BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of the present invention will become readily apparent from the detailed description that follows, with reference to the accompanying drawings, in which:
FIG. 1 is a plan view illustrating a semiconductor substrate which may be utilized in an embodiment of the present invention; and
FIGS. 2A through 2G are sectional views for describing a method of fabricating a thin semiconductor package according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as being 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 concept of the invention to those skilled in the art. Like reference numerals in the drawings denote like elements, and thus their description will not be repeated.
FIG. 1 is a plan view illustrating a semiconductor substrate which may be utilized in an embodiment of the present invention. FIGS. 2A through 2G are sectional views for use in describing a method of fabricating a thin semiconductor package according to an embodiment of the present invention. In particular, FIG. 2A is a sectional view taken along a line II-II′ of FIG. 1.
Referring to FIGS. 1 and 2A, a semiconductor substrate 10 includes a plurality of semiconductor chips C formed with semiconductor devices, and scribe lanes S located between the plurality of semiconductor chips C. Since the semiconductor chips C are arranged in row and column directions, the scribe lanes S intersect one another to define crisscross pattern.
By etching the semiconductor substrate 10, a trench T is defined within and along the scribe lanes S. The semiconductor substrate 10 may, for example, be etched using a diamond blade or a laser.
Referring to FIG. 2B, a mask 12 is disposed on the substrate 10. The mask includes openings which expose the trench T along the scribe lanes S.
The openings in the mask 12 and the trench T is then filled with a photolytic polymer to define a photolytic polymer layer 13. The photolytic polymer layer 13 may, for example, be formed by roller coating. In the illustrated example of FIG. 2B, the photolytic polymer layer is also be formed on an upper surface of the mask 12.
The photolytic polymer may include polymer having a photosensitive functional group. More specifically, an ethylene•carbonmonoxide(CO) copolymer, a vinyl keton copolymer or a combination of these materials may be included. The photolytic polymer may include photo-sensitizer as an additive. The photosensitizer may be an aromatic keton group, a metal composite material that can form radicals by light, or a combination of these materials. The aromatic keton group may include benzophenone, acetophenone and anthraquinone.
Referring to FIG. 2C, the mask 12 and the photolytic polymer within the openings of the mask 12 are removed to expose a front surface of the substrate 10. As a result, the photolytic polymer layer 13 remains within the trench T along the scribe lanes S.
Thereafter, a protection tape 15 is attached on the front surface of the substrate 10. The protection tape 15 shields the front surface of the substrate 10 during back grinding (described later).
Referring to FIG. 2D, a back side of the substrate 10 is ground until the trench T is partially etched (i.e., until the photolytic polymer layer 13 is exposed). For example, the back side of the substrate 10 is ground until reaching a position shown by the dot-lined of FIG. 2C. As a result, the semiconductor chips C are connected to each other by the protection tape 15, and the photolytic polymer layer 13 is positioned between the semiconductor chips C. Since the semiconductor chips C remain connected and spaced from each other by the photolytic polymer layer 13, misalignment between the semiconductor chips C during the back grinding process is prevented. Subsequently, a mounting tape 17 is attached on the back side of the back-ground substrate 10.
Referring to FIG. 2E, the protection tape 15 is detached to expose the front surface of the substrate 10. Thereafter, light L is radiated on the front surface of the substrate 10. The light L may be ultraviolet rays having a wavelength range of 290 nm˜315 nm.
Referring to FIG. 2F, the photolytic polymer is dissolved by the radiation of the light L. As a result, the semiconductor chips C are separated from each other under the state of being attached onto the mounting tape 17. Therefore, the semiconductor chips C can be easily separated without performing additional sawing after back grinding of the substrate 10. Consequently, the occurrence of chipping or cracking at an edge of the semiconductor chips C can be prevented.
Subsequently, the substrate 10 may be cleansed. The cleansing of the substrate 10 may be performed by jetting distilled water onto the substrate 10. Thus, the photolytic polymer is dissolved and completely removed.
Referring to FIG. 2G, any one of the semiconductor chips C is extracted from the mounting tape 17 using an apparatus 30 of FIG. 2F such as vacuum tweezers. Then, a bonding film 22 is attached on the back side of the extracted semiconductor chip C, which is attached on an circuit substrate 20. Thereafter, a terminal pad (not shown) of the semiconductor chip C is electrically connected to a terminal pad (not shown) of the circuit substrate 20 using wires 25. Thereafter, a molding layer 27 for embedding the terminal pads and the semiconductor chips C is formed to complete the semiconductor package. However, the method of manufacturing the semiconductor package using the semiconductor chip C is not restricted to the example of FIG. 2G.
According to the present invention as described above, semiconductor chips can be easily separated without requiring additional sawing after back grinding of a semiconductor substrate. Therefore, the occurrence of chipping or cracking at an edge of the semiconductor chips can be prevented. Consequently, a semiconductor package having a semiconductor chip of relatively small thickness can be readily manufactured.
While the present invention has been particularly shown and described with reference to exemplary 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 present invention as defined by the following claims.
Patent Application
20080064215
