JP2011258625A - Method for handling semiconductor wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for handling a semiconductor wafer, which is capable of preventing cracks from being generated in a semiconductor wafer when an adhesive tape adhering to an adhesive layer is removed.SOLUTION: A handling method uses an adhesive sheet 11 having weak adhesion and a semiconductor wafer 1 that is bonded to a semiconductor supporting plate via an adhesive layer 3 and provides multiple chips 5 in the region other than a periphery 4. In the handling method, the chips 5 of the semiconductor wafer 1 are placed to face the adhesive sheet 11 and are stuck on the adhesive sheet 11, and the semiconductor supporting plate is removed from the semiconductor wafer 1. Then an adhesive tape 12 is stuck on and removed from the residual adhesive layer 3 of the semiconductor wafer 1 to remove the adhesive layer 3. The adhesive layer 3 is divided into a pair of small adhesive layers 3a and 3b at an approximately central portion, and the adhesive tape 12 is successively stuck on and removed from the pair of small adhesive layers 3a and 3b to gradually remove the adhesive layer 3 from the approximately central portion.

Description

  The present invention relates to a method for handling a semiconductor wafer which is transferred to an adhesive sheet and set in a solder reflow apparatus.

  There are various types of semiconductor wafers, but in recent years, chip-on-wafers that contribute to semiconductor three-dimensional stacking technology have attracted attention. As shown in FIGS. 7 and 8, this type of semiconductor wafer 1 is bonded to a semiconductor support plate 2 with an adhesive layer 3 to ensure strength and rigidity, and a peripheral portion (2. A plurality of chips 5 are mounted side by side in an area other than 4 (part of about 5 to 3 mm). When a plurality of chips 5 are mounted side by side, a flux is printed and a plurality of solder balls are mounted and used for a solder reflow device. From the viewpoint of convenience of manufacturing work, as shown in FIG. 9 and FIG. Then, it is transferred to the pressure-sensitive adhesive sheet 11 which is a holder before printing the flux (see Patent Documents 1 and 2).

  The handling operation in this case is as follows. First, a plurality of chips 5 of a thin semiconductor wafer 1 are adhered to an adhesive sheet 11 adhered to a sheet support plate 10 so as to oppose each other (see FIG. 9). The plate 2 is peeled off. At this time, in the semiconductor wafer 1, although the plurality of chips 5 adhere to the adhesive sheet 11, the unnecessary peripheral edge 4 faces the adhesive sheet 11 with a gap. The adhesive layer 3 remains on the semiconductor wafer 1 at least most of the adhesive layer 3 regardless of the peeling of the semiconductor support plate 2.

  After the semiconductor support plate 2 is peeled from the semiconductor wafer 1, an adhesive tape 12 having a size substantially corresponding to the semiconductor wafer 1 is adhered onto the remaining adhesive layer 3 of the semiconductor wafer 1 (see FIG. 10). Is peeled by strongly pulling at once from the edge of the periphery, that is, the peeling start point 13 shown in FIG. 11, thereby removing the adhesive layer 3 remaining on the semiconductor wafer 1 together with the adhesive tape 12.

JP 2006-32488 A JP 2002-324767 A

  The conventional handling of the semiconductor wafer 1 is as described above, and the unnecessary peripheral edge 4 of the thin semiconductor wafer 1 is simply opposed to the adhesive sheet 11 with a gap, and is in a non-adhesive floating state that does not adhere. When the pressure-sensitive adhesive tape 12 adhered to the adhesive layer 3 is pulled up and peeled off, the peripheral edge 4 of the semiconductor wafer 1 at the peeling start point 13 of the pressure-sensitive adhesive tape 12 is also lifted, and as a result, stress acts on the thin semiconductor wafer 1. Thus, there is a problem that the crack 6 shown in FIG. 11 occurs and seriously hinders the subsequent manufacturing process.

  The present invention has been made in view of the above, and an object of the present invention is to provide a method of handling a semiconductor wafer that can prevent cracks in the semiconductor wafer when the adhesive tape adhered to the adhesive layer is peeled off.

In order to solve the above-mentioned problems in the present invention, the pressure-sensitive adhesive sheet includes a slightly pressure-sensitive adhesive sheet and a semiconductor wafer that is bonded to the semiconductor support plate via an adhesive layer and has irregularities in regions other than the peripheral portion. The adhesive layer remaining on the semiconductor wafer is removed by sticking the adhesive tape to the adhesive layer remaining on the semiconductor wafer and removing the semiconductor support plate from the semiconductor wafer. A method of handling a semiconductor wafer to be removed,
The adhesive layer is divided and peeled from the vicinity of the substantially central portion by repeating the work of sticking the adhesive tape to a part of the adhesive layer and peeling it a plurality of times.

Note that the adhesive layer can be divided into a plurality of small adhesive layers with the vicinity of the substantially central portion as a boundary, and an adhesive tape can be adhered to each small adhesive layer to start peeling from the vicinity of the approximate central portion of the adhesive layer.
Moreover, the division | segmentation groove | channel which divides | segments an contact bonding layer into several small contact bonding layers can be formed in the support plate for semiconductors.
Further, the semiconductor support plate can be removed from the semiconductor wafer by laser irradiation.

  Here, the pressure-sensitive adhesive sheet in the claims can have a single-layer structure, a two-layer structure, a multilayer structure, or the like by an elastomer such as silicone rubber or fluororubber. The support plate for semiconductor is not particularly limited to glass, resin, or metal. The semiconductor wafer includes at least φ100, 150, 200, 300, and 450 mm chip-on-wafers.

  The pressure-sensitive adhesive area of the pressure-sensitive adhesive tape with respect to a part of the adhesive layer is preferably less than half of the total area of the adhesive layer from the viewpoint of facilitating the peeling operation. Further, the vicinity of the substantially central portion of the adhesive layer includes at least the central portion of the adhesive layer and the vicinity thereof. The adhesive layer is divided into a plurality of parts with the vicinity of the substantially central portion as a starting point. In this case, the divided small adhesive layers may or may not be completely separated. Further, the dividing groove is not particularly limited to a plurality, and can be appropriately formed in a planar linear shape, a substantially cross shape, or the like.

  According to the present invention, focusing on the vicinity of the substantially central portion of the adhesive layer separated from the peripheral portion, the adhesive layer is divided in the vicinity of the substantially central portion and peeled off by the adhesive tape. It will never be. Therefore, when the adhesive tape is pulled up and peeled off, the peripheral edge of the semiconductor wafer is not lifted together.

  According to the present invention, when peeling the pressure-sensitive adhesive tape adhered to the adhesive layer, the peripheral edge of the semiconductor wafer at the peeling start point of the pressure-sensitive adhesive tape is pulled up, and it is possible to effectively prevent the semiconductor wafer from cracking. effective.

  Moreover, if a dividing groove for dividing the adhesive layer into a plurality of small adhesive layers is formed on the support plate for a semiconductor, a gap is formed between the plurality of small adhesive layers to completely divide them into each small adhesive layer. It is possible to reduce the force necessary for peeling off the pressure-sensitive adhesive tape adhered to the surface.

It is a fragmentary sectional view showing typically a semiconductor wafer, a semiconductor support board, and an adhesion layer in an embodiment of a semiconductor wafer handling method concerning the present invention. It is a partial section explanatory view showing typically the state where the chip of the semiconductor wafer was made to oppose and adhere to the adhesive sheet in the embodiment of the semiconductor wafer handling method concerning the present invention. FIG. 3 is a partial cross-sectional explanatory view schematically showing a state where an adhesive tape is adhered to and peeled from a small adhesive layer that is half of an adhesive layer remaining on a semiconductor wafer in an embodiment of a semiconductor wafer handling method according to the present invention. FIG. 4 is a partial cross-sectional explanatory view schematically showing a state in which a pressure-sensitive adhesive tape is adhered and peeled to the remaining half of the small adhesive layer of the adhesive layer of FIG. 3. It is plane explanatory drawing which shows typically other embodiment of the handling method of the semiconductor wafer which concerns on this invention. It is plane explanatory drawing which shows typically other embodiment of the handling method of the semiconductor wafer which concerns on this invention. It is explanatory drawing which shows a semiconductor wafer and its several chip | tip typically. It is a fragmentary sectional view showing typically the state where the semiconductor wafer was pasted up to the support board for semiconductors. It is a partial section explanatory view showing typically the state where a plurality of chips of a semiconductor wafer were stuck to an adhesive sheet. It is a partial section explanatory view showing typically the state where the adhesive tape was stuck to the adhesion layer of the semiconductor wafer. It is explanatory drawing which shows typically the state which the crack produced in the semiconductor wafer.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. A method for handling a semiconductor wafer in the present embodiment is an adhesive that adheres to a rigid sheet support plate 10 as shown in FIGS. A sheet 11 and a semiconductor wafer 1 that is bonded to the semiconductor support plate 2 via the adhesive layer 3 and includes a plurality of chips 5, and the semiconductor wafer 1 having the chips 5 is attached from the semiconductor support plate 2 to the adhesive sheet 11. In the case of transferring to, the adhesive layer 3 is divided into a plurality of small adhesive layers 3a and 3b in the vicinity of the substantially central portion, and the adhesive tape 12 is adhered to the divided small adhesive layers 3a and 3b and peeled off sequentially. By doing so, the adhesive layer 3 is peeled off stepwise from the vicinity of its substantially central portion.

The sheet support plate 10 is made of, for example, a flat circular glass plate whose front and back surfaces are flat, and has at least a size equal to or larger than the size of the semiconductor wafer 1, and the adhesive sheet 11 is detachably adhered to the surface. The
The pressure-sensitive adhesive sheet 11 is formed into a thin sheet with both front and back surfaces made of a single layer of silicone rubber having flexibility, durability, heat resistance, weather resistance, flame retardancy, slight adhesion, and the like. It is detachably adhered to the surface of the plate 10.

  The semiconductor support plate 2 is made of, for example, a flat planar rectangular glass plate. As shown in FIG. 1, a substantially U-shaped dividing groove 7 for the adhesive layer 3 is peeled off from the adhesive tape 12 at a substantially central portion of the surface. An adhesive layer 3 that is linearly recessed in advance in a direction orthogonal to the direction (the back direction in FIG. 1), and that is adhesively applied to a thin semiconductor wafer 1 by thinly applying an adhesive to the surface including the dividing grooves 7. Laminated to a thickness of about 30 μm.

  As shown in FIG. 1, the adhesive layer 3 has a substantially central portion facing the linear dividing grooves 7 as the adhesive is applied to the surface of the semiconductor support plate 2 having the dividing grooves 7. Thus, it is divided into a plurality of pieces, for example, divided into two. The pair of divided small adhesive layers 3a and 3b are completely separated and separated through a gap at a substantially central portion.

  The semiconductor wafer 1 is made of, for example, a silicon wafer having a diameter of 200 mm and a thickness of 100 μm or less that is thin and flexible, and is bonded to the adhesive layer 3 of the semiconductor support plate 2, that is, a pair of small adhesive layers 3 a and 3 b that are divided in advance. After the rigidity is secured, a plurality of chips 5 are mounted side by side in a region excluding the unnecessary peripheral edge 4 to form a chip-on-wafer.

  In the above, when the semiconductor wafer 1 having the chip 5 is transferred from the semiconductor support plate 2 to the adhesive sheet 11, first, the plurality of chips 5 of the semiconductor wafer 1 are placed on the adhesive sheet 11 adhered to the sheet support plate 10. The semiconductor support plate 2 is peeled from the semiconductor wafer 1 to expose the pair of small adhesive layers 3a and 3b. The method for peeling the semiconductor support plate 2 is not particularly limited. For example, when a laser irradiation method is employed, the semiconductor support plate 2 can be peeled appropriately and easily.

  When the pair of small adhesive layers 3a and 3b remaining on the semiconductor wafer 1 are exposed, the adhesive tape 12 is selected and adhered to one surface of the remaining pair of small adhesive layers 3a and 3b. For example, as shown in FIG. 3, when the small adhesive layer 3b is first selected from the pair of small adhesive layers 3a and 3b, the peripheral edge on the opposite side from the end located near the dividing groove 7 of the small adhesive layer 3b. The adhesive tape 12 having a width equal to or larger than the size of the semiconductor wafer 1 is adhered to the portion through a roller or the like.

  As the adhesive tape 12, for example, an acrylic, urethane, silicone, synthetic rubber, natural rubber, or mixed adhesive is laminated on one side of a film made of polyethylene terephthalate, cellophane, vinyl chloride resin or the like. Commercially available types can be used. However, it is preferable to select the adhesive tape 12 according to the material of the remaining adhesive layers 3, 3a, 3b.

  Next, the scraper 20 is pressed against the end side of the adhesive tape 12 located in the vicinity of the dividing groove 7 of the semiconductor support plate 2, and the adhesive tape 12 is gradually moved while shifting the pressed scraper 20 toward the peripheral edge of the adhesive tape 12. The half of the adhesive layer 3 remaining on the semiconductor wafer 1, that is, the small adhesive layer 3 b is removed together with the adhesive tape 12 by pulling up obliquely (see FIG. 3).

  At this time, if the small adhesive layer 3b is grasped as the entire adhesive layer 3, the adhesive layer 3 is peeled off from the substantially central portion instead of the peripheral portion thereof. It is not equivalent to 4. Therefore, when the adhesive layer 3 is peeled off from the semiconductor wafer 1 by the adhesive tape 12, the peripheral edge 4 of the semiconductor wafer 1 is not pulled up.

  Further, since the small adhesive layer 3b is completely separated from the small adhesive layer 3a, the adhesive tape 12 can be reliably adhered only to the small adhesive layer 3b having an area less than half of the total area of the adhesive layer 3. . Therefore, when the small adhesive layer 3b is peeled and removed, a part of the small adhesive layer 3a is not broken and pulled up together, and the burden required for peeling and removing the small adhesive layer 3b can be reduced.

  Next, the adhesive tape 12 is adhered again with a roller or the like from the end of the remaining small adhesive layer 3 a located near the dividing groove 7 to the opposite peripheral edge, and the scraper is placed on the end side of the adhesive tape 12 located near the dividing groove 7. After pressing 20, the adhesive tape 12 is gradually lifted obliquely while shifting the pressed scraper 20 toward the peripheral edge of the adhesive tape 12, that is, the other half of the adhesive layer 3 remaining on the semiconductor wafer 1, that is, The small adhesive layer 3a can be removed together with the adhesive tape 12 (see FIG. 4).

  The peeling start location of the adhesive tape 12 at this time is not the peripheral portion 4 of the semiconductor wafer 1 that is not adhered to the adhesive sheet 11 but the substantially central portion or chip 5 portion of the semiconductor wafer 1 that is already adhered to the adhesive sheet 11. Therefore, stress does not act on the semiconductor wafer 1 and the crack 6 does not occur. The semiconductor wafer 1 from which the adhesive layer 3 has been completely removed is then printed with a flux, and a plurality of solder balls are mounted and used for a solder reflow apparatus.

  According to the above, the adhesive layer 3 is divided into a pair of small adhesive layers 3a and 3b at a substantially central portion away from the peripheral portion, and the small adhesive layers 3a and 3b are sequentially peeled from the approximate central portion of the adhesive layer 3. Thus, the adhesive layer 3 remaining on the semiconductor wafer 1 is peeled off in a plurality of times, so that the peeling start location does not become the peripheral edge 4 of the semiconductor wafer 1. Therefore, when the adhesive tape 12 is pulled up and peeled off, the peripheral edge 4 of the semiconductor wafer 1 is not lifted up at all.

  By preventing such pulling-up, it is possible to prevent the thin semiconductor wafer 1 from being stressed and to generate cracks 6 and to effectively suppress and prevent serious troubles in the subsequent manufacturing process. Moreover, since the adhesive tape 12 is peeled little by little while pressing the scraper 20, the adhesive tape 12 does not peel at once over a wide range. As a result, the remaining adhesive layer 3 can be appropriately and reliably peeled without damaging the semiconductor wafer 1.

  The semiconductor support plate 2 and the sheet support plate 10 of the above-described embodiment may be planar rectangles or circles, but are not limited thereto, and may be planar polygons or the like. The semiconductor support plate 2 may be a silicon wafer plate different from the semiconductor wafer 1. Moreover, in the said embodiment, although the division | segmentation groove | channel 7 was dented and formed in the surface of the support plate 2 for semiconductors, a pair of small adhesion layers 3a * 3b were defined, but it is not limited to this at all. For example, a pair of small adhesive layers 3a and 3b can be partitioned by appropriately arranging a dividing thread, tape, or the like in the vicinity of the substantially central portion of the surface of the semiconductor support plate 2 and applying an adhesive thereon. Also good.

  Further, the pair of small adhesive layers 3a and 3b may be connected via a perforation or the like, or the adhesive layer 3 may be divided into three parts, four parts, etc. in the vicinity of the substantially central part thereof. In the above embodiment, the adhesive layer 3 is divided in advance into a pair of small adhesive layers 3a and 3b at substantially the center thereof, but the present invention is not limited to this. For example, the adhesive layer 3 can also be divided | segmented at the time of peeling by sticking the adhesive tape 12 partially from the substantially center part vicinity of an adhesive layer 3 to a peripheral part, and peeling.

  Moreover, in the said embodiment, although the adhesive tape 12 which has the width | variety more than the size of the semiconductor wafer 1 was used, it is not limited to this. For example, as shown in FIG. 5, a plurality of elongate adhesive tapes 12 are adhered to the surface of the adhesive layer 3 in a substantially cross shape so that one end of each adhesive tape 12 is positioned near the approximate center of the adhesive layer 3. The adhesive layer 3 can also be separated and peeled from the vicinity of the center by sequentially peeling the plurality of adhesive tapes 12 from the one end side toward the peripheral edge portion on the opposite side (see the arrow in FIG. 5).

  Further, as shown in FIG. 6, a plurality of adhesive tapes 12 each having a flat rectangular shape are adhered to the surface of the adhesive layer 3 in the vertical and horizontal directions, and one corner of each adhesive tape 12 is opposed to the vicinity of the substantially central portion of the adhesive layer 3. The adhesive layer 3 is separated and peeled from the vicinity of the central portion thereof by sequentially separating the plurality of adhesive tapes 12 from one corner to the peripheral corner on the opposite side (see arrows in FIG. 6). It is also possible.

  Further, although silicone rubber is used for the pressure-sensitive adhesive sheet 11 in the above embodiment, an elastomer such as fluororubber having self-adhesiveness can also be used. Furthermore, it is possible to perform the peeling operation by dividing the adhesive tape 12 into three times, four times or the like instead of dividing the adhesive tape 12 into two times.

DESCRIPTION OF SYMBOLS 1 Semiconductor wafer 2 Support board 3 for semiconductors Adhesion layer 3a Small adhesion layer 3b Small adhesion layer 4 Peripheral part 5 Chip (unevenness)
6 Crack 7 Dividing Groove 10 Sheet Support Plate 11 Adhesive Sheet 12 Adhesive Tape 13 Peeling Start Location 20 Scraper

Claims (3)

It includes a slightly sticky pressure-sensitive adhesive sheet and a semiconductor wafer that is bonded to a semiconductor support plate via an adhesive layer and has unevenness in a region other than the peripheral portion, and the pressure-sensitive adhesive sheet and the unevenness of the semiconductor wafer are made to face each other Then, removing the semiconductor support plate from the semiconductor wafer, and sticking the adhesive tape to the adhesive layer remaining on the semiconductor wafer and peeling off, the semiconductor wafer handling method for removing the adhesive layer remaining from the semiconductor wafer,
A method of handling a semiconductor wafer, wherein the adhesive layer is separated and separated from the vicinity of its substantially central portion by repeating the work of adhering the adhesive tape to a part of the adhesive layer and peeling it a plurality of times.   2. The semiconductor according to claim 1, wherein the adhesive layer is divided into a plurality of small adhesive layers with the vicinity of the substantially central portion as a boundary, an adhesive tape is adhered to each small adhesive layer, and peeling is started from the approximate central portion of the adhesive layer. Wafer handling method.   The method for handling a semiconductor wafer according to claim 2, wherein a dividing groove for dividing the adhesive layer into a plurality of small adhesive layers is formed in the semiconductor support plate.

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