The formation of integrated circuits includes forming integrated circuit devices on semiconductor wafers, and then sawing the semiconductor wafers into device dies. The device dies may be bonded to package components such as interposers, package substrates, printed circuit boards, or the like. To protect the device dies and the bonding structures that bond a device die to a package component, an encapsulant such as a molding compound, an underfill, or the like, may be used to encapsulate the device dies.
Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
Further, spatially relative terms, such as “underlying,” “below,” “lower,” “overlying,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.
A semiconductor package with a recessed stiffener ring and the method of forming the same are provided. In accordance with some embodiments of the present disclosure, one or more semiconductor dies and/or semiconductor packages are bonded to an underlying substrate. Underfill is formed between the one or more semiconductor dies or semiconductor packages and the substrate. The recessed stiffener ring is placed on the underlying substrate and encircles the one or more semiconductor dies and/or semiconductor packages. The recessed stiffener ring has a reduced stiffness in the recessed portion so that it reduces cracking and/or delamination of the corner regions of the underfill adjacent the recessed portion. The reduction of cracking and/or delamination of the underfill leads to better long-term reliability of the semiconductor package.
Embodiments discussed herein provide examples to enable making and using the subject matter of this disclosure, and a person having ordinary skill in the art will readily understand modifications that can be made while remaining within contemplated scopes of different embodiments. Throughout the various views and illustrative embodiments, like reference numbers are used to designate like features. Although method embodiments may be discussed as being performed in a particular order, other method embodiments may be performed in any logical order.
Through vias 34 may be formed extending through the core material 32. The through vias 34 may comprise a conductive material such as copper, a copper alloy, or other conductors, and may include a barrier layer (not shown), liner (not shown), seed layer (not shown), and/or a fill material 36. The through vias 34 may provide vertical electrical connections from one side of the core material 32 to the other side of the core material 32. For example, some of the through vias 34 may be coupled between conductive features on one side of the core material 32 and conductive features on an opposite side of the core material 32. In some embodiments, openings for the through vias 34 may be formed in the core material 32 using a drilling process, a photolithography process, a laser process, or another suitable process. The openings for the through vias 34 may be filled or plated with conductive material. In some embodiments, the through vias 34 may have centers that are filled with a fill material 36, which may be insulating.
Redistribution structures 38 may be formed on opposing sides of the core material 32. The redistribution structures 38 may each comprise one or more dielectric layers 40, formed of ABF, pre-preg, or the like, and metallization patterns 42. Each respective metallization pattern 42 may have line portions on and extending along a major surface of a respective dielectric layer 40 and via portions (not shown) extending through the respective dielectric layer 40. The metallization patterns 42 of the redistribution structures 38 may be electrically coupled by the through vias 34. The redistribution structures 38 each may comprise under-bump metallurgies (UBMs) 44 for external connection, and solder resists 46 protecting the features of the redistribution structures 38. UBMs 44 may comprise, for example, nickel, copper, titanium, or multi-layers thereof. In some embodiments, each of UBMs 44 includes a titanium layer and a copper layer over the titanium layer. Each redistribution structure 38 of the substrate 30 may have more dielectric layers 40 and metallization patterns 42 than shown in
Referring to
Underfill 56 is formed between the package component 50A and the substrate 30 to reduce stress and protect the joints between the package component 50A and the substrate 30, such as electrical connectors 52. In some embodiments, underfill 56 may include a base material, such as an epoxy, and filler particles in the epoxy, and may be deposited by a capillary flow process after the package component 50A is attached to the substrate 30 or may be formed by a suitable deposition method before the package component 50A is attached to the substrate 30. For example, underfill 56 may be dispensed from one side of the package component 50A, and flows into the gaps between the package component 50A and the substrate 30. Underfill 56 may be cured to harden.
Referring to
The numbers of the package component 50A and the package components 50B, and the relative locations of the package component 50A and the package components 50B shown in
Each of the package component 50A and the package components 50B may be a device die, a stack of device dies, a package with one or more device dies packaged therein, a System-on-Chip (SoC) die including a plurality of device dies packaged as a system, or the like. In some embodiments, the package component 50A and the package components 50B are or contain a same type of die. The device dies in the package component 50A and the package components 50B may be logic dies, memory dies, input-output dies, Integrated Passive Devices (IPDs), or the like, or combinations thereof. For example, the logic device dies in the package component 50A and the package components 50B may be Central Processing Unit (CPU) dies, Graphic Processing Unit (GPU) dies, mobile application dies, Micro Control Unit (MCU) dies, BaseBand (BB) dies, Application processor (AP) dies, power management integrated circuit (PMIC) dies, radio frequency (RF) dies, sensor dies, micro-electro-mechanical-system (MEMS) dies, digital signal processing (DSP) dies, analog front-end (AFE) dies, or the like. The memory dies in the package component 50A and the package components 50B may be Static Random Access Memory (SRAM) dies, Dynamic Random Access Memory (DRAM) dies, chip scale package (CSP), high bandwidth memory (HBM) or the like. In some embodiments, the package component 50A and the package components 50B are or contain different types of dies. For example, the package component 50A may be or contain logic dies, such as CPU or GPU, and the package components 50B may be or contain memory dies, such as DRAM, CSP, or HBM. The package component 50A and the package components 50B may be collectively referred to as package components 50.
Referring to
Still referring to
A top segment 58A of the stiffener ring 58 has a width W1, which may be in a range between about 2 mm and about 22 mm, such as about 5 mm. A bottom segment 58B of the stiffener ring 58 has a width W2, which may be in a range between about 1 mm and about 21 mm, such as about 3 mm. In some embodiments, the width W1 may be greater than the width W2, and the top segment 58A of the stiffener ring 58 may have a greater stiffness than the bottom segment 58B of the stiffener ring 58. A bottom edge of the top segment 58A of the stiffener ring 58 may be spaced apart from a top edge of the package component 50B by a distance D3, which may be in a range between about 1 mm and about 15 mm, such as about 3 mm.
Still referring to 4B, the top segment 58A of the stiffener ring 58 has a recess 64 that faces the package component 50A, and the recess 64 may be laterally centered about the package component 50A. The recessed portion of the stiffener ring 58C has a width W3, which may be in a range between about 0.5 mm and about 20 mm, such as about 4.5 mm. In some embodiments, the width W3 may be smaller than the width W1, and the recessed portion of the stiffener ring 58C may have a smaller stiffness than the thicker portions of the top segment 58A of the stiffener ring 58. A distance D4 may extend from a bottom of the recess 64 to a top edge of the package component 50A, wherein the distance D4 may be in a range between about 1.5 mm and about 20 mm, such as about 5.5 mm. In some embodiments, the distance D4 may be greater than a width W3. The package component 50A may have a width W4, which may be in a range between about 5 mm and about 35 mm, such as about 20 mm. The recess 64 may have a width W5, which may be in a range between about 5 mm and about 35 mm, such as about 20 mm. In some embodiments, the width W4 may be the same as the width W5. Since the recessed portion of the stiffener ring 58C may have a smaller stiffness than the thicker portions of the top segment 58A of the stiffener ring 58 and the recessed portion of the stiffener ring 58C may be laterally centered about the package component 50A, the recessed portion of the stiffener ring 58C may reduce the stress of the underfill 56 disposed between the package component 50A and the substrate 30, and along the top segment 58A of the stiffener ring 58, thereby reducing the cracking and/or delamination of the corner regions of the underfill 56 that face the recess 64. The reduction of cracking and/or delamination of the underfill 56 leads to better long-term reliability of the semiconductor package 62.
In
For example, referring to
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A carrier swap process is performed to reveal the bottom surface of the insulating layer 74, which is patterned to form openings that reveal portions of RDLs 76. UBMs 96 are formed in the openings in insulating layer 74 using the same or similar materials and techniques used for forming UBMs 88. Electrical connectors 94 are formed on UBMs 96 using the same or similar materials and techniques used for forming electrical connectors 92.
Referring to
The embodiments of the present disclosure have some advantageous features. By including the stiffener ring 58 in the semiconductor package 62, wherein the recess 64 is disposed in the top segment 58A of the stiffener ring 58, not only may the warpage or other types of deformation of the substrate 30 be reduced, but also the cracking and/or delamination of the corner regions of the underfill 56 that face the recess 64 may be reduced. The reduction of the warpage or other types of deformation of the substrate 30 and the cracking and/or delamination of the underfill 56 both lead to better long-term reliability of semiconductor package 62.
In an embodiment, a semiconductor package includes a substrate comprising a first edge and a second edge opposite the first edge; a package component bonded to the substrate, wherein the package component comprises a semiconductor die, wherein a first edge of the package component is a closest edge of the package component to the first edge of the substrate; an underfill between the package component and the substrate; and a ring structure attached to the substrate, wherein the ring structure encircles the package component in a top view, the ring structure comprising: a first segment extending along the first edge of the substrate, wherein the first segment has a first width, the first width being a distance between an outer edge of the first segment and an inner edge of the first segment, wherein the first segment comprises a recess extending at least partially through the ring structure, and wherein the recess faces the first edge of the package component in the top view. In an embodiment, the first edge of the package component and the first edge of the substrate are spaced apart by a first distance, wherein a second edge of the package component is a closest edge of the package component to the second edge of the substrate, wherein the second edge of the package component and the second edge of the substrate are spaced apart by a second distance, wherein the first distance is greater than the second distance. In an embodiment, the ring structure further comprises a second segment extending along the second edge of the substrate, the second segment having a second width, wherein the second width is a distance between an outer edge of the second segment and an inner edge of the second segment, wherein the first width is greater than the second width. In an embodiment, wherein the first segment has a second width, wherein the second width is a distance between the outer edge of the first segment and a bottom of the recess, wherein the first edge of the package component and the bottom of the recess are spaced apart by a first distance, wherein the first distance is greater than the second width. In an embodiment, the recess extends completely through the first segment. In an embodiment, the recess is one of a plurality of recesses in the first segment, wherein the plurality of recesses faces the first edge of the package component in the top view, wherein the plurality of recesses extends at least partially through the first segment. In an embodiment, each of the plurality of recesses has a same width, and wherein each of the plurality of recesses is spaced apart from a neighboring recess by a same distance. In an embodiment, the plurality of recesses is laterally centered about the package component in the top view.
In an embodiment, a semiconductor package includes a substrate; a package component bonded to the substrate, wherein the package component comprises a semiconductor die; an underfill between the package component and the substrate; and a frame structure attached to the substrate, wherein the frame structure encloses the package component in a top view, the frame structure comprising: a first bar along a first edge of the substrate, wherein the first bar comprises a first portion having a first width, a second portion having a second width, and a third portion having the first width, wherein the first width is greater than the second width, wherein the second portion is disposed between the first portion and the third portion, and wherein a closest edge of the second portion to the first edge of the substrate is level with a closest edge of the first portion to the first edge of the substrate and a closest edge of the third portion to the first edge of the substrate. In an embodiment, a first edge of the package component and the first edge of the substrate are spaced apart by a first distance, wherein a second edge of the package component and a second edge of the substrate are spaced apart by a second distance, wherein the first distance is greater than the second distance. In an embodiment, the frame structure further comprises a second bar along a second edge of the substrate, wherein the second bar has a uniform third width, wherein the first width is greater than the third width. In an embodiment, the first edge of the package component and a closest edge of the second portion to the first edge of the package component are spaced apart by a first distance, wherein the first distance is greater than the second width. In an embodiment, the second portion is laterally centered about the package component.
In an embodiment, a method of manufacturing a semiconductor package, the method includes bonding one or more package components to a substrate, wherein the one or more package components comprise one or more semiconductor dies, wherein a first package component of the one or more package components is disposed at a center of the substrate, wherein the substrate comprises a first edge and a second edge opposite the first edge, and wherein a first edge of the first package component is a closest edge of the first package component to the first edge of the substrate; placing an underfill between the one or more package components and the substrate; and attaching a ring structure to the substrate, wherein the ring structure encircles the one or more package components in a top view, the ring structure comprising: a first segment extending along the first edge of the substrate, wherein the first segment has a first width, the first width being a distance between an outer edge of the first segment and an inner edge of the first segment, wherein the first segment comprises an indentation extending at least partially through the ring structure, and wherein the indentation opens towards the first edge of the package component in the top view. In an embodiment, the first edge of the first package component is closer to the first edge of the substrate than a second edge of the first package component is to a second edge of the substrate. In an embodiment, the ring structure further comprises a second segment opposite the first segment, a width of the second segment being less than the first width. In an embodiment, the first segment further comprises one or more additional indentations. In an embodiment, the indentation forms an opening in the first segment. In an embodiment, the indentation is laterally centered about the first package component in the top view. In an embodiment, one or more additional package components of the one or more package components are disposed near corners of the substrate.
The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.