FIELD OF THE INVENTION The disclosed embodiments relate generally to the manufacture of integrated circuit devices and, more particularly, to a carrier tape and a heat shrinkable cover tape for handling integrated circuit devices.
BACKGROUND OF THE INVENTION A carrier tape capable of holding a number of integrated circuit (IC) die may be utilized to facilitate automation and handling of these components. A typical carrier tape comprises a flexible tape having a row (or multiple rows) of evenly spaced pockets distributed along its length. Each pocket is configured to receive an individual die (or die assembly or packaged die), and a cover tape is adhered to an upper surface of the carrier tape to cover each pocket and retain the die on the carrier. The carrier tape can be wound onto a tape reel, and a row of small indexing holes may be distributed along the length of the carrier tape adjacent an edge of the tape, these indexing holes enabling movement of the carrier tape and/or tape reel by automated handing equipment.
The typical carrier tape described above may work well for thick integrated circuit die (e.g., die having a thickness greater than about 200 μm). However, in order to facilitate smaller form factors and die stacking architectures, IC device manufacturers may be producing die having thicknesses less than 200 μm, and perhaps having thicknesses less than about 50 μm. At these relatively small thicknesses (e.g., thicknesses less than about 200 μm), migration of die between the pockets of a carrier tape may occur, as the die may be capable of sliding through any gap that exists between the cover tape and carrier tape.
BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A-1D are schematic diagrams illustrating embodiments of a carrier medium including a carrier tape and a heat shrinkable cover tape.
FIGS. 2A-2F are schematic diagrams illustrating other embodiments of a carrier medium including a carrier tape and a heat shrinkable cover tape.
FIGS. 3A-3F are schematic diagrams illustrating further embodiments of a carrier medium including a carrier tape and a heat shrinkable cover tape.
FIG. 4 is a block diagram illustrating an embodiment of a method for securing die in a carrier medium using a heat shrinkable cover tape.
FIG. 5 is a schematic diagram illustrating an embodiment of a system for securing die in a carrier medium having a heat shrinkable cover tape.
DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1A through 1D, illustrated are embodiments of a carrier tape 100 and a cover tape 150. A top plan view of the carrier and cover tapes is provided in FIG. 1A, whereas a side elevation view of the carrier and cover tapes is shown in FIG. 1B. Cross-sectional views, as taken along line X-X of FIGS. 1A and 1B, of various embodiments of the carrier and cover tapes are provided in each of FIGS. 1C and 1D. In FIGS. 1A-1D, the carrier tape 100 and cover tape 150 are shown after application of the cover tape to the carrier tape. Together, the carrier tape 100 and cover tape 150 provide a carrier medium for a number of integrated circuit die 5 (or other components).
With reference to FIGS. 1A-1C, in one embodiment, the carrier tape 100 comprises a base 110 having an upper side 111 and an opposing lower side 112. Disposed on the base 110 is a row of spaced-apart pockets 120 (or other retaining areas or features). Each of the pockets 120 provides a recess accessible from the upper side 111, and this recess can receive an integrated circuit die 5 (or, alternatively, a packaged die, die assembly, or other component). An aperture 122 at the bottom of each pocket 120 may allow for insertion of a pin (from lower side 112) to assist in extraction of any component placed in a pocket 120. Although a single row of pockets 120 is shown in the figures, in other embodiments, multiple rows of pockets may be distributed along the length of the carrier tape 100.
Disposed along the edges (or, perhaps, one of the edges) of the base 110 is a row of indexing holes 115. A drive gear having teeth adapted to engage the indexing holes 115, or other mechanism capable of engaging the indexing holes, can be used to advance the carrier tape 100 (either alone or in combination with motion of a take-up reel). The carrier tape 100 may be constructed from any suitable flexible material, including plastic materials such as polycarbonate or highly carbon black reinforced polystyrene, as well as other materials.
The carrier medium depicted in FIGS. 1A-1C (and 1D) also includes a cover tape 150. As illustrated in these figures, the cover tape 150 has been applied to the carrier tape 100. The cover tape 150 retains the die 5 (or other components) placed into the pockets 120 and also protects these die. Cover tape 150 comprises a flexible heat shrinkable material, such as a heat shrinkable polymer (e.g., a heat shrinkable polyester or polyolefin). After application of the cover tape 150 to the carrier tape 100, heat is applied to shrink the cover tape. Shrinkage of the cover tape 150 can minimize sagging of the cover tape, thereby eliminating or substantially reducing any gaps that may have existed between the cover tape 150 and carrier tape 100. Eliminating or reducing such gaps can help to prevent the migration of die between the pockets 120 of the carrier tape.
The cover tape 150 may be secured to the carrier tape 100 using any suitable technique. According to one embodiment, as shown in FIGS. 1A-1C, the cover tape 150 is secured to the carrier tape 100 using layers of adhesive 190 (e.g., a pressure sensitive adhesive). After the cover tape 150 is adhered to the carrier tape 100, heat can be applied to shrink the cover tape and reduce sag between the adhesive strips 190. In an alternative embodiment, as shown in FIG. 1D, the cover tape 150 is adhered to the carrier tape 100 though shrinkage of the cover tape itself. As shown in FIG. 1D, the cover tape 150 has a width that is greater than a width of the carrier tape 100. Upon application of heat and shrinkage of the cover tape 150, the outer edges of the cover tape 150 wrap around the outer edges of the carrier tape 100, thereby securing the cover tape to the carrier tape and also reducing sag in the cover tape.
Referring next to FIGS. 2A through 2F, illustrated are further embodiments of a carrier tape 200 and a cover tape 250. A top plan view of the carrier and cover tapes is provided in FIG. 2A, whereas a side elevation view of the carrier and cover tapes is shown in FIG. 2B. Cross-sectional views, as taken along line Y-Y of FIGS. 2A and 2B, of various other embodiments of the carrier and cover tapes are provided in each of FIGS. 2C and 2D. Also, each of FIGS. 2E and 2F illustrates further embodiments (in plan view) of the carrier tape 200. In FIGS. 2A-2D, the carrier tape 200 and cover tape 250 are shown after application of the cover tape to the carrier tape. Together, the carrier tape 200 and cover tape 250 provide a carrier medium for a number of integrated circuit die 5 (or other components).
Turning to FIGS. 2A-2C, in one embodiment, the carrier tape 200 comprises a base 210 having an upper side 211 and an opposing lower side 212. Disposed on the base 210 is a row of spaced-apart die retaining areas 205. According to one embodiment, each die retaining area 205 comprises a pocket 220 formed in the base 210 and one or more raised features 230 extending upwards for the upper surface 211 of base 210. Each of the pockets 220 provides a recess accessible from the upper side 211, and this recess can receive an integrated circuit die 5 (or, alternatively, a packaged die, die assembly, or other component). The raised features 230, in conjunction with cover tape 250, function to minimize gaps between the cover tape and carrier tape 200 that could allow die to migrate between retaining areas. An aperture 222 at the bottom of each pocket 220 may allow for insertion of a pin (from lower side 212) to assist in extraction of any component placed in a pocket 220. Although a single row of retaining areas 205 is shown in the figures, in other embodiments, multiple rows of retaining areas may be distributed along the length of the carrier tape 200.
Disposed along the edges (or, perhaps, one of the edges) of the base 210 is a row of indexing holes 215. A drive gear having teeth adapted to engage the indexing holes 215, or other mechanism capable of engaging the indexing holes, can be used to advance the carrier tape 200 (either alone or in combination with motion of a take-up reel). The carrier tape 200 may be constructed from any suitable flexible material, including plastic materials such as polycarbonate or highly carbon black reinforced polystyrene, as well as other materials.
The carrier medium depicted in FIGS. 2A-2C (and 2D) also includes a cover tape 250. As illustrated in these figures, the cover tape 250 has been applied to the carrier tape 200. The cover tape 250 retains the die 5 (or other components) placed into the pockets 220 and also protects these die. In one embodiment, cover tape 250 comprises a flexible heat shrinkable material, such as a heat shrinkable polymer (e.g., a heat shrinkable polyester or polyolefin). After application of the cover tape 250 to the carrier tape 100, heat is applied to shrink the cover tape. Shrinkage of the cover tape 250 can minimize sagging of the cover tape over the pockets 220, and this reduction in sagging in conjunction with the raised features 230 can serve to eliminate or substantially reduce gaps between the cover tape 250 and carrier tape 200. Eliminating or reducing such gaps can help to prevent the migration of die between the retaining areas 205 of the carrier tape 200.
The cover tape 250 may be secured to the carrier tape 200 using any suitable technique. According to one embodiment, as shown in FIGS. 2A-2C, the cover tape 250 is secured to the carrier tape 200 using layers of adhesive 290 (e.g., a pressure sensitive adhesive). After the cover tape 250 is adhered to the carrier tape 200, heat can be applied to shrink the cover tape and reduce sag between the adhesive strips 290. In an alternative embodiment, as shown in FIG. 2D, the cover tape 250 is adhered to the carrier tape 200 though shrinkage of the cover tape itself. As shown in FIG. 2D, the cover tape 250 has a width that is greater than a width of the carrier tape 200. Upon application of heat and shrinkage of the cover tape 250, the outer edges of the cover tape 250 wrap around the outer edges of the carrier tape 200, thereby securing the cover tape to the carrier tape and also reducing sag in the cover tape.
In FIGS. 2A through 2D, each of the retaining areas 205 includes four raised features 230 surrounding the periphery of a generally rectangular-shaped pocket 220. Each of the raised features 230 extends along a portion of one side of the rectangular-shaped pocket 220. It should be understood, however, that FIGS. 2A-2D present just one embodiment of the configuration of a retaining area 205 and, further, that a retaining area—including raised features 230— may have any suitable configuration. By way of example, with reference to FIG. 2E, a retaining area 205 may include a single raised feature 230 that extends fully around the periphery of a generally rectangular shaped pocket 220. Referring to FIG. 2F, by way of further example, a retaining area 205 may include four raised features 230, each of the raised features located at one corner of the pocket 220 and extending about a portion of the pocket's periphery. Also, as the reader will appreciate, the pockets 220 are not limited to the generally rectangular-shaped pockets shown in the figures, and the pockets may have any other suitable shape or configuration, depending upon the shape and size of the components that are to be placed on the carrier tape 200 (e.g., generally circular, oval, etc.).
Turning now to FIGS. 3A through 3F, illustrated are additional embodiments of a carrier tape 300 and a cover tape 350. A top plan view of the carrier and cover tapes is provided in FIG. 3A, whereas a side elevation view of the carrier and cover tapes is shown in FIG. 3B. Cross-sectional views, as taken along line Z-Z of FIGS. 3A and 3B, of various other embodiments of the carrier and cover tapes are provided in each of FIGS. 3C and 3D. Also, each of FIGS. 3E and 3F illustrates further embodiments (in plan view) of the carrier tape 300. In FIGS. 3A-3D, the carrier tape 300 and cover tape 350 are shown after application of the cover tape to the carrier tape. Together, the carrier tape 300 and cover tape 350 provide a carrier medium for a number of integrated circuit die 5 (or other components).
Referring to FIGS. 3A-3C, in one embodiment, the carrier tape 300 comprises a base 310 having an upper side 311 and an opposing lower side 312. Disposed on the base 310 is a row of spaced-apart die retaining areas 305. According to one embodiment, each die retaining area 305 comprises one or more raised features 330 extending upwards for the upper surface 311 of base 310. The raised features 330 of each retaining area define a slot capable of receiving an integrated circuit die 5 (or other component) and, upon application of the cover tape 350, any die placed in this slot will be retained and prevented from migrating to other areas of the carrier tape 200. An aperture 322 in each retaining area 305 may allow for insertion of a pin (from lower side 312) to assist in extraction of any component placed in the slot defined by the raised features 330. Also, although a single row of retaining areas 305 is shown in the figures, in other embodiments, multiple rows of retaining areas may be distributed along the length of the carrier tape 300.
Disposed along the edges (or, perhaps, one of the edges) of the base 310 is a row of indexing holes 315. A drive gear having teeth adapted to engage the indexing holes 315, or other mechanism capable of engaging the indexing holes, can be used to advance the carrier tape 300 (either alone or in combination with motion of a take-up reel). The carrier tape 300 may be constructed from any suitable flexible material, including plastic materials such as polycarbonate or highly carbon black reinforced polystyrene, as well as other materials.
The carrier medium depicted in FIGS. 3A-3C (and 3D) also includes a cover tape 350. As illustrated in these figures, the cover tape 350 has been applied to the carrier tape 300. The cover tape 350 retains the die 5 (or other components) placed into the retaining areas 305 and also protects these die. In one embodiment, cover tape 350 comprises a flexible heat shrinkable material, such as a heat shrinkable polymer (e.g., a heat shrinkable polyester or polyolefin). After application of the cover tape 350 to the carrier tape 300, heat is applied to shrink the cover tape. Shrinkage of the cover tape 350 can minimize sagging of the cover tape between the raised features 330, and this reduction in sagging can help to retain components in the retaining areas 305.
The cover tape 350 may be secured to the carrier tape 300 using any suitable technique. According to one embodiment, as shown in FIGS. 3A-3C, the cover tape 350 is secured to the carrier tape 300 using layers of adhesive 390 (e.g., a pressure sensitive adhesive). After the cover tape 350 is adhered to the carrier tape 300, heat can be applied to shrink the cover tape and reduce sag between the adhesive strips 390. In an alternative embodiment, as shown in FIG. 3D, the cover tape 350 is adhered to the carrier tape 300 though shrinkage of the cover tape itself. As shown in FIG. 3D, the cover tape 350 has a width that is greater than a width of the carrier tape 300. Upon application of heat and shrinkage of the cover tape 350, the outer edges of the cover tape 350 wrap around the outer edges of the carrier tape 300, thereby securing the cover tape to the carrier tape and also reducing sag in the cover tape.
In FIGS. 3A through 3D, each of the retaining areas 305 includes four raised features 330 that define, at least in part, the periphery of a slot capable of receiving an IC die 5 or other component, as described above. It should be understood, however, that FIGS. 3A-3D present just one embodiment of the configuration of a retaining area 305 and, further, that a retaining area— including raised features 330—may have any suitable configuration. By way of example, with reference to FIG. 3E, a retaining area 305 may include a single raised feature 330 that fully defines the periphery of a generally rectangular shaped slot capable of receiving an IC die 5 or other component (this slot, in essence, being similar to the pocket 220 described above, but extending above the upper surface 311 of base 310 rather than below this surface). Referring to FIG. 3F, by way of further example, a retaining area 305 may include four raised features 330, wherein the raised features define, in part, the periphery of a slot—in particular, the corners of such a slot— that is capable of receiving an IC die or other component. Also, as the reader will appreciate, a slot defined by raised features 330 is not limited to the generally rectangular-shaped slots shown in the figures, and these slots may have any other suitable shape or configuration, depending upon the shape and size of the components that are to be placed on the carrier tape 300 (e.g., generally circular, oval, etc.).
In the embodiments described above in FIGS. 2A-2F and in FIGS. 3A-3F, the carrier medium included a heat shrinkable cover tape. However, the disclosed embodiments are not limited to use of a heat shrinkable cover tape. Thus, it should be understood that, in other embodiments, the cover tape 250, 350 may comprise a material that does not shrink (or that does not substantially shrink) upon application of heat and/or that is not otherwise subjected to heat after being adhered to the carrier tape.
Referring now to FIG. 4, illustrated is an embodiment of a method 400 for securing die in a carrier medium using a heat shrinkable cover tape. As set forth in block 410, a die is placed in a retaining area of a carrier tape. A cover tape is then applied to the carrier tape, as shown at block 420, this cover tape comprising a heat-shrinkable material. Referring to block 430, heat is applied to the cover tape to shrink the cover tape. In one embodiment, shrinkage of the cover tape itself secures the cover tape to the carrier tape. According to another embodiment, as set forth in block 440, the cover tape is secured to the carrier tape using an adhesive (e.g., a pressure sensitive adhesive). As the reader will appreciate, in many applications, the method 400 described above will take place in a continuous manner, wherein die are consecutively placed in successive retaining areas of the carrier tape, the cover tape is secured to the carrier tape, and the carrier medium with die is wound onto a take-up reel.
Referring to FIG. 5, illustrated is an embodiment of a system 500 for securing die in a carrier medium having a heat shrinkable cover tape. System 500 includes a carrier tape mechanism 510, which comprises a source tape reel 512, a take-up reel 514, and an actuator 516 coupled with the take-up reel 514 (and/or source reel 512). Wound on the source tape reel 512 is a length of carrier tape 100, 200, 300 having a number of retaining areas 205, 305 (or simply pockets 120), each retaining area for receiving a die 5. The carrier tape is advanced by motion of the take-up reel 514 (and/or source reel 512) initiated by actuator 516, and the carrier tape (with die 5 and a cover tape) is wound onto the take-up reel 514. Alternatively, movement of the carrier tape may be initiated by a mechanism that engages a series of indexing holes on the carrier tape (either alone or in combination with motion of the take-up reel 514 produced by actuator 516).
The system 500 further includes a cover tape applicator 520. Cover tape applicator 520 comprises any suitable mechanism capable of disposing a cover tape 150, 250, 350 onto the carrier tape in a continuous manner. The system 500 may also include a heat source 530. Heat source 530 may comprise any suitable heat source capable of heating the cover tape in order to shrink this tape. For example, the heat source 530 may comprise a hot air blower, a heat lamp, an infrared heater, or an electric resistive element. Embodiments of the cover tape 150, 250, 350 and carrier tape 100, 200, 300, as well as the application of this cover tape to the carrier tape to create a carrier medium for integrated circuit die (or other components), are described above.
The system 500 also includes a pick-and-place mechanism 540. Pick-and-place mechanism 540 includes a pick-and-place head 545 that “picks” individual die 5 from a wafer 2 that has been diced or singulated into a number of die. Wafer 2 may be held by a wafer holding device 550 (e.g., a wafer chuck, an adhesive tape disposed on a substrate, etc.). System 500 may also include a controller 560 communicatively coupled with the heat source 530, the pick-and-place mechanism 540, and the actuator 516 of carrier tape mechanism 510, and each of these devices may send signals to controller and receive signals from the controller (and perform actions in response to signals received from the controller). The controller 560 may comprise any suitable computing device.
The foregoing detailed description and accompanying drawings are only illustrative and not restrictive. They have been provided primarily for a clear and comprehensive understanding of the disclosed embodiments and no unnecessary limitations are to be understood therefrom. Numerous additions, deletions, and modifications to the embodiments described herein, as well as alternative arrangements, may be devised by those skilled in the art without departing from the spirit of the disclosed embodiments and the scope of the appended claims.
