Patent Publication Number: US-8970025-B2

Title: Stacked packages having through hole vias

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 13/614,931, filed on Sep. 13, 2012, which is a divisional of U.S. application Ser. No. 13/027,511, filed Feb. 15, 2011, which claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2010-26393 filed on Mar. 24, 2010, the disclosure of each of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     1. Field 
     Example embodiments of the inventive concepts relate to a semiconductor device and a method of forming the same, and more particularly, to a method of forming a package-on-package and a device related thereto. 
     2. Description of Related Art 
     As electronic devices have become thinner and smaller-sized, techniques related to a package-on-package (PoP) have been widely researched. The PoP refers to a package in which the same or different kinds of semiconductor packages are stacked to reduce a horizontal mounting surface, increasing the degree of integration thereof. However, it is very difficult to stack the plurality of semiconductor packages while controlling the width and height of the PoP. 
     SUMMARY 
     Example embodiments of the inventive concepts provide a method of forming a package-on-package (PoP) capable of easily reducing the width and height of the PoP. 
     In accordance with an example embodiment of the inventive concepts, a method of forming a semiconductor package may include forming an encapsulant with openings on a wafer using a wafer level molding process, the wafer including a plurality of first semiconductor chips and a plurality of through silicon vias (TSVs) passing through the plurality of first semiconductor chips, dividing the encapsulant and the wafer to form a plurality of first semiconductor packages, the plurality of first semiconductor packages including the plurality of first semiconductor chips, and stacking a second semiconductor package on one first semiconductor package selected from the plurality of first semiconductor packages, wherein the second semiconductor package is electrically connected to the TSVs of the one first semiconductor package via the openings. 
     In accordance with another example embodiment of the inventive concepts, a method of forming a semiconductor package, may include forming a plurality of through silicon vias (TSVs) through an upper surface of a wafer, the wafer having a plurality of first semiconductor chips, the plurality of TSVs being formed to have lower ends buried in the wafer and upper ends exposed by one surface of the wafer, forming an encapsulant on the wafer using a wafer level molding process, the encapsulant being formed to cover the upper ends of the TSVs, partially removing a lower surface of the wafer to expose the lower ends of the TSVs, forming openings through the encapsulant, the openings being aligned on the upper ends of the TSVs, dividing the encapsulant and the wafer to form a plurality of first semiconductor packages, and stacking a second semiconductor package on a first semiconductor package selected from the plurality of first semiconductor packages, the second semiconductor package being electrically connected to the TSVs. 
     In accordance with an example embodiment, a method of forming a semiconductor package may include forming a plurality of through silicon vias (TSVs) through an upper surface of a wafer, the wafer having a plurality of semiconductor chips, the plurality of TSVs being formed to have lower ends buried in the wafer and upper ends exposed by the upper surface of the wafer, partially removing a lower surface of the wafer to expose the lower ends of the TSVs, forming an encapsulant on at least one of the upper and lower surfaces of the wafer using a wafer level molding process, forming openings passing through the encapsulant, the openings being aligned with the TSVs, dividing the encapsulant and the wafer to form a plurality of first semiconductor packages, and stacking a second semiconductor package on a first semiconductor package selected from the plurality of first semiconductor packages, wherein the second semiconductor package is electrically connected to the TSVs. 
     In accordance with an example embodiment of the inventive concepts, a method of forming a semiconductor package may include forming an encapsulant on at least one of an upper and lower surface of a wafer, the wafer including a plurality of first semiconductor chips and a plurality of first through silicon vias, forming a plurality of first openings in the encapsulant, dividing the encapsulant and the wafer to form a first plurality of first semiconductor packages, each of the first semiconductor packages including at least one first semiconductor chip, at least one first opening, and at least one first through silicon via, providing a second semiconductor package including at least one external contact terminal and at least one second semiconductor chip, and mounting the second semiconductor package on one of the first semiconductor packages, wherein mounting the second semiconductor package on the one of the first semiconductor packages includes inserting the at least one external contact terminal into the at least one first opening of the of the one of the first semiconductor packages to electrically connect the at least one second semiconductor chip to the at least one first semiconductor chip of the one of the first semiconductor packages. 
     In accordance with an example embodiment of the inventive concepts, a semiconductor package may include a first semiconductor package and a second semiconductor package. The first semiconductor package may include a first semiconductor chip having a plurality of through silicon vias extending therethrough and an encapsulant on at least one of an upper surface and a lower surface of the first semiconductor chip. In this example embodiment, the encapsulant may include a plurality of openings corresponding to the plurality of through silicon vias. The second semiconductor package may be on the first semiconductor package and the second semiconductor package may include a second semiconductor chip and a plurality of external connection terminals below the second semiconductor chip. In this example embodiment the plurality of external connection terminals may be inserted into the plurality of openings to electrically connect the first semiconductor chip to the second semiconductor chip. 
     In accordance with an aspect of the inventive concepts, a method of forming a package-on-package is provided. An encapsulant configured to cover a wafer is formed using a wafer level molding process. The wafer includes a plurality of semiconductor chips, and a plurality of through silicon vias (TSVs) passing through the semiconductor chips. The encapsulant has openings. The encapsulant and the semiconductor chips are divided to form a plurality of semiconductor packages. Another semiconductor package is stacked on one package selected from the semiconductor packages. The other semiconductor package is electrically connected to the TSVs via the openings. 
     In some example embodiments, the semiconductor packages may have substantially the same width as the semiconductor chips. The other semiconductor package may have a width equal to that of the one package selected from the semiconductor packages, or smaller than that of the one package selected from the semiconductor packages. 
     In another example embodiment, the other semiconductor package may be another one package selected from the semiconductor packages. 
     In still another example embodiment, the openings may be aligned with the TSVs. 
     In yet another example embodiment, the semiconductor chips may include a re-distribution layer (RDL) electrically connected to the TSVs. At least one of the openings may be aligned with the RDL. 
     In yet another example embodiment, the other semiconductor package may include another semiconductor chip attached to a printed circuit board. The other semiconductor chip may be electrically connected to the TSVs via the printed circuit board. Another package selected from the semiconductor packages may be attached between the one selected package and the other semiconductor package of the semiconductor packages. 
     In yet another example embodiment, another printed circuit board may be attached to a lower part of one selected from the semiconductor packages. The other printed circuit board may have a width equal to or smaller than that of one selected from the semiconductor packages. The other semiconductor package may be electrically connected to the printed circuit board via the TSVs. 
     In yet another example embodiment, forming the encapsulant may include forming the TSVs on an upper surface of the wafer, forming the encapsulant on the upper surface of the wafer, and partially removing a lower surface of the wafer to expose the TSVs. 
     In yet another example embodiment, forming the encapsulant may include forming the TSVs on an upper surface of the wafer, partially removing a lower surface of the wafer to expose the TSVs such that the upper and lower surfaces face each other, and forming the encapsulant on at least one surface of the upper and lower surfaces. The encapsulant may be formed to cover the upper surface and the lower surface. 
     In yet another example embodiment, connection terminals may be formed on the TSVs. The connection terminals may be one selected from the group consisting of a conductive bump, a solder ball, a conductive spacer, a pin grid array (PGA), a lead grid array (LGA), and a combination thereof. 
     In accordance with another aspect of the inventive concepts, a method of forming a package-on-package is provided. A plurality of through silicon vias (TSVs) are formed on an upper surface of a wafer having a plurality of semiconductor chips. Lower ends of the TSVs are buried in the wafer. Upper ends of the TSVs are exposed to one surface of the wafer. An encapsulant is formed on the wafer using a wafer level molding process. The encapsulant covers the upper ends of the TSVs. A lower surface of the wafer is partially removed to expose the lower ends of the TSVs. Openings passing through the encapsulant are formed. The openings are aligned on the upper ends of the TSVs. The encapsulant and the wafer are divided to form a plurality of semiconductor packages. Another semiconductor package is stacked on one selected from the semiconductor packages. The other semiconductor package is electrically connected to the TSVs. 
     In some example embodiments, the semiconductor packages may have substantially the same width as the semiconductor chips. The other semiconductor package may have the width equal to or smaller than that of one selected from the semiconductor packages. Further, the other semiconductor package may have a width larger than that of one selected from the semiconductor packages. 
     In another example embodiment, before forming the encapsulant, internal connection terminals may be formed at the upper ends of the TSVs. The internal connection terminals may be one selected from the group consisting of a conductive bump, a solder ball, a conductive spacer, a pin grid array (PGA), a lead grid array (LGA), and a combination thereof. 
     In still another example embodiment, another one selected from the semiconductor packages may be attached between the one selected from the semiconductor packages and the other semiconductor package. 
     In yet another example embodiment, a printed circuit board may be attached to a lower part of one selected from the semiconductor packages. The printed circuit board may have a width equal to or smaller than that of one selected from the semiconductor packages. The other semiconductor package may be electrically connected to the printed circuit board via the TSVs. 
     In accordance with still another aspect of the inventive concepts, a method of forming a package-on-package is provided. A plurality of through silicon vias (TSVs) are formed on an upper surface of a wafer having a plurality of semiconductor chips. Lower ends of the TSVs are buried in the wafer. Upper ends of the TSVs are exposed to the upper surface of the wafer. A lower surface of the wafer is partially removed to expose the lower ends of the TSVs. An encapsulant is formed on at least one surface of the upper and lower surfaces of the wafer using a wafer level molding process. Openings passing through the encapsulant are formed. The openings are aligned with the TSVs. The encapsulant and the wafer are divided to form a plurality of semiconductor packages. Another semiconductor package is stacked on one selected from the semiconductor packages. The other semiconductor package is electrically connected to the TSVs. 
     In some example embodiments, the encapsulant may be formed to cover the upper surface and the lower surface of the wafer. 
     In another example embodiment, the semiconductor packages may have substantially the same width as the semiconductor chips. The other semiconductor package may have a width equal to or smaller than that of one of the semiconductor packages. Further, the other semiconductor package may have a width larger than that of one selected from the semiconductor packages. 
     In still another example embodiment, connection terminals may be formed on the TSVs. The connection terminals may be one selected from the group consisting of a conductive bump, a solder ball, a conductive spacer, a pin grid array (PGA), a lead grid array (LGA), and a combination thereof. 
     In yet another example embodiment, another one selected from the semiconductor packages may be attached between the one selected from the semiconductor packages and the other semiconductor package. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other features and advantages of the inventive concepts will be apparent from the more particular description of the example embodiments of the inventive concepts, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the inventive concepts. In the drawings: 
         FIG. 1  is a plan view illustrating a method of forming a PoP in accordance with a first example embodiment of the inventive concepts; 
         FIGS. 2 to 13  are cross-sectional views illustrating the method of forming a PoP in accordance with the first example embodiment of the inventive concepts; 
         FIGS. 14 to 20  are cross-sectional views illustrating a method of forming a PoP in accordance with a second example embodiment of the inventive concepts; 
         FIGS. 21 and 22  are cross-sectional views illustrating a method of forming a PoP in accordance with a third example embodiment of the inventive concepts; 
         FIG. 23  is a cross-sectional view illustrating a method of forming a PoP in accordance with a fourth example embodiment of the inventive concepts; 
         FIGS. 24 to 26  are cross-sectional views illustrating a method of forming a PoP in accordance with a fifth example embodiment of the inventive concepts; 
         FIG. 27  is a plan view of a semiconductor module employing a PoP in accordance with a sixth example embodiment of the inventive concepts; 
         FIG. 28  is a block diagram of an electronic system employing a PoP in accordance with a seventh example embodiment of the inventive concepts; 
         FIG. 29  is a perspective view of an electronic device employing a PoP in accordance with an eighth example embodiment of the inventive concepts; and 
         FIG. 30  is a system block diagram of an electronic device employing a PoP in accordance with a ninth example embodiment of the inventive concepts. 
     
    
    
     DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS 
     Example embodiments will now be described more fully with reference to the accompanying drawings in which the example embodiments are shown. The inventive concepts may, however, be embodied in different forms and should not be construed as limited to the example embodiments set forth herein. Rather, the example embodiments are provided so that this disclosure is thorough and complete and fully conveys the inventive concepts to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. 
     It will be understood that when an element or layer is referred to as being “on,” “connected to” or “coupled to” another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers that may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Like numerals refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present inventive concepts. 
     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&#39;s or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that 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. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present inventive concepts. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Example embodiments are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures). As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an implanted region illustrated as a rectangle will, typically, have rounded or curved features and/or a gradient of implant concentration at its edges rather than a binary change from implanted to non-implanted region. Likewise, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation takes place. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the present inventive concepts. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the inventive concepts belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     [First Embodiment] 
       FIG. 1  is a plan view illustrating a method of forming a POP in accordance with a first example embodiment of the inventive concepts, and  FIGS. 2 to 13  are cross-sectional views illustrating the method of forming a PoP in accordance with the first example embodiment of the inventive concepts. Here,  FIGS. 2 to 6  and  8  are cross-sectional views taken along line I-I′ of  FIG. 1 , and  FIG. 7A  is an enlarged view of a portion K of  FIG. 6 . 
     Referring to  FIGS. 1 and 2 , the method of forming a PoP in accordance with the first example embodiment of the inventive concepts may include forming a plurality of through silicon vias (TSVs)  21  on a wafer  11 . The wafer  11  may include a plurality of semiconductor chips  13 . The semiconductor chips  13  may be disposed in a two-dimensional array having rows and columns. 
     The TSVs  21  may be a conductive layer formed of at least one selected from the group consisting of tungsten (W), tungsten nitride (WN), titanium (Ti), titanium nitride (TiN), tantalum (Ta), tantalum nitride (TaN), aluminum (Al), copper (Cu), and a combination thereof. The TSVs  21  may be formed to penetrate the wafer  11  from one surface to a depth that may or may not be predetermined. That is, upper ends of the TSVs  21  may be exposed to one surface of the wafer  11 . Sidewalls and lower ends of the TSVs  21  may be buried in the wafer  11 . 
     The wafer  11  may be formed of a semiconductor substrate such as a silicon wafer or a silicon on insulator (SOI) wafer. While various kinds of active/passive devices (not shown) for constituting the semiconductor chips  13 , for example, transistors, data storage elements and/or interconnections, may be formed on the wafer  11 , detailed descriptions thereof will be omitted for the convenience of description. In the first example embodiment of the inventive concepts, the TSVs  21  will be described, provided that the TSVs  21  are formed on the same surface as the active/passive devices. However, in some embodiments, the TSVs  21  may be formed on a different surface than the active/passive devices. 
     The semiconductor chips  13  may include volatile memory chips such as a dynamic random access memory (DRAM) and a static random access memory (SRAM), non-volatile memory chips such as a flash memory, a phase change memory, a magnetic random access memory (MRAM), and a resistive random access memory (RRAM), non-memory chips such as a logic device and a microprocessor, or a combination thereof. 
     Referring to  FIG. 3 , internal connection terminals  23  may be formed on the TSVs  21 . The internal connection terminals  23  may be a conductive bump, a solder ball, a conductive spacer, a pin grid array (PGA), a lead grid array (LGA), and/or a combination thereof. For example, the internal connection terminals  23  may be formed by attaching the solder ball thereto. The internal connection terminals  23  may contact upper ends of the TSVs  21 . In some embodiments, the internal connection terminals  23  may be omitted. 
     Referring to  FIG. 4 , an encapsulant  25  may be formed on the wafer  11  using a wafer level molding process. The encapsulant  25  may cover the internal connection terminals  23  and the TSVs  21 . The encapsulant  25  may be formed of an epoxy molding compound (EMC) containing resin and filler. In some embodiments, the encapsulant  25  may be formed using liquid resin such as an underfill. 
     Referring to  FIG. 5 , the wafer  11  may be partially removed to expose lower ends of the TSVs  21 . For example, a lower surface of the wafer  11  may be partially removed using a chemical mechanical polishing (CMP) process, an etch-back process, a back grinding process, and/or a combination thereof, until the lower ends of the TSVs  21  are exposed. As a result, the thickness of the wafer  11  can be remarkably reduced. The encapsulant  25  may protect the semiconductor chips  13  and the internal connection terminals  23  from physical/chemical damages. 
     Referring to  FIG. 6 , openings  25 H may be formed to expose the internal connection terminals  23  through the encapsulant  25 . The openings  25 H may be formed using a laser drilling technique or a dry etch technique. The openings  25 H may refer to mold vias. The openings  25 H may be aligned on the TSVs  21 . The openings  25 H may have sizes corresponding to the internal connection terminals  23 . Upper surfaces of the internal connection terminals  23  may be exposed by the bottoms of the openings  25 H. In some embodiments, when the internal connection terminals  23  are omitted, the upper ends of the TSVs  21  may be exposed by the bottoms of the openings  25 H. In another example, a process of forming the openings  25 H may be performed before a process of partially removing the wafer  11  to expose the TSVs  21 . In still another embodiment, some of the openings  25 H may be aligned on a re-distribution layer (RDL, not shown) electrically connected to the TSVs  21 . 
     A portion K of  FIG. 6  will be described with reference to  FIG. 7A  in detail. A first insulating layer  31  covering one surface of the semiconductor chip  13  may be provided. The TSV  21  may pass through the first insulating layer  21  and the semiconductor chip  13 . A second insulating layer  32  may be provided between the TSV  21  and the semiconductor chip  13 . The second insulating layer  32  may cover the first insulating layer  31 . The TSV  21  may be electrically insulated from the semiconductor chip  13  by the second insulating layer  32 . A third insulating layer  33  may be provided to cover the other surface of the semiconductor chip  13 . The first and second insulating layers  31  and  32  may face each other. The TSV  21  may pass through the first and third insulating layers  31  and  33 . 
     The third insulating layer  33  may be formed after a process of partially removing the wafer  11  to expose the TSVs  21  (see  FIG. 5 ). Otherwise, the third insulating layer  33  may be formed before exposing the TSVs  21 . 
     Both ends of the TSV  21  may be substantially flush with surfaces of the semiconductor chip  13 , or protrude or be recessed with respect to the surfaces of the semiconductor chip  13 . For example, an upper end of the TSV  21  may protrude from an upper surface of the semiconductor chip  13 , and a lower end of the TSV  21  may be substantially flush with a lower surface of the semiconductor chip  13 . The internal connection terminal  23  may be attached to the upper end of the TSV  21 . 
     The semiconductor chip  13  may include a chip pad  35 . The first and second insulating layers  31  and  32  may cover the chip pad  35  and the semiconductor chip  13 . An RDL layer  37  contacting the chip pad  35  through the first and second insulating layers  31  and  32  may be formed on the semiconductor chip  13 . The RDL layer  37  may be electrically connected to active/passive devices (not shown) in the semiconductor chip  13  via the chip pad  35 . 
     In some embodiments, the RDL  37  may be electrically connected to the TSV  21 . In this case, the TSV  21  may be electrically connected to the active/passive devices (not shown) in the semiconductor chip  13  via the RDL  37  and the chip pad  35 . 
     One surface of the semiconductor chip  13  may be covered by the encapsulant  25 . That is, the encapsulant  25  may cover the RDL  37 , the chip pad  35 , the first and second insulating layers  31  and  32 , and the TSV  21 . The internal connection terminal  23  may be exposed by the opening  25 H. That is, the opening  25 H may be aligned with the TSV  21 . 
     In some embodiments, another opening  25 H″ (see  FIG. 7B ) similar to the opening  25 H may also be formed on the RDL  37 . That is, at least one of the openings  25 H″ (see  FIG. 7B ) may be aligned with the RDL  37 . 
     The first, second and third insulating layers  31 ,  32  and  33  may be a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, and/or a combination thereof. The chip pad  35  may be a conductive layer comprising W, WN, Ti, TiN, Ta, TaN, Al, Cu, and/or a combination thereof. The RDL  37  may be a conductive layer comprising W, WN, Ti, TiN, Ta, TaN, Al, Cu, and a combination thereof. 
     Referring to  FIG. 8 , external connection terminals  43  may be attached to one surface of the wafer  11 . The external connection terminals  43  may contact lower ends of the TSVs  21 . The external connection terminals  43  and the internal connection terminals  23  may face each other. The external connection terminals  43  may a conductive bump, a solder ball, a conductive spacer, a PGA, a LGA, and/or a combination thereof. For example, the external connection terminals  43  may be formed using a solder ball attachment technique, a plating technique, and/or a screen printing technique. 
     In some embodiments, the external connection terminals  43  may be omitted. 
     Referring to  FIG. 9 , the encapsulant  25  and the wafer  11  may be divided into appropriate sizes to form a plurality of semiconductor packages. The plurality of semiconductor packages may be configured similar to a first semiconductor package  111  shown in  FIG. 9 . The first semiconductor package  111  may include the semiconductor chip  13 , the encapsulant  25 , the TSVs  21 , the external connection terminals  43 , and the internal connection terminals  23 . Dividing the encapsulant  25  and the wafer  11  into appropriate sizes may be performed using a singulation process. 
     The first semiconductor package  111  may have substantially the same width as the semiconductor chip  13 . The thickness of the first semiconductor package  111  may be determined by the encapsulant  25  and the semiconductor chip  13 . Eventually, the size of the first semiconductor package  111  may be reduced remarkably in comparison with the conventional art. In example embodiments, the dividing operations may divide the wafer and encapsulant such that the resulting semiconductor packages include only a single semiconductor chip, however, example embodiments are not limited thereto as the semiconductor packages may include more than one semiconductor chip. 
     In some embodiments, after dividing the encapsulant  25  and the wafer into appropriate sizes, the external connection terminals  43  may be formed. 
     Referring to  FIG. 10 , the method of forming a PoP in accordance with a first example embodiment of the inventive concepts may include stacking a second semiconductor package  152  on the first semiconductor package  111 . The first semiconductor package  111  may be formed using a method similar to that described with reference to  FIGS. 1 to 9 . 
     The second semiconductor package  152  may be formed by attaching a second semiconductor chip  53  onto a printed circuit board  52 . The second semiconductor chip  53  may be electrically connected to the printed circuit board  52  using a bonding wire  51 . The printed circuit board  52  and the second semiconductor chip  53  may be covered by a second encapsulant  55 . Second external connection terminals  45  may be formed on one surface of the printed circuit board  52 . The second semiconductor chip  53  may be electrically connected to the second external connection terminals  45  via the bonding wire  51  and the printed circuit board  52 . 
     The printed circuit board  52  may be a flexible printed circuit board, a rigid printed circuit board, or a combination thereof. The bonding wire  51  may be formed using a wire bonding technique, a beam lead bonding technique, a tape bonding technique, and/or a combination thereof. The bonding wire  51  may be gold wire, an aluminum wire, a beam lead, a conductive tape, and/or a combination thereof. 
     The second semiconductor chip  53  may include volatile memory chips such as a DRAM and a SRAM, non-volatile memory chips such as a flash memory, a phase change memory, a MRAM, and a RRAM, non-memory chips such as a logic device and a microprocessor, or a combination thereof. The second external connection terminals  45  may be a conductive bump, a solder ball, a conductive spacer, a PGA, a LGA, and/or a combination thereof. 
     An underfill  39  may be formed between the first semiconductor package  111  and the second semiconductor package  152 . The second external connection terminals  45  may contact the internal connection terminals  23  through the underfill  39 . In this example embodiment, the external connection terminals  43  may be electrically connected to the second semiconductor chip  53  via the TSV  21 , the internal connection terminals  23 , the second external connection terminals  45 , the printed circuit board  52 , and the bonding wire  51 . 
     The first semiconductor package  111  may have substantially the same width as the semiconductor chip  13 . The thickness of the first semiconductor package  111  may be determined by the encapsulant  25  and the semiconductor chip  13 . The printed circuit board  52  may have a width substantially equal to or smaller than that of the first semiconductor package  111 . That is, the second semiconductor package  152  may have a width substantially equal to or smaller than that of the first semiconductor package  111 . In accordance with the first example embodiment of the inventive concepts, since additional electric means disposed at an outer periphery of the semiconductor chip  13  to electrically connect the first semiconductor package  111  and the second semiconductor package  152  can be omitted, it is possible to remarkably reduce the size of the PoP in comparison with the conventional art. 
     In another embodiment, the printed circuit board  52  may have a width larger than that of the first semiconductor package  111 . That is, the second semiconductor package  152  may have a width larger than that of the first semiconductor package  111 . 
     Referring to  FIG. 11 , methods of forming a PoP in accordance with some example embodiments of the inventive concepts may include stacking the second semiconductor package  152  and a third semiconductor package  112  on the first semiconductor package  111 . The first semiconductor package  111  and the third semiconductor package  112  may be formed through a method similar to that of  FIGS. 1 to 9 . The second semiconductor package  152  may be similar to that described with reference to  FIG. 10 . The third semiconductor package  112  may be stacked between the first semiconductor package  111  and the second semiconductor package  152 . 
     Referring to  FIG. 12 , methods of forming a PoP in accordance with some example embodiments of the inventive concepts may include sequentially stacking the first semiconductor package  111  and the second semiconductor package  152  on a second printed circuit board  63 . The first semiconductor package  111  may be formed through a method similar to that described with reference to  FIG. 9 . The second semiconductor package  152  may be similar to that described with reference to  FIG. 10 . 
     The second printed circuit board  63  may be a flexible printed circuit board, a rigid printed circuit board, or a combination thereof. An underfill  39  may be formed between the second printed circuit board  63  and the first semiconductor package  111 . The external connection terminals  43  may contact the second printed circuit board  63  through the underfill  39 . 
     Board connection terminals  47  may be formed on one surface of the second printed circuit board  63 . The board connection terminals  47  may be a conductive bump, a solder ball, a conductive spacer, a PGA, a LGA, and a combination thereof. 
     The semiconductor chip  13  and the second semiconductor chip  53  may be electrically connected to the board connection terminals  47  via the TSVs  21  and the second printed circuit board  63 . Therefore, the second printed circuit board  63  does not require a marginal space  63 ′ to dispose bypass connection terminals  143 . 
     The width of the first semiconductor package  111  may be determined by the semiconductor chip  13 . For example, the width of the first semiconductor package  111  may be substantially equal to that of the semiconductor chip  13 . The width of the second printed circuit board  63  may be determined by the first semiconductor package  111 . For example, the width of the second printed circuit board  63  may be substantially equal to or smaller than that of the first semiconductor package  111 . In addition, the width of the second semiconductor package  152  may also be substantially equal to or smaller than that of the first semiconductor package  111 . Eventually, in accordance with some example embodiments of the inventive concepts, it is possible to remarkably reduce the size of the PoP in comparison with the conventional art. 
     In another example embodiment, the width of the second semiconductor package  152  may be larger than that of the first semiconductor package  111 . 
     Referring to  FIG. 13 , methods of forming a PoP in accordance with some example embodiments of the inventive concepts may include sequentially stacking the third semiconductor package  112 , a fourth semiconductor package  113  and a fifth semiconductor package  114  on the first semiconductor package  111 . The first, third, fourth and fifth semiconductor packages  111 ,  112 ,  113  and  114  may be formed through a method similar to that described with reference to  FIGS. 1 to 9 . The fifth semiconductor package  114  may be formed by omitting the process of forming the openings  25 H (see  FIG. 6 ). 
     In another embodiment, the fifth semiconductor package  114  may be formed by omitting the process of forming the internal connection terminals  23  (see  FIG. 3 ). In still another embodiment, the fifth semiconductor package  114  may not include the TSV  21 . 
     In the above example embodiment the wafer is cut in a manner such that the resulting semiconductor packages including only a single semiconductor chip. However, example embodiments of the inventive concepts are not limited thereto as the resulting semiconductor packages may include more than one semiconductor chip. Likewise, although the second semiconductor package is illustrated as having one semiconductor chip, the second semiconductor package may include several semiconductor chips. For example, the wafer may be cut such that two (or more) adjacent semiconductor chips arranged on the wafer are formed in one first package and the two semiconductor chips of the first package may be connected to two chips of a second semiconductor package.in the manner described above. 
     [Second Embodiment] 
       FIGS. 14 to 20  are cross-sectional views illustrating a method of forming a PoP in accordance with a second example embodiment of the inventive concepts. 
     Referring to  FIG. 14 , the method of forming a PoP in accordance with a second example embodiment of the inventive concepts may include forming a plurality of TSVs  21  in a wafer  11 . The wafer  11  may include a plurality of semiconductor chips  13 . The TSVs  21  may be formed to penetrate the wafer  11  from one surface to a depth that may or may not be predetermined. 
     An encapsulant  25  may be formed on the wafer  11  using a wafer level molding process. The encapsulant  25  may cover the TSVs  21 . The encapsulant  25  may be formed of EMC containing resin and filler. In some embodiments, the encapsulant  25  may be formed using liquid resin such as an underfill. 
     Referring to  FIG. 15 , the wafer  11  may be partially removed to expose the TSVs  21 . For example, a lower surface of the wafer  11  may be partially removed using a CMP process, an etch-back process, a back grinding process, and/or a combination thereof, until one ends of the TSVs  21  are exposed. As a result, the thickness of the wafer  11  can be remarkably reduced. 
     Openings  25 H exposing the TSVs  21  through the encapsulant  25  may be formed. The openings  25 H may be formed using a laser drilling technique or a dry etch technique. The openings  25 H may be referred to as mold vias. Upper surfaces of the TSVs  21  may be exposed by the bottoms of the openings  25 H. In some embodiments, the process of forming the openings  25 H may be performed prior to the process of partially removing the wafer  11  to expose the TSVs  21 . 
     External connection terminals  43  may be attached to one surface of the wafer  11 . One ends of the TSVs  21  may contact the external connection terminals  43 , and the other ends of the TSVs  21  may be exposed to the openings  25 H. In some embodiments, the external connection terminals  43  may be omitted. In another embodiment, the external connection terminals  43  may be formed prior to the process of forming the openings  25 H. 
     Referring to  FIG. 16 , the encapsulant  25  and the wafer  11  may be divided into appropriate sizes to form a plurality of semiconductor packages. The plurality of semiconductor packages may be configured similar to the first semiconductor package  111  shown in  FIG. 16 . The first semiconductor package  111  may include the semiconductor chip  13 , the encapsulant  25 , the TSVs  21 , and the external connection terminals  43 . Dividing the encapsulant  25  and the wafer  11  into appropriate sizes may be performed using a singulation process. 
     In some embodiments, after dividing the encapsulant  25  and the wafer  11  into appropriate sizes, the external connection terminals  43  may be formed. 
     Referring to  FIG. 17 , the method of forming a PoP in accordance with the second example embodiment of the inventive concepts may include stacking a second semiconductor package  152  on the first semiconductor package  111 . The first semiconductor package  111  may be formed through a method similar to that described with reference to  FIGS. 14 to 16 . 
     The second semiconductor package  152  may be formed by attaching a second semiconductor chip  53  onto a printed circuit board  52 . The second semiconductor chip  53  may be electrically connected to the printed circuit board  52  using a bonding wire  51 , or connected to the printed circuit board through a flip chip bonding method. The printed circuit board  52  and the second semiconductor chip  53  may be covered by a second encapsulant  55 . Second external connection terminals  45  may be formed on one surface of the printed circuit board  52 . The second semiconductor chip  53  may be electrically connected to the second external connection terminals  45  via the printed circuit board  52 . 
     An underfill  39  may be formed between the first and second semiconductor package  111  and  152 . The second external connection terminals  45  may contact the TSVs  21  through the underfill  39 . The external connection terminals  43  may be electrically connected to the second semiconductor chip  53  via the TSVs  21 , the second external connection terminals  45 , the printed circuit board  52 , and the bonding wire  51 . 
     Referring to  FIG. 18 , methods of forming a PoP in accordance with some example embodiments of the inventive concepts may include stacking the second and third semiconductor packages  152  and  112  on the first semiconductor package  111 . The first and third semiconductor packages  111  and  112  may be formed through a method similar to that described with reference to  FIGS. 14 to 16 . The second semiconductor package  152  may be similar to that described with reference to  FIG. 17 . The third semiconductor package  112  may be stacked between the first and second semiconductor packages  111  and  152 . 
     Referring to  FIG. 19 , methods of forming a PoP in accordance with some example embodiments of the inventive concepts may include sequentially stacking the first and second semiconductor packages  111  and  152  on the second printed circuit board  63 . The first semiconductor package  111  may be formed through a method similar to that described with reference to  FIGS. 14 to 16 . The second semiconductor package  152  may be similar to that described with reference to  FIG. 17 . An underfill may be formed between the second printed circuit board  63  and the first semiconductor package  111 . The external connection terminals  43  may contact the second printed circuit board  63  through the underfill  39 . Board connection terminals  47  may be formed on one surface of the second printed circuit board  63 . The semiconductor chip  13  and the second semiconductor chip  53  may be electrically connected to the board connection terminals  47  via the TSVs  21  and the second printed circuit board  63 . 
     The width of the first semiconductor package  111  may be determined by the semiconductor chip  13 . For example, the first semiconductor package  111  may have substantially the same width as the semiconductor chip  13 . The width of the second printed circuit board  63  may be determined by the first semiconductor package  111 . For example, the second printed circuit board  63  may have a width substantially equal to or smaller than that of the first semiconductor package  111 . In addition, the second semiconductor package  152  may also have a width substantially equal to or smaller than that of the first semiconductor package  111 . In accordance with some example embodiments of the inventive concepts, it is possible to remarkably reduce the size of the PoP. 
     In another embodiment, the second printed circuit board  63  may have a larger width than the first semiconductor package  111 . 
     Referring to  FIG. 20 , methods of forming a PoP in accordance with some example embodiments of the inventive concepts may include sequentially stacking the third, fourth and fifth semiconductor packages  112 ,  113  and  114  on the first semiconductor package  111 . The first, third, fourth and fifth semiconductor packages  111 ,  112 ,  113  and  114  may be formed through a method similar to that described with reference to  FIGS. 14  to  16 . The fifth semiconductor package  114  may be formed by omitting the process of forming the openings  25 H (see  FIG. 15 ). 
     [Third Embodiment] 
       FIGS. 21 and 22  are cross-sectional views illustrating a method of forming a PoP in accordance with a third example embodiment of the inventive concepts. 
     Referring to  FIG. 21 , the method of forming a PoP in accordance with the third example embodiment of the inventive concepts may include forming a plurality of TSVs  21  on a wafer  11 . The wafer  11  may include a plurality of semiconductor chips  13 . The wafer  11  may be partially removed to expose the TSVs  21 . For example, a lower surface of the wafer  11  may be partially removed using a CMP process, an etch-back process, a back grinding process, and/or a combination thereof, until one ends of the TSVs  21  are exposed. As a result, the thickness of the wafer  11  can be remarkably reduced. One ends of the TSVs  21  may be exposed by one surface of the wafer  11 , and the other ends of the TSVs  21  may be exposed by the other surface of the wafer  11 . 
     Referring to  FIG. 22 , internal connection terminals  23  may be formed on the TSVs  21 . The internal connection terminals  23  may be a conductive bump, a solder ball, a conductive spacer, a PGA, a LGA, and a combination thereof. The internal connection terminals  23  may contact the TSVs  21 . 
     The internal connection terminals  23  may be formed on an upper surface of the wafer  11 . That is, the internal connection terminals  23  may be formed on the same surface of the wafer  11  on which the active/passive devices (not shown) are formed. Otherwise, the internal connection terminals  23  may be formed on a lower surface of the wafer  11 . In some embodiments, the internal connection terminals  23  may be omitted. 
     An encapsulant  25  may be formed on the wafer  11  using a wafer level molding process. The encapsulant  25  may cover the internal connection terminals  23  and the TSVs  21 . The encapsulant  25  may be formed of EMC containing resin and filler. In some embodiments, the encapsulant  25  may be formed using liquid resin such as an underfill. Here, one surface of the wafer  11  may be exposed. 
     Openings  25 H exposing the internal connection terminals  23  through the encapsulant  25  may be formed. The openings  25 H may be formed using a laser drilling technique or a dry etch technique. The openings  25 H may be referred to as mold vias. Upper surfaces of the internal connection terminals  23  may be exposed by bottoms of the openings  25 H. In some embodiments, when the internal connection terminals  23  are omitted, the TSVs  21  may be exposed to the bottoms of the openings  25 H. 
     Then, the PoP may be formed through a method similar to that described with reference to  FIGS. 7 to 13 . 
     [Fourth Embodiment] 
       FIG. 23  is a cross-sectional view illustrating a method of forming a PoP in accordance with a fourth example embodiment of the inventive concepts. 
     Referring to  FIG. 23 , the method of forming a Pop in accordance with the fourth example embodiment of the inventive concepts may include forming a plurality of TSVs  21  on a wafer  11 . The wafer  11  may include a plurality of semiconductor chips  13 . The wafer  11  may be partially removed to expose the TSVs  21 . For example, a lower surface of the wafer  11  may be partially removed using a CMP process, an etch-back process, a back grinding process, and/or a combination thereof, until one ends of the TSVs  21  are exposed. As a result, the thickness of the wafer  11  can be remarkably reduced. One ends of the TSVs  21  may be exposed by one surface of the wafer  11 , and the other ends of the TSVs  21  may be exposed by the other surface of the wafer  11 . 
     An encapsulant  25  may be formed on the wafer  11  using a wafer level molding process. The encapsulant  25  may cover the TSVs  21 . The encapsulant  25  may be formed of EMC containing resin and filler. In some embodiments, the encapsulant  25  may be formed using liquid resin such as an underfill. 
     The encapsulant  25  may be formed on an upper surface of the wafer  11 . That is, the encapsulant  25  may be formed on the same surface of the wafer  11  on which active/passive devices (not shown) are formed. Otherwise, the encapsulant  25  may be formed on a lower surface of the wafer  11 . Here, one surface of the wafer  11  may be exposed. 
     Then, the PoP may be formed through a method described with reference to  FIGS. 15 to 20 . 
     [Fifth Embodiment] 
       FIGS. 24 to 26  are cross-sectional views illustrating a method of forming a PoP in accordance with a fifth example embodiment of the inventive concepts. 
     Referring to  FIG. 24 , the method of forming a PoP in accordance with the fifth example embodiment of the inventive concepts may include forming a plurality of TSVs  21  in a wafer  11 . The wafer  11  may include a plurality of semiconductor chips  13 . The wafer  11  may be partially removed to expose the TSVs  21 . For example, a lower surface of the wafer  11  may be partially removed using a CMP process, an etch-back process, a back grinding process, and/or a combination thereof, until one ends of the TSVs  21  are exposed. As a result, the thickness of the wafer  11  can be remarkably reduced. One ends of the TSVs  21  may be exposed by one surface of the wafer  11 , and the other ends of the TSVs  21  may be exposed by the other surface of the wafer  11 . 
     Encapsulants  25  and  25 ′ may be formed to cover opposite surfaces of the wafer  11  using a wafer level molding process. The encapsulants  25  and  25 ′ may cover the TSVs  21 . The encapsulants  25  and  25 ′ may be formed of EMC containing resin and filler. In some embodiments, the encapsulants  25  and  25 ′ may be formed using liquid resin such as an underfill. The encapsulants  25  and  25 ′ may include a first encapsulant  25  and a second encapsulant  25 ′. 
     Openings  25 H and  25 H′ exposing the TSVs  21  through the encapsulants  25  and  25 ′ may be formed. The openings  25 H and  25 H′ may be formed using a laser drilling technique. The openings  25 H and  25 H′ may be referred to as mold vias. Surfaces of the TSVs  21  may be exposed to bottoms of the openings  25 H and tops of the openings  25 H′. 
     Referring to  FIG. 25 , lower and upper connection terminals  49  and  49 ′ may be formed at lower and upper parts of the wafer  11 . One ends of the TSVs  21  may contact the lower connection terminals  49 , and the other ends of the TSVs  21  may contact the upper connection terminals  49 ′. In some embodiments, the lower and upper connection terminals  49  and  49 ′ may be selectively omitted. For example, all of the upper connection terminals  49 ′ may be omitted. The lower and upper connection terminals  49  and  49 ′ may protrude from surfaces of the encapsulants  25  and  25 ′. 
     The lower connection terminals  49  may be a conductive bump, a solder ball, a conductive spacer, a PGA, a LGA, and a combination thereof. The upper connection terminals  49 ′ may be one selected from the group consisting of a conductive bump, a solder ball, a conductive spacer, a PGA, a LGA, and a combination thereof. 
     The encapsulants  25  and  25 ′ and the wafer  11  may be divided into appropriate sizes to form a plurality of semiconductor packages. The plurality of semiconductor packages may have a constitution similar to the first semiconductor package  111  shown in  FIG. 26 . The first semiconductor package  111  may include the semiconductor chip  13 , the encapsulants  25  and  25 ′, the TSVs  21 , and the lower and upper connection terminals  49  and  49 ′. Dividing the encapsulants  25  and  25 ′ and the wafer  11  into appropriate sizes may be performed using a singulation process. 
     In some embodiments, after dividing the encapsulants  25  and  25 ′ and the wafer  11  into appropriate sizes, the lower and upper connection terminals  49  and  49 ′ may be formed. 
     Referring to  FIG. 26 , the method of forming a PoP in accordance with the fifth example embodiment of the inventive concepts may include stacking a second semiconductor package  152  on the first semiconductor package  111 . The first semiconductor package  111  may be formed through a method similar to that described with reference to  FIGS. 24 and 25 . 
     The second semiconductor package  152  may be formed by attaching a second semiconductor chip  53  onto a printed circuit board  52 . The second semiconductor chip  53  may be electrically connected to the printed circuit board  52  using a bonding wire  51  or a flip chip bonding method. The printed circuit board  52  and the second semiconductor chip  53  may be covered by a second encapsulant  55 . Second external connection terminals  45  may be formed at one surface of the printed circuit board  52 . The second semiconductor chip  53  may be electrically connected to the second external connection terminals  45  via the bonding wire  51  and the printed circuit board  52 . 
     An underfill  39  may be formed between the first and second semiconductor packages  111  and  152 . The second external connection terminals  45  may contact the TSVs  21  through the underfill  39 . The lower connection terminals  49  may be electrically connected to the second semiconductor chip  53  via the TSVs  21 , the second external connection terminals  45 , the printed circuit board  52 , and the bonding wire  51 . 
     [Sixth Embodiment] 
       FIG. 27  is a plan view of a semiconductor module employing a PoP in accordance with a sixth embodiment of the inventive concepts. 
     Referring to  FIG. 27 , the semiconductor module employing a PoP in accordance with the sixth example embodiment of the inventive concepts may include a module substrate  210 , a plurality of PoPs  207 , and a control chip package  203 . Input/output terminals  205  may be formed at the module substrate  210 . The PoPs  207  may be configured similar to that described with reference to  FIGS. 1 to 26 . 
     The PoPs  207  and the control chip package  203  may be mounted on the module substrate  210 . The PoPs  207  and the control chip package  203  may be electrically connected to the input/output terminals  205  in series or parallel. 
     The control chip package  203  may be omitted. The PoP  207  may include volatile memory chips such as a DRAM and a SRAM, non-volatile memory chips such as a flash memory, a phase change memory, a MRAM, and a RRAM, non-memory chips such as a logic device and a microprocessor, or a combination thereof. In this case, the semiconductor module in accordance with a sixth example embodiment of the inventive concepts may be a memory module. 
     [Seventh Embodiment] 
       FIG. 28  is a block diagram of an electronic system employing a PoP in accordance with a seventh example embodiment of the inventive concepts. 
     Referring to  FIG. 28 , an electronic system  1100  in accordance with the seventh example embodiment of the inventive concepts may include a controller  1110 , an input/output device  1120 , a memory device  1130 , an interface  1140 , and a bus structure  1150 . The memory device  1130  may be constituted by a PoP similar to that described with reference to  FIGS. 1 to 26 . In addition, the controller  1110  may also be constituted by a PoP similar to that described with reference to  FIGS. 1 to 26 . Further, a combination of the controller  1110  and the memory device  1130  may be constituted by a PoP similar to that described with reference to  FIGS. 1 to 26 . The bus structure  1150  may function to provide a path through which data moves between the controller  1110 , the input/output device  1120 , the memory device  1130 , and the interface  1140 . 
     The controller  1110  may include at least one microprocessor, a digital signal processor, a microcontroller, and/or at least one of logic devices capable of performing functions similar to the above. The input/output device  1120  may include at least one selected from a keypad, a keyboard, a display device, etc. The memory device  1130  may function to store data and/or a command, etc., performed by the controller  1110 . 
     The memory device  1130  may include volatile memory chips such as a DRAM and a SRAM, non-volatile memory chips such as a flash memory, a phase change memory, a MRAM, and a RRAM, non-memory chips such as a logic device and a microprocessor, and/or a combination thereof. For example, the electronic system  1100  may be a solid state disk (SSD). 
     The interface  1140  may function to transmit data to a communication network or receive data from the communication network. The interface  1140  may be a wired or wireless system. For example, the interface  1140  may include an antenna, a wired/wireless transceiver, etc. The electronic system  1100  may further include an application chipset, a camera image processor (CIS), an input/output device, etc. 
     The electronic system  1100  may be implemented by a mobile system, a personal computer, an industrial computer, logic systems performing various functions, etc. For example, the mobile system may be any one of a personal digital assistant (PDA), a mobile computer, a web tablet, a mobile phone, a wireless phone, a laptop computer, a memory card, a digital music system, and an information transmission/reception system. When the electronic system  1100  is wireless communication equipment, the electronic system  1100  may be used in communication systems such as code division multiple access (CDMA), global system for mobile communication (GSM), north American digital cellular (NADC), enhanced-time division multiple access (E-TDMA), wideband code division multiple access (WCDMA), and CDMA2000. 
     [Eighth Embodiment] 
       FIG. 29  is a perspective view of an electronic device employing a PoP in accordance with an eighth example embodiment of the inventive concepts. 
     Referring to  FIG. 29 , a PoP similar to that described with reference to  FIGS. 1 to 26  may be applied to an electronic device  2000  such as a mobile phone. Since the PoP is advantageous for reduction in size and improvement in performance, the electronic device  2000  simultaneously performing various functions becomes lightweight and compact. The electronic device  2000  is not limited to the mobile phone shown in  FIG. 29 , but includes various electronic devices such as a mobile electronic device, a laptop computer, a mobile computer, a portable multimedia player (PMP), an MP3 player, a camcorder, a web tablet, a wireless phone, a navigation device, a PDA, etc. 
     [Ninth Embodiment] 
       FIG. 30  is a system block diagram of an electronic device employing a PoP in accordance with a ninth example embodiment of the inventive concepts. 
     Referring to  FIG. 30 , a PoP similar to that described with reference to  FIGS. 1 to 26  may be applied to an electronic system  2100 . The electronic system  2100  may include a body  2110 , a microprocessor unit  2120 , a power unit  2130 , a function unit  2140 , and a display controller unit  2150 . The body  2110  may include a mother board formed of a printed circuit board, and the microprocessor unit  2120 , the power unit  2130 , the function unit  2140 , and the display controller unit  2150  may be mounted on the body  2110 . The display unit  2160  may be disposed in the body  2119  or on a surface of the body  2110 . For example, the display unit  2160  may be disposed on the surface of the body  2110  to display an image processed by the display control unit  2150 . 
     The power unit  2130  may function to receive a certain voltage from an external battery (not shown), etc., distribute the voltage into required voltage levels, and supply the voltage levels to the microprocessor unit  2120 , the function unit  2140 , the display controller unit  2150 , etc. 
     The microprocessor unit  2120  may receive a voltage from the power unit  2130  to control the function unit  2140  and the display unit  2160 . The function unit  2140  may perform various functions of the electronic system  2100 . For example, when the electronic system  2100  is a mobile phone, the function unit  2140  may include various elements that can perform functions of the mobile phone such as dialing, image output to the display unit  2160  through communication with an external apparatus  2170 , sound output to a speaker, etc. When the electronic system  2100  includes a camera, the function unit  2140  may be a camera image processor. 
     For example, when the electronic system  2100  is connected to a memory card, etc., to expand the capacity thereof, the function unit  2140  may be a memory card controller. The function unit  2140  may communicate with the external apparatus  2170  through a wired or wireless communication unit  2180 . Further, when the electronic system  2100  requires a universal serial bus (USB) to expand functions, the function unit  2140  may be an interface controller. 
     The PoP similar to that described with reference to  FIGS. 1 to 26  may be applied to at least one of the microprocessor unit  2120  and the function unit  2140 . For example, the external connection terminals  43 , the board connection terminals  47 , and the lower connection terminals  49  may be connected to a bond finger formed at the body  2110 . 
     As can be seen from the foregoing, an encapsulant covering a wafer is formed using a wafer level molding process, and the encapsulant and semiconductor chips are divided to form a plurality of semiconductor packages. Another semiconductor package is stacked on one selected from the semiconductor packages. The other semiconductor package is electrically connected to TSVs. The semiconductor packages may have substantially the same width as the semiconductor chips. The other semiconductor package may have a width equal to or smaller than that of one selected from the semiconductor packages. Further, the other semiconductor package may have a larger width than that of one selected from the semiconductor packages. Eventually, it is possible to remarkably reduce the size of a PoP in comparison with the conventional art, and improve reliability thereof through the wafer level molding process. 
     The foregoing is illustrative of example embodiments and is not to be construed as limiting thereof. Although a few example embodiments have been described, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from the novel teachings and advantages. Accordingly, all such modifications are intended to be included within the scope of the inventive concepts as defined in the claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function, and not only structural equivalents but also equivalent structures. Therefore, it is to be understood that the foregoing is illustrative of various example embodiments and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed example embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims.