JP6535508B2 - Substrate film used for adhesive film for semiconductive process - Google Patents

Description

  The present invention relates to a base film used for an adhesive film used in a semiconductor manufacturing process, and more specifically, a base film having heat resistance and load resistance that can withstand manufacturing processes at high temperatures, and using the same The present invention relates to a pressure-sensitive adhesive film for semiconductor manufacturing process or dicing process.

  There are various steps in the process of manufacturing a semiconductor. For example, in the process of manufacturing a semiconductor wafer such as silicon or gallium arsenide, dicing is performed to cut and separate the semiconductor wafer into individual chips. At this time, there is a process of sticking and cutting a pressure-sensitive adhesive film for fixing a wafer and thereafter expanding the pressure-sensitive adhesive film radially to pick up individual chips.

  Such semiconductor wafers are becoming thinner along with recent miniaturization of electronic devices, and since the strength of the wafers is decreasing, they are easily damaged in the manufacturing process. For this reason, in order to reduce the load to the semiconductor wafer which generate | occur | produces at the time of expansion and pickup, and to prevent the damage of a chip | tip, the adhesive film excellent in the softness | flexibility is calculated | required.

  In order to obtain a flexible adhesive film, a method using a polypropylene resin, an olefin elastomer, a styrenic elastomer or the like as a substrate film of the adhesive film is known.

  For example, Patent Document 1 discloses a substrate film for multilayer dicing characterized in that a resin composition comprising a vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer hydrogenated substance and a polypropylene resin is laminated. ing.

  However, in the method of Patent Document 1, although the expandability is sufficient, the heat resistance of the base material is poor, so the film melts during the heat treatment in the lamination step of the high function layer and the transfer step, and the weight of the wafer Causes the film to sag.

  In recent years, a technology of providing a high functional layer such as a die bond film or a die back side film on a dicing film is further utilized. Such a dicing film with a high functional layer may be heat treated in the step of laminating the high functional layer or in the step of transferring the high functional layer to a semiconductor wafer, and therefore the base material has expandability. In addition to the above, heat resistance is required.

  In order to correspond to these uses, for example, Patent Document 2 discloses a dicing sheet with a protective film-forming layer which is expandable and whose substrate has heat resistance, and a polypropylene film or a polybutylene terephthalate film is used as the substrate film. The base film used is a base film having a melting point exceeding 130 ° C. or no melting point, and having a breaking elongation of 100% or more and a 25% stress of 100 MPa or less in the MD direction and the TD direction. It is disclosed.

  However, in the method of Patent Document 2, although the base film has heat resistance, since the strength of the base film is high, the performance of the expand is still not sufficiently satisfactory.

JP, 2009-94418, A Patent No. 5363662 gazette

  The present invention is intended to solve the problems associated with the prior art as described above, and is for a semiconductor manufacturing process that is compatible with heat load resistance that can withstand the load of a semiconductor wafer even at high temperatures and expandability in a dicing process. It aims at providing a substrate film used for an adhesive film.

  MEANS TO SOLVE THE PROBLEM As a result of earnestly examining about the base film used for the adhesive film for semiconductor manufacturing processes in order to solve the said problem, this inventor discovers that the said objective can be achieved by using a specific olefin type modified polymer for a base film. The present invention has been completed.

  That is, this invention is a base film used for the following adhesive films for semiconductor manufacturing processes.

[1] A base film containing 40% by mass or more of an olefin-based modified polymer based on the total mass of the base film,
The olefin-based modified polymer is a polyamide block graft copolymer in which at least one polyamide is graft-bonded to a main chain of polyolefin, and the polyolefin domain and the polyamide domain have a co-continuous structure, for semiconductor process Substrate film used for adhesive film.

[2] The base film used for the adhesive film for a semiconductor process according to [1], wherein the olefin-based modified polymer has a melting peak temperature of 180 ° C. or higher.

[3] The adhesive film for a semiconductor process according to [1] or [2], which has a tensile elastic modulus of 50 to 200 MPa and a thermal load elongation at 150 ° C. of 10% or less Base film.

[4] A base film used for an adhesive film for a semiconductor process according to any one of [1] to [3], further comprising a polyolefin resin having a melting peak temperature of 100 ° C. or higher .

The base film used for the adhesive film for semiconductor processes provided with at least one base film of any one of [5] [1]-[4].

[6] A pressure-sensitive adhesive film for a semiconductor manufacturing process, which comprises a pressure-sensitive adhesive layer laminated on at least one side of the substrate film according to any one of [1] to [4].

[7] A pressure-sensitive adhesive film for a dicing process, which comprises a pressure-sensitive adhesive layer laminated on at least one side of the substrate film according to any one of [1] to [4].

  According to the present invention, it is possible to provide a base film used for a pressure-sensitive adhesive film for a semiconductor manufacturing process which has heat resistance to withstand the manufacturing process under high temperature and is excellent in expandability.

  The base film (hereinafter also referred to as "base film of the present invention") used for the adhesive film for semiconductor manufacturing process of the present invention comprises a base film containing an olefin-based modified polymer relative to the total mass of the base film. The olefin-based modified polymer is a polyamide block graft copolymer in which at least one polyamide is graft-bonded to a main chain of a polyolefin, and the polyolefin domain and the polyamide domain have a co-continuous structure. . By containing the olefin-based modified polymer, it is possible to effectively impart heat and load resistance to the substrate film.

  In addition, it is important that the base material film of the present invention contains the olefin-based modified polymer in an amount of 40% by mass or more based on the total mass of the base film, and preferably 45% by mass or more, 55% by mass It is more preferable to contain above, and it is still more preferable to contain 65 mass% or more. By setting the content of the olefin-based modified polymer to 40% by mass or more, the phase of the olefin-based modified polymer having heat resistance can be used as a matrix, and thus the heat load resistance can be maintained, which is preferable.

[Olefin-based modified polymer]
The olefin-based modified polymer used in the substrate film of the present invention is a polyamide block graft copolymer in which at least one polyamide is grafted to the main chain of polyolefin, and the polyolefin domain and the polyamide domain have a co-continuous structure. is important. By making the main chain of the polymer into a polyolefin, it is possible to give flexibility to the substrate film, and by grafting polyamide, it is possible to give high heat and load resistance, and furthermore, it is possible to add polyolefin of the block graft copolymer. By co-structuring the domains and the domains of the polyamide in nanoscale, it is possible to achieve both flexibility and heat resistance without inhibiting the properties of both components. When both components do not form a co-continuous structure but are made sea-island structured (polyolefin component is matrix / polyamide component is domain), the polyamide network is divided, so the heat load resistance is extremely poor.

  The proportion of the polyamide component in the block graft copolymer is not particularly limited, but a grafting ratio of 20% to 40% is preferable because the balance between heat resistance and moldability is good.

  An example of the process for producing such an olefin-based modified polymer is described, for example, in JP-A-2004-510865.

  Here, a bicontinuous structure is a structure in which both components form a continuous phase and are entangled with each other three-dimensionally, or both phases form a continuous phase and regularly arranged in three dimensions (with a periodic structure) Although it is an entangled structure, for example, there may be a portion where the phase is partially interrupted, or a sea-island structure may partially exist. In addition, the description of the bicontinuous structure is made, for example, in “Polymer alloy” (edited by Polymer Society, edited by Tokyo Kagaku Dojin, 1993).

  Note that the co-continuous structure can be observed using a scanning electron microscope, a transmission electron microscope (TEM), or another analytical instrument.

  In addition, the melting peak temperature of the olefin-based modified polymer used in the substrate film of the present invention is preferably 180 ° C. or higher, more preferably 190 ° C. or higher, and still more preferably 200 ° C. or higher, It is particularly preferable that the temperature is 210 ° C. or higher. By setting the melting peak temperature of the olefin-based modified polymer to 180 ° C. or higher, the base film can be effectively provided with heat load resistance. When a plurality of melting peaks exist in the olefin-based modified polymer, the melting peak temperature on the highest side may be 180 ° C. or higher.

  The melting peak temperature in the present invention refers to a differential scanning calorimeter (DSC), and after raising the temperature of 5 mg of the sample to 230 ° C., crystallizes at 25 ° C. at a temperature decrease rate of 10 ° C./min. It says the temperature of the position where the peak of the DSC chart (melting curve) which is drawn when melted at the temperature rising rate of 1 / min.

  The base film of the present invention preferably has a tensile modulus of 50 to 200 MPa, more preferably 50 to 150 MPa, and still more preferably 50 to 130 MPa. By making the tensile elasticity modulus of a base film into said range, a base film has moderate intensity | strength and expandability becomes preferable.

  The base film of the present invention preferably has a thermal load elongation at 150 ° C. of 10% or less, more preferably 7% or less, and still more preferably 5% or less. By setting the thermal load elongation to 10% or less, it is possible to prevent the film from melting and the film from being slackened due to the weight of the wafer when performing heat treatment in the step of laminating the high function layer and the step of transferring. Therefore, the workability in the subsequent dicing step and the pickup step is preferable. Further, the lower limit value of the thermal load elongation is not particularly limited, and the smaller the elongation, the better.

  In the present invention, the thermal load elongation refers to a numerical value calculated by the method of the following heat resistance load resistance test, and the thermal load elongation may result in 0 or less, that is, an expansion and contraction.

[Heating resistance test]
Using test pieces of 100 mm in length and 10 mm in width, draw marking lines at intervals of 40 mm in the longitudinal direction. Then attach a weight of 5.5 g (including the mounting jig) to the lower part of the marked line, hold the test piece vertically, and cure for 30 minutes in an environment with a test temperature of 150 ° C. And the obtained result is taken as the thermal load elongation.

[Equation 1]
Thermal load elongation = (marked line length after heating−marked line length before heating) / (length between marked lines before heating) × 100

  The base film of the present invention preferably further contains a polyolefin resin having a melting peak temperature of 100 ° C. or higher. The base film of the present invention can contain the polyolefin resin preferably at most 65% by mass, more preferably at most 55% by mass, further preferably at most 40% by mass. By containing a polyolefin resin having a melting peak temperature of 100 ° C. or higher, the compatibility with the above-mentioned olefin-based modified polymer can be excellent, and the heat resistance of the base film can be suppressed from being reduced. Is preferred.

  The polyolefin resin is not particularly limited as long as the melting peak temperature is 100 ° C. or higher, and examples thereof include polyethylene resins, polypropylene resins, and mixtures thereof. Examples of polyethylene resins include homopolymers of ethylene, copolymers of ethylene and other monomers copolymerizable with ethylene (low density polyethylene (LDPE), high pressure low density polyethylene, linear Examples include low density polyethylene (LLDPE), high density polyethylene (HDPE), ethylene-α-olefin copolymer (metallocene polyethylene) obtained by polymerization using a metallocene catalyst, and mixtures thereof, etc. Examples of polypropylene resins include homopolymers of propylene (homopolypropylene), copolymers of propylene, reactor-type polypropylene thermoplastic elastomers, and mixtures thereof. Among these, polyethylene resins are preferable from the viewpoint of excellent compatibility with the olefin-based modified polymer, and low density polyethylene resins (LDPE and LLDPE) are particularly preferable from the viewpoint of flexibility.

  Moreover, the base film of this invention can contain another resin and additive as needed. Such resins include polyolefins such as polypropylene and polyethylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, acrylics such as ethylene-methyl acrylate copolymer, ethylene-methacrylic acid copolymer and ethylene-methyl methacrylate copolymer Resins and ionomers, polyvinyl chloride, polyurethane, polyamide, ethylene-vinyl alcohol copolymer and the like can be mentioned.

  Further, examples of the additive include an antistatic agent, a heat stabilizer, an antioxidant, an ultraviolet light absorber, a lubricant, an antiblocking agent, a coloring agent and the like.

[Layer Configuration of Substrate Film of the Present Invention]
The layer structure of the substrate film of the present invention may be a single layer film or a multilayer film. In the case of forming a multilayer film, at least one layer may contain 40% by mass or more of the olefin-based modified polymer defined in the present invention. Moreover, the tensile elastic modulus as the whole multilayer film is 50-200 Mpa, and the heat load elongation in 150 degreeC should just be 10% or less. The multilayer film can also be a two-kind / two-layer laminated film consisting of a surface layer and a back layer and / or a two-kind / three-layer film consisting of a surface layer and a back layer and an intermediate layer.

  One preferable aspect of the substrate film of the present invention is a laminated film provided with at least a surface layer, a back layer, and an intermediate layer, and at least the intermediate layer contains 40% by mass or more of the olefin-based modified polymer specified in the present invention. The surface layer and the back layer preferably contain a polyolefin resin as a main component, and more preferably a laminated film containing a polyolefin resin having a melting peak temperature of 100 ° C. or more as a main component. Moreover, 50% or more is preferable with respect to the total mass of front and back layer, as for content of the polyolefin resin which is a main component, 65% or more is more preferable, and 80% or more is still more preferable. Here, the intermediate layer more preferably contains a polyolefin resin having a melting peak temperature of 100 ° C. or higher. Such a laminated film is excellent in flexibility and heat load resistance, and further is excellent in moldability because it can suppress smoke and roll contamination during molding.

  In a preferred embodiment of the present invention, the thickness of the substrate film is 30 μm to 500 μm, and more preferably 50 μm to 300 μm. If the thickness of the substrate film is in the range of 30 μm to 500 μm, the substrate film has sufficient strength as the substrate film used for the adhesive film for the semiconductor manufacturing process while maintaining the flexibility, and is excellent in moldability and processability.

[Manufacturing method of substrate film of the present invention]
In the substrate film of the present invention, a resin composition is prepared by kneading any additives and other resins as needed in addition to the olefin-based modified polymer, using a dry blend or an extruder, and the resin composition The product can be produced by a general thermoplastic resin film forming method such as extrusion molding such as T-die extrusion molding, inflation molding and calendar molding. In the method for producing a substrate film of the present invention, an extrusion method is particularly suitable. The melt flow rate of the resin composition during extrusion is 1 to 20 g / 10 minutes, preferably 5 to 15 g / 10 minutes. If the melt flow rate of the resin composition is 1 g / 10 min or more, the melt viscosity does not become too high and the extrusion processability is good, and if it is 20 g / 10 min or less, the melt viscosity does not become too low Good flowability and excellent processability.

[Adhesive film]
The adhesive film which is another aspect of this invention should just contain the base film of the single layer or multilayer obtained by this invention at least 1 layer. The pressure-sensitive adhesive film of the present invention is obtained by laminating a pressure-sensitive adhesive layer on at least one side of a substrate film.

  Although the adhesive used as an adhesive layer is not specifically limited, For example, various adhesives, such as natural rubber resin, acrylic resin, a styrene resin, silicon resin, polyvinyl ether resin, are used. In addition, functional layers such as an adhesive layer and a thermosetting resin layer may be further provided on the pressure-sensitive adhesive layer.

  In the pressure-sensitive adhesive film of the present invention, at least one side of the substrate film may be surface-treated by a method such as plasma treatment, corona treatment, ozone treatment, or flame treatment. Moreover, you may provide a primer layer as needed between a base film and an adhesion layer. Further, as long as the purpose of the present invention is not impaired, a resin layer may be further provided on the surface of the base film opposite to the side on which the adhesive layer is provided.

  The adhesive film of the present invention is suitably used as an adhesive film for various semiconductor manufacturing processes. Examples of the adhesive film for the semiconductor manufacturing process include a back grind film, a dicing film, a surface protection film of a semiconductor wafer and chips obtained by singulating the wafer, and the like, and from the viewpoint of expandability, it is particularly suitably used as a dicing film.

  The dicing film may be a dicing film for semiconductor wafers such as silicon or gallium arsenide, or a dicing film for package substrates such as BGA or QFN, but from the viewpoint of heat resistance load resistance, such as adhesive layer or thermosetting resin It is suitably used as a dicing film formed by laminating a functional layer.

  The dicing method is not particularly limited. However, since it has a high melting peak temperature, it is possible to suppress the problem that the adhesive film melts and fuses to the chuck table when it is used for laser dicing.

  Hereinafter, the embodiments of the present invention will be described in detail using examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded.

[Material used]
Resin A: "Aporya LP 21 H" (polyolefin / polyamide 6-block graft copolymer, melting peak temperature: 215 ° C) manufactured by Arkema
Resin B: "Novatec LC500" manufactured by Japan Polyethylene Corporation (low density polyethylene, melting peak temperature: 106 ° C)
Resin C: "Novaduran 5510S" manufactured by Mitsubishi Engineering Plastics (polybutylene terephthalate, melting peak temperature: 217 ° C)

The analysis method of each resin used in the examples is as follows.
[Melting peak temperature]
About 5 mg of sample is heated from 25 ° C to 230 ° C at a heating rate of 10 ° C / min using a differential scanning calorimeter (DSC823e manufactured by METTLER TOLEDO), and then cooled to 25 ° C at a cooling rate of 10 ° C / min. The peak temperature of the chart measured when the temperature was raised again to 230 ° C. at a heating rate of 10 ° C./min was regarded as the melting peak temperature.

[Preparation of base film]
Each resin was dry-blended according to the composition described in Table 1, and made by Toshiba Machine single screw extruder (interlayer extruder: 50φ mm, L / D = 32, front and back layer extruder: 35φ mm, L / D = 28) Charge to each hopper, set each extruder temperature as C1: 190 ° C, C2: 210 ° C, C3: 230 ° C, C4: 230 ° C, C5: 230 ° C, 550 mm width T die (temperature setting: 210 C., lip opening 0.5 mm). The extruded molten resin is cooled and solidified by a winder equipped with a cooling roll (cooling roll 700 mm width × φ 350 mm, roll temperature 30 ° C.), and a single layer of 0.08 mm thickness and two types of three layers (surface / intermediate) The base film of layer / surface layer, layer ratio 1/8/1) was obtained.

  The following evaluation items were evaluated for each of the obtained films. The results are shown in Table 1.

[Flexibility (tensile modulus)]
Using the obtained base film, No. 1 dumbbell test pieces are collected according to JIS K 7127, and the tensile speed is measured using an autograph (AGS-X manufactured by Shimadzu Corporation) under an atmosphere of 23 ° C. and 60% RH. The tensile modulus was measured at 50 mm / min.

[Heat resistance (heat load elongation)]
The obtained base film is used to prepare a test piece of 100 mm in length and 10 mm in width, and marks are drawn at intervals of 40 mm in the length direction. Next, attach a weight of 5.5 g (including the mounting jig) to the lower part of the marked line, hold the test piece vertically, and use a gear oven (STD60-P manufactured by Toyo Seiki Seisakusho) in an environment with a test temperature of 150 ° C. I was cured for a minute.
After curing, it was taken out of the gear oven, the length between marks was measured, and the thermal load elongation was determined by the following equation.
Thermal load elongation [%] = (length between marked lines after heating−length between marked lines before heating) / (length between marked lines before heating) × 100

[Formability]
About the productivity at the time of film forming of a base film, it was confirmed about the smoke from a dice | dies, and a cooling roll contamination.
The evaluation was conducted based on the following criteria. Note that Δ is within the practical range.
:: There is no smoke from the die and no contamination of the cooling roll.
○: There is almost no smoke from the die and no contamination of the cooling roll.
:: There is slight smoke and cooling roll contamination from the die.
X: There is smoke from the die and contamination of the cooling roll.

なお、質量部は、各層毎における質量部を示す。

In addition, a mass part shows the mass part in each layer.

From Table 1, it is recognized that the substrate films of Examples 1 to 5 are excellent in flexibility and heat load resistance. In particular, it can be seen that the base films of Examples 4 and 5 are excellent in moldability and have more preferable performance.
On the other hand, Comparative Examples 1 and 2 can not withstand loads under high temperature conditions, resulting in breakage of the base material, and it is recognized that the heat load resistance is insufficient.
In addition, although Comparative Example 3 has good heat load resistance, it is confirmed that the tensile elastic modulus is high, the flexibility is insufficient, and the expandability is not excellent.

  From this result, the base film used for the adhesive film for the semiconductor manufacturing process of the present invention can simultaneously achieve the heat load resistance that can withstand the load of the semiconductor wafer even under high temperature environment in the semiconductor manufacturing process and the expandability in the dicing process. It turns out that it is a base film used for the adhesive film for semiconductor manufacturing processes.

Claims (7)

A base film containing 40% by mass or more of an olefin-based modified polymer, based on the total mass of the base film,
Wherein the olefin based modified polymer is a polyamide block graft polymer in which at least one polyamide is grafted to the main chain of the polyolefin, the polyolefin domains and polyamide domain has a co-continuous structure, Ru tensile modulus 50~200MPa der A substrate film used for an adhesive film for semiconductor process, characterized in that   The base film used for the adhesive film for a semiconductor process according to claim 1, wherein the olefin based modified polymer has a melting peak temperature of 180 ° C. or higher. The base film used for the adhesive film for semiconductor processes according to claim 1 or 2, characterized in that the thermal load elongation at 50 ° C is 10% or less.   The base film used for the adhesive film for semiconductor processes according to any one of claims 1 to 3, further comprising a polyolefin resin having a melting peak temperature of 100 ° C or higher. A base film for use in a pressure-sensitive adhesive film for semiconductor processing, comprising at least one layer consisting of a base film containing 40% by mass or more of an olefin-based modified polymer based on the total mass of the base film,
  The olefin-based modified polymer is a polyamide block graft copolymer in which at least one polyamide is graft-bonded to the main chain of polyolefin, and the polyolefin domain and the polyamide domain have a co-continuous structure,
And the base film used for the adhesive film for semiconductor processes whose tensile elasticity modulus of the said base film is 50-200 Mpa. The adhesive film for semiconductor manufacturing processes formed by laminating | stacking an adhesive layer in the at least single side | surface side of the base film of any one of Claims 1-5 . The adhesive film for a dicing process which laminates | stacks an adhesive layer on the at least single side | surface side of the base film of any one of Claims 1-5 .