Stress and warpage improvement for stiffener ring package with exposed die

Abstract

The present disclosure relates to stress and warpage improvement for stiffener ring packages with exposed dies. A package and a method for building the package are disclosed. The package includes a substrate having a first surface. The package further includes a die having opposite first and second surfaces and a lateral surface, where the second surface of the die is coupled to the first surface of the substrate. The package further includes a stiffening element having a first surface and a lateral surface, where the first surface of the stiffening element is coupled to the first surface of the substrate. The package further includes a molding material disposed on the first surface of the substrate and the lateral surface of the die. A coefficient of thermal expansion (CTE) value of the molding material is greater than a CTE value of the die. A first molding surface of the molding material is coplanar with the first surface of the die.

Description

Technical Field

[0001] This disclosure relates to stress and warpage improvements in stiffening ring packages with exposed bare dies. Background Technology

[0002] Semiconductor packages with exposed dies are susceptible to damage when bonded to heat sinks and other components, leading to device failures in the form of die cracks and chipping, especially at the corners and edges of the die. To reduce warpage in large packages with exposed dies (e.g., greater than 45 mm x 45 mm), stiffening rings are typically attached to the periphery of the package substrate. However, due to the mismatch in coefficients of thermal expansion (CTE) between the die, substrate, and stiffening ring, stiffening ring packages are generally susceptible to high tensile stresses at the contact interface between the stiffening ring and the package substrate. During package manufacturing and use, the interaction of thermal stresses can cause cracks to initiate and grow in the substrate at or near the contact interface with the stiffening ring. Furthermore, as package sizes continue to increase (e.g., greater than 65 mm x 65 mm), stiffening rings become less effective at reducing package warpage. Therefore, solutions are desired to reduce warpage and prevent package failures in these larger packages under temperature variations during manufacturing processes and field applications. Summary of the Invention

[0003] A system is disclosed. In one embodiment, the system includes a package, which further includes a substrate having a first surface and a die having opposing first and second surfaces. In one embodiment, the second surface of the die is coupled to the first surface of the substrate. In one embodiment, the system includes a stiffening element having a first surface and a lateral surface, wherein the first surface of the stiffening element is coupled to the first surface of the substrate at a first interface. In one embodiment, the system includes a molding material disposed on the first surface of the substrate and the lateral surface of the die. In one embodiment, the coefficient of thermal expansion (CTE) of the molding material is greater than the CTE of the die.

[0004] A method is disclosed. In one embodiment, the system includes providing a die having a first surface and a second surface opposite to the first surface. In one embodiment, the method includes coupling the die to a first surface of a substrate. In one embodiment, the method includes coupling a first stiffening element to the first surface of the substrate. In one embodiment, the method further includes disposing a molding material on the first surface of the substrate, at least one lateral side of the stiffening element, and at least one lateral surface of the die. In one embodiment, a first molding surface of the molding material is substantially flush with the first surface of the die.

[0005] This summary is provided solely as an introduction to the subject matter fully described in the detailed description and accompanying drawings. The summary should not be construed as describing essential features, nor should it be used to define the scope of the claims. Furthermore, it should be understood that both the foregoing summary and the following detailed description are merely illustrative and explanatory, and do not necessarily limit the claimed subject matter. Attached Figure Description

[0006] A detailed description is provided with reference to the accompanying drawings. The use of the same element symbols in different contexts in the description and figures may indicate similar or identical items. Various embodiments or examples (“Examples”) of this disclosure are disclosed in the following detailed description and accompanying drawings. The drawings are not necessarily to scale. Generally, the operations of the disclosed processes can be performed in any order unless otherwise specified in the claims. In the drawings:

[0007] Figure 1A The accompanying drawing is a cross-sectional side view illustrating a system including electronic component portions according to one or more embodiments of the present disclosure;

[0008] Figure 1B The accompanying drawings are cross-sectional side views illustrating one or more embodiments of the package according to the present disclosure;

[0009] Figure 1C The accompanying drawings are plan views illustrating one or more embodiments of the package according to the present disclosure;

[0010] Figure 1D The accompanying drawing is a cross-sectional side view illustrating a package including a heat sink in one or more embodiments of the present disclosure;

[0011] Figure 2A The accompanying drawings are plan views illustrating one or more embodiments of the package according to the present disclosure;

[0012] Figure 2B The accompanying drawings are cross-sectional side views illustrating one or more embodiments of the package according to the present disclosure;

[0013] Figure 2C The accompanying drawings are plan views illustrating one or more embodiments of the package according to the present disclosure;

[0014] Figures 3A to 3B This is a flowchart illustrating a method for constructing an encapsulation according to one or more embodiments of the present disclosure.

[0015] Figures 4A to 4B The accompanying drawings are cross-sectional side views illustrating one or more embodiments of the package according to the present disclosure;

[0016] Figures 5A to 5C The accompanying drawing is a cross-sectional side view illustrating a package including a chip-on-a-substrate package according to one or more embodiments of the present disclosure;

[0017] Figures 6A to 6C The accompanying drawings are cross-sectional side views illustrating one or more embodiments of the package according to the present disclosure;

[0018] Figures 7A to 7B The accompanying drawings are cross-sectional side views illustrating an encapsulation with different molded portions according to one or more embodiments of the present disclosure. Detailed Implementation

[0019] Before explaining one or more embodiments of this disclosure in detail, it should be understood that the embodiments are not limited to the details of the construction and arrangement of the components, steps, or methods set forth in the following description or illustrated in the accompanying drawings. Many specific details are set forth in the following detailed description of the embodiments to provide a more thorough understanding of this disclosure. However, those skilled in the art to which this disclosure pertains will understand that the embodiments disclosed herein can be practiced without some of these specific details. In other instances, well-known features may not be described in detail to avoid unnecessarily complicating this disclosure.

[0020] As used herein, letters following reference numerals are intended to refer to embodiments of features or elements that are similar to, but not necessarily identical to, previously described elements or features that have the same reference numerals (e.g., 1, 1a, 1b). Such shorthand notation is for convenience only and should not be construed as limiting this disclosure in any way unless expressly stated otherwise.

[0021] Furthermore, unless explicitly stated otherwise, "or" refers to an inclusive "or," not an exclusive "or." For example, condition A or B is satisfied by either of the following: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); and both A and B are true (or exist).

[0022] Additionally, the use of “a” or “an” can be used to describe elements and components of the embodiments disclosed herein. This is done for convenience only, and “a” and “an” are intended to include “one” or “at least one”, and the singular includes the plural, unless it is obvious otherwise.

[0023] As used herein, directional terms such as “top,” “bottom,” “above,” “below,” “upper,” “upward,” “lower,” “downward,” and “downward” are intended to provide relative positions for descriptive purposes and are not intended to specify an absolute frame of reference. Various modifications to the described embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments.

[0024] It should be understood that, conceptually, any arrangement of components that achieve the same functionality, common goal, purpose, result, or structure is effectively “associated” or “coupled” to achieve the desired functionality, common goal, purpose, result, or structure. Therefore, any two components of this document combined to achieve a particular structure can be considered “coupled” to each other to achieve the desired structure and / or functionality, regardless of the architecture or intermediate components. Similarly, any two such associated components can also be considered “connected” or “placed” to each other to achieve the desired functionality, and any two components that can be such associated can also be considered “coupleable” to each other to achieve the desired structure or functionality (e.g., “operably coupled”). Furthermore, unless otherwise indicated, descriptions indicating that one component is “connected to” another component or “between” “two components” indicate that these components are functionally connected and do not necessarily indicate that these components are physically in contact. Rather, these components may be physically in contact or may alternatively contain intermediary elements. Similarly, a description that a particular component is “manufactured” “above” another component (or alternatively, “located on,” “placed on,” or similar) indicates the relative position of these components but not necessarily that they are in physical contact. These components may be in physical contact or may alternatively contain intervening elements.

[0025] Ultimately, as used herein, any reference to “one embodiment” or “some embodiments” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment disclosed herein. The phrase “in some embodiments” appearing in various places in the specification does not necessarily refer to the same embodiment, and an embodiment may include one or more features explicitly described or inherently present herein, or any combination of sub-combinations of two or more such features, and any other features not necessarily explicitly described or inherently present in this disclosure.

[0026] An electronic package comprising a substrate, a die, stiffening components, and molding material is disclosed. The molding material is deposited on the package such that the top of the die is substantially flush with or coplanar with the molding material. The molding material protects the die from cracking when coupled to other package components (e.g., a heat sink). The molding material also reduces substrate stress and warpage at the interface between the substrate and the stiffening components. The molding material is formulated to exhibit a coefficient of thermal expansion (CTE) value that minimizes package warpage and substrate stress.

[0027] Figure 1AThis is a cross-sectional side view illustrating a system 90 comprising an integrated circuit (IC) semiconductor chip and other electronic components according to one or more embodiments of the present disclosure. System 90 includes a package 100, also referred to as a semiconductor package, IC package, chip package, or electronic package. Package 100 organizes and provides connectivity for the semiconductor chip (e.g., integrated circuit) within system 90. In some embodiments, system 90 includes only package 100 and one or more semiconductor chips within package 100.

[0028] In an embodiment, the package includes a substrate 104 configured to provide electrical connectivity and structural protection to the packaged elements. The substrate 104 can be of any type, including, but not limited to, Ajinomoto laminated film (ABF) substrates, BT (bismaleimide triazine) laminated substrates, ceramic substrates, and the like. In an embodiment, system 90 further includes or is connected to a circuit board 108 (e.g., a printed circuit board (PCB)). The printed circuit board 108 itself can be a component of a larger system containing user devices (e.g., mobile phones, smartwatches, gaming systems, tablet computers, or computers). The substrate 104 can be coupled to the printed circuit board 108 via solder balls 112 (e.g., BGA balls) or other connection technologies attached to the bottom side of the substrate 104 (e.g., second surface 114). The substrate 104 can be configured for large package sizes. For example, the substrate 104 can have dimensions (e.g., length or width) approximately equal to or greater than 45 mm. For example, the substrate can have approximately dimensions of a 45 mm x 45 mm square. In another example, the substrate may have a size of approximately equal to or greater than 65 mm. For example, the substrate may have an approximate size of a 65 mm x 65 mm square.

[0029] In an embodiment, package 100 includes at least one die 116 (e.g., a semiconductor chip containing an integrated circuit) coupled to the top side (e.g., first surface 118) of substrate 104. Die 116 includes a first die surface 121 (e.g., a first surface) and a second die surface 122 (e.g., a second surface). The first die surface 121 and the second die surface 122 are opposite to each other (e.g., positioned opposite each other), wherein the second die surface 122 is coupled to the first surface of substrate 104. Die 116 may be configured as one or more semiconductor devices of any type, including but not limited to IC chips, multiple semiconductor chips, chip systems in a package module, integrated passive devices, or microelectromechanical systems (MEMS) devices. For example, die 116 may be configured as a chip on a through-silicon via (TSV) interposer, such as in CoWoS (Chip-on-a-Substrate Package or 2.5D Integrated Circuit Package).

[0030] The die 116 can be configured to be bonded to the substrate 104 via any type of connection element 120, including, but not limited to, flip-chip, surface-mount, or wire-mount package elements. For example, the die 116 can be configured to be coupled to the substrate 104 via a flip-chip die attachment method. The die 116 can be bonded to the substrate 104 in any orientation or type of configuration. For example, the die 116 can be configured as a flip chip with flip-chip connections, also known as controlled-collapse chip connections or C4. The flip-chip connector allows the die 116 to be coupled to the substrate 104 via solder bumps, copper pillars with solder caps, or other connection elements deposited on the connection pads on the die. During the flip-chip mounting process, the die 116 is flipped, and the connection elements 120 mate with corresponding pads on the substrate 104. In this way, the side of the die 116 containing the integrated circuit is guided downward as the second die surface 122, while the back side of the die 116 is guided upward as the first die surface 121.

[0031] In some embodiments, the package further includes a stiffening element 124. The stiffening element 124 has a first surface 125 that is bonded to a first surface 118 of the substrate 104 via a stiffening attachment adhesive 128 (e.g., a first interface). The stiffening attachment adhesive 128 may comprise a thermosetting resin / epoxy resin or other types of adhesive material. When the substrate 104 is heated (e.g., heat is generated during the production of the package 100 or in the die 116 during use), the stiffening element 124 restricts the warping of the substrate 104. Without the stiffening element 124, the substrate 104 could expand to a greater extent than the die as temperature increases due to the difference in the coefficient of thermal expansion (CTE) between the two materials. This difference in CTE values ​​results in different expansion of the materials within the package, leading to a bent appearance that applies stress to both the die 116 and the substrate 104, potentially causing cracking and failure of either the die 116 or the substrate 104. Warpage of substrate 104 can also lead to improper bonding of package 100 to printed circuit board 108, resulting in short circuits or open circuit contacts. The bonding of stiffening element 124 to substrate 104 partially reduces warpage of substrate 104 and also conducts heat away from substrate 104. Stiffening element 124 can be made of any type of material, including but not limited to metals such as copper, and can have any size or shape. For example, stiffening element 124 can be configured or formed as a ring. The shape of stiffening element 124 can also be configured as, but not limited to, cross-shaped, square, or strip-shaped. Additionally, stiffening element 124 may contain cavities and / or slots therein to provide space for other surface-mount components (e.g., capacitors) on substrate surface 118 under the shadow of stiffening first surface 125.

[0032] CTE is used to predict the linear expansion of materials when heated, and can be determined according to the following equation:

[0033]

[0034] Where X i CTE is the linear dimension (e.g., length or width) of the i-th material component, and T is the temperature. CTE values ​​are typically reported in ppm / °C. For example, for a copper length of 1 cm, copper has a CTE value of approximately 16.6 ppm / °C, and increasing the temperature of copper from 0°C to 100°C will result in an expected expansion of 1.67 μm for a 1 mm length of copper. CTE value for substrate 104. substrate The CTE value is within the range of 10 to 17 ppm / ℃. (CTE value for bare die 116) die It can be in the range of 2 to 4 ppm / ℃.

[0035] In this embodiment, the stiffening element 124 has a similar design to CTE. substrate CTE value stiffener For example, the stiffening element 124 may have a CTE of approximately 16 ppm / °C. stiffener The substrate 104 may have a CTE value in the range of approximately 16 ppm / °C. substrate Values ​​(e.g., in the range of 10 to 17 ppm / ℃). In another example, CTE... stiffener Value and CTE substrate The ratio of values ​​is equal to or less than 1.6. For example, CTE stiffener The value can be approximately 16 ppm / ℃, and CTE substrate The value can be approximately 10 ppm / ℃ (e.g., CTE). stiffener CTE substrate It is approximately 1.6). In another case, CTE stiffener CTE substrate The ratio is equal to or less than 1.4. In another case, CTE stiffener :CTE substrate The ratio is equal to or less than 1.2. In another case, CTE stiffener CTE substrate The ratio is equal to or less than 1.0.

[0036] It should be understood that the CTE values ​​described herein represent values ​​below the glass transition temperature (T0) of the packaged component. g The CTE value at a temperature of 130°C. For example, for a temperature of 130°C... g Substrate 104, CTE used in this paper substrate The value may include CTE values ​​for temperatures less than 130°C. substrate Value. For example, the CTE of substrate 104 used in this paper. substrateThe CTE value may include temperatures ranging from 0°C to 120°C, 0°C to 100°C, 10°C to 100°C, 20°C to 100°C, 22°C (e.g., room temperature) to 100°C, 30°C to 80°C, or 50°C to 70°C. substrate Value. Specifically, the CTE of substrate 104 used in this paper. substrate The value may include CTE values ​​of approximately 0°C, approximately 20°C, approximately 22°C, approximately 25°C (e.g., room temperature), or approximately 100°C. substrate value.

[0037] Figure 1B This is a cross-sectional side view illustrating a package 100 according to one or more embodiments of the present disclosure. In an embodiment, the package 100 further includes molding material 132 applied or disposed on both a first surface 118 of a substrate 104 and at least one lateral die surface 136 (e.g., a lateral surface of die 116). The molding material 132 may be disposed as a single body in a continuous manner on the first surface 118 of the substrate 104 and at least one lateral die surface 136 of the die 116. For example, a continuous line of molding material 132 may be applied to the package 100, the continuous line contacting both the first surface 118 of the substrate 104 and one lateral die surface 136 of the die 116. In another example, a single piece of molding material 132 may be applied to the package 100, the single piece of molding material contacting both the first surface 118 of the substrate 104 and one lateral die surface 136 of the die 116. For example, the molding material 132 may have several openings or holes (e.g., where the die 116 or other packaging element portions pass through the molding material 132, or where the first surface 118 of the substrate 104 is not covered), wherein continuous portions of the molding material 132 connect the first surface 118 of the substrate 104 to at least one lateral die surface 136 of the die 116. Along with the continuous form or single body of the molding material 132 disposed on the first surface 118 of the substrate 104 and at least one lateral surface 136 of the die 116, the molding material 132 may also be disposed continuously or discontinuously on other portions of the package 104.

[0038] In one embodiment, the molding material 132 substantially covers the entire lateral die surface 136 of the die 116, and the first molding surface 140 of the molding material 132 (e.g., the top surface of the molding material) is substantially flush with or coplanar with the first die surface 121 of the die. For example, the first molding surface 140 and the first die surface 121 may be within 1 mm of each other. In another example, the first molding surface 140 and the first die surface 121 may be within 1.0 mm of each other. In another example, the first molding surface 140 and the first die surface 121 may be within 0.1 mm of each other. In another example, the first molding surface 140 and the first die surface 121 may be within 0.01 mm of each other. In yet another example, the first molding surface 140 and the first die surface 121 may be within 0.001 mm of each other. Molding materials may include any type of molding material, including but not limited to molding compounds, thermosetting resins, epoxy resins, or adhesives, and may be formulated to have a specific CTE value or a set of CTE values.

[0039] In embodiments, molding material 132 contacts or couples to the lateral surface 144 of stiffening element 124 (e.g., the bulk of molding material 132 contacts stiffening element 124, die 116, and substrate 104 in a continuous manner). For example, for stiffening element 124 configured or shaped as a ring around die, molding material 132 may be deposited to cover a portion of substrate 104, having a first molding surface 140 substantially flush with the first die surface 121, and / or contacting the inner lateral surface 144 of the stiffening element, such as... Figure 1B Displayed in [the text]. Figure 1C The diagram illustrates a plan view of package 100, showing a die 116, a stiffening element 124 (e.g., configured as a ring), and a molded substrate. A molding material 132 mitigates stress along the substrate 104. For example, the molding material 132 reduces tensile stress on or near the stiffening element 124 by distributing tensile stress present at or near the interface between the interface of the inner lateral surface 144 of the stiffening element 124 and the interface between the molding material 132 and the first surface 118 of the substrate 104, thereby preventing cracking that may occur in the substrate 104 near the stiffening adhesive 128. It should be noted that in some cases, the molding material 132 does not contact the stiffening element 124. Therefore, the above description should not be considered a limitation of this disclosure but rather an illustration.

[0040] In some embodiments, system 90 includes a heat sink 148 configured to couple to a first die surface 121 and a first molded surface 140, such as Figure 1D As shown in the image. The heat sink 148 also transfers heat away from the die 116 and substrate 104, such as... Figure 1DThe heat sink 148 can be configured as any type of heat dissipation element, including but not limited to active cooling heat sinks, passive cooling heat sinks, vapor chamber and heat pipe heat sinks, fan-cooled heat sinks, thermoelectric cooling heat sinks, and the like. For example, the heat sink 148 can be configured as a passive heat sink 148 having a heat sink base 152 coupled to a first bare surface 121 and a first molded surface 140 at a heat sink coupling surface 156 (e.g., the first surface of the heat sink 148). The heat sink may also include one or more heat transfer elements 160. The heat transfer elements 160 may have any type, size, shape, or number.

[0041] In one embodiment, at least one dimension (e.g., X or Y) of the heat sink coupling surface 156 is longer than at least one dimension of the first die surface 121, wherein the heat sink coupling surface overlaps the first molded surface 140. The overlap of the heat sink coupling surface 156 over the first die surface 121 maximizes heat dissipation from the die 116 through the heat sink 148. Making the first molded surface 140 flush with or coplanar with the first die surface 121 prevents the corners and edges of the die 116 from contacting the heat sink surface 156 at angles that could cause chipping and breakage of the die.

[0042] Figure 2A This illustration shows a plan view of a package 100 configured with a cross-shaped stiffening element 124 according to one or more embodiments of the present disclosure. In embodiments, the package 100 may include a plurality of dies 116a to 116j, wherein molding material 132 covers the entire or substantially the entire area (e.g., all exposed areas of the substrate 104 not coupled to, for example, the stiffening element 124 and the plurality of dies 116a to 116j) of the first surface 118 of the substrate 104 that is not coupled to the package assembly (e.g., all exposed areas of the substrate 104 not coupled to, for example, the stiffening element 124 and the plurality of dies 116a to 116j of the package assembly) (e.g., greater than 90%). In other words, the molding material, the stiffening element, and the plurality of dies cover all or substantially all (e.g., greater than 90%) of the first surface 118 of the substrate 104. The lateral sides of each die 116 of the plurality of dies 116a to 116j may be bonded by molding material 132. Figure 2B illustrate Figure 2A A cross-sectional side view of the package. As shown, the first molded surface 140 is substantially flush with the first die surfaces 121a to 121d.

[0043] The molding material 132 can cover the entire first surface 118 of the substrate 104, such as Figure 2A The first surface 118 is not shown. The molding material 132 may also partially cover the first surface 118 of the first substrate 104, leaving a portion of the first surface 118 (e.g., on the periphery 204 of the first surface 118) uncovered or exposed, such as... Figure 2CAs shown in the diagram. For example, package 100 may not require molding material 132 in portions of the package (e.g., the periphery), where the stress applied to the substrate is minimal. Periphery 204 may comprise an area less than 10%, less than 5%, or less than 1% of the total area of ​​the first surface 118 of substrate 104.

[0044] Figure 3A This is a flowchart illustrating a method 300 for constructing a package 100 according to one or more embodiments of the present disclosure. The package 100 may include any type or size as described herein, and may include any shape, size, or number of die 116 and stiffening elements 124.

[0045] In an embodiment, method 300 includes step 302 of providing a die having a first die surface 121 (e.g., a top surface or a first surface) and a second die surface 122 (e.g., a bottom surface or a second surface). For example, die 116 may be configured to be coupled to a flip-chip die of substrate 104 via controlled collapsed chip connections (e.g., micro solder bumps) disposed on the second die surface 122.

[0046] In an embodiment, method 300 includes step 304 of coupling a second die surface 122 (e.g., bottom side) of die 116 to a first surface 118 of substrate 104. Die 116 may be any type of semiconductor chip containing integrated circuits and has any type of physical connector. For example, die 116 may be configured as a flip-chip die with microbump connectors coupled to a corresponding pad array located on substrate 104.

[0047] In an embodiment, method 300 further includes step 308 of coupling a first surface 125 of the stiffening element 124 to a first surface 118 of the substrate 104. For example, the stiffening element 124 may be coupled to the substrate 104 via a stiffening attachment adhesive 128 comprising an adhesive material.

[0048] In an embodiment, method 300 further includes step 312 of disposing molding material 132 on a first surface 118 of substrate 104, at least one lateral surface 144 of stiffening element 124, and at least one lateral die surface 136, wherein the first molding surface of molding material 132 is substantially flush with the first surface of die 116. Molding material 132 provides both protection for the die, preventing breakage when heat sink 148 is coupled to die 116, and reduces localized stress on substrate 104, such as stress at stiffening interface 128 attributable to the CTE value of molding material 132, as detailed below. Method 300 may further include the step of coupling heat sink 148 to the first die surface 121 and the first molding surface 140, as... Figure 1D It is displayed in the middle.

[0049] Figure 3B This is a flowchart illustrating a method 350 for constructing a package 100 according to one or more embodiments of the present disclosure, wherein the molding material 132 does not contact the stiffening element 124. The package 100 produced by this method 350 includes die protection of the molding material 132, but does not provide stress reduction at the stiffening interface 128. Similar to method 300, method 350 includes a step 352 of providing a die 116 having a first die surface 121 and a second die surface 122 opposite to the first die surface 121. Method 350 further includes a step 354 of coupling the second die surface 122 to a first surface 118 of a substrate 104. Method 350 further includes a step 358 of disposing the molding material on at least one lateral surface of the first surface 118 of the substrate 104 and the die 116, wherein the first molding surface 140 of the molding material 132 is substantially flush with the first surface of the die 116. Method 350 further includes step 362 of coupling the first surface 125 of the stiffening element 124 to the first surface 118 of the substrate 104.

[0050] In some embodiments, according to one or more embodiments of this disclosure, the stiffening element 124 is partially or completely covered by the molding material 132, such as Figures 4A to 4B As shown in the diagram. For example, the height of the stiffening element 124 may be lower than the height of the die 116, so that when the molding material 132 is placed on the substrate 104 and the first molding surface 140 is substantially flush with or coplanar with the first die surface 121. The molding material 132 may also partially or completely cover the top stiffening surface 404 of the stiffening element. For example, as shown in the diagram. Figure 4A The image shows a cross-sectional side view illustrating package 100, wherein stiffening element 124 is configured to cover a ring around the boundary / edge of a first surface 118 of the substrate, and molding material 132 covers more than half of the top stiffening surface 404. In another example, a cross-sectional side view illustrating package 100 with stiffening element 124 configured as a strip along the center of package 100 is shown. Figure 4B In the middle, the molding material 132 covers the entire top stiffening surface.

[0051] Figures 5A to 5CThis illustration shows a cross-sectional side view of a CoWoS (Chip-on-Wafer-on-Substrate) package 200 including a CoW (Chip-on-Wafer) 504, according to one or more embodiments of this disclosure. The CoWoS package 200 may include one or more or all of the components of package 100, and vice versa. For example, the CoW 504 may include an interposer 512 coupled to a first surface 118 of substrate 104, wherein a die 116, a memory stack 508, or other semiconductor components are coupled to the interposer 512. The CoW 504 may be assembled at another manufacturing location prior to placement onto substrate 104 to complete the CoWoS package assembly. Components on top of the interposer 512 are typically encapsulated with an encapsulation molding compound (EMC) 516, which protects or stabilizes the components and their interconnections with the interposer 512.

[0052] In an embodiment, one of the CoW 504 dies 116 includes a die 116 having a first die surface 121 that is nearly flush with or substantially flush with the first surface 140 of the molding material 132. For example, molding material 132 may be added to package 100 such that the first surface 140 is substantially flush with the first die surface 121 of the highest die 116 in the CoW 504 or CoWoS package 200. The stiffening element 124 may be higher than the first surface 140 of the molding material 132. For example, a top stiffening surface 404 may be higher than the first surface 140 of the molding material 132, and the molding material 132 may be deposited such that no molding material 132 covers the top stiffening surface, such as... Figure 5A As shown in the diagram. In another example, the stiffening element 124 is shorter than the first bare die surface 121, and the molding material 132 is deposited such that the molding material 132 partially or completely covers the top stiffening surface 404, as shown in the diagram. Figure 5B As shown in the image. In another example, the molding material 132 does not contact the stiffening element 124, as... Figure 5C It is displayed in the middle.

[0053] In some embodiments, die 116 is configured as a chiplet module comprising a plurality of chips. The chips are smaller than conventional dies, and several chips are assembled within a conventional package 100. Package 100 may contain a plurality of chiplet modules and may contain one or more dies 116 within a larger chiplet module.

[0054] Figures 6A to 6CThis is a cross-sectional side view illustrating a package 100 having an annular stiffening element 124 and a plurality of dies 116a to 116c according to one or more embodiments of the present disclosure. In embodiments, the dies 116a to 116c have similar heights, and molding material 132 is deposited onto the package 100 such that a first molding surface 140 is substantially flush with or coplanar with first die surfaces 121a to 121c or two or more or all of the dies 116a to 116c. In cases where dies 116 have different heights, molding material 132 may be deposited onto the package 100 such that one of the first die surfaces 121 (e.g., the highest die 116) is substantially flush with the first molding surface 140. For example, in Figure 6B In this configuration, the first molding surface 140 is coplanarly deposited with the first die surface 121 of the highest chip 116b. In some cases, the first molding surface 140 is flush with the first die surface of the die 116, which is not the highest chip or package assembly disposed on the substrate 104. In another example, the package 100 may include multiple first molding surfaces 140 based on different regions of the package 100. For example, the package 100 may include multiple molding material surfaces 140 for dies 116 with different heights.

[0055] Figures 6A to 6C Different configurations of stiffening elements 124 and molding materials 132 are also presented. For example, the molding material 132 may be deposited such that it covers a portion of the transverse surface 144 of the stiffening element 124, such as... Figure 6A The surface is shown in the middle, or covers part or all of the top stiffened surface 404, such as Figure 6B The molding material 132 does not contact the stiffening element 124, as shown in the image. Figure 6C It is displayed in the middle.

[0056] In this embodiment, the molding material 132 is formulated to exhibit a CTE value. mold The CTE value is intended to reduce localized stress at interfaces between package components (e.g., stiffening adhesive 128) or at the interface between die 116 and substrate 104. For example, molding materials may be formulated to exhibit CTE values. stiffener Value and CTE die CTE between values mold Values ​​(e.g., CTE) die < CTE mold < CTE stiffener For example, molding material 132 can be formulated to exhibit a CTE of approximately 7 ppm / °C. mold Value, the CTE mold The value falls within CTE die Value (e.g., approximately 3 ppm / ℃) and CTE stiffenerValues ​​(e.g., typically between 10 and 16 ppm / °C). In another example, package 100 may contain a CTE with approximately 10 ppm / °C. mold The molding material 132 has a CTE of approximately 3 ppm / ℃. die The bare film 116 has a value of approximately 15 ppm / ℃ and a CTE. stiffener The stiffening plate is worthwhile.

[0057] Figures 7A to 7B This is a cross-sectional side view illustrating a package 100 having an annular stiffening element 124, a die 116, and molding material 132 divided into molding portions 704a to 704b according to one or more embodiments of the present disclosure. In embodiments, molding portions 704a to 704b (e.g., molding material portions) have different CTE values. For example, the first molding portion 704a may have a first molding portion CTE value CTE. mold1 Furthermore, the second molded portion 704b may have a second molded portion CTE value (CTE). mold2 Next, molded portions 704a to 704b with different CTE values ​​can be applied to package 100, such that package components with significantly different CTE values ​​(e.g., die 116 and stiffening element 124) will contact molded portions 704 with similar CTE values. For example, and referring to... Figure 7A Package 100 may contain CTE with 10 ppm / ℃ mold1 The first molded portion 704a of the value has a CTE of 15 ppm / ℃. stiffener The reinforcing element 124 with a value of 3 ppm / ℃ and CTE die The bare wafer 116 contact has a CTE of 7 ppm / ℃. mold2 The second molded portion of the value 704b (e.g., CTE) die < CTE mold2 <CTE mold1 < CTE stiffener By positioning materials with different CTE values ​​onto substrate 104, a gradual gradient of CTE values ​​is created. This gradient of CTE values ​​reduces local stress at the stiffened interface 128, thereby resulting in reduced warpage.

[0058] The molded portions 704a to 704b can be added in any order or sequence. For example, molded portion 704a can be added first to the first surface 118 of substrate 104 and the lateral die surface 136 of die 116. Next, stiffening element 124 can be coupled to the first surface 118 of substrate 104. Finally, molded portion 704b can be added to fill the gap between stiffening element 124 and molded portion 704a. Other combinations of steps for adding molded portions 704a to 704b to package 100 are possible.

[0059] like Figure 7B As shown in the illustration, according to one or more embodiments of the present disclosure, the molding portion 704 may also be arranged vertically (e.g., a third molding portion 704c is disposed on the first surface 118 of the substrate 104, and a fourth molding portion 704d is disposed on the third molding portion 704c). For example, the package 100 may include portions initially applied to or disposed on the first surface 118 of the substrate having a relative proximity (e.g., 80% to 100%) or greater than the CTE. substrate CTE value mold3 The third molding portion 704c. The package may also include a portion having a smaller CTE on top of the third molding portion 704c. mold3 CTE value mold4 (For example, CTE) mold3 <CTE mold4 The fourth molding portion 704d of the package. For example, package 100 may contain a CTE having 12 ppm / °C. substrate Substrate 104 with a CTE of 10 ppm / ℃ mold3 The third molding part 704c with a value of 7 ppm / ℃ and CTE mold4 The fourth molded portion 704d is a value. The vertical stacking arrangement of the molded portions 704 is used to alleviate localized stresses in the substrate, such as at the stiffening interface 128. In addition to vertical or horizontal layering, the molded portions 704 can also be deposited in other arrangements. For example, the molded portions can be arranged diagonally or in a configuration specific to the application of system 90.

[0060] The package may include any number of molded portions 704, each with a different CTE value, including, but not limited to, two, three, four, five, or more molded portions 704. In some embodiments, the molding material is formulated to exhibit a gradient of CTE values ​​from one end of the first molding surface 140 to the other. This gradient of CTE values ​​can result in the molding material 132 having virtually unlimited molded portions 704 with corresponding CTE values. The CTE value of the molding material 132 comprising a plurality of molded portions 704 can be determined according to the following equation:

[0061]

[0062] Where m and ρ are the mass and density of the entire molding material 132, respectively, and m i and ρ i These are the mass and density components of the molded part 704.

[0063] The molding material 132 and the molding portion 704 can be formulated to exhibit any CTE value within any range of CTE values. For example, the molding material 132 and the molding portion 704 can have CTE values ​​in the range of 2 to 20 ppm / ℃, 3 to 18 ppm / ℃, 4 to 16 ppm / ℃, or 5 to 14 ppm / ℃. For example, the molding material can exhibit any CTE value, including but not limited to approximately 3 ppm / ℃, approximately 4 ppm / ℃, approximately 5 ppm / ℃, approximately 6 ppm / ℃, approximately 7 ppm / ℃, approximately 8 ppm / ℃, approximately 9 ppm / ℃, approximately 10 ppm / ℃, approximately 11 ppm / ℃, approximately 12 ppm / ℃, approximately 13 ppm / ℃, approximately 14 ppm / ℃, approximately 15 ppm / ℃, approximately 16 ppm / ℃, or approximately 15 ppm / ℃.

[0064] It should be understood that the placement of the molding material 132 on the substrate 104, die 116, or stiffening element 124 may include one or more interlayers between the molding material 132 and the substrate, die 116, or stiffening element 124. For example, the substrate 104, die 116, and / or stiffening element 124 may include one or more coatings (e.g., waterproof coatings, lamination or conformal coatings, such as acrylic resins, silicone resins, or polyurethane resins) applied prior to the deposition of the molding material 132. Therefore, the above description should not be considered as a limitation of this disclosure, but rather as illustrative.

[0065] It should be understood that embodiments of the methods disclosed herein may include one or more steps described herein. Furthermore, these steps may be performed in any desired order, and two or more steps may be performed simultaneously with each other. Two or more steps disclosed herein may be combined into a single step, and in some embodiments, one or more steps may be performed as two or more sub-steps. In addition, other steps or sub-steps may be performed besides, or as alternatives to, the steps disclosed herein.

[0066] Although the inventive concept has been described with reference to embodiments illustrated in the accompanying drawings, equivalents and substitutions may be made herein without departing from the scope of the claims. The components described herein are merely examples of systems / apparatus and components that can be used to implement the inventive concept and may be replaced with other apparatuses and components without departing from the scope of the claims. Furthermore, any dimensions, degrees, and / or numerical ranges provided herein should be understood as non-limiting examples unless otherwise specified in the claims.

Claims

1. A semiconductor system comprising: The package includes: A substrate having a first surface; A die having a first surface, a second surface, and a lateral surface, wherein the first surface and the second surface are opposite to each other, and the second surface of the die is coupled to the first surface of the substrate; A stiffening element having a first surface, wherein the first surface of the stiffening element is coupled to the first surface of the substrate via a first interface; and A molding material having a first molding surface disposed on the first surface of the substrate and the lateral surface of the die, wherein the coefficient of thermal expansion (CTE) of the molding material is greater than the CTE of the die. The molding material is further disposed on the transverse surface of the stiffening element, wherein the CTE value of the molding material is less than the CTE value of the stiffening element. The molding material comprises multiple molding portions, wherein the multiple molding portions include a first molding portion having a first molding portion CTE value and a second molding portion having a second molding portion CTE value, wherein the CTE value of the first molding portion is greater than the CTE value of the second molding portion, and The first molded portion contacts the lateral surface of the stiffening element and the second molded portion contacts the lateral surface of the die, or the first molded portion is formed on the first surface of the substrate and the second molded portion is formed on the first molded portion.

2. The semiconductor system of claim 1, wherein the first molding surface of the molding material is coplanar with the first surface of the die.

3. The semiconductor system of claim 2, further comprising a heat sink coupled to the first surface and the first molded surface of the die.

4. The semiconductor system of claim 1, wherein the stiffening element further includes a top stiffening surface, wherein the first molded surface covers at least a portion of the top stiffening surface.

5. The semiconductor system of claim 4, wherein the first molded surface covers the entirety of the top stiffening surface.

6. The semiconductor system of claim 1, wherein the stiffening element is formed into a ring.

7. The semiconductor system of claim 1, wherein the stiffening element is shaped into at least one of a cross shape or a strip shape.

8. The semiconductor system of claim 1, wherein the die is configured as a chip-on-a-wafer (CoWoS) substrate.

9. The semiconductor system of claim 1, wherein the semiconductor system comprises a circuit board operatively coupled to the substrate.

10. The semiconductor system of claim 1, further comprising a plurality of dies, wherein the molding material, the stiffening element, and the plurality of dies cover more than 90% of the first surface of the substrate.

11. The semiconductor system of claim 1, wherein the periphery of the substrate is not covered by the molding material.

12. The semiconductor system of claim 1, wherein the substrate has a dimension equal to or greater than 45 mm.

13. The semiconductor system of claim 1, wherein the substrate has a dimension equal to or greater than 65 mm.

14. A method for constructing a semiconductor package, comprising: A bare die is provided having a first surface and a second surface opposite to the first surface; The second surface of the bare die is coupled to the first surface of the substrate; The first surface of the stiffening element is coupled to the first surface of the substrate; and Place the molding material on the following: The first surface of the substrate; At least one transverse surface of the stiffening element; and At least one transverse surface of the bare die, wherein the first molding surface of the molding material is coplanar with the first surface of the bare die. The molding material includes multiple molding portions, wherein the multiple molding portions include a first molding portion having a first molding portion CTE value and a second molding portion having a second molding portion CTE value, wherein the CTE value of the first molding portion is greater than the CTE value of the second molding portion. The first molded portion is positioned to contact at least one lateral surface of the stiffening element and the second molded portion is positioned to contact at least one lateral surface of the die, or the first molded portion is formed on the first surface of the substrate and the second molded portion is formed on the first molded portion.

15. The method of claim 14, further comprising coupling a heat sink to the first surface and the first molded surface of the die.

16. A semiconductor system comprising: The package includes: A substrate having a first surface and having a dimension equal to or greater than 45 mm; A die having a first surface, a second surface, and a lateral surface, wherein the first surface and the second surface are opposite to each other, and the second surface of the die is coupled to the first surface of the substrate; A stiffening element having a first surface, wherein the first surface of the stiffening element is coupled to the first surface of the substrate via a first interface; and A molding material having a first molding surface disposed on the first surface of the substrate and the lateral surface of the die, wherein the coefficient of thermal expansion (CTE) of the molding material is greater than the CTE of the die. The molding material comprises multiple molding portions, wherein the multiple molding portions include a first molding portion having a first molding portion CTE value and a second molding portion having a second molding portion CTE value, wherein the CTE value of the first molding portion is greater than the CTE value of the second molding portion, and The first molded portion contacts the lateral surface of the stiffening element and the second molded portion contacts the lateral surface of the die, or the first molded portion is formed on the first surface of the substrate and the second molded portion is formed on the first molded portion.

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