KR101169479B1 - Adhesive sheet for dicing - Google Patents

Abstract

An object of the present invention is to provide a dicing adhesive sheet capable of completely preventing fracture during an expanding process, a method for processing a cut single body using the same, and a cut single piece obtained by the method.

It is comprised with the adhesive layer 2 in at least one surface of the base material 1, It is the dicing adhesive sheet 11 used at the time of the process of a cut body, The tensile elasticity modulus of the said base material 1 is 50-250 Mpa, It is characterized by breaking elongation of 200% or more, and breaking resistance of 2.5 or more represented by the following formula.

[Equation 1]

Breaking resistance = [breaking strength of the base material 1] / [tensile strength at 30% of tensile elongation of the base material 1]

Base material, pressure-sensitive adhesive layer, pressure-sensitive adhesive sheet for dicing, single cut piece, semiconductor chip

Description

Adhesive sheet for dicing {ADHESIVE SHEET FOR DICING}

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows the outline of the adhesive sheet for dicing which concerns on embodiment of this invention.

Fig. 2 is a graph showing the relationship between tensile elongation and tensile strength of the base film in the dicing adhesive sheet.

Figure 3 (a) is an explanatory view showing the expansion of the dicing adhesive sheet attached to the semiconductor wafer, Figure 3 (b) is a semiconductor chip and the dicing ring is adhesively fixed to the dicing adhesive sheet Floor plan showing the appearance.

4A is a cross-sectional view showing a semiconductor chip and a dicing adhesive sheet after dicing, and FIG. 4B is a cross-sectional view showing a state of an expanded semiconductor chip and a dicing adhesive sheet.

5 is a graph showing a relationship between tensile elongation and tensile strength in a base film of a pressure-sensitive adhesive sheet for dicing according to an embodiment.

<Explanation of symbols for the main parts of the drawings>

1: base film (base material)

2: Pressure-sensitive adhesive layer

3: separator

11: adhesive sheet for dicing

12: semiconductor chip

13: dicing ring

14: outer ring

15: inner ring

16: dicing street

[Document 1] Japanese Unexamined Patent Application Publication No. 5-156214

[Document 2] Japanese Unexamined Patent Publication No. 11-43656

[Document 3] Japanese Unexamined Patent Publication No. 2000-124169

TECHNICAL FIELD This invention relates to the dicing adhesive sheet, the processing method of the cut single piece using the same, and the cut single piece obtained by the method.

BACKGROUND ART Conventionally, a semiconductor wafer made of silicon, gallium, arsenic, or the like is manufactured in a large diameter state, and then cut and diced into element pieces and then moved to a mounting process. At that time, each step of the dicing step, the cleaning step, the expansion step, the pick-up step, and the mounting step is carried out while the semiconductor wafer is attached to and held on the dicing adhesive sheet (hereinafter referred to as "adhesive sheet"). . As the pressure-sensitive adhesive sheet, an acrylic adhesive or the like is applied onto a substrate made of a plastic film, and a pressure-sensitive adhesive layer having a thickness of about 1 to 200 μm is generally used.

In the said dicing process, a semiconductor wafer is cut | disconnected by the round knife which moves while rotating, and formation of a semiconductor chip is performed. In the said process, the cutting system called full cut which cuts in into the base material of the adhesive sheet holding a semiconductor wafer becomes the mainstream.

In the expansion step, the pressure-sensitive adhesive sheet is expanded for the purpose of securing a sufficient chip spacing and easily picking up the semiconductor chip to be performed thereafter. However, in the cutting method by full cut, since the incision is performed to the inside of an adhesive sheet, when the adhesive sheet is going to expand large, the adhesive sheet might break from the cut part. As a result, the semiconductor chip cannot be picked up in the pick-up step, and there is a problem that the workability and the yield of processing are significantly reduced.

In order to avoid the said problem, in the conventional adhesive sheet, the base film which consists of polyvinyl chloride has been used. However, when such an adhesive sheet is stored for a long time in a state where it is attached to a semiconductor wafer, additives such as a plasticizer contained in vinyl chloride move to the adhesive layer, resulting in deterioration of adhesive properties. As a result, chip scattering at the time of dicing and peeling failure at the time of pick-up may occur.

In order to solve the change with the passage of time of the adhesive characteristic in an adhesive sheet, for example, the following patent document 1 discloses the adhesive sheet for wafer adhesion using the ethylene methyl methacrylate copolymer film as a base film. . In addition, Patent Document 2 discloses a pressure sensitive adhesive sheet for wafer adhesion using a non-stretched polypropylene layer as a base film. However, none of these prior art considers workability in the expand process. Moreover, when a semiconductor wafer was processed using each adhesive sheet for wafer adhesion disclosed by these prior arts, the break | disconnection of the adhesive sheet for wafer adhesion was actually generate | occur | produced in the expansion process.

Moreover, in following patent document 3, it is a dicing tape containing a base material sheet and the adhesive layer provided on the one side surface, The upper layer contacting an adhesive layer, The intermediate | middle layer provided in the lower part of this upper layer, and the lower part of this intermediate | middle layer Disclosed is a dicing tape having a base sheet composed of a lower layer provided on the substrate. Moreover, in the said dicing tape, the anti-elongation (A) of an upper layer and the anti-elongation (B) of an intermediate | middle layer regarding the anti-elongation (product of tensile modulus (Young's modulus) and thickness) represented by the product of an elasticity modulus and a layer thickness. ) And that the anti-elongation (C) of the lower layer satisfies the relationship of B <A ≤ C. According to Patent Document 3, in the expansion step in dicing, the spacing of the dicing lines can be widened uniformly and sufficiently without being affected by the elastic modulus of the pressure-sensitive adhesive, and breakage in the dicing lines is unlikely to occur. Is described. However, even when the dicing tape of the above configuration is not sufficient to break the elongation of each layer constituting the base film, or when the breaking strength is not large enough compared with the tensile modulus, the dicing tape is broken in the expansion step This may occur. That is, even the dicing tape of the said structure is inadequate prevention of the fracture at the time of an expansion process.

[Patent Document 1]

Japanese Patent Laid-Open No. 5-156214

[Patent Document 2]

Japanese Patent Laid-Open No. 11-43656

[Patent Document 3]

Japanese Patent Laid-Open No. 2000-124169

The present invention has been made in view of the above problems, and an object thereof is to provide a dicing adhesive sheet capable of completely preventing fracture during an expanding process, a method for processing a cut single body using the same, and a cut single piece obtained by the method. have.

MEANS TO SOLVE THE PROBLEM In order to solve the said conventional problem, the present inventors examined the adhesive sheet for dicing, the processing method of the cut single body using the same, and the cut single piece obtained by the method. As a result, by discovering that the tensile physical property value of a base material can be controlled in a predetermined range, the breakage at the time of the expansion process insufficient in the conventional dicing adhesive sheet was completely prevented, and the present invention was completed.

That is, the adhesive sheet for dicing which concerns on this invention is an adhesive sheet for dicing which is comprised with an adhesive layer in at least one surface of a base material, and is used at the time of processing of a cut body, in order to solve said subject, and the tensile elasticity modulus of the said base material is It is 50-250 Mpa, Elongation at break is 200% or more, It is characterized by the breakthrough resistance represented by a following formula at 2.5 or more.

[Equation 1]

Breaking resistance = (break strength of the substrate) / (tensile strength at 30% of tensile elongation of the substrate)

In the said structure, it is preferable that the yield point elongation of the said base material is 30% or more. Here, the yield point elongation of a base material is read out from the yield point in the S-S curve obtained by the tensile force test based on JISK7126 under predetermined conditions.

Moreover, in the said structure, it is preferable that the said base material contains at least 1 sort (s) or more chosen from the group which consists of a polypropylene thermoplastic elastomer, an acrylic resin, and a polyester thermoplastic elastomer.

Moreover, in the said structure, it is preferable that the thickness of the said adhesive layer is 1 micrometer or more, and is 1/3 or less of the thickness of the said base material.

Moreover, in the said structure, it is preferable that the said adhesive layer is comprised including the radiation-curable adhesive.

Moreover, the processing method of the cut single body which concerns on this invention is an adhesive sheet for dicing which is comprised with an adhesive layer in at least one surface of a base material, and solves the said subject, and is used at the time of processing of a cut single body, The tension of the said base material A step of attaching a pressure-sensitive adhesive sheet for dicing to a cut single body having an elastic modulus of 50 to 250 MPa, an elongation at break of 200% or more, and a cut resistance of 2.5 or more represented by the following formula; A step of forming the cutting to the base material of the dicing pressure sensitive adhesive sheet from the side of the cut single body, and expanding the dicing pressure sensitive adhesive sheet to separate the intervals of the individual cut pieces that are adhesively fixed to the dicing pressure sensitive adhesive sheet. Characterized in that it has a step of widening and a step of peeling the cut piece of small piece provided with the pressure-sensitive adhesive layer from the base material. .

&Quot; (2) &quot;

Breaking resistance = (break strength of the substrate) / (tensile strength at 30% of tensile elongation of the substrate)

In the said method, it is preferable that the yield point elongation of the said base material is 30% or more.

Moreover, in the said method, it is preferable that the said base material contains at least 1 sort (s) or more chosen from the group which consists of a polypropylene thermoplastic elastomer, an acrylic resin, and a polyester thermoplastic elastomer.

Moreover, in the said method, it is preferable that the thickness of the said adhesive layer is 1 micrometer or more, and is 1/3 or less of the thickness of the said base material.

Moreover, in the said method, it is preferable that the said adhesive layer is comprised including the radiation-curable adhesive.

In the above method, a semiconductor element can be used as the cut body.

Moreover, the cut single piece which concerns on this invention was produced by the processing method of the cut single piece as described in order to solve the said subject, It is characterized by the above-mentioned.

The present invention will be described below with reference to the drawings. The adhesive sheet 11 for dicing of this invention is a structure which has the adhesive layer 2 in at least one surface of the base film (base material) 1, as shown in FIG. The inventors of the present application examine the physical properties of the base film 1, the dicing conditions when dicing a semiconductor wafer (semiconductor element) as a cut body, and the expand conditions when expanding a dicing adhesive sheet. The mechanism by which breakage of the pressure sensitive adhesive sheet 11 for dicing occurs is explained. First, the base film 1 was subjected to a tensile test with a tensile tester, and measured for tensile elongation and tensile strength. As a result, for example, a stretch-strength curve (hereinafter referred to as an "S-S curve") shown in FIG. 2 was obtained. 1 is a graph showing the relationship between tensile elongation and tensile strength. When the base film 1 expands by addition of the tensile load, it breaks at the point represented by the breaking strength and the breaking elongation in the S-S curve of FIG. The breaking of the adhesive sheet 11 for dicing after dicing which arises at the time of expansion is also produced by the breaking of the said base film 1.

The expansion of the dicing adhesive sheet 11 is performed as shown, for example in FIG.3 (a) and FIG.3 (b). FIG. 3A is an explanatory view showing an expanded state of the dicing adhesive sheet 11 attached to a semiconductor wafer, and FIG. 3B is a plurality of semiconductor chips (small piece of cut piece) and a die. It is a top view which shows the state in which the Singh ring is adhesively fixed to the adhesive sheet 11 for dicing. The plurality of semiconductor chips 12 formed by dicing the semiconductor wafer are adhesively fixed to the dicing adhesive sheet 11. Moreover, the dicing ring 13 is carried out to the dicing adhesive sheet 11 for dicing from the area | region where the some semiconductor chip 12 is adhesively fixed to the outside of the formation area | region of each semiconductor chip 12 through a predetermined | prescribed area | region. The adhesive is fixed. Expanding is performed using the conventionally well-known expander, after irradiating the radiation to the adhesive sheet 11 for dicing as needed. The expander is a donut-shaped outer ring 14 capable of pressing down the dicing adhesive sheet 11 downward through the dicing ring 13 and a dicing adhesive smaller than the outer ring 14. It has an inner ring 15 for supporting the seat 11.

The expansion is performed as follows. First, the outer ring 14 is positioned at a sufficient distance above the inner ring 15 to the extent that the adhesive sheet 11 for dicing can be interposed. Next, between the outer ring 14 and the inner ring 15, the adhesive sheet 11 for dicing with which the semiconductor chip 12 and the dicing ring 13 was adhesively fixed is interposed. At this time, the area | region to which the semiconductor chip 12 is adhesively fixed is set so that it may be located in the center part of the inner ring 15. FIG. Thereafter, the outer ring 14 moves downward along the inner ring 15 and simultaneously pushes the dicing ring 13 down. As the dicing ring 13 is pressed down, the pressure-sensitive adhesive sheet 11 for dicing is enlarged due to the difference in altitude between the dicing ring and the inner ring to expand. The purpose of the expansion is to prevent the semiconductor chips 12 from coming into contact with each other and being damaged during pickup.

The gap (hereinafter referred to as a "dicing street") 16 of each semiconductor chip 12 formed by dicing is also based on the thickness of the dicing blade (blade), but is generally 15 to 60 µm [Fig. 4 (a)]. When the adhesive sheet 11 for dicing which the semiconductor chip 12 is adhesively fixed is expanded, the width of the dicing street 16 expands to about 100-500 micrometers (refer FIG. 4 (b)). The insertion depth of the outer ring 14 into the inner ring 15 during expansion is appropriately adjusted by the dicing ring inner diameter, the size of the semiconductor wafer, the size of the semiconductor chip 12, the number of dicing streets, and the like. . For example, when processing a semiconductor wafer as a semiconductor wafer using a conventional expander, the insertion depth is generally set to about 2 to 15 mm, more preferably about 5 to 10 mm. The insertion depth can be appropriately set according to the semiconductor chip size, the number of dicing streets, the productivity, and the like.

The area | region extended in the adhesive sheet 11 for dicing at the time of expansion is attached to the semiconductor chip 12, such as the area | region between the dicing street 16, the dicing ring 13, and the semiconductor chip 12, It is limited to the area which is not. The region where each semiconductor chip 12 is bonded and fixed is not expanded.

At the time of dicing of a semiconductor wafer, cutting is performed to the depth of about 1/4 to 1/2 of the thickness with respect to the base film 1 of the adhesive sheet 11 for dicing, for example. At the time of expansion, first, the portion of the dicing street 16 is opened in a V shape and expanded. However, it is difficult to make the space | interval of each semiconductor chip 12 into sufficient interval only by extending the part of the dicing street 16. FIG. Accordingly, the dicing of the pressure-sensitive adhesive sheet 11 for dicing is continued until the above gap is sufficiently widened. Here, when the dicing street 16 does not have a breaking elongation enough to cope with the expansion by expansion, the dicing adhesive sheet 11 breaks at the portion of the dicing street 16. .

In addition, even if the fracture elongation of the base film 1 is increased to sufficiently correspond to the above-described expansion, for the convenience of processing many kinds of semiconductor wafers having different chip sizes, the number of dicing streets, and the like when expanding, Therefore, expansion may be performed even after the dicing street 16 reaches a predetermined width. Also in the case where the expansion is carried out, if only the portion of the dicing street 16 is to be coped with, elongation to break several times to several tens of times is further required. Therefore, the correspondence is difficult in the base film which consists of a general plastic film.

Here, the inventors pay attention to the SS curve illustrated in Fig. 1, and before dicing street 16 breaks, the dicing adhesive sheet 11 has a strength balance in which the area in the outer peripheral portion of the semiconductor wafer extends, thereby dicing. The method which can completely prevent the fracture of the adhesive sheet 11 was discovered. That is, in this invention, the breaking elongation of the base film 1 is made into 200% or more, Preferably it is 400% or more. Moreover, cut-in degree of the base film 1 shall be 2.5 or more, Preferably it is three or more. Thereby, the intensity | strength balance which the area | region in the outer peripheral part of the semiconductor wafer of the dicing adhesive sheet 11 expands before the dicing street 16 reaches breaking is attained. The value of the elongation at break can be increased or decreased within the above range by, for example, controlling the molecular orientation occurring during film formation. In addition, it is preferable that breaking elongation falls in the said numerical range in MD direction and TD direction, respectively.

The break-in degree of the base film 1 is an index indicating the expand resistance of the base film 1 to the depth of cut, and can be obtained by the following formula. For example, the depth of cut means to withstand cutting and leaving up to one inverse. For example, when the cutting depth is 3, it indicates that the substrate film 1 is cut in 1/3 and left, that is, even if it is cut to 2/3 of its thickness with respect to the substrate film 1, it is sufficiently endurable to expand.

&Quot; (3) &quot;

Breaking resistance = [breaking strength of base film 1] / [tensile strength at 30% of tensile elongation of base film 1]

In this invention, making cut-in resistance of the base film 1 into 2.5 or more is based on the following reason. That is, if the tensile strength which leads to breaking of the base film 1 exceeds the tensile strength required in order to expand the area | region in the outer peripheral part of the semiconductor wafer in the adhesive sheet 11 for dicing to 30% of tensile elongation, It is possible to prevent break of the film 1. This is the same also in the part of the dicing street 16 where the cutting is performed to the depth of about 1/4 to 1/2 of the thickness of the base film 1, for example. In other words, it is necessary for the value of 3/4-1/2 of the breaking strength in the state which is not cut to exceed the tensile strength at the time of extending | stretching to 30% of tensile elongation. Therefore, considering the error of the depth of cut and the like, the breaking strength is preferably 2.5 times or more, preferably 3 times or more of the tensile strength when the tensile elongation is expanded to 30%. That is, in this invention, the cut-in degree of the base film 1 shall be 2.5 or more, Preferably it is three or more. In addition, it is preferable that the break-in degree falls within the numerical range in each of the MD direction and the TD direction.

In addition, in this invention, the tensile elasticity modulus of the base film 1 is 50-250 Mpa, Preferably it is 80-150 Mpa. Pickup can be performed favorably by setting tensile modulus in the range of 50-250 Mpa. Moreover, while using the base film which does not have a yield point in the extension | stretching elongation between 0 to less than 30%, the tensile elasticity modulus is in the said numerical range, and the yield point elongation of the base film 1 is made into 30% or more. It is preferable. Thereby, with expansion of the dicing street 16 at the time of expansion, it becomes possible to gradually expand the semiconductor wafer outer peripheral portion. In addition, the value of the tensile elasticity modulus can be increased or decreased within the said range by adjusting the molecular structure (hard segment, soft segment ratio, etc.) of resin which comprises the base film 1, for example. In addition, it is preferable that the tensile modulus falls within the numerical range in each of the MD direction and the TD direction. The yield point elongation of the base film 1 is read from the yield point in the S-S curve obtained by the tension test based on JISK7126 under predetermined conditions. The value of yield point elongation can be increased or decreased within the said range by adjusting the molecular structure of resin which comprises the base film 1 similarly to a tensile elasticity modulus, for example. In addition, yield point elongation should just be 30% or more in either MD direction or TD direction.

As the said base film 1, it is preferable to contain at least 1 sort (s) of polymer chosen from the group which consists of a polypropylene thermoplastic elastomer, an acrylic resin, and a polyester thermoplastic elastomer. As content of the said polymer, when it contains only one type, it is preferable that the ratio which occupies for the whole base film 1 is 30 wt% or more. Moreover, when using two or more types of the said polymers, it is preferable to set it as 30 wt% or more of the ratio which the sum total of those content occupies for the base film 1 whole.

As said polypropylene thermoplastic elastomer, a propylene-SEBS copolymer, a propylene-SEPS copolymer, a propylene-EPR copolymer, etc. are mentioned, for example. As said acrylic resin, the copolymer of methacrylic resin, various acrylic acid ester, etc. are mentioned. Examples of the polyester-based thermoplastic elastomers include TPEE (thermoplastic ester elastomer) composed of PBT (polybutylene terephthalate) -PE (polyether) -PBT.

The base film 1 may have any laminated structure among a single layer and a multilayer. When it is set as a multilayer structure, it is preferable to consist of an odd layer. In the case of an odd layer, it is more preferable to have a control structure in which a layer made of the same physical properties, constituent materials, and the like is laminated on both sides so as to be contrasted with respect to the center layer. Moreover, when the adhesive layer 2 is a radiation curing type, it is preferable to use what transmits at least one part of radiation, such as X-rays, an ultraviolet-ray, an electron beam.

In the base film 1, various additives such as softeners such as mineral oil, fillers such as calcium carbonate, silica, talc, mica, clay, antioxidants, light stabilizers, antistatic agents, lubricants, dispersants, neutralizers, and colorants may be used as necessary. It may be combined. Moreover, you may apply an antistatic agent, a coloring agent, etc. as needed.

Although the thickness of the base film 1 is not specifically limited and can be determined suitably, Generally, it is 10-300 micrometers, Preferably it is about 50-200 micrometers.

In addition, the base film 1 may be used without extending | stretching, and you may perform a uniaxial or biaxial stretching process as needed. The surface of the substrate film 1 thus produced can be subjected to conventional physical or chemical treatments such as mat treatment, corona discharge treatment, primer treatment, crosslinking treatment and the like as necessary.

As a film forming method of the base film 1, a conventionally well-known method can be employ | adopted. Specifically, calender film forming, casting film forming, inflation extrusion, T-die extrusion, or the like can be suitably used. In addition, when the base film 1 consists of a multilayer film, as a film forming method of the base film 1, the usual film lamination methods, such as a coextrusion method and a dry lamination method, can be used.

The adhesive layer 2 can use a well-known or usual adhesive. Although such an adhesive is not restrict | limited at all, Various adhesives, such as rubber type, an acryl type, silicone type, polyester type, polyvinyl acetate type, are used, for example.

As said adhesive, an acrylic adhesive is preferable. As the acrylic polymer that is the base polymer of the acrylic pressure sensitive adhesive, a copolymer of an alkyl (meth) acrylate or a copolymerizable monomer is usually used. As a main monomer of an acryl-type polymer, the alkyl (meth) acrylate whose glass transition temperature of this homopolymer is 20 degrees C or less is preferable.

As an alkyl group of (meth) acrylate, a methyl group, an ethyl group, a butyl group, 2-ethylhexyl group, an octyl group, an isononyl group, etc. are mentioned, for example. Moreover, as said copolymerizable monomer, hydroxyalkyl ester of (meth) acrylic acid (for example, hydroxyethyl ester, hydroxybutyl ester, hydroxyhexyl ester, etc.), (meth) acrylic acid glycidyl ester, (meth) ) Acrylic acid, itaconic acid, maleic anhydride, (meth) acrylic acid amide, (meth) acrylic acid N-hydroxymethylamide, (meth) acrylic acid alkylaminoalkyl (e.g., dimethylaminoethyl methacrylate, t-butylaminoethyl Methacrylate, etc.), vinyl acetate, styrene, acrylonitrile, acryloyl morpholine, etc. are mentioned.

As the pressure-sensitive adhesive, a radiation-curable pressure-sensitive adhesive or a heat-expandable pressure-sensitive adhesive that is cured by ultraviolet rays, electron beams, or the like can also be used. Thereby, when peeling the semiconductor chip 12 from the adhesive sheet 11 for dicing, the adhesive force of the said adhesive layer 2 can be reduced by irradiating radiation to the adhesive layer 2, or predetermined heating. As a result, the semiconductor chip 12 can be easily peeled off. Moreover, the adhesive which can be used for dicing and die-bonding may be sufficient. In this invention, it is preferable to use radiation curing type, especially ultraviolet curing type. In addition, when using a radiation curable adhesive as an adhesive, since the adhesive is irradiated before or after a dicing process, it is preferable that the said base film 1 has sufficient radiation transmittance.

The radiation curable pressure sensitive adhesive contains, for example, the base polymer (acrylic polymer) and a radiation curable component. The radiation hardening component can use a monomer, an oligomer, or a polymer which has a carbon-carbon double bond in a molecule | numerator, and can be hardened by radical polymerization without a restriction | limiting in particular. As a radiation hardening component, For example, trimethylol propane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1, 6- hexanediol di (meth) acrylate Esters of (meth) acrylic acid and polyhydric alcohols such as neopentyl glycol di (meth) acrylate and dipentaerythritol hexa (meth) acrylate; ester acrylate oligomers; Isocyanurs such as 2-propenyldi-3-butenylcyanurate, 2-hydroxyethylbis (2-acryloxyethyl) isocyanurate, tris (2-methacryloxyethyl) isocyanurate Elate or isocyanurate compound, urethane acrylate, etc. are mentioned.

In addition, the radiation curable pressure sensitive adhesive may be a radiation curable polymer having a carbon-carbon double bond in the polymer side chain as the base polymer (acrylic polymer), and in this case, it is not particularly necessary to add the radiation curable component.

In the case of curing the radiation curable pressure sensitive adhesive with ultraviolet rays, a photopolymerization initiator is required. As a photoinitiator, For example, benzoin alkyl ether, such as benzoin methyl ether, benzoin propyl ether, benzoin isobutyl ether: aromatic ketones, such as benzyl, benzoin, benzophenone, and (alpha)-hydroxycyclohexyl phenyl ketone ; Aromatic ketals such as benzyl dimethyl ketal; Polyvinyl benzophenone; Thioxanthones, such as a chloro thioxanthone, a dodecyl thioxanthone, a dimethyl thioxanthone, and a diethyl thioxanthone, etc. are mentioned.

The said adhesive can be made to contain common additives, such as a crosslinking agent, a tackifier, a filler, an antioxidant, and a coloring agent as needed. Examples of the crosslinking agent include polyisocyanate compounds, melamine resins, urea resins, aziridine compounds, epoxy resins, anhydrides, and polyaminecarboxyl group-containing polymers.

The thickness of the pressure-sensitive adhesive layer 2 can be appropriately set in consideration of the type of the pressure-sensitive adhesive and the depth of cut at the time of dicing. It is preferable that the thickness of the adhesive layer 2 is 1 micrometer or more specifically, and it is 1/3 or less of the thickness of the base film 1. By making thickness of the adhesive layer 2 into 1 micrometer or more, the adhesive force as the adhesive sheet 11 for dicing can be maintained. Moreover, by making the thickness of the adhesive layer 2 into 1/3 or less of the thickness of the base film 1, suppression that the tensile elasticity modulus, breaking strength, etc. of the adhesive layer 2 are reduced too much, and the base film 1 This characteristic can be sufficiently exhibited.

In the adhesive sheet 11 for dicing of this invention, you may laminate | stack the separator 3 on the adhesive layer 2 for the purpose of label processing, or for the purpose of making the adhesive layer 2 smooth. As a constituent material of the separator 3, synthetic resin films, such as paper, polyethylene, a polypropylene, and a polyethylene terephthalate, etc. are mentioned. In order to improve the peelability from the adhesive layer 2, the surface of the separator 3 may be subjected to peeling treatments such as silicon treatment, long chain acrylic treatment, and fluorine treatment as necessary. Moreover, you may laminate | stack by uniaxial or biaxial stretching process, another plastic film, etc. according to the purpose of raising rigidity. Although the thickness of the separator 3 is not specifically limited, For example, it is preferable that it is 10-200 micrometers, and it is more preferable that it is 25-100 micrometers.

In FIG. 1, although the adhesive layer 2 is provided in one side of the base film 1, the adhesive layer 2 can also be formed in both surfaces of the base film 1. As shown in FIG. Moreover, the dicing adhesive sheet 11 can also wind up a sheet, and can make it a tape shape.

In the adhesive sheet 11 for dicing of this invention, an adhesive is apply | coated to the surface of the base film 1, for example, it is made to dry (heat crosslinking as needed), and the adhesive layer 2 is needed, Therefore, it can manufacture by bonding a separator to the surface of this adhesive layer 2. Moreover, after forming the adhesive layer 2 in a separator separately, the method etc. which join them to the base film 1 can be employ | adopted.

Moreover, in the process of attaching the dicing adhesive sheet 11 to a semiconductor wafer, the semiconductor wafer fixed to the support wafer (support plate) is bonded to the dicing adhesive sheet 11 via a double-sided adhesive sheet, and this dicing ring ( 13). The said process is performed, while covering the semiconductor wafer and the adhesive sheet 11 for dicing so that the adhesive layer 2 side may become a joining surface, and pressing by pressing means, such as a crimping roll. Moreover, in a container which can be pressurized (for example, an octocrave etc.), the semiconductor wafer and the dicing adhesive sheet 11 can be piled up as mentioned above, and can be attached by pressurizing the inside of a container. At this time, you may adhere, pressing by a press means. Moreover, it can also attach in the vacuum chamber similarly to the above. Although the adhesion temperature at the time of adhesion is not limited at all, It is preferable that it is 20-80 degreeC.

The process of cutting (dicing) the semiconductor wafer to form the semiconductor chip 12 is performed according to a conventional method from the circuit surface side of the semiconductor wafer. As the dicing, a known method such as blade dicing, laser dicing, plasma dicing, or braking can be used. Moreover, it does not specifically limit as a dicing apparatus used at this process, A conventionally well-known thing can be used.

In the process of peeling each semiconductor chip 12 with the adhesive layer 2 from the base film 1, each semiconductor chip 12 is, for example, with a needle from the dicing adhesive sheet 11 side. A method of picking up the pushed up semiconductor chip 12 by the pick-up device or the like is performed.

In the above description, the case where a semiconductor wafer is used as the cut body is described as an example. However, the present invention is not limited thereto, and the present invention can also be applied to cut bodies such as semiconductor packages, glasses, ceramics, and the like.

EMBODIMENT OF THE INVENTION Below, the Example from which this invention is suitable is demonstrated to detail in an example. However, unless otherwise indicated, the material, compounding quantity, etc. which are described in this Example are only the explanatory examples which are not the meaning which limits the scope of this invention only to them.

(Physical property evaluation of base film)

The base film produced above was evaluated by the following method. The results are shown in Table 1.

(1) tensile modulus

The test method was performed based on JISK7126. As measurement conditions, the base film as a sample was made into a single strip of 120 mm in initial length and 10 mm in width, and a tensile test was performed in the MD direction or the TD direction at a distance between the chucks of 50 mm and a tensile speed of 300 mm / min. The change in elongation (mm) of the sample of was measured. As a result, a tangent line was drawn to the initial vertical rise portion of the obtained S-S curve (see FIG. 1), and the tensile strength when the tangent line corresponds to 100% elongation was divided by the cross-sectional area of the base film to obtain a tensile modulus of elasticity. The results are shown in Table 1 below.

(2) Yield Point Elongation, Break Elongation, Internal Break

The tensile test was done similarly to the method shown in said (1), and the S-S curve was obtained. Moreover, the tensile strength, breaking strength, and breaking elongation in MD direction or TD direction at the time of 30% of tensile elongation were calculated | required, respectively. The break-in degree was determined by the following equation. In addition, as the SS curve is shown in Fig. 5, when the tensile strength does not increase with expansion and a yield point that rises again occurs after tensile strength decreases, the tensile elongation at the yield point is stretched. By doing this, this was obtained.

&Quot; (4) &quot;

Breaking resistance = (break strength of base film) / (tensile strength at 30% of tensile elongation of base film)

(First embodiment)

<Production of base film>

Mitsubishi Chemical Corporation (trade name: "Jeras") was supplied to the T die molding machine (setting temperature 230 degreeC) by the Praco Corporation, and was formed into a film, and the base film of thickness 100micrometer and width 35cm was produced. "Brand name: Geras" by Mitsubishi Chemical Corporation is a propylene thermoplastic elastomer containing a propylene component and an ethylene propylene rubber component.

<Evaluation of Physical Properties of Base Film>

Thus, the physical properties of tensile elasticity modulus, yield point elongation, breaking elongation, and cut-in degree were evaluated about the obtained base film.

<Production of adhesive sheet for dicing>

90 parts by weight of butyl acrylate and 10 parts by weight of acrylic acid were copolymerized in a toluene solution by a conventional method to obtain an acrylic copolymer having a weight average molecular weight of 500,000. To a solution containing this acryl-based copolymer, 80 parts by weight of dipentaerythritol hexaacrylate (trade name "Kayarad DPHA", manufactured by Nihon Kayaku Co., Ltd.), a photopolymerization initiator (trade name "Singacure 184", Chiba? 5 parts by weight of Specialty Chemicals Co., Ltd. and 5 parts by weight of a polyisocyanate compound (trade name "Colonate L", manufactured by Nippon Polyurethane Co., Ltd.) were added to prepare an acrylic ultraviolet curable pressure-sensitive adhesive solution.

The adhesive solution prepared above was apply | coated on the corona treatment surface of the base film obtained above, and it heat-crosslinked at 80 degreeC for 10 minutes, and formed the ultraviolet curable adhesive layer of thickness 10micrometer. Subsequently, the separator was bonded to the said adhesive layer surface, and the adhesive sheet for ultraviolet curable dicing was produced.

(Second Embodiment)

<Production of base film>

(Brand name: parapet SA-F "(methacrylic acid ester resin) of crarese was formed into a film by calendering (setting temperature 170 degreeC), and the base film of thickness 100micrometer and width 35cm was produced. .

<Evaluation of Physical Properties of Base Film>

The physical properties of the obtained base film were evaluated in the same manner as in the first example. The results are shown in Table 1 below.

<Production of adhesive sheet for dicing>

The adhesive solution prepared in Example 1 was apply | coated on the corona treatment surface of the base film obtained above, and it heat-crosslinked at 80 degreeC for 10 minutes, and formed the ultraviolet curable adhesive layer of thickness 10micrometer. Subsequently, the separator was bonded to the said adhesive layer surface, and the adhesive sheet for ultraviolet curable dicing was produced.

(Third Embodiment)

<Production of base film>

"Brand name: Nuberan" (polyester elastomer resin) made by Teijin Kasei Co., Ltd. was supplied to a T die molding machine (set temperature 230 deg. C) made by Fraco Co., Ltd., to form a film having a thickness of 100 µm and a width of 35 cm. A film was produced.

<Evaluation of Physical Properties of Base Film>

The physical properties of the obtained base film were evaluated in the same manner as in the first example. The results are shown in Table 1.

<Production of adhesive sheet for dicing>

The adhesive solution prepared in Example 1 was apply | coated on the corona treatment surface of the base film obtained above, and it heat-crosslinked at 80 degreeC for 10 minutes, and formed the ultraviolet curable adhesive layer of thickness 10micrometer. Subsequently, the separator was bonded to the said adhesive layer surface, and the adhesive sheet for ultraviolet curable dicing was produced.

(Comparative Example 1)

In this comparative example, a film was formed by T-die extrusion method using the low density polyethylene [brand name: Sumikacene, MFR = 1.5, Mitsui Sumitomo polyolefin (made by Mitsui Co., Ltd.)] as a base film (thickness 100 micrometers). Except having used the corona treatment to one side of the said film, it carried out similarly to Example 1, and produced the adhesive sheet for ultraviolet curable dicing.

(Comparative Example 2)

In this comparative example, a film was formed into a film by T-die extrusion method using the ethylene-methacrylic acid copolymer [brand name: Nucrel, MFR = 2.0, Mitsui Dupont Polychemical (made by Mitsui Chemicals)] as a base film. (100 micrometers in thickness) Except having used the corona treatment to one side of the said film, it carried out similarly to Example 1, and produced the adhesive sheet for ultraviolet curable dicing.

(evaluation)

Each adhesive sheet for dicing obtained by the Example and the comparative example was evaluated by the following method. The results are shown in Table 1 below.

(1) Expandability Evaluation

The 8-inch wafer of 350 micrometers in thickness was mounted on the adhesive sheet for dicing, and it diced on condition of the following.

Dicer: DFD-651 (brand name) made in DISCO company

Blade: made by DISCO, NBC-ZH2050 27HEDD (brand name)

Blade Speed: 45,000 rpm

Dicing Speed: 100 mm / sec

Dicing Depth: 40 μm for the base film

Dicing Size: 8 mm × 8 mm

The work after dicing is changed to die bonder (device name: "CPS-100", manufactured by NEC Machinery Co., Ltd.), and the insertion depth of the outer ring to the inner ring is changed to 5 mm, 10 mm, and 15 mm, respectively. It expanded and confirmed the presence or absence of the fracture | rupture of each adhesive sheet for dicing.

[Table 1]

Seal
Modulus (N) Depth of cut
(-) Elongation at break
(%) Yield Elongation
(%) Expandability 5 mm 10 mm 15 mm First embodiment
MD 200 3.4 900 34 ○
○
○
TD 200 3.5 1000 37 Second embodiment
MD 70 3.0 200 No yield point ○
○
○
TD 70 3.0 280 No yield point Third embodiment
MD 150 4.0 1000 No yield point ○
○
○
TD 150 4.0 1000 No yield point Comparative Example 1
MD 130 2.2 600 No yield point ○
Breaking
Breaking
TD 130 1.9 700 No yield point 2nd comparative example
MD 120 2.4 700 25 ○
○
Breaking
TD 120 2.4 700 25

(2) results

As can be seen from Table 1, in the case of the pressure-sensitive adhesive sheet for dicing according to the example, it was found that no breakage occurred and the expandability was excellent. On the other hand, in the case of the pressure-sensitive adhesive sheet for dicing according to the comparative example, no breakage occurred when the insertion depth was 5 mm, but it was confirmed that breakage occurred when the insertion depth was 10 mm or 15 mm.

According to the present invention, even when an incision is formed in the pressure-sensitive adhesive sheet for dicing by setting the tensile modulus of the base material to 50 to 250 MPa, the breaking elongation to 200% or more, and the cut-in resistance to 2.5 or more, for example, When the expansion is performed, the adhesive sheet for dicing is prevented from breaking. As a result, it is possible to satisfactorily pick up the cut individual pieces, and the workability and the product ratio can be improved.

Claims (12)

It is comprised so that an adhesive layer may be provided in at least one surface of a base material, and it is an adhesive sheet for dicing used at the time of processing of a cut body, The tensile elasticity modulus of the said base material is 50-250 Mpa, the elongation at break is 200% or more, and the incision degree represented by a following formula is 2.5 or more, The adhesive sheet for dicing characterized by the above-mentioned. [Equation 1] Breaking resistance = (break strength of the substrate) / (tensile strength at 30% of tensile elongation of the substrate) The yield point elongation of the said base material is 30% or more, The adhesive sheet for dicing of Claim 1 characterized by the above-mentioned. The adhesive sheet for dicing according to claim 1, wherein the base material contains at least one or more selected from the group consisting of a polypropylene thermoplastic elastomer, an acrylic resin, and a polyester thermoplastic elastomer. The thickness of the said adhesive layer is 1 micrometer or more, and is 1/3 or less of the thickness of the said base material, The adhesive sheet for dicing of Claim 1 characterized by the above-mentioned. The pressure sensitive adhesive sheet for dicing according to claim 1, wherein the pressure sensitive adhesive layer is configured to include a radiation curable pressure sensitive adhesive. It is comprised so that an adhesive layer may be provided on at least one surface of a base material, It is a dicing adhesive sheet used at the time of processing of a cut body, The tensile elasticity modulus of the said base material is 50-250 Mpa, The elongation at break is 200% or more, Attaching the pressure-sensitive adhesive sheet for dicing having a cut resistance of 2.5 or more to the cut body; Cutting the cut single piece to form a cut single piece, and performing the cutting from the cut single side to the base material of the dicing adhesive sheet; Expanding the dicing adhesive sheet to widen the interval of each cut piece piece that is adhesively fixed to the dicing adhesive sheet; And a step of peeling the cut piece small piece provided with the pressure-sensitive adhesive layer from the base material. &Quot; (2) &quot; Breaking resistance = (break strength of the substrate) / (tensile strength at 30% of tensile elongation of the substrate) The yield point elongation of the said base material is 30% or more, The processing method of the single body of Claim 6 characterized by the above-mentioned. The method for processing a cutle member according to claim 6, wherein the base material contains at least one or more selected from the group consisting of polypropylene-based thermoplastic elastomers, acrylic resins and polyester-based thermoplastic elastomers. The thickness of the said adhesive layer is 1 micrometer or more, and is 1/3 or less of the thickness of the said base material, The processing method of the single body of Claim 6 characterized by the above-mentioned. The processing method of a single body according to claim 6, wherein the pressure-sensitive adhesive layer is configured to include a radiation-curable pressure-sensitive adhesive. The method for processing a cut single member according to claim 6, wherein a semiconductor element is used as the cut single member. A cut body piece, which is produced by a method for processing a cut body according to claim 6.

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