JP2011216563A - Dicing film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyolefin-system dicing film having an excellent pickup property of a semiconductor member after being diced.SOLUTION: In a dicing film provided with an adhesive layer on at least one surface of a base material film, the base material film has an yield point stress of 8 MPa or larger (measuring method: specified method, measuring temperature: 25°C), and breaking energy in a predetermined breaking energy evaluation test is 30 mJ or larger.

Description

  The present invention relates to a dicing film.

  In the process of manufacturing a semiconductor device, an adhesive film for processing a semiconductor wafer is used when cutting a semiconductor wafer, a package, or the like. This adhesive film is used for picking up the semiconductor wafer or the like by attaching a semiconductor wafer, a package, or the like, dicing (cutting), and expanding the adhesive film.

  The dicing film is composed of a base film and an adhesive layer provided on at least one side of the base film. Conventionally, a polyvinyl chloride (PVC) resin sheet is often used as a base film. However, in recent years, polyolefin materials such as olefin sheets, ethylene vinyl alcohol sheets, and ethylene methacrylic acid acrylate sheets have been used to prevent contamination of wafers due to adhesion of plasticizers caused by PVC and heightened awareness of environmental problems. The base film which has been developed is developed (for example, refer patent document 1).

  In recent years, semiconductor elements (wafers) are becoming smaller and thinner. As wafers become smaller and thinner, the wafer becomes more susceptible to cracking, and therefore, further dilation (pickup) properties are required for the dicing film. Until now, the improvement of the adhesive layer as shown in the prior art document 2 has been carried out in order to improve the pickup property, but further improvement is required.

JP2003-257893A JP2008-060434

  The objective of this invention is providing the dicing film excellent in the pick-up property and expandability of a semiconductor element.

The above problems can be solved by the present invention described below.
[1] A dicing film in which an adhesive layer is provided on at least one surface of a base film, wherein the base film has a yield point stress of 8 MPa or more (measurement method: JIS K 7161 compliant, measurement temperature: 25 ° C.) A dicing film having a breaking energy of 30 mJ or more in a breaking energy evaluation test.
[Break energy evaluation test]
Create a cross cut on one side of the film under the following cut creation conditions.
With the face where the cut was created facing down, the following drop weight test condition for the cross cut intersection,
A falling weight test is performed, and the potential energy at which the base material breaks is defined as the breaking energy.
[Cut creation conditions]
Using a blade, a cut with a depth of 20 μm and a length of 40 mm or more is made into a cross.
[Falling weight test conditions]
Weight: 1.02 kg
Conical tip shape: Fixed shape of hemispherical test piece with a diameter of 20 mm: Circular shape with a diameter of 40 mm

[2] The dicing film according to [1], wherein the base film is mainly composed of an olefin resin.

[3] The dicing film according to [2], wherein the olefin resin is one or more resins selected from the group consisting of polypropylene, polyethylene, and polystyrene.

[4] The dicing film according to [3], wherein the base film further contains an olefin elastomer.

[5] The olefin elastomer is styrene / isoprene copolymer, styrene / ethylene / butylene copolymer, ethylene / α-olefin copolymer, propylene / α-olefin copolymer, butene / α-olefin copolymer. A copolymer, an ethylene / propylene / α-olefin copolymer, an ethylene / butene / α-olefin copolymer, a propylene / butene / α-olefin copolymer, and an ethylene / propylene / butene / α / olefin copolymer. The dicing film as described in [2] above, which contains at least one or two or more resins selected from the group.

[6] Any of the above [1] to [5], wherein the film after UV irradiation has a storage elastic modulus (E ′) at 25 ° C. of 1.0 × 10 ⁵ Pa or more and 1.0 × 10 ¹⁰ Pa or less. The dicing film according to crab.

[7] A method of manufacturing a semiconductor device comprising a step of attaching a dicing film and a semiconductor member, and a step of dicing the semiconductor member, wherein the dicing film is any one of [1] to [6]. The manufacturing method of the semiconductor device which is a dicing film of description.

ADVANTAGE OF THE INVENTION According to this invention, the dicing film excellent in the pick-up property and expandability of a semiconductor element can be provided.

It is a schematic sectional drawing which shows an example of the dicing film of this invention. It is the film for a test after preparation of a cross cut used for a fracture energy evaluation test.

  The dicing film according to the present invention is used when dicing (cutting) a semiconductor wafer, a package, or the like mainly in a process of manufacturing a semiconductor device. For example, it is attached to a semiconductor wafer, a package or the like, and is used for picking up a semiconductor element obtained by dicing the semiconductor wafer or the like and then expanding the wafer to cut the wafer.

The dicing film of the present invention is characterized in that the base film has a predetermined physical property value, and is excellent in expanding property and pickup property due to the feature.
The structural requirements of the present invention will be described below with reference to the drawings.

(Base film)
The dicing film 10 according to the present invention has at least a base film 1 and an adhesive layer 2 as illustrated in FIG.
The base film 1 preferably has a yield point stress (JIS 7161 compliant measurement temperature: 25 ° C.) of 8 MPa or more, more preferably 10 MPa or more and 20 MPa or less. By setting it to the range lower limit value or more, the pickup property is excellent, and by setting the range upper limit value or less, the expandability is excellent.

Moreover, it is preferable that the base film 1 is 30 mJ or more in a predetermined breaking energy evaluation test, More preferably, it is 100 mJ or more and 500 mJ or less. By being above the lower limit of the range, it is possible to suppress breakage of the base material during expansion. By being below the upper limit of the range, the pickup property is excellent.

Details of the fracture energy evaluation test in the present invention are as follows.
A test film having a thickness of 80 μm and a diameter of 50 mm or more is prepared, and a cross cut 3 having a depth of 20 μm and a length of 40 mm or more is formed on one side of the test piece as shown in FIG.

  Cuts made on the surface of the test film are made using a blade. For example, it can be created using a dicer for semiconductor wafer dicing.

  The film on which the cut has been made as described above is fixed with a predetermined jig so that the face on which the cut is made is down. Then, a hemispherical weight having a tip shape of 1.02 kg is dropped from the upper surface side of the test film (that is, the surface side where the cut is not made), and the weight of the weight is measured from the fall height of the weight at which the test film breaks. The potential energy is calculated as the breaking energy of the test film. The breaking energy evaluation test is performed in a 25 ° C. environment.

  The above breaking energy evaluation test is based on the breaking energy evaluation method specified in JIS K7124-2, and conforms to the standard except that a cut is made on the test film surface. It is.

As the base film used in the present invention, a known resin material can be used as long as it satisfies the above yield stress and rupture energy. From the viewpoint of easily satisfying these characteristics, an olefin resin is mainly used. The component is preferably used. Among these, those mainly composed of polypropylene, polyethylene and polystyrene are preferable from the viewpoint of film production and material cost. The resin material as the main component may be composed of two or more kinds of resins.

Moreover, in order to raise the breaking energy of a base film, it is preferable to contain an olefin type elastomer further.

  Examples of olefin elastomers include ethylene / α-olefin copolymers, propylene / α-olefin copolymers, butene / α-olefin copolymers, ethylene / propylene / α-olefin copolymers, ethylene / butene / α-olefins. At least one selected from the group consisting of a copolymer, a propylene / butene-α-olefin copolymer, an ethylene / propylene / butene-α / olefin copolymer, a styrene / isoprene copolymer and a styrene / ethylene / butylene copolymer. Alternatively, it may contain two or more resins. Among these, it is particularly preferable to use a styrene / isoprene copolymer from the viewpoint of improving expandability.

The base film preferably has 10 to 65 parts by weight of olefin elastomer and more preferably 20 to 40 parts by weight with respect to 100 parts by weight of olefin resin.
By setting it to the range lower limit value or more, the expandability is excellent, and by setting the range upper limit value or less, the pickup property is excellent.

Various resins and additives can be added to the dicing substrate film according to the present invention in accordance with the purpose within a range not impairing the effects of the present invention. For example, in order to impart antistatic properties, a polymer type antistatic agent such as polyether polyolefin block polymer or polyether ester amide, carbon black or the like can be added. In the case of imparting an antistatic effect, an ion conductive antistatic agent using a polyether polyolefin copolymer is preferable from the viewpoint of compatibility with the olefin resin.

  The thickness of the base film is preferably 50 μm or more and 150 μm or less, more preferably 70 μm or more and 100 μm or less for wafer cutting. For cutting special members such as packages, the thickness is preferably from 100 μm to 300 μm, and more preferably from 150 μm to 200 μm. By setting it as the said range lower limit value or more, the base film at the time of expansion becomes difficult to break, and by setting it as the said range upper limit value or less, generation | occurrence | production of the substrate whisker at the time of dicing can be suppressed.

(Adhesive layer)
As illustrated in FIG. 1, an adhesive layer 2 is provided on at least one surface of a base film 1 of a dicing film 10 according to the present invention. Examples of the resin composition used for the pressure-sensitive adhesive layer 2 include an acrylic pressure-sensitive adhesive, a UV curable urethane acrylate resin, and an isocyanate-based crosslinking agent. Among these, it is preferable to use an acrylic pressure-sensitive adhesive containing a polar group in order to suppress wafer mantle, chip jump and chipping. In particular, an acrylic pressure-sensitive adhesive containing an amide group as a polar group is preferably used.

  The thickness of the adhesive layer 2 is preferably 3 μm or more and 10 μm or less for wafer cutting. Further, for cutting special members such as packages, it is preferably 10 μm or more and 50 μm or less. By setting it to the range lower limit value or more, the holding power of the adherend is excellent, and by setting it to the range upper limit value or less, the workability during dicing is excellent.

  The pressure-sensitive adhesive layer 2 of the dicing film 10 according to the present invention is a coating liquid obtained by appropriately dissolving or dispersing a resin used as the pressure-sensitive adhesive layer 2 in a base film 1 or a resin film including the base film 1 in a solvent. It is formed by applying and drying by a known coating method such as roll coating or gravure coating.

The dicing film after UV irradiation preferably has a storage elastic modulus (E ′) at 25 ° C. of 1.0 × 10 ⁵ Pa or more and 1.0 × 10 ¹⁰ Pa or less. By setting it to the range lower limit value or more, the pickup property is excellent, and by setting the range upper limit value or less, the expandability is excellent.

The dicing film according to the present invention may be provided with another resin layer such as an antistatic layer in accordance with the purpose within a range not impairing the effects of the present invention.

The present invention will be described in more detail by way of examples, but this is merely an example, and the present invention is not limited thereby.
<Preparation of base material>
After the following raw materials were mixed by dry blending at the ratio shown in Table 1, a 50 mm full flight extruder (L / D = 25 compression ratio = 2.9 effective length = 1245 mm), discharge = 30 kg / hour, resin temperature = 210 Sheeting was performed at 0 ° C. (screw tip) to obtain a sheet having a thickness of 80 μm.

<Production of adhesive>
Acrylic resin (acrylamide monomer / acrylic (methacrylic acid) ester / hydroxyl group-containing (meth) acrylate copolymer, weight average molecular weight: 500,000, glass transition temperature: −15 ° C., amine value: 115 mgKOH / g, hydroxyl value : 10 mgKOH / g) 100 parts by weight of polyfunctional urethane acrylate (1290KAE manufactured by Daicel Cytec Co., Ltd.) 110 parts by weight, polyhydric alcohol adduct of tolylene diisocyanate (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.) 13 parts by weight 7 parts by weight of 2,2-dimethoxy-2-phenylacetophenone was dissolved in ethyl acetate to obtain a pressure-sensitive adhesive.

<Production of dicing film>
The pressure-sensitive adhesive was subjected to a release treatment on a polyester film (thickness 38 μm) so that the thickness after drying was 5 μm to obtain an adhesive layer.
The above-mentioned pressure-sensitive adhesive layer was laminated on a sheet having an average thickness of 80 μm obtained at a blending ratio shown in Table 1 using a laminating roll at 30 ° C. to obtain a dicing film.

<Raw materials used in Examples / Comparative Examples>
(Polypropylene resin)
Random Polypyropylene F327 (made by Prime Polymer Co., Ltd.)
Homopolypropylene F704NP (manufactured by Prime Polymer Co., Ltd.)
Homopolypropylene VS200A (manufactured by Sun Allomer Co., Ltd.)
Block polypropylene VB170A (manufactured by Sun Allomer Co., Ltd.)
Linear low-density polyethylene FV202 (corresponding to the base material in the examples of Prior Art Literature and Patent Literature 2 manufactured by Sumitomo Chemical Co., Ltd.)
(Olefin elastomer)
Styrene / isoprene copolymer 7125 (Kuraray Co., Ltd.)
Styrene / ethylene / butylene copolymer H1221 (Asahi Kasei Chemicals Corporation)
Ethylene-α-olefin copolymer A0550S (Mitsui Chemicals)

(Yield point stress)
The yield stress of the base material was measured based on JISK7161 (sample width 10 mm, tensile speed 500 mm / min).

(Breaking energy)
After the substrate film is diced under the following dicing condition 1, the falling weight test is performed under the following falling weight test condition 1 from the back of the substrate to the intersection of the cut line cross with the cutting line down. The potential energy of the breaking weight was measured and used as the breaking energy.

<Dicing condition 1>
Blade: NBC-ZH 2050 27HEDD (manufactured by DISCO Corporation)
Blade rotation speed: 40000 rpm
Cutting speed: 50 mm / sec
Blade height: 60 μm

<Falling weight test condition 1>
Weight: 1.02 kg
Conical tip shape: Fixed shape of hemispherical test piece with a diameter of 20 mm: Circular shape with a diameter of 40 mm

(Elastic modulus)
The obtained dicing film was subjected to UV irradiation under the following UV irradiation condition 1. The storage elastic modulus (E ′) of the sheet after UV irradiation was measured under the following elastic modulus measurement condition 1.

<UV irradiation condition 1> (UV irradiation is performed 1 hour after dicing)
Illuminance: 65 mW / cm2
Integrated light quantity: 200 mJ / cm2
UV lamp: High-pressure mercury lamp H03-L21 80 W / cm
(Made by Eye Graphics Co., Ltd.)
UV illuminance meter: UV-PFA1 (made by Eye Graphics Co., Ltd.)

<Elastic modulus measurement condition 1>
Sample size: 4mm x 20mm
Measurement frequency: 1 Hz
Measurement temperature: 25 ° C
Measuring instrument: DMS6100 (manufactured by Seiko Instruments)

<Evaluation items>
(Expandable)
Using the dicing film produced under the above conditions, dicing is performed under the following dicing condition 2, and after UV irradiation under the following UV irradiation condition 2, the expansion is performed under the following expanding condition. The thing was set as x.

<Dicing condition 2>
(The wafer is attached to a dicing film and left at room temperature for 1 hour before dicing)
Wafer / Ring Size: 12 inches Wafer Thickness: 100μ (Back Finish # 2000 Wafer 5 minutes after wafer grinding is affixed to dicing film)
Cut size: 10x13mm
Blade: NBC-ZH 2050 27HEDD (manufactured by DISCO Corporation)
Blade rotation speed: 40000 rpm
Cutting speed: 50 mm / sec
Blade height: 60 μm

<UV irradiation condition 2> (UV irradiation is performed 1 hour after dicing)
Illuminance: 65 mW / cm2
Integrated light quantity: 200 mJ / cm2
UV lamp: High-pressure mercury lamp H03-L21 80 W / cm
(Made by Eye Graphics Co., Ltd.)
UV illuminance meter: UV-PFA1 (made by Eye Graphics Co., Ltd.)

<Expanding conditions>
Expanding device: DB-700
Expanding amount: 7mm
Expanding speed: 100%

(Pickup property)
After expanding under the above conditions, the pickup was carried out under the following pickup condition 1, and the minimum needle height at which the chip could be picked up was measured at the top, bottom, left and right center of the wafer.

<Pickup condition 1>
Pickup device: DB-700
Number of needles: 9 (9 = 3 × 3 Needle arrangement outer circumference 8 × 12 mm)
Needle thrust speed: 10 mm / sec
Collet suction pressure: -60KPa
Collet load: 0.5N
Collet waiting time: 100 msec

(Comprehensive judgment)
The above characteristics were confirmed, and those that were applicable to all of the following were marked with ◯, and those that did not fit even one were marked with ×.
Yield point stress: 6 MPa or more Break energy: 30 mJ or more Expandability: Pickup property without base material breakage: Needle height 250 μm or less

Since the dicing film of the present invention has excellent expandability and semiconductor member pick-up properties, it can be suitably used as a dicing film in the dicing process of manufacturing a semiconductor device.

DESCRIPTION OF SYMBOLS 1 ... Base film 2 ... Adhesive layer 3 ... Cut 10 ... Dicing film 20 ... Breaking energy evaluation test film

Claims (7)

A dicing film provided with an adhesive layer on at least one surface of a base film, wherein the base film has a yield point stress of 8 MPa or more (measurement method: JIS K 7161 compliant, measurement temperature: 25 ° C.) and the following breaking energy: A dicing film having a breaking energy of 30 mJ or more in an evaluation test.
[Break energy evaluation test]
Create a cross cut on one side of the film under the following cut creation conditions.
With the face where the cut was created facing down, the following drop weight test condition for the cross cut intersection,
A falling weight test is performed, and the potential energy at which the base material breaks is defined as the breaking energy.
[Cut creation conditions]
Using a blade, a cut with a depth of 20 μm and a length of 40 mm or more is made into a cross.
[Falling weight test conditions]
Weight: 1.02 kg
Conical tip shape: Fixed shape of hemispherical test piece with a diameter of 20 mm: Circular shape with a diameter of 40 mm The dicing film according to claim 1, wherein the base film is mainly composed of an olefin resin. The dicing film according to claim 2, wherein the olefin resin is one or more resins selected from the group consisting of polypropylene, polyethylene, and polystyrene. The dicing film according to claim 3, wherein the base film further contains an olefin-based elastomer. The olefin elastomer is a styrene / isoprene copolymer, a styrene / ethylene / butylene copolymer, an ethylene / α-olefin copolymer, a propylene / α-olefin copolymer, a butene / α-olefin copolymer, ethylene.・ Selected from the group consisting of propylene / α-olefin copolymer, ethylene / butene / α-olefin copolymer, propylene / butene / α-olefin copolymer, and ethylene / propylene / butene / α / olefin copolymer The dicing film according to claim 2, comprising at least one or two or more resins. 6. The dicing film according to claim 1, wherein the film after UV irradiation has a storage elastic modulus (E ′) at 25 ° C. of 1.0 × 10 ⁵ Pa or more and 1.0 × 10 ¹⁰ Pa or less. . A dicing film according to any one of claims 1 to 6, wherein the dicing film is a method for manufacturing a semiconductor device comprising a step of attaching a dicing film and a semiconductor member and a step of dicing the semiconductor member. A method for manufacturing a semiconductor device.