Package and manufacturing method thereof

Abstract

A method for manufacturing a package structure includes: bonding a package element to a substrate; forming a thermal interface material on the package element; forming a first adhesive layer on the substrate, wherein the first adhesive layer laterally surrounds the package element; and attaching a cap-like structure to the thermal interface material and the first adhesive layer, wherein the cap-like structure has a recess that overlaps the thermal interface material.

Description

Technical Field

[0001] none Prior Technology

[0002] The integrated circuit (IC) industry has experienced rapid growth. Technological advancements in IC materials and design have led to the production of generation after generation of ICs, each smaller and more complex than the previous one. However, these advancements have also increased the complexity of handling and manufacturing ICs, and similar developments in IC handling and manufacturing are necessary to realize these advancements.

[0003] In the evolution of integrated circuits, functional density (i.e., the number of interconnect components per wafer region) has typically increased, while geometry (i.e., the smallest component (or line) that can be created using manufacturing processes) has decreased. This scaling down process generally provides benefits by increasing production efficiency and reducing associated costs. This scaling down also results in relatively high power dissipation values, which can be addressed by using low-power dissipation components such as complementary metal-oxide-semiconductor (CMOS) devices. Summary of the Invention

[0004] none Simple Explanation of the Diagram

[0005] When viewed in conjunction with the accompanying drawings, the following detailed illustrations provide the best understanding of the nature of this disclosure. Note that, in accordance with standard industry practice, the various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or decreased for clarity of explanation. Figures 1 through 7D, 8 and 9 illustrate schematic diagrams of intermediate stages in the encapsulation process according to some embodiments of this disclosure. Figures 7E and 7F illustrate schematic diagrams of the encapsulation according to some embodiments of this disclosure. Figures 10 through 17B, 18, and 19 illustrate schematic diagrams of intermediate stages in the encapsulation process according to some embodiments of this disclosure. Figures 17C through 17J illustrate schematic diagrams of the encapsulation according to some embodiments of the present disclosure. Implementation

[0006] The following disclosure provides numerous different implementations or examples for implementing various features of the provided object. Specific examples of components and configurations are illustrated below to simplify this disclosure. Of course, these are merely examples and are not intended to be limiting. For instance, in the following illustrations, the formation of a first feature above or on a second feature may include implementations where the first and second features are formed in direct contact, and may also include implementations where additional features are formed between the first and second features so that the first and second features are not in direct contact. Furthermore, in various instances, references to numbers and / or letters may be repeated in this disclosure. This repetition is for simplicity and clarity and does not, in itself, define the relationships between the various implementations and / or configurations discussed.

[0007] Additionally, for ease of illustration, spatial relative terms such as "beneath," "below," "lower," "above," and "upper," and similar terms, may be used herein to illustrate the relationship between one element or feature as illustrated in the figures and another. These spatial relative terms are intended to cover not only the orientations depicted in the figures but also different orientations of elements in use or operation. Elements may be oriented in other ways (rotated 90 degrees or otherwise), and the spatial relative illustration terms used herein may be interpreted accordingly. As used herein, "approximately," "probably," "around," or "substantially" may mean within 20%, 10%, or 5% of a given value or range. However, those skilled in the art will understand that the values ​​or ranges listed throughout the illustrations are merely examples and may decrease as integrated circuits shrink. The values ​​disclosed herein are approximate and are meant to be interpreted as “approximately,” “about,” “similar,” or “substantially” unless otherwise specified.

[0008] Unless otherwise defined, all terms used in this disclosure (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that terms such as those defined in common dictionaries shall be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and this disclosure, and shall not be interpreted as having an idealized or overly formal meaning, unless expressly defined herein.

[0009] In some implementations, a reduction in the thickness of the thermal interface material (TIM) layer in the package (e.g., a reduction of approximately 80%) can lead to a high void ratio. Non-uniform distribution of the TIM layer thickness (e.g., below 40 micrometers) can cause delamination during reliability testing and thermal performance. Furthermore, in cases with thermal resistance below 3 K·mm² / W (e.g., in ball grid array (BGA) configurations), extremely thin TIM layers (e.g., less than 60 micrometers) must address the warpage challenge during ball solder reflow, which often results in voids.

[0010] Therefore, various embodiments disclosed herein provide a lid structure to achieve stable control of the void rate when the thickness of the thermal interface material layer is reduced (e.g., reduced by about 80% to less than 60 micrometers), thereby reducing the thermal resistance of the thermal interface material layer (e.g., reduced by 30% to 50% to less than 3 K·mm² / W). By using a lid structure with recesses (e.g., protrusions) above the thermal interface material layer, the thickness variation of the entire package structure can be reduced (e.g., less than 20 micrometers), thereby improving power efficiency (e.g., increasing by 2% to 5%) and expanding the reliability window. Furthermore, the lid structure can be modified to combine annular structures and flat lids to reduce warpage variations during ball bonding reflow, ensuring that the thermal interface material layer maintains more than 95% coverage after reflow. Further, the annular structure can have a bridge structure near the die edge to improve warpage control, further stabilizing the assembly process and improving the overall performance and reliability of the package.

[0011] See Figures 1 through 7D, 8, and 9. Figures 1 through 7D, 8, and 9 illustrate schematic diagrams of intermediate stages in the formation process of the package structure 10 according to some embodiments of this disclosure. Specifically, Figure 2A illustrates a top view of the package structure 10 according to some embodiments of this disclosure. Figures 1, 2B, 3, 4, 5, 6, 7A, 8, and 9 illustrate cross-sectional views of the package structure 10 obtained from reference section A-A' in Figure 2A according to some embodiments of this disclosure. Figure 7B illustrates a cross-sectional view of the cap-like structure 70 in Figure 7A according to some embodiments of this disclosure. Figure 7C illustrates a cross-sectional view of the cap-like structure 70 in Figure 7A according to some embodiments of this disclosure obtained from reference section B-B'. Figure 7D illustrates a top view of the cap-like structure 70 in Figure 7A according to some embodiments of this disclosure. In some embodiments, the package structure 10 may be a land grid array (LGA) package or a ball grid array (BGA) package. It is understood that additional operations may be provided before, during, and after the processes shown in Figures 1 through 7D, 8, and 9, and some of the described operations may be replaced or omitted to accommodate other implementations of the method. The order of operations / processes may be interchanged.

[0012] See Figures 1 through 2B. In Figure 1, a package element 20 may be provided. The package element 20 may include a plurality of package substrates 22 therein. According to some embodiments, the package element 20 may be a package substrate strip including a plurality of package substrates 22. The package substrates 22 may be cored package substrates including cores or coreless package substrates. According to alternative embodiments, the package element 20 may be another type, such as an interposer wafer, a printed circuit board, a reconstructed wafer, etc. The package element 20 may or may not contain active components, such as transistors and diodes. The package element 20 may or may not contain passive components, such as capacitors, inductors, resistors, etc.

[0013] According to some embodiments of this disclosure, the encapsulation element 20 includes a plurality of dielectric layers, which may include dielectric layer 24, dielectric layer 26 on dielectric layer 24, and dielectric layer 28 below dielectric layer 24. According to some embodiments, dielectric layer 26 and dielectric layer 28 may be made of dry films, such as Ajinomoto build-up films (ABF). Alternatively, dielectric layer 26 and dielectric layer 28 may be made of or contain polybenzoxazole (PBO), polyimide, benzocyclobutene (BCB), etc., which can be applied in a flow form and then cured. Dielectric layer 24 (when in the core) may be made of epoxy resin, glass fiber, prepreg (including epoxy resin, glass fiber, and / or prepreg), glass, encapsulation compound, plastic, combinations thereof, and / or multiple layers. According to alternative embodiments, dielectric layer 24 may be made of a polymer, such as polybenzoxazole, polyimide, benzocyclobutene, etc. Redistribution lines 30, including metal lines / pads and vias, are formed in dielectric layer 24. The redistribution lines 30 may be interconnected to form via connections in package element 20. According to some embodiments, when package element 20 is not rigid enough to support itself and upper structures, a first carrier (not shown) may be provided to support package element 20. According to alternative embodiments, package element 20 is thick and rigid (e.g., when rebuilding a wafer) and capable of supporting structures formed thereon. Therefore, a first carrier may not be used. When used, the first carrier may be a glass carrier, an organic carrier, etc. According to alternative embodiments, package element 20 may be pre-formed. According to alternative embodiments, package element 20 is built layer by layer on a first carrier.

[0014] Referring further to Figure 1, a package structure PKG can be placed on package component 20. Although only one package structure PKG is shown in the figure, multiple package structure PKGs can be placed in the process, each placed on a corresponding package component 22. According to some embodiments, the package structure PKG can be interchangeably referred to as a package component or a package. The package structure PKG includes a component die therein and may include other package components, such as interposers, packages, die stacks, etc. According to some embodiments, the package structure PKG may include package component 34 and package components 46A and 46B. According to some embodiments, package component 34 may be an interposer, including a substrate 36 and a corresponding dielectric layer 38. Therefore, package component 34 may also be referred to as an interposer, and package component 34 may also be of other types. The structure of package component 34 is schematic and details of the dielectric layers, metal lines and vias, metal pads, etc. on the top and bottom surfaces are not shown. Through-substrate vias 40 can penetrate the substrate 36. Through-substrate vias 40 can be used to interconnect conductive features on the top and bottom surfaces of substrate 36. Solder regions 42 may be located below and connected to the interposer, used to connect packaged element 34 to packaged element 20. Other connection methods, such as metal-to-metal direct connections and hybrid connections, can also be used to connect packaged element 34 to packaged element 20.

[0015] According to some embodiments, package elements 46A and 46B are connected to their respective underlying package elements 34. Figure 1 shows a cross-section showing one package element 46A and two package elements 46B connected to the same package element 34. Package elements 46A and 46B can be different types of package elements, collectively referred to as package elements 46. Each package element 46 can be a component chip, a package containing component chips, a system-on-a-chip (SoC) chip containing multiple integrated circuits (or component chips), etc. Component chips in package element 46 may include logic chips, memory chips, input / output chips, integrated passive devices (IPDs), etc., or combinations thereof. For example, logic component chips in package element 46 may be central processing unit (CPU) chips, graphics processing unit (GPU) chips, mobile application chips, microcontroller units (MCU) chips, baseband (BB) chips, application processors (AP) chips, etc. The memory chip in package element 46 may include a static random access memory (SRAM) chip, a dynamic random access memory (DRAM) chip, etc. The component chip in package element 46 may include a semiconductor substrate and an interconnect structure.

[0016] In the following discussion, according to some exemplary embodiments, package element 46A may be referred to as a component chip, which, according to some embodiments, may be a system chip for an integrated system. Package element 46B may be a memory stack, such as a high-performance memory (HBM) stack. Package element 46B may include memory chips 60 forming the chip stack and a packaging material 62 (e.g., molding compound) encapsulating the memory chips 60. From a top view (see Figure 2A), the packaging material 62 may form a ring structure surrounding the memory chips 60 and may extend into the gaps between the memory chips 60.

[0017] Referring further to Figure 1, package element 46 can be connected to the underlying package element 34 via solder region 50. Underfill 54 can be distributed between package element 46 and the underlying package element 34. In some embodiments, the material of underfill 54 can be an insulating material, including resin (e.g., epoxy resin), filler material, stress release agent (SRA), adhesion promoter, other materials, or combinations thereof. In some embodiments, underfill 54 is optional. According to some embodiments, the package structure PKG can be formed via a chip-on-wafer (CoW) interconnect process, wherein discrete wafers / packages (i.e., package element 46) are connected to package element 34 on an uncuttered wafer to form a reconstructed wafer.

[0018] After the filler 54 is dispensed, an encapsulation material (e.g., a molding compound) 52 may be applied, followed by planarization so that its top surface is flush with the top surface of the encapsulation element 46. In some embodiments, the encapsulation compound 52 may be an encapsulation compound, a molding filler, a resin (e.g., epoxy resin, phenolic resin), etc. In some alternative embodiments, the material of the encapsulation compound 52 may include silicon dioxide (SiOx, x>0), silicon oxynitride (SiOxNy, x>0 and y>0), silicon nitride (SiNx, x>0), or other suitable dielectric materials. In some embodiments, the encapsulation compound 52 includes a filler. The filler may be particles made of silicon dioxide, aluminum oxide, etc. In some embodiments, the encapsulation compound 52 is formed by molding processes, injection processes, film deposition processes, combinations thereof, or similar methods. Molding processes include, for example, transfer molding processes, compression molding processes, etc. Thin film deposition processes include, for example, CVD, HDPCVD, PECVD, ALD, or combinations thereof.

[0019] Referring further to Figure 1, a conductive layer BSM1 can be formed on package elements 46A and 46B, as well as on the encapsulation compound 52, to form a reconstructed wafer. The conductive layer BSM1 can be in physical contact with the top surface of package elements 46A, 46B, 52, and the top surface of the filler 54. In some embodiments, the conductive layer BSM1 may comprise multiple metal layers, including an adhesive layer to ensure strong adhesion formation, a diffusion barrier layer to prevent unwanted material migration, and an antioxidant layer (e.g., gold) to prevent environmental damage. However, this is not limited to this disclosure. In some embodiments, the material of the conductive layer BSM1 may include metals such as aluminum (Al), titanium (Ti), nickel (Ni), vanadium (V), tantalum (Ta), silver (Ag), and gold (Au). The thickness of the conductive layer BSM1 can range from about 10 angstroms (Å) to 10,000 Å, for example, about 10, 100, 1000, or 10,000 Å, allowing for application flexibility. In some implementations, the conductive layer BSM1 can be formed by sputtering, electroplating, deposition, or deposition processes. It should be noted that the conductive layer BSM1 can promote the adhesion between the subsequently formed metal thermal interface material (thermal interface material) layer (e.g., thermal interface material layer 65 in Figure 4) and the package structure PKG, and can be interchangeably referred to as backside metallization or backside metal layer.

[0020] The reconstructed wafer can be diced to form discrete package structures PKG, which can be connected to package element 20. A monolithic process is performed on package compound 52 and package element 34 to obtain the package structure PKG shown in Figure 1. Although Figure 1 illustrates only one package structure PKG for illustrative purposes, those skilled in the art will understand that multiple package structure PKGs can be obtained after monolithic processing. In some embodiments, the monolithic process may include dicing using a rotation blade and / or a laser beam. In other words, the monolithic process may include laser dicing, mechanical dicing, laser grooving, other suitable processes, or combinations thereof. In some embodiments, since package element 34 is in wafer form, the package structure PKG is considered to be formed by a wafer-on-a-chip process, and the package structure PKG is also referred to as wafer-on-a-chip packaging.

[0021] As shown in Figures 2A and 2B, after the package structure PKG is placed onto the package element 20, the soldering area 42 can be reflowed, and filler 44 (see Figure 2B) can be applied to fill the gap between the package structure PKG and the package element 20. In some embodiments, the filler 44 is made of an insulating material, including resin (e.g., epoxy resin), filler material, stress-relieving agent, adhesion promoter, other materials, or combinations thereof. In some embodiments, the filler 44 is optional. Other package elements, such as surface mount devices (SMDs) 47, may be attached to the package element 20. According to some embodiments, the surface mount device 47 may be a discrete capacitor, a discrete inductor, a discrete resistor, etc. In some embodiments, no active element, such as a transistor, is formed in the surface mount device 47; the surface mount device 47 may be interchangeably referred to as an Independent Passive Device (IPD). As shown in Figure 2A, the package structure PKG may include one or more package elements 46A and multiple package elements 46B. Each package element 46B may include stacked memory chips 60 and encapsulation material 62 encapsulating (and surrounding) the memory chips 60. The encapsulation material (e.g., encapsulation compound 52) may fill the space between adjacent package elements 46. Surface mount elements 47 may be attached to the peripheral area of ​​the package substrate 22.

[0022] Referring to Figure 3, flux 64 can be applied to the conductive layer BSM1 to improve adhesion. For example, flux 64 can be formed on the package structure PKG before the metal thermal interface material layer 65 (see Figure 4) is placed on the conductive layer BSM1. In some embodiments, the process of forming flux 64 may include a jetting process or a dispensing process. In some embodiments, the flux may be a soldering flux. In some embodiments, the material of flux 64 may include rosin or acid.

[0023] Referring to Figure 4, the thermal interface material layer 65 can be formed on the flux 64. In some embodiments, the thermal interface material layer 65 can be of sheet type. In some embodiments, the thermal interface material layer 65 can be formed on the flux 64 by a pick-and-place process. In some embodiments, the material of the thermal interface material layer 65 can be a soldering material. In some embodiments, the thermal interface material layer 65 can be formed of a pure metallic material and can be interchangeably referred to as a metal thermal interface material. In some embodiments, the thermal interface material layer 65 may be free of organic and polymeric materials. In some embodiments, the material of the thermal interface material layer 65 includes metallic materials, such as indium, copper, tin, silver, or alloys thereof. In some embodiments, the thermal conductivity of the thermal interface material layer 65 ranges from about 10 W / (m·K) to about 90 W / (m·K). In some embodiments, the Young's modulus of the thermal interface material layer 65 ranges from about 5 GPa to about 70 GPa. In some embodiments, the thickness T1 of the thermal interface material layer 65 is in the range of less than about 100 micrometers, for example about 5, 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100 micrometers.

[0024] Referring to Figure 5, flux 66 can be applied to the thermal interface material layer 65 to improve adhesion. For example, flux 66 can be formed on the thermal interface material layer 65 before the cap structure 70 (see Figure 7A) is placed on it. In some embodiments, the process of forming flux 66 may include a spraying process or a dispensing process. In some embodiments, the flux may be a soldering flux. In some embodiments, the material of flux 66 may include rosin or acid.

[0025] Referring to Figure 6, adhesive structures 61 and 68 can be formed on the package element 20. Specifically, adhesive structure 61 can be formed near the edge of the package element 20, surrounding / around the package structure PKG. In some embodiments, adhesive structure 61 can have a ring shape in a plan view. In some embodiments, the pattern of adhesive structure 61 can be designed according to different designs. For example, adhesive structure 61 can have a linear shape, an L-shape, a U-shape, a dot shape, etc. In some embodiments, the shape of adhesive structure 61 can depend on the shape of the package element 20. For example, when the package structure PKG is in the form of a panel (i.e., has a rectangular or square top view), adhesive structure 61 can be shown as a rectangular or square ring in the top view. According to some embodiments, adhesive structure 61 can be interchangeably referred to as an adhesive layer.

[0026] Adhesive structure 68 may be formed near the encapsulation structure PKG, surrounding / around the thermal interface material layer 65, and spaced apart from adhesive structure 61. Adhesive structure 61 may surround / around adhesive structure 68. In some embodiments, the top of adhesive structure 68 may be higher than the top surface of the encapsulation structure. In some embodiments, adhesive structure 68 may be annular in plan view. In some embodiments, adhesive structure 68 may be a multilayer structure with several vertically stacked layers, the number of which is greater than 2, such as 2, 3, 4, or 5. For example, but not limited to, adhesive structure 68 may be a two-layer annular structure, with a first layer 68a and a second layer 68b on top of it contacting and covering each other. In some embodiments, the first layer 68a of adhesive structure 68 may be interchangeably referred to as the first adhesive layer, and the second layer 68b of adhesive structure 68 may be interchangeably referred to as the second adhesive layer. In some embodiments, the pattern of adhesive structure 68 may be designed according to different designs. For example, adhesive structure 68 may have a linear shape, an L-shape, a U-shape, a dot shape, etc. In some embodiments, the shape of the adhesive structure 68 may depend on the shape of the encapsulation element 20. For example, when the encapsulation element 20 is in the form of a panel (i.e., having a rectangular or square top view), the adhesive structure 68 may appear as a rectangular or square ring in the top view.

[0027] In some embodiments, adhesive structures 61 and 68 can be applied to the packaged element 20 via a dispensing process, spin coating process, or similar methods. A first layer 68a of adhesive structures 61 and 68 can be formed first, followed by a second layer 68b of adhesive structure 68 formed on top of the first layer 68a. The formation of adhesive structures 68 and 61 in a semiconductor package can be flexible and adaptable to different assembly processes. In some embodiments, adhesive structure 68 can be formed after adhesive structure 61. In this sequence, a wider-boundary adhesive structure 61 can be applied first, surrounding the boundary of the packaged element. This initial application provides a base layer to secure the outer edges of the assembly. Subsequently, a more centrally located adhesive structure 68 can be applied, surrounding the thermal interface material layer 65 and other internal components. In some embodiments, adhesive structure 68 can be formed before adhesive structure 61. In some embodiments, the width of adhesive structure 68 can be smaller than the width of adhesive structure 61.

[0028] In some embodiments, the thermal conductivity of the adhesive structure 61 / adhesive structure 68 can be greater than about 0 W / m·K to 5 W / m·K. In some embodiments, the adhesive structure 61 / adhesive structure 68 may comprise a silicon-based material, an acrylic-based material, an epoxy-based polymer, or a combination thereof. However, this disclosure is not limited thereto. In some alternative embodiments, other adhesive polymeric materials can be used as the adhesive structure 61 / adhesive structure 68. In some embodiments, the adhesive structure 68 may be made of the same material as the adhesive structure 61. In some embodiments, the adhesive structure 68 may be made of a different material than the adhesive structure 61. In some embodiments, the first layer 68a of the adhesive structure 68 may be made of a different material from the second layer 68b of the adhesive structure 61, thus a distinguishable interface can be formed between the first layer 68a and the second layer 68b. In some embodiments, the first layer 68a of the adhesive structure 68 may be made of the same material as the second layer 68b of the adhesive structure 61, thus no distinguishable interface may be formed between the first layer 68a and the second layer 68b.

[0029] Referring to Figures 7A through 7D, the cap structure 70 can be placed on the thermal interface material layer 65 and the adhesive structures 61 and 68, such that the package structure PKG can be located between the cap structure 70 and the package element 20. In some embodiments, the cap structure 70 can be used for heat dissipation. In other words, the heat generated by the package structure PKG during operation can be dissipated through the path formed by the cap structure 70. In some embodiments, the cap structure 70 can be made of metal, plastic, ceramic, etc. The metals of the cap structure 70 include, but are not limited to, aluminum, copper, stainless steel, solder, gold, nickel, molybdenum, alloy 42, iron, silver, nickel-iron, or nickel-iron-chromium. In some embodiments, the thermal conductivity of the cap structure 70 ranges from about 80 W / (m·K) to about 450 W / (m·K). In some embodiments, the Young's modulus of the cap structure 70 ranges from about 50 GPa to about 200 GPa.

[0030] In some embodiments, the cap-like structure 70 may include a central cap portion 70c and legs 70g extending around its periphery to form a cavity 70t. In some embodiments, the central cap portion 70c may be a flat structure. In some embodiments, the legs 70g may be interchangeably referred to as feet, protrusions, or peripheral regions. In some embodiments, the extension direction of the central cap portion 70c may be perpendicular to the extension direction of the legs 70g. From another perspective, in some embodiments, the central cap portion 70c extends along the X and Y directions, while the legs 70g extend along the Z direction. In some embodiments, the central cap portion 70c and the legs 70g may be integrally formed. In some embodiments, the legs 70g of the cap-like structure 70 may be attached to the encapsulation element 20 during a curing process via an adhesive structure 61. In some embodiments, the shape of the legs 70g may depend on the shape of the encapsulation element 20. For example, when the encapsulation element 20 is in the form of a panel (i.e., having a rectangular or square top view), the legs 70g may appear as a rectangular or square ring in the top view.

[0031] In some embodiments, reducing the thickness of the thermal interface material layer 65, for example by up to 80% to less than about 60 micrometers, can improve thermal performance and component compactness. A thinner thermal interface material layer 65 can improve thermal conductivity between the package structure PKG and the cap structure 70 by minimizing the thermal resistance at the interface, thereby enabling more efficient cooling and improving overall component performance. However, a thinner thermal interface material layer may be more prone to uneven application or distribution, making it difficult to achieve a consistent layer between the cap structure 70 and the package structure PKG. Uneven thickness distribution of the thermal interface material layer 65 (i.e., thickness non-uniformity) can lead to delamination under reliability testing conditions and result in degraded thermal performance. In some embodiments, the thickness of the thermal interface material layer 65 located between the cap structure 70 and the package structure PKG can be interchangeably referred to as the intercap thermal interface material thickness (BLT).

[0032] In some implementations, when the thickness of the thermal interface material layer 65 is less than, for example, 60 micrometers and has a thermal conductivity of less than 3 K‧mm² / W, warpage effects experienced during ball grid array (PKG) reflow may need to be addressed in ball grid array (PKG) configurations. This warpage can lead to void formation, affecting the reliability and thermal efficiency of the package structure (PKG). In some implementations, voids may arise due to the evaporation of solvents or flux. The reflow soldering process, involving the melting and solidification of solder to form electrical and mechanical connections, can exacerbate void formation in thinner thermal interface material layers due to thermal cycling. These thermal cycles can trigger the evaporation of the thermal interface material layer 65, further increasing the risk of voids. Due to the low thermal conductivity of air, voids can act as thermal insulators, reducing the heat dissipation effect of the PKG to the cap structure 70.

[0033] The cap-like structure 70 can solve the problem of uneven thickness distribution of the thermal interface material layer 65, which may lead to delamination and impaired thermal performance. The cap-like structure 70 may have a recess 70r on the central cap portion 70c to form a groove R1. In some embodiments, the recess 70r may be interchangeably referred to as a hump. The extent of the recess 70r can be adjusted according to the dimensions of the package structure PKG to ensure precise alignment. The footprint of the adhesive structure 68 can form a non-overlapping boundary around the recess 70r. The footprint of the recess 70r of the cap-like structure 70 can overlap with the footprint of the package structure PKG and the thermal interface material layer 65, improving thermal contact efficiency, while the footprint of the recess 70r of the cap-like structure 70 does not overlap with the footprint of the adhesive structure 68 on the package element 20.

[0034] Specifically, the concave bottom surface 70b of the recess 70r can have a gradient structure, recessed from the leg 70g, and include multiple regions (e.g., more than two different regions, such as regions 2, 3, 4, 5, 6, 7, 8, 9, and 10), such as a central region C1 (see Figures 7B to 7D), a transition region C2 surrounding the central region C1 (see Figures 7B to 7D), and a peripheral region C3 surrounding the transition region C2 (see Figures 7B to 7D), allowing continuous recessing from the peripheral region C3 towards the central region C1, gradually deepening closer to the center. Therefore, the recess 70r can form a region with different thickness levels, which can alleviate the problem of uneven thickness distribution of the thermal interface material layer 65. The central region C1 can be the thinnest region in the recess 70r, gradually thickening towards the peripheral region C3. After attaching the cap-like structure to the thermal interface material layer 65, the top surface of the thermal interface material layer 65 can conform to the concave bottom surface 70b of the cap-like structure 70. This gradient concave design ensures a more uniform application of the thermal interface material layer 65, reduces the risk of voids and delamination, and optimizes thermal conductivity. By addressing thickness variability, the cap-like structure 70 can improve the overall reliability and thermal efficiency of the semiconductor package. Subsequently, near-complete coverage of the thermal interface material layer 65 on the package structure PKG can be achieved. In some embodiments, the coverage can be greater than about 95%, for example, about 95, 96, 97, 98, 99, 99.5, or 99.9%. In some embodiments, the thickness of the recess 70r in the central region C1, transition region C2, and peripheral region C3 is a constant value, so the bottom surface 70b of the recess 70r can exhibit a stepped structure. In some embodiments, the transition region C2 and / or the peripheral region C3 can be interchangeably referred to as annular regions.

[0035] Therefore, even if the thickness of the thermal interface material layer 65 is reduced by approximately 80%, for example, to less than approximately 60 micrometers, the cap structure 70 can achieve consistent control over the void formation rate. Thus, the cap structure 70 can further reduce the thermal resistance (TR) by 30% to approximately 50%, resulting in a TR of less than approximately 3 K·mm² / W for the thermal interface material layer 65. Furthermore, using the cap structure 70 with the recess 70r can reduce the thickness variation of the thermal interface material layer 65 to less than approximately 20 micrometers. Therefore, the power performance of the packaging structure 10 can be improved by 2% to 5%, and the reliability range can be expanded.

[0036] As shown in Figure 7A, the central cover portion 70c of the cap-like structure 70 may have a minimum vertical dimension H0 and a maximum vertical dimension H1, and the maximum vertical dimension H2 of the recess R1 is less than the maximum vertical dimension H1. In some embodiments, the ratio between the minimum vertical dimension H0 and the maximum vertical dimension H1 may be in the range of approximately 90% to 99.5%, for example, approximately 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 99.5%. The distance L1 from the center C0 to the leg 70g may be greater than the distance L2 from the thermal interface material layer 65 to the leg 70g. In some embodiments, the shape of the recess 70r may depend on the shape of the encapsulation structure PKG. For example, when the encapsulation structure PKG has a rectangular top view, the recess 70r may be drawn as a rectangular top view corresponding to the encapsulation structure PKG.

[0037] As shown in Figure 7D, the peripheral region C3 of the recess 70r may have a third rectangular annular profile P3, the transition region C2 may have a second rectangular annular profile P2, and the central region C1 may have a first rectangular annular profile P1. In some embodiments, the first rectangular annular profile P1 of the central region C1 may have a dimension D11 extending in the X direction and a dimension D12 extending in the Y direction. The second rectangular annular profile P2 of the transition region C2 may have a dimension D21 extending in the X direction and a dimension D22 extending in the Y direction. The third rectangular annular profile P3 of the peripheral region C3 may have a dimension D31 extending in the X direction and a dimension D32 extending in the Y direction. For example, but not limited to, the ratio between dimensions D11, D21, and D31 may be approximately 0.3:0.6:1, and the ratio between dimensions D12, D22, and D32 may be approximately 0.3:0.6:1. In some embodiments, the distance L3 between the two opposite parts of the leg 70g can be in the range of about 0.6 to 0.9, for example about 0.6, 0.65, 0.7, 0.75, 0.8, 0.85 or 0.9.

[0038] In some embodiments, a conductive layer BSM2 may be formed on the recess 70r of the central cover portion 70c of the cover structure 70 before the cap structure 70 is attached. It should be noted that the conductive layer BSM2 can be used to promote adhesion between the metal thermal interface material layer 65 and the cap structure 70, and may be referred to as back metallization or a back metal layer. In some embodiments, the material of the conductive layer BSM2 may be the same as the material of the conductive layer BSM1. In some alternative embodiments, the material of the conductive layer BSM2 may be different from the material of the conductive layer BSM1. In some embodiments, the conductive layer BSM2 may be formed on the cap structure 70 by electroplating, sputtering, or deposition processes. In some embodiments, the material of the conductive layer BSM2 may include metals such as aluminum (Al), titanium (Ti), nickel (Ni), vanadium (V), gold (Au), silver (Ag), or copper (Cu). In some embodiments, the conductive layer BSM2 may be a gold-plated heat sink. That is, the back side of the cap structure 70 may be gold-plated (Au) to improve thermal conductivity and resist oxidation. In some embodiments, the conductive layer BSM2 may be interchangeably referred to as a gold plating layer. In some alternative embodiments, the conductive layer BSM2 is not formed on the cap structure 70.

[0039] In some embodiments, after the conductive layer BSM2 is formed on the cap structure 70, the cap structure 70 and the conductive layer BSM2 can be placed on the thermal interface material layer 65 and the adhesive structure 61 and the adhesive structure 68, so that the cap structure 70 can be in physical contact with the top surface of the adhesive structure 61 and the adhesive structure 68.

[0040] Referring to Figure 8, the cap structure 70 and the conductive layer BSM2 are pressed onto the thermal interface material layer 65 and the adhesive structures 61 and 68. In some embodiments, pressing the cap structure 70 and the conductive layer BSM2 onto the thermal interface material layer 65 and the adhesive structures 61 and 68 includes performing a clamping process P11, wherein the process temperature of the clamping process P11 ranges from approximately 60°C to approximately 300°C. In some embodiments, the clamping process P11 may be interchangeably referred to as a thermal clamping process. Subsequently, the adhesive structures 61 and 68 may be cured to attach the cap structure 70 to the package element 20 via the adhesive structures 61 and 68. Specifically, the adhesive structures 61 and 68 may be cured to securely fix the cap structure 70 to the package element 20. In some embodiments, the process temperature of the curing process ranges from approximately 60°C to approximately 300°C. However, this disclosure is not limited thereto. In some embodiments, during the curing process, the cap structure 70 can be attached to the encapsulation structure PKG via a thermal interface material layer 65. That is, in these embodiments, there is a good physical and metallurgical bond between the cap structure 70 and the encapsulation structure PKG during the curing process.

[0041] Referring to Figure 9, a plurality of conductive terminals 63 may be formed on the surface S2 of the package element 20. In some embodiments, the conductive terminals 63 are solder balls, ball grid array (BGA) balls, or the like. In some embodiments, the conductive terminals 63 are made of a conductive material with low resistivity, such as tin (Sn), lead (Pb), silver (Ag), copper (Cu), nickel (Ni), bismuth (Bi), or alloys thereof. In some embodiments, the conductive terminals 63 may be in physical contact with redistribution lines 30 (or wiring patterns) exposed on the surface S2 of the package element 20. In some embodiments, the conductive terminals 63 may be used to physically and electrically connect the package element 20 to other components, package structures, connecting elements, etc. That is, the conductive terminals 63 may be used to provide physical and / or electrical connections to external components. As shown in Figure 9, the conductive terminals 63 and the package structure PKG are located on opposite sides of the package element 20, and some of the conductive terminals 63 are electrically connected to the package structure PKG via the redistribution lines 30 and solder areas 42. In some embodiments, the conductive terminal 63 can be formed on the surface S2 of the package element 20 through a ball placement process and a reflow process. In some embodiments, a reflow process can be performed to reshape the conductive terminal 63, thereby achieving a good physical and metallurgical connection between the conductive terminal 63 and the package element 20.

[0042] See Figures 7E and 7F. Figures 7E and 7F respectively illustrate schematic diagrams of encapsulation structures 110 and 210 according to some embodiments of this disclosure. Although the cap-like structure configurations of encapsulation structures 110 and 210 illustrated in Figures 7E and 7F differ from that of encapsulation structure 10 in Figures 1 through 7D, 8, and 9, reference numerals and / or letters may be repeated in various examples in this disclosure. Such repetition is for simplicity and clarity and does not, in itself, indicate a relationship between the various embodiments and / or configurations.

[0043] As shown in Figure 7E, the cap structure 170 in the encapsulation structure 110 may include a recess 170r to improve thermal interface efficiency. The recess 170r may include three distinct regions: a central region C11, a transition region C12, and a peripheral region C13. The central region C11, the transition region C12, and the peripheral region C13 may have constant thicknesses T2, T3, and T4, thereby forming a stepped structure S4 on the bottom surface of the recess 170r. The stepped structure S4 can provide a more uniform and controllable application of the thermal interface material 65 on the encapsulation structure 110. In some embodiments, the stepped structure S4 can facilitate a gradual and more precise distribution of pressure and material during assembly, ensuring optimal contact between the thermal interface material layer and the encapsulation structure 110 and the cap structure 170.

[0044] As shown in Figure 7F, the cap-like structure 270 of the encapsulation structure 210 may have a protrusion 270p projecting from the back of the central cap portion 70c. In other words, the protrusion 270p and the central cap portion 70c may form a stepped structure 270s on the back of the cap-like structure 270, located above the CoW region. The recess 270r shown in Figures 7A to 7D may be formed on the protrusion 270p. In some embodiments, the footprint of the protrusion 270p may overlap with the footprint of the encapsulation structure PKG. In some embodiments, the shape of the protrusion 270p may depend on the shape of the encapsulation structure PKG. For example, when the encapsulation structure PKG has a rectangular top view, the protrusion 270p may be shown as a rectangular top view corresponding to the encapsulation structure PKG. In some embodiments, the central cap portion 70c and the protrusion 270p may be integrally formed. For example, the material of the protrusion 270p may be the same as the material of the central cap portion 70c. However, this disclosure is not limited thereto. In some alternative embodiments, the protrusion 270p may be mounted on the central cover 70c. For example, the material of the protrusion 270p may be different from that of the central cover 70c. In some embodiments, the protrusion 270p may allow the cover structure 70 to be more securely attached to the encapsulation structure 210, providing better protection and stability.

[0045] See Figures 10 through 17B, 18, and 19. Figures 10 through 17B, 18, and 19 illustrate schematic diagrams of intermediate stages in the formation process of the encapsulation structure 310 according to some embodiments of this disclosure. The steps preceding Figure 10 may correspond to the steps shown in Figures 1 through 2B. For understanding the processes and structures involved up to this step, please refer to Figures 1 through 2B. To avoid repetition, these foregoing steps will not be repeated in this section. Furthermore, reference numerals and / or letters may be repeated in various examples in this disclosure. Such repetition is for simplification and clarity and does not, in itself, indicate a relationship between the various embodiments and / or configurations. Figures 10 through 17B, 18, and 19 illustrate cross-sectional views similar to reference section A-A' in Figure 2B. Figure 17B illustrates a top view of the cap-like structure 370 according to some embodiments of this disclosure. It should be understood that additional operations may be performed before, during, and after the processes shown in Figures 10 through 17B, 18, and 19, and some operations described below may be replaced or eliminated to achieve other embodiments of the method. The order of operations / processes may be interchangeable.

[0046] See Figure 10. An adhesive layer 360 may be formed on the surface S1 of the package element 20. For example, the adhesive layer 360 may be formed near the edge of the surface S1 of the package element 20 to surround / around the package structure PKG, the filler 44, and the surface mount element 47. In some embodiments, the adhesive layer 360 partially covers the surface S1 of the package element 20. The package structure PKG, the filler 44, and the surface mount element 47 are physically isolated from the adhesive layer 360. In some embodiments, the adhesive layer 360 has a ring shape in a plan view. In some embodiments, the pattern of the adhesive layer 360 may be designed according to different designs. For example, the adhesive layer 360 may have a linear, L-shaped, U-shaped, dotted, etc. In some embodiments, the shape of the adhesive layer 360 may depend on the shape of the package element 20. For example, when the package element 20 is in wafer form (i.e., has a circular top view), the adhesive layer 360 may be drawn as a circular ring shape when viewed from the top view. For example, when the packaged element 20 is in panel form (i.e., has a rectangular or square top view), the adhesive layer 360 may be drawn in a rectangular or square annular shape when viewed from the top view. In some embodiments, the adhesive layer 360 may be applied to the packaged element 20 by a dispensing process, a spin coating process, or a similar process. In some embodiments, the thermal conductivity of the adhesive layer 360 may be greater than about 0 W / m·K to 5 W / m·K. In some embodiments, the adhesive layer 360 may comprise a silicone-based material, an acrylic-based material, an epoxy-based polymer, or a combination thereof. However, this disclosure is not limited thereto. In some alternative embodiments, other polymeric materials with adhesive properties may be used as the adhesive layer 360.

[0047] See Figure 11. The annular structure 367 is attached to the package element 20. In some embodiments, the annular structure 367 may be made of robust materials such as stainless steel, copper (Cu), or Alloy 42, providing structural integrity and facilitating thermal management within the CoWoS configuration. In some embodiments, the annular structure 367 may be made of metal. In some embodiments, the Young's modulus of the annular structure 367 may be between approximately 50 GPa and approximately 200 GPa. In some embodiments, the annular structure 367 may surround the package structure PKG and the surface mount element 47. As shown in Figure 11, the annular structure 367 may be separate from the package structure PKG, filler 44, and surface mount element 47. In some embodiments, the top surface of the annular structure 367 may be located at a height level above the top surface of the conductive layer BSM1. Specifically, the annular structure 367 may be attached to the package element 20 via an adhesive layer 360. For example, the annular structure 367 may first be placed on the package element 20 to physically contact the adhesive layer 360.

[0048] See Figure 12. The annular structure 367 can be pressed onto the adhesive layer 360. In some embodiments, pressing the annular structure 367 onto the adhesive layer 360 includes performing a clamping process P21, wherein the process temperature of the clamping process P21 ranges from approximately 60°C to approximately 300°C. In some embodiments, the clamping process P21 may be interchangeably referred to as a thermal clamping process. Subsequently, the adhesive layer 360 may be cured to allow the annular structure 367 to be attached to the package element 20 through the adhesive layer 360. Specifically, the adhesive layer 360 may be cured to securely fix the annular structure 367 to the package element 20. In some embodiments, the process temperature of the curing process ranges from approximately 60°C to approximately 300°C. However, this disclosure is not limited thereto.

[0049] Referring to Figure 13, flux 364 can be applied to the conductive layer BSM1 to improve adhesion. For example, flux 364 can be formed on the package structure PKG before the metal thermal interface material layer 365 (see Figure 14) is placed on the conductive layer BSM1. In some embodiments, the formation of flux 364 may include performing a spraying process or a dispensing process. In some embodiments, the flux may be a solder flux. In some embodiments, the material of flux 364 may include rosin or acid.

[0050] See Figure 14. The thermal interface material layer 365 may be formed on the flux 364. In some embodiments, the thermal interface material layer 365 may be sheet-like. In some embodiments, the thermal interface material layer 365 may be formed on the flux 364 via a pick-and-place process. In some embodiments, the material of the thermal interface material layer 365 may be a solderable material. In some embodiments, the thermal interface material layer 365 may be made of a pure metallic material and may be interchangeably referred to as a metallic thermal interface material. In some embodiments, the thermal interface material layer 365 may be free of organic and polymeric materials. In some embodiments, the material of the thermal interface material layer 365 includes metallic materials such as indium, copper, tin, Ag, or alloys thereof. In some embodiments, the thermal conductivity of the thermal interface material layer 365 ranges from about 10 W / (m·K) to about 90 W / (m·K). In some embodiments, the Young's modulus of the thermal interface material layer 365 ranges from about 5 GPa to about 70 GPa.

[0051] See Figure 15. Flux 366 can be applied to the thermal interface material layer 365 to improve adhesion. For example, flux 366 can be formed on the thermal interface material layer 365 before the cap structure 370 (see Figure 7A) is placed on it. In some embodiments, the formation of flux 366 may include performing a spraying process or a dispensing process. In some embodiments, the flux may be a solder flux. In some embodiments, the material of flux 366 may include rosin or acid.

[0052] See Figure 16. An adhesive structure 361 can be formed on the annular structure 367, and an adhesive structure 362 can be formed on the packaged element 20. Specifically, the adhesive structure 361 can have an annular shape in a planar view. In some embodiments, the pattern of the adhesive structure 361 can be designed according to different designs. For example, the adhesive structure 361 can be linear, L-shaped, U-shaped, dot-shaped, etc. In some embodiments, the shape of the adhesive structure 361 can depend on the shape of the annular structure 367. In some embodiments, the adhesive structure 361 can be interchangeably referred to as an adhesive layer.

[0053] Adhesive structure 362 may be formed near the package structure PKG to surround / around the package structure PKG. Adhesive structure 362 may be located between the package structure PKG and the surface mount element 47. Alternatively, adhesive structure 361 may surround / around adhesive structure 362. In some embodiments, adhesive structure 362 may have a ring shape in a plan view. In some embodiments, adhesive structure 362 may be a structure with a multi-layer vertical stacked structure, with more than two layers, such as 2, 3, 4, or 5. For example, adhesive structure 362 may be a double-layer ring structure with a first layer 362a and a second layer 362b, the second layer 362b being on top of and in contact with the first layer 362a. In some embodiments, the first layer 362a of adhesive structure 362 may be interchangeably referred to as the first adhesive layer, and the second layer 362b of adhesive structure 362 may be interchangeably referred to as the second adhesive layer. In some embodiments, the pattern of adhesive structure 362 may be designed according to different designs. For example, the adhesive structure 362 can be linear, L-shaped, U-shaped, dot-shaped, etc. In some embodiments, the shape of the adhesive structure 362 can depend on the shape of the encapsulation element 20. For example, when the encapsulation element 20 is in the form of a panel (i.e., having a rectangular or square top view), the adhesive structure 362 can be drawn as a rectangular or square ring shape when viewed from the top view.

[0054] In some embodiments, adhesive structures 361 and 362 can be applied to the annular structure 367 and the package element 20 via a dispensing process, spin coating process, or similar process. A first layer 362a of adhesive structures 361 and 362 can be formed first, followed by the formation of a second layer 362b of adhesive structure 362 on top of the first layer 362a. The formation of adhesive structures 361 and 362 in the semiconductor package structure can be flexible and adaptable to different assembly processes. In some embodiments, adhesive structure 362 can be formed after adhesive structure 361. In this sequence, adhesive structure 361 with a wider boundary can be applied first, surrounding the periphery of the package element. This initial application provides a base layer, securing the outer edges of the assembly. Subsequently, adhesive structure 362, more centrally located, can be applied around the thermal interface material layer 365 and other internal components. In some embodiments, adhesive structure 362 can be formed before adhesive structure 361. In some embodiments, the width of the adhesive structure 362 may be narrower than the width of the adhesive structure 361.

[0055] In some embodiments, the thermal conductivity of the adhesive structure 361 / adhesive structure 362 can be greater than about 0 W / m·K to 5 W / m·K. In some embodiments, the adhesive structure 361 / adhesive structure 362 may comprise a silicon-based material, an acrylic-based material, an epoxy-based polymer, or a combination thereof. However, this disclosure is not limited thereto. In some alternative embodiments, other polymeric materials with adhesive properties can be used as the adhesive structure 361 / adhesive structure 362. In some embodiments, the adhesive structure 362 may be made of the same material as the adhesive structure 361. In some embodiments, the adhesive structure 362 may be made of a different material than the adhesive structure 361. In some embodiments, the first layer 362a of the adhesive structure 362 may be made of a different material than the second layer 362b of the adhesive structure 361, thus forming a distinguishable interface between the first layer 362a and the second layer 362b. In some embodiments, the first layer 362a of the adhesive structure 362 may be made of the same material as the second layer 362b of the adhesive structure 361, so that a distinguishable interface may not be formed between the first layer 362a and the second layer 362b.

[0056] See Figures 17A and 17B. A cap-like structure 370 can be placed on the annular structure 367, the encapsulation element 20, the encapsulation structure PKG, and the surface mount element 47, such that the encapsulation structure PKG and the thermal interface material layer 365 are located between the encapsulation element 20 and the cap-like structure 370. The cap-like structure 370 can be used for heat dissipation. In other words, the heat generated by the encapsulation structure PKG during operation can be dissipated through the channels formed by the cap-like structure 370. The cap-like structure 370, the annular structure 367, and the encapsulation element 20 together encapsulate the encapsulation structure PKG and the surface mount element 47. In other words, the cap-like structure 370 and the annular structure 367 can be formed to accommodate the encapsulation structure PKG and / or the surface mount element 47. For example, the central cap portion 370c of the cap-like structure 70 and the annular structure 367 can be drawn as an inverted U-shape in cross-sectional view, as shown in Figure 17A. In some embodiments, the cap-like structure 370 can be made of metal, plastic, ceramic, or similar materials. The metal of the cap structure 370 may include, but is not limited to, copper, stainless steel, solder, gold, nickel, molybdenum, NiFe, or NiFeCr. In some embodiments, the thermal conductivity of the cap structure 370 ranges from about 80 W / (m·K) to about 450 W / (m·K). In some embodiments, the Young's modulus of the cap structure 370 ranges from about 50 GPa to about 200 GPa.

[0057] In some implementations, the combination of the annular structure 367 and the flat cap structure 370 within the package structure 310 can reduce warpage during ball-bonded remelting. By implementing the flat cap structure 370 above the annular structure 367, this structure introduces structural stability and support during remelting, ensuring that the thermal interface material layer 365 is uniformly distributed on the contact surface between the package structure PKG and the cap structure 370, ensuring no air gaps or uneven areas that could potentially act as thermal insulators. Therefore, the coverage of the thermal interface material layer can remain greater than approximately 95% after remelting to achieve optimal thermal performance and semiconductor device reliability.

[0058] In some embodiments, the cap-like structure 370 may include a central cap portion 370c and a protrusion 370p. The central cap portion 370c may extend in both the X and Y directions and may be sheet-like. In some embodiments, the central cap portion 370c may be interchangeably referred to as the main body portion. The protrusion 370p may protrude from the surface S3 (or back side) of the central cap portion 370c. In some embodiments, the protrusion 370p may be thicker than the adhesive structure 361. In other words, the protrusion 370p and the central cap portion 370c may form a stepped structure 370s on the back side of the cap-like structure 370, which is positioned above the CoW region. This stepped structure 370s can be adjusted according to the height of the annular structure 367 to ensure a suitable and optimized thermal interface. However, not all embodiments have this stepped structure, allowing for application flexibility. In some embodiments, the central cap portion 370c and the protrusion 370p may be integrally formed. For example, the material of the protrusion 370p can be the same as the material of the central cover 370c. However, this disclosure is not limited thereto. In some alternative embodiments, the protrusion 370p can be mounted on the central cover 370c. For example, the material of the protrusion 370p can be different from the material of the central cover 370c. In some embodiments, the maximum dimension T5 (or thickness) of the cover structure 370 ranges from about 0.5 to 4.0 mm, such as about 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, or 4.0 mm.

[0059] The cap-like structure 370 can be securely fixed to the annular structure 367 by attaching the central cap portion 370c to the adhesive structure 361, allowing the protrusion 370p to extend into the opening O of the annular structure 367. In some embodiments, the contour P4 of the protrusion 370p (see Figure 17B) may substantially correspond to the contour of the opening O of the annular structure 367. Therefore, the thermal interface material layer 365 can be sandwiched between the protrusion 370p of the cap-like structure 370 and the encapsulation structure PKG.

[0060] In some embodiments, a conductive layer BSM3 may be formed on the protrusion 370p of the cap structure 370 before the cap structure 370 is attached. Specifically, as shown in Figure 17A, the conductive layer BSM3 and the protrusion 370p are disposed in the opening O of the annular structure 367. It should be noted that the conductive layer BSM3 can be used to promote adhesion between the thermal interface material layer 365 and the cap structure 370, and may be referred to as back metallization or back metal layer. In some embodiments, the material of the conductive layer BSM3 may be the same as the material of the conductive layer BSM1. In some alternative embodiments, the material of the conductive layer BSM3 may be different from the material of the conductive layer BSM1. In some embodiments, the conductive layer BSM3 may be formed on the cap structure 370 by electroplating, sputtering, or deposition processes. In some embodiments, the material of the conductive layer BSM3 may include metals such as aluminum (Al), titanium (Ti), nickel (Ni), vanadium (V), gold (Au), silver (Ag), or copper (Cu). In some embodiments, the conductive layer BSM3 may be integrated as a gold-plated heat sink. In other words, the back side of the cap-like structure 370 can be plated with gold (Au) to improve thermal conductivity and oxidation resistance, while its main composition may include materials such as copper (Cu) or aluminum (Al). However, this disclosure is not limited to this. In some alternative embodiments, the conductive layer BSM3 is not formed on the cap-like structure 370.

[0061] Specifically, after forming the conductive layer BSM3 on the cap-shaped structure 370, the cap-shaped structure 370 and the conductive layer BSM3 can be placed on the thermal interface material layer 365 and the annular structure 367, so that the conductive layer BSM3 can be in physical contact with the top surface of the flux 366, and the outer periphery of the central cap portion 370c of the cap-shaped structure 370 can be in physical contact with the adhesive structure 361. Subsequently, the cap-shaped structure 370 and the conductive layer BSM3 are pressed onto the thermal interface material layer 365 and the adhesive structure 361.

[0062] See Figure 18. The cap structure 370 and the conductive layer BSM3 are pressed onto the thermal interface material layer 365 and the adhesive structures 361 and 362. In some embodiments, pressing the cap structure 370 and the conductive layer BSM3 onto the thermal interface material layer 365 and the adhesive structures 361 and 362 may include performing a clamping process P31, wherein the temperature range of the clamping process P31 is approximately 60°C to 300°C. In some embodiments, the clamping process P31 may be interchangeably referred to as a thermal clamping process. Subsequently, a curing process may be performed on the adhesive structures 361 and 362 to attach the cap structure 370 to the package element 20 via the adhesive structures 361 and 362. Specifically, a curing process may be performed on the adhesive structures 361 and 362 to ensure that the cap structure 370 is securely fixed to the package element 20. In some embodiments, the curing process temperature ranges from approximately 60°C to 300°C. However, this disclosure is not limited thereto. In some embodiments, during the curing process, the cap structure 370 can be attached to the encapsulation structure PKG via a thermal interface material layer 365. That is, in these embodiments, a good physical and metallurgical bond is formed between the cap structure 370 and the encapsulation structure PKG during the curing process.

[0063] See Figure 19. Conductive terminals 363 may be formed on the surface S2 of the package element 20. In some embodiments, the conductive terminals 363 are solder balls, ball grid array (BGA) balls, or the like. In some embodiments, the conductive terminals 363 are made of a conductive material with low resistivity, such as tin (Sn), lead (Pb), silver (Ag), copper (Cu), nickel (Ni), bismuth (Bi), or alloys thereof. In some embodiments, the conductive terminals 363 may be in physical contact with redistribution lines 30 (or wiring patterns) exposed on the surface S2 of the package element 20. In some embodiments, the conductive terminals 363 may be used for physical and electrical connections of the package element 20 to other components, package structures, connection elements, etc. That is, the conductive terminals 363 may be used to provide physical and / or electrical connections to external components. As shown in Figure 19, the conductive terminals 363 and the package structure PKG are located on opposite sides of the package element 20, with some of the conductive terminals 363 electrically connected to the package structure PKG via the redistribution lines 30 and solder areas 42. In some embodiments, the conductive terminal 363 can be formed on the surface S2 of the package element 20 through a ball placement process and a remelting process. In some embodiments, a remelting process can be performed to reshape the conductive terminal 363, thereby forming a good physical and metallurgical connection between the conductive terminal 363 and the package element 20.

[0064] See Figures 17C through 17J. Figures 17C through 17J illustrate schematic diagrams of encapsulation structures 410, 510, 610, 710, 810, 910, 1010, and 1110 according to some embodiments of this disclosure. Although Figures 17C through 17J illustrate encapsulation structures 410, 510, 610, 710, 810, 910, 1010, and 1110, which differ from encapsulation structure 310 in Figures 10 through 17B, 18, and 19 in their cap-like and / or annular configurations, reference numerals and / or letters may be repeated in various examples in this disclosure. Such repetition is for simplification and clarity and does not itself constitute a basis for the relationship between the various embodiments and / or configurations.

[0065] As shown in Figure 17C, the annular structure 467 in the package structure 410 has an inverted L-shaped cross-section in the cross-sectional view, such that the ring thickness W1 of the upper portion 467a is greater than the ring thickness W2 of the lower portion 467b. The upper portion 467a of the annular structure 467 is close to the package structure PKG at a distance of L4, while the lower portion 467b of the annular structure 467 is farther away at a distance of L5, such that distance L5 is greater than distance L4, causing the upper portion 467a of the annular structure 467 to extend laterally into the package structure PKG, providing additional coverage over at least a portion of the surface mount element 47. Therefore, the annular structure 467 can protect the surface mount element during assembly and operation. Furthermore, by extending laterally into the package structure PKG, the annular structure 467 can help distribute pressure more evenly, reduce the likelihood of mechanical failure, and enhance warpage control. In some embodiments, the protruding portion of the upper portion 467a of the annular structure 467 near the wafer edge can be interchangeably referred to as a bridge structure.

[0066] The upper portion 467a of the annular structure 467 is spaced H3 away from the packaged element 20 to ensure it does not interfere with the surface mount element 47, which has a height of H4. In other words, the distance H3 is greater than the height H4, thus avoiding physical contact between the annular structure 467 and the surface mount element 47 and maintaining assembly integrity. In some embodiments, the vertical spacing between the upper portion 467a of the annular structure 467 and the surface mount element 47 is between approximately 0.05 and 0.30 mm, such as approximately 0.05, 0.10, 0.15, 0.20, 0.25, or 0.30 mm. Furthermore, the outer wall of the upper portion 467a of the annular structure 467 can be aligned with the outer wall of the lower portion 467b of the annular structure 467 to ensure a uniform appearance. The central cover 370c is spaced H5 away from the packaged element 20 that is greater than the sum of the distance H3 and the height H4. The vertical dimension H6 (or ring width) of the annular structure 467 is greater than the distance H5, and the upper part 467a of the annular structure 467 has a vertical dimension H7 (or ring width). In some embodiments, the vertical dimension H7 of the upper part 467a of the annular structure 467 is greater than the thickness of the thermal interface material layer 365.

[0067] As shown in Figure 17D, two stacked annular structures 567a and 567b are located between the package element 20 and the central cover 370c to enhance the mechanical stability of the package structure 510. Furthermore, by placing an adhesive structure 561 between these two annular structures 567a and 567b, not only is stronger adhesion within the assembly facilitated, but an additional layer of mechanical pressure distribution is also provided. This configuration is a modification of the single annular structure 367 illustrated in Figures 10 through 17B, 18, and 19. The possibility of incorporating 3, 4, or up to 10 annular structures beyond the dual-ring configuration demonstrates that the package structure can be tailored to different thermal and mechanical requirements. More annular structures mean more pressure distribution interfaces to meet performance demands.

[0068] In some embodiments, the thickness of the upper annular structure 567a is greater than the thickness of the lower annular structure 567b, by thicknesses W3 and W4, respectively. The upper annular structure 567a is close to the package structure PKG at a distance of L6, while the lower annular structure 567b is farther away at a distance of L7, making distance L7 greater than distance L6. This causes the upper annular structure 567a to extend laterally into the package structure PKG, providing additional coverage over at least a portion of the surface mount element 47. Therefore, the upper annular structure 567a can protect the surface mount element during assembly and operation.

[0069] In some embodiments, the vertical dimension H8 (or ring width) of the upper annular structure 567a is greater than the vertical dimension H9 of the lower annular structure 567b. In some embodiments, the distance H5 between the central cover 370c and the packaged element 20 is greater than the sum of the vertical dimensions H8 and H9. In some embodiments, the lateral distance between the edge of the upper annular structure 567a and the central cover 370c is distance L8, while the lateral distance between the edge of the lower annular structure 567b and the central cover 370c is distance L9, and the lateral distance L8 is less than the lateral distance L9. For example, the lateral distance L8 may be less than about 0.8 mm, such as about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8 mm. The lateral distance L9 may be less than about 0.8 mm, such as about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8 mm.

[0070] See Figures 17E and 17F. The package structures 610 and 710 illustrated in Figures 17E and 17F can be considered variations of package structures 410 and 510 in Figures 17C and 17D. The difference between these two sets of package structures may lie in their cap-like structures. Specifically, cap-like structures 670 and 770 in Figures 17E and 17F lack the protrusion 370p found in cap-like structures 470 and 570 in Figures 17C and 17D. This difference may mean that while cap-like structures 470 and 570 include the protrusion 370p, which could potentially enhance mechanical support and thermal interface efficiency, cap-like structures 670 and 770 offer a simplified configuration that omits this feature. The absence of the protrusion 370p may imply different approaches to thermal management and mechanical stability, potentially simplifying the manufacturing process or meeting different packaging requirements.

[0071] See Figure 17G and Figure 17H. The package structures 810 and 910 illustrated in Figures 17G and 17H can be considered variations of package structures 410 and 510 in Figures 17C and 17D. The difference between these two sets of package structures may lie in their cap-like structures. Specifically, the protrusions 370p of the cap-like structures 870 and 970 in Figures 17G and 17H can include the recesses 70r shown in earlier Figures 1 through 7D, 8, and 9. By combining the protrusions 370p with the recesses 70r, package structures 810 and 910 can improve the efficiency of thermal management and mechanical stability. The recesses 70r in the protrusions 370p help to distribute the thermal interface material more evenly, minimize thermal resistance, and optimize heat dissipation.

[0072] See Figures 17I and 17J. The package structures 1010 and 1110 illustrated in Figures 17I and 17J can be considered variations of package structures 610 and 710 in Figures 17E and 17F. The difference between these two sets of package structures may lie in their cap-like structures. Specifically, the central cap portion 370c of cap-like structures 1070 and 1170 in Figures 17I and 17J can include the recess 70r shown in earlier Figures 1 through 7D, 8, and 9. By combining the central cap portion 370c with the recess 70r, package structures 1010 and 1110 can improve the efficiency of thermal management and mechanical stability. The recess 70r in the central cap portion 370c helps to distribute the thermal interface material more evenly, minimize thermal resistance, and optimize heat dissipation.

[0073] Therefore, based on the above discussion, it can be seen that this disclosure provides advantages. However, it should be understood that other embodiments may offer additional advantages, not all advantages are disclosed herein, and not all embodiments necessarily possess specific advantages. This disclosure provides a cap-like structure in various embodiments to achieve stable control of the void ratio when the thickness of the thermal interface material layer is reduced (e.g., reduced by about 80% to less than 60 micrometers), thereby reducing the thermal resistance of the thermal interface material layer (e.g., reduced by 30% to 50% to less than 3 K·mm² / W). By using a cap-like structure with recesses (e.g., protrusions) on the thermal interface material layer, thickness variations in the package structure can be reduced (e.g., less than 20 micrometers), thereby improving power efficiency (e.g., by 2% to 5%) and expanding the reliability window. Furthermore, the cap-like structure can be modified to combine annular structures and flat caps to reduce warpage during ball soldering reflow, ensuring that the thermal interface material layer maintains more than 95% coverage after reflow. In addition, the ring structure can be equipped with a bridge structure near the edge of the wafer to improve warpage control, further stabilize the assembly process, and improve the overall performance and reliability of the packaging structure.

[0074] In some embodiments, a method of manufacturing a package structure includes: bonding a package element to a substrate; forming a thermal interface material on the package element; forming a first adhesive layer on the substrate, wherein the first adhesive layer laterally surrounds the package element; and attaching a cap-like structure to the thermal interface material and the first adhesive layer, wherein the cap-like structure has a recess that overlaps the thermal interface material. In some embodiments, the recess of the cap-like structure has a concave bottom surface, and after the step of attaching the cap-like structure to the thermal interface material, a top surface of the thermal interface material conforms to the concave bottom surface of the cap-like structure. In some embodiments, viewed from a top view, the recess of the cap-like structure has a central region and a first annular region surrounding the central region, and the vertical thickness of the central region of the cap-like structure is less than the vertical thickness of the first annular region of the cap-like structure. In some embodiments, viewed from a top view, the recess of the cap-like structure has a second annular region surrounding the first annular region, and the vertical thickness of the first annular region of the cap-like structure is less than the vertical thickness of the second annular region of the cap-like structure. In some embodiments, the first adhesive layer has a top, which is positioned above the top surface of the encapsulation element, and the recess of the cap-like structure does not overlap with the first adhesive layer. In some embodiments, the method of manufacturing the encapsulation structure further includes: forming a second adhesive layer on a substrate before attaching the cap-like structure to the thermal interface material and the first adhesive layer, wherein the second adhesive layer laterally surrounds the encapsulation element, and the step of attaching the cap-like structure to the thermal interface material and the first adhesive layer includes attaching the cap-like structure to the second adhesive layer, and the second adhesive layer does not overlap with the recess of the cap-like structure. In some embodiments, the step of forming the first adhesive layer on the substrate is performed before the step of forming the second adhesive layer on the substrate. In some embodiments, the step of forming the first adhesive layer on the substrate is performed after the step of forming the second adhesive layer on the substrate. In some embodiments, the first adhesive layer comprises a silicone-based material, an acrylic-based material, an epoxy polymer, or any combination of the foregoing. In some implementations, the vertical thickness of the thermal interface material is less than about 60 micrometers.

[0075] In some embodiments, the method of manufacturing a package structure includes: bonding the package structure to a substrate; attaching an annular structure to the substrate, wherein the annular structure surrounds the package structure and the thickness of the upper portion of the annular structure is greater than the thickness of the lower portion of the annular structure; forming a thermal interface material layer on the package structure; and attaching a cap-like structure to the thermal interface material layer and the annular structure. In some embodiments, the lateral distance from the upper portion of the annular structure to the package structure is shorter than the lateral distance from the lower portion of the annular structure to the package structure. In some embodiments, the outer sidewall of the upper portion of the annular structure is aligned with the outer sidewall of the lower portion of the annular structure. In some embodiments, the method of manufacturing a package structure further includes: bonding a surface mount element to the substrate before attaching the cap-like structure to the thermal interface material layer and the annular structure, wherein after attaching the cap-like structure to the thermal interface material layer and the annular structure, the upper portion of the annular structure at least partially overlaps the surface mount element, while the lower portion of the annular structure does not overlap the surface mount element. In some embodiments, after the step of attaching the cap-like structure to the thermal interface material layer and the annular structure, the cap-like structure has a first portion above the thermal interface material layer and a second portion above the annular structure, and the thickness of the first portion of the cap-like structure is greater than the thickness of the second portion of the cap-like structure.

[0076] In some embodiments, the encapsulation structure includes a substrate, an encapsulation element, a thermal interface material layer, a first annular structure, a second annular structure, and a cap structure. The encapsulation element is located on the substrate. The thermal interface material layer is located on the encapsulation element. The first annular structure is located on the substrate and surrounds the encapsulation element. The second annular structure is located on the first annular structure. The cap structure is located above the thermal interface material layer and the second annular structure. In some embodiments, the lateral distance from the second annular structure to the encapsulation element is shorter than the lateral distance from the first annular structure to the encapsulation element. In some embodiments, the lateral distance from the outermost wall of the second annular structure to the edge of the cap structure is shorter than the lateral distance from the outermost wall of the first annular structure to the edge of the cap structure. In some embodiments, the ring width of the second annular structure is greater than the ring width of the first annular structure. In some embodiments, the encapsulation structure further includes a surface mount element. The surface mount element is located on the substrate. The second annular structure at least partially overlaps the surface mount element, while the first annular structure does not overlap the surface mount element.

[0077] The foregoing summary outlines the features of several embodiments, enabling those skilled in the art to better understand the nature of this disclosure. Those skilled in the art should understand that this disclosure can be readily used as a basis for designing or modifying other processes and structures to achieve the same purpose and / or attain the same advantages of the embodiments described herein. Those skilled in the art should also recognize that such equivalent constructions do not depart from the spirit and scope of this disclosure, and that various changes, substitutions, and modifications can be made without departing from the spirit and scope of this disclosure.

[0078] 10: Packaging Structure 20: Packaged Components 22: Packaging substrate 24: Dielectric layer 26: Dielectric layer 28: Dielectric layer 30: Redistribution line 34: Packaged Components 36: Substrate 38: Dielectric layer 40: Through-substrate perforation 42: Welding area 44: Filler 46: Packaged Components 46A: Packaged Component 46B: Packaged Component 47: Surface Mount Components 50: Welding area 52: Encapsulated Compounds 54: Filler 60: Memory chip 61: Adhesive structure 62: Packaging materials 63: Conductive terminal 64: Flux 65: Thermal interface material layer 66: Flux 68: Adhesive structure 68a: First layer 68b: Second layer 70: Cap-like structure 70b: Concave bottom surface 70c: Central cover 70g: Legs 70r: Recessed area 70t: Cavity 110: Packaging Structure 170: Cap-like structure 170r: Recessed area 210: Packaging Structure 270: Cap-like structure 270p: Protrusion 270r: Recessed area 270s: Stepped structure 310: Packaging Structure 360: Adhesive layer 361: Adhesive Structure 362: Adhesive Structure 362a: First layer 362b: Second layer 363: Conductive terminal 364: Flux 365: Thermal interface material layer 366: Flux 367: Ring structure 370: Cap-like structure 370c: Central cover 370p: Protrusion 370s: Stepped structure 410: Package structure 467: Ring structure 467a: upper part 467b:lower part 470: Cap-like structure 510: Package Structure 561: Adhesive structure 567a: Ring structure 567b: Ring structure 570: Cap-like structure 610: Package structure 670: Cap-like structure 710: Package Structure 770: Cap-like structure 810: Package Structure 910: Package Structure 1010: Package Structure 1070: Cap-like structure 1110: Packaging Structure 1170: Cap-like structure A-A': Reference section B-B': Reference section BSM1: Conductive layer BSM2: Conductive Layer BSM3: Conductive layer C0: Center C1: Central Area C11: Central Area C12: Transition Region C13: Surrounding Area C2: Transition Region C3: Surrounding Area D11: Dimensions D12: Dimensions D21: Dimensions D22: Dimensions D31: Dimensions D32: Size H0: Minimum vertical dimension H1: Maximum vertical dimension H2: Maximum vertical dimension H3: Distance H4: Height H5: Distance H6: Vertical dimension H7: Vertical Dimensions H8: Vertical dimension H9: Vertical dimension L1: Distance L2: Distance L3: Distance L4: Distance L5: Distance L6: Distance L7: Distance L8: Distance L9: Distance O: Opening P1: First rectangular annular outline P11: Clamping Process P2: Second rectangular ring-shaped outline P21: Clamping Process P3: Third rectangular ring-shaped outline P31: Clamping Process P4: Outline PKG: Packaging Structure R1: Groove S1: Surface S2: Surface S3: Surface S4: Stepped structure T1: Thickness T2: Thickness T3: Thickness T4: Thickness T5: Maximum Size W1: Ring thickness W2: Ring thickness W3: Ring thickness W4: Ring thickness

Claims

1. A method for manufacturing a packaging structure, comprising: To bond a packaged component to a substrate; A thermal interface material is formed on the packaged element; A first adhesive layer is formed on the substrate, wherein the first adhesive layer laterally surrounds the encapsulation element; and a cap-like structure is attached to the thermal interface material and the first adhesive layer, wherein the cap-like structure has a recess that overlaps the thermal interface material, wherein, from a top view, the recess of the cap-like structure has a central region and a first annular region surrounding the central region, and the vertical thickness of the central region of the cap-like structure is less than the vertical thickness of the first annular region of the cap-like structure.

2. The method as described in claim 1, wherein the recess of the cap-like structure has a concave bottom surface, and after the step of attaching the cap-like structure to the thermal interface material, a top surface of the thermal interface material is conformally to the concave bottom surface of the cap-like structure.

3. The method of claim 1, wherein, viewed from the top view, the recess of the cover structure has a second annular region surrounding the first annular region, and the vertical thickness of the first annular region of the cover structure is less than the vertical thickness of the second annular region of the cover structure.

4. The method of claim 1, wherein the first adhesive layer has a top, the top of the first adhesive layer is positioned above a top surface of the encapsulation element, and the recess of the cap structure does not overlap the first adhesive layer.

5. The method as described in claim 1, further comprising: Prior to the step of attaching the cap-like structure to the thermal interface material and the first adhesive layer, a second adhesive layer is formed on the substrate, wherein the second adhesive layer laterally surrounds the encapsulation element, and the step of attaching the cap-like structure to the thermal interface material and the first adhesive layer includes attaching the cap-like structure to the second adhesive layer, wherein the second adhesive layer does not overlap the recess of the cap-like structure.

6. A method for manufacturing a packaging structure, comprising: A packaging structure is bonded to a substrate; A ring structure is attached to the substrate, wherein the ring structure surrounds the encapsulation structure and the thickness of an upper ring of the ring structure is greater than the thickness of a lower ring of the ring structure; a thermal interface material layer is formed on the encapsulation structure; and a cap-like structure is attached to the thermal interface material layer and the ring structure.

7. The method as described in claim 6, wherein the lateral distance from the upper part of the annular structure to the lateral distance from the encapsulation structure is shorter than the lateral distance from the lower part of the annular structure to the lateral distance from the encapsulation structure.

8. A packaging structure, comprising: One substrate; A packaged component is located on the substrate; A thermal interface material layer is located on the packaged element; A first annular structure is located on the substrate and surrounds the encapsulation element; a second annular structure is located on the first annular structure; and a cap-like structure is located on the thermal interface material layer and the second annular structure.

9. The packaging structure as claimed in claim 8, wherein the lateral distance from the second annular structure to the packaging element is shorter than the lateral distance from the first annular structure to the packaging element.

10. The encapsulation structure as described in claim 8, further comprising: A surface mount element is located on the substrate, wherein the second annular structure at least partially overlaps the surface mount element, while the first annular structure does not overlap the surface mount element.

Images