Die bond sheets and dicing die bond films

Abstract

To provide a die bond sheet that can be combined with relatively good cuteness at low temperatures and peeling suppression performance from an adhesive body after curing.SOLUTION: A die bond sheet includes at least an acrylic resin containing epoxy group with epoxy group in molecules as an organic ingredient, and the epoxy equivalent of the acrylic resin containing epoxy group is 1300 or more and less than 6000, and the ratio of the acrylic resin containing epoxy group in the organic ingredient is 90.0% or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a die bond sheet and a dicing die bond film equipped with the die bond sheet, for example, used when manufacturing semiconductor integrated circuits. [Background technology]

[0002] Conventionally, dicing die bond films used in the manufacture of semiconductor integrated circuits are known. This type of dicing die bond film comprises, for example, a dicing tape and a die bond sheet laminated on the dicing tape and adhered to a wafer. The dicing tape has a substrate layer and an adhesive layer in contact with the die bond sheet. This type of dicing die bond film is used in the manufacture of semiconductor integrated circuits, for example, as described below.

[0003] A method for manufacturing semiconductor integrated circuits generally comprises a front-end process in which a circuit surface is formed on one side of a wafer using highly integrated electronic circuits, and a back-end process in which chips are cut out from the wafer with the circuit surface formed on it and assembled.

[0004] The subsequent processes include, for example, a cutting step of cutting the wafer (semiconductor wafer) on which the circuit surface is formed into chips, and a pickup step of peeling off the die bond sheet attached to the adhesive layer of the dicing die bond film from the adhesive layer together with the chips. Before the cleavage process, preparations are made for processing the semiconductor wafer into chips (dies) by cleavage. In the preparation before cleavage, for example, a weak area may be formed on the semiconductor wafer to allow for cleavage into small chips (dies), or a half-cut process may be performed to make cuts in the semiconductor wafer with a blade. Furthermore, for example, a back-grinding process can be performed to reduce the thickness of the semiconductor wafer by polishing and cutting the side of the semiconductor wafer opposite to the circuit surface. In back-grinding, the semiconductor wafer can be polished and cut to reduce its thickness until it is individualized, using the weak area or cut as the boundary. Alternatively, the semiconductor wafer can be polished and cut to a thickness that does not allow for individualization into chips. Next, a die bond sheet may be attached to the polished and cut surface opposite the circuit side, and then the die bond sheet may be attached to the adhesive layer of the dicing tape. This allows the semiconductor wafer or individualized chip (die) to be bonded to the dicing tape via the die bond sheet. Furthermore, before the die bond sheet is peeled off from the adhesive layer along with the chips by the pickup process, the dicing tape may be stretched in the planar direction to separate the semiconductor wafer into chips (dies) using the aforementioned weak points or cuts as boundaries, thereby widening the gaps between adjacent chips (dies). The die bond sheet can also be separated in the same way when the dicing tape is stretched in this manner. On the other hand, if the semiconductor wafer has already been separated by the backgrinding process described above, only the die bond sheet may be separated by stretching the dicing tape, or the die bond sheet may be separated in advance by laser light or the like before stretching the dicing tape. Subsequently, in the pickup process, the individualized chips and die bond sheets are peeled off from the adhesive layer of the dicing tape.

[0005] The post-processing steps described above include, for example, a dicing step in which a weak area is formed on the wafer using a laser or the like to cut the wafer into smaller chips (dies); a backgrinding step in which the wafer opposite to the circuit surface on which the weak area has been formed is polished and cut to divide and individualize the wafer so that the weak area becomes the boundary; a mounting step in which the side of the individualized wafer opposite to the circuit surface is attached to a die bond sheet and the chips (dies) are fixed to the dicing tape via the die bond sheet; an expanding step in which the die bond sheet is divided and individualized and the spacing between adjacent individualized chips (dies) is widened; a pick-up step in which the die bond sheet and adhesive layer are separated and the chips (dies) with the die bond sheet attached are removed; a die bonding step in which the chips (dies) with the die bond sheet attached are bonded to a substrate via the die bond sheet; and a curing step in which the die bond sheet bonded to the substrate is cured. Semiconductor integrated circuits are manufactured, for example, through these steps.

[0006] In the semiconductor integrated circuit manufacturing method described above, for example, in the die bonding process, relatively thin chips (dies) with die bonding sheets attached are sometimes stacked multiple times. To improve the performance of the stacking of chips (dies) in the die bonding process, die bonding sheets containing specific components and having specific physical properties are known (for example, Patent Document 1).

[0007] More specifically, the die bond sheet described in Patent Document 1 contains a filler with an average particle size in the range of 5 nm to 100 nm, a thermoplastic resin, and a phenolic resin, and its tensile storage modulus at 150°C before heat curing is greater than 0.3 MPa and 30 MPa or less. According to the die bond sheet described in Patent Document 1, warping of thin chips (dies) can be suppressed, and stacking of chips (dies) multiple times can be carried out smoothly. [Prior art documents] [Patent Documents]

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] By the way, for example, in the above expansion process, the dicing sheet may be cut under low temperature conditions of 0 °C or lower. At this time, the dicing sheet needs to be cut well. Therefore, there is a demand for a dicing sheet having good cutting properties at such a low temperature. Further, for example, in the above curing process and the subsequent heating process, there is a demand for a dicing sheet designed to suppress the peeling phenomenon that occurs between the curing dicing sheet and the adherend.

[0010] However, regarding a dicing sheet having relatively good cutting properties at low temperature and capable of suppressing peeling that may occur between the adherend after the curing treatment, and a dicing dicing film provided with the dicing sheet, it cannot yet be said that they have been sufficiently studied.

[0011] Therefore, an object of the present invention is to provide a dicing sheet having relatively good cutting properties at low temperature and peeling suppression performance from the adherend after the curing treatment, and a dicing dicing film.

Means for Solving the Problems

[0012] In order to solve the above problems, the dicing sheet according to the present invention contains at least an epoxy group-containing acrylic resin having an epoxy group in the molecule as an organic component, the epoxy equivalent of the epoxy group-containing acrylic resin is 1300 or more and less than 6000, and the ratio of the epoxy group-containing acrylic resin in the organic component is 90.0% by mass or more.

[0013] In the above die bond sheet, the ratio of the mass-average molecular weight Mw to the number-average molecular weight Mn of the epoxy group-containing acrylic resin [Mw / Mn], measured by gel permeation chromatography, is 2.5 or more and 50.0 or less. The phenolic resin content may be less than 5% by mass.

[0014] In the above die bond sheet, the mass-average molecular weight of the epoxy group-containing acrylic resin is 1.0 × 10⁻⁶. 5 The above 1.5 × 10 6 The following is also acceptable.

[0015] In the die bond sheet described above, the epoxy group-containing acrylic resin may include a first acrylic resin and a second acrylic resin having a smaller mass-average molecular weight than the first acrylic resin. The mass-average molecular weight of the first acrylic resin is 4.0 × 10⁻⁶. 5 The above 2.0 × 10 6 The following applies, and the mass-average molecular weight of the second acrylic resin is 5.0 × 10⁻⁶. 3 The above 2.0 × 10 5 It is acceptable to be less than [a certain value].

[0016] The dicing die bond film according to the present invention comprises the die bond sheet described above and a dicing tape bonded to the die bond sheet. [Effects of the Invention]

[0017] The die bond sheet according to the present invention can combine relatively good cleavage at low temperatures with performance in suppressing peeling from the adherend after curing. [Brief explanation of the drawing]

[0018] [Figure 1] A cross-sectional view of the dicing die bond film of this embodiment, cut in the thickness direction. [Figure 2A] A schematic cross-sectional view illustrating the stealth dicing process in the manufacturing method of semiconductor integrated circuits. [Figure 2B]A schematic cross-sectional view illustrating the stealth dicing process in the manufacturing method of semiconductor integrated circuits. [Figure 2C] A schematic cross-sectional view illustrating the stealth dicing process in the manufacturing method of semiconductor integrated circuits. [Figure 2D] A schematic cross-sectional view illustrating the backgrinding process in the manufacturing method of semiconductor integrated circuits. [Figure 3A] A schematic cross-sectional view illustrating the mounting process in the manufacturing method of semiconductor integrated circuits. [Figure 3B] A schematic cross-sectional view illustrating the mounting process in the manufacturing method of semiconductor integrated circuits. [Figure 4A] A schematic cross-sectional diagram illustrating the low-temperature expansion process in the manufacturing method of semiconductor integrated circuits. [Figure 4B] A schematic cross-sectional diagram illustrating the low-temperature expansion process in the manufacturing method of semiconductor integrated circuits. [Figure 4C] A schematic cross-sectional diagram illustrating the low-temperature expansion process in the manufacturing method of semiconductor integrated circuits. [Figure 5A] A schematic cross-sectional view illustrating the expansion process at room temperature in the manufacturing method of semiconductor integrated circuits. [Figure 5B] A schematic cross-sectional view illustrating the expansion process at room temperature in the manufacturing method of semiconductor integrated circuits. [Figure 6] A schematic cross-sectional view illustrating the pickup process in the manufacturing method of semiconductor integrated circuits. [Figure 7] A schematic cross-sectional view illustrating the die bonding process in the manufacturing method of semiconductor integrated circuits. [Figure 8] A schematic cross-sectional view illustrating the wire bonding process in the manufacturing method of semiconductor integrated circuits. [Figure 9] A schematic cross-sectional view illustrating the encapsulation process in the manufacturing method of semiconductor integrated circuits. [Modes for carrying out the invention]

[0019] Hereinafter, an embodiment of the die bond sheet and a dicing die bond film equipped with the die bond sheet according to the present invention will be described with reference to the drawings.

[0020] As shown in Figure 1, the dicing die bond film 1 of this embodiment comprises a dicing tape 20 and a die bond sheet 10 which is laminated on the adhesive layer 22 of the dicing tape 20 and adhered to a semiconductor wafer. The die bond sheet 10 is adhered to an adherend such as a circuit board or a semiconductor chip in the manufacturing of a semiconductor integrated circuit. Please note that the diagrams in the drawings are schematic representations and do not necessarily reflect the actual aspect ratio of the object.

[0021] <Die bond sheet for dicing die bond film> The Diebond sheet 10 contains at least an epoxy group-containing acrylic resin as an organic component, wherein the epoxy equivalent of the epoxy group-containing acrylic resin is 1300 or more and less than 6000, and the proportion of the epoxy group-containing acrylic resin in the organic component is 90.0% by mass or more. In the above-described die bond sheet 10, preferably, the ratio of the mass-average molecular weight Mw to the number-average molecular weight Mn of the epoxy group-containing acrylic resin [Mw / Mn], as measured by gel permeation chromatography, is 2.5 or more and 50.0 or less.

[0022] In the die bond sheet with the above configuration, the epoxy equivalent of the epoxy group-containing acrylic resin is within a predetermined range that is relatively large, so the number of epoxy groups per unit mass is relatively small, and the progress of curing during the curing treatment is suppressed to some extent. Moreover, this epoxy group-containing acrylic resin is contained in a considerably large proportion, 90.0% or more by mass, of the organic components. Therefore, the curing of the die bond sheet proceeds relatively slowly. Consequently, even if voids occur between the adherend and the die bond sheet, the voids can diffuse into the interior of the die bond sheet, which has not yet fully cured. This suppresses the persistence of voids between the adherend and the die bond sheet, preventing delamination in the remaining void areas. Therefore, delamination that may occur between the adherend and the die bond sheet after the curing treatment is suppressed. Furthermore, epoxy group-containing acrylic resins can react with each other's epoxy groups. In addition, if the die bond sheet further contains a phenolic resin having active hydrogen groups, the epoxy groups of the epoxy group-containing acrylic resin can react with the active hydrogen groups.

[0023] The epoxy group-containing acrylic resin described above is a polymer compound in which at least (meth)acrylic acid ester monomers are polymerized. Both the first acrylic resin and the second acrylic resin (described later) as epoxy group-containing acrylic resins are polymers in which at least (meth)acrylate monomers are polymerized. In this specification, the term "(meth)acrylic acid" refers to at least one of methacrylic acid and acrylic acid, and the term "(meth)acrylate" refers to at least one of methacrylate (methacrylic acid ester) and acrylate (acrylic acid ester).

[0024] The epoxy group-containing acrylic resin described above is preferably a polymer in which alkyl (meth)acrylate is the most abundant structural unit by mass. Examples of such alkyl (meth)acrylate include C2-C8 alkyl (meth)acrylate, and preferably C2-C4 alkyl (meth)acrylate. The notation C2 in the above-mentioned C2-C8 alkyl (meth)acrylate, etc., represents the number of carbon atoms in the alkyl portion (hydrocarbon portion) of the alkyl (meth)acrylate. Such alkyl portion is usually a saturated hydrocarbon. For example, the notation C2-C8 represents the number of carbon atoms between 2 and 8. The same applies hereafter. Specifically, the epoxy group-containing acrylic resin described above includes structural units derived from alkyl (meth)acrylate monomers and structural units derived from glycidyl group-containing monomers. The epoxy group-containing acrylic resin described above may further contain various constituent units derived from, for example, carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, acrylamide, acrylonitrile and other polar functional group-containing monomers, or various other polyfunctional monomers.

[0025] The epoxy group-containing acrylic resin described above is preferably a copolymer of at least an alkyl (meth)acrylate, particularly an alkyl (meth)acrylate with four or fewer carbon atoms in the alkyl portion, and a glycidyl group-containing (meth)acrylate.

[0026] The epoxy group-containing acrylic resin described above typically has epoxy groups in its side chains. The epoxy group-containing acrylic resin may also have epoxy groups at the ends of its side chains.

[0027] The molecular weight distribution chart obtained by measuring the above epoxy group-containing acrylic resin by gel permeation chromatography (GPC) preferably has at least two peaks that are separated from each other, one on the low molecular weight side and the other on the high molecular weight side. In a chart showing the molecular weight distribution, the two peaks only need to have their respective vertices separated from each other. In other words, even if the shoulders of the two peaks overlap each other, as long as the vertices are separated from each other, the chart has two peaks.

[0028] By the above GPC measurement, the number average molecular weight Mn, mass average molecular weight Mw, etc. of the above epoxy group-containing acrylic resin can be determined.

[0029] The mass average molecular weight of the above epoxy group-containing acrylic resin is 1.0×10 5 or more and 1.5×10 6 or less, and may also be 2.0×10 5 or more and 1.2×10 6 or less, and may also be 5.5×10 5 or more and 1.0×10 6 or less. Such a value of the mass average molecular weight is the value obtained when measuring the epoxy group-containing acrylic resin containing both the first acrylic resin and the second acrylic resin described later by GPC. When the mass average molecular weight of the above epoxy group-containing acrylic resin is 1.0×10 5 or more, the die bond sheet 10 can have higher shape retention performance while having appropriate flexibility. Also, when the mass average molecular weight of the above epoxy group-containing acrylic resin is 1.0×10 6 or less, there is an advantage that the cutability at low temperatures becomes better.

[0030] The ratio [Mw / Mn] of the mass average molecular weight Mw to the number average molecular weight Mn of the above epoxy group-containing acrylic resin measured by the above gel permeation chromatography is preferably 2.5 or more and 50.0 or less. Such a ratio [Mw / Mn] is an index representing the degree of the molecular weight distribution of the above epoxy group-containing acrylic resin. The closer such a ratio [Mw / Mn] is to 1, the closer the molecular weight distribution is to monodisperse. When the above ratio [Mw / Mn] is 2.5 or higher, the molecular weight distribution of the epoxy group-containing acrylic resin becomes wider. As the molecular weight distribution becomes wider, the above die bond sheet 10 contains epoxy group-containing acrylic resin with a relatively low molecular weight. Since epoxy group-containing acrylic resin with a relatively low molecular weight does not necessarily have high performance in maintaining the shape of the die bond sheet 10, the above die bond sheet has better cleavage properties at low temperatures because it contains epoxy group-containing acrylic resin with a relatively low molecular weight. In addition, when the above ratio [Mw / Mn] is 50.0 or lower, the separation of low molecular weight epoxy group-containing acrylic resin from high molecular weight epoxy group-containing acrylic resin can be further suppressed, and the decrease in adhesive strength of the die bond sheet 10 can be further suppressed.

[0031] The above ratio [Mw / Mn] is preferably greater than 3.0, and more preferably 5.0 or greater. Furthermore, the above ratio [Mw / Mn] is preferably 17.0 or less, more preferably less than 16.0, and even more preferably 15.0 or less.

[0032] The details of the GPC measurement conditions are as follows. Note that the number-average molecular weight (Mn) and an index of molecular weight distribution (Mw / Mn) can also be obtained through GPC measurement. [Preparation of the measurement sample] (1) Obtain a sample of approximately 0.2 g from the die bond sheet before curing. (2) The sample, wrapped in a mesh sheet, is immersed in approximately 30 mL of toluene at room temperature for one week. (3) By removing the mesh sheet from the toluene, the toluene-insoluble matter remaining in the mesh sheet is removed to obtain a toluene solution containing toluene-soluble components. (4) The toluene solution is subjected to reduced pressure at a temperature of 45°C or lower to remove toluene from the toluene solution and obtain a solid of toluene-soluble components. (5) Dissolve the solid in tetrahydrofuran (THF) to prepare a THF solution so that the concentration of the solid is 0.2% by mass, and then leave it overnight. (6) The THF solution, left overnight, is filtered through a membrane filter (0.45 μm), and the resulting filtrate is used as the measurement sample. [GPC measurement conditions] • Equipment: Gel permeation chromatography apparatus • Columns: 3 in total One TSKgel quaudcolumn SuperHZ-L (hereinafter referred to as "Column 1") manufactured by Tosoh Corporation, and Two TSKgel SuperHAM-M tubes manufactured by Tosoh Corporation (hereinafter referred to as the second column). Two second columns were connected in series downstream of the first column, and the columns were positioned so that the eluent, described later, flows in from the first column side. Column temperature: 40°C • Eluent: Tetrahydrofuran (THF) • Flow rate: Sample pump flow rate 0.3 mL / min Reference pump flow rate: 1.0 mL / min • Injection volume: 10 μL (sample concentration: 0.2% by mass as stated above) • Detector: Differential refractive index detector (RI) • Standard material: Standard polystyrene

[0033] The epoxy equivalent of the epoxy group-containing acrylic resin described above is 1,300 [g / eq] or more and 6,000 [g / eq] or less. Such epoxy equivalent may be 1,400 [g / eq] or more, or 1,500 [g / eq] or more. Furthermore, such epoxy equivalent may be 5,000 [g / eq] or less, 2,500 [g / eq] or less, 2,000 [g / eq] or less, or 1,900 [g / eq] or less. Such epoxy equivalent values ​​are the values ​​obtained when measuring the epoxy equivalent of an epoxy group-containing acrylic resin containing both the first acrylic resin and the second acrylic resin. By having an epoxy equivalent of 1,300 [g / eq] or more in the epoxy group-containing acrylic resin, the curing process of the die bond sheet during curing treatment can be slowed down, thereby further suppressing the occurrence of voids and delamination between the die bond sheet and the adherend. Furthermore, by having an epoxy equivalent of 6,000 [g / eq] or less in the epoxy group-containing acrylic resin, the die bond sheet can be more aggregated during curing treatment. Therefore, while suppressing the occurrence of voids, the die bond sheet 10 can have sufficient resistance to high-temperature heat treatment during reflow.

[0034] The epoxy equivalent of the epoxy group-containing acrylic resin described above is measured by NMR analysis. The method for preparing the sample for measurement and the measurement conditions will be described in the following examples.

[0035] In this embodiment, the epoxy group-containing acrylic resin having epoxy groups in its molecule preferably comprises a first acrylic resin and a second acrylic resin having a smaller mass-average molecular weight than the first acrylic resin.

[0036] Preferably, the mass-average molecular weight of the first acrylic resin is greater than the mass-average molecular weight of the second acrylic resin, and the epoxy equivalent of the first acrylic resin is greater than the epoxy equivalent of the second acrylic resin.

[0037] The mass-average molecular weight of the first acrylic resin is 4.0 × 10⁻⁶. 5 The above 2.0 × 10 6 The following is also acceptable: 5.0 × 10 5 The above 1.5 × 10 6 The following is also acceptable: 7.0 × 10 5 The above 1.3 × 10 6 The following is also acceptable. The mass-average molecular weight of the first acrylic resin is 4.0 × 10 5 As a result of the above, the die bond sheet 10 can have higher shape retention performance. Also, the mass average molecular weight of the first acrylic resin is 2.0 × 10 6 The following factors can improve cleavage at low temperatures.

[0038] The mass-average molecular weight of the second acrylic resin is 5.0 × 10⁻⁶. 3 The above 2.0 × 10 5 It may be less than 1.0 × 10 4 The above 1.0 × 10 5 The following is also acceptable: 2.9 × 10 4 The above 8.0 x 10 4 The following is also acceptable. The mass-average molecular weight of the second acrylic resin is 5.0 × 10 3 As a result of the above, the amount of the second acrylic resin with a lower molecular weight is reduced, which further suppresses the separation (bleed-out) of the low molecular weight second acrylic resin from the high molecular weight second acrylic resin. Therefore, the adhesion of the die bond sheet 10 to the wafer can be improved. In addition, the mass average molecular weight of the second acrylic resin is 2.0 × 10⁻⁶. 5 Being below this level allows for better cleavage at low temperatures.

[0039] The epoxy equivalent of the first acrylic resin may be 1,500 [g / eq] or more and 8,000 [g / eq] or less, 1,700 [g / eq] or more and 6,000 [g / eq] or less, 1,800 [g / eq] or more and 5,000 [g / eq] or less, 4,000 [g / eq] or less, or 3,000 [g / eq] or less. By having an epoxy equivalent of 1,500 [g / eq] or more in the first acrylic resin, the curing process of the die bond sheet can be slowed down, thereby further suppressing the occurrence of voids and delamination between the die bond sheet and the adherend. Furthermore, by having an epoxy equivalent of 8,000 [g / eq] or less in the first acrylic resin, the die bond sheet can be more firmly bonded to the adherend through the curing process.

[0040] The epoxy equivalent of the second acrylic resin may be 200 [g / eq] or more and less than 1,500 [g / eq], 300 [g / eq] or more and 1,200 [g / eq] or less, or 400 [g / eq] or more and 900 [g / eq] or less. By having an epoxy equivalent of 200 g / eq or more of the second acrylic resin, the curing process of the die bond sheet can be slowed down, thereby further suppressing the occurrence of voids and delamination between the die bond sheet and the adherend. Furthermore, by having an epoxy equivalent of 1,500 g / eq or less of the second acrylic resin, the die bond sheet can be more firmly bonded to the adherend through the curing process.

[0041] Preferably, the die bond sheet 10 of this embodiment contains more of the first acrylic resin than the second acrylic resin. In the die bond sheet 10 of this embodiment, the mass ratio of the second acrylic resin to the first acrylic resin is preferably 0.80 or less, more preferably 0.60 or less, even more preferably 0.50 or less, and particularly preferably 0.40 or less. The above mass ratio may also be 0.10 or more, or 0.20 or more. By having a mass ratio of 0.8 or less, the die bond sheet 10 can have higher shape retention performance. Having such a mass ratio of 0.1 or higher allows for better cleavage at low temperatures.

[0042] The die bond sheet 10 of this embodiment preferably contains 30.0% by mass or more of the first acrylic resin, more preferably 40.0% by mass or more, and even more preferably 43.0% by mass or more. The die bond sheet 10 may contain 70.0% by mass or less of the first acrylic resin, preferably 60.0% by mass or less, and more preferably 55.0% by mass or less. By containing 30.0% or more of the first acrylic resin in the die bond sheet 10, the die bond sheet 10 can have moderate flexibility while also possessing higher shape retention performance.

[0043] The die bond sheet 10 of this embodiment preferably contains 40.0% by mass or less of the second acrylic resin, more preferably 30.0% by mass or less, and even more preferably 20.0% by mass or less. The die bond sheet 10 may contain 5.0% by mass or more of the second acrylic resin, preferably 10.0% by mass or more, and more preferably 15.0% by mass or more. By including 40.0% by mass or less of the second acrylic resin in the die bond sheet 10, the adhesion of the die bond sheet 10 to the wafer can be improved.

[0044] Commercially available products can be used as the first acrylic resin and the second acrylic resin. Alternatively, the first and second acrylic resins may be synthesized, for example, by polymerizing glycidyl (meth)acrylate with other acrylic monomers using general methods.

[0045] In this embodiment, the die bond sheet 10 preferably has a tensile modulus of elasticity (tensile storage modulus E') at 150°C before heat curing treatment that is greater than 0.3 MPa and 30.0 MPa or less. Such a tensile modulus of elasticity may be 0.4 MPa or more, or 0.5 MPa or more. Furthermore, such a tensile modulus of elasticity may be 20.0 MPa or less, 10.0 MPa or less, 5.0 MPa or less, or 1.5 MPa or less. Because the tensile modulus is greater than 0.3 MPa and less than or equal to 30 MPa, the delamination of the die bond sheet 10 from the wafer during reflow processing can be further suppressed.

[0046] The tensile modulus of the die bond sheet 10 can be increased, for example, by increasing the proportion of constituent units (such as acrylonitrile) of polar functional group-containing monomers that constitute the epoxy group-containing acrylic resin. On the other hand, the tensile modulus can be decreased, for example, by decreasing the proportion of constituent units (such as acrylonitrile) of polar functional group-containing monomers that constitute the epoxy group-containing acrylic resin.

[0047] The tensile modulus mentioned above is measured under the following conditions. • Measuring device: Solid viscoelasticity measuring device • Measurement sample: 200 μm thick (made by laminating die-bonded sheets) • Test specimen: Strip-shaped, 10mm wide and 50mm long, with an initial chuck distance of 22.5mm. • Measurement mode: Tensile mode • Frequency 1Hz, heating rate 10℃ / min, distortion 0.1% • Measurement temperature range: 0°C to 200°C (heating starts after holding at 0°C for 5 minutes) Read the tensile modulus (tensile storage modulus) [MPa] at 150℃.

[0048] In the die bond sheet 10 of this embodiment, the elongation at break at 0°C may be 5.0% or less, 3.0% or less, 2.0% or less, or 1.5% or less. The above elongation at break may also be 0.1% or more.

[0049] The diebond sheet 10 may contain components other than the first acrylic resin and the second acrylic resin described above. For example, in addition to the first acrylic resin and the second acrylic resin, the diebond sheet 10 may further contain at least one of a thermosetting resin and a thermoplastic resin as an organic component.

[0050] Examples of thermosetting resins include epoxy resins, phenolic resins, amino resins, unsaturated polyester resins, polyurethane resins, silicone resins, and thermosetting polyimide resins. One or more of these thermosetting resins may be used. The thermosetting resin may, for example, contain at least one of epoxy resin and phenolic resin, or it may contain phenolic resin.

[0051] In the die bond sheet 10 of this embodiment, the content of thermosetting resin is preferably less than 5% by mass, more preferably less than 3% by mass, even more preferably less than 1% by mass, and it is particularly preferable that the die bond sheet 10 does not contain any thermosetting resin. Furthermore, in the die bond sheet 10 of this embodiment, the phenol resin content is preferably less than 5% by mass, more preferably less than 3% by mass, even more preferably less than 1% by mass, and it is particularly preferable that the die bond sheet 10 does not contain phenol resin. The low content of thermosetting resin (especially phenolic resin) in the die bond sheet 10, as described above, has the advantage of allowing the curing process of the die bond sheet 10 to proceed relatively slowly. In the die bond sheet 10 of this embodiment, the total content of phenolic resin and epoxy resin may be less than 5% by mass, 3% by mass or less, less than 3% by mass, or less than 1% by mass. Preferably, the die bond sheet 10 does not contain either phenolic resin or epoxy resin.

[0052] Examples of the epoxy resins mentioned above include bisphenol A type, bisphenol F type, bisphenol S type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol AF type, biphenyl type, naphthalene type, fluorene type, phenol novolac type, orthocresol novolac type, trishydroxyphenylmethane type, tetraphenyloleethane type, hydantoin type, trisglycidyl isocyanurate type, or glycidylamine type epoxy resins.

[0053] The hydroxyl groups of phenolic resins can crosslink with the epoxy groups of the epoxy-containing acrylic resins mentioned above. Furthermore, phenolic resins can act as curing agents for epoxy resins. Examples of phenolic resins include novolac-type phenolic resins, resol-type phenolic resins, and polyoxystyrenes such as polyparaoxystyrene. Examples of novolac-type phenolic resins include phenol novolac resin, phenol aralkyl resin, cresol novolac resin, tert-butylphenol novolac resin, and nonylphenol novolac resin. The above-mentioned phenolic resin may be of one type or two or more types.

[0054] In addition to the epoxy group-containing acrylic resins mentioned above, thermoplastic resins that may be included in the Diebond Sheet 10 include, for example, natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polybutadiene resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resins such as 6-polyamide resin and 6,6-polyamide resin, phenoxy resin, acrylic resins that do not contain epoxy groups in their molecules (hereinafter referred to as non-crosslinkable acrylic resins), saturated polyester resins such as PET and PBT, polyamide-imide resins, fluororesins, and the like. The above thermoplastic resin may be of one type or two or more types.

[0055] The above-mentioned non-crosslinkable acrylic resin is preferably a polymer in which alkyl (meth)acrylate units constitute the largest proportion by mass among the constituent units of the molecule. Examples of such alkyl (meth)acrylates include C2-C8 alkyl (meth)acrylates in which the hydrocarbon portion has 2 to 8 carbon atoms.

[0056] If the Diebond sheet 10 further contains a thermosetting resin or a thermoplastic resin in addition to the epoxy group-containing acrylic resin described above, the content of the epoxy group-containing acrylic resin in the Diebond sheet 10 is 90.0% by mass or more and 100% by mass or less of the total mass of organic components excluding fillers (in addition to the epoxy group-containing acrylic resin, for example, thermosetting resins, thermoplastic resins, curing catalysts, silane coupling agents, dyes, etc.). Preferably, it is 95.0% by mass or more. The above organic components refer to organic substances other than fillers in the Diebond sheet 10.

[0057] The die bond sheet 10 preferably contains a filler. By changing the amount of filler in the die bond sheet 10, the elasticity and viscosity of the die bond sheet 10 can be more easily adjusted. Furthermore, the physical properties of the die bond sheet 10, such as electrical conductivity, thermal conductivity, and elastic modulus, can be adjusted. Examples of fillers include inorganic fillers and organic fillers. Inorganic fillers are preferred as fillers. Even if the filler includes an organic filler, the organic components in the die bond sheet 10 do not include the organic filler. Examples of inorganic fillers include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, boron nitride, silica such as crystalline silica and amorphous silica, and other fillers. The material of the inorganic filler may be a single metal such as aluminum, gold, silver, copper, or nickel, or an alloy. Fillers such as aluminum borate whiskers, amorphous carbon black, or graphite may also be used. The filler may take various shapes, such as spherical, needle-shaped, or flake-shaped. Only one type of filler, or two or more types, may be used. Silica filler is preferred as the inorganic filler. Since the -OH groups present on the surface of the silica filler readily react with the epoxy group-containing acrylic resin during the curing process, there is an advantage in that the curing of the die bond sheet 10 can be advanced more sufficiently.

[0058] The average particle size of the filler (average particle size of primary particles) may be, for example, 5 nm or more and 500 nm or less. Preferably, the average particle size of the filler is 10 nm or more and 200 nm or less, more preferably 100 nm or less, even more preferably 50 nm or less, particularly preferably 20 nm or less, and most preferably 15 nm or less. By having an average particle size of 5 nm or more, the occurrence of voids between the die bond sheet 10 and the adherend during the curing process and the resulting delamination can be more effectively suppressed. By having an average particle size of 500 nm or less, the cleavability of the die bond sheet 10 at low temperatures before the curing process can be improved.

[0059] The average particle size of the filler (average particle size of primary particles) is measured as follows. For example, a dispersion of filler is dropped onto a flat plate, and then dried to prepare a sample for measurement. An observation image of the filler particles in the sample for measurement is obtained using a field emission scanning electron microscope (FE-SEM). For example, a backscattered electron image is obtained using a scanning electron microscope "HITACHI S-4800" (acceleration voltage 5kV). Alternatively, a phase contrast image is obtained using a scanning electron microscope "HITACHI SU8020" (acceleration voltage 5kV). Then, the particle size of each of 1000 or more filler particles is measured by image analysis (ImageJ, Image Pro), and the average value is calculated to determine the average particle size of the filler. The above dispersion may also be prepared by mixing the filler and solvent so that the filler concentration (solid content concentration) is 1% by mass or less. The above dispersion may also be prepared as follows, for example. For details, the organic components contained in the Diebond sheet 10 are burned off by calcination (for example, 500°C for 5 hours under air conditions). The dispersion may be prepared by diluting the remaining ash concentration (solid content concentration) with a solvent to 1% by mass or less. As the solvent, for example, pure water, methanol, ethanol, isopropyl alcohol, methyl ethyl ketone, chloroform, or pH-adjusted water adjusted to a pH far from the isoelectric point of the filler can be used, in which the filler can be dispersed in the form of primary particles.

[0060] When the die bond sheet 10 contains a filler, the mass ratio of the filler to the epoxy group-containing acrylic resin is preferably 0.2 or more and 1.0 or less, and more preferably 0.4 or more and 0.9 or less. This allows the die bond sheet 10 to have appropriate viscoelasticity.

[0061] If the die bond sheet 10 contains a filler, the filler content is preferably 20.0% by mass or more, more preferably 25.0% by mass or more, even more preferably 30.0% by mass or more, and particularly preferably 35.0% by mass or more, based on the total mass of the die bond sheet 10. The filler content is preferably 60.0% by mass or less, more preferably 50.0% by mass or less, and even more preferably 45.0% by mass or less.

[0062] The Dyebond sheet 10 may contain other components as needed. Examples of these other components include curing catalysts, flame retardants, silane coupling agents, ion trapping agents, dyes, and the like. Examples of flame retardants include antimony trioxide, antimony pentoxide, and brominated epoxy resins. Examples of silane coupling agents include β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane. Examples of ion trapping agents include hydrotalcites, bismuth hydroxide, and benzotriazole. In addition to the above-mentioned additives, one or more types may be used.

[0063] The die bond sheet 10 preferably contains the above-mentioned first acrylic resin, the above-mentioned second acrylic resin, and a silica filler, but does not contain a phenolic resin, in that its elasticity and viscosity can be easily adjusted.

[0064] The thickness of the die bond sheet 10 is not particularly limited, but for example, it is between 1 μm and 100 μm. Such a thickness may be 3 μm or more, 5 μm or more, or 7 μm or more. The thickness of the die bond sheet 10 may be 50 μm or less, or 40 μm or less. If the die bond sheet 10 is a laminate, the above thickness is the total thickness of the laminate.

[0065] The diebond sheet 10 may have a single-layer structure, for example, as shown in Figure 1. In this specification, a single layer means having only layers formed of the same composition. A configuration in which multiple layers formed of the same composition are laminated together is also considered a single layer. On the other hand, the die bond sheet 10 may have a multilayer structure in which layers formed from two or more different compositions are laminated. If the die bond sheet 10 has a multilayer structure, at least one layer constituting the die bond sheet 10 may contain the first and second acrylic resins and the second acrylic resin described above.

[0066] In the dicing die bond film 1 of this embodiment, the adhesive layer 22 is cured when exposed to active energy rays (e.g., ultraviolet light) during use. Specifically, a die bond sheet 10 with a semiconductor wafer bonded to one side and an adhesive layer 22 bonded to the other side of the die bond sheet 10 are laminated together, and ultraviolet light or the like is irradiated onto at least the adhesive layer 22. For example, ultraviolet light or the like is irradiated from the side where the base layer 21 is located, and the ultraviolet light or the like passes through the base layer 21 and reaches the adhesive layer 22. The adhesive layer 22 is cured by the irradiation of ultraviolet light or the like. Since the adhesive layer 22 hardens after irradiation, its adhesive strength can be reduced, making it relatively easy to peel the die bond sheet 10 (with the semiconductor wafer attached) from the adhesive layer 22 after irradiation.

[0067] In this embodiment, the die bond sheet 10 preferably contains, in particular, a first acrylic resin having a larger epoxy equivalent and a larger mass-average molecular weight, and a second acrylic resin having a smaller epoxy equivalent and a smaller mass-average molecular weight as epoxy group-containing acrylic resins, with the first acrylic resin being present in greater quantities than the second acrylic resin, and further contains silica filler with an average primary particle size of 200 nm or less. Furthermore, the mass ratio of silica filler to epoxy group-containing acrylic resin is more preferably 1.0 or less. In this case, even if the thickness of the die bond sheet 10 is 10 μm or less, the following performance can be achieved. The composition of the die bond sheet 10 in this way suppresses the damage to the die caused by silica fillers with a small average particle size. In addition, because the average particle size of the silica fillers is small, the cleavage of the die bond sheet 10 at low temperatures before curing is improved. On the other hand, although a small average particle size of silica fillers makes it difficult for voids formed between the die bond sheet 10 and the adherend to diffuse into the die bond sheet 10 during curing, the curing process is moderately suppressed by two specific epoxy group-containing acrylic resins. Therefore, delamination between the die bond sheet 10 and the adherend after curing can be more effectively suppressed. Therefore, the die bond sheet 10 of this embodiment can exhibit relatively good cleavage at low temperatures. In addition, delamination that may occur between the sheet and the adherend after curing is suppressed.

[0068] Next, an embodiment of the dicing die bond film according to the present invention will be described.

[0069] The dicing die bond film 1 of this embodiment comprises the die bond sheet 10 described above and a dicing tape 20 bonded to the die bond sheet 10.

[0070] <Dicing tape for dicing die bond film> The dicing tape 20 described above is typically a long sheet and is stored wound up until use. The dicing die bond film 1 of this embodiment is stretched over an annular frame having an inner diameter slightly larger than the silicon wafer to be diced, and then cut for use.

[0071] The dicing tape 20 described above comprises a base layer 21 and an adhesive layer 22 superimposed on the base layer 21.

[0072] The base layer 21 may have a single-layer structure or a laminated structure. Each layer of the base material layer 21 is, for example, a metal foil, a fibrous sheet such as paper or cloth, a rubber sheet, or a resin film. Examples of fiber sheets constituting the base material layer 21 include paper, woven fabric, and nonwoven fabric. Examples of resin film materials include polyolefins such as polyethylene (PE), polypropylene (PP), and ethylene-propylene copolymer; ethylene copolymers such as ethylene-vinyl acetate copolymer (EVA), ionomer resin, ethylene-(meth)acrylic acid copolymer, and ethylene-(meth)acrylic acid ester (random, alternating) copolymer; polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); polyacrylate; polyvinyl chloride (PVC); polyurethane; polycarbonate; polyphenylene sulfide (PPS); polyamides such as aliphatic polyamides and fully aromatic polyamides (aramids); polyether ether ketone (PEEK); polyimide; polyetherimide; polyvinylidene chloride; ABS (acrylonitrile-butadiene-styrene copolymer); cellulose or cellulose derivatives; silicone-containing polymers; and fluorine-containing polymers. These can be used individually or in combination of two or more.

[0073] The base layer 21 is preferably composed of a polymer material such as a resin film. If the base layer 21 has a resin film, the resin film may be subjected to stretching or other treatments to control its deformability, such as its elongation rate. The surface of the substrate layer 21 may be surface-treated to improve adhesion with the adhesive layer 22. Examples of surface treatments include chemical or physical oxidation treatments such as corona treatment, antistatic treatment, chromic acid treatment, ozone exposure, flame exposure, high-voltage electric shock exposure, and ionizing radiation treatment. Furthermore, the substrate layer may be coated with a coating agent such as an anchor coating agent, primer, antistatic agent, or adhesive.

[0074] The base layer 21 may be a single layer or may consist of multiple layers (for example, three layers). The thickness (total thickness) of the base layer 21 may be 80 μm or more and 150 μm or less.

[0075] The back side of the base material layer 21 (the side where the adhesive layer 22 does not overlap) may be treated with a release agent (release agent) such as a silicone resin or a fluororesin to provide release properties. The base layer 21 is preferably a light-transmitting (ultraviolet-transmitting) resin film or the like, as it allows active energy rays such as ultraviolet light to be supplied to the adhesive layer 22 from the back side.

[0076] The dicing tape 20 described above may include a release liner that covers one side of the adhesive layer 22 (the side where the adhesive layer 22 does not overlap with the base layer 21) before use. The release liner is used to protect the adhesive layer 22 and is peeled off before the die bond sheet 10 is attached to the adhesive layer 22.

[0077] As the release liner, for example, a plastic film or paper that has been surface-treated with a release agent such as a silicone-based release agent, a long-chain alkyl-based release agent, a fluorine-based release agent, or molybdenum sulfide can be used. Furthermore, the release liner can be used as a support material to support the adhesive layer 22. In particular, the release liner is preferably used when layering the adhesive layer 22 on top of the base layer 21. Specifically, the adhesive layer 22 can be layered on top of the base layer 21 by layering the adhesive layer 22 on top of the base layer 21 with the release liner and adhesive layer 22 laminated together, and then peeling off (transferring) the release liner.

[0078] In this embodiment, the adhesive layer 22 includes, for example, an acrylic polymer, an isocyanate compound, and a polymerization initiator. The adhesive layer 22 may have a thickness of 5 μm or more and 40 μm or less. The shape and size of the adhesive layer 22 are usually the same as those of the base layer 21.

[0079] The above-described acrylic polymer contains at least alkyl (meth)acrylate structural units, hydroxyl group-containing (meth)acrylate structural units, and polymerizable group-containing (meth)acrylate structural units in its molecule. These structural units constitute the main chain of the acrylic polymer. Each side chain in the above-described acrylic polymer is included in each structural unit that constitutes the main chain.

[0080] In the acrylic polymer contained in the adhesive layer 22, the above-mentioned constituent units are, 1 H-NMR, 13 This can be confirmed by NMR analysis such as 13C-NMR, pyrolysis GC / MS analysis, and infrared spectroscopy. The molar proportions of the above constituent units in acrylic polymers are usually calculated from the blending amounts (starting amounts) used when polymerizing the acrylic polymer.

[0081] The constituent units of the alkyl (meth)acrylates described above are derived from alkyl (meth)acrylate monomers. In other words, the molecular structure after the polymerization reaction of alkyl (meth)acrylate monomers is the constituent unit of alkyl (meth)acrylate. The notation "alkyl" indicates the number of carbon atoms in the hydrocarbon portion esterified to (meth)acrylic acid. The hydrocarbon portion of the alkyl (meth)acrylate constituent unit may be a saturated hydrocarbon or an unsaturated hydrocarbon. Furthermore, it is preferable that the alkyl portion does not contain polar groups such as oxygen (O) or nitrogen (N). This suppresses an extreme increase in the polarity of the acrylic polymer. Consequently, the adhesive layer 22 is prevented from having an excessive affinity for the die bond sheet 10. Therefore, the dicing tape 20 can be peeled off the die bond sheet 10 more easily. The number of carbon atoms in the alkyl portion may be 6 or more and 10 or less.

[0082] Examples of constituent units for alkyl (meth)acrylates include hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n- or iso-nonyl (meth)acrylate, decyl (meth)acrylate, and lauryl (meth)acrylate.

[0083] Acrylic polymers have hydroxyl group-containing (meth)acrylate constituent units, and the hydroxyl groups in such constituent units readily react with isocyanate groups. By having an acrylic polymer containing hydroxyl group-containing (meth)acrylate constituent units and an isocyanate compound coexist in the adhesive layer 22, the adhesive layer 22 can be moderately cured. As a result, the acrylic polymer can gel sufficiently. Therefore, the adhesive layer 22 can exhibit adhesive properties while maintaining its shape.

[0084] The constituent units of hydroxyl group-containing (meth)acrylate are preferably the constituent units of hydroxyl group-containing C2-C14 alkyl (meth)acrylate. The notation "C2-C14 alkyl" represents the hydrocarbon portion esterified to (meth)acrylic acid and its carbon number. In other words, a hydroxyl group-containing C2-C14 alkyl (meth)acrylate monomer refers to a monomer in which (meth)acrylic acid and an alcohol (usually a dihydric alcohol) having 2 to 14 carbon atoms are esterified. The C2-C14 alkyl hydrocarbon portion is usually a saturated hydrocarbon. For example, the C2-C14 alkyl hydrocarbon portion is a linear saturated hydrocarbon or a branched saturated hydrocarbon. It is preferable that the C2-C14 alkyl hydrocarbon portion does not contain polar groups such as oxygen (O) or nitrogen (N).

[0085] Examples of constituent units of hydroxyl group-containing C2-C14 alkyl (meth)acrylate include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxy-n-butyl (meth)acrylate, and hydroxy-iso-butyl (meth)acrylate, which are all constituent units of hydroxybutyl (meth)acrylate. In the constituent units of hydroxybutyl (meth)acrylate, the hydroxyl group (-OH group) may be bonded to the terminal carbon (C) of the hydrocarbon portion, or to a carbon (C) other than the terminal carbon of the hydrocarbon portion.

[0086] The above acrylic polymer contains polymerizable group-containing (meth)acrylate units that have polymerizable unsaturated double bonds in their side chains. The above-mentioned acrylic polymer contains polymerizable group-containing (meth)acrylate structural units, which allows the adhesive layer 22 to be cured by irradiation with active energy rays (such as ultraviolet light) before the pickup process. Specifically, irradiation with active energy rays such as ultraviolet light generates radicals from the photopolymerization initiator, and the action of these radicals causes a crosslinking reaction between the acrylic polymers. This reduces the adhesive strength of the adhesive layer 22 before irradiation, and allows the die bond sheet 10 to be easily peeled off the adhesive layer 22. Ultraviolet light, radiation, and electron beams are used as the active energy rays.

[0087] Specifically, the polymerizable group-containing (meth)acrylate constituent unit may have a molecular structure in which the isocyanate group of an isocyanate group-containing (meth)acrylate monomer is urethane-bonded to the hydroxyl group in the hydroxyl group-containing (meth)acrylate constituent unit described above.

[0088] Polymerizable group-containing (meth)acrylate constituent units can be prepared after polymerization reactions for synthesizing acrylic polymers. For example, polymerizable group-containing (meth)acrylate constituent units can be obtained by copolymerizing an alkyl (meth)acrylate monomer with a hydroxyl group-containing (meth)acrylate monomer, followed by a urethane reaction between the hydroxyl group in a portion of the hydroxyl group-containing (meth)acrylate constituent unit and the isocyanate group of the isocyanate group-containing polymerizable monomer.

[0089] The above-mentioned isocyanate group-containing (meth)acrylate monomer preferably has one isocyanate group and one (meth)acryloyl group in its molecule. Examples of such monomers include 2-isocyanatoethyl (meth)acrylate.

[0090] In this embodiment, the adhesive layer 22 of the dicing tape 20 further contains an isocyanate compound. A portion of the isocyanate compound may be in a state after a reaction such as a urethane reaction. Isocyanate compounds have multiple isocyanate groups in their molecules. The presence of multiple isocyanate groups in the molecule of an isocyanate compound allows for the crosslinking reaction between acrylic polymers in the adhesive layer 22 to proceed. Specifically, the crosslinking reaction mediated by the isocyanate compound can be promoted by reacting one isocyanate group of the isocyanate compound with a hydroxyl group of an acrylic polymer, and the other isocyanate group with a hydroxyl group of another acrylic polymer.

[0091] Examples of isocyanate compounds include diisocyanates such as aliphatic diisocyanates, alicyclic diisocyanates, or aromatic aliphatic diisocyanates.

[0092] Furthermore, examples of isocyanate compounds include polymerized polyisocyanates such as dimers and trimers of diisocyanates, and polymethylene polyphenylene polyisocyanates.

[0093] In addition, examples of isocyanate compounds include polyisocyanates obtained by reacting an excess amount of the above-mentioned isocyanate compound with an active hydrogen-containing compound. Examples of active hydrogen-containing compounds include active hydrogen-containing low molecular weight compounds and active hydrogen-containing high molecular weight compounds. In addition, allophanate-modified polyisocyanates, biuret-modified polyisocyanates, and the like can also be used as isocyanate compounds. The above isocyanate compounds can be used individually or in combination of two or more.

[0094] As the above isocyanate compound, a reaction product of an aromatic diisocyanate and an active hydrogen-containing low molecular weight compound is preferred. Since the reaction rate of the isocyanate group in the reaction product of aromatic diisocyanate is relatively slow, excessive hardening of the adhesive layer 22 containing such a reaction product is suppressed. As the above isocyanate compound, one having three or more isocyanate groups in the molecule is preferred.

[0095] The polymerization initiator contained in the adhesive layer 22 is a compound that can initiate a polymerization reaction in response to applied heat or light energy. The presence of the polymerization initiator in the adhesive layer 22 allows for the promotion of crosslinking reactions between acrylic polymers when thermal or light energy is applied to the adhesive layer 22. Specifically, it enables the initiation of polymerization reactions between polymerizable groups within acrylic polymers having polymerizable group-containing (meth)acrylate constituent units, thereby curing the adhesive layer 22. This reduces the adhesive strength of the adhesive layer 22, allowing for easy peeling of the die bond sheet 10 from the cured adhesive layer 22 during the pick-up process. For example, photopolymerization initiators or thermal polymerization initiators can be used as polymerization initiators. Commonly available commercially produced products can be used as polymerization initiators.

[0096] The adhesive layer 22 may further contain other components in addition to those described above. Examples of other components include tackifiers, plasticizers, fillers, anti-aging agents, antioxidants, UV absorbers, light stabilizers, heat stabilizers, antistatic agents, surfactants, and light release agents. The types and amounts of other components may be appropriately selected depending on the purpose.

[0097] The dicing die bond film 1 of this embodiment may include a release liner that covers one side of the die bond sheet 10 (the side of the die bond sheet 10 that does not overlap with the adhesive layer 22) before use. The release liner is used to protect the die bond sheet 10 and is peeled off immediately before the adherend (e.g., a semiconductor wafer) is attached to the die bond sheet 10. This release liner can be used as a support material to support the diebond sheet 10. The release liner is preferably used when layering the diebond sheet 10 onto the adhesive layer 22. Specifically, the diebond sheet 10 can be layered onto the adhesive layer 22 by layering the diebond sheet 10 onto the adhesive layer 22 with the release liner and the diebond sheet 10 laminated together, and then peeling off (transferring) the release liner after layering.

[0098] Next, the manufacturing methods for the die bond sheet 10 and the dicing die bond film 1 of this embodiment will be described.

[0099] <Method for manufacturing dicing die bond film> The method for manufacturing the dicing die bond film 1 of this embodiment is: The process of manufacturing the die bond sheet 10, The process of making dicing tape 20, The process includes a step of overlapping the manufactured die bond sheet 10 and the dicing tape 20.

[0100] <Process for manufacturing die-bonded sheets> The process for manufacturing the die bond sheet 10 is as follows: A resin composition preparation step for preparing a resin composition for forming a die bond sheet 10, The process includes a die bond sheet forming step of forming a die bond sheet 10 from a resin composition.

[0101] In the resin composition preparation process, for example, the epoxy group-containing acrylic resin, phenolic resin, filler, and solvent are mixed and dissolved in the solvent to prepare the resin composition. The viscosity of the composition can be adjusted by changing the amount of solvent. Commercially available products can be used as these resins.

[0102] In the die bond sheet formation process, for example, the resin composition prepared as described above is applied to the release liner. The application method is not particularly limited, and general application methods such as roll coating, screen coating, and gravure coating can be used. Next, if necessary, the applied composition is solidified by desolvation treatment or curing treatment to form the die bond sheet 10.

[0103] <Process for making dicing tape> The process for making dicing tape is: The synthesis process for synthesizing acrylic polymers, A step to prepare an adhesive layer 22 by volatilizing the solvent from an adhesive composition containing the aforementioned acrylic polymer, an isocyanate compound, a polymerization initiator, a solvent, and other components added as appropriate depending on the purpose, A substrate layer fabrication process for creating the substrate layer 21, The method includes a lamination step of bonding the adhesive layer 22 and the base material layer 21 together to laminate the base material layer 21 and the adhesive layer 22.

[0104] In the synthesis process, for example, an acrylic polymer intermediate is synthesized by radical polymerization of an alkyl (meth)acrylate monomer and a hydroxyl group-containing (meth)acrylate monomer. Radical polymerization can be carried out by general methods. For example, acrylic polymer intermediates can be synthesized by dissolving each of the above monomers in a solvent, stirring while heating, and adding a polymerization initiator. Polymerization may be carried out in the presence of a chain transfer agent to adjust the molecular weight of the acrylic polymer. Next, some of the hydroxyl groups in the hydroxyl group-containing (meth)acrylate constituent units contained in the acrylic polymer intermediate are bonded to the isocyanate groups of the isocyanate group-containing polymerizable monomer through a urethane reaction. As a result, some of the constituent units of the hydroxyl group-containing (meth)acrylate become constituent units of the polymerizable group-containing (meth)acrylate. The urethane reaction can be carried out by a general method. For example, an acrylic polymer intermediate and an isocyanate group-containing polymerizable monomer are stirred while heating in the presence of a solvent and a urethane catalyst. This allows some of the hydroxyl groups of the acrylic polymer intermediate to be bonded to the isocyanate groups of the isocyanate group-containing polymerizable monomer by urethane bonding.

[0105] In the adhesive layer preparation process, for example, an acrylic polymer, an isocyanate compound, and a polymerization initiator are dissolved in a solvent to prepare an adhesive composition. The viscosity of the composition can be adjusted by changing the amount of solvent. Next, the adhesive composition is applied to the release liner. Common application methods such as roll coating, screen coating, and gravure coating are used. The applied adhesive composition is solidified by desolvation treatment, solidification treatment, etc., to produce an adhesive layer 22.

[0106] In the substrate layer preparation process, the substrate layer can be prepared by forming a film using a general method. Examples of film formation methods include calendering, casting in organic solvents, inflation extrusion in a closed system, T-die extrusion, and dry lamination. Co-extrusion molding may also be used. In addition, commercially available films or the like may be used as the substrate layer 21.

[0107] In the lamination process, the adhesive layer 22 and the base layer 21, which are overlapping the release liner, are laminated together. The release liner may remain overlapping the adhesive layer 22 until just before use. Furthermore, in order to promote the reaction between the crosslinking agent and the acrylic polymer, and to promote the reaction between the crosslinking agent and the surface portion of the substrate layer 21, an aging process may be carried out after the lamination process at a temperature of 50°C for 48 hours.

[0108] These processes enable the manufacture of the dicing tape 20.

[0109] <Step of overlapping the die bond sheet 10 and the dicing tape 20> In the process of overlapping the diebond sheet 10 and the dicing tape 20, the diebond sheet 10 is attached to the adhesive layer 22 of the dicing tape 20 manufactured as described above.

[0110] In this bonding process, the release liner is peeled off from the adhesive layer 22 of the dicing tape 20 and from the die bond sheet 10, respectively, and the two are bonded together so that the die bond sheet 10 and the adhesive layer 22 are in direct contact. For example, they can be bonded by pressing. The temperature at which bonding occurs is not particularly limited, but for example, it is above room temperature, between 30°C and 50°C, and preferably between 35°C and 45°C. The linear pressure at which bonding occurs is not particularly limited, but is preferably between 0.1 kgf / cm and 20 kgf / cm, and more preferably between 1 kgf / cm and 10 kgf / cm.

[0111] The dicing die bond film 1 manufactured through the process described above is used, for example, as an auxiliary tool for manufacturing semiconductor integrated circuits. Specific examples of its use are described below.

[0112] <Method of using dicing die bond film when manufacturing semiconductor integrated circuits> In semiconductor integrated circuit manufacturing methods, chips are generally cut from a semiconductor wafer on which the circuit surface has been formed and then assembled. In this process, the dicing die bond film of this embodiment is used as a manufacturing aid.

[0113] The method for manufacturing semiconductor integrated circuits generally involves cutting chips from a semiconductor wafer on which a circuit surface has been formed and assembling them. This process includes, for example, a stealth dicing process in which a backgrind tape is attached to a semiconductor wafer and a laser beam is used to create a weak area inside the wafer, preparing it for processing into a chip (die) by a dicing process; a backgrinding process in which the semiconductor wafer with the backgrind tape attached to the circuit surface is ground down to reduce its thickness until the weak area becomes the boundary and the semiconductor wafer is individualized; a mounting process in which one side of the thinned semiconductor wafer (for example, the side opposite to the circuit surface) is attached to a die bond sheet 10 and the semiconductor wafer is fixed to the dicing tape 20; and a die process in which the dicing tape 20 is stretched to form a die. The process includes an expansion step of cutting the bond sheet 10 and widening the spacing between chips; a pickup step of peeling the die bond sheet 10 from the adhesive layer 22 and removing the semiconductor chip (die) with the die bond sheet 10 attached; a die bonding step of bonding the die bond sheet 10 attached to the semiconductor chip (die) to a substrate; a curing step of hardening the die bond sheet 10 bonded to the substrate; a wire bonding step of electrically connecting the electrodes of the electronic circuit on the semiconductor chip (die) to the substrate with wires; and a sealing step of sealing the semiconductor chip (die) and wires on the substrate with a thermosetting resin. The dicing tape (dicing die bond film) of this embodiment is used as a manufacturing aid when carrying out these steps.

[0114] In the stealth dicing process, as shown in Figures 2A to 2C, vulnerable regions are formed inside the semiconductor wafer W to separate the semiconductor integrated circuit into small pieces (dies). Specifically, a backgrind tape G is attached to the circuit surface of the semiconductor wafer W (see Figure 2A). With the backgrind tape G attached, the semiconductor wafer W is ground using a grinding pad K (pre-backgrinding) until it reaches a predetermined thickness (see Figure 2B). By irradiating the thinned semiconductor wafer W with laser light, vulnerable regions are formed inside the semiconductor wafer W (see Figure 2C).

[0115] In the backgrinding process, as shown in Figure 2D, the semiconductor wafer W with the backgrinding tape G attached is further ground to reduce its thickness until it reaches the thickness of the chips (dies) that will be produced by subsequent cleavage. At this time, the thickness of the semiconductor wafer W is reduced until, for example, the semiconductor wafer W is separated into individual chips (dies) with the aforementioned weak areas as boundaries. The force applied during grinding can cause cleavage at the weak areas, separating the semiconductor wafer W into individual chips (dies).

[0116] In the mounting process, the semiconductor wafer W is fixed to the dicing die bond film 1 as shown in Figures 3A and 3B. Specifically, the dicing ring R is attached to the adhesive layer 22 of the dicing tape 20, and the semiconductor wafer W, whose thickness has been reduced by the cutting process as described above, is attached to the exposed surface of the die bond sheet 10 (see Figure 3A). Subsequently, the backgrind tape G is peeled off from the semiconductor wafer W (see Figure 3B).

[0117] In the expanding process, as shown in Figures 4A to 4C, the spacing between semiconductor chips (dies) X created by cleavage is increased. Specifically, after attaching the dicing ring R to the adhesive layer 22 of the dicing tape 20, it is fixed to the holder H of the expanding device (see Figure 4A). The push-up member U of the expanding device pushes up from below the dicing die bond film 1, stretching the dicing die bond film 1 in the planar direction (see Figure 4B). This causes the semiconductor wafer W to cleave under specific temperature conditions. The above temperature conditions are, for example, -20°C or higher and 0°C or lower, preferably -15°C or higher and 0°C or lower, and more preferably -10°C or higher and -5°C or lower. The expanded state is released by lowering the push-up member U (see Figure 4C; this concludes the low-temperature expanding process). When performing the expansion process at low temperatures, the die bond sheet 10 needs to be cleaved. The die bond sheet 10 of this embodiment described above is designed to cleavage well at this time. Furthermore, in the expanding process, as shown in Figures 5A to 5B, the dicing tape 20 is stretched to increase its surface area under higher temperature conditions (for example, between 10°C and 25°C). This pulls adjacent semiconductor chips X apart in the planar direction of the film surface after cleavage, further widening the kerf (spacing) (room temperature expanding process).

[0118] In the pickup process, as shown in Figure 6, the semiconductor chip X, to which the small piece 10' of the die bond sheet is attached, is peeled off from the adhesive layer 22 of the dicing tape 20. Specifically, the pin member P is raised to push up the semiconductor chip X to be picked up via the dicing tape 20. The pushed-up semiconductor chip X is held by the suction jig J.

[0119] In the die bonding process, a semiconductor chip X with small pieces 10' of the die bonding sheet attached is bonded to a substrate Z. When bonding, if sufficient curing treatment (temperature, pressure, time, etc.) is not necessarily required, voids (air bubbles) are relatively likely to occur between the die bonding sheet pieces 10' and the substrate. If the die bonding sheet pieces 10' have not cured too much at a stage prior to the subsequent sealing process (molding process), and the resin components inside the die bonding sheet pieces 10' have relatively high molecular mobility, then the voids that have formed as described above can be eliminated by diffusion between the molecular chains of the resin components. Therefore, if the die bonding sheet pieces 10' have not cured excessively when voids have formed, the voids can diffuse inside the die bonding sheet pieces 10'. By diffusing the voids, delamination between the die bonding sheet pieces 10' and the substrate can be suppressed. In the die bonding process, as shown in Figure 7, semiconductor chips X with small pieces 10' of the die bonding sheet attached are sometimes stacked multiple times.

[0120] In the curing process, a heat treatment is performed at a temperature of, for example, 100°C to 150°C to increase the reactivity of the epoxy groups in the epoxy group-containing acrylic resin contained in the die bond sheet pieces 10' and to promote the hardening of the die bond sheet pieces 10'. At this time, pressure can be applied to the die bond sheet pieces 10'. Preferably, the heat treatment is performed while applying a pressure of 0.2 MPa to 2 MPa, more preferably 0.4 MPa to 1 MPa. Although hardening can be promoted by the heat treatment, if hardening progresses too far, the molecular mobility of the resin components constituting the die bond sheet 10 decreases, which is thought to make it easier for the aforementioned voids to remain without disappearing.

[0121] In the wire bonding process, as shown in Figure 8, the semiconductor chip X (die) and the adherend Z are connected while being heated. Therefore, the epoxy groups of the epoxy group-containing acrylic resin contained in the die bond sheet 10 become reactive upon heating, and the curing reaction of the die bond sheet 10 can proceed.

[0122] In the sealing process, as shown in Figure 9, the semiconductor chip X (die) and the small piece 10' of the die bond sheet are sealed with a thermosetting resin M such as epoxy resin. In the sealing process, the thermosetting resin M is heated at a temperature of 150°C to 200°C under pressure in order to allow it to flow and then cure. At this time, voids present between the small piece 10' of the die bond sheet and the adherend may disappear. However, if the curing reaction has progressed too much due to the heat treatment prior to the sealing process, the molecular mobility of the resin components constituting the die bond sheet 10 has already decreased, and it is thought that the aforementioned voids are more likely to remain without disappearing.

[0123] After the sealing process, a reflow soldering process may be performed to electrically join the electrodes using molten solder. In the reflow soldering process, for example, a heat treatment is performed at a temperature of 230°C to 270°C. In such a heat treatment, the temperature rises rapidly. Therefore, for example, if voids remain after the sealing process, the gas inside the voids will expand rapidly. Alternatively, if moisture accumulates between the die bond sheet piece 10' and the adherend due to moisture absorption after the sealing process, the moisture will expand or vaporize rapidly. As a result, the die bond sheet 10 may not be able to absorb the rapidly expanding gas or moisture, which may cause the voids to enlarge or delamination to occur between the die bond sheet piece 10' and the adherend.

[0124] Furthermore, in the semiconductor industry in recent years, with the further advancement of integration technology, there is a demand for thinner semiconductor chips (for example, thicknesses of 20 μm to 50 μm) and thinner die bond sheets (for example, thicknesses of 1 μm to 40 μm, preferably 7 μm or less, and more preferably 5 μm or less).

[0125] The die bond sheet and dicing die bond film of this embodiment are as illustrated above, but the present invention is not limited to the die bond sheet and dicing die bond film as illustrated above. In other words, various forms used in general die bond sheets and dicing die bond films can be adopted as long as they do not impair the effects of the present invention.

[0126] The matters disclosed herein include the following: (1) It contains at least an epoxy group-containing acrylic resin having an epoxy group in its molecule as an organic component, The epoxy equivalent of the epoxy group-containing acrylic resin is 1300 or more and less than 6000. A die bond sheet in which the proportion of the epoxy group-containing acrylic resin in the organic component is 90.0% by mass or more. (2) The ratio of the mass-average molecular weight Mw to the number-average molecular weight Mn of the epoxy group-containing acrylic resin, as measured by gel permeation chromatography, [Mw / Mn] is 2.5 or more and 50.0 or less. The die bond sheet described in (1) above, wherein the phenolic resin content is less than 5% by mass. (3) A die bond sheet as described in (1) or (2) above, wherein the total content of phenolic resin and epoxy resin is 3% by mass or less. (4) The mass-average molecular weight of the epoxy group-containing acrylic resin is 1.0 × 10⁻⁶. 5 The above 1.5 × 10 6 The die bond sheet described in any of (1) to (3) above, which is as follows: (5) A die bond sheet according to any one of (1) to (4) above, further comprising silica filler having an average particle size of 10 nm or more and 200 nm or less. (6) A die bond sheet according to any one of (1) to (5) above, wherein the tensile storage modulus at 150°C before hardening treatment is greater than 0.3 MPa and 30 MPa or less. (7) The die bond sheet according to any one of (1) to (6) above, wherein the epoxy group-containing acrylic resin comprises a first acrylic resin and a second acrylic resin having a smaller mass-average molecular weight than the first acrylic resin. (8) The mass-average molecular weight of the first acrylic resin is 1.0 × 10⁻⁶. 5 The above 1.0 × 10 6 The following applies, and the mass-average molecular weight of the second acrylic resin is 2.0 × 10⁻⁶. 3 The above 1.0 × 10 5 The die bond sheet described in (7) above, which is less than [a certain value]. (9) A die bond sheet according to (7) or (8) above, wherein the epoxy equivalent of the first acrylic resin is 1,500 [g / eq] or more and 8,000 [g / eq] or less, and the epoxy equivalent of the second acrylic resin is 200 [g / eq] or more and less than 1,500 [g / eq]. (10) A die bond sheet according to any one of (7) to (9) above, wherein the epoxy equivalent of the first acrylic resin is greater than the epoxy equivalent of the second acrylic resin. (11) A die bond sheet according to any one of (7) to (10) above, which contains more of the first acrylic resin than the second acrylic resin. (12) The die bond sheet according to any one of (7) to (11) above, wherein the mass ratio of the second acrylic resin to the first acrylic resin is 0.5 or less. (13) A die bond sheet according to any one of (1) to (12) above, comprising a filler, wherein the mass ratio of the filler to the epoxy group-containing acrylic resin is 0.2 or more and 1.0 or less. (14) A dicing die bond film comprising a die bond sheet as described in any of (1) to (13) above, and a dicing tape bonded to the die bond sheet. [Examples]

[0127] The present invention will be further explained with experimental examples, but the present invention is not limited to these.

[0128] The die bond sheet was manufactured as follows. Furthermore, this die bond sheet was bonded to dicing tape to produce a dicing die bond film.

[0129] <Preparation of Diebond Sheet> The raw materials with the formulations shown in Tables 1 and 2 were added to methyl ethyl ketone and mixed to obtain a die bond sheet composition with a solid content of 40% by mass. Details of each raw material are shown below. (First Acrylic Resin) [P1-1] An acrylic resin solution (15% solids by mass) prepared by dissolving a copolymer of ethyl acrylate (EA), butyl acrylate (BA), acrylonitrile (AN), and glycidyl methacrylate (GMA) in methyl ethyl ketone (MEK). Mass average molecular weight: 1,000,000 (Mw=1 million), Epoxy equivalent: 2,000 [g / eq] Glass transition temperature Tg: 15℃ [P1-2] An acrylic resin solution (15% solids by mass) prepared by dissolving a copolymer of ethyl acrylate (EA), butyl acrylate (BA), acrylonitrile (AN), and glycidyl methacrylate (GMA) in methyl ethyl ketone (MEK). Mass average molecular weight: 800,000 (Mw=800,000), Epoxy equivalent: 1,800 [g / eq] Glass transition temperature Tg: 15℃ Acrylic resin solution dissolved in methyl ethyl ketone (MEK) [P1-3] An acrylic resin solution (15% solids by mass) prepared by dissolving a copolymer of ethyl acrylate (EA), butyl acrylate (BA), acrylonitrile (AN), and glycidyl methacrylate (GMA) in methyl ethyl ketone (MEK). Mass average molecular weight: 1,200,000 (Mw=1.2 million), Epoxy equivalent: 2,000 [g / eq] Glass transition temperature Tg: 4℃ (Second Acrylic Resin) [P2-1] An acrylic resin solution (70% solids by mass) prepared by dissolving a copolymer of ethyl acrylate (EA), butyl methacrylate (BMA), and glycidyl methacrylate (GMA) in methyl ethyl ketone (MEK). Mass average molecular weight: 56,000 (Mw=56,000), Epoxy equivalent: 450 [g / eq] Glass transition temperature Tg: 15℃ [P2-2] An acrylic resin solution (67% solids by mass) prepared by dissolving a copolymer of ethyl acrylate (EA), butyl methacrylate (BMA), and glycidyl methacrylate (GMA) in methyl ethyl ketone (MEK). Mass average molecular weight: 73,000 (Mw=73,000), Epoxy equivalent: 450 [g / eq] Glass transition temperature Tg: 15℃ [P2-3] An acrylic resin solution (70% solids by mass) prepared by dissolving a copolymer of ethyl acrylate (EA), butyl methacrylate (BMA), and glycidyl methacrylate (GMA) in methyl ethyl ketone (MEK). Mass average molecular weight: 30,000 (Mw=30,000), Epoxy equivalent: 450 [g / eq] The glass transition temperature (Tg) is 15°C. [P2-4] An acrylic resin solution (70% solids by mass) prepared by dissolving a copolymer of ethyl acrylate (EA), butyl methacrylate (BMA), and glycidyl methacrylate (GMA) in methyl ethyl ketone (MEK). Mass average molecular weight: 31,000 (Mw=31,000), Epoxy equivalent: 890 [g / eq] Glass transition temperature Tg: 15℃ (Filler) [F1] Spherical silica dispersion SiO2 particles (manufactured by CIK Nanotech) with an average primary particle size of 100 nm were surface-treated with vinyl groups and alkyl groups, dispersed in methyl ethyl ketone, and then the coarse particles were removed using a 1 μm pore size filter to obtain the dispersion. Dispersion with an average particle size of 100 nm and a solid content of 50% by mass. [F2] Spherical silica dispersion, product name "MEK-ST-ZL", manufactured by Nissan Chemical Corporation. Dispersion with an average particle size of 80 nm and a solid content of 30% by mass. [F3] Spherical silica dispersion, product name "MEK-EC-2130Y", manufactured by Nissan Chemical Corporation. Dispersion with an average particle size of 12 nm and a solid content of 30% by mass. [F4] Spherical silica dispersion A dispersion obtained by dispersing spherical silica (product name "SO-E2", manufactured by Admatex, average particle size 500 nm) in methyl ethyl ketone, and then removing coarse particles using a 3 μm pore size filter. Dispersion with an average particle size of 500 nm and a solid content of 60% by mass. (Phenolic resin) [Ph1] Product name: MEHC-7851SS, manufactured by Meiwa Kasei Co., Ltd. (Contains a biphenyl aralkyl structure in its molecule) Hydroxyl group equivalent: 203[g / eq] Next, the die bond sheet composition was applied to one side of the release liner (the silicone-treated side of a 50 μm thick PET sheet) using an applicator. The application was carried out so that the thickness after drying would be 40 μm, and then the solvent was evaporated from the die bond sheet composition by drying at 130°C for 2 minutes. In this way, a die bond sheet was obtained overlapping the release liner.

[0130] <Base layer of dicing tape> A single-layer substrate was fabricated using the following products as resin raw materials. Product name: Evaflex P1007 (manufactured by Mitsui Dow Polychemicals) Ethylene-vinyl acetate copolymer resin (EVA) Contains 9% by mass of vinyl acetate monomer units.

[0131] (Forming of the base layer) The base material layer was formed using an extrusion T-die molding machine. The extrusion temperature was 190°C. The base material layer was wound into a roll and stored.

[0132] <Adhesive layer of dicing tape> (Preparation of the adhesive layer (adhesive composition)) The following raw materials were mixed to prepare the first resin composition. • INA (Isononyl Acrylate) 173 parts by mass • HEA (Hydroxyethyl Acrylate) 54.5 parts by mass • AIBN (2,2'-azobisisobutyronitrile) 0.46 parts by mass • 372 parts by mass of ethyl acetate Next, the first resin composition was placed in a round-bottom separable flask (capacity 1 L), a thermometer, a nitrogen inlet tube, and a stirring blade, which were all part of a polymerization experimental apparatus. While stirring the first resin composition, the liquid temperature of the first resin composition was adjusted to room temperature (23°C), and the contents of the round-bottom separable flask were replaced with nitrogen gas for 6 hours. Next, nitrogen gas was introduced into the round-bottom separable flask while stirring the first resin composition, and the liquid temperature of the first resin composition was maintained at 62°C for 3 hours. After that, the temperature was further maintained at 75°C for 2 hours to carry out the polymerization reaction of INA, HEA, and AIBN described above, and the second resin composition was prepared. After that, the inflow of nitrogen gas into the round-bottom separable flask was stopped. After cooling the second resin composition to room temperature, the following raw materials were added to the second resin composition to prepare the third resin composition. ·2-Methacryloyloxyethyl isocyanate Compounds having polymerizable carbon-carbon double bonds Product name: "Kalenz MOI", manufactured by Showa Denko Corporation) 52.5 parts per inch • Dibutyltin IV dilaurate (manufactured by Wako Pure Chemical Industries, Ltd.) 0.26 parts by mass The obtained third resin composition was stirred at 50°C for 24 hours in an atmospheric environment. Finally, the following raw materials were added to 100 parts by mass of the polymer solids content of the third resin composition. Isocyanate compound (product name "Coronate L", manufactured by Tosoh Corporation) 0.75 parts by mass Photopolymerization initiator (product name "Omnirad127", manufactured by IGM Resins) 2 parts by mass Then, the third resin composition was diluted with ethyl acetate to a solid content concentration of 20% by mass to prepare an adhesive composition.

[0133] <Making dicing tape> The adhesive composition was applied to one surface of the substrate layer using an applicator to a thickness of 10 μm after drying. After applying the adhesive composition, a heat drying treatment was performed at 110°C for 3 minutes to form an adhesive layer. A dicing tape was manufactured in this manner.

[0134] <Manufacturing of dicing die bond film> (Bonding the Diebond sheet and dicing tape together) The adhesive layer of the dicing tape was bonded to the die bond sheet (the side without the release liner) of the die bond sheet. Then, the release liner was peeled off from the die bond sheet to create a dicing die bond film with the die bond sheet.

[0135] As described above, die bond sheets and dicing die bond films for the examples and comparative examples were manufactured, respectively. Details of each die bond sheet are shown in Tables 1 and 2. In Tables 1 and 2, the content [mass%] of the first acrylic resin, second acrylic resin, filler, and phenolic resin are shown as a percentage of their total amount based on solid content.

[0136] [Table 1]

[0137] [Table 2]

[0138] <Molecular weight measurement of epoxy group-containing acrylic resin (GPC measurement)> GPC measurements were performed on the die bond sheets of each example and comparative example before heat curing treatment according to the following procedure. The obtained GPC measurement results (chart) were analyzed to obtain information on molecular weight. [Preparation of the measurement sample] (1) Approximately 0.2 g of sample was taken from the die bond sheet before heat curing treatment and weighed. (2) The sample was dissolved in tetrahydrofuran (THF) to a concentration of 0.2% by mass, and the THF solution was left to stand overnight. (3) The THF solution, left overnight, was filtered through a 0.45 μm membrane filter, and the resulting filtrate was used as the measurement sample. [Measurement conditions] As stated above, the analytical instrument used was the "HLC-8220GPC" manufactured by Tosoh Corporation. To obtain molecular weight distribution curves, standard polystyrene was used as a standard substance. Specifically, each standard polystyrene manufactured by Tosoh Corporation was weighed to the predetermined blending mass, and each weighed standard polystyrene was dissolved in 100 mL of THF to prepare standard polystyrene solution STD1 and standard polystyrene solution STD2. These standard polystyrene solutions were also subjected to GPC measurement using the above-described measuring apparatus and measurement conditions. The results of GPC measurements of the sample and standard polystyrene solution were analyzed using Tosoh Corporation's analysis software, GPC-8020 Model II (Data Management Version 5.10). In the data analysis using the above analysis software, calibration curves (with time (min) on the horizontal axis and the logarithm of the mass-average molecular weight on the vertical axis) were first created for STD1 and STD2. Based on these calibration curves, data analysis regarding the molecular weight of the measured samples was performed. The data analysis regarding the molecular weight of the aforementioned measurement sample was performed after obtaining a molecular weight distribution curve for peak P1 (the peak with the highest molecular weight) which was detected earliest on the chromatogram. By performing data analysis on the molecular weight distribution curve for peak P1, the number-average molecular weight Mn and mass-average molecular weight Mw for peak P1 were obtained. When the die bond sheet contains both the first acrylic resin and the second acrylic resin, peak P1 corresponds to the peak of the first acrylic resin. Furthermore, since an overlap was observed between the falling portion of peak P1, which was detected earliest, and the rising portion of peak P2, which was detected next to peak P1, a baseline was drawn extending horizontally from the starting point of the rising portion of peak P1. Next, a line was drawn perpendicularly from the baseline towards the valley portion (the most recessed part) that occurs between the falling portion of peak P1 and the rising portion of peak P2. Then, the region demarcated from the starting point of the rising portion of peak P1 to the valley portion, the baseline, and the line drawn perpendicularly from the baseline to the valley portion was used as the analysis target, and the number-average molecular weight Mn and mass-average molecular weight Mw were obtained for peak P1. Similarly, the number-average molecular weight Mn and mass-average molecular weight Mw were obtained for peak P2. The baseline of peak P2 was drawn horizontally, starting from the beginning of the rise of peak P1 and extending toward the falling portion of peak P2. A line was drawn perpendicularly from the baseline of peak P2 toward the valley (the most concave part) that occurs between the falling portion of peak P1 and the rising portion of peak P2. Then, the region from the valley to the end of the falling portion of peak P2, the baseline of peak P2, and the line drawn perpendicularly from the baseline of peak P2 toward the valley were used as the analysis target for peak P2, and the number-average molecular weight Mn and mass-average molecular weight Mw were obtained for peak P2. Peak P2 appears to the right of Peak P1 in the GPC measurement chart and corresponds to the peak of the second acrylic resin. Furthermore, for the molecular weight distribution across the entire range of mass-average molecular weights from 5 million to 12 million, the ratio of mass-average molecular weight Mw to number-average molecular weight Mn [Mw / Mn] was determined.

[0139] <Epoxy equivalent of epoxy group-containing acrylic resin> The epoxy equivalent was measured by NMR analysis as follows. [Sample preparation] Approximately 350 mg of chromium(III) acetylacetonate (molecular weight 349.32 g / mol) was weighed as a relaxation reagent and diluted to 20 mL in CDCl3 to a concentration of 50 mM. Subsequently, approximately 50 mg of hexamethyldisiloxane standard (molecular weight 162.38 g / mol) was weighed as an internal standard and diluted to 10 mL in CDCl3 containing chromium(III) acetylacetonate (the aforementioned solution) to prepare the quantitative standard solution for NMR measurement. Next, approximately 40 mg of the sample was weighed, 0.5 mL of the quantitative standard solution was added to dissolve it, and the epoxy equivalent [g / eq] was measured by 13C NMR (NNE, absolute quantification method). [Analyzer] Bruker Biospin,AVANCEIII-600 with Cryo Probe [Measurement conditions] Observation frequency: 150MHz (13C) Measurement solvent: CDCl3 Measurement temperature: 300K Chemical shift standard: Measurement solvent (13C: 77.05 ppm) Formula for calculating epoxy equivalent:

number

[0140] <Measurement of tensile modulus of die bond sheet> The die-bond sheets of each example and comparative example, before thermosetting treatment, were laminated to a thickness of 200 μm. Next, this laminated sample was cut into strips 10 mm wide and 50 mm long using a utility knife to prepare test specimens. The dynamic storage modulus was measured in tensile mode in the temperature range from 0°C to 200°C using a solid viscoelasticity measuring device (RSA-G2, Rheometrics Scientific Corporation (TA Instruments Corporation)) under the conditions of frequency 1 Hz, heating rate 10°C / min, initial chuck distance 22.5 mm, and strain 0.1%. The heating was started after holding at 0°C for 5 minutes. The value at 150°C was read and this value was defined as the tensile modulus (tensile storage modulus) [MPa] at 150°C.

[0141] <Measurement of break elongation (breaking length) of die bond sheets at low temperatures> The above fracture elongation (breaking length) was measured under the following measurement conditions. • Measuring device: Solid viscoelasticity measuring device • Measurement sample: Thickness 20 μm (If less than 20 μm, for example, in the case of a 5 μm die bond sheet, laminate so that the total thickness is 20 μm) • Test specimen: Strip-shaped, 10mm wide and 50mm long, with an initial chuck distance of 20mm. • Temperature 0°C, tensile speed 1 mm / sec, • Measurement temperature: 0°C (Measurement begins after holding at 0°C for 5 minutes) The elongation at the time of fracture was defined as the fracture elongation (fracture elongation), and the test force at the time of fracture was defined as the fracture test force. Specifically, sheet samples were prepared by coating the diebond sheets of each example and comparative example to a thickness of 20 μm before heat curing treatment, or by laminating them to create laminated sheet samples. Next, these samples were cut into strips 10 mm wide and 50 mm long using a utility knife to create test specimens. Tensile tests were performed using a solid viscoelasticity measuring device (RSA-G2, manufactured by Rheometrics Scientific, Inc. (TA Instruments Inc.)) under the conditions of a temperature of 0°C, a tensile speed of 1 mm / sec, and an initial chuck distance of 20 mm. The measurement was started after holding the sample at 0°C for 5 minutes. The elongation at the time of fracture was defined as the elongation at fracture. The test force at the time of fracture was confirmed as the fracture test force.

[0142] <Evaluation of the peeling suppression performance of die bond sheets after reflow treatment (heat treatment)> The die bond sheets for each example and comparative example, before heat curing, were attached to 10 mm square mirror chips at 70°C. The mirror chips with the die bond sheets attached were then bonded to a BGA substrate under the conditions of 120°C, 0.1 MPa pressure, and 1 second time. Next, the sample was heat-treated in a dryer at 150°C for a specified time. Subsequently, a sealing process was performed using a molding machine (TOWA Press, manual press Y-1) under the conditions of a molding temperature of 175°C, a clamping pressure of 184kN, a transfer pressure of 5kN, and a time of 120 seconds. Furthermore, a thermosetting treatment was performed at 175°C for 5 hours. After that, a moisture absorption operation was performed under the conditions of a temperature of 85°C, a humidity of 60%RH, and a time of 168 hours. Finally, the sample was passed through an IR reflow oven set to maintain a temperature of 260°C or higher for 10 seconds. For nine mirror chips, we used an ultrasonic microscope (HITACHI, model FS200II) to observe whether delamination had occurred at the interface between the dicing die bonding film and the BGA substrate. If delamination occurred in even one of the nine packages, it was judged as "NG," and if there was no delamination at all, it was judged as "OK."

[0143] As can be seen from the evaluation results above, the die bond sheet of the example was able to combine relatively good cleavage at low temperatures and peeling suppression performance from the adherend after curing treatment, compared to the die bond sheet of the comparative example. In particular, the die bond sheet contains two types of epoxy group-containing acrylic resins with different epoxy equivalents and mass-average molecular weights, along with silica filler. The low (or absence) phenolic resin content and the average particle size of the silica filler (200 nm or less) enable it to exhibit relatively good cleavage at low temperatures. Furthermore, it is believed that voids formed between the die bond sheet and the adherend during the curing process can be dispersed internally. Therefore, it is thought that delamination between the die bond sheet and the adherend can be suppressed.

[0144] By using a die bond sheet (dicing die bond film) having the physical properties described above in the manufacturing of semiconductor integrated circuits, so-called NAND flash memory and the like can be manufactured efficiently. [Industrial applicability]

[0145] The die bond sheet and dicing die bond film of the present invention are suitably used, for example, as auxiliary tools when manufacturing semiconductor integrated circuits. [Explanation of Symbols]

[0146] 1: Dicing die bond film, 10: Diebond sheet, 20: Dicing tape, 21: Base material layer, 22: Adhesive layer.

Claims

1. It contains at least an epoxy group-containing acrylic resin having an epoxy group in its molecule as an organic component, The epoxy equivalent of the epoxy group-containing acrylic resin is 1300 or more and less than 6000. The ratio of the mass-average molecular weight Mw to the number-average molecular weight Mn of the epoxy group-containing acrylic resin, as measured by gel permeation chromatography, [Mw / Mn] is 2.5 or more and 50.0 or less. The proportion of the epoxy group-containing acrylic resin in the organic component is 90.0% by mass or more. A die bond sheet having a phenolic resin content of less than 5% by mass.

2. The mass-average molecular weight of the epoxy group-containing acrylic resin is 1.0 × 10⁻⁶. ５ The above 1.5 x 10 ６ The die bond sheet according to claim 1, which is as follows:

3. The die bond sheet according to claim 1 or 2, wherein the epoxy group-containing acrylic resin comprises a first acrylic resin and a second acrylic resin having a smaller mass-average molecular weight than the first acrylic resin.

4. The mass-average molecular weight of the first acrylic resin is 4.0 × 10⁻⁶. ５ The above 2.0 x 10 ６ The following applies, and the mass-average molecular weight of the second acrylic resin is 5.0 × 10⁻⁶. ３ The above 2.0 x 10 ５ The die bond sheet according to claim 3, which is less than [a certain value].

5. A dicing die bond film comprising a die bond sheet according to claim 1 or 2 and a dicing tape bonded to the die bond sheet.

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