TWI851723B - Die-cut-die bonding integrated film and method for manufacturing semiconductor device - Google Patents

Abstract

The pickup evaluation method disclosed in the present invention comprises: preparing a wafer-cut-and-bond integrated film as an evaluation object, wherein the wafer-cut-and-bond integrated film comprises a substrate layer, an adhesive layer and a bonding agent layer in sequence; a first measurement step of measuring the adhesion of the adhesive layer to the bonding agent layer under a peeling angle of 30°; a step of bonding a wafer having a thickness of 10 μm to 100 μm to the bonding agent layer of the wafer-cut-and-bond integrated film; singulating the wafer and the bonding agent layer into a 9 mm area wafer; ² or below with a chip having an adhesive sheet; and a second measuring step of pressing the center of the chip having the adhesive sheet from the substrate layer side to measure the edge peeling strength when the edge of the chip having the adhesive sheet is peeled off from the adhesive layer.

Description

Method for manufacturing a wafer-cutting-and-bonding integrated film and a semiconductor device

The present disclosure relates to a pickup evaluation method, a wafer-cut-and-bond integrated film, a wafer-cut-and-bond integrated film evaluation method and selection method, and a semiconductor device manufacturing method.

Semiconductor devices are manufactured through the following steps. First, the wafer cutting step is performed with the wafer cutting adhesive film attached to the wafer. Then, the expansion step, pickup step, mounting step, and die bonding step are performed.

In the manufacturing process of semiconductor devices, a film called a dicing-bonding integrated film is used (see Patent Document 1 and Patent Document 2). The film has a structure in which a base layer, an adhesive layer, and a bonding agent layer are sequentially laminated, and is used, for example, in the following manner. First, the wafer is diced while the bonding agent layer is attached to the surface of the wafer and the wafer is fixed by a dicing ring. In this way, the wafer is singulated into a plurality of chips. Next, after the adhesive layer is irradiated with ultraviolet light to weaken the adhesive force of the adhesive layer relative to the bonding agent layer, the chip is picked up from the adhesive layer together with the bonding agent sheet formed by singulating the chip together. After that, the semiconductor device is manufactured by mounting the chip on a substrate via the bonding agent sheet. Hereinafter, the laminated body of the chip and the bonding agent sheet is referred to as a "chip with bonding agent sheet" as the case may be.

As described above, an adhesive layer (cut-die film) whose adhesive force is weakened by ultraviolet irradiation is called an ultraviolet (UV) curing type. In contrast, an adhesive layer whose adhesive force remains constant without ultraviolet irradiation during the semiconductor device manufacturing process is called a pressure-sensitive type. A cut-die-bond integrated film having a pressure-sensitive adhesive layer has the following advantages: the user (mainly a semiconductor device manufacturer) does not need to perform the ultraviolet irradiation step, and the equipment used for this step is not required. Patent document 3 discloses a wafer-bonding film, which can be called a UV-curing type in that the adhesive layer contains a component that is cured by ultraviolet rays, and can also be called a pressure-sensitive type in that only a specified portion of the adhesive layer is pre-irradiated with ultraviolet rays, and the user does not need to irradiate ultraviolet rays during the manufacturing process of the semiconductor device.

[Prior art literature]

[Patent Literature]

[Patent document 1] Japanese Patent Publication No. 2012-069586

[Patent Document 2] Japanese Patent Publication No. 2014-135469

[Patent Document 3] Japanese Patent No. 4443962

The adhesive layer of the die-attach film is required to have high adhesion to the adhesive layer and the die ring during the die-cutting step. If the adhesive layer has insufficient adhesion, the die-cutting blade may rotate at high speed, causing the adhesive layer to peel off from the adhesive layer, causing the die with the adhesive film to fly (hereinafter referred to as "DAF flying"; DAF is a die attach film); or the die ring may peel off from the adhesive layer due to the flow of cutting water (hereinafter referred to as "ring peeling"). On the other hand, in the picking step, from the perspective of excellent picking performance, the adhesion of the adhesive layer to the adhesive layer is required to be somewhat low. If the adhesion of the adhesive layer is too strong, the chip with the adhesive sheet will not be peeled off from the adhesive layer, resulting in poor picking, or chip cracking, and reduced yield.

However, the inventors of the present invention have found that when a wafer is singulated into small chips (e.g., with a top view area of less than ⁹ mm2) by dicing, a unique picking behavior is exhibited in the subsequent picking step in terms of previous understanding. That is, if a chip of a relatively large size (e.g., 8 mm in length × 6 mm in width) is picked up, even if the adhesive force of the adhesive layer is reduced to a level that can achieve excellent picking performance, the picking performance will be insufficient when the chip is a small chip. The inventors of the present invention have conducted in-depth research on the main cause thereof, and as a result, have come to the conclusion that, in the case of small chips, the peeling of the edge of the chip from the adhesive layer (hereinafter referred to as "edge peeling") is the dominant factor in the pickup performance.

According to the research conducted by the inventors, it is speculated that in the case of a larger chip, the peeling of the interface between the chip surface and the adhesive layer (hereinafter referred to as "interface peeling") is the dominant factor in the pick-up performance, compared with the edge of the chip. That is, when a large chip (e.g., the area of the chip in a top view exceeds 20 mm ² ) is picked up by pushing up the center of the chip from below using the pins of the push-up fixture, as the pins rise, although the interface peeling of the adhesive layer and the bonding agent sheet progresses from the edge of the chip to the center, if the adhesive force of the adhesive layer to the bonding agent layer is too strong, the interface peeling cannot catch up with the rise of the pins, so that the chip is cracked or a pick-up error is easily caused. That is, the inventors have found that the pickup of large chips is mainly governed by the interfacial peeling between the adhesive layer and the adhesive sheet, and the adhesion of the adhesive layer should be set to a value as small as possible (for example, less than 1.2N/25mm).

In contrast, the inventors and others have found that the pick-up performance of small chips is mainly dominated by the edge peeling strength of the chip with the adhesive sheet. Once the edge peeling occurs due to the upward push caused by the pin, the interface peeling between the adhesive layer and the adhesive sheet proceeds smoothly. Therefore, even if the adhesive layer has a strong adhesion, excellent pick-up performance can be achieved in the case of small chips. In addition, the strong adhesion of the adhesive layer can fully suppress the DAF scattering in the crystal cutting step.

The inventors of the present invention conducted further research and found that if the adhesive layer has an adhesion force of more than 3.0N/25mm to the adhesive sheet, even for small chips, interface peeling is not easy to develop, and there is a tendency for pickup errors to increase. Based on this insight, the inventors of the present invention found that by suppressing the edge peeling strength to less than 1.2N and setting the adhesive layer adhesion to less than 3.0N/25mm, better pickup performance can be obtained.

The present disclosure provides an evaluation method and a selection method of a wafer-on-chip integrated film that considers the effects of edge peeling and interface peeling of small chips (area of less than ⁹ mm2). In addition, the present disclosure provides an evaluation method of pickup performance that considers the effects of edge peeling and interface peeling of small chips, and a wafer-on-chip integrated film with excellent pickup performance for small chips and a method for manufacturing a semiconductor device using the same.

One aspect of the present disclosure is a method for evaluating a wafer-cut-and-bond film. The evaluation method is used to evaluate the pick-up property of the wafer-cut-and-bond film used in a semiconductor device manufacturing process, wherein the semiconductor device manufacturing process includes a step of singulating a wafer into a plurality of chips with an area of 9 mm ² or less. The evaluation method includes the following steps (A) to (E), and when the peel strength (adhesion of the adhesive layer) measured in step (B) is 3.0 N/25 mm or less and the edge peel strength measured in step (E) is 1.2 N or less, the wafer-cut-and-bond film is judged to have good pick-up property.

(A) preparing a wafer-cut-and-bonded integrated film as an evaluation object, wherein the wafer-cut-and-bonded integrated film includes a substrate layer, an adhesive layer and a bonding agent layer, wherein the adhesive layer has a first surface facing the substrate layer and a second surface opposite thereto, and the bonding agent layer is arranged so as to cover the central portion of the second surface of the adhesive layer; (B) a first measuring step of measuring the peeling strength of the adhesive layer from the bonding agent layer at a temperature of 23° C., a peeling angle of 30°, and a peeling speed of 60 mm/min; (C) measuring the peeling strength of the wafer-cut-and-bonded integrated film at a temperature of 23° C., a peeling angle of 30°, and a peeling speed of 60 mm/min. (D) The step of bonding a 50μm thick silicon wafer to the adhesive layer of the mold film, and bonding a diced ring to the second side of the adhesive layer; (D) The step of singulating the silicon wafer and the adhesive layer into a plurality of chips with adhesive sheets to obtain square chips with a side length of 2mm with adhesive sheets; (E) The second measurement step of pressing the center of the chip with adhesive sheet from the substrate layer side at a temperature of 23°C at a speed of 60mm/min to measure the edge peel strength of the edge of the chip with adhesive sheet when it is peeled off from the adhesive layer.

According to the research of the inventors and others, by measuring the edge peeling strength under the above conditions (thickness of the silicon wafer and the size of the wafer with the adhesive sheet, etc.), a measurement result with sufficiently high reproducibility can be obtained. In addition, by measuring the peeling strength of the adhesive layer from the adhesive layer under the condition of a peeling angle of 30°, the quality of the interface peeling property can be judged. Therefore, even if the pick-up is not actually performed using the die bonding device used in the manufacture of semiconductor devices, the pick-up property of the wafer-bonding integrated film can be efficiently evaluated. This evaluation method is useful, for example, in efficiently selecting a wafer-bonding integrated film suitable for a new manufacturing process when there are certain changes in the manufacturing process of the semiconductor device.

One aspect of the present disclosure is to evaluate the pick-up performance in a semiconductor device manufacturing process using a die-cut-die-bond film. The evaluation method includes the following steps.

(i) preparing a cut-and-bond film as an evaluation object, wherein the cut-and-bond film comprises a substrate layer, an adhesive layer and a bonding agent layer, wherein the adhesive layer has a first surface facing the substrate layer and a second surface opposite thereto, and the bonding agent layer is arranged so as to cover the central portion of the second surface of the adhesive layer; (ii) performing a first test (iii) bonding a wafer with a thickness of 10 μm to 100 μm to the adhesive layer of the wafer-bonding film and bonding a wafer ring to the second side of the adhesive layer; (iv) singulating the wafer and the adhesive layer into a 9 mm2 wafer. (v) a second measuring step of pressing the center of the chip with the bonding agent sheet from the substrate layer side and measuring the edge peeling strength of the edge of the chip with the bonding agent sheet ^when it is peeled off from the adhesive layer.

One aspect of the present disclosure is related to a wafer-cutting-bonding film. The wafer-cutting-bonding film includes: a substrate layer; an adhesive layer having a first surface facing the substrate layer and a second surface opposite thereto; and a bonding agent layer arranged to cover the central portion of the second surface of the adhesive layer, and the peeling strength of the adhesive layer from the bonding agent layer is measured at a temperature of 23°C, a peeling angle of 30°, and a peeling speed of 60 mm/min. The peeling strength is less than 3.0 N/25 mm and the edge peeling strength measured by the following steps is less than 1.2 N.

<Measurement of edge peeling strength>

． The step of attaching a 50μm thick silicon wafer to the adhesive layer and attaching a wafer cut ring to the second side of the adhesive layer; ． The step of singulating the silicon wafer and the adhesive layer into a plurality of wafers with adhesive sheets to obtain a square wafer with an edge length of 2mm with adhesive sheets; ． The step of pressing the center of the wafer with adhesive sheets from the substrate layer side at a speed of 60mm/min at a temperature of 23°C and measuring the edge peeling strength of the edge of the wafer with adhesive sheets when it is peeled off from the adhesive layer.

The wafer-cutting-and-bonding integrated film has an edge peel strength of less than 1.2N for a chip (size: 2mm×2mm) with an adhesive sheet and a peel strength of less than 3.0N/25mm for the adhesive layer from the adhesive layer, and can achieve excellent pickup properties in a semiconductor device manufacturing process including the step of singulating a wafer into multiple chips with an area of less than ^9mm2 .

When the bonding agent layer is singulated together with the wafer by cutting with a blade, burrs are easily generated at the edge of the bonding agent layer, and the edge peeling strength of the chip with the bonding agent sheet tends to be improved. The cutting-bonding integrated film is preferably such that even when multiple chips with bonding agent sheets are obtained by cutting with a blade, the conditions of edge peeling strength and interface peeling strength of the chip with bonding agent sheet are met respectively. In order to make the cutting-bonding integrated film meet these conditions, for example, the following technical means can be appropriately adopted.

． By making the adhesive layer higher in viscosity (higher elasticity) or thinner (e.g. less than 60μm), the cutting performance of the adhesive layer during blade cutting can be improved.

． By changing the amount of the adhesive layer components (such as the crosslinking agent or photopolymerization initiator), the adhesive layer can be made more elastic or the adhesive force can be adjusted.

．Reduce the elongation at break of the substrate layer.

． Make the adhesive layer thicker (for example, more than 30μm) to prevent the blade from cutting into the substrate layer when dicing.

One aspect of the present disclosure is a method for manufacturing a semiconductor device. The method includes: preparing the wafer-bonding integrated film; bonding a wafer to the adhesive layer of the wafer-bonding integrated film and bonding a wafer ring to the second side of the adhesive layer; singulating the wafer and the adhesive layer into a plurality of chips with an area of 9 mm2 ^or less with adhesive chips; picking up the chips with adhesive chips from the adhesive layer; and mounting the chips with adhesive chips on a substrate or other chips. According to the method for manufacturing a semiconductor device, excellent pick-up performance of the chips with adhesive chips can be achieved, and semiconductor devices can be manufactured with a sufficiently high yield.

One aspect of the present disclosure is a method for selecting a die-cut and die-bond integrated film. According to the following selection method, a die-cut and die-bond integrated film capable of manufacturing semiconductor devices with high yield can be efficiently selected. The first aspect of the selection method of the wafer-cut-and-bond integrated film includes: preparing two or more wafer-cut-and-bond integrated films, wherein the two or more wafer-cut-and-bond integrated films respectively include a substrate layer, an adhesive layer and a bonding agent layer, wherein the adhesive layer has a first surface facing the substrate layer and a second surface opposite thereto, and the bonding agent layer is arranged in a manner covering the central portion of the second surface of the adhesive layer; and comparing the peeling strength and edge peeling strength of the adhesive layer from the bonding agent layer of the two or more wafer-cut-and-bond integrated films.

A second aspect of the method for selecting a wafer-cutting-die-bonding integrated film includes: preparing a plurality of wafer-cutting-die-bonding integrated films, wherein the plurality of wafer-cutting-die-bonding integrated films include a substrate layer, an adhesive layer, and a bonding agent layer, wherein the adhesive layer has a first surface facing the substrate layer and a second surface opposite thereto, and the bonding agent layer covers the center of the second surface of the adhesive layer. The peel strength of the adhesive layer from the bonding agent layer is less than 3.0N/25mm; and for multiple cut-die-bonded films, the edge peel strength measured by the following steps is checked to see if it is less than 1.2N.

<Measurement of edge peeling strength>

． The step of attaching a 50μm thick silicon wafer to the adhesive layer and attaching a diced ring to the second side of the adhesive layer; ． The step of singulating the silicon wafer and the adhesive layer into a plurality of chips with adhesive chips to obtain square chips with a side length of 2mm with adhesive chips; ． The step of pressing the center of the chip with adhesive chips from the substrate layer side at a speed of 60mm/min at a temperature of 23°C and measuring the edge peeling strength of the chip with adhesive chips when the edge is peeled from the adhesive layer.

According to the present disclosure, a method for evaluating and selecting a wafer-cut-and-bond integrated film is provided, which takes into account the influence of edge peeling and interface peeling of small chips (area of less than ⁹ mm2). In addition, according to the present disclosure, a method for evaluating the pickup performance is provided, which takes into account the influence of edge peeling and interface peeling of small chips, and a method for manufacturing a wafer-cut-and-bond integrated film with excellent pickup performance for small chips and a semiconductor device using the same.

1: Base material layer

3: Adhesive layer

3a: First area

3b: Second area

5: Next is the agent layer

5c: Hardened material

5p: Next tablet

10: Crystal cutting-crystal bonding-body film

42: Sales

44: Suction chuck

50: Sealing layer

60:Structure

70: Substrate

80: Support plate

100:Semiconductor devices

A: Measurement area

B-B: section line

DR: Cutting Ring

F1: First page

F2: Second side

M:Mark

N: Gap

P: Press-in clamp

Rw: Region

T1, T2, T3, T4, Ts: Chip

Ta, Tb: Chip with adhesive

W: Wafer

Ws:Silicon wafer

W1, W2, W3, W4: Conductor

FIG1(a) is a plan view showing an implementation form of a wafer-bonding integrated film, and FIG1(b) is a schematic cross-sectional view along the B-B line shown in FIG1(a).

Figure 2 is a cross-sectional view schematically showing the steps for measuring edge peeling strength.

Figure 3 is a graph showing an example of the relationship between the displacement (mm) caused by pressing and the pressing force (N).

FIG4 is a plan view schematically showing a state where a mark is added to a position corresponding to the center of a wafer to be measured.

FIG5 is a plan view schematically showing an example of the measurement area of edge peeling strength.

Figure 6 is a cross-sectional view schematically showing the measurement of the 30° peel strength of the adhesive layer relative to the adhesive layer.

FIG7 is a schematic cross-sectional view of an embodiment of a semiconductor device.

FIG8 is a cross-sectional view schematically showing the process of manufacturing a wafer with a bonding agent.

FIG9 is a cross-sectional view schematically showing the process of manufacturing the semiconductor device shown in FIG7.

FIG10 is a cross-sectional view schematically showing the process of manufacturing the semiconductor device shown in FIG7.

FIG11 is a cross-sectional view schematically showing the process of manufacturing the semiconductor device shown in FIG7.

The following is a detailed description of the embodiments of the present disclosure with reference to the drawings. However, the present invention is not limited to the following embodiments. Furthermore, in this specification, "(meth)acrylic acid" refers to acrylic acid or methacrylic acid, and "(meth)acrylate" refers to acrylate or its corresponding methacrylate. The so-called "A or B" only needs to include either A or B, or both.

In this specification, the term "layer" includes not only structures with shapes formed on the entire surface, but also structures with shapes formed partially when viewed in a plan view. In addition, in this specification, the term "step" refers not only to independent steps, but also to steps that cannot be clearly distinguished from other steps as long as the intended effect of the step can be achieved. In addition, the numerical range expressed by "~" indicates a range that includes the numerical values before and after "~" as the minimum and maximum values, respectively.

In this specification, when there are multiple substances corresponding to each component in the composition, unless otherwise specified, the content of each component in the composition refers to the total amount of the multiple substances present in the composition. In addition, unless otherwise specified, the exemplified materials can be used alone or in combination of two or more. In addition, in the numerical ranges recorded in stages in this specification, the upper limit or lower limit of the numerical range of a certain stage can also be replaced by the upper limit or lower limit of the numerical range of another stage. In addition, in the numerical ranges recorded in this specification, the upper limit or lower limit of the numerical range can also be replaced by the value shown in the embodiment.

<Crystal cutting-crystal bonding one-piece film>

FIG. 1( a ) is a plan view of a wafer-cut-and-bond integrated film of the present embodiment, and FIG. 1( b ) is a schematic cross-sectional view along line BB of FIG. 1( a ). The wafer-cut-and-bond integrated film 10 (hereinafter referred to as “film 10 ” as the case may be) can be applied to a semiconductor device manufacturing process, wherein the semiconductor device manufacturing process includes a wafer-cutting step of singulating a wafer W into a plurality of chips with an area of 9 mm ² or less and a subsequent picking-up step (see FIG. 8( c ) and FIG. 8( d )).

The film 10 includes, in order: a substrate layer 1, an adhesive layer 3 having a first surface F1 facing the substrate layer 1 and a second surface F2 opposite thereto, and an adhesive layer 5 provided to cover the central portion of the second surface F2 of the adhesive layer 3. In the present embodiment, a square substrate layer 1 is illustrated, but the substrate layer 1 may also be circular and have the same size as the adhesive layer 3. In addition, in this embodiment, an example is shown in which a laminate of an adhesive layer 3 and an adhesive layer 5 is formed on a base layer 1. Alternatively, the base layer 1 may have a predetermined length (e.g., more than 100 m) and the laminate of the adhesive layer 3 and the adhesive layer 5 may be arranged at predetermined intervals in a manner arranged along its long side direction.

The edge peel strength of the film 10 is less than 1.2N. The edge peel strength is measured through the following steps. The upper limit of the edge peel strength of the film 10 can be 1.1N or 0.9N, and the lower limit is, for example, 0.1N, or 0.15N or 0.2N.

<Measurement of edge peeling strength>

． A step of adhering a 50μm thick silicon wafer Ws to the adhesive layer 5 and adhering a diced ring DR to the second surface F2 of the adhesive layer 3 (see (a) in FIG2 ); ． A step of singulating the silicon wafer Ws and the adhesive layer 5 into a plurality of chips Ta with adhesive chips (hereinafter referred to as "chips Ta" as the case may be) (see (b) in FIG2 ); ． A step of pressing the center of the chip Ta from the substrate layer 1 side at a speed of 60mm/min at a temperature of 23°C (see (c) in FIG2 ) and measuring the edge peeling strength of the chip Ta when the edge is peeled from the adhesive layer 3.

Since the edge peel strength of the film 10 is within the above range, the film 10 can be evaluated as being suitable for a dicing step of singulating a wafer into a plurality of small chips with an area of 9 mm ² or less and a subsequent picking step.

As shown in FIG2(b), the chip Ta includes a chip Ts and an adhesive layer 5p. The step of singulating the silicon wafer Ws and the adhesive layer 5 into a plurality of chips Ta can be performed, for example, by cutting with a blade under the following conditions.

<Crystal cutting conditions>

．Crystal cutting machine: DFD6361 (manufactured by DISCO Co., Ltd.)

． Blade: ZH05-SD4000-N1-70-BB (manufactured by DISCO Co., Ltd.)

． Blade speed: 40000rpm

．Crystal cutting speed: 30mm/sec

．Blade height: 90μm

． Cutting depth from the surface of adhesive layer 3: 20μm

． Shape of chip Ta when viewed from above: 2mm×2mm square

As for the type of blade, in order to ensure the processing quality of the chip and to suppress the cutting chips (burrs) generated from the base material layer 1, etc., if the blade is manufactured by DISCO Co., Ltd., it is better to use a blade with a fine particle size of #4000~#4800.

The reason for using a silicon wafer Ws with a thickness of 50 μm is as follows. For example, when the thickness of the silicon wafer is 30 μm or less, problems such as wafer defects and wafer breakage are likely to occur when singulation is performed by cutting with a blade. In addition, there is a risk of wafer breakage when the edge peel strength is measured. On the other hand, for example, when the thickness of the silicon wafer is 80 μm or more, step cutting is sometimes required when singulation is performed by cutting with a blade, so the selection of the blade and the setting of the conditions become difficult. In addition, if the wafer is thick, the wafer is less likely to bend when the edge peel strength is measured, so the peelability of the edge becomes good, and it is also possible that differences between films are less likely to occur. In addition, as semiconductor wafers have been thinning in recent years, 50μm thick silicon wafers are also used to match market trends.

The reason why the size of the wafer Ta with adhesive is set to 2mm×2mm is as follows. For example, when the size of the wafer Ta with adhesive is set to 1mm×1mm, the distance between the center of the wafer (the part where the pressure is applied to the wafer) and the edge is too close, so the peeling property of the edge becomes good, and the difference between films may not easily appear. In addition, since the wafer is too small, it is difficult to mark the center of the wafer, and under visual observation without marking, measurement errors may occur due to position deviation. On the other hand, for example, when the size of the chip Ta with the adhesive sheet is set to 3mm×3mm, when measuring the peeling strength of the chip edge, the distance between the center of the chip and the edge is too far, so the pressure caused by the press becomes difficult to transmit, and it is difficult to accurately measure the edge peeling strength. In addition, a large amount of press is required to peel the edge, and there is a risk that the chip will bend significantly and break during the measurement.

In the step of measuring the edge peeling strength, as shown in FIG2(c), the center of the chip Ta is pressed in from the substrate layer 1 side using a pressing jig P. For example, the edge peeling strength can be measured under the following conditions using the following device, etc.

<Measurement conditions>

． Measuring device: Small desktop testing machine EZ-SX (manufactured by Shimadzu Corporation)

．Load cell: 50N

． Press-in fixture: ZTS series accessory (shape: cone-shaped, manufactured by IMADA Co., Ltd.)

． Pressing speed: 60mm/min

．Temperature: 23℃

．Humidity: 45±10%

FIG3 is a graph showing an example of the relationship between the displacement (mm) caused by pressing and the pressing force (N). When the edge of the chip is peeled off, as shown in FIG3, the pressing force temporarily decreases and a change point occurs in the graph. The value of the pressing force at this change point is taken as the edge peeling strength.

When measuring the edge peeling strength, it is better to mark the position of the substrate layer 1 corresponding to the center of the chip Ta in advance using an oil pen or the like. By marking in advance, the measurement can be performed with good accuracy, and the alignment becomes easier, thereby improving the measurement efficiency.

The reason for setting the pressing speed to 60 mm/min is as follows. That is, the pressing speed is preferably 60 mm/min to 1200 mm/min (1 mm/sec to 20 mm/sec) in the sense of matching the actual pickup conditions. For example, if the pressing speed is too fast, a pressing force greater than necessary is applied to the sample during the period from the edge peeling off to the stopping of the pressing, and the wafer around the wafer to be measured may be peeled off, or the substrate layer may be broken, which may have an adverse effect on subsequent measurements. Therefore, a pressing speed as low as possible within the above range is selected.

It is preferred to measure the edge peeling strength of multiple chips Ta and set the average value of the multiple measured values as the edge peeling strength of the film 10. For example, it is sufficient to measure more than 5 (preferably 10 to 20) chips Ta to calculate the average value. When the edge peeling strength of the second chip Ta is measured after the edge peeling strength of the first chip Ta is measured, it is preferred that the second chip Ta is sufficiently separated from the first chip Ta to prevent the pressure on the first chip Ta from affecting the second chip Ta. For example, it is preferred that there are more than two chips Ta between the first chip Ta and the second chip Ta. FIG. 4 is a plan view schematically showing a state in which a mark M is added at a position corresponding to the central portion of the chip to be measured. In this figure, there is a gap of three chips between two chips Ta to be measured.

When the silicon wafer Ws is a 12-inch wafer, it is preferable to measure a plurality of wafers Ta in the measurement area A shown in FIG5 . That is, as shown in FIG5 , when the position of the notch N of the wafer cutting ring DR is set above the paper surface, it is preferable to measure in an area of 80 mm×20 mm at a distance of 50 mm from the end of the lower side of the silicon wafer Ws. There are differences in the tension of the substrate layer 1 and the elongation of the substrate layer 1 during pressing at the end and the center of the silicon wafer Ws, so the measured value may deviate depending on the position. The same setting as the measurement area can also be applied to the case of an 8-inch wafer. Furthermore, the measurement area A is not limited to the position shown in FIG. 5 , and for example, it may be the upper side, left side, or right side in FIG. 5 as long as it is separated from the end of the wafer Ws by a specified distance.

Furthermore, in addition to evaluating the pick-up performance by measuring the edge peel strength, the pick-up performance can also be evaluated by actually picking up the same sample using a die bonder. In this case, it is better to first measure the edge peel strength. Pick-up using a die bonder is usually performed in a state where the substrate film is expanded. After the expanded state is released, there is a possibility that the relaxation of the substrate layer 1 caused by the expansion cannot be restored, and there is a risk that it is difficult to measure the edge peel strength with good accuracy.

The adhesion of the first area 3a to the adhesive layer 5 is less than 3.0N/25mm. The upper limit of the adhesion may be 2.75N/25mm or 2.5N/25mm. The adhesion is the 30° peel strength measured at a temperature of 23°C, a peel angle of 30°, and a peel speed of 60mm/min. FIG6 is a cross-sectional view schematically showing the state in which the adhesive layer 5 of the test sample (width 25mm×length 100mm) is fixed to the support plate 80 and the 30° peel strength of the adhesive layer 3 is measured. By setting the adhesion (30° peeling strength) of the first region 3a to the adhesive layer 5 within the above range, excellent pickup properties can be achieved, and semiconductor devices can be manufactured with a sufficiently high yield. From the perspective of suppressing DAF scattering during wafer cutting, the adhesion is preferably above 1.2N/25mm.

Next, the various layers that make up the cut-and-bond integrated film are explained.

(Base layer)

As the substrate layer 1, a known polymer sheet or film can be used. There is no particular limitation as long as the expansion step can be carried out under low temperature conditions. Specifically, the polymer constituting the substrate layer 1 includes: crystalline polypropylene, amorphous polypropylene, high-density polyethylene, medium-density polyethylene, low-density polyethylene, ultra-low-density polyethylene, low-density linear polyethylene, polybutene, polymethylpentene and other polyolefins, ethylene-vinyl acetate copolymers, ionic polymer resins, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylate (random, alternating) copolymers, ethylene-butene copolymers, ethylene-hexene copolymers, Polyurethane, polyethylene terephthalate, polyethylene naphthalate and other polyesters, polycarbonate, polyimide, polyetheretherketone, polyimide, polyetherimide, polyamide, wholly aromatic polyamide, polyphenylene sulfide, aromatic polyamide (aramid) (paper), glass, glass cloth, fluororesin, polyvinyl chloride, polyvinylidene chloride, cellulose resin, silicone resin, or a mixture of these with a plasticizer, or a hardened product cross-linked by electron beam irradiation.

The substrate layer 1 preferably has a surface mainly composed of at least one resin selected from polyethylene, polypropylene, polyethylene-polypropylene random copolymer, and polyethylene-polypropylene block copolymer, and the surface is in contact with the adhesive layer 3. These resins are also good substrates from the perspectives of Young's modulus, stress relaxation, melting point, etc., as well as price, and waste material recycling after use. The substrate layer 1 can be a single layer, or it can have a multi-layer structure formed by stacking layers including different materials as needed. In order to control the adhesion with the adhesive layer 3, the surface of the substrate layer 1 can also be subjected to surface roughening treatment such as matte treatment and corona treatment. The thickness of the substrate layer 1 is, for example, 10 μm to 200 μm, or 20 μm to 180 μm or 30 μm to 150 μm.

(Adhesive layer)

The adhesive layer 3 has: a first region 3a, which at least includes a region Rw corresponding to the attachment position of the adhesive layer 5 on the silicon wafer Ws; and a second region 3b, which is positioned in a manner to surround the first region 3a. The dotted line in FIG1 represents the boundary between the first region 3a and the second region 3b. The first region 3a and the second region 3b contain the same composition before irradiation with active energy rays. The first region 3a is a region in which the adhesive force is reduced compared with the second region 3b by irradiation with active energy rays such as ultraviolet rays. The second region 3b is a region for attaching the wafer ring DR (refer to FIG2 (a)). The second region 3b is a region that is not irradiated with active energy rays and has a high adhesive force to the wafer ring DR.

The thickness of the adhesive layer 3 can be appropriately set according to the conditions of the expansion step (temperature and tension, etc.), for example, 1μm~200μm, or 5μm~50μm or 15μm~45μm. If the thickness of the adhesive layer 3 is less than 1μm, the adhesion is likely to be insufficient, and if it exceeds 200μm, the incision width is narrow during expansion (relaxing the stress when the pin is pushed up), and the pickup is likely to be insufficient.

The first area 3a has an adhesive force within the range (3.0N/25mm or less) to the adhesive layer 5 and is formed by irradiation with active energy lines. The inventors and others have found that reducing the adhesive force of the adhesive layer 3 by irradiation with active energy lines will affect the edge peeling strength of the chip with the adhesive sheet. That is, if the adhesive force of the first area 3a is excessively reduced by irradiation with active energy lines, the 30° peeling strength of the first area 3a relative to the adhesive layer 5 becomes lower. On the other hand, when the object to be picked up is a small chip, there is a tendency that the edge of the chip with the adhesive sheet is not easy to peel off, so that the chip is excessively deformed and easily cracked or picked up incorrectly. The adhesion of the first region 3a to the adhesive layer 5 is preferably such that the adhesion before the active energy ray is irradiated does not drop excessively, thereby making it easy to peel off the edge of a wafer with an adhesive sheet having an area of ⁹ mm2 or less from the adhesive layer 3 (first region 3a). In this embodiment, the adhesion of the first region 3a of the adhesive layer 3 can be adjusted, for example, by reducing the amount of crosslinking agent in the adhesive layer 3 or reducing the irradiation amount of the active energy ray.

The adhesion of the second area 3b to the stainless steel substrate is preferably 0.2N/25mm or more. The adhesion is the 90° peeling strength measured at a temperature of 23°C, a peeling angle of 90°, and a peeling speed of 50mm/min. By having an adhesion of 0.2N/25mm or more, ring peeling during crystal cutting can be fully suppressed. The lower limit of the adhesion can be 0.3N/25mm or 0.4N/25mm, and the upper limit can be, for example, 2.0N/25mm, and can also be 1.0N/25mm.

The adhesive layer before the active energy ray irradiation includes, for example, an adhesive composition containing a (meth) acrylic resin, a photopolymerization initiator, and a crosslinking agent. The second area 3b not irradiated with the active energy ray includes the same composition as the adhesive layer before the active energy ray irradiation. The components contained in the adhesive composition are described in detail below.

[(Meth) acrylic resin]

The adhesive composition is preferably a (meth) acrylic resin containing a chain polymerizable functional group, and the functional group is at least one selected from an acryl group and a methacrylic group. The content of the functional group in the adhesive layer before irradiation with active energy rays is, for example, 0.1mmol/g to 1.2mmol/g, and may also be 0.3mmol/g to 1.0mmol/g or 0.5mmol/g to 0.8mmol/g. By having a content of the functional group of 0.1mmol/g or more, it is easy to form a region (first region 3a) where the adhesive force is moderately reduced by irradiation with active energy rays. On the other hand, by having a content of 1.2mmol/g or less, it is easy to achieve excellent pickup properties.

(Meth) acrylic resins can be synthesized by known methods. Examples of the synthesis methods include solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization, precipitation polymerization, gas phase polymerization, plasma polymerization, and supercritical polymerization. In addition, as the types of polymerization reactions, in addition to free radical polymerization, cationic polymerization, anionic polymerization, living free radical polymerization, living cationic polymerization, living anionic polymerization, coordination polymerization, and immortal polymerization, methods such as atom transfer radical polymerization (ATRP) and reversible addition fragmentation chain transfer (RAFT) polymerization can also be cited. Among these, the solution polymerization method and the synthesis by free radical polymerization have the advantages of good economy, high reaction rate, easy polymerization control, etc., and also have the following advantages: the resin solution obtained by polymerization can be directly used for formulation, etc.

Here, the method of synthesizing (meth)acrylic resin is described in detail, taking the method of obtaining (meth)acrylic resin by free radical polymerization using a solution polymerization method as an example.

The monomer used in the synthesis of the (meth)acrylic resin is not particularly limited as long as it has one (meth)acryloyl group in one molecule. Specific examples thereof include: methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, butoxyethyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octylheptyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, Aliphatic (meth)acrylates such as tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, stearyl (meth)acrylate, behenyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, ethoxypolypropylene glycol (meth)acrylate, mono(2-(meth)acryloyloxyethyl) succinate; (meth)acrylate Cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, tetrahydrophthalic acid mono (2-(meth)acryloyloxyethyl) ester, hexahydrophthalic acid mono (2-(meth)acryloyloxyethyl) ester and other alicyclic (meth)acrylates; benzyl (meth)acrylate, phenyl (meth)acrylate, o-biphenyl (meth)acrylate, 1-naphthyl (meth)acrylate, 2-naphthyl (meth)acrylate, (meth) ) phenoxyethyl acrylate, p-cumylphenoxyethyl (meth)acrylate, o-phenylphenoxyethyl (meth)acrylate, 1-naphthyloxyethyl (meth)acrylate, 2-naphthyloxyethyl (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate, phenoxypolypropylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-(o-phenylphenoxy)propyl (meth)acrylate, 2-hydroxy-3 -(1-naphthyloxy)propyl ester, (meth) acrylate 2-hydroxy-3-(2-naphthyloxy)propyl ester and other aromatic (meth) acrylates; (meth) acrylate 2-tetrahydrofurfuryl ester, N-(meth)acryloyloxyethyl hexahydroxylene dimethicone imide, 2-(meth)acryloyloxyethyl-N-carbazole and other heterocyclic (meth) acrylates, caprolactone modified products of these compounds; ω-carboxy-polycaprolactone mono(meth) acrylate, (meth) acrylate glycidyl ester, (meth) acrylate α-ethyl glycidyl ester, (meth) acrylate α-propyl glycidyl (meth)acrylate, α-butyl glycidyl (meth)acrylate, 2-methyl glycidyl (meth)acrylate, 2-ethyl glycidyl (meth)acrylate, 2-propyl glycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 3,4-epoxyheptyl (meth)acrylate, α-ethyl-6,7-epoxyheptyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, Compounds having ethylenically unsaturated groups and epoxy groups, such as oleyl ether and p-vinylbenzyl glycidyl ether; (meth)acrylate (2-ethyl-2-oxocyclobutyl) methyl ester, (meth)acrylate (2-methyl-2-oxocyclobutyl) methyl ester, (meth)acrylate 2-(2-ethyl-2-oxocyclobutyl) ethyl ester, (meth)acrylate 2-(2-methyl-2-oxocyclobutyl) ethyl ester, (meth)acrylate 3-(2-ethyl-2-oxocyclobutyl) propyl ester, (meth)acrylate 3-(2-methyl-2-oxocyclobutyl) The target (meth)acrylic resin can be obtained by appropriately combining compounds having ethylenically unsaturated groups and oxycyclobutyl groups, such as 2-(meth)acryloyloxyethyl isocyanate, and compounds having ethylenically unsaturated groups and isocyanate groups, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate.

In terms of the reaction with the functional group-introducing compound or crosslinking agent described later, the (meth)acrylic resin preferably has at least one functional group selected from hydroxyl, glycidyl and amino groups. As monomers for synthesizing (meth)acrylic resins having hydroxyl groups, there can be listed compounds having ethylenically unsaturated groups and hydroxyl groups, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. These compounds can be used alone or in combination of two or more.

Examples of monomers for synthesizing the (meth)acrylic resin having a glycidyl group include glycidyl (meth)acrylate, α-ethyl glycidyl (meth)acrylate, α-propyl glycidyl (meth)acrylate, α-butyl glycidyl (meth)acrylate, 2-methyl glycidyl (meth)acrylate, 2-ethyl glycidyl (meth)acrylate, 2-propyl glycidyl (meth)acrylate, and 2-butyl glycidyl (meth)acrylate. Compounds having an ethylenically unsaturated group and an epoxide group such as 3,4-epoxybutyl (meth)acrylate, 3,4-epoxyheptyl (meth)acrylate, α-ethyl-6,7-epoxyheptyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, and p-vinylbenzyl glycidyl ether may be used alone or in combination of two or more.

The (meth)acrylic resin synthesized from these monomers preferably contains a chain-polymerizable functional group. The chain-polymerizable functional group is, for example, at least one selected from an acryl group and a methacrylic group. The chain-polymerizable functional group can be introduced into the (meth)acrylic resin by reacting the following compound (functional group-introducing compound) with the (meth)acrylic resin synthesized as described above. Specific examples of the functional group-introducing compound include: 2-methacryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1-(diacryloyloxymethyl)ethyl isocyanate; an acryl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth)acrylate or 4-hydroxybutylethyl (meth)acrylate; an acryl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate, etc. Among these, 2-methacryloyloxyethyl isocyanate is particularly preferred. These compounds may be used alone or in combination of two or more.

The weight average molecular weight (Mw) of the (meth) acrylic resin is, for example, 100,000 to 2,000,000 or more, preferably 150,000 to 1,000,000, and more preferably 200,000 to 800,000. If the weight average molecular weight (Mw) of the (meth) acrylic resin is within this range, an adhesive layer 3 having excellent adhesion and less low molecular weight components can be formed, which can prevent contamination of the adherend.

The hydroxyl value of the (meth)acrylic resin is preferably 10mgKOH/g~150mgKOH/g, and more preferably 20mgKOH/g~100mgKOH/g. When the hydroxyl value of the (meth)acrylic resin is within the above range, the initial adhesion can be adjusted by reaction with the crosslinking agent, and the peeling force after the reaction of the chain polymerizable functional group can be reduced.

[Photopolymerization initiator]

As a photopolymerization initiator, there is no particular limitation if it is a substance that generates chain-polymerizable active species by irradiating active energy rays (selected from at least one of ultraviolet rays, electron beams, and visible rays), and an example thereof is a photo-radical polymerization initiator. The chain-polymerizable active species referred to here refers to a substance that initiates polymerization by reacting with a chain-polymerizable functional group.

As the photo-radical polymerization initiator, there can be listed: benzoin ketal such as 2,2-dimethoxy-1,2-diphenylethane-1-one; α-hydroxy ketones such as 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one; 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butane-1-one, 1,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropane-1-one; α-amino ketones such as 1-[4-(phenylthio)phenyl]-1,2-octanedione-2-(benzoyl)oxime; phosphine oxides such as bis(2,4,6-trimethylbenzyl)phenylphosphine oxide, bis(2,6-dimethoxybenzyl)-2,4,4-trimethylpentylphosphine oxide, 2,4,6-trimethylbenzyldiphenylphosphine oxide; 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenyl 2,4,5-triarylimidazole dimers such as 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer and 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer; benzophenone compounds such as benzophenone, N,N'-tetramethyl-4,4'-diaminobenzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone and 4-methoxy-4'-dimethylaminobenzophenone; 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3 -Benzoanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthrenequinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone and other quinone compounds; benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether; benzoin compounds such as benzoin, methyl benzoin, ethyl benzoin; benzoyl compounds such as benzoyl dimethyl ketal; acridine compounds such as 9-phenylacridine, 1,7-bis(9,9'-acridinylheptane); N-phenylglycine, coumarin.

The content of the photopolymerization initiator in the adhesive composition is, for example, 0.1 to 30 parts by mass, preferably 0.3 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of the (meth) acrylic resin. If the content of the photopolymerization initiator is less than 0.1 parts by mass, the adhesive layer will not be sufficiently cured after being irradiated with active energy rays, which may easily lead to poor pickup. If the content of the photopolymerization initiator exceeds 30 parts by mass, contamination of the adhesive layer (transfer of the photopolymerization initiator to the adhesive layer) may easily occur.

[Crosslinking agent]

The crosslinking agent is used, for example, for the purpose of controlling the elastic modulus and/or adhesion of the adhesive layer. The crosslinking agent can be a compound having two or more functional groups in one molecule that can react with at least one functional group selected from hydroxyl, glycidyl and amine groups possessed by the (meth) acrylic resin. As the bond formed by the reaction of the crosslinking agent and the (meth) acrylic resin, ester bonds, ether bonds, amide bonds, imide bonds, urethane bonds, urea bonds, etc. can be listed.

In this embodiment, as a crosslinking agent, it is preferred to use a compound having two or more isocyanate groups in one molecule. If such a compound is used, it is easy to react with the hydroxyl group, glycidyl group and amino group of the (meth) acrylic resin to form a strong crosslinking structure.

Examples of compounds having two or more isocyanate groups in one molecule include isocyanate compounds such as 2,4-methylphenylene diisocyanate, 2,6-methylphenylene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, and lysine isocyanate.

As a crosslinking agent, the reaction product of the isocyanate compound and a polyol having two or more OH groups in one molecule (oligomer containing an isocyanate group) can also be used. Examples of polyols having two or more OH groups in one molecule include: ethylene glycol, propylene glycol, butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, glycerol, pentaerythritol, dipentaerythritol, 1,4-cyclohexanediol, and 1,3-cyclohexanediol.

Among these, the crosslinking agent is preferably a reaction product (isocyanate group oligomer) of a polyfunctional isocyanate having two or more isocyanate groups in one molecule and a polyol having three or more OH groups in one molecule. By using such an isocyanate group-containing oligomer as a crosslinking agent, the adhesive layer 3 forms a dense crosslinking structure, thereby sufficiently suppressing the adhesive from attaching to the adhesive layer 5 in the pickup step.

The content of the crosslinking agent in the adhesive composition can be appropriately set according to the cohesive force and elongation at break required for the adhesive layer, as well as the adhesion with the adhesive layer 5. Specifically, the content of the crosslinking agent is, for example, 2 to 30 parts by mass, or 4 to 15 parts by mass, or 7 to 10 parts by mass, relative to 100 parts by mass of the (meth)acrylic resin. By setting the content of the crosslinking agent to the above range, the properties required for the adhesive layer in the crystal cutting step and the properties required for the adhesive layer 3 in the crystal bonding step can be well balanced, and excellent pickup properties can also be achieved.

If the content of the crosslinking agent is less than 2 parts by mass relative to 100 parts by mass of the (meth)acrylic resin, the formation of the crosslinking structure is likely to be insufficient, and thus, in the pickup step, the interfacial adhesion with the adhesive layer 5 will not be sufficiently reduced, and it is easy to cause defects during pickup. On the other hand, if the content of the crosslinking agent exceeds 30 parts by mass relative to 100 parts by mass of the (meth)acrylic resin, the adhesive layer 3 is likely to become too hard, and thus, in the expansion step, the semiconductor chip is easily peeled off.

The content of the crosslinking agent relative to the total mass of the adhesive composition is, for example, 0.1 mass% to 20 mass%, or 2 mass% to 17 mass% or 3 mass% to 15 mass%. When the content of the crosslinking agent is 0.1 mass% or more, it is easy to form a region (first region 3a) where the adhesive force is moderately reduced by irradiation with active energy rays. On the other hand, when it is 15 mass% or less, it is easy to achieve excellent pickup properties.

As a method for forming the adhesive layer 3, a known method can be adopted. For example, a laminate of the base layer 1 and the adhesive layer 3 can be formed by a double-layer extrusion method, or a varnish for forming the adhesive layer 3 can be prepared and applied to the surface of the base layer 1, or the adhesive layer 3 can be formed on a film subjected to a demolding treatment and transferred to the base layer 1.

The varnish for forming the adhesive layer 3 is preferably prepared using an organic solvent that can dissolve the (meth)acrylic resin, the photopolymerization initiator and the crosslinking agent and volatilize by heating. Specific examples of organic solvents include aromatic hydrocarbons such as toluene, xylene, 1,3,5-trimethylbenzene, cumene, and p-cumene; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol, and propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone; carbonates such as ethyl carbonate and propyl carbonate; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, Ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether and other polyol alkyl ether acetates; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate and other polyol alkyl ether acetates; N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and other amides.

Among them, from the viewpoint of solubility and boiling point, preferred are toluene, methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, N,N-dimethylacetamide, and acetylacetone. These organic solvents may be used alone or in combination of two or more. The solid content concentration of the varnish is generally preferably 10% to 60% by mass.

(followed by the agent layer)

The adhesive layer 5 may be a known adhesive composition for forming a die bonding film. Specifically, the adhesive composition for forming the adhesive layer 5 preferably contains an epoxy-containing acrylic copolymer, an epoxy resin, and an epoxy resin hardener. The adhesive layer 5 containing these components is preferably characterized by excellent bonding between chip/substrate and chip/chip, and can also provide electrode embedding and wire embedding properties, etc., and can be bonded at a low temperature in the die bonding step, and can be cured in a short time, and has excellent reliability after molding with a sealant, etc.

The thickness of the adhesive layer 5 is, for example, 1μm to 300μm, preferably 5μm to 150μm, and may also be 10μm to 100μm or 15μm to 35μm. If the thickness of the adhesive layer 5 is less than 1μm, the adhesion is likely to be insufficient, while if it exceeds 300μm, the cutting and picking properties are likely to be insufficient.

Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, alicyclic epoxy resins, aliphatic chain epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, diglycidyl ethers of biphenol, diglycidyl ethers of naphthalene diol, diglycidyl ethers of phenols, diglycidyl ethers of alcohols, and bifunctional epoxy resins such as alkyl substituted products, halides, and hydrides thereof, and novolac type epoxy resins. In addition, other commonly known epoxy resins such as multifunctional epoxy resins and epoxy resins containing heterocycles can also be used. These can be used alone or in combination of two or more. Furthermore, components other than epoxy resins can be included as impurities within a range that does not impair the properties.

Examples of epoxy resin curing agents include phenol resins obtained by reacting a phenol compound with a xylylene compound as a divalent linking group in the absence of a catalyst or in the presence of an acid catalyst. Examples of the phenolic compound used in the production of the phenolic resin include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, p-ethylphenol, o-n-propylphenol, m-n-propylphenol, p-n-propylphenol, o-isopropylphenol, m-isopropylphenol, p-isopropylphenol, o-n-butylphenol, m-n-butylphenol, p-n-butylphenol, o-isobutylphenol, m-isobutylphenol, p-isobutylphenol, octylphenol, nonylphenol, 2,4-dimethylphenol, 2,6- xylenol, 3,5-xylenol, 2,4,6-trimethylphenol, resorcin, o-catechol, hydroquinone, 4-methoxyphenol, o-phenylphenol, m-phenylphenol, p-phenylphenol, p-cyclohexylphenol, o-allylphenol, p-allylphenol, o-benzylphenol, p-benzylphenol, o-chlorophenol, p-chlorophenol, o-bromophenol, p-bromophenol, o-iodophenol, p-iodophenol, o-fluorophenol, m-fluorophenol, p-fluorophenol, etc. These phenol compounds may be used alone or in combination of two or more. As the xylyl compound as a divalent linking group used in the production of the phenol resin, the following xylyl dihalides, xylyl diglycol, and derivatives thereof may be used. That is, they can be listed as follows: α,α'-dichloro-p-xylene, α,α'-dichloro-m-xylene, α,α'-dichloro-o-xylene, α,α'-dibromo-p-xylene, α,α'-dibromo-m-xylene, α,α'-dibromo-o-xylene, α,α'-diiodo-p-xylene, α,α'-diiodo-m-xylene, α,α'-diiodo-o-xylene, α,α '-Dihydroxy-p-xylene, α,α'-dihydroxy-m-xylene, α,α'-dihydroxy-o-xylene, α,α'-dimethoxy-p-xylene, α,α'-dimethoxy-m-xylene, α,α'-dimethoxy-o-xylene, α,α'-diethoxy-p-xylene, α,α'-diethoxy-m-xylene, α,α'-diethoxy-o-xylene Benzene, α,α'-di-n-propoxy-p-xylene, α,α'-n-propoxy-m-xylene, α,α'-di-n-propoxy-o-xylene, α,α'-di-isopropoxy-p-xylene, α,α'-di-isopropoxy-m-xylene, α,α'-di-isopropoxy-o-xylene, α,α'-di-n-butoxy-p-xylene, α,α'-di-n-butoxy-m-xylene, α,α'-di-n-butoxy-o-xylene, α,α'-diisobutoxy-p-xylene, α,α'-diisobutoxy-m-xylene, α,α'-diisobutoxy-o-xylene, α,α'-di-tert-butoxy-p-xylene, α,α'-di-tert-butoxy-m-xylene, α,α'-di-tert-butoxy-o-xylene. These can be used alone or in combination of two or more.

When the phenol compound is reacted with the xylyl compound, mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and polyphosphoric acid; organic carboxylic acids such as dimethylsulfuric acid, diethylsulfuric acid, p-toluenesulfonic acid, methanesulfonic acid, and ethanesulfonic acid; superacids such as trifluoromethanesulfonic acid; strongly acidic ion exchange resins such as alkanesulfonic acid type ion exchange resins; and superacidic ion exchange resins such as perfluoroalkanesulfonic acid type ion exchange resins can be used. The product is obtained by reacting with acidic catalysts such as zeolite (trade name: Nafion, manufactured by DuPont, "Nafion" is a registered trademark), natural and synthetic zeolites, and activated clay (acid clay) at 50℃~250℃ until the xylene compound, which is essentially the raw material, disappears and the reaction composition becomes fixed. The reaction time also depends on the raw materials and the reaction temperature, and is about 1 hour to 15 hours. In practice, it can be determined by tracking the reaction composition through gel permeation chromatography (GPC) and other methods.

The epoxy-containing acrylic copolymer is preferably a copolymer obtained by using glycidyl acrylate or glycidyl methacrylate as a raw material in an amount of 0.5 mass% to 6 mass% relative to the obtained copolymer. When the amount is 0.5 mass% or more, high adhesion is easily obtained, while when it is 6 mass% or less, gelation can be suppressed. The remainder can be a mixture of alkyl acrylates having an alkyl group with 1 to 8 carbon atoms such as methyl acrylate and methyl methacrylate, alkyl methacrylates, styrene, acrylonitrile, etc. Among these, ethyl (meth)acrylate and/or butyl (meth)acrylate are particularly preferred. The mixing ratio is preferably adjusted in consideration of the Tg of the copolymer. If Tg is less than -10°C, the viscosity of the adhesive layer 5 in the B stage tends to increase, and the operability tends to deteriorate. Furthermore, the upper limit of the glass transition temperature (Tg) of the epoxy-containing acrylic copolymer is, for example, 30°C. The polymerization method is not particularly limited, and examples thereof include pearl polymerization and solution polymerization. Examples of commercially available epoxy-containing acrylic copolymers include: HTR-860P-3 (trade name, manufactured by Nagase ChemteX Co., Ltd.).

The weight average molecular weight of the epoxy-containing acrylic copolymer is 100,000 or more. If it is within this range, the adhesion and heat resistance are high. It is preferably 300,000 to 3,000,000, and more preferably 500,000 to 2,000,000. If the weight average molecular weight is 3,000,000 or less, the filling property between the semiconductor chip and the substrate supporting it can be suppressed. The weight average molecular weight is a polystyrene conversion value obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

The next agent layer 5 may further contain a curing accelerator such as a tertiary amine, imidazole, or quaternary ammonium salt as needed. Specific examples of the curing accelerator include: 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-phenylimidazolium trimellitate. These may be used alone or in combination of two or more.

The next agent layer 5 may further contain inorganic fillers as needed. Specific 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, aluminum borate whiskers, boron nitride, crystalline silicon dioxide, and amorphous silicon dioxide. These may be used alone or in combination of two or more.

Furthermore, the adhesive layer 5 may be free of thermosetting resin. For example, when the adhesive layer 5 includes a (meth)acrylic copolymer containing a reactive group, the adhesive layer 5 only needs to include a (meth)acrylic copolymer containing a reactive group, a curing accelerator, and a filler.

<Method for manufacturing a wafer-cut-and-bond integrated film>

The method for manufacturing the film 10 sequentially comprises: a step of manufacturing a laminate on the surface of the substrate layer 1, the laminate comprising an adhesive layer and an adhesive layer 5, the adhesive layer comprising an adhesive composition whose adhesive force decreases by irradiation with active energy rays, the adhesive layer 5 being formed on the surface of the adhesive layer; and a step of irradiating an active energy ray to a region of the adhesive layer included in the laminate that will form the first region 3a. The amount of active energy ray irradiated to the region that will form the first region 3a is, for example, 10mJ/ ^cm2 to 1000mJ/ ^cm2 , and may also be 100mJ/ ^cm2 to 700mJ/ ^cm2 or 200mJ/ ^cm2 to 500mJ/ ^cm2 .

The manufacturing method is a method of first preparing a laminate of an adhesive layer and a bonding agent layer 5, and then irradiating a specific area of the adhesive layer with active energy rays. As described below, the adhesive layer before being bonded to the bonding agent layer 5 may also be irradiated with active energy rays to form the first area 3a. That is, the manufacturing method of the film 10 may also sequentially include: a step of forming an adhesive layer on the surface of the substrate layer 1, wherein the adhesive layer contains a composition whose adhesive force decreases by irradiating active energy rays; a step of irradiating an area of the adhesive layer that will form the first area 3a with active energy rays; and a step of laminating the bonding agent layer 5 on the surface of the adhesive layer 3 after irradiating the active energy rays.

<Semiconductor device and method for manufacturing the same>

FIG7 is a cross-sectional view schematically showing a semiconductor device of the present embodiment. The semiconductor device 100 shown in the figure includes: a substrate 70; four chips T1, T2, T3, and T4 stacked on the surface of the substrate 70; wires W1, wires W2, wires W3, and wires W4 electrically connecting electrodes (not shown) on the surface of the substrate 70 to the four chips T1, T2, T3, and T4; and a sealing layer 50 covering them.

The substrate 70 is, for example, an organic substrate, or a metal substrate such as a lead frame. From the perspective of suppressing the warping of the semiconductor device 100, the thickness of the substrate 70 is, for example, 70 μm to 140 μm, or 80 μm to 100 μm.

The four chips T1, T2, T3, and T4 are stacked via the hardened material 5c of the adhesive sheet 5p. The shapes of the chips T1, T2, T3, and T4 when viewed from above are, for example, square or rectangular. The areas of the chips T1, T2, T3, and T4 are ⁹ mm2 or less, and may be 0.1 ^mm2 to 4 ^mm2 or 0.1 ^mm2 to 2 ^mm2 . The length of one side of the chips T1, T2, T3, and T4 is, for example, 3 mm or less, and may be 0.1 mm to 2.0 mm or 0.1 mm to 1.0 mm. The thickness of the chips T1, T2, T3, and T4 is, for example, 10 μm to 170 μm, and may be 25 μm to 100 μm. Furthermore, the lengths of one side of the four chips T1, T2, T3, and T4 may be the same or different from each other, and the same applies to their thicknesses.

The manufacturing method of the semiconductor device 100 includes: a step of preparing the film 10; a step of adhering a wafer W to the adhesive layer 5 of the film 10 and a step of adhering a dicing ring DR to the second surface F2 of the adhesive layer 3; a step of singulating the wafer W into a plurality of chips T1, T2, T3, and T4 with an area of less than 9 ^mm2 (dicing step); a step of picking up a chip Tb with an adhesive chip from the first area 3a of the adhesive layer 3 (a laminate of the chip and the adhesive chip 5p, refer to (d) of Figure 8); and a step of mounting the chip T1 on the substrate 70 via the adhesive chip 5p.

An example of a method for manufacturing a wafer Tb with an adhesive sheet is described with reference to FIG8 . First, the film 10 is prepared. As shown in FIG8 (a) and FIG8 (b), the film 10 is attached in such a manner that the adhesive layer 5 is in contact with one surface of the wafer W. In addition, a wafer cut ring DR is attached to the second surface F2 of the adhesive layer 3.

Wafer W, adhesive layer 5 and adhesive layer 3 are cut. As shown in FIG8(c), wafer W is singulated to form chip T1, chip T2, chip T3 and chip T4. Adhesive layer 5 is also singulated to form adhesive chip 5p. As a method of cutting, a method using a cutting blade or a laser can be cited. Furthermore, wafer W can also be thinned by grinding before cutting wafer W.

After the wafer is cut, the adhesive layer 3 is not irradiated with active energy rays. Instead, as shown in FIG8(d), the wafers are separated from each other by expanding the substrate layer 1 at room temperature or under cooling conditions, and the adhesive sheet 5p is peeled off from the adhesive layer 3 by pushing up with the pin 42, and the wafer Tb with the adhesive sheet is sucked and picked up by the suction chuck 44.

The manufacturing method of the semiconductor device 100 is specifically described with reference to FIG. 9 to FIG. 11. First, as shown in FIG. 9, the first layer chip T1 is pressed to a predetermined position of the substrate 70 via the bonding agent sheet 5p. Next, the bonding agent sheet 5p is hardened by heating. Thus, the bonding agent sheet 5p is hardened to become a hardened material 5c. From the perspective of reducing voids, the hardening treatment of the bonding agent sheet 5p can also be performed in a pressurized environment.

The second layer of chip T2 is mounted on the surface of chip T1 in the same manner as the mounting of chip T1 on substrate 70. Furthermore, the structure 60 shown in FIG10 is manufactured by mounting the third layer of chip T3 and the fourth layer of chip T4. After the chips T1, T2, T3, and T4 are electrically connected to the substrate 70 using wires W1, W2, W3, and W4 (see FIG11), the semiconductor elements and wires are covered by a sealing layer 50, thereby completing the semiconductor device 100 shown in FIG7.

The above is a detailed description of the embodiments of the present disclosure, but the present invention is not limited to the embodiments. For example, the film 10 may further include a covering film (not shown) covering the adhesive layer 5. In the embodiments, the adhesive force of the first area 3a of the adhesive layer 3 decreases compared with the second area 3b by irradiation with active energy rays, but the adhesive layer 3 may also be a UV curable type or a pressure sensitive type.

The peeling strength and edge peeling strength of the adhesive layer from the bonding agent layer can also be used in the selection of the cut-die-bonded film. The first aspect of the method for selecting the cut-die-bonded film includes: preparing two or more cut-die-bonded films; and comparing the peeling strength and edge peeling strength of the adhesive layer from the bonding agent layer of the two or more cut-die-bonded films.

The second aspect of the selection method of the cut-die-bonded integrated film includes: preparing a plurality of cut-die-bonded integrated films having a peel strength of the adhesive layer from the adhesive layer of less than 3.0N/25mm under the conditions of a temperature of 23°C, a peel angle of 30° and a peel speed of 60mm/min; and checking whether the edge peel strength of the plurality of cut-die-bonded integrated films is less than 1.2N. In this selection method, for example, the peel strength of the adhesive layer from the bonding agent layer is 3.0N/25mm or less, which is useful for efficiently selecting a cut-and-bond film that can manufacture semiconductor devices with a high yield from a plurality of cut-and-bond films that have been inspected and purchased. Furthermore, the plurality of cut-and-bond films mentioned here may be of the same type or of different types.

[Implementation example]

The present disclosure is described in more detail below based on examples, but the present invention is not limited to these examples. Furthermore, unless otherwise specified, all chemicals are reagents.

[Synthesis of acrylic resin (Production example 1)]

Place the following ingredients in a 2000ml flask equipped with a three-one motor, stirring blades, and a nitrogen inlet tube.

．Ethyl acetate (solvent): 635g

．2-Ethylhexyl acrylate: 395g

．2-Hydroxyethyl acrylate: 100g

．Methacrylic acid: 5g

． Azobis(isobutyronitrile): 0.08g

After the contents are fully stirred until uniform, bubbling is performed for 60 minutes at a flow rate of 500 ml/min to degas the dissolved oxygen in the system. The temperature is raised to 78°C over 1 hour, and polymerization is performed for 6 hours after the temperature is raised. Next, the reaction solution is transferred to a 2000 ml autoclave equipped with a Sany motor, stirring blades, and a nitrogen inlet tube, and heated at 120°C and 0.28 MPa for 4.5 hours, and then cooled to room temperature (25°C, the same below).

Next, 490 g of ethyl acetate was added, stirred, and diluted. After adding 0.10 g of dioctyltin dilaurate as a urethane catalyst, 48.6 g of 2-methylacryloyloxyethyl isocyanate (Karenz MOI (trade name) manufactured by Showa Denko Co., Ltd.) was added, reacted at 70°C for 6 hours, and then cooled to room temperature. Subsequently, ethyl acetate was added, and the non-volatile component content in the acrylic resin solution was adjusted to 35% by mass to obtain a solution containing (A) acrylic resin (Production Example 1), wherein (A) acrylic resin has a chain polymerizable functional group.

The solution containing (A) acrylic resin obtained in the above manner was vacuum dried at 60°C overnight. The solid component obtained in this way was subjected to elemental analysis using a fully automatic elemental analysis device (manufactured by Elemental, trade name: Variol EL), and the content of the introduced 2-methacryloyloxyethyl isocyanate was calculated based on the nitrogen content, and the result was 0.50 mmol/g.

In addition, the following device was used to determine the polystyrene-equivalent weight average molecular weight of (A) acrylic resin. That is, SD-8022/DP-8020/RI-8020 manufactured by Tosoh Co., Ltd. was used, the column was the gel pack GL-A150-S/GL-A160-S manufactured by Hitachi Chemical Co., Ltd., and tetrahydrofuran was used as the eluent for GPC measurement. As a result, the polystyrene-equivalent weight average molecular weight was 800,000. The hydroxyl value and acid value measured according to the method described in Japanese Industrial Standards (JIS) K0070 were 56.1 mgKOH/g and 6.5 mgKOH/g. These results are summarized in Table 1.

[Synthesis of acrylic resin (Production Example 2~Production Example 4)]

The raw material monomer compositions shown in Production Examples 2 to 4 were used instead of the raw material monomer compositions shown in Production Example 1 in Table 1. The solutions of (A) acrylic resins of Production Examples 2 to 4 were obtained in the same manner as Production Example 1. The measurement results of (A) acrylic resins of Production Examples 2 to 4 are shown in Table 1.

<Implementation Example 1>

[Production of cut crystal film (adhesive layer)]

The varnish for forming an adhesive layer was prepared by mixing the following components (see Table 2). The amount of ethyl acetate (solvent) was adjusted so that the total solid content of the varnish would be 25% by mass.

． (A) Acrylic resin solution (Production Example 1): 100g (solid content)

． (B) Photopolymerization initiator (2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propane-1-one, manufactured by Ciba Specialty Chemicals Co., Ltd., Irgacure 127, "Irgacure" is a registered trademark): 1.0g

． (C) Crosslinking agent (multifunctional isocyanate, manufactured by Japan Polyurethane Industry Co., Ltd., Coronate L, solid content: 75%): 8.0g (solid content)

．Ethyl acetate (solvent)

A polyethylene terephthalate film (width 450 mm, length 500 mm, thickness 38 μm) was prepared with a mold release treatment applied to one side. The varnish for forming the adhesive layer was applied to the surface subjected to the mold release treatment using an applicator, and then dried at 80°C for 5 minutes. In this way, a laminate (cut film) including the polyethylene terephthalate film and the adhesive layer with a thickness of 30 μm formed thereon was obtained.

A polyolefin film (width 450 mm, length 500 mm, thickness 80 μm) with one side subjected to corona treatment was prepared. The side subjected to corona treatment and the adhesive layer of the laminate were bonded at room temperature. Then, the adhesive layer was transferred to the polyolefin film (covering film) by pressing with a rubber roller. After that, it was placed at room temperature for 3 days to obtain a cut crystal film with a covering film.

[Preparation of the adhesive film (followed by the agent layer A)]

First, add cyclohexanone (solvent) to the following composition and stir to mix, then use a bead mill to mix for 90 minutes.

． Epoxy resin (YDCN-700-10 (trade name), cresol novolac type epoxy resin manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd., epoxy equivalent 210, molecular weight 1200, softening point 80°C): 14 parts by mass

． Phenolic resin (Milex XLC-LL (trade name), manufactured by Mitsui Chemicals Co., Ltd., phenolic resin, hydroxyl equivalent 175, water absorption 1.8%, heating weight loss rate at 350°C 4%): 23 parts by mass

． Silane coupling agent (NUC A-189 (trade name), manufactured by NUC Co., Ltd., γ-butylpropyltrimethoxysilane): 0.2 parts by mass

． Silane coupling agent (NUC A-1160 (trade name), manufactured by Nippon Unicar Co., Ltd., γ-ureidopropyltriethoxysilane): 0.1 parts by mass

． Filler (SC2050-HLG (trade name), manufactured by Admatechs Co., Ltd., silicon dioxide, average particle size 0.500μm): 32 parts by mass

After adding the following ingredients to the composition obtained in the above manner, a varnish for forming a follower layer is obtained through stirring, mixing and vacuum degassing steps.

． Epoxy-containing acrylic copolymer (HTR-860P-3 (trade name), manufactured by Nagase Chemicals Co., Ltd., weight average molecular weight 800,000): 16 parts by weight

． Curing accelerator (Curezol 2PZ-CN (trade name), manufactured by Shikoku Chemical Industries, Ltd., 1-cyanoethyl-2-phenylimidazole, "Curezol" is a registered trademark): 0.01 parts by mass

A polyethylene terephthalate film (35 μm thick) with one side subjected to mold release treatment was prepared. A varnish for forming an adhesive layer was applied to the side subjected to mold release treatment using an applicator, and then heated and dried at 140°C for 5 minutes. Thus, a laminate (die bonding film) including a polyethylene terephthalate film (carrier film) and a 25 μm thick adhesive layer (B stage state) formed thereon was obtained.

[Preparation of a one-piece film of cut-crystal-bonded crystal]

The wafer bonding film including the adhesive layer and the carrier film is cut into a circle with a diameter of 335 mm together with the carrier film. After the wafer-cut film from which the polyethylene terephthalate film is peeled is attached at room temperature, it is left at room temperature for 1 day. Thereafter, the wafer-cut film is cut into a circle with a diameter of 370 mm. The area (the first area of the adhesive layer) corresponding to the attachment position of the wafer in the adhesive layer of the wafer-cut wafer-bonding integrated film obtained in this way is irradiated with ultraviolet rays in the following manner. That is, a pulsed xenon lamp is used to partially irradiate with ultraviolet rays at an irradiation amount of 70 W and 300 mJ/ ^cm2 . Furthermore, a light shielding curtain is used to irradiate the part with an inner diameter of 318 mm from the center of the film. In this way, a plurality of cut-die-bond integrated films were obtained for use in various evaluation tests described later.

<Implementation Example 2>

When preparing the cut-die film, a plurality of cut-die-bonded integrated films were obtained in the same manner as in Example 1, except that 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by Ciba Specialty Chemicals, Inc., Irgacure 184, "Irgacure" is a registered trademark) was used instead of "Irgacure 127" and the ultraviolet irradiation amount was set to 200 mJ/ ^cm2 instead of 300 mJ/ ^cm2 .

<Implementation Example 3>

A plurality of cut-and-bond integrated films were obtained in the same manner as in Example 2 except that the ultraviolet irradiation dose was set to 250 mJ/cm ² instead of 200 mJ/cm ² .

<Implementation Example 4>

A plurality of die-cut-and-bond integrated films were obtained in the same manner as in Example 2 except that the irradiation amount of ultraviolet rays was set to 300 mJ/cm ² instead of 200 mJ/cm ² .

<Implementation Example 5>

As a die bonding film, a die having an adhesive layer B formed as follows is used instead of a die having an adhesive layer A, and a plurality of die-cutting-die bonding integrated films are obtained in the same manner as in Example 4, except that.

[Preparation of the adhesive film (followed by the agent layer B)]

First, add cyclohexanone (solvent) to the following ingredients and stir to mix, then use a bead mill to knead for 90 minutes.

． Filler (SC2050-HLG (trade name), manufactured by Yaduma Co., Ltd., silicon dioxide, average particle size 0.500μm): 50 parts by mass

After adding the following ingredients to the composition obtained in the above manner, a varnish for forming a follower layer is obtained through stirring, mixing and vacuum degassing steps.

． Epoxy-containing acrylic copolymer (HTR-860P-3 (trade name), manufactured by Nagase Chemicals Co., Ltd., weight average molecular weight 800,000): 100 parts by mass

． Curing accelerator (Curezol 2PZ-CN (trade name), manufactured by Shikoku Chemical Industries, Ltd., 1-cyanoethyl-2-phenylimidazole, "Curezol" is a registered trademark): 0.1 parts by mass

<Comparison Example 1>

When preparing the cut crystal film, the acrylic resin of Preparation Example 2 was used instead of the acrylic resin of Preparation Example 1, and the amount of the crosslinking agent was set to 6.0 parts by mass instead of 8.0 parts by mass. In addition, a plurality of cut crystal-bonded integrated films were obtained in the same manner as in Example 1.

<Comparison Example 2>

When making the cut crystal film, the amount of the crosslinking agent was set to 6.0 parts by mass instead of 8.0 parts by mass. In addition, multiple cut crystal-bonded integrated films were obtained in the same manner as in Example 1.

<Comparison Example 3>

When preparing the cut crystal film, the acrylic resin of Preparation Example 3 was used instead of the acrylic resin of Preparation Example 2. In addition, a plurality of cut crystal-bonded integrated films were obtained in the same manner as Comparative Example 1.

<Comparison Example 4>

When making the cut crystal film, the acrylic resin of Manufacturing Example 4 was used instead of the acrylic resin of Manufacturing Example 2, and no ultraviolet light was irradiated. In addition, a plurality of cut crystal-bonded integrated films were obtained in the same manner as in Comparative Example 1.

[Evaluation test]

(1) Determination of the adhesion of the adhesive layer to the adhesive layer (30° peel strength)

The adhesion of the adhesive layer to the adhesive layer was evaluated by measuring the 30° peel strength. That is, a test sample with a width of 25 mm and a length of 100 mm was cut from a die-cut-die-bonded film. The test sample was set as a laminate of the adhesive layer and the adhesive layer. The peel strength of the adhesive layer relative to the adhesive layer was measured using a tensile tester. The measurement conditions were set as a peel angle of 30° and a tensile speed of 60 mm/min. In addition, the sample was stored and the peel strength was measured at a temperature of 23°C and a relative humidity of 40%. For Example 1 to Example 5 and Comparative Example 1 to Comparative Example 3, the adhesion of the UV-irradiated area of the adhesive layer was evaluated, and for Comparative Example 4, the adhesion of the adhesive layer was evaluated.

(2) Measurement of chip edge peeling strength

The wafer-bonding integrated film was attached to a silicon wafer (diameter: 12 inches, thickness: 50μm) and a wafer ring under the following conditions. The elongation of the wafer-bonding integrated film in the MD direction (machine direction) after attaching the silicon wafer and the wafer ring was about 1.0%~1.3%.

<Attachment conditions>

． Attachment device: DFM2800 (manufactured by DISCO Co., Ltd.)

．Attachment temperature: 70℃

．Attachment speed: 10mm/s

． Attachment tension level: Level 6

Then, the silicon wafer with the integrated die-cutting and die-bonding film is singulated into multiple chips (size 2mm×2mm) with bonding agents by blade dicing.

<Crystal cutting conditions>

．Crystal cutting machine: DFD6361 (manufactured by DISCO Co., Ltd.)

． Blade: ZH05-SD4000-N1-70-BB (manufactured by DISCO Co., Ltd.)

． Blade speed: 40000rpm

．Crystal cutting speed: 30mm/sec

．Blade height: 90μm

． Cutting depth from the surface of the adhesive layer: 20μm

．The amount of water when cutting crystals

Blade cooler: 1.5L/min

Shower: 1.0L/min

Spray: 1.0L/min

One day after the crystal was cut, the edge peel strength of the chip with the adhesive sheet was measured by pressing the chip with the adhesive sheet from the substrate layer side under the following measurement conditions (see Figure 2 (c)). In addition, before the measurement, the surface of the substrate layer corresponding to the center of the chip was marked with an oil pen. The center of the chip was measured and determined with a ruler. The measurement was performed with N=10. After measuring one chip, the following measurement was performed with an interval of three chips (see Figure 4).

<Measurement conditions>

． Measuring device: Small desktop testing machine EZ-SX (manufactured by Shimadzu Corporation)

．Load cell: 50N

． Press-in fixture: ZTS series accessory (shape: cone-shaped, manufactured by IMADA Co., Ltd.)

． Pressing speed: 60mm/min

．Temperature: 23℃

．Humidity: 45±10%

(3) Evaluation of crystallinity

The shear properties were evaluated using the following evaluation criteria. The results are shown in Tables 2 and 3.

<Chip scattering>

Those where no chip scattering occurred after cutting were evaluated as "A", those where even a small amount of cutting water was observed to penetrate between the adhesive layer and the adhesive layer, although the chip scattering did not occur, were evaluated as "B", and those where chip scattering occurred even once were evaluated as "C".

<Cracks>

Use a microscope to check the cut section of the wafer after cutting to evaluate whether the wafer has defects. Observe the cut sections of 10 wafers, and evaluate the samples with no defects as "A", and the samples with even slight defects as "B".

(4) Evaluation of pick-up ability

After the edge peel strength was measured, 100 wafers with adhesive sheets were picked up under the following conditions.

<Pickup conditions>

． Die bonding device: DB800-HSD (manufactured by Hitachi High-Tech Co., Ltd.)

． Upper ejector pin: Ejector needle SEN2-83-05 (diameter: 0.7mm, tip shape: semicircle with a radius of 350μm, manufactured by Micromechanics)

． Push-up height: 150μm

． Pushing speed: 1mm/sec

Furthermore, an upper push pin is arranged in the center of the chip. The success rate of picking up is evaluated as "A" when it is 100%, "B" when it is more than 80% and less than 100%, "C" when it is more than 60% and less than 80%, and "D" when it is less than 60%. The results are shown in Tables 2 and 3.

As shown in Tables 2 and 3, the pick-up properties of Examples 1 to 5 are better than those of Comparative Examples 1 to 4. Specifically, although the 30° peel strength of Comparative Example 1 is a significantly lower value than that of Examples 1 to 4, the pick-up properties are significantly deteriorated because the edge peel strength is as high as 1.6 N. In addition, in Comparative Example 2, although the 30° peel strength is 2.6 N/25 mm and is less than 3.0 N/25 mm, it is considered that the pick-up properties are deteriorated because the edge peel strength is high, 1.3 N. On the other hand, it is believed that although the edge peel strength in Comparative Examples 3 and 4 is lower than the values of Examples 1 to 4, the 30° peel strength is 3.0N/25mm or more, so the pickup performance deteriorates. In addition, from the results of Examples 1 to 5, it is known that if the edge peel strength is controlled below 1.2N, good pickup performance can be obtained in a wide range of 30° peel strength below 3.0N/25mm.

Regarding the crystal cutting properties, the 30° peel strength in Example 1 was too low, so traces of cutting water infiltration were visible between the adhesive layer and the adhesive layer, and cracks were generated on the side of the chip. It is believed that the cracks were caused by the movement of the chip due to the infiltration of cutting water during crystal cutting, and the contact with the blade.

From the above results, it can be seen that in the semiconductor device manufacturing process using small chips, by setting the edge peel strength to less than 1.2N and the 30° peel strength to less than 3.0N/25mm, both the cutting property and the pickup property can be achieved at a sufficiently high level.

[Industrial availability]

According to the present disclosure, a method for evaluating and selecting a wafer-cut-and-bond integrated film is provided, which takes into account the influence of edge peeling and interface peeling of small chips (area of less than ⁹ mm2). In addition, according to the present disclosure, a method for evaluating the pickup performance is provided, which takes into account the influence of edge peeling and interface peeling of small chips, and a method for manufacturing a wafer-cut-and-bond integrated film with excellent pickup performance for small chips and a semiconductor device using the same.

1: Base material layer

3: Adhesive layer

3a: First area

3b: Second area

5: Next is the agent layer

5p: Next tablet

DR: Cutting Ring

F1: First page

F2: Second side

P: Press-in clamp

Ta: A chip with a bonding agent

Ts: chip

Ws:Silicon wafer

Claims (4)

A wafer-cutting-and-bonding integrated film, comprising: a substrate layer; an adhesive layer having a first surface facing the substrate layer and a second surface opposite thereto; and an adhesive layer arranged to cover the central portion of the second surface of the adhesive layer, wherein the adhesive layer has a peeling strength of 3.0 N/25 mm or less when measured at a temperature of 23° C., a peeling angle of 30°, and a peeling speed of 60 mm/min, and an edge peeling strength of 1.2 N or less when measured by the following steps. The step of adhering a 50μm thick silicon wafer to the adhesive layer and adhering a diced ring to the second surface of the adhesive layer; the step of singulating the silicon wafer and the adhesive layer into a plurality of wafers with adhesive wafers to obtain the wafers with a side length of 2mm in a square shape; the step of pressing the center of the wafer with adhesive wafer from the side of the substrate layer at a speed of 60mm/min at a temperature of 23°C and measuring the edge peeling strength of the edge of the wafer with adhesive wafer when it is peeled off from the adhesive layer. The wafer-cutting-and-bonding integrated film as described in claim 1 is applied in a semiconductor device manufacturing process, wherein the semiconductor device manufacturing process includes the step of singulating a wafer and an adhesive layer into a plurality of chips with an area of less than ⁹ mm2 and with adhesive sheets. The wafer-cutting-and-bonding integrated film as described in claim 2, wherein in the singulation step, the plurality of wafers with bonding agents are obtained by wafer cutting with a blade. A method for manufacturing a semiconductor device, comprising: preparing a wafer-cutting-bonding integrated film as described in any one of claims 1 to 3; attaching a wafer to the adhesive layer of the wafer-cutting-bonding integrated film and attaching a wafer-cutting ring to the second surface of the adhesive layer; singulating the wafer and the adhesive layer into a plurality of chips with an area of less than ⁹ mm2 and with adhesive wafers; picking up the chips with adhesive wafers from the adhesive layer; and mounting the chips with adhesive wafers on a substrate or other chips.

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