TW202246439A - Adhesive film for wafer processing - Google Patents

Abstract

The present invention provides an adhesive film for wafer processing, which includes: a multi-layer substrate including an upper substrate layer and a lower substrate layer; a first adhesive layer arranged on the upper substrate layer; and a second adhesive layer arranged between the upper substrate layer and the lower substrate layer, wherein the second adhesive layer is made of a second adhesive composition comprising an adhesive resin and core-shell nanoparticles. According to the present invention, when a wafer is processed, the surface protection effect of the wafer is excellent, and the fluidity of the adhesive layer can be controlled.

Description

Adhesive film for wafer processing

The present invention relates to an adhesive film for wafer processing used in wafer processing such as thin film back grinding of wafers. More specifically, the present invention relates to an adhesive film for wafer processing that is excellent in the surface protection effect (buffer effect) of the wafer during wafer polishing processing.

Recently, with the development of technology, there has been a demand for miniaturization and thinning of semiconductor wafers.

As a representative example of wafer thinning, there is a method of reducing the thickness by grinding the back surface of the wafer forming the wafer.

Recently, thinned wafers can be obtained by the Dicing Before Grinding (DBG) method. After forming grooves on the surface of the wafer with a dicing drill, the backside of the wafer is ground to obtain dicing from the wafer. melted wafers. In the case of using the wafer back grinding method, since the back grinding of the wafer and the dicing of the wafer are performed at the same time, thinner semiconductor wafers can be efficiently produced.

Generally, when performing back grinding of a wafer, in order to maintain a semiconductor wafer, it is necessary to perform the back grinding of the wafer with an adhesive film attached to the surface of the wafer. The adhesive film includes an adhesive layer for bonding the substrate and the wafer surface, and a cushioning layer or vibration damping layer, such as urethane acrylate, can be formed on the backside of the substrate with a cushioning effect.

The lower the modulus of the buffer layer, the better the buffer effect, thereby effectively protecting the surface of the wafer. However, there may be a problem that, for a buffer layer with a low modulus, when the back grinding process is performed, the buffer layer may flow at high temperature or become uneven in thickness due to an increase in temperature.

The problem to be solved by the invention

The object of the present invention is to provide an adhesive film for wafer processing that protects the surface of the wafer with an excellent cushioning effect and improves fluidity control and thickness at high temperatures during back grinding of the wafer. Uniformity.

The object of the present invention is not limited to the above-mentioned object, and other objects and advantages of the present invention not mentioned can be understood through the following description, and can be more clearly understood through the embodiments of the present invention. Furthermore, it is obvious that the objects and advantages of the present invention can be realized by means and combinations thereof indicated in the claims.

technical means to solve problems

In order to solve the above-mentioned technical problems, the adhesive film for wafer processing of the present invention may include: a multi-layer base material, including an upper base material layer and a lower base material layer; a first adhesive layer configured on the above-mentioned upper base material layer; and a second Two adhesive layers, configured between the upper substrate layer and the lower substrate layer, the second adhesive layer can be made of a second adhesive composition, the second adhesive composition includes an adhesive resin and a core-shell nano particle.

The average particle diameter of the above-mentioned core-shell nanoparticles may be 5nm-400nm.

The core of the above-mentioned core-shell nanoparticles can be polyalkyl (meth)acrylate with a glass transition temperature of -50°C to 40°C, and the shell of the above-mentioned core-shell nanoparticles can be polyalkylene (meth)acrylate with a glass transition temperature of 50°C. ℃～150℃ polyalkyl (meth)acrylate.

With respect to 100 parts by weight of the bonding resin in the second bonding composition, 0.1 parts by weight to 20 parts by weight of core-shell nanoparticles may be included.

The modulus of the second adhesive layer in the temperature range of 60° C. to 90° C. may be 0.05 MPa˜2 MPa.

The recovery force of the above-mentioned adhesive membrane measured according to the following formula 1 may be 55% to 90%. The method of measuring the restoring force using Equation 1 will be specifically described below.

Formula 1: Restoration force (%)=(1-(X _f /X ₀ ))×100

In the above formula 1, X ₀ refers to the thickness of 1/2 times the initial thickness of the adhesive membrane, and X _f is the pressure of the adhesive membrane when no force is applied to the adhesive membrane when X 0 is held at X ₀ for 10 seconds and then restored. thickness of.

Under the temperature condition of 23° C., the modulus of the lower base material layer and the upper base material layer may be 1000 MPa or more.

The above-mentioned lower base material layer and upper base material layer may respectively comprise polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, wholly aromatic polyester, One or more of the group consisting of polyimide, polyamide, polycarbonate, polyacetal, modified polyphenylene ether, polyphenylene sulfide, polysulfone, polyether ketone, and biaxially oriented polypropylene.

The adhesive resin of the second adhesive layer may include a thermosetting acrylic adhesive.

A primer layer may be additionally formed on at least one of the upper surface of the upper base material layer, the lower surface of the upper base material layer, and the upper surface of the lower base material layer.

Efficacy compared to prior art

The adhesive film for wafer processing of the present invention can achieve an excellent cushioning effect on the wafer surface during back grinding of the wafer by including the second adhesive layer containing the core-shell nanoparticles ( recovery), and improve flow control and thickness uniformity at high temperatures.

The effects of the present invention are not limited to the effects mentioned above, and those of ordinary skill in the art can clearly understand other effects not mentioned from the following description.

In addition to the above-mentioned effects, the specific effects of the present invention will be described together in the description of the specific embodiments of the present invention below.

Hereinafter, the above objects, features and advantages will be described in detail with reference to the accompanying drawings, so that those skilled in the art of the present invention can easily implement the technical idea of the present invention. In describing the present invention, when it is judged that the detailed description of known technologies related to the present invention may obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals denote the same or similar structural elements.

In this specification, the arrangement of any structure on the "upper (or lower)" of a structural element or the "on (or lower)" of a structural element may not only mean that any structure is arranged to be opposite to the upper surface (or lower surface) of the above-mentioned structural element Contact can also mean that other structures can be arranged between the above-mentioned structural elements and any structure arranged on (or under) the above-mentioned structural elements.

In this specification, expressions of the singular number used include expressions of the plural number unless the context clearly indicates otherwise. In this application, terms such as "consisting" or "comprising" should not be interpreted as necessarily including all the structural elements described in the specification, but should be interpreted as not including some of the structural elements, or may also include additional structural elements.

Terms such as "one side", "another side" and "both sides" in this description are only used to distinguish one structural element from other structural elements, and the structural elements are not limited to the above terms.

In the present invention, wafer processing may include a wafer back grinding (back grinding) process, a dicing process, a pick-up process of a diced semiconductor wafer, and the like.

Hereinafter, in describing the present invention, detailed descriptions of known technologies that may unnecessarily obscure the gist of the present invention will be omitted.

Hereinafter, the adhesive film for wafer processing of this invention is demonstrated in detail.

The adhesive film for wafer processing of the present invention may include: a multi-layer substrate, including an upper substrate layer and a lower substrate layer; a first adhesive layer disposed on the upper substrate layer; and a second adhesive layer configured Between the upper substrate layer and the lower substrate layer, the second adhesive layer is made of a second adhesive composition, and the second adhesive composition includes an adhesive resin and core-shell nanoparticles.

FIG. 1 is a cross-sectional view schematically showing an adhesive film for wafer processing according to an embodiment of the present invention. Referring to Fig. 1, the bonding film for wafer processing of the present invention comprises: a multilayer substrate 110; a first adhesive layer 120 configured on the upper substrate layer 112 of the multilayer substrate; and a second adhesive layer 115 configured on between the upper substrate layer 112 and the lower substrate layer 111 .

multilayer substrate

The multi-layer substrate 110 includes a lower substrate layer 111 , an upper substrate layer 112 and a second adhesive layer 115 . The first adhesive layer 120 is disposed on the upper base material layer 112 , and the second adhesive layer 115 is disposed between the lower base material layer 111 and the upper base material layer 112 . In the adhesive film for wafer processing of the present invention, the multi-layer substrate forms a sandwich structure in which the second adhesive layer 115 is disposed between the lower substrate layer 111 and the upper substrate layer 112 .

The lower substrate layer 111 and the upper substrate layer 112 can be made of high modulus materials. More specifically, the lower base material layer 111 and the upper base material layer 112 have a modulus of 1000 MPa or more, for example, may have a modulus of 1200 MPa or more, 1500 MPa or more, 2000 MPa or more, or 3000 MPa or more. The measured value under the condition is the reference. The feature of the present invention is that, on the side where the wafer is bonded, both the upper substrate layer 112 and the lower substrate layer 111 are made of high modulus materials.

When the modulus of the upper substrate layer 112 and the lower substrate layer 111 is relatively low, in other words, under the situation of less than 1000 MPa, the support force of the wafer or the diced semiconductor wafer may be reduced, which may cause the backside grinding process There is a possibility of collision of the semiconductor wafer.

The lower base material layer 111 and the upper base material layer 112 may respectively comprise polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), fully aromatic polyester and other polyesters, polyimide (PI), polyamide (PA), polycarbonate (PC), polyacetal, modified polyphenylene ether, polyphenylene sulfide, One or more types from the group consisting of polypyrene, polyether ketone, and biaxially oriented polypropylene (Oriented Poly-propylene).

Preferably, the material of the lower substrate layer 111 and the upper substrate layer 112 may be the same. As an example, the lower base material layer 111 and the upper base material layer 112 may be made of polyethylene terephthalate (PET).

Although the lower substrate layer 111 and the upper substrate layer 112 may have the same thickness, they are not limited thereto. The lower substrate layer 111 and the upper substrate layer 112 may respectively have a thickness of about 10 μm˜150 μm. On the other hand, in the present invention, although the lower base material layer 111 and the upper base material layer 112 have high modulus, when the thickness of the lower base material layer 111 and the upper base material layer 112 is relatively thick, especially , if the thickness of the upper substrate layer 112 is too thick, it is difficult to withstand the impact generated during wafer processing such as back grinding. Therefore, preferably, the thickness of the lower base material layer 111 and the upper base material layer 112 should be set at 150 μm or less.

On the other hand, the lower substrate layer 111 and/or the upper substrate layer 112 may contain a small amount of various additives, such as coupling agents, plasticizers, antistatic agents, antioxidants, and the like.

first adhesive layer

The first adhesive layer 120 shown in FIG. 1 is a part bonded to the wafer.

The first adhesive layer 120 is not particularly limited, as long as it has proper adhesiveness under normal temperature conditions, various adhesives can be used, for example, known ultraviolet (UV) adhesives and the like.

The thickness of the first adhesive layer 120 is not particularly limited, for example, it may be 10 μm˜100 μm.

2 is a cross-sectional view schematically showing an adhesive film for wafer processing according to still another embodiment of the present invention.

Referring to FIG. 2 , a primer layer 113 may be additionally included on the upper surface of the upper substrate layer 112 of the multilayer substrate. This primer layer 113 can be used to improve the adhesion between the first adhesive layer 120 and the multi-layer substrate 110 .

The primer layer 113 is formed on the upper surface of the upper substrate layer 112 , that is, a separate layer may be formed on the side where the first adhesive layer 120 is formed. As another example, the primer layer 113 may be formed by modifying the upper surface of the upper substrate layer 112 .

As an example, although FIG. 2 shows that the primer layer 113 is formed on the upper surface of the upper substrate layer 112, the present invention is not limited thereto, and the primer layer may also be formed on the lower surface or lower portion of the upper substrate layer 112. the upper surface of the substrate layer 111 .

Although not shown in FIG. 2 , the present invention may also include a release film disposed on the upper surface of the first adhesive layer and bonded by the above adhesive layer. One side of the above-mentioned release film may be subjected to a release treatment. Regarding the above-mentioned release treatment, any material generally used for release treatment in this field can be used without limitation. For example, silicon is preferably used for release treatment.

second adhesive layer

In the present invention, the second adhesive layer 115 is an adhesive layer arranged between the upper base material layer 112 and the lower base material layer 111, and can be used as a buffer with high buffering effect to protect the wafer surface during wafer processing. layer or damping layer.

Preferably, the second adhesive layer of the present invention is made of a second adhesive composition, and the second adhesive composition includes an adhesive resin and core-shell nanoparticles. The second adhesive layer may be manufactured by thermally curing the above-mentioned second adhesive composition.

The adhesive resin of the above-mentioned second adhesive composition may include a thermosetting acrylic adhesive resin, and in addition to the adhesive resin, the second adhesive composition may further include a thermosetting agent.

For example, the thermosetting acrylic binding resin may be a methyl acrylate compound. Methyl acrylate compounds that can be used for thermosetting acrylic adhesives include (meth)acrylates, alkyl (meth)acrylates with an alkyl group having 4 or more carbon atoms, and non-urethane Ethyl ester polyfunctional (meth)acrylate, etc., but not limited thereto.

Curing agents that can be used for thermosetting acrylic adhesives include isocyanate crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, peroxide etc., but not limited thereto. The content of the curing agent may be 2 parts by weight or less with respect to 100 parts by weight of the adhesive resin in the second adhesive composition, but is not limited thereto.

For the buffer effect, the lower the modulus of the second adhesive layer as the buffer layer, the better. However, if the modulus is too low, the following problem may occur. Elevation causes the buffer layer to flow or become uneven in thickness at high temperatures.

Therefore, the present inventors found that in order to control the fluidity of the second adhesive layer due to the heat generated when performing the back grinding process of the wafer, the second adhesive layer contains nanoparticles of a core-shell structure, so that can solve the above problems.

Preferably, the above-mentioned nanoparticles with core-shell structure have an average particle diameter of 5 nm to 400 nm, more preferably 100 nm to 300 nm. If the average particle size of the nanoparticles is less than 5nm, the dispersion may be uneven due to aggregation caused by static electricity between the particles. If the average particle size of the nanoparticles is larger than 400nm, the surface of the coating layer may become uneven. The problem of poor uniformity of equal thickness.

The core of the above-mentioned core-shell nanoparticles plays a role of maintaining modulus at high temperature by forming a cross-linked structure, and therefore, is preferably made of a material with a low glass transition temperature.

The glass transition temperature of the core of the core-shell nanoparticles may be -50°C to 40°C, more preferably -30°C to 30°C, most preferably -30°C to 20°C. In the above-mentioned glass transition temperature range, it is possible to realize the cushioning effect necessary for the process temperature range (40°C to 90°C) against the impact generated during back grinding.

If the glass transition temperature of the nucleus is greater than 40°C, the ability to absorb the shock generated in the temperature range of the processing process is limited, which may cause chip cracks. If the glass transition temperature of the nucleus is less than -50°C, This will cause the shape of the particles to be easily deformed by the pressure during the processing process, which may cause problems in the impact absorption function.

For example, the core may comprise one or more polyalkyl(meth)acrylates having a glass transition temperature in the range of -50°C to 40°C. Preferably, the core may comprise polymethylacrylate, polyethylacrylate, polycyclohexylacrylate, polybenzylacrylate, polyisopropylacrylate, polybutylmethacrylate, polyhexylmethacrylate, polycyano One or more of methyl acrylate and poly-2-cyanoethyl methacrylate, but not limited thereto. More preferably, the core may contain one or more of polymethyl acrylate and polybutyl methacrylate.

Preferably, the shell of the above-mentioned core-shell nanoparticles functions to form a hard structure, and is made of a material with a high glass transition temperature in order to ensure dispersibility in the binder layer.

The glass transition temperature of the shell of the above-mentioned core-shell nanoparticles may be 50°C-150°C, more preferably, 60°C-130°C, most preferably, 80°C-130°C.

If the glass transition temperature of the above-mentioned shell is lower than 50° C., there may be a problem that aggregation (aggregation) is caused due to a decrease in particle dispersibility, or organic particles are deformed due to heat generated during a processing process, thereby causing a problem. The recovery performance of the conjunctiva under impact is reduced. If the glass transition temperature of the shell exceeds 150° C., the cushioning effect may be deteriorated due to an increase in the hardness of the particles.

For example, the shell may comprise polyalkyl(meth)acrylate having a glass transition temperature of 50°C to 150°C. Preferably, the shell may comprise polymethylmethacrylate (PMMA), polyethylmethacrylate, polypropylmethacrylate, polybutylmethacrylate, polyisopropylmethacrylate, polyisopropylmethacrylate One or more of butyl ester and polycyclohexyl methacrylate, but not limited thereto. More preferably, the shell may comprise polymethyl methacrylate.

With respect to 100 parts by weight of the core-shell nanoparticles, the shell may contain 1 to 70 parts by weight, preferably, 5 to 60 parts by weight, more preferably, 10 to 50 parts by weight. parts by weight. If the content of the shell in the core-shell nanoparticles is less than 1 part by weight, the core cannot be fully surrounded, and the surface protection effect of the wafer during the back grinding process will decrease. If it is greater than 70 parts by weight, the hard shell will Too much will reduce the cushioning effect, so it will not be able to maintain the recovery of the conjunctiva well. Therefore, only when the above-mentioned shell satisfies the range of 1 to 70 parts by weight of the core-shell nanoparticles, can the buffering effect and the balance of the modulus be maintained.

With respect to 100 parts by weight of the bonding resin of the above-mentioned second bonding composition, 0.1 to 20 parts by weight of core-shell nanoparticles may be included, more preferably, 1 to 10 parts by weight may be included, most preferably , may contain 2 to 8 parts by weight. If the content of the core-shell nanoparticles is less than 0.1 parts by weight, the buffering effect of the nanoparticles may not be significant; Creates uneven aggregation, resulting in half the cushioning effect, etc.

Preferably, the modulus of the above-mentioned second adhesive layer in the temperature range of 60°C to 90°C is 0.05MPa˜2MPa, more preferably 0.05MPa˜1MPa.

Preferably, the modulus of the second adhesive layer is less than 2 MPa because the use of low modulus materials is beneficial to further improve the cushioning effect. However, if the modulus is too low, the fluidity of the adhesive layer will increase. Therefore, the thickness may be uneven due to the pressure received during the back grinding process of the wafer. Therefore, it is preferable that the first The modulus of the second adhesive layer is above 0.05 MPa.

Preferably, the recovery force of the conjunctiva of the present invention determined based on the following formula 1 is 55% to 90%, more preferably 65% to 90%, most preferably 70% to 90%.

Formula 1: Restoration force (%)=(1-(X _f /X ₀ ))×100

In the above formula 1, X ₀ is the thickness of 1/2 times the initial thickness of the adhesive membrane, and X _f is the thickness of the adhesive membrane when no force is applied to the adhesive membrane when X 0 is held at X ₀ for 10 seconds and then restored. thickness.

According to the present invention, according to the adhesive film having a restoring force of 55% to 90%, even under the heat and pressure generated in the back grinding process of the wafer, the adhesive film will not be deformed, so that the stability of the wafer can be maintained. Uniformity of thickness. If the restoring force is less than 55%, the surface protection effect during the wafer processing process is insufficient, and if the restoring force exceeds 90%, the buffering effect will be reduced, causing the impact generated during the back grinding process to be transmitted to the wafer, so There is a possibility that it will break.

In the present invention, the recovery force of the adhesive film is intended to measure the recovery force of the film including the adhesive layer, and is measured using a physical property tester (Texture Analyzer, TA.XT_Plus). The specific measurement method is as follows.

test methods

In the order of polyethylene terephthalate (PET) film (50 μm) / adhesive film (length × width: 20mm × 20mm, thickness: 60 μm) / polyethylene terephthalate film (50 μm) The bonded test piece is fixed on the board, and then pressed at a speed of 300mm/min with a rectangular probe at a high temperature (60°C) until the thickness becomes 1/2 times the initial thickness of the above-mentioned adhesive film, that is, X ₀ (unit: μm), then hold for 10 seconds, and then recover at the same speed (300mm/min) as when pressing, and the thickness of the conjunctiva that is pressed when a force of 0kPa is applied to the above-mentioned conjunctiva is set to When X _f (unit: μm), the restoring force (%) was calculated using the above formula 1.

Hereinafter, the structure and function of the present invention will be described in more detail through preferred embodiments of the present invention. However, these are preferred examples of the present invention, and should not be construed as limiting the present invention from any angle.

Preparation example

Preparation Example 1: Second Adhesive Layer Forming Composition ("M1")

Under a nitrogen atmosphere, 42 parts by weight of butyl acrylate, 10 parts by weight of ethylhexyl acrylate, 30 parts by weight of methyl acrylate, 5 parts by weight of 2-hydroxyethyl acrylate, 13 parts by weight of Acrylic acid, 0.05 parts by weight of azobisisobutyronitrile, and 100 parts by weight of ethyl acetate were polymerized for 6 hours at a temperature of 60°C to obtain an acrylic resin polymer solution with a weight average molecular weight of 800,000 a.

2 parts by weight of an isocyanate-based curing agent (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate C") was added to 100 parts by weight of the above-mentioned acrylic resin polymer solution A to obtain a composition for forming a second adhesive layer. (labeled "M1").

Preparation Example 2: Second Adhesive Layer Forming Composition ("M2")

Under a nitrogen atmosphere, 20 parts by weight of butyl acrylate, 10 parts by weight of ethylhexyl acrylate, 55 parts by weight of methyl acrylate, 7 parts by weight of 2-hydroxyethyl acrylate, 8 parts by weight of Acrylic acid, 0.05 parts by weight of azobisisobutyronitrile, and 100 parts by weight of ethyl acetate were polymerized for 6 hours at a temperature of 60°C to obtain an acrylic resin polymer solution with a weight average molecular weight of 600,000 b.

With respect to 100 parts by weight of the above-mentioned acrylic resin polymer solution B, 3 parts by weight of an isocyanate curing agent (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate C") was added to obtain a composition for forming a second adhesive layer ( marked "M2").

Preparation Example 3: First Adhesive Layer Forming Composition ("A1")

Into a reactor equipped with a cooling device to allow nitrogen circulation and facilitate temperature adjustment, a single unit composed of 27g of butyl acrylate (BA), 48g of methyl acrylate (MA) and 25g of hydroxyethyl acrylate (HEA) was put into the reactor. body mixture.

Next, put 100 parts by weight of ethyl acetate (EAc) as a solvent into 100 parts by weight of the above-mentioned monomer mixture, inject nitrogen into the above-mentioned reactor in order to remove oxygen, and fully mix at a temperature of 30°C for 30 minutes or more. Next, the temperature was kept at 50° C., and azobisisobutyronitrile was put in at a concentration of 0.1 parts by weight as a reaction initiator to initiate a reaction, and then polymerized for 24 hours to prepare a first reactant.

Prepare 24.6 parts by weight of methacryloxyethyl isocyanate (MOI) and a catalyst (DBTDL: dibutyl tin dilaurate) of 1 weight percent relative to MOI to the above-mentioned first reactant, and react 24 parts at a temperature of 40°C. hours, thereby obtaining an acrylic acid polymer C with a weight average molecular weight of 500,000.

To 100 parts by weight of the above-mentioned acrylic polymer C, 0.1 parts by weight of photoinitiator (Irgacure) 184 (manufactured by BASF, trade name) as a photopolymerization initiator was blended, and 2 parts by weight of isocyanate was added to cure agent (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate C") to obtain a composition for forming the first adhesive layer (marked as "A1").

Preparation 4: Core-Shell Nanoparticles ("b1")

The core is formed of polymethyl acrylate (PMA, Tg: 10°C), and the shell is formed of polymethyl methacrylate (PMMA, Tg: 105°C), thus forming a core-shell structure. In the core-shell nanoparticles , relative to 100 parts by weight of core-shell nanoparticles, the shell is 40 parts by weight, and the average particle size is 230nm.

Preparation 5: Core-Shell Nanoparticles ("b2")

The core is formed by polymethyl acrylate (PMA), and the shell is formed by polymethyl methacrylate (PMMA), thereby forming a core-shell structure. In core-shell nanoparticles, relative to 100 parts by weight of core-shell Nanoparticles, the shell is 30 parts by weight, and the average particle diameter is 130nm.

Example

Example 1

On a release-treated polyethylene terephthalate (PET) film (50 μm in thickness), the composition for forming the first adhesive layer ("A1") in Preparation Example 3 was coated so that the first adhesive The thickness of the layer was 20 μm, and then, a film with a first adhesive layer with a total thickness of 120 μm was produced by bonding a polyethylene terephthalate base film (thickness 50 μm) formed with a primer layer .

Next, the second adhesive layer formation in Preparation Example 2 was combined in such a manner that the ratio between the acrylic resin polymer solution B and the core-shell nanoparticles b1 in Preparation Example 4 was 100 parts by weight to 4 parts by weight. ("M2") was added and mixed with the core-shell nanoparticles b1 in Preparation 4, and then coated on a polyethylene terephthalate film (20 μm thick) with a thickness of 20 μm to produce A film with a second adhesive layer with a total thickness of 40 μm was obtained.

The film having the above-mentioned first adhesive layer and the film having the second adhesive layer were joined to prepare a composite film with a total thickness of 160 μm, and finally an adhesive film for wafer processing was prepared by using a protective sheet.

Example 2

Except that the second adhesive layer-forming adhesive composition ("M1") in Preparation Example 1 is used instead of the second adhesive layer-forming adhesive composition ("M2") in Preparation Example 2 as the second adhesive layer The preparation was carried out in the same manner as in Example 1, except that "b1" in Preparation Example 4 was replaced by "b2" in Preparation Example 5 as the core-shell nanoparticles.

Example 3

As in Example 1, except that "M2" was used and coated on a polyethylene terephthalate film (thickness 20 μm) at a thickness of 50 μm to form a second adhesive layer with a total thickness of 70 μm Prepare in the same way.

Example 4

Except using "M1" and coating on polyethylene terephthalate film (thickness 20μm) at a thickness of 50μm to form a second adhesive layer with a total thickness of 70μm and make the core-shell nano In Preparation Example 5 of particles, the content of "b2" was 2 parts by weight, and it was prepared in the same manner as in Example 2.

Example 5

Except using "M2" and coating on a polyethylene terephthalate film (thickness 20 μm) at a thickness of 80 μm to form a second adhesive layer with a total thickness of 100 μm and 8 parts by weight of Preparation Example Preparation was carried out in the same manner as in Example 1, except that "b2" in Preparation Example 4 was used as core-shell nanoparticles instead of "b1" in Preparation Example 4.

Example 6

Except using “M1” and coating on a polyethylene terephthalate film (20 μm thick) at a thickness of 80 μm to form a second adhesive layer with a total thickness of 100 μm and using 8 parts by weight of the preparation Except for the core-shell nanoparticles "b2" in 5, it was prepared in the same manner as in Example 2.

Comparative example 1

It was prepared in the same manner as in Example 4, except that the core-shell nanoparticles were not included in the second binder layer.

Comparative example 2

Preparation was performed in the same manner as in Example 3, except that "b1" in Preparation Example 4 was used instead of "b2" in Preparation Example 5 as the core-shell nanoparticles and the content thereof was 25 parts by weight.

Experimental example

Experimental Example 1: Determination of the modulus of the adhesive membrane (60°C and 90°C)

Under the condition of 1 Hz, by using a modulus measuring device rheometer (Rheometer, American Thermal Analysis Instruments (TA instruments), ARES-G2), the second adhesive layer used in the examples and comparative examples was laminated. The modulus was measured in a temperature environment from -20°C to 120°C on a sample having a size of 8mm in diameter x 1mm in thickness obtained by forming a single-layer adhesive layer formed from a solution of the composition, and recorded temperatures of 60°C and 90°C modulus and is reported in Table 1.

Experimental Example 2: Resilience

The resilience of the adhesive film is intended to measure the resilience of the film including the adhesive layer, measured by using a physical property tester (Texture Analyzer, TA.XT_Plus), calculated based on the following formula 1, and the specific measurement method is as follows.

Formula 1: Restoration force (%)=(1-(X _f /X ₀ ))×100

test methods

In the order of polyethylene terephthalate (PET) film (50 μm) / adhesive film (length × width: 20mm × 20mm, thickness: 60 μm) / polyethylene terephthalate film (50 μm) The bonded test piece is fixed on the board, and then pressed at a speed of 300mm/min with a rectangular probe at a high temperature (60°C) until the thickness becomes 1/2 times the initial thickness of the above-mentioned adhesive film, that is, X ₀ (unit: μm), then hold for 10 seconds, and then recover at the same speed (300mm/min) as when pressing, and the thickness of the conjunctiva that is pressed when a force of 0kPa is applied to the above-mentioned conjunctiva is set to When X _f (unit: μm), the restoring force (%) was calculated using the above formula 1.

According to the above-mentioned formula 1 and the measurement method, the restoring force of the adhesive membrane in the above-mentioned Examples 1 to 6 and Comparative Examples 1 to 2 was measured and shown in Table 1.

Experimental Example 3: Wafer Grinding Test (Thickness Uniformity)

The adhesive films in Examples 1 to 6 and Comparative Examples 1 to 2 were respectively attached to the semiconductor circuit surface, and then a 725 μm wafer was back ground to a thickness of 100 μm. The adhesive film was removed by irradiating UV A 300 mJ/cm², and then the average thickness uniformity of 10 points in the wafer after grinding was compared. If the average value of the variation in thickness at each dot was 4 μm or less, the evaluation was “O” (good), and if it was 6 μm or more, the evaluation was “X” (failure).

Table 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative example 1 Comparative example 2 60°C modulus (MPa) 0.36 0.27 0.36 0.19 0.76 0.62 0.18 2.84 90°C modulus (MPa) 0.28 0.21 0.28 0.15 0.61 0.49 0.03 2.33 Resilience (%) 75.1 72.9 68.6 59.5 84.5 79.4 43.4 96.7 Thickness Uniformity o o o o o o x -

As shown in Table 1 above, compared with Comparative Example 1, Examples 1 to 6 including core-shell nanoparticles have excellent recovery force and thickness uniformity. In addition, in Comparative Example 2, the modulus value of the second adhesive layer was greater than 2 MPa, the restoring force was greater than 90%, the cushioning properties were insufficient, and it was difficult to measure the thickness uniformity.

Above, the present invention has been described with reference to the accompanying drawings, but the present invention is not limited to the embodiments disclosed in the specification and the accompanying drawings. It is obvious that those of ordinary skill in the technical field of the present invention can understand within the scope of the technical thought of the present invention. Make various modifications. Also, it should be understood that even the effects of the structures of the present invention that are not explicitly described in the description of the embodiments of the present invention include effects that can be predicted by the corresponding structures.

110: Substrate 111: lower substrate layer 112: upper substrate layer 113: primer layer 115: the second adhesive layer 120: the first adhesive layer

FIG. 1 is a cross-sectional view schematically showing an adhesive film for wafer processing according to an embodiment of the present invention.

2 is a cross-sectional view schematically showing an adhesive film for wafer processing according to another embodiment of the present invention.

110: Substrate

111: lower substrate layer

112: upper substrate layer

115: the second adhesive layer

120: the first adhesive layer

Claims (11)

An adhesive film for wafer processing, comprising: a multi-layer substrate comprising an upper substrate layer and a lower substrate layer; a first adhesive layer configured on the upper substrate layer; and The second adhesive layer is configured between the upper substrate layer and the lower substrate layer, Wherein the second adhesive layer is made of a second adhesive composition, and the second adhesive composition includes an adhesive resin and core-shell nanoparticles. The adhesive film for wafer processing according to Claim 1, wherein the average particle diameter of the core-shell nanoparticles is 5 nm to 400 nm. The adhesive film for wafer processing as claimed in item 1, wherein, The core of the core-shell nanoparticles is a polyalkyl (meth)acrylate with a glass transition temperature of -50°C to 40°C. The shell of the core-shell nanoparticles is polyalkyl (meth)acrylate with a glass transition temperature of 50°C to 150°C. The adhesive film for wafer processing according to claim 1, wherein relative to 100 parts by weight of the adhesive resin of the second adhesive composition, 0.1 to 20 parts by weight of core-shell nanoparticles are included. The adhesive film for wafer processing according to claim 1, wherein the modulus of the second adhesive layer in the temperature range of 60° C. to 90° C. is 0.05 MPa to 2 MPa. For example, the adhesive film for wafer processing in Claim 1, wherein the recovery force of the adhesive film measured according to the following formula 1 is 55% to 90%, formula 1: recovery force (%)=(1-(X _f /X ₀ ))×100 In Formula 1, X ₀ is the thickness of 1/2 times the initial thickness of the adhesive membrane, and X _f is when no force is applied to the adhesive membrane when X 0 is held at X ₀ for 10 seconds and then restored. The thickness of the conjunctiva to be compressed. The adhesive film for wafer processing according to claim 1, wherein, under the temperature condition of 23° C., the modulus of the lower base material layer and the upper base material layer is 1000 MPa or more. The adhesive film for wafer processing as claimed in claim 1, wherein the lower base material layer and the upper base material layer respectively comprise polyethylene terephthalate, polyethylene naphthalate, polyethylene terephthalate Butylene phthalate, fully aromatic polyester, polyimide, polyamide, polycarbonate, polyacetal, modified polyphenylene ether, polyphenylene sulfide, polysulfide, polyether ketone and two-way More than one type in the group consisting of stretched polypropylene. The adhesive film for wafer processing according to claim 8, wherein the material of the lower substrate layer and the upper substrate layer is polyethylene terephthalate. The adhesive film for wafer processing according to claim 1, wherein the adhesive resin of the second adhesive layer includes a thermosetting acrylic adhesive resin. The adhesive film for wafer processing according to claim 1, wherein a bottom is additionally formed on at least one of the upper surface of the upper base material layer, the lower surface of the upper base material layer, and the upper surface of the lower base material layer. paint layer.

Images