JP5662744B2 - Holding device - Google Patents

Description

  The present invention relates to a holding device that holds a substrate such as a wafer.

  In recent years, electronic devices such as IC cards and mobile phones have been required to be thinner, smaller, and lighter. In order to satisfy these requirements, a thin semiconductor chip must be used as a semiconductor chip to be incorporated. For this reason, the thickness (film thickness) of the semiconductor wafer that is the basis of the semiconductor chip is currently 125 μm to 150 μm, but it is said that it must be 25 μm to 50 μm for next-generation chips. Therefore, in order to obtain a semiconductor wafer having the above film thickness, a semiconductor wafer thinning step is indispensable.

  The process of thinning the semiconductor wafer is performed as follows. First, a support plate for protecting the semiconductor wafer is attached via a tape or adhesive having adhesive layers on both sides so as to cover the circuit formation surface of the semiconductor wafer. Next, this is reversed, and the back surface of the semiconductor wafer is ground by a cylinder to make it thinner. Subsequently, the back surface of the thinned semiconductor wafer is fixed on a dicing tape held by a dicing frame. Further, in this state, the support plate that covers the circuit forming surface of the semiconductor wafer is peeled, and then divided into chips by a dicing apparatus.

  When the thinning process is performed as described above, an adhesive or the like remains on the circuit formation surface of the semiconductor wafer after the support plate is peeled off. For this reason, it is necessary to remove the adhering adhesive and the like so that the circuit formation surface of the semiconductor wafer becomes a clean surface. In other words, with the semiconductor wafer fixed on the dicing tape, after the support plate covering the circuit formation surface of the semiconductor wafer is peeled off, the surface of the semiconductor wafer is cleaned before being divided into chips by a dicing device. It is necessary to.

  When this cleaning process is performed or when the previous support plate is peeled off, the semiconductor wafer may be mounted on a holding table or the like and fixed.

  Patent Documents 1 to 3 have been reported as holding devices for holding a semiconductor wafer.

  The substrate processing apparatus described in Patent Document 1 is for peeling from a support plate without damaging a semiconductor wafer.

  Patent Document 2 describes a peeling device that includes a pressing member that holds down a ring frame in order to fix the protective tape when peeling a protective tape from a wafer.

  Patent Document 3 describes a spinner cleaning apparatus that includes a pressing unit that holds down a plurality of wafers to which a tape is adhered.

JP 2009-59776 A (published March 19, 2009) JP 2003-59862 A (published February 28, 2003) JP 2006-128359 A (published May 18, 2006)

  The substrate processing apparatus described in Patent Document 1 performs processing by adhering a dicing tape having a dicing frame around it to a wafer and sucking the wafer onto a support base. In this substrate processing apparatus, if the wafer and the dicing frame are warped and the dicing tape has wrinkles, there is a possibility that a suction failure may occur. Patent Documents 2 and 3 do not describe the problem caused by the warpage of the wafer, and do not disclose a technique that contributes to the solution. As will be described later, in the present invention, the support film bonded to the substrate is strongly pressed downward on the outside of the sucked portion and pulled until it is located below the inside, thereby warping the wafer and the dicing frame and Reduce the effect of wrinkles on the dicing tape. On the other hand, in the devices of Patent Documents 2 and 3, since the outside of the dicing tape is not strongly pulled downward, it is affected by the warp of the wafer and the dicing frame and the wrinkles of the dicing tape, and temporarily tries to suck the support table. However, there is a risk of poor adsorption.

  Therefore, the present invention provides a holding device capable of adsorbing and holding a wafer satisfactorily even if the wafer and the dicing frame are warped and the dicing tape has wrinkles.

  In order to solve the above-described problems, a holding device according to the present invention is a holding device that holds a substrate having a supporting film bonded to one side thereof, and is a surface on the side where the supporting film is bonded to the substrate. When the suction part that sucks from the substrate and the substrate are installed so as to be horizontal, a vertically downward force is applied to a part outside the part sucked by the suction part in the support film. A force-applying portion that causes the added portion to be positioned vertically downward from the inside of the portion.

  According to the present invention, even if a substrate such as a wafer and a support film such as a dicing frame warp and a support film such as a dicing tape has wrinkles, the substrate can be adsorbed and held satisfactorily.

It is a figure which shows the outline of the structure of the holding | maintenance apparatus which concerns on one Embodiment of this invention. It is a figure which shows the outline of the structure of the holding | maintenance apparatus which concerns on another embodiment of this invention. It is a figure which shows the outline of the structure of the holding | maintenance apparatus which concerns on another embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail.

Embodiment 1
The holding device 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a diagram schematically showing a structure of a holding device 1 according to the first embodiment. FIG. 1A shows the holding device 1 in a state where a wafer 10 is not fixed by a clamp 3, and FIG. FIG. 4B shows the vicinity of the clamp 3 in a state where the wafer 10 is fixed by the clamp 3.

  The holding device 1 includes a holding base 2, a clamp 3 (a force applying unit), and a rotation driving unit 5.

  The holding table 2 includes a suction unit 4. The holding table 2 is for placing the wafer 10 (substrate) thereon. In addition, the surface on which the wafer 10 of the holding stand 2 is placed is circular.

  As shown in FIG. 1A, a dicing tape 11 (support film) is bonded to the lower side of the wafer 10 (one side on the holding table 2 side), and the upper side of the wafer 10 (the side opposite to the holding table 2). A support plate 13 (support plate) is placed on one side) via an adhesive layer 12.

  For example, in the present embodiment, first, the wafer 10 is subjected to a thinning process. Specifically, an adhesive is applied to one side of the wafer 10 to form an adhesive layer 12 and then the support plate 13 is bonded. Then, the wafer 10 is thinned by polishing the surface opposite to the surface to which the support plate 13 is bonded. The support plate 13 is a member that plays a role of supporting the wafer 10 in the thinning process. The support plate 13 is made of, for example, glass having a film thickness of 500 to 1000 μm.

  Next, the dicing tape 11 is bonded to the surface of the wafer 10 opposite to the surface to which the support plate 13 is bonded, and placed on the holding table 2.

  The dicing tape 11 includes a dicing frame 11a (frame portion) on the outer periphery. As the dicing tape 4a, a resin film such as PVC (polyvinyl chloride), polyolefin, or polypropylene is used as the base film.

  The dicing tape 11 supplements the strength of the wafer 10 after the support plate is removed, and serves to facilitate handling.

  Next, by supplying a solvent from the support plate 13, the adhesive constituting the adhesive layer 12 is dissolved, the adhesive layer 12 is removed, and the support plate 13 can be removed. The support plate 13 has a through-hole perpendicular to the surface direction so that the solvent supplied from the upper surface reaches the adhesive layer 12. At this time, the adhesive remains on the wafer 10 without being completely removed. The support plate 2 may be placed after the support plate is removed. The distance from the end of the surface of the dicing tape 11 that is in close contact with the holding table 2 to the location where force is applied by the clamp 3 on the dicing frame 11a The width) is preferably a distance that can sufficiently secure a tensile force by the clamp 3. By sufficiently securing this distance, the bending of the dicing tape 11 can be sufficiently absorbed.

  The suction unit 4 sucks the wafer 10 from the surface to which the dicing tape 11 is bonded. A conventionally known suction mechanism may be provided as the suction mechanism. For example, a suction hole (not shown) for sucking gas on the adsorption surface may be provided. The suction hole is connected to a decompression unit such as a vacuum pump. By placing the wafer 10 and operating the suction unit, the space between the wafer 10 and the suction surface is decompressed. It can be adsorbed by. The suction hole can be provided by forming a hole at a predetermined position of the plate-like member. For example, the suction hole may be a through-hole penetrating the plate. Moreover, you may form using a porous material. Examples of the porous material include polypropylene, carbon, aluminum, and ceramic. Thereby, the wafer 10 is fixed on the holding table 2. The surface of the suction unit 4 on which the wafer 10 is placed is circular.

  The clamp 3 is for holding the dicing frame 11a. The clamp 3 is located outside the suction part 4. As shown in FIG. 1B, the clamp 3 is set so that the wafer 10 is horizontal with respect to the dicing frame 11a which is a part outside the part sucked by the suction part 4 in the dicing tape 11. When applied, a force is applied that is in a vertically downward direction (the direction of arrow A). And the site | part to which the said force was applied is located vertically lower than the inner side of the said site | part. Specifically, the dicing frame 11a is pressed until the pressed position is positioned below the inner side. In the present invention, the inner side of the portion to which force is applied may be at least a part of the inner region, but the portion to which force is applied may be positioned below the entire inner side. preferable. In other words, the larger the area of the part located above the part where the force is applied, the stronger the force that the support film is pulled downward, and the warp of the substrate such as the wafer and the support film such as the dicing frame and the like. The influence of wrinkles on a support film such as a dicing tape can be reduced.

  The clamp 3 includes a spring (elastic body; not shown). The force by the spring works vertically downward, and the force applied to the wafer 10 increases.

  Further, the location where the force is applied by the clamp 3 on the dicing frame 11 a is located below the wafer 10. With such a configuration, the dicing tape 11 can be sufficiently pulled, and the wafer 10 can be more firmly fixed.

  The dicing tape 11 is pulled outward from the center and vertically downward by the function of the clamp 3 described above, and the holding device 1 has the warp of the wafer 10 and the dicing tape 11 and wrinkles in the dicing tape 11. However, the wafer 10 can be favorably adsorbed and held.

  In addition, although this embodiment demonstrated the case where the clamp 3 was provided with the spring, the force application part of the holding | maintenance apparatus which concerns on this invention does not need to be provided with an elastic body. However, from the viewpoint of pressing the substrate with a stronger force, it is more preferable that the force applying portion of the holding device according to the present invention includes an elastic body.

  In the present embodiment, the case where the clamp 3 presses the dicing frame 11a from above has been described. However, the force applying portion of the holding device according to the present invention may not be configured to press the support film from above. For example, the force applying part may pull the support film from below, and the form of the force applying part is not limited as long as a vertically downward force can be applied to the support film.

  The rotation drive unit 5 is for rotating the wafer 10 placed on the holding table 2 together with the holding table 2. The rotation drive unit 5 is configured to rotate the wafer 10 about a straight line perpendicular to the surface direction of the wafer 10 as a rotation axis. The wafer 10 is placed on the holding table 2 so that the center thereof is on the rotation axis. Thereby, the holding device 1 can rotate the wafer 10. While rotating the wafer 10 by the holding device 1, the remaining adhesive is removed using a stripping solution, for example, a solvent used for the adhesive.

Rotational speed of the wafer 10 by the rotary drive unit 5 may be appropriately set in accordance with the application etc., for example, 500 min ^-1 or more may be 3000 min ^-1 or less.

[Embodiment 2]
Another embodiment of the present invention will be described with reference to FIG. For convenience of explanation, constituent elements having the same functions as those of the constituent elements according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, differences from the first embodiment will be mainly described.

  The holding device 20 is different from the holding device 2 according to the first embodiment in that the holding device 20 includes a clamp 23 (forced portion) having a shape different from that of the clamp 3.

  The clamp 23 rotates in the direction of arrow B to hold the dicing frame 11a in the direction of arrow A. An arrow A direction is a vertically downward direction when the wafer 10 is horizontally installed. By applying this force, at least the portion to which the force is applied is positioned below the portion (part of the inside of the portion to which the force is applied) supported by the protrusion 2a described later. Become. As a result, the dicing frame 11a is strongly pulled downward, and the influence of the warp of the substrate such as a wafer and the support film such as the dicing frame and the support film such as the dicing tape can be reduced.

  In addition, the holding device 20 is different from the holding device 2 according to the first embodiment in that the holding table 2 includes the protrusion 2a.

  The protrusion 2a is for pushing up a part of the part of the dicing tape 11 outside the wafer 10 vertically upward (in the direction of arrow C) when the wafer 10 is placed so as to be horizontal. By applying a force in the direction of the arrow C in addition to the direction of the arrow A, the dicing tape 11 can be pulled more favorably, and as a result, the suction of the wafer 10 by the suction unit 4 is improved and more reliably. The wafer 10 can be fixed.

[Embodiment 3]
Another embodiment of the present invention will be described with reference to FIG. For convenience of explanation, constituent elements having the same functions as those of the constituent elements according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, differences from the second embodiment will be mainly described.

  The holding device 30 is different from the holding device 2 according to the first embodiment in that the holding device 30 includes a clamp 33 (a force applying portion) whose shape is different from that of the clamp 23.

  The clamp 33 includes a pressing portion 33a. The clamp 33 rotates in the direction of the arrow B ′, thereby pressing the dicing frame 11a in the direction of the arrow A ″ and pressing the support plate 13 in the direction of the arrow D by the pressing portion 33a. When the wafer 10 is placed on the holding base 2 with the substrate 13 adhered, the wafer 10 can be more reliably fixed, that is, force is applied in the directions of the arrows A, C, and D (triple). As a result, the force for fixing the wafer 10 can be further strengthened.

  In the present embodiment, the case where the member that presses the dicing frame 11a and the member that presses the support plate 13 are integrally formed has been described. However, these members are not integrated but are formed separately. Also good.

[Example 1: Influence of wrinkles of dicing tape]
In this embodiment, the apparatus has the same configuration as the holding apparatus 1 shown in FIG. 1, an apparatus (hereinafter referred to as “apparatus A”) in which the diameter of the holding base 2 is 330 mm and the diameter of the suction unit 4 is 302 mm, and the holding base. An apparatus (hereinafter referred to as “apparatus B”) having a diameter 2 of 340 mm and a suction part 4 of 302 mm was used.

On the apparatus A and the apparatus B, a wafer in which a wrinkle was intentionally wrinkled in advance on a dicing tape was adhered and placed on the wafer. A wafer having a diameter of 300 mm was used as the wafer, and a dicing tape that was sufficiently larger than the area of the holding table 2 was used. Next, the dicing frame was fixed with the clamp 3, and the holding table 2 was rotated at a rotational speed of 500 to 3000 min ⁻¹ , and at the same time, suction was performed at the suction part 4.

  As a result, in all the apparatuses, the adsorption was good and the wafer could be fixed sufficiently. Also, the device A was better in absorbing tape deflection. Further, the force for pressing the dicing frame was stronger in the apparatus B.

[Example 2: Influence of wafer warpage]
The holding table 2 was rotated, pressed by the clamp 3, and suctioned by the suction part 4 in the same manner as in Example 1 except that the dicing tape was not wrinkled and the wafer was warped by 5 mm.

  As a result, in all the apparatuses, the adsorption was good and the wafer could be fixed sufficiently. For comparison, when pressing by the clamp 3 was not performed, an adsorption error of the vacuum pressure of the porous portion occurred, and it could not be sufficiently adsorbed and fixed.

[Example 3: Influence of warping of dicing frame]
The dicing tape is not wrinkled, the dicing frame is warped by 2 mm, and only the device B is used. The holding table 2 is rotated, pressed by the clamp 3, and sucked by the suction portion 4 in the same manner as in Example 1. Was done.

  As a result, the adsorption was good and the wafer could be sufficiently fixed.

  The present invention can be used, for example, for surface treatment of a thinned wafer.

1, 20, 30 Holding device 2 Holding base 2a Protruding part 3, 23, 33 Clamp (forced part)
4 Suction unit 5 Rotation drive unit 10 Wafer (substrate)
11 Dicing tape (support film)
11a Dicing frame (frame part)
13 Support plate (support plate)
33a Pressing part

Claims (6)

A holding device for holding a substrate having a support film bonded on one side,
A suction part for sucking the substrate from the surface to which the support film is bonded;
When the substrate is installed to be horizontal, a vertical downward force is applied to a portion outside the portion sucked by the suction portion in the support film, and the portion to which the force is applied is the portion A force applying portion that is positioned vertically downward from the inside of the
The substrate has a support plate bonded to a surface opposite to the surface to which the support film is bonded,
A holding device including a pressing portion that presses the support plate from a surface opposite to the surface that is bonded to the substrate. The support membrane has a frame portion on its outer periphery,
The holding device according to claim 1, wherein the force applying portion applies force to the frame portion.   The holding device according to claim 1 or 2, wherein a portion to which a force is applied by the force applying unit is positioned below the substrate when the substrate is installed so as to be horizontal.   The holding device according to any one of claims 1 to 3, further comprising a rotation drive unit that rotates the substrate about a straight line perpendicular to the surface direction as a rotation axis.   The holding device according to any one of claims 1 to 4, wherein the force applying portion includes an elastic body, and a force is applied by the elastic body.   When the substrate is installed to be horizontal, a projection is provided that pushes up a part of the outer portion vertically upward, and the force-applying portion is more than the portion of the support film that is pushed up by the projection. The holding device according to any one of claims 1 to 5, wherein a force is further applied to an outer portion.

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