lower surfaces of each sub-dry film are formed individually through drilling, the sidewalls of the sub-through holes can maintain a good morphology, and the process difficulty of forming deep through holes is reduced. After stacking several sub-dry films on the first substrate to form a dry film, the through holes composed of multiple sub-through holes in the dry film also have a good sidewall morphology. This allows the taller metal pillars formed in the through holes to have a good sidewall morphology. Moreover, the aforementioned method can also ensure that the aforementioned taller metal pillars can maintain a small spacing and size.

[0033] The number or number of layers of the plurality of discrete sub-dry membranes is greater than or equal to 2 layers, and can be 2, 3, 4, 5, 6, 7, 8, 9, or 10 layers. The specific number of sub-dry membranes can be set according to actual needs. In this embodiment, two layers of the aforementioned sub-dry membranes are used as an example for illustration, including sub-dry membrane 101a and sub-dry membrane 101b.

[0034] In some embodiments, the thickness of each sub-dry film can be 20-200 micrometers.

[0035] In some embodiments, each sub-dry film (e.g., 101a, 101b) also has a protective film 102 on its upper and lower surfaces.

[0036] refer to Figure 3 , Figure 3 exist Figure 1 Based on this, a plurality of through holes 103 penetrating the upper and lower surfaces of the dry film 101 are formed in the dry film 101 by drilling operation 11.

[0037] In some embodiments, when the dry film 101 has a protective film 102 on its upper and lower surfaces, the drilling operation 11 drills through at least the protective film 102 on the upper surface of the dry film 101. In other embodiments, the protective film 102 on both the upper and lower surfaces of the dry film 101 can be drilled through.

[0038] In some embodiments, the depth of the formed through hole 103 is 20 micrometers to 1000 micrometers, and the diameter of the through hole 103 is greater than 25 micrometers.

[0039] In some embodiments, the drilling operation 11 is performed using a drill bit or a laser.

[0040] When forming through-holes 103 in the dry film 101 using drilling operation 11 in this application, the formed through-holes 103 can have a relatively deep depth and a good sidewall morphology, while maintaining a small spacing and size. Furthermore, since the dry film does not require exposure and development operations during the formation of through-holes 103 in this application, costs are saved and contamination problems are avoided.

[0041] In another embodiment, reference Figure 4 , Figure 4 exist Figure 2 Based on this, when the dry film includes multiple discrete sub-dry films (e.g., 101a and 101b), a plurality of sub-through holes (e.g., 103a and 103b) penetrating the upper and lower surfaces of each sub-dry film (e.g., the corresponding 101a and 101b) are formed in each sub-dry film (e.g., 101a and 101b) through a drilling operation 11. In a specific embodiment, when the dry film includes two discrete sub-dry films (e.g., 101a and 101b), a plurality of sub-through holes 103a penetrating the upper and lower surfaces of the sub-dry film 101a are first formed in the sub-dry film 101a through a drilling operation 11; after the sub-dry film 101a has formed the sub-through holes 103a, a plurality of sub-through holes 103b penetrating the upper and lower surfaces of the sub-dry film 101b are then formed in the sub-dry film 101b through a drilling operation 11.

[0042] In some embodiments, the depth of the formed sub-via (e.g., 103a or 103b) is 20-200 micrometers, and the diameter of the sub-via (e.g., 103a or 103b) is greater than 25 micrometers.

[0043] It should be noted that when drilling operation 11 is performed on each of the sub-dry membranes, the same parameters are used in the drilling operation, so that the position, size and morphology of the sub-through holes formed in each of the sub-dry membranes are the same. In this embodiment, drilling operation 11 is performed individually on each of the sub-dry films (e.g., 103a and 103b) to form several sub-through holes (e.g., 103a or 103b) penetrating the upper and lower surfaces of the sub-dry films (e.g., 103a and 103b). The sidewalls of the sub-through holes (e.g., 103a or 103b) can maintain a good morphology. Furthermore, by first forming sub-through holes on multiple sub-dry films, and then stacking and adhering the multiple sub-dry films to form a dry film, the dry film contains through-holes composed of multiple sub-through holes (e.g., 103a or 103b). This approach reduces the process difficulty when forming deeper through-holes (deep vias) and allows the through-holes composed of multiple sub-through holes (e.g., 103a or 103b) in the dry film to also have a good sidewall morphology, thereby enabling the formation of taller metal pillars within the through-holes to have a good sidewall morphology. In addition, the aforementioned method also allows the formed taller metal pillars to maintain a small spacing and size.

[0044] refer to Figure 5 A first substrate 201 is provided, the upper and lower surfaces of the first substrate 201 respectively have a first pad 203 and a second pad 204, and the first substrate 201 has a first line (not shown in the figure) that electrically connects the first pad 203 and the second pad 204; the dry film 101 with through holes 103 is attached to the upper surface of the first substrate 201, and the through holes 103 expose the surface of the corresponding first pad 203.

[0045] The first substrate 201 includes an upper surface and a lower surface opposite to each other. The upper surface has a plurality of first pads 203 and the lower surface has a plurality of second pads 204. The first substrate 201 has a first circuit. The first circuit may include one or more of the following: metal wire, metal plug, through-hole connection structure, and via connection structure. The first pads 203 and the second pads 204 are connected to the first circuit.

[0046] In some embodiments, the first substrate 201 may be one of a resin substrate, a ceramic substrate, a glass substrate, a silicon substrate, a metal substrate, a printed circuit board (PCB), or a flexible printed circuit board (FPC). The first substrate 201 may be a single-layer board or a multi-layer board. The materials of the first pad 203, the second pad 204, and the first circuit are metals, specifically one or more of Al, Cu, Ag, Au, Pt, Ni, Ti, TiN, TaN, Ta, TaC, TaSiN, W, WN, and WSi.

[0047] In one embodiment, when attaching the dry film 101 with the through-hole 103 to the upper surface of the first substrate 201, the protective film 102 on the upper and lower surfaces of the dry film 101 is removed or peeled off (see reference). Figure 3 After removing or peeling off the protective film, the dry film 101 with the through-hole 103 is aligned with the first substrate 201 (establishing the positional relationship between the dry film 101 and the first substrate 201, thereby improving the accuracy of the attachment position) and then attached to the upper surface of the first substrate 201. In a specific embodiment, the alignment and attachment actions are performed by an attachment device or apparatus.

[0048] In some embodiments, before being applied to the upper surface of the first substrate 201, a metal conductive layer is formed on the upper surface of the first substrate 201, the metal conductive layer serving as a conductive layer when a metal pillar is subsequently formed in the through hole using an electroplating process; the dry film 101 having the through hole 103 is attached to the conductive layer surface of the upper surface of the first substrate 201.

[0049] In another embodiment, reference Figure 6When the dry film 101 includes multiple discrete sub-dry films (e.g., 101a and 101b), the multiple sub-dry films having sub-through holes (e.g., 103a, 103b) are sequentially stacked and attached to the upper surface of the first substrate 201 in a direction perpendicular to the upper surface of the first substrate 201. The multiple stacked sub-dry films (e.g., 101a and 101b) constitute the dry film 101, and the multiple corresponding sub-through holes (e.g., 103a, 103b) in the multiple sub-dry films (e.g., 101a and 101b) are vertically connected to form the through hole 103. In a specific embodiment, when the dry film 101 includes two discrete sub-dry films (101a and 101b), sub-dry film 101a is first attached to the upper surface of the first substrate 201, and then sub-dry film 101b is attached to the upper surface of sub-dry film 101a. In one specific embodiment, before attaching multiple sub-dry films (e.g., 101a and 101b) sequentially to the upper surface of the first substrate 201, each sub-dry film (e.g., 101a and 101b) needs to be aligned with the first substrate 201 first, and then the corresponding sub-dry film (e.g., 101a or 101b) is attached to the upper surface of the first substrate 201. In one specific embodiment, before sequentially attaching multiple sub-dry films (e.g., 101a and 101b) to the upper surface of the first substrate 201, the bottommost sub-dry film to be attached (e.g., 101a) is aligned with the first substrate 201, and then the sub-dry film (e.g., 101a) is attached to the upper surface of the first substrate 201; the subsequent sub-dry films (e.g., 101b) to be attached can be aligned with the already attached previous sub-dry film (e.g., 101a), and then the sub-dry film (e.g., 101b) to be attached is attached to the surface of the previous sub-dry film (e.g., 101a).

[0050] refer to Figure 7 or Figure 8 This forms a structure that fills the through-hole 103 (reference). Figure 5 or Figure 6 ) metal column 104.

[0051] The top surface of the formed metal column 104 is flush with or slightly lower than the upper surface of the dry film 101.

[0052] The metal pillar 104 is formed using an electroplating process. In this application, because the aforementioned through-hole 103 can have a greater depth and a better sidewall morphology (and can also have a smaller spacing and size), the formed metal pillar 104 can also have a greater height and a better sidewall morphology (and can also have a smaller spacing and size), thus improving the electrical performance of the formed metal pillar 104. Furthermore, since the dry film does not need to be exposed and developed during the formation of the metal pillar 104, costs can be saved and contamination problems can be avoided.

[0053] In some embodiments, the height of the formed metal column 104 can range from 20 micrometers to 1000 micrometers, and the diameter of the metal column 104 is greater than 25 micrometers.

[0054] In some embodiments, the material of the metal pillar 104 is one or more of W, Al, Cu, Ti, Ag, Au, Pt, and Ni.

[0055] refer to Figure 9 Remove the dry film 101; provide a first chip 301, mount the first chip 301 on the upper surface of the first substrate 201 between the metal pillars 104, the first chip 301 is electrically connected to a portion of the first pads 203, and the top surface of the first chip 301 (the surface of the first chip 301 that is not in contact with the first substrate 201) is lower than the top surface of the metal pillars 104.

[0056] The dry film 101 can be removed using a dry film peeling process.

[0057] The first chip 301 includes, but is not limited to, sensor chips, power chips, signal processing chips, logic control chips, memory chips, and radio frequency chips.

[0058] In some embodiments, the first chip 301 includes a first functional surface and a first back surface, and an integrated circuit (not shown) with a specific function is formed in the first chip 301. The first functional surface of the first chip 301 has a first external terminal, which is electrically connected to the integrated circuit. In some embodiments, the first external terminal is a pad located on the first functional surface of the first chip 301 (the surface of the pad may be flush with the surface of the first functional surface). In other embodiments, the first external terminal includes a pad located on the first functional surface of the first chip and a first solder bump protruding from the surface of the first functional surface on the pad. In some embodiments, the first solder bump may be a solder bump or include a metal bump and a solder bump located on the top surface of the metal bump. In some embodiments, the material of the pad is one or more of aluminum, nickel, tin, tungsten, platinum, copper, titanium, chromium, tantalum, gold, and silver. The material of the metal bump is one or more of aluminum, nickel, tin, tungsten, platinum, copper, titanium, chromium, tantalum, gold, and silver. The material of the solder protrusion is one or more of tin, tin silver, tin lead, tin silver copper, tin silver zinc, tin zinc, tin bismuth indium, tin indium, tin gold, tin copper, tin zinc indium, or tin silver antimony.

[0059] The process of mounting the first chip 301 on the upper surface of the first substrate 201 on one side of the metal pillar 104 can include a flip-chip process or a forward-mount process. In the flip-chip process, the first functional surface of the first chip 301 faces the upper surface of the first substrate 201, and the first external terminal on the first chip 301 is soldered to the first pad 203 on the first substrate 201. In this method, the top surface of the first chip 301 refers to the first back surface. In the forward-mount process, the first back surface of the first chip 301 is attached to the upper surface of the first substrate 201 on one side of the metal pillar 104 using an adhesive layer, forming a metal lead or electrical connection structure that electrically connects the first external terminal on the first chip 301 to the first pad 203 on the first substrate 201. In this method, the top surface of the first chip 301 refers to the first functional surface.

[0060] refer to Figure 10 A first molding layer 205 is formed covering the surface of the first chip 301, the sidewall surface and top surface of the metal pillar 104, and the upper surface of the first substrate 201.

[0061] The first molding compound 205 can be made of silicone-based resin, thermoplastic resin, thermosetting resin, or UV-curable resin. Forming the first molding compound 205 includes injection molding or transfer molding. The top surface of the formed first molding compound 205 is flush with the top surface of the metal pillar 104.

[0062] On the encapsulation structure formed by this disclosure (on the first molding layer), other encapsulation bodies (second encapsulation bodies) can be subsequently stacked. Before stacking other encapsulation bodies (second encapsulation bodies), the top surface of the metal pillar 104 needs to be exposed.

[0063] In some embodiments, reference Figure 11 The first molding compound 205 is planarized using a chemical mechanical polishing process, exposing the top surface of the metal pillar 104. In some embodiments, a redistribution layer 206 may be formed on the planarized surface of the first molding compound 205, and the redistribution layer 206 is electrically connected to the metal pillar 104. When other packages (second packages) are subsequently stacked on the first molding compound 205, the other packages (second packages) are electrically connected to the redistribution layer 206. The redistribution layer 206 is made of metal.

[0064] In another embodiment, reference Figure 12 The first molding compound 205 is etched using an etching process to form an opening 207 in the first molding compound 205 that exposes the top surface of the metal pillar 104. The etching process includes laser etching. Subsequently, when other packages (second packages) are stacked on the first molding compound 205, the other packages (second packages) are electrically connected to the metal pillar 104 exposed by the opening 207.

[0065] The other encapsulation (second encapsulation) may have different specific structures.

[0066] In some embodiments, reference Figure 13 or Figure 14 The second package includes a second substrate 202, a second chip 302 mounted on the upper surface of the second substrate 202, solder protrusions 210 on the lower surface of the second substrate 202, and a second molding compound 212 covering the second chip 302 and the upper surface of the second substrate 202. The upper and lower surfaces of the second substrate 202 have a third pad 209 and a fourth pad 208, respectively. The second substrate 202 also has a second line electrically connecting the third pad 209 and the fourth pad 208. It should be noted that the specific structure of the second package in this embodiment is only an example; in other embodiments, the specific structure of the second package may be different.

[0067] refer to Figure 13 or Figure 14 The second package is stacked on top of the first molding layer 205, and the second package is connected to the exposed metal pillar 104. In one embodiment, reference is made to... Figure 13When the second package is stacked on top of the first molding compound 205, the solder protrusions 210 in the second package are soldered to the redistribution layer 206. In another embodiment, refer to... Figure 14 When the second package is stacked on top of the first molding layer 205, the welding protrusion 210 in the second package is welded to the metal post 104 exposed in the opening 207.

[0068] In some embodiments, the method further includes forming a raised external connection bump 213 on a second pad 204 on the lower surface of the first substrate 201.

[0069] It should be noted that the terms "comprising" and "having," and their variations, used in this disclosure are intended to cover non-exclusive inclusion. The terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence, unless explicitly indicated by the context. It should be understood that such data used interchangeably where appropriate. Furthermore, embodiments and features within embodiments of this disclosure can be combined with each other unless otherwise specified. In addition, descriptions of well-known components and technologies have been omitted in the above description to avoid unnecessarily obscuring the concepts of this disclosure. In the various embodiments described above, each embodiment focuses on its differences from other embodiments; similar or identical parts between embodiments can be referred to (or understood) interchangeably.

[0070] Although this application has been disclosed above with reference to preferred embodiments, it is not intended to limit this application. Any person skilled in the art can make possible changes and modifications to the technical solutions of this application by utilizing the methods and techniques disclosed above without departing from the spirit and scope of this application. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the content of the technical solutions of this application shall fall within the protection scope of the technical solutions of this application.

Claims

1. A method for forming an encapsulation structure, characterized in that, include: A dry membrane is provided, the dry membrane comprising a plurality of discrete sub-dry membranes; The process of forming a plurality of through holes penetrating the upper and lower surfaces of the dry film by drilling includes: forming a plurality of sub-through holes penetrating the upper and lower surfaces of each sub-dry film by drilling. A first substrate is provided, wherein the upper and lower surfaces of the first substrate have a first pad and a second pad respectively, and the first substrate has a first line that electrically connects the first pad and the second pad. The process of attaching a dry film with through-holes to the upper surface of the first substrate, wherein the through-holes expose the surfaces of the corresponding first pads, includes: first aligning the bottommost sub-dry film to be attached with the first substrate; attaching the aligned sub-dry film to the upper surface of the first substrate; aligning the subsequent sub-dry films to be attached with the previously attached sub-dry films; then attaching the aligned sub-dry films to the surface of the previous sub-dry films; and then sequentially stacking multiple sub-dry films along a direction perpendicular to the upper surface of the first substrate to attach them to the upper surface of the first substrate, wherein the multiple stacked sub-dry films constitute the dry film, and multiple corresponding sub-through-holes in the multiple sub-dry films are vertically connected to form the through-holes; A metal pillar is formed that fills the through-hole; Remove the dry film; A first chip is provided and mounted on the upper surface of a first substrate between metal pillars, wherein the first chip is electrically connected to a portion of the first pad. A first molding compound is formed covering the surface of the first chip, the sidewalls and top surface of the metal pillar, and the upper surface of the first substrate.

2. The method for forming the packaging structure as described in claim 1, characterized in that, The drilling operation is performed using a drill bit or a laser.

3. The method for forming the packaging structure as described in claim 1, characterized in that, The thickness of the dry film is 20 micrometers to 1000 micrometers, the depth of the through-hole is 20 micrometers to 1000 micrometers, the height of the metal pillar is 20 micrometers to 1000 micrometers, and the diameter of the metal pillar is greater than 25 micrometers.

4. The method for forming the packaging structure as described in claim 3, characterized in that, The dry film is a single-layer structure or comprises multiple discrete sub-dry films.

5. The method for forming the packaging structure as described in claim 4, characterized in that, The upper and lower surfaces of the dry film, or the upper and lower surfaces of each sub-dry film, are covered with a protective film; the protective film is removed after drilling and before attachment.

6. The method for forming the packaging structure as described in claim 1, characterized in that, A metal pillar is formed in the through hole by electroplating.

7. The method for forming the packaging structure as described in claim 1, characterized in that, The first molding layer is planarized by a chemical mechanical polishing process to expose the top surface of the metal pillar, or the first molding layer is etched by an etching process to form an opening in the first molding layer that exposes the top surface of the metal pillar.

8. The method for forming the packaging structure as described in claim 7, characterized in that, A second package is provided; the second package is stacked on top of the first molding layer, and the second package is connected to an exposed metal pillar.

9. The method for forming the packaging structure as described in claim 8, characterized in that, The second package includes a second substrate, a second chip mounted on the upper surface of the second substrate, a solder bump located on the lower surface of the second substrate, and a second molding compound covering the second chip and the upper surface of the second substrate, wherein the solder bump is electrically connected to the exposed metal pillar.

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