This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2005-0073001, filed on Aug. 9, 2005, in the Korean Intellectual Property Office (KIPO), the entire contents of which are incorporated herein by reference.
1. Field
Example embodiments of the present invention relate to a method of packaging a semiconductor device. Other example embodiments of the present invention relate to a method of fabricating wafer chips for packaging a semiconductor device.
2. Description of the Related Art
As electronic appliances continue to become smaller, efforts for reducing the thickness of semiconductor packages are being made. One of the methods of reducing the thickness of semiconductor packages is to lap the back surface of a wafer (e.g., a back lapping process). After performing the back lapping process, the wafer undergoes a dicing process to form wafer chips and the wafer chips are attached onto a substrate, for example, a lead frame and/or a printed circuit board and/or another wafer chip.
The wafer chip may be attached using resin or paste according to the conventional art. A resin bleed-out phenomenon (e.g., leakage of the applied resin or paste out of an attaching region of the wafer chip) may occur more frequently. The wafer chip may be attached onto the substrate with a height variation or may be attached at a slant on the substrate. Instead of applying resin or paste, attaching a die attach film (DAF) on the wafer chip has been suggested to solve the above problems.
Because the wafer chip undergoing the back lapping process is relatively thin (e.g., a thickness of about 50 μm˜about 80 μm), the tensile stress generated due to warping of the wafer chip 10b may induce cracks on the wafer chips 10b or degrade properties of an electronic device fabricated on the wafer chips 10b. Productiveness and reliability of electronic products may be degraded.
Example embodiments of the present invention relate to a method of packaging a semiconductor device. Other example embodiments of the present invention relate to a method of fabricating wafer chips for packaging a semiconductor device. Example embodiments of the present invention provide a method of fabricating a wafer chip, which may decrease tensile stress during a pick-up process by removing the adhesive component adhering onto the cutting surfaces of the wafer chips, the diced DAF and the first base film.
According to example embodiments of the present invention, there is provided a method of fabricating wafer chips, the method including preparing at least one wafer, attaching at least one film onto a back surface of the wafer to support the wafer, forming wafer chips by dicing the wafer, detaching the at least one film from the wafer chips and attaching at least one base film onto the wafer chips to support the wafer chips. The at least one film may be a first base film, a die attach film and/or both. The at least one base film may be a first base film or a second base film. The first base film and the second base film include an attaching layer and a base film layer. The step of forming wafer chips may be performed using a blade sawing method and/or a laser cutting method. The step of forming wafer chips may be performed by cutting the wafer all at once from a front surface of the wafer to the surface of the attaching layer of the first base film or to some degree of thickness into the base film layer.
The method may further include coupling a fixing unit for fixing the wafer chips to the front surface of the wafer chips, after the step of forming the wafer chips. The fixing unit may be a fixing film having an attaching layer attached to the front surface of the wafer chips and/or a vacuum chuck having a vacuum stage for absorbing the wafer chips. The step of detaching the first base film may be performed by pulling the first base film from the wafer chips at an angle within a range of about 90°˜about 180° between the first base film and an attaching/detaching surface of the wafer chip. The second base film may be the same as the first base film and/or a new base film. The attaching layer of the first base film and/or the second base film may be a photosensitive attaching layer which may lose its adhesive force by ultraviolet ray irradiation. The attaching layer of the first base film and/or the second base film may be a foaming attaching layer which may lose its adhesive force by heating. The method may further include attaching a die attach film (DAF) onto the back surface of the wafer before attaching the first base film, and dicing the DAF in one piece with the wafer. A DAF may be attached onto the attaching layer of the first base film and the DAF may be attached onto the back surface of the wafer with the first base film.
According to other example embodiments of the present invention, there is provided a method of fabricating a wafer chip including preparing a plurality of wafer chips, attaching a DAF and a first base film including an attaching layer and a base film layer onto back surfaces of the wafer chips to support the wafer chips, dicing the DAF in one piece with the wafer chips, detaching the first base film from the diced DAF and attaching a second base film including an attaching layer and a base film layer onto the diced DAF to support the wafer chips. The method may further include coupling a fixing unit for fixing the wafer chips to the front surface of the wafer chips, after the step of forming the wafer chips. The fixing unit may be a fixing film having an attaching layer attached to the front surface of the wafer chips and/or a vacuum chuck having a vacuum stage for absorbing the wafer chips.
The DAF and the first base film may be sequentially attached onto the wafer chips, or the DAF and the first base film may be attached simultaneously onto the wafer chips after being coupled to each other. The step of forming wafer chips may be performed using a blade sawing method and/or a laser cutting method. The step of forming wafer chips may be performed by cutting the wafer in one piece from a front surface of the wafer to the surface of the attaching layer of the first base film or to some degree of thickness into the base film layer. The step of detaching the first base film may be performed by pulling the first base film from the wafer chips at within a range of about 90°˜about 180° between the first base film and an attaching/detaching surface of the wafer chip.
According to still other example embodiments of the present invention, there is provided a method of fabricating a wafer chip including preparing a plurality of wafer chips, attaching a DAF onto back surfaces of the wafer chips, dicing the DAF in one piece with each of the wafer chips and attaching a first base film, including an attaching layer and a base film layer, onto the diced DAF to support the wafer chips. The step of dicing the DAF may be performed using a laser cutting method. The method may further include picking up the wafer chips attached with the diced DAF.
Example embodiments of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.
Various example embodiments of the present invention are described more fully hereinafter with reference to the accompanying drawings, in which example embodiments of the present invention are shown. Example embodiments of the present invention may, however, be embodied in many different forms and should not be construed as limited to the example 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 example embodiments of the present invention to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity.
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 are no intervening elements or layers present. Like reference numerals refer to like elements throughout. 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. 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 example embodiments of the present invention.
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'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 turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. The exemplary 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.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the example embodiments of the present invention. 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” 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.
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 of the present invention 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.
Example embodiments of the present invention relate to a method of packaging a semiconductor device. Other example embodiments of the present invention relate to a method of fabricating wafer chips for packaging a semiconductor device.
Referring to
Referring to
Referring to
As shown in
According to example embodiments of the present invention, the pick-up force may be determined by the adhesive force of the second base film 400 and the attaching area of the wafer chip 100b with the second base film 400 during the pick-up process of the wafer chips 100b. Example embodiments of the present invention may provide a more reliable pick-up process to retard or prevent warping of the wafer chips even if the wafer chips are relatively thin (e.g., a thickness of 50 μm˜80 μm) due to back lapping process,
Referring to
Referring to
According to example embodiments of the present invention, the adhesive component adhering onto the cutting surfaces of the wafer chips 100b, the diced DAF 200b and the first base film 300 may be removed by a simple process (e.g., detaching the first base film 300 from the wafer chip 100b). Because the tensile stress on the wafer chips due to the adhesive component might not be generated during the pick-up process, the process yield of fabricating the wafer chips may be improved. Because the adhesive component that may interfere with the pick-up process may be removed, the pick-up force may be determined by the adhesive force between the DAF and the second base film and the attaching area of the diced DAF 200b with the second base film 400. The uniform pick-up force may provide a more reliable pick-up process for fabricating the wafer chips. The method of fabricating the wafer chips which may be sawed prior to a back lapping process as follows.
Referring to
Referring to
Referring to
Like the other example embodiments of the present invention described above, as shown in
According to example embodiments of the present invention, because the first base film 300 is attached after performing the dicing process of the DAF in which the adhesive component of the DAF may be locally heated and melted, the adhesive component that may affect the pick-up process of the wafer chips 100b may not adhere on the first base film 300. The pick-up force of the wafer chip 100b may be determined by the adhesive force between the diced DAF 200b and the first base film 300 and the attaching area of the diced DAF 200b with the first base film 300 during the pick-up process. Example embodiments of the present invention may provide a more reliable pick-up process to retard or prevent warping of the wafer chips.
As mentioned above, according to example embodiments of the present invention, the adhesive component, adhering on the cutting surfaces of the wafer chips, the diced DAF and the first base film during the dicing process, may be removed by detaching the first film from the diced DAF. A tensile stress may not occur on the wafer chips 100b during the pick-up process due to the attachment of the second base film onto the wafer chips 100b. Because the pick-up force may be determined by the adhesive force between the diced DAF, the second base film and the attaching area of the diced DAF with the second base film, the uniform pick-up force may provide a more reliable pick-up process for fabricating the wafer chips.
While various example embodiments of the present invention have been particularly shown and described with reference to example embodiments thereof, 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 example embodiments of the present invention as defined by the following claims.
Number | Date | Country | Kind |
---|---|---|---|
10-2005-0073001 | Aug 2005 | KR | national |