KR102106923B1 - Semiconductor processing sheet and production method of semiconductor device - Google Patents

Abstract

It is possible to suppress the generation of dicing powder, particularly thread-shaped dicing powder, generated during dicing of an object to be cut, and also has good pickup performance, and can also suppress the temporal deterioration of the pickup performance. Provides a semiconductor processing sheet having good expandability and a method for manufacturing a semiconductor device using the same.
As a semiconductor processing sheet 1 having a base film 2 and an adhesive layer 3 laminated on one side of the base film 2, the base film 2 is a number located on the adhesive layer 3 side. The resin layer (A) is provided with a resin layer (B) stacked on the opposite side to the base layer (A) and the adhesive layer (3) of the resin layer (A), and the resin layer (A) contains the norbornene-based compound as at least one kind of monomer. An olefin-based resin having a polymer other than norbornene-based resin (a1) and a norbornene-based resin (a1) having a resin density of 0.870 to 0.910 g / cm ³ and a heat of fusion (ΔH) of 85 J / g or less. (a2), and the resin layer (B) is characterized by a semiconductor processing sheet 1 having an olefinic resin as a main component, a tensile modulus of 50 to 300 MPa, and an elongation at break of 100% or more.

Description

{Semiconductor processing sheet and production method of semiconductor device}

The present invention relates to a semiconductor processing sheet used for processing semiconductors, for example dicing and die bonding, and a method for manufacturing a semiconductor device using the semiconductor processing sheet.

Semiconductor wafers, such as silicon and gallium arsenide, and various packages (hereinafter sometimes referred to as `` cut materials '' in combination) are manufactured in a large-diameter state, and these are element pieces (hereinafter referred to as `` chips ''). After being cut and separated (dicing) with each other, and then peeled (picked up) to each, it is transferred to the next step, the mounting process. At this time, the object to be cut, such as a semiconductor wafer, is adhered to the adhesive sheet in advance, and is provided to each process of dicing, cleaning, drying, expanding, pick-up and mounting.

Conventionally, in the process from the dicing step of the object to be cut to the pick-up step, a dicing sheet formed by forming an adhesive layer on a base film is used as a semiconductor processing sheet. Specifically, the object to be cut is provided to the dicing while being fixed to the dicing sheet through the pressure-sensitive adhesive layer, and the chip after dicing is picked up from the pressure-sensitive adhesive layer of the dicing sheet.

As the base film of the dicing sheet, a polyolefin-based film, polyvinyl chloride-based film, or the like is generally used. Here, in general full cut dicing as a specific method of the dicing process, cutting of the object to be cut is performed by a rotating round blade. In full-cut dicing, the pressure-sensitive adhesive layer may be cut beyond the object to be cut so that the object to be cut with the dicing sheet attached is reliably cut over the entire surface, and a part of the base film may also be cut.

At this time, dicing powder composed of the material constituting the pressure-sensitive adhesive layer and the base film is generated from the dicing sheet, and the resulting chip may be contaminated with the dicing powder. One such form of dicing powder is a threaded dicing powder, which is attached on a dicing line or near a cross section of a chip separated by dicing.

When the sealing of the chip is performed while the above-described thread-shaped dicing powder is attached to the chip, the thread-shaped dicing powder attached to the chip is decomposed into heat of sealing, and this thermal decomposition product breaks or obtains the package. It can also cause malfunction in devices. Since it is difficult to remove the thread-shaped dicing powder by washing, the yield of the dicing process is remarkably lowered due to generation of the thread-shaped dicing powder. For this reason, when dicing is performed using a dicing sheet, it is desired to prevent generation of thread-shaped dicing powder.

On the other hand, in order to simplify the process of the pick-up process and the mounting process, a dicing die bonding sheet may be used as a semiconductor processing sheet having both a dicing function and a chip bonding function. When using such a sheet, the object to be cut is provided to the dicing in a state fixed to the base film through the adhesive layer, and the chip after dicing is picked up with the adhesive layer from the base film. Then, the adhesive layer attached to the chip is used to adhere (mount) the chip to a substrate or the like. As such a dicing die bonding sheet, what is disclosed by patent documents 1-3 is mentioned, for example.

In the above dicing die bonding sheet, in order to pick up the chip with the adhesive layer, it is required that the base film and the adhesive layer have good peelability.

Special Publication No. 2-32181 Special Publication 2006-156754 Publication 2007-012670

However, in the conventional dicing die-bonding sheet, the peelability of the base film and the adhesive layer is deteriorated due to aging, particularly when the sheet is stored for a long time, and there is a case where chip pick-up cannot be performed satisfactorily. .

Particularly, as the size and thickness of semiconductor devices have been reduced in recent years, thinning of semiconductor chips mounted on the semiconductor devices has progressed. Therefore, if the peelability of the base film and the adhesive layer decreases, it is difficult to pick up chips. Not only that, but in some cases, defects such as cracking or missing chips occur.

In addition, in order to perform the above-expanding process, good dilatability is required for the dicing sheet. When the base film is a polyvinyl chloride-based film, it is excellent in expandability, but is not preferable from the viewpoint of environmental conservation. On the other hand, when the base film is a polyolefin-based film, the expandability is not constant, and the alignment of the chips after the expansion is inferior, which may cause a malfunction at the time of pickup.

This invention is made | formed in light of the above situation, and can suppress the generation | occurrence | production of the dicing powder, especially the thread-shaped dicing powder which generate | occur | produces when dicing a to-be-cut object, and also has a favorable pick-up performance, and is also applicable. An object of the present invention is to provide a semiconductor processing sheet capable of suppressing a drop in pick-up performance over time, and also having excellent expandability, and a method of manufacturing a semiconductor device using the same.

In order to achieve the above object, firstly, the present invention is a semiconductor processing sheet having a base film and an adhesive layer laminated on one side of the base film, wherein the base film is a resin layer (A ), And a resin layer (B) laminated on the opposite side of the adhesive layer of the resin layer (A), wherein the resin layer (A) is a polymer having a norbornene-based compound as at least one kind of monomer. Norbornene-based resin (a1) and olefin-based resin (a2) having a resin density of 0.870 to 0.910 g / cm ³ and a heat of fusion (ΔH) of 85 J / g or less as resins other than the norbornene-based resin (a1). ), And the resin layer (B) has a olefin-based resin as a main component, has a tensile modulus of 50 to 300 MPa, and provides a semiconductor processing sheet characterized in that the elongation at break is 100% or more (Invention 1). .

In the semiconductor processing sheet according to the invention (invention 1), the resin layer (A) contains at least norbornene-based resin (a1) and olefin-based resin (a2), thereby dicing occurring during dicing of the object to be cut. It is possible to suppress the generation of powder, particularly thread-like dicing powder, and has good pick-up performance, and can also suppress the deterioration of the pick-up performance over time, and further expandability. Further, the semiconductor processing sheet exhibits excellent expandability due to the presence of the resin layer (B), but the resin layer (A) also satisfies the resin layer (B) by containing an olefinic resin (a2). , Expandability becomes good.

In the invention (invention 1), the content of the norbornene-based resin (a1) in all resin components in the resin layer (A) is preferably 3 to 60% by mass (invention 2).

In the invention (inventions 1 and 2), the content of the olefin-based resin (a2) in the total resin component in the resin layer (A) is preferably 10 to 97% by mass (invention 3).

In the above invention (invention 1 to 3), wherein the resin layer (A) is preferably a resin density further contain the olefin-based resin 0.910g / cm ³ greater than, ~0.930g / cm ³ (a3) (Invention 4).

In the invention (Inventions 1 to 4), the resin layer (A) preferably has a tensile modulus of 1000 MPa or less (Invention 5).

In the above invention (Inventions 1 to 5), it is preferable that the base film has a tensile modulus of 80 to 500 MPa (Invention 6).

In the above invention (Inventions 1 to 6), it is preferable that the adhesive layer contains a thermoplastic resin and a thermosetting adhesive component (Invention 7).

Secondly, the present invention, after attaching the semiconductor processing sheet (inventions 1 to 7) to the semiconductor wafer through the adhesive layer, cutting the semiconductor wafer into semiconductor chips, and a base film for the semiconductor processing sheet A semiconductor comprising a step of peeling both at the interface of the adhesive layer to form a chip with the adhesive layer, and a step of bonding the chip with the adhesive layer to a circuit board through the adhesive layer. A method for manufacturing a device is provided (Invention 8).

The semiconductor processing sheet according to the present invention can be preferably used as a dicing die bonding sheet.

In the present invention, the "norbornene-based compound" is selected from the group consisting of norbornene, a compound having a cyclic structure containing a bicyclo ring according to norbornene (for example, dicyclopentadiene), and derivatives thereof, or It means more than two species (two types).

The semiconductor processing sheet according to the present invention can suppress the generation of dicing powder, especially thread-shaped dicing powder, generated during dicing of an object to be cut, has good pickup performance, and also overlooks the pickup performance. It is possible to suppress the reduction in redness, and furthermore, the expandability is also good.

1 is a cross-sectional view of a semiconductor processing sheet according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described.

1 is a cross-sectional view of a semiconductor processing sheet 1 according to an embodiment of the present invention. As shown in FIG. 1, the semiconductor processing sheet 1 according to the present embodiment includes a base film 2 and an adhesive layer 3 laminated on one side (surface in FIG. 1) of the base film 2. I have it. On the other hand, before using the semiconductor processing sheet 1, in order to protect the adhesive layer 3, it is preferable to laminate a peelable release sheet on the exposed surface (surface in FIG. 1) of the adhesive layer 3. The semiconductor processing sheet 1 can take any shape, such as a tape shape or a label shape.

The base film 2 in this embodiment has the resin layer (A) located on the adhesive layer 3 side and the resin layer (B) laminated on the opposite side to the adhesive layer 3 of the resin layer (A). It consists of.

1. Resin layer (A)

The resin layer (A) is a resin other than the norbornene-based resin (a1) and the norbornene-based resin (a1), which are polymers in which the norbornene-based compound is at least one kind of monomer, and has a resin density of 0.870 to 0.910 g / cm. ³ , and also contains an olefin-based resin (a2) having a heat of fusion (ΔH) of 85 J / g or less.

1-1. Norbornene-based resin (a1)

The norbornene-based resin (a1) is a polymer in which the norbornene-based compound is at least one kind of monomer.

As described above, the norbornene-based compound is a norbornene (bicyclo [2.2.1] hepta-2-ene), a compound having a cyclic structure containing a bicyclo ring according to norbornene (for example, dicyclopentadiene) ) And one or more compounds selected from the group consisting of these derivatives, and specific examples other than norbornene include cyclopentadiene and tetracyclododecene.

Since the norbornene-based resin (a1) is a polymer in which the norbornene-based compound is at least one kind of monomer, it has a bicyclo [2.2.1] heptane ring structure in the main chain or side chain.

The preferred structure of the norbornene-based resin (a1) is a structure in which the cyclic structure constitutes at least a part of the main chain of the polymer constituting the resin, and the bicyclo ring portion in the cyclic structure constitutes a part of the main chain. More preferred. As a resin having such a structure, a ring-opening metathesis polymer hydrogenated polymer of a norbornene-based monomer (specifically available as ZEONEX (registered trademark) series manufactured by Nippon Zeon), a nose of norbornene and ethylene Polymer (specifically available as TOPAS (registered trademark) series manufactured by Polyplastics), copolymer based on ring-opening polymerization of dicyclopentadiene and tetracyclopentadodecene (specifically, ZEONOR manufactured by Nippon Zeon Co., Ltd.) (Available as a registered trademark) series), a copolymer of ethylene and tetracyclododecene (specifically available as a Mitsui Chemicals Apel (registered trademark) series), dicyclopentadiene and methacrylic acid Preferred are cyclic olefin resins containing a polar group using an ester as a raw material (specifically available as Atone (registered trademark) series manufactured by JSR). . When such a resin is used, in the region subjected to shearing force or frictional heat based on dicing, the dispersion of the phase of the norbornene-based resin (a1) and the phase of the olefin-based resin (a2) generates dicing powder. It becomes a state especially suitable for suppressing.

The polymer constituting the norbornene-based resin (a1) may be one type, or may be a mixture of a plurality of types of polymers. Here, the different types of polymers mean that the state of branching (that is, the architecture of the polymer), molecular weight, the blending balance of the monomers constituting the polymer, the composition of the monomers constituting the polymer, and these combinations have a significant effect on physical properties, etc. It means that the degree is different. When there are a plurality of types of polymers, they may form a phase separation structure with the olefin-based resin (a2) without forming phases in the resin layer (A), and they form different phases in the resin layer (A). You may form a phase-separated structure with the olefin resin (a2).

Here, the norbornene-based resin (a1) may have a crosslinked structure. The type of the crosslinking agent that results in the crosslinking structure is arbitrary, and compounds having an organic peroxide or epoxy group such as dicumyl peroxide are typical. The crosslinking agent may be crosslinked between one type of the polymers constituting the norbornene-based resin (a1), or may be crosslinked between different types of polymers. The bonding site of the crosslinking agent is also arbitrary. In the polymer constituting the norbornene-based resin (a1), it may be cross-linked with atoms constituting the main chain, or may be cross-linked with atoms constituting other than the main chain, such as side chains and functional groups. Although the degree of crosslinking is also arbitrary, if the degree of crosslinking proceeds excessively, the workability (especially formability) of the resin layer (A) containing the norbornene-based resin (a1) is excessively reduced, or the resin layer (A) Since it is concerned that the surface properties are excessively deteriorated or the odor resistance of the resin layer (A) is lowered, it is necessary to stay within a range in which such a problem does not occur.

The degree of thermoplasticity of the norbornene-based resin (a1) can be represented by a melt flow rate (MFR) indicating the viscosity at the time of melting. On the other hand, if the specific degree of the desired thermoplasticity of the norbornene-based resin (a1) should be provided in detail, the melt flow rate of the norbornene-based resin (a1) at a temperature of 230 ° C. and a load of 2.16 kgf according to JIS K7210: 1999. It is preferable that the value of is 0.1 g / 10 min or more from the viewpoint of suppressing generation of dicing powder and processability. From the viewpoint of stably realizing the suppression of the generation of dicing powder while ensuring high productivity (processability), the melt flow rate of the norbornene-based resin (a1) is preferably 0.5 to 50.0 g / 10min, and 1.0 to 25.0 g It is more preferable if it is / 10min. When the MFR is too high, it is excellent in workability such as molding, but there is a fear that the function of suppressing the generation of dicing powder is lowered. On the contrary, when the MFR is too low, there is a fear that workability such as molding is lowered.

It is preferable that the tensile modulus of elasticity of norbornene-based resin (a1) at 23 ° C is more than 1.5 GPa. Meanwhile, details of the method for measuring the tensile modulus will be described later in Examples. By setting the tensile modulus in this range, the difference in physical properties with the olefin-based resin (a2) increases, and a phase separation structure suitable for suppressing the generation of dicing powder is obtained in the resin layer (A). From the viewpoint of stably obtaining this phase separation structure, it is preferable that the tensile modulus of elasticity of norbornene-based resin (a1) at 23 ° C is 2.0 GPa or more. The upper limit of the tensile modulus at 23 ° C of the norbornene-based resin (a1) is not particularly limited from the viewpoint of suppressing the generation of dicing powder, but if the tensile modulus is excessively high, the chemistry of the norbornene-based resin (a1) Depending on the structure, the fluidization temperature described below may be excessively high, and in this case, there is a high possibility that the phase of the norbornene-based resin (a1) in the resin layer (A) becomes rough and loose. As a result, chipping may occur or the resin layer (A) may embrittle significantly. Therefore, it is preferable that the upper limit of the tensile modulus of elasticity of the norbornene-based resin (a1) at 23 ° C is 4.0 GPa or less.

The fluidization temperature of the norbornene-based resin (a1) is preferably 225 ° C or lower, more preferably 200 ° C or lower, and even more preferably 180 ° C or lower. The fluidization temperature is the lowest temperature at which fluidization of the entire sample occurs when the sample is further heated beyond the state where the intermolecular interaction increases due to the increase in the degree of freedom of deformation of the molecule as the heated resin sample passes through the softening point. When the fluidization temperature is 225 ° C or less, the situation in which the phase of the norbornene-based resin (a1) in the resin layer (A) does not occur is coarse and coarse, and while effectively suppressing the generation of dicing powder, chipping or resin layer ( Significant embrittlement of A) can be prevented. When the fluidization temperature of the norbornene-based resin (a1) is excessively low, the tensile modulus at 23 ° C may be lowered to 1.5 GPa or less. In this case, the difference in physical properties with the olefin-based resin (a2) becomes small, and it is concerned that the phase separation structure suitable for suppressing the generation of dicing powder in the resin layer (A) cannot be obtained. Therefore, the lower limit of the fluidization temperature is preferably 100 ° C or higher.

Here, the "fluidization temperature" in the present specification is a value obtained by a solidification type flow tester (for example, Shimadzu Corporation, model number: CFT-100D is a product example). Specifically, a stroke displacement speed (with a load of 49.05 N, a hole shape of φ2.0 mm and a length of 5.0 mm is used, and the temperature of the sample is increased at a heating rate of 10 ° C./min, and fluctuates with heating. mm / min) to obtain a temperature dependence chart of the stroke displacement speed. When the sample is a thermoplastic resin, the stroke displacement speed rises on the basis that the sample temperature reaches the softening point, and then falls once after reaching a predetermined peak. The stroke displacement speed rapidly rises as the entire sample flows, after reaching the lowest point by this drop. In the present invention, when the sample temperature is raised beyond the softening point, the temperature giving the lowest value of the stroke displacement speed after the stroke displacement speed once reaches the peak is defined as the fluidization temperature.

The resin density of the norbornene-based resin (a1) makes it easy to obtain a phase-separated structure suitable for suppressing the generation of dicing powder in the resin layer (A) by sufficiently increasing the difference in physical properties with the olefin-based resin (a2) described later. From a perspective, 0.98 g / cm ³ It is preferable that it is above.

The norbornene-based resin (a1) may have crystallinity or may be amorphous, but in order to sufficiently increase the difference in physical properties with the olefin-based resin (a2), it is preferably amorphous.

The content of the norbornene-based resin (a1) in the total resin component in the resin layer (A) is preferably 3 to 60% by mass, more preferably 3.5 to 55% by mass, and still more preferably 5 to 45% by mass desirable. When the content of the norbornene-based resin (a1) is less than 3% by mass, an effect of suppressing generation of dicing powder cannot be stably obtained.

On the other hand, when the content of the norbornene-based resin (a1) exceeds 60% by mass, there is a fear that the workability of the resin layer (A) is lowered. In addition, since the tensile modulus of the resin layer (A) becomes too high, there is a possibility that the expandability is lowered.

1-2.olefin resin (a2)

The olefin-based resin (a2) is a resin other than the norbornene-based resin (a1), has a resin density of 0.870 to 0.910 g / cm ³ , and is an olefin-based resin having a heat of fusion (ΔH) of 85 J / g or less. The olefin resin (a2) particularly contributes to the peeling performance between the resin layer (A) and the adhesive layer (3), that is, pickup performance.

Here, the resin density of the olefin resin (a2) in the present specification is a value obtained by measuring in accordance with JIS K7112: 1999. In this specification, the heat of fusion (ΔH) is a value obtained by a differential scanning calorimeter (DSC). In the present embodiment, using a DSC, the sample is heated from -40 ° C to 250 ° C at a rate of 20 ° C / min, rapidly cooled to -40 ° C, and again raised to a temperature of 250 ° C at a rate of 20 ° C / min. Then, after maintaining at 250 ° C for 5 minutes, by lowering to -40 ° C at a rate of 20 ° C / min, a melting curve indicating a melting peak was obtained, and from the obtained melting curve, the heat of fusion (ΔH) and the melting peak to be described later Calculate the heat flow.

By using the base film 2 having the resin layer A containing the olefin-based resin (a2) in which the resin density and the heat of fusion (ΔH) are specified as described above, the semiconductor processing sheet 1 is avoided. The generation of dicing powder generated during dicing of the cut material is suppressed, and at the same time, it has good peelability between the base film 2 and the adhesive layer 3, that is, good pick-up performance, and also pick-up performance. It becomes possible to suppress the deterioration with time.

The resin density of the olefin resin (a2) is 0.870 to 0.910 g / cm ³ as described above. The resin density of the olefin resin (a2) is 0.870 g / cm ³ Below, when forming the resin layer (A), clogging occurs in the hopper portion, or when the base film (2) provided with the resin layer (A) is wound up and taken out, interference such as blocking between films occurs. On the other hand, when the resin density of the olefin-based resin (a2) exceeds 0.910 g / cm ³ , the peelability of the base film 2 and the adhesive layer 3 decreases with time, and the base film of the adhesive layer 3 The pick-up force with respect to (2) increases, and the effect of the above favorable pick-up performance and its continuity is not obtained.

Meanwhile, in the present specification, the density is 0.870 g / cm ³ Or more, 0.910 g / cm ³ The following polyethylene is referred to as ultra low density polyethylene (VLDPE). In the present embodiment, the olefin-based resin (a2) preferably has a density of 0.890 to 0.900 g / cm ³ and particularly preferably 0.895 to 0.900 g / cm ³ among the ultra-low density polyethylenes. Such ultra-low density polyethylene is easy to obtain as an olefin resin (a2) satisfying the above conditions.

In this embodiment, the heat of fusion (ΔH) of the olefin-based resin (a2) is 85.0 J / g or less, preferably 80.0 J / g or less, and particularly preferably 75.0 J / g or less, as described above. When the heat of fusion (ΔH) of the olefin resin (a2) exceeds 85.0 J / g, good pickup performance is not obtained. On the other hand, although the lower limit of the heat of fusion (ΔH) is naturally determined by the relationship between density and the skeleton of each resin, it is theoretically zero.

In the olefin-based resin (a2), if the heat of fusion (ΔH) is 85.0 J / g or less, the molecular weight distribution of the olefin-based resin (a2) is somewhat widened, whereby the crystallinity of the resin layer (A) is suppressed. Thereby, the low molecular weight component in the resin layer (A) is transferred to the surface of the resin layer (A) (that is, the interface between the resin layer (A) and the adhesive layer (3)), and good pickup performance It is thought that this is expressed.

In addition, in this embodiment, the heat flow rate at the melting peak of the olefin-based resin (a2) is preferably 2.5 W / g or less, more preferably 2.3 W / g or less, and particularly preferably 2.0 W / g or less. . If the heat flow at the melting peak exceeds 2.5 W / g, there is a fear that good pickup performance may not be obtained. Moreover, it is preferable that the lower limit of the heat flow rate in the melting peak of the olefin resin (a2) in this embodiment is 1.0 W / g. If the heat flow rate at the melting peak is less than 1.0 W / g, the surface of the resin layer (A) starts sticking to a sticky surface, and is used for forming an adhesive layer on the molded base film 2 or during molding the resin composition. When applying the coating liquid to form the adhesive layer 3, handling properties may be remarkably reduced.

As the olefin-based resin (a2), a homopolymer or copolymer obtained by polymerizing one or two or more selected from olefin monomers having a resin density and a heat of fusion (ΔH) within the above range is preferable. Examples of the olefin monomer include an olefin monomer having 2 to 18 carbon atoms, an α-olefin monomer having 3 to 18 carbon atoms, and the like. Examples of the olefin monomers include olefin monomers having 2 to 8 carbon atoms such as ethylene, propylene, 2-butene and octene; And α-olefin monomers such as propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, and 1-octadecene. have. The olefin-based resin (a2), which is a homopolymer or copolymer of such olefin monomers, can be used alone or in combination of two or more.

As the olefin-based resin (a2), a homopolymer or copolymer of ethylene is preferable, and a copolymer of ethylene and α-olefin monomer is more preferable. The above-mentioned thing is mentioned as an alpha-olefin monomer. Among the olefin-based resins (a2), homopolymers or copolymers of ethylene (hereinafter sometimes referred to as "polyethylene") containing 60 to 100% by mass, particularly 70 to 99.5% by mass, of ethylene as monomer units. desirable.

The content of the olefin-based resin (a2) in the total resin component in the resin layer (A) is preferably 10 to 97% by mass, more preferably 20 to 80% by mass, and even more preferably 25 to 60% by mass. Do. When the content of the olefin-based resin (a2) is less than 10% by mass, there is a fear that the above-described good pick-up performance and the effect of its continuity may not be obtained, and the expandability of the resin layer (A) may decrease. . On the other hand, when the content of the olefin-based resin (a2) exceeds 97% by mass, the content of the norbornene-based resin (a1) becomes relatively small, and there is a fear that generation of dicing powder cannot be suppressed. Moreover, the tensile elastic modulus of the obtained resin layer (A) becomes too low, and when performing secondary processing or the like, there is a possibility that a problem arises regarding handling property, and furthermore, from the low density of the olefin resin (a2), the resin layer When the base film 2 provided with (A) is wound and rolled in a roll shape, blocking may occur in the resin layer A, and there is a concern that handling properties in, for example, unwinding the base film 2 from the roll may be deteriorated.

1-3. Olefin resin (a3)

The resin layer (A) is a component other than the norbornene-based resin (a1) and the olefin-based resin (a2), and is referred to as an olefin-based resin other than the olefin-based resin (a2) (hereinafter referred to as “olefin-based resin (a3)”). It is preferred to contain. When the resin layer (A) contains such an olefin resin (a3), blocking of the resin layer (A) can be effectively suppressed.

The olefin-based resin (a3) is a resin whose resin density does not satisfy one or both of the requirements of 0.870 to 0.910 g / cm ³ and the heat of fusion (ΔH) of 85 J / g or less. Resin density of the olefin resin (a3) is, 0.910g / cm ³ greater than, 0.930g / cm ³ It is preferable that it is the following. In addition, the heat of fusion (ΔH) of the olefin-based resin (a3) is preferably more than 85 J / g, more preferably 86 J / g or more, and particularly preferably 100 J / g or more.

As the olefin-based resin (a3), for example, as a monomer, 60 to 100% by mass of ethylene, particularly 70 to 99.5% by mass, a homopolymer or copolymer of ethylene (hereinafter referred to as "polyethylene"), as a monomer And propylene homopolymers or copolymers (hereinafter referred to as "polypropylene") containing 60 to 100 mass% of propylene, particularly 70 to 99.5 mass%. Examples of the copolymer of ethylene include ethylene-propylene copolymer, ethylene-butene copolymer, and the like. Among these, polyethylene having a resin density of 0.915 to 0.925 g / cm ³ (hereinafter sometimes referred to as “low density polyethylene”) is more preferable. The olefin-based resin (a3), such as low-density polyethylene, has the advantage of high phase solubility with the olefin-based resin (a2). The content of the olefin-based resin (a3) in the total resin component in the resin layer (A) is preferably 20 to 70% by mass, more preferably 25 to 65% by mass, and even more preferably 30 to 60% by mass. Do.

The resin layer (A) in this embodiment contains the norbornene-based resin (a1) and the olefin-based resin (a2) to obtain the following effects.

(1) The generation of dicing powder, particularly thread-shaped dicing powder, generated during dicing of an object to be cut can be suppressed.

(2) It has good pick-up performance and can suppress the deterioration of the pick-up performance over time.

The effects of the above (1) will be described below.

The norbornene-based resin (a1) and the olefin-based resin (a2) differ from the viewpoint of whether or not the polymer constituting each resin has a chemical structure having a ring skeleton containing a norbornene ring. On the basis of this, physical properties such as tensile modulus, fluidization temperature, and crystallinity are different. For this reason, in the resin layer (A), the norbornene-based resin (a1) and the olefin-based resin (a2) form a phase-separated structure. Due to this phase separation structure, generation of thread-shaped dicing powder during dicing is suppressed.

The detailed form of the phase-separated structure varies depending on the chemical structure and content ratio of each resin. In general, it becomes a form in which the phase of a resin with a low content is dispersed (hereinafter referred to as a "dispersed form") in a matrix composed of a phase of a resin with a high content.

From the viewpoint of more effectively suppressing the generation of dicing powder, the phase-separated structure in the resin layer (A) does not have the above-described dispersion form and is a phase of the resin to be dispersed (hereinafter referred to as "dispersion phase", forming a matrix). The resin phase of is referred to as the “matrix phase.” A smaller diameter is preferred. When the size of the dispersed phase in the dispersed form is excessively large, in addition to the tendency for the function of suppressing the generation of dicing powder to deteriorate, the surface properties of the resin layer (A) are deteriorated (specifically, the surface is roughened) , When used as the semiconductor processing sheet 1, it is concerned that chipping is likely to occur in the end face of the object to be cut. Furthermore, when the size of the dispersed phase is excessively large, the dispersed phases are connected to each other, and as a result, the length in the thickness direction of the resin layer (A) at the interface between the dispersed phase and the matrix phase is equal to the thickness of the resin layer (A). It becomes more likely. At this time, it is concerned that the resin layer (A) is excessively retracted.

On the other hand, it can be confirmed that the size of the dispersed phase in the resin layer (A) has a dispersion form by observing the cross section using a high magnification microscope (for example, a scanning electron microscope).

The effect of the above (2) is mainly obtained by the olefin-based resin (a2) having the above resin density and heat of fusion (ΔH). Although the reason why such an effect is obtained is not necessarily clear, it is thought that the crystallinity of the resin layer (A) is suppressed by the olefin-based resin (a2) in which the resin density and the amount of heat of fusion (ΔH) are defined, and good pickup performance is exhibited. do.

1-4. Properties of resin layer (A)

The resin layer (A) preferably has a tensile modulus of 1000 MPa or less, more preferably 50 to 750 MPa, and even more preferably 80 to 600 MPa. When the tensile elastic modulus of the resin layer (A) is 1000 MPa or less, the expandability of the base film 2 can be made good without impairing the flexibility of the resin layer (B) described later.

On the other hand, if the tensile modulus of the resin layer (A) is too low, blocking occurs in the resin layer (A) that is wrapped up, and marks are formed on the surface of the resin layer (A), and the base film (2) is released from the roll. Since there is a possibility that handling properties at times may deteriorate, the tensile modulus of the resin layer (A) is preferably 50 MPa or more.

Moreover, the fluidization temperature of the resin layer (A) is preferably 90 to 120 ° C, particularly preferably 100 to 115 ° C. When the fluidization temperature of the resin layer (A) is 90 ° C or higher, blocking of the base film 2 does not occur, and the base film 2 can secure good handling properties. In addition, when the fluidization temperature of the resin layer (A) exceeds 120 ° C, there is a fear that the base film 2 may be necked in the expansion step after dicing and the chip spacing cannot be uniformly extended.

The thickness of the resin layer (A) is preferably 10 to 120 μm, more preferably 20 to 100 μm, and particularly preferably 30 to 80 μm.

2. Resin layer (B)

The resin layer (B) has an olefin-based resin as a main component, a tensile modulus of 50 to 300 MPa, and an elongation at break of 100% or more. The resin layer (B) having such high flexibility (extension property) can impart excellent expandability to the base film 2. In addition, when the resin layer (B) has an olefinic resin as a main component, a base film 2 in which interlayer peeling between the resin layer (A) and the resin layer (B) does not occur can be obtained.

When the tensile modulus of the resin layer (B) exceeds 300 MPa, the flexibility is lowered, so that the desired expand performance cannot be obtained. On the other hand, when the tensile modulus of the resin layer (B) is less than 50 MPa, blocking occurs in the resin layer (B) that is wrapped and the surface of the resin layer (B) is stained, and the base film (2) or semiconductor processing sheet (1) The handling property at the time of unwinding from a roll, etc. worsens. The preferred tensile modulus of the resin layer (B) is 80 to 250 MPa, and the particularly preferred tensile modulus is 100 to 200 MPa.

In addition, when the elongation at break of the resin layer (B) is less than 100%, when the semiconductor processing sheet (1) is expanded, fracture occurs at the resin layer (B), so that the desired expand performance is not obtained. The preferred elongation at break of the resin layer (B) is 150% or more, and particularly preferably the elongation at break is 200% or more. Meanwhile, the upper limit of the elongation at break of the resin layer (B) is not particularly limited, but is generally 800% or less.

Examples of the olefin-based resin constituting the resin layer (B) include (co) polymers obtained by polymerizing one or two or more olefin monomers such as polyethylene and polypropylene; What consists of a resin composition which has as a main component the copolymer etc. which copolymerized 1 type (s) or 2 or more types of an olefin monomer and an acrylic monomer is mentioned. These resins may be used alone or in combination of two or more.

Examples of the acrylic monomer include (meth) acrylic acid; (Meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate; And vinyl acetate. Here, "(meth) acrylic acid" in this specification means both acrylic acid and methacrylic acid.

Among these, as the olefin-based resin constituting the resin layer (B), ethylene-based copolymers such as ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, and ethylene-vinyl acetate copolymer are used as main components. It is preferred, and particularly, it is preferably made of a resin composition containing ethylene- (meth) acrylic acid copolymer as a main component. The ethylene component in the ethylene-based copolymer imparts good extensibility and expand performance to the resin layer (B).

The content of the acrylic monomer as a constituent component in the ethylene-based copolymer is preferably 3 to 20% by mass, more preferably 4 to 15% by mass, and particularly preferably 5 to 12% by mass. When the content of the acrylic monomer is less than 3% by mass, the crystallinity of the resin layer (B) is increased, and there is a fear that the base film 2 is necked at the time of expansion after dicing and the chip spacing is not uniformly expanded. On the other hand, when the content of the acrylic monomer exceeds 20% by mass, stickiness may occur in the resin layer (B) itself, and when dicing using an apparatus, the semiconductor processing sheet (1) is conveyed. There is a fear that it will not be possible.

The thickness of the resin layer (B) is preferably 40 to 120 μm, particularly preferably 45 to 100 μm. Moreover, it is more preferable that the thickness of the resin layer (B) is thicker than the thickness of the resin layer (A). When the thickness of the resin layer (B) is within the above range, good expand performance can be provided to the base film 2.

The elongation at break of the resin layer (B) is preferably 100% or more, particularly preferably 200% or more. When the elongation at break of the resin layer (B) is 100% or more, the base film 2 is difficult to break at the time of the expand process, and it becomes easy to separate chips formed by cutting the object to be cut.

3. Properties of base film (2)

The tensile modulus of the base film 2 is preferably 80 to 500 MPa, more preferably 80 to 400 MPa, and particularly preferably 80 to 300 MPa. When the tensile modulus of elasticity is less than 80 MPa, when the wafer is adhered to the semiconductor processing sheet 1 and fixed to the ring frame, the base film 2 is soft, which causes sagging, which may cause conveying errors. On the other hand, when the tensile modulus exceeds 500 MPa, since the load applied during the expansion process has to be increased, there is a concern that problems such as peeling of the semiconductor processing sheet 1 itself from the ring frame may occur.

In order for the base film 2 to have the above preferred tensile modulus of elasticity, the ratio of the thickness of the resin layer (A) to the resin layer (B) (thickness of the resin layer (A) / thickness of the resin layer (B)), It is preferably 1.0 or less, and particularly preferably 0.25 to 1.0.

The adhesive layer 3 included in the semiconductor processing sheet 1 according to the present embodiment may contain an ultraviolet curable compound. Here, the light source used for curing of the ultraviolet curing compound is not particularly limited, and examples thereof include a high pressure mercury lamp, a metal halide lamp, an electrodeless lamp, and a xenon lamp, and the maximum peak wavelength is 365 nm. Therefore, in order to cure this ultraviolet curable compound, it is preferable that the base film 2 has a total light transmittance of 75% or more so that light can penetrate the base film 2 and reach the adhesive layer 3 sufficiently. This total light transmittance can be measured by a known method using a spectrophotometer.

4. Manufacturing method of base film (2)

The base film 2 may all be produced by forming and simultaneously laminating the resin layer (A) and the resin layer (B) by extrusion molding or the like, and after forming the respective resin layers (A) and (B), The resin layer (A) and the resin layer (B) may be produced by laminating them with an adhesive or the like.

On the other hand, the resin layer (A) blends the norbornene-based resin (a1), the olefin-based resin (a2), and the olefin-based resin (a3) and other resins as desired, and directly from the kneaded product, or Once the pellets are produced, they can be formed by extrusion or the like.

5. Adhesive layer (3)

As a material constituting the adhesive layer 3, any material having both a wafer fixing function and a die bonding function can be used without particular limitation. As the material constituting the adhesive layer 3, a thermoplastic resin and a low molecular weight thermosetting adhesive component, a B-stage (semi-cured) thermosetting adhesive component, or the like is used. Among these, it is preferable to include a thermoplastic resin and a thermosetting adhesive component as a material constituting the adhesive layer 3. Examples of the thermoplastic resin include acrylic polymer, polyester resin, urethane resin, phenoxy resin, polybutene, polybutadiene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, ethylene (meth) acrylic acid copolymer, and ethylene (meth) Acrylic ester copolymers, polystyrenes, polycarbonates, polyimides, etc. may be mentioned, and among them, acrylic polymers are preferred from the viewpoints of adhesiveness and film formability (sheet workability). Examples of the thermosetting adhesive component include epoxy resins, polyimide resins, phenolic resins, silicone resins, cyanate resins, bismaleimide triazine resins, allylated polyphenylene ether resins (thermosetting PPE), and formaldehyde resins. , Unsaturated polyester or these copolymers, and the like, among them, epoxy-based resins are preferred from the viewpoint of adhesiveness. The material constituting the adhesive layer 3 is particularly excellent in adhesiveness to a semiconductor wafer and contains an acrylic polymer (d) and an epoxy-based resin (e), especially from the viewpoint of excellent peelability with the base film 2 Materials to be preferred are preferred.

The acrylic polymer (d) is not particularly limited, and conventionally known acrylic polymers can be used. The weight average molecular weight (Mw) of the acrylic polymer (d) is preferably 10,000 to 2 million, and more preferably 100,000 to 1.5 million. When the Mw of the acrylic polymer (d) is too low, the peelability of the adhesive layer 3 and the base film 2 is lowered, and there is a case where defective pickup of chips occurs. When the Mw of the acrylic polymer (d) is too high, the adhesive layer 3 may not be able to follow the unevenness of the adherend, which may be a cause of generation of voids and the like.

The glass dislocation temperature (Tg) of the acrylic polymer (d) is preferably -60 to 70 ° C, more preferably -30 to 50 ° C. When the Tg of the acrylic polymer (d) is too low, the peelability of the adhesive layer 3 and the base film 2 is lowered, and there is a case where defective pickup of the chip occurs. If the Tg of the acrylic polymer (d) is too high, there is a fear that the adhesive force for fixing the wafer becomes insufficient.

Examples of the monomer constituting the acrylic polymer (d) include (meth) acrylic acid ester monomers or derivatives thereof, and more specifically, methyl (meth) acrylate, ethyl (meth) acrylate, ethyl (meth) acrylate (Meth) acrylic acid alkyl esters having 1 to 18 carbon atoms in alkyl groups such as propyl and (meth) acrylate butyl; (Meth) acrylic acid cycloalkyl ester, (meth) acrylic acid benzyl ester, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) ) (Meth) acrylic acid esters having cyclic skeletons such as acrylate and imide (meth) acrylate; Hydroxyl group-containing (meth) acrylic acid esters such as hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxypropyl (meth) acrylate; And glycidyl acrylate and glycidyl methacrylate. Moreover, you may use the unsaturated monomer containing carboxyl groups, such as acrylic acid, methacrylic acid, and itaconic acid. These may be used alone or in combination of two or more.

As a monomer constituting the acrylic polymer (d), it is preferable to use at least a hydroxyl group-containing (meth) acrylic acid ester from the viewpoint of phase solubility with the epoxy resin (e) among the above. In this case, in the acrylic polymer (d), the structural unit derived from the hydroxyl group-containing (meth) acrylic acid ester is preferably contained in the range of 1 to 20% by mass, more preferably 3 to 15% by mass. desirable. As the acrylic polymer (d), specifically, a copolymer of a (meth) acrylic acid alkyl ester and a hydroxyl group-containing (meth) acrylic acid ester is preferable.

Moreover, you may copolymerize monomers, such as vinyl acetate, acrylonitrile, and styrene, in the range which does not impair the objective of this invention, acrylic polymer (d).

As the epoxy resin (e), various conventionally known epoxy resins can be used. As an epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenylene skeleton type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, dicyclopentadiene (DCPD) type epoxy resin, biphenyl Type epoxy resins, triphenolmethane type epoxy resins, heterocyclic epoxy resins, stilbene type epoxy resins, condensed ring aromatic hydrocarbon-modified epoxy resins, and epoxy resins containing two or more functional groups in structural units such as halides You can. These epoxy resins may be used alone or in combination of two or more.

The epoxy equivalent of the epoxy resin is not particularly limited, but is preferably 150 to 1000 (g / eq). On the other hand, the epoxy equivalent is a value measured according to JIS K7236: 2008.

The content of the epoxy resin (e) is preferably 1 to 1500 parts by mass, more preferably 3 to 1000 parts by mass, relative to 100 parts by mass of the acrylic polymer (d). When the content of the epoxy-based resin (e) is less than the above range, there is a fear that sufficient adhesive strength may not be obtained, and when the content of the epoxy-based resin (e) exceeds the above range, film forming property decreases, and the adhesive layer (3). ) May be difficult to form.

It is preferable that the material constituting the adhesive layer 3 further contains a curing agent (f). The curing agent (f) functions as a curing agent for the epoxy resin (e). Examples of the curing agent (f) include a compound having two or more functional groups capable of reacting with an epoxy group in the molecule, and examples of the functional group include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and acid anhydride groups. Among these, phenolic hydroxyl groups, amino groups and acid anhydride groups are preferred, and phenolic hydroxyl groups and amino groups are more preferred.

Specific examples of the curing agent (f) include phenolic thermosetting agents such as novolac-type phenolic resins, dicyclopentadiene-based phenolic resins, triphenolmethane-type phenolic resins, and aralkylphenol resins; amines such as DICY (dicyandiamide) And thermosetting agents. The curing agent (f) may be used alone or in combination of two or more.

The content of the curing agent (f) is preferably 0.1 to 500 parts by mass, more preferably 1 to 200 parts by mass, relative to 100 parts by mass of the epoxy resin (e). When the content of the curing agent (f) is less than the above range, the adhesive layer 3 having sufficient adhesive strength may not be obtained. When the content of the curing agent (f) exceeds the above range, the moisture absorption rate of the adhesive layer 3 is increased, and the reliability of the semiconductor package may be lowered.

The materials (adhesive composition) constituting the adhesive layer 3, other than the above, as desired, may be a curing accelerator, a coupling agent, a crosslinking agent, an ultraviolet curing compound, a photoinitiator, a plasticizer, an antistatic agent, an antioxidant, a pigment, a dye, and an inorganic filler. Various additives, such as, may be contained. Each of these additives may be contained singly or in combination of two or more kinds.

The curing accelerator is used to adjust the curing rate of the adhesive composition. As the curing accelerator, a compound capable of promoting the reaction of the epoxy group with a phenolic hydroxyl group or an amine is preferable. Examples of such a compound include tertiary amines, imidazoles such as 2-phenyl-4 and 5-di (hydroxymethyl) imidazole, organic phosphine, and tetraphenyl boron salt.

The coupling agent has a function of improving adhesiveness and adhesion to the adherend of the adhesive composition. In addition, by using a coupling agent, the water resistance of the cured product can be improved without impairing the heat resistance of the cured product obtained by curing the adhesive composition. It is preferable that the coupling agent is a compound having a group that reacts with a functional group of the acrylic polymer (d) and the epoxy-based resin (e). As such a coupling agent, a silane coupling agent is preferable. The silane coupling agent is not particularly limited, and a known one can be used.

The crosslinking agent is for controlling the cohesive force of the adhesive layer 3. The crosslinking agent of the acrylic polymer (d) can be used without particular limitation, and examples thereof include organic polyisocyanate compounds, organic polyimine compounds, and the like.

The ultraviolet curable compound is a compound that undergoes polymerization and curing upon irradiation with energy rays such as ultraviolet rays. When the ultraviolet curable compound is cured by irradiation with ultraviolet rays, peelability between the adhesive layer 3 and the base film 2 is improved, so that picking is easy.

As the ultraviolet curing compound, an acrylate-based compound is preferable, and it is particularly preferable to have at least one polymerizable double bond in the molecule. As such an acrylate type compound, specifically, dicyclopentadiene dimethoxy diacrylate, trimethylolpropane triacrylate, pentaerythryl triacrylate, pentaerythryl tetraacrylate, dipentaerythryl monohydroxypenta Acrylate, dipentaerythryl hexaacrylate, 1, 4-butylene glycol diacrylate, 1, 6-hexanediol diacrylate, polyethylene glycol diacrylate, oligoester acrylate, urethane acrylate oligomer, epoxy And modified acrylates, polyether acrylates, and itaconic acid oligomers.

The weight average molecular weight of the acrylate-based compound is usually 100 to 300,000, and preferably about 300 to 10,000.

When the adhesive composition contains an ultraviolet curable compound, the content of the ultraviolet curable compound is usually 1 to 400 parts by mass, preferably 3 to 300 parts by mass, more preferably 10 to 100 parts by mass of the acrylic polymer (d). It is -200 parts by mass.

In the case where the adhesive layer 3 contains the ultraviolet curing type compound, the photoinitiator can reduce the polymerization curing time and the irradiation amount of ultraviolet rays when polymerization and curing by irradiation with ultraviolet rays. As a photoinitiator, a well-known thing can be used.

The thickness of the adhesive layer 3 is usually 3 to 100 μm, preferably about 5 to 80 μm.

6. Manufacturing method of semiconductor processing sheet (1)

The semiconductor processing sheet 1 according to the present embodiment can be produced by a conventional method. For example, a coating agent further comprising a material constituting the adhesive layer 3 and a solvent if desired, and a roll coater, knife coater, roll knife coater, air knife coater, die coater, bar coater, gravure coater , It can be produced by coating the exposed surface of the resin layer (A) of the base film 2 with a coating machine such as a curtain coater and drying it to form an adhesive layer 3. Alternatively, the coating agent is applied to a release surface of a desired release sheet and dried to form an adhesive layer 3, and then the resin layer (A) side of the base film 2 is pressed against the adhesive layer 3 It can also be manufactured by.

7. Use of semiconductor processing sheet (1)

The semiconductor processing sheet 1 according to the present embodiment can be preferably used as a dicing die bonding sheet used in a dicing step, an expanding step, and a die bonding step.

The embodiments described above are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents falling within the technical scope of the present invention.

For example, a release sheet may be laminated on the exposed surface of the adhesive layer 3.

[Example]

Hereinafter, the present invention will be described more specifically by examples and the like, but the scope of the present invention is not limited to these examples and the like.

[Examples 1 to 17, Comparative Examples 1 to 6]

1. Preparation of base film

(1) Preparation of the material of the resin layer (A)

The following raw materials were mixed at the blending ratio (parts by mass) shown in Table 1, and melt-kneaded in a twin-screw kneader (Toyo Seiki Seisaku Co., Ltd., Labo Plast Mill) to obtain a material for the resin layer (A).

<Raw material for resin layer (A)>

(a1)

・ Norbornene-based resin 1: Polyplastics, product name: TOPAS8007, resin density at 23 ° C: 1.02 g / cm ³ , tensile modulus at 23 ° C: 2.0 GPa, fluidization temperature: 142 ° C, temperature 230 ° C, load 2.16 MFR at kgf: 12g / 10min

・ Norbornene-based resin 2: Polyplastics, product name: TOPAS7010, resin density at 23 ° C: 1.02 g / cm ³ , tensile modulus at 23 ° C: 2.2 GPa, fluidization temperature: 163 ° C, temperature 230 ° C, load 2.16 MFR at kgf: 11g / 10min

· Norbornene resin 3: Polyplastics, product name: TOPAS5013, resin density at 23 ° C: 1.02 g / cm ³ , tensile modulus at 23 ° C 2.3 GPa, fluidization temperature: 175 ° C

(a2)

Olefin resin 1: Ultra-low density polyethylene (Sumitomo Chemical Co., Ltd., Excellen VL200, resin density 0.900 g / cm ³ , heat of fusion ΔH 79.1J / g, tensile modulus at 23 ° C 64 MPa)

Olefin resin 2: Ultra-low density polyethylene (Sumitomo Chemical Co., Ltd., Excellen VL EUL731, resin density 0.895 g / cm ³ , heat of fusion ΔH 69.5 J / g, tensile modulus at 23 ° C 40 MPa)

(a3)

Olefin resin 3: ultra-low-density polyethylene (Prime Polymer Co., Ltd., SP90100 evo, resin density 0.890g / cm ³ , heat of fusion ΔH 87.7J / g, tensile modulus at 23 ° C 30MPa)

Olefin resin 4: low density polyethylene (Sumitomo Chemical Co., Ltd. product name: Sumikasen L705, resin density 0.918 g / cm ³ , heat of melting ΔH: 126.0 J / g, tensile modulus at 23 ° C., 140 MPa)

Olefin resin 5: low density polyethylene (manufactured by Tosoh Corporation, product name: Lumitak 43-1, resin density 0.905 g / cm ³ , heat of fusion ΔH: 88.9 J / g, tensile modulus at 23 ° C., 80 MPa)

(2) Preparation of the material of the resin layer (B)

At the compounding ratio (parts by mass) shown in Table 1, the following raw materials were melt-kneaded in a twin-screw kneader (Toyo Seiki Seisaku Co., Ltd., laboplast mill) to obtain a material for the resin layer (B).

<Raw material for resin layer (B)>

-Ethylene-methacrylic acid copolymer 1: Mitsui-DuPont Poly Chemical, product name "New Kreel AN4214C", content of methacrylic acid: 4 mass%, tensile modulus at 23 ° C 200 MPa

· Ethylene-methacrylic acid copolymer 2: manufactured by Mitsui-DuPont Polychemical, product name “New Kreel AN42012C”, content of methacrylic acid: 9 mass%, tensile modulus at 23 ° C. 150 MPa

-Ethylene-methacrylic acid copolymer 3: Mitsui-DuPont polychemical, product name "New Kreel AN1207C", content of methacrylic acid: 12% by mass, tensile modulus at 23 ℃ 140MPa

-Ethylene-methacrylic acid copolymer 4: Mitsui-DuPont Polychemical, product name "Neucrel N1525", the content of methacrylic acid: 15% by mass, tensile modulus at 23 ℃ 83MPa

-Ethylene-methacrylic acid copolymer 5: manufactured by Sumitomo Chemical Co., Ltd., product name "Acroft # 201", tensile modulus of 65 MPa at 23 ° C

-Ethylene-methacrylic acid copolymer 6: manufactured by Sumitomo Chemical Co., Ltd., product name "Acroft # 203-1", content of methacrylic acid: 5.0% by mass, tensile modulus of 90 MPa at 23 ° C

-Ethylene-vinyl acetate copolymer 1: manufactured by Tosoh Corporation, product name "Ultracene 537", content of vinyl acetate: 6.0% by mass, tensile modulus at 23 ° C of 120 MPa

Polyethylene resin: manufactured by Prime Polymer, product name "Eboryu SP4030", tensile modulus of 550 MPa at 23 ° C

-Ethylene-vinyl acetate copolymer 2: manufactured by Tosoh Corporation, product name "Ultracene636", content of vinyl acetate: 19% by mass, tensile modulus of 40 MPa at 23 ° C

・ Ester elastomer: Mitsubishi Chemical Co., Ltd. product name "Primeroy B1920N", tensile modulus at 23 ° C 200 MPa

(3) Extrusion molding of resin layer (forming of base film)

When the material for the resin layer (A) and the material for the resin layer (B) are co-extruded with a small T die extruder (Toyo Seiki Seisaku Co., Ltd., Labo Plast Mill), a 40 μm thick resin layer (A ) And a base film of a two-layer structure composed of a resin layer (B) having a thickness of 60 μm.

2. Preparation of coating liquid for forming adhesive layer

The following components were blended to prepare a coating liquid for forming an adhesive layer. On the other hand, the numerical value (mass%) of each component represents the mass% in terms of solid content, and the solid content in this specification means all components other than the solvent.

[Acrylic polymer (d)]

An acrylic copolymer containing n-butyl acrylate as a main component (manufactured by Nippon Kosei Chemical Co., Ltd., product name `` Cofonyl N2359-6 '', Mw: about 800,000, solid content concentration: 34% by mass): 14% by mass

[Epoxy clock resin (e)]

Bisphenol A type epoxy resin (Mitsubishi Chemical Corporation, product name "JER828", epoxy equivalent 189 g / eq): 18% by mass

DCPD type epoxy resin (manufactured by Dainippon Ink Kagaku, product name "EPICLON HP-7200HH", epoxy equivalent 265-300 g / eq, softening point 75-90 ° C): 55% by mass

[Curing agent (f)]

Dicyandiamide (manufactured by Asahi Denka, product name `` Adeka Hardener 3636AS ''): 1.6% by mass

[Curing agent]

2-phenyl-4, 5-di (hydroxymethyl) imidazole (manufactured by Shikoku Chemical Co., Ltd., product name `` Curesol 2PHZ ''): 1.5% by mass

[Silane coupling agent]

Silicate compound added with γ-glycidoxypropyl trimethoxysilane (Mitsubishi Chemical Corporation, product name "MKC Silicate MSEP2"): 0.5% by mass

[Energy ray polymerizable compound]

Dicyclopentadienedimethoxydiacrylate (manufactured by Nippon Kayaku Co., Ltd., product name `` Karayard R684 ''): 9.1 mass%

[Photopolymerization initiator]

-Α-hydroxycyclohexyl phenyl ketone (manufactured by Chiba Special T Chemical, product name `` Mongacure 184 ''): 0.3% by mass

3. Formation of adhesive layer (preparation of semiconductor processing sheet)

The obtained coating liquid for forming an adhesive layer was applied to the peeling-treated surface of the release sheet (Lintec, SP-PET38111 (S)) peeled with silicone so that the film thickness after drying was 20 μm, and the temperature was 1 at 100 ° C. It was dried for a minute to form an adhesive layer. By attaching this adhesive layer on the resin layer (A) of the base film, the adhesive layer was transferred onto the base film to produce a semiconductor processing sheet.

[Test Example 1] (Measurement of tensile properties)

The material for the resin layer (A) and the material for the resin layer (B) used in Examples and Comparative Examples were extruded by a small T die extruder (Toyo Seiki Seisaku Co., Ltd., Labo Plast Mill), respectively, to obtain a thickness. A 100 μm single layer resin film was prepared.

The base film of Examples and Comparative Examples and the resin films of the resin layer (A) and the resin layer (B) monolayer obtained above were cut into test pieces of 15 mm × 140 mm, according to JIS K7161: 1994 and JIS K7127: 1999, 23 The tensile modulus at ° C was measured. Specifically, the test piece, in a tensile tester (manufactured by Shimadzu Corporation, Autograph AG-IS 500N), after setting the distance between the chuck 100mm, and then subjected to a tensile force test at a speed of 200mm / min, tensile modulus (MPa) And the elongation at break (%) was measured (only the resin film of the resin layer (B) monolayer was measured for the elongation at break). On the other hand, the measurement of the tensile properties was performed in both the extrusion direction (MD) at the time of molding the resin film and in the direction perpendicular to the CD (CD), and the average value of the measurement results was taken as the tensile modulus and elongation at break of the resin film. . Table 1 shows the results.

(Test Example 2) (Expandability test)

After attaching the 6-inch wafer to the adhesive layer of the semiconductor processing sheet prepared in Examples and Comparative Examples, the semiconductor processing sheet was mounted on a flat frame, and the wafer was pulled with a chip of 10 mm each by a diamond blade having a thickness of 20 μm. It was cut. Then, using an expanding jig (NEC Masinari Co., Ltd., die-bonder CSP-100VX), the semiconductor processing sheet was pulled out under two conditions of 5 mm at a speed of 300 mm / min and 10 mm at 600 mm / min. The presence or absence of fracture of the semiconductor processing sheet at this time was confirmed. As a result, it was judged that ○ when the breakage was not confirmed in both conditions, Δ when either breakage was confirmed in either condition, or × when breakage was confirmed in both conditions. Table 1 shows the results.

(Test Example 3) (observing dicing powder)

After attaching the adhesive layer of the semiconductor processing sheet prepared in Examples and Comparative Examples to the BGA type package module, it was set in a dicing device (manufactured by DISCO, DFD-651), and dicing was performed under the following conditions.

· Work (adherent): Silicon wafer

Work size: 6inch, thickness 350μm

Dicing blade: NBC-27HEEE made by Disco

Blade speed: 50,000 rpm

Dicing speed: 10mm / sec

Depth of cut: Cut into the depth of 20μm from the base film surface

Dicing size: 10mm × 10mm

Thereafter, ultraviolet rays were irradiated (160 mJ / cm ² ) on the base film side to peel the cut chips. Among the vertical and horizontal dicing lines, the number of thread-like powders having a length of 100 μm or more generated in one vertical line and one horizontal line in the vicinity of each center is digital microscope (VHX-100 manufactured by Keyence Corporation, magnification: 100 times). ). The number of yarn-like powders was evaluated as 0 to 10, 11 to 15 to ○, and 16 to 16. ◎ and ○ were judged to be good, and × was judged to be bad. Table 1 shows the results.

〔Test Example 4〕 (Handling evaluation)

When performing the observation of the dicing powder, dicing is performed by a dicing apparatus (manufactured by DISCO, DFD-651), but at this time, when a conveying error occurs or when reattached to the wafer cassette, a semiconductor processing sheet Was bent, and the case where it came into contact with a separate semiconductor processing sheet provided at the lower stage was referred to as x, and it was evaluated as ○ that no problem occurred.

[Test Example 5] (Evaluation of degree of change over time in pickup performance)

The semiconductor processing sheets prepared in Examples and Comparative Examples were cut to 25 mm × 250 mm to prepare test pieces. The test piece was affixed to a grinding surface of a # 2000 silicon wafer (200 mm diameter, 350 μm thick), and both were pressed by reciprocating a 2 kg rubber roll. In this state, after standing for 20 minutes or more under conditions of 23 ° C. and 50% RH, 180 ° peeling was performed at a rate of 300 mm / min using an all-purpose tensile force tester (Tensiron, manufactured by Orien Tech) as an indicator of the pickup force. The peel force between the adhesive layer and the base film was measured, and the value was taken as (initial value: f1 (mN / 25 mm)).

On the other hand, after heating the semiconductor processing sheet under conditions of 40 ° C. (a constant temperature bath at 40 ° C.) for 24 hours, it is returned to room temperature, and as an index of the pick-up force, the peeling force between the adhesive layer and the base film (pickup force) as described above. ) Was measured, and the value (value after acceleration: f2 (mN / 25 mm)) was determined. Both of these values were introduced into the following formula, and the rate of change of peeling force: R (%) was calculated. The pick-up performance was set to ◎ if R is 50% or less, ○ if R is 50% or more, and 100% or less, and × if R is 100% or more. Table 1 shows the results.

R = (f2-f1) × 100 / f1

X ¹ : Interlayer peeling occurred between the resin layer (A) and the resin layer (B), and it was not possible to evaluate peeling force measurement and pickup performance.

As can be seen from Table 1, the semiconductor processing sheet obtained in the Examples was excellent in expandability, and the generation of yarn-shaped dicing powder was suppressed. In addition, good pick-up performance was maintained even after acceleration.

The semiconductor processing sheet according to the present invention is particularly suitable for use in dicing die bonding sheets.

One… Semiconductor processing sheet
2… Base film (resin layer (A) / resin layer (B))
3… Adhesive layer

Claims (8)

A semiconductor processing sheet comprising a base film and an adhesive layer laminated on one side of the base film,
The base film includes a resin layer (A) positioned on the adhesive layer side and a resin layer (B) laminated on the opposite side of the adhesive layer of the resin layer (A),
The resin layer (A) is a resin other than the norbornene-based resin (a1) and the norbornene-based resin (a1), which are polymers in which the norbornene-based compound is at least one kind of monomer, and has a resin density of 0.870 to 0.910 g. / cm ³ , and also contains an olefin-based resin (a2) having a heat of fusion (ΔH) of 85 J / g or less,
The resin layer (B) is composed of an olefin-based resin, the tensile modulus is 50 to 300 MPa, and the elongation at break is 100% or more. The method according to claim 1,
The content of the norbornene-based resin (a1) in the total resin component in the resin layer (A) is 3 to 60% by mass, a semiconductor processing sheet. The method according to claim 1,
The content of the olefin-based resin (a2) in the total resin component in the resin layer (A) is 10 to 97% by mass, a semiconductor processing sheet. The method according to claim 1,
The resin layer (A) has a resin density of semiconductor processing sheet according to claim 1, further containing 0.910g / cm ³ greater than, 0.930g / cm ³ or lower olefin resin (a3). The method according to claim 1,
The resin layer (A) is a semiconductor processing sheet, characterized in that the tensile modulus is 1000MPa or less. The method according to claim 1,
The base film is a semiconductor processing sheet, characterized in that the tensile modulus is 80 to 500MPa. The method according to claim 1,
The adhesive layer, a semiconductor processing sheet, characterized in that it contains a thermoplastic resin and a thermosetting adhesive component. After the semiconductor processing sheet according to any one of claims 1 to 7 is adhered to a semiconductor wafer through the adhesive layer, a step of cutting the semiconductor wafer into semiconductor chips,
A process of peeling both at the interface between the base film for semiconductor processing sheet and the adhesive layer to form a chip with the adhesive layer;
And attaching the chip with the adhesive layer to a circuit board with the adhesive layer.

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