Abstract:
A semiconductor chip, semiconductor package including the same, and a method of manufacturing the semiconductor chip and semiconductor package to block up electrical contacts between bonding wires and the semiconductor chip by providing insulation over the edge of the semiconductor chip.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 of Korean Patent Application No. 10-2008-56441 filed on Jun. 16, 2008, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     Field of the Invention 
     The exemplary embodiments disclosed herein relate to a semiconductor package and manufacturing method thereof. 
     By lightening, filming, shortening, and miniaturizing electronic machines, their core components packages are heading for higher density and more inclusion therein. In computing systems, semiconductor chips are usually enlarged in size, as like large-capacity random access memories and flash memories, in need of extension of data preservability, whereas packages (or assemblies) are focused on miniaturization in correspondence with such requirements. As even semiconductor chips of the same capacity are relatively scaled down while trending from edge pad types toward center pad types, those are being mostly associated with the center pad types in order to yield more chips from a semiconductor wafer that is confined in 6, 8, or 12 inches. 
     Additionally, an important one of technologies to efficiently implement product designs for semiconductor chips is a package framing, exemplarily a ball grid array (BGA) style that has been developed in recent years. The BGA packages are more advantageous than traditional plastic packages in shrinking down practical areas on mother boards and in electrical characteristics. 
     The BGA package employs a printed circuit board instead of a lead frame, which is different from a plastic package. Such a printed circuit board is helpful to entirely providing the backside of a face, which contacts with a semiconductor chip, for a region of solder balls that act as connection terminals to the outside of the package. That construction would be useful to increasing packing density on a mother board. 
     However, in a case of mounting a center-pad semiconductor chip on a lead frame or a BGA-specific printed circuit board and using bonding wires for electrical connection thereto, there could be electrical shorts due to the bonding wires making contact with corners of the active surface of the semiconductor chip. 
     SUMMARY 
     The exemplary embodiments disclosed herein provide a semiconductor package and manufacturing method thereof capable of preventing electrical shorts between bonding wires and a semiconductor chip. 
     Additional aspects and utilities of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept. 
     An exemplary embodiment provides a method of isolating a semiconductor chip. This method includes preparing a semiconductor wafer including a chip region having a semiconductor chip and a scribing lane adjacent to the chip region. An insulation layer is formed to cover the chip region. The scribing lane is etched to divide the semiconductor chips by using a photoresist pattern as an etching mask. 
     Another exemplary embodiment provides a method of manufacturing a semiconductor package. The method of manufacturing a semiconductor package includes preparing a semiconductor wafer including chip regions having respective semiconductor chips and a scribing lane disposed between the chip regions. An insulation layer is formed to cover the semiconductor chips and to cover a portion of the scribing lane. A first tape is formed to cover a top side of the semiconductor wafer. The scribing lane is etched to expose the insulation layer by using a photoresist pattern as an etching mask and to divide the semiconductor chips. A second tape is attached to a bottom side of the semiconductor wafer. 
     Another exemplary embodiment provides a semiconductor chip. The semiconductor chip includes an integrated circuit substrate in which an integrated circuit is formed. An electrode pad is electrically connected to the integrated circuit on a top surface of the integrated circuit substrate. An insulation layer entirely covers the top surface of the integrated circuit substrate, except the electrode pad, to protect the integrated circuit, and extends out beyond the edge of the integrated circuit substrate. 
     Another exemplary embodiment provides a semiconductor package. The semiconductor package includes a semiconductor chip attached to a substrate. A bonding wire electrically connects an electrode pad of the semiconductor chip to a conductive pad of the substrate. An insulation layer is placed between the bonding wire and the edge of the semiconductor chip and extends out beyond the edge of the semiconductor chip while entirely covering a top surface of the semiconductor chip except the electrode pad of the semiconductor chip. 
     Another exemplary embodiment provides a method of isolating a semiconductor chip, the method including: forming an insulation layer over a top surface of a semiconductor wafer including chip regions, the insulation layer including scribe lanes formed therein; forming a resist pattern with openings across a bottom surface of the semiconductor wafer, the resist patterns aligning with and being larger than the scribe lanes; and etching the semiconductor wafer to divide the semiconductor chip by using a photoresist pattern as an etching mask such that ends of the insulation layers extend beyond the divided semiconductor chips. 
     Embodiments proposed throughout this description are relevant to an isolation method of semiconductor chips, a semiconductor chip formed by the isolation method, a semiconductor package manufacturing method, and a semiconductor package formed by the package manufacturing method. The semiconductor package is made by first dividing semiconductor chips from a wafer, attaching the semiconductor chip to a base substrate such a printed circuit board, and electrically connecting the semiconductor chip to the printed circuit board by wire bonding. 
     According to these embodiments of the present general inventive concept, even a simplified process makes it possible to prevent electrical shorts between the semiconductor chip and bonding wires. 
     A further understanding of the nature and advantages of the present general inventive concept herein may be realized by reference to the remaining portions of the specification and the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects and utilities of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
       Non-limiting and non-exhaustive embodiments of the present general inventive concept will be described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various figures unless otherwise specified. In the figures: 
         FIGS. 1 through 9  are sections of processing operations to isolate individual semiconductor chips from a wafer in accordance with an embodiment of the present general inventive concept; and 
         FIGS. 10 and 11  are sections illustrating a feature of wired bonding patterns on an individually isolated semiconductor chip in accordance with an embodiment of the present general inventive concept. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures. 
     In a semiconductor fabrication process, isolating semiconductor chips from each other begins after a tape mounting operation for attaching a supporting tape to the backside of an active surface of a semiconductor wafer. To separate semiconductor chips from the wafer, it is permissible to utilize a wafer sawing device installed at a diamond wheel blade, as well as laser beam or plasma. In general, grits of the diamond wheel blade is sized in 2˜2 μm or 0.3˜3 μm. And the blade cuts away the wafer by 20 mm per second along a scribing lane in rotation rate of 35,000˜40,000 rpm. 
     According to an embodiment of the present general inventive concept, chip isolation (chip separation or chip division) can be carried out by means of a plasma or chemical etching method using an etching gas or an etchant, instead of a physical method, which is often performed by using a diamond blade. For example, plasma or chemical etching is able to isolate the semiconductor chips from the wafer by means of SF 6  plasma. 
     Now will be described exemplary embodiments of the present general inventive concept with reference to the accompanying figures. However, the present general inventive concept may be performed in other forms, and is not restrictive hereto. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present general inventive concept to those skilled in the art. 
       FIGS. 1 through 9  are sections of processing operations to isolate pluralities of semiconductor chips from a wafer in accordance with embodiments of the present general inventive concept. Referring to  FIG. 1 , a semiconductor wafer  200  includes a plurality of chip regions  100  on a semiconductor substrate  210  such as an integrated circuit substrate which can be made of silicon. The chip regions  100  are separated by a scribing lane  260 . Each of the chip regions  100  includes a semiconductor chip having an integrated circuit (not shown). An insulation layer  240 , for example, a polyimide layer, is formed to protect the integrated circuit from external forces, such as air, dust, etc. A backlap tape  250  (first tape) is attached to the top side  220  of the semiconductor wafer  200 , i.e., the active surface of the semiconductor substrate  210 . The backlap tape  250  protects the top side  220  of the semiconductor wafer  200  when processing a bottom side  230  of the semiconductor chip  200 , i.e., the backside of the semiconductor substrate. The polyimide layer  240  may be formed to expose at least a portion of the scribing lane  260 , which makes it easier to isolate the semiconductor chips. 
     The insulation layer  240  may be made of an epoxy-series plastic resin. For instance, after forming polyimide to entirely cover the top side of the semiconductor wafer, a photolithography process is conducted to partly remove the polyimide therefrom. Thereby, the polyimide layer  240  covers the top side of the chip regions, i.e., the top surface of the chip, while exposing a portion of the electrode pads and the scribing lane (e.g., covering a portion of the scribing lane). 
     Next, referring to  FIG. 2 , the bottom side  230  of the wafer  200  is processed to have a predetermined thickness. The bottom side  230  of the wafer  200  may be processed by means of chemical and mechanical polishing (CMP) that uses a diamond wheel  300  while spraying a slurry onto the wafer  200 , dry polishing with a silica adhesive pad, wet etching with chemicals, or plasma processing with plasma and chemicals. In addition, a plasma stress relief process is further conducted to relieve plasma stress on the wafer. 
     Then, referring to  FIG. 3 , a photoresist resin  280  is formed on the bottom side  230  of the semiconductor wafer  200 , which has been processed to a predetermined thickness, by means of a spin coating technique. During this process, it is permissible to add a hardening process thereto before or after forming the photoresist resin  280 . 
     The photoresist resin  280  formed on the bottom side  230  of the semiconductor wafer  200  is patterned to result in a photoresist pattern  285  as shown in  FIG. 4 . The photoresist pattern  285  includes openings  287  corresponding to the scribing lane  260  so as to separate the semiconductor chips (chip regions) in the next processing operation. The openings  287  of the photoresist pattern  285  can be variably formed in width. 
     Next, referring to  FIG. 5 , parts of the semiconductor wafer exposed by the openings  287 , i.e., the scribing lane, are removed to isolate the individual semiconductor chips  110 . For instance, SF 6  plasma may be used to selectively etch away portions of the semiconductor wafer  200 . A width of the opening  287  of the photoresist pattern  285  may be designed to make the polyimide layer  240  extend outward over the edge of the individual semiconductor chip  110 . 
     The polyimide layer  240  extending out of the edge of the semiconductor chip  110  functions to prevent the edge of the semiconductor chip  110  from contacting the bonding wires during a wire bonding process subsequent thereto. According to the chip isolation method of the present embodiment, it simplifies processing operations because the polyimide layer is partly used to protect the semiconductor chips without an additional process thereof. Moreover, according to the chip isolation method of the present embodiment, it is easy to control the photolithography process to adjust a length of the part of the polyimide layer  240  extending out of the edge of the semiconductor chip  110 . 
     After physically isolating the individual semiconductor chips  110  from the semiconductor substrate  210 , referring to  FIG. 6 , the photoresist pattern  285  is removed from the bottom side of the wafer. An ashing technique may be used to remove the photoresist pattern  285  by employing oxygen (O 2 ) plasma. 
     Next, as shown in  FIG. 7 , a die attaching film  310  (second tape) is formed on the bottom side of the semiconductor wafer  200  (i.e., back side of the semiconductor chip  110 ) for the subsequent chip bonding process. 
     Then, referring to  FIGS. 8 and 9 , by removing the backlap tape  250  and separating the die attaching film  310  in correspondence with the individual semiconductor memory chips, it terminates the process to separate the wafer  200  into the individual semiconductor chips  110 . 
       FIGS. 10 and 11  are sections illustrating a feature of wired bonding patterns on the individually isolated semiconductor chip in accordance with an embodiment of the present general inventive concept, illustrating a packaging process with an individual semiconductor chip  400  that is fabricated by the procedure as like that shown in  FIGS. 1 through 9 . Referring to  FIG. 10 , the semiconductor chip  400  according to an embodiment of the present general inventive concept may include an integrated circuit substrate  410  in which an integrated circuit is placed, an electrode pad electrically connected to the integrated circuit, and an insulation layer  240  protecting the integrated circuit. The insulation layer  240  can be formed to extend out beyond the edge of the semiconductor chip  400 , and entirely covering the top of the semiconductor chip except for the electrode pads  420 . In an embodiment, the insulation layer  240  may cover even the edge of the electrode pads  420 . The insulation layer  240  may be made of a material, e.g., polyimide, suitable to protect the semiconductor chip from external environments or preventing the integrated circuit from damages. The insulation layer  240  may be formed to cover the edge of the semiconductor chip  400  by which bonding wires are passing. In an embodiment, the insulation layer  240  may extend out of the edge of the semiconductor chip  400 , i.e., outward from the side of the semiconductor chip  400  by about 1 μm or more. 
     Although flying debris or sticking particles arising from bonding connections or other conductive layers during the isolation process of the semiconductor wafer may be present around the edge at which bonding wires  430  are connected to the electrode pads  420 , the polyimide formed around the edge is helpful in restraining generation of short circuits between the semiconductor chip  400  and the bonding wires  430 . 
     After isolating the semiconductor chips from the wafer, the semiconductor chip  400  is attached on a substrate  500 , such as a printed circuit board, by means of an adhesive  600 . The adhesive  600  may be used with the die attaching film  310  aforementioned. Then, the bonding wires  430  are formed to electrically connect the electrode pads  420  with conductive pads  510  of the substrate  500 . As another embodiment, in a structure in which wires are connected to bonding pads of a semiconductor chip, it is permissible to form an insulative tape instead of the polyimide layer, or additionally, to cover the corners of the semiconductor chip as like the aforementioned. This is also useful to provide electrical isolation for preventing the bonding wires from contacting to the semiconductor chip. 
     Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.