Die bond sheets, dicing die bond films, and semiconductor devices

Abstract

The objective is to provide a die bond sheet that can suppress the penetration of thermosetting resin into the interior when it is sealed with a thermosetting resin while bonded to a semiconductor chip. [Solution] A die bond sheet containing at least one of a thermosetting resin and a thermoplastic resin as an organic component, wherein when the die bond sheet is subjected to dynamic viscoelasticity measurement, the ratio of the storage modulus G' to the loss modulus G'' (G' / G'') is Q, and the ratio Q at a vibration frequency of 1.0 Hz 1.0 The ratio Q at a vibration frequency of 0.1 Hz 0.1 The relative value (Q 0.1 / Q 1.0 The present invention provides a die bond sheet, etc., in which the coefficient of viscosity is 0.8 or higher at 170°C, and when the die bond sheet is subjected to the dynamic viscoelasticity measurement, the complex viscosity coefficient at a vibration frequency of 1.0 Hz is 10 kPa·s or higher at 170°C.

Description

Technical Field

[0001] The present invention relates to a die bond sheet used when manufacturing, for example, a semiconductor device, and a dicing die bond film including the die bond sheet. The present invention also relates to a semiconductor device including the die bond sheet.

Background Art

[0002] Conventionally, a dicing die bond film used in manufacturing a semiconductor device or the like is known. This type of dicing die bond film includes, for example, a dicing tape and a die bond sheet laminated on the dicing tape and adhered to a semiconductor wafer. The dicing tape has a base material layer and an adhesive layer in contact with the die bond sheet. This type of dicing die bond film is used in manufacturing a semiconductor device, for example, as follows.

[0003]

[0004] A method for manufacturing a semiconductor device generally includes a pre-process of forming a circuit surface on one side of a disk-shaped bare wafer by a highly integrated electronic circuit, and a post-process of cutting out semiconductor chips from the semiconductor wafer having the circuit surface formed thereon and performing assembly.For example, the post-processes include a stealth dicing process of forming a weak portion for dicing a semiconductor wafer into small semiconductor chips (dies) on the semiconductor wafer by laser light, a mounting process of attaching the surface of the semiconductor wafer opposite to the circuit surface to a die bond sheet and fixing the semiconductor wafer to a dicing tape through the die bond sheet, an expand process of stretching the dicing tape in the radial direction of the semiconductor wafer, dicing the semiconductor wafer with the weak portion formed together with the die bond sheet into small pieces, and widening the interval between adjacent small semiconductor chips (dies), a pickup process of peeling between a small piece of the die bond sheet and an adhesive layer and taking out the semiconductor chip in a state where the die bond sheet is attached, a die bonding process of bonding the semiconductor chip in a state where the small piece of the die bond sheet is attached to an adherent through the small piece of the die bond sheet, a wire bonding process of electrically connecting an electrode of an electronic circuit in the semiconductor chip and the adherent with a wire, and a sealing process of sealing the semiconductor chip and the wire on the adherent with a thermosetting resin. The semiconductor device is manufactured through these processes, for example.

[0005] In the method for manufacturing a semiconductor device as described above, various problems can occur. For example, in the die bonding process described above, relatively thin chips (dies) in a state where the die bond sheet is attached may be stacked multiple times, and at this time, warping may occur in the thin chips (dies), and the problem that the chips (dies) cannot be stacked well multiple times may occur. In contrast, in order to perform the stacking of chips (dies) in the die bonding process well, a die bond sheet containing specific components and having specific physical property values is known (for example, Patent Document 1).

[0006] The die bond sheet described in Patent Document 1 contains a filler having an average particle size in the range of 5 nm to 100 nm, a thermoplastic resin, and a phenol resin, and the tensile storage modulus at 150 °C before thermosetting 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]

[0007] [Patent Document 1] Japanese Patent Publication No. 2017-216273 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, other problems may arise in the semiconductor device manufacturing method described above. For example, in the sealing process described above, the thermosetting resin used for sealing may penetrate into the interior of the die bond sheet. If the thermosetting resin used for sealing penetrates into the interior of the die bond sheet, the die bond sheet will not be able to perform its intended function.

[0009] Because the above-mentioned problems can occur, there is a demand for die bond sheets that can suppress the penetration of thermosetting resin into the interior when the sheet is bonded to a semiconductor chip and then sealed with the thermosetting resin.

[0010] Therefore, the object of the present invention is to provide a die bond sheet that can suppress the penetration of thermosetting resin into the interior when it is sealed with a thermosetting resin while adhered to a semiconductor chip. Furthermore, an objective is to provide a dicing die bond film equipped with the die bond sheet described above, and a semiconductor device equipped with the die bond sheet described above. [Means for solving the problem]

[0011] In order to solve the above problems, the die bond sheet according to the present invention is A die bond sheet containing at least one of a thermosetting resin and a thermoplastic resin as an organic component, When the die bond sheet is subjected to dynamic viscoelasticity measurement, the ratio of the storage modulus G' to the loss modulus G'' (G' / G'') is denoted as Q, and the ratio Q at a vibration frequency of 1.0 Hz is... 1.0 The ratio Q at a vibration frequency of 0.1 Hz 0.1 The relative value (Q 0.1 / Q 1.0 ) is 0.8 or higher at 170℃, When the die bond sheet is subjected to the dynamic viscoelasticity measurement, the complex viscosity at a vibration frequency of 1.0 Hz is 10 kPa·s or more at 170°C.

[0012] The dicing die bond film according to the present invention comprises the above-mentioned die bond sheet and The dicing tape comprises a base layer and an adhesive layer superimposed on the base layer, The die bond sheet is placed on top of the adhesive layer of the dicing tape. The semiconductor device according to the present invention comprises the die bond sheet described above. [Effects of the Invention]

[0013] According to the die bond sheet of the present invention, when the die bond sheet is sealed (molded) with a thermosetting resin while adhered to a semiconductor chip, it is possible to suppress the penetration of the thermosetting resin into the interior. [Brief explanation of the drawing]

[0014] [Figure 1] A cross-sectional view of a dicing die bond film equipped with the die bond sheet of this embodiment, cut in the thickness direction. [Figure 2] A cross-sectional view of a dicing tape cut in the thickness direction. [Figure 3A] A schematic cross-sectional view illustrating the stealth dicing process in the manufacturing of semiconductor devices. [Figure 3B] A schematic cross-sectional view illustrating the stealth dicing process in the manufacturing of semiconductor devices. [Figure 3C] A schematic cross-sectional view illustrating the stealth dicing process in the manufacturing of semiconductor devices. [Figure 3D] A schematic cross-sectional view illustrating the backgrinding process in the manufacturing of semiconductor devices. [Figure 4A] A schematic cross-sectional view illustrating the mounting process in the manufacturing of semiconductor devices. [Figure 4B] A schematic cross-sectional view illustrating the mounting process in the manufacturing of semiconductor devices. [Figure 5A] A schematic cross-sectional diagram illustrating the low-temperature expansion process in semiconductor device manufacturing. [Figure 5B] A schematic cross-sectional diagram illustrating the low-temperature expansion process in semiconductor device manufacturing. [Figure 5C] A schematic cross-sectional diagram illustrating the low-temperature expansion process in semiconductor device manufacturing. [Figure 6A] A schematic cross-sectional view illustrating the expansion process at room temperature in the manufacturing method of semiconductor devices. [Figure 6B] A schematic cross-sectional view illustrating the expansion process at room temperature in the manufacturing method of semiconductor devices. [Figure 7A] A schematic cross-sectional view illustrating the half-cutting process in the manufacturing method of semiconductor integrated circuits. [Figure 7B] A schematic cross-sectional view illustrating the half-cutting process in the manufacturing method of semiconductor integrated circuits. [Figure 7C] A schematic cross-sectional view illustrating the half-cutting process in the manufacturing method of semiconductor integrated circuits. [Figure 7D] A schematic cross-sectional view illustrating the half-cutting process in the manufacturing method of semiconductor integrated circuits. [Figure 8] A schematic cross-sectional view illustrating the pickup process in the manufacturing of semiconductor devices. [Figure 9] A schematic cross-sectional view showing the state after the die bonding process and the wire bonding process in the manufacturing method of a semiconductor device. [Figure 10] A schematic cross-sectional view illustrating the encapsulation process in the manufacturing method of semiconductor devices. [Figure 11A]A schematic cross-sectional view illustrating the evaluation of the performance in preventing the penetration of sealing resin into the die bond sheet. [Figure 11B] A schematic cross-sectional view illustrating the evaluation of the performance in preventing the penetration of sealing resin into the die bond sheet. [Figure 12A] A chart showing the results of dynamic viscoelasticity measurement of the die bond sheet of Example 3. [Figure 12B] This chart shows the results of dynamic viscoelasticity measurement of the die bond sheet of Comparative Example 3. [Figure 13] A microscopic image illustrating an example of how embedding resin has penetrated the tissue. [Modes for carrying out the invention]

[0015] Hereinafter, one embodiment of the die bond sheet according to the present invention will be described with reference to the drawings.

[0016] The die bond sheet 10 of this embodiment can be used, for example, as a component of a dicing die bond film 1. The dicing die bond film 1 comprises, for example, a dicing tape 20 and a die bond sheet 10 which is laminated on the adhesive layer 22 (described later) of the dicing tape 20 and adhered to a semiconductor wafer, as shown in Figure 1. Please note that the diagrams in the drawings are schematic representations and do not necessarily reflect the actual aspect ratio of the object.

[0017] <Diebond Sheet> The diebond sheet 10 is placed on top of the adhesive layer 22 of the dicing tape 20 described above, for example, as shown in Figure 1.

[0018] The thickness of the die bond sheet 10 is not particularly limited, but is, for example, 1 μm or more and 200 μm or less. Such a thickness may also be 3 μm or more and 150 μm or less, or 5 μm or more and 140 μm or less. If the die bond sheet 10 is a laminate, the above thickness is the total thickness of the laminate.

[0019] The die bond sheet 10 may have a single-layer structure, for example, as shown in FIG. 1. In this specification, a single layer means having only layers formed of the same composition. A form in which a plurality of layers formed of the same composition are laminated is also a single layer. On the other hand, the die bond sheet 10 may have a multilayer structure in which layers formed of two or more different compositions are laminated, for example.

[0020] The die bond sheet 10 contains at least one of a thermosetting resin and a thermoplastic resin as an organic component. When the ratio (G' / G") of the storage modulus G' to the loss modulus G" when the die bond sheet 10 is subjected to dynamic viscoelasticity measurement is defined as Q, the ratio Q at a vibration frequency of 1.0 Hz 1.0 with respect to the ratio Q at a vibration frequency of 0.1 Hz 0.1 of the relative value (Q 0.1 / Q 1.0 ) is 0.8 or more at 170°C. In other words, when Q at 170°C at a vibration frequency of 1.0 Hz is defined as Q, which is the reciprocal of the loss factor Tanδ, which is the ratio (G" / G') of the loss modulus G" to the storage modulus G', 1.0 and Q at 170°C at a vibration frequency of 0.1 Hz 0.1 satisfy the following relational expression. (Q 0.1 / Q 1.0 ) ≥ 0.8

[0021] Generally, based on the results of dynamic viscoelasticity measurement, the characteristic physical properties of the viscoelastic body can be known. If the vibration frequency is low, the strain rate applied to the viscoelastic body is small, and if the vibration frequency is high, the strain rate applied to the viscoelastic body is large. Among viscoelastic bodies, there are those that exhibit different behaviors depending on the vibration frequency (depending on the strain rate). There are viscoelastic materials (hereinafter referred to as the former) that exhibit properties in which both the storage modulus G' and the loss modulus G'' increase as the vibration frequency increases, and in which the relationship G'' > storage modulus G' at low vibration frequencies is reversed at high vibration frequencies. On the other hand, there are viscoelastic materials (hereinafter referred to as the latter) that exhibit properties in which neither the storage modulus G' nor the loss modulus G'' changes significantly even at high vibration frequencies. The behavior in the former case is called "concentrated solution type behavior," and it exhibits fluidity even when left stationary. In other words, in the low-frequency range where long-term stability is observed, the loss modulus G is higher, resulting in a behavior that allows for slow movement. On the other hand, the behavior in the latter case is called "weak gel-type behavior," and the relationship "storage modulus G' > loss modulus G" is maintained regardless of whether the vibration frequency is low or high. Therefore, it does not exhibit much fluidity in the low-frequency range, which shows long-term stability, or in the high-frequency range, which shows short-term stability. However, it may exhibit fluidity when a relatively large strain force is applied. Furthermore, if there is almost no frequency dependence and the storage modulus G' is approximately 10 times or more the loss modulus G'' at any frequency, it is called "true gel-type behavior" or "elastic gel behavior." The die bond sheet 10 of this embodiment is a viscoelastic material that exhibits the above-mentioned "weak gel-type behavior" at relatively high temperatures (e.g., 170°C). In terms of specific physical properties, the die bond sheet 10 of this embodiment exhibits the above-mentioned relationship (the above-mentioned relative value (Q)). 0.1 / Q 1.0 The condition (at 170°C, the value is 0.8 or higher) is satisfied.

[0022] Since the above relationship is satisfied, and as will be described later, the complex viscosity at a vibration frequency of 1.0 Hz is 10 kPa·s or more at 170°C, the die bond sheet 10 of this embodiment can suppress penetration into the thermosetting resin when it is sealed with the thermosetting resin while bonded to a semiconductor chip.

[0023] The above relative value (Q) 0.1 / Q 1.0The relative value (Q) is preferably 0.80 or higher at 170°C, more preferably 0.84 or higher, even more preferably 0.87 or higher, and particularly preferably 0.9 or higher. 0.1 / Q 1.0 The coefficient of the ion () is preferably 2.0 or less, more preferably 1.5 or less, even more preferably 1.3 or less, and particularly preferably 1.0 or less at 170°C. Such relative value (Q 0.1 / Q 1.0 ) being within the above range further suppresses the penetration of the thermosetting resin for sealing into the interior of the die bond sheet 10.

[0024] The above relative value (Q) 0.1 / Q 1.0 To adjust the value of ), the above Q at a vibration frequency of 1.0 Hz 1.0 This can be increased, for example, by increasing the crosslinking density of the thermosetting resin or thermoplastic resin in the die bond sheet 10, or by increasing the molecular weight of the thermosetting resin or thermoplastic resin. On the other hand, the above Q at an vibration frequency of 1.0 Hz can be increased, for example, by decreasing the crosslinking density of the thermosetting resin or thermoplastic resin in the die bond sheet 10, or by decreasing the molecular weight of the thermosetting resin or thermoplastic resin. 1.0 It can be made smaller. The above relative value (Q) 0.1 / Q 1.0 To adjust the value of ), the above Q at a vibration frequency of 0.1 Hz 0.1 This can be increased, for example, by increasing the crosslinking density of the thermosetting resin or thermoplastic resin in the die bond sheet 10, or by increasing the molecular weight of the thermosetting resin or thermoplastic resin. On the other hand, the above Q at an vibration frequency of 0.1 Hz can be increased, for example, by decreasing the crosslinking density of the thermosetting resin or thermoplastic resin in the die bond sheet 10, or by decreasing the molecular weight of the thermosetting resin or thermoplastic resin. 0.1 It can be made smaller.

[0025] The dynamic viscoelasticity measurements described above are performed under the following measurement conditions. Measurement device: "HAAKE MARSIII" (manufactured by TA Instruments) Sample size: 8mm in diameter, 0.3mm thick (using uncured diebond sheet) (If the thickness is less than 0.3 mm, multiple sheets are stacked to form a laminate.) Measurement thickness: 0.25mm Measurement temperature: 170℃ Measurement mode: Oscillation mode (vibration shear mode) Vibration frequency: Measure from 0.05 Hz to 50 Hz, and read the physical properties (storage modulus, loss modulus, complex viscosity, tanδ) at 0.1 Hz and 1 Hz. Distortion: 1.0%

[0026] When the ratio of the storage modulus G' to the loss modulus G'' is Q (G' / G''), the ratio Q at a vibration frequency of 0.1 Hz is given by Q. 0.1 The ratio Q at 170°C is preferably 1.5 or higher, more preferably 2.0 or higher, even more preferably 2.5 or higher, and particularly preferably 3.0 or higher. 0.1 The storage modulus G' is preferably 10.0 or less, more preferably 5.0 or less, even more preferably 4.5 or less, and particularly preferably 4.2 or less at 170°C. The above numerical range, where the storage modulus G' is greater than the loss modulus G'', allows for greater suppression of plastic deformation when a shear force is applied to the die bond sheet 10.

[0027] When the ratio of the storage modulus G' to the loss modulus G'' is Q (G' / G''), the ratio Q at a vibration frequency of 1.0 Hz is given by Q. 1.0 The ratio Q at 170°C is preferably 2.0 or higher, more preferably 2.4 or higher, even more preferably 2.8 or higher, and particularly preferably 3.0 or higher. 1.0The storage modulus G' is preferably 10.0 or less, more preferably 5.0 or less, and even more preferably 4.5 or less at 170°C. The above numerical range, where the storage modulus G' is greater than the loss modulus G'', allows for greater suppression of plastic deformation when a shear force is applied to the die bond sheet 10.

[0028] The ratio of the storage modulus G' to the loss modulus G'' (G' / G'') is preferably in the range of 1.5 to 10.0 at 170°C, and more preferably in the range of 2.0 to 5.0, for both vibration frequencies of 0.1 Hz and 1.0 Hz. By being within this numerical range, the penetration of the thermosetting resin for sealing into the interior of the die bond sheet can be further suppressed.

[0029] The storage modulus G' at a vibration frequency of 0.1 Hz is 1.0 × 10⁻⁶ at 170°C. 4 It is preferable that the pressure be Pa or higher (0.01 MPa or higher), and 5.0 × 10 4 It is more preferable that the pressure be Pa or higher (0.05 MPa or higher), and 1.0 × 10 5 It is even more preferable that the pressure be Pa or higher (0.10 MPa or higher), and 2.0 × 10 5 It is particularly preferable that the pressure be Pa or higher (0.20 MPa or higher). The storage modulus G' at a vibration frequency of 0.1 Hz is 1.0 × 10⁻⁶ at 170°C. 7 It is preferable that the pressure be Pa or less (10.0 MPa or less), and 5.0 × 10 6 It is more preferable that the pressure be Pa or less (5.0 MPa or less), and 2.0 × 10 6 It is even more preferable that the pressure is Pa or less (2.0 MPa or less). By being within the above numerical range, the die bond sheet 10 has the advantage of being able to remove voids against relatively low-speed shear forces while suppressing the penetration of the thermosetting resin for sealing.

[0030] The loss modulus G'' at a vibration frequency of 0.1 Hz is 0.5 × 10¹⁶ at 170°C. 4 It is preferable that the pressure be Pa or higher (0.005 MPa or higher), and 1.0 × 104 It is more preferable that the pressure be Pa or higher (0.010 MPa or higher), and 1.5 × 10 4 It is even more preferable that the pressure be Pa or higher (0.015 MPa or higher), and 3.0 × 10 4 It is particularly preferable that the pressure be Pa or higher (0.030 MPa or higher). The loss modulus G'' at a vibration frequency of 0.1 Hz is 5.0 × 10¹⁶ at 170°C. 6 It is preferable that the value be Pa or less (5.0 MPa or less), and 1.0 × 10 6 It is more preferable that the pressure be Pa or less (1.0 MPa or less), and 0.2 × 10 6 It is even more preferable that the pressure be Pa or less (0.2 MPa or less), and 0.1 × 10 6 It is even more preferable that the pressure is Pa or less (0.1 MPa or less). Being within the above numerical range has the advantage of allowing the die bond sheet 10 to suppress the penetration of the sealing thermosetting resin while still having the function of removing voids against relatively low-speed shear forces.

[0031] The storage modulus G' at a vibration frequency of 1.0 Hz is 1.0 × 10⁻⁶ at 170°C. 4 It is preferable that the pressure be Pa or higher (0.01 MPa or higher), and 5.0 × 10 4 It is more preferable that the pressure be Pa or higher (0.05 MPa or higher), and 1.0 × 10 5 It is even more preferable that the pressure be Pa or higher (0.10 MPa or higher), and 3.0 × 10 5 It is even more preferable that the pressure be Pa or higher (0.30 MPa or higher), and 4.0 × 10 5 It is particularly preferable that the pressure be Pa or higher (0.40 MPa or higher). The storage modulus G' at a vibration frequency of 1.0 Hz is 5.0 × 10⁻⁶ at 170°C. 7 It is preferable that the pressure be Pa or less (50.0 MPa or less), and 1.0 × 10 7 It is more preferable that it be Pa or less (10.0 MPa or less), 2.0 × 10 6 It is even more preferable that the value be Pa or less (2.0 MPa or less), and 1.2 × 10 6It is even more preferable that the pressure be Pa or less (1.2 MPa or less), and 1.0 × 10 6 It is particularly preferable that the pressure be Pa or less (1.0 MPa or less), and 0.8 × 10 6 It is particularly preferable that the pressure be Pa or less (0.8 MPa or less). Being within this numerical range has the advantage that the die bond sheet 10 can suppress the penetration of the sealing thermosetting resin while having the function of removing voids against relatively high-speed shear forces.

[0032] The loss modulus G'' at a vibration frequency of 1.0 Hz is 1.0 × 10¹⁶ at 170°C. 4 It is preferable that the pressure be Pa or higher (0.01 MPa or higher), and 5.0 × 10 4 It is more preferable that the pressure be Pa or higher (0.05 MPa or higher). The loss modulus G'' at a vibration frequency of 1.0 Hz is 5.0 × 10¹⁶ at 170°C. 6 It is preferable that the pressure be Pa or less (5.0 MPa or less), and 2.0 × 10 5 It is more preferable that the pressure be Pa or less (0.2 MPa or less), and 1.0 × 10 5 It is even more preferable that the pressure be less than Pa (less than 0.1 MPa). Being within the above numerical range has the advantage that the die bond sheet 10 can suppress the penetration of the sealing thermosetting resin while having the function of removing voids against relatively high-speed shear forces.

[0033] When the die bond sheet 10 is subjected to dynamic viscoelasticity testing, the complex viscosity at a vibration frequency of 1.0 Hz is 10 kPa·s or more at 170°C. Preferably, such complex viscosity is 20 kPa·s or more. However, such complex viscosity may be 500 kPa·s or less. Since the above complex viscosity is 10 kPa·s or more at 170°C, and as mentioned above, (Q 0.1 / Q 1.0 Since the above relationship )≧0.8 is satisfied, the die bond sheet 10 of this embodiment can suppress penetration into the thermosetting resin when it is sealed with the thermosetting resin while bonded to the semiconductor chip.

[0034] The above complex viscosity can be increased, for example, by increasing the filler content of the die bond sheet 10, increasing the crosslinking density of the thermosetting resin or thermoplastic resin in the die bond sheet 10, or increasing the molecular weight of the thermosetting resin or thermoplastic resin. On the other hand, the above complex viscosity can be decreased, for example, by decreasing the filler content of the die bond sheet 10, decreasing the crosslinking density of the thermosetting resin or thermoplastic resin in the die bond sheet 10, or decreasing the molecular weight of the thermosetting resin or thermoplastic resin.

[0035] The complex viscosity values ​​mentioned above are measured values ​​obtained when dynamic viscoelasticity measurements were performed under the same measurement conditions as described above.

[0036] The die bond sheet 10 preferably has a tensile elongation at break of 10% or less at 0°C. More preferably, this tensile elongation at break is 5% or less. This tensile elongation at break may be 0.1% or more. Because the tensile elongation at break is 10% or less at 0°C, the die bond sheet 10 can be easily cleaved in the low-temperature expansion process, which will be described in detail later. Therefore, the die bond sheet can have better cleavage properties.

[0037] The tensile elongation at break described above can be reduced, for example, by increasing the filler content or decreasing the content of thermoplastic or thermosetting resin. On the other hand, the tensile elongation at break described above can be increased by decreasing the filler content or increasing the content of thermoplastic or thermosetting resin.

[0038] The tensile elongation at break described above is measured under the following conditions. The measurement is performed on a test specimen of the die-bond sheet before it has hardened. • Measurement device: Dynamic viscoelasticity measuring device (e.g., "RSA-G2" manufactured by TA Instruments Corporation) • 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 ± 2 μm) • Test specimen: Strip-shaped, 10mm wide and 50mm long, with an initial chuck distance of 20mm. • Tensile speed: 1 mm / sec, • Measurement temperature: 0°C (Measurement begins after holding at 0°C for 5 minutes) The elongation rate at the time of fracture is defined as the tensile fracture elongation (fracture elongation). Elongation rate [%] = 100 × [(Distance between chucks at break - Initial distance between chucks) / Initial distance between chucks]

[0039] The die bond sheet 10 includes, for example, an organic component and an inorganic component. The organic component includes at least one of a thermosetting resin and a thermoplastic resin. Thermosetting resins include, for example, thermosetting resins such as epoxy resins or phenolic resins, which will be described in detail later. Thermoplastic resins include, for example, thermoplastic resins such as acrylic polymers obtained by polymerizing at least (meth)acrylic acid ester monomers.

[0040] (thermoplastic resin) The acrylic polymer that may be included in the thermoplastic resin may be a crosslinkable group-containing acrylic polymer that has crosslinkable groups in its molecule that undergo a crosslinking reaction by thermosetting treatment.

[0041] The above-described acrylic polymer containing crosslinkable groups typically has the above-described crosslinkable groups in its side chains. The above-described acrylic polymer containing crosslinkable groups may also have the above-described crosslinkable groups at the ends of its side chains. Furthermore, the above-described acrylic polymer containing crosslinkable groups may have the above-described crosslinkable groups at at least one of the ends of its main chain.

[0042] The crosslinkable group contained in the above-mentioned acrylic polymer is not particularly limited as long as it is a functional group that undergoes a crosslinking reaction by thermal curing treatment.

[0043] Examples of crosslinkable groups include hydroxyl groups and carboxyl groups. These crosslinkable groups can undergo crosslinking reactions with glycidyl groups or isocyanate groups. For example, the above-mentioned acrylic polymer containing crosslinkable groups, which has at least one of a hydroxyl group or a carboxyl group in its molecule, can undergo crosslinking reactions with compounds that have a glycidyl group or an isocyanate group in their molecule (for example, epoxy resins, which will be described in detail later).

[0044] Examples of crosslinkable groups include glycidyl groups and isocyanate groups. These crosslinkable groups can undergo crosslinking reactions with hydroxyl groups and carboxyl groups. For example, the above-mentioned acrylic polymer containing a crosslinkable group having at least one of a glycidyl group or an isocyanate group in its molecule can undergo crosslinking reactions with a compound having at least one of a hydroxyl group or a carboxyl group in its molecule (for example, a phenol resin, which will be described in detail later).

[0045] In this embodiment, it is preferable that the crosslinkable group-containing acrylic polymer contained in the die bond sheet 10 contains at least one of a hydroxyl group or a carboxyl group as a crosslinkable group. This allows the die bond sheet 10 to adhere to the substrate more effectively.

[0046] In the above-described acrylic polymer containing a crosslinkable group, the proportion of the constituent units of the crosslinkable group-containing monomer may be 0.01% by mass or more and 50.0% by mass or less. In the above-mentioned acrylic polymer containing a crosslinkable group, the proportion of constituent units of the crosslinkable group-containing monomer containing a carboxyl group may be 0.1% by mass or more and 20.0% by mass or less, 0.2% by mass or more and 10.0% by mass or less, or 0.5% by mass or more and 5.0% by mass or less. In the above-mentioned crosslinkable group-containing acrylic polymer, the proportion of constituent units of the crosslinkable group-containing monomer containing a glycidyl group may be 10% by mass or more and 45.0% by mass or less, or 20% by mass or more and 40.0% by mass or less. The constituent units are the structures derived from each monomer (e.g., 2-ethylhexyl acrylate, hydroxyethyl acrylate, etc.) after polymerization when a crosslinkable group-containing acrylic polymer is polymerized. The same applies hereafter.

[0047] The above-mentioned acrylic polymers containing crosslinkable groups can be synthesized, for example, by a general polymerization method using a radical polymerization initiator.

[0048] The above-mentioned crosslinkable group-containing acrylic polymer preferably contains alkyl (meth)acrylate monomer components in the largest mass proportion among the constituent units of the molecule. Examples of such alkyl (meth)acrylate monomers include C1-C18 alkyl (meth)acrylate monomers having 1 to 18 carbon atoms in the alkyl group (hydrocarbon group). The alkyl (meth)acrylate monomer may be, for example, a C1-C12 alkyl (meth)acrylate monomer having 1 to 12 carbon atoms in the alkyl group (hydrocarbon group), a C1-C8 alkyl (meth)acrylate monomer having 1 to 8 carbon atoms in the alkyl group (hydrocarbon group), or a C1-C6 alkyl (meth)acrylate monomer having 1 to 6 carbon atoms in the alkyl group (hydrocarbon group).

[0049] Examples of alkyl (meth)acrylate monomers include saturated linear alkyl (meth)acrylate monomers and saturated branched alkyl (meth)acrylate monomers.

[0050] Examples of saturated linear alkyl (meth)acrylate monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, and stearyl (meth)acrylate. Preferably, the number of carbon atoms in the linear alkyl group is between 2 and 8. Examples of saturated branched alkyl (meth)acrylate monomers include isoheptyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. The alkyl group portion may have an iso structure, sec structure, neo structure, or tert structure.

[0051] The above-mentioned crosslinkable group-containing acrylic polymer contains structural units derived from crosslinkable group-containing monomers that can copolymerize with alkyl (meth)acrylate monomers. In this embodiment, the above-mentioned crosslinkable group-containing acrylic polymer is an acrylic polymer copolymerized with at least an alkyl (meth)acrylate monomer and a crosslinkable group-containing monomer. In other words, the above-mentioned crosslinkable group-containing acrylic polymer has a structure in which the constituent units of the alkyl (meth)acrylate monomer and the constituent units of the crosslinkable group-containing monomer are linked together in a random order.

[0052] Examples of the above-mentioned crosslinkable group-containing monomers include carboxyl group-containing (meth)acrylic monomers, acid anhydride (meth)acrylic monomers, hydroxyl group-containing (meth)acrylic monomers, glycidyl group-containing (epoxy group)-containing (meth)acrylic monomers, isocyanate group-containing (meth)acrylic monomers, sulfonic acid group-containing (meth)acrylic monomers, phosphate group-containing (meth)acrylic monomers, and monomers containing functional groups such as acrylamide. The above-mentioned crosslinkable group-containing monomers may also contain ether groups or ester groups in their molecules.

[0053] The above crosslinkable group-containing acrylic polymer is preferably, A crosslinkable group-containing monomer selected from the group consisting of carboxyl group-containing (meth)acrylic monomers, hydroxyl group-containing (meth)acrylic monomers, and glycidyl group-containing (meth)acrylic monomers, It is a copolymer of alkyl (meth)acrylate (especially alkyl (meth)acrylate with 10 or fewer carbon atoms in the alkyl portion).

[0054] Examples of carboxyl group-containing (meth)acrylic monomers include (meth)acrylic acid and mono(2-(meth)acryloyloxyethyl) succinate monomers. The carboxyl group may be located at the terminal end of the monomer structure or bonded to hydrocarbons other than the terminal end. Examples of hydroxyl group-containing (meth)acrylic monomers include hydroxyethyl (meth)acrylate monomer, hydroxypropyl (meth)acrylate monomer, and hydroxybutyl (meth)acrylate monomer. The hydroxyl group may be located at the terminal end of the monomer structure, or it may be bonded to hydrocarbons other than the terminal end. Examples of glycidyl group-containing (meth)acrylic monomers include glycidyl (meth)acrylate monomers and 4-hydroxybutyl (meth)acrylate glycidyl ether. The glycidyl group may be located at the terminal end of the monomer structure or bonded to hydrocarbons other than the terminal end.

[0055] The die bond sheet 10 preferably contains a glycidyl group-containing acrylic polymer and a carboxyl group-containing acrylic polymer as the crosslinkable group-containing acrylic polymer. This has the advantage of making it easier to control the reactivity of the crosslinking reaction when the die bond sheet 10 hardens, and also has the advantage of further suppressing the penetration of the thermosetting resin into the interior of the die bond sheet as described above.

[0056] The Diebond sheet 10 may also contain thermoplastic resins other than the crosslinkable group-containing acrylic polymer described above.

[0057] (thermosetting resin) 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.

[0058] 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.

[0059] 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 hydroxyl group equivalent [g / eq] of the phenolic resin may be, for example, 90 to 220. The above-mentioned phenolic resin may be of one type or two or more types.

[0060] In this embodiment, it is preferable that the die bond sheet 10 contains the above-mentioned crosslinkable group-containing acrylic polymer and thermosetting resin that crosslink with each other. This can further suppress the penetration of the sealing thermosetting resin into the interior of the die bond sheet. For example, the die bond sheet 10 may contain a glycidyl group-containing acrylic polymer as a crosslinkable group-containing acrylic polymer, and a phenol resin as a thermosetting resin. This allows the glycidyl groups of the crosslinkable group-containing acrylic polymer and the hydroxyl groups of the phenol resin to undergo a crosslinking reaction, enabling the die bond sheet 10 to be sufficiently cured. On the other hand, for example, the die bond sheet 10 may contain a carboxyl group-containing acrylic polymer as a crosslinkable group-containing acrylic polymer, and an epoxy resin as a thermosetting resin. This allows the carboxyl groups of the crosslinkable group-containing acrylic polymer and the glycidyl groups of the epoxy resin to undergo a crosslinking reaction, enabling the die bond sheet 10 to be sufficiently cured.

[0061] The proportion of organic components in the die bond sheet 10 is preferably 85% by mass or less, and more preferably 80% by mass or less. In other words, the die bond sheet 10 preferably contains 85% by mass or less in total amount of organic components such as thermoplastic resin and thermosetting resin. This allows the die bond sheet 10 to have better cleavage properties in the expansion process described later. Furthermore, the proportion of organic components in the die bond sheet 10 may be 40% by mass or more. This proportion is preferably 50% by mass or more, and more preferably 60% by mass or more.

[0062] In the die bond sheet 10, the amount of the above-mentioned crosslinkable group-containing acrylic polymer in 100 parts by mass of the organic components (for example, the above-mentioned crosslinkable group-containing acrylic polymer, thermosetting resin, curing catalyst, silane coupling agent, dye, etc.) is preferably 70 parts by mass or more, and more preferably 85 parts by mass or more. The amount of the above-mentioned crosslinkable group-containing acrylic polymer in 100 parts by mass of the above-mentioned organic components is preferably 100 parts by mass or less. The die bond sheet 10 preferably contains 30% by mass or more, and more preferably 50% by mass or more, of the above-mentioned crosslinkable group-containing acrylic polymer. The die bond sheet 10 preferably contains 75% by mass or less, and more preferably 85% by mass or less, of the above-mentioned crosslinkable group-containing acrylic polymer. The above numerical range has the advantage of allowing for more reliable removal of voids in the sealing process described later.

[0063] In the die bond sheet 10, the proportion of thermosetting resin to 100 parts by mass of organic components is preferably 30 parts by mass or less, and more preferably 5% by mass or more and 20% by mass or less. The die bond sheet 10 does not need to contain thermosetting resin. The die bond sheet 10 preferably contains 5% by mass or more of thermosetting resin. The die bond sheet 10 preferably contains 20% by mass or less of thermosetting resin, and more preferably 15% by mass or less. By staying within the above numerical range, voids that have formed inside the die bond sheet 10 are more likely to disappear, and the expansion of formed voids in high-temperature environments can be further suppressed. In other words, the heat resistance reliability described later can be further improved. Furthermore, the elasticity and viscosity of the die bond sheet 10 can be adjusted by changing the content of the thermosetting resin in the die bond sheet 10.

[0064] The die bond sheet 10 may or may not contain a filler. It is preferable that the die bond sheet 10 contains a filler, as this improves its cleavability in the expansion process described later. 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.

[0065] Inorganic fillers are one type of inorganic component. 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, and silica such as crystalline silica and amorphous silica. The materials of inorganic fillers include elemental metals such as aluminum, gold, silver, copper, and nickel, as well as alloys. Fillers such as aluminum borate whiskers, amorphous carbon black, and graphite may also be used.

[0066] As the inorganic filler, silica filler is preferred. As the raw material containing silica filler, organosilica sol is preferred. As the organosilica sol, for example, a commercially available product in which silica filler is dispersed in an organic solvent can be used.

[0067] The average primary particle size of the filler is preferably between 10 nm and 500 nm, and more preferably between 50 nm and 500 nm. This allows for a better balance between the cleavage performance and heat resistance reliability of the die bond sheet 10.

[0068] The average primary particle diameter of the filler can be measured as follows: First, the die bond sheet containing the filler is subjected to a calcination treatment at 500°C for 3 hours in an oxygen-containing atmosphere. Next, the ashed sample is fixed to the sample stage and then subjected to a conductive treatment. After that, surface FE-SEM observation is performed. SEM observation images are obtained in five fields of view at different observation locations (for example, using Hitachi High-Technologies' field emission scanning electron microscopes "S-4800" or "SU-8020"). Image processing is performed on each acquired SEM observation image to identify each particle (for example, using image analysis software such as "Image J" or Media Cybernetics' "Image-Pro"). The equivalent diameter of a perfect circle is calculated as the primary particle diameter of each identified particle, and then the arithmetic mean of the equivalent diameters of a perfect circle is calculated to determine the average primary particle diameter.

[0069] The particle shape of the filler may be spherical (perfectly spherical or ellipsoidal, etc.), needle-shaped, flake-shaped, chain-shaped, or any other shape. A die bond sheet 10 containing an organosilica sol with chain-shaped silica particles as an inorganic filler may also exhibit the "weak gel-like behavior" described above. In an organosilica sol containing chain-shaped particles, multiple particle units are linked together in rows to form a string-like structure. In the die bond sheet 10, the chain-shaped silica particles are, for example, in a state where at least three particle units are linked together in rows, with adjacent particles connected to each other. Either one or two or more of the above types of fillers may be used.

[0070] If the die bond sheet 10 contains a filler, the filler content may be 50% by mass or less of the total mass of the die bond sheet 10. Alternatively, the filler content may be, for example, 5% by mass or more. The amount of the filler may be 60 parts by mass or more and 120 parts by mass or less per 100 parts by mass of the organic component contained in the Diebond sheet 10.

[0071] The diebond sheet 10 may contain additives as needed. Examples of additives include curing catalysts, crosslinking agents, silane coupling agents, flame retardants, dyes, and the like. Examples of flame retardants include antimony trioxide, antimony pentoxide, and brominated epoxy resins.

[0072] Examples of crosslinking agents include compounds having multiple nitrogen atoms in their molecule, each of which has a crosslinking group bonded to it. Examples of such compounds include 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, or the product name "TS-G" described in later examples. Examples of silane coupling agents include β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane.

[0073] The die bond sheet 10 preferably contains an additive in an amount of 0.05% to 2.00% by mass. More preferably, the die bond sheet 10 contains at least one of the above-mentioned 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane or "TS-G" in a total amount of 0.05% to 2.00% by mass as an additive. This can further suppress the penetration of the thermosetting resin for sealing into the interior of the die bond sheet. In addition, the die bond sheet 10 can have better cleavage properties in the expansion process described later.

[0074] The above-mentioned additives may be used in the form of one type or two or more types.

[0075] The die bond sheet 10 preferably contains the above-mentioned crosslinkable group-containing acrylic polymer, thermosetting resin, and filler, in that its elasticity and viscosity can be easily adjusted.

[0076] Next, we will explain in detail the dicing tape that makes up the dicing die bond film.

[0077] <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.

[0078] The dicing tape 20 described above comprises, for example, a base layer 21 and an adhesive layer 22 superimposed on the base layer 21, as shown in Figure 2. The adhesive layer 22 of the dicing tape 20 is, for example, a pressure-sensitive adhesive layer. A commercially available product may be used as the dicing tape 20.

[0079] In the dicing die bond film 1 described above, 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. After irradiation, the adhesive layer 22 hardens, which reduces its adhesive strength. As a result, the die bond sheet 10 (with the semiconductor chip attached) can be peeled off relatively easily from the adhesive layer 22 after irradiation. The die bond sheet 10 is bonded to an adherend such as a circuit board or a semiconductor chip in the manufacturing of semiconductor devices.

[0080] [The adhesive layer of dicing tape] In this embodiment, the adhesive layer 22 includes, for example, an acrylic copolymer, an isocyanate compound, and a polymerization initiator. The adhesive layer 22 may have a thickness of 40 μm or less. Preferably, the thickness of the adhesive layer 22 is 10 μm or less, more preferably 7 μm or less, and even more preferably 5 μm or less. The adhesive layer 22 may have a thickness of 1 μm or more. The shape and size of the adhesive layer 22 are usually the same as those of the base layer 21.

[0081] In this embodiment, the adhesive layer 22 contains an acrylic copolymer having at least alkyl (meth)acrylate units and crosslinkable group-containing (meth)acrylate units as monomer units in its molecule. Note that "unit" refers to the structure derived from each monomer after polymerization of the monomers (e.g., 2-ethylhexyl acrylate, hydroxyethyl acrylate, etc.) during the polymerization of acrylic copolymers. The same applies hereafter.

[0082] In this specification, the term "(meth)acrylate" refers to at least one of methacrylate (methacrylic acid ester) and acrylate (acrylic acid ester). The same applies to the term "(meth)acrylic."

[0083] The above-described acrylic copolymer contains at least alkyl (meth)acrylate units and crosslinkable group-containing (meth)acrylate units as monomer units in its molecule. Monomer units are the units that constitute the main chain of the acrylic copolymer. In other words, monomer units are derived from the monomers used to polymerize the acrylic copolymer. Each side chain in the above-described acrylic copolymer is contained within each monomer unit that constitutes the main chain.

[0084] The alkyl (meth)acrylate units described above are derived from alkyl (meth)acrylate monomers. In other words, the alkyl (meth)acrylate unit is the molecular structure after the polymerization reaction of alkyl (meth)acrylate monomers. The notation "alkyl" represents the hydrocarbon portion that is esterified to (meth)acrylic acid.

[0085] The alkyl portion (hydrocarbon) in the alkyl (meth)acrylate unit may be a saturated hydrocarbon or an unsaturated hydrocarbon. The alkyl portion (hydrocarbon) in the alkyl (meth)acrylate unit may be a linear hydrocarbon, a branched hydrocarbon, or may contain a cyclic structure. The number of carbon atoms in the alkyl portion (hydrocarbon) of the alkyl (meth)acrylate unit may be between 6 and 22.

[0086] The above acrylic copolymer more preferably contains saturated alkyl (meth)acrylate units as alkyl (meth)acrylate units, wherein the alkyl portion is a saturated hydrocarbon having 6 to 22 carbon atoms.

[0087] In the above-mentioned acrylic copolymer, it is preferable that the proportion (on a molar basis) of alkyl (meth)acrylate units with 6 or more carbon atoms in the alkyl portion is the highest among all monomer units in the molecule. For example, alkyl (meth)acrylate units with 6 or more carbon atoms (preferably 8 or more) in the alkyl portion may account for 50% to 90% on a molar basis among all monomer units.

[0088] The saturated alkyl (meth)acrylate unit of the alkyl portion preferably does not contain a benzene ring or any polar groups such as an ether linkage (-CH2-O-CH2-), an -OH group, or an -COOH group in the molecule. In saturated alkyl (meth)acrylate units with 6 or more carbon atoms in the alkyl portion, the alkyl portion may be a saturated linear hydrocarbon or a saturated branched hydrocarbon composed of 6 to 10 carbon atoms, without containing any atoms other than C and H.

[0089] The above-mentioned acrylic copolymer may contain one type of alkyl (meth)acrylate unit alone, or it may contain two or more types.

[0090] Crosslinkable group-containing (meth)acrylate units have either a hydroxyl group capable of forming urethane bonds through a urethane reaction, or a polymerizable group capable of polymerization through a radical reaction. More specifically, crosslinkable group-containing (meth)acrylate units have either an unreacted hydroxyl group or a radically polymerizable carbon-carbon double bond as a polymerizable group. In other words, some crosslinkable group-containing (meth)acrylate units have an unreacted hydroxyl group, while other parts (all others) do not have a hydroxyl group and have a radically polymerizable carbon-carbon double bond.

[0091] The above acrylic copolymer has hydroxyl group-containing (meth)acrylate units as crosslinkable group-containing (meth)acrylate units, in which a hydroxyl group is bonded to an alkyl portion having 4 or fewer carbon atoms. When the adhesive layer 22 contains an isocyanate compound, the isocyanate group of the isocyanate compound and the hydroxyl group of the hydroxyl group-containing (meth)acrylate unit can react readily. By having an acrylic copolymer containing hydroxyl group-containing (meth)acrylate units and an isocyanate compound coexist in the adhesive layer 22, the adhesive layer 22 can be moderately cured. As a result, the acrylic copolymer can gel sufficiently. Therefore, the adhesive layer 22 can exhibit adhesive properties while maintaining its shape.

[0092] The hydroxyl group-containing (meth)acrylate unit is preferably a hydroxyl group-containing C2-C4 alkyl (meth)acrylate unit in which an OH group is bonded to a hydrocarbon portion having 2 to 4 carbon atoms. The notation "C2-C4 alkyl" indicates the number of carbon atoms in the hydrocarbon portion ester-bonded to (meth)acrylic acid. In other words, a hydroxyl group-containing C2-C4 alkyl (meth)acrylic monomer refers to a monomer in which (meth)acrylic acid and an alcohol (usually a dihydric alcohol) having 2 to 4 carbon atoms are ester-bonded. The same applies hereafter in this specification. The C2-C4 alkyl hydrocarbon portion is usually a saturated hydrocarbon. For example, the C2-C4 alkyl hydrocarbon portion is a linear saturated hydrocarbon or a branched saturated hydrocarbon. It is preferable that the C2-C4 alkyl hydrocarbon portion does not contain polar groups such as oxygen (O) or nitrogen (N).

[0093] The above acrylic copolymer contains polymerizable (meth)acrylate units as crosslinkable group-containing (meth)acrylate units, which have radical polymerizable carbon-carbon double bonds (polymerizable unsaturated double bonds) in their side chains.

[0094] Specifically, the polymerizable (meth)acrylate unit has a molecular structure in which the isocyanate group of an isocyanate group-containing (meth)acrylic monomer is urethane-bonded to the hydroxyl group in the hydroxyl group-containing (meth)acrylate unit described above.

[0095] The above-mentioned acrylic copolymer contains radically polymerizable carbon-carbon double bonds of crosslinkable group-containing (meth)acrylate units, which allows the adhesive layer 22 to be cured by irradiation with active energy rays (such as ultraviolet light) before the pickup step described above. For example, irradiation with active energy rays such as ultraviolet light generates radicals from the photopolymerization initiator, and these radicals cause the acrylic copolymer to crosslink with each other. This reduces the adhesive strength of the adhesive layer 22 before irradiation to a lower level after irradiation. As a result, the die bond sheet 10 can be easily peeled off the adhesive layer 22. Ultraviolet light, radiation, and electron beams are used as the active energy rays.

[0096] Polymerizable (meth)acrylate units can be prepared by a urethane reaction following the polymerization reaction of an acrylic copolymer. For example, polymerizable (meth)acrylate units can be obtained by copolymerizing an alkyl (meth)acrylate monomer with a hydroxyl group-containing (meth)acrylic monomer, and then urethane reacting the hydroxyl groups in a portion of the hydroxyl group-containing (meth)acrylate units with the isocyanate groups of the isocyanate group-containing polymerizable monomer.

[0097] The above-mentioned isocyanate group-containing (meth)acrylic monomer preferably has one isocyanate group and one (meth)acryloyl group in its molecule. An example of such a monomer is 2-methacryloyloxyethyl isocyanate.

[0098] In this embodiment, the isocyanate compound that may further be contained in the adhesive layer 22 of the dicing tape 20 has multiple isocyanate groups in its molecule. Having multiple isocyanate groups in its molecule allows the crosslinking reaction between acrylic copolymers in the adhesive layer 22 to proceed. Specifically, the crosslinking reaction mediated by the isocyanate compound can be carried out by reacting one isocyanate group of the isocyanate compound with a hydroxyl group of an acrylic copolymer and the other isocyanate group with a hydroxyl group of another acrylic copolymer. Furthermore, the isocyanate compound may be a compound synthesized via a urethane reaction or the like.

[0099] Examples of isocyanate compounds include diisocyanates such as aliphatic diisocyanates, alicyclic diisocyanates, or aromatic aliphatic diisocyanates.

[0100] Furthermore, examples of isocyanate compounds include polymerized polyisocyanates such as dimers and trimers of diisocyanates, and polymethylene polyphenylene polyisocyanates.

[0101] 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.

[0102] 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.

[0103] In this embodiment, 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. By containing the polymerization initiator in the adhesive layer 22, when thermal or light energy is applied to the adhesive layer 22, a crosslinking reaction between the acrylic copolymers can be promoted. Specifically, the polymerization reaction between polymerizable groups is initiated between acrylic copolymers having polymerizable (meth)acrylate units containing radical polymerizable carbon-carbon double bonds, thereby curing the adhesive layer 22. This reduces the adhesive strength of the adhesive layer 22, allowing the die bond sheet 10 to be easily peeled off 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.

[0104] 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.

[0105] The adhesive layer 22 may have a thickness of 40 μm or less. Preferably, the thickness of the adhesive layer 22 is 20 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less. The adhesive layer 22 may have a thickness of 1 μm or more. The shape and size of the adhesive layer 22 are usually the same as those of the base layer 21.

[0106] [Base layer of dicing tape] The substrate layer 21 superimposed on the adhesive layer 22 may have a single-layer structure or a laminated structure (for example, a two-layer or three-layer structure).

[0107] The base layer 21 may consist of two layers or three layers. In such a laminated structure, the base layer 21 may be formed by, for example, each layer being manufactured by co-extrusion molding and multiple layers being integrated together.

[0108] The thickness (total thickness) of the substrate layer 21 may be, for example, 80 μm or more and 150 μm or less.

[0109] Each layer of the base material layer 21 is, for example, a metal foil, a rubber sheet, or a resin film.

[0110] Each layer of the base material layer 21 may contain, for example, polyolefins such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), and ethylene-propylene copolymer; ionomer resins; ethylene-vinyl acetate copolymer resins; ethylene copolymers such as ethylene-(meth)acrylic acid ester (random, alternating) copolymers; polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); polyacrylates; 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; fluorine-containing polymers, etc.

[0111] If each layer of 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.

[0112] 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.

[0113] Each layer of the substrate layer 21 may further contain an antistatic agent. The antistatic agent prevents static electricity buildup in the substrate layer 21. Therefore, it is possible to sufficiently prevent electrostatic discharge damage to the electronic circuits in the semiconductor chip. In addition, by preventing static electricity buildup, it is possible to sufficiently prevent foreign matter such as dust from adhering to the substrate layer 21.

[0114] 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.

[0115] On the other hand, the surface of the substrate layer 21 in contact with the adhesive layer 22 may be subjected to a surface treatment to enhance adhesion with the adhesive layer 22. Examples of surface treatments include oxidation treatments by chemical or physical methods such as chromic acid treatment, ozone exposure, flame exposure, high-voltage electric shock exposure, and ionization radiation treatment. Furthermore, the substrate may be coated with a coating agent such as an anchor coating agent, primer, or adhesive.

[0116] 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. As the release liner, for example, a plastic film or paper that has been surface-treated with a release agent such as silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide can be used. The 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.

[0117] Next, the manufacturing methods for the die bond sheet 10 and the dicing die bond film 1 of this embodiment will be described.

[0118] <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.

[0119] [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.

[0120] In the resin composition preparation process, for example, the above-mentioned crosslinkable group-containing acrylic polymer is mixed with an epoxy resin, phenolic resin, curing catalyst, or solvent to dissolve each resin in the solvent, thereby preparing 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.

[0121] 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.

[0122] <Process for making dicing tape> The process for making dicing tape is: The synthesis process for synthesizing acrylic copolymers, A step to prepare an adhesive layer 22 by volatilizing the solvent from an adhesive composition containing the above-mentioned acrylic copolymer, 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.

[0123] In the synthesis process, for example, an acrylic copolymer intermediate is synthesized by radical polymerization of the alkyl (meth)acrylate monomer and the hydroxyl group-containing (meth)acrylic monomer described above. Radical polymerization can be carried out by general methods. For example, an acrylic copolymer intermediate 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 copolymer. Next, some of the hydroxyl groups in the hydroxyl group-containing (meth)acrylate units contained in the acrylic copolymer intermediate are bonded to the isocyanate groups of the isocyanate group-containing polymerizable monomer through a urethane reaction. As a result, some of the hydroxyl group-containing (meth)acrylate units become polymerizable (meth)acrylate units containing radical polymerizable carbon-carbon double bonds. The urethane reaction can be carried out by a general method. For example, an acrylic copolymer intermediate and an isocyanate-containing polymerizable monomer are stirred while heating in the presence of a solvent and a urethane catalyst. This allows for the urethane bonding of some of the hydroxyl groups of the acrylic copolymer intermediate to the isocyanate groups of the isocyanate-containing polymerizable monomer.

[0124] In the adhesive layer preparation process, for example, an acrylic copolymer, 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.

[0125] In the substrate layer fabrication process, the substrate layer can be fabricated by general methods. Examples of film fabrication 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. Commercially available films may be used as the substrate layer 21, or as each layer constituting the substrate layer 21.

[0126] 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 copolymer, 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.

[0127] These processes enable the manufacture of the dicing tape 20.

[0128] [The process of overlapping the die bond sheet and dicing tape] 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.

[0129] 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 bonding temperature is not particularly limited, but is, for example, 30°C to 50°C, preferably 35°C to 45°C. The bonding pressure is not particularly limited, but is preferably 0.1 kgf / cm to 20 kgf / cm, more preferably 1 kgf / cm to 10 kgf / cm.

[0130] The dicing die bond film 1 manufactured as described above through the process described above is used, for example, as an auxiliary tool for manufacturing semiconductor devices (semiconductor integrated circuits).

[0131] A method for manufacturing a semiconductor device using the above-described dicing die bond film 1 is, for example, A method for manufacturing a semiconductor device having a semiconductor chip, comprising using a dicing die bond film comprising the above-mentioned dicing tape and the above-mentioned die bond sheet superimposed on the dicing tape, The process involves arranging the die bond sheet between the adhesive layer of the dicing tape and the semiconductor wafer, thereby fixing the semiconductor wafer to the dicing tape via the die bond sheet. The process includes the step of breaking the semiconductor wafer into smaller pieces together with the die bond sheet to obtain a plurality of semiconductor chips to which pieces of the die bond sheet are attached.

[0132] The following provides a more detailed explanation of the manufacturing method for semiconductor devices (the method of using dicing die bond film).

[0133] <Method of manufacturing semiconductor devices (Method of using dicing die bond film when manufacturing semiconductor devices)> In semiconductor device manufacturing methods, semiconductor chips are generally cut from a semiconductor wafer on which a 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.

[0134] An example of a method for manufacturing the semiconductor device of this embodiment is: This is a method for manufacturing a semiconductor device having a semiconductor chip, using a dicing die bond film comprising a dicing tape having a base layer and an adhesive layer superimposed on the base layer, and a die bond sheet superimposed on the dicing tape. The semiconductor device manufacturing method of this embodiment includes a mounting step of attaching one side of a semiconductor wafer to the die bond sheet 10 of the dicing die bond film 1 described above, and fixing the semiconductor wafer to the dicing tape 20 via the die bond sheet 10, The process includes an expansion step in which the dicing tape 20 is stretched to cleave the semiconductor wafer together with the die bond sheet 10, using the weak areas of the semiconductor wafer as boundaries. Furthermore, the semiconductor device manufacturing method of this embodiment includes a pickup step of peeling off the small pieces of die bond sheet 10 attached to the adhesive layer 22 of the dicing tape 20 together with the semiconductor chip from the adhesive layer 22.

[0135] More specifically, the semiconductor device manufacturing method of this embodiment includes, for example, a stealth dicing step in which a weak portion is formed inside a semiconductor wafer to which a backgrind tape is attached by laser light, and the semiconductor wafer is prepared to be processed into a semiconductor chip (die) by a cleavage process; a backgrinding step in which the semiconductor wafer to which the backgrind tape is attached is ground to reduce its thickness; a mounting step in which one side of the semiconductor wafer whose thickness has been reduced (for example, the side opposite to the circuit side) is attached to a die bond sheet 10 and the semiconductor wafer is fixed to the dicing tape 20 via the die bond sheet 10; an expanding step in which the semiconductor wafer is cleaved by stretching the dicing tape 20 to produce a semiconductor chip and widen the spacing between adjacent semiconductor chips; and a pickup step in which the die bond sheet 10 and the adhesive layer 22 are peeled apart and the semiconductor chip (die) is removed with the die bond sheet 10 attached. The semiconductor device manufacturing method of this embodiment further includes a die bonding step of adhering a die bond sheet 10 attached to a semiconductor chip to a substrate, a curing step of hardening the die bond sheet 10 adhering to the substrate, a wire bonding step of electrically connecting the electrodes of the electronic circuit on the semiconductor chip to the substrate with wires, and a sealing step of sealing the semiconductor chip and wires on the substrate with a thermosetting resin.

[0136] The stealth dicing process is a step in the so-called SDBG (Stealth Dicing Before Grinding) process. In the stealth dicing process, as shown in Figures 3A to 3C, a vulnerable portion is formed inside the semiconductor wafer W for cleaving the patterned wafer with the circuit surface into semiconductor chips. Specifically, first, a backgrind tape G is attached to the circuit surface of the semiconductor wafer W (see Figure 3A). Next, with the backgrind tape G attached, the semiconductor wafer W is ground with a grinding pad K (pre-backgrinding) until it reaches a predetermined thickness (see Figure 3B). Then, a laser beam is shone on the thinned semiconductor wafer W to form a vulnerable portion inside the semiconductor wafer W (see Figure 3C).

[0137] The dicing die bond film of this embodiment is preferably used in an SDBG (Stealth Dicing Before Grinding) process or a DBG (Dicing Before Grinding) process (described in detail later) for manufacturing semiconductor chips by dicing a semiconductor wafer as described above.

[0138] In the backgrinding process, as shown in Figure 3D, the semiconductor wafer W to which the backgrinding tape G is attached is further ground to reduce the thickness of the semiconductor wafer W until it reaches the thickness of the semiconductor chip (die) that will be produced by the subsequent cleavage process. For example, the half-cut semiconductor wafer W is ground to a predetermined thickness so that it does not become individualized. When this grinding process is performed, the subsequent expand process (especially the low-temperature expand process) will cleave the semiconductor wafer W into semiconductor chips and simultaneously cleave the die bond sheet 10.

[0139] In the mounting process, the semiconductor wafer W is fixed to the dicing tape 20 as shown in Figures 4A and 4B. Specifically, while attaching the dicing ring R to the adhesive layer 22 of the dicing tape 20, the semiconductor wafer W, whose thickness has been reduced by the cutting process described above, is attached to the exposed surface of the die bond sheet 10 (see Figure 4A). Subsequently, the backgrind tape G is peeled off from the semiconductor wafer W (see Figure 4B).

[0140] In the expanding process, as shown in Figures 5A to 5C, the semiconductor wafer W is cleaved to create small semiconductor chips X, and the spacing between the created semiconductor chips X is increased. Specifically, a dicing ring R is attached to the adhesive layer 22 of the dicing tape 20 and then fixed to the holder H of the expanding device (see Figure 5A). The dicing die bond film 1 is stretched in the planar direction by pushing up the push-up member U of the expanding device from below (see Figure 5B). This cleaves the semiconductor wafer W under specific temperature conditions. The above temperature conditions are, for example, -20 to 0°C, preferably -15 to 0°C, and more preferably -10 to -5°C. The expanded state is released by lowering the push-up member U (see Figure 5C; this concludes the low-temperature expanding process). Furthermore, in the expanding process, as shown in Figures 6A to 6B, the dicing tape 20 is stretched to increase its area under higher temperature conditions (e.g., 10°C to 25°C). This pulls adjacent semiconductor chips X apart in the planar direction of the film surface after cleavage, further increasing the kerf (the distance between adjacent semiconductor chips) (room temperature expanding process).

[0141] In this embodiment, the dicing tape 20 is stretched in the planar direction by the expansion process. At this time, if the dicing tape 20 is not heat-treated around the numerous small semiconductor chips, the portion of the dicing tape 20 that overlaps with the numerous semiconductor chips (the central portion) will shrink back to its original shape. To suppress this shrinkage of the dicing tape 20, a portion of the dicing tape 20 along the periphery of the numerous small semiconductor chips is heat-treated. The heat treatment is carried out, for example, so that the surface of the heated portion of the dicing tape 20 reaches a temperature of approximately 90°C to 120°C. In a specific example, the heat treatment is performed on the portion of the dicing tape 20 that does not overlap with the numerous semiconductor chips and is located along the outer periphery of the numerous semiconductor chips.

[0142] Instead of the stealth dicing process, a half-cutting process may be performed. The half-cutting process is a step in the so-called DBG (Dicing Before Grinding) process. In the half-cutting process, grooves are formed in the semiconductor wafer to process it into a semiconductor chip (die) through a cutting process, and then the semiconductor wafer is ground down to reduce its thickness. Specifically, in the half-cut process, as shown in Figures 7A to 7D, a semiconductor wafer with a circuit surface formed on it is subjected to a half-cut process to divide it into semiconductor chips (dies). More specifically, a wafer processing tape T is attached to the side of the semiconductor wafer opposite to the circuit surface. With the wafer processing tape T attached to the semiconductor wafer, a groove for division is formed in the semiconductor wafer using a dicing saw S (dicing blade) or the like. A backgrind tape G is attached to the grooved surface, while the wafer processing tape T that was initially attached is peeled off. With the backgrind tape G attached, the semiconductor wafer is ground until it reaches a predetermined thickness.

[0143] Before the subsequent pick-up process, for example, the adhesive layer 22 superimposed on the base layer 21 is cured by irradiating it with ultraviolet light from the base layer 21 side (curing process).

[0144] In the pickup process, as shown in Figure 8, 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.

[0145] 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. In the die bonding process, multiple semiconductor chips X with small pieces 10' of the die bonding sheet attached may be stacked, for example, as shown in Figure 9.

[0146] In the curing process, a heat treatment is performed at a temperature of, for example, 100°C to 180°C to increase the reaction activity of the crosslinking groups (e.g., glycidyl groups) in the aforementioned crosslinking group-containing acrylic polymer contained in the die bond sheet pieces 10', thereby promoting the curing of the die bond sheet pieces 10'.

[0147] In the wire bonding process, the semiconductor chip X (die) and the substrate Z are heated and connected with a wire L (see, for example, Figure 9).

[0148] In the sealing process, as shown in Figure 10, the semiconductor chip X 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, a heat treatment is performed at a temperature of, for example, 100°C to 180°C to allow the curing reaction of the thermosetting resin M to proceed.

[0149] In recent years, the semiconductor industry has seen a demand for thinner semiconductor chips (for example, with a thickness of 20 μm to 50 μm) and thinner die bond sheets (for example, with a thickness of 1 μm to 40 μm, preferably 7 μm or less, and more preferably 5 μm or less) as integration technology has advanced further.

[0150] In the semiconductor device manufacturing method described above (method of using dicing die bond film), for example, a pick-up step is performed after the expansion step described above. In this case, the die bonding step may be performed in such a way that multiple semiconductor chips with small pieces 10' of the die bond sheet attached are stacked on top of each other. Subsequently, a curing process is performed to harden the multiple small pieces 10' of die bond sheets stacked on top of each other via the semiconductor chip. Then, a wire bonding process is performed to electrically connect the electrodes of the electronic circuit on the semiconductor chip to the adherend with wires. Furthermore, a sealing process may be performed to seal the semiconductor chip and wires on the adherend with a thermosetting resin (such as epoxy resin). On the other hand, the subsequent wire bonding process may be performed without performing the curing process. If the curing process is not performed as described above, the small pieces 10' of the die bond sheet will not harden sufficiently and will remain relatively soft when the subsequent wire bonding and sealing processes are carried out. In the state described above, where multiple small pieces 10' of the die bond sheet are stacked on top of each other via the semiconductor chip, the thermosetting resin used for sealing in the sealing process can easily penetrate into the interior from the interface between the small pieces 10' of the die bond sheet and the semiconductor chip. At this time, regarding the physical properties of the die bond sheet, as mentioned above, the relative value (Q) 0.1 / Q 1.0 The relationship ) is satisfied as 0.8 or higher at 170°C, and furthermore, the complex viscosity at a vibration frequency of 1.0 Hz is 10 kPa·s or higher at 170°C. Therefore, the die bond sheet exhibits so-called "weak gel-type behavior," and thus has relatively high shape retention performance at 170°C. Consequently, it is possible to suppress the penetration of the thermosetting resin used for sealing into the interior of the small pieces 10' of the die bond sheet. Therefore, the die bond sheet 10 of this embodiment can suppress the penetration of the thermosetting resin into the interior when it is sealed with a thermosetting resin while adhered to a semiconductor chip.

[0151] In the die bond sheet 10 of this embodiment, the relatively low proportion of thermosetting resin in the organic components makes it easier for voids that have formed inside to disappear. Specifically, during the sealing process, a portion of the die bond sheet's small pieces 10' can flow to fill the voids (exhibiting embedding properties), thereby suppressing the expansion of internal voids at high temperatures. Therefore, good heat resistance reliability can be achieved.

[0152] The semiconductor device manufactured as described above includes a die bond sheet 10 (a small piece 10' of the die bond sheet) placed between the substrate Z and the semiconductor chip X. The substrate Z is, for example, a substrate or a semiconductor chip X.

[0153] The die bond sheet of this embodiment is as illustrated above, but the present invention is not limited to the die bond sheet illustrated above. In other words, various forms commonly used in die-bond sheets can be adopted as long as they do not impair the effects of the present invention.

[0154] The matters disclosed herein include the following: (1) A die bond sheet containing at least one of a thermosetting resin and a thermoplastic resin as an organic component, When the die bond sheet is subjected to dynamic viscoelasticity measurement, the ratio of the storage modulus G' to the loss modulus G'' (G' / G'') is denoted as Q, and the ratio Q at a vibration frequency of 1.0 Hz is... 1.0 The ratio Q at a vibration frequency of 0.1 Hz 0.1 The relative value of (Q 0.1 / Q 1.0 ) is 0.8 or higher at 170℃, A die bond sheet wherein, when the die bond sheet is subjected to the dynamic viscoelasticity measurement, the complex viscosity at a vibration frequency of 1.0 Hz is 10 kPa·s or more at 170°C. (2) The die bond sheet described in (1) above, having a tensile elongation at break of 10% or less at 0°C. (3) The die bond sheet according to (1) or (2) above, wherein the proportion of the organic component in the die bond sheet is 85% by mass or less. (4) A die bond sheet according to any one of (1) to (3) above, comprising, as an additive, a compound having multiple nitrogen atoms in its molecule, wherein each of the nitrogen atoms is bonded to a crosslinking group. (5) A die bond sheet according to any one of (1) to (4) above, further comprising a filler as an inorganic component, wherein the average primary particle diameter of the filler is 50 nm or more and 500 nm or less. (6) A die bond sheet according to any one of (1) to (5) above, wherein the proportion of the thermosetting resin in the organic component is 15% or less. (7) The die bond sheet according to any one of (1) to (6) above, wherein the thermoplastic resin includes a thermoplastic resin having a carboxyl group or a glycidyl group in its molecule. (8) A die bond sheet according to any one of (1) to (7) above, further comprising a filler as an inorganic component, wherein the filler comprises chain-like silica particles. (9) A die bond sheet as described in any of (1) to (8) above, The dicing tape comprises a base layer and an adhesive layer superimposed on the base layer, A dicing die bond film in which the die bond sheet is superimposed on the adhesive layer of the dicing tape. (10) A semiconductor device comprising a die bond sheet as described in any of (1) to (8) above. [Examples]

[0155] The present invention will be further explained with experimental examples, but the present invention is not limited to these.

[0156] The die bond sheet was manufactured as follows. Furthermore, this die bond sheet was laminated with dicing tape to produce a dicing die bond film.

[0157] <Preparation of Diebond Sheet> [Liquid monomers for acrylic polymers] AN (Acrylonitrile) GMA (Glycidyl methacrylate) AA (acrylic acid) BA (Butyl Acrylate) EA (Ethyl Acrylate) • BMA (butyl methacrylate) (Acrylic polymer) The acrylic polymers shown in Table 1 were synthesized under the following conditions. Specifically, each monomer raw material was placed in a reaction vessel equipped with a condenser, nitrogen inlet tube, thermometer, and stirring device. 0.2 parts by mass of azobisisobutyronitrile (AIBN) was used as a thermal polymerization initiator for every 100 parts by mass of total monomers. Ethyl acetate was added as the reaction solvent to achieve a total monomer concentration of 35% by mass. Polymerization was carried out at 62°C for 5 hours under a nitrogen atmosphere, followed by 75°C for 2 hours, to obtain the acrylic polymers. • Acrylic polymer A (The monomer composition during polymerization is shown in Table 1) Mass-average molecular weight: 140,000, glass transition temperature: -9°C, acid value: 2 [mgKOH / g] • Acrylic polymer B (Monomer composition during polymerization is shown in Table 1) Mass-average molecular weight: 60,000, glass transition temperature: 16°C Theoretical epoxy equivalent: 444 [g / eq] • Acrylic polymer C (monomer composition during polymerization is shown in Table 1) Mass-average molecular weight: 150,000, glass transition temperature: -9°C, acid value: 3 [mgKOH / g] • Acrylic polymer D (The monomer composition during polymerization is shown in Table 1) Mass-average molecular weight: 1,000,000, epoxy value: 0.04 [eq / 100g] Glass transition temperature: 4°C • Acrylic polymer E (commercial product) (Product name: Teisan Resin SG-P3, manufactured by Nagase ChemteX Corporation, glass transition temperature 12°C, contains glycidyl groups, epoxy value: 0.21 [eq / kg]) Mass-average molecular weight: 850,000 • Acrylic polymer F (commercial product) (Product name: "Teisan Resin SG-708-6", manufactured by Nagase ChemteX Corporation, glass transition temperature 4°C, contains carboxyl and hydroxyl groups, acid value: 9 [mgKOH / g]) (contains 20% by mass of solids)

[0158] [Table 1]

[0159] (Epoxy resin) Trisphenolmethane type epoxy resin (Product name "EPPN501HY", manufactured by Nippon Kayaku Co., Ltd.) Epoxy equivalent: 170 [g / eq] Tg: 233℃

[0160] (Phenolic resin) • Biphenylaralkyl type phenolic resin (Product name "MEH-7851H", manufactured by UBE) Hydroxyl group equivalent: 199 [g / eq], Softening temperature: 82℃) • Phenolic novolac resin (Product name "MEHC-7800H", manufactured by UBE) Hydroxyl group equivalent: 178 [g / eq], Softening temperature: 86 ℃) • Biphenyldimethylene type phenolic resin (Product name "MEH-7851SS", manufactured by UBE) Hydroxyl group equivalent: 198 [g / eq], Softening temperature: 66℃)

[0161] (Filler) · Filler a Silica filler (product name "S38", manufactured by CIK Nanotech) Average primary particle diameter 100 nm · Filler b Silica filler (product name "MEK-EC-2130Y", manufactured by Nissan Chemical Corporation) Average primary particle size 12 nm · Filler c Silica filler (product name "SE-2050MCV", manufactured by Admatex Co., Ltd.) Average primary particle diameter 500nm · Filler d Silica filler (product name "MEK-ST-UP", manufactured by Nissan Chemical Corporation) Contains chain-like particles with a particle size of 40-100 nm (dynamic light scattering method).

[0162] (Additives) • Additive I: Silane coupling agent Chemical name: 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (Manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-303") • Additive II: Crosslinking agent Chemical name: 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane (Manufactured by Mitsubishi Gas Chemical Company, product name "TETRAD-C") • Additive III: Crosslinking agent Reaction product of thionyl chloride, tetrahydro-1,3,4,6-tetrakis(2-hydroxyethyl)imidazo[4,5-d]imidazole-2,5(1H,3H)-dione, and thiourea (Manufactured by Shikoku Chemicals Co., Ltd., product name "TS-G")

[0163] (Examples 1-8, Comparative Examples 1-4) [Making a die bond sheet] The composition of the components contained in each die bond sheet is shown in Tables 2A and 2B. Each raw material shown in Tables 2A and 2B was added to a predetermined amount of methyl ethyl ketone and mixed to prepare an adhesive composition solution with a total solids content of 18% by mass. Next, an adhesive composition was applied to the silicone-release surface of a PET release liner, which had a silicone-release treated surface, using an applicator to form a coating film. This coating film was then subjected to a heat-drying treatment at 130°C for 2 minutes to produce a 10 μm thick die-bond sheet on the PET release liner.

[0164] [Table 2A]

[0165] [Table 2B]

[0166] <Measurement of physical properties of die bond sheets> The physical properties of the die bond sheets for each example and comparative example were measured as follows.

[0167] [Dynamic viscoelasticity measurement of die bond sheets] The details of the measurement method for dynamic viscoelasticity are as described above. When Q is the ratio of the storage modulus G' to the loss modulus G'' (G' / G''), the Q at 170°C and a vibration frequency of 1.0 Hz is... 1.0 Q at vibration frequency of 0.1 Hz 0.1 The relative value of (Q 0.1 / Q 1.0 The results are shown in Tables 2A and 2B. Furthermore, the complex viscosity [Pa·s] of each die bond sheet at 170°C is shown in Tables 2A and 2B. As specific examples, the measurement results (measurement charts) of the dynamic viscoelasticity measurement in Example 3 and Comparative Example 3 are shown in Figures 12A and 12B, respectively.

[0168] [Tensile break elongation of Dybond sheet] The details of the measurement method for tensile elongation at fracture are as described above. The measurement results for tensile elongation at fracture at 0°C are shown in Tables 2A and 2B.

[0169] Furthermore, the performance of the die bond sheets manufactured as described above was evaluated as follows.

[0170] <Performance evaluation (performance in suppressing the intrusion of sealing resin)> As described below, substrate chips with small pieces of each die bond sheet attached were bonded to a substrate, and then glass chips with small pieces of each die bond sheet attached were bonded to the substrate chips to prepare evaluation test samples (see Figure 11A). [Materials used, etc.] • PCB chip: Solder-resistant BGA board (manufactured by Daisho Electronics Co., Ltd., product name "CABGA board (AUS308 / AUS410 / SR-1Z) cut to the following size) (A square with sides of 10mm × 250μm thickness) • Glass chips: Cut glass chips (made by Matsunami Co., Ltd.) to the following sizes. (10mm square x 150μm thickness) [Conditions for bonding small pieces of Diebond sheet] ·Temperature: 110℃ • Bonding time: 1 second • Number of tiers: 2 tiers (see Figure 11A) (Shift the glass chip V of the second layer so that it protrudes 600 μm from the first layer.) • Pressure: 4.5 kgf The thickness of the 10' small pieces of the diebond sheet was 20 μm in the first layer and 10 μm in the second layer. [Observation of the degree of penetration of sealing resin] As described above, embedding resin was supplied so that the entirety of the two stacked layers was embedded, and the two layers were sealed by molding at 175°C for 90 seconds. Subsequently, the embedding resin was further cured by heat treatment at 175°C for 5 hours. Next, the cured embedding resin was polished until the top surface of the second layer of glass chip was exposed (see Figure 11B). Then, the area enclosed by the dashed line in Figure 11B was observed from above at 200x magnification using an optical microscope. The penetration distance (amount of penetration) of the embedding resin that had penetrated from the edge of the first layer of substrate chip into the interior was measured. The results are shown in Tables 2A and 2B. Figure 13 shows a micrograph illustrating the penetration of the embedding resin. This photograph is provided for reference only and is not part of the above-mentioned examples or comparative examples. Figure 13 is an optical microscope image observed from one side in the thickness direction of the laminate as described above. The area enclosed by the dashed line indicates the area where the embedding resin has penetrated.

[0171] <Performance Evaluation (Heat Resistance Reliability)> The heat resistance reliability of each die bond sheet was evaluated as follows. [Test Samples for Evaluation] · Bare wafer before dicing: Mirror-finished silicon wafer · Chip (die) size: Square with 10 mm sides × 50 μm thickness · Number of chip (die) layers: 2 layers · Thickness of each die bond sheet: 20 μm · Adhered body (substrate): AUS308 (manufactured by Daechang Electronics Co., Ltd.) [Evaluation Test Conditions] · Chip (die) adhesion: 120 °C, 0.1 MPa, 1 second · Applied heat history: Up to 130 °C, 8 hours · Molding conditions: 175 °C, 90 seconds · Post-mold cure (PMC): 175 °C, 5 hours · Reflow conditions: 260 °C, MSL2 · After bonding the chips, after varying the time for applying the above heat history, the presence or absence of delamination at the substrate-chip interface or at the chip-chip interface (due to the so-called popcorn phenomenon) was confirmed under reflow conditions. The heat resistance reliability was evaluated based on the length of the time for applying the heat history. The longer such time, the higher the heat resistance reliability. In addition, the presence or absence of delamination was confirmed by ultrasonic flaw detection inspection (SAT observation). The results are shown in Table 2A and Table 2B.

[0172] <Performance Evaluation (Die Bond Sheet Cleavability)> [Preparation of Samples for Evaluation] A dicing die bond film with chips (dies) prepared using a bare wafer was prepared and used as a sample for evaluation. [Preparation of Wafer] First, a wafer processing tape (product name "UB-3083D", manufactured by Nitto Denko Corporation) was attached to the first surface of a bare wafer (12 inches in diameter, 780 μm thick, manufactured by Tokyo Chemical Industry Co., Ltd.) where the modified region was to be formed. Next, a stealth dicing device (product name "DAL7360 (SDE05)", Power: 0.25 W, Frequency: 80 kHz, manufactured by Disco Corporation) was used to form a modified region inside this bare wafer. Specifically, a laser beam focused on the side of the wafer closest to the first surface was irradiated from the back side (second surface) opposite to the first surface. Irradiation was performed in BHC mode along the planned lines for dividing the bare wafer. As a result, ablation by multiphoton absorption formed a modified region for fragmentation inside the wafer (50 μm deep from the first surface of the wafer), creating a grid of 4 mm × 12 mm sections. Subsequently, using a backgrinding device (product name "DGP8760," manufactured by Disco Corporation), the wafer was thinned to a thickness of 30 μm by grinding from the second surface. In this way, a wafer was formed that was held on a wafer processing tape. This wafer contains sections for fragmenting the wafer into multiple chips (4 mm x 12 mm). [Chip (die) manufacturing] The bare wafer prepared as described above was attached to a dicing die bond film. The bare wafer, while attached to the dicing die bond film, was then cleaved into smaller pieces using an expansion process. The expansion process was performed using a die separator (product name "Die Separator DDS2300, manufactured by Disco Corporation") with the wafer processing tape removed from the bare wafer. In the expansion process, cool expansion was performed first, followed by room temperature expansion. Cool expansion was performed as follows. Specifically, a 12-inch diameter stainless steel ring frame (manufactured by Disco Corporation) was attached at room temperature to the area on the adhesive layer of the dicing die bond film attached to the bare wafer where the frame was to be attached. Next, the bare wafer with the stainless steel ring frame attached was mounted in a die separator. Then, using a cool expander unit, the wafer and die bond sheet were cut under the conditions of an expansion temperature of 0°C, an expansion speed of 200 mm / second, and an expansion amount of 12 mm to obtain multiple chips with die bond sheet layers. Furthermore, room temperature expansion was performed under conditions of room temperature, expansion speed of 10 mm / sec, and expansion amount of 8 mm. Then, while maintaining the expanded state, the dicing tape surrounding the outer edge of the wafer was thermally shrunk by a heater under conditions of heat temperature of 250°C, heat distance of 20 mm, and rotation speed of 3° / sec. After that, a cooling process was performed for 30 seconds in a static state. [Breakability of Dybond Sheets] After the thermal shrinkage and cooling described above, light was shone from the back of the tape, and the entire surface was observed to check whether the chip and die bond sheet had fractured. A more detailed examination was performed using a microscope. We checked the number of chips that were successfully fractured along with the die bond sheet out of the total number of chips that should have been fractured. A fracture rate of 100% was evaluated as "good (○)", and all other cases were evaluated as "poor (×)". The results are shown in Tables 2A and 2B.

[0173] As can be seen from the evaluation results above, the die bond sheet of the example can suppress the penetration of the thermosetting resin into the interior of the semiconductor chip when it is sealed with the thermosetting resin while bonded to the semiconductor chip, compared to the die bond sheet of the comparative example. Furthermore, the specific die bond sheets in the examples also possessed good cleavage properties, enabling them to cleanly cleave semiconductor wafers. In addition, the specific die bond sheets in the examples also possessed good heat resistance reliability. [Industrial applicability]

[0174] The die bond sheet of the present invention is suitably used, for example, as an auxiliary tool when manufacturing semiconductor devices (semiconductor integrated circuits). [Explanation of Symbols]

[0175] 1: Dicing die bond film, 10: Diebond sheet, 20: Dicing tape, 21: Base material layer, 22: Adhesive layer.

Claims

1. A die bond sheet containing at least one of a thermosetting resin and a thermoplastic resin as an organic component, When the die bond sheet is subjected to dynamic viscoelasticity measurement, the ratio of the storage modulus G' to the loss modulus G'' (G' / G'') is denoted as Q, and the ratio Q at a vibration frequency of 1.0 Hz is... １．０ The ratio Q at a vibration frequency of 0.1 Hz ０．１ The relative value of (Q ０．１ / Q １．０ ) is 0.8 or higher at 170°C, A die bond sheet wherein, when the die bond sheet is subjected to the dynamic viscoelasticity measurement, the complex viscosity at a vibration frequency of 1.0 Hz is 10 kPa·s or more at 170°C.

2. The die bond sheet according to claim 1, having a tensile elongation at break of 10% or less at 0°C.

3. The die bond sheet according to claim 1 or 2, wherein the proportion of the organic component in the die bond sheet is 85% by mass or less.

4. The die bond sheet according to claim 1 or 2, comprising, as an additive, a compound having a plurality of nitrogen atoms in its molecule, wherein each of the nitrogen atoms is bonded to a crosslinking group.

5. The die bond sheet according to claim 1 or 2, further comprising a filler as an inorganic component, wherein the average primary particle diameter of the filler is 50 nm or more and 500 nm or less.

6. The die bond sheet according to claim 1 or 2, wherein the proportion of the thermosetting resin in the organic component is 15% or less.

7. The die bond sheet according to claim 1 or 2, wherein the thermoplastic resin includes a thermoplastic resin having a carboxyl group or a glycidyl group in its molecule.

8. A die bond sheet according to claim 1 or 2, The dicing tape comprises a base layer and an adhesive layer superimposed on the base layer, A dicing die bond film in which the die bond sheet is superimposed on the adhesive layer of the dicing tape.

9. A semiconductor device comprising the die bond sheet according to claim 1 or 2.

Images