Example embodiments will be described with reference to the accompanying drawings.
Example embodiments will now be described with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as being limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those skilled in the art.
It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.).
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, 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. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the scope of the example embodiments.
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 a relationship between a feature and another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the Figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, for example, the term “below” can encompass both an orientation which is above as well as below. The device may be otherwise oriented (rotated 90 degrees or viewed or referenced at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly.
Example embodiments are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures). As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, may be expected. Thus, example embodiments should not be construed as limited to the particular shapes of regions illustrated herein but may include deviations in shapes that result, for example, from manufacturing. For example, an implanted region illustrated as a rectangle may have rounded or curved features and/or a gradient (e.g., of implant concentration) at its edges rather than an abrupt change from an implanted region to a 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 may take place. Thus, the regions illustrated in the figures are schematic in nature and their shapes do not necessarily illustrate the actual shape of a region of a device and do not limit the scope.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. 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.
According to example embodiments, a semiconductor package may be formed having a heterogeneous underfill in which product defects caused by cracks may be reduced or prevented despite a coefficient of thermal expansion (CTE) difference between a semiconductor chip and a substrate. According to example embodiments, the semiconductor chip may be more easily separated from the substrate, thereby significantly enhancing reworkability for repairing.
Referring to
The underfill 140 may be a heterogeneous underfill including a plurality of underfill regions having different physical properties and that are stacked on each other. The heterogeneous underfill may include polymer resins, for example, epoxy based resins. However, epoxy based resins may vary widely in physical properties, for example, glass transition temperature, Young's modulus, and the like, depending on molecular weight distribution, number-average molecular weight, weight-average molecular weight, polydispersity index, etc. Accordingly, the heterogeneous underfill may include a stack of two different polymer resins having different physical properties or a stack of two epoxy based resins having different properties.
According to an example embodiment as shown in
A polymer resin having a relatively higher glass transition temperature may have a higher Young's modulus than a polymer resin having a relatively lower glass transition temperature. Accordingly, the first underfill region 142 may have a higher Young's modulus than the second underfill region 146. However, the value of the Young's modulus is not limited to a specific range.
Because the first underfill region 142 has a higher Young's modulus than that of the second underfill region 146, the stress, which was conventionally concentrated on the interfacial surface between the semiconductor chip 110 and conductive bumps 130, may be partially transferred to regions of the conductive bumps in the vicinity of the interfacial surface between the first underfill region 142 and the second underfill region 146. Thus, cracks may be reduced or prevented from occurring in an interfacial surface between the conductive bumps 130 and the semiconductor chip 110. Further, because the Young's modulus of the second underfill region 146 is lower than that of the first underfill region 142, the second material composing the second underfill region 146 may be more easily separated from the substrate 120, thereby improving reworkability of the semiconductor package.
The first underfill region 142 may include a filler 150 (shown in
Referring to
Referring to
A proper ratio may be maintained between height of the first underfill region 142 and the second underfill region 146. The interfacial surface h between the first underfill region 142 and the second underfill region 146 may be positioned at a distance t from the interfacial surface between contacts 115 of the semiconductor chip 110 and the conductive bump 130. The distance t may correspond to about 1% to 99% of a height T of the conductive bump 130, for example, about 30% to 70%, or about 45% to 55%.
If the position of the interfacial surface h between the first underfill region 142 and the second underfill region 146 is outside this range, enough of the stress may not be transferred to the center of the conductive bumps 130 and the amount of cracks in the interfacial surfaces f and g may not be reduced.
Referring to
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Referring to
Referring to
Referring to
The fluid layer 160 may include a flux to allow the conductive bumps 130 and the external contact terminals 125 to be bonded to each other without much difficulty.
In
Because the fluid layer 160 in
According to example embodiments, a semiconductor package with heterogeneous underfill may concentrate the majority of stress at an interfacial surface between a semiconductor chip and conductive bumps, bonding the semiconductor chip to a substrate, toward a center of the conductive bumps; thereby reducing or preventing cracks from occurring between the semiconductor chip and the conductive bumps and facilitating the reworkability of the package.
While example embodiments have been particularly shown and described, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.
Number | Date | Country | Kind |
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10-2006-0077810 | Aug 2006 | KR | national |