JP2022030093A - Manufacturing method of semiconductor device and expanded tape - Google Patents

Abstract

To provide a manufacturing method of a semiconductor device in which the displacement of semiconductor chips is sufficiently suppressed when a distance between the pieces of semiconductor chips is widened.SOLUTION: A manufacturing method of a semiconductor device including a semiconductor chip includes a tape expanding step of widening the distance between a plurality of semiconductor chips 2 fixed on an expanding tape 1 at a widening ratio of more than 1 time and less than 3 times by heating and stretching the expanding tape 1. In the expanded tape 1, when the tensile stress at 25°C is f1 (MPa) and the tensile stress at the heating temperature of the tape expanding step is f2 (MPa), f2 is less than 5 MPa, and the difference (f1-f2) between f1 and f2 is less than 9 MPa.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a semiconductor device and an expanded tape.

In recent years, along with the miniaturization, high functionality, and high integration of semiconductor devices, the number of pins of semiconductors has increased, the density has increased, and the pitch of wiring has become narrower. Therefore, a fragile layer such as a low-K layer for the purpose of miniaturization or low dielectric constant of pins or wiring is applied, and along with this, high reliability technology is required.

Against this background, wafer level package (WLP) technology that enables high reliability, high production, and the like is advancing. The WLP technology is characterized in that the wafer is assembled in the state of the wafer and the wafer is separated by dicing in the final process. It is a technology that enables high production and high reliability because it is assembled (sealed) at the wafer level. In WLP technology, a rewiring layer in which a rewiring pattern is formed with polyimide, copper wiring, etc. is formed on the insulating film on the circuit surface of a semiconductor chip, and a metal pad, solder ball, etc. are mounted on the rewiring and connected. Configure terminal bumps.

The WLP includes a semiconductor package such as WLCSP (Wafer Level Chip Scale Package) or FI-WLP (Fan In Wafer Level Package), which has a package area similar to that of a semiconductor chip, and a FO-WLP (Fan Out Wave). ), There is a semiconductor package in which the package area is larger than the semiconductor chip area and the terminals can be extended to the outside of the chip. In such semiconductor packages, miniaturization and thinning are rapidly progressing, and sealing is performed at the wafer level to ensure reliability, and after protecting the periphery of the semiconductor chip, a rewiring layer is formed. Individualization of each package is performed.

In such a semiconductor package, reliability is ensured by sealing at the wafer level as described above and then handling such as secondary mounting. Further, even in the field of mounting a single-function semiconductor such as a discrete semiconductor, sealing is performed at the wafer level for the purpose of reducing the stress applied to the crack of the semiconductor chip or the peripheral portion of the pad during handling. Next, after the periphery of the semiconductor chip is protected, each package is individualized and the next step (SMT process or the like) is performed. Discrete semiconductors are often smaller than system LCIs, and in order to protect the semiconductor chips to a higher degree, 5-sided or 6-sided encapsulation of the semiconductor chips is particularly required.

In order to seal the side surface of such a semiconductor chip, it is necessary to widen the distance between the semiconductor chips after the wafer is separated into individual pieces to produce the semiconductor chip. For example, in Patent Document 1, a method of fixing a plurality of chips on an expanded tape, stretching the expanded tape to widen the interval between the semiconductor chips, and then peeling the expanded tape from the semiconductor chip, and a method used in the method. Expanded tapes that can be disclosed.

International Publication No. 2018/216621

However, when stretching using the conventional expanding tape, a phenomenon that the semiconductor chip fixed on the expanding tape moves to a position different from the position expected after stretching, that is, a case where the semiconductor chip is misaligned occurs. There is. If the position of the semiconductor chip is large, for example, the semiconductor chip may be damaged in dicing after batch encapsulation, pickup failure may occur, and productivity may decrease.

Therefore, it is a main object of the present invention to provide a method for manufacturing a semiconductor device in which the misalignment of semiconductor chips is sufficiently suppressed when the distance between the fragmented semiconductor chips is widened.

One aspect of the present invention relates to a method for manufacturing a semiconductor device having a semiconductor chip. One embodiment of the method for manufacturing a semiconductor device is to stretch an expanded tape while heating it to widen the space between a plurality of semiconductor chips fixed on the expanded tape at a widening magnification of more than 1 time and less than 3 times. The tape expanding process is provided. In the expanded tape, when the tensile stress at 25 ° C. is f1 (MPa) and the tensile stress at the heating temperature in the tape expanding step is f2 (MPa), f2 is less than 5 MPa, and the difference between f1 and f2 (f1-f2). ) Is less than 9 MPa. In such a method for manufacturing a semiconductor device, the displacement of the semiconductor chips is sufficiently suppressed when the distance between the individualized semiconductor chips is widened. Here, f1 may be less than 15 MPa.

The above-mentioned method for manufacturing a semiconductor device may further include a transfer step of transferring a plurality of semiconductor chips to a carrier so that the surface opposite to the surface fixed on the expanding tape is fixed. ..

In another embodiment of the method for manufacturing the semiconductor device, the distance between a plurality of semiconductor chips fixed on the expansion tape for transfer is increased by more than 1 time and less than 3 times by stretching the expanded tape for transfer while heating. The tape expanding process that widens with the widening magnification of the above, and the transfer that transfers the surface of multiple semiconductor chips to the expanded tape to be transferred so that the surface opposite to the surface fixed on the expanding tape for transfer is fixed. It has a process. In the expanded tape for transfer and the expanded tape to be transferred, when the tensile stress at 25 ° C. is f1 (MPa) and the tensile stress at the heating temperature in the tape expanding step is f2 (MPa), f2 is less than 5 MPa, and f1. The difference from f2 (f1-f2) is less than 9 MPa. These tape expanding steps and transfer steps are repeated a plurality of times in this order.

According to the studies by the present inventors, it has been found that when an attempt is made to widen the semiconductor chip once with a widening magnification in the range of 3 times or more by using the conventional expanded tape, the misalignment of the semiconductor chip tends to increase. .. On the other hand, in the above-mentioned method for manufacturing a semiconductor device, the tape expanding step and the transfer step are repeated a plurality of times in this order to sufficiently suppress the misalignment of the semiconductor chips and to reduce the distance between the individualized semiconductor chips. , The width can be gradually widened to a range of 3 times or more with respect to the spacing of the initial semiconductor chips. Here, f1 may be less than 15 MPa.

One aspect of the present invention relates to an expanded tape. In the expanded tape, when the tensile stress at 25 ° C. is f1 (MPa) and the tensile stress at 50 ° C. is f2a (MPa), f2a is less than 5 MPa, and the difference between f1 and f2a (f1-f2a) is less than 9 MPa. Is. According to such an expanded tape, it is possible to suppress the misalignment of the semiconductor chips when the distance between the individualized semiconductor chips is widened. Here, f1 may be less than 15 MPa.

INDUSTRIAL APPLICABILITY According to the present invention, there is provided a method for manufacturing a semiconductor device in which the misalignment of semiconductor chips is sufficiently suppressed when the spacing between the fragmented semiconductor chips is widened. Further, according to the present invention, there is provided an expanded tape capable of suppressing misalignment of semiconductor chips when the spacing between the fragmented semiconductor chips is widened.

FIG. 1 is a schematic cross-sectional view for explaining one aspect of the first embodiment of the method for manufacturing a semiconductor device, and FIGS. 1 (a), 1 (b), and 1 (c) show each step. It is a figure which shows. FIG. 2 is a schematic cross-sectional view for explaining one aspect of the first embodiment of the method for manufacturing a semiconductor device, and FIGS. 2 (a), 2 (b), and 2 (c) show each step. It is a figure which shows. FIG. 3 is a schematic cross-sectional view for explaining another aspect of the first embodiment of the method for manufacturing a semiconductor device, and FIGS. 3 (a), 3 (b), and 3 (c) are steps. It is a figure which shows. FIG. 4 is a schematic cross-sectional view for explaining another aspect of the first embodiment of the method for manufacturing a semiconductor device, and FIGS. 4 (a), 4 (b), and 4 (c) are steps. It is a figure which shows.

Hereinafter, the present embodiment will be described in detail with reference to the drawings. In the following description, the same or corresponding parts will be designated by the same reference numerals, and duplicate description will be omitted. In addition, the positional relationship such as up, down, left, and right shall be based on the positional relationship shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios in the drawings are not limited to the ratios shown.

[Manufacturing method of semiconductor devices]
<First Embodiment>
In the method for manufacturing a semiconductor device of the first embodiment, the distance between a plurality of semiconductor chips fixed on the expand tape is increased by more than 1 time and less than 3 times by stretching a predetermined expanded tape described later while heating. It is equipped with a tape expanding process that widens at a widening magnification.

The method for manufacturing a semiconductor device according to the first embodiment may include, for example, the following steps.
-Preparation step for preparing a laminate having a predetermined expanded tape and a plurality of semiconductor chips fixed on the expanded tape, which will be described later.-A plurality of semiconductors fixed on the expanded tape by stretching the expanded tape while heating it. Tape expanding process that widens the chip spacing with a widening magnification of more than 1x and less than 3x ・ Tension holding process that holds the tension of the stretched expanded tape ・ Fixing to the carrier on the expanding tape of multiple semiconductor chips Transfer step to transfer so that the surface opposite to the surface to be fixed is fixed.

The expanded tape has a base film and an adhesive layer provided on the base film. The pressure-sensitive adhesive layer may contain, for example, a pressure-sensitive pressure-sensitive adhesive or an ultraviolet-curable pressure-sensitive adhesive. The pressure-sensitive adhesive layer may be made of a pressure-sensitive pressure-sensitive adhesive or may be made of an ultraviolet-curable pressure-sensitive adhesive. When the adhesive layer contains an ultraviolet curable pressure-sensitive adhesive, the method for manufacturing a semiconductor device according to the first embodiment further includes an ultraviolet irradiation step of irradiating the expanded tape with ultraviolet rays. The ultraviolet irradiation step may be provided before and after any step. The ultraviolet irradiation step depends on the properties of the ultraviolet curable pressure-sensitive adhesive, but may be provided between the preparation step and the tape expanding step, or may be provided between the tension holding step and the transfer step.

1 and 2 are schematic cross-sectional views for explaining one aspect of the first embodiment of the method for manufacturing a semiconductor device, and FIGS. 3 and 4 are other than the first embodiment of the method for manufacturing a semiconductor device. It is a schematic cross-sectional view for demonstrating the aspect of.

Hereinafter, the details of each step will be described.

In the preparation step, the laminate 6 including the expand tape 1 and the plurality of semiconductor chips 2 fixed on the expand tape 1 is prepared. The expanded tape 1 has a base film 1b and an adhesive layer 1a provided on the base film 1b, and the adhesive layer 1a is in contact with the semiconductor chip 2. Further, the semiconductor chip 2 may have a circuit surface provided with a pad (circuit) 3. The surface of the semiconductor chip 2 opposite to the circuit surface may be fixed to the expand tape 1 (FIG. 1 (a)), or the circuit surface may be fixed to the expand tape 1 (FIG. 3 (FIG. 3). a)).

In the tape expanding step, by stretching the expanding tape 1 while heating it, the distance between the plurality of semiconductor chips 2 fixed on the expanding tape 1 is widened at a widening ratio of more than 1 time and less than 3 times (FIG. 1). (B) or FIG. 3 (a)).

In the tension holding step, the stretched expand tape 1 is fixed by using the fixing jig 4 to hold the tension of the expand tape 1 (FIG. 1 (c) or FIG. 3 (c)).

In the ultraviolet irradiation step, which is provided between the tension holding step and the transfer step as needed, the stretched expanded tape 1 is irradiated with ultraviolet rays to obtain the adhesive strength (peel strength) of the expanded tape 1 to the semiconductor chip 2. (FIG. 2 (a) or FIG. 4 (a)). The ultraviolet irradiation step may be provided between the preparation step and the tape expanding step.

In the transfer step, the semiconductor chip 2 is transferred to the carrier 5 so that the surface opposite to the surface fixed on the expand tape is fixed. In the preparatory step, when the surface of the semiconductor chip 2 opposite to the circuit surface is fixed to the expand tape 1, the circuit surface is fixed to the carrier 5 by the above transfer (FIG. 2 (b)), and the semiconductor chip 2 is fixed. When the circuit surface of the above is fixed to the expand tape 1, the surface opposite to the circuit surface is fixed to the carrier 5 by the above transfer (FIG. 4 (b)).

Finally, the semiconductor device 10 can be obtained by peeling the expand tape 1 from the semiconductor chip 2 (FIG. 2 (c) or FIG. 4 (c)).

(Preparation process)
In the preparation step, a laminate including the expand tape and a plurality of semiconductor chips fixed on the expand tape is prepared. The laminate can be produced, for example, by laminating a semiconductor wafer on a dicing tape or the like, dicing with a blade or a laser to produce a plurality of individualized semiconductor chips, and transferring these to an expanded tape. can.

Dicing may be performed by forming a fragile layer with a laser and expanding it. Further, from the viewpoint of improving productivity, the laminate may be produced by directly laminating the semiconductor wafer on the expanding tape without the above transfer and dicing the semiconductor wafer by the above method.

From the viewpoint of improving productivity and reducing cost, the initial distance between semiconductor chips (distance between semiconductor chips before the tape expanding process) is preferably narrow, for example, 100 μm or less, preferably 80 μm or less, more preferably. It is 60 μm or less. In the cutting of the semiconductor wafer by dicing, if the initial distance between the semiconductor chips is wide, the semiconductor wafer is wasted. Therefore, the narrower one as described above is preferable from the viewpoint of cost reduction. From the viewpoint of avoiding stress on the semiconductor chips when widening the distance between the semiconductor chips, the initial distance between the semiconductor chips is preferably 10 μm or more. When the distance between the initial semiconductor chips is smaller than 10 μm, the expanded tape region between the plurality of semiconductor chips is small and it tends to be difficult to widen.

The size of the semiconductor chip is not particularly limited, but is, for example, 25 (5 × 5) mm ² or less, preferably 9 (3 × 3) mm ² or less.

The type of pad on the circuit surface of the semiconductor chip is not particularly limited as long as it can be formed on the circuit surface of the semiconductor chip, and even bumps (projection electrodes) such as copper bumps and solder bumps are Ni / Au. It may be a relatively flat metal pad such as a plating pad.

The semiconductor chip may be provided with a resin portion that protects from the outside, an external terminal for electrically connecting the semiconductor element, and the like.

In the present specification, the term "semiconductor chip" includes a semiconductor package provided with a resin portion that protects from the outside, an external terminal for electrically connecting a semiconductor element, and the like. When a semiconductor package is used in the preparatory step, for example, a semiconductor package manufactured at the substrate level is laminated on a dicing tape or the like, and then diced with a blade or a laser to obtain a plurality of individualized semiconductor chips. Can be prepared by transferring to an expanded tape.

(Tape expanding process)
In the tape expanding step, by stretching the expanding tape, the distance between the plurality of semiconductor chips fixed on the expanding tape is widened at a widening ratio of more than 1 time and less than 3 times.

Examples of the expanding tape stretching method include a push-up method and a pulling method. In the push-up method, after the expand tape is fixed, the expanded tape is stretched by raising the stage having a predetermined shape. The tension method is a method in which the expand tape is stretched by fixing the expand tape and then pulling it in a predetermined direction in parallel with the installed expand tape surface. The push-up method is preferable because the distance between the semiconductor chips can be uniformly extended and the required (occupied) device area is small and compact.

The stretching conditions can be appropriately set according to the characteristics of the expanded tape. For example, when the push-up method is adopted, the push-up amount (pulling amount) is preferably 10 to 150 mm, more preferably 10 to 120 mm. When the push-up amount is 10 mm or more, the distance between the plurality of semiconductor chips is easily widened, and when the push-up amount is 150 mm or less, the semiconductor chips are less likely to be scattered or misaligned.

The temperature at the time of stretching can also be appropriately set according to the characteristics of the expanded tape. The temperature at the time of stretching may be, for example, 25 to 200 ° C, 25 to 150 ° C or 30 to 100 ° C. When the temperature at the time of stretching is 25 ° C. or higher, the expanded tape is easily stretched, and when the temperature at the time of stretching is 200 ° C. or lower, the position of the semiconductor chip due to distortion or sagging due to thermal expansion or low elasticity of the expanded tape. It is possible to prevent displacement (peeling between the expanding tape and the semiconductor chip), scattering of the semiconductor chip, and the like to a higher degree.

The push-up speed can also be appropriately set according to the characteristics of the expanded tape. The push-up speed may be, for example, 0.1 to 500 mm / sec, 0.1 to 300 mm / sec, or 0.1 to 200 mm / sec. When the push-up speed is 0.1 mm / sec or more, the productivity can be further improved. When the push-up speed is 500 mm / sec or less, peeling between the semiconductor chip and the expanding tape is less likely to occur.

The spacing between the plurality of semiconductor chips after the tape expanding process is the spacing between the plurality of semiconductor chips before the tape expanding process in order to secure the space required for providing the rewiring pattern and the pad for the connection terminal outside the area of the semiconductor chip. The width is widened at a widening ratio of more than 1 time and less than 3 times with respect to (initial spacing of semiconductor chips). By widening the width at such a widening ratio by using a predetermined expand tape described later, the displacement of the semiconductor chip can be sufficiently suppressed. The widening magnification may be, for example, 1.2 times or more or 1.5 times or more, or may be 2.8 times or less, 2.5 times or less, or 2.3 times or less.

The misalignment in the tape expanding process is defined as follows, for example.
1. 1. Before and after the tape expanding step, the coordinate position of the central semiconductor chip is measured, and then the coordinate position of any semiconductor chip is measured.
2. 2. Assuming widening to a predetermined widening magnification, the assumed ideal coordinate position of the semiconductor chip at that time is determined.
The average value of the difference between the coordinate position of 3.1 and the coordinate position of 2 is calculated, and this is defined as the positional deviation.

More specifically, the positional deviation in the tape expanding step can be obtained by the method described in Examples. The positional deviation in the tape expanding step is preferably suppressed to, for example, 10 μm or less.

(Tension holding process)
In the tension holding step, the tension of the expanded tape is held in order to prevent the stretched expanded tape from returning to the original state.

The method of holding the tension of the expanded tape is not particularly limited as long as the tension is held and the distance between the semiconductor chips is not restored. For example, a method of fixing using a fixing jig such as a grip ring (manufactured by Technovision Co., Ltd.), a method of heating and shrinking the outer peripheral portion of the expand tape (heat shrink), and the like to hold the tension can be mentioned.

(Ultraviolet irradiation process)
The method for manufacturing a semiconductor device according to the first embodiment may further include an ultraviolet irradiation step, if necessary. In the ultraviolet irradiation step, the stretched expanded tape is irradiated with ultraviolet rays to reduce the adhesive force of the expanded tape to the semiconductor chip. In the present embodiment, it is preferable to use ultraviolet rays having a wavelength of 200 to 400 nm, and as the irradiation conditions, it is preferable to irradiate with an illuminance of 30 to 240 mW / cm ² and an irradiation amount of 200 to 500 mJ / cm ² . ..

The ultraviolet irradiation step may be provided between the preparation step and the tape expanding step, or may be provided between the tension holding step and the transfer step.

(Transfer process)
In the transfer step, the semiconductor chip is transferred (laminated) so as to be fixed to the carrier. The laminating method is not particularly limited, but a roll laminator, a diaphragm type laminator, a vacuum roll laminator, and a vacuum diaphragm type laminator can be adopted.

The laminating conditions may be appropriately set according to the physical properties and characteristics of the expanded tape, the semiconductor chip and the carrier. For example, in the case of a roll laminator, the temperature may be 25 to 200 ° C, preferably 25 to 150 ° C, and more preferably 25 to 100 ° C. When the temperature is 25 ° C or higher, the semiconductor chip is easily transferred (laminated) to the carrier, and when the temperature is 200 ° C or lower, the semiconductor chip is displaced due to distortion or sagging due to thermal expansion or low elasticity of the expanded tape (with the expanded tape). (Peeling between semiconductor chips), scattering of semiconductor chips, etc. can be prevented to a higher degree. If it is a diaphragm type laminator, the temperature conditions are the same as those of the above-mentioned roll laminator. The crimping time may be 5 to 300 seconds, preferably 5 to 200 seconds, and more preferably 5 to 100 seconds. When the crimping time is 5 seconds or more, the semiconductor chip is easily transferred (laminated) to the carrier, and when the crimping time is 300 seconds or less, the productivity can be improved. The pressure at the time of crimping may be 0.1 to 3 MPa, preferably 0.1 to 2 MPa, and more preferably 0.1 to 1 MPa. When the pressure at the time of crimping is 0.1 MPa or more, the semiconductor chip is easily transferred (laminated) to the carrier, and when the pressure at the time of crimping is 3 MPa or less, the damage to the semiconductor chip is reduced.

The method for manufacturing a semiconductor device according to the first embodiment includes a first peeling step of peeling an expanded tape from a plurality of semiconductor chips, a sealing (molding) step of sealing a plurality of semiconductor chips on a carrier with a sealing material, and the like. The second peeling step of peeling the carrier from the plurality of semiconductor chips sealed with the encapsulant, the plurality of semiconductor chips sealed with the encapsulant are individualized for each semiconductor chip, and a plurality of semiconductor packages are formed. It may further include a step of forming a semiconductor package to be formed, a step of picking up an individualized semiconductor chip or an individualized semiconductor package, and the like.

Next, the materials used in each step will be described.

[Expanded tape]
The expanding tape is a semiconductor comprising a tape expanding step of expanding the distance between a plurality of semiconductor chips fixed on the expanding tape at a widening ratio of more than 1 time and less than 3 times by stretching the expanding tape while heating it. It may be suitably used in a method for manufacturing a semiconductor device having a chip.

In the expanded tape, when the tensile stress at 25 ° C. is f1 (MPa) and the tensile stress at the heating temperature in the tape expanding step is f2 (MPa), f2 is less than 5 MPa, and the difference between f1 and f2 (f1-f2). ) Is less than 9 MPa. The tensile stress was 100% when the base film was cut out to a width of 20 mm and a length of 50 mm by a commercially available precision universal tester and stretched 100% at a chuck spacing of 50 mm and a tensile speed of 1 mm / s. It means stress. The heating temperature in the tape expanding step is the stage temperature at which the expanded tape is expanded, and means the maximum temperature in heating. The heating temperature in the tape expanding step can be, for example, 50 ° C. The tensile stress at 50 ° C. is f2a (MPa).

The expanded tape has a base film and an adhesive layer provided on the base film. The tensile strength of the expanded tape depends on the base film. Therefore, the tensile strength of the base film alone may be measured, and the numerical value measured thereby may be used as the tensile strength of the expanded tape.

By using such an expanded tape, it is possible to suppress the misalignment of the semiconductor chips when the spacing between the individualized semiconductor chips is widened. Although it is not always clear that such an effect is obtained, the present inventors consider as follows.

It is speculated that in the tape expanding process, it is the elongation of the expanded tape in the region where the semiconductor chip is fixed that contributes to widening the spacing of the semiconductor chips, and the stretching of the other regions does not contribute to widening the spacing. Will be done. Here, in the tape expanding step, the base film of the expanding tape in the region where the semiconductor chip is fixed is heated on the stage, while the other regions are not heated and are near room temperature (25 ° C.). The heated region of the base film tends to have a small tensile stress and easily stretches, while the unheated region tends to have a large tensile stress and is difficult to stretch. It is presumed that the misalignment of the semiconductor chip in the tape expanding process is caused by the large difference in tensile stress between these two regions. Therefore, it is considered that by setting f1 and (f1-f2) in a predetermined range, it is possible to suppress the positional deviation that occurs when the expanded tape is stretched when the expanded tape is widened at a predetermined widening ratio in the tape expanding step. ing.

The tensile stress f1 (MPa) at 25 ° C. may be less than 15 MPa, 14 MPa or less, 13 MPa because it is possible to further suppress the misalignment while further securing the spacing between the semiconductor chips after the tape expanding step. Hereinafter, it may be 12 MPa or less, 11 MPa or less, or 10 MPa or less. f1 (MPa) may be, for example, 6 MPa or more, 7 MPa or more, 8 MPa or more, or 9 MPa or more.

The tensile stress f2 (MPa) of the heating temperature in the tape expanding step is less than 5 MPa and 4.5 MPa or less because it is possible to suppress the misalignment while sufficiently securing the spacing between the semiconductor chips after the tape expanding step. It may be 4 MPa or less, 3.5 MPa or less, or 3 MPa or less. f2 (MPa) may be, for example, 0.1 MPa or more, 1 MPa or more, or 2 MPa or more.

The heating temperature in the tape expanding step can be, for example, 50 ° C. The tensile stress f2a at 50 ° C. is less than 5 MPa, and may be 4.5 MPa or less, 4 MPa or less, 3.5 MPa or less, or 3 MPa or less. f2a (MPa) may be, for example, 0.1 MPa or more, 1 MPa or more, or 2 MPa or more.

The difference (f1-f2) (MPa) between f1 and f2 is less than 9 MPa and 8.5 MPa because it is possible to suppress misalignment while sufficiently ensuring the spacing between semiconductor chips after the tape expanding step. It may be less than or equal to 8 MPa or less. (F1-f2) (MPa) may be, for example, 5 MPa or more, 6 MPa or more, or 7 MPa or more.

The difference (f1-f2a) (MPa) between f1 and f2a is less than 9 MPa and 8.5 MPa because it is possible to suppress misalignment while sufficiently ensuring the spacing between semiconductor chips after the tape expanding step. It may be less than or equal to 8 MPa or less. (F1-f2a) (MPa) may be, for example, 5 MPa or more, 6 MPa or more, or 7 MPa or more.

The tensile stress f1 (MPa) at 25 ° C., the tensile stress f2 (MPa) at the heating temperature of the tape expanding step, and the tensile stress f2a (MPa) at 50 ° C. are either the MD direction or the TD direction of the base film. It suffices to satisfy the above range in the direction, and it is preferable to satisfy the above range in the TD direction. According to the studies by the present inventors, it was found that the misalignment tends to increase in the X-axis direction in the same direction as the TD direction of the base film. Therefore, by satisfying the above range with f1 (MPa), f2 (MPa), and f2a (MPa) in the TD direction, the displacement of the semiconductor chips after the tape expanding step is more sufficiently secured and the misalignment is caused. It is presumed that it can be further suppressed.

The adjustment of the tensile stress f1 (MPa) at 25 ° C., the tensile stress f2 (MPa) at the heating temperature of the tape expanding step, and the tensile stress f2a (MPa) at 50 ° C. is, for example, the type, layer structure, and thickness of the base film. It can be done by adjusting the stress and the like.

(Base film)
The base film can be used without particular limitation as long as it satisfies the above tensile strength. Examples of the base film include polyester films such as polyethylene terephthalate film; α- such as polytetrafluoroethylene film, polyethylene film, polypropylene film, polymethylpentene film, polyvinylacetate film, and poly-4-methylpentene-1. Examples thereof include homopolymers of olefins and copolymers thereof, polyolefin-based films such as ionomers of these homopolymers or copolymers; polyvinyl chloride films; polyimide films; and various plastic films such as urethane resin films. The base film is not limited to a single-layer film, and may be a multilayer film obtained by combining two or more types of plastic films or two or more plastic films of the same type.

The base film is preferably a polyolefin-based film or a urethane resin film from the viewpoint of tensile stress and stretchability. The base film may contain various additives such as an antiblocking agent, if necessary.

The thickness of the base film is preferably 50 to 500 μm. If the thickness of the base film is thinner than 50 μm, the stretchability is lowered, and if it is larger than 500 μm, there is a possibility that distortion is likely to occur and the handleability is lowered.

The thickness of the base film is appropriately selected within a range that does not impair workability. However, when a high-energy ray (especially ultraviolet) curable pressure-sensitive adhesive is used as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, it is necessary to make the thickness so as not to hinder the transmission of the high-energy ray. From such a viewpoint and the viewpoint of tensile stress, the thickness of the base film may be usually 10 to 500 μm, preferably 50 to 400 μm, and more preferably 70 to 300 μm.

When the base film is a multilayer film, it is preferable to adjust the thickness of the entire base film within the above range. The base film may be chemically or physically surface-treated, if necessary, in order to improve the adhesion to the adhesive layer. Examples of the surface treatment include corona treatment, chromic acid treatment, ozone exposure, flame exposure, high-voltage impact exposure, ionizing radiation treatment and the like.

(Adhesive layer)
The adhesive layer is not particularly limited as long as the adhesive strength can be controlled. The adhesive layer may contain, for example, a pressure-sensitive adhesive or an ultraviolet curable adhesive, but since the adhesive strength can be easily adjusted by ultraviolet irradiation, the adhesive layer is an ultraviolet curable type. It may contain an adhesive. Such an adhesive layer (ultraviolet curable adhesive) preferably contains an acrylic copolymer (acrylic resin), a cross-linking agent, and a photopolymerization initiator.

The acrylic copolymer has at least a radiation-curable carbon-carbon double bond-containing group and a hydroxyl group with respect to the main chain.

Acrylic resin or methacrylic resin as an acrylic copolymer (hereinafter referred to as "(meth) acrylic resin") contains an unsaturated bond in the side chain and the resin itself has adhesiveness. If there is, there is no limit. Specifically, the glass transition temperature is -40 ° C or less, the hydroxyl value is 20 to 150 mgKOH / g, the chain-growth-polymerizable functional group is contained in 0.3 to 1.5 mmol / g, and the acid value is high. Examples thereof include resins having a weight average molecular weight of 300,000 or more, which are not substantially detected.

A (meth) acrylic resin having such characteristics can be obtained by synthesizing it by a known method. Examples of the method for producing the (meth) acrylic resin include a solution polymerization method, a suspension polymerization method, an emulsion polymerization method, a bulk polymerization method, a precipitation polymerization method, a gas phase polymerization method, a plasma polymerization method, and a supercritical polymerization method. Can be mentioned. Examples of the type of polymerization reaction include radical polymerization, cationic polymerization, anionic polymerization, living radical polymerization, living cationic polymerization, living anionic polymerization, coordination polymerization, immortal polymerization and the like, as well as methods such as ATRP or RAFT. Among these, radical polymerization using the solution polymerization method has good economic efficiency, high reaction rate, ease of polymerization control, etc., and also has the convenience of compounding such that the resin solution obtained by the polymerization can be used as it is. It is preferable because there is.

The monomer used for synthesizing the (meth) acrylic resin is not particularly limited as long as it has one (meth) acryloyl group in one molecule. Examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, butoxyethyl (meth) acrylate, and isoamyl (. Meta) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, octylheptyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, lauryl (Meta) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxy Acrylate (meth) acrylates such as polyethylene glycol (meth) acrylates, methoxypolypropylene glycol (meth) acrylates, ethoxypolypropylene glycol (meth) acrylates, and mono (2- (meth) acryloyloxyethyl) succinates; cyclopentyl (meth) acrylates. , Cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate, mono (2- (meth) acryloyloxyethyl) tetrahydrophthalate , Mono (2- (meth) acryloyloxyethyl) hexahydrophthalate and other alicyclic (meth) acrylates; benzyl (meth) acrylate, phenyl (meth) acrylate, o-biphenyl (meth) acrylate, 1-naphthyl ( Meta) acrylate, 2-naphthyl (meth) acrylate, phenoxyethyl (meth) acrylate, p-cumylphenoxyethyl (meth) acrylate, o-phenylphenoxyethyl (meth) acrylate, 1-naphthoxyethyl (meth) acrylate, 2- Naftoxyethyl (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-naphthoxy) propyl (meth) acrylate, 2-hydroxy-3- (2-naphthoxy) propyl Aromatic (meth) acrylates such as (meth) acrylates; 2-tetrahydrofurfuryl (meth) acrylates, N- (meth) acryloyloxyethyl hexahydrophthalimide, 2- (meth) acryloyloxyethyl-N-carbazole and the like. Heterocyclic (meth) acrylates, modified caprolactones of these, ω-carboxy-polycaprolactone mono (meth) acrylates, glycidyl (meth) acrylates, α-ethylglycidyl (meth) acrylates, α-propyl glycidyl (meth) acrylates. , 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 an ethylenically unsaturated group and an epoxy group such as p-vinylbenzyl glycidyl ether; (2-ethyl-2-oxetanyl) methyl (meth) acrylate, (2-methyl-2-oxetanyl) methyl (meth) acrylate, 2- (2-Ethyl-2-oxetanyl) ethyl (meth) acrylate, 2- (2-methyl-2-oxetanyl) ethyl (meth) acrylate, 3- (2-ethyl-2-oxetanyl) propyl (meth) acrylate , 3- (2-Methyl-2-oxetanyl) propyl (meth) acrylate and other ethylenically unsaturated groups and compounds having an oxetanyl group; 2- (meth) acryloyloxyethyl isocyanate and other ethylenically unsaturated groups and isocyanate groups. Compounds with; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) ) A compound having an ethylenically unsaturated group such as acrylate and a hydroxyl group Things and the like can be mentioned. This may be used alone or in combination of two or more.

As the monomer used for synthesizing the (meth) acrylic resin, styrene and its derivatives copolymerizable with the above-mentioned monomers, maleimide compounds such as alkylmaleimide, cycloalkylmaleimide, and arylmaleimide are used, if necessary. be able to.

Among these, it is preferable to use at least one selected from (meth) acrylic esters which are aliphatic esters of C8 to C23. The (meth) acrylic resin obtained by copolymerizing such a monomer component has a low glass transition temperature and is preferable because it exhibits excellent adhesive properties.

A known polymerization initiator can be used to obtain such a (meth) acrylic resin. Such a polymerization initiator can be used without particular limitation as long as it is a compound that generates radicals by heating at 30 ° C. or higher.

The reaction solvent used in the solution polymerization is not particularly limited as long as it is a solvent (organic solvent) capable of dissolving the (meth) acrylic resin. The organic solvent can be used alone or in combination of two or more. Further, supercritical carbon dioxide or the like can be used as a solvent for polymerization.

Photosensitivity can be imparted by chemically binding a (meth) acrylic resin to a functional group that can react by irradiation with ultraviolet rays, electron beams, and / or visible light. The functional groups that can react by irradiation with ultraviolet rays, electron beams, and / or visible light are, if specific examples, a (meth) acryloyl group, a vinyl group, an allyl group, a glycidyl group, and a fat. Examples include a cyclic epoxy group and an oxenyl group.

The method for imparting photosensitivity to the (meth) acrylic resin is not particularly limited, but for example, when synthesizing the above (meth) acrylic resin, a functional group capable of an addition reaction in advance, for example, a hydroxyl group or a carboxyl group A functional group capable of an addition reaction to a (meth) acrylic resin is introduced by copolymerizing with a monomer having a maleyl anhydride group, a glycidyl group, an amino group, etc., and at least one ethylenically unsaturated group and an epoxy are introduced therein. A (meth) acrylic resin is obtained by subjecting a compound having at least one functional group selected from a group, an oxetanyl group, an isocyanate group, a hydroxyl group, a carboxyl group, etc. to an addition reaction to introduce an ethylenically unsaturated group into the side chain. Can be imparted with photosensitivity.

Examples of the compound to be subjected to such an addition reaction include glycidyl (meth) acrylate, α-ethyl glycidyl (meth) acrylate, α-propyl glycidyl (meth) acrylate, α-butyl glycidyl (meth) acrylate, and 2-methyl glycidyl (. Meta) acrylate, 2-ethylglycidyl (meth) acrylate, 2-propylglycidyl (meth) acrylate, 3,4-epoxybutyl (meth) acrylate, 3,4-epoxyheptyl (meth) acrylate, α-ethyl-6, Ethylene unsaturated groups such as 7-epoxyheptyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether and epoxy. Compounds with groups; (2-ethyl-2-oxetanyl) methyl (meth) acrylate, (2-methyl-2-oxetanyl) methyl (meth) acrylate, 2- (2-ethyl-2-oxetanyl) ethyl (meth) Acrylate, 2- (2-methyl-2-oxetanyl) ethyl (meth) acrylate, 3- (2-ethyl-2-oxetanyl) propyl (meth) acrylate, 3- (2-methyl-2-oxetanyl) propyl (meth) ) Compounds having an ethylenically unsaturated group such as acrylate and an oxetanyl group; Compounds having a saturated group and an isocyanate group; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, etc. Compounds with ethylenically unsaturated groups and hydroxyl groups; (meth) acrylic acid, crotonic acid, silicic acid, succinic acid (2- (meth) acryloyloxyethyl), 2-phthaloylethyl (meth) acrylate, 2 -Tetrahydrophthaloylethyl (meth) acrylate, 2-hexahydrophthaloylethyl (meth) acrylate, ω-carboxy-polycaprolactone mono (meth) acrylate, 3-vinylbenzoic acid, 4-vinylbenzoic acid, etc. Compounds having a saturation group and a carboxyl group, etc. Can be mentioned.

Among such compounds to be subjected to an addition reaction, 2- (meth) acryloyloxyethyl isocyanate, glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, and isocyanic acid from the viewpoint of cost and / or reactivity. Ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, (meth) acrylic acid, crotonic acid, 2-hexahydrophthaloylethyl ( It is preferable to use (meth) acrylate or the like to react with the (meth) acrylic resin to impart photosensitivity. These compounds may be used alone or in combination of two or more. If necessary, a catalyst that promotes the addition reaction can be added, or a polymerization inhibitor can be added for the purpose of avoiding the cleavage of the double bond during the reaction. The (meth) acrylic resin imparted with photosensitivity is preferably a (meth) acrylic resin containing a hydroxyl group and at least one selected from 2-methacryloyloxyethyl isocyanate and 2-acryloyloxyethyl isocyanate. It is a reaction product of.

The content of the acrylic copolymer contained in the pressure-sensitive adhesive layer is preferably more than 50 parts by mass with respect to 100 parts by mass of the composition constituting the pressure-sensitive adhesive layer.

The cross-linking agent is a compound having at least one selected from the hydroxyl group, glycidyl group, amino group and the like introduced into the (meth) acrylic resin and two or more functional groups capable of reacting with these functional groups. There are no restrictions on its structure. Examples of the bond formed by such a cross-linking agent include an ester bond, an ether bond, an amide bond, an imide bond, a urethane bond, and a urea bond.

The cross-linking agent is preferably an isocyanate compound having two or more isocyanate groups. By using such an isocyanate compound, it easily reacts with the hydroxyl group, glycidyl group, amino group, etc. introduced into the (meth) acrylic resin to form a strong crosslinked structure, and the adhesive layer becomes brittle after irradiation with ultraviolet rays. It can be suppressed.

Examples of the cross-linking agent having two or more isocyanate groups include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene 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, lysine isocyanate, etc. Isocyanate compound and the like.

As the cross-linking agent, an isocyanate-containing oligomer obtained by reacting the above-mentioned isocyanate compound with a polyhydric alcohol having two or more hydroxyl groups can also be used. Examples of the polyhydric alcohol used for obtaining such an oligomer include ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, and 1, Examples thereof include 10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, glycerin, pentaerythritol, dipentaerythritol, 1,4-cyclohexanediol, and 1,3-cyclohexanediol.

Among these, the cross-linking agent is more preferably a reaction product of a polyfunctional isocyanate having two or more isocyanate groups and a polyhydric alcohol having three or more hydroxyl groups. By using such an isocyanate group-containing oligomer, the adhesive layer can form a dense crosslinked structure, and it is possible to prevent the adhesive layer from becoming brittle after irradiation with ultraviolet rays.

The content of the cross-linking agent contained in the adhesive layer is preferably 0.05 to 1.5 parts by mass with respect to 100 parts by mass of the acrylic copolymer. If the content of the cross-linking agent is less than 0.05 parts by mass, it may cause the adhesive layer to become brittle after irradiation with ultraviolet rays. On the other hand, when the content of the cross-linking agent exceeds 1.5 parts by mass, the adhesive force of the adhesive layer before irradiation with ultraviolet rays tends to be weakened, and the force for fixing the semiconductor chip tends to be insufficient.

The photopolymerization initiator is particularly limited as long as it generates an active species capable of causing chain polymerization of the acrylic copolymer by irradiation with one or more kinds of light selected from ultraviolet rays, electron beams, and visible light. However, for example, it may be a photoradical polymerization initiator or a photocationic polymerization initiator. The active species capable of chain polymerization is not particularly limited as long as the polymerization reaction is started by reacting with the functional group of the acrylic copolymer.

The optimum value of the content of the photopolymerization initiator contained in the pressure-sensitive adhesive layer varies depending on the thickness of the target pressure-sensitive adhesive layer and / or the light source used, but is preferably 0.5 to 1.5 parts by mass. If the content of the photopolymerization initiator is less than 0.5 parts by mass, the peeling force after irradiation with ultraviolet rays does not sufficiently decrease, and problems tend to occur when the amount of push-up is low at the time of pickup. If the content of the photopolymerization initiator exceeds 1.5 parts by mass, there is no advantage in properties and it becomes uneconomical.

The thickness of the adhesive layer is usually 1 to 100 μm, preferably 2 to 50 μm, and more preferably 5 to 40 μm. When the thickness of the adhesive layer is 1 μm or more, sufficient adhesive force with the semiconductor chip can be secured, so that the scattering of the semiconductor chip can be prevented more highly during the tape expanding step. On the other hand, if the thickness of the adhesive layer exceeds 100 μm, there is no advantage in the characteristics and it becomes uneconomical.

When the thickness of the adhesive layer is 10 μm or more, preferably 20 to 50 μm, more preferably 30 to 50 μm, even if the semiconductor wafer is diced on the expanded tape without using the dicing tape, the base film is damaged (cut). Etc.) are not included, so that the step of dicing the semiconductor wafer on the dicing tape and transferring (pasting) it to the expanding tape can be omitted in the preparation step.

(How to make expanded tape)
The expanded tape can be manufactured according to a technique well known in the art. For example, it can be manufactured according to the following method. By applying a varnish containing an adhesive component and a solvent on the protective film by a knife coating method, a roll coating method, a spray coating method, a gravure coating method, a bar coating method, a curtain coating method, etc., and removing the solvent. Form an adhesive layer. Specifically, it is preferable to heat at 50 to 200 ° C. for 0.1 to 90 minutes. If there is no effect on void generation or viscosity adjustment in each step, it is preferable to set the condition to volatilize until the solvent becomes 1.5% or less. Next, the prepared protective film with an adhesive layer and the base film are laminated under a temperature condition of 25 to 60 ° C. so that the adhesive layer and the base film face each other.

The expanded tape is used by peeling off the protective film.

Examples of the protective film include A-63 (manufactured by Toyobo Film Solution Co., Ltd., mold release treatment agent: modified silicone type), A-31 (manufactured by Toyobo Film Solution Co., Ltd., mold release treatment agent: Pt-based silicone type) and the like. Can be mentioned.

The thickness of the protective film is appropriately selected within a range that does not impair workability. The thickness of the protective film is usually preferably 100 μm or less from an economical point of view. The thickness of the protective film is more preferably 10 to 75 μm, still more preferably 25 to 50 μm. If the thickness of the protective film is 10 μm or more, problems such as tearing of the film during the production of the expanded tape are unlikely to occur. Further, when the thickness of the protective film is 75 μm or less, the protective film can be easily peeled off when the expand tape is used.

(Career)
The carrier is not particularly limited as long as it can withstand the temperature and pressure at the time of transfer (the chips do not break, the chip spacing does not change), and can also withstand the temperature and pressure at the time of encapsulation. For example, when the sealing temperature is 100 to 200 ° C., it is preferable to have heat resistance that can withstand the temperature range. The thermal expansion rate is preferably 100 ppm / ° C. or lower, more preferably 50 ppm / ° C. or lower, and even more preferably 20 ppm / ° C. or lower. If the thermal expansion rate is large, problems such as misalignment of the semiconductor chip tend to occur. Further, the thermal expansion rate is preferably 3 ppm / ° C. or higher because distortion or warpage occurs when the thermal expansion rate is smaller than that of the semiconductor chip.

The material of the carrier is not particularly limited, and examples thereof include silicon (wafer), glass, SUS, iron, plates such as Cu, and glass epoxy substrates.

The thickness of the carrier may be 100 to 5000 μm, preferably 100 to 4000 μm, and more preferably 100 to 3000 μm. When the thickness of the carrier is 100 μm or more, the handleability is improved. The thickness of the carrier may be 5000 μm or less in consideration of economic aspects, because even if it is thick, it is not expected to significantly improve the handleability.

The carrier may be composed of a plurality of layers. In addition to the layer responsible for heat resistance and handleability, there may be an adhesive layer or a layer laminated with a temporary fixing material from the viewpoint of imparting adhesion control. The adhesion force can be appropriately set in consideration of the adhesion force of the semiconductor chip or the expanded tape. When composed of a plurality of layers, the thickness thereof is not particularly limited, but may be, for example, 1 to 300 μm, preferably 1 to 200 μm. When the thickness is 1 μm or more, sufficient adhesive strength with the semiconductor chip can be ensured. On the other hand, if the thickness exceeds 300 μm, there is no advantage in the characteristics, which is uneconomical.

<Second Embodiment>
In the method for manufacturing a semiconductor device of the second embodiment, the distance between a plurality of semiconductor chips fixed on the transfer expand tape is increased by more than 1 time and less than 3 times by stretching the transfer expanded tape while heating it. A tape expanding step that widens at a widening magnification, and a transfer that transfers the semiconductor chips to the expanded tape to be transferred so that the surface of the plurality of semiconductor chips opposite to the surface fixed on the transfer expand tape is fixed. It has a process. In the expanded tape for transfer and the expanded tape to be transferred, when the tensile stress at 25 ° C. is f1 (MPa) and the tensile stress at the heating temperature of the tape expanding step is f2 (MPa), f2 is less than 5 MPa and f1. The difference (f1-f2) between f2 and f2 is less than 9 MPa. In the method for manufacturing a semiconductor device according to the second embodiment, the tape expanding step and the transfer step are repeated a plurality of times in this order.

The difference between the method for manufacturing the semiconductor device of the second embodiment and the method for manufacturing the semiconductor device of the first embodiment is that in the method for manufacturing the semiconductor device of the first embodiment, the semiconductor device is transferred to the carrier after the tape expanding step. On the other hand, in the method for manufacturing a semiconductor device of the second embodiment, after a tape expanding step using an expand tape (expand tape for transfer), the semiconductor device is transferred to another expand tape (expand tape for transfer) and finally. The point is that the tape expanding step and the transfer step are repeated a plurality of times in this order before being transferred to the carrier. According to the studies by the present inventors, it has been found that when an attempt is made to widen the semiconductor chip once with a widening magnification in the range of 3 times or more by using the conventional expanded tape, the misalignment of the semiconductor chip tends to increase. .. On the other hand, in the above-mentioned method for manufacturing a semiconductor device, the tape expanding step and the transfer step are repeated a plurality of times in this order to sufficiently suppress the misalignment of the semiconductor chips and to reduce the distance between the individualized semiconductor chips. , The width can be gradually widened to a range of 3 times or more with respect to the spacing of the initial semiconductor chips.

In the method for manufacturing a semiconductor device according to the second embodiment, each step (preparation step, necessary) other than the above points (a point in which a predetermined tape expanding step and a predetermined transfer step are provided and these steps are repeated a plurality of times in this order). The steps provided accordingly), the materials used (expanded tape, carriers, etc.), tensile stress (f1, f2, f2a, etc.) and the like are the same as those described in the method for manufacturing the semiconductor device of the first embodiment. Therefore, in the second embodiment, the duplicate description will be omitted.

The expansion tape for transfer has a base film and an adhesive layer provided on the base film. The expanded tape for transfer has a base film and an adhesive layer provided on the base film. The base film is the same as that exemplified in the base film of the method for manufacturing the semiconductor device of the first embodiment. As the adhesive layer, the material exemplified in the adhesive layer of the method for manufacturing a semiconductor device of the first embodiment can be used.

The expanded tape for transfer and the expanded tape for transfer may be the same or different as long as they satisfy the above conditions of tensile stress. If the expanded tape for transfer and the expanded tape for transfer are the same, the same expanded tape can be used, which is efficient.

When the tape expanding step and the transfer step are repeated a plurality of times in this order, the expanded tape for transfer can be used as the expanded tape for transfer in the tape expand step, and the expanded tape for transfer is separately prepared in the transfer step. Will be done. The expanded tape for transfer prepared separately is not particularly limited as long as it satisfies the above conditions of tensile stress.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

(Preparation of acrylic resin solution)
1000 g of ethyl acetate, 650 g of 2-ethylhexyl acrylate, 350 g of 2-hydroxyethyl acrylate, and 3.0 g of azobisisobutyronitrile were blended into an autoclave with a capacity of 4000 mL equipped with a three-one motor, a stirring blade, and a nitrogen introduction tube. After stirring until uniform, nitrogen bubbling was carried out at a flow rate of 100 mL / min for 60 minutes to degas the dissolved oxygen in the system. The temperature was raised to 60 ° C. over 1 hour, and after the temperature was raised, polymerization was carried out for 4 hours. After that, the temperature was raised to 90 ° C. over 1 hour, kept at 90 ° C. for 1 hour, and then cooled to room temperature. Next, 1000 g of ethyl acetate was added, and the mixture was stirred and diluted. To this, 0.1 g of methquinone as a polymerization inhibitor and 0.05 g of dioctyltin dilaurate as a urethanization catalyst were added, and then 100 g of 2-methacryloyloxyethyl isocyanate (Carens MOI (registered trademark) manufactured by Showa Denko KK). added. After reacting at 70 ° C. for 6 hours, the mixture was cooled to room temperature. Then, ethyl acetate was added to adjust the non-volatile content in the acrylic resin solution to 35% by mass to obtain an acrylic resin solution having a functional group capable of chain polymerization.

When the acid value and the hydroxyl value of this acrylic resin were measured according to JIS K0070, the acid value was not detected and the hydroxyl value was 121 mgKOH / g. Further, the obtained acrylic resin solution was vacuum-dried at 60 ° C. overnight, and the obtained solid content was elementally analyzed by a fully automatic elemental analyzer (varioEL manufactured by Elemental Co., Ltd.). When the content of 2-methacryloyloxyethyl isocyanate introduced into the acrylic resin was calculated from the measured nitrogen content, it was 0.59 mmol / g. Further, SD-8022 / DP-8020 / RI-8020 (manufactured by Tosoh Corporation) is used, and Gelpack GL-A150-S / GL-A160-S (manufactured by Hitachi Kasei Co., Ltd.) is used as the column for elution. As a result of GPC measurement using tetrahydrofuran as the liquid, the polystyrene-equivalent weight average molecular weight was 420,000.

(Preparation of base film)
The base film is a resin in which Hymilan 1706 (manufactured by Mitsui-Dupont Polychemical Co., Ltd., ionomer resin), ethylene / 1-hexene copolymer and butene / α-olefin copolymer, and Hymilan 1706 are laminated in this order. A film was used. When the thickness of each layer is Hymilan 1706: ethylene / 1-hexene copolymer and butene / α-olefin copolymer: Hymilan 1706, the base film A (thickness 100 μm) is 1: 2: 1. ), 1: 3: 1 was used as the base film B (thickness 100 μm), and 1: 1: 1 was used as the base film C (thickness 100 μm). Further, a film composed of only one layer of Hymilan 1706 was used as a base film D (thickness 100 μm).

[Example 1]
<Making expanded tape>
With respect to the above acrylic resin solution (solid content: 100 parts by mass), polyfunctional isocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L, solid content 75%) was used as a solid content in 0.2 parts by mass, and photopolymerization was started. 1.0 part by mass of 1-hydroxycyclohexylphenyl ketone (manufactured by BASF Corporation, Irgacure 184) was added as an agent, and 2-butanone was added so that the total solid content was 25% by mass, and the mixture was uniformly stirred for 10 minutes. .. Then, the obtained solution was applied and dried on a protective film (surface release-treated polyethylene terephthalate, thickness 25 μm) to form an adhesive layer. At this time, the thickness of the adhesive layer at the time of drying was set to 10 μm. Next, the base film A was prepared, the pressure-sensitive adhesive layer surface was laminated on the base film A, and the obtained tape was aged at 40 ° C. for 4 days. In this way, the expanded tape of Example 1 was obtained.

The adhesive layer, the protective film, and the base film were laminated with a roll laminator at 40 ° C. to form a protective film / adhesive layer / base film in this order. When used as an expanding tape, the protective film was peeled off before use.

<Manufacturing of semiconductor chip (process 1)>
A 4-inch silicon wafer (thickness 200 μm) is laminated on a dicing tape (TRO-9515, Tsukasa Trading Co., Ltd.) attached to a 12-inch dicing ring at 40 ° C, and a laminating device (V130, manufactured by Nikko Materials Co., Ltd.). Dicing with a blade to a size of 3 mm × 3 mm using a dicing device (DFD3360, manufactured by DISCO Corporation) to obtain a plurality of individualized semiconductor chips. Then, using a UV exposure machine (ML-320FSAT, manufactured by Mikasa Co., Ltd.), UV (ultraviolet rays) was irradiated at 600 mJ to reduce the adhesion of the dicing tape.

<Transfer of semiconductor chip to expanded tape (step 2)>
Multiple semiconductor chips were transferred onto an expanding tape attached to an 8-inch dicing ring using a hand roller on a hot plate at 40 ° C. The sample from which the dicing tape was peeled off after the transfer was used as a sample for expansion, and each 8-inch dicing ring was set in an 8-inch expander device (MX-5154FN manufactured by Omiya Kogyo Co., Ltd.). At this time, the distance between the initial semiconductor chips was 45 μm.

<Tape expanding process and tension holding process (process 3)>
The expanded tape was stretched by pushing it up at an appropriate height so that the semiconductor chip spacing was widened to 100 μm (widening magnification 2.22 (= 100/45) times) at a push-up speed of 1 mm / sec and a temperature (stage temperature) of 50 ° C. .. The sample in which the expanded tape was stretched was fixed with a 6-inch dicing ring to retain the tension. This was used as a sample for misalignment observation.

[Example 2 and Comparative Examples 1 and 2]
Expanded tapes of Examples 2 to 5 and Comparative Example 1 were obtained in the same manner as in Example 1 except that the amounts of the cross-linking agent and the photopolymerization initiator used were changed as shown in Table 1. Using the expanded tapes of Examples 2 to 5 and Comparative Example 1, the same steps 1 to 5 as in Example 1 were carried out.

<Evaluation method>
(Measurement of tensile stress of base film)
An autograph (AG-Xplus, manufactured by Shimadzu Corporation) was used for measuring the tensile stress of the base films A to D. Evaluation samples were cut out from the base films A to D in the MD direction and the TD direction with a width of 20 mm and a length of 50 mm. Using this evaluation sample, the tensile stress when the chuck distance was 50 mm and the tensile speed was 100% stretched at 1 mm / s was measured. The measurement was performed at room temperature (25 ° C.) and at a stage temperature of 50 ° C. when the expanded tape was widened using a high temperature test device (TCRN type, manufactured by Shimadzu Corporation). The results are shown in Table 1.

<Evaluation of misalignment during widening>
The coordinate position of the semiconductor chip after the above step 1 (before widening) was measured using NEXIV VMZ-K (Nikon Instick Co., Ltd.). Next, the coordinate position of the semiconductor chip after step 3 (after widening) was measured. At this time, as measurement points, 1 point was measured at the central portion and 36 points were measured at the peripheral portion (5 points each in the vertical and horizontal directions around the central portion, and 4 points in the diagonal direction), for a total of 37 points. Based on the measurement result of the coordinate position of the semiconductor chip after the above step 1 (before widening), the assumed ideal coordinate position of the semiconductor chip when the width is widened to 2.22 (= 100/45) times is obtained. Were determined. Next, the difference between the ideal coordinate position after widening and the actual coordinate position after widening was obtained, and the average value of the difference was taken as the positional deviation. It can be said that the larger the average value of the difference between the ideal coordinate position after widening and the actual coordinate position after widening, the larger the positional deviation. When the misalignment was less than 10 μm, it was evaluated as “A” as the misalignment was suppressed, and when the misalignment was 10 μm or more, it was evaluated as “B” as the misalignment was not suppressed. The results are shown in Table 1.

As shown in Table 1, by using the expanded tapes of Examples 1 and 2, the displacement of the semiconductor chips was suppressed when the distance between the semiconductor chips was widened. From these results, it was confirmed that the method for manufacturing a semiconductor device of the present invention sufficiently suppresses the misalignment of semiconductor chips when the distance between the separated semiconductor chips is widened.

1 ... Expanded tape, 1a ... Adhesive layer, 1b ... Base film, 2 ... Semiconductor chip, 3 ... Pad (circuit), 4 ... Fixing jig, 5 ... Carrier, 6 ... Laminated body, 10 ... Semiconductor device.

Claims (7)

A method for manufacturing a semiconductor device having a semiconductor chip.
A tape expanding step is provided in which the distance between a plurality of semiconductor chips fixed on the expanded tape is widened by a widening ratio of more than 1 time and less than 3 times by stretching the expanded tape while heating it.
In the expanded tape, when the tensile stress at 25 ° C. is f1 (MPa) and the tensile stress at the heating temperature in the tape expanding step is f2 (MPa), f2 is less than 5 MPa, and the difference between f1 and f2 (f1). -F2) is less than 9 MPa,
Manufacturing method of semiconductor devices. The f1 is less than 15 MPa.
The method for manufacturing a semiconductor device according to claim 1. The carrier is further provided with a transfer step of transferring the plurality of semiconductor chips so that the surface of the semiconductor chip opposite to the surface fixed on the expanded tape is fixed.
The method for manufacturing a semiconductor device according to claim 1 or 2. A method for manufacturing a semiconductor device having a semiconductor chip.
A tape expanding step in which the distance between a plurality of semiconductor chips fixed on the transfer expanding tape is widened at a widening ratio of more than 1 time and less than 3 times by stretching the expanding tape for transfer while heating.
A transfer step of transferring a plurality of the semiconductor chips to the expanded tape to be transferred so that the surface opposite to the surface fixed on the expanded tape for transfer is fixed.
Equipped with
In the transfer expanded tape and the expanded tape to be transferred, when the tensile stress at 25 ° C. is f1 (MPa) and the tensile stress at the heating temperature of the tape expanding step is f2 (MPa), f2 is less than 5 MPa. , The difference between f1 and f2 (f1-f2) is less than 9 MPa.
The tape expanding step and the transfer step are repeated a plurality of times in this order.
Manufacturing method of semiconductor devices. The f1 is less than 15 MPa.
The method for manufacturing a semiconductor device according to claim 4. When the tensile stress at 25 ° C. is f1 (MPa) and the tensile stress at 50 ° C. is f2a (MPa), f2a is less than 5 MPa, and the difference between f1 and f2a (f1-f2a) is less than 9 MPa.
Expanded tape. The f1 is less than 15 MPa.
The expanded tape according to claim 6.

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