Patent Publication Number: US-2022216159-A1

Title: Semiconductor package and manufacturing method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional application of and claims priority benefit of a prior application Ser. No. 16/009,208, filed on Jun. 15, 2018. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
    
    
     BACKGROUND 
     The semiconductor industry experiences rapid growth due to continuous improvements in the integration density of various electronic components (e.g., transistors, diodes, resistors, capacitors, etc.). This improvement in integration density comes from repeated reductions in minimum feature size, which allows more of the smaller components to be integrated into a given area. For these smaller electronic components, compact and smaller packages are needed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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. 
         FIG. 1A  to  FIG. 1Y  are schematic cross-sectional views illustrating various process steps for a manufacturing process of an integrated fan-out (InFO) package in accordance with some embodiments of the disclosure. 
         FIG. 2  is a top view illustrating the InFO package at the stage of  FIG. 1G . 
         FIG. 3  is a schematic cross-sectional view illustrating an electronic device including the InFO package in  FIG. 1Y . 
         FIG. 4  is a schematic cross-sectional view illustrating an InFO package in accordance with some alternative embodiments of the disclosure. 
         FIG. 5A  to  FIG. 5F  are schematic cross-sectional views illustrating various process steps for a manufacturing process of an InFO package in accordance with some alternative embodiments of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. 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 “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;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. 
       FIG. 1A  to  FIG. 1Y  are schematic cross-sectional views illustrating various process steps for a manufacturing process of an integrated fan-out (InFO) package  10  in accordance with some embodiments of the disclosure. Referring to  FIG. 1A , a carrier C having a de-bonding layer DB formed thereon is provided. In some embodiments, the carrier C is a glass substrate. However, other materials may be adapted as a material of the carrier C as long as the material is able to withstand the following manufacturing processes while supporting the elements formed thereon. In some embodiments, the de-bonding layer DB includes a light-to-heat conversion (LTHC) release layer. The de-bonding layer DB allows the structure subsequently formed on the carrier C in the following processes to be separated from the carrier C. 
     Referring to  FIG. 1A , a redistribution structure  100  is formed over the carrier C. In some embodiments, the redistribution structure  100  is formed on and attached to the de-bonding layer DB. In some embodiments, the redistribution structure  100  includes at least a redistribution conductive layer  102  and a dielectric layer  104 . In some embodiments, the redistribution conductive layer  102  may be constituted by a plurality of conductive redistribution patterns  103 . In certain embodiments, the dielectric layer  104  is illustrated as one single dielectric layer and the redistribution conductive layer  102  is embedded within the dielectric layer  104  with portions of the conductive redistribution patterns  103  are exposed by openings of the dielectric layer  104  in  FIG. 1A . Nevertheless, from the perspective of the manufacturing process, in some embodiments, the dielectric layer  104  may include two or more dielectric layers and the redistribution conductive layer  102  may include more than one conductive layers respectively sandwiched between the two most adjacent dielectric layers. In some embodiments, the material of the redistribution conductive layer  102  includes aluminum, titanium, copper, nickel, tungsten, and/or alloys thereof, respectively. The method of forming the redistribution conductive layer  102  may include, for example, electroplating process, deposition process, and/or photolithography and etching process. In some embodiments, the material of the dielectric layer  104  includes polyimide, epoxy resin, acrylic resin, phenol resin, benzocyclobutene (BCB), polybenzooxazole (PBO), or any other suitable polymer-based dielectric material. In some embodiments, the dielectric layer  104 , for example, may be formed by suitable fabrication techniques such as spin-on coating, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), or the like. 
     It should be noted that the number of the redistribution conductive layer  102  and the number of the dielectric layer  104  illustrated in  FIG. 1A  are merely for illustrative purposes, and the disclosure is not limited thereto. In some alternative embodiments, more layers of the redistribution conductive layer and more layers of the dielectric layer may be formed depending on the circuit design. When more layers of redistribution conductive layer and more layers of the dielectric layer are adapted, these redistribution conductive layers and these dielectric layers are stacked alternately, and the redistribution conductive layers may be interconnected with one another by redistribution conductive vias therebetween. In some embodiments, the redistribution structure  100  is referred to as a back-side redistribution structure. 
     Referring to  FIG. 1A , conductive structures  200  are formed on the redistribution structure  100 . In some embodiments, the InFO package  10  has an active region AR and a border region BR surrounding the active region AR. The conductive structures  200  may be formed, for example, in the active region AR. In some embodiments, the conductive structures  200  are conductive pillars formed following a photolithography process, a plating process, a photoresist stripping processes, and/or any other suitable processes. In some embodiments, the conductive structures  200  are formed on the exposed conductive redistribution patterns  103  and are in contact with the conductive redistribution patterns  103  to render electrical connection with the redistribution structure  100 . In some embodiments, the conductive structures  200  may be formed simultaneously on the redistribution structure  100 . For example, after forming the openings in the dielectric layer  104  exposing the conductive redistribution patterns  103 , a seed material layer (not shown) extending into the openings may be formed over the dielectric layer  104 . After forming a mask pattern (not shown) on the seed material layer with via openings to define the locations of the conductive structures  200 , the conductive structures  200  are formed by filling a conductive material into openings of the mask pattern and directly on the exposed conductive redistribution patterns  103  through a electroplating process or deposition process. Thereafter, the mask pattern and the seed layer underneath the mask pattern are removed. However, the disclosure is not limited thereto. Other suitable methods may be utilized to form the conductive structures  200 . 
     In some embodiments, the material of the conductive structures  200  includes aluminum, titanium, copper, nickel, tungsten, and/or alloys thereof. It should be noted that the arrangement and the number of the conductive structure  200  shown in  FIG. 1A  merely serves as an exemplary illustration, and the arrangement and the number of the conductive structure  200  may be varied based on demand. 
     Referring to  FIG. 1B , one or more dies  300  are provided on the redistribution structure  100 . In some embodiments, the dies  300  are placed in the active region AR, beside and between the conductive structures  200 . For example, the conductive structures  200  are arranged beside the dies  300  and surrounding the dies  300 . In some embodiments, the dies  300  are picked and placed onto the redistribution structure  100 . In some embodiments, one die  300 , for example, includes a semiconductor substrate  310 , a conductive pad  320 , a passivation layer  330 , a post passivation layer  340 , an via  350 , and a protection layer  360 . In some embodiments, the conductive pad  320  is disposed over the semiconductor substrate  310 . The passivation layer  330  is formed over the semiconductor substrate  310  and has a contact opening that partially expose the conductive pad  320 . The semiconductor substrate  310  may be a silicon substrate including active components (e.g., transistors or the like) and passive components (e.g., resistors, capacitors, inductors, or the like) formed therein. The conductive pad  320  may be an aluminum pad, a copper pad, or other suitable metal pad. The passivation layer  330  may be a silicon oxide layer, a silicon nitride layer, a silicon oxy-nitride layer, or a dielectric layer formed by other suitable dielectric materials. Furthermore, the post-passivation layer  340  is formed over the passivation layer  330 . The post-passivation layer  340  covers the passivation layer  330  and has a contact opening. The conductive pad  320  is partially exposed by the contact opening of the post passivation layer  340 . The post-passivation layer  340  may be a polyimide (PI) layer, a PBO layer, or a dielectric layer formed by other suitable polymers. In some embodiments, the post-passivation layer  340  may be optional. In addition, the via  350  is formed on the conductive pad  320 . In some embodiments, the via  350  is made of conductive materials and are plated on the conductive pad  320 . The protection layer  360  is formed on the post-passivation layer  340  to cover the via  350 . 
     As illustrated in  FIG. 1B , each die  300  has a rear surface  300   a  and a front surface  300   b  opposite to the rear surface  300   a . In some embodiments, the rear surfaces  300   a  of the dies  300  are attached (or adhered) to the redistribution structure  100  through an adhesive layer AD. In some embodiments, the adhesive layer AD may include a die attach film (DAF). On the other hand, the front surfaces  300   b  of the dies  300  face upward in  FIG. 1B . As illustrated in  FIG. 1B , top surfaces (front surface  300   b ) of the dies  300  are substantially coplanar with top surfaces of the conductive structures  200 . However, the disclosure is not limited thereto. In some alternative embodiments, the top surfaces (front surface  300   b ) of the dies  300  may be located at a level height lower than or higher than the top surfaces of the conductive structures  200  along the direction perpendicular to the front surface  300   b  of the dies  300 . Although two dies  300  are shown in  FIG. 1B , the configuration merely serves as an exemplary illustration. In some alternative embodiments, more or less number of dies may be formed based on demand. It should be noted that the number of the conductive pad  320  and the number of the via  350  in each die  300  shown in  FIG. 1B  merely serves as an exemplary illustration, and the number of the conductive pad  320  and the number of the via  350  in each die  300  may be varied based on demand. 
     Referring to  FIG. 1C , an encapsulation material  400   a  is formed over the redistribution structure  100  to encapsulate the conductive structures  200  and the dies  300 . For example, the conductive structures  200  and the dies  300  are fully encapsulated by the encapsulation material  400   a , without exposing the conductive structures  200  and the protection layers  360  of the dies  300 . In some embodiments, the encapsulation material  400   a  is a molding compound, a molding underfill, a resin (such as epoxy), or the like. The encapsulation material  400   a  may be formed by a molding process. For example, the encapsulation material  400   a  may be formed by a compression molding process. 
     Referring to  FIG. 1C  and  FIG. 1D , the encapsulation material  400   a  and the protection layers  360  of the dies  300  are grinded until top surfaces of the vias  350  of the dies  300  are exposed. After the encapsulation material  400   a  is grinded, an encapsulant  400  is formed over the redistribution structure  100  to encapsulate the conductive structures  200  and the dies  300 . In some embodiments, the encapsulant material  400   a  is grinded by a mechanical grinding process and/or a chemical mechanical polishing (CMP) process. In some embodiments, during the grinding process of the encapsulant material  400   a , the protection layers  360  are grinded to reveal the vias  350 . In some embodiments, portions of the vias  350  and portions of the conductive structures  200  are slightly grinded as well. After grinding, each die  300  has an active surface  300   c  opposite to the rear surface  300   a . The exposed portion of the vias  350  is located on the active surfaces  300   c  of the dies  300 . It is noted that the top surfaces of the conductive structures  200 , the top surfaces of the protection layers  360 , and the top surfaces of the vias  350  are substantially coplanar with a top surface of the encapsulant  400 . 
     Referring to  FIG. 1E , a seed material layer  510  is formed on the encapsulant  400 , the conductive structures  200 , and the dies  300 . In some embodiments, the seed material layer  510  is blanketly formed over the encapsulant  400 , the conductive structures  200 , and the dies  300 . For example, the seed material layer  510  is formed to locate in both of the active region AR and the border region BR. In some embodiments, the seed material layer  510  is formed to be in direct contact with the conductive structures  200 , the encapsulant  400 , the protection layers  360  of the dies  300 , and the vias  350  of the dies  300 . The seed material layer  510  may be formed through, for example, a sputtering process, a physical vapor deposition (PVD) process, or the like. In some embodiments, the seed material layer  510  may include, for example, copper, titanium-copper alloy, or other suitable choice of materials. 
     Referring to  FIG. 1E  again, a photoresist layer PR 1  is formed over the seed material layer  510 . In some embodiments, the photoresist layer PR 1  may be formed through spin-coating or other suitable formation methods. As illustrated in  FIG. 1E , the photoresist layer PR 1  has a plurality of openings OP 1  exposing at least a portion of the seed material layer  510  in the active region AR and the border region BR. In some embodiments, the size of the openings OP 1  in the border region BR may be same as the size of the openings OP 1  in the active region AR. However, the disclosure is not limited thereto. In some alternative embodiments, the size of the openings OP 1  in the border region BR may be different from the size of the openings OP 1  in the active region AR. For example, the size of the openings OP 1  in the border region BR may be larger the size of the openings OP 1  in the active region AR. In some embodiments, the openings OP 1  in the active region AR correspond to the locations of the vias  350  of the dies  300 . For example, a vertical projection of the openings OP 1  in the active region AR along a direction perpendicular to the active surface  300   c  of the dies  300  overlaps with the vias  350  of the dies  300 . 
     Referring to  FIG. 1E  and  FIG. 1F , a plurality of conductive patterns  520   a , a plurality of conductive patterns  520   b  are formed on the seed material layer  510 . In some embodiments, the openings OP 1  of the photoresist layer PR 1  in the active region AR and the border region BR are filled up with a conductive material (not shown). Thereafter, the photoresist layer PR 1  is removed to obtain the conductive patterns  520   a ,  520   b . Upon removal of the photoresist layer PR 1 , portions of the seed material layer  510 , which are not covered by the conductive patterns  520   a ,  520   b , are exposed. In some embodiments, the conductive material may be formed by a plating process. The plating process is, for example, electro-plating process, electroless-plating process, immersion plating process, or the like. In some embodiments, the conductive material includes, for example, copper, copper alloys, or the like. The photoresist pattern layer PR 1  may be removed/stripped through, for example, etching, ashing, or other suitable removal processes. In some embodiments, the conductive patterns  520   a  are located in the active region AR and the conductive patterns  520   b  are located in the border region BR. 
     Referring to  FIG. 1F  and  FIG. 1G , portions of the seed material layer  510  that are not covered by the conductive patterns  520   a ,  520   b  are removed to render seed layers  510   a ,  510   b . That is, the seed material layer  510  underneath the photoresist layer PR 1  as shown in  FIG. 1E  is removed. The exposed portions of the seed material layer  510  may be removed through an etching process. In some embodiments, the material of the conductive patterns  520   a ,  520   b  may be different from the material of the seed material layer  510 , so the exposed portion of the seed material layer  510  may be removed through selective etching. The seed layer  510   a  is located in the active region AR and the seed layer  510   b  is located in the border region BR. In some embodiments, the seed layer  510   a  is sandwiched between the vias  350  and the conductive patterns  520   a . In some embodiments, the seed layer  510   b  is sandwiched between the encapsulant  400  and the conductive patterns  520   b.    
     In some embodiments, the conductive patterns  520   a  and the seed layer  510   a  located in the active region AR are collectively referred to as first conductive vias CV 1 , and the conductive patterns  520   b  and the seed layer  510   b  located in the border region BR may be collectively referred to as a first seal ring element SE 1 . In some embodiments, the first conductive vias CV 1  are located in the active region AR and is located in the border region BR. The first conductive vias CV 1  are physically in contact with the dies  300 . For example, the seed layer  510   a  of the first conductive vias CV 1  may be directly in contact with the vias  350  of the dies  300 . The first seal ring element SE 1  is physically in contact with the encapsulant  400 . For example, the seed layer  510   b  of the first seal ring element SE 1  may be directly in contact with the encapsulant  400 . The first conductive vias CV 1  may electrically connect the vias  350  of the dies  300  with other subsequently formed elements. In some embodiments, the first seal ring element SE 1  is electrically floating. For example, the first seal ring element SE 1  is electrically insulated from the first conductive vias CV 1 , the conductive structures  200 , the vias  350  of the dies  300 , and the redistribution structure  100 . 
     The first seal ring element SE 1  shown in  FIG. 1G  is part of a subsequently formed seal ring structure SR (in  FIG. 1U ). In some embodiments, the contour of the first seal ring element SE 1  (and the seal ring structure SR) may be in a loop pattern, referring to  FIG. 2  which is a top view illustrating the InFO package  10  at the stage of  FIG. 1G , and in which some elements are omitted for clearly illustrating the disposition relationship between the first seal ring element SE 1  and the dies  300 . From the top plan view, the shape of the first seal ring element SE 1  may be an octagonal ring shape. However, the disclosure is not limited thereto. In some alternative embodiments, the shape of the first seal ring element SE 1  may be a circle, any other suitable polygon, or any other suitable shape from a top plan view. In addition, in some alternative embodiments, the first seal ring element SE 1  is not a closed loop, but may have openings therein. In some embodiments, the first seal ring element SE 1  surrounds the active region AR. As mentioned above, since the first seal ring element SE 1  is formed by filling the conductive material into the openings OP 1  in the border region BR, the openings OP 1  in the border region BR are parts of a loop opening which may have shape corresponding to the contour of the first seal ring element SE 1 . 
     In some embodiments, from the cross-sectional view, the top dimension TD SE1  of the first seal ring element SE 1  is substantially equal to the bottom dimension BD SE1  of the first seal ring element SE 1 . However, the disclosure is not limited thereto. In some alternative embodiments, from the cross-sectional view, the top dimension TD SE1  of the first seal ring element SE 1  is smaller than the bottom dimension BD SE1  of the first seal ring element SE 1 , as shown in the schematic cross-sectional view on the left side of  FIG. 1G . As mentioned above, since the first seal ring element SE 1  is formed by filling the conductive material into the openings OP 1  in the border region BR, an included angle may be formed between the sidewalls of the openings OP 1  and a virtual line extending along the direction perpendicular to the front surface  300   c  of the dies  300 . 
     In some embodiments, from the cross-sectional view, the top dimension TD CV1  of each first conductive via CV 1  is substantially equal to the bottom dimension BD CV1  of each first conductive via CV 1 . However, the disclosure is not limited thereto. In some alternative embodiments, the top dimension TD CV1  of each first conductive via CV 1  is smaller than the bottom dimension BD CV1  of each first conductive via CV 1 , as shown in the schematic cross-sectional view on the left side of  FIG. 1G . In some embodiments, from the cross-sectional view, the top dimension TD CV1  and the bottom dimension BD CV1  of each first conductive via CV 1  are in the range of approximately 0.8 μm to 5 μm, respectively. Besides, in some embodiments, the contour of each first conductive via CV 1  may be cylinder. However, the disclosure is not limited thereto. In some alternative embodiments, the contour of each first conductive via CV 1  may be polygonal cylinder, such as square cylinder, pentagonal cylinder, or hexagonal cylinder. In the case that the contour of each first conductive via CV 1  is cylinder, then the top dimension TD CV1  and the bottom dimension BD CV1  may be the diameter. In the case that the contour of each first conductive via CV 1  is polygonal cylinder, then the top dimension TD CV1  and the bottom dimension BD CV1  may be the maximum dimension. As mentioned above, since the first conductive vias CV 1  are formed by filling the conductive material into the openings OP 1  in the active region AR, each opening OP 1  in the active region AR may have shape corresponding to the contour of each first conductive via CV 1 . 
     Referring to  FIG. 1H , a first dielectric material layer  530   a  is formed over the encapsulant  400 , the conductive structures  200 , and the dies  300  to encapsulate the first conductive vias CV 1  and the first seal ring element SE 1 . In other words, the first conductive vias CV 1  and the first seal ring element SE 1  are not revealed and are well protected by the first dielectric material layer  530   a . In some embodiments, the material of the first dielectric material layer  530   a  includes polyimide, epoxy resin, acrylic resin, phenol resin, BCB, PBO, or any other suitable polymer-based dielectric material. The first dielectric material layer  530   a  may be formed by suitable fabrication techniques, such as spin-on coating, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), or the like. 
     Referring to  FIG. 1H  and  FIG. 1I , the first dielectric material layer  530   a  is partially removed by performing a planarization process to form a first dielectric layer  530  exposing the top surfaces T CV1  of the first conductive vias CV 1  and the top surface T SE1  of the first seal ring element SE 1 . For example, the first dielectric material layer  530   a  may be planarized/grinded until the top surfaces T CV1  of the first conductive vias CV 1  and the top surface T SE1  of the first seal ring element SE 1  are exposed. In some embodiments, the first dielectric material layer  530   a  is planarized/grinded by a chemical mechanical polishing (CMP) process. In some embodiments, the degree of planarization (DOP) for the first dielectric layer  530  is in a range of approximately 90% to 100%. In some embodiments, the uniformity of the first dielectric layer  530  is in a range of approximately 10% to 25%. 
     In some embodiments, the first dielectric material layer  530   a  is planarized/grinded such that the top surface T 530  of the first dielectric layer  530  is substantially coplanar with the top surfaces T CV1  of the first conductive vias CV 1  and the top surface T SE1  of the first seal ring element SE 1 . That is, the first dielectric layer  530  has a thickness substantially equivalent to those of the first conductive vias CV 1  and the first seal ring element SE 1 . For example, in some embodiments, the first dielectric layer  530 , the first conductive vias CV 1 , and the first seal ring element SE 1  may have substantially the same thickness of 2 μm to 10 μm. In some alternative embodiments, due to grinding selectivity between different materials, a thickness difference in the thickness direction parallel to the direction perpendicular to the active surface  300   c  of the dies  300  may be seen between the first dielectric layer  530  and the first conductive vias CV 1  and between the first dielectric layer  530  and the first seal ring element SE 1 . However, since the first dielectric layer  530  is formed by the planarization process, the thickness difference is negligible. 
     In some embodiments, the first dielectric layer  530  wraps around the first conductive vias CV 1  and the first seal ring element SE 1 . In detail, in some embodiments, the first conductive vias CV 1  and the first seal ring element SE 1  are embedded in the first dielectric layer  530 . 
     Referring to  FIG. 1J , the first dielectric layer  530  is recessed by performing a plasma process to form the recessed first dielectric layer  530   r . As described above, the first dielectric layer  530 , the first conductive vias CV 1 , and the first seal ring element SE 1  may have substantially the same thickness, therefore after the first dielectric layer  530  is recessed by the plasma process, the first conductive vias CV 1  and the first seal ring element SE 1  protrude from the top surface T 530r  of the recessed first dielectric layer  530   r  along the direction perpendicular to the active surface  300   c  of the dies  300 . In other words, the thickness of the recessed first dielectric layer  530   r  is smaller than the thickness of the first conductive vias CV 1  and the thickness of the first seal ring element SE 1 . In some embodiments, the plasma process is, for example, an oxide plasma process. 
     In some embodiments, the recessed first dielectric layer  530   r  wraps around the first conductive vias CV 1  and the first seal ring element SE 1 . In detail, in some embodiments, the first conductive vias CV 1  and the first seal ring element SE 1  are partially embedded in the recessed first dielectric layer  530   r , and the recessed first dielectric layer  530   r  partially wraps around sidewalls of the first conductive vias CV 1  and the first seal ring element SE 1 . 
     In some embodiments, the thickness of the first dielectric layer  530  removed by the plasma process is accounted for approximately 5% to 20% thickness of the first dielectric layer  530 . In other words, in some embodiments, a thickness difference T 1  in the thickness direction between the thickness of the recessed first dielectric layer  530   r  and the thickness of each first conductive vias CV 1  is accounted for approximately 5% to 20% thickness of the first dielectric layer  530 , and a thickness difference T 2  between the thickness of the recessed first dielectric layer  530   r  and the thickness of the first seal ring element SE 1  is accounted for approximately 5% to 20% thickness of the first dielectric layer  530 . For example, the thickness difference T 1  is between 0.1 μm and 0.3 μm. Similarly, the thickness difference T 2  is between 0.1 μm and 0.3 μm, for example. 
     In some embodiments, since a distance along the direction perpendicular to the active surface  300   c  of the dies  300  (the thickness difference T 1 ) is between the top surface T 530r  of the recessed first dielectric layer  530   r  and the top surface T CV1  of each first conductive via CV 1 , the top surface T 530r  of the recessed first dielectric layer  530   r  is lower than the top surfaces T CV1  of the first conductive vias CV 1 . Similarly, in some embodiments, since a distance along the direction perpendicular to the active surface  300   c  of the dies  300  (the thickness difference T 2 ) is between the top surface T 530r  of the recessed first dielectric layer  530   r  and the top surface T SE1  of the first seal ring element SE 1 , the top surface T 530r  of the recessed first dielectric layer  530   r  is lower than the top surface T SE1  of the first seal ring element SE 1 . 
     In some embodiments, the first conductive vias CV 1 , the first seal ring element SE 1 , and the recessed first dielectric layer  530   r  may constitute a first sub-layer of a subsequently formed redistribution structure  500  (shown in  FIG. 1U ). As illustrated in  FIG. 1J , the first sub-layer is formed over the encapsulant  400 , the dies  300 , and the conductive structures  200 . 
     In some embodiments, the DOP for the recessed first dielectric layer  530   r  is in a range of approximately 90% to 100%. In some embodiments, the uniformity of the recessed first dielectric layer  530   r  is in a range of approximately 10% to 25%. As such, good topography of the first sub-layer constituted by the first conductive vias CV 1 , the first seal ring element SE 1 , and the recessed first dielectric layer  530   r  may be provided, thereby the subsequently formed elements may be accurately formed on the designated location and may be formed with the designated dimension, thereby enhancing the reliability of the InFO package  10 . 
     In some embodiments, from the cross-sectional view, the angle θ 1  of each top corner of each first conductive via CV 1  is approximately 90 degrees. However, the disclosure is not limited thereto. In some alternative embodiments, from the cross-sectional view, each top corner of each first conductive via CV 1  is rounded due to the plasma process in the range of approximately 0.5 to 0.7 π rad (larger than 90 degrees to 120 degrees), as shown in the schematic cross-sectional view on the left side of  FIG. 1J . In some embodiments, from the cross-sectional view, the angle θ 2  of each top corner of the first seal ring element SE 1  is approximately 90 degrees. However, the disclosure is not limited thereto. In some alternative embodiments, from the cross-sectional view, each top corner of the first seal ring element SE 1  is rounded due to the plasma process in the range of approximately 0.5 to 0.7 π rad (larger than 90 degrees to 120 degrees), as shown in the schematic cross-sectional view on the left side of  FIG. 1J . 
     Referring to  FIG. 1K , a seed material layer  512  is formed over the first sub-layer. The seed material layer  512  may be similar to the seed material layer  510 , so the detailed descriptions thereof are omitted herein. In some embodiments, the seed material layer  512  is blanketly formed to be in direct contact with the recessed first dielectric layer  530   r , the first conductive vias CV 1 , and the first seal ring element SE 1 . The seed material layer  512  is formed to locate in both of the active region AR and the border region BR. 
     A photoresist layer PR 2  is formed over the seed material layer  512 . In some embodiments, the photoresist layer PR 2  may be formed through spin-coating or other suitable formation methods. As illustrated in  FIG. 1K , the photoresist layer PR 2  has a plurality of openings OP 2  exposing at least a portion of the seed material layer  512  in the active region AR and the border region BR. In some embodiments, the openings OP 2  in the active region AR correspond to the locations of the first conductive vias CV 1 . For example, a vertical projection of the openings OP 2  in the active region AR along the direction perpendicular to the active surface  300   c  of the dies  300  overlaps with the first conductive vias CV 1 . On the other hand, the openings OP 2  in the border region BR correspond to the location of the first seal ring element SE 1 . For example, a vertical projection of the openings OP 2  in the border region BR along the direction perpendicular to the active surface  300   c  of the dies  300  overlaps with the first seal ring element SE 1 . 
     Referring to  FIG. 1K  and  FIG. 1L , a plurality of conductive patterns  540   a , a plurality of conductive patterns  540   b  are formed on the seed material layer  512 . In some embodiments, the openings OP 2  of the photoresist layer PR 2  in the active region AR and the border region BR are filled up with a conductive material (not shown). Thereafter, the photoresist layer PR 2  is removed to obtain the conductive patterns  540   a ,  540   b . Upon removal of the photoresist layer PR 2 , portions of the seed material layer  512 , which are not covered by the conductive patterns  540   a ,  540   b , are exposed. In some embodiments, the conductive material may be formed by a plating process. The plating process is, for example, electro-plating process, electroless-plating process, immersion plating process, or the like. In some embodiments, the conductive material includes, for example, copper, copper alloys, or the like. The photoresist pattern layer PR 2  may be removed/stripped through, for example, etching, ashing, or other suitable removal processes. In some embodiments, the conductive patterns  540   a  are located in the active region AR and the conductive patterns  540   b  are located in the border region BR. 
     Referring to  FIG. 1M , a photoresist layer PR 3  is formed over the seed material layer  512  and the conductive patterns  540   a ,  540   b . In some embodiments, the photoresist layer PR 3  may be formed through spin-coating or other suitable formation methods. As illustrated in  FIG. 1M , the photoresist layer PR 3  has a plurality of openings OP 3  exposing at least a portion of the conductive patterns  540   a ,  540   b . In some embodiments, the size of the openings OP 3  in the border region BR may be same as the size of the openings OP 3  in the active region AR. However, the disclosure is not limited thereto. In some alternative embodiments, the size of the openings OP 3  in the border region BR may be different from the size of the openings OP 3  in the active region AR. For example, the size of the openings OP 3  in the border region BR may be larger the size of the openings OP 3  in the active region AR. 
     In some embodiments, the openings OP 3  in the active region AR correspond to the locations of the conductive patterns  540   a . For example, a vertical projection of the openings OP 3  in the active region AR along the direction perpendicular to the active surface  300   c  of the dies  300  overlaps with the conductive patterns  540   a . On the other hand, the openings OP 3  in the active region AR do not correspond to the locations of the first conductive vias CV 1 . For example, a vertical projection of the openings OP 3  in the active region AR along the direction perpendicular to the active surface  300   c  of the dies  300  does not overlap with the first conductive vias CV 1 . However, the disclosure is not limited thereto. In some alternative embodiments, the openings OP 3  in the active region AR correspond to the locations of the first conductive vias CV 1 . For example, a vertical projection of the openings OP 3  in the active region AR along the direction perpendicular to the active surface  300   c  of the dies  300  overlaps with the first conductive vias CV 1 . 
     In some embodiments, the openings OP 3  in the border region BR correspond to the locations of the conductive patterns  540   b . For example, a vertical projection of the openings OP 3  in the border region BR along the direction perpendicular to the active surface  300   c  of the dies  300  overlaps with the conductive patterns  540   b . On the other hand, the openings OP 3  in the border region BR do not correspond to the location of the first seal ring element SE 1 . For example, a vertical projection of the openings OP 3  in the border region BR along the direction perpendicular to the active surface  300   c  of the dies  300  does not overlap with the first seal ring element SE 1 . However, the disclosure is not limited thereto. In some alternative embodiments, the openings OP 3  in the border region BR correspond to the location of the first seal ring element SE 1 . For example, a vertical projection of the openings OP 3  in the border region BR along the direction perpendicular to the active surface  300   c  of the dies  300  overlaps with the first seal ring element SE 1 . 
     Referring to  FIG. 1M  and  FIG. 1N , a plurality of conductive patterns  522   a  and a plurality of conductive patterns  522   b  are respectively formed on the conductive patterns  540   a  and the conductive patterns  540   b . In some embodiments, the openings OP 3  of the photoresist layer PR 3  in the active region AR and the border region BR are filled up with a conductive material (not shown). Thereafter, the photoresist layer PR 3  is removed to obtain the conductive patterns  522   a ,  522   b . In some embodiments, the conductive material may be formed by a plating process. The plating process is, for example, electro-plating process, electroless-plating process, immersion plating process, or the like. In some embodiments, the conductive material includes, for example, copper, copper alloys, or the like. In some embodiments, the plating process of the conductive patterns  522   a ,  522   b  shares the same seed material layer  512  with the plating process of the conductive patterns  540   a ,  540   b . That is, the seed material layer  512  may be utilized for plating for both of the conductive patterns  540   a ,  540   b  and the conductive patterns  522   a ,  522   b . As a result, the conductive patterns  522   a  are physically in contact with the conductive patterns  540   a , and the conductive patterns  522   b  are physically in contact with the conductive patterns  540   b . In detail, the conductive patterns  522   a  are directly in contact with the conductive patterns  540   a , and the conductive patterns  522   b  are directly in contact with the conductive patterns  540   b . The photoresist pattern layer PR 3  may be removed/stripped through, for example, etching, ashing, or other suitable removal processes. In some embodiments, the conductive patterns  522   a  are located in the active region AR and the conductive patterns  522   b  are located in the border region BR. 
     Referring to  FIG. 1N  and  FIG. 1O , portions of the seed material layer  512  that are not covered by the conductive patterns  540   a ,  540   b  are removed to render seed layers  512   a ,  512   b . The seed layer  512   a  is located in the active region AR and the seed layer  512   b  is located in the border region BR. In some embodiments, the seed layer  512   a  is sandwiched between the first conductive vias CV 1  and the conductive patterns  540   a . On the other hand, the seed layer  512   b  is sandwiched between the first seal ring element SE 1  and the conductive patterns  540   b . Moreover, the conductive patterns  540   a  is sandwiched between the conductive patterns  522   a  and the seed layer  512   a , and the conductive patterns  540   b  is sandwiched between the conductive patterns  522   b  and the seed layer  512   b . The exposed portions of the seed material layer  512  may be removed through an etching process. In some embodiments, the material of the conductive patterns  522   a ,  522   b ,  540   a ,  540   b  may be different from the material of the seed material layer  512 , so the exposed portion of the seed material layer  512  may be removed through selective etching. 
     In some embodiments, the conductive patterns  540   a  and the seed layer  512   a  located in the active region AR are collectively referred to as first routing patterns RP 1 . In some embodiments, the conductive patterns  522   a  located in the active region AR may be referred to as a second conductive vias CV 2 . That is, in some embodiments, the second conductive vias CV 2  are free of seed layer, and no seed layer exists between the conductive patterns  522   a  and the conductive patterns  540   a . In some embodiments, the conductive patterns  540   b  and the seed layer  512   b  located in the border region BR are collectively referred to as a second seal ring element SE 2 . In some embodiments, the conductive patterns  522   b  located in the border region BR may be referred to as a third seal ring element SE 3 . That is, in some embodiments, the third seal ring element SE 3  is free of seed layer, and no seed layer exists between the conductive patterns  522   b  and the conductive patterns  540   b . In some embodiments, the second conductive vias CV 2  are disposed on the first routing patterns RP 1 . In some embodiments, the first routing patterns RP 1  are sandwiched between the first conductive vias CV 1  and the second conductive vias CV 2 . In some embodiments, the third seal ring element SE 3  is disposed on second seal ring element SE 2 . In some embodiments, the second seal ring element SE 2  connects with the first seal ring element SE 1 . In some embodiments, the second seal ring element SE 2  is sandwiched between the first seal ring element SE 1  and the third seal ring element SE 3 . 
     The first routing patterns RP 1  may include routing traces for signal transmission along the horizontal plane. The second conductive vias CV 2  may electrically connect the first routing patterns RP 1  with other subsequently formed elements. In some embodiments, the second seal ring element SE 2  and the third seal ring element SE 3  are electrically floating. For example, the second seal ring element SE 2  and the third seal ring element SE 3  are electrically insulated from the first routing patterns RP 1 , the second conductive vias CV 2 , the first conductive vias CV 1 , the conductive structures  200 , the vias  350  of the dies  300 , and the redistribution structure  100 . 
     In some embodiments, the first routing patterns RP 1  are in physical contact with the first conductive vias CV 1  and the recessed first dielectric layer  530   r . For example, the seed layer  512   a  of the first routing patterns RP 1  may be directly in contact with the first conductive vias CV 1  and the recessed first dielectric layer  530   r . In some embodiments, the second seal ring element SE 2  is in physical contact with the first seal ring element SE 1  and the recessed first dielectric layer  530   r . For example, the seed layer  512   b  of the second seal ring element SE 2  may be directly in contact with the first seal ring element SE 1  and the recessed first dielectric layer  530   r.    
     As mentioned above, since the second conductive vias CV 2  are formed by filling the conductive material into the openings OP 3  in the active region AR, the locations of the second conductive vias CV 2  correspond to the locations of the opening OP 3  in the active region AR. For example, in some embodiments, a vertical projection of the second conductive vias CV 2  along the direction perpendicular to the active surface  300   c  of the dies  300  does not overlap with the first conductive vias CV 1 . For another example, in some embodiments, a vertical projection of the second conductive vias CV 2  along the direction perpendicular to the active surface  300   c  of the dies  300  overlaps with the first conductive vias CV 1 . Similarly, as mentioned above, since the third seal ring element SE 3  is formed by filling the conductive material into the openings OP 3  in the border region BR, the location of the third seal ring element SE 3  correspond to the locations of the opening OP 3  in the border region BR. For example, in some embodiments, a vertical projection of the third seal ring element SE 3  along the direction perpendicular to the active surface  300   c  of the dies  300  does not overlap with the first seal ring element SE 1 . For another example, in some embodiments, a vertical projection of the third seal ring element SE 3  along the direction perpendicular to the active surface  300   c  of the dies  300  overlaps with the first seal ring element SE 1 . 
     In some embodiments, each of the first routing patterns RP 1  has a protrusion P 1  due to the underlying first conductive vias CV 1 . As mentioned above, the first conductive vias CV 1  protrude out of the recessed first dielectric layer  530   r  along the direction perpendicular to the active surface  300   c  of the dies  300 , therefore a portion of the seed layer  512   a  located directly on the top surfaces T CV1  of the first conductive vias CV 1  protrudes form the rest of the seed layer  512   a  located directly the top surface T 530r  of the recessed first dielectric layer  530   r . That is, in some embodiments, a portion of the seed layer  512   a  located directly on the top surfaces T CV1  of the first conductive vias CV 1  is higher than the rest of the seed layer  512   a  located directly on the top surface T 530r  of the recessed first dielectric layer  530   r . Accordingly, after the conductive patterns  540   a  disposed on the seed layer  512   a  are formed, the protrusions P 1  are created correspond to the locations of the first conductive vias CV 1 . That is, in some embodiments, a portion of each conductive pattern  540   a  may be slightly raised with respect to the rest portion of each conductive pattern  540   a . In some embodiments, the protrusion angle θ 3  of each protrusion P 1  with respect to a virtual line extending along a direction parallel to the active surface  300   c  of the dies  300  may be in the range of approximately 5 degrees to 20 degrees. Herein, the protrusion angle θ 3  of each protrusion P 1  is defined as an included angle between the tangent line of the protruding portion of each conductive pattern  540   a  (the protrusion P 1 ) initially protrudes from the rest portion of each conductive pattern  540   a  and the virtual line extending along a direction parallel to the active surface  300   c  of the dies  300 . In some embodiments, the protruding portion of each conductive pattern  540   a  (the protrusion P 1 ) may be raised of approximately 0.1 μm up to 0.3 μm with respect to the rest portion of each conductive pattern  540   a.    
     In some embodiments, from the cross-sectional view, the top dimension TD CV2  of each second conductive via CV 2  is substantially equal to the bottom dimension BD CV2  of each second conductive via CV 2 . However, the disclosure is not limited thereto. In some alternative embodiments, the top dimension TD CV2  of each second conductive via CV 2  is smaller than the bottom dimension BD CV2  of each second conductive via CV 2 . The contour or structure of the second conductive vias CV 2  may be similar to the first conductive vias CV 1 , so some detailed descriptions of the second conductive vias CV 2  are referred to the foregoing embodiments of the first conductive vias CV 1  and are omitted herein omitted herein. 
     The second seal ring element SE 2  is part of the subsequently formed seal ring structure SR (shown in  FIG. 1U ). Therefore, in some embodiments, the contour or structure of the second seal ring element SE 2  may be similar to the first seal ring element SE 1 , and some detailed descriptions of the second seal ring element SE 2  are referred to the foregoing embodiments of the first seal ring element SE 1  and are omitted herein omitted herein. In some embodiments, the second seal ring element SE 2  has a protrusion P 2  due to the underlying first seal ring element SE 1 . As mentioned above, the first seal ring element SE 1  protrudes out of the recessed first dielectric layer  530   r  along the direction perpendicular to the active surface  300   c  of the dies  300 , therefore a portion of the seed layer  512   b  located directly on the top surface T SE1  of the first seal ring element SE 1  protrudes form the rest of the seed layer  512   b  located directly on the top surface T 530r  of the recessed first dielectric layer  530   r . That is, in some embodiments, a portion of the seed layer  512   b  located directly on the top surface T SE1  of the first seal ring element SE 1  is higher than the rest of the seed layer  512   b  located directly on the top surface T 530r  of the recessed first dielectric layer  530   r . Accordingly, after the conductive patterns  540   b  disposed on the seed layer  512   b  are formed, the protrusion P 2  is created correspond to the location of the first seal ring element SE 1 . That is, in some embodiments, a portion of each conductive pattern  540   b  may be slightly raised with respect to the rest portion of each conductive pattern  540   b . In some embodiments, the protrusion angle θ 4  of the protrusion P 2  with respect to a virtual line extending along a direction parallel to the active surface  300   c  of the dies  300  may be in the range of approximately 5 degrees to 20 degrees. Herein, the definition of the protrusion angle θ 4  of the protrusion P 2  is similar to the protrusion angle θ 3  of the protrusion P 1 , so the definition of the protrusion angle θ 4  is referred to the foregoing definition of the protrusion angle θ 3  and is omitted herein omitted herein. In some embodiments, the protruding portion of each conductive pattern  540   b  (the protrusion P 2 ) may be raised of approximately 0.1 μm up to 0.3 μm with respect to the rest portion of each conductive pattern  540   b.    
     The third seal ring element SE 3  is part of the subsequently formed seal ring structure SR (shown in  FIG. 1U ). Therefore, in some embodiments, the contour or structure of the third seal ring element SE 3  may be similar to the first seal ring element SE 1 , and some detailed descriptions of the third seal ring element SE 3  are referred to the foregoing embodiments of the first seal ring element SE 1  and are omitted herein omitted herein. 
     Referring to  FIG. 1P , a second dielectric material layer  532   a  is formed over the recessed first dielectric layer  530   r  to encapsulate the first routing patterns RP 1 , the second conductive vias CV 2 , the second seal ring element SE 2  and the third seal ring element SE 3 . In other words, the first routing patterns RP 1 , the second conductive vias CV 2 , the second seal ring element SE 2  and the third seal ring element SE 3  are not revealed and are well protected by the second dielectric material layer  532   a . The second dielectric material layer  532   a  may be similar to the first dielectric material layer  530   a , so the detailed descriptions thereof are omitted herein. 
     Referring to  FIG. 1P  and  FIG. 1Q , the second dielectric material layer  532   a  is partially removed by performing a planarization process to form a second dielectric layer  532  exposing the top surfaces T CV2  of the second conductive vias CV 2  and the top surface T SE3  of the third seal ring element SE 3 . For example, the second dielectric material layer  532   a  may be planarized/grinded until the top surfaces T CV2  of the second conductive vias CV 2  and the top surface T SE3  of the third seal ring element SE 3  are exposed. In some embodiments, the second dielectric material layer  532   a  is planarized/grinded by a chemical mechanical polishing (CMP) process. As illustrated in  FIG. 1Q , the second dielectric layer  532  is stacked over the recessed first dielectric layer  530   r . In some embodiments, the DOP for the second dielectric layer  532  is in a range of approximately 90% to 100%. In some embodiments, the uniformity of the second dielectric layer  532  is in a range of approximately 10% to 25%. 
     In some embodiments, the second dielectric material layer  532   a  is planarized/grinded such that the top surface T 532  of the second dielectric layer  532  is substantially coplanar with the top surfaces T CV2  of the second conductive vias CV 2  and the top surface T SE3  of the third seal ring element SE 3 . In some alternative embodiments, due to grinding selectivity between different materials, a height difference along the direction perpendicular to the active surface  300   c  of the dies  300  may be seen between the top surface T 532  of the second dielectric layer  532  and the top surfaces T CV2  of the second conductive vias CV 2  and between the top surface T 532  of the second dielectric layer  532  and the top surface T SE3  of the third seal ring element SE 3 . However, since the second dielectric layer  532  is formed by the planarization process, the height difference is negligible. 
     The second dielectric layer  532  wraps around the first routing patterns RP 1 , the second conductive vias CV 2 , the second seal ring element SE 2  and the third seal ring element SE 3 . In detail, the first routing patterns RP 1 , the second conductive vias CV 2 , the second seal ring element SE 2  and the third seal ring element SE 3  are embedded in the second dielectric layer  532 . 
     Referring to  FIG. 1R , the second dielectric layer  532  is recessed by performing a plasma process to form the recessed second dielectric layer  532   r . As described above, the top surface T 532  of the second dielectric layer  532  is substantially coplanar with the top surfaces T CV2  of the second conductive vias CV 2  and the top surface T SE3  of the third seal ring element SE 3 , therefore after the second dielectric layer  532  is recessed by the plasma process, the second conductive vias CV 2  and the third seal ring element SE 3  protrude from the top surface T 532r  of the recessed second dielectric layer  532   r  along the direction perpendicular to the active surface  300   c  of the dies  300 . In other words, the second dielectric layer  532  is thinned to have the second conductive vias CV 2  and the third seal ring element SE 3  protruding from the top surface T 532r  of the recessed second dielectric layer  532   r . In some embodiments, the recessed second dielectric layer  532   r  wraps around the first routing patterns RP 1 , the second conductive vias CV 2 , the second seal ring element SE 2  and the third seal ring element SE 3 . In detail, in some embodiments, the first routing patterns RP 1  and the second seal ring element SE 2  are embedded in the recessed second dielectric layer  532   r , while the second conductive vias CV 2  and the third seal ring element SE 3  are partially embedded in the recessed second dielectric layer  532   r . In other words, the recessed second dielectric layer  532   r  partially wraps around sidewalls of the second conductive vias CV 2  and the third seal ring element SE 3 . In some embodiments, the plasma process is, for example, an oxide plasma process. 
     In some embodiments, the thickness of the second dielectric layer  532  removed by the plasma process is accounted for approximately 5% to 20% thickness of the second dielectric layer  532 . In other words, in some embodiments, a protruding thickness T 3  of each second conductive via CV 2  protruding from the top surface T 532   r  of the recessed second dielectric layer  532   r  is accounted for approximately 5% to 20% thickness of the second dielectric layer  532 , and a protruding thickness T 4  of the third seal ring element SE 3  protruding from the top surface T 532   r  of the recessed second dielectric layer  532   r  is accounted for approximately 5% to 20% thickness of the second dielectric layer  532 . For example, the protruding thickness T 3  is between 0.1 μm and 0.3 μm. Similarly, the protruding thickness T 4  is between 0.1 μm and 0.3 μm, for example. 
     In some embodiments, since a distance along the direction perpendicular to the active surface  300   c  of the dies  300  (the protruding thickness T 3 ) is between the top surface T 532r  of the recessed second dielectric layer  532   r  and the top surface T CV2  of each second conductive via CV 2 , the top surface T 532r  of the recessed second dielectric layer  532   r  is lower than the top surfaces T CV2  of the second conductive vias CV 2 . Similarly, in some embodiments, since a distance along the direction perpendicular to the active surface  300   c  of the dies  300  (the protruding thickness T 4 ) is between the top surface T 532r  of the recessed second dielectric layer  532   r  and the top surface T SE3  of the third seal ring element SE 3 , the top surface T 532r  of the recessed second dielectric layer  532   r  is lower than the top surface T SE3  of the third seal ring element SE 3 . 
     In some embodiments, the first routing patterns RP 1 , the second conductive vias CV 2 , the second seal ring element SE 2 , the third seal ring element SE 3 , and the recessed second dielectric layer  532   r  may constitute a second sub-layer of the subsequently formed redistribution structure  500  (shown in  FIG. 1U ). In some embodiments, the second sub-layer is formed over the first sub-layer. 
     In some embodiments, the DOP for the recessed second dielectric layer  532   r  is in a range of approximately 90% to 100%. In some embodiments, the uniformity of the recessed second dielectric layer  532   r  is in a range of approximately 10% to 25%. As such, good topography of the second sub-layer constituted by the first routing patterns RP 1 , the second conductive vias CV 2 , the second seal ring element SE 2 , the third seal ring element SE 3 , and the recessed second dielectric layer  532   r  may be provided, thereby the subsequently formed elements may be accurately formed on the designated location and may be formed with the designated dimension, thereby enhancing the reliability of the InFO package  10 . 
     In some embodiments, from the cross-sectional view, the angle θ 5  of each top corner of each second conductive via CV 2  is approximately 90 degrees. However, the disclosure is not limited thereto. In some alternative embodiments, from the cross-sectional view, each top corner of each second conductive via CV 2  is similar to each top corner of each first conductive via CV 1  to be rounded due to the plasma process in the range of approximately 0.5 to 0.7 π rad (larger than 90 degrees to 120 degrees), referring to the schematic cross-sectional view on the left side of  FIG. 1J . In some embodiments, from the cross-sectional view, the angle θ 6  of each top corner of the third seal ring element SE 3  is approximately 90 degrees. However, the disclosure is not limited thereto. In some alternative embodiments, from the cross-sectional view, each top corner of the third seal ring element SE 3  is similar to each top corner of each first seal ring element SE 1  to be rounded due to the plasma process in the range of approximately 0.5 to 0.7 π rad (larger than 90 degrees to 120 degrees), referring to the schematic cross-sectional view on the left side of  FIG. 1J . 
     Referring to  FIG. 1S , a plurality of second routing patterns RP 2  and a fourth seal ring element SE 4  are respectively formed on the second conductive vias CV 2  and the third seal ring element SE 3 . In some embodiments, the second routing patterns RP 2  are constituted by a seed layer  514   a  and a plurality of conductive patterns  542   a . In some embodiments, the fourth seal ring element SE 4  is constituted by a seed layer  514   b  and a plurality of conductive patterns  542   b . In some embodiments, the second routing patterns RP 2  may be formed by similar methods as that of the first routing patterns RP 1  or the first conductive vias CV 1 . In some embodiments, the fourth seal ring element SE 4  may be formed by similar methods as that of the second seal ring element SE 2  or the first seal ring element SE 1 . Therefore, some of detailed descriptions of the second routing patterns RP 2  and the fourth seal ring element SE 4  are omitted herein. 
     In some embodiments, the second routing patterns RP 2  are located in the active region AR and the fourth seal ring element SE 4  is located in the border region BR. In some embodiments, the seed layer  514   a  is sandwiched between the second conductive vias CV 2  and the conductive patterns  542   a . On the other hand, the seed layer  514   b  is sandwiched between the third seal ring element SE 3  and the conductive patterns  542   b.    
     The second routing patterns RP 2  may include routing traces for signal transmission along the horizontal plane. In some embodiments, the fourth seal ring element SE 4  is electrically floating. For example, the fourth seal ring element SE 4  is electrically insulated from the second routing patterns RP 2 , the first routing patterns RP 1 , the second conductive vias CV 2 , the first conductive vias CV 1 , the conductive structures  200 , the vias  350  of the dies  300 , and the redistribution structure  100 . 
     In some embodiments, the second routing patterns RP 2  are in physical contact with the second conductive vias CV 2  and the recessed first dielectric layer  530   r . For example, the seed layer  514   a  of the second routing patterns RP 2  may be directly in contact with the second conductive vias CV 2  and the recessed first dielectric layer  530   r . In some embodiments, the fourth seal ring element SE 4  is in physical contact with the third seal ring element SE 3  and the recessed first dielectric layer  530   r . For example, the seed layer  514   b  of the fourth seal ring element SE 4  may be directly in contact with the third seal ring element SE 3  and the recessed first dielectric layer  530   r.    
     In some embodiments, each of the second routing patterns RP 2  has a protrusion P 3  due to the underlying second conductive vias CV 2 . As mentioned above, the second conductive vias CV 2  protrude out of the recessed second dielectric layer  532   r  along the direction perpendicular to the active surface  300   c  of the dies  300 , therefore a portion of the seed layer  514   a  located directly on the top surfaces T CV2  of the second conductive vias CV 2  protrudes form the rest of the seed layer  514   a  located directly on the top surface T 532r  of the recessed second dielectric layer  532   r . That is, in some embodiments, a portion of the seed layer  514   a  located directly on the top surfaces T CV2  of the second conductive vias CV 2  is higher than the rest of the seed layer  514   a  located directly on the top surface T 532r  of the recessed second dielectric layer  532   r . Accordingly, after the conductive patterns  542   a  disposed on the seed layer  514   a  are formed, the protrusions P 3  are created correspond to the locations of the second conductive vias CV 2 . That is, in some embodiments, a portion of each conductive pattern  542   a  may be slightly raised with respect to the rest portion of each conductive pattern  542   a . In some embodiments, the protrusion angle θ 7  of each protrusion P 3  with respect to a virtual line extending along a direction parallel to the active surface  300   c  of the dies  300  may be in the range of approximately 5 degrees to 20 degrees. Herein, the definition of the protrusion angle θ 7  of the protrusion P 3  is similar to the protrusion angle θ 3  of the protrusion P 1 , so the definition of the protrusion angle θ 7  is referred to the foregoing definition of the protrusion angle θ 3  and is omitted herein omitted herein. In some embodiments, the protruding portion of each conductive pattern  542   a  (the protrusion P 3 ) may be raised of approximately 0.1 μm up to 0.3 μm with respect to the rest portion of each conductive pattern  542   a.    
     The fourth seal ring element SE 4  is part of the subsequently formed seal ring structure SR (shown in  FIG. 1U ). Therefore, in some embodiments, the contour or structure of the fourth seal ring element SE 4  may be similar to the first seal ring element SE 1 , and some detailed descriptions of the fourth seal ring element SE 4  are referred to the foregoing embodiments of the first seal ring element SE 1  and are omitted herein omitted herein. 
     In some embodiments, a protrusion P 4  is in the fourth seal ring element SE 4  due to the underlying third seal ring element SE 3 . As mentioned above, the third seal ring element SE 3  protrudes out of the recessed second dielectric layer  532   r  along the direction perpendicular to the active surface  300   c  of the dies  300 , therefore a portion of the seed layer  514   b  located directly on the top surface T SE3  of the third seal ring element SE 3  protrudes form the rest of the seed layer  514   b  disposed on the top surface T 532r  of the recessed second dielectric layer  532   r . That is, in some embodiments, a portion of the seed layer  514   b  located directly on top surface T SE3  of the third seal ring element SE 3  is higher than the rest of the seed layer  514   b  located directly on the top surface T 532r  of the recessed second dielectric layer  532   r . Accordingly, after the conductive patterns  542   b  disposed on the seed layer  514   b  are formed, the protrusion P 4  is created correspond to the location of the third seal ring element SE 3 . That is, in some embodiments, a portion of each conductive pattern  542   b  may be slightly raised with respect to the rest portion of each conductive pattern  542   b . In some embodiments, the protrusion angle θ 5  of the protrusion P 4  with respect to a virtual line extending along a direction parallel to the active surface  300   c  of the dies  300  may be in the range of approximately 5 degrees to 20 degrees. Herein, the definition of the protrusion angle θ 5  of the protrusion P 4  is similar to the protrusion angle θ 3  of the protrusion P 1 , so the definition of the protrusion angle θ 5  is referred to the foregoing definition of the protrusion angle θ 3  and is omitted herein omitted herein. In some embodiments, the protruding portion of each conductive pattern  542   b  (the protrusion P 4 ) may be raised of approximately 0.1 μm up to 0.3 μm with respect to the rest portion of each conductive pattern  542   b.    
     Referring to  FIG. 1T , a third dielectric layer  534  is formed over the second sub-layer in the active region AR and the border region BR. For example, the third dielectric layer  534  is stacked on the recessed second dielectric layer  532   r . The third dielectric layer  534  has a plurality of openings OP 4  exposing at least a portion of the second routing patterns RP 2  and at least a portion of the fourth seal ring element SE 4 . The third dielectric layer  534  may be formed by the following steps. First, a dielectric material layer (not shown) is formed over the recessed second dielectric layer  532   r  to cover the second routing patterns RP 2  and the fourth seal ring element SE 4 . In some embodiments, the material of the dielectric material layer includes polyimide, epoxy resin, acrylic resin, phenol resin, BCB, PBO, or any other suitable polymer-based dielectric material. The dielectric material layer may be formed by suitable fabrication techniques, such as spin-on coating, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), or the like. Thereafter, the dielectric material layer may be patterned through a photolithography process and an etching process to render the third dielectric layer  534  having the openings OP 4 . 
     Referring to  FIG. 1U , a plurality of third routing patterns RP 3  and a fifth seal ring element SE 5  are respectively formed on the second routing patterns RP 2  and the fourth seal ring element SE 4  to obtain the redistribution structure  500 . In some embodiments, the third routing patterns RP 3  are constituted by a seed layer  516   a  and a plurality of conductive patterns  544   a . In some embodiments, the fifth seal ring element SE 5  is constituted by a seed layer  516   b  and a plurality of conductive patterns  544   b . In some embodiments, the third routing patterns RP 3  are located in the active region AR and the fifth seal ring element SE 5  is located in the border region BR. The third routing patterns RP 3  and the fifth seal ring element SE 5  may be formed by the following steps. First, a seed material layer (not shown) extending into the openings OP 4  of the third dielectric layer  534  may be formed over the third dielectric layer  534 . The seed material layer may be formed through, for example, a sputtering process, a physical vapor deposition (PVD) process, or the like. In some embodiments, the seed material layer may include, for example, copper, titanium-copper alloy, or other suitable choice of materials. A mask pattern (not shown) may then be formed on the seed material layer. The mask pattern has openings exposing the seed material layer located inside of the openings OP 4  of the third dielectric layer  534 . In some embodiments, the openings of the mask pattern also expose portions of the seed material layer in proximity of the openings OP 4 . Thereafter, a conductive material (not shown) is filled into the openings of the mask pattern and the openings OP 4  of the third dielectric layer  534  by electroplating process or deposition process. Then, the mask pattern and the seed material layer underneath the mask pattern are removed to obtain the third routing patterns RP 3  and the fifth seal ring element SE 5 . 
     In some embodiments, the second routing patterns RP 2 , the third routing patterns RP 3 , the fourth seal ring element SE 4 , the fifth seal ring element SE 5 , and the third dielectric layer  534  may be considered as a third sub-layer of the redistribution structure  500 . In some embodiments, the third routing patterns RP 3  may include a plurality of pads. In some embodiments, the above-mentioned pads include a plurality of under-ball metallurgy (UBM) patterns for ball mount. 
     In some embodiments, the fifth seal ring element SE 5 , the fourth seal ring element SE 4 , the third seal ring element SE 3 , the second seal ring element SE 2  and the first seal ring element SE 1  located in the border region BR are collectively referred to as the seal ring structure SR. In some embodiments, the contour of the fifth seal ring element SE 5  may be a single loop pattern, referring to  FIG. 2 . From the top plan view of the InFO package  10 , the shape of the fifth seal ring element SE 5  may be an octagon. However, the disclosure is not limited thereto. In some alternative embodiments, the shape of the fifth seal ring element SE 5  may be a circle, any other suitable polygon, or any other suitable shape from a top plan view. In addition, in some alternative embodiments, the fifth seal ring element SE 5  is not a closed loop, but may have openings therein. In some embodiments, the fifth seal ring element SE 5  surrounds the active region AR. 
     As illustrated in  FIG. 1U , a redistribution structure  500  includes the recessed first dielectric layer  530   r , the recessed second dielectric layer  532   r , the third dielectric layer  534 , the first conductive vias CV 1 , the second conductive vias CV 2 , the first routing patterns RP 1 , the second routing patterns RP 2 , the third routing patterns RP 3 , and the seal ring structure SR including the fifth seal ring element SE 5 , the fourth seal ring element SE 4 , the third seal ring element SE 3 , the second seal ring element SE 2  and the first seal ring element SE 1 . The first conductive vias CV 1  and the first seal ring element SE 1  are partially embedded in the recessed first dielectric layer  530   r . The first routing patterns RP 1  and the second seal ring element SE 2  are embedded in the recessed second dielectric layer  532   r , while the second conductive vias CV 2  and the third seal ring element SE 3  are partially embedded in the recessed second dielectric layer  532   r . The second routing patterns RP 2  and the fourth seal ring element SE 4  are embedded in the third dielectric layer  534  while the third routing patterns RP 3  and the fifth seal ring element SE 5  are partially embedded in the third dielectric layer  534 . The first conductive vias CV 1  are in physical contact with the vias  350  of the dies  300  and the first routing patterns RP 1 . That is, the first conductive vias CV 1  electrically connect the dies  300  and the first routing patterns RP 1 . The second conductive vias CV 2  are in physical contact with the first routing patterns RP 1  and the second routing patterns RP 2 . That is, the second conductive vias CV 2  electrically interconnect the first routing patterns RP 1  and the second routing patterns RP 2 . The second routing patterns RP 2  are in physical contact with the second conductive vias CV 2  and the third routing patterns RP 3 . That is, the second routing patterns RP 2  are electrically connected to the second conductive vias CV 2  and the third routing patterns RP 3 . 
     In some embodiments, the redistribution structure  500  is referred to as a front-side redistribution structure. It should be noted that although the redistribution structure  500  is illustrated to have three sub-layers in  FIG. 1U , the disclosure is not limited thereto. In some alternative embodiments, the redistribution structure  500  may be constituted by more or less layers of sub-layers depending on the circuit design. 
     Referring to  FIG. 1V , after the redistribution structure  500  is formed, a plurality of conductive terminals  600  are placed on the third routing patterns RP 3  (the UBM patterns) of the redistribution structure  500 . In some embodiments, the conductive terminals  600  are electrically connected to the redistribution structure  500 . In some embodiments, the conductive terminals  600  include solder balls. In some embodiments, the conductive terminals  600  may be placed on the UBM patterns through a ball placement process. 
     Referring to  FIG. 1V  and  FIG. 1W , after the conductive terminals  600  are formed on the redistribution structure  500 , the redistribution structure  100  is separated from the de-bonding layer DB and the carrier  100 . In some embodiments, the de-bonding layer DB (e.g., the LTHC release layer) may be irradiated by an UV laser such that the carrier C and the de-bonding layer DB may be peeled off. Nevertheless, the de-bonding process is not limited thereto. Other suitable de-carrier methods may be used in some alternative embodiments. 
     Referring to  FIG. 1X , after removing the de-bonding layer DB and the carrier C, a plurality of openings OP 5  is formed in the dielectric layer  104  to partially expose the redistribution conductive layer  102 . In some embodiments, when multiple redistribution conductive layers  102  are present, the openings OP 5  expose the bottommost redistribution conductive layer  102 . In some embodiments, the openings OP 5  are formed by a laser drilling process, a mechanical drilling process, a photolithography process, or other suitable processes. Thereafter, a plurality of conductive terminals  602  is formed over the redistribution structure  100 . In some embodiments, at least part of the conductive terminals  602  extends into the openings OP 5  to be in contact with the redistribution conductive layer  102 , thereby rendering electrical connection with the redistribution structure  100 . In some embodiments, the conductive terminals  602  are attached to the redistribution conductive layer  102  through a solder flux (not shown). In some embodiments, the conductive terminals  602  are, for example, solder balls. In some embodiments, the conductive terminals  602  may be disposed on the redistribution conductive layer  102  by a ball placement process and/or a reflow process. 
     Referring to  FIG. 1X  and  FIG. 1Y , the structure illustrated in  FIG. 1X  is diced or singulated to form a plurality of InFO packages  10 . In some embodiments, the dicing process or the singulation process typically involves dicing with a rotating blade or a laser beam. In other words, the dicing or singulation process is, for example, a laser cutting process, a mechanical cutting process, or other suitable processes. 
       FIG. 3  is a schematic cross-sectional view illustrating an electronic device  1000  including the InFO package  10  in  FIG. 1Y . Referring to  FIG. 3 , another package  20  is provided. The package  20  is, for example, a memory device or other suitable semiconductor devices. The package  20  is stacked over and is electrically connected to the InFO package  10  in  FIG. 1Y  through the conductive terminals  602  such that a package-on-package (POP) structure is fabricated. Referring to  FIG. 3  again, the InFO package  10  having the package  20  stacked thereon may be further disposed on a printed circuit board  30  to form the electronic device  1000 . The InFO package  10  may be electrically connected to the printed circuit board  30  through the conductive terminals  600 . In some embodiments, an underfill (not shown) is provided between the package  20  and the InFO package  10 , and an underfill (not shown) is provided between the InFO package  10  and the printed circuit board  30  to increase the physical resistance of the electronic device  1000 , and protect the connection between the InFO package  10  and the package  20  and the connection between the InFO package  10  and the printed circuit board  30 . 
     In the embodiments of  FIG. 1A  to  FIG. 1Y , after the planarization process is performed to the first dielectric material layer  530   a  to form the first dielectric layer  530 , the plasma process is performed to the first dielectric layer  530  to form the recessed first dielectric layer  530   r , and after the planarization process is performed to the first dielectric material layer  532   a  to form the first dielectric layer  532 , the plasma process is performed to the first dielectric layer  532  to form the recessed first dielectric layer  532   r . However, the disclosure is not limited thereto. In some alternative embodiments, the first dielectric layer  530  and the first dielectric layer  532  respectively are not recessed by a plasma process. The details will be described below with reference to  FIG. 4 . 
       FIG. 4  is a schematic cross-sectional view illustrating an InFO package  40  in accordance with some alternative embodiments of the disclosure. Referring to  FIG. 4  and  FIG. 1Y , the InFO package  40  is similar to the InFO package  10  illustrated in  FIG. 1Y , except the difference therebetween lies: in the InFO package  40 , the first routing patterns RP 1  and the second seal ring element SE 2  are formed on the first dielectric layer  530 , and the second routing patterns RP 2  and the fourth seal ring element SE 4  are formed on the second dielectric layer  532 ; while in the InFO package  10 , the first routing patterns RP 1  and the second seal ring element SE 2  are formed on the recessed first dielectric layer  530   r , and the second routing patterns RP 2  and the fourth seal ring element SE 4  are formed on the recessed second dielectric layer  532   r . That is, the manufacturing process of the InFO package  40  is similar to the manufacturing process of the InFO package  10 , except the steps of performing plasma process to the first dielectric layer  530  and the first dielectric layer  532  are omitted. As such, the detailed descriptions of the manufacturing process of the InFO package  40  and some detailed descriptions of the structure of the InFO package  40  are referred to the foregoing embodiments and will not be repeated hereinafter. 
     Referring to  FIG. 4 , in some embodiments, the first conductive vias CV 1 , the first seal ring element SE 1 , and the first dielectric layer  530  may constitute a first sub-layer of the redistribution structure  500 . As illustrated in  FIG. 4 , the first sub-layer is formed over the encapsulant  400 , the dies  300 , and the conductive structures  200 . In some embodiments, since the top surface T SE1  of the first seal ring element SE 1  is substantially coplanar with the top surface T 530  of the first dielectric layer  530  adjacent thereto and the top surfaces T CV1  of the first conductive vias CV 1  are substantially coplanar with the top surface T 530  of the first dielectric layer  530  adjacent thereto, good and uniform topography of the first sub-layer constituted by the first conductive vias CV 1 , the first seal ring element SE 1 , and the first dielectric layer  530  may be provided. As such, the subsequently formed elements may be accurately formed on the designated location and may be formed with the designated dimension, thereby enhancing the reliability of the InFO package  40 . 
     In some embodiments, the first routing patterns RP 1 , the second conductive vias CV 2 , the second seal ring element SE 2 , the third seal ring element SE 3 , and the second dielectric layer  532  may constitute a second sub-layer of the redistribution structure  500 . In some embodiments, the second sub-layer is formed over the first sub-layer. In some embodiments, since the top surface T SE3  of the third seal ring element SE 3  is substantially coplanar with the top surface T 532  of the second dielectric layer  532  adjacent thereto and the top surfaces T CV2  of the second conductive vias CV 2  are substantially coplanar with the top surface T 532  of the second dielectric layer  532  adjacent thereto, good and uniform topography of the second sub-layer constituted by the first routing patterns RP 1 , the second conductive vias CV 2 , the second seal ring element SE 2 , the third seal ring element SE 3 , and the second dielectric layer  532  may be provided. As such, the subsequently formed elements may be accurately formed on the designated location and may be formed with the designated dimension, thereby enhancing the reliability of the InFO package  40 . 
     In the embodiments of  FIG. 1A  to  FIG. 1Y , after the planarization process for forming the first dielectric layer  530  is performed, the plasma process for recessing the first dielectric layer  530  is performed, and after the planarization process for forming the first dielectric layer  532  is performed, the plasma process for recessing the first dielectric layer  532  is performed. However, the disclosure is not limited thereto. In some alternative embodiments, the recessing treatment is not preformed to the first dielectric layer  530  and the first dielectric layer  532 , but to the other elements. The details will be described below with reference to  FIG. 5A  to  FIG. 5F . 
       FIG. 5A  to  FIG. 5F  are schematic cross-sectional views illustrating various process steps for a manufacturing process of an InFO package  50  in accordance with some alternative embodiments of the disclosure. The difference between the manufacturing process of  FIG. 1A  to  FIG. 1Y  and the manufacturing process of  FIG. 5A  to  FIG. 5F  lies: in the manufacturing process of  FIG. 5A  to  FIG. 5F , the recessing treatment is preformed to the first dielectric layer  530  and the first dielectric layer  532 ; while in the manufacturing process of  FIG. 5A  to  FIG. 5F , the recessing treatment is preformed to the first conductive vias CV 1 , the first seal ring element SE 1 , the second conductive vias CV 2  and, the third seal ring element SE 3 . As such, the difference is illustrated in details below, and the similarity is not iterated herein. 
     Referring to  FIG. 5A , a structure of  FIG. 1I  is provided, and the conductive patterns  520   a  of the first conductive vias CV 1  and the conductive patterns  520   b  of the first seal ring element SE 1  are recessed by performing a cleaning process to form the recessed first conductive vias CV 1   r  and the recessed first seal ring element SE 1   r . In other word, the recessed first conductive vias CV 1   r  are constituted by the seed layer  510   a  and the recessed conductive patterns  520   a , and the recessed first seal ring element SE 1   r  is constituted by the seed layer  510   b  and the recessed conductive patterns  520   b . In some embodiments, the cleaning process is, for example, a wet acid cleaning process. In some embodiments, in the cleaning process, a solution containing oxalic acid, citric acid, or succinic acid is used. 
     As described above, the first dielectric layer  530 , the first conductive vias CV 1 , and the first seal ring element SE 1  may have substantially the same thickness, therefore after the first conductive vias CV 1  and the first seal ring element SE 1  are recessed by the cleaning process, the recessed first conductive vias CV 1   r  and the recessed first seal ring element SE 1   r  are recessed from the top surface T 530  of the first dielectric layer  530 . In other words, the first conductive vias CV 1  and the first seal ring element SE 1  are selectively thinned, so that the thickness of the first dielectric layer  530  is larger than the thickness of the recessed first conductive vias CV 1   r  and the thickness of the recessed first seal ring element SE 1   r  to have the first dielectric layer  530  protruding over the recessed first conductive vias CV 1   r  and the recessed first seal ring element SE 1   r . In some embodiments, the first dielectric layer  530  wraps around the recessed first conductive vias CV 1   r  and the recessed first seal ring element SE 1   r . In detail, in some embodiments, the recessed first conductive vias CV 1   r  and the recessed first seal ring element SE 1   r  are embedded in the first dielectric layer  530 . 
     In some embodiments, the thickness of the conductive patterns  520   a  and the conductive patterns  520   b  removed by the cleaning process is accounted for approximately 2.5% to 10% thickness of the conductive patterns  520   a  and the conductive patterns  520   b . In other words, in some embodiments, a thickness difference T 5  in the thickness direction between the thickness of the first dielectric layer  530  and the thickness of each recessed first conductive vias CV 1   r  is accounted for approximately 2.5% to 10% thickness of the conductive patterns  520   a , and a thickness difference T 6  between the thickness of the first dielectric layer  530  and the thickness of the recessed first seal ring element SE 1   r  is accounted for approximately 2.5% to 10% thickness of the conductive patterns  520   b . For example, the thickness difference T 5  is between 0.1 μm and 0.3 μm. Similarly, the thickness difference T 6  is between 0.1 μm and 0.3 μm, for example. 
     In some embodiments, since a distance along the direction perpendicular to the active surface  300   c  of the dies  300  (the thickness difference T 5 ) is between the top surface T 530  of the first dielectric layer  530  and the top surface T CV1r  of each recessed first conductive via CV 1   r , the top surface T 530  of the first dielectric layer  530  is non-coplanar with the top surfaces T CV1r  of the recessed first conductive vias CV 1   r . In other words, in some embodiments, along the direction perpendicular to the active surface  300   c  of the dies  300 , the top surface T 530  of the first dielectric layer  530  is located at a level height higher than the top surfaces T CV1r  of the recessed first conductive vias CV 1   r . Similarly, in some embodiments, since a distance along the direction perpendicular to the active surface  300   c  of the dies  300  (the thickness difference T 6 ) is between the top surface T 530  of the first dielectric layer  530   r  and the top surface T SE1r  of the recessed first seal ring element SE 1   r , the top surface T 530  of the first dielectric layer  530   r  is located at a level height higher than the top surface T SE1r  of the recessed first seal ring element SE 1   r.    
     In some embodiments, the recessed first conductive vias CV 1   r , the recessed first seal ring element SE 1   r , and the first dielectric layer  530  may constitute a first sub-layer of a subsequently formed redistribution structure  700  (shown in  FIG. 5E ). As illustrated in  FIG. 5A , the first sub-layer is formed over the encapsulant  400 , the dies  300 , and the conductive structures  200 . 
     As mentioned above, the DOP for the first dielectric layer  530  is in a range of approximately 90% to 100%, or the uniformity of the first dielectric layer  530  is in a range of approximately 10% to 25%, thereby good topography of the first sub-layer constituted by the recessed first conductive vias CV 1   r , the recessed first seal ring element SE 1   r , and the first dielectric layer  530  may be provided, thereby the subsequently formed elements may be accurately formed on the designated location and may be formed with the designated dimension, thereby enhancing the reliability of the InFO package  50 . 
     In some embodiments, from the cross-sectional view, the angle θ 9  of each top corner of each recessed first conductive via CV 1   r  is approximately 90 degrees. However, the disclosure is not limited thereto. In some alternative embodiments, from the cross-sectional view, each top corner of each recessed first conductive via CV 1   r  has a curved outline due to the cleaning process in the range of approximately 0.9 to 1.1 π rad (170 degrees to 200 degrees), as shown in the schematic cross-sectional view on the left side of  FIG. 5A . In some embodiments, from the cross-sectional view, the angle θ 10  of each top corner of the recessed first seal ring element SE 1   r  is approximately 90 degrees. However, the disclosure is not limited thereto. In some alternative embodiments, from the cross-sectional view, each top corner of the recessed first seal ring element SE 1   r  has a curved outline due to the cleaning process in the range of approximately 0.9 to 1.1 π rad (170 degrees to 200 degrees), as shown in the schematic cross-sectional view on the left side of  FIG. 5A . 
     Referring to  FIG. 5B , a plurality of first routing patterns RP 4  and a second seal ring element SE 6  are respectively formed on the recessed second conductive vias CV 1   r  and the recessed first seal ring element SE 1   r , and a plurality of second conductive vias CV 3  and a third seal ring element SE 7  are respectively formed on the first routing patterns RP 4  and the second seal ring element SE 6 . In some embodiments, the first routing patterns RP 4  are constituted by a seed layer  712   a  and a plurality of conductive patterns  740   a . In some embodiments, the second seal ring element SE 6  is constituted by a seed layer  714   b  and a plurality of conductive patterns  740   b . In some embodiments, the second conductive vias CV 3  are constituted by a plurality of conductive patterns  722   a . In some embodiments, the third seal ring element SE 7  is constituted by a plurality of conductive patterns  722   b . In some embodiments, the first routing patterns RP 4  and the second seal ring element SE 6  may be respectively formed by similar methods as that of the first routing patterns RP 1  and the second seal ring element SE 2  in the embodiments of  FIG. 1A  to  FIG. 1Y . In some embodiments, the second conductive vias CV 3  and the third seal ring element SE 7  may be respectively formed by similar methods as that of the second conductive vias CV 2  and the third seal ring element SE 3  in the embodiments of  FIG. 1A  to  FIG. 1Y . Therefore, some of detailed descriptions of the first routing patterns RP 4 , the second seal ring element SE 6 , the second conductive vias CV 3  and the third seal ring element SE 7  are referred to the foregoing embodiments of  FIG. 1A  to  FIG. 1Y  and are omitted herein. 
     In some embodiments, each of the first routing patterns RP 4  has a recess R 1  due to the underlying recessed first conductive vias CV 1   r . As mentioned above, the recessed first conductive vias CV 1   r  are recessed with respect to the first dielectric layer  530 , therefore a portion of the seed layer  712   a  located directly on the top surfaces T CV1r  of the recessed first conductive vias CV 1   r  is recessed with respect to the rest of the seed layer  712   a  located directly on the top surface T 530  of the first dielectric layer  530 . That is, in some embodiments, a portion of the seed layer  712   a  located directly on the top surfaces T CV1r  of the recessed first conductive vias CV 1   r  is lower than the rest of the seed layer  712   a  located directly on the top surface T 530  of the first dielectric layer  530 . Accordingly, after the conductive patterns  740   a  disposed on the seed layer  712   a  are formed, the recesses R 1  are created correspond to the locations of the recessed first conductive vias CV 1   r . That is, in some embodiments, a portion of each conductive pattern  740   a  may be slightly lower than the rest portion of each conductive pattern  740   a . In some embodiments, the recess angle θ 11  of each recess R 1  with respect to a virtual line extending along a direction parallel to the active surface  300   c  of the dies  300  may be in the range of approximately 5 degrees to 15 degrees. Herein, the recess angle θ 11  of each recess R 1  is defined as an included angle between the tangent line of the recessed portion of each conductive pattern  740   a  initially recessed from the rest portion of each conductive pattern  740   a  and the virtual line extending along a direction parallel to the active surface  300   c  of the dies  300 . In some embodiments, the depth of the recessed portion of each conductive pattern  740   a  (the recess R 1 ) may be of approximately 0.1 μm up to 0.3 μm with respect to the rest portion of each conductive pattern  740   a.    
     In some embodiments, the second seal ring element SE 6  has a recess R 2  due to the underlying recessed first seal ring element SE 1   r . As mentioned above, the recessed first seal ring element SE 1   r  are recessed with respect to the first dielectric layer  530 , therefore a portion of the seed layer  712   b  located directly on the top surface T SE1r  of the recessed first seal ring element SE 1   r  is recessed with respect to the rest of the seed layer  712   b  located directly on the top surface T 530  of the first dielectric layer  530 . That is, in some embodiments, a portion of the seed layer  712   b  located directly on the top surface T SE1r  of the recessed first seal ring element SE 1   r  is lower than the rest of the seed layer  712   b  located directly on the top surface T 530  of the first dielectric layer  530 . Accordingly, after the conductive patterns  740   b  disposed on the seed layer  712   b  are formed, the recess R 2  is created correspond to the location of the recessed first seal ring element SE 1   r . That is, in some embodiments, a portion of each conductive pattern  740   b  may be slightly lower than the rest portion of each conductive pattern  740   b . In some embodiments, the recess angle θ 12  of the recess R 2  with respect to a virtual line extending along a direction parallel to the active surface  300   c  of the dies  300  may be in the range of approximately 5 degrees to 15 degrees. Herein, the definition of the recess angle θ 12  of the recess R 2  is similar to the recess angle θ 11  of the recess R 1 , so the definition of the recess angle θ 12  is referred to the foregoing definition of the recess angle θ 11  and is omitted herein omitted herein. In some embodiments, the depth of the recessed portion of each conductive pattern  740   b  (the recess R 2 ) may be of approximately 0.1 μm up to 0.3 μm with respect to the rest portion of each conductive pattern  740   b.    
     Referring to  FIG. 5B  again, a second dielectric layer  732  exposing the top surfaces T CV3  of the second conductive vias CV 3  and the top surface T SE7  of the third seal ring element SE 7  is formed. In some embodiments, the second dielectric layer  732  may be respectively formed by similar methods as that of the second dielectric layer  532  in the embodiments of  FIG. 1A  to  FIG. 1Y . Therefore, some of detailed descriptions of the second dielectric layer  732  are referred to the foregoing embodiments of  FIG. 1A  to  FIG. 1Y  and are omitted herein. 
     In some embodiments, the DOP for the second dielectric layer  732  is in a range of approximately 90% to 100%. In some embodiments, the uniformity of the second dielectric layer  732  is in a range of approximately 10% to 25%. In some embodiments, the top surface T 732  of the second dielectric layer  732  is substantially coplanar with the top surfaces T CV3  of the second conductive vias CV 3  and the top surface T SE7  of the third seal ring element SE 7 . In some embodiments, the second dielectric layer  732  wraps around the first routing patterns RP 4 , the second conductive vias CV 3 , the second seal ring element SE 6  and the third seal ring element SE 7 . In detail, the first routing patterns RP 4 , the second conductive vias CV 3 , the second seal ring element SE 6  and the third seal ring element SE 7  are embedded in the second dielectric layer  732 . 
     Referring to  FIG. 5C , the second conductive vias CV 3  and the third seal ring element SE 7  are recessed by performing a cleaning process to form the recessed second conductive vias CV 3   r  and the recessed third seal ring element SE 7   r . As described above, the top surface T 732  of the second dielectric layer  732  is substantially coplanar with the top surfaces T CV3  of the second conductive vias CV 3  and the top surface T SE7  of the third seal ring element SE 7 , therefore after the second conductive vias CV 3  and the third seal ring element SE 7  are recessed by the cleaning process, the recessed second conductive vias CV 3   r  and the recessed third seal ring element SE 7   r  are recessed form the top surface T 732  of the second dielectric layer  732 . In other words, the second conductive vias CV 3  and the third seal ring element SE 7  are selectively thinned to have the second dielectric layer  732  protruding from the top surfaces T CV3r  of the recessed second conductive vias CV 3   r  and the top surface T SE7r  of the recessed third seal ring element SE 7   r . In some embodiments, the second dielectric layer  732  wraps around the first routing patterns RP 4 , the recessed second conductive vias CV 3   r , the second seal ring element SE 6  and the recessed third seal ring element SE 7   r . In detail, in some embodiments, the first routing patterns RP 4 , the recessed second conductive vias CV 3   r , the second seal ring element SE 6  and the recessed third seal ring element SE 7   r  are embedded in the recessed second dielectric layer  532   r . In some embodiments, the cleaning process is, for example, a wet acid cleaning process. In some embodiments, in the cleaning process, a solution containing oxalic acid, citric acid, or succinic acid is used. 
     In some embodiments, the thickness of the second conductive vias CV 3  and the third seal ring element SE 7  removed by the cleaning process is accounted for approximately 2.5% to 10% thickness of the second conductive vias CV 3  and the third seal ring element SE 7 . In other words, in some embodiments, a protruding thickness T 7  of the second dielectric layer  732  protruding from the top surfaces TCV 3   r  of the recessed second conductive vias CV 3   r  and the top surface TSE 7   r  of the recessed third seal ring element SE 7   r  is accounted for approximately 2.5% to 10% thickness of the second conductive vias CV 3  and the third seal ring element SE 7 . For example, the protruding thickness T 7  is between 0.1 μm and 0.3 μm. 
     In some embodiments, since a distance along the direction perpendicular to the active surface  300   c  of the dies  300  (the protruding thickness T 7 ) is between the top surface T 732  of the second dielectric layer  732  and the top surface T CV3r  of each second conductive via CV 3   r , the top surface T 732  of the second dielectric layer  732  is higher than the top surfaces T CV3r  of the second conductive vias CV 3   r . Similarly, in some embodiments, since a distance along the direction perpendicular to the active surface  300   c  of the dies  300  (the protruding thickness T 7 ) is between the top surface T 732  of the second dielectric layer  732  and the top surface T SE7r  of the third seal ring element SE 7   r , the top surface T 732  of the second dielectric layer  732  is higher than the top surface T SE7r  of the third seal ring element SE 7   r.    
     In some embodiments, the first routing patterns RP 4 , the recessed second conductive vias CV 3   r , the second seal ring element SE 6 , the recessed third seal ring element SE 7   r , and the second dielectric layer  732  may constitute a second sub-layer of the subsequently formed redistribution structure  700  (shown in  FIG. 5E ). In some embodiments, the second sub-layer is formed over the first sub-layer. 
     As mentioned above, the DOP for the second dielectric layer  732  is in a range of approximately 90% to 100%, or the uniformity of the second dielectric layer  732  is in a range of approximately 10% to 25%, thereby good topography of the second sub-layer constituted by the first routing patterns RP 4 , the recessed second conductive vias CV 3   r , the second seal ring element SE 6 , the recessed third seal ring element SE 7   r , and the second dielectric layer  732  may be provided, thereby the subsequently formed elements may be accurately formed on the designated location and may be formed with the designated dimension, thereby enhancing the reliability of the InFO package  50 . 
     In some embodiments, from the cross-sectional view, the angle θ 13  of each top corner of each recessed second conductive via CV 3   r  is approximately 90 degrees. However, the disclosure is not limited thereto. In some alternative embodiments, from the cross-sectional view, each top corner of each recessed second conductive via CV 3   r  is similar to each top corner of each recessed second conductive via CV 1   r  to has a curved outline due to the cleaning process in the range of approximately 0.9 to 1.1 π rad (170 degrees to 200 degrees), referring to the schematic cross-sectional view on the left side of  FIG. 5A . In some embodiments, from the cross-sectional view, the angle θ 14  of each top corner of the recessed third seal ring element SE 7   r  is approximately 90 degrees. However, the disclosure is not limited thereto. In some alternative embodiments, from the cross-sectional view, each top corner of the recessed third seal ring element SE 7   r  is similar to each top corner of each recessed first seal ring element SE 1   r  to has a curved outline due to the cleaning process in the range of approximately 0.9 to 1.1 π rad (170 degrees to 200 degrees), referring to the schematic cross-sectional view on the left side of  FIG. 5A . 
     Referring to  FIG. 5D , a plurality of second routing patterns RP 5  and a fourth seal ring element SE 8  are respectively formed on the recessed second conductive vias CV 3   r  and the recessed third seal ring element SE 7   r . In some embodiments, the second routing patterns RP 5  are constituted by a seed layer  714   a  and a plurality of conductive patterns  542   a . In some embodiments, the fourth seal ring element SE 8  is constituted by a seed layer  714   b  and a plurality of conductive patterns  742   b . In some embodiments, the second routing patterns RP 5  may be formed by similar methods as that of the second routing patterns RP 2  in the embodiments of  FIG. 1A  to  FIG. 1Y . In some embodiments, the fourth seal ring element SE 8  may be formed by similar methods as that of the fourth seal ring element SE 4  in the embodiments of  FIG. 1A  to  FIG. 1Y . Therefore, some of detailed descriptions of the second routing patterns RP 5  and the fourth seal ring element SE 8  are referred to the foregoing embodiments of  FIG. 1A  to  FIG. 1Y  and are omitted herein. 
     In some embodiments, each of the second routing patterns RP 5  has a recess R 3  due to the underlying recessed second conductive vias CV 3   r . As mentioned above, the recessed second conductive vias CV 3   r  are recessed with respect to the second dielectric layer  732 , therefore a portion of the seed layer  714   a  located directly on the top surfaces T CV3r  of the recessed second conductive vias CV 3   r  is recessed with respect to the rest of the seed layer  714   a  located directly on the top surface T 732  of the second dielectric layer  732 . That is, in some embodiments, a portion of the seed layer  714   a  located directly on the top surfaces T CV3r  of the recessed second conductive vias CV 3   r  is lower than the rest of the seed layer  714   a  located directly on the top surface T 732  of the second dielectric layer  732 . Accordingly, after the conductive patterns  742   a  disposed on the seed layer  714   a  are formed, the recesses R 3  are created correspond to the locations of the recessed second conductive vias CV 3   r . That is, in some embodiments, a portion of each conductive pattern  742   a  may be slightly lower than the rest portion of each conductive pattern  742   a . In some embodiments, the recess angle θ 15  of each recess R 3  with respect to a virtual line extending along a direction parallel to the active surface  300   c  of the dies  300  may be in the range of approximately 5 degrees to 15 degrees. Herein, the definition of the recess angle θ 15  of the recess R 3  is similar to the recess angle θ 11  of the recess R 1 , so the definition of the recess angle θ 15  is referred to the foregoing definition of the recess angle θ 11  and is omitted herein omitted herein. In some embodiments, the depth of the recessed portion of each conductive pattern  742   a  (the recess R 3 ) may be of approximately 0.1 μm up to 0.3 μm with respect to the rest portion of each conductive pattern  742   a.    
     In some embodiments, the fourth seal ring element SE 8  has a recess R 4  due to the underlying recessed third seal ring element SE 7   r . As mentioned above, the recessed third seal ring element SE 7   r  are recessed with respect to the second dielectric layer  732 , therefore a portion of the seed layer  714   b  located directly on the top surface T SE7r  of the recessed third seal ring element SE 7   r  is recessed with respect to the rest of the seed layer  714   b  located directly on the top surface T 732  of the second dielectric layer  732 . That is, in some embodiments, a portion of the seed layer  714   b  located directly on the top surface T SE7r  of the recessed third seal ring element SE 7   r  is lower than the rest of the seed layer  714   b  located directly on the top surface T 732  of the second dielectric layer  732 . Accordingly, after the conductive patterns  742   b  disposed on the seed layer  714   b  are formed, the recess R 4  is created correspond to the location of the recessed third seal ring element SE 7   r . That is, in some embodiments, a portion of each conductive pattern  742   b  may be slightly lower than the rest portion of each conductive pattern  742   b . In some embodiments, the recess angle θ 16  of the recess R 4  with respect to a virtual line extending along a direction parallel to the active surface  300   c  of the dies  300  may be in the range of approximately 5 degrees to 15 degrees. Herein, the definition of the recess angle θ 16  of the recess R 4  is similar to the recess angle θ 11  of the recess R 1 , so the definition of the recess angle θ 16  is referred to the foregoing definition of the recess angle θ 11  and is omitted herein omitted herein. In some embodiments, the depth of the recessed portion of each conductive pattern  742   b  (the recess R 4 ) may be of approximately 0.1 μm up to 0.3 μm with respect to the rest portion of each conductive pattern  742   b.    
     Referring to  FIG. 5E , a redistribution structure  700  including the first dielectric layer  530 , the second dielectric layer  732 , a third dielectric layer  734 , the recessed first conductive vias CV 1   r , the recessed second conductive vias CV 3   r , the first routing patterns RP 4 , the second routing patterns RP 5 , a plurality of third routing patterns RP 6 , and a seal ring structure SR 1  including a fifth seal ring element SE 9 , the fourth seal ring element SE 8 , the recessed third seal ring element SE 7   r , the second seal ring element SE 6  and the recessed first seal ring element SE 1   r  is formed. In some embodiments, the third routing patterns RP 6  are constituted by a seed layer  716   a  and a plurality of conductive patterns  744   a . In some embodiments, the fifth seal ring element SE 9  is constituted by a seed layer  716   b  and a plurality of conductive patterns  744   b . In some embodiments, the third routing patterns RP 6  may be formed by similar methods as that of the third routing patterns RP 3  in the embodiments of  FIG. 1A  to  FIG. 1Y . In some embodiments, the fifth seal ring element SE 9  may be formed by similar methods as that of the fifth seal ring element SE 5  in the embodiments of  FIG. 1A  to  FIG. 1Y . In some embodiments, the third dielectric layer  734  may be formed by similar methods as that of the third dielectric layer  534  in the embodiments of  FIG. 1A  to  FIG. 1Y . Therefore, detailed descriptions of the third routing patterns RP 6 , the fifth seal ring element SE 9  and the third dielectric layer  534  are referred to the foregoing embodiments of  FIG. 1A  to  FIG. 1Y  and are omitted herein. 
     The recessed first conductive vias CV 1   r  and the recessed first seal ring element SE 1   r  are embedded in the first dielectric layer  530 . The first routing patterns RP 4 , the second seal ring element SE 6 , the recessed second conductive vias CV 3   r  and the recessed third seal ring element SE 7   r  are embedded in the second dielectric layer  732 . The second routing patterns RP 5  and the fourth seal ring element SE 8  are embedded in the third dielectric layer  734  while the third routing patterns RP 6  and the fifth seal ring element SE 9  are partially embedded in the third dielectric layer  734 . The recessed first conductive vias CV 1   r  are in physical contact with the vias  350  of the dies  300  and the first routing patterns RP 4 . That is, the recessed first conductive vias CV 1   r  electrically connect the dies  300  and the first routing patterns RP 4 . The recessed second conductive vias CV 3   r  are in physical contact with the first routing patterns RP 4  and the second routing patterns RP 5 . That is, the recessed second conductive vias CV 3   r  electrically interconnect the first routing patterns RP 4  and the second routing patterns RP 5 . The second routing patterns RP 5  are in physical contact with the recessed second conductive vias CV 3   r  and the third routing patterns RP 6 . That is, the second routing patterns RP 5  are electrically connected to the recessed second conductive vias CV 3   r  and the third routing patterns RP 6 . In some embodiments, the second routing patterns RP 5 , the third routing patterns RP 6 , the fourth seal ring element SE 8 , the fifth seal ring element SE 9 , and the third dielectric layer  734  may be considered as a third sub-layer of the redistribution structure  700 . In some embodiments, the third routing patterns RP 6  may include a plurality of pads. In some embodiments, the above-mentioned pads include a plurality of under-ball metallurgy (UBM) patterns for ball mount. 
     In some embodiments, the redistribution structure  700  is referred to as a front-side redistribution structure. It should be noted that although the redistribution structure  700  is illustrated to have three sub-layers in  FIG. 5E , the disclosure is not limited thereto. In some alternative embodiments, the redistribution structure  700  may be constituted by more or less layers of sub-layers depending on the circuit design. 
     Referring to  FIG. 5E  again, a plurality of conductive terminals  800  are placed on the third routing patterns RP 6  (the UBM patterns) of the redistribution structure  700 , and a plurality of conductive terminals  802  is formed over the redistribution structure  100 . In some embodiments, the conductive terminals  800  may be formed by similar methods as that of the conductive terminals  600  in the embodiments of  FIG. 1A  to  FIG. 1Y . In some embodiments, the conductive terminals  802  may be formed by similar methods as that of the conductive terminals  602  in the embodiments of  FIG. 1A  to  FIG. 1Y . Therefore, detailed descriptions of the conductive terminals  800  and the conductive terminals  802  are referred to the foregoing embodiments of  FIG. 1A  to  FIG. 1Y  and are omitted herein. 
     Referring to  FIG. 5E  and  FIG. 5F , the structure illustrated in  FIG. 5E  is diced or singulated to form a plurality of InFO packages  50 . In some embodiments, the dicing process or the singulation process typically involves dicing with a rotating blade or a laser beam. In other words, the dicing or singulation process is, for example, a laser cutting process, a mechanical cutting process, or other suitable processes. 
     In accordance with some embodiments of the disclosure, a package includes a die and a redistribution structure. The die has an active surface and is wrapped around by an encapsulant. The redistribution structure is disposed on the active surface of the die and located above the encapsulant. The redistribution structure includes a conductive via connected with the die, a routing pattern located above and connected with the conductive via, and a seal ring structure including a first seal ring element and a second seal ring element located above and connected with the first seal ring element. The second seal ring element includes a seed layer sandwiched between the first seal ring element and the second seal ring element. A top surface of the first seal ring element is substantially coplanar with a top surface of the conductive via. 
     In accordance with some embodiments of the disclosure, a package includes a die, an encapsulant, and a seal ring structure. The encapsulant encloses the die. The seal ring structure is disposed on the encapsulant. The seal ring structure includes a first seal ring element, a second seal ring element, and a seed layer sandwiched between the first and second seal ring elements, wherein the first and second seal ring elements are respectively wrapped around by a first dielectric layer and a second dielectric layer, and a thickness of the first seal ring element is different from a thickness of the first dielectric layer. 
     In accordance with some embodiments of the disclosure, a manufacturing method of a package includes at least the following steps. A carrier is provided. A die is provided over the carrier. The die is encapsulated by an encapsulant. A first conductive via is formed on the die and a first seal ring element is formed over the encapsulant, wherein the first conductive via is electrically connected with the die. A first dielectric material layer over the encapsulant and the die to encapsulate the first conductive via and the first seal ring element is formed. A planarization process is performed to partially remove the first dielectric material layer to form a first dielectric layer exposing a top surface of the first conductive via and a top surface of the first seal ring element. 
     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.