KR20170099695A - Surface protecting adhesive film for semiconductor wafer - Google Patents

Abstract

Wherein the intermediate layer comprises a photo-cured product of an acrylic photo-curable polymer of a monomer component comprising an alicyclic (meth) acrylate monomer and an alkyl (meth) acrylate monomer, wherein the intermediate layer the storage modulus is in a 25 ℃ ⁴ × 10 4 Pa to 1 × 10 ⁵ Pa, and the glass transition temperature of the intermediate layer -40 ℃ to -10 ℃, one surface of the intermediate layer which is in contact with the adhesive layer has a hydroxy group is introduced into the semiconductor Provided is a pressure sensitive adhesive film for wafer surface protection.

Description

TECHNICAL FIELD [0001] The present invention relates to a pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer (SURFACE PROTECTING ADHESIVE FILM FOR SEMICONDUCTOR WAFER)

The present invention relates to an adhesive film which serves to protect a surface of a semiconductor wafer by adhering to a surface of a semiconductor wafer when it is necessary to protect the surface of the semiconductor wafer.

Recently, miniaturization and lightening of electronic products are rapidly proceeding, and there is an increasing demand for leadless, thinned, and highly integrated chips in semiconductor packages. In response to this demand, there is also an increasing demand for large-scale curing and thinning of the wafers included in the semiconductor package.

However, due to the progress of the hardening of the wafer, wafers are often damaged such as wafer contamination and cracking during the backgrinding process, and thus the role of the adhesive film for protecting the surface of the semiconductor wafer becomes more important.

The adhesive film for protecting the surface of the semiconductor wafer may have a multi-layered structure, and generally includes a substrate layer serving as a basic support. The base layer plays an important role in ensuring the stability of the film during the processing of the semiconductor wafer, and it can be structured so that the adhesive film can be adhered flatly by an appropriate external force and, if necessary, To give appropriate stiffness and stretching performance.

One embodiment of the present invention provides a pressure-sensitive adhesive film for protecting the surface of a semiconductor wafer which is excellent in step absorption ability and free from residue upon peeling.

In one embodiment of the present invention, the intermediate layer comprises a base layer, an intermediate layer and an adhesive layer, wherein the intermediate layer is an acryl-based photo-curable polymer of a monomer component comprising an alicyclic (meth) acrylate monomer and an alkyl (meth) And the intermediate layer has a storage elastic modulus of 4 x 10 < ⁴ > Pa to 1 x 10 < ⁵ > Pa at 25 DEG C, and the glass transition temperature of the intermediate layer is -40 DEG C to -10 DEG C, Provides a pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer into which a hydroxy group is introduced.

The above-mentioned adhesive film for protecting the surface of a semiconductor wafer has excellent step difference absorbing ability and can improve workability upon peeling.

1 schematically shows a cross section of a pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view of a pressure-sensitive adhesive film for protecting a semiconductor wafer according to another embodiment of the present invention applied to a semiconductor wafer having bumps formed on one surface thereof.
3 is a schematic cross-sectional view of a semiconductor wafer formed with a predetermined thickness by back grinding after applying the above-described adhesive film for protecting the semiconductor wafer surface to a semiconductor wafer formed on one surface of a bump.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

In the drawings of the present specification, the thicknesses are enlarged to clearly indicate layers and regions. In the drawings, for the convenience of explanation, the thicknesses of some layers and regions are exaggerated.

Hereinafter, the formation of any structure in the "upper (or lower)" or the "upper (or lower)" of the substrate means that any structure is formed in contact with the upper surface (or lower surface) of the substrate However, the present invention is not limited to not including other configurations between the substrate and any structure formed on (or under) the substrate.

In one embodiment of the invention:

A base layer, an intermediate layer and an adhesive layer,

Wherein the intermediate layer comprises a photo-cured product of an acrylic photocurable polymer of a monomer component comprising an alicyclic (meth) acrylate monomer and an alkyl (meth) acrylate monomer,

Wherein the intermediate layer has a storage modulus of about 4 x 10 < ⁴ > Pa to about 1 x 10 < ⁵ > Pa at about 25 &

Wherein the intermediate layer has a glass transition temperature of about -40 캜 to about -10 캜,

The one side of the intermediate layer in contact with the pressure-sensitive adhesive layer has a

A pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer.

FIG. 1 schematically shows a cross-section of a pressure-sensitive adhesive film 100 for protecting a surface of a semiconductor wafer according to an embodiment of the present invention.

1, the adhesive film 100 for protecting a surface of a semiconductor wafer includes a base layer 10, an intermediate layer 20, and an adhesive layer 30. The adhesive film has a structure in which the intermediate layer 20 is included between the base layer 10 and the adhesive layer 30, thereby achieving excellent step difference absorption performance.

The adhesive film 100 for protecting a surface of a semiconductor wafer is a film for holding or protecting a semiconductor wafer or a product in a process of precision processing a semiconductor product such as a semiconductor wafer or an optical system product or the like, .

In one embodiment, the adhesive film 100 for protecting a semiconductor wafer surface is applied to a back grinding process (or a 'backgrinding process') of a wafer having bumps formed on one surface thereof. The adhesive film 100 for protecting the surface of the semiconductor wafer exhibits an excellent step absorbability against the step of bumps when applied to a wafer having a bump such as a circuit or the like, Can be minimized to provide excellent non-contamination performance, which is suitable for application to wafers formed with such bumps.

In order to perform the back grinding process, a wafer having bumps formed on one surface such as an electrode, a circuit, and the like is first adhered to one surface of the semiconductor wafer surface protecting surface for protecting the surface of the semiconductor wafer, ≪ / RTI > If the surface level difference caused by the bump is large, the stress can be concentrated on the bump portion and the wafer can be easily broken. Therefore, after attaching the adhesive film 100 for protecting the semiconductor wafer surface to the bump formed surface, Protects against damage.

Since the adhesive film 100 for protecting the semiconductor wafer surface has a three-layer structure of the base layer 10, the intermediate layer 20 and the adhesive layer 30, the semiconductor wafer surface protective adhesive film 100 is applied to the back grinding process of the wafer on which the bumps are formed The interface adhesion between the intermediate layer 20 and the pressure-sensitive adhesive layer 30 is excellent at the same time as it exhibits an excellent step absorbing ability at the time of peeling the semiconductor wafer surface protecting adhesive film 100, .

The base layer 10 is at least one selected from the group consisting of a polyethylene terephthalate film, a polyolefin film, a polyvinyl chloride film, a polyurethane film, an ethylene-vinyl acetate copolymer film, an ethylene-alkyl acrylate copolymer film, One can be included.

The thickness of the base layer 10 influences the strength of the adhesive film 100 for protecting the surface of the semiconductor wafer itself and also affects the prevention of wafer breakage during the backside grinding process. It is preferable to select an appropriate thickness.

The base layer 10 may be produced by an extrusion process, a photo-curing process, a casting process, a calendering process, a heat curing process, or the like.

For example, the acrylic film can be obtained through ultraviolet curing, and an ethylene-vinyl acetate copolymer film can be produced by an extrusion process, and a polyurethane film can be produced by a thermosetting process. Further, a polyvinyl chloride film May be formed by a casting process or a calendering process.

The thickness of the substrate layer 10 may be about 50 탆 to about 200 탆. Although there is no limitation on the thickness of the base layer 10, it is advantageous in that it is advantageous in that it is advantageous in terms of the production process of the adhesive film 100 for protecting the surface of the semiconductor wafer to maintain unnecessary step elevation by maintaining the thickness within the above range.

The intermediate layer 20 may be formed by preparing a composition for forming the intermediate layer 20 including an acrylic photo-curable polymer obtained by polymerizing a monomer component, and then photo-curing the composition.

The monomer component may specifically include the alicyclic (meth) acrylate monomer and the alkyl (meth) acrylate monomer.

For example, first, the monomer mixture is thermally polymerized to obtain an acrylic photo-curable polymer. The obtained acrylic photo-curable polymer may be in the form of an oligomer and / or a prepolymer depending on the degree of polymerization, and unreacted monomers may be included in the composition for forming the intermediate layer 20 together.

The polymerization degree of the acrylic photo-curable polymer may be appropriately selected according to the physical properties of the intermediate layer 20 to be obtained. Specifically, the weight average molecular weight of the acrylic photo-curable polymer may be about 500,000 to about 1,500,000 g / mol.

The alicyclic (meth) acrylate monomer may be a (meth) acrylate containing a C3-C10 alicyclic group.

In one embodiment, the alicyclic (meth) acrylate monomer may be an alicyclic condensed ring or a fused ring containing acrylate.

The alicyclic (meth) acrylate monomer may be at least one selected from the group consisting of cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, . ≪ / RTI >

The alkyl (meth) acrylate monomer may be, for example, an alkyl (meth) acrylate having a linear or branched C1-C14 alkyl group.

More specifically, the alkyl (meth) acrylate monomer may be at least one selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) Butyl (meth) acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, 2-ethylhexyl (Meth) acrylate, isooctyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, lauryl One can be included.

The intermediate layer 20 contains the alicyclic (meth) acrylate monomer or a structural unit derived from the alicyclic (meth) acrylate monomer to improve the adhesion, and on the other hand, Since the glass transition temperature increases the storage modulus to an undesirable level, the storage elastic modulus can be controlled by lowering the glass transition temperature by including the alkyl (meth) acrylate monomer or a structural unit derived therefrom. As a result, the monomer component and the acryl-based photo-curable polymer may not contain a separate hydroxy group-containing acrylic monomer or a structural unit thereof due to adhesiveness.

That is, the intermediate layer 20 includes the alicyclic (meth) acrylate monomer or a structural unit derived from the alicyclic (meth) acrylate monomer and the alkyl (meth) acrylate monomer or a structural unit derived therefrom, .

The modulus is a value corresponding to the initial slope of the tensile curve in the tensile test, and the intermediate layer 20 having the modulus in the numerical range is excellent in the step difference absorbing ability.

The intermediate layer 20 may contain the alicyclic (meth) acrylate monomer or a structural unit derived therefrom in a relatively high content, instead of containing a hydroxy group-containing acrylic monomer or a structural unit derived therefrom.

The storage modulus of the intermediate layer 20 may be about 4 x 10 ⁴ Pa to about 1 x 10 ⁵ Pa at 25 ° C and the glass transition temperature of the intermediate layer 20 may be about -40 ° C to about -10 ° C.

The storage elastic modulus can be measured using a rheometer.

The glass transition temperature (Tg) can be measured using differential scanning calorimetry (DSC).

The acrylic photocurable polymer of the monomer component may be polymerized in the weight ratio of the alicyclic (meth) acrylate monomer to the alkyl (meth) acrylate monomer of 30:70 to 75:25.

When the acrylic photocurable polymer of the monomer component includes the alicyclic (meth) acrylate monomer or a structural unit derived therefrom and an alkyl (meth) acrylate monomer or a structural unit derived therefrom in the content range, ) At a predetermined level while at the same time achieving a desired level difference absorbing ability by properly attaining the glass transition temperature of the intermediate layer 20.

The monomer component may be composed of unreacted monomers remaining as a result of polymerizing the monomer mixture to obtain the photo-curable polymer. Specifically, the monomer component may include about 30 to about 75 wt% of the alicyclic (meth) acrylate monomer, ) Acrylate monomers from about 25 to about 70 weight percent.

The intermediate layer 20 contains a hydroxyl group-containing acrylic monomer or a structural unit thereof. Instead, the intermediate layer 20, which is in contact with the adhesive layer 30 contacting the adhesive layer 30, The adhesive force at the interface between the adhesive layer 30 and the intermediate layer 20 is improved. As described above, when the interfacial adhesion between the adhesive layer 30 and the intermediate layer 20 is improved, the residue can be removed when the adhesive film 100 for protecting a surface of the semiconductor wafer is peeled off.

For example, one surface of the intermediate layer 20 in contact with the adhesive layer 30 may have increased surface energy by introducing a polar group generated by surface oxidation according to corona treatment. The polar group may be, for example, C = O, COH, COOH, COOR, COR, etc., and R may be a C1-C5 alkyl group.

The thickness of the intermediate layer 20 may be about 50 탆 to about 350 탆. The thickness of the intermediate layer 20 can be suitably selected within a range that does not impair the retention of the wafer and the protective property of the wafer, and the thickness of the intermediate layer 20 can be appropriately selected, It is possible to suppress the generation of dimples on the backside of the wafer and to exhibit an excellent step absorbing ability when applied to a wafer on which bumps are formed and to form the adhesive layer 30 on the intermediate layer 20 The work efficiency can be improved.

To prepare the intermediate layer 20, first, the acrylic photo-curable polymer can be prepared by thermally polymerizing a mixture of the monomer components. The monomer components may be partially polymerized by thermal polymerization to form an acrylic syrup, and the composition for forming the intermediate layer 20 may be prepared by mixing the acrylic syrup with an additive.

The acrylic syrup formed by partial polymerization of the monomer component may have a solids concentration of about 4% to about 15%. The solids content can mean the concentration of the polymer. The acrylic syrup can maintain the stability of the acrylic photopolymerizable polymer obtained by controlling the degree of polymerization with the solid concentration in the range of the above range and can secure a range of the storage elastic modulus which facilitates the step difference absorbency.

The additive to be added to the composition for forming the intermediate layer 20 may be added to the surface of the semiconductor wafer by a conventional adhesive agent such as antioxidant, filler, pigment, colorant, flame retardant, antistatic agent, ultraviolet absorber, It can be added within a range that does not impair the function of the film. These additives may be used in usual amounts depending on the kind thereof.

After the composition for forming the intermediate layer 20 is applied on the base layer 10, the intermediate layer 20 is irradiated with radiation such as ionizing radiation or ultraviolet rays, visible light or the like depending on the type of the photopolymerization initiator, . The kind of the radiation and the type of the lamp used for the irradiation can be appropriately selected and a low pressure lamp such as a fluorescent chemical lamp, a black light, a sterilizing lamp, a high pressure lamp such as a metal halide lamp, a high pressure mercury lamp, .

Specifically, the intermediate layer 20 may be formed by curing by a black light UV lamp that emits UV light. For example, the black light UV lamp may be about 5 W and the main wavelength may be about 365 nm. The use of the above-mentioned black light UV lamp can improve the heat generation problem in partial polymerization or the like during the process of forming the intermediate layer 20 and can be cured without any difference in curing on the surface and inside of the intermediate layer, It is advantageous to use a UV lamp.

The adhesive layer 30 is formed on the intermediate layer 20 of the adhesive sheet 100 for protecting a surface of the semiconductor wafer and may be made of a photo-curing pressure-sensitive adhesive. Specifically, the pressure-sensitive adhesive layer 30 is a pressure-sensitive adhesive containing a photocurable acrylic resin.

The adhesive layer 30 has an appropriate adhesive force when processing a product such as a semiconductor wafer and is firmly attached to the semiconductor wafer during the process. After the process, the adhesive layer 30 should be easily peeled off without imposing a load on the product. For example, the pressure-sensitive adhesive layer 30 is formed on the intermediate layer 20 by thermosetting a composition for forming the pressure-sensitive adhesive layer 30 containing a certain amount of a thermosetting agent and a photoinitiator in addition to the photocurable acrylic resin, The pressure-sensitive adhesive layer 100 for protecting the semiconductor wafer surface is manufactured, and after the back-grinding process is completed, the pressure-sensitive adhesive layer 30 can be further photocured by further light irradiation to peel off the wafer. The adhesive layer 30 is easily peeled off by the additional photocuring since the peeling force before the light irradiation is large since the peeling force after the light irradiation is large.

The pressure-sensitive adhesive layer 30 may be formed by further mixing a pressure-sensitive adhesive containing a photo-curable acrylic resin, if necessary, with a solvent or the like, and applying the pressure-sensitive adhesive directly onto the intermediate layer 20, May be applied on the release film to form the adhesive layer 30 in advance, and then the adhesive layer 30 may be bonded to the intermediate layer (20).

The adhesive layer 30 may include a photocurable acrylic resin. Specifically, in the photocurable acrylic resin, the photocurable acrylic resin has a structure having a carbon-carbon double bond in the molecule and attributable to a monomer containing a hydrophilic functional group Unit.

Specifically, the hydrophilic functional group may be selected from the group consisting of a hydroxyl group, an amino group, a carboxyl group, a sulfonic group, a morpholine group, a glycidyl group, and combinations thereof.

For example, the photocurable acrylic resin may contain at least one selected from the group consisting of a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an isobutyl group, an amyl group, an isoamyl group, a hexyl group, An isohexyl group, an isoamyl group, an isoamyl group, an isoamyl group, an isoamyl group, an isoamyl group, an isoamyl group, an isoamyl group, (Meth) acrylic acid alkyl ester having a carbon number of 30 or less and a straight chain or branched alkyl group having 4 to 18 carbon atoms such as a dodecyl group; An aryl group such as a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, t-butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, heptyl group, cyclohexyl group, Such as an alkyl group having 30 or less carbon atoms such as a methyl group, an ethyl group, an ethyl group, an ethyl group, an ethyl group, an ethyl group, an ethyl group, an ethyl group, , A cycloalkyl ester having a straight chain or branched alkyl group having 4 to 18 carbon atoms, and the like.

The photocurable acrylic resin may be obtained by polymerizing a monomer component having the carbon-carbon double bond and containing about 1% by weight to about 30% by weight of a hydrophilic functional group-containing monomer, It is possible to form a pressure-sensitive adhesive layer 30 having a proper cohesive strength by including a structural unit derived from a monomer having a carbon-carbon double bond and a hydrophilic functional group in accordance with the content of the above range. As a result, The adhesive film 100 can be provided.

The pressure-sensitive adhesive layer 30 can appropriately adjust the weight-average molecular weight of the photocurable acrylic resin to form a pressure-sensitive adhesive layer 30 having a proper cohesive strength. As a result, the pressure-sensitive adhesive layer 100 for semiconductor wafer surface- ). ≪ / RTI > Specifically, the photocurable acrylic resin may have a weight average molecular weight of about 200,000 to about 200. [

The glass transition temperature of the photocurable acrylic resin may be about -60 캜 to about -20 캜. By maintaining the glass transition temperature of the photocurable acrylic resin at about -60 캜 to about -20 캜, it is possible to form the adhesive layer 30 having an appropriate cohesive force, (100).

The thickness of the adhesive layer 30 may be about 1 [mu] m to about 40 [mu] m. The thickness of the adhesive layer 30 can be suitably set within a range that does not impair the retention and protection of the wafer. However, by maintaining the thickness in the above range, the breakage of the adhesive layer 30 affects the intermediate layer 20 And adhesion and peeling can be facilitated when the above-mentioned semiconductor wafer surface-protecting adhesive film 100 is applied to a wafer.

2 is a schematic cross-sectional view of applying the adhesive film 100 for protecting the semiconductor wafer surface to a semiconductor wafer 50 having bumps 40 formed on one surface thereof. 2, in the adhesive film 100 for protecting a semiconductor wafer surface, the adhesive layer 30 is attached in a direction tangential to a surface of the semiconductor wafer 50 on which the bumps 40 are formed, that is, in the direction of an arrow.

3 is a schematic sectional view of the semiconductor wafer 50 formed to have a predetermined thickness by back grinding after the adhesive film 100 for protecting the surface of the semiconductor wafer is applied to the semiconductor wafer 50 formed on one surface of the bump 40 . In Fig. 3, the portion indicated by the dotted line is cut by the back grinding process.

The adhesive film 100 for protecting the surface of the semiconductor wafer is used in a process of precisely machining the semiconductor wafer 50 in such a manner that the circuit pattern existing on the surface is damaged or the semiconductor wafer 50 is contaminated . The adhesive film 100 for protecting the semiconductor wafer surface must be removed after the semiconductor wafer is precisely processed, and the adhesive film 100 for protecting the semiconductor wafer surface does not damage the surface of the semiconductor wafer 50 during the backgrinding process And can be removed without peeling residue after the backgrinding process.

As described above, the adhesive film 100 for protecting the surface of the semiconductor wafer can be advantageously applied to the back grinding process of the semiconductor wafer 50 on which the bumps 40 are formed since the step absorbing ability is excellent.

In one embodiment, the backside grinding process is performed by applying the adhesive film 100 for protecting the semiconductor wafer surface to a semiconductor wafer 50 having a height of the bump 40 of about 50 μm to about 200 μm, 50) can be effectively protected.

Hereinafter, examples and comparative examples of the present invention will be described. The following embodiments are only examples of the present invention, and the present invention is not limited to the following embodiments.

( Example )

Example  One

A polyethylene terephthalate (PET) film having a thickness of 120 mu m was prepared as a base layer.

In order to obtain the composition for forming the intermediate layer, an acrylic photo-curable polymer (weight average molecular weight: 97,000: 1) obtained by partially polymerizing a monomer component obtained by mixing 40% by weight of isobornyl acrylate and 60% by weight of ethylhexyl acrylate, GPC, 1260, Agilent); Glass transition temperature-23 [deg.] C: measured using SC (mettler toledo, TGA / DSC 1). Subsequently, 100 parts by weight of the syrup solution was mixed with 100 parts by weight of a urethane-based acrylate curing agent 0.3 And 0.15 parts by weight of Irgacure 651 as a photoinitiator were added to prepare a composition for forming an intermediate layer.

The intermediate layer forming composition was coated between the release PET films and cured by a black light UV lamp having a wavelength of 5 W and a main wavelength of 365 nm to form an intermediate layer having a thickness of 200 탆 and transferred to the base layer to form a base- Respectively.

The glass transition temperature of the intermediate layer measured using DSC (mettler toledo, TGA / DSC 1) was -17 ° C.

The storage modulus of the intermediate layer measured using a Rheometer (TA instruments, ARES-G2) was 10 < ⁵ > Pa.

One side of the upper surface of the intermediate layer was subjected to corona treatment under the conditions of 150 mV, 5 A, and a speed of 1.5 m / min.

Separately, a polymer obtained by polymerizing 85 wt% of ethylhexyl acrylate and 15 wt% of hydroxyethyl acrylate (weight average molecular weight: 500,000, glass transition temperature: -56 DEG C) was obtained, and then the above hydroxyethyl acrylate 93% by weight of the resulting structural units were reacted with 2-isocyanato methylacrylate to prepare a photocurable acrylic resin. 5 parts by weight of Irgacure 651 as a photoinitiator was added to 100 parts by weight of the photocurable acrylic resin to prepare a composition for forming an adhesive layer. The pressure-sensitive adhesive layer-forming composition was coated on a release PET film and allowed to stand in an oven at 90 DEG C for 3 minutes to form a pressure-sensitive adhesive layer having a thickness of 10 mu m. The adhesive layer was laminated with the intermediate layer to form a base layer, To prepare a pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer.

Example  2

The composition for forming an intermediate layer was prepared in the same manner as in Example 1, and an intermediate layer was prepared under the same conditions.

Separately, a polymer (weight average molecular weight 80,000, glass transition temperature -23 ° C) obtained by polymerizing 54% by weight of ethylhexyl acrylate, 23% by weight of methyl acrylate and 23% by weight of hydroxyethyl acrylate was obtained, The photocurable acrylic resin was prepared by reacting 93% by weight of the structural units derived from hydroxyethyl acrylate with 2- (acryloyloxy) ethylisocyanate. 5 parts by weight of Irgacure 651 as a photoinitiator was added to 100 parts by weight of the photocurable acrylic resin to prepare a composition for forming an adhesive layer. The pressure-sensitive adhesive layer-forming composition was coated on a release PET film and allowed to stand in an oven at 90 DEG C for 3 minutes to form a pressure-sensitive adhesive layer having a thickness of 10 mu m. The adhesive layer was laminated with the intermediate layer to form a base layer, To prepare a pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer.

Example  3

The composition for forming an intermediate layer was prepared in the same manner as in Example 1, and an intermediate layer was prepared under the same conditions.

Separately, a polymer (weight average molecular weight: 500,000, glass transition temperature: -48 ° C) obtained by polymerizing 89 wt% of ethylhexyl acrylate, 5 wt% of methyl acrylate and 6 wt% of hydroxyethyl acrylate was obtained, 93% by weight of the structural unit derived from hydroxyethyl acrylate was reacted with 2- (acryloyloxy) ethyl cyrosocyanate to prepare a photocurable acrylic resin. 5 parts by weight of Irgacure 651 as a photoinitiator was added to 100 parts by weight of the photocurable acrylic resin to prepare a composition for forming an adhesive layer. The pressure-sensitive adhesive layer-forming composition was coated on a release PET film and allowed to stand in an oven at 90 DEG C for 3 minutes to form a pressure-sensitive adhesive layer having a thickness of 10 mu m. The adhesive layer was laminated with the intermediate layer to form a base layer, To prepare a pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer.

Comparative Example  One

A pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer was produced in the same manner as in Example 1, except that corona treatment was not applied to the upper surface of the intermediate layer before the pressure-sensitive adhesive layer was formed after the formation of the intermediate layer in Example 1.

Comparative Example  2

A pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer was produced in the same manner as in Example 2, except that corona treatment was not applied to the upper surface of the intermediate layer before the pressure-sensitive adhesive layer was formed after the formation of the intermediate layer in Example 2.

Comparative Example  3

A pressure-sensitive adhesive film for protecting a surface of a semiconductor wafer was produced in the same manner as in Example 3, except that corona treatment was not applied to the upper surface of the intermediate layer before the pressure-sensitive adhesive layer was formed after the intermediate layer was formed in Example 3.

Comparative Example  4

A polyethylene terephthalate (PET) film having a thickness of 120 mu m was prepared as a base layer.

In order to obtain the composition for forming the intermediate layer, first, a monomer component obtained by mixing 35% by weight of isobornyl acrylate, 55% by weight of ethylhexyl acrylate and 10% by weight of hydroxyethyl acrylate was heat-treated and partially polymerized to obtain an acrylic photo- (Weight average molecular weight: 890,000, glass transition temperature: -24 占 폚) was prepared. Subsequently, 0.3 part by weight of a urethane-based acrylate curing agent and 0.15 part by weight of Irgacure 651 as a photoinitiator were added to 100 parts by weight of the syrup solution to prepare a composition for forming an intermediate layer.

The intermediate layer forming composition was coated between the release PET films and cured by a black light UV lamp having a wavelength of 5 W and a main wavelength of 365 nm to form an intermediate layer having a thickness of 200 탆 and transferred to the base layer to form a base- Respectively.

The glass transition temperature of the intermediate layer measured using DSC (mettler toledo, TGA / DSC 1) was -18 ° C.

The storage modulus of the intermediate layer measured using a Rheometer (TA instruments, ARES-G2) was 10 < ⁵ > Pa.

Separately, a polymer (weight average molecular weight 80,000, glass transition temperature -23 ° C) obtained by polymerizing 54% by weight of ethylhexyl acrylate, 23% by weight of methyl acrylate and 23% by weight of hydroxyethyl acrylate was obtained, The photocurable acrylic resin was prepared by reacting 93% by weight of the structural units derived from hydroxyethyl acrylate with 2- (acryloyloxy) ethylisocyanate. 5 parts by weight of Irgacure 651 as a photoinitiator was added to 100 parts by weight of the photocurable acrylic resin to prepare a composition for forming an adhesive layer. The pressure-sensitive adhesive layer-forming composition was coated on the mold release PET, followed by laminating with the intermediate layer, and allowed to stand in an oven at 90 캜 for 3 minutes to form a pressure-sensitive adhesive layer having a thickness of 10 탆, To prepare a pressure-sensitive adhesive film for protecting the surface of a semiconductor wafer.

Experimental Example

Each of the pressure sensitive adhesive films for protecting the surface of the semiconductor wafer of Examples 1-3 and Comparative Examples 1-3 was attached so that the pressure sensitive adhesive layer adhered on the wafer patterned with a bump height of 50 탆 and a width of 50 탆 .

(1) The peel strength was evaluated by peeling off the adhesive film for protecting the surface of the semiconductor wafer before UV irradiation, and is shown in Table 1 below. The peel force was measured by a texture analyzer ASTM D330 method on a PI (polyimide) plate.

(2) The adhesive film for protecting the surface of the semiconductor wafer attached to the PI plate was photocured at 500 mJ / cm ² using a metal halide lamp as described above. Then, the peeling force of the adhesive film for protecting the surface of the semiconductor wafer was evaluated to evaluate the peeling force, and whether or not the residue was generated after peeling was visually evaluated as?,?, And x.

<Evaluation Criteria>

○: Remnant is clearly formed

Δ: Residual marks are visible

X: no residue occurred

Peel force (g / 25mm) Before UV irradiation Residue After UV irradiation Residue Example 1 756 × 66 × Example 2 863 × 41 × Example 3 920 × 799 × Comparative Example 1 334 ○ 71 ○ Comparative Example 2 355 ○ 46 ○ Comparative Example 3 140 ○ 106 ○ Comparative Example 4 632 △ 46 △

It can be confirmed that the intermediate layer of Example 1-3 improves the interfacial adhesion between the intermediate layer and the adhesive layer by the corona treatment as compared with the intermediate layer of Comparative Example 1-3 and does not leave any residue.

In addition, since the intermediate layer of Example 1-3 can be free of hydroxyethyl acrylate as compared with the intermediate layer of Comparative Example 4, a higher content of the isobornyl acrylate monomer component relative to Comparative Example 4 By using the acrylic photo-curable polymer, it is confirmed that the interfacial adhesion between the intermediate layer and the adhesive layer is improved and no residue is left.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, And falls within the scope of the invention.

10: substrate layer
20: middle layer
30: Adhesive layer
40: Bump
50: semiconductor wafer
100: Adhesive film for semiconductor wafer surface protection

Claims (16)

A base layer, an intermediate layer and an adhesive layer,
Wherein the intermediate layer comprises a photo-cured product of an acrylic photocurable polymer of a monomer component comprising an alicyclic (meth) acrylate monomer and an alkyl (meth) acrylate monomer,
Wherein the intermediate layer has a storage modulus of 4 x 10 &lt; ⁴ &gt; Pa to 1 x 10 &lt; ⁵ &gt; Pa at 25 [
Wherein the intermediate layer has a glass transition temperature of -40 캜 to -10 캜,
The one side of the intermediate layer in contact with the pressure-sensitive adhesive layer has a
Adhesive film for protecting the surface of a semiconductor wafer.
The method according to claim 1,
The acrylic photocurable polymer of the monomer component is polymerized at a weight ratio of the alicyclic (meth) acrylate monomer to the alkyl (meth) acrylate monomer of 30:70 to 75:25
Adhesive film for protecting the surface of a semiconductor wafer.
The method according to claim 1,
Wherein the monomer component does not contain a hydroxyl group-containing acrylic monomer
Adhesive film for protecting the surface of a semiconductor wafer.
The method according to claim 1,
The weight average molecular weight of the acrylic photopolymerizable polymer is 500,000 to 1,500,000 g / mol
Adhesive film for protecting the surface of a semiconductor wafer.
The method according to claim 1,
The one side of the intermediate layer in contact with the pressure-sensitive adhesive layer is subjected to corona treatment so that a polar group is introduced
Adhesive film for protecting the surface of a semiconductor wafer.
The method according to claim 1,
The pressure-sensitive adhesive layer is made of a photo-curable pressure-sensitive adhesive
Adhesive film for protecting the surface of a semiconductor wafer.
The method according to claim 1,
Wherein the adhesive layer is a pressure-sensitive adhesive containing a photocurable acrylic resin, and the peeling force before light irradiation is larger than the peeling force after light irradiation
Adhesive film for protecting the surface of a semiconductor wafer.
8. The method of claim 7,
The photocurable acrylic resin contains a structural unit derived from a monomer having a carbon-carbon double bond in a molecule and having a hydrophilic functional group
Adhesive film for protecting the surface of a semiconductor wafer.
9. The method of claim 8,
Wherein the hydrophilic functional group is one selected from the group consisting of a hydroxyl group, an amino group, a carboxyl group, a sulfonic group, a morpholine group, a glycidyl group,
Adhesive film for protecting the surface of a semiconductor wafer.
8. The method of claim 7,
The glass transition temperature of the photocurable acrylic resin is from -55 캜 to -20 캜
Adhesive film for protecting the surface of a semiconductor wafer.
The method according to claim 1,
The base layer includes at least one selected from the group consisting of a polyethylene terephthalate film, a polyolefin film, a polyvinyl chloride film, a polyurethane film, an ethylene-vinyl acetate copolymer film, an ethylene-alkyl acrylate copolymer film, doing
Adhesive film for protecting the surface of a semiconductor wafer.
The method according to claim 1,
Wherein the base layer has a thickness of 50 mu m to 200 mu m
Adhesive film for protecting the surface of a semiconductor wafer.
The method according to claim 1,
Wherein the intermediate layer has a thickness of 50 mu m to 350 mu m
Adhesive film for protecting the surface of a semiconductor wafer.
The method according to claim 1,
Wherein the thickness of the adhesive layer is 1 占 퐉 to 40 占 퐉
Adhesive film for protecting the surface of a semiconductor wafer.
The method according to claim 1,
Is applied to a back grinding process of a wafer on which bumps are formed on one surface, and the adhesive layer is attached to one surface of the wafer on which bumps are formed
Adhesive film for protecting the surface of a semiconductor wafer.
16. The method of claim 15,
Wherein the height of the bumps is 50 占 퐉 to 200 占 퐉
Adhesive film for protecting the surface of a semiconductor wafer.

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