阅读说明：本技术 封装结构的形成方法 (Forming method of packaging structure ) 是由 蔡宗甫 叶宫辰 黄怡婷 林士庭 卢思维 于 2020-04-24 设计创作，主要内容包括：本公开提供一种封装结构的形成方法,包括：形成基板通孔结构于基板之中；形成第一沟槽于基板之中；使用第一接合结构堆叠第一堆叠晶粒封装结构于基板之上,第一接合结构位于基板及第一堆叠晶粒封装结构之间,且空腔位于两邻近第一接合结构之间；形成底胶层于第一堆叠晶粒封装结构之上且于空腔之中,其中底胶层形成于第一沟槽的部分之中；以及形成封装层于底胶层之上。(The present disclosure provides a method for forming a package structure, including: forming a substrate through hole structure in the substrate; forming a first trench in the substrate; stacking a first stacked die package structure on a substrate using a first bonding structure, the first bonding structure being located between the substrate and the first stacked die package structure, and a cavity being located between two adjacent first bonding structures; forming a bottom glue layer on the first stacked die package structure and in the cavity, wherein the bottom glue layer is formed in a portion of the first trench; and forming a packaging layer on the bottom glue layer.)

1. A method for forming a package structure includes:

forming a substrate through hole structure in a substrate;

forming a first trench in the substrate;

stacking a first stacked die package structure on the substrate using a plurality of first bonding structures, wherein the first bonding structures are located between the substrate and the first stacked die package structure, and a plurality of cavities are located between two adjacent first bonding structures;

Forming a bottom adhesive layer on the first stacked die package structure and in the plurality of cavities, wherein the bottom adhesive layer is formed in a portion of the first trench; and

forming a packaging layer on the bottom glue layer.

Technical Field

Embodiments of the present invention relate to a method for manufacturing a semiconductor device, and more particularly, to a method for forming a package structure.

Background

Semiconductor devices are used in a variety of electronic applications, such as personal computers, cellular phones, digital cameras, and other electronic devices. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductive layer materials on a semiconductor substrate, and lithographically patterning the material layers to form circuit elements and features thereon. Many integrated circuits are typically fabricated on a single semiconductor wafer, and the individual dies on the diced wafer are sawed between the integrated circuits along dicing lanes. The individual dies are typically packaged separately, for example in a multi-chip module, or in other package types.

New package technologies, such as package on package (PoP), have been developed in which a top package with a device die is bonded to a bottom package with another device die. By using new packaging techniques, packages of different or similar functionality can be integrated.

While existing packaging structures and methods of manufacturing packaging structures are adequate for their intended purposes, they are not satisfactory in every aspect.

Disclosure of Invention

The embodiment of the invention comprises a forming method of a packaging structure, which comprises the following steps: forming a substrate through hole structure in the substrate; forming a first trench in the substrate; stacking a first stacked die package structure on a substrate using a first bonding structure, the first bonding structure being located between the substrate and the first stacked die package structure, and a cavity being located between two adjacent first bonding structures; forming a bottom glue layer on the first stacked die package structure and in the cavity, wherein the bottom glue layer is formed in a portion of the first trench; and forming a packaging layer on the bottom glue layer.

Drawings

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be noted that the various features are not drawn to scale and are merely illustrative examples. In fact, the dimensions of the elements may be exaggerated or minimized to clearly illustrate the technical features of the embodiments of the present invention.

FIGS. 1A-1M are cross-sectional views illustrating various stages in forming a package structure, according to some embodiments.

FIG. 2A is a top view illustrating a package structure according to some embodiments.

Fig. 2B-2C are enlarged cross-sectional views depicting region a of fig. 2A, according to some embodiments.

Fig. 3A-3B are cross-sectional views illustrating various stages in forming a package structure, according to some embodiments.

Fig. 4A-4B are cross-sectional views illustrating various stages in forming a package structure, according to some embodiments.

FIGS. 5A-5B are cross-sectional views illustrating various stages in the formation of a package structure, according to some embodiments.

FIGS. 6A-6B are cross-sectional views illustrating various stages in forming a package structure, according to some embodiments.

The reference numerals are explained below:

100a,100b,100c,100d,100e packaging structure

11 first grain region

12 second die region

13 cutting street area

19 refluxing process

102 substrate

102a front surface

102b rear surface

103 barrier layer

104 conductive structure

105 substrate via structure

106 conductive layer

108 dielectric layer

110: interconnect structure

112 under bump metallurgy

114 conductive connector

116 adhesion layer

118 carrier substrate

119 protective glue

120 passivation layer

123,123a,123b first trenches

125 second trench

127,127a,127b third grooves

130 first die

132 bonding structure

133 barrier layer

134 first conductive connector

135-substrate through hole structure

136 second conductive connector

137 conductive structure

138 welding point

141 cavity(s)

150 first stacked die package structure

150a first side wall

150b second side wall

158 primer material

160 primer layer

170 encapsulation layer

172 frame adhesive tape

230 second die

250 second stacked die package structure

250a first side

W₁,W₁A first width

W₂,W₂' second width

W₃The third width

W₄The fourth width

H₁,H₁A first depth

H₂,H₂' second depth

H₃A third depth

H₄The fourth depth

D₁A first distance

D₂The second distance

D₃Third distance

D₄The fourth distance

A-A' wire

A is a region

Detailed Description

The following disclosure provides many different embodiments, or examples, for implementing different features of the disclosure. The following disclosure describes specific examples of components and arrangements thereof to simplify the description. Of course, these specific examples are not intended to be limiting. For example, if embodiments of the present invention describe a first feature formed on or above a second feature, that is, embodiments that may include the first feature in direct contact with the second feature, embodiments may also include additional features formed between the first feature and the second feature such that the first feature and the second feature may not be in direct contact. In addition, embodiments of the present invention 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.

Some embodiments of the invention are described. Like elements may be represented by like numbers throughout the various views and the described embodiments. It should be understood that additional operations may be provided before, during, and/or after the stages described in these embodiments. Various embodiments may replace or eliminate some of the stages described.

Other components and processes may also be included. For example, test structures may be included to facilitate verification testing of three-dimensional packages or three-dimensional integrated circuit components. The test structures may include, for example, test pads formed in or on a substrate in a redistribution structure that allows for testing of three-dimensional packages or three-dimensional integrated circuit elements, the use of probes and/or probe cards, and the like. In addition to the final structure, verification testing may also be performed on the relay structure. In addition, the structures and methods shown herein may be used in combination with testing methods, including intermediate verification of known good dice, to increase yield and reduce cost.

Embodiments of semiconductor device structures and methods of forming the same are provided. Fig. 1A-1M illustrate cross-sectional views of various stages in the formation of a package structure 100a, according to some embodiments. The memory crystal grain is stacked on the base substrate, and a groove is formed in the base substrate. When the underfill material is dispensed into the cavity between two adjacent memory dies, excess underfill material flows into the first trench. As the bottom glue layer is divided into discrete parts by the first grooves, the warping of the packaging structure is further reduced.

Referring to fig. 1A, a substrate 102 is provided. The substrate 102 includes a first die region 11, a second die region 12, and a scribe line region 13 between the first die region 11 and the second die region 12. The substrate 102 includes a front surface 102a and a back surface 102 b. The substrate 102 is a basic die for a logic circuit. Substrate 102 is a logic die to control an overlying stacked die, such as a memory die (to be subsequently formed).

The substrate 102 may be made of silicon or other semiconductor material. Alternatively or in addition, the substrate 102 may comprise other elemental semiconductor materials such as germanium. In some embodiments, the substrate 102 is made of a compound semiconductor such as silicon carbide (silicon carbide), gallium arsenide (gallium arsenide), indium arsenide (indium arsenide), or indium phosphide (indium phosphide). In some embodiments, the substrate 102 is made of an alloy semiconductor such as silicon germanium (sige), silicon germanium carbide (sige), gallium arsenide (gan) or gallium indium phosphide (inp). In some embodiments, substrate 102 comprises an epitaxial layer. For example, the substrate 102 has an epitaxial layer covering a bulk semiconductor.

A plurality of conductive structures 104 are formed in the substrate 102. The conductive structure 104 extends from the front surface 102a of the substrate 102 toward the back surface 102b of the substrate 102. In some embodiments, the conductive structure 104 is formed by forming a plurality of trenches (not shown) extending from the front surface 102a of the substrate 102. Thereafter, the barrier layer 103 is filled in each trench, and a conductive structure 104 is formed on the barrier layer 103 and in each trench.

An interconnect structure 110 is formed over the conductive structure 104 and the substrate 102. Interconnect structure 110 may be used as a Redistribution (RDL) structure for routing. Interconnect structure 110 includes a plurality of conductive layers 106 formed in a plurality of dielectric layers 108. In some embodiments, a portion of conductive layer 106 is exposed or protruding from the top surface of the top of dielectric layer 108. The exposed or protruding conductive layer 106 can serve as a bond pad where conductive bumps (e.g., tin-containing solder bumps) and/or conductive pillars (e.g., copper pillars) are to be formed.

The dielectric layer 108 may be made of, or include, one or more polymeric materials. The polymer material may include Polybenzoxazole (PBO), Polyimide (PI), one or more other suitable polymer materials, or a combination thereof. In some embodiments, the polymeric material is photosensitive. In some embodiments, part or all of the dielectric layer is made of or includes a dielectric material other than a polymeric material. The dielectric material may include silicon oxide (silicon oxide), silicon carbide (silicon carbide), silicon nitride (silicon nitride), silicon oxynitride (silicon nitride), one or more other suitable materials, or a combination thereof.

Next, an under bump metallurgy 112 is formed on the interconnect structure 110, and a conductive connector 114 is formed on the under bump metallurgy 112. The under bump metallurgy 112 may be made of titanium (titanium), titanium nitride (titanium nitride), tantalum (tantalum), tantalum nitride (tantalum nitride), tungsten (tungsten), titanium tungsten (titanium tungsten), nickel (nickel), gold (gold), chromium (chrome), copper (copper), copper alloy, other suitable materials, or combinations thereof. The conductive connector 114 may be made of copper, copper alloy, or other suitable material.

Thereafter, according to some embodiments, as depicted in fig. 1B, the substrate 102 is attached to a carrier substrate 118 by an adhesion layer 116. Thereafter, a protective paste 119 is formed between the interconnect structure 110 and the carrier substrate 118. A protective gel 119 is used to protect the conductive connectors 114 from damage in subsequent process steps.

The adhesive layer 116 serves as a temporary adhesive layer. The attachment layer 116 may be glue or tape. In some embodiments, the adhesion layer is photosensitive and easily separated from the carrier substrate 118 by illumination. For example, Ultraviolet (UV) light or laser is irradiated onto the substrate 118 to separate the adhesion layer. In some embodiments, the adhesion layer is a light-to-heat-conversion (LTHC) coating. In some other embodiments, the attachment layer 116 is thermally sensitive and easily separates from the carrier substrate 118 when exposed to heat.

The carrier substrate 118 is configured to provide temporary mechanical and structural support for subsequent processing steps. The carrier substrate 118 includes glass, silica, alumina, metal, combinations thereof, and/or the like. According to some embodiments, the carrier substrate 118 includes a metal frame.

Next, according to some embodiments, as illustrated in fig. 1C, the carrier substrate 118 is used as a support for thinning the substrate 102. In some embodiments, substrate 102 is thinned from back surface 102b until conductive structures 104 are exposed. As a result, a through-substrate via (TSV) structure 105 is formed in the substrate 102. The substrate via structure 105 may be referred to as a through-silicon via (tsv).

In some embodiments, substrate 102 is thinned using a planarization process. The planarization process may include a Chemical Mechanical Polishing (CMP) process, a polishing process, an etching process, other suitable processes, or a combination thereof.

Next, according to some embodiments, as illustrated in fig. 1D, the substrate 102 is further thinned from the back surface 102 b. As a result, the substrate via structure 105 protrudes from the substrate 102. In some embodiments, substrate 102 is thinned using an etching process or other suitable process.

Thereafter, according to some embodiments, as illustrated in fig. 1E, a passivation layer 120 is deposited over the substrate 102. The passivation layer 120 surrounds the protruding portion of the substrate via structure 105.

In some embodiments, the passivation layer 120 is made of silicon oxide, silicon nitride, another suitable material, or a combination thereof. In some embodiments, the passivation layer 120 is deposited using a spin-on process, a Chemical Vapor Deposition (CVD) process, other suitable processes, or a combination thereof.

Thereafter, according to some embodiments, as illustrated in fig. 1F, a planarization process is performed on the deposited passivation layer 120 to expose the substrate via structure 105.

Next, a first trench 123 and a second trench 125 are formed in the first die region 11, and a third trench 127 is formed in the second die region 12. The first trench 123, the second trench 125, and the third trench 127 extend through the passivation layer 120 and extend from the back surface 102b into a portion of the substrate 102.

The first trench 123, the second trench 125, and the third trench 127 are formed in the peripheral regions of the first die region 11 and the second die region 12, and no die is formed directly on the first trench 123, the second trench 125, and the third trench 127. First trench 123, second trench 125, and third trench 127 are configured to receive excess underfill material 158 (subsequently formed in FIG. 1I).

The first groove 123 has a first width W in the horizontal direction₁And has a first depth H in the vertical direction₁. The second groove 125 has a second width W in the horizontal direction₂And has a second depth H in the vertical direction₂. The third groove 127 has a third width W in the horizontal direction₃And has a third depth H in the vertical direction₃. In some embodiments, the first width W₁A second width W₂Or a third width W₃Independently in the range of about 25 μm to about 150 μm. In some embodiments, the first depth H₁A second depth H₂Or a third depth H₃Independently in the range of about 2 μm to about 20 μm. When the widths of the first trench 123, the second trench 125, and the third trench 127 are within the above ranges, the underfill material 158 can effectively block the first trench 123, the second trench 125, and the third trench 127. When the depths of the first trench 123, the second trench 125, and the third trench 127 are within the above ranges, the first trench 123, the second trench 125, and the third trench 127 have enough space to accommodate the underfill material 158.

In some embodiments, the substrate 102 has a depth in a range from about 40 μm to about 60 μm. In some embodiments, the first depth H ₁The ratio to the thickness of the substrate 102 ranges from about 5% to about 35%.

The planarization process may include a chemical mechanical polishing process, a polishing process, an etching process, another suitable process, or a combination thereof. In some embodiments, the first trench 123, the second trench 125, and the third trench 127 are formed in a laser etching process. In some embodiments, the first trench 123, the second trench 125, and the third trench 127 are formed in an etching process, such as a dry etching process or a wet etching process.

Thereafter, according to some embodiments, as illustrated in fig. 1G, a first memory die 130 is formed on the substrate 102 in the first die region 11, and a second memory die 230 is formed on the substrate 102 in the second die region 12. The first die 130 and the second die 230 are cut from the wafer and may be "known good dies". In some embodiments, the first die 130 and the second die 230 are memory dies. The first die 130 and the second die 230 may include Static Random Access Memory (SRAM) devices, Dynamic Random Access Memory (DRAM) devices, High Bandwidth Memory (HBM) devices, or other memory dies.

The first die 130 and the second die 230 are bonded to the substrate 102 through the bonding structure 132. The bonding structure 132 includes a first conductive connector 134, a second conductive connector 136, and a solder joint 138 between the first conductive connector 134 and the second conductive connector 136.

A first conductive connector 134 is formed over the substrate via structure 105, and a first solder layer (not shown) is formed over the first conductive connector 134. A second conductive connector 136 is formed under the first die 130, and a second solder layer (not shown) is formed under the second conductive connector 136. The first conductive connector 134 is bonded to the second conductive connector 136 in a reflow process. Then, the first solder layer and the second solder layer are melted and reshaped to form the solder joint 138. In some embodiments, an intermetallic compound (IMC) (not shown) is formed between the solder joint 138 and the first and second conductive connectors 134, 136.

A plurality of Through Substrate Via (TSV) structures 135 are formed in one of the first die 130 and the second die 230. The substrate via structure 135 is electrically connected to the substrate via structure 105 by the bonding structure 132. Each through-substrate via structure 135 includes a conductive structure 137 and a barrier layer 133 surrounding the conductive structure 137. The through substrate via structure 135 of each die is electrically connected to a corresponding Through Substrate Via (TSV) structure 105 of the substrate 102.

Next, according to some embodiments, as illustrated in fig. 1H, a number of dies are stacked on the first die 130 and the second die 230 to form a first stacked die package 150 in the first die region 11 and a second stacked die package 250 in the second die region 12, respectively. Then, the reflow process 19 is performed on the first stacked die package 150 and the second stacked die package 250 to reflow and bond the bonding structure 132 between two adjacent dies (e.g., memory dies). As a result, a first stacked die package 150 is formed on the substrate 102 in the first die region 11, and a second stacked die package 250 is formed on the substrate 102 in the second die region 12.

In some embodiments, the reflow process 19 is a bulk reflow process. The reflow process (reflow phase) is performed at a temperature in a range from about 220 degrees celsius to about 275 degrees celsius. In some embodiments, the reflow process (reflow stage) is performed for a time in the range of about 60 seconds to about 120 seconds.

It should be noted that during the reflow process 19, no pressure is applied to the first stacked die package structure 150 and the second stacked die package structure 250 to avoid extruding the extra solder layer in the bonding structure 132 and to avoid unwanted connection between two adjacent bonding structures 132.

In some embodiments, the first stacked die package structure 150 includes a plurality of memory dies. In some embodiments, the second stacked die package structure 250 includes a number of memory dies. Each memory die is stacked with a number of bonding structures 132. Signals between memory dies may be communicated Through Substrate Via (TSV) structures 135 and bonding structures 132. The through substrate via structure 135 of the die in each of the first stacked die package structure 150 or the second stacked die package structure 250 is electrically connected to the Through Substrate Via (TSV) structure 105 of the corresponding substrate 102. The number of memory dies is not limited to four and can be adjusted depending on the application.

A plurality of cavities 141 are located between adjacent dies in the first stacked die package structure 150 and the second stacked die package structure 250. More specifically, the cavity 141 is located between two adjacent bonding structures 132.

Thereafter, according to some embodiments, as illustrated in fig. 1I, the underfill material 158 is dispensed from the first side 150a of the first stacked die package structure 150 by the nozzle 15 (the underfill material 158 is from an inlet end of the nozzle 15). Further, underfill material 158 is dispensed from a first side 250a of the second stacked die package structure 250 with nozzle 15 (underfill material 158 from an inlet end of nozzle 15). The arrows depict the flow of primer material 158. The primer material 158 is dispensed onto the substrate 102 using a nozzle 15 of a primer dispensing device (not shown).

The primer layer 160 surrounds and protects the first conductive connector 134 and the second conductive connector 136. In some embodiments, the primer layer 160 directly contacts the first conductive connector 134 and the second conductive connector 136. The underfill layer 160 is disposed between the cavities 141 to protect the first stacked die package structure 150, the second stacked die package structure 250, and the bonding structure 132 between the substrates 102.

In some embodiments, the make coat 160 includes an epoxy-based resin (epoxy-based resin) in which the filler is dispersed. The filler may include insulating fibers, insulating particles, other suitable elements, or combinations thereof.

It should be noted that when underfill material 158 flows into cavity 141, underfill material 158 flows into first grooves 123 with capillary force. Since the second trench 125 is located at the second side 150b of the first stacked die package structure 150 and the underfill material 158 does not touch the second side 150b, the second trench 125 is still empty. In some embodiments, the underfill layer 160 fills a portion of the first trench 123, but the second trench 125 is still empty because the underfill material 158 first flows into the first trench 123.

In some embodiments, the primer layer 160 completely fills the first trench 123. In some other embodiments, the primer layer 160 fills the bottom of the first trench 123, but the top of the first trench 123 remains empty. Similar to the first trench 123, in some embodiments, the primer layer 160 fills the bottom of the third trench 127.

A first distance D is formed between the first sidewall 150a (the inlet end of the nozzle 15) of the first stacked die package structure 150 and the first sidewall of the first trench 123₁. A second distance D is between the second sidewall 150b (the exit end of the underfill material 158) of the first stacked die package structure 150 and the first sidewall of the second trench 125₂. A third distance D is formed between the first sidewall 250a of the second stacked die package structure 250 (the inlet end of the underfill material 158 from the nozzle 15) and the first sidewall of the third trench 127₃. A fourth distance D is formed between the second sidewall 150b (outlet end of the underfill material 158) of the first stacked die package structure 150 and the first sidewall 250a (inlet end of the underfill material 158 from the nozzle 15) of the second stacked die package structure 250₄。

Since the amount of primer material 158 is greater at the inlet end than the amount of primer material 158 at the outlet end, the tongue (or primer fillet) area initially dispensed at the inlet end by primer material 158 is wider than the side edge area of primer material 158 at the outlet end. In some embodiments, the second trench 125 is closer to the first stacked die package structure 150 than the first trench 123.

In some embodiments, the first distance D₁Greater than the second distance D₂Such that the underfill material 158 flows through a long path to reach the first trench 123. Thus, the risk of overloading the first trench 123 is reduced.

In some embodiments, the first distance D₁Is substantially equal to the third distance D₃. In some embodiments, the fourth distance D₄In the range of about 1000 μm to about 1200 μm. In some embodiments, the second distance D₂In the range of about 200 μm to about 300 μm. In some embodiments, the first distance D₁In the range of about 300 μm to about 400 μm. In some embodiments, the first distance D₁At a fourth distance D₄The proportion of (c) is in the range of about 25% to about 40%.

Next, as illustrated in fig. 1J, the underfill material 158 continues to flow from the first side 150a of the first stacked die package structure 150 to the second side 150b of the first stacked die package structure 150, according to some embodiments. The cavity 141 is completely filled with the underfill material 158.

In some embodiments, a portion of the primer layer 160 is formed at the bottom of the second trench 125. In some other embodiments, the primer layer 160 is not formed in the second trench 125.

In some embodiments, forming the primer layer 160 involves an injection process, a coating process, a dispensing process, a lamination process, an application process, one or more other available processes, or a combination thereof. In some embodiments, a thermal curing process is used in forming the make layer 160. In some embodiments, the curing process operates at a temperature in a range from about 150 degrees celsius to about 250 degrees celsius. In some embodiments, the curing process is operated for about 10 minutes to about 10 hours.

It should be noted that the underfill material 158 has a relatively large Coefficient of Thermal Expansion (CTE) relative to the CTE of the substrate 102. In some embodiments, the underfill material 158 has a coefficient of thermal expansion of about 30ppm/C and the substrate 102 has a coefficient of thermal expansion of less than 10 ppm/C. Thus, warpage of package structure 100a may occur after the curing process due to a mismatch in the coefficients of thermal expansion of underfill material 158 and substrate 102. To reduce or avoid warpage of the package structure 100a, the trenches 123, 125, 127 are formed in the substrate 102 to separate the underfill layer 160 into discrete portions. More specifically, the underfill bridging is blocked by trenches 123, 125, 127.

As illustrated in fig. 1J, the underfill layer 160 includes a first portion located on the first stacked die package structure 150 in the first die region 11 and a second portion located on the second stacked die package structure 250 in the second die region 12. The first portion is separate from the second portion. There is no underfill bridge between the first stacked die package 150 and the second stacked die package 250. More specifically, the primer layer 160 is not accumulated in the scribe line region 13. The shrinkage volume of the make layer 160 is reduced and thus the warpage problem is reduced.

Next, according to some embodiments, as illustrated in fig. 1K, an encapsulation layer 170 is formed on the bottom glue layer 160. An interface exists between the make layer 160 and the encapsulation layer 170. The encapsulation layer 170 surrounds and protects the first stacked die package structure 150 and the second stacked die package structure 250. The encapsulation layer 170 is between the separated first and second portions of the primer layer 160.

The encapsulation layer 170 is made of a molding compound material. The molding compound material may include a polymeric material, such as an epoxy-based resin in which the filler is dispersed. In some embodiments, a liquid molding compound material is applied over the first stacked die package structure 150 and the second stacked die package structure 250. The liquid molding compound material may flow into the space between the first stacked die package structure 150 and the second stacked die package structure 250. A thermal process is then used to cure the liquid molding compound material and transfer it into the encapsulation layer 170.

Next, according to some embodiments, as illustrated in fig. 1L, the carrier substrate 118 and the protection adhesive 119 are removed, and the first stacked die package 150 and the second stacked die package 250 are flipped upside down and placed on the frame tape 172. Then, a singulation process is performed to separate the wafer level package structure into a multi-die level package structure. In some embodiments, the singulation process is a cutting process. In some embodiments, the dicing process is performed along the dicing street region 13.

The frame tape 172 serves as a temporary substrate. The frame tape 172 substrate provides mechanical and structural support during subsequent processing steps, such as those described in more detail below.

Next, as illustrated in fig. 1M, the frame tape 172 is removed, and a multi-grain level package structure is obtained. An interconnect structure 110 is formed on the front surface 102a of the substrate 102, and a passivation layer 120 is formed on the back surface 102b of the substrate 102.

A first stacked die package structure 150 is formed on the rear surface 102b of the substrate 102, and an underfill layer 160 is formed on the first stacked die package structure 150. The underfill layer 160 includes a first protruding portion that extends below the top surface of the Through Substrate Via (TSV) structure 105, and the encapsulation layer 170 includes a protruding structure that extends below the top surface of the Through Substrate Via (TSV) structure 105.

A second stacked die package structure 250 is formed on the rear surface 102b of the substrate 102, and an underfill layer 160 is formed on the second stacked die package structure 250. The underfill layer 160 includes a first protruding portion that extends below the top surface of the Through Substrate Via (TSV) structure 105, and the encapsulation layer 170 includes a protruding structure that extends below the top surface of the Through Substrate Via (TSV) structure 105.

It should be noted that the underfill material 158 flows into the first trench 123, the second trench 125, and the third trench 127, so that the underfill layer 160 is divided into a plurality of separated portions. The underfill layer 160 is discontinuous between the first stacked die package structure 150 and the second stacked die package structure 250. Therefore, the primer layer 160 is not accumulated in the scribe line region 13, and the shrinkage volume of the primer layer is reduced. Therefore, warpage of the package structure 110a caused by thermal expansion mismatch can be reduced.

According to some embodiments, fig. 2A illustrates a top view of the package structure 100 a. 2B-2C illustrate enlarged cross-sectional views of region A of FIG. 2A, according to some embodiments. FIG. 1H depicts a cross-sectional view taken along line A-A' of FIG. 2A.

As shown in fig. 2B, in the first die region 11, a first trench 123 and a second trench 125 are formed at two sides of the first stacked die package structure 150. The first trench 123 is parallel to the second trench 125, and the first trench 123 is connected to the second trench 125 by other trenches. Thus, an annular trench structure surrounding the first stacked die package structure 150 is formed.

In the second die region 12, the third trench 127 is located at one side of the second stacked die package structure 250. A U-shaped trench structure is formed to surround the second stacked die package structure 250.

As shown in fig. 2C, in the first die region 11, the ring structure includes a first trench 123 and a second trench 125 surrounding the first stacked die package structure 150. Within the second die region 12, the third trench 127 surrounds the second stacked die package structure 250.

Fig. 3A-3B illustrate cross-sectional views of stages in forming a package structure 100B, according to some embodiments. The package structure 100b is similar to or the same as the package structure 100a shown in fig. 1H, except that a fourth trench 129 is formed in the scribe line region 13. The processes and materials used to form the semiconductor device structure 100b may be similar to or the same as the processes and materials used to form the semiconductor device structure 100a, and are not repeated here.

The fourth groove 129 has a fourth width W in the horizontal direction₄And a fourth depth H in the vertical direction₄. In some embodiments, the fourth width is in a range from about 50 μm to about 100 μm. In some embodiments, the fourth depth H₄Independently in the range of about 4 μm to about 6 μm.

Thereafter, as shown in fig. 3B, in the second die region 12, the bottom adhesive layer 160 completely fills the third trench 127, but the bottom adhesive layer 160 does not completely fill the fourth trench 129. A primer layer 160 is formed at the bottom of the fourth trench 129, and an encapsulation layer 170 is formed at the top of the fourth trench 129. In the first die region 11, in some embodiments, the make layer 160 occupies about 80% of the first trenches 123, and the encapsulation layer occupies about 20% of the first trenches 123. In some embodiments, the make layer 160 occupies about 20% of the second trench 125 and the encapsulation layer occupies about 80% of the second trench 125. Thereafter, the structure of FIG. 3B continues with the steps of FIGS. 1L-1M.

Fig. 4A-4B illustrate cross-sectional views of various stages in the formation of a package structure 100c, according to some embodiments. The package structure 100c is similar to or identical to the package structure 100a shown in fig. 1H, except that two first trenches 123a, 123b are located at a first side of the first stacked-die package structure 150, and two third trenches 127a, 127b are located at a first side of the second stacked-die package structure 250. A first strip of the first trenches is designated 123a and a second strip of the first trenches is designated 123 b. Further, the first strip of the third trench is denoted as 127a, and the second strip of the third trench is denoted as 127 b.

The processes and materials used to form the semiconductor device structure 100c may be similar to or the same as the processes and materials used to form the semiconductor device structure 100a, and are not repeated here. It should be noted that the number of the first trenches 123, the number of the second trenches 125, or the number of the third trenches 127 may be adjusted according to practical applications.

Next, as shown in fig. 4B, in the first die region 11, the first strip 123a of the first trench is closer to the first stacked die package structure 150 than the second strip 123B of the first trench. The second strip 123b of the first trench is further away from the first stacked die package structure 150 than the first strip 123a of the first trench. The primer layer 160 may occupy half of the first bar 123a of the first trench, and the encapsulation layer 170 may occupy half of the first bar 123a of the first trench. The underfill layer 160 does not flow into the second strip 123b of the first trench, and the second strip 123b of the first trench is completely filled with the encapsulation layer 170.

In the second die region 12, the first strip 127a of the third trench is closer to the second stacked die package structure 250 than the second strip 127b of the third trench. The primer layer 160 may occupy half of the first strip 127a of the third trench, but the primer layer 160 does not flow into the second strip 127b of the third trench. Thereafter, the structure of FIG. 4B continues with the steps of FIGS. 1L-1M.

Fig. 5A-5B illustrate cross-sectional views of various stages in the formation of a package structure 100d, according to some embodiments. The package structure 100d is similar or identical to the package structure 100c depicted in fig. 4A, except that the second bar 123b of the first trench is deeper and narrower than the first bar 123a of the first trench, and the second bar 127b of the third trench is deeper and narrower than the first bar 127a of the third trench. More specifically, the bottom surface of the second bar 123b of the first trench is lower than the bottom surface of the first bar 123a of the first trench.

In some other embodiments, the first bar of first trenches 123a is deeper and narrower than the second bar of first trenches 123 b. In some other embodiments, the first strip 127a of the third trench is deeper and narrower than the second strip 127b of the third trench. The second strip 123b of the first trench has a first width W in the horizontal direction ₁' and a first depth H in the vertical direction₁'. The second strip 127b of the third trenches has a second width W in the horizontal direction₂' and a second depth H in the vertical direction₂’。

The processes and materials used to form the semiconductor device structure 100d may be similar to or the same as the processes and materials used to form the semiconductor device structure 100a, and are not repeated here.

Next, as illustrated in fig. 5B, in the first die region 11, the first strip 123a of the first trench is completely filled with the underfill layer 160, and the underfill layer 160 flows into the bottom of the second strip 123B of the first trench. The top of the second strip 123b of first trenches is filled with an encapsulation layer 170. In the first die region 11, the underfill layer 160 has a first protruding portion (in the first strip 123a of the first trench) and a second protruding portion (in the second strip 123b of the first trench) extending below the top surface of the substrate via structure 105. The second protruding portion is farther away from the top surface of the substrate via structure 105 than the first protruding portion.

In addition, in the second die region 12, the first strip 127a of the third trench is completely filled with the primer layer 160 and the primer layer 160 continuously flows into the bottom of the second strip 127b of the third trench. Thereafter, the structure of FIG. 5B continues with the steps of FIGS. 1L-1M.

Fig. 6A-6B illustrate cross-sectional views of various stages in forming a package structure 100e, according to some embodiments. The package structure 100e is similar or identical to the package structure 100a depicted in fig. 1H, except that the second trench 125 is formed in the first die region 11, and the fifth trench 131 is formed in the second die region 12. The processes and materials used to form the semiconductor device structure 100e may be similar to or the same as the processes and materials used to form the semiconductor device structure 100a, and are not repeated here.

Thereafter, as illustrated in fig. 6B, the underfill material 158 flows from the second die region 12 to the second trench 125 in the first die region 11 through the scribe lane region 13. Thereafter, an encapsulation layer 170 is formed on the bottom glue layer 160. Thus, the primer layer 160 is divided into two discrete portions by the second groove 125. Therefore, since the second trench 125 blocks the underfill bridge, warpage of the package structure 100e is avoided. Thereafter, the structure of FIG. 6B continues with the steps of FIGS. 1L-1M.

It is noted that the first trench 123, the second trench 125, and the third trench 127 are formed on the rear surface 102b of the substrate 102. Grooves 123, 125, and 127 provide a receiving space for underfill material 158 to ensure minimal shrinkage of underfill material 158. Therefore, the warpage problem of the packaging structure can be effectively reduced.

Embodiments of forming a package structure and methods of forming the same are provided. The package structure includes a via structure formed in a substrate and a first trench formed in the substrate. The memory die is stacked on the substrate, and the underfill material is dispensed into the cavity between two adjacent memory dies. When the primer material is dispensed into the cavity, the primer material flows into the first groove. And finally, carrying out a curing process on the primer material to form a primer layer. The first trench divides the primer layer into separate or discrete portions. After the curing process, the shrinkage volume of the bottom glue layer is reduced, and the warping problem of the packaging structure is further reduced. Therefore, the yield and the efficiency of the packaging structure are improved.

In some embodiments, a method of forming a package structure is provided. The method includes forming a substrate via structure in a substrate and forming a first trench in the substrate. The method includes stacking a first stacked die package structure on a substrate using a plurality of first bonding structures. The first bonding structure is between the substrate and the first stacked die package structure, and the plurality of cavities are between two adjacent first bonding structures. The method also includes forming a primer layer over the first stacked die package structure and in the cavity, and forming the primer layer in a portion of the first trench. The method also includes forming an encapsulation layer over the primer layer. In one embodiment, the method further comprises removing a portion of the substrate such that the substrate via structure protrudes above a top surface of the substrate; forming a passivation layer on the substrate through hole structure and the substrate; and removing a portion of the passivation layer to expose the substrate via structure. In one embodiment, the method further comprises forming a first connector over the substrate via structure; forming a second connector under the first stacked die package structure; and joining the first connector and the second connector to form one of the joint structures. In one embodiment, a first stacked die package structure includes a plurality of memory dies. In one embodiment, forming a substrate via structure in a substrate comprises: forming a conductive connector on the front surface of the substrate, the first connector being located on the substrate via structure; bonding the conductive connector to the carrier substrate; and thinning the substrate from the back surface of the substrate. In one embodiment, the method further includes forming a second trench in the substrate, the second trench being further from the first stacked die package structure than the first trench; and forming an encapsulation layer in the second trench. In one embodiment, the second trench is deeper than the first trench. In one embodiment, the method further includes forming a second trench in the substrate, the first stacked die package structure being located between the first trench and the second trench; dispensing a primer material from a first side of the first stacked die package structure to a second side of the first stacked die package structure to form a primer layer, the first side being closer to the first trench than to the second trench; and filling a portion of the second trench with a primer material after filling a portion of the first trench with the primer layer. In one embodiment, a first distance is provided between the first sidewall of the first stacked die package and the first trench, a second distance is provided between the second sidewall of the first stacked die package and the second trench, and the first distance is greater than the second distance. In one embodiment, the method further comprises forming an interconnect structure on the front surface of the substrate; forming a substrate via structure on a rear surface of a substrate; and forming a first trench on the rear surface of the substrate.

In some embodiments, a method of forming a package structure is provided. The method includes providing a substrate. The substrate includes a first die region, a second die region, and a scribe line region between the first die region and the second die region. The method also includes forming a first trench in the first die region of the substrate and forming a second trench in the second die region of the substrate. The method further includes stacking a plurality of first memory dies on the substrate, and the first stacked die package structure is adjacent to the first trench. The method includes stacking a plurality of second memory dies on the substrate, and the second stacked die package structure is adjacent to the second trench. The method also includes forming a primer layer between the first memory die, the second memory die, and the substrate, the primer layer including a first portion on the first memory die and a second portion on the second memory die, the first portion being spaced apart from the second portion. The method includes forming a packaging layer on the bottom adhesive layer, wherein the packaging layer is located between the first portion and the second portion of the bottom adhesive layer. In one embodiment, the method further includes forming a plurality of bonding structures between the first memory die, the plurality of cavities being between two adjacent bonding structures; and forming a primer layer in the cavity. In one embodiment, the method further includes forming a third trench in the scribe line region, the third trench being located between the first trench and the second trench. In one embodiment, the method further includes forming a third trench in the substrate, the first memory die being located between the first trench and the third trench; dispensing a primer layer from a first side of the first memory die to a second side of the first memory die to form a primer layer, the first side being closer to the first trench than to the second trench; and filling a portion of the second trench with a primer material after filling a portion of the first trench with the primer layer. In one embodiment, the method further includes separating the first stacked die package structure and the second stacked die package structure by performing a dicing process along the dicing street region.

In some embodiments, a package structure is provided. The package structure includes a Through Substrate Via (TSV) structure formed over a substrate, and a first stacked die package structure over the TSV structure. The first stacked die package structure includes a plurality of memory dies. The package structure also includes an underfill layer over the first stacked die package structure, and the underfill layer includes a first protrusion extending below a top surface of the substrate via structure. The package structure includes a package layer over the underfill layer, and the package layer has a first protruding portion extending below a top surface of the substrate via structure. In one embodiment, the first stacked die package structure further includes: a plurality of bonding structures located between two adjacent memory dies; and a plurality of substrate via structures formed in each memory die, the substrate via structure of each memory die being electrically connected to the substrate via structure of the corresponding substrate. In one embodiment, the underfill layer includes a first portion over the first memory die and a second portion over the second memory die, and the first portion is spaced apart from the second portion. In one embodiment, the first trench has a ring-shaped structure or a U-shaped structure. In one embodiment, the underfill layer further includes a second protrusion extending below the top surface of the substrate via structure, the second protrusion being further away from the top surface of the substrate via structure than the first protrusion.

The foregoing outlines features of many embodiments so that those skilled in the art may better understand the aspects of the present embodiments. 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. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. Various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the embodiments of the invention as defined by the appended claims. Moreover, while the present invention has been described in terms of several preferred embodiments, it is not intended to be limited to the embodiments disclosed herein, and not all advantages have been described in detail.