This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 of Korean Patent Application No. 10-2014-0084647, filed on Jul. 7, 2014, the disclosure of which is hereby incorporated by reference in its entirety.
The present disclosure herein relates to a semiconductor device, and more particularly, to a semiconductor package and a method for manufacturing the same.
An image sensor, such as a CCD sensor or a CMOS sensor are used in various electronic products, such as mobile phones, digital cameras, optical mice, security cameras, and biometric devices. As electronic products are miniaturized and multi-functionalized, a semiconductor package including an image sensor requires miniaturization/high density, low power consumption, multi-functionality, high-speed signal processing, high reliability, low price and clear image quality. Various studies are performed corresponding to such requirements.
The present disclosure provides a semiconductor package capable of improving a degree of warpage of an image sensor chip.
The present disclosure also provides a method for manufacturing capable of reducing the warpage of an image sensor chip.
Embodiments of the inventive concept provide a semiconductor package including: a substrate; an image sensor chip disposed on the substrate and including a first surface that faces the substrate and a second surface that is opposed to the first surface; an adhesion layer interposed between the substrate and the image sensor chip; and a first cavity surrounded by the first surface, an upper surface of the substrate and a side surface of the adhesion layer, wherein the first surface comprises a first central portion and a first edge portion, and the adhesion layer comprises a first adhesion part or portion directly contacting the first central portion and a second adhesion part or portion directly contacting the upper surface of the substrate, wherein the first adhesion part has an area corresponding to about 5% to about 50% of an area of the first surface.
In some embodiments, the substrate may include a second central portion and a second edge portion, and the second adhesion part directly contacts the second central portion.
In some embodiments, the adhesion layer may have a thickness of about 1 μm to about 80 μm, and the second adhesion part may have an area greater than that of the first adhesion part.
In some embodiments, the first adhesion part may be spaced apart from the first edge portion, and may have a circular shape on the image sensor chip first surface.
In some embodiments, the adhesion layer may have a modulus of about 2.7 MPa to about 4.2 MPa at a temperature of about −60° C. to about 230° C.
In some embodiments, the substrate may be a plastic substrate.
In some embodiments, the plastic substrate may be a printed circuit board (PCB).
In some embodiments, the substrate may have a thermal expansion coefficient of about 13 ppm/° C. or less at room temperature.
In some embodiments, the image sensor may have a warpage of about 10 μm or less.
In some embodiments, the semiconductor package may further include: a holder having an upper surface spaced apart from the second surface of the image sensor chip; and a transparent substrate disposed so as to be adjacent to the upper surface of the holder.
In some embodiments, the semiconductor package may further include: a second cavity surrounded by the transparent substrate, the holder and the image sensor chip.
In some embodiments, the substrate, the image sensor chip, the adhesion layer, the holder and the transparent substrate may be comprised of materials having different material characteristics.
In some embodiments, the semiconductor package may further include: a transparent substrate on the image sensor chip; and a mold film covering a side surface of the transparent substrate and a side surface of the image sensor chip, wherein the first cavity is surrounded by the first surface, the upper surface of the substrate, the side surface of the adhesion layer, and the mold film.
In other embodiments of the inventive concept, a semiconductor package includes: a substrate; an image sensor chip disposed on the substrate and including a first surface that faces the substrate and a second surface that is opposed to the first surface; and an adhesion layer interposed between the substrate and the image sensor chip, wherein the adhesion layer comprises a first adhesion part or portion directly contacting the first surface, wherein an area of the first adhesion part corresponds to about 5% to about 50% of an area of the first surface, and wherein the adhesion layer has an elastic modulus of about 2.7 MPa to about 4.2 MPa at a temperature of about −60° C. to about 230° C.
In some embodiments, the substrate may have a thermal expansion coefficient of about 13 ppm/° C. or less at room temperature.
In other embodiments of the inventive concept, a semiconductor package includes: a substrate; an image sensor chip on the substrate; an adhesion layer between the substrate and the image sensor chip. The substrate includes a printed circuit board (PCB) and first and second opposing sides. The image sensor chip includes a first side that faces the substrate and a second side opposing the first side. The first side of the image sensor chip comprises a first central portion and a first edge portion. The adhesion layer includes: a first adhesion surface directly contacting the first central portion and spaced apart from the first edge portion of the image sensor chip; and a second adhesion surface directly contacting the first side of the substrate.
In some embodiments, the semiconductor package may include: a holding member on the substrate, the holding member including an upper surface spaced apart from the second side of the image sensor chip; and a transparent substrate on the upper surface of the holding member.
In some embodiments, the semiconductor package may include: a transparent substrate on the image sensor chip; and a mold film covering at least a portion of a side surface of the transparent substrate and a side surface of the image sensor chip. The first side of the image sensor chip, the first side of the substrate, the side surface of the adhesion layer, and the mold film may define a first cavity.
In some embodiments, the semiconductor package may include a microlens array in a recessed region defined in the second side of the image sensor chip.
In some embodiments, the first adhesion surface has an area of about 5% to about 50% of an area of the first side of the image sensor chip.
In still other embodiments of the inventive concept, a method for manufacturing a semiconductor package includes: preparing a substrate; forming an adhesion layer on the substrate; and attaching an image sensor chip on the substrate by using the adhesion layer, wherein the mounting the image sensor chip allows the adhesion layer to form a circular shape as viewed from a plan view, and the attaching image sensor is performed such that a coverage ratio in which the adhesion layer covers a lower surface of the image sensor chip is about 5% to about 50%.
In some embodiments, the forming the adhesion layer may be performed by using an epoxy resin having a modulus of about 2.7 MPa to about 4.2 MPa at a temperature of about −60° C. to about 230° C.
The accompanying drawings are included to provide a further understanding of the inventive concept, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the inventive concept and, together with the description, serve to explain principles of the inventive concept. In the drawings:
Preferred embodiments of the inventive concept will be described below in more detail with reference to the accompanying drawings in order to fully understand the constitution and effect of the inventive concept. The inventive concept may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art.
In addition, it will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. Like reference numerals refer to like elements throughout.
Additionally, the embodiments in the detailed description will be described with sectional views and/or plain views as ideal exemplary views of the inventive concept. In the figures, the dimensions of elements, layers and regions may be exaggerated for clarity of illustration. Areas exemplified in the drawings may have general properties, and may be used to illustrate a specific shape of a semiconductor package region. Thus, this should not be construed as limiting the scope of the inventive concept. It will be understood that although the terms first, second and third are used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element, region or layer from another element, region or layer.
In the following description, the technical terms are used only for explaining a specific exemplary embodiment while not limiting the inventive concept. The terms of a singular form may include plural forms unless referred to the contrary. It will be understood that the terms “include,” “comprise,” “including,” 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.
In addition, spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
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Meanwhile, in an imaging device, such as a DSLR camera, a warpage phenomenon of an image sensor chip in the semiconductor package may occur. The warpage of the image sensor chip may cause resolution and shading differences between a central portion and a peripheral portion in an output image of the image sensor.
In the semiconductor package according to
In the semiconductor package according to
In the semiconductor package according to
In the semiconductor package according to
The result is shown in Table 1 and
Referring to Table 1, it may be confirmed that the thermal expansion coefficient (CTE) of the substrate 10, the modulus of the adhesion layer 30 and the coverage ratio in which the adhesion layer 30 covers the lower surface of the image sensor chip 20 are effective factors that influence the warpage and concurrently generate an interaction effect. However, according to the experimental example 1, it may be confirmed that the thermal expansion coefficient (CTE) of the transparent substrate 50 is an effective factor influencing the warpage, but does not represent an overlapping effect. For example, in comparison between G6 and G5, it may be confirmed that as the thermal expansion coefficient of the substrate (PCB) 10 is reduced, the maximum warpage (Max warpage) is improved by 1.11 μm, and the average degree of warpage (Ave warpage) is improved by about 1.8 μm. Meanwhile, in comparison between G6 and G15, it may be confirmed that as the thermal expansion coefficient of the transparent substrate (Glass) 50 is increased, the maximum warpage is improved by 0.48 μm, and the average degree of warpage degree is improved by about 0.59 μm. Even if a factor is an effective factor influencing the warpage, it may be seen that a combination of effective factors capable of generating a synergy effect is restrictive.
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Hereinafter, exemplary embodiments of the inventive concept will be described in detail with reference to accompanying drawings.
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The image sensor chip 20 may include a first or lower surface 20a facing the substrate 10 and a second or upper surface 20b opposed to the first surface 20a. The first surface 20a may include a first central portion CA1 and a first edge or peripheral portion EA1, and the second surface 20b may include a pixel portion PA and a third edge or peripheral portion EA3. The first central portion CA1 may be aligned with or correspond to the pixel portion PA, and the first edge portion EA1 may be aligned with or correspond to the third edge portion EA3. Although not shown, a plurality of photoelectric conversion units and a plurality of transistors for transferring and processing a signal transmitted from the photoelectric conversion units may be disposed on the pixel portion PA of the image sensor chip 20. A micro lens array 25 may be disposed on the pixel portion PA. Peripheral circuits may be disposed on the first edge portion EA1 and/or the third edge portion EA3. A chip connection terminal 23 may be disposed on the third edge portion EA3 of the image sensor chip 20. In this embodiment, the image sensor chip 20 may be mounted on the substrate 10 through a wire bonding method. Thus, the chip connection terminal 23 and the first substrate connection terminal 3 may be connected by a wire 4.
The image sensor chip 20 may be attached on or to the upper surface 1a of the substrate 10 by disposing the adhesion layer 30 on the upper surface 1a. In more detail, the adhesion layer 30 may include a first or upper adhesion part, portion or surface 30a directly contacting the first central portion CA1 of the image sensor chip 20 and a second or lower adhesion part, portion or surface 30b directly contacting the second central portion CA2 of the substrate 10. That is, the first adhesion part 30a may be an upper surface of the adhesion layer 30, and the second adhesion layer 30b may be a lower surface of the adhesion layer 30. As described above, it may be preferable that a modulus of the adhesion layer 30 (e.g., an elastic modulus of the adhesion layer 30) be about 2.7 MPa to about 4.2 MPa at a temperature of about −60° C. to about 230° C. in order to improve (reduce) the warpage of the image sensor chip 20 (Experimental examples 1 and 2). Therefore, the adhesion layer 30 may have a modulus of about 2.7 MPa to about 4.2 MPa at a temperature of about −60° C. to about 230° C. In more detail, the modulus of the adhesion layer 30 may be a modulus of an adhesion material for forming the adhesion layer 30. Meanwhile, when the adhesion layer 30 has the modulus of about 2.7 MPa to about 4.2 MPa at a temperature of about −60° C. to about 230° C., the adhesion layer 30 may have viscosity lower than that of an adhesion layer having a modulus higher than the modulus thereof. That is, the adhesion layer 30 may be thinner than an adhesion layer having a modulus higher than the modulus thereof, and the second adhesion part 30b may have an area greater than that of the first adhesion part 30a. Thus, the adhesion layer 30 may have a cross-section having a trapezoid shape. The adhesion layer 30 may have a thickness of about 1 μm to about 80 μm. The adhesion layer 30 may be comprised of, for example, an epoxy resin.
The adhesion layer 30 may be spaced apart from the first edge portion EA1 when viewed from a plan view. That is, the first adhesion part 30A may cover only a part of the image sensor chip first surface 20a, and may not cover or reach the first edge portion EA1 on the first surface 20a. Furthermore, the adhesion layer 30 may have a circular shape when viewed from a plan view. That is, the first adhesion part 30a and the second adhesion part 30b may have a circular shape. When the adhesion layer 30 has a circular shape, the first adhesion part 30a may be spaced relatively far apart from each corner or vertex 21 of the first surface 20a. When the adhesion layer 30 has a square shape, a spaced apart distance from the vertices 21 is reduced, and thus a warpage phenomenon of the image sensor chip 20 may worsen.
As described above, it may be preferable that a coverage ratio of an adhesion layer covering a lower surface of an image sensor chip be not more than about 50% in order to improve (reduce) the warpage of the image sensor chip 20 (Experimental examples 1 and 2). Therefore, the first adhesion part 30a may have an area corresponding to about 5% to about 50% of an area of the image sensor chip first surface 20a. For example, when the area of the first adhesion part 30a is called “A”, and the area of the first surface 20a is called “B”, A/B may be about 0.05 to about 0.5.
The semiconductor package 100 according to an embodiment of the inventive concept may include a first cavity S1 surrounded by the image sensor chip first surface 20a, the upper surface 1a of the substrate 10 and a side surface of the adhesion layer 30. That is, since the first adhesion part 30a covers a part of the first surface 20a, the first cavity S1 may be an empty space defined below the image sensor chip 20. Furthermore, the first cavity S1 may further extend to be connected to or be in communication with a second cavity S2 surrounded by a transparent substrate 50, a holder or holding member 40 and the substrate 10. The degree of warpage of the image sensor chip 20 may be improved due to the first cavity S1 defined below the image sensor chip 20.
The holder 40 may be disposed on the upper surface 1a of the substrate 10. The holder 40 may have an upper surface 40fs spaced apart from a surface of the image sensor chip 20. In more detail, the holder 40 may include an outer or outside cover portion 40a adjacent to the third edge portion EA3 and formed on the upper surface 1a, and an upper cover portion 40b connected to the outside cover portion 40a and adjacent to the transparent substrate 50. The spaced upper surface 40fs may be an upper surface of the upper cover portion 40b. The outside cover portion 40a and the upper cover portion 40b may be integrally connected to each other. Although not shown, at least a part of the third edge portion EA3 of the image sensor chip 20 may be covered by the holder 40 when viewed from a plan view. For example, the holder 40 may cover the third edge portion EA3, and may expose the pixel portion PA. The holder 40 may have a closed curve shape (or generally square shape) as viewed from a plan view. The holder 40 may be a plastic holder, and in more detail, may be formed of a polymer material such as polyamide. The holder 40 may be attached on the second edge portion EA2 of the substrate 10 by disposing a first adhesion film 45 on the second edge portion EA2.
The holder 40 may help isolate the image sensor chip 20 from the outside, and thus may help prevent an outside foreign substance from entering the pixel portion PA. Thus, a pixel distortion caused due to pollution by a foreign substance may be prevented. Furthermore, the holder 40 may protect a bonding between the wire 4 and the chip connection terminal 23 and a bonding between the wire 4 and the first substrate connection terminal 3 from the outside.
The transparent substrate 50 may be disposed on the upper cover portion 40b to thus provide the second cavity S2 between the transparent substrate 50 and the image sensor chip 20. In more detail, the transparent substrate 50 may be disposed so as to be adjacent to the upper surface 40fs of the holder 40. The transparent substrate 50 may be formed of transparent glass, plastic or the like. A second adhesion film 55 may be interposed between an edge or peripheral portion of the transparent substrate 50 and the upper surface 40fs of the holder 40. The second adhesion film 55 may include the same material as the first adhesion film 45. The second adhesion film 55 may extend to cover at least a portion of a side surface of the transparent substrate 50 and/or at least a portion of a side surface of the upper cover portion 40b. Thus, an area on which the second adhesion film 55 contacts the transparent substrate 50 and/or the holder 40 may become wider to enhance an adhesion force.
A solder bump 60 may be attached to the second substrate connection terminal 7 of the substrate 10.
The semiconductor package 100 according to an embodiment of the inventive concept may adjust three factors including a coefficient of thermal expansion of the substrate 10, a modulus of the adhesion layer 30 (e.g., an elastic modulus of the adhesion layer 30) and a coverage ratio of the adhesion layer 30 with respect to the image sensor 20 to considerably improve (reduce) the warpage by using an interaction effect of the three factors.
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The image sensor chip 20 may be disposed such that the first central portion CA1 on the first surface 20a thereof directly contacts a first adhesion part 30a of the adhesion layer 30. When the image sensor chip 20 is disposed on the adhesion layer 30, the adhesion layer 30 may be applied with a pressure to be spread in an outward direction. At this time, when the adhesion layer 30 is formed in a star shape, the image sensor chip 20 is disposed on the adhesion layer 30, and thus the adhesion layer 30 may be changed into a circular shape. When the adhesion layer 30 has a circular shape as viewed from a plan view, the warpage of the image sensor chip 20 may be improved as described above. Furthermore, the first adhesion part 30a of the adhesion layer 30 may have an area corresponding to about 5% to about 50% of an area of the first surface 20a of the image sensor chip 20. Meanwhile, since the first adhesion part 30a covers only a part of the first surface 20a, a first cavity S1 surrounded by the first surface 20a, the upper surface 1a of the substrate 10 and the side surface of the adhesion layer 30 may be defined.
After the image sensor chip 20 is attached, a wire bonding may be performed to form a wire 4 connecting a chip connection terminal 23 and a first substrate connection terminal 3.
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A semiconductor package 200 according to Embodiment 2 of the inventive concept will be described with reference to
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The image sensor chip 20 may include a first surface 20a facing the substrate 10 and a second surface 20b opposed to the first surface 20a. Here, the second surface 20b may include a pixel portion PA and a third edge portion EA3. A recess or recessed region V may be formed on the pixel portion PA of the second surface 20b, and a micro lens array 25 may be disposed inside the recess region V.
The pixel portion PA of the image sensor chip 20 may be covered with a transparent substrate 50. The transparent substrate 50 may have a width narrower than that of the image sensor chip 20 (or an area less than that of the image sensor chip 20). The transparent substrate 50 may expose a part of the third edge portion EA3 and a chip connection terminal 23. A second cavity S2 may be defined between the transparent substrate 50 and the pixel portion PA. A second adhesion film 55 may be interposed between an edge or peripheral portion of the transparent substrate 50 and the third edge portion EA3 of the image sensor chip 20. The second cavity S2 between the transparent substrate 50 and the pixel portion PA may be closed or sealed by the second adhesion film 55.
The image sensor chip 20 may be attached on the upper surface 1a of the substrate 10 by disposing the adhesion layer 30 on the upper surface 1a. The adhesion layer 30 may include a first adhesion part or portion 30a directly contacting the first central portion CA1 and a second adhesion part or portion 30b directly contacting the second central portion CA2. The adhesion layer 30 may have a modulus (e.g., an elastic modulus) of about 2.7 MPa to about 4.2 MPa at a temperature of about −60° C. to about 230° C. The second adhesion part 30b may have an area greater than that of the first adhesion layer 30a, and thus the adhesion layer 30 may have a cross-section having a trapezoid shape. Furthermore, the adhesion layer 30 may have a thickness of about 1 μm to about 80 μm.
The adhesion layer 30 may be spaced apart from the first edge portion EA1 of the image sensor 20 when viewed from a plan view. Furthermore, the adhesion layer 30 may have a circle shape. In this case, the warpage of the image sensor chip 20 may be improved (reduced) as described above.
The first adhesion part 30a may have an area corresponding to 5% to 50% of an area of the image sensor chip first surface 20a. For example, when the area of the first adhesion part 30a is called “A”, and the area of the first surface 20a is called “B”, A/B may be about 0.05 to about 0.5. Thus, a first cavity S1 being an empty space formed below the image sensor chip 20 may be defined.
At least a part of a side surface of the transparent substrate 50, a part of the third edge portion EA3 of the image sensor 20 and a part of the second edge portion EA2 of the substrate 10 may be covered with a mold film 38. Since the mold film 38 may extend from the side surface of the transparent substrate 50 onto the third edge portion EA3, a side surface of the image sensor 20 may be also covered with the mold film 38. However, as described above, since the adhesion layer 30 may have a relatively low modulus, the adhesion layer 30 may have a relatively small thickness. Therefore, the mold film 38 may not cover the first central portion CA1 and the first edge portion EA1 of the image sensor chip 20. Alternatively, the mold film 38 may cover only a part of the first edge portion EA1. The first cavity S1 surrounded by the first surface 20a of the image sensor chip 20, the upper surface 1a of the substrate 10, the side surface of the adhesion layer 30, and the mold film 38 may be defined. The warpage of the image sensor chip 20 may be improved (reduced) due to the first cavity S1 defined below the image sensor chip 20.
Furthermore, the mold film 38 may cover the chip connection terminal 23, a first substrate connection terminal 3 and a wire 4. Thus, the mold film 38 may protect a bonding between the wire 4 and the chip connection terminal 23 and a bonding between the wire 4 and the first substrate connection terminal 3 from the outside.
Although not shown, an upper surface of the mold film 38 may be coplanar with an upper surface of the transparent substrate 50. Therefore, upper surfaces of the mold film 38 and the transparent 50 may be flat and coplanar. Alternatively, the upper surface of the mold film 38 may be located below or on a level lower than that of the upper surface of the transparent substrate 50. The mold film 38 may be formed by using an epoxy resin.
The semiconductor package 200 according to an embodiment of the inventive concept may adjust three factors including a coefficient of thermal expansion of the substrate 10, a modulus of the adhesion layer 30 (e.g., an elastic modulus of the adhesion layer 30) and a coverage ratio of the adhesion layer 30 with respect to the image sensor 20 to considerably improve (reduce) the warpage by using an interaction effect of the three factors.
Processes of manufacturing a semiconductor package 200 according to Embodiment 2 of the inventive concept will be described with reference to
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In the drawings and specification, there have been disclosed embodiments of the inventive concept and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the inventive concept being set forth in the following claims.
Number | Date | Country | Kind |
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10-2014-0084647 | Jul 2014 | KR | national |