JP5074881B2 - Multilayer dicing substrate film and dicing film - Google Patents

Description

  The present invention relates to a dicing film for attaching and fixing a semiconductor wafer or the like when dicing a semiconductor wafer or the like into a chip shape, and a base film for multilayer dicing which is a base of the dicing film.

  Semiconductor wafers made in a large area in advance are polished as necessary, and after a back grinding process to adjust the thickness, they are affixed and fixed to a dicing film set on a ring frame. After being cut into a shape and separated at equal intervals in the surface direction in the expanding process, it is picked up in the pickup process and mounted on a predetermined base.

  The dicing film set on the ring frame is removed by heating after the pickup is completed, and stored in the storage rack. At this time, if the slack is not sufficiently removed, the storage in the storage rack is not successful, causing a trouble.

In order to solve such a problem, a dicing sheet having a shape restoring property by heating has been proposed. (For example, Patent Document 1)
JP 2002-141306 A

  Conventionally, if the interval between each chip after dicing is narrow, the position of the chip cannot be specified and a malfunction may be caused. The expanding rate in the process tends to decrease.

  The present invention has been made in view of such circumstances, and it is a main object of the present invention to provide a substrate film for dicing and a dicing film whose shape is restored by removing the tension in the expanding process without heating. And

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.

  In the present invention, the A layer and the C layer are based on 100 parts by weight of a resin composition comprising 30 to 90% by weight of a vinyl aromatic hydrocarbon-conjugated diene copolymer hydrogenated product and 10 to 70% by weight of a polypropylene resin. Styrene-butadiene copolymer hydrogenated product having at least one functional group selected from the group consisting of carboxylic acid group, acid anhydride group, amino group, epoxy group and hydroxyl group in the molecule The layer B contains a resin composition comprising 70 to 90% by weight of a vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer hydrogenated product and 10 to 30% by weight of a polypropylene resin. A base film for dicing is provided in which A layer / B layer / C layer are laminated in this order.

  Moreover, this invention provides the dicing film which has an adhesive layer and a release film further on A layer of the said base film for dicing.

  The substrate film for dicing of the present invention has a recoverability of 90% or more simply by removing the tension without heating, and thus has excellent rack recoverability.

I. Multilayer Dicing Substrate Film The multi-layer dicing substrate film of the present invention is a multi-layer dicing substrate film having at least three layers, wherein the A layer and the C layer are hydrogenated vinyl aromatic hydrocarbon-conjugated diene copolymer 30. At least selected from the group consisting of a carboxylic acid group, an acid anhydride group, an amino group, an epoxy group and a hydroxyl group with respect to 100 parts by weight of a resin composition consisting of ˜90% by weight and 10% to 70% by weight of a polypropylene resin. A resin composition containing 30 to 400 parts by weight of a hydrogenated styrene-butadiene copolymer having one kind of functional group in the molecule, and the B layer is a vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer A resin composition comprising 70 to 90% by weight of a hydrogenated product and 10 to 30% by weight of a polypropylene resin is included, and A layer / B layer / C layer are laminated in this order. It is characterized by that.

  Details will be described below.

  Examples of the vinyl aromatic hydrocarbon constituting the hydrogenated vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer used in the present invention include styrene, o-methylstyrene, p-methylstyrene, and p-tert-butylstyrene. 1,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinylanthracene, 1,1-diphenylethylene, N, N-dimethyl-p-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene, etc. And styrene is a particularly common one. These may be used alone or in combination of two or more.

  The conjugated diene hydrocarbon constituting the hydrogenated vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer is a diolefin having a pair of conjugated double bonds, such as 1,3-butadiene, 2-methyl- 1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and the like. And isoprene. These may be used alone or in combination of two or more.

  The content ratio of the vinyl aromatic hydrocarbon and the conjugated diene hydrocarbon copolymer is 5 to 40% by weight, preferably 5 to 15% by weight of the vinyl aromatic hydrocarbon, and 60 to 95% by weight of the conjugated diene hydrocarbon. Preferably it is 85 to 95 weight%.

  The hydrogenated vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer can be obtained by hydrogenating the vinyl aromatic hydrocarbon / conjugated diene hydrocarbon copolymer.

  The hydrogenation reaction is generally performed in a temperature range of 0 to 200 ° C, more preferably 30 to 150 ° C. The pressure of hydrogen used for the hydrogenation reaction is 0.1 to 15 MPa, preferably 0.2 to 10 MPa, and more preferably 0.3 to 7 MPa. The hydrogenation reaction time is usually 3 minutes to 10 hours, preferably 10 minutes to 5 hours. The hydrogenation reaction can be any of a batch process, a continuous process, or a combination thereof.

  In the hydrogenated vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer used in the present invention, the hydrogenation rate of unsaturated double bonds based on the conjugated diene hydrocarbon in the block copolymer before hydrogenation (water The addition ratio is 60% or more, preferably 75% or more, more preferably 85% or more, particularly preferably 90% or more of the unsaturated double bond based on the conjugated diene hydrocarbon in the copolymer. It is desirable that The hydrogenation rate can be known by a nuclear magnetic resonance apparatus (NMR).

  Examples of the hydrogenated vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer include “Clayton G” manufactured by Kraton Polymer Japan Co., Ltd., “Hyblar” manufactured by Kuraray Co., Ltd., and “Dynalon” manufactured by JSR Co., Ltd. Can be mentioned.

  The polypropylene resin used in the present invention is preferably crystalline. Examples of the crystalline propylene-based resin include a propylene homopolymer or a random or block copolymer of propylene and a small amount of α-olefin and / or ethylene. When the polypropylene resin is a copolymer, in the case of a random copolymer, the copolymerization ratio of other α-olefin and / or ethylene in the copolymer is generally 10% by weight or less, preferably Is 0.5 to 7% by weight. In the case of a block copolymer, the copolymerization ratio of other α-olefin and / or ethylene in the copolymer is generally 1 to 40% by weight, preferably 1 to 25%. % By weight, more preferably 2 to 20% by weight, particularly preferably 3 to 15% by weight. These polypropylene polymers may be a mixture of two or more polymers. As an index of the crystallinity of polypropylene, for example, a melting point, a heat of crystal melting, and the like are used.

  The polypropylene-based resin can employ multistage polymerization by combining a gas phase polymerization method, a bulk polymerization method, a solvent polymerization method and any combination thereof, and there is no particular limitation on the number average molecular weight of the polymer, Preferably, it is adjusted to 10,000 to 1,000,000.

  As this crystalline polypropylene resin, MFR (melt flow rate) measured at a temperature of 230 ° C. and a load of 21.18 N in accordance with JIS K7210 is 0.5-20 g / 10 minutes, preferably 0.5-10 g / The thing of the range for 10 minutes is good.

  In the present invention, the hydrogenated styrene-butadiene copolymer having at least one functional group selected from the group consisting of a carboxylic acid group, an acid anhydride group, an amino group, an epoxy group, and a hydroxyl group in the molecule, For example, maleic anhydride-modified styrene-ethylene / butylene-styrene block copolymer (maleic anhydride-modified SEBS resin), amine-modified styrene-ethylene / butylene-styrene block copolymer (amine-modified SEBS resin), amine-modified styrene- A butadiene / butylene-styrene block copolymer (amine-modified SBBS resin) or a carboxylic acid-modified styrene-butadiene / butylene-styrene block copolymer (carboxylic acid-modified SBBS resin) is preferred.

  Both the SEBS resin and the SBBS resin can be obtained by hydrogenating the SBS resin, and further, grafted with maleic anhydride or reacted with an amine compound, a carboxylic acid compound or the like to form an amine or carboxylic acid at the terminal portion. A modified product can be easily obtained by adding an acid.

  The styrene component in the hydrogenated product of a styrene-butadiene copolymer having in its molecule at least one functional group selected from the group consisting of the carboxylic acid group, acid anhydride group, amino group, epoxy group and hydroxyl group. The preferable lower limit of the content is 20% by weight, and the preferable upper limit is 80% by weight.

  The functional group in the hydrogenated product of a styrene-butadiene copolymer having in its molecule at least one functional group selected from the group consisting of the carboxylic acid group, acid anhydride group, amino group, epoxy group and hydroxyl group The preferable lower limit of the content of is 0.05% by weight, and the preferable upper limit is 5.0% by weight. If it is less than 0.05% by weight, the blocking resistance tends to be reduced, and if it exceeds 5.0% by weight, the resin is thermally deteriorated when the functional group is added, and foreign matters such as gel are generated. May be easier. A more preferred lower limit is 0.1% by weight, and a more preferred upper limit is 3.0% by weight.

  The hydrogenated styrene-butadiene copolymer having at least one functional group selected from the group consisting of the carboxylic acid group, acid anhydride group, amino group, epoxy group and hydroxyl group in the molecule is, for example, “Tough Tech” manufactured by Asahi Kasei Chemicals Corporation.

  The ratio of the vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer hydrogenated product, the polypropylene resin and the hydrogenated styrene-butadiene copolymer having a functional group in the molecule in the layer A of the present invention is vinyl aromatic. Styrene-butadiene having a functional group in the molecule with respect to 100 parts by weight of a resin composition comprising 30 to 90% by weight of a hydrogenated hydrocarbon-conjugated diene hydrocarbon copolymer and 10 to 70% by weight of a polypropylene resin. 30 to 400 parts by weight of copolymer hydrogenated product. This range is preferable because blocking can be prevented. Further, a preferred ratio of vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer hydrogenated product, polypropylene resin and styrene-butadiene copolymer hydrogenated product having a functional group in the molecule is vinyl aromatic hydrocarbon- Styrene-butadiene copolymer having a functional group in the molecule with respect to 100 parts by weight of the resin composition in which 40 to 60% by weight of hydrogenated conjugated diene hydrocarbon copolymer and 40 to 60% by weight of polypropylene resin are combined. The hydrogenated product is 50 to 300 parts by weight.

  The vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer hydrogenated product and polypropylene resin used in the B layer of the present invention may be the same as or different from those used in the A layer.

  The ratio of the vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer hydrogenated product in layer B is a resin composition that combines the vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer hydrogenated product and the polypropylene resin. On the other hand, it is 70 to 90% by weight, preferably 80 to 90% by weight. Moreover, the ratio of a polypropylene-type resin is 10-30 weight% with respect to this resin composition, Preferably it is 10-20 weight%. Such a range is preferable because high recoverability can be exhibited.

  The C layer of the present invention may be the same as or different from the resin composition and mixing ratio used in the A layer.

  An anti-blocking agent or the like may be further added to the C layer as long as the effects of the present invention are not adversely affected. By adding an anti-blocking agent, blocking such as when the substrate film for dicing is rolled up is preferably suppressed. Examples of the anti-blocking agent include inorganic or organic fine particles.

  The total thickness of the base film for multi-layer dicing in the present invention is not limited as long as it is thicker than the cutting depth of the dicing blade and can be easily wound in a roll shape, for example, about 50 to 300 μm, preferably Is about 60 to 250 μm, more preferably 70 to 200 μm.

  The base film for multilayer dicing in the present invention preferably has a three-layer structure of A layer / B layer / C layer.

  The thickness of each layer is as follows.

  In the base film for multi-layer dicing in the present invention, in order to obtain high resilience, the thickness ratio of the B layer is desirably 50% or more with respect to the total thickness.

  The thicknesses of the A layer and the C layer in the present invention may be 5 μm or more, respectively, and the preferable upper limit is that the total thickness of the A layer and the C layer is 50% or less with respect to the total thickness of the base film for multilayer dicing. is there. When the thickness is less than 5 μm, it is difficult to form a uniform and stable layer mechanically, and when the total thickness of the A layer and the C layer exceeds 50% with respect to the total thickness of the base film for multi-layer dicing, it is highly restored. It is not preferable because the properties are lowered.

  The base film for multilayer dicing having a three-layer structure is manufactured by multilayer coextrusion molding of the resins constituting the A layer to C layer. Specifically, a vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer hydrogenated product of 30 to 90% by weight and a polypropylene resin of 10 to 70% by weight, a carboxylic acid group, an acid A resin composition containing 30 to 400 parts by weight of a hydrogenated styrene-butadiene copolymer having at least one functional group selected from the group consisting of an anhydride group, amino group, epoxy group and hydroxyl group in the molecule. A resin for layer A and resin for layer C, and a resin composition comprising 70 to 90% by weight of a vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer hydrogenated product and 10 to 30% by weight of a polypropylene resin. The resin for B layer is manufactured by multilayer coextrusion molding in the order of A layer / B layer / C layer.

  The above-mentioned A layer resin, B layer resin and C layer resin are respectively supplied to the screw type extruder in this order and extruded from a multilayer T die at 180 to 230 ° C., and this is extruded at 10 to 70 ° C. It is cooled while passing through a cooling roll and taken up substantially unstretched. Alternatively, the resin for each layer may be once obtained as pellets and then extruded as described above.

  The reason why the film is substantially unstretched at the time of taking is to effectively extend the film after dicing. This substantially non-stretching includes non-stretching or slight stretching that does not adversely affect the expansion of the dicing film. In general, the film may be pulled to such an extent that no sagging occurs when the film is taken up.

II. Dicing Film The substrate film for multi-layer dicing obtained as described above is formed by coating a known pressure-sensitive adhesive on the film to form a pressure-sensitive adhesive layer, and further providing a release film on the pressure-sensitive adhesive layer. Manufactured. An adhesive layer and a release film are formed on the first layer of the base film for multilayer dicing.

  As the pressure-sensitive adhesive component used in the pressure-sensitive adhesive layer, known ones are used. For example, the pressure-sensitive adhesive component described in JP-A No. 5-21234 can be used. A known release film is also used.

The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is preferably an acrylic pressure-sensitive adhesive. Specifically, the pressure-sensitive adhesive layer was selected from a homopolymer and a copolymer having (meth) acrylic acid ester as a main constituent monomer unit. Acrylic polymers, copolymers with other functional monomers, and mixtures of these polymers are used. For example, (meth) acrylic acid ester includes ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, Glycidyl acrylate, 2-hydroxyethyl acrylate and the like can be preferably used. The molecular weight of the acrylic polymer is 1.0 × 10 ^{5 to} 10.0 × 10 ⁵ , and preferably 4.0 × 10 ^{5 to} 8.0 × 10 ⁵ .

  In addition, by including a radiation polymerizable compound in the pressure-sensitive adhesive layer as described above, the adhesive strength can be reduced by irradiating the pressure-sensitive adhesive layer with radiation after the wafer is cut and separated. As such a radiation polymerizable compound, for example, a low molecular weight compound having at least two photopolymerizable carbon-carbon double bonds in a molecule that can be three-dimensionally reticulated by light irradiation is widely used (for example, JP JP-A-60-196,956, JP-A-60-223,139, etc.).

  Specifically, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and the like are used.

  Furthermore, in addition to the acrylate compounds as described above, urethane acrylate oligomers can also be used as the radiation polymerizable compound. The urethane acrylate oligomer is obtained by reacting an acrylate or methacrylate having a hydroxyl group with a terminal isocyanate urethane prepolymer obtained by reacting a polyol compound such as a polyester type or a polyether type with a polyvalent isocyanate compound. This urethane acrylate oligomer is a radiation polymerizable compound having at least one carbon-carbon double bond.

  Further, in the pressure-sensitive adhesive layer, in addition to the pressure-sensitive adhesive and the radiation-polymerizable compound as described above, a compound (such as a leuco dye) that is colored by radiation irradiation, a light-scattering inorganic compound powder, and abrasive grains, as necessary. (A particle size of about 0.5 to 100 μm), an isocyanate curing agent, a UV initiator, and the like can also be contained.

  The dicing film is usually obtained in a rolled state cut into a tape shape.

Hereinafter, the present invention will be described in more detail using Examples and Comparative Examples, but the present invention is not limited to these Examples.

  The following abbreviations have the following meanings:

SEBS: Styrene-butadiene copolymer hydrogenated product (Clayton Polymer Japan Co., Ltd. MD6945)
SEPS: Styrene-isoprene copolymer hydrogenated product (Kuraray Co., Ltd. Hibler 7311)
Mod-SEBS: Maleic anhydride-modified styrene-butadiene copolymer hydrogenated product (Tuftec M1913 manufactured by Asahi Kasei Chemicals Corporation)
PP: Polypropylene resin (PC412A manufactured by Sun Allomer Co., Ltd.)
“%” Means wt%, and “part” means part by weight.

Example 1
60 parts by weight of Mod-SEBS was dry blended with 100 parts by weight of a resin composition consisting of 90% by weight of SEBS and 10% by weight of PP, and this was used as the resin for the A layer. 80% by weight of SEBS and 20% by weight of PP were dry blended, and this was used as a resin for the B layer. 60 parts by weight of Mod-SEBS was dry blended to 100 parts by weight of a resin composition consisting of 90% by weight of SEBS and 10% by weight of PP, and this was used as a resin for the C layer.

  A layer resin, B layer resin, and C layer resin were supplied in this order to a multilayer extruder having a barrel temperature of 180 to 220 ° C. It was extruded from a 230 ° C. T-die, cooled and solidified with a take-up roll having a set temperature of 40 ° C., and wound up in an unstretched state.

  The thickness of the obtained multilayer film was A layer 25 μm, B layer 100 μm, C layer 25 μm and total thickness 150 μm. See Table 1.

(Example 2)
A multilayer film was obtained by treating in the same manner as in Example 1 with the blending amounts shown in Table 1. The thickness of each film is as shown in Table 1.

(Example 3)
60 parts by weight of Mod-SEBS was dry blended with 100 parts by weight of a resin composition consisting of 90% by weight of SEPS and 10% by weight of PP, and this was used as the resin for the A layer. 80% by weight of SEPS and 20% by weight of PP were dry blended, and this was used as a resin for the B layer. 60 parts by weight of Mod-SEBS was dry blended with 100 parts by weight of a resin composition composed of 90% by weight of SEPS and 10% by weight of PP, and this was used as a resin for the C layer.

  A layer resin, B layer resin, and C layer resin were supplied in this order to a multilayer extruder having a barrel temperature of 180 to 220 ° C. It was extruded from a 230 ° C. T-die, cooled and solidified with a take-up roll having a set temperature of 40 ° C., and wound up in an unstretched state.

  The thickness of the obtained multilayer film was A layer 25 μm, B layer 100 μm, C layer 25 μm and total thickness 150 μm. See Table 1.

Example 4
A multilayer film was obtained by the same treatment as in Example 3 with the blending amounts shown in Table 1. The thickness of each film is as shown in Table 1.

(Comparative Example 1)
20 parts by weight of Mod-SEBS was dry blended with 100 parts by weight of a resin composition consisting of 90% by weight of SEBS and 10% by weight of PP, and these were used as A layer resin and C layer resin. Except for the above, the same treatment as in Example 1 was carried out to obtain a multilayer film. The thickness of the film is as shown in Table 2.

(Comparative Example 2)
20 parts by weight of Mod-SEBS is dry blended to 100 parts by weight of a resin composition consisting of 90% by weight of SEPS and 10% by weight of PP, except that this is used as the resin for the A layer and the resin for the C layer. Were processed in the same manner as in Example 3 to obtain a multilayer film. The thickness of the film is as shown in Table 2.

Test Example 1 (Evaluation of restorability)
From an arbitrary location of the film obtained in the examples, 100 mm long × 10 mm wide (when the sample is cut out with the film flowing direction as the vertical direction, the MD is evaluated, and the width direction of the film is set as the vertical direction. A sample for measurement was cut out to a size of (the evaluation of TD was the case of cutting out), and two lines were inserted so that the distance between the marked lines was 40 mm at the center in the vertical direction. This measurement sample was set in a tensile tester “AGS100A” manufactured by Shimadzu Corporation with a distance between chucks of 40 mm so that the mark of the measurement sample was aligned with the chuck, and stretched by 20% at a pulling speed of 200 mm / min. After holding in that state for 1 minute, the chuck is opened and the measurement sample is taken out. 10 seconds after taking out, the distance L (mm) of the marked line of the measurement sample is measured. The restoration rate (%) in the vertical direction with respect to 20% elongation is obtained from the following formula.
Restoration rate (%) = [{40− (L−40)} / 40] × 100 Equation 1
The above measurement is performed 10 times in the MD direction and 10 times in the TD direction, and an average value thereof is obtained. If the restoration rate is 90% or more, the rack recoverability is excellent. It was set as "x" as inferior. The results are shown in Table 2.

Test Example 2 (Evaluation of blocking resistance)
Two samples for measurement from an arbitrary place of the film obtained in the example to a size of 100 mm × width 30 mm (the sample was cut with the film flow direction as the vertical direction and the width direction as the horizontal direction). Cut out. Two measurement samples are placed so that the same surface (surface in contact with the cooling roll) overlaps with an area of 40 mm × 30 mm wide, and the overlapped measurement samples are sandwiched between two glass plates, from above A 600 g weight was placed on the part where the samples overlapped. This was placed in a constant temperature bath at 40 ° C. and left for 7 days. Seven days later, the sample taken out of the thermostatic chamber was set in a peel tester (Peeling TESTER HEIDON-17) manufactured by Shinto Kagaku Co., Ltd., and the 180 ° shear peel strength was measured at a pulling speed of 200 mm / min. If it was / 10 mm or less, no blocking was considered.

Claims (2)

  The A layer and the C layer are carboxylic acid groups based on 100 parts by weight of a resin composition comprising 30 to 90% by weight of a vinyl aromatic hydrocarbon-conjugated diene copolymer hydrogenated product and 10 to 70% by weight of a polypropylene resin. , A resin containing 30 to 400 parts by weight of a hydrogenated styrene-butadiene copolymer having in the molecule at least one functional group selected from the group consisting of an acid anhydride group, an amino group, an epoxy group and a hydroxyl group The layer B contains a resin composition comprising 70 to 90% by weight of a vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer hydrogenated product and 10 to 30% by weight of a polypropylene-based resin. A substrate film for multi-layer dicing, wherein B layer / C layer are laminated in this order.   A dicing film further comprising an adhesive layer and a release film on the A layer of the substrate film for dicing according to claim 1.