KR20230066116A - Semiconductor processing sheet - Google Patents

Abstract

A sheet for semiconductor processing comprising at least a substrate, wherein the recovery rate is 70% or more and 100% or less, or 100% as measured in the MD direction of the substrate at 23°C relative to 100% stress measured in the CD direction of the substrate at 23°C. The % stress ratio is 0.8 or more and 1.2 or less, or the tensile modulus measured in the MD direction and the CD direction of the substrate at 23°C is 10 MPa or more and 350 MPa or less, respectively, and the MD direction of the substrate at 23°C and 100% stress measured in the CD direction is 3 MPa or more and 20 MPa or less, respectively, and elongation at break measured in the MD direction and CD direction of the base material at 23°C is 100% or more, respectively. Such a sheet for semiconductor processing can be greatly stretched, and semiconductor chips can be sufficiently separated from each other.

Description

Sheet for semiconductor processing {SEMICONDUCTOR PROCESSING SHEET}

The present invention relates to a semiconductor processing sheet, and preferably relates to a semiconductor processing sheet used in order to widen an interval between a plurality of semiconductor chips.

In recent years, miniaturization, weight reduction, and high functionality of electronic devices are progressing. Semiconductor devices mounted in electronic devices are also being demanded for miniaturization, thinning, and high density. A semiconductor chip may be mounted in a package close to its size. Such a package is sometimes referred to as a ChiP Scale Package (CSP). As one of the CSPs, a wafer level package (WLP) can be mentioned. In WLP, external electrodes and the like are formed on the wafer before it is separated into pieces by dicing, and finally the wafer is diced and separated into pieces. WLP includes a fan-in type and a fan-out type. In a fan-out type WLP (hereinafter sometimes abbreviated as "FO-WLP"), a semiconductor chip is covered with a sealing member to form an area larger than the chip size, forming a semiconductor chip encapsulation body; A redistribution layer and an external electrode are formed not only on the circuit surface of the semiconductor chip but also on the surface region of the sealing member.

For example, in Patent Literature 1, a plurality of semiconductor chips separated from a semiconductor wafer are surrounded by a mold member to form an expanded wafer, leaving the circuit formation surface thereof, and cultivating them in an area other than the semiconductor chip. A method of manufacturing a semiconductor package formed by extending a line pattern is disclosed. In the manufacturing method described in Patent Literature 1, before enclosing a plurality of individual semiconductor chips with a mold member, they are newly attached to a wafer mount tape for expansion, and the wafer mount tape is spread to form a plurality of semiconductor chips. The distance between them is widening.

International Publication No. 2010/058646

In the manufacturing method of the above FO-WLP, in order to form the above-mentioned rewiring pattern etc. in the area|region other than a semiconductor chip, it is necessary to separate semiconductor chips sufficiently.

The present invention has been made in view of the above reality, and an object of the present invention is to provide a sheet for semiconductor processing that can be greatly stretched and is suitable for applications in which semiconductor chips need to be sufficiently separated from each other.

In order to achieve the above object, first, the present invention is a semiconductor processing sheet having at least a substrate, wherein the semiconductor processing sheet has a recovery rate of 70% or more and 100% or less, and the restoration rate is 150 In the test piece cut into mm × 15 mm, both ends in the longitudinal direction are held with a gripper so that the length between the grippers is 100 mm, and then at a rate of 200 mm/min until the length between the grippers is 200 mm. Tensed, held for 1 minute in a state where the length between the grippers was expanded to 200 mm, and then returned to the longitudinal direction at a rate of 200 mm/min until the length between the grippers reached 100 mm, and the length between the grippers is held for 1 minute in a state where it has returned to 100 mm, and then pulled in the longitudinal direction at a speed of 60 mm/min, and the length between the grippers when the measured value of the tensile force indicates 0.1 N/15 mm is measured. L2 (mm) is the length obtained by subtracting 100 mm of the length between the initial grippers from the length, and the length obtained by subtracting the length of 100 mm between the initial grippers from the length of 200 mm between the grippers in the extended state When L1 (mm) is used, the following formula (I)

Recovery rate (%) = {1 - (L2 ÷ L1)} × 100 … (I)

Provides a sheet for semiconductor processing characterized in that the value calculated from (Invention 1).

According to the above invention (invention 1), when the restoration ratio is within the above range, it is possible to greatly extend the film. Therefore, it can be used suitably for the use which needs to fully separate semiconductor chips, such as manufacture of FO-WLP, for example.

Second, the present invention is a sheet for semiconductor processing comprising at least a base material, wherein the sheet for semiconductor processing at 23° C. measures in the MD direction of the base material at 23° C. against 100% stress of the sheet for semiconductor processing measured in the CD direction of the base material. The ratio of the 100% stress of the sheet for semiconductor processing to be measured is 0.8 or more and 1.2 or less, and the 100% stress is a test piece cut out of the sheet for semiconductor processing to 150 mm x 15 mm, both ends in the longitudinal direction between the grippers. By holding it with a gripper so that the length becomes 100 mm, then pulling it in the longitudinal direction at a speed of 200 mm/min, and dividing the measured value of the tensile force when the length between the grippers becomes 200 mm by the cross-sectional area of the sheet for semiconductor processing Provided is a sheet for semiconductor processing characterized in that it is an obtained value (Invention 2).

According to the above invention (invention 2), when the ratio of 100% stress is in the above range, it is possible to greatly extend it. Therefore, it can be used suitably for the use which needs to fully separate semiconductor chips, such as manufacture of FO-WLP, for example.

Thirdly, the present invention is a sheet for semiconductor processing comprising at least a substrate, wherein the tensile modulus of elasticity of the sheet for semiconductor processing measured in the MD and CD directions of the substrate at 23°C is 10 MPa or more and 350 MPa or less, respectively. , 100% stress of the sheet for semiconductor processing measured in the MD direction and the CD direction of the substrate at 23 ° C. is 3 MPa or more and 20 MPa or less, respectively, and the 100% stress is 150 mm × In the test piece cut out to 15 mm, both ends in the longitudinal direction were held with a gripper so that the length between the grippers was 100 mm, and then pulled in the longitudinal direction at a speed of 200 mm/min, and the length between the grippers was 200 mm. It is a value obtained by dividing the measured value of the tensile force when it becomes a cross-sectional area of the sheet for semiconductor processing, and the breaking elongation of the sheet for semiconductor processing measured in the MD direction and the CD direction of the substrate at 23 ° C. is 100% or more, respectively. Provided is a sheet for semiconductor processing characterized by (Invention 3).

According to the above invention (invention 3), when the tensile elastic modulus and the elongation at break are within the above ranges, it is possible to greatly extend the film. Therefore, it can be used suitably for the use which needs to fully separate semiconductor chips, such as manufacture of FO-WLP, for example.

In the above inventions (Inventions 1 to 3), it is preferable to further include a pressure-sensitive adhesive layer laminated on at least one surface of the base material (Invention 4).

In the above inventions (Inventions 1 to 4), it is preferable that the substrate contains a thermoplastic elastomer (Invention 5).

In the above invention (Invention 5), it is preferable that the thermoplastic elastomer is a urethane-based elastomer (Invention 6).

In the above inventions (Inventions 1 to 6), the space between adjacent semiconductor chips in a plurality of semiconductor chips laminated on one side of the sheet for semiconductor processing is used to widen the distance between 200 µm and more and 6000 µm and less Preferred (Invention 7).

In the above inventions (Inventions 1 to 7), tension is applied in four directions of the +X-axis direction, -X-axis direction, +Y-axis direction, and -Y-axis direction in the X-axis and Y-axis orthogonal to each other, thereby forming a semiconductor It is preferable to use in order to widen the space|interval of the some semiconductor chips laminated|stacked on one side of the said sheet for semiconductor processing by extending the sheet|seat for processing elongate (Invention 8).

In the above inventions (Inventions 1 to 8), a step of forming a plurality of individual semiconductor chips on one side of a pressure-sensitive adhesive sheet, and a step of extending the distance between the plurality of semiconductor chips by elongating the pressure-sensitive adhesive sheet In the manufacturing method of the provided semiconductor device, it is preferable to use as the pressure-sensitive adhesive sheet (Invention 9).

In the above inventions (Inventions 1 to 9), it is preferable to use for manufacturing a fan-out type semiconductor wafer level package (Invention 10).

The sheet for semiconductor processing according to the present invention can be greatly stretched, and semiconductor chips can be sufficiently separated from each other.

1 is a cross-sectional view illustrating a first aspect of a method of using a sheet for semiconductor processing according to an embodiment of the present invention.
2 is a cross-sectional view illustrating a first aspect of a method of using a sheet for semiconductor processing according to an embodiment of the present invention.
3 is a cross-sectional view illustrating a first aspect of a method of using a sheet for semiconductor processing according to an embodiment of the present invention.
4 is a cross-sectional view illustrating a second aspect of a method of using a sheet for semiconductor processing according to an embodiment of the present invention.
5 is a cross-sectional view illustrating a second aspect of a method of using a sheet for semiconductor processing according to an embodiment of the present invention.
6 is a cross-sectional view illustrating a second aspect of a method of using a sheet for semiconductor processing according to an embodiment of the present invention.
7 is a cross-sectional view illustrating a second aspect of a method of using a sheet for semiconductor processing according to an embodiment of the present invention.
Fig. 8 is a plan view illustrating a biaxial stretching expander used in Examples.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described.

The sheet for semiconductor processing according to the present embodiment includes at least a substrate.

It is preferable that the restoration rate of the sheet|seat for semiconductor processing which concerns on this embodiment is 70 % or more and 100 % or less.

In this specification, a restoration rate means what is calculated as follows. First, the sheet|seat for semiconductor processing is cut out to 150 mm x 15 mm, and a test piece is obtained. The said cutting is performed so that the MD direction of the base material in a sheet|seat for semiconductor processing and the longitudinal direction of a test piece may match. Next, both ends of the test piece in the longitudinal direction are gripped with a gripper so that the distance between the grippers is 100 mm. The length between the grippers at this time is defined as the length L0 (mm) between the initial grippers. Next, the gripper span is pulled in the longitudinal direction at a speed of 200 mm/min, and held for 1 minute in a state where the gripper span is 200 mm. The length obtained by subtracting the length L0 (mm) between the initial grippers (i.e., 100 mm) from the length between the grippers after being expanded to 200 mm is taken as the extended length L1 (mm) (= 100 mm). After holding for 1 minute, the length between grippers is returned at a speed of 200 mm/min, and held for 1 minute in a state where the distance between grippers is 100 mm (ie, L0 (mm)). After that, the length between the grippers was stretched in the longitudinal direction at a rate of 60 mm/min, and the length between the grippers at the time when the measured value of the tensile force showed 0.1 N/15 mm was recorded. The value obtained by subtracting the length L0 (mm) between the initial grippers from the length is L2 (mm). The restoration rate (%) is obtained by applying the values of L1 and L2 obtained as described above to the following formula (I).

Recovery rate (%) = {1 - (L2 ÷ L1)} × 100 … (I)

In addition, in this tensile test, the thickness of the test piece is not particularly limited, and may be the same as the thickness of the sheet for semiconductor processing to be tested. In addition, the specific measurement method is as showing in the test example mentioned later.

Further, in the semiconductor processing sheet according to the present embodiment, 100% of the semiconductor processing sheet measured in the MD direction of the substrate at 23°C relative to the 100% stress of the semiconductor processing sheet measured in the CD direction of the substrate at 23°C. It is preferable that the ratio of stress is 0.8 or more and 1.2 or less. Here, the MD direction refers to the flow direction at the time of manufacturing the substrate, and the CD direction refers to a direction perpendicular to the MD direction.

In this specification, 100% stress means what is calculated as follows. In the test piece cut out of the sheet|seat for semiconductor processing to 150 mm x 15 mm, the both ends in the longitudinal direction were held with a gripper so that the distance between the grippers was 100 mm, and the length between the grippers was pulled in the longitudinal direction at a speed of 200 mm/min. 100% stress (MPa) is obtained by dividing the 100% strength expressed as the strength of tensile force (measured value of tensile force) in mm by the cross-sectional area of the semiconductor process sheet. The said cutting is performed so that the flow direction (MD direction) at the time of manufacture of the sheet|seat for semiconductor processing, or the direction orthogonal to MD direction (CD direction), and the longitudinal direction of a test piece may match. In addition, in this tensile test, the thickness of the test piece is not particularly limited, and may be the same as the thickness of the sheet for semiconductor processing to be tested. In addition, the specific measurement method is as showing in the test example mentioned later.

Further, in the sheet for semiconductor processing according to the present embodiment, the tensile modulus of elasticity of the sheet for semiconductor processing measured in the MD direction and the CD direction of the base material at 23°C is 10 MPa or more and 350 MPa or less, respectively, and at 23°C The 100% stress of the sheet for semiconductor processing measured in the MD direction and the CD direction is 3 MPa or more and 20 MPa or less, respectively, and the elongation at break of the sheet for semiconductor processing measured in the MD direction and the CD direction of the base material at 23 ° C. , It is preferable that each is 100% or more.

Since the sheet for semiconductor processing according to the present embodiment has the above-described physical properties, it becomes easy to stretch without causing breakage, and as a result, it becomes possible to greatly stretch.

In particular, when the restoration ratio is within the above range, it means that the sheet for semiconductor processing is easily restored even after being greatly stretched. In general, when a sheet having a yield point is stretched beyond the yield point, the sheet undergoes plastic deformation, and the portion where the plastic deformation occurs, that is, the extremely stretched portion becomes unevenly distributed. If the sheet in such a state is further stretched, breakage occurs from the above extremely stretched portion, or even if breakage does not occur, the expand becomes non-uniform. In addition, in the stress-strain diagram in which strain is plotted on the X axis and elongation on the Y axis, respectively, the slope dx/dy does not take a stress value that changes from a positive value to 0 or a negative value. Even if the sheet does not have a clear yield point and does not show a clear yield point, the sheet undergoes plastic deformation as the amount of tension increases, resulting in similar breakage or non-uniform expansion. On the other hand, when elastic deformation rather than plastic deformation occurs, the sheet is likely to be restored to its original shape by removing the stress. Therefore, when the recovery rate, which is an index indicating how much restoration is performed after 100% elongation, which is a sufficiently large tensile amount, is within the above range, plastic deformation of the film is suppressed to a minimum and breakage is less likely to occur when the sheet for semiconductor processing is greatly stretched. and uniform expansion is possible.

Further, when the ratio of 100% stress is within the above range, and when the tensile modulus, 100% stress and elongation at break are the above, when the sheet for semiconductor processing is stretched in the MD direction and the CD direction of the substrate (hereinafter, such stretching (sometimes referred to as "biaxial stretching"), it is possible to greatly stretch without breakage.

Specifically, in the above semiconductor processing sheet, it becomes possible to separate the semiconductor chips until the distance between them becomes a distance such as 200 µm or more. Such a sheet for semiconductor processing can be suitably used for a method for manufacturing a semiconductor device, such as a method for manufacturing FO-WLP, which requires sufficiently widening a space between semiconductor chips.

1. Physical properties of semiconductor processing sheets, etc.

In the sheet for semiconductor processing according to the present embodiment, the restoration rate is preferably 70% or more, particularly preferably 80% or more, and more preferably 85% or more. Moreover, it is preferable that the said restoration rate is 100 % or less. When the restoration ratio is within the above range, it becomes possible to greatly extend the sheet for semiconductor processing as described above.

In the sheet for semiconductor processing according to the present embodiment, 100% stress of the sheet for semiconductor processing measured in the MD direction of the substrate at 23°C relative to the 100% stress of the sheet for semiconductor processing measured in the CD direction of the substrate at 23°C It is preferable that ratio is 0.8 or more, It is especially preferable that it is 0.83 or more, Furthermore, it is preferable that it is 0.85 or more. In addition, the ratio is preferably 1.2 or less, particularly preferably 1.17 or less, and more preferably 1.15 or less. When the 100% stress ratio is within the above range, breakage of the semiconductor processing sheet is suppressed even when stress is easily applied only in a specific direction, such as in the case of biaxially stretching the semiconductor processing sheet. As a result, it becomes possible to stretch the sheet|seat for a semiconductor process larger.

In the sheet for semiconductor processing according to the present embodiment, the elongation at break of the sheet for semiconductor processing measured in the CD direction of the base material at 23°C is preferably 100% or more, particularly preferably 150% or more, and more preferably 200% or more desirable. Moreover, it is preferable that the said elongation at break is 1200 % or less, and it is especially preferable that it is 1000 % or less. When the elongation at break is within the above range, it is possible to greatly extend the sheet for semiconductor processing in the CD direction of the substrate. In addition, the measuring method of the breaking elongation in the CD direction is as showing in the test example mentioned later.

In the sheet for semiconductor processing according to the present embodiment, the elongation at break of the sheet for semiconductor processing measured in the MD direction of the substrate at 23 ° C. is preferably 100% or more, particularly preferably 150% or more, and more preferably 200% or more desirable. Moreover, it is preferable that the said elongation at break is 1200 % or less, and it is especially preferable that it is 1000 % or less. When the elongation at break is within the above range, it is possible to greatly extend the sheet for semiconductor processing in the MD direction of the substrate. In addition, the measuring method of the breaking elongation in MD direction is as showing the test example mentioned later.

In the sheet for semiconductor processing according to the present embodiment, the tensile modulus of elasticity of the sheet for semiconductor processing measured in the CD direction of the substrate at 23°C is preferably 10 MPa or more, particularly preferably 20 MPa or more, and more preferably 25 MPa or more. desirable. Further, the tensile modulus of elasticity is preferably 350 MPa or less, particularly preferably 300 MPa or less, and more preferably 250 MPa or less. When the said tensile elasticity modulus is 10 Mpa or more, when a semiconductor chip etc. are laminated|stacked on the sheet|seat for semiconductor processing, it becomes possible to support the semiconductor chip etc. favorably. Moreover, because the said tensile elasticity modulus is 350 Mpa or less, the sheet|seat for semiconductor processing becomes what has moderate softness|flexibility, and it becomes easy to extend|stretch the sheet|seat for semiconductor processing more greatly. In addition, the measuring method of the said tensile modulus is as showing the test example mentioned later.

In the sheet for semiconductor processing according to the present embodiment, the tensile modulus of elasticity of the sheet for semiconductor processing measured in the MD direction of the substrate at 23°C is preferably 10 MPa or more, particularly preferably 20 MPa or more, and more preferably 25 MPa or more. desirable. Further, the tensile modulus of elasticity is preferably 350 MPa or less, particularly preferably 300 MPa or less, and more preferably 250 MPa or less. When the said tensile elasticity modulus is 10 Mpa or more, when a semiconductor chip etc. are laminated|stacked on the sheet|seat for semiconductor processing, it becomes possible to support the semiconductor chip etc. favorably. Moreover, because the said tensile elasticity modulus is 350 Mpa or less, the sheet|seat for semiconductor processing becomes what has moderate softness|flexibility, and it becomes easy to extend|stretch the sheet|seat for semiconductor processing more greatly. In addition, the measuring method of the said tensile modulus is as showing the test example mentioned later.

In the sheet for semiconductor processing according to the present embodiment, the 100% stress of the sheet for semiconductor processing measured in the CD direction of the substrate at 23°C is preferably 3 MPa or more, particularly preferably 5 MPa or more, and more preferably 6 MPa or more. it is desirable When the 100% stress is 3 MPa or more, even if the thickness of the base material is reduced by greatly stretching the sheet for semiconductor processing, it is possible to maintain the force required to support the separated chips. In addition, the 100% stress is preferably 20 MPa or less, particularly preferably 18 MPa or less, and more preferably 16 MPa or less. When the elongation at break is 20 MPa or less, it is possible to greatly stretch the sheet for semiconductor processing without applying an excessive load to the expander, and even if the device is used continuously for a long period of time, it can be expected to prevent failure of the device. . The method for measuring the 100% stress in the CD direction is as shown in the test examples described later.

In the sheet for semiconductor processing according to the present embodiment, the 100% stress of the sheet for semiconductor processing measured in the MD direction of the substrate at 23°C is preferably 3 MPa or more, particularly preferably 5 MPa or more, and further preferably 6 MPa or more. it is desirable When the 100% stress is 3 MPa or more, even if the thickness of the base material is reduced by greatly stretching the sheet for semiconductor processing, it becomes possible to maintain the force necessary for supporting the separated chips, and the sheet for semiconductor processing is Large stretching in the CD direction becomes possible. In addition, the 100% stress is preferably 20 MPa or less, particularly preferably 18 MPa or less, and more preferably 16 MPa or less. When the elongation at break is 20 MPa or less, it is possible to greatly stretch the sheet for semiconductor processing without applying an excessive load to the expander, and even if the device is used continuously for a long period of time, it can be expected to prevent failure of the device. . In addition, the measuring method of 100% stress in MD direction is as showing the test example mentioned later.

It is preferable that at least one surface of the sheet|seat for semiconductor processing concerning this embodiment has adhesiveness. This makes it possible to attach and fix a semiconductor chip or the like to the surface. In addition, in this specification, the surface which has adhesiveness in a sheet|seat for semiconductor processing and to which a semiconductor chip etc. are stuck may be called "adhesive surface." The adhesive strength of the sheet for semiconductor processing according to the present embodiment is preferably 300 mN/25 mm or more, particularly preferably 800 mN/25 mm or more, and more preferably 1000 mN/25 mm or more. Moreover, it is preferable that the said adhesive force is 30000 mN/25 mm or less, It is especially preferable that it is 15000 mN/25 mm or less, Furthermore, it is preferable that it is 10000 mN/25 mm or less. When the said adhesive force is 300 mN/25 mm or more, a semiconductor chip etc. can be satisfactorily adhered and fixed to the adhesive surface. In addition, when the adhesive force is 30000 mN/25 mm or less, new bonding of semiconductor chips and the like from the sheet for semiconductor processing according to the present embodiment to other adhesive sheets, and semiconductor chips and the like from the sheet for semiconductor processing according to the present embodiment It becomes possible to satisfactorily perform transfer of a semiconductor chip or the like to a holding member capable of adsorbing holding, pick-up of a semiconductor chip from the sheet for semiconductor processing according to the present embodiment, and the like. The adhesive force in this specification is the adhesive force (mN/25 mm) measured by the 180° peeling method according to JIS Z0237:2009 using a mirror wafer made of silicon as an adherend. In the case where the sheet for semiconductor processing according to the present embodiment is composed of only the base material, the adhesive strength is assumed to be measured on one surface of the base material, and the sheet for semiconductor processing according to the present embodiment is composed of the base material and an adhesive layer described later. In this case, the adhesive strength shall be measured with respect to the surface opposite to the substrate in the pressure-sensitive adhesive layer.

The sheet for semiconductor processing according to the present embodiment preferably has heat resistance. When manufacturing a wafer-level package using the sheet for semiconductor processing according to this embodiment, there is a case where a semiconductor chip is sealed with a sealing member on the sheet for semiconductor processing according to this embodiment. Generally, a thermosetting material is used as the sealing member, and the material is heated during sealing. When the sheet|seat for semiconductor processing has heat resistance, it becomes possible to suppress the deformation of the sheet|seat for semiconductor processing by the said heating.

The thickness of the sheet for semiconductor processing according to the present embodiment is preferably 30 μm or more, and particularly preferably 50 μm or more. Moreover, it is preferable that the said thickness is 300 micrometers or less, and it is especially preferable that it is 250 micrometers or less.

2. Registration

The base material of the semiconductor processing sheet according to this embodiment is not particularly limited as long as the semiconductor processing sheet can achieve the above-mentioned physical properties, and is usually composed of a film containing a resin-based material as the main material. In particular, it is preferable to use a thermoplastic elastomer or a rubber-based material as the base material from the viewpoint of easy to achieve the above-mentioned physical properties, and among these, from the viewpoint of easier to achieve the above-mentioned physical properties, thermoplastic elastomer is used. It is particularly desirable to Further, from the viewpoint of easily achieving the above-mentioned physical properties, it is preferable to use a resin having a relatively low glass transition temperature (Tg) as a constituent material of the base material. In particular, the glass transition temperature (Tg) of such a resin is , It is preferably 90°C or less, particularly preferably 80°C or less, and more preferably 70°C or less.

Examples of the thermoplastic elastomer include urethane-based elastomers, olefin-based elastomers, vinyl chloride-based elastomers, polyester-based elastomers, styrene-based elastomers, acrylic-based elastomers, and amide-based elastomers. Among these, it is preferable to use a urethane-based elastomer from the viewpoint of more easily achieving the above-mentioned physical properties.

The urethane-based elastomer is generally obtained by reacting a long-chain polyol, a chain extender and a diisocyanate, and a polyurethane structure obtained from the reaction of a soft segment having structural units derived from the long-chain polyol, and a chain extender and diisocyanate It consists of a hard segment with

Urethane-based elastomers can be classified into polyester-based polyurethane elastomers, polyether-based polyurethane elastomers, polycarbonate-based polyurethane elastomers, and the like, depending on the type of long-chain polyol used as the soft segment component. In the sheet for semiconductor processing according to the present embodiment, among these, it is preferable to use a polyether polyurethane elastomer from the viewpoint of easily achieving the above-mentioned physical properties.

Examples of the long-chain polyol include polyester polyols such as lactone-based polyester polyols and adipate-based polyester polyols; polyether polyols such as polypropylene (ethylene) polyol and polytetramethylene ether glycol; Polycarbonate polyol etc. are mentioned. Among these, it is preferable to use an adipate-based polyester polyol from the viewpoint of easily achieving the above-mentioned physical properties.

Examples of the diisocyanate include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and hexamethylene diisocyanate. Among these, it is preferable to use hexamethylene diisocyanate from the viewpoint of easy achievement of the above-mentioned physical properties.

Examples of the chain extender include low molecular polyhydric alcohols such as 1,4-butanediol and 1,6-hexanediol, and aromatic diamines. Among these, it is preferable to use 1,6-hexanediol from the viewpoint of easy achievement of the above-mentioned physical properties.

Examples of the olefin elastomer include ethylene/α-olefin copolymers, propylene/α-olefin copolymers, butene/α-olefin copolymers, ethylene/propylene/α-olefin copolymers, ethylene/butene/α-olefin copolymers, containing at least one resin selected from the group consisting of a propylene/butene-α olefin copolymer, an ethylene/propylene/butene-α/olefin copolymer, a styrene/isoprene copolymer, and a styrene/ethylene/butylene copolymer; can be heard

The density of the olefin-based elastomer is not particularly limited, but is preferably 0.860 g/cm 3 or more and less than 0.905 g/cm 3 from the viewpoint of more stably obtaining a base material having excellent unevenness followability when attaching a semiconductor wafer to a sheet for semiconductor processing. and more preferably 0.862 g/cm 3 or more and less than 0.900 g/cm 3 , and particularly preferably 0.864 g/cm 3 or more and less than 0.895 g/cm 3 .

The olefinic elastomer preferably has a mass ratio of monomers composed of an olefinic compound (also referred to as "olefin content" in this specification) of 50 to 100% by mass among all the monomers used to form the elastomer. When the olefin content is excessively low, properties as an elastomer containing structural units derived from olefins are difficult to exhibit, and flexibility and rubber elasticity are not well exhibited. From the standpoint of stably obtaining these effects, the olefin content is preferably 50% by mass or more, and more preferably 60% by mass or more.

Examples of the styrenic elastomer include styrene-conjugated diene copolymers and styrene-olefin copolymers. Specific examples of the styrene-conjugated diene copolymer include a styrene-butadiene copolymer, a styrene-butadiene-styrene copolymer (SBS), a styrene-butadiene-butylene-styrene copolymer, a styrene-isoprene copolymer, and a styrene-isoprene- Unhydrogenated styrene-conjugated diene copolymers, such as a styrene copolymer (SIS) and a styrene-ethylene-isoprene-styrene copolymer; Hydrogenated styrene, such as styrene-ethylene/propylene-styrene copolymer (SEPS, hydrogenated product of styrene-isoprene-styrene copolymer) and styrene-ethylene-butylene-styrene copolymer (SEBS, hydrogenated product of styrene-butadiene copolymer) -Conjugated diene copolymer etc. are mentioned. Further, industrially, Toughrene (manufactured by Asahi Kasei Co., Ltd.), Kraton (manufactured by Kraton Polymer Japan Co., Ltd.), Sumitomo TPE-SB (manufactured by Sumitomo Chemical Co., Ltd.), Epofriend (manufactured by Daicel Chemical Industry Co., Ltd.), Lavalon ( Trade names, such as Mitsubishi Chemical Corporation), Septon (Kuraray Corporation), and Tuftec (Asahi Kasei Corporation), are mentioned. The styrenic elastomer may be a hydrogenated substance or an unhydrogenated substance.

Examples of rubber-based materials include natural rubber, synthetic isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), acrylonitrile-butadiene copolymer rubber (NBR), Butyl rubber (IIR), halogenated butyl rubber, acrylic rubber, urethane rubber, polysulfide rubber, etc. can be mentioned, and these 1 type can be used individually or in combination of 2 or more types.

As the base material, a laminate of a plurality of layers of films made of the above materials may be used. Further, a laminate of a film made of the above materials and another film may also be used.

In the case of laminating multiple layers of films, in achieving the above-mentioned physical properties, a film with a high contribution rate is placed in the center with a relatively thick thickness, and the film is placed between other films with a relatively small thickness with a low contribution rate. configuration can be done. In addition, the use of a resin having a relatively low glass transition temperature (Tg) is preferable for achieving the above-described physical properties, but since such a resin has high adhesiveness, when forming such a resin on the surface of a sheet for semiconductor processing, a semiconductor There is a possibility that the handling at the time of production or use of the sheet for processing becomes difficult. Therefore, a resin film having a relatively low glass transition temperature (Tg) is sandwiched between a resin film having a relatively high glass transition temperature (Tg), or a resin film having a relatively low glass transition temperature (Tg) has a relatively low glass transition temperature (Tg). By laminating a relatively high resin film or the like, it is possible to achieve both the above-described physical properties and handling properties.

When the sheet for semiconductor processing according to the present embodiment is constituted only of a base material, the base material preferably has adhesiveness. In the case where the adhesiveness is exhibited in a normal state, it is preferable to use a substrate having self-adhesiveness as the base material.

Further, in the case where the sheet for semiconductor processing according to the present embodiment is composed of only a base material and the base material is formed by laminating a plurality of films, only the film positioned in the outermost layer or one of them is used among the plurality of laminated films. It may have adhesiveness. For example, by laminating a resin film having a relatively high glass transition temperature (Tg) on one surface of a resin film having a relatively low glass transition temperature (Tg), adhesiveness can be exhibited only on the one surface. In addition, the outermost layer of the sheet for semiconductor processing in this specification shall not include a release sheet or the like that is removed during use.

In the base material in this embodiment, various additives such as pigments, dyes, flame retardants, plasticizers, antistatic agents, lubricants, and fillers may be contained in the film containing the above resin-based material as a main material. As a pigment, titanium dioxide, carbon black, etc. are mentioned, for example. Moreover, examples of the filler include organic materials such as melamine resin, inorganic materials such as fumed silica, and metal materials such as nickel particles. The content of these additives is not particularly limited, but is preferably within a range in which the base material can exhibit desired functions.

When the sheet for semiconductor processing has a pressure-sensitive adhesive layer described later, the base material is surface-treated on one or both surfaces by an oxidation method, a concavo-convex method or the like, or a primer, as desired, for the purpose of improving adhesion with the pressure-sensitive adhesive layer laminated on the surface thereof. Primer treatment to form a layer can be performed. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment. A sand blast method, a thermal spray treatment method, etc. are mentioned.

Further, when the pressure-sensitive adhesive layer contains an energy ray-curable pressure-sensitive adhesive, the base material preferably has energy ray permeability. In particular, when ultraviolet rays are used as energy rays, the base material preferably has ultraviolet light transmittance, and when electron beams are used as energy rays, the base material preferably has electron beam transmittance.

In the sheet for semiconductor processing according to the present embodiment, the method for manufacturing the substrate is not particularly limited, and examples thereof include any method such as a cast molding method (melt casting method), a melt extrusion method such as a T-die method or an inflation method, or a calender method. You can also use Especially, it is preferable to manufacture a base material by the cast molding method from a viewpoint of being easy to suppress the unevenness of thickness. In this case, it is preferable that the base material can be produced by casting a liquid formulation (resin before curing, resin solution, etc.) serving as the material of the base material in a thin film form on a process sheet, and then curing the coating film to form a film. .

The thickness of the substrate is not limited as long as the sheet for semiconductor processing can properly function in a desired step. The thickness of the substrate is preferably 20 μm or more, particularly preferably 40 μm or more. Moreover, it is preferable that the said thickness is 250 micrometers or less, and it is especially preferable that it is 200 micrometers or less.

In addition, the standard deviation of the thickness of the substrate when the thickness is measured at intervals of 2 cm is preferably 2 μm or less, particularly preferably 1.5 μm or less, and more preferably 1 μm or less. When the said standard deviation is 2 micrometers or less, the sheet|seat for semiconductor processing will have a thickness with high precision, and it becomes possible to extend|stretch the sheet|seat for semiconductor processing uniformly.

3. Adhesive layer

It is preferable that the sheet for semiconductor processing according to this embodiment further includes an adhesive layer laminated on at least one side of the substrate. Thereby, the sheet|seat for semiconductor processing becomes easy to exhibit desired adhesiveness in the surface at the side of the said adhesive layer, and it becomes possible to stick a semiconductor chip etc. to the said surface satisfactorily.

The pressure-sensitive adhesive layer is not particularly limited as long as it can achieve the physical properties described above in the sheet for semiconductor processing. The pressure-sensitive adhesive layer may be composed of a non-energy ray-curable pressure-sensitive adhesive or may be composed of an energy ray-curable pressure-sensitive adhesive. As the non-energy ray curable adhesive, those having desired adhesive strength and re-peelability are preferable. For example, acrylic adhesives, rubber-based adhesives, silicone-based adhesives, urethane-based adhesives, polyester-based adhesives, polyvinyl ether-based adhesives, etc. can be used. there is. Among these, when the sheet for semiconductor processing is stretched, an acrylic pressure-sensitive adhesive that can effectively suppress dropping of semiconductor chips and the like is preferable.

On the other hand, energy-beam-curable pressure-sensitive adhesives are cured by energy-beam irradiation and their adhesive strength decreases. Therefore, when separating a semiconductor chip from a semiconductor processing sheet, they can be easily separated by energy-beam irradiation.

The energy ray-curable pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer may have a polymer having energy ray curability as a main component, and may include a non-energy ray curable polymer (a polymer having no energy ray curable property) and a monomer having at least one energy ray curable group. And/or a mixture of oligomers as a main component may be used. Further, it may be a mixture of an energy ray curable polymer and a non-energy ray curable polymer, or a mixture of an energy ray curable polymer and a monomer and/or oligomer having at least one energy ray curable group, or a mixture of three of these. may be continued

First, a case where an energy ray-curable pressure-sensitive adhesive contains a polymer having energy ray curability as a main component will be described below.

The energy ray-curable polymer is a (meth)acrylic acid ester (co)polymer (A) in which a functional group (energy ray-curable group) is introduced into the side chain (hereinafter referred to as "energy ray-curable polymer (A)"). may be) is preferable. This energy ray-curable polymer (A) is preferably obtained by reacting an acrylic copolymer (a1) having a functional group-containing monomer unit with an unsaturated group-containing compound (a2) having a functional group bonded to the functional group. In addition, in this specification, (meth)acrylic acid ester means both acrylic acid ester and methacrylic acid ester. Other similar terms are also the same.

The acrylic copolymer (a1) preferably contains a structural unit derived from a functional group-containing monomer and a structural unit derived from a (meth)acrylic acid ester monomer or a derivative thereof.

The functional group-containing monomer as the structural unit of the acrylic copolymer (a1) is preferably a monomer having a polymerizable double bond and a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, or an epoxy group in the molecule.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc. are mentioned, These are used individually or in combination of 2 or more types.

Examples of the carboxyl group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. These may be used independently and may be used in combination of 2 or more type.

Examples of the amino group-containing monomer or the substituted amino group-containing monomer include aminoethyl (meth)acrylate, n-butylaminoethyl (meth)acrylate, and the like. These may be used independently and may be used in combination of 2 or more type.

As the (meth)acrylic acid ester monomer constituting the acrylic copolymer (a1), in addition to an alkyl (meth)acrylate having an alkyl group having 1 to 20 carbon atoms, for example, a monomer having an alicyclic structure in the molecule (alicyclic structure containing monomer) is preferably used.

As the alkyl (meth) acrylate, in particular, an alkyl (meth) acrylate having 1 to 18 carbon atoms in the alkyl group, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate and the like are preferably used. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the alicyclic structure-containing monomer include cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, adamantyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclophene (meth)acrylate. tenyl, dicyclopentenyloxyethyl (meth)acrylate and the like are preferably used. These may be used individually by 1 type, and may be used in combination of 2 or more type.

The acrylic copolymer (a1) contains a structural unit derived from the functional group-containing monomer in an amount of preferably 1% by mass or more, particularly preferably 5% by mass or more, and still more preferably 10% by mass or more. In addition, the acrylic copolymer (a1) contains structural units derived from the functional group-containing monomers in an amount of preferably 35% by mass or less, particularly preferably 30% by mass or less, and even more preferably 25% by mass or less. do.

In addition, the acrylic copolymer (a1) contains preferably 50% by mass or more, particularly preferably 60% by mass or more, and still more preferably 70% by mass or more of structural units derived from a (meth)acrylic acid ester monomer or a derivative thereof. contain in proportion. In addition, the acrylic copolymer (a1) contains preferably 99% by mass or less, particularly preferably 95% by mass or less, and still more preferably 90% by mass of structural units derived from a (meth)acrylic acid ester monomer or a derivative thereof. It is contained in the following ratio.

The acrylic copolymer (a1) is obtained by copolymerizing the above functional group-containing monomer with a (meth)acrylic acid ester monomer or a derivative thereof by a conventional method. In addition to these monomers, dimethyl acrylamide, vinyl formate, vinyl acetate, styrene, etc. This may be copolymerized.

The energy ray-curable polymer (A) is obtained by reacting the acrylic copolymer (a1) having the functional group-containing monomer unit with the compound (a2) containing an unsaturated group having a functional group bonded to the functional group.

The functional group of the unsaturated group-containing compound (a2) can be appropriately selected depending on the kind of functional group of the functional group-containing monomer unit of the acrylic copolymer (a1). For example, when the functional group of the acrylic copolymer (a1) is a hydroxyl group, amino group or substituted amino group, the functional group of the unsaturated group-containing compound (a2) is preferably an isocyanate group or an epoxy group, and the acrylic copolymer (a1 When the functional group of ) is an epoxy group, the functional group of the unsaturated group-containing compound (a2) is preferably an amino group, a carboxyl group or an aziridinyl group.

In addition, the compound containing an unsaturated group (a2) contains at least one, preferably 1 to 6, more preferably 1 to 4 energy ray polymerizable carbon-carbon double bonds per molecule. Specific examples of such an unsaturated group-containing compound (a2) include 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl Isocyanate, 1,1-(bisacryloyloxymethyl) ethyl isocyanate; Acryloyl monoisocyanate compound obtained by reaction of a diisocyanate compound or a polyisocyanate compound, and hydroxyethyl (meth)acrylate; Acryloyl monoisocyanate compound obtained by reaction of a diisocyanate compound or a polyisocyanate compound, a polyol compound, and hydroxyethyl (meth)acrylate; glycidyl (meth)acrylate; (meth)acrylic acid, 2-(1-aziridinyl)ethyl (meth)acrylate, 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline and the like.

The amount of the unsaturated group-containing compound (a2) is preferably 50 mol% or more, particularly preferably 60 mol% or more, still more preferably 70 mol% or more, based on the number of moles of the functional group-containing monomer in the acrylic copolymer (a1). used in proportion. The amount of the unsaturated group-containing compound (a2) is preferably 95 mol% or less, particularly preferably 93 mol% or less, and still more preferably 90 mol%, relative to the number of moles of the functional group-containing monomer in the acrylic copolymer (a1). It is used in a ratio of less than %.

In the reaction between the acrylic copolymer (a1) and the unsaturated group-containing compound (a2), the reaction temperature, pressure, The solvent, time, the presence or absence of a catalyst, and the type of catalyst can be appropriately selected. As a result, the functional group present in the acrylic copolymer (a1) reacts with the functional group in the unsaturated group-containing compound (a2), the unsaturated group is introduced into the side chain in the acrylic copolymer (a1), and the energy ray curable polymer (A) is obtained. is obtained

The weight average molecular weight (Mw) of the energy ray curable polymer (A) thus obtained is preferably 10,000 or more, particularly preferably 150,000 or more, and more preferably 200,000 or more. Moreover, it is preferable that it is 1.5 million or less, and, as for the said weight average molecular weight (Mw), it is especially preferable that it is 1 million or less. In addition, the weight average molecular weight (Mw) in this specification is a standard polystyrene conversion value measured by the gel permeation chromatography method (GPC method).

Even when the energy ray-curable pressure-sensitive adhesive contains, as a main component, a polymer having energy ray-curable property such as the energy ray-curable polymer (A), the energy ray-curable pressure-sensitive adhesive further contains an energy ray-curable monomer and/or oligomer (B). You can do it.

As an energy ray-curable monomer and/or oligomer (B), ester of a polyhydric alcohol and (meth)acrylic acid etc. can be used, for example.

Examples of such an energy ray-curable monomer and/or oligomer (B) include monofunctional acrylic acid esters such as cyclohexyl (meth)acrylate and isobornyl (meth)acrylate, and trimethylolpropane tri(meth) Acrylates, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanedioldi(meth)acrylate, 1,6- Polyfunctional acrylic acid esters such as hexanedioldi(meth)acrylate, polyethylene glycoldi(meth)acrylate, dimethyloltricyclodecanedi(meth)acrylate, polyester oligo(meth)acrylate, polyurethane oligo( Meth) acrylate etc. are mentioned.

When blending the energy ray curable polymer (A) with the energy ray curable monomer and/or oligomer (B), the content of the energy ray curable monomer and/or oligomer (B) in the energy ray curable pressure-sensitive adhesive is It is preferably more than 0 parts by mass, and particularly preferably 60 parts by mass or more with respect to 100 parts by mass of the energy ray curable polymer (A). Further, the content is preferably 250 parts by mass or less, particularly preferably 200 parts by mass or less, based on 100 parts by mass of the energy ray curable polymer (A).

Here, when using an ultraviolet ray as an energy ray for curing the energy ray-curable pressure-sensitive adhesive, it is preferable to add a photopolymerization initiator (C), and by using this photopolymerization initiator (C), the polymerization curing time and light rays Irradiation can be reduced.

As a photoinitiator (C), specifically, benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin benzoic acid Methyl, benzoindimethylketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexylphenylketone, benzyldiphenylsulfide, tetramethylthiurammonosulfide, azobisisobutyronitrile, benzyl, di Benzyl, diacetyl, β-chloroanthraquinone, (2,4,6-trimethylbenzyldiphenyl)phosphine oxide, 2-benzothiazole-N,N-diethyldithiocarbamate, oligo{2-hydride oxy-2-methyl-1-[4-(1-propenyl)phenyl]propanone}, 2,2-dimethoxy-1,2-diphenylethan-1-one, and the like. These may be used independently and may use 2 or more types together.

The photopolymerization initiator (C) is the energy ray curable copolymer (A) (when the energy ray curable monomer and/or oligomer (B) is blended, the energy ray curable copolymer (A) and the energy ray curable monomer and It is preferably used in an amount of 0.1 part by mass or more, particularly 0.5 part by mass or more, based on 100 parts by mass of/or 100 parts by mass of the total amount of the oligomer (B). In addition, the photopolymerization initiator (C) is the energy ray curable copolymer (A) (when blending the energy ray curable monomer and/or oligomer (B), the energy ray curable copolymer (A) and the energy ray curable copolymer (A) It is preferably used in an amount of 10 parts by mass or less, particularly 6 parts by mass or less, based on 100 parts by mass of the total amount of the monomers and/or oligomers (B)).

In the energy ray-curable pressure-sensitive adhesive, other components may be appropriately blended in addition to the above components. Examples of other components include a non-energy ray-curable polymer component or oligomer component (D), a crosslinking agent (E), and the like.

Examples of the non-energy ray-curable polymer component or oligomer component (D) include polyacrylic acid esters, polyesters, polyurethanes, polycarbonates, polyolefins, etc., and have a weight average molecular weight (Mw) of 3,000 to 2,500,000 Polymers or oligomers are preferred. By blending the component (D) into the energy ray-curable pressure-sensitive adhesive, the adhesiveness and peelability before curing, the strength after curing, the adhesiveness to other layers, storage stability, and the like can be improved. The blending amount of the component (D) is not particularly limited, and is appropriately determined within a range of more than 0 parts by mass and 50 parts by mass or less with respect to 100 parts by mass of the energy ray curable copolymer (A).

As the crosslinking agent (E), a polyfunctional compound having reactivity with the functional group of the energy ray curable copolymer (A) or the like can be used. Examples of such multifunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts, and reactive phenolic resins. etc. can be mentioned.

The blending amount of the crosslinking agent (E) is preferably 0.01 part by mass or more, particularly preferably 0.03 part by mass or more, and more preferably 0.04 part by mass or more with respect to 100 parts by mass of the energy ray curable copolymer (A). Further, the blending amount of the crosslinking agent (E) is preferably 8 parts by mass or less, particularly preferably 5 parts by mass or less, and more preferably 3.5 parts by mass or less with respect to 100 parts by mass of the energy ray curable copolymer (A). .

Next, a case where the energy ray-curable pressure-sensitive adhesive contains, as a main component, a mixture of a non-energy ray-curable polymer component and a monomer and/or oligomer having at least one or more energy ray-curable groups will be described below.

As the non-energy ray-curable polymer component, for example, the same component as the acrylic copolymer (a1) described above can be used.

As the monomer and/or oligomer having at least one or more energy ray-curable groups, those similar to those of the component (B) described above can be selected. The blending ratio of the non-energy ray-curable polymer component and the monomer and/or oligomer having at least one energy ray-curable group is based on 100 parts by mass of the non-energy ray-curable polymer component, and the monomer and/or oligomer having at least one energy ray-curable group It is preferable that it is 1 mass part or more of an oligomer, and it is especially preferable that it is 60 mass parts or more. The blending ratio is preferably 200 parts by mass or less of the monomer and/or oligomer having at least one energy ray-curable group, and particularly preferably 160 parts by mass or less, based on 100 parts by mass of the non-energy ray-curable polymer component.

Also in this case, the photopolymerization initiator (C) and the crosslinking agent (E) can be appropriately blended in the same manner as above.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, and is preferably, for example, 3 μm or more, and particularly preferably 5 μm or more. Moreover, it is preferable that the said thickness is 50 micrometers or less, and it is especially preferable that it is 40 micrometers or less.

4. Release sheet

In the sheet for semiconductor processing according to the present embodiment, a release sheet may be laminated on the adhesive face for the purpose of protecting the adhesive face until the adhesive face is attached to an adherend such as a semiconductor chip. The configuration of the release sheet is arbitrary, and a release treatment of a plastic film with a release agent or the like is exemplified. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, silicone-based, fluorine-based, long-chain alkyl-based, and the like can be used, and among these, since inexpensive and stable performance is obtained, silicone-based is preferable. The thickness of the release sheet is not particularly limited, but is usually about 20 to 250 μm.

5. Manufacturing method of sheet for semiconductor processing

The sheet for semiconductor processing according to this embodiment can be manufactured in the same way as a conventional sheet for semiconductor processing. In particular, as a method for producing a sheet for semiconductor processing comprising a substrate and an adhesive layer, the detailed method is not particularly limited as long as the adhesive layer formed from the above-described adhesive composition can be laminated on one surface of the substrate. For example, a pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer and a coating solution containing a solvent or a dispersion medium as desired are prepared, and on one side of the substrate, a die coater, a curtain coater, a spray coater, a slit coater, An adhesive layer can be formed by applying the coating liquid with a knife coater or the like to form a coating film, and drying the coating film. The properties of the coating liquid are not particularly limited as long as it can be applied, and may contain a component for forming the pressure-sensitive adhesive layer as a solute or as a dispersoid in other cases.

In another example of a method for manufacturing a sheet for semiconductor processing, a coating solution is applied on the release surface of the above-described release sheet to form a coating film, and this is dried to form a laminate composed of an adhesive layer and a release sheet. The surface on the side opposite to the surface on the side of the release sheet in the pressure-sensitive adhesive layer of the laminate may be affixed to a substrate to obtain a laminate of the sheet for semiconductor processing and the release sheet. The release sheet in this layered body may be peeled off as a process material, or may protect the adhesive layer until it is attached to an adherend such as a semiconductor chip or semiconductor wafer.

When the coating solution contains a crosslinking agent, the non-energy ray-curable acrylic pressure-sensitive adhesive (N) or energy ray-curable pressure-sensitive adhesive ( What is necessary is just to advance the crosslinking reaction of A) and a crosslinking agent, and to form a crosslinked structure with a desired density in the adhesive layer. In order to sufficiently advance this crosslinking reaction, after laminating the pressure-sensitive adhesive layer on the substrate by the above method or the like, the obtained sheet for semiconductor processing is allowed to stand in an environment of, for example, 23 ° C. and a relative humidity of 50% for several days. Curing may be performed.

6. How to use the sheet for semiconductor processing

The sheet for semiconductor processing according to this embodiment can be used in order to widen the space|interval of the some semiconductor chips laminated|stacked on one side of the sheet for semiconductor processing, for example.

In particular, it is preferable to use in order to widen the mutual space|interval of the adjacent semiconductor chip in some semiconductor chip laminated|stacked on the single side|surface of the sheet|seat for semiconductor processing by 200 micrometers or more. The upper limit of the interval is not particularly limited, but may be, for example, 6000 μm.

Moreover, the sheet|seat for semiconductor processing which concerns on this embodiment can be used also when the space|interval of the some semiconductor chip laminated|stacked on one side of the sheet|seat for semiconductor processing is widened by at least biaxial stretching. In this case, the sheet for semiconductor processing is applied with tension in four directions of, for example, +X-axis direction, -X-axis direction, +Y-axis direction, and -Y-axis direction in the mutually orthogonal X-axis and Y-axis, It elongates, and more specifically, it elongates in MD direction and CD direction in a base material, respectively.

Biaxial stretching as described above can be performed using a spacer device that applies tension in the X-axis direction and the Y-axis direction, for example. Here, the X axis and the Y axis are assumed to be orthogonal, and one of the directions parallel to the X axis is the +X axis direction, and the direction opposite to the +X axis direction is the -X axis direction and one of the directions parallel to the Y axis. The +Y axis direction and the direction opposite to the +Y axis direction are referred to as -Y axis directions.

The separation device applies tension to the sheet for semiconductor processing in four directions of +X-axis direction, -X-axis direction, +Y-axis direction, and -Y-axis direction, and a plurality of retainers are applied to each of these four directions. It is preferable to provide means and a plurality of tension applying means corresponding to them. The number of holding means and tension imparting means in each direction varies depending on the size of the sheet for semiconductor processing, but may be, for example, 3 or more and 10 or less.

Here, for example, in the group including a plurality of holding means and a plurality of tension imparting means provided for imparting tension in the +X-axis direction, each holding means includes a holding member for holding the sheet for semiconductor processing. It is preferable that each tension imparting means applies tension to the semiconductor processing sheet by moving a holding member corresponding to the tension imparting means in the +X-axis direction. And it is preferable that the plurality of tension imparting means is formed so as to independently move the holding means in the +X-axis direction. In addition, the three groups including a plurality of holding means and a plurality of tension imparting means provided for applying tension in the -X axis direction, +Y axis direction, and -Y axis direction, respectively, have the same configuration. desirable. Thereby, the said separation device can apply the tension of different magnitude|size with respect to the sheet|seat for semiconductor processing for every area|region of the direction orthogonal to each direction.

In general, when a sheet for semiconductor processing is held in four directions of +X-axis direction, -X-axis direction, +Y-axis direction, and -Y-axis direction, respectively, using four holding members, and stretched in the four directions, In addition to these four directions, the sheet for semiconductor processing includes these composite directions (e.g., +X-axis direction and +Y-axis direction synthesis direction, +Y-axis direction and -X-axis direction synthesis direction, -X-axis direction and Tension is also applied to the composite direction of the -Y axis direction and the composite direction of the -Y axis direction and the +X axis direction). As a result, a difference may arise between the space|interval of the semiconductor chip in the inside of the sheet|seat for semiconductor processing, and the space|interval of the semiconductor chip in the outer side.

However, in the separation device described above, in each direction of +X-axis direction, -X-axis direction, +Y-axis direction, and -Y-axis direction, a plurality of tension imparting means each independently applies tension to the semiconductor processing sheet. Since it can provide, the sheet|seat for semiconductor processing can be extended|stretched so that the difference of the space|interval between the inside and the outside of the sheet|seat for semiconductor processing as mentioned above is eliminated. As a result, it is possible to accurately adjust the spacing between the semiconductor chips.

It is preferable that the spacer device further includes a measuring means for measuring a mutual distance between the semiconductor chips. Here, it is preferable that the said tension imparting means is formed so that a plurality of holding members can be moved individually based on the measurement result of the measuring means. As a result of this, it becomes possible to further adjust the interval based on the measurement result of the interval between the semiconductor chips by the measuring means, and as a result, it becomes possible to more accurately adjust the interval between the semiconductor chips.

Further, in the above separation device, the holding means may be a chuck means such as a mechanical chuck or a chuck cylinder, a pressure reducing means such as a pressure reducing pump or a vacuum ejector, or may have a structure in which the sheet for semiconductor processing is supported by an adhesive, magnetic force, or the like. do. Further, as the holding member in the chuck means, for example, a lower support member supporting the semiconductor processing sheet from below, a drive device supported by the lower support member, and a drive device supported by an output shaft of the drive device. What has a structure provided with the upper support member which can press the sheet|seat for semiconductor processing from above by being driven can be used. Examples of the drive device include electric devices such as rotary motors, linear motors, linear motors, single axis robots and articulated robots, actuators such as air cylinders, hydraulic cylinders, rodless cylinders and rotary cylinders, etc. can be heard

Moreover, in the said separation device, the tension imparting means may be provided with a drive device, and may move the holding member by the drive device. As the driving device, those described above can be used. For example, the tension imparting unit may have a linear motor as a driving device and an output shaft interposed between the linear motion motor and the holding member, and the driven linear motor moves the holding member via the output shaft.

When using the sheet for semiconductor processing according to the present embodiment to widen the intervals between semiconductor chips, the intervals may be widened in a state where semiconductor chips are in contact with each other or in a state where the intervals between semiconductor chips are hardly widened, or between semiconductor chips. In a state where the interval of is already widened to a predetermined interval, the interval may be further widened.

In the case where the semiconductor chips are in contact with each other or the gap between the semiconductor chips is widened in a state where the gap is hardly widened, for example, after obtaining a plurality of semiconductor chips by dividing a semiconductor wafer on a dicing sheet , It is possible to transfer a plurality of semiconductor chips from the dicing sheet to the sheet for semiconductor processing according to the present embodiment, and subsequently widen the space between the semiconductor chips. Or, after dividing a semiconductor wafer on the sheet for semiconductor processing concerning this embodiment and obtaining a some semiconductor chip, the space|interval of the said semiconductor chip can also be widened.

In a state where the distance between semiconductor chips has already been widened to a predetermined distance, when the distance is further widened, the distance between semiconductor chips is reduced by using another semiconductor processing sheet, preferably a semiconductor processing sheet according to the present embodiment. After extending to a predetermined distance, the semiconductor chips can be further widened by transferring the semiconductor chips from the sheet to the sheet for semiconductor processing according to the present embodiment, and then stretching the sheet for semiconductor processing according to the present embodiment. In addition, you may repeat the transfer|transfer of such a semiconductor chip and extending|stretching of the sheet|seat for semiconductor processing a plurality of times until the space|interval of a semiconductor chip becomes a desired distance.

Further, the semiconductor processing sheet according to the present embodiment is preferably used for applications requiring a relatively large distance between semiconductor chips. An example of such applications is a fan-out type semiconductor wafer level package (FO-WLP). ) is preferred. As an example of the manufacturing method of such a FO-WLP, the 1st aspect and the 2nd aspect demonstrated below are mentioned.

(1) First aspect

Hereinafter, the first aspect of the manufacturing method of FO-WLP using the sheet|seat for semiconductor processing concerning this embodiment is demonstrated. In this first aspect, the sheet for semiconductor processing according to the present embodiment is used as a second adhesive sheet 20 described later.

1(A) shows a semiconductor wafer W stuck to the first adhesive sheet 10 . The semiconductor wafer W has a circuit surface W1, and a circuit W2 is formed on the circuit surface W1. The first adhesive sheet 10 is adhered to the back surface W3 of the semiconductor wafer W on the opposite side to the circuit surface W1. The first pressure sensitive adhesive sheet 10 includes a first base film 11 and a first pressure sensitive adhesive layer 12 . The first pressure sensitive adhesive layer 12 is laminated on the first base film 11 .

[Dicing process]

1(B) shows a plurality of semiconductor chips CP held on the first adhesive sheet 10 .

The semiconductor wafer W held on the first adhesive sheet 10 is separated into pieces by dicing to form a plurality of semiconductor chips CP. Cutting means, such as a dicing saw, are used for dicing. The depth of cutting at the time of dicing is set to the depth which considered the thickness of the semiconductor wafer W, the sum of the 1st adhesive layer 12, and the wear of a dicing saw. By dicing, the 1st adhesive layer 12 is also cut into the same size as semiconductor chip CP. In addition, incisions may also be formed in the first base film 11 by dicing.

In addition, you may perform dicing by irradiating a laser beam with respect to the semiconductor wafer W instead of using the above-mentioned cutting means, such as a dicing saw. For example, the semiconductor wafer W may be completely divided into pieces into a plurality of semiconductor chips CP by irradiation with laser light. Alternatively, after forming a modified layer inside the semiconductor wafer W by irradiation with laser light, the semiconductor wafer W is modified by elongating the first adhesive sheet 10 in the first expand step described later. It may be broken at the position of the layer and separated into semiconductor chips (CP) (stealth dicing). In the case of stealth dicing, laser light irradiation is performed so that, for example, infrared laser light is focused on a focal point set inside the semiconductor wafer W. In addition, in these methods, the irradiation of the laser light may be performed from any side of the semiconductor wafer W.

[First expand process]

FIG. 1(C) shows a diagram explaining a step of elongating the first adhesive sheet 10 holding a plurality of semiconductor chips CP (hereinafter sometimes referred to as a "first expand step"). .

After being singulated into a plurality of semiconductor chips CP by dicing, the first adhesive sheet 10 is elongated to widen the space between the plurality of semiconductor chips CP. In the case of performing stealth dicing, by elongating the first adhesive sheet 10, the semiconductor wafer W is broken at the position of the modified layer and separated into a plurality of semiconductor chips CP, The gap between the plurality of semiconductor chips (CP) is widened. The method of elongating the first adhesive sheet 10 in the first expand step is not particularly limited. As a method of elongating the first adhesive sheet 10, for example, a method of elongating the first adhesive sheet 10 by pressing an annular or circular expander, or a method of elongating the first adhesive sheet 10 using a holding member or the like. 2. A method of grasping the outer periphery of the pressure-sensitive adhesive sheet and elongating it, and the like are exemplified.

It is preferable that the 1st adhesive sheet 10 has a tensile elasticity modulus suitable also for the 1st expand process while being suitable for the above-mentioned dicing process. From this point of view, the first adhesive sheet 10 preferably has a higher tensile modulus than the second adhesive sheet 20 described later. As a result, the first adhesive sheet 10 can exhibit a predetermined expandability without impairing performance during dicing, and the second adhesive sheet 20 can exhibit a more excellent expandability. can

In addition, as shown in FIG. 1(C), the distance between semiconductor chips CP is set to D1. As the distance D1, it is preferable to set it as 15 micrometers or more and 110 micrometers or less, for example.

[Transcription process]

2(A) is a diagram explaining a step of transferring a plurality of semiconductor chips CP to the second adhesive sheet 20 after the first expand step (hereinafter sometimes referred to as a "transfer step"). appear After extending the distance D1 between the plurality of semiconductor chips CP by elongating the first adhesive sheet 10, the second adhesive sheet 20 is attached to the circuit surface W1 of the semiconductor chips CP. Here, as the second adhesive sheet 20, the sheet for semiconductor processing according to the present embodiment is used.

The second pressure sensitive adhesive sheet 20 includes a second base film 21 and a second pressure sensitive adhesive layer 22 . The second adhesive sheet 20 is preferably attached so as to cover the circuit surface W1 with the second adhesive layer 22 .

It is preferable that the adhesive force of the 2nd adhesive layer 22 is larger than the adhesive force of the 1st adhesive layer 12. When the adhesive force of the second pressure sensitive adhesive layer 22 is larger, the first pressure sensitive adhesive sheet 10 is easily peeled off after transferring the plurality of semiconductor chips CP to the second pressure sensitive adhesive sheet 20 .

The second adhesive sheet 20 may be attached to the second ring frame together with a plurality of semiconductor chips CP. In this case, a second ring frame is placed on the second pressure-sensitive adhesive layer 22 of the second pressure-sensitive adhesive sheet 20, lightly pressed, and fixed. Thereafter, the second pressure sensitive adhesive layer 22 exposed from the inside of the annular shape of the second ring frame is pressed against the circuit surface W1 of the semiconductor chip CP to form a plurality of semiconductor chips ( CP) is fixed.

When the first adhesive sheet 10 is peeled off after attaching the second adhesive sheet 20, the back surfaces W3 of the plurality of semiconductor chips CP are exposed. It is preferable that the distance D1 between the plurality of semiconductor chips CP expanded in the first expand step is maintained even after the first adhesive sheet 10 is peeled off.

[Second expand process]

FIG. 2(B) shows a diagram explaining a step of elongating the second adhesive sheet 20 holding a plurality of semiconductor chips CP (hereinafter sometimes referred to as a "second expand step"). .

In the second expand process, the interval between the plurality of semiconductor chips CP is further widened. The method of elongating the second adhesive sheet 20 in the second expand step is not particularly limited. As a method of elongating the second adhesive sheet 20, for example, a method of elongating the second adhesive sheet 20 by pressing an annular or circular expander, or a method of elongating the second adhesive sheet 20 by using a gripping member or the like. A method of holding the outer periphery and lengthening it may be mentioned. As the latter method, the method of biaxial stretching using the above-mentioned separation device etc. is mentioned, for example. Among these, the method of biaxial stretching is preferable from a viewpoint that it becomes possible to enlarge the space|interval between semiconductor chips CP more.

In addition, as shown in Fig. 2(B), the interval between the semiconductor chips CP after the second expand process is set to D2. Distance D2 is greater than distance D1. As distance D2, it is preferable to set it as 200 micrometers or more and 6000 micrometers or less, for example.

[Encapsulation process]

FIG. 2(C) shows a diagram illustrating a process of sealing a plurality of semiconductor chips CP using the sealing member 60 (hereinafter sometimes referred to as a “sealing process”).

The sealing process is performed after the 2nd expand process. The sealing member 3 is formed by covering the plurality of semiconductor chips CP with the sealing member 60 leaving the circuit surface W1. The sealing member 60 is also filled between the plurality of semiconductor chips CP. Here, since the circuit surface W1 and the circuit W2 are covered with the second adhesive sheet 20, the circuit surface W1 can be prevented from being covered with the sealing member 60.

Through the sealing step, a sealed body 3 in which a plurality of semiconductor chips CP separated by a predetermined distance is embedded in the sealing member 60 is obtained. In the sealing process, it is preferable to cover the plurality of semiconductor chips CP with the sealing member 60 in a state where the distance D2 is maintained.

After the sealing step, when the second adhesive sheet 20 is peeled off, the circuit surface W1 of the semiconductor chip CP and the surface 3A of the sealing body 3 in contact with the second adhesive sheet 20 are exposed. do.

[Rewiring Layer Formation Process and Connection Process with External Terminal Electrodes]

3(A) shows a cross-sectional view of the encapsulation body 3 after the second adhesive sheet 20 is peeled off. With respect to this encapsulant 3, the redistribution layer forming process of forming a redistribution layer, and the process of connecting external terminal electrodes to the formed redistribution layer are performed in order. 3(A) shows the circuit W2 shown in FIG. 2(C) in more detail, and the internal terminal electrode W4 is shown.

By the redistribution layer formation process and the external terminal electrode connection process, as shown in FIG. 3(B), the redistribution layer 5 connected to the internal terminal electrode W4 and the external terminal connected to the redistribution layer 5 Electrode 6 is formed. Specifically, it is formed as follows. First, the first insulating layer 4A is formed on the circuit surface W1 of the semiconductor chip CP and the surface 3A of the sealing body 3 . Subsequently, the redistribution layer 5 is formed so as to be electrically connected to the internal terminal electrode W4. Also, a second insulating layer 4B covering the redistribution layer 5 is formed. At this time, the redistribution layer 5 is covered with the second insulating layer 4B leaving the external electrode pads 5A. Finally, an external terminal electrode 6 such as a solder ball is placed on the external electrode pad 5A, and the external terminal electrode 6 and the external electrode pad 5A are electrically connected by solder bonding or the like.

[Second dicing process]

FIG. 3(C) shows a cross-sectional view illustrating a step of separating the encapsulation body 3 to which the external terminal electrode 6 is connected (hereinafter sometimes referred to as a "second dicing step"). In this second dicing process, the encapsulation body 3 is singulated into semiconductor chip CP units. The method of separating the sealing body 3 into pieces is not particularly limited. For example, the sealing body 3 can be divided into pieces by employing the same method as the method of dicing the semiconductor wafer W described above. The step of separating the encapsulation body 3 into pieces may be performed by adhering the encapsulation body 3 to an adhesive sheet such as a dicing sheet.

By separating the encapsulation body 3 into pieces, the semiconductor package 1 in units of semiconductor chips (CP) is manufactured. As described above, the semiconductor package 1 in which the external terminal electrode 6 is connected to the external electrode pad 5A fanned out outside the area of the semiconductor chip CP is a fan-out type wafer level package (FO-WLP). ) is prepared as

[modified example]

In the FO-WLP manufacturing method according to the first aspect described above, some steps may be changed or some steps may be omitted.

(2) Second aspect

Hereinafter, the second aspect of the manufacturing method of FO-WLP using the sheet|seat for semiconductor processing concerning this embodiment is demonstrated. Also in this second aspect, the sheet for semiconductor processing according to this embodiment is used as the second adhesive sheet 20 described later.

4(A) shows a semiconductor wafer W attached to a protective sheet 30 as a third adhesive sheet. The semiconductor wafer W has a circuit surface W1 as a first surface, and a circuit W2 is formed on the circuit surface W1. The protective sheet 30 is attached to the circuit surface W1 of the semiconductor wafer W. The protective sheet 30 protects the circuit surface W1 and the circuit W2.

The protective sheet 30 has a third base film 31 and a third pressure sensitive adhesive layer 32 . The 3rd adhesive layer 32 is laminated|stacked on the 3rd base film 31.

[Groove formation process]

FIG. 4(B) shows a diagram for explaining a step of forming a groove of a predetermined depth on the side of the circuit surface W1 of the semiconductor wafer W (hereinafter sometimes referred to as a "groove forming step").

In the groove forming process, a notch is made in the semiconductor wafer W using a dicing blade of a dicing device or the like from the protective sheet 30 side. At that time, the protective sheet 30 is completely cut, and further, an incision shallower than the thickness of the semiconductor wafer W is made from the circuit surface W1 of the semiconductor wafer W to form a groove W5. The groove W5 is formed to partition a plurality of circuits W2 formed on the circuit surface W1 of the semiconductor wafer W. The depth of the groove W5 is not particularly limited as long as it is slightly deeper than the target thickness of the semiconductor chip. When the groove W5 is formed, cutting chips from the semiconductor wafer W are generated. In the manufacturing method according to the second aspect, since the grooves W5 are formed in a state where the circuit surface W1 is protected by the protective sheet 30, the circuit surface W1 and the circuit by cutting chips are Contamination or damage to (W2) can be prevented.

[Grinding process]

FIG. 4(C) is a view for explaining a process of grinding the back surface W6 as the second surface of the semiconductor wafer W after forming the grooves W5 (hereinafter sometimes referred to as a “grinding process”). is appearing

In the manufacturing method according to the second aspect, the first adhesive sheet 10 is attached to the protective sheet 30 side before grinding. After the first adhesive sheet 10 is attached, the semiconductor wafer W is ground from the back surface W6 side using the grinder 50 . By grinding, the thickness of the semiconductor wafer W is reduced, and it is finally divided into a plurality of semiconductor chips CP. Grinding is performed from the back surface W6 side until the bottom of the groove W5 is removed, and the semiconductor wafer W is divided into pieces for each circuit W2. After that, if necessary, backside grinding is further performed to obtain a semiconductor chip CP having a predetermined thickness. In the manufacturing method according to the second aspect, grinding is performed until the back surface W3 as the third surface is exposed.

FIG. 4(D) shows a state in which a plurality of divided semiconductor chips CP are held by the protective sheet 30 and the first adhesive sheet 10 . In addition, in this specification, as described above, the method of dividing the semiconductor wafer W into semiconductor chips CP by first forming the groove W5 and then grinding the back surface is referred to as "separation". There is a case called "Issing method".

[Applying process (second adhesive sheet)]

FIG. 5(A) shows a diagram explaining a step of attaching the second adhesive sheet 20 to a plurality of semiconductor chips CP after the grinding step (hereinafter sometimes referred to as “attachment step”). .

The second adhesive sheet 20 is attached to the back surface W3 of the semiconductor chip CP. The second pressure sensitive adhesive sheet 20 includes a second base film 21 and a second pressure sensitive adhesive layer 22 . Here, as the second adhesive sheet 20, the sheet for semiconductor processing according to the present embodiment is used.

It is preferable that the adhesive force of the 2nd adhesive layer 22 to the semiconductor wafer W is larger than the adhesive force of the 3rd adhesive layer 32 to the semiconductor wafer W. When the adhesive force of the second pressure sensitive adhesive layer 22 is larger, the first pressure sensitive adhesive sheet 10 and the protective sheet 30 are easily peeled off.

The second adhesive sheet 20 may be attached to the ring frame together with the plurality of semiconductor chips CP. In this case, a ring frame is placed on the second pressure sensitive adhesive layer 22 of the second pressure sensitive adhesive sheet 20, and this is lightly pressed and fixed. Thereafter, the second pressure sensitive adhesive layer 22 exposed from the inside of the annular shape of the ring frame is pressed against the circuit surface W1 of the semiconductor chip CP, thereby forming a plurality of semiconductor chips CP on the second pressure sensitive adhesive sheet 20. fix the

[Peel process (first adhesive sheet)]

In FIG. 5(B), a step of peeling the first adhesive sheet 10 and the protective sheet 30 after the second adhesive sheet 20 is applied (hereinafter sometimes referred to as a "peeling step") is explained. A drawing is shown.

In the peeling step, when peeling the first adhesive sheet 10, the cut protective sheet 30 is accompanied and peeled off. When the protective sheet 30 is peeled off, the circuit surfaces W1 of the plurality of semiconductor chips CP are exposed. Here, as shown in FIG. 5(B), the distance between the semiconductor chips CP divided by the pre-dicing method is D1. As the distance D1, it is preferable to set it as 15 micrometers or more and 110 micrometers or less, for example.

[Expand Process]

5(C) shows a diagram explaining a process of elongating the second adhesive sheet 20 holding a plurality of semiconductor chips CP (hereinafter sometimes referred to as an “expand process”).

In the expand process, the interval between the plurality of semiconductor chips CP is further expanded. The method of lengthening the second adhesive sheet 20 in the expand step is not particularly limited. As a method of elongating the second adhesive sheet 20, for example, a method of elongating the second adhesive sheet 20 by pressing an annular or circular expander, or a method of elongating the second adhesive sheet 20 by using a gripping member or the like. A method of holding the outer periphery and lengthening it may be mentioned. As the latter method, the method of biaxial stretching using the above-mentioned separation device etc. is mentioned, for example. Among these, the method of biaxial stretching is preferable from a viewpoint that it becomes possible to enlarge the space|interval between semiconductor chips CP more.

In the manufacturing method according to the second aspect, as shown in Fig. 5(C), the distance between the semiconductor chips CP after the expand step is set to D2. The distance D2 is greater than the distance D1. As distance D2, it is preferable to set it as 200 micrometers or more and 6000 micrometers or less, for example.

[Encapsulation process]

6 shows a diagram for explaining a process of sealing a plurality of semiconductor chips CP using the sealing member 60 (hereinafter sometimes referred to as a “sealing process”).

FIG. 6(A) shows a diagram explaining a step of attaching a surface protection sheet 40 as a fourth adhesive sheet to a plurality of semiconductor chips CP after the expand step.

After extending the second adhesive sheet 20 to extend the distance between the plurality of semiconductor chips CP to the distance D2, the surface protection sheet 40 is attached to the circuit surface W1 of the semiconductor chips CP. . The surface protection sheet 40 has a fourth base film 41 and a fourth pressure sensitive adhesive layer 42 . The surface protection sheet 40 is preferably attached so as to cover the circuit surface W1 with the fourth pressure sensitive adhesive layer 42 .

After attaching the surface protection sheet 40, when the 2nd adhesive sheet 20 is peeled off, the back surface W3 of several semiconductor chip CP is exposed. Even after peeling the second adhesive sheet 20, it is preferable that the distance D2 between the plurality of semiconductor chips CP expanded in the expand step is maintained. When the energy ray polymerizable compound is blended in the second pressure-sensitive adhesive layer 22, the energy ray-polymerizable compound is cured by irradiating the second pressure-sensitive adhesive layer 22 with energy rays from the second base film 21 side. It is preferable to peel the 2nd adhesive sheet 20 after making it.

FIG. 6(B) shows a diagram explaining a process of sealing a plurality of semiconductor chips CP held by the surface protection sheet 40 .

The sealing body 3 is formed by covering the some semiconductor chip CP with the sealing member 60 leaving the circuit surface W1. The sealing member 60 is also filled between the plurality of semiconductor chips CP. Here, since the circuit surface W1 and the circuit W2 are covered with the surface protection sheet 40, it is possible to prevent the circuit surface W1 from being covered with the sealing member 60.

Through the sealing step, a sealed body 3 in which a plurality of semiconductor chips CP separated by a predetermined distance is embedded in a sealing member is obtained. In the sealing process, it is preferable to cover the plurality of semiconductor chips CP with the sealing member 60 in a state where the distance D2 is maintained.

After the sealing step, when the surface protection sheet 40 is peeled off, the circuit surface W1 of the semiconductor chip CP and the surface 3S of the sealing body 3 in contact with the surface protection sheet 40 are exposed ( See Figure 3(A)).

[Rewiring layer formation process, connection process with external terminal electrodes, and second dicing process]

Following the sealing process, a redistribution layer formation process, a connection process with external terminal electrodes, and a second dicing process are performed. These steps can be carried out in the same manner as the manufacturing method according to the first aspect (see Figs. 3(B) and 3(C)). By passing through these steps, FO-WLP is obtained.

[modified example]

In the FO-WLP manufacturing method according to the second aspect described above, some steps may be changed or some steps may be omitted. Such modifications are described below.

As a first modified example of the manufacturing method according to the second aspect, a step of peeling only the first PSA sheet 10 may be performed subsequent to the step of attaching the second PSA sheet 20 . That is, in the second aspect described above, when the first adhesive sheet 10 is peeled, the cut protective sheet 30 is peeled along with it, whereas in this modified example, the protective sheet 30 is separated from the semiconductor chip ( The first adhesive sheet 10 is peeled while remaining on the circuit surface W1 of the CP). By peeling the first adhesive sheet 10, as shown in FIG. 7(A) , a plurality of semiconductor chips CP to which the cut protective sheet 30 is attached are placed on the second adhesive sheet 20. It becomes a layered state.

Subsequently, as shown in Fig. 7(B), the above-described expand step is performed. That is, in a state where the cut protection sheet 30 is attached to the circuit surface W1 of the semiconductor chip CP, the second adhesive sheet 20 is stretched to a long distance, and the distance D2 between the plurality of semiconductor chips CP ) expands to

After the expand process, as shown in FIG. 7(C) , a process of sealing a plurality of semiconductor chips CP is performed. In the second aspect described above, as shown in FIG. 6(B), the semiconductor chip CP was sealed on the surface protection sheet 40, whereas in this modified example, as shown in FIG. 7(C), On the second adhesive sheet 20, the semiconductor chip CP is sealed using the sealing member 60. Here, since the protection sheet 30 is attached to the circuit surface W1, it is not necessary to attach the surface protection sheet 40, and the semiconductor chip CP is sealed with the second adhesive sheet attached to the back surface W3. can do. The sealing member 3 is formed by covering the plurality of semiconductor chips CP with the sealing member 60 leaving the circuit surface W1. It is preferable that the surface 3S of the sealing body 3 and the circuit surface W1 of the semiconductor chip CP are the same surface.

After the sealing step, the protective sheet 30 and the second adhesive sheet 20 are peeled off. After that, FO-WLP is obtained by carrying out the redistribution layer formation process described above, the connection process with external terminal electrodes, and the second dicing process.

Since the sheet for semiconductor processing according to the present embodiment can be greatly stretched, it can be suitably used in applications where it is necessary to widen the space between semiconductor chips as described above.

The embodiments described above are described for facilitating understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

For example, in the case where the sheet for semiconductor processing has a configuration including a base material and an adhesive layer, another layer may be interposed between the base material and the pressure-sensitive adhesive layer.

Example

Hereinafter, the present invention will be described more specifically by examples and the like, but the scope of the present invention is not limited to these examples and the like.

[Example 1]

(1) Preparation of adhesive composition

An acrylic copolymer obtained by reacting butyl acrylate/2-hydroxyethyl acrylate = 85/15 (mass ratio) with 80 mol% of methacryloyloxyethyl isocyanate (MOI) relative to the 2-hydroxyethyl acrylate ) was reacted to obtain an energy ray curable polymer. The weight average molecular weight (Mw) of this energy ray curable polymer was 600,000.

100 parts by mass of the obtained energy ray curable polymer, 3 parts by mass of 1-hydroxycyclohexylphenylketone (manufactured by BASF, product name "Irgacure 184") as a photopolymerization initiator, and a tolylene diisocyanate-based crosslinking agent as a crosslinking agent (Tosoh Corporation) Production, product name "Colonate L") 0.45 mass part was mixed in a solvent, and the adhesive composition was obtained.

(2) Manufacture of sheet for semiconductor processing

By applying the above adhesive composition to the release surface of a release film (manufactured by Lintec, product name "SP-PET3811") in which a silicone-based release agent layer is formed on one side of a polyethylene terephthalate (PET) film, and drying it by heating , An adhesive layer having a thickness of 10 μm was formed on the peeling film. Thereafter, to the exposed surface of the pressure-sensitive adhesive layer, one side of a polyester-based polyurethane elastomer sheet (manufactured by Seaderm, product name "High-Gress DUS202", thickness: 50 µm) as a base material is bonded to the pressure-sensitive adhesive layer. A sheet for semiconductor processing was obtained in a state where the film was stuck.

[Comparative Example 1]

Polyvinyl chloride resin (PVC, average degree of polymerization: 1050) 100 parts by mass, 42 parts by mass of an adipic acid polyester plasticizer, and a small amount of a stabilizer are kneaded and formed into a film shape using a calender, with a thickness of 80 μm. A sheet for semiconductor processing was prepared in the same manner as in Example 1, except that the vinyl chloride film of was used as a base material.

[Comparative Example 2]

A sheet for semiconductor processing was manufactured in the same manner as in Example 1, except that an 80 µm-thick polypropylene film (PP, manufactured by Dia Plus Films, product name "LT01-06051") was used as the base material.

[Test Example 1] (tensile test)

The sheet for semiconductor processing manufactured in Examples and Comparative Examples was cut into 15 mm x 140 mm, and the release sheet was peeled to obtain a test piece. About the said test piece, the elongation at break and tensile modulus at 23 degreeC were measured based on JISK7161:2014 and JISK7127:1999. Specifically, the test piece was subjected to a tensile test at a speed of 200 mm/min after setting the distance between chucks to 100 mm with a tensile tester (manufactured by Shimadzu Corporation, product name "Autograph AG-IS 500N"), and breaking Elongation (%) and tensile modulus (MPa) were measured. In addition, the measurement was performed in both the flow direction (MD) and the direction perpendicular to this (CD) at the time of manufacturing the base material. A result is shown in Table 1.

[Test Example 2] (Measurement of 100% stress and recovery rate)

The test piece was obtained by cutting|disconnecting the sheet|seat for semiconductor processing obtained by the Example or the comparative example to 150 mm x 15 mm, and peeling off the peeling sheet. Moreover, it cut so that the flow direction (MD direction) at the time of manufacture of the sheet|seat for semiconductor processing might become the longitudinal direction of a test piece. After that, both ends of the test piece in the longitudinal direction were fixed with grippers of a tensile tester (manufactured by Shimadzu Corporation, product name "Autograph AG-IS 50N"). At this time, the test piece was gripped with the gripper so that the length between the grippers was 100 mm. This length was taken as length L0 (mm) between initial grippers. Then, it was stretched by 100 mm in the longitudinal direction at a speed of 200 mm/min, and the length between the grippers was 200 mm. The length obtained by subtracting the length L0 (mm) (i.e., 100 mm) between the initial grippers from this length was defined as the extended length L1 (mm). The test force at this time was measured, and the 100% strength (N) in the tensile test was determined, and it was set as the 100% strength (N) in the MD direction. And 100% stress (MPa) in MD direction was calculated|required by dividing 100% intensity|strength (N) of MD direction by the cross-sectional area of a semiconductor process sheet|seat. Further, after holding for 1 minute in a state where the length between the grippers reached 200 mm, the gripper was returned at a rate of 200 mm/min until the length between the grippers reached L0 (mm), and the length between the grippers reached L0 (mm ) was maintained for 1 minute. After that, it was pulled in the longitudinal direction at a rate of 60 mm/min, and the length between the grippers at the time when the tensile force reached 0.1 N/15 mm was recorded. From this length, the length L0 (mm) between the initial grippers was set to u value as L2 (mm).

The recovery rate (%) was calculated by applying the values of L1 and L2 to the following formula (I). The results are shown in Table 1.

Recovery rate (%) = {1 - (L2 ÷ L1)} × 100 … (I)

In addition, the sheet for semiconductor processing obtained in Examples or Comparative Examples was cut into 150 mm × 15 mm such that the direction (CD direction) orthogonal to the flow direction at the time of production was the longitudinal direction of the test piece, and a release sheet was obtained. Also for the test piece obtained by peeling, the 100% strength (N) and 100% stress (MPa) were measured in the same manner as above, and the 100% strength (N) in the CD direction and the 100% stress (MPa) in the CD direction were respectively measured. ) was made. Their results are shown in Table 1. Further, the ratio of the 100% stress (MPa) in the MD direction to the 100% stress (MPa) in the CD direction was calculated. The results are also shown in Table 1.

[Test Example 3] (Expand Test)

The release sheet of the dicing tape (manufactured by Lintec, product name “ADWILL D-675”) was peeled off, and the exposed adhesive surface was placed on a ring frame and a 6-inch silicon mirror wafer (diameter: 150 mm, thickness: 350 μm, ground surface). #2000) was attached to the grinding surface. Next, the silicon mirror wafer was full-cut diced using a dicer (manufactured by Disco, product name "DFD-651") under the following conditions. Thus, a plurality of individual silicon chips were obtained on the dicing tape. After that, the dicing tape was subjected to UV irradiation (illuminance: 120 mW/cm 2 , light amount: 70 mJ/cm 2 ) using a UV irradiation device (manufactured by Lintec, product name “RAD-2000m/12”). .

・Dicing blade: manufactured by Disco, product name "NBC-ZH205O 27HECC"

Rotation speed: 30,000 rpm

·Height: 0.06 mm

·Cut speed: 60 mm/sec

·Chip size: 3 mm × 3 mm

Subsequently, the sheet for semiconductor processing obtained in Examples or Comparative Examples was cut into a square size of 210 mm x 210 mm. At this time, each side of the sheet|seat after cutting was cut so that it might become parallel or perpendicular|vertical to the MD direction of the base material in a sheet|seat for semiconductor processing. Next, the release sheet was peeled off, and all the silicon chips obtained by the dicing were transferred to the exposed adhesive face. At this time, one group of silicon chips was transferred so as to be located in the central portion of the sheet for semiconductor processing. Moreover, it transferred so that the dicing line at the time of dividing a silicon wafer into pieces might be parallel or perpendicular to each side of the sheet|seat for semiconductor processing.

Next, the sheet|seat for semiconductor processing from which the silicon chip was transferred was installed in the expander (separator) which can biaxially stretch. 8 shows a plan view illustrating the expander 100 in question. 8, the X axis and the Y axis are orthogonal to each other, the positive direction of the X axis is the +X axis direction, the negative direction of the X axis is the -X axis direction, the positive direction of the Y axis is the +Y axis direction, The negative direction of the Y axis is the -Y axis direction. The sheet|seat 200 for semiconductor processing was installed in the expander 100 so that each side might be parallel to the X-axis or Y-axis. As a result, the MD direction of the substrate in the sheet 200 for semiconductor processing is parallel to the X axis or Y axis. In Fig. 8, silicon chips are omitted.

As shown in Fig. 8, the expander 100 has five holding means 101 in each of the +X-axis direction, -X-axis direction, +Y-axis direction, and -Y-axis direction (20 holding means in total). (101)). Among the five holding means 100 in each direction, the holding means 101A is the one located at both ends, the holding means 101C is the one located in the center, and the holding means 101A and the holding means 101C ) is used as the holding means 101B. Each side of the sheet|seat 200 for a semiconductor process was hold|gripped by these holding means 101.

Here, as shown in FIG. 8, one side of the sheet|seat 200 for semiconductor processing is 210 mm. Moreover, the space|interval of holding means 101 comrades in each side is 40 mm. Moreover, the space|interval between the edge part (apex of a sheet|seat) in one side of the sheet|seat 200 for semiconductor processing, and the holding means 101A which exists in the said side and is closest to the said edge part is 25 mm.

Subsequently, a plurality of tension imparting means (not shown) corresponding to each of the holding means 101 were driven to move the holding means 101 independently of each other. At this time, about the five holding means 101 holding one side of the +X-axis direction side in the sheet|seat 200 for semiconductor processing, it moved in the +X-axis direction at stretching speed: 2.5 mm/sec for 40 seconds. . At the same time, among these five holding means 101, the holding means 101A and the holding means 101B are moved away from the holding means 101C (that is, the +Y axis direction or the -Y axis direction). moved At this time, the holding means 101A was moved at a speed of 2/3 of the stretching speed: 2.5 mm/sec, and the holding means 101B was moved at a speed of 1/3 of the stretching speed: 2.5 mm/sec. In addition, the holding means 101C was not moved in the +Y axis direction and -Y axis direction. Also about the holding means 101 located in the 3-direction side other than the +X-axis direction in the sheet|seat 200 for semiconductor processing, movement in each direction similarly to the +X-axis direction, and holding means 101A and movement of the holding means 101B in a direction away from the holding means 101C.

As a result of moving each holding means 101 as described above, while the sheet 200 for semiconductor processing is stretched by 100 mm each in the +X-axis direction and -X-axis direction, respectively, in the +Y-axis direction and -Y-axis direction. Each was stretched by 100 mm. That is, each side of the sheet|seat 200 for semiconductor processing was extended|stretched 200 mm at a time. As a result, the length of each side of the sheet|seat 200 for a semiconductor process after extending|stretching became 410 mm.

About the sheet|seat 200 for semiconductor processing in the state stretched as mentioned above, the presence or absence of fracture was evaluated based on the following criteria. A result is shown in Table 1.

(circle): It extended satisfactorily without fracture.

x: fracture occurred.

In addition, for the sheet 200 for semiconductor processing in which the evaluation of the presence or absence of fracture was "○", in the state in which the sheet 200 for semiconductor processing was stretched, the outer diameter in a substantially circular shape composed of a plurality of silicon chips ( The length corresponding to the outer diameter of the silicon wafer before dicing and stretching) was measured as the length (mm) corresponding to the outer diameter of the wafer. A result is shown in Table 1.

In addition, the chip spacing (mm) was calculated by applying the measured length (mm) corresponding to the outer diameter of the wafer to the following formula (II). A result is shown in Table 1.

Chip spacing (mm) = {wafer outer diameter corresponding length (mm) - 150 mm (silicon wafer diameter)} ÷ 49 (number of dicing lines)... (II)

In the above formula (II), the reason why the number of dicing lines is 49 is that when a silicon wafer having a diameter of 150 mm is diced into a chip size of 3 mm x 3 mm, the silicon wafer is formed in one direction and in a direction orthogonal to the direction diced at intervals of 3 mm, and divided into 50 equal parts in each direction at most, but based on the fact that the number of dicing lines at that time is 49 in each direction.

As is clear from Table 1, the sheets for semiconductor processing of Examples could be greatly stretched without breaking.

The sheet for semiconductor processing according to the present invention is preferably used, for example, in the manufacture of FO-WLP.

W… semiconductor wafer
W1... circuit side
W2... Circuit
W3... the other side
W4... internal terminal electrode
W5... home
W6... the other side
CP … semiconductor chip
One… semiconductor package
3... encapsulation
4A... 1st insulating layer
4B... 2nd insulating layer
5... redistribution layer
5A... external electrode pad
6... external terminal electrode
10... 1st adhesive sheet
11... 1st base film
12... 1st adhesive layer
20... 2nd adhesive sheet
21... 2nd base film
22... 2nd adhesive layer
30... protective sheet
40... surface protection sheet
41... 4th base film
42... 4th adhesive layer
50... grindstone
60... no sealing
100... expand device
101, 101A, 101B, 101C... means of maintenance
200... Sheet for semiconductor processing

Claims (9)

A sheet for semiconductor processing comprising at least a substrate,
The ratio of the 100% stress of the sheet for semiconductor processing measured in the MD direction of the substrate at 23°C to the 100% stress of the sheet for semiconductor processing measured in the CD direction of the substrate at 23°C is 0.8 or more and 1.2 below,
The 100% stress is obtained by holding both ends in the longitudinal direction with a gripper so that the length between the grippers is 100 mm, and then at a speed of 200 mm/min. It is a value obtained by dividing the measured value of the tensile force when the length between the grippers is 200 mm by the cross-sectional area when it is stretched in the longitudinal direction and cut in the plane orthogonal to the longitudinal direction of the sheet for semiconductor processing,
The MD direction is the flow direction of the substrate,
The CD direction is a direction perpendicular to the MD direction.
A sheet for semiconductor processing, characterized in that. A sheet for semiconductor processing comprising at least a substrate,
At 23 ° C., the tensile modulus of elasticity of the sheet for semiconductor processing measured in the MD direction and the CD direction of the base material is 10 MPa or more and 350 MPa or less, respectively,
At 23 ° C., the 100% stress of the sheet for semiconductor processing measured in the MD direction and the CD direction of the base material is 3 MPa or more and 20 MPa or less, respectively,
The 100% stress is obtained by holding both ends in the longitudinal direction with a gripper so that the length between the grippers is 100 mm, and then at a speed of 200 mm/min. It is a value obtained by dividing the measured value of the tensile force when the length between the grippers is 200 mm by the cross-sectional area when it is stretched in the longitudinal direction and cut in the plane orthogonal to the longitudinal direction of the sheet for semiconductor processing,
At 23 ° C., the elongation at break of the sheet for semiconductor processing measured in the MD direction and the CD direction of the base material is 100% or more, respectively,
The MD direction is the flow direction of the substrate,
The CD direction is a direction perpendicular to the MD direction,
The tensile elastic modulus and the elongation at break are respectively based on JIS K7161: 2014 and JIS K7127: 1999, using a tensile tester at 23 ° C., setting the distance between chucks to 100 mm, and pulling at a rate of 200 mm / min which was measured by conducting a test
A sheet for semiconductor processing, characterized in that. According to claim 1 or 2,
A sheet for semiconductor processing characterized by further comprising an adhesive layer laminated on at least one surface of the substrate. According to claim 1 or 2,
The sheet for semiconductor processing characterized in that the base material contains a thermoplastic elastomer. According to claim 4,
A sheet for semiconductor processing, characterized in that the thermoplastic elastomer is a urethane-based elastomer. According to claim 1 or 2,
A sheet for semiconductor processing characterized in that it is used to widen a mutual distance between adjacent semiconductor chips in a plurality of semiconductor chips laminated on one side of the sheet for semiconductor processing to 200 μm or more and 6000 μm or less. According to claim 1 or 2,
By elongating the semiconductor processing sheet by applying tension in four directions of +X-axis direction, -X-axis direction, +Y-axis direction, and -Y-axis direction in the mutually orthogonal X-axis and Y-axis, the semiconductor processing sheet is elongated. A sheet for semiconductor processing characterized in that it is used to widen the interval between a plurality of semiconductor chips stacked on one side of the. According to claim 1 or 2,
A step of forming a plurality of individual semiconductor chips on one side of the pressure-sensitive adhesive sheet;
A sheet for semiconductor processing characterized in that it is used as the adhesive sheet in a method for manufacturing a semiconductor device including a step of extending the adhesive sheet to widen a distance between the plurality of semiconductor chips. According to claim 1 or 2,
A semiconductor processing sheet characterized in that it is used to manufacture a fan-out type semiconductor wafer level package.

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