JP4834010B2 - Handling method of semiconductor wafer - Google Patents

Description

  The present invention relates to a method for handling a semiconductor wafer thinned by grinding of a grinding region.

  In assembling the semiconductor package, as shown in FIG. 3, the entire back surface 3 of the thick semiconductor wafer 2 whose pattern forming surface is protected by the protective sheet 1 is thinned by back grinding with a grinding device 5, and the thinned semiconductor The wafer 2 is sent to the dicing process (see Patent Document 1). However, if the thick semiconductor wafer 2 is simply back-ground and thinned, the rigidity of the semiconductor wafer 2 is reduced, causing a large amount of bending and warping. There is a problem that risks arise.

In view of such a problem, conventionally, as shown in FIG. 4, the back surface 3 of the semiconductor wafer 2 excluding the peripheral portion 4 is back-ground by the grinding device 5, and the peripheral portion 4 of the semiconductor wafer 2 is left to improve rigidity. There is a proposed method.
JP 2002-208625 A

  However, if the peripheral edge 4 of the semiconductor wafer 2 is left, improvement in rigidity and ease of handling can be expected, but the peripheral edge 4 of the semiconductor wafer 2 must be finally removed for dicing. After the peripheral edge portion 4 of the semiconductor wafer 2 is removed, bending or warping occurs, and there is a risk that the semiconductor wafer 2 may be transported or handled.

  The present invention has been made in view of the above, and an object of the present invention is to provide a method for handling a semiconductor wafer that is less likely to bend or warp even after the peripheral edge of the semiconductor wafer is removed.

In the present invention, in order to solve the above problems , a semiconductor wafer handling method for holding a semiconductor wafer on a holding jig and sending it to a dicing process ,
The semiconductor wafer was thinned to a thickness of 100 μm or less by grinding the back surface except the peripheral edge of the semiconductor wafer, and either the front or back surface of the semiconductor wafer was formed in a recess hole on the surface of the base material of the holding jig. is freely held directly detachably attached to a plurality of resilient retaining layer of the flexible covering the projections Rutotomoni causes protrude the periphery of the semiconductor wafer from the elastic holding layer holding jig, then, resilient retaining layer holding jig It is characterized in that the peripheral portion of the semiconductor wafer protruding from the surface is removed .

In addition, the base material of the holding jig can be provided with an exhaust hole that communicates with the recessed hole covered with the elastic holding layer (in which a gas flows) .

  Here, the size and material of the semiconductor wafer in the claims are not particularly limited. Accordingly, for example, the size may be φ150 mm, 200 mm, 300 mm, 450 mm or the like, and the material may be Si type or GaP. The entire surface of the thinned semiconductor wafer may be held by the elastic holding layer of the holding jig, or a part of the surface may be held by the elastic holding layer. In addition, the plurality of protrusions of the holding jig and the elastic holding layer are preferably bonded, but a relationship in which some of the protrusions and the elastic holding layer are bonded may be used.

According to the present invention, there is an effect that it is possible to effectively reduce the possibility of bending or warping of the semiconductor wafer even after the peripheral portion of the semiconductor wafer is removed. Further, since the semiconductor wafer is directly held on the elastic holding layer of the holding jig, the protective sheet is omitted and the material can be reduced. Further, since the semiconductor wafer is held by the elastic holding layer of the holding jig and its peripheral portion is devoured, the elastic holding layer is less likely to become an obstacle when removing the peripheral portion of the semiconductor wafer, and the elastic holding layer Can be expected to prevent damage.
In addition, if an exhaust hole communicating with the recess hole covered with the elastic holding layer is provided in the base material of the holding jig, the elastic holding layer is deformed by exhausting the air in the recess hole from the exhaust hole to the outside, and the semiconductor wafer It is possible to release the close contact state by forming a gap between the elastic holding layer and the elastic holding layer.

  Hereinafter, a preferred embodiment of a method for handling a semiconductor wafer according to the present invention will be described with reference to the drawings. The method for handling a semiconductor wafer according to this embodiment excludes a peripheral portion 4 as shown in FIGS. The semiconductor wafer 2 thinned by grinding of the back surface 3 is detachably held by the elastic holding layer 14 covering the plurality of protrusions 13 arranged in the recessed holes 12 of the base material 11 of the holding jig 10, and thereafter The peripheral edge 4 of the semiconductor wafer 2 protruding from the elastic holding layer 14 is removed.

  The semiconductor wafer 2 is made of, for example, a silicon wafer having a diameter of 200 mm or 300 mm, a circuit pattern is formed on the front surface, and the back surface 3 excluding the peripheral edge 4 of about 3 mm is back-ground by the grinding device 5, thereby The thickness is reduced from about 800 μm to 100 μm or less.

  The holding jig 10 includes a base material 11 having a diameter equal to or smaller than the diameter of the semiconductor wafer 2 or slightly smaller and thinner, and a flat circular recess 12 is formed in a flat surface of the base material 11. A plurality of protrusions 13 are formed in a protruding manner, and a flexible elastic holding layer 14 that covers the recessed holes 12 and the plurality of protrusions 13 is bonded to the peripheral edge of the surface of the substrate 11. The base material 11 of this holding jig is formed in a flat circular shape using PC, PP, PE, aluminum alloy, magnesium alloy or the like having excellent rigidity, and an exhaust hole 15 communicating with the recessed hole 12 is drilled in the thickness direction. The vacuum pump 16 is detachably connected to the exhaust hole 15 via a switching valve.

  The plurality of protrusions 13 are juxtaposed at intervals, and each protrusion 13 is formed in a columnar shape, a truncated cone shape, or the like. The elastic holding layer 14 is bonded to the flat upper surface of the protrusion 13. The elastic holding layer 14 is formed into a flat circular shape using a predetermined thin elastomer (for example, a silicone-based, urethane-based, olefin-based, or fluorine-based elastomer), and is in close contact with the surface of the semiconductor wafer 2 in a flat state. At the same time, it is deformed into irregularities according to the plurality of protrusions 13 based on the driving of the vacuum pump 16, thereby releasing the contact state with the semiconductor wafer 2.

  In the above, the grinding region of the semiconductor wafer 2 excluding the peripheral portion 4, in other words, the back surface 3 is back-ground with the grinding device 5, and the peripheral portion 4 of the semiconductor wafer 2 is left to improve the rigidity. The semiconductor wafer 2 is held in close contact with the elastic holding layer 14 of the holding jig 10 without any gap (see FIG. 1), and then the thick peripheral edge 4 of the semiconductor wafer 2 protruding from the peripheral edge of the elastic holding layer 14 is removed. Remove (see FIG. 2).

  At this time, the thinned surface of the semiconductor wafer 2 may be held by the elastic holding layer 14 of the holding jig 10, or the back surface 3 of the semiconductor wafer 2 may be held by the elastic holding layer 14 of the holding jig 10. Also good. Examples of the method for removing the peripheral edge 4 of the semiconductor wafer 2 include a grinding method, a laser cutting method, a blade cutting method, and the like.

  If the peripheral edge 4 of the semiconductor wafer 2 is removed in this way, the semiconductor wafer 2 can be handled smoothly by the holding jig 10, but when removing the semiconductor wafer 2 from the elastic holding layer 14 of the holding jig 10, The vacuum pump 16 connected to the exhaust hole 15 may be driven to exhaust the air in the recessed hole 12 from the exhaust hole 15 to the outside. Then, the elastic holding layer 14 covering the recessed hole 12 and the plurality of protrusions 13 is deformed in accordance with the protrusions 13, and the close contact state between the semiconductor wafer 2 and the elastic holding layer 14 is released. It can be removed from the holding layer 14.

  According to the above, after the semiconductor wafer 2 is held on the elastic holding layer 14 of the rigid holding jig 10, the peripheral edge 4 of the semiconductor wafer 2 is removed for dicing, so that it is integrated with the holding jig 10. There is no risk of bending or warping of the semiconductor wafer 2. Therefore, it is possible to eliminate the risk of risk in transporting and handling the semiconductor wafer 2. Furthermore, since the semiconductor wafer 2 can be directly held by the elastic holding layer 14 of the holding jig 10, the protective sheet 1 can be omitted and the material can be reduced.

  In the above embodiment, the peripheral edge 4 of the semiconductor wafer 2 protruding from the peripheral edge of the elastic holding layer 14 of the holding jig 10 is removed, but the present invention is not limited to this. For example, even if the peripheral edge 4 of the semiconductor wafer 2 back-ground in a substantially concave shape is aligned with the peripheral edge of the elastic holding layer 14 and the surface of the peripheral edge 4 protruding above the semiconductor wafer 2 is ground and removed again. good. At this time, the surface of the peripheral edge 4 protruding above the semiconductor wafer 2 may be completely removed, but the surface of the peripheral edge 4 protruding from the semiconductor wafer 2 may be partially removed as long as the dicing is not particularly hindered. However, the surface of the peripheral edge 4 may be left to some extent.

  Furthermore, the semiconductor wafer 2 and the holding jig 10 in FIG. 1 can be turned upside down, and the semiconductor wafer 2 can be held in close contact with the elastic holding layer 14 of the holding jig 10.

It is explanatory drawing which shows typically embodiment of the handling method of the semiconductor wafer which concerns on this invention. It is explanatory drawing which shows typically the state which removed the peripheral part of the semiconductor wafer which protruded from the elastic holding layer in embodiment of the handling method of the semiconductor wafer which concerns on this invention. It is explanatory drawing which shows the state which back-grinds the semiconductor wafer by which the pattern formation surface was protected by the protective sheet with a grinding device. It is explanatory drawing which shows the state which back-grinds the back surface of the semiconductor wafer except a peripheral part with a grinding device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Protective sheet 2 Semiconductor wafer 3 Back surface 4 Peripheral part 5 Grinding device 10 Holding jig 11 Base material 12 Recessed hole 13 Protrusion 14 Elastic holding layer 15 Exhaust hole 16 Vacuum pump

Claims (2)

A method of handling a semiconductor wafer that is held in a holding jig and sent to a dicing process ,
The semiconductor wafer was thinned to a thickness of 100 μm or less by grinding the back surface except the peripheral edge of the semiconductor wafer, and either the front or back surface of the semiconductor wafer was formed in a recess hole on the surface of the base material of the holding jig. is freely held directly detachably attached to a plurality of resilient retaining layer of the flexible covering the projections Rutotomoni causes protrude the periphery of the semiconductor wafer from the elastic holding layer holding jig, then, resilient retaining layer holding jig A method of handling a semiconductor wafer, comprising removing a peripheral portion of the semiconductor wafer protruding from the surface.   2. The method of handling a semiconductor wafer according to claim 1, wherein an exhaust hole communicating with the recess hole covered with the elastic holding layer is provided in the base material of the holding jig.

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