JP2009101437A - Method of treating fragile member and adhesive sheet used for the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of treating a fragile member capable of stably holding the fragile member when the fragile member such as a semiconductor wafer is conveyed or the rear surface thereof is ground, and after a predetermined treatment is completed, capable of peeling the fragile member without being damaged, and also provide an adhesive sheet used desirably for the method. <P>SOLUTION: This method of treating a fragile member comprises a step of re-releasably securing the fragile member 2 to one surface of the adhesive sheet 1 manufactured by forming adhesive agent layers 11a, 12a on both outer surfaces of an airtight bag-like film base 10 and re-releasably securing a hard plate 3 to the other surface, a step of treating the fragile member 2, a step of introducing a fluid into the internal space of the bag-like film base 10 for expanding the adhesive sheet 1, and a step of peeling the treated fragile member 2 from the adhesive sheet 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a brittle member processing method including various processing steps represented by processing such as conveyance of a brittle member such as a semiconductor wafer and back grinding of a semiconductor wafer, and an adhesive sheet used in the method.

  With the spread of IC cards in recent years, thinning of wafers as constituent members has been promoted. It has been demanded to reduce the thickness of a conventional wafer having a thickness of about 350 μm to 50 to 100 μm or less.

  As the wafer that is a brittle member becomes thinner, the risk of breakage increases during processing and transportation. For this reason, when grinding a wafer to an extremely thin thickness or transporting an extremely thin wafer, the wafer is fixed and protected on a hard plate such as a glass plate or an acrylic plate with a double-sided adhesive sheet. It is desirable to proceed.

  However, in the method of bonding a wafer and a hard plate with a double-sided pressure-sensitive adhesive sheet, the wafer may be broken when the wafer is peeled off from the hard plate after a series of steps. When peeling a laminate formed by laminating two thin-layer products, it is necessary to bend either one of the thin-layer products or both. However, since it is impossible or difficult to curve the hard plate, the wafer side must be curved. For this reason, a fragile wafer is distorted and cracked.

  As a means for solving such a problem, a method of performing separation while reducing deformation of the wafer as much as possible, a method of performing separation after reinforcing the wafer by laminating a protective film on the wafer, and the like As a means for fixing the wafer to the hard plate, there is a method of using a pressure-sensitive adhesive or double-sided pressure-sensitive adhesive tape whose adhesive force can be controlled, and performing peeling after reducing the adhesive force by an appropriate means such as foaming of the adhesive during peeling. Various proposals have been made (Patent Documents 1 to 5).

Patent Document 6 discloses a method for protecting a brittle member using a resin film having a relatively high rigidity without using a hard plate.
JP 2004-153227 A JP 2005-116678 A JP 2003-324142 A JP 2005-277037 A International Patent Publication WO2003 / 049164 JP 2004-63678 A

  When the wafer is held on a hard plate, the wafer side is deformed when the wafer is peeled off. For this reason, it is difficult to completely prevent the wafer from being damaged. In addition, when a special pressure-sensitive adhesive or double-sided pressure-sensitive adhesive tape designed to reduce the adhesive force by foaming or the like is used, the adhesive may remain on the wafer and contaminate the wafer. In the method proposed in Patent Document 6, since the rigid resin film side is deformed and peeled off from the wafer, the problem of wafer breakage can be solved. However, since it is a resin film, shape retention is not always sufficient, and the wafer may be damaged when the wafer is transferred.

  The present invention seeks to solve the problems associated with the prior art as described above. That is, the present invention can stably hold a brittle member when performing processing such as conveyance of a brittle member such as a semiconductor wafer or back grinding, and after the required processing is completed, It aims at providing the processing method of the brittle member which can be peeled without being damaged, and the adhesive sheet preferably used for this processing method.

  The gist of the present invention aimed at solving such problems is as follows.

(1) A brittle member is removably fixed to one side of an adhesive sheet having an adhesive layer formed on both outer surfaces of an airtight bag-like film base, and a hard plate is removably fixed to the other side. Process,
Processing the brittle member;
Introducing a fluid into the internal space of the bag-shaped film substrate and inflating the adhesive sheet;
The processing method of a brittle member including the process of peeling the processed brittle member from an adhesive sheet.

(2) The processing method according to (1), wherein the brittle member is a semiconductor wafer, and the processing performed on the semiconductor wafer is backside grinding of the semiconductor wafer or conveyance of the semiconductor wafer.

(3) A pressure-sensitive adhesive sheet used in the processing method according to (1) above,
A bag-like film base material having a first film and a second film, the peripheral edges of which are bound, and
A pressure-sensitive adhesive sheet comprising pressure-sensitive adhesive layers formed on both outer surfaces of the bag-like film substrate.

(4) The pressure-sensitive adhesive sheet according to (3), wherein an opening communicating with the internal space of the bag-shaped film is provided in a part of the peripheral edge of the bag-shaped film substrate.

(5) The pressure-sensitive adhesive sheet according to (3), wherein a coefficient of static friction between the inner surfaces of the bag-shaped film substrate is 0.1 or more.

(6) The pressure-sensitive adhesive sheet according to (3), wherein the first film and the second film are spot-bound on the inner peripheral portion of the bag-shaped film substrate.

(7) a bag-like film base material having a first film and a second film, and having a peripheral edge bound thereto;
It consists of an adhesive layer formed on both outer surfaces of the bag-like film substrate,
A pressure-sensitive adhesive sheet in which an opening communicating with the internal space of the bag-shaped film substrate is provided in a part of the peripheral edge of the bag-shaped film substrate.

(8) A bag-like film base material having a first film and a second film, and having peripheral edges bound to each other,
It consists of an adhesive layer formed on both outer surfaces of the bag-like film substrate,
A pressure-sensitive adhesive sheet in which the first film and the second film are spot-bound on the inner peripheral portion of the bag-shaped film substrate.

  In the present invention, a brittle member such as a semiconductor wafer is fixed to and protected by a hard plate via an adhesive sheet having an airtight bag-like film base material. The brittle member can be held without being deformed. In addition, after the required treatment, fluid is introduced into the air-tight bag-like film base material and the bag-like film base material is expanded to reduce the bonding area between the brittle member and the pressure-sensitive adhesive sheet. Separation of the member is facilitated, and breakage of the brittle member is prevented.

  Hereinafter, the present invention will be described more specifically with reference to the drawings. As shown in FIG. 1, in the processing method of a brittle member according to the present invention, first, a pressure-sensitive adhesive sheet 11 having adhesive layers 11a and 12a formed on both outer surfaces of an airtight bag-like film substrate 10 is brittle on one side. The material member 2 is fixed so as to be removable, and the hard plate 3 is fixed to the other surface so as to be removable.

  Examples of the brittle member 2 include, but are not limited to, various semiconductor wafers such as a silicon wafer and a gallium / arsenic wafer, a ceramic plate, a glass plate, and a metal plate. Among these, the treatment method of the present invention is particularly preferably applied to a semiconductor wafer having a circuit formed on the surface. Furthermore, it can be preferably applied to a semiconductor wafer that has been subjected to backside grinding and has a very thin thickness and extremely low strength.

  The hard plate 3 functions to support and protect the brittle member 2 during transportation, storage, and processing. As the hard plate 3, for example, a glass plate, a quartz plate, an acrylic plate, a polyvinyl chloride plate, a polyethylene terephthalate plate, a polypropylene plate, a polycarbonate plate, or the like can be used. The hardness defined by ASTM D 883 of the hard plate 3 is preferably 70 MPa or more. The thickness of the hard plate 3 is usually about 0.1 to 10 mm, although it depends on the material. The diameter of the hard plate 3 is the same as or slightly larger than the diameter of the brittle member 2. Furthermore, as will be described later, when an ultraviolet curable pressure sensitive adhesive is used as the pressure sensitive adhesive layers 11a and 12a of the pressure sensitive adhesive sheet 1, the hard plate 3 is formed of an ultraviolet light transmissive material.

  In the present invention, the brittle member 2 is fixed on the hard plate 3 via the adhesive sheet 1.

  The pressure-sensitive adhesive sheet 1 is formed by forming pressure-sensitive adhesive layers 11 a and 12 a on both outer surfaces of an airtight bag-shaped film substrate 10.

  The air-tight bag-shaped film base 10 is a structure that normally expands by intimately integrating two films to form a substantially vacuum internal space and introducing a fluid into the internal space through a required operation. Indicates. Details of specific examples and modifications of the bag-shaped film substrate 10 will be described later.

  As shown in FIG. 1, the pressure-sensitive adhesive sheet 1 is composed of a bag-shaped film substrate 10 and a structure in which pressure-sensitive adhesive layers 11 a and 12 a are provided on both outer surfaces. The pressure-sensitive adhesive layers 11a and 12a are not particularly limited as long as they can be removed again, and conventionally known pressure-sensitive adhesives can be used. For example, it may be a normal weak pressure-sensitive adhesive, or an ultraviolet curable pressure-sensitive adhesive whose peeling force can be controlled by ultraviolet irradiation. The thickness of the pressure-sensitive adhesive layers 11a and 12a is not particularly limited, and is usually about 1 to 300 μm, preferably 5 to 50 μm.

  The pressure-sensitive adhesive layers 11a and 12a provided on both outer surfaces of the bag-shaped film substrate 10 may be the same, or may be made of different materials on both sides. If the adhesive 11a on the side to be attached to the brittle member 2 at the time of peeling is selected so that the peeling force is smaller than the adhesive 12a provided on the hard plate 3 side, it is hard When the plate 3 is peeled from the brittle member 2, the adhesive sheet 1 remains on the hard plate 3 side and is peeled off without remaining on the brittle member 2 side, so that the adhesive sheet 1 is removed from the brittle member 2 again. The process of peeling becomes unnecessary.

  In the present invention, the brittle member 2 may be reinforced by further bonding a protective tape or the like on the brittle member 2.

  In the processing method of the present invention, as described above, the brittle member 2 is fixed on the hard plate 3 via the adhesive sheet 1. The order in this case is not particularly limited, and the brittle member 2 may be attached to the hard plate 3 to which the adhesive sheet 1 has been attached in advance, or vice versa. When the brittle member 2 is a semiconductor wafer having a circuit formed on the surface, the circuit surface side is bonded to the adhesive sheet 1 to protect the circuit surface.

  Next, an arbitrary treatment is performed on the brittle member 2. This process varies depending on the use of the brittle member 2, and includes various processing processes, conveyance, storage, and the like. For example, in the case where the brittle member 2 is a semiconductor wafer having a circuit formed on the surface, the processing includes etching, polishing, sputtering, vapor deposition, and grinding on the wafer back surface. If the processing applied to the brittle member 2 is storage or transportation, a protective tape or the like is further bonded to the brittle member 2 to reinforce the brittle member 2 prior to such processing. Also good.

  Thereafter, the hard plate 3 is peeled from the brittle member 2. Prior to the peeling step, as shown in FIG. The fluid may be a liquid such as water, or a gas such as air or nitrogen gas. The introduction of the fluid may be performed by press-fitting the fluid into the inner space of the bag-like film base material 10 through a hollow needle such as an injection needle, and as will be described later, the fluid is communicated with the inner space of the bag-like film base material. An opening may be provided in advance, and fluid may be introduced through the opening.

  By introducing a fluid into the internal space of the bag-shaped film substrate 10, the pressure-sensitive adhesive sheet 1 expands in a balloon shape. As a result, since the bonding area between the brittle member 2 and the pressure-sensitive adhesive sheet 1 is reduced, the brittle member 2 can be easily peeled off, and damage during the brittle member peeling is prevented. Further, the end of the brittle member 2 is peeled off from the pressure-sensitive adhesive sheet 1 by deformation of the pressure-sensitive adhesive sheet 1. Since peeling can be performed starting from this end, the peeling operation is facilitated.

  When either or both of the pressure-sensitive adhesive layers 11a and 12a are formed of an ultraviolet curable pressure-sensitive adhesive, the pressure-sensitive adhesive sheet 1 is irradiated with ultraviolet rays before the introduction of the fluid or the brittle member 2 is peeled off. Thereby, since adhesive force reduces, peeling of the brittle member 2 becomes still easier.

  Next, the preferable aspect of the bag-like film base material 10 is demonstrated about the adhesive sheet 1 used by this invention.

  As described above, the bag-shaped film substrate 10 normally expands by tightly integrating the two films to form a substantially vacuum internal space and introducing a fluid into the internal space by a required operation. It is a structure.

  Such a bag-shaped film substrate 10 has a first film 11 and a second film 12 as shown in the cross-sectional views of FIGS. The bag-shaped film base material formed is mention | raise | lifted. In FIG. 1 and FIG. 2, reference numeral 13 in the peripheral portion at the contact surface between the first film 11 and the second film 12 indicates the binding portion 13 between the first film 11 and the second film 12. . In the normal state, the first film 11 and the second film 12 are airtightly closely integrated. That is, the bag-like film substrate is a laminated film in which two films are bound and fixed at the peripheral edge. The binding portion 13 is provided so as to be located outside the outer edge of the brittle member 2 to be stuck.

  The 1st film 11 and the 2nd film 12 will not be specifically limited if it is a resin film which does not permeate | transmit a fluid, Various resin films can be used. Examples of such resin films include polyolefins such as low density polyethylene, linear low density polyethylene, polypropylene, and polybutene, ethylene vinyl acetate copolymers, ethylene (meth) acrylic acid copolymers, and ethylene (meth) acrylic acid. Examples thereof include ethylene copolymers such as ester copolymers, polyesters such as polyethylene terephthalate and polyethylene naphthalate, and resin films such as polyvinyl chloride, acrylic rubber, polyamide, urethane, and polyimide. In addition, each of the film 11 and the film 12 may be a single layer or a laminate. Moreover, the film which gave the process of bridge | crosslinking etc. may be sufficient. Further, the first film 11 and the second film 12 may be a film obtained by forming a thermoplastic resin into a sheet by extrusion molding, or a film obtained by thinning and curing a curable resin by a predetermined means. May be used. Examples of the curable resin include a resin composition in which an energy ray-curable urethane acrylate oligomer is a main component, an acrylate monomer having a relatively bulky group is a diluent, and a photopolymerization initiator is blended as necessary. Used.

  The first film 11 and the second film 12 may be formed of the same type of resin film, or may be formed of different types of resin films as long as they can be bonded and closely integrated.

  The thickness of each of the first film 11 and the second film 12 is preferably 5 to 200 μm, more preferably 10 to 150 μm, and particularly preferably 20 to 100 μm. Therefore, the total thickness of the first film 11 and the second film 12 is preferably 10 to 400 μm, more preferably 20 to 300 μm, and particularly preferably 40 to 200 μm.

  The binding between the first film and the second film may be fusion by heat or adhesion by an adhesive. When using an adhesive, it is preferable to use a strong adhesive such as acrylic.

  The bag-shaped film substrate 10 is formed by, for example, superimposing the first film 11 and the second film 12 and thermocompression bonding the first film 11 and the second film 12 with a thermocompression bonding apparatus provided with a ring-shaped heating unit. Is obtained. Moreover, the bag-shaped film base material 10 can also be obtained by forming an adhesive layer in a ring shape on one film surface and laminating the other film. After manufacturing the bag-shaped film substrate 10, the substrate may be cut along the outer diameter of the binding portion.

  The binding portion 13 between the first film 11 and the second film 12 is a bag as shown in a plan view (a plan view at the contact surface between the first film 11 and the second film 12) in FIG. It may be provided on the entire circumference of the peripheral edge of the film-like film substrate 10. The binding portion 13 may have a portion from which a part of the fluid is removed, but it is preferable that the binding portion 13 is continuously provided on the entire periphery of the peripheral portion. In the inner region surrounded by the binding portion 13, the first film 11 and the second film 12 are hermetically tightly integrated, and an internal space having a volume of 0 (zero) is formed in a substantially vacuum. .

  In the present invention, the brittle member 2 is peeled by introducing a fluid into the internal space of the bag-shaped film substrate 10 to expand the adhesive sheet 1. When the entire periphery of the peripheral portion of the bag-shaped film substrate 10 is bound, the introduction of the fluid is performed by inserting a hollow needle such as an injection needle into the bag-shaped film substrate 10 and allowing the fluid to pass through the bag-shaped film substrate 10. This is performed by press-fitting into the internal space of the material 10.

  In order to introduce a fluid into the internal space, as shown in FIG. 4, an opening 14 that communicates with the internal space may be provided at a part of the peripheral edge of the bag-shaped film substrate 10. When the opening 14 binds the peripheral portion of the bag-shaped film base material 10, a non-binding portion (a portion where the first film 11 and the second film 12 are not bonded) is partly formed. It is formed by providing. For example, the non-binding portion is formed by providing a cutout portion in a part of the ring-shaped heating portion described above, or by providing a cutout portion in a part of the ring-shaped adhesive layer. It can be formed simultaneously with the binding with the second film 12.

  When the processing of the brittle member 2 in the present invention is back grinding of a semiconductor wafer, stress is applied to the semiconductor wafer in the shearing direction (lateral direction) and simultaneously the bag-like film substrate 10 is also sheared. The stress propagates. As a result, the film may slip on the contact surface between the first film 11 and the second film 12, and the film may be misaligned. When such a positional shift of the film occurs, it becomes impossible to grind the back surface of the wafer.

In order to prevent the positional displacement of the film as described above, the coefficient of static friction between the contact surfaces of the first film 11 and the second film 12, that is, the inner surfaces of the bag-like film substrate 10, is preferably 0. 1 or more, more preferably 0.15 or more, particularly preferably 0.2 or more. Here, the coefficient of static friction between the inner surfaces of the bag-shaped film substrate 10 is a value measured according to JIS K 7125 at the contact surface between the first film 11 and the second film 12. Static friction means the friction when exceeding the “threshold value” at the start of sliding, and the static friction coefficient is a coefficient obtained from the “threshold value” and is defined by μ _S = F _s / F _p . Here, μ _S is a static friction coefficient, F _s is a static friction force, and F _p is a normal force generated by the mass of the sliding piece. The measurement conditions for the static friction coefficient will be described more specifically with reference to the static friction coefficient measuring apparatus shown in FIG.

The static friction coefficient measuring device 20 shown in FIG. 9 includes a horizontal table 21, a sliding piece 22, and a drive mechanism (not shown) that moves the table 21 in the horizontal direction. The sliding piece 22 has a contact area (bottom area) of 40 cm ² (length of one side of 63 mm) and a bottom surface covered with a felt 22a, and has a total mass of 200 ± 2 g. The test films 23 and 24 are each one of the first film 11 and the second film 12, and the test film 23 is set so as to cover the bottom surface of the sliding piece 22. The size of the test film 23 is 63 mm × 80 mm, and the size of the test film 24 is 80 mm × 100 mm. The test films 23 and 24 are set so that when the bag-shaped film substrate 10 is configured, the surfaces that are the contact surfaces of the first film 11 and the second film 12 are in contact with each other. The sliding piece 22 on which the test film 23 is set is connected to a load cell 26 via a spring 25. The spring constant of the spring 25 is 0.2 N / mm. After the static friction coefficient measuring device 20 is configured as described above, the table 21 is moved horizontally at 100 mm / min, and the load is read by the load cell 26. From the measured value, the coefficient of static friction is calculated according to JIS K 7125.

  The surfaces of the first film 11 and the second film 12 may be subjected to blast treatment, corona treatment, coating treatment, plasma treatment, electron beam treatment, etc. in order to obtain a desired coefficient of static friction.

  Similarly, in order to prevent positional displacement of the film, in the inner peripheral portion A of the bag-shaped film base material 10, as shown in a sectional view in FIG. 5 and a plan view in FIG. The film 12 may be spot-bound. In addition, the inner peripheral part A of the bag-shaped film substrate 10 means an internal region surrounded by the binding part 13. In FIG. 6, the dot-like spot-like binding portion 15 is shown. The binding between the first film 11 and the second film 12 may be fusion by heat as in the case of the peripheral portion, or may be adhesion by an adhesive.

  The spot-like binding portion 15 may be formed in a dot shape as shown in FIG. 6, or may be a stripe shape (FIG. 7) or a radial shape (FIG. 8). These spot-like binding portions 15 are formed in an arrangement that does not inhibit the introduction of the fluid.

  The spot-like binding part 15 is a thermocompression bonding apparatus provided with a heating part corresponding to the shape and arrangement of the spot-like binding part, for example, by overlapping the first film 11 and the second film 12. And the second film 12 are obtained by thermocompression bonding. At this time, the peripheral edge may be bound at the same time. Also, by forming a ring-shaped adhesive layer on one film surface and an adhesive layer corresponding to the shape and arrangement of the spot-like binding part, and laminating the other film, Alternatively, the spot-like binding portion 15 can be formed.

  When the processing of the brittle member 2 in the present invention is back grinding of a semiconductor wafer, the bag-shaped film substrate 10 is required to have a high degree of thickness accuracy. That is, when the thickness accuracy of the bag-shaped film substrate 10 is low, the unevenness of the bag-shaped film substrate 10 also affects the wafer held on the bag-shaped film substrate 10 and ground on the back surface. It may not be possible to grind to a proper thickness. In particular, as described above, when the spot-like binding portion 15 is formed on the inner peripheral portion of the bag-shaped film substrate 10 to which the brittle member 2 is fixed, the thickness accuracy of the bag-shaped film substrate 10 is likely to be lowered. For this reason, it is preferable to perform the binding between the first film and the second film by heat fusion. According to heat fusion, since the total thickness of the film is substantially maintained, a bag-shaped film substrate with high thickness accuracy can be obtained. Moreover, even when the binding between the first film and the second film is performed with an adhesive, the thickness accuracy of the bag-like film substrate is reduced by reducing the thickness of the adhesive layer as much as possible. improves.

  The specific examples and preferred examples of the bag-like film substrate 10 used in the present invention have been described above.

The pressure-sensitive adhesive sheet according to the present invention is a double-sided pressure-sensitive adhesive sheet having the bag-shaped film base material as a core material, and as a preferred embodiment thereof,
A bag-like film base material 10 having a first film 11 and a second film 112, and having peripheral edges bound to each other;
The adhesive layer 11a, 12a formed on both outer surfaces of the bag-shaped film substrate 10,
An adhesive sheet in which an opening 14 communicating with the internal space of the bag-shaped film substrate 10 is provided in a part of the peripheral edge of the bag-shaped film substrate 10 is exemplified.

Moreover, as another preferable aspect,
A bag-like film base material 10 having a first film 11 and a second film 12, and having peripheral edges bound to each other;
The adhesive layer 11a, 12a formed on both outer surfaces of the bag-shaped film substrate 10,
Examples thereof include a pressure-sensitive adhesive sheet in which the first film 11 and the second film 12 are spot-bound on the inner peripheral portion of the bag-shaped film substrate 10.

  In the present invention, since the brittle member is fixed and protected to the hard plate through the pressure-sensitive adhesive sheet having an air-tight bag-like film substrate, the brittle member is removed during transportation, storage and processing of the brittle member. Can be held without deformation. In addition, after the required treatment, fluid is introduced into the air-tight bag-like film base material and the bag-like film base material is expanded to reduce the bonding area between the brittle member and the pressure-sensitive adhesive sheet. Separation of the member is facilitated, and breakage of the brittle member is prevented.

One process of the processing method of the brittle member of this invention is shown. One process of the processing method of the brittle member of this invention is shown. The top view of a bag-shaped film base material is shown. The top view of the bag-shaped film base material which concerns on a modification is shown. One process of the processing method of the brittle member which concerns on the example of a change is shown. The top view of the bag-shaped film base material which concerns on a modification is shown. The top view of the bag-shaped film base material which concerns on a modification is shown. The top view of the bag-shaped film base material which concerns on a modification is shown. 1 shows a static friction coefficient measuring device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Adhesive sheet 10 ... Bag-shaped film base material 11 ... 1st film 11a ... Adhesive layer 12 ... 2nd film 12a ... Adhesive layer 13 ... Conclusion Wearing part 14 ... Opening part 15 ... Spot-like binding part 2 ... Brittle member 3 ... Hard plate 20 ... Static friction coefficient measuring device 21 ... Table 22 ... Sliding piece 22a ... Felt 23 ... Test film 24 ... Test film 25 ... Spring 26 ... Load cell A ... Inner circumference of bag-like film substrate

Claims (8)

Fixing the brittle member to one side of the pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer formed on both outer surfaces of the air-tight bag-like film substrate so as to be removable, and fixing the hard plate to the other surface so as to be removable again;
Processing the brittle member;
Introducing a fluid into the internal space of the bag-shaped film substrate and inflating the adhesive sheet;
The processing method of a brittle member including the process of peeling the processed brittle member from an adhesive sheet.   The processing method according to claim 1, wherein the brittle member is a semiconductor wafer, and the processing applied to the semiconductor wafer is back grinding of the semiconductor wafer or conveyance of the semiconductor wafer. It is an adhesive sheet used for the processing method according to claim 1,
A bag-like film base material having a first film and a second film, the peripheral edges of which are bound, and
A pressure-sensitive adhesive sheet comprising pressure-sensitive adhesive layers formed on both outer surfaces of the bag-like film substrate.   The pressure-sensitive adhesive sheet according to claim 3, wherein an opening that communicates with the internal space of the bag-shaped film is provided in a part of the peripheral edge of the bag-shaped film substrate.   The pressure-sensitive adhesive sheet according to claim 3, wherein a coefficient of static friction between the inner surfaces of the bag-shaped film substrate is 0.1 or more.   The pressure-sensitive adhesive sheet according to claim 3, wherein the first film and the second film are spot-bound on the inner peripheral portion of the bag-shaped film substrate. A bag-like film base material having a first film and a second film, the peripheral edges of which are bound, and
It consists of an adhesive layer formed on both outer surfaces of the bag-like film substrate,
A pressure-sensitive adhesive sheet in which an opening communicating with the internal space of the bag-shaped film substrate is provided in a part of the peripheral edge of the bag-shaped film substrate. A bag-like film base material having a first film and a second film, the peripheral edges of which are bound, and
It consists of an adhesive layer formed on both outer surfaces of the bag-like film substrate,
A pressure-sensitive adhesive sheet in which the first film and the second film are spot-bound on the inner peripheral portion of the bag-shaped film substrate.

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