Abstract:
An image sensor package may include a transparent substrate, an image sensor chip having a sensing region disposed over the transparent substrate, a resin protection dam disposed between the image sensor chip and the transparent substrate inside a wiring pattern, the resin protection dam having an aperture formed to expose a sensing region of the image sensor chip and defining a cavity between the sensing region and the transparent substrate, a resin filled on the transparent substrate outside the resin protection dam, and a black matrix pattern disposed on each side of the transparent substrate and configured to block excess transmission of light.

Description:
FOREIGN PRIORITY INFORMATION 
       [0001]    A claim of priority is made under 35 U.S.C. §119 to Korean Patent Application 2006-66527 filed on Jul. 14, 2006, the entirety of which is hereby incorporated by reference. 
       BACKGROUND 
       [0002]    Example embodiments of the present invention may relate to semiconductor devices and methods of fabricating the same. More specifically, the example embodiments of the present invention may relate to an image sensor package and a method of fabricating the same. 
         [0003]    Image sensors are semiconductor electronic components, which is used for converting optical information to an electric signal. The image sensors may be classified into two categories: (1) charge coupled device (CCD) image sensors and (2) complementary metal-oxide-semiconductor (CMOS) image sensors. 
         [0004]    An image sensor package is configured to protect an image sensor and enable light to impinge on a photo receiving surface or an active surface thereof. 
         [0005]    The image sensor package may include a housing and a window through which light impinges on the photo receiving surface or the active surface of the image sensor. The image sensor package may further include a housing with a lens support, configured to support a lens, and an aperture into which the lens support is inserted. 
         [0006]      FIGS. 1A and 1B  are cross-sectional views illustrating conventional image sensors. 
         [0007]    Referring to  FIG. 1A , an image sensor chip  18  with a sensing region  18   s  is bonded directly to a transparent window  10 . The transparent window  10  has a wiring pattern  12  connected to an external circuit (not shown). The wiring pattern  12  is electrically connected to the image sensor chip  18  by means of a bump  22  and electrically connected to the external circuit by a solder ball  13 . A cavity  19  is provided between the sensing region  18   s  and the transparent window  10 . 
         [0008]    Referring to  FIG. 1B , an image sensor chip  18  with a sensing region  18   s  is bonded to a housing-type substrate  20 . The housing type substrate  20  has a wiring pattern  12  connected to an external circuit (not shown). The wiring pattern  12  is electrically connected to the image sensor chip  18  by means of a bump  22 . The wiring pattern  12  may include a medium such as a solder ball (not shown) for connection to the external circuit. A transparent window  10  is bonded to the housing-type substrate  20 . Thus, a cavity  19  is provided between the sensing region  18   s  and the transparent window  10 . 
         [0009]    The conventional image sensor package configurations illustrated in  FIGS. 1A and 1B  are achieved by bonding an image sensor chip to a window or a substrate. In general, a bonding process includes a thermal compression process. Therefore, a thin image sensor chip applied to an image sensor module used in small-sized devices may break/crack during the bonding process. This may hinder being able to decrease the thickness of the image sensor chip. Also, in the conventional image senor packages that light may be transmitted from sides of a transparent window, which could degrade sensitivity of the image senor chip. 
       SUMMARY OF THE INVENTION 
       [0010]    Example embodiments of the present invention may be directed to an image sensor package and a method of fabricating the same. 
         [0011]    In an example embodiment, an image sensor package may include a transparent substrate, at least one wiring pattern disposed on the transparent substrate, and an image sensor chip electrically connected to the wiring pattern, the image sensor chip having a sensing region. The example embodiment may further include a resin protection dam disposed between the image sensor chip and the transparent substrate, the resin protection dam having an aperture formed to expose the sensing region of the image sensor chip and define a cavity between the sensing region and the transparent substrate, and a resin filled on the transparent substrate outside the resin protection dam. 
         [0012]    In another example embodiment, the image sensor package may include a black matrix pattern disposed on each side of the transparent substrate and configured to block excess transmission of light. 
         [0013]    In an example embodiment, a method of fabricating an image sensor package may include forming a plurality of wiring patterns on a transparent substrate, forming a plurality of resin protection dams on the transparent substrate in association with the plurality of wiring patterns, each resin protection dam having an aperture defining a cavity, electrically connecting a plurality of image sensor chips to the plurality of wiring patterns, each image sensor chip having a sensing region, each image sensor chip being associated with one of the plurality of resin protection dams such that the sensing region of the image sensor chip is disposed in the cavity of the associated resin protection dam, performing a filling process with a resin to cover the transparent substrate including the plurality of image sensor chips. Resin-free cavity is formed between the sensing region of the image sensor chip and the transparent substrate. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIGS. 1A and 1B  are cross-sectional views illustrating conventional image sensor packages. 
           [0015]      FIG. 2A  is a perspective view illustrating an image sensor package according to an example embodiment of the present invention. 
           [0016]      FIG. 2B  is a cross-sectional view taken along a line IIB-IIB′ of  FIG. 2A . 
           [0017]      FIGS. 3A through 3L  are cross-sectional views illustrating a method of fabricating an image sensor package according to an example embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    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 may be directly on, connected or coupled to the other element or layer or intervening elements or layers 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 may be no intervening elements or layers present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
         [0019]    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 may be 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 invention. 
         [0020]    Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms may be 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 example 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. 
         [0021]    The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” may be 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. 
         [0022]    Example embodiments may be described herein with reference to cross-section illustrations that may be 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, the 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 drawings 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 example embodiments. 
         [0023]    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. 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. 
         [0024]      FIG. 2A  is a perspective view illustrating an image sensor package according to an example embodiment of the present invention, and  FIG. 2B  is a cross-sectional view taken along a line IIB-IIB′ of  FIG. 2A . 
         [0025]    Referring to  FIGS. 2A and 2B , a plurality of wiring patterns  112  may be arranged on a transparent substrate  110  to form a desired configuration. A plurality of post bumps  114   a  may be provided on the plurality of wiring patterns  112  to electrically connect the plurality of wiring patterns  112  to an external circuit (not shown). An image sensor chip  118   a  may be provided and electrically connected to each of the plurality of wiring patterns  112 . A resin protection dam  116  with an aperture (space) formed to expose a sensing region  118   s  of the image sensor chip  118   a  may be provided between the transparent substrate  110  and the image sensor chip  118   a.  The resin protection dam  116  may be a resin blocking wall. A resin  120  may be provided to fill a space on the transparent substrate  110  external to the resin protection dam  116 . Thus, a cavity  119  between the sensing region  118   s  of the image sensor chip  118   a  and the transparent substrate  110  may be provided. On an opposite face of the substrate  110 , an infrared filter (IR filter)  111  may be formed. 
         [0026]      FIGS. 3A through 3L  are cross-sectional views, taken along a line IIB-IIB′ of  FIG. 2A , illustrating a method of fabricating an image sensor package according to an example embodiment of the present invention. 
         [0027]    Referring to  FIG. 3A , a seed metal film (not shown) may be formed to cover the entire surface of the transparent substrate  110 . The transparent substrate  110  may be a glass substrate with excellent light transmission properties. The transparent substrate  110  may be made of soda-lime glass or borosilicate glass. An infrared filter  111  may be formed on a surface of the transparent substrate  110 , opposite the seed metal film to block light (infrared region) impinging on an image sensor. 
         [0028]    The seed metal film may serve to facilitate a wiring pattern, and may also function as an electrode in an electroplating process to form the wiring pattern and a post bump in subsequent processes. The seed metal film may be formed by a physical vapor deposition (PVD) process. The seed metal film may be a multi-layer film including first, second, and third layers. The first layer may include titanium (Ti), titanium tungsten (TW), chrome (Cr), and/or titanium nitride (TiN). The second layer may include copper (Cu), nickel (Ni), nickel vanadium (NiV), gold (Au), and/or silver (Ag). The third layer may include gold (Au), silver (Ag), and/or platinum (Pt). In example embodiments, the seed metal film may only include two layer films including the first layer and the second layer. In other example embodiments, the seed metal film may be more than three layers. 
         [0029]    A photoresist pattern (not shown) for the wiring pattern with a desired-shaped aperture to partially expose a surface of the seed metal film may be formed on the seed metal layer. The seed metal film may then be etched to form a plurality of wiring patterns  112  having a desired configuration. After forming a plurality of wiring patterns  112  in the apertures, the photoresist pattern may be removed. The desired configuration of the wiring patterns  112  may be identical to that of bonding pads (not shown) in an image sensor chip. The plurality of wiring patterns  112  may act as a connection between the image sensor chip and an external circuit (not shown). 
         [0030]    The plurality of wiring patterns  112  may be formed to a thickness ranging from about 1 to 10 micrometers. The plurality of wiring patterns  112  may include gold (Au), silver (Ag), nickel (Ni), and/or copper (Cu). The plurality of wiring patterns  112  may have a protrusion for connecting to the bonding pads of the image sensor chip in a subsequent process. Accordingly, additional steps of a photoresist pattern process and an electroplating process may be added to form the protrusion. In the case where the bonding pads of an image sensor chip includes a protrusive bump, the plurality of wiring patterns  112  may have a flat shape without any protrusions. Protrusions on the wiring pattern  112  and bumps on the image sensor chip may be provided to achieve better bonding therebetween. 
         [0031]    Referring to  FIG. 3B , a photoresist pattern (not shown) with apertures formed to partially expose surfaces of the plurality of wiring patterns  112  may be formed on the plurality of wiring patterns  112 . Post bumps  114  are then formed in the apertures, and the photoresist pattern may be removed. The post bumps  114  may also act as a connection between the plurality of wiring patterns  112  and an external circuit. 
         [0032]    The post bumps  114  may be formed to a thickness ranging from about 20 to 200 micrometers by an electroplating process. The post bumps  114  may include gold (Au), silver (Ag), nickel (Ni), tin-alloy (Sn-alloy), and/or combinations thereof, for example, copper-nickel-lead (Cu—Ni—Pb), copper-nickel-gold (Cu—Ni—Au), copper-nickel (Cu—Ni), nickel-gold (Ni—Au), nickel-silver (Ni—Ag), etc. 
         [0033]    Referring to  FIG. 3C , residual seed metal film on the exposed transparent substrate  110  adjacent to the plurality of wiring patterns  112  may be removed. The residual seed metal film may be removed by a wet etch process. Resin protection dams  116 , each having an aperture formed to define a sensing region  118   s  of the image sensor chip may be formed on the transparent substrate  110  inside the plurality of wiring patterns  112 . The resin protection dams  116  may serve to prevent resin from filling the space between sensing regions of each the image sensor chips and the transparent substrate  110  during a resin filling process described below. 
         [0034]    The resin protection dams  116  may be formed to a thickness ranging from about 10 to 30 micrometers by means of a screen printing process or a metal plating process. The resin protection dams  116  may include benzocyclobuten (BCB), polyimide, epoxy, and/or metal material such as copper or nickel. 
         [0035]    Referring to  FIG. 3D , image sensor chips  118  may be connected (e.g., bonded) to the plurality of wiring patterns  112  such that the resin protection dams  116  may adhere closely to the image sensor chips  118 . The image sensor chips  118  may have a thickness ranging from about 600 to 750 micrometers. 
         [0036]    Bonding the image sensor chips  118  to the plurality of wiring patterns  112  may include a thermocompression process or a thermosonic compression process. The sensing region  118   s  may be defined between the image sensor chips  118  and the transparent substrate  110 . Cavities  119  surrounded by the resin protection dams  116  may be formed between the sensing regions  118   s  of the image sensor chips  118  and the transparent substrate  110 . As previously described with reference to  FIG. 3A , wiring patterns  112  may include a protrusion connected to the bonding pads of the image sensor chip  118 . Or, if the bonding pad of the image sensor chips  118  includes a protrusive bump, the wiring patterns  112  may have a flat shape without the protrusion. A protrusion of the wiring pattern  112  and a bump of an image sensor chip  118  are provided to achieve easy bonding therebetween. 
         [0037]    Referring to  FIG. 3E , a filling process may be performed with resin  120  to cover the entire surface of the transparent substrate  110  including the image sensor chips  118 . The resin  120  may function as a buffer during a subsequent polishing process to reduce the thickness of the image sensor chips  118 . 
         [0038]    The filling process with the resin  120  may be performed by a dispensing process. The resin  120  may include an epoxy group. The resin  120  may fill all spaces on the transparent substrate  110  external to the resin protection dams  116 . Accordingly, the resin protection dams  116  may protect the cavities  119  from penetration of the resin  120 , and prevent/reduce the degradation of sensitivity characteristics of the image sensor chips  118 . For example, if the transparent resin  120  migrates between the sensing region  118   s  and the transparent substrate  110  during the filing process, light loss may be 5-10 percent higher. 
         [0039]    Referring to  FIG. 3F , after the filling process with the resin  120 , a polishing process may be performed to polish the resin  120  and the image sensor chips  118 . The polishing process may include a back lap process or a chemical mechanical polishing (CMP) process. The polishing process may decrease the thickness of the image sensor chips  118  and expose the post bumps  114 . As a result of the polishing process, thin image sensor chips  118   a,  post bumps  114   a,  and a thin resin  120   a  may be formed. Each of the thin image sensor chips  118   a  may have a thickness ranging from about 20 to 200 micrometers. 
         [0040]    Referring to  FIG. 3G , a holder  130  may be connected (e.g., bonded) to the polished surface. For example, the holder  130  may be connected to the exposed surface of the thin image sensor chips  118   a.  The holder  130  may serve to hold a formation obtained after the polishing process. 
         [0041]    Generally, the holder  130  may include inflexible material. The formation obtained after the polishing process may be connected to the holder  130  by a tape. Both surfaces of the tape may be adhesive for use during a wafer cutting process or a back lap process. 
         [0042]    Referring to  FIGS. 3H and 3I , portions of the transparent substrate  110  and the resin  120  between two adjacent thin image sensor chips  118   a  may be removed to form a groove  132 . A saw blade may be used to form the groove  132  such that the groove  132  has a V-shaped cross-section. Further, the transparent substrate  110  of each image sensor package may have a tapered edge. 
         [0043]    A black matrix pattern  134  may be formed in the groove  132  to prevent unnecessary transmission of light from impinging on the thin image sensor chip  118   a.  Forming the black matrix pattern  134  may include a dispensing process or a screen printing process. The black matrix pattern  134  may include a black epoxy group, and the black matrix pattern  134  may protrude above the surface of the transparent substrate  110 . 
         [0044]    Referring to  FIGS. 3J and 3K , lens supports  136  may be formed on the black matrix pattern  134 . The formation of the lens supports  136  may be accomplished by compressing a mash-type plastic. Lenses  138  may be mounted between the lens supports  136 . The lenses  138  may also be mounted between the lens supports  136  by a spacer  137 . 
         [0045]    Referring to  FIG. 3L , individual image sensor packages may be formed by cutting the lens support  136  and the black matrix pattern  134  between two adjacent thin image sensor chips  118   a.  The holder  130  may be removed from the image sensor packages to finish the fabrication of the individual and separate image sensor packages. 
         [0046]    An image sensor package fabricated according to example embodiments of the present invention described above may reduce/prevent degradation of the sensing characteristic. 
         [0047]    Sensing characteristic degradation of the image sensor may result from transmitted light impinging on sides of the image sensor. A transmission blocking pattern formed to surround edges of the image sensor may be provided to prevent the degradation. Further, a lens unit mounted on the transparent substrate formed without a housing simplifies the fabrication process. 
         [0048]    Although example embodiments of the present invention have been described and in connection with the accompanying drawings, the example embodiments of the present invention are not limited thereto. It will be apparent to those skilled in the art that various substitutions, modifications and changes may be made without departing from the present invention.