JP4319859B2 - Method for peeling brittle members - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for peeling a brittle member, and more particularly, to a method for peeling a brittle member such as a semiconductor wafer attached to a hard plate via a double-sided pressure-sensitive adhesive sheet.
[0002]
[Prior art]
Conventionally, semiconductor wafers, which are brittle members having a circuit pattern formed on the surface, have been widely used in the electronics industry, the optical industry, and the like. The semiconductor wafer has been conventionally ground to a thickness of about 200 μm to 300 μm. However, due to the recent demand for miniaturization and thinning of IC chips, processing to ultra-thin of 100 μm or less is required. For this reason, when the semiconductor wafer after grinding is stored and transported, the semiconductor wafer is likely to be cracked or scratched. Therefore, there is a case where a method of fixing the semiconductor wafer to a hard plate such as a glass plate is used in order to reinforce the semiconductor wafer and ensure handling of the semiconductor wafer before grinding. When fixing a semiconductor wafer to a hard board, the method of sticking these through wax is known.
[0003]
However, when pasting through the wax, it is difficult to uniformly apply the thickness of the wax, and it becomes difficult to smooth and grind the semiconductor wafer. In addition, the tendency of the wax to protrude from the end of the hard plate is strong, resulting in inconvenience that workability is hindered. Furthermore, after the semiconductor wafer is peeled from the hard plate, it must be cleaned using an organic solvent, which is not preferable in that it causes pollution of the natural environment.
[0004]
Therefore, as described in Patent Document 1, a method has been proposed in which a hard plate and a semiconductor wafer are attached using a double-sided pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on both sides of a heat-shrinkable film instead of wax. Yes.
[0005]
[Patent Document 1]
JP-A-2000-136362 [0006]
However, when a semiconductor wafer is affixed to a hard plate using the sheet described in Patent Document 1, there is a disadvantage that it cannot be used in a process having a heat treatment after grinding. In addition, since such a sheet is usually set to substantially the same plane size as the semiconductor wafer, it is difficult to create a trigger for starting the peeling when the semiconductor wafer is peeled from the hard plate. For this reason, an excessive force is required at the initial stage of peeling, and the semiconductor wafer is damaged, or if it is carefully operated so as not to apply a force, peeling cannot be performed.
[0007]
OBJECT OF THE INVENTION
The present invention has been devised by paying attention to such inconveniences, and its purpose is to easily prevent brittle members such as semiconductor wafers attached to a hard plate from being cracked or scratched. It is in providing the method which can be peeled.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention uses a support unit in which a brittle member is attached to a hard plate via a double-sided pressure-sensitive adhesive sheet, and in the method of peeling the brittle member from the hard plate,
On the upper surface of the table, a concave portion having substantially the same depth as the thickness of the hard plate is provided, and the support unit is arranged so that the hard plate is positioned in the concave portion,
The brittle member is made to slide while applying the tip of the stripping piece member to the upper surface of the table, and inserting the peeling piece member between the hard plate and the brittle member along a direction parallel to the upper surface. Is taken from the hard plate. According to such a method, when the peeling piece member is inserted between the double-sided pressure-sensitive adhesive tape and the hard plate, peeling for an area corresponding to the insertion amount can be performed. At this time, since the peeling piece member is inserted in a direction substantially parallel to the upper surface of the table, almost no force is applied in a direction intersecting the surface of the brittle member. Therefore, it is possible to effectively prevent the occurrence of cracks and the like by separating the brittle member without deforming the surface shape of the brittle member.
In the case where the stripping piece member is inserted into the entire pasting region of the double-sided pressure-sensitive adhesive tape and the hard plate, the brittle member can be completely peeled off. However, with the insertion amount of the peeling piece member stopped at a part of the pasting area, the peeling area formed by inserting the peeling piece member is set as a peeling start part in a state where the support unit is set in a separate peeling device. The brittle member can be peeled from the hard plate.
[0009]
In the peeling method, it is preferable to use a tip provided on the insertion side of the peeling piece member that is thinner than the thickness of the adhesive layer on the hard plate side in the adhesive double-sided sheet. By using such a peeling piece member, the hard member and the brittle member are peeled in a state of maintaining a substantially parallel relative position.
[0010]
Further, a method is adopted in which the brittle member is peeled from the hard plate by rotating the table in a plane in a state where the support unit has a substantially circular shape in plan view and the peeling piece member is inserted. I can also do it. According to this, peeling of the width | variety according to the insertion amount of the piece member for peeling can be formed now along the circumferential direction of a support unit.
[0011]
The brittle member may be a semiconductor wafer. By applying the present invention to such a semiconductor wafer, it is possible to sufficiently meet demands for strict processing accuracy.
[0012]
Furthermore, the present invention provides a through-hole penetrating the inside of the hard plate in the vicinity of the outer periphery of the hard plate, and before inserting the peeling piece member, injecting fluid into the through-hole, the hard plate It is also possible to employ a technique in which a peeling region is provided in advance at the interface between the adhesive sheet and the double-sided pressure-sensitive adhesive sheet, and the brittle member is peeled by inserting the peeling piece member into the peeling region. By using fluid injection in combination, partial peeling of the interface with the fluid can be performed in advance, and then the stripping piece member can be made to enter from the region where the stripping has been completed. Can be performed more easily and smoothly.
Moreover, the said hard board is the same shape as a brittle member, and may be provided in the same size.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
[First Embodiment]
FIG. 1 shows a schematic cross-sectional view of an implementation apparatus to which the peeling method of the first embodiment is applied, and FIG. 2 shows an exploded cross-sectional view thereof. In these drawings, a support unit U is disposed on the upper surface side of the table T. The support unit U includes a hard plate P having a surface capable of supporting a brittle member, and a semiconductor wafer W as a brittle member attached to one surface of the hard plate P via a double-sided adhesive sheet S. It is prepared for.
[0015]
As the hard plate P, for example, a plastic plate such as a glass plate, a quartz plate, an acrylic plate, a polyvinyl chloride plate, a polyethylene terephthalate plate, a polypropylene plate, or a polycarbonate plate can be used. The hardness defined by ASTM D 883 of the hard plate P is preferably 70 MPa or more. When at least one of the pressure-sensitive adhesive layers used in the double-sided pressure-sensitive adhesive sheet S is composed of an ultraviolet curable pressure-sensitive adhesive, a material capable of transmitting the wavelength of ultraviolet light to be used is selected for the hard plate P. The thickness of the hard plate P is usually about 0.1 to 10 mm, although it depends on the material. The shape or size of the hard plate P may be larger than the size of the brittle member to be supported and fixed, but it is more preferably substantially the same shape and the same size.
[0016]
The double-sided pressure-sensitive adhesive sheet S includes a base material sheet S1, a pressure-sensitive adhesive layer S2 formed on the hard plate P side of the base material sheet S1, and a pressure-sensitive adhesive layer S3 formed on the side to which the semiconductor wafer W is applied. It consists of. Since the base sheet S1 is excellent in dimensional stability and heat resistance, a polyester film such as a polyethylene naphthalate film or a polyethylene terephthalate film is preferably used. The pressure-sensitive adhesive layers S2 and S3 are rubber-type, acrylic-type, silicone-type, polyurethane-type, polyvinyl ether-type, etc. adhesives, UV-curable adhesives, or water-swellable adhesives, as long as they are removable. It can be used without any limitation. In particular, it is preferable to use an ultraviolet curable pressure-sensitive adhesive for the pressure-sensitive adhesive layer S2 in contact with the hard plate P side. By irradiating the adhesive layer S2 with ultraviolet rays from the hard plate P side and curing the adhesive layer S2, the adhesive force disappears or decreases. This facilitates the insertion of the stripping strip member 11 between the double-sided pressure-sensitive adhesive sheet S and the hard plate P, and also after the fluid is injected into the support unit U and the semiconductor wafer W and the hard plate P are peeled off. There is no risk of reattachment.
[0017]
As the semiconductor wafer W, a semiconductor wafer having a circuit formed on the front surface and an unground back surface is used in a pre-process of semiconductor manufacturing. The semiconductor wafer W is adhesively fixed to the hard plate P through the double-sided adhesive sheet S on the circuit side surface, and a support unit U is formed. In this state, what has been processed to grind the back surface side of the semiconductor wafer W to a thickness of about 100 μm or less is an object in this embodiment.
In the present invention, regardless of the grinding process, the back surface of the semiconductor wafer W may be processed by vapor deposition, sputtering, etching, or the like, or may be processed after the grinding process. Furthermore, a semiconductor wafer in which an adhesive sheet (die attach sheet) is heat bonded to the ground surface may be used. Further, a semiconductor wafer that has been diced into chips may be targeted.
[0018]
The table T has a recess T1 formed on the upper surface TS, and a rotation center shaft 10 connected to a motor (not shown) is provided on the lower surface side. The plane area of the recess T1 is substantially the same as the plane area of the hard plate P, and the depth D of the recess T1 is set to a depth that matches the thickness (height) H of the hard plate P. Accordingly, when the hard plate P is disposed in the recess T1, the upper surface TS position of the table T substantially coincides with the interface position between the adhesive layer S2 and the hard plate P, and this coincides. The semiconductor wafer W can be peeled from the hard plate P by inserting the peeling piece member 11 into the position. Further, a suction hole (not shown) for restricting relative rotation between the hard plate P and the table T is formed on the bottom surface of the recess T1. Note that the peeling piece member 11 is constituted by, for example, a thin blade made of stainless steel or the like, and at least the thickness of the tip on the insertion side is equal to or less than the thickness of the pressure-sensitive adhesive layer S2.
[0019]
Next, a method for peeling the semiconductor wafer W in the first embodiment will be described.
[0020]
As shown in FIG. 2, the support unit U is accommodated in the recess T <b> 1 of the table T so that the hard plate P is on the lower surface side. Then, the hard plate P is adsorbed to the table T to restrict relative movement, and the peeling piece member 11 may be inserted from the outer peripheral side of the support unit U toward the center as shown in FIG. And by the rotation operation | movement of the table T, the peeling area | region of the width | variety according to the insertion amount will be formed in the outer peripheral side between adhesive layer S2 and the hard board P. FIG. Therefore, when the peeling piece member 11 is inserted to the center of the support unit U, the semiconductor wafer W is completely peeled from the hard plate P. On the other hand, if the tip insertion amount of the stripping strip member 11 is, for example, about ¼ of the diameter of the support unit U, a stripping region having a width corresponding to this is formed. Therefore, when it is necessary to completely peel the semiconductor wafer W in a separate process without completely peeling the semiconductor wafer W, the peeling may be performed only on the outer peripheral side fixed region. Even in this case, since the separation region is formed on the outer peripheral side, the subsequent separation resistance can be greatly reduced, and the separation can be performed while preventing cracking of the semiconductor wafer.
[0021]
Therefore, according to the first embodiment as described above, the tip of the stripping strip member 11 is slid while being applied to the upper surface of the table T, and only inserted along a direction parallel to the upper surface TS of the table T. The semiconductor wafer W can be peeled from the hard plate P without being damaged.
[0022]
Second Embodiment
FIG. 3 shows a second embodiment of the peeling method according to the present invention. In this embodiment, a separation region A is formed in advance by injecting a fluid into the interface between the pressure-sensitive adhesive layer S2 and the hard plate P, and the separation piece member 11 is inserted from the separation region A so that the separation can be performed. It has the characteristics in that place.
[0023]
That is, in the vicinity of the outer periphery of the hard plate P, a single through hole P1 that penetrates the surface of the hard plate P is formed, and the center of the syringe C is inserted into the through hole P1, and deionized water or pure water is inserted. In addition, a surfactant-containing aqueous solution, a polyethylene glycol-containing aqueous solution, a liquid such as an alcohol, or a fluid composed of a gas such as air or nitrogen can be injected. And by this fluid injection | pouring, the peeling area | region A used as a trigger at the time of fluid entering the interface of adhesive layer S2 and the hard board P and peeling is formed. The peeling region A is provided in a circular size reaching the outer peripheral edge portion of the semiconductor wafer W and the hard plate P. Note that the inner diameter of the through hole P1 is usually 10 mm or less, preferably 3 mm, more preferably 1 mm or less, and the lower limit of the inner diameter is a size with which an injection portion such as a syringe for injecting fluid is engaged. When the through hole P1 is too large, there is a risk of causing processing unevenness when processing the brittle member. Specifically, when grinding a semiconductor wafer, if it is processed to an extremely thin thickness, a dimple is generated at a position corresponding to the through hole P1, which may cause damage to the semiconductor wafer or decrease the reliability of the completed device. There is sex.
The position of the through hole P1 in the hard plate P is 30 mm or less, preferably 20 mm or less, particularly preferably 10 mm or less from the outer edge of the hard plate P. If the strength of the hard plate P is strong, a position as close to the outer edge as possible is preferable. Further, the number of through holes P1 may be one or plural.
[0024]
As shown in FIG. 3C, the support unit U provided with such a separation region A is disposed in the recess T1 of the table T, and the support unit U in which the separation region A is formed. The peeling area A can be enlarged by inserting the stripping strip member 11 from the outer edge of the tape. Note that the peeling piece member 11 is inserted from the outer edge of the peeling area A without rotating the table T, and then the table T is rotated. Further, without rotating the table T, the peeling piece member 11 may be simply inserted toward the center to increase the peeling area of the peeling area A and peel off.
[0025]
Therefore, according to the second embodiment, the peeling region A is formed in advance at the interface between the pressure-sensitive adhesive layer S2 and the hard plate P before inserting the peeling piece member 11, so that it is easier. In addition, the semiconductor wafer W can be reliably peeled off.
[0026]
In the embodiment of the present invention, when the semiconductor wafer W is completely peeled from the hard plate P, the semiconductor wafer W on which the double-sided adhesive sheet S is adhered by a robot arm or the like with an appropriate suction mechanism is used as a tape peeling device. What is necessary is just to transfer and peel the double-sided adhesive sheet S.
Further, when a part of the semiconductor wafer W is peeled from the hard plate P, the semiconductor wafer W and the hard plate P may be peeled off gradually by any means starting from the formed peeled area A. As such means, for example, another adhesive tape such as a dicing tape is adhered to the semiconductor wafer W side, and a support (ring frame or the like) for fixing another adhesive sheet is provided to support the semiconductor wafer W. By lifting the semiconductor wafer W together with the body, it can be completely peeled from the hard plate P. When peeled in this way, the double-sided pressure-sensitive adhesive sheet S is peeled from the semiconductor wafer W with a tape peeling device or the like on an adhesive tape such as a dicing tape. Subsequently, the semiconductor wafer W is diced as desired to form chips. The semiconductor wafer W formed into chips on the dicing tape can be picked up and taken out by the conventional method.
[0027]
Although the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, the present invention is not limited to this.
That is, the invention has been illustrated and described with particular reference to particular embodiments, but it should be understood that the above-described embodiments are not deviated from the technical idea and scope of the invention. On the other hand, those skilled in the art can make various modifications in shape, material, quantity, and other detailed configurations.
Therefore, the description limited to the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.
[0028]
For example, in each of the above embodiments, the case where the table T rotates is illustrated and described, but the table T does not necessarily need to be rotated. In this case, providing the suction hole on the bottom surface side of the recess T1 of the table T can be omitted.
[0029]
Further, while providing the peeling piece member 11 to be held at a fixed position, the peeling piece is provided between the adhesive layer S2 and the hard plate P by providing the table T so as to be movable in the left-right direction in FIG. The member 11 may be inserted. In short, the present invention suffices if the peeling piece member 11 and the table T can be relatively moved in a direction substantially parallel to each other.
[0030]
Furthermore, the present invention is not limited to the brittle member intended for the semiconductor wafer W, and can also be applied to other thin brittle members.
[0031]
Moreover, although the through hole P1 in 2nd Embodiment illustrated and demonstrated the case where one piece was formed in the outer periphery vicinity of the hard board P, you may provide the said through hole P1 in multiple places.
[0032]
【The invention's effect】
As described above, according to the present invention, it is possible to perform peeling for an area corresponding to the amount of insertion only by inserting a peeling piece member between a hard plate and a brittle member. Moreover, since the stripping strip member is inserted in a direction substantially parallel to the upper surface of the table, the brittle member can be stripped without deforming the surface shape of the brittle member, and the brittle member can be cracked. Can be prevented.
[0033]
Further, in the method of peeling while rotating the table on which the support unit is arranged in a plane, peeling with a width according to the insertion amount of the peeling piece member can be formed along the circumferential direction of the supporting unit, and the peeling area Can be effectively expanded.
[0034]
Further, in the method using the method of injecting a fluid between the hard plate and the release sheet to form the release region, the partial interface peeling by the fluid is performed in advance before the peeling piece member is inserted. It is possible to perform the peeling operation by inserting the peeling piece member more smoothly.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a peeling method according to a first embodiment.
FIG. 2 is an exploded cross-sectional view of FIG.
FIGS. 3A and 3B are schematic cross-sectional views showing a peeling method according to a second embodiment, wherein FIG. 3A is a cross-sectional view showing a state in which a fluid is injected from a through hole, and FIG. Sectional drawing which shows the performed state, (C) is sectional drawing which shows the state which arrange | positions a support unit to a table and peels with the piece member for peeling.
[Explanation of symbols]
11 Peeling piece member A Peeling area C Syringe U Support unit P Hard plate P1 Through hole S Double-sided adhesive sheet S1 Base film S2, S3 Adhesive layer T Table TS Upper surface T1 Recess W Semiconductor wafer (brittle member)

Claims (6)

In the method of peeling the brittle member from the hard plate using a support unit in which the brittle member is stuck to the hard plate via a double-sided adhesive sheet,
On the upper surface of the table, a concave portion having substantially the same depth as the thickness of the hard plate is provided, and the support unit is arranged so that the hard plate is positioned in the concave portion,
The brittle member is made to slide while applying the tip of the stripping piece member to the upper surface of the table, and inserting the peeling piece member between the hard plate and the brittle member along a direction parallel to the upper surface. A method for peeling a brittle member, comprising peeling off a hard plate.   The brittle member peeling method according to claim 1, wherein the insertion-side tip of the peeling piece member is provided thinner than the thickness of the adhesive material layer on the hard plate side in the double-sided adhesive sheet.   The brittle member is peeled from the hard plate by rotating the table in a plane in a state where the support unit is substantially circular in a plan view and the stripping piece member is inserted. The peeling method of the brittle member of 1 or 2.   4. The brittle member peeling method according to claim 1, wherein the brittle member is a semiconductor wafer.   In the vicinity of the outer periphery of the hard plate, a through hole penetrating the in-plane of the hard plate is provided, and before inserting the peeling piece member, a fluid is injected into the through hole so that the hard plate and the double-sided adhesive sheet 5. A method for peeling a brittle member according to claim 1, 2, 3 or 4, wherein a peeling region is provided in advance at the interface, and the brittle member is peeled by inserting the peeling piece member into the peeling region. . The brittle member peeling method according to any one of claims 1 to 5, wherein the hard plate has the same shape and the same size as the brittle member.

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