Patent Publication Number: US-2017372964-A1

Title: Semiconductor device and method comprising redistribution layers

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No.  15 / 292 , 082 , titled “Semiconductor Device and Method Comprising Redistribution Layers,” filed Oct. 12, 2016, now pending, which is a continuation in part of U.S. application Ser. No. 14/930,514, titled “Semiconductor Device and Method Comprising Redistribution Layers,” filed Nov. 2, 2015, now issued as U.S. Pat. No. 9,576,919, which is a continuation in part of U.S. application Ser. No. 14/642,531 entitled “Semiconductor Device and Method Comprising Thickened Redistribution Layers,” which was filed on Mar. 9, 2015, now issued as U.S. Pat. No. 9,177,926, which application claims the benefit of U.S. Provisional Patent No. 61/950,743, entitled “Wafer-Level-Chip-Scale-Packages with Thick Redistribution Layer Traces,” which was filed on Mar. 10, 2014, and application Ser. No. 14/642,531 is also a continuation in part of U.S. application Ser. No. 14/584,978, entitled “Die Up Fully Molded Fan-Out Wafer Level Packaging,” which was filed on Dec. 29, 2014, now issued as U.S. Pat. No. 9,337,086, which application is a continuation of U.S. application Ser. No. 14/024,928, entitled “Die Up Fully Molded Fan-Out Wafer Level Packaging,” which was filed on Sep. 12, 2013, now issued as U.S. Pat. No. 8,922,021, which application claims the benefit of the filing date of U.S. Provisional Patent No. 61/672,860, entitled “Fan-Out Semiconductor Package,” which was filed on Jul. 18, 2012, and application Ser. No. 14/024,928 is also a continuation of U.S. application Ser. No. 13/632,062, entitled “Die Up Fully Molded Fan-Out Wafer Level Packaging,” which was filed on Sep. 30, 2012, now issued as U.S. Pat. No. 8,535,978, which application is a continuation in part of U.S. application Ser. No. 13/341,654, entitled “Fully Molded Fan-Out,” which was filed on Dec. 30, 2011, now issued as U.S. Pat. No. 8,604,600, the disclosures of each of which are hereby incorporated by this reference in their entireties. 
     Application Ser. No. 15/292,082 is also a continuation in part application of U.S. application Ser. No. 14/261,265, titled “Panelized Packaging With Transferred Dielectric,” filed Apr. 24, 2014, now abandoned, which is a divisional application of U.S. application Ser. No. 12/985,212, titled “Panelized Packaging With Transferred Dielectric,” filed Jan. 5, 2011, now abandoned, which claims the benefit of U.S. Provisional Patent No. 61/305,122, filed Feb. 16, 2010, the disclosures of each of which are hereby incorporated by this reference in their entireties. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present invention relate to the field of packaging semiconductor die. 
     BACKGROUND 
     Semiconductor devices are commonly found in modern electronic products. Semiconductor devices vary in the number and density of electrical components. Discrete semiconductor devices generally contain one type of electrical component, for example, light emitting diode (LED), small signal transistor, resistor, capacitor, inductor, and power metal oxide semiconductor field effect transistor (MOSFET). Integrated semiconductor devices typically contain hundreds to millions of electrical components. Examples of integrated semiconductor devices include microcontrollers, microprocessors, charged-coupled devices (CCDs), solar cells, and digital micro-mirror devices (DMDs). 
     Semiconductor devices perform a wide range of functions such as signal processing, high-speed calculations, transmitting and receiving electromagnetic signals, controlling electronic devices, transforming sunlight to electricity, and creating visual projections for television displays. Semiconductor devices are found in the fields of entertainment, communications, power conversion, networks, computers, and consumer products. Semiconductor devices are also found in military applications, aviation, automotive, industrial controllers, and office equipment. 
     Semiconductor devices exploit the electrical properties of semiconductor materials. The atomic structure of semiconductor material allows its electrical conductivity to be manipulated by the application of an electric field or base current or through the process of doping. Doping introduces impurities into the semiconductor material to manipulate and control the conductivity of the semiconductor device. 
     A semiconductor device contains active and passive electrical structures. Active structures, including bipolar and field effect transistors, control the flow of electrical current. By varying levels of doping and application of an electric field or base current, the transistor either promotes or restricts the flow of electrical current. Passive structures, including resistors, capacitors, and inductors, create a relationship between voltage and current necessary to perform a variety of electrical functions. The passive and active structures are electrically connected to form circuits, which enable the semiconductor device to perform high-speed calculations and other useful functions. 
     Semiconductor devices are generally manufactured using two complex manufacturing processes, that is, front-end manufacturing, and back-end manufacturing, each involving potentially hundreds of steps. Front-end manufacturing involves the formation of a plurality of semiconductor die on the surface of a semiconductor wafer. Each semiconductor die is typically identical and contains circuits formed by electrically connecting active and passive components. Back-end manufacturing involves singulating individual semiconductor die from the finished wafer and packaging the die to provide structural support and environmental isolation. The term “semiconductor die” as used herein refers to both the singular and plural form of the words, and accordingly can refer to both a single semiconductor device and multiple semiconductor devices. 
     One goal of semiconductor manufacturing is to produce smaller semiconductor devices. Smaller devices typically consume less power, have higher performance, and can be produced more efficiently. In addition, smaller semiconductor devices have a smaller footprint, which is desirable for smaller end products. A smaller semiconductor die size can be achieved by improvements in the front-end process resulting in semiconductor die with smaller, higher density, active and passive components. Back-end processes may result in semiconductor device packages with a smaller footprint by improvements in electrical interconnection and packaging materials. 
     A common implementation of panelized packaging gaining acceptance in industry is fan-out wafer level packaging (WLP) in which multiple semiconductor die are placed face down on a temporary tape carrier. The multiple semiconductor die and temporary tape carrier are overmolded with a molding compound using a compression molding process. After molding, the tape carrier is removed leaving the active surface of the multiple semiconductor die exposed in a structure commonly referred to as a reconstituted wafer. Subsequently, a wafer level chip scale package (WLCSP) build-up structure is formed on top of the reconstituted wafer. Bail grid array (BGA) balls are attached to the reconstituted wafer and then the reconstituted wafer is saw singulated to form individual packages. It has been observed that the die unit placement and overmolding processes may cause displacement and/or rotation of the semiconductor die, resulting in defective packages and yield loss. 
     SUMMARY 
     Accordingly, in an aspect, a method of making a plurality of semiconductor device can include placing a single layer dielectric film comprising a first surface and a second surface opposite the first surface directly on a temporary carrier substrate. The first surface and the second surface of the single layer dielectric film can be substantially parallel. A plurality of semiconductor die can be placed face down directly on the first surface of the single layer dielectric film opposite the second surface of the dielectric film attached to the temporary carrier substrate. The plurality of semiconductor die can be disposed over the temporary carrier substrate. The single layer dielectric film can be cured after placing the plurality of semiconductor die on the first surface of the single layer dielectric film to lock the plurality of semiconductor die in place on the single layer dielectric film and render the single layer dielectric film non-photoimageable. The plurality of semiconductor die can be encapsulated on the cured single layer dielectric film with an encapsulant while the temporary carrier substrate supports the single layer dielectric film and the plurality of semiconductor die. The temporary carrier substrate can be released from the cured single layer dielectric film after encapsulating the plurality of semiconductor die on the cured single layer dielectric film, and prior to patterning the cured single layer dielectric film. The cured single layer dielectric film can be patterned utilizing a mask-less patterning technique to form redistribution layer (RDL) trace pattern openings and to form a via hole that extends from the first surface of the cured single layer dielectric film to the second surface of the cured single layer dielectric film after having removed the temporary carrier substrate. A thick conductive layer comprising a thickness greater than 8 micrometers (μm) can be formed and extend over the plurality of semiconductor die and directly contacts the second surface of the patterned cured single layer dielectric film and the via hole, the conductive layer being substantially parallel to, and extending across, the second surface of the patterned cured single layer dielectric film. The plurality of semiconductor die can be singulated by cutting through the encapsulant and the cured single layer dielectric film to form individual packages. 
     The method of making the plurality of semiconductor packages can further comprise placing the plurality of semiconductor die on the first surface of the single layer dielectric film by placing the plurality of semiconductor die on a surface of a B-stage cured epoxy. The via holes and the RDL trace pattern openings can be formed within the single layer dielectric film using laser ablation, the RDL trace pattern openings intersecting with the via holes in the single layer dielectric film in a stair step fashion. The method can further comprise applying a photoimageable polymer layer over the patterned cured single layer dielectric film, forming a plurality of openings in the photoimageable polymer layer using a photolithographic patterning technique, and cutting through the cured single layer dielectric film and the encapsulant without cutting through the photoimageable polymer layer to singulate the plurality of semiconductor die. The thick conductive layer can be formed comprising a thickness greater than or equal to 20 μm. A composition of the encapsulant can be the same as a composition of the dielectric film. The single layer dielectric film can comprise a thickness in a range of 5-50 micrometers, a glass transition temperature (Tg) in a range of 140-190° C., and 50-90% of ceramic filler or silica filler by weight. An active surface of the plurality of semiconductor die can be placed on the first surface of the single layer dielectric film. 
     In another aspect, a method of making a semiconductor device can comprise placing a single layer dielectric film on a temporary carrier substrate, the single layer dielectric film comprising a first surface and a second surface opposite the first surface. A plurality of semiconductor die can be placed directly on the first surface of the single layer dielectric film opposite the second surface of the single layer dielectric film attached to the temporary carrier substrate. The single layer dielectric film can be cured after placing the plurality of semiconductor die on the first surface of the single layer dielectric film to lock the plurality of semiconductor die in place on the single layer dielectric film. The plurality of semiconductor die can be encapsulated directly on the single layer dielectric film with an encapsulant. The single layer dielectric film can be patterned utilizing a mask-less patterning technique to form a via hole that extends from the first surface of the cured single layer dielectric film to the second surface of the cured single layer dielectric film after removing the temporary carrier substrate. A conductive layer can be formed directly on, substantially parallel to, and extending across, the second surface of the patterned single layer dielectric film, within the vial hole, and over the plurality of semiconductor die. 
     The method of making the semiconductor packages can further comprise placing an active surface of the plurality of semiconductor die on the first surface of the single layer dielectric film. The single layer dielectric film can be laminated to the temporary carrier substrate at a temperature in a range of 100-130° C., wherein the single layer dielectric film comprises a thickness in a range of 5-50 micrometers, a glass transition temperature (Tg) in a range of 140-190° C., and further comprises 50-90% of ceramic filler or silica filler by weight. After laminating the single layer dielectric film to the temporary carrier, placing the plurality of semiconductor die directly on the first surface of the single layer dielectric film, and curing the single layer dielectric film at a temperature greater than the glass transition temperature (Tg) of the single layer dielectric film. Laser ablation can be used to form the via hole comprising a first depth and RDL trace pattern openings comprising a second depth less than the first depth to intersect with the via hole in the single layer dielectric film. The conductive layer can be formed as a thick RDL trace comprising a thickness greater than or equal to 20 μm. The plurality of semiconductor die can be formed with thick RDL traces formed while the plurality of semiconductor die is part of a native wafer, and the plurality of semiconductor die can be placed directly on the first surface of the single layer dielectric film with the thick RDLs directly contacting the first surface of the single layer dielectric film. 
     In another aspect, the a method of making a semiconductor device can comprise placing a single layer dielectric film on a temporary carrier substrate, the single layer dielectric film comprising a first surface and a second surface opposite the first surface. A plurality of semiconductor die can be placed directly on the first surface of the single layer dielectric film with the plurality of semiconductor die disposed over the temporary carrier substrate. The single layer dielectric film can be cured after placing the plurality of semiconductor die on the surface of the single layer dielectric film. The plurality of semiconductor die can be encapsulated on the single layer dielectric film with an encapsulant while the temporary carrier substrate supports the single layer dielectric film and the plurality of semiconductor die. The single layer dielectric film can be patterned and leave a portion of the single layer dielectric film disposed over an active surface of the plurality of semiconductor die. A conductive layer can be formed directly on, and extend across, the second surface of the patterned single layer dielectric film and over the plurality of semiconductor die. 
     The method of making the plurality of semiconductor packages can further comprise forming a composition of the encapsulant the same as a composition of the single layer dielectric film. A conductive layer can be formed directly on a surface of the patterned single layer dielectric film. The single layer dielectric film can comprise a thickness in a range of 5-50 micrometers, a glass transition temperature (Tg) in a range of 140-190° C., and further comprises 50-90% of ceramic filler or silica filler by weight. Laser ablation can be used to form both vias and a redistribution layer trace pattern openings in within the single layer dielectric film, the RDL trace pattern intersecting with the vias in the single layer dielectric film in a stair step fashion. The conductive layer can comprise a thick redistribution layer comprising a thickness greater than or equal to 20 μm. 
     The foregoing and other aspects, features, and advantages will be apparent to those artisans of ordinary skill in the art from the DESCRIPTION and DRAWINGS, and from the CLAIMS. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A-1N  illustrate an aspect of a method of forming a fan-out WLP. 
         FIGS. 2A-2L  illustrate an aspect of a method of forming a fan-out WLP. 
         FIG. 3  illustrates a cross-sectional side view of an embodiment of a semiconductor package. 
         FIG. 4  illustrates a cross-sectional side view of another embodiment of a semiconductor package. 
         FIG. 5  illustrates a cross-sectional side view of another embodiment of a semiconductor package. 
         FIG. 6  illustrates a cross-sectional side view of another embodiment of a semiconductor package. 
         FIG. 7  illustrates a top or plan view of a semiconductor package. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure includes one or more embodiments in the following description with reference to the figures, in which like numerals represent the same or similar elements. It will be appreciated by those skilled in the art that the description is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the disclosure as defined by the appended claims and their equivalents as supported by the following disclosure and drawings. 
     In the following description, numerous specific details are set forth, such as specific configurations, compositions, and processes, etc., in order to provide a thorough understanding of the disclosure. In other instances, well-known processes and manufacturing techniques have not been described in particular detail in order to not unnecessarily obscure the disclosure. Furthermore, the various embodiments shown in the FIGs. are illustrative representations and are not necessarily drawn to scale. 
     Embodiments of the present invention disclose methods and structures to improve panelized packaging, such as fan-out WLCSP. In the following description, specific embodiments are described with regard to single die applications. Embodiments of the present invention may also be useful in multi-die modules or some combination of die and passive components (such as a capacitor, inductor or resistor) and/or other components (such as an optical element, connector or other electronic component) within modules. 
     In the following description, numerous specific details are set forth, such as specific configurations, compositions, and processes, etc., in order to provide a thorough understanding of the present invention. In other instances, well-known processes and manufacturing techniques have not been described in particular detail in order to not unnecessarily obscure the present invention. Furthermore, it is to be understood that the various embodiments shown in the Figures are illustrative representations and are not necessarily drawn to scale. 
     The terms “over”, “between” and “on” as used herein refer to a relative position of one layer with respect to other layers. One layer deposited or disposed over or under another layer may be directly in contact with the other layer or may have one or more intervening layers. One layer deposited or disposed between layers may be directly in contact with the layers or may have one or more intervening layers. In contrast, a first layer “on” a second layer is in contact with that second layer. 
     In an embodiment, a panelized package is created by placing a plurality of semiconductor die face down on a dielectric film, which may be laminated on a temporary carrier substrate. The dielectric film is then cured to lock the plurality of semiconductor die in place, rendering the dielectric film non-photoimageable. During cure changes occur at the molecular level in the dielectric film material where the mechanical properties of the dielectric film substantially fully develop and the semiconductor die permanently adhere to the resultant rigid dielectric film. Depending upon the particular materials employed curing may be associated with cross-linking. The plurality of semiconductor die are then encapsulated on the dielectric film. In an embodiment, encapsulation may be achieved by an overmolding process such as compression molding. In an embodiment, encapsulation may be performed by a lamination process such as vacuum lamination. Because the plurality of semiconductor die have been locked into place prior to encapsulation, displacement and/or rotation of the individual semiconductor die may be reduced during encapsulation where displacement and/or rotation of the individual semiconductor die can be problematic due to pressures exerted on the individual semiconductor die. The temporary carrier substrate may then be released from the dielectric film. A water level chip scale package (WLCSP) build-up structure may then be formed including the rigid, cured, continuous dielectric film which may be patterned utilizing a maskless patterning technique. 
     It has been observed that die unit placement and encapsulation processes of conventional processing technologies may cause displacement and/or rotation of the orientation of any of the plurality of semiconductor die on a temporary tape carrier. This may be attributed to the semiconductor die not being rigidly attached to the temporary tape carrier, deformation of the tape carrier, as well as shrinkage of the encapsulant during curing of the encapsulant. The impact of conventional methods utilizing a temporary tape carrier is either yield loss due to misalignment of first vias to the die unit bond pads, or the addition of some intermediate form of bond pad re-routing in native wafer form (prior to panelization) to make large bond pads as targets to ensure the first vias make connection despite die unit movement. As a result, conventional processing technology requires that bond pads on the semiconductor die be larger than necessary to avoid yield loss from the panel, thereby reducing the application space for WLP technology. 
     In accordance with embodiments of the present invention, a continuous dielectric film, such as a laminated epoxy film, can replace both the temporary, sacrificial tape and the first dielectric layer in the build-up structure. This has the potential to reduce cost and process steps. Locking the plurality of semiconductor die in place on the continuous dielectric film prior to encapsulation may reduce displacement and/or rotation of the orientation of the individual semiconductor die within a panel or reticulated wafer thereby eliminating or reducing package assembly yield loss caused by misalignment of the semiconductor die during panelization and allowing for a smaller bond pad opening on the semiconductor die. Epoxy is a suitable material from which to form the dielectric film because it may be cured to lock the plurality of semiconductor die in place, and also because a similar epoxy can be utilized as an overmolding or lamination encapsulant. Other materials having suitable adhesive properties for locking the plurality of semiconductor die in place are also contemplated with embodiments of the invention such as, but not limited to, polyimide and silicone. 
     In another aspect, embodiments of the present invention disclose methods of panelized packaging which may utilize lamination techniques. For example, lamination may provide for uniform thickness of a laminated dielectric film across a temporary carrier substrate. A laminated dielectric film may also be subsequently removable from the temporary carrier substrate. In a particular embodiment, a B-stage cured dielectric film material such as a B-stage cured epoxy material is laminated onto the temporary carrier substrate. A B-stage cured material is commonly one in which a limited reaction between a resin and hardener has taken place so that the material is in a solid state with partially developed network (semi-cured). In this state, the B-stage cured material may still be fusible. The B-stage cured material may be final cured by additional exposure to heat and/or radiation, where the network may become fully developed (e.g. cross-linked), rigid and non-photoimageable. Final ring may also be accompanied by moderate flow. 
     Such a B-stage cured dielectric film material may retain adhesive properties (tack) that assist with retaining the location of the plurality of semiconductor die during placement of the plurality of semiconductor die on the dielectric film, and experiences only moderate flow during final cure to lock the plurality of semiconductor die in place. As a result, the laminated dielectric film formed from a B-stage cured material may exhibit desirable planarity after across the panel after cure. Additionally, as a result of the planarity of the dielectric film surface upon which the plurality of semiconductor die are placed, a discontinuity does not exist in the dielectric film adjacent the edges of the semiconductor die. Accordingly, the active surfaces of the semiconductor die and the dielectric film surface upon which the due units are placed are both in the same plane which may be beneficial for device reliability metrics such as delamination during moisture sensitivity testing, or mounting to a motherboard or other product. 
     Lamination may also be utilized to encapsulate the plurality of semiconductor die on the dielectric film. For example, vacuum encapsulation can be utilized with a B-stage cured epoxy of similar or identical composition as the dielectric film. As a result, the physical properties such as coefficient of thermal expansion (CTE), hardness and elastic modulus or weight percent of filler in the laminated encapsulant layer and the dielectric film can be closely matched or identical, thereby improving the integrity of the final packages. In addition, singulation of packages having similar or identical compositions for the dielectric film and encapsulant may be associated with reduced chipping or delamination between layers. 
       FIGS. 1A-1N  and  FIGS. 2A-2L  illustrate methods for forming a fan-out WLCSP in which a permanent dielectric film  102  is patterned during the formation of alternative build-up structures in accordance with various embodiments.  FIGS. 1A-1N  illustrate an embodiment in which a RDL trace  120  of the build-up structure is formed over the dielectric film  102 .  FIGS. 2A-2L  illustrate an embodiment in which a RDL trace of the build-up structure is formed within the dielectric film. Various modifications and changes may be made to the particular build-up structures illustrated including, but not limited to, build-up structures with multiple dielectric layers and device interconnect traces, which may or may not be associated with the RDL traces. Such multi-layer build-up structures can be utilized in both single-die package applications as well as multi-device modules. Accordingly, the specific embodiments illustrated in  FIGS. 1A-1N  and  FIGS. 2A-2L , are to be regarded in an illustrative sense rather than a restrictive sense. 
     Referring to  FIG. 1A , in an embodiment, the process begins with attaching a dielectric film  102  to a temporary carrier substrate  104 . In an embodiment, the dielectric film  102  is laminated to the temporary carrier substrate  104 . Such a laminated dielectric film  102  may be uniformly applied across the temporary carrier substrate  104  and also be readily releasable from the temporary carrier substrate  104  at a later stage. For example, lamination can be performed by rolling under heat and pressure. Other methods of attaching the dielectric film  102  to the temporary carrier substrate  104  are also contemplated such as spin coating, printing, and spraying. 
     In an embodiment, the dielectric film  102  is formed of a material such as an epoxy, polyimide or silicone in which the mechanical properties of the material are substantially full developed by curing. Dielectric film  102  may be formed of a printed circuit board (PCB) prepreg material. For example, dielectric film  102  may be formed of a partially cured, B-stage cured epoxy, and may include additional filler(s). In an embodiment, it is possible to laminate the dielectric film  102  at temperatures significantly below the glass transition temperature (Tg) of the resultant fully cured dielectric film  102 . For example, a dielectric film  102  including a B-stage cured epoxy having a resultant film Tg of approximately 140-190° C. can be vacuum laminated at approximately 100-130° C. Dielectric film  102  may be opaque, or alternatively at least partially translucent. Temporary carrier substrate  104  may be formed of a variety of materials such as, but not limited to, steel, glass, and sapphire which are rigid enough not to move during a subsequent molding operation, and releasable from dielectric film  102  after the molding operation. In an embodiment, the dielectric film is 5 to 50 microns thick, and the temporary carrier substrate  104  is approximately 2 mm thick. 
     The dielectric film  102  can comprise a first surface and a second surface opposite the first surface, the first and second surfaces being substantially parallel. As used herein, substantially parallel can mean that the first surface and the second surface vary by an angle less than 20 degrees, 10, degrees, 5 degrees, or 1 degree. Substantially parallel can also mean the opposing first and second surfaces vary by a thickness, offset, or distance less than or equal to 20 percent, 10, percent, 5 percent, or 1 percent of the thickness, offset, or distance, along a length, width, or both length and width of the first and second surfaces of the dielectric film  102 . 
     Referring to  FIG. 1B , a plurality of semiconductor die, die units, or components  106  may be placed on a surface of dielectric film  102 , for example, by utilizing a pick and place die attach machine, and the dielectric film  102  may be cured to lock the plurality of semiconductor die  106  into place on the cured, rigid dielectric film  102 , which may be rendered non-photoimageable by the curing process. Curing may be performed during or after placement and may be performed by a variety of method such as thermal, ultraviolet (UV), or microwave curing cycles until the dielectric film  102  is rigid and substantially cross-linked. In an embodiment, dielectric film  102  includes a B-stage epoxy material, and is final cured at temperature sufficient to fully cross-link the material, typically above the resultant Tg of the final cured dielectric film  102 . For example, a dielectric film including a B-stage epoxy having a final cured Tg of approximately 140-160° C. may be cured at approximately 170° C. In an embodiment, dielectric film  102  has a final cured Tg greater than or equal to 190° C. In an embodiment, the dielectric film  102  includes greater than 50%, by weight, of a particulate ceramic filler such as silica. In an embodiment, the dielectric film  102  includes 60-90%, by weight, ceramic filler. In an embodiment, the dielectric film  102  may have a CTE of 11-18 ppm/° C. at room temperature, such as approximately 12 ppm/° C. at room temperature. In an embodiment, curing achieves enough adhesion between the dielectric film  102  and plurality of semiconductor die  106  to meet first level package reliability metrics such as delamination during moisture sensitivity testing, or mounting to a motherboard or other product. 
     After curing the dielectric film  102 , the plurality of semiconductor die  106  on the dielectric film  102  are encapsulated with an encapsulant layer  108  as illustrated in  FIG. 1C  such that the plurality of semiconductor die  106  are encapsulated by the encapsulant layer  108  and dielectric film  102 . During encapsulation, the temporary carrier substrate  104  prevents flexing or movement of the cured dielectric film  102 , and the cured dielectric film  102  holds the plurality of individual semiconductor die  106  in place, thereby improving alignment within the panel or reticulated wafer. As illustrated in  FIG. 1C , in an embodiment, the active surfaces of the plurality of semiconductor die  106  are substantially flush with the surface of the encapsulant layer  108  on dielectric film  102 . 
     In an embodiment, encapsulation is performed by an overmolding process such as compression molding with a molding compound. The molding compound may be a powder including epoxy resin and filler(s). For example, compression molding may be performed at approximately 170° C. to completely melt a powder epoxy resin included in an encapsulant layer  108  having a final Tg of approximately 140-160° C. In an embodiment, the molding compound includes greater than 50%, by weight, of a particulate ceramic filler such as silica. In an embodiment, the molding compound includes 60-90%, by weight, ceramic filler. In an embodiment, the final cured molding compound may have a CTE of 11-18 ppm/° C. at room temperature, such as approximately 12 ppm/° C. at room temperature. It is also contemplated that overmolding in accordance with embodiments of the invention can be accomplished with other methods such as liquid epoxy molding, transfer molding, screen printing, and injection molding. 
     In an embodiment, encapsulation is performed by vacuum lamination in which final curing may be performed during or after lamination. Similar to dielectric film  102 , encapsulant layer  108  can include a B-stage cured material and additional filler(s). In an embodiment, dielectric film  102  and encapsulant layer  108  may be formed of identical materials or materials having similar physical properties. Lamination of encapsulant layer  108  may allow for the use of a printed circuit board (PCB) prepreg material sheet, and may be relatively lower cost than injection molding materials. Lamination performed under heat and vacuum can take advantage of the fusible (compliant) nature of a B-stage cured material to encapsulate the plurality of semiconductor die  106 . In addition, because an encapsulant layer  108  component is B-stage cured it is possible to encapsulate at a temperature well below the final cured Tg of the encapsulant layer  108 , and to perform final curing after the encapsulant layer  108  has been formed/shaped around the plurality of semiconductor die  106 . In an embodiment, lamination may include placing a semi-cured encapsulant film (e.g. including B-stage cured epoxy) over the plurality of semiconductor die  106  on the cured dielectric film  102  and applying heat and pressure under vacuum to the semi-cured encapsulant film to for /shape encapsulant layer  108 . For example, lamination may be performed at approximately 130° C. and 30 kg/cm 2  for an encapsulant layer  108  having a final cured Tg of approximately 140-215° C. In an embodiment, laminated encapsulant layer  108  is formed of a material having a final cured Tg greater than or equal to 190° C. In an embodiment, the lamination film includes greater than 50%, by weight, such as 60-90% of a particulate ceramic filler such as silica. In an embodiment, the final cured laminated encapsulant layer  108  may have a CTE of 11-18 ppm/° C. at room temperature, such as approximately 12 ppm/° C. at room temperature. Final curing may subsequently be performed after lamination at a temperature sufficient to fully cross-link the encapsulant material, typically above the resultant Tg of the final cured encapsulant layer  108 . 
     The temporary carrier substrate  104  may then be released from the dielectric film  102  as illustrated in  FIG. 1D , leaving the dielectric film  102  attached to what is commonly referred to as a panel or reconstituted wafer including the plurality of semiconductor die  106  and encapsulant  108 . Releasing may be accomplished by a variety of techniques such as UV irradiation, peeling, laser release, etching, and grinding. As such, the permanent dielectric film  102  may be permanent in the sense that instead of being removed from the panel or reconstituted wafer with the temporary carrier substrate  104 , a portion or majority of the permanent dielectric film  102  may be incorporated as a permanent part of the final semiconductor device structure. As discussed in greater detail below, portions of the permanent dielectric film  102  can be removed to form openings through the permanent dielectric film, such as for electrical interconnection, and still be considered permanent for purposes of this description. 
     Referring to  FIG. 1E , first level via holes  110  may then be formed in the permanent dielectric film  102  utilizing a mask-less patterning technique such as laser ablation. In an embodiment, the formation of first level via holes  110  exposes a bond pad (not illustrated in  FIGS. 1 , but similar to bond pad  32 ) formed on semiconductor die  106 . First level via holes  110  may have a diameter of approximately 25 to 50 microns, for example. In one embodiment, dielectric film  102  is at least partially translucent. In accordance with embodiments of the present invention, an optical inspection operation may optionally be performed to measure the true location of any or all semiconductor die  106  after removal of the temporary carrier substrate  104  in  FIG. 1D  and prior to the formation of the first level via holes  110  illustrated in  FIG. 1E . If the true location does not match a nominal, reference location, then the x-y position and/or orientation of the first level via holes  110 , or any of the other features in the build-up structure, may be adjusted for any of the individual semiconductor die  106  as described in co-pending U.S. patent application Ser. No. 12/876,915, incorporated herein by reference. 
     The via holes  110  can extend completely through the dielectric layer  102 , between the first surface and the second surface of the transfer dielectric (such as surfaces  102   a  and  102   b ). A slope of the sidewalls of the via holes  110  can be perpendicular, or at a 90 degree angle with respect to the first surface, the second surface, or both the first and second surface of the transfer dielectric  102 . The slope of the sidewalls of the via holes  110  can also be any other suitable angle that intersects with, and is not parallel to, the first and second opposing surfaces of the transfer dielectric  102 . The slope of the sidewalls of the via holes  110  can be angled, sloped, linear, quadratic, organic, geometric, constant, or vary along a height or depth of the via holes  110 . 
     A barrier and/or seed layer  112  may then be formed over the entire surface and within first level via holes  110  as illustrated in FIG. IF. For example, layer  112  may include a Ti, Ti/W or Ti/TiN bi-layer barrier layer of approximately 500 to 1,500 angstroms thick, and a copper seed layer of approximately 1,500 to 4,000 angstroms thick. In an embodiment, layer  112  may be formed by sputtering. In some instances, the layer  112  can be omitted, or combined with first level via metal  118  or RDL  218  so that the RDL  218  directly contacts the dielectric film  102 . 
     Referring to  FIG. 1G , a photoresist layer  114  may then be formed over layer  112  by a suitable method such as laminating or spin coating. Photoresist layer  114  may then be patterned to form RDL trace pattern openings  116  as illustrated in  FIG. 1H . Plating may then follow to fill the openings  110 ,  116  with the first level via metal  118  and RDL trace  120 , respectively, which may be in electrical communication with the active surface of the semiconductor die  106 . In some instances, the seed layer  112  may be omitted, or considered as part of the RDL traces  120  such that the RDL traces  120  can be formed directly contacting the permanent dielectric film  102 . In some instances RDL traces  120  may be one or more layers of Al, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductive material, and can include one or more of a seed layer, adhesion layer, or barrier layer. The deposition of conductive layers or RDL traces  120  can use PVD, CVD, electrolytic plating, electroless plating, or other suitable process, and can be in direct contact with a top or second surface of the dielectric film  102  opposite the first surface of the dielectric film  102  that contacts the temporary carrier. In an embodiment, the first level via metal  118  and RDL, trace  120  are copper. In any event, the conductive RDL  120  may be greater than or equal to 2 micrometers (μm) thick. Additionally, the RDL  120  may be formed as a thick RDL or RDL trace, comprising a thickness greater than, or greater a or equal to, 4 μm, 8 μm, 12 μm, 16 μm, or 20 μm. Patterned photoresist  114  and underlying portions of barrier/seed layer  112  are then removed as illustrated in  FIG. 1I . Removal of barrier/seed layer  112  may also slightly reduce the thickness of the plated layer  120 . 
     Referring to  FIG. 1J , a second polymer layer  122  is formed over the patterned dielectric film  102  and RDL traces  120 . In an embodiment, the second polymer layer  122  is formed from a photoimageable material such as polyimide, benzocylobutene (BCB), polybenzoxazole (PBO), etc. The second polymer layer  122  may then be patterned to form openings  124  to expose RDL traces  120  as illustrated in  FIG. 1K . Openings  126  may also be formed to expose portions of dielectric film  102  to assist in singulation. Patterning of openings  124 ,  126  may be performed utilizing suitable photolithographic techniques. Layer  122  is not limited to polymer materials, and may be formed of other materials having suitable dielectric and sealing properties. 
     As illustrated in  FIG. 1L , bumps or balls  128  may then be applied over the exposed portions of the RDL, traces  120 . More specifically, an electrically conductive bump material can be deposited over, and in direct contact with RDL traces  120 , or a UBM pad. An electrically conductive bump material can be deposited using an evaporation, electrolytic plating, electroless plating, ball drop, or screen printing process. The bump material can be Al, Sn, Ni, Au, Ag, Pb, Bi, Cu, solder, and combinations thereof, with an optional flux solution. For example, the bump material can be eutectic Sn/Pb, high-lead solder, or lead-free solder. The bump material can be bonded to RDL traces  120  using a suitable attachment or bonding process. In an embodiment, the bump material is reflowed by heating the material above its melting point to form spherical balls or bumps  128 . In some applications, bumps  128  are reflowed a second time to improve electrical contact to RDL traces  120 . Bumps  128  can also be compression bonded to RDL traces  120 . Bumps  128  represent one type of interconnect structure that can be formed over RDL traces  120 . Other interconnect structures can also be used, including conductive paste, stud bump, micro bump, or other electrical interconnect. 
     Referring to  FIG. 1M , individual packages may then be singulated. As illustrated in  FIG. 1M , singulation may include cutting of only the dielectric film  102  and encapsulant  108 , where lateral edges of the second polymer layer  122  do not extend to, and are not flush with the lateral edges of dielectric film  102  and encapsulant  108  for the individual packages. Such a structure may be associated with reduced chipping and/or delamination between layers during singulation. In an embodiment where the encapsulant  108  and die bonding film  102  are both formed from an epoxy material, and second polymer layer  122  is formed of a polyimide, cutting during singulation is only required to be made through layers of similar composition, characteristics and therefore chipping and/or delamination is reduced. 
     It is understood that additional layers may be formed such as ball grid array capture pads prior to applying solder balls  128 . For example, as illustrated in FIG. IN the processes of  FIGS. 1G-1H  may be repeated to form barrier/seed layer  132  and ball grid array capture pads  134  prior to attaching solder balls  128 . Similarly, additional conductive layers or RDLs and insulating layers a can be formed as part of a build-up interconnect structure to provide desired routing between the semiconductor die  106  and points outside the semiconductor die  106 . 
     Referring to  FIGS. 2A-2L , in a second embodiment, an alternative WLCSP build-up structure can be formed. As illustrated in  FIGS. 2A-2D , a dielectric film or permanent dielectric  202  may be laminated to a temporary carrier substrate  204 . A plurality of semiconductor die  206  is attached to dielectric film  202 . Dielectric film  202  is then cured to lock the plurality of semiconductor die  206  into place. The plurality of semiconductor die  206  are then overmolded or laminated with an encapsulant  208 . The temporary carrier substrate  204  is then removed. 
     Referring to  FIG. 2E , first level via holes  210  and RDL trace patterns or trace pattern openings  211  may be formed in the dielectric film  202  utilizing a mask-less patterning technique such as laser ablation. The mask-less patterning technique, such as laser ablation, can form the via holes  210  comprising a first depth D 1  and the RDL, trace pattern openings comprising a second depth D 2  that is less than the first depth D 1 . Thus, the RDL trace pattern openings  211  may intersect with the vias holes  210  in the single layer dielectric film  202  in a stair step fashion, the via holes  210  and the dielectric film  202  intersecting in the dielectric film  202  between the first surface of the dielectric film contacting the semiconductor die  206  and the second surface of the dielectric film opposite the first surface. 
     In one embodiment, dielectric film  202  is at least partially translucent. In accordance with embodiments of the present invention, an optical inspection operation may optionally be performed to measure the true location of any or all semiconductor die  206  after removal of the temporary carrier substrate  204  in  FIG. 2D  and prior to the formation of the first level via holes  210  and RDL trace pattern  211  illustrated in  FIG. 2E . If the true location does not match a nominal, reference location, then the x-y position and/or orientation of the first level via holes  210 , or any of the other features in the build-up structure, may be adjusted for any of the individual semiconductor die as described in co-pending U.S. patent application Ser. No 12/876,915, incorporated herein by reference. 
     A barrier and/or seed layer  212  may be formed following by plating of metallic layer  214  such as copper, which may then be etched back to isolate first level vias  218  and RDL traces  220  within the dielectric film  202  as illustrated in  FIGS. 2F-2G . The RDL traces  220  can be formed comprising a thickness of 2 μm. Additionally, the RDL  120  may be formed as a thick RDL or RDL trace, comprising a thickness greater than, or greater than or equal to, 4 μm, 8 μm, 12 μm, 16 μm, or 20 μm. In some instances, the seed layer  212  can be omitted, or considered as part of the RDL traces  220  such that the RDL traces  220  can be formed directly contacting the permanent dielectric film  202 . In some instances RDL traces  220 , like RDL traces  120 , can be one or more layers of Al, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductive material, and can include one or more of a seed layer, adhesion layer, or barrier layer. The deposition of conductive layers or RDL traces  120  and  220  can use PVD, CVD, electrolytic plating, electroless plating, or other suitable process, and can be in direct contact with a top or second surface of the dielectric film  202  opposite the first surface of the dielectric film  202  that contacts the temporary carrier. 
     After formation of the RDL  220 , second polymer layer  222  may then be formed and patterned utilizing suitable lithographic techniques to form openings  224 ,  226  as illustrated in  FIGS. 2H-2I . Bumps or balls  228 , like bumps or balls  128 , may be applied within openings  224  over the exposed portions of the RDL trace  220 , while openings  226  may assist in singulation of the individual packages as illustrated in  FIGS. 2J-2K . In an embodiment illustrated in  FIG. 2L  a barrier/seed layer  232  and ball grid array capture pad  234  may be formed similarly as described with regard to  FIG. 1N . 
       FIGS. 3-6  show cross-sectional profile views of an individual semiconductor devices or package in an X-Z plane, like  FIGS. 1A-2L , that can be produced by a process similar to those illustrated in  FIGS. 1A-1N  and  FIGS. 2A-2L . Thus, while aspects of  FIGS. 3-6  may be discussed with respect to reference numbers in  FIGS. 1A-1N  or  FIGS. 2A-2L , the corresponding reference numbers or analogous structures in the other FIGs. may also be applicable, but are omitted for brevity.  FIG. 3  shows a cross-sectional profile view of an individual semiconductor device or package, while  FIG. 7  show a representative top or plan view of the semiconductor device  250 , in a x-y plane that is perpendicular, transverse, or orthogonal to the x-z plane of  FIG. 3 . Package  250  differs from packages  130 ,  140 ,  230 , and  40  by the inclusion of thick RDL pattern or thick RDL traces  40 . The thick RDL  40  can comprise a plurality of RDL traces comprising a thickness or height T 3  greater than, or greater than or equal to, 4 μm, 8 μm, 12 μm, 16 μm, or 20 μm. The thickness T 3  of the thick RDLs  40  can extend in a z-direction that is perpendicular to, and extends away from, an active surface  30  of the semiconductor die  106 . The thick RDLs  40  can be couple to the active surface  30  of the semiconductor die  106  through the contact pads  32  of the semiconductor die. Contact pads  32  or a similar conductive feature can also serve as a point of electrical interconnection for the semiconductor die  106  shown in the semiconductor die shown in  FIGS. 1B-2L . 
     The thick RDL traces  40  can be formed before the semiconductor die  106  are mounted to the permanent dielectric film  102 ,  202  and the temporary carrier  104 ,  204 . For example, the thick RDL  40  can be formed on the semiconductor die  106 ,  206  when the semiconductor die  106 , 206  are unsingulated from, and are part of, a native wafer from which the semiconductor die  106 ,  206  are formed. After singulation of the semiconductor die  106  comprising thick RDL traces  40 , the plurality of semiconductor die  106  can be placed face down directly on the first surface of the single layer dielectric film  106  with the thick RDLs  40  directly contacting the first surface of the single layer dielectric film  102 , similar to the placement of the semiconductor die  106  shown in  FIGS. 1B and 2B . A difference between the semiconductor package  250  comprising the additional thick RDLs  40  and the packages  130 ,  140 ,  230 , and  240  without the thick RDLs  40 , can include the additional portion of encapsulant  108  disposed over the active surface  30  of the semiconductor die  106  and the build-up interconnect including the permanent dielectric film  102  and the conductive layer  120 . An insulating or passivation layer  36  can also be optionally disposed over the active surface  30  and the contact pads  32  of the semiconductor die  106 , at the native wafer level, such as before the formation of the thick RDLs  40 . Thus, the insulating layer  36 , like the encapsulant  108 , can also be disposed between the active surface  30  of the semiconductor die  106  and the transfer dielectric  102 . Opposite the insulating layer  36 , an insulating layer or epoxy film  50  (which can include a solder mask laminate film or die attach epoxy film) can be applied on backside  28  of the semiconductor die  106  and the backside  109  of the encapsulant  108 . A thickness of the film  50  disposed on the back surface  28  of the semiconductor die  106  can similar to or equal to the final thickness of the encapsulant, epoxy mold compound, or laminate film, disposed over or on the active surface  30  of the semiconductor die  106  between the active surface  30  and the transfer dielectric  102 . 
     The molding or encapsulating of the semiconductor  106  can be done in such as way that a spacing or offset O 1  of encapsulant  108  is formed among the semiconductor die  106  and around a perimeter or sidewall  242  of each of the semiconductor die  106 ,  206 . The offset O 1  can be sufficient for additional fan-out structures, or semiconductor components, to be formed within the package  250  and coupled to the semiconductor die  106 ,  206 . 
     The offset O 1 , present in  FIGS. 3-7  inclusive, may serve to form an edge-protected package with the offset, width, distance, or buffer O 1  of encapsulant  108  disposed around and contacting at least four side surfaces  242  of the semiconductor die  106 . The offset O 1  may comprise a distance in a range of 30-140 μm, 30-100 μm, or 30-60 μm of the encapsulant material  108  around the periphery  242  of the semiconductor die  106  to prevent chipping of the semiconductor die  106  during singulation, to provide a more robust package, and to provide periphery  244  or footprint of the semiconductor packages  250 ,  260 ,  270 ,  280  that is larger that the periphery  242  and footprint of the semiconductor die  106  to absorb wear and tear, such as chipping, in place of the semiconductor die  106  absorbing the wear and tear. In some instances, the offset O 1  can provide an area that is free from, or outside a footprint of, the thick RDLs  40 . 
     By forming semiconductor package  250  as shown in  FIG. 3 , the final semiconductor package  250  can comprise an active surface  230  and at least four side surfaces  242  that are encapsulated with a single mold compound or encapsulant  108 . As shown in  FIG. 4 , the encapsulant  108  can also be disposed over the backside  28  of the semiconductor die  106  so that 6 sides or all sides of the semiconductor die  106  can be overmolded or covered with the encapsulant  108 . The mold compound  108  can also be disposed around the thick RDL traces  40  to contact sidewalls of the thick RDL traces  40 , after which a surface  244  of the thick RDL traces  40  may be exposed through the transfer dielectric  102  by maskless patterning, such as laser ablation. As such, the encapsulation or molding process can be more easily accomplished in a single step than with previous structures and methods requiring a second or separate molded underfill material. 
       FIG. 4  shows an individual semiconductor package or embedded die package  260  similar to semiconductor package  250  from  FIG. 3 . Semiconductor package  260  differs from semiconductor package  250  by the omission of conductive layer  120 , and insulating or passivation layer  122 , resulting in a simplified build-up interconnect structure, and relying on the routing provided by thick RDLs  40  to correctly position bumps  128 , rather than relying on both thick RDLs  40  and conductive layer  120 . 
       FIGS. 5 and 6  show individual semiconductor packages  270 ,  280 , similar to semiconductor packages  240  and  250 , shown in  FIGS. 3 and 4 , respectively. Semiconductor packages  270 ,  280  differ from semiconductor packages  240 ,  250  by being placed face-up on the transfer dielectric layer  102 ,  202  before being encapsulated with the encapsulant  108 ,  208 , rather than being placed face-up on the transfer dielectric  102 ,  202 . As a result, the back surface  28  of semiconductor die  106 , as shown in both  FIGS. 5 and 6 , are positioned on, or are in direct contact with, a first surface  102   a  of the transfer dielectric layer  102 . A second surface  102   b  of the transfer dielectric  102  can be opposite the first surface  102   a,  the second surface being disposed at, or forming, an outer surface of the packages  270 ,  280 . 
     When overmolding the face-up semiconductor die  106  and thick RDL traces  40 , the encapsulant  108  can also be disposed over, and cover, the top surface  44  of the RDL  40 , the top surface  44  being the surface of the RDL  40  not in contact or adjacent the semiconductor die  106 , the surface  44  facing away from the semiconductor die  106  and being opposite the surface of the RDL  40  adjacent the semiconductor die  106 . A thickness of encapsulant  108  can cover and be disposed over the RDL  40 , including the surface  44  of the RDL. In some instances, the surface  44  can be exposed by grinding or etching of the encapsulant  108  until the RDL  40  is exposed with respect to the encapsulant as shown in  FIGS. 3 and 4 . Alternatively, a thickness or portion of encapsulant  108  can remain over a majority of the RDL  40 , while select portions of the encapsulant  108  are removed to form openings or vias that expose portions of the RDL  40  through the encapsulant  108 . The openings  108  can be formed in the encapsulant  108  by a maskless patterning process, maskless process, or laser ablation, examples of which are shown in both  FIGS. 5 and 6 . 
     As shown in  FIG. 5 , a build-up interconnect structure  160  can be formed over the active surface  30  of semiconductor die  106 , and thick RDLs  40 . As part of the build-up interconnect structure  160 , an insulating layer  162  is conformally applied to, and can have a first surface that follows the contours of, encapsulant  108  and top surface  44  of thick RDL traces  42 . Insulation layer  162  can have a second planar surface opposite the first surface. Insulating layer  162  can contain one or more layers of photosensitive low curing temperature dielectric resist, photosensitive composite resist, LCP, laminate compound film, insulation paste with filler, solder mask resist film, liquid molding compound, granular molding compound, polyimide, BCB, PBO, SiO2, Si3N4, SiON, Ta2O5, Al2O3, or other material having similar insulating and structural properties. Insulating layer  162  can be deposited using printing, spin coating, spray coating, lamination, or other suitable process. Insulating layer  162  can be subsequently patterned and cured using UV exposure followed by developing, or other suitable process. A portion of insulating layer  162  can be removed by laser ablation, etching, or other suitable process to form openings that expose portions of top surface  44  of thick RDL traces  42 , according to the configuration and design of semiconductor die  106  and the final semiconductor package  270 . In some embodiments, insulating layer  162  can be formed or deposited before the formation of openings in the encapsulant  108  to expose the thick RDLs  40 , so that the openings can be formed both in and through insulating layer  162  and encapsulant  108  at a same time or during a same processing step. Alternatively, insulating layer  162  can be formed or deposited after the formation of openings in encapsulant  108  so that the openings in the insulating layer  162  are only formed through the insulating layer and extend to surface  44  of thick RDL traces  40 . 
     An electrically conductive layer  164  can be patterned and deposited over, and in contact with, thick RDL traces  42 , encapsulant  108 , and insulation layer  162 . Conductive layer  164  can be one or more layers of Al, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductive material, and can include one or more of a seed layer, adhesion layer, or barrier layer. The deposition of conductive layer  164  can use PVD, CVD, electrolytic plating, electroless plating, or other suitable process. The openings in insulation layer  162  can extend completely through the insulation layer over thick RDL traces  40 . Conductive layer  164  can operate as an RDL comprising a plurality of RDL traces that assist in extending electrical connection from semiconductor die  106  and thick conductive RDL traces  40  to points external to semiconductor die  106 . A portion of conductive layer  164  formed within the openings in insulating layer  162  can form vertical interconnect structures or vias that provide electrical interconnection through insulating layer  162 . While a non-limiting example of a build-up interconnect structure  160  is illustrated in  FIG. 5  comprising a single RDL  164 , additional RDLs can also be formed within build-up interconnect structure  160  between conductive layer  168  and thick RDL  40  to provide additional flexibility for routing signals between semiconductor die  24  and points external to the semiconductor die. 
       FIG. 5  further shows an insulating or passivation layer  166  is conformally applied to, and follows the contours of, insulation layer  162  and conductive layer  164 . Insulating layer  166  can contain one or more layers of photosensitive low curing temperature dielectric resist, photosensitive composite resist, LCP, laminate compound film, insulation paste with filler, solder mask resist film, liquid molding compound, granular molding compound, polyimide, BCB, PBO, SiO2, Si3N4, SiON, Ta2O5, Al2O3, or other material having similar insulating and structural properties. Insulating layer  166  can be deposited using printing, spin coating, spray coating, lamination, or other suitable process. Insulating layer  166  can be subsequently patterned and cured using UV exposure followed by developing, or other suitable process. A portion of insulating layer  166  can be removed by laser ablation, etching, or other suitable process to form openings through the insulating layer that expose portions of conductive layer  164 . 
     An electrically conductive layer  168  can be patterned and deposited over, and be in contact with, conductive layer  164  and insulating layer  166 . Conductive layer  168  can be one or more layers of Al, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductive material. The deposition of conductive layer  168  can use PVD, CVD, electrolytic plating, electroless plating, or other suitable process. The openings in insulating layer  166  into which conductive layer  168  is disposed can extend completely through the insulation layer over conductive layer  164 . At least a portion of conductive layer  168  can be formed within the openings in insulating layer  166  and form a vertical interconnect structure or vias that provide electrical interconnection through insulating layer  166  to connect to conductive layer  164 . 
     Conductive layer  168  can comprise a top portion or surface that is formed as a pad  170 . Pad  170  can comprise a horizontal component that includes an area greater than an area of the opening formed in insulating layer  166  such that pad  170  of conductive layer  168  extends over a top or upper surface of insulating layer  166 . Pad  170  of conductive layer  168  can be an I/O interconnect at a periphery of a completed semiconductor package. As such, pads  170  can be formed as UBM pads or LGA pads that are coupled to I/O interconnects at a periphery of a completed semiconductor package such as, for example, solder bumps; or alternatively, can be themselves I/O interconnects. Pads  170  can be stacks of multiple metal layers including adhesion, barrier, seed, and wetting layers. Pads  170  can comprise one or more layers of Ti, TiN, TiW, Al, Cu, Cr, CrCu, Ni, NiV, Pd, Pt, Au, Ag or other suitable material or combination of materials. In an embodiment, pads  170  can comprise a TiW seed layer, a Cu Seed layer, and a Cu UBM layer. 
       FIG. 5  shows an electrically conductive bump material can be deposited over pads  170 , which as indicated above, can be UBM pads that act as an intermediate conductive layer between semiconductor die  106  and subsequently formed bumps or other I/O interconnect structures. Pads  170  can comprise UBM pads that provide a low resistive interconnect to conductive layers  164  and thick RDL traces  40 , and can also provide a barrier to solder diffusion, and an increase in solder wettability. An electrically conductive bump material can be deposited over pads  170  using an evaporation, electrolytic plating, electroless plating, ball drop, or screen printing process. The bump material can be Al, Sn, Ni, Au, Ag, Pb, Bi, Cu, solder, and combinations thereof, with an optional flux solution. For example, the bump material can be eutectic Sn/Pb, high-lead solder, or lead-free solder. The bump material can be bonded to pads  170  using a suitable attachment or bonding process. In an embodiment, the bump material is reflowed by heating the material above its melting point to form spherical balls or bumps  272 . In some applications, bumps  272  are reflowed a second time to improve electrical contact to pads  170 . Bumps  272  can also be compression bonded to pads  170 . Bumps  272  represent one type of interconnect structure that can be formed over pads  170 . Other interconnect structures can also be used, including conductive paste, stud bump, micro bump, or other electrical interconnect. 
       FIG. 6  shows the semiconductor package  280  differs from the semiconductor package  270  by omission of build-up interconnect structure  160 , resulting in a simplified interconnect structure that relies on the routing provided by thick RDLs  40  to correctly position bumps  282 , rather than relying on both thick RDLs  40  and conductive layer  120  or  162 . As such, a footprint of the thick conductive RDL traces  40  and the bumps or balls  282  can be contained within a footprint of the semiconductor die  106 . 
       FIG. 7  shows a top or plan view of an edge protected package like packages  130 ,  140 ,  230 ,  240 ,  250 ,  260 ,  270 , and  280  with an offset, width, distance, or buffer O 1 . 
     In the foregoing specification, various embodiments of the invention have been described. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. It is contemplated that a variety of build-up structures and processes could be applied after formation of the first level via in the dielectric film utilizing a mask-less patterning technique such as laser ablation. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.