JP2007157953A - Substrate housing cassette - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate housing cassette capable of suppressing the substrate from having any trouble when it is taken out by being easily damaged and deformed, even if a substrate is thin. <P>SOLUTION: The substrate housing cassette comprises a plurality of shelf plates 20 supported on a side wall 2 of a cassette case 1, a recessed hole 30 recessed in the surface of each shelf plate 20, a flexible holding layer 40 for demountably and closely holding a thinned semiconductor wafer W by covering the recessed hole 30, and an exhaust passage 50 for exhausting the air in the recessed hole 30 covered with the holding layer 40 to the outside. It is possible to closely support the semiconductor wafer W substantially flatly by adhesion force of the holding layer 40, so that the semiconductor wafer W is prevented from being simply damaged even if it is made thin pieces by back grinding. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate storage cassette used for storage and transport of semiconductor wafers. In particular, the present invention relates to a substrate storage cassette that handles a semiconductor wafer thinned by a back grinding process.

  The semiconductor wafer is preferably thick so that it does not warp in the pre-process of semiconductor manufacturing, but the thickness as it is is not suitable for recent semiconductor packages that require thinning, miniaturization, and weight reduction. After the back surface is shaved and thinned by a grinder apparatus in a process called, it is transferred to the next process (see Patent Document 1).

  When the semiconductor wafer W is thinned in the back grinding process and transferred to the next process, first, the protective sheet 70 is attached to the pattern forming surface of the semiconductor wafer W having a thickness of about 750 μm and cut into a preferable size ( Then, the semiconductor wafer W is stored in the substrate storage cassette 84 and transferred to the grinder device 80 shown in FIG.

  After the substrate storage cassette 84 is conveyed to the grinder device 80, the semiconductor wafer W is set on the chuck table 81 of the grinder device 80, and the chuck table 81 is rotated to perform rough grinding and finish grinding on the back surface of the semiconductor wafer W. Then, the semiconductor wafer W thinned to about 50 μm by back grinding is cleaned by the cleaning device 82.

Then, the thinned semiconductor wafer W is transferred from the cleaning device 82 of the grinder device 80 to the stress relief device 83 in-line downstream, and the damaged layer on the back surface where the strength of the semiconductor wafer W is reduced is removed by an etching solution or After the removal by polishing to improve the bending strength, if the semiconductor wafer W is stored in the substrate storage cassette 84, the thinned semiconductor wafer W can be transferred to the next process by the substrate storage cassette 84 (Patent Document). 2).
JP 2005-223359 A JP 2000-100924 A

  The conventional semiconductor wafer W is thinned as described above and simply stored in the substrate storage cassette 84, but it is very thin (for example, 50 μm or less), easily bent, and easily broken, so that it is easy during operation. There is a big problem that it will be damaged. In addition, as shown in FIG. 9, the bow is often warped, so that there is a problem that it cannot be stored in the substrate storage cassette 84 or handled in the subsequent work.

  The present invention has been made in view of the above, and an object of the present invention is to provide a substrate storage cassette that can be easily damaged even when the substrate is thin or can be prevented from being deformed and hindering removal.

In the present invention, in order to solve the above problems, a substrate is stored on a shelf board,
Side walls that support the shelf board, a recess formed on the top surface of the shelf board, a flexible holding layer that covers the recess and holds the substrate in a detachable manner, and in the recess that is covered with the holding layer And an exhaust passage for exhausting the gas to the outside.
Note that a plurality of support protrusions that support the holding layer can be provided side by side at intervals in the recesses of the shelf board.

Further, it is preferable that the exhaust passage is detachably connected to the negative pressure source, and the negative pressure source is driven to deform the holding layer.
In addition, a pair of side walls having a shelf plate therebetween may be provided, and at least a lower portion of the pair of side walls may be connected by a connection plate, and a plurality of shelf plates may be provided in a vertical direction at a predetermined interval.

Further, the rear opening of the pair of side walls may be covered with a wall, and an observation window for the substrate may be formed on the wall.
Further, the exhaust passage is formed of a first passage formed in the shelf plate and communicated with the recess (continuously communicated with the gas flow state) and a second passage formed in the side wall and communicated with the first passage. And it is also possible to open the downstream part of this 2nd channel | path to a side wall.
Furthermore, it is also possible to form an exhaust passage in the shelf plate, the side wall, and the connecting plate and to open the downstream portion of the exhaust plate in the connecting plate.

  Here, the substrate in the claims is mainly a back-ground thin semiconductor wafer having a thickness of 300 μm or less (for example, a silicon wafer having a diameter of 200 mm or 300 mm), but is not limited thereto. . For example, it may be a thick semiconductor wafer, a glass substrate that requires a thickness of 1 mm or less, a flexible high-density flexible wiring board that requires a thickness of 100 μm or less, a liquid crystal cell, or a printed wiring board. .

  The shelf board and the side wall may be integrally injection-molded or may be assembled by a fastener. These shelf plates and side walls may be transparent, opaque, or translucent. The number of shelf boards may be one, but it can be increased to a plurality of, for example, 5 to 7, 13, 25, or 26. The shelf board can be formed in a circular shape, a polygonal shape, or the like in plan view.

  The recess can be formed in a circular shape, a polygonal shape, or the like in plan view. The holding layer may be made of a single elastomer, or may be a plurality of laminated elastomers having different properties (material, hardness, elasticity, etc.). The plurality of support protrusions may be regularly arranged in the recess, or may be irregularly arranged.

  Each support protrusion can be formed in a truncated cone shape, a prism shape, a truncated pyramid shape, or the like, and may or may not be adhered to the holding layer. The exhaust passage may be integrated with the substrate storage cassette or may be attached as a separate body. Further, the negative pressure source connected to the exhaust passage is composed of, for example, various vacuum pumps, vacuum blowers and the like, and does not particularly ask whether or not the ejector is attached. The negative pressure source may or may not be built in various semiconductor manufacturing apparatuses and their associated devices used from the back grinding process to the dicing process.

According to the present invention, when a substrate is to be stored in the substrate storage cassette, the substrate may be placed on the holding layer of the shelf board. Then, a board | substrate adheres substantially flatly with the contact | adhesion power which a holding | maintenance layer has irrespective of the thickness.
When it is desired to remove the substrate from the holding layer, the gas in the recess formed on the shelf plate may be exhausted out of the recess by the exhaust passage. Then, as the gas is exhausted, the holding layer is deformed in the bottom direction of the recess to form a gap between the substrate and the contact portion between the holding layer and the substrate is reduced.

According to the present invention, since the function of holding the thin substrate flat is given to the substrate storage cassette, the substrate storage cassette can be easily damaged or deformed even when the substrate is thick and strong or thin and fragile. There is an effect that it is possible to effectively prevent troubles from being taken out from the machine.
In particular, in the case of a semiconductor wafer with a back-ground substrate, it is possible to prevent the thin and easily broken semiconductor wafer from being easily damaged. Further, since the entire surface of the semiconductor wafer can be supported and fixed, the warpage of the semiconductor wafer can be corrected and wafer cracking can be prevented.

In addition, if a plurality of support protrusions that support the holding layer are arranged at intervals in the concave portion of the shelf board, the holding layer can be prevented from being excessively deformed, and the position and posture of the substrate can be stabilized.
Further, if the exhaust passage is detachably connected to the negative pressure source, and the negative pressure source is driven to forcibly deform the holding layer, gas flows between the deformed holding layer and the substrate. Therefore, the non-contact part of the substrate with respect to the holding layer is increased, and the removal becomes easy.

In addition, a substrate having a pair of side walls sandwiching the shelf board, connecting at least the lower part of the upper and lower parts of the pair of side walls by a coupling plate, and arranging a plurality of the shelf boards at predetermined intervals in the vertical direction, The strength and rigidity of the storage cassette can be increased.
Furthermore, if the rear opening of the pair of side walls is covered with a wall and an observation window for the substrate is formed on this wall, the state of the substrate and the holding layer can be grasped visually. There is an effect that the substrate storage cassette can be used in a good state.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 5, a substrate storage cassette according to the present embodiment is arranged in a cassette case 1 of a front open box type. A plurality of shelf plates 20 formed, the recessed holes 30 formed in each shelf plate 20, and the semiconductor wafer W covered with the recessed holes 30 and thinned by the back grind are detachably adhered and held elastically. A holding layer 40 and a plurality of exhaust passages 50 for exhausting the air in the recessed holes 30 covered with the holding layer 40 are provided, and positioned on a semiconductor manufacturing apparatus and its opener 60 used from the back grinding process to the subsequent process. Installed.

  As shown in FIGS. 1 to 4, the cassette case 1 includes a pair of left and right side walls 2 facing each other with a sufficient space for housing the semiconductor wafer W, and a bottom plate 3 is interposed between the lower portions of the pair of side walls 2. Is mounted horizontally, and a top plate 4 is horizontally mounted between the upper end portions. A vertically long back wall 5 is mounted on the opened rear surface, and the semiconductor wafer W is thinned by opening the front surface. It functions as a loading / unloading port 6.

  The semiconductor wafer W is made of, for example, a silicon wafer having a diameter of 300 mm, and a notch n that facilitates discrimination and alignment of the crystal direction is cut out in a substantially semi-elliptical plane at the peripheral edge. Further, the side wall 2, the bottom plate 3, the top plate 4 and the back wall 5 of the cassette case 1 are made of, for example, a resin molding material such as transparent polycarbonate or polyether air ketone having excellent impact resistance, heat resistance, water resistance and the like. Are separately molded and assembled via screws, nuts, or the like.

  The side wall 2 of the cassette case 1 is formed as a vertically long plate extending in the vertical direction, and a plurality of positioning tools 7 are arranged on both sides of the front portion and the rear portion of the bottom plate 3 so as to draw a triangle in bottom view. . Each positioning tool 7 is formed into a substantially track-shaped block in a plane, and a V groove 8 slidably contacting a positioning pin 61 protruding from the stage of the opener 60 is cut out in the longitudinal direction. By fitting the positioning pin 61 from above, the substrate storage cassette functions to be positioned with high accuracy.

  A non-contact IC tag 9 for constructing a wafer management system is attached to the top plate 4 of the cassette case 1, and a handle 10 for gripping is detachably attached to the back wall 5. A vertically long observation window 11 that enables visual recognition is selectively formed.

  As shown in FIG. 1 and FIG. 2, the plurality of shelf boards 20 are arranged at a predetermined pitch in the cassette case 1 in the vertical direction (shown in three or four stages in the figure). A space that does not hinder the loading and unloading of the semiconductor wafer W is ensured between 20 and 20. Each shelf board 20 is formed in a planar rectangle larger than the semiconductor wafer W and the holding layer 40 using a predetermined material, and is horizontally installed between both side walls of the cassette case 1 via screws, nuts, or the like.

  The material of the shelf board 20 is not particularly limited. For example, polyether sulfone, polyamide imide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyether imide, polyether ether ketone, polyphenylene sulfide, polyarylate. Resin molding materials such as aluminum, magnesium, copper, stainless steel and nickel, glass, ceramics and the like.

  As shown in FIGS. 1 and 5, the recess hole 30 is formed in a shallow recess on the surface of each shelf plate 20 and has a planar rectangle larger than the semiconductor wafer W. A plurality of support protrusions 31 that support the holding layer 40 from below are regularly arranged in parallel on the bottom surface of the recess hole 30, and each support protrusion 31 has a length and height substantially the same as the depth of the recess hole 30. It is formed in a cylindrical shape.

  As shown in FIGS. 1, 2, and 5, the holding layer 40 is formed into a flexible thin film with a planar rectangle larger than the semiconductor wafer W using a flexible, adhesive, and elastic material. It is laminated and adhered to the surface of the plate 20, and is adhered to the surface of each support protrusion 31, and covers the recessed hole 30 to divide a space for air circulation between the bottom surface. The material of the holding layer 40 is not particularly limited. For example, a silicone-based, urethane-based, olefin-based, or fluorine-based elastomer having excellent heat resistance, weather resistance, water resistance, peelability, stability over time, and the like. Is used.

  As shown in FIGS. 1 to 3 and 5, the plurality of exhaust passages 50 are formed inside the substrate storage cassette according to the number of the shelf boards 20 and the holding layers 40, and the substrate storage cassette is connected to the opener 60. By being positioned and mounted with high accuracy, it is automatically connected to a vacuum unit 62 built in the opener 60.

  Each exhaust passage 50 is formed in the shelf 20 so as to be bent, and the first passage 51 whose upper end communicates with the recessed hole 30 from below, and the first passage 51 is formed in the vertical direction inside the one side wall 2. And a second passage 52 communicating with the downstream end portion opened on the side surface of the shelf plate of the passage 51, and the downstream end portion of the second passage 52 opens at the bottom surface of the side wall 2, and the connection nozzle 63 a of the vacuum unit 62. Are detachably connected to each other through an O-ring or the like.

  As shown in FIG. 1, the vacuum unit 62 includes, for example, a vacuum pump 64 in which a connection channel 63 is erected on the stage of an opener 60 to expose a connection nozzle 63a at the tip thereof, an associated tank, and the like. Driven in accordance with the adsorption of the W handling device 65, the air in the space of the recessed hole 30 (see arrows in FIGS. 1 and 5) is exhausted to the outside, and the flat holding layer 40 is directed toward the bottom surface of the recessed hole 30. Deformation of the semiconductor wafer W is facilitated by forming a gap for inflow of air at the interface between the holding layer 40 and the semiconductor wafer W, thereby making it easy to peel off the semiconductor wafer W.

  As shown in FIG. 2, a handling device 65 for loading and unloading the semiconductor wafer W includes a pad 66 that vacuum-sucks the semiconductor wafer W and a rear portion of the pad 66 that is supported by a robot (not shown) so as to be rotatable. And an arm 67 movable in the XYZ directions, and the pad 66 and the arm 67 are integrally molded using a predetermined molding material.

The pad 66 is formed in a disk having substantially the same diameter as the semiconductor wafer W, and a plurality of suction groove holes are formed at predetermined intervals on the suction surface for vacuum-sucking the semiconductor wafer W. Further, a discharge path communicating with the plurality of suction groove holes is formed in the longitudinal direction inside the arm 67, and a downstream end portion of the discharge path is connected to the vacuum device.
The handling device 65 may be installed in the opener 60 via a robot (not shown) or may exist as an independent device. The other parts are the same as those in the conventional example, and thus the description thereof is omitted.

  In the above, the handling device 65 vacuum-sucks the entire surface of the attracted surface of the semiconductor wafer W thinned by the grinder device 80 and enters the substrate storage cassette, and the semiconductor wafer W is slightly placed on the surface of the holding layer 40. When pressed and stacked with force, the semiconductor wafer W adheres in a stable flat posture without warping due to the adhesion force of the holding layer 40, so that cracking and deformation of the semiconductor wafer W can be prevented. Further, when fixing the semiconductor wafer W, no processing, power, and energy are required other than the holding layer 40 being brought into close contact with each other. Therefore, the semiconductor wafer W can be moved as it is, stored, and transported to the next process. it can.

  In order to pick up the semiconductor wafer W in close contact with the holding layer 40, the vacuum unit 62 may be driven in conjunction with the vacuum driving of the pad 66. That is, when the vacuum unit 62 is driven by adjusting the timing to the suction signal to the pad 66 when the pad 66 is stacked on the surface of the semiconductor wafer W from above and vacuum-sucked, the air in the recessed hole 30 is exhausted from the exhaust passage 50. Since the holding layer 40 is evacuated along the plurality of support protrusions 31 to form a gap between the semiconductor wafer W and the semiconductor layer W is in close contact with the holding layer 40. The wafer W is easily picked up by the handling device 65.

  According to the above configuration, the semiconductor wafer W can be supported in a substantially flat manner without gaps by the adhesive force of the holding layer 40 having elasticity, so that the semiconductor wafer W is thinned to 50 μm or less by back grinding and becomes brittle. However, it is not easily damaged during transportation or handling. Further, since the warpage of the thinned semiconductor wafer W is corrected, the peripheral portion of the semiconductor wafer W can be prevented from interfering with the surroundings, and the semiconductor wafer W can be smoothly and reliably stored in the substrate storage cassette. It can contribute to the safety of handling between processes, remarkably improving the handleability in the subsequent work.

  Further, since the semiconductor wafer W can be supported in close contact with the holding layer 40 only for a long time, a dedicated vacuum device or the like for holding the semiconductor wafer W flat can be omitted, and the apparatus can be simplified. Significant cost reduction can be achieved. In addition, since a plurality of support protrusions 31 for adhering and supporting the holding layer 40 are arranged on the bottom surface of the recessed hole 30, the holding layer 40 is excessively recessed over a wide range, or the posture of the semiconductor wafer W on the holding layer 40 It is possible to reliably prevent the material from being tilted and broken, or displaced and displaced.

  Further, the handling device 65 is not simply stacked on the center of the semiconductor wafer W and vacuum-adsorbed, but the handling device 65 is stacked and vacuum-adsorbed on all the surfaces to be adsorbed of the semiconductor wafer W. The peripheral edge of W is bent downward and does not break. Furthermore, since the non-contact IC tag 9 is attached to the cassette case 1, the semiconductor wafer W and the substrate storage cassette can be clearly identified in a non-contact manner, and the non-contact IC tag 9 and the reader of the wafer management system can be identified. / Even if an obstacle exists between the writer and the device that transmits radio waves, reliable communication is possible.

  In the above embodiment, the front open box type cassette case 1 is shown. However, the rear wall 5 may be omitted, and the front and rear portions may be opened to serve as the entrance / exit 6 for the semiconductor wafer W. In addition, a detachable lid or an openable / closable door may be provided. Further, a handle and a flange for the operator to hold on each side wall of the cassette case 1 may be mounted.

  Further, the protective sheet surface side of the semiconductor wafer W may be mounted on the holding layer 40, or the back surface side of the semiconductor wafer W may be mounted. Further, the peripheral portion of the holding layer 40 may be bonded and supported on the peripheral surface of the recessed hole 30, and a space may be partitioned between the bottom surface of the recessed hole 30 and the holding layer 40. If the holding of the semiconductor wafer W and the deformation of the holding layer 40 are not particularly hindered, the support protrusion 31 is omitted and the holding layer 40 is formed by laminating a mesh body having a certain degree of strength and an elastomer. The recessed layer 30 may be covered with the holding layer 40.

  Further, as shown in FIG. 6, a first passage 51 communicating with the peripheral surface of the recessed hole 30 is cut out in a substantially groove shape on the surface of the shelf plate 20, and the first passage 51 is formed on the side surface of the shelf plate 20. It is also possible to connect to the upstream end portion of the second passage 52 formed in the side wall 2 and extend the first passage 51 to the enlarged holding layer 40. Further, the exhaust passage 50 is formed in the shelf plate 20 and communicated with the recessed hole 30, and the exhaust passage 50 is formed in the side wall 2 and the bottom plate 3 in the downstream end of the first passage 51. It is also possible to form a second passage 52 that communicates, and to open the downstream end of the second passage 52 to the back surface of the bottom plate 3.

  Further, the connection nozzle 63a with the seal of the vacuum pump 64 is moved up and down with respect to the stage of the opener 60 by an actuator such as an air cylinder, and the vacuum pump 64 is connected to the downstream end portion of the exhaust passage 50 of the positioned substrate storage cassette. It is also possible. In addition, the handling device 65 can be formed to be transparent, opaque, or translucent, and the pad 66 can be formed to have a substantially polygonal shape. Further, the substrate storage cassette can be used only immediately after the back grinding operation in the back grinding process.

  Furthermore, the substrate storage cassette according to the present invention is not only used as a wafer storage device for the grinder device 80 or the stress relief device 83, but also as a wafer storage device for a dicing tape or die attach film sticking device or a protective sheet peeling device. It can also be used.

  As described above, since the substrate storage cassette according to the present invention can safely handle the thinned semiconductor wafer W, it is used as a wafer storage device for a process from the back grinding process until the semiconductor wafer W is chipped. It can also be used. However, the substrate storage cassette according to the present invention does not preclude use for substrate applications other than the back grinding process and the semiconductor wafer W.

It is a fragmentary sectional view showing typically an embodiment of a substrate storage cassette concerning the present invention. FIG. 3 is a partially exploded perspective view schematically showing a usage state in the embodiment of the substrate storage cassette according to the present invention. It is a bottom view showing typically an embodiment of a substrate storage cassette concerning the present invention. It is a rear view showing typically an embodiment of a substrate storage cassette concerning the present invention. It is a section explanatory view showing typically a shelf board, a maintenance layer, etc. in an embodiment of a substrate storage cassette concerning the present invention. It is a section explanatory view showing typically the exhaust passage in other embodiments of the substrate storage cassette concerning the present invention. It is explanatory drawing which shows the state which closely_contact | adheres and cuts a protective sheet to the pattern formation surface of a semiconductor wafer. It is plane explanatory drawing which shows a grinder apparatus etc. It is front explanatory drawing which shows the relationship between the semiconductor wafer which curved in the shape of a bow, and a substrate storage cassette.

Explanation of symbols

1 Cassette case 2 Side wall 3 Bottom plate (connection plate)
4 Top plate (connection plate)
5 Back wall 6 Entrance / exit 11 Observation window 20 Shelf 30 Recessed hole (recessed part)
31 support protrusion 40 holding layer 50 exhaust passage 51 first passage 52 second passage 60 opener 62 vacuum unit (negative pressure source)
63 Connection flow path 63a Connection nozzle 64 Vacuum pump (negative pressure source)
65 Handling device 70 Protective sheet 80 Grinder device (semiconductor manufacturing device)
82 Cleaning device 83 Stress relief device 84 Substrate storage cassette W Semiconductor wafer (substrate)

Claims (7)

  A substrate storage cassette for storing a substrate on a shelf board, a side wall for supporting the shelf board, a recess formed on the top surface of the shelf board, and a flexible cover that covers the recess and detachably holds the substrate. A substrate storage cassette comprising: a conductive holding layer; and an exhaust passage for exhausting the gas in the recess covered by the holding layer to the outside.   The substrate storage cassette according to claim 1, wherein a plurality of support protrusions for supporting the holding layer are arranged in the recess of the shelf board at intervals.   3. The substrate storage cassette according to claim 1, wherein the exhaust passage is detachably connected to a negative pressure source, and the holding layer is deformed by driving the negative pressure source.   A pair of side walls having a shelf plate therebetween, wherein at least a lower portion of the pair of side walls is connected by a connection plate, and a plurality of shelf plates are arranged in a vertical direction at a predetermined interval. Or 3. A substrate storage cassette according to 3.   5. The substrate storage cassette according to claim 4, wherein a rear opening of the pair of side walls is covered with a wall, and an observation window for the substrate is formed on the wall.   An exhaust passage is formed from a first passage formed in the shelf plate and communicating with the recess, and a second passage formed in the side wall and communicating with the first passage, and a downstream portion of the second passage is formed 6. The substrate storage cassette according to claim 1, wherein the substrate storage cassette is opened in a side wall.   7. The substrate storage cassette according to claim 4, wherein an exhaust passage is formed in the shelf plate, the side wall, and the connecting plate, and a downstream portion thereof is opened to the connecting plate.

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