TW202323473A - Protective film-forming film, protective film-forming sheet, protective film-forming composite sheet and device manufacturing method that has good splittability of workpiece with a protective film and can suppress poor appearance of the split protective film - Google Patents

Abstract

The present invention provides a protective film-forming film that has good splittability of workpiece with a protective film and can suppress poor appearance of the split protective film, a protective film-forming sheet and a protective film-forming composite sheet including the protective film-forming film , and a method for manufacturing devices such as semiconductor devices. The protective film-forming film is a protective film-forming film that becomes a protective film after curing, wherein, when the cured protective film-forming film is subjected to a right-angle tear test at 23 DEG C, the right-angle tear strength is 10 N/mm or more. In addition, in the right-angle tear test, the elongation at break of the cured protective film-forming film is 10% or less.

Description

Film for forming protective film, sheet for forming protective film, composite sheet for forming protective film, and manufacturing method of device

The present invention relates to a protective film forming film, a sheet for forming a protective film, a composite sheet for forming a protective film, and a method for producing a device. In particular, it relates to a protective film forming film suitable for protecting a workpiece such as a semiconductor wafer or a processed product such as a semiconductor wafer obtained by processing a workpiece, a sheet for forming a protective film provided with the protective film forming film, and a sheet for forming a protective film. A method for manufacturing a composite sheet and a device including a semiconductor wafer or the like.

In recent years, semiconductor devices have been manufactured using a mounting method called flip-chip bonding (Flip-Chip Bonding). In this mounting method, when mounting a semiconductor wafer having a circuit surface on which protruding electrodes such as bumps are formed, the semiconductor wafer is turned over (flip-chip) in such a manner that the circuit surface of the semiconductor wafer faces the wafer mounting surface of the substrate. (face down)), so that the circuit surface of the semiconductor chip and the chip mounting surface of the substrate are wirelessly bonded. Therefore, the surface of the semiconductor wafer opposite to the circuit surface (the surface on which no circuit is formed, hereinafter also referred to as the back surface) is exposed to the outside.

If the back surface of the semiconductor wafer is exposed to the outside, chipping such as cracking or chipping due to impacts during transportation or the like may occur in subsequent steps. Therefore, in order to protect the semiconductor wafer from such edge chipping, a hard resin film made of an organic material is often formed as a protective film on the back surface of the semiconductor wafer.

Such a protective film is formed by curing an uncured resin film (hereinafter, also referred to as a protective film forming film) as its precursor. The protective film forming film is attached to the back surface of the semiconductor wafer. Before or after the protective film forming film is cured, the semiconductor wafer and the protective film forming film or protective film are diced and divided (singulated) into a plurality of small pieces. Before the protective film forming film is cured, the protective film forming film is cured after being divided. The divided small pieces thus obtained are semiconductor wafers (semiconductor wafers with protective films) having a protective film on their back surfaces.

Stealth dicing is also known as a method of singulating workpieces such as semiconductor wafers by dicing, in addition to blade dicing in which a rotating blade is used to cut the workpiece while spraying liquid for cleaning, cooling, etc. ((Stealth-dicing) registered trademark).

For stealth dicing, first, a laser is focused on the inside of the workpiece to form modified regions along planned dividing lines. The modified region is a region whose intensity becomes lower than other regions due to laser irradiation, which generates cracks along the thickness direction of the workpiece. Next, a tensile force is applied to the workpiece with the modified region formed in a direction perpendicular to the thickness direction, and the cracks generated in the modified region are extended to both main surfaces of the workpiece by the tensile stress. The final workpiece is divided into a plurality of small pieces along the planned dividing line (singulated).

As a method of applying tensile force to the workpiece, the following method can be exemplified: placing the workpiece with an elastic tape or sheet on the table, and placing the tape or sheet along the thickness of the workpiece. A method of stretching (expanding) in a direction perpendicular to the direction.

At this time, tensile stress is also generated on the protective film formed on the back surface of the workpiece, and it is necessary to divide the protective film into substantially the same shape as the wafer while dividing the workpiece.

As an example of a protective film forming film that can be appropriately divided together with a wafer when spreading in stealth dicing, Patent Document 1 discloses a protective film forming film whose product of breaking stress and breaking strain at 0°C is within a predetermined range. membrane. prior art literature patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2016-115943

The technical problem to be solved in the present invention

However, there is a problem that even if tensile stress due to expansion occurs on the workpiece, it cannot be divided along the planned dividing line, so that a predetermined number of wafers with protective films cannot be obtained, and the yield of wafers decreases. The main cause of this problem is considered to be that the protective film was not reliably divided during expansion. On the other hand, expansion at low temperature (cold expansion) has been proposed in order to make the protective film easy to split, however, there is a problem that it takes a lot of time and energy to cool the expansion device etc. to a low temperature.

In addition, the inventors of the present application found that when the strength of the protective film is lowered to make the protective film easily split, the protective film may be accidentally split due to impact or the like applied before expansion. When the protective film is divided not by expansion but by impact or the like, the outer peripheral line of the protective film tends to be a zigzag line rather than a straight line when the protective film is viewed from above. A wafer whose outer peripheral line of the protective film is a jagged line is judged to be poor in appearance, and there is a problem that the yield of the wafer decreases.

The present invention was made in view of the above-mentioned circumstances, and an object of the present invention is to provide a protective film-forming film capable of suppressing poor appearance of a protective film after separation, and a protective film forming film provided with the protective film-forming film. A method of manufacturing a sheet, a composite sheet for forming a protective film, and a device such as a semiconductor device. Technical means to solve technical problems

Technical scheme of the present invention is as follows. (1) A protective film-forming film, which is a protective film-forming film that becomes a protective film after curing, wherein, at 23° C., when the cured protective film-forming film is subjected to a right-angle tear test, the right-angle tear strength is 10 N/mm or more, and in the right-angle tear test, the elongation of the cured protective film-forming film at rupture is 10% or less. (2) The protective film forming film as described in (1) whose protective film is a thermosetting material or an energy-beam hardening material. (3) The protective film forming film as described in (1) or (2) whose right-angle tear strength is 25 N/mm or less. (4) The protective film-forming film according to any one of (1) to (3), which is used to form a modified region by focusing laser light on the protective film. (5) A sheet for forming a protective film comprising the protective film forming film according to any one of (1) to (4) and a release film disposed on at least one main surface of the protective film forming film in a releasable manner . (6) A composite sheet for forming a protective film, comprising the protective film forming film according to any one of (1) to (4), and a support sheet for supporting the protective film forming film. (7) The composite sheet for forming a protective film according to (6), wherein the right-angle tear strength of the protective film-forming film after curing at 23° C. is TS1, and the protective film forming film at 23° C. When the right-angle tear strength of the support sheet when performing the right-angle tear test is TS2, TS1/TS2 is 0.15 or less. (8) A method of manufacturing a device, comprising: a step of attaching a protective film forming film to the back surface of the workpiece; making the attached protective film forming film solidified, thereby forming a protective film on the back side of the workpiece to obtain a workpiece with a protective film; Focusing the laser on a pre-set area inside the workpiece, thereby forming a first modified area; Focusing the laser on a predetermined area inside the protective film to form a second modified area; and applying a tensile force to the workpiece with a protective film on which the first modified region and the second modified region are formed, thereby singulating the workpiece with a protective film to obtain a plurality of workpieces with a protective film Processed product steps. (9) The method for manufacturing a device according to (8), wherein the protective film forming film is the protective film forming film included in the protective film forming sheet described in (5), or the protective film forming film described in (6) or (7). The protective film forming film which the composite sheet for protective film formation mentioned above is equipped with. Invention effect

According to the present invention, it is possible to provide a protective film forming film which has good splittability of a workpiece with a protective film and which can suppress the appearance defect of the divided protective film, a protective film forming sheet and a protective film forming sheet comprising the protective film forming film. A method for manufacturing devices such as a composite sheet and a semiconductor device.

Hereinafter, based on specific embodiments, the present invention will be described in detail using the drawings. First, the main terms used in this specification will be explained.

The workpiece is a plate-shaped body to be processed by attaching the sheet for forming a protective film or the composite sheet for forming a protective film according to the present embodiment. Examples of the workpiece include wafers and panels. Specific examples thereof include semiconductor wafers and semiconductor panels. Examples of workpiece processed products include wafers obtained by singulating wafers. Specifically, a semiconductor wafer obtained by singulating a semiconductor wafer can be exemplified.

The "surface" of a workpiece such as a wafer refers to the surface on which circuits and convex electrodes such as bumps are formed, and the "back surface" refers to the surface on which no circuits or electrodes (such as convex electrodes such as bumps) are formed. The protective film is formed on the wafer and the backside of the chip.

Singulation of a wafer refers to obtaining a wafer by dividing the wafer for each circuit.

In this specification, for example, "(meth)acrylate" is a term used to represent both "acrylate" and "methacrylate", and other similar expressions are also the same.

"Energy rays" refer to ultraviolet rays, electron beams, etc., preferably ultraviolet rays.

The release film is a film that supports the adhesive layer or the protective film forming film in a peelable manner. The term "film" is used to include the concept of a sheet and does not limit its thickness.

The mass ratio in the description of compositions such as the protective film-forming composition is based on the active ingredient (solid content), and the solvent is not included unless otherwise specified.

(1. Protective film forming film) The protective film-forming film of this embodiment can be used to form a protective film that is attached to a workpiece and protects a workpiece or a processed workpiece.

(1.1 Protective film) In this embodiment, a protective film can be obtained by hardening the protective film forming film of this embodiment. That is, the protective film-forming film of this embodiment is curable. By laminating the curable protective film-forming film on the workpiece and then curing the protective film-forming film, the protective film can be firmly adhered to the workpiece and a durable protective film can be formed.

The protective film is a cured product of the protective film forming film, and is different from the protective film forming film. As cured products, for example, heat cured products and energy ray cured products can be exemplified. In this embodiment, it is more preferable that the protective film is a thermally cured product.

Whether or not the protective film forming film is thermosetting can be judged in the following manner. First, a protective film-forming film at normal temperature (23° C.) was heated to a temperature higher than normal temperature, and then cooled to normal temperature to prepare a heated and cooled protective film-forming film. Next, at the same temperature, the hardness of the protective film-forming film after heating and cooling is compared with the hardness of the protective film-forming film before heating. If the protective film-forming film after heating and cooling is harder at this time, the The protective film forming film was judged to be thermosetting.

Moreover, it is preferable that the protective film forming film has adhesiveness at normal temperature (23 degreeC), or develops adhesiveness by heating. Thereby, when laminating|stacking a protective film forming film and a work, both can be bonded together. Therefore, the position can be reliably identified before the protective film forming film is cured.

The protective film forming film may be composed of one layer (single layer), or may be composed of a plurality of two or more layers. When the protective film forming film has plural layers, these plural layers may be the same as each other or may be different from each other, and the combination of the layers constituting these plural layers is not particularly limited.

In this embodiment, it is preferable that the protective film forming film is one layer (single layer). Since the one-layer protective film forming film can be obtained with a relatively high-precision thickness, it is easy to produce. In addition, if the protective film forming film is composed of a plurality of layers, it is necessary to consider the adhesiveness between the layers and the stretchability of each layer, and therefore there is a risk of peeling from the adherend. When the protective film is formed as a single film, the above risks can be reduced, and the degree of freedom in design can also be increased. In addition, it is also possible to reduce the risk of interlayer delamination due to differences in thermal stretchability between layers in steps where temperature changes (during reflow processing or when using a device).

The thickness of the protective film forming film is not particularly limited, but is preferably not more than 100 μm, not more than 70 μm, not more than 45 μm, and not more than 30 μm. In addition, the thickness of the protective film-forming film is preferably 5 μm or more, 10 μm or more, and 15 μm or more. When the thickness of a protective film forming film exists in the said range, the protective performance of the protective film obtained will become favorable.

In addition, the thickness of a protective film forming film means the thickness of the whole protective film forming film. For example, the thickness of the protective film forming film which consists of several layers means the total thickness of all the layers which comprise a protective film forming film.

The protective film-forming film of the present embodiment is attached to a workpiece and cured to form a protective film. Finally, a work (work with a protective film) on which a protective film is formed as a cured product can be obtained.

A workpiece 100 with a protective film is shown in FIG. 1 . In the workpiece 100 with a protective film, the protective film 1 is formed on the back side of the workpiece 6 (lower side in FIG. 1 ), and the protruding electrode 6 b is formed on the front side of the workpiece 6 (upper side in FIG. 1 ). A circuit is formed on the surface side of the workpiece 6, and the protruding electrode 6b is formed so as to be electrically connected to the circuit. A bump, a pillar electrode, etc. can be illustrated as the convex electrode 6b.

In this embodiment, the workpiece 100 with a protective film is attached to a stretchable tape or sheet such as a dicing tape or a dicing sheet with the main surface opposite to the main surface of the protective film 1 in contact with the workpiece 6. The state above is for stealth cutting.

In stealth dicing, first, a predetermined laser is focused on the inside of the workpiece to form modified regions along planned dividing lines. Then, the stretchable adhesive tape or sheet is stretched (expanded) in such a manner that a tensile force acts on the workpiece 6 in a direction toward the outer periphery of the workpiece 6, and the crack generated in the modified region is extended to the The two main faces of the workpiece. Finally, the workpiece is divided into a plurality of small pieces (singulated) along the planned dividing line to obtain a workpiece.

At this time, tensile stress is also generated on the protective film, so that the protective film is stretched and then divided into shapes corresponding to the planned dividing lines. Therefore, by this expansion, the work 100 with a protective film shown in FIG. 1 is divided, and as shown in FIG. 2 , a plurality of wafers with a protective film 100 a are obtained as workpieces. In the protective film-attached wafer 100a, the protective film 1 is formed on the back side (lower side in FIG. 2) of the wafer 6a, and the protruding electrodes 6b are formed on the front side (upper side in FIG. 2) of the wafer 6a.

However, sometimes, even if tensile stress due to expansion occurs on the workpiece with a protective film, it cannot be divided along the planned dividing line, resulting in the failure to obtain a predetermined number of protective films. of wafers. FIG. 3 is a view of a plurality of wafers 100a with protective films obtained by expansion in FIG. 2 when viewed from the III direction. That is, FIG. 3 shows the planar shape of the protective film-attached wafer 100a when viewed from the III direction.

In the upper left of FIG. 3 , there are non-segmented unsegmented protective film-attached wafers 101 a of the protective film-attached wafer 100 a that should be divided along the dividing line 200 . Since such an unsegmented protective film-attached wafer 101a is a defective product, there is a problem that the yield of the wafer decreases.

Conventionally, in order to cope with this problem, cold spreading in which spreading in stealth dicing is carried out at a low temperature (eg, 0° C. or lower) has been employed. However, the time and energy required for cooling are problematic.

On the other hand, in this embodiment, not only the inside of the workpiece but also the inside of the protective film are formed with modified regions along the planned division lines. Since the modified region is formed inside the protective film, even if the expansion in stealth dicing is carried out at room temperature (for example, 23°C), the workpiece with the protective film can be surely divided along the planned dividing line, and the planned cutting can be obtained. Quantity of wafers with protective film.

However, when a region with low strength is formed inside the protective film due to the formation of a modified region inside the protective film, there may be an accidental split not due to expansion but due to an impact applied before expansion. The case where the protective film is split. When the protective film is divided not by expansion but by impact or the like, as shown in the lower right of FIG. The tendency of the attached protective film wafer 102a. Such a wafer with a protective film 102a is judged to be poor in appearance, and there is a problem that the wafer yield decreases.

In order to suppress this appearance defect, in addition to forming a modified region in the protective film, the breaking strength (right-angle tear strength) and the elongation at break in the right-angle tear test of the protective film are also carried out. Control is as follows. As mentioned above, the protective film is a cured product of the protective film-forming film, and the right-angle tear strength of the protective film is synonymous with the right-angle tear strength of the cured protective film-forming film, and the elongation at break of the protective film is the same as that after curing. The elongation at break of the protective film forming film is synonymous.

(1.1.1 Right angle tear strength) In the present embodiment, the right-angle tear strength (TS1) of the cured protective film-forming film (protective film) at 23° C. is 10 N/mm or more. By setting the right-angle tear strength within the above-mentioned range, it is possible to suppress unintentional splitting of the protective film due to impact applied before expansion. Therefore, the protective film will not be divided before the expansion of the stealth dicing, even if it is expanded at room temperature, it can be divided reliably and appropriately, and a predetermined number of protective films in which the outer peripheral line of the protective film is a straight line when viewed from above are obtained. Membrane wafers.

The right-angle tear strength (TS1) of the cured protective film-forming film is preferably 13 N/mm or more, more preferably 15 N/mm or more, further preferably 17 N/mm or more.

On the other hand, in order to more reliably divide the protective film during expansion, the right-angle tear strength (TS1) of the cured protective film forming film at 23° C. is preferably 25 N/mm or less, more preferably 22 N/mm or less .

The right-angle tear strength (TS1) of the protective film forming film after curing was measured in accordance with JIS K 7128-3:1998. That is, the right-angle tear strength of the cured protective film-forming film is measured in the same manner as the measurement method (right-angle tear method) prescribed in JIS K 7128-3:1998, and the measurement conditions may be different. The specific measurement method will be described in the examples. The test piece has the shape shown in FIG. 2 in JIS K 7128-3:1998, and the central part of the test piece is a concave shape at an angle of 90°. The right-angle tear test was implemented by pulling both ends of the test piece.

(1.1.2 Elongation at break) In the present embodiment, the elongation at breakage of the cured protective film-forming film (protective film) is 10% or less in the test for measuring the right-angle tear strength at 23°C. By setting the elongation within the above range, the protective film can be appropriately divided even when stretched at room temperature, and a predetermined number of wafers with protective film can be obtained in which the outer peripheral line of the protective film is a straight line in plan view.

The elongation at break of the protective film-forming film after curing is preferably 8% or less, more preferably 7% or less, further preferably 4% or less. On the other hand, the lower limit of the elongation is not particularly limited, but it is preferably 0.2% or more from the viewpoint of reducing the risk of cracks or chipping at positions other than the outer peripheral line of the protective film when the protective film is viewed from above during expansion. .

As described above, the elongation at the time of film rupture due to the formation of the cured protective film is the measured value in the test for measuring the right-angle tear strength shown in (1.1.1), which is in accordance with JIS K 7128-3:1998 And measure. That is, the right-angle tear strength of the cured protective film-forming film is measured in the same manner as the measurement method prescribed in JIS K 7128-3:1998, and the measurement conditions may be different. The specific measurement method will be described in the examples.

(1.2 Composition for Forming a Protective Film) The composition of the protective film forming film is not particularly limited as long as the protective film has the above-mentioned physical properties. In this embodiment, the composition constituting the protective film forming film (the composition for forming a protective film) is preferably a resin composition containing at least a polymer component (A), a curable component (B) and a filler (E). thing. The polymer component is regarded as a component formed by polymerizing a polymeric compound. In addition, a curable component is a component which can undergo a curing (polymerization) reaction. In addition, in the present invention, the polymerization reaction also includes polycondensation reaction.

In addition, components contained in polymer components may also belong to curable components. In this embodiment, when the composition for forming a protective film contains such a component as both a polymer component and a curable component, it is deemed that the composition for forming a protective film contains both a polymer component and a curable component. ingredients.

(1.2.1 Polymer composition) The polymer component (A) not only imparts film-forming properties (film-forming properties) to the protective film-forming film, but also imparts appropriate tack to ensure uniform adhesion of the protective film-forming film to the workpiece. The weight-average molecular weight of the polymer component is usually 50,000 to 2 million, preferably 100,000 to 1.5 million, most preferably 200,000 to 1 million. As such a polymer component, for example, acrylic resin, urthane resin, phenoxy resin, silicone resin, saturated polyester resin, etc. can be used, and acrylic resin is particularly preferably used.

In addition, in this specification, unless otherwise specified, "weight average molecular weight" means the polystyrene conversion value measured by the gel permeation chromatography (GPC) method. Measurement based on this method is carried out, for example, as follows: High-speed columns "TSK guard column H _XL -H", "TSK Gel GMH XL ", "TSK Gel GMH _XL ", " TSK Gel G2000 H _XL ” (all above are manufactured by TOSOH CORPORATION) uses a differential refractive index detector as a detector under the conditions of a column temperature of 40°C and a liquid feed rate of 1.0mL/min.

As an acrylic resin, the (meth)acrylate copolymer which consists of a (meth)acrylate monomer and the structural unit derived from a (meth)acrylic acid derivative is mentioned, for example. Among them, as the (meth)acrylate monomer, preferably an alkyl (meth)acrylate with an alkyl group having 1 to 18 carbon atoms, specifically methyl (meth)acrylate, (meth)acrylate, base) ethyl acrylate, propyl (meth)acrylate, butyl (meth)acrylate, etc. Moreover, as a (meth)acrylic acid derivative, (meth)acrylic acid, glycidyl (meth)acrylate, hydroxyethyl (meth)acrylate, etc. are mentioned, for example.

In the present embodiment, it is preferable to introduce hydroxyl groups into the acrylic resin using hydroxyethyl acrylate or the like in order to control the adhesiveness or stickiness to the workpiece.

The glass transition temperature of the acrylic resin is preferably -70°C~40°C, -60°C~30°C, -50°C~25°C, -40°C~20°C, -35°C~15°C. By setting the glass transition temperature of the acrylic resin within the above-mentioned range, it is possible to moderately increase the viscosity of the protective film-forming film and at the same time improve the adhesion of the protective film-forming film to the workpiece, and to moderately improve the adhesion of the protective film to the workpiece. At the same time, it is easier to set the right-angle tear strength and elongation at break in the right-angle tear test within the above-mentioned ranges.

When the acrylic resin has m types (m is an integer greater than or equal to 2) of structural units, the glass transition temperature of the acrylic resin can be calculated in the following manner. That is, when m types of monomers from which structural units in acrylic resins are derived are sequentially assigned any non-repeating serial numbers from 1 to m and named "monomer m", it can be calculated using the Fox formula shown below Glass transition temperature (Tg) of acrylic resins.

式中，Tg為丙烯酸樹脂的玻璃轉化溫度；m為2以上的整數；Tgk為單體m的均聚物的玻璃轉化溫度；Wk為丙烯酸樹脂中衍生自單體m的結構單元m的質量分率，且Wk滿足下述式。 [mathematical formula 1]

In the formula, Tg is the glass transition temperature of the acrylic resin; m is an integer above 2; Tgk is the glass transition temperature of the homopolymer of the monomer m; Wk is the mass fraction of the structural unit m derived from the monomer m in the acrylic resin rate, and Wk satisfies the following formula.

式中，m及Wk與上述m及Wk相同。 [mathematical formula 2]

In the formula, m and Wk are the same as above-mentioned m and Wk.

As Tgk, the value described in a polymer data handbook, an adhesive handbook, a polymer handbook (Polymer Handbook), etc. can be used. For example, the Tgk of the homopolymer of methyl acrylate is 10°C, the Tgk of the homopolymer of n-butyl acrylate is -54°C, the Tgk of the homopolymer of methyl methacrylate is 105°C, 2-hydroxyethyl acrylate Tgk of ester homopolymer is -15℃, Tgk of glycidyl methacrylate homopolymer is 41℃, Tgk of 2-ethylhexyl acrylate homopolymer is -70℃, ethyl acrylate The Tgk of the homopolymer was -24°C.

The content of the polymer component when the total weight of the composition for forming a protective film is 100 parts by mass is preferably 5 to 60 parts by mass, 10 to 50 parts by mass, 13 to 40 parts by mass, and 16 to 30 parts by mass. By setting the content of the polymer component within the above range, it becomes easier to set the right-angle tear strength in the right-angle tear test and the elongation at break within the above-mentioned range. Also, it is easier to control the tackiness of the protective film forming film.

(1.2.2 Thermosetting components) The curable component (B) forms a protective film as a cured product by curing the protective film-forming film. As described above, the protective film is preferably a thermosetting material or an energy ray curable material, and as a curable component, a thermosetting component, an energy ray curable component, or a mixture thereof can be used.

Since the protective film-forming film of this embodiment contains a filler, a colorant, etc. which will be described later, light transmittance falls. An energy ray-curable protective film-forming film is cured by irradiating an energy ray. Therefore, for example, when the thickness of the protective film-forming film becomes thicker, the curing by the energy ray tends to become insufficient.

However, since a thermosetting protective film forming film can be fully cured by heating even if its thickness becomes thick, the protective film with high protective performance can be formed. Moreover, by using normal heating means, such as a heating oven, several protective film formation films can be heated collectively and can be thermally cured.

Since the protective film is preferably a thermosetting material, the curable component contained in the protective film forming film is preferably thermosetting. That is, the protective film-forming film of the present embodiment is preferably thermosetting.

As the thermosetting component, for example, epoxy resins, thermosetting polyimide resins, unsaturated polyester resins, and mixtures thereof are preferably used. In addition, a thermosetting polyimide resin is a collective term for low molecular weight and low viscosity monomers or precursor polymers that form polyimide resins by thermal curing. Non-limiting specific examples of thermosetting polyimide resins are described, for example, in the Journal of the Fiber Society (Journal of the Textile Society) "Vision and Industry", Vol.50, No.3 (1994), P106-P118.

Epoxy resin, which is a thermosetting component, has the property of becoming a three-dimensional network when heated to form a strong coating. As such an epoxy resin, various known epoxy resins can be used. In this embodiment, the molecular weight (formula weight) of the epoxy resin is preferably 300 to less than 50,000, 300 to less than 10,000, 300 to less than 5,000, and 300 to less than 3,000. In addition, the epoxy equivalent of the epoxy resin is preferably 50-5000 g/eq, more preferably 100-2000 g/eq, further preferably 150-1000 g/eq.

Specific examples of such epoxy resins include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolac, and cresol novolak; butylene glycol, polyethylene glycol, Glycidyl ethers of alcohols such as polypropylene glycol; glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; glycidyl substituted aniline isocyanurate, etc. Glycidyl-type or alkylglycidyl-type epoxy resins made of active hydrogen bonded to nitrogen atoms; vinylcyclohexane diepoxide, 3,4-epoxycyclohexylmethyl- 3,4-dicyclohexane carboxylate, 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-dioxane, etc. A so-called alicyclic epoxide in which an epoxy group is introduced by oxidizing a carbon-carbon double bond in the molecule. In addition, epoxy resins having a biphenyl skeleton, a dicyclohexadiene skeleton, a naphthalene skeleton, and the like can also be used.

When a thermosetting component is used as the curable component (B), it is preferable to use a curing agent (C) as an auxiliary agent together. As a curing agent for epoxy resin, a thermally active latent epoxy resin curing agent is preferable. "Heat-activated latent epoxy resin curing agent" refers to a type of curing agent that does not easily react with epoxy resin at room temperature (23°C), but is activated by heating above a certain temperature to react with epoxy resin . There are the following methods in the activation method of thermally active latent epoxy resin curing agent: the method of generating active species (anion, cation) by chemical reaction based on heating; stable dispersion in epoxy resin near normal temperature, but at high temperature Compatible with epoxy resin. The method of dissolving and starting the curing reaction; the method of using molecular sieve sealing type curing agent to dissolve at high temperature and starting the curing reaction; the method of using microcapsules, etc.

In the exemplified method, it is preferable to be stably dispersed in epoxy resin near normal temperature, but compatible with epoxy resin at high temperature. A method of dissolving and starting the curing reaction.

Specific examples of thermally active latent epoxy resin curing agents include various onium salts, dibasic acid dihydrazide compounds, dicyandiamide, amine adduct curing agents, and high melting point active hydrogen compounds such as imidazole compounds. . These thermoactive latent epoxy resin curing agents may be used alone or in combination of two or more. In this embodiment, dicyandiamide is particularly preferable.

In addition, as a curing agent for epoxy resins, phenolic resins are also preferable. As the phenolic resin, condensates of phenols such as alkylphenols, polyhydric phenols, and naphthols and aldehydes can be used without particular limitation. Specifically, phenol novolac resin, o-cresol novolac resin, p-cresol novolac resin, tertiary butylphenol novolac resin, dicyclopentadiene cresol resin, polyvinylphenol resin, bisphenol A type Novolak resins or modified products thereof, etc.

The phenolic hydroxyl group contained in these phenolic resins can easily perform addition reaction with the epoxy group of the said epoxy resin by heating, and can form the hardened|cured material with high impact resistance.

The content of the curing agent (C) is preferably 0.5-100 parts by mass, 0.8-20 parts by mass, 1.2-8 parts by mass, or 1.6-4 parts by mass relative to 100 parts by mass of the epoxy resin. By making the content of the curing agent (C) within the above-mentioned range, the network structure of the protective film becomes dense, therefore, it is easy to obtain the performance of protecting the workpiece as a protective film, and it is easier to make the right-angle tear in the right-angle tear test The strength and elongation at break are within the above ranges.

When dicyandiamide is used as the curing agent (C), it is preferred to further use a curing accelerator (D) together. As a curing accelerator, for example, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl imidazoles (imidazoles in which one or more hydrogen atoms are replaced by groups other than hydrogen atoms) such as 4-methyl-5-hydroxymethylimidazole. Among them, 2-phenyl-4,5-dimethylolimidazole is particularly preferred.

The content of the curing accelerator is preferably 0.5-10 parts by mass, 0.8-7 parts by mass, 1.2-5 parts by mass, or 1.6-4 parts by mass relative to 100 parts by mass of the epoxy resin. By making the content of the curing accelerator (D) within the above-mentioned range, the network structure of the protective film becomes dense, therefore, it is easy to obtain the performance of protecting the workpiece as a protective film, and it is easier to make the right-angle tearing in the right-angle tear test easier. The crack strength and elongation at break are within the above ranges.

When the total weight of the composition for forming a protective film is 100 parts by mass, the total content of the thermosetting component and the curing agent is preferably 6 to 80 parts by mass, 8 to 70 parts by mass, 10 to 60 parts by mass, 12 to 50 parts by mass. parts by mass, 14 to 40 parts by mass. By making the total content of a thermosetting component and a hardening|curing agent more than the said lower limit, moderate viscosity can be expressed before hardening, and sticking operation can be performed stably. In addition, after curing, it is easy to obtain the performance of protecting workpieces as a protective film. Adjusting the degree of curing by setting the total content of the thermosetting component and the curing agent within the above-mentioned range makes it easier to make the right-angle tear strength and elongation at break in the right-angle tear test within the above-mentioned range.

(1.2.3 Energy ray curable components) When the curable component (B) is an energy ray curable component, the energy ray curable component is preferably uncured, preferably has adhesiveness, more preferably is uncured and has adhesiveness.

The energy ray curable component is a component that is cured by irradiation with energy rays, and is also a component for imparting film-forming properties, flexibility, and the like to a protective film-forming film.

As the energy ray curable component, for example, a compound having an energy ray curable group is preferable. As such a compound, the compound which has a well-known energy-ray curable group is mentioned.

(1.2.4 Filling material) By making the protective film forming film contain the filler (E), the adjustment of the thermal expansion coefficient of the protective film obtained by making the protective film forming film into a protective film becomes easier, and by making the thermal expansion coefficient close to the thermal expansion coefficient of the workpiece , the bonding reliability of the wafer with a protective film obtained by forming a film using the protective film is further improved. In addition, by making the protective film forming film contain the filler (E), a hard protective film can be obtained, the moisture absorption rate of the protective film can be further reduced, and the adhesion reliability of the wafer with the protective film is further improved.

The filler (E) may be either an organic filler or an inorganic filler, and is preferably an inorganic filler from the viewpoint of shape stability at high temperature.

As preferred inorganic fillers, for example, powders of silicon dioxide, alumina, talc, calcium carbonate, red iron oxide, silicon carbide, boron nitride, etc. are exemplified; these inorganic fillers are made spherical to obtain Beads of these inorganic fillers; surface modifications of these inorganic fillers; single crystal fibers of these inorganic fillers; glass fibers, etc. Among them, silicon dioxide and surface-modified silicon dioxide are preferred. The surface-modified silica is preferably surface-modified by a coupling agent, more preferably surface-modified by a silane coupling agent.

The average particle size of the filler is preferably 0.02-10 μm, 0.05-5 μm, or 0.10-3 μm.

By setting the range of the average particle diameter of a filler to the said range, the handleability of the composition for protective film formation becomes favorable. As a result, it becomes easy to stabilize the quality of the composition for protective film forming films and a protective film forming film.

In addition, in this specification, unless otherwise specified, "average particle diameter" refers to the particle diameter (D50) when the cumulative value is 50% in the particle size distribution curve obtained by the laser diffraction scattering method. value.

The content of the filler when the total weight of the composition for forming a protective film is 100 parts by mass is preferably 15-80 parts by mass, 30-75 parts by mass, 40-70 parts by mass, or 45-65 parts by mass.

By setting the lower limit of the content of the filler to the above-mentioned value, the adhesion reliability of the wafer with a protective film obtained by forming a film using a protective film further increases. Moreover, by making the upper limit of content of a filler into the said value, the adhesive force of a protective film forming film to a workpiece|work increases, and the adhesive force of a protective film to a workpiece increases moderately. Moreover, by making content of a filler exist in the said range, it becomes easier to make the right-angled tear strength in a right-angled tear test, and the elongation at the time of fracture fall in the said range.

(1.2.5 Coupler) It is preferable that a protective film forming film contains a coupling agent (F). By containing the coupling agent, after the protective film forming film is cured, the adhesion between the protective film and the workpiece can be improved without impairing the heat resistance of the protective film, and the water resistance (moisture and heat resistance) can also be improved. As the coupling agent, a silane coupling agent is preferred from the viewpoint of versatility and cost advantages.

Examples of silane coupling agents include γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropylmethyldiethoxysilane, β-(3,4-epoxy Hexyl)ethyltrimethoxysilane, γ-(methacryloxypropyl)trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropyl Trimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureapropyltriethyl Oxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis(3-triethoxypropyl)tetrasulfide, methyltrimethoxysilane, methyl Triethoxysilane, Vinyltrimethoxysilane, Vinyltriacetoxysilane, Imidazolesilane, etc.

As a preferable silane coupling agent, the oligomer type silane coupling agent which has a plurality of alkoxysilyl groups in one molecule can also be mentioned. Since the oligomer-type silane coupling agent is less volatile and has a plurality of alkoxysilyl groups in one molecule, it is preferable in terms of effectively improving durability. Examples of the oligomer type silane coupling agent include "X-41-1053", "X-41-1059A", "X-41-1056" which are epoxy group-containing oligomer type silane coupling agents. " and "X-40-2651" (both manufactured by Shin-Etsu Chemical Co., Ltd.); "X-41-1818" and "X-41-1810" which are mercapto-containing oligomer type silane coupling agents and "X-41-1805" (both manufactured by Shin-Etsu Chemical Co., Ltd.), etc. These silane coupling agents can be used alone or in combination of two or more.

The content of the coupling agent when the total weight of the composition for forming a protective film is 100 parts by mass is preferably 0.01 to 20 parts by mass, 0.1 to 10 parts by mass, 0.2 to 5 parts by mass, or 0.3 to 3 parts by mass.

(1.2.6 Colorants) It is preferable that a protective film forming film contains a coloring agent (G). Thus, since the back surface of workpieces such as wafers is covered, various electromagnetic waves generated in electronic equipment can be shielded, and failures of workpieces such as wafers can be reduced.

As the colorant (G), known colorants such as organic pigments, organic dyes, and inorganic pigments can be used, for example. In this embodiment, inorganic pigments are preferable.

Examples of inorganic pigments include carbon black, cobalt-based pigments, iron-based pigments, chromium-based pigments, titanium-based pigments, vanadium-based pigments, zirconium-based pigments, molybdenum-based pigments, ruthenium-based pigments, platinum-based pigments, ITO ( Indium tin oxide) pigments, ATO (antimony tin oxide) pigments, etc. Among them, it is particularly preferable to use carbon black. With carbon black, electromagnetic waves in a wide wavelength range can be shielded.

The blending amount of the colorant (especially carbon black) in the protective film-forming film varies depending on the thickness of the protective film-forming film. For example, when the thickness of the protective film-forming film is 25 μm, the composition for protective film-forming film The content of the colorant when the total weight is 100 parts by mass is preferably 0.01 to 10 parts by mass, 0.03 to 7 parts by mass, or 0.05 to 4 parts by mass.

The average particle size of the colorant (especially carbon black) is preferably 1-500 nm, 3-100 nm, 5-50 nm. When the average particle diameter of the coloring agent is within the above-mentioned range, it is easy to control the light transmittance within the desired range.

(1.2.7 Other additives) The composition for forming a protective film may contain, for example, a photopolymerization initiator, a crosslinking agent, a plasticizer, an antistatic agent, an antioxidant, a gettering agent, a Adhesives, release agents, etc. are used as other additives.

(2. Sheet for protective film formation) The sheet for protective film formation of this embodiment has the said protective film forming film, and the peeling film arrange|positioned at least one main surface of a protective film forming film. The peeling film is peeled when forming a film using a protective film.

The protective film forming sheet 51 shown in FIG. 4 has a structure in which a first release film 21 supporting the protective film forming film 10 is disposed on one main surface 10a of the protective film forming film 10, and a first release film 21 is disposed on the other main surface 10b. A second release film 22 is provided.

The protective film-forming sheet of this embodiment is used to attach a protective film-forming film to the back surface of the workpiece before singulating the workpiece, and to cure the protective film-forming film to form a protective film on the rear surface of the workpiece. The workpiece on which the protective film was formed (workpiece with protective film) is singulated by stealth dicing to obtain a wafer with protective film as a processed workpiece.

Moreover, the sheet|seat for protective film formation may be the form of the elongated sheet whose length in the longitudinal direction is very long with respect to the length in the width direction. In addition, it may be in the form of a sheet roll obtained by winding such a long sheet.

Furthermore, the sheet for forming a protective film may be a sheet for forming a protective film that has been punched so that the forming film to be attached to the workpiece has a predetermined closed shape. The predetermined closed shape is not particularly limited, and is preferably approximately the same shape as the attached workpiece.

(2.1 Peel-off film) The peeling film is a film that supports the protective film forming film in a peelable manner. The peeling film may be composed of one layer (single layer) or two or more layers of substrates, and the surface of the substrates may be subjected to a peeling treatment from the viewpoint of controlling peelability. That is, the surface of the base material may be modified, or a material not derived from the base material (release agent layer) may be formed on the surface of the base material.

The substrate is not particularly limited as long as it is a material that can support the protective film forming film before the protective film forming film is attached to the workpiece, and is usually made of a resin-based film (hereinafter referred to as "resin film"). )constitute.

As specific examples of the resin film, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyterephthalene film, Ethylene formate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate copolymer film, ionomer resin film, ethylene-(methyl ) acrylic copolymer film, ethylene-(meth)acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, and the like. In addition, crosslinked films of these resin films can also be used. Furthermore, a laminated film of these resin films may also be used. In the present embodiment, a polyethylene terephthalate film is preferable from the viewpoints of environmental safety, cost, and the like.

The aforementioned resin film may contain various additives such as coloring agents, flame retardants, plasticizers, antistatic agents, lubricants, and fillers.

The release agent layer can be obtained by applying a coating agent containing a composition for a release agent layer on one surface of a substrate, and then drying and curing the coating film. The composition for a release agent layer is not particularly limited as long as it is a material capable of imparting releasability with a protective film forming film to a base material. In this embodiment, as the composition for the release agent layer, for example, alkyd-based release agents, silicone-based release agents, fluorine-based release agents, unsaturated polyester-based release agents, polyolefin-based release agents, etc. are preferable. Molding agent, paraffin type release agent, among them, silicone type release agent is preferred.

The thickness of the release film is not particularly limited, but is preferably 15-100 μm, more preferably 25-80 μm, and more preferably 35-60 μm.

In addition, as shown in FIG. 4, when a peeling film is formed on both main surfaces of the protective film forming film, it is preferable to set the peeling force of one peeling film to be larger as a heavy peeling type peeling film, and set The peeling force of the other peeling film was set to be small as a light peeling type peeling film.

(3. Composite sheet for protective film formation) The composite sheet for protective film formation of this embodiment has the said protective film forming film, and the support sheet which supports a protective film forming film.

The protective film-forming composite sheet of this embodiment is used to attach the protective-film-forming film contained in the protective-film-forming composite sheet to the back surface of the workpiece before singulating the workpiece, and form the protective film into a film. Curing forms a protective film on the workpiece.

Furthermore, when the work on which the protective film is formed (work with the protective film) is singulated by stealth dicing, the support sheet included in the composite sheet for forming the protective film is subjected to a tensile force acting on the modified film. Artifacts in the region are stretched. Finally, a wafer with a protective film can be obtained as a workpiece to be processed.

Therefore, it is preferable that the support sheet has stretchability to a degree that can achieve a predetermined amount of expansion, and can closely adhere to the work to such an extent that the work can be held and tensile force can be transmitted to the work when it is expanded.

Specifically, the support sheet is preferably an adhesive sheet having a base material and an adhesive layer.

The composite sheet 61 for protective film formation shown in FIG. 42, the protective film forming film 10 is laminated on the adhesive layer 42 side of the adhesive sheet 4, and is formed with a diameter smaller than the adhesive layer 42, and the adhesive layer 5 for jigs is laminated on The peripheral portion of the adhesive sheet 4 near the outer side. That is, the adhesive sheet 4 is a supporting sheet. Moreover, the adhesive agent layer 5 for jigs is a layer for adhering the composite sheet 61 for protective film formation to jig|tools, such as a ring frame.

(3.1 Adhesive sheet) In this embodiment, the adhesive sheet which has a base material and an adhesive layer as a support sheet is demonstrated.

(3.1.1 Right angle tear strength ratio) In the present embodiment, when the right-angle tear strength of the support sheet when the support sheet is subjected to the right-angle tear test at 23° C. is TS2, the right-angle tear strength of the protective film forming film after curing at 23° C. The ratio of cracking strength) to TS2, that is, TS1/TS2 is preferably 0.15 or less.

The supporting sheet needs to have such strength that it does not break when expanded. However, the amount of expansion is directly proportional to the force stretching the support sheet. When TS1/TS2 is within the above range, since TS2 is sufficiently larger than TS1, even if the amount of expansion is set larger, the protective film can be reliably divided without breaking the support sheet during expansion. That is, it is possible to cope with a wide range of changes in the amount of expansion, and it is possible to ensure a sufficient margin for the amount of expansion.

TS1/TS2 is more preferably at most 0.125, further preferably at most 0.116.

On the other hand, although the lower limit of TS1/TS2 is not particularly limited, it is preferable from the viewpoint of the selectivity of the material constituting the support sheet and the viewpoint of making the outer peripheral line of the divided protective film a good straight line. It is at least 0.03, more preferably at least 0.06.

When TS1/TS2 is outside the above range, TS2 is low, meaning TS2 is not that large relative to TS1. That is, compared with the case where TS1/TS2 is within the above-mentioned range, it means that the supporting sheet is easily broken when expanded. When the support sheet breaks while expanding, the tensile force becomes unable to act on the protected filmed workpiece, and therefore, most of the protected filmed workpiece cannot be divided. As a result, wafer yields are greatly reduced.

Therefore, a sheet made of a material having a high TS2 is generally used as a support sheet. By making TS2 higher, it is possible to further reduce the risk of the support sheet breaking even if the support sheet is accidentally left in a state where it is more easily broken than usual when using the support sheet. For example, even if the sheet is made of the same material, if there is a flaw on the sheet, it will break starting from the flaw. Therefore, the support sheet will be easily broken when it expands. However, by making TS2 higher and TS1 /TS2 is small, and it is easy to take into account the reduction of the risk of fracture of the support sheet and the good splittability of the protective film. The above-mentioned scratches may be caused by shocks during transportation steps and the like.

When the support sheet is an adhesive sheet having a base material and an adhesive layer, the composition of the base material and the adhesive layer is not particularly limited as long as TS2 of the adhesive sheet satisfies the composition in the range of TS1/TS2.

(3.1.2. Substrate) The base material 41 of the adhesive sheet 4 is generally composed of a film (hereinafter referred to as a resin film) mainly composed of a resin material.

Specific examples of the resin film include polyethylene films such as low-density polyethylene (LDPE) films, linear low-density polyethylene (LLDPE) films, and high-density polyethylene (HDPE) films, polypropylene films, and polybutylene films. , polybutadiene film, polymethylpentene film, ethylene-norbornene copolymer film, norbornene resin film and other polyolefin films; ethylene-vinyl acetate copolymer film, ethylene-(meth)acrylic acid Ethylene-based copolymer films such as copolymer films and ethylene-(meth)acrylate copolymer films; polyvinyl chloride films such as polyvinyl chloride films and vinyl chloride copolymer films; polyethylene terephthalate films, Polyester films such as polybutylene terephthalate films; polyurethane films; polyimide films; polystyrene films; polycarbonate films; fluororesin films, etc. In addition, a modified film such as a crosslinked film of these resin films or an ionomer film can also be used. The above-mentioned base material 41 may be a film composed of one of these resin films, or may be a laminated film obtained by further combining two or more of these resin films. In the present embodiment, a polypropylene film and a polyvinyl chloride film are preferable from the viewpoint of expansibility and right-angle tear strength.

For the purpose of improving the adhesiveness between the above-mentioned resin film and the adhesive layer 42 laminated on the surface of the above-mentioned resin film, one side or both sides of the above-mentioned resin film may be subjected to an oxidation method or a concave-convex method, etc. Surface treatment, or primer treatment. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromating treatment (wet method), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment. Sandblasting, thermal spraying, etc.

The above-mentioned resin film may contain various additives such as a colorant, a flame retardant, a plasticizer, an antistatic agent, a lubricant, and a filler.

The thickness of the base material 41 is not specifically limited as long as it can function suitably in each process which uses the composite sheet for protective film formation. It is preferably in the range of 20-200 μm, more preferably in the range of 40-170 μm, particularly preferably in the range of 50-140 μm.

(3.1.3. Adhesive layer) The adhesive layer 42 included in the adhesive sheet 4 of the composite sheet for forming a protective film according to this embodiment may be composed of a non-energy ray-curable adhesive or an energy ray-curable adhesive. The non-energy ray-curable adhesive is preferably an adhesive having required adhesive force and re-peelability, for example, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane ( urethane) adhesives, polyester adhesives, polyvinyl ether adhesives, etc. Among these, an acrylic adhesive is preferable from the viewpoint of having high adhesion with the protective film forming film 10 and being able to reliably hold a wafer with a protective film during expansion. Moreover, an acrylic adhesive is also preferable from a viewpoint of easy control of the pick-up property of the wafer with a protective film.

On the other hand, since the adhesive force of the energy ray-curable adhesive is lowered by irradiating energy rays, when it is necessary to separate the workpiece or workpiece from the adhesive sheet, it can be easily separated by irradiating the energy ray.

The energy ray-curable adhesive constituting the adhesive layer 42 may contain an energy-ray-curable polymer as a main component, or may contain a non-energy-ray-curable polymer and an energy-ray-curable monomer and/or a low-energy ray-curable adhesive. A mixture of polymers as the main component.

As a polymer having energy ray curability, for example, a (meth)acrylate (co)polymer into which an energy ray curable group has been introduced can be exemplified. As an energy ray curable monomer and/or oligomer, the ester of a polyhydric alcohol and (meth)acrylic acid is mentioned. In addition, the energy ray-curable adhesive may contain additives such as photopolymerization initiators and crosslinking agents in addition to energy ray-curable components.

The thickness of the pressure-sensitive adhesive layer 42 is not particularly limited as long as it can function appropriately in each step of using the composite sheet for protective film formation. Specifically, the thickness of the adhesive layer is preferably 1-50 μm, 2-30 μm, 2-20 μm, 3-10 μm, 3-8 μm.

As the adhesive constituting the adhesive layer 5 for jigs, an adhesive having required adhesive force and re-peelability is preferable, and for example, acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, etc. can be used. Ester adhesives, polyester adhesives, polyvinyl ether adhesives, etc. Among them, an acrylic adhesive is preferable because it has high adhesion to jigs such as a ring frame and can effectively suppress peeling of the protective film-forming composite sheet from the ring frame or the like in a cutting step or the like. Moreover, the base material which is a core material may exist in the middle of the thickness direction of the adhesive agent layer 5 for jigs.

From the viewpoint of adhesiveness to jigs such as ring frames, the thickness of the adhesive layer 5 for jigs is preferably 5 to 200 μm, particularly preferably 10 to 100 μm.

(4. Manufacturing method of protective film forming film and protective film forming sheet) The manufacturing method of the protective film forming film is not specifically limited. The film can be produced using the above-mentioned composition for forming a protective film or a composition obtained by diluting the composition for forming a protective film with a solvent (these two compositions are referred to as "coating agent"). The coating agent can be prepared by mixing the components constituting the protective film-forming composition by a known method.

The obtained coating agent is coated with a coating machine such as a roll coater, a knife coater, a roll coater, an air knife coater, a die coater, a rod coater, a gravure coater, or a curtain coater. It is applied to the release surface of the first release film and dried as necessary to form a protective film-forming film on the first release film.

Next, the peeling surface of the 2nd peeling film was bonded to the exposed surface of the protective film forming film formed on the 1st peeling film, and the sheet|seat for protective film formation shown in FIG. 4 was obtained.

(5. Manufacturing method of composite sheet for protective film formation) The manufacturing method of the composite sheet for protective film formation is not specifically limited. For example, it can be produced by a method of separately producing a first laminate including a protective film-forming film and a second laminate including an adhesive sheet as a support sheet, and then using the first laminate and the second laminate to attach the protective film Form film and adhesive sheet laminate.

The 1st laminated body can be manufactured by the method similar to the said sheet|seat for protective film formation. That is, the protective film forming film is formed on the peeling surface of the 1st peeling film, and the peeling surface of the 2nd peeling film is bonded to the exposed surface of the protective film forming film.

On the other hand, in order to manufacture the second laminate, first, an adhesive composition constituting the adhesive layer, or a composition obtained by diluting the adhesive composition with a solvent (these two compositions are referred to as " coating agent"). Next, a coating agent is applied on the release surface of the third release film, and dried as necessary to form an adhesive layer on the third release film. Then, the substrate was attached to the exposed surface of the adhesive layer to obtain a laminate (second laminate) composed of an adhesive sheet composed of the substrate and the adhesive layer and a third release film.

However, when the adhesive layer is composed of an energy ray-curable adhesive, the adhesive layer may be cured by irradiating the adhesive layer with energy rays at this stage, or may be cured after forming a film laminate with the protective film. . Furthermore, when the adhesive layer is cured after forming a film laminate with the protective film, the adhesive layer may be cured before the dicing step, or may be cured after the dicing step.

As the energy rays, ultraviolet rays, electron beams, and the like are generally used. The irradiation amount of energy rays varies depending on the type of energy rays. For example, when ultraviolet rays are used, the amount of light is preferably 50-1000 mJ/cm ² , and particularly preferably 100-500 mJ/cm ² . In addition, when an electron beam is used, it is preferably about 10 to 1000 krad.

After the first laminate and the second laminate are obtained in the above manner, the second release film in the first laminate is peeled off, and the third release film in the second laminate is peeled off at the same time, and the exposed part of the first laminate is The protective film forming film is bonded to the adhesive layer of the adhesive sheet exposed in the second laminate.

Thus, a composite sheet for forming a protective film is obtained, which is composed of an adhesive sheet on which an adhesive layer is laminated on a base material, a protective film forming film laminated on the adhesive layer side of the adhesive sheet, and a laminated film on the protective film. The first release film on the opposite side to the adhesive sheet forming the film is constituted. After peeling off the 1st peeling film as needed, the adhesive agent layer for clips is formed in the peripheral part of the exposed adhesive agent layer.

(6. Manufacturing method of device) As an example of the manufacturing method using the apparatus for forming a protective film according to this embodiment, a method for obtaining a processed workpiece with a protective film made by attaching a protective film forming film will be described. obtained by singulating the workpiece.

The manufacturing method of the device of this embodiment has at least the following steps 1 to 5. Step 1: a step of attaching the protective film forming film to the back surface of the workpiece; Step 2: curing the attached protective film to form a film, thereby forming a protective film on the back of the workpiece to obtain a workpiece with a protective film; Step 3: focusing the laser on a pre-set area inside the workpiece to form a first modified area; Step 4: Focusing the laser on a pre-set area inside the protective film to form a second modified area; Step 5: applying a tensile force to the workpiece with the protective film formed with the first modified region and the second modified region, thereby singulating the workpiece with the protective film to obtain a plurality of workpieces with the protective film. step of the object.

In addition, step 2 is implemented before step 4. In addition, it is preferable that step 2 is implemented before step 3.

The manufacturing method of the device having the above steps 1 to 5 will be described with reference to the drawings. Hereinafter, a case where the workpiece is a wafer will be described. First, a protective film forming film is attached to the back surface of a workpiece (wafer) (step 1). The protective film-forming film to be attached is not particularly limited, and is preferably, for example, the above-mentioned protective film-forming film.

When the protective film forming film is included in the protective film forming sheet, as shown in FIG. 6A , the protective film forming film 10 of the protective film forming sheet 51 is attached to the back surface of the workpiece 6 (step 1). After sticking, the first release film 21 is peeled off as necessary.

Further, when the protective film forming film is included in the protective film forming composite sheet, as shown in FIG. 6B , the protective film forming film 10 of the protective film forming composite sheet 61 is attached to the wafer 6 as the workpiece (step 1) . At this time, the outer peripheral portion of the adhesive layer 42 can be fixed by the ring frame 7 . In this embodiment, as shown in FIG. 5 , since the adhesive layer 5 for the jig is provided on the outer peripheral portion of the adhesive layer 42 , the adhesive layer 5 for the jig is attached to the ring frame 7 . The protective film forming film 10 is attached to the back surface of the wafer 6 . The adhesive sheet 4 as a support sheet functions as a dicing tape for stealth dicing.

Then, as shown in FIG. 7 , the attached protective film-forming film 10 is cured to form a protective film to obtain a protective film-attached wafer 100 (step 2). When the protective film forming film 10 is thermosetting, the protective film 1 may be formed by heating the protective film forming film 10 at a predetermined temperature for an appropriate time. For example, the heating temperature is preferably 100-200°C, for example, may be any range of 110-180°C and 120-170°C. The heating time is preferably 0.5 to 5 hours, for example, may be in any range of 0.5 to 3 hours and 1 to 2 hours. Moreover, what is necessary is just to form the protective film 1 by making the energy ray inject from the side of the adhesive sheet 4 or the peeling film 21, when the protective film forming film 10 is energy-ray curable. For example, the illuminance of energy rays is preferably 120-280 mW/cm ² , and the light intensity of energy rays is preferably 100-1000 mJ/cm ² .

A support sheet as a dicing tape for stealth dicing is attached to a wafer with a protective film obtained by curing the protective film forming film 10 of the protective film forming sheet 51 shown in FIG. 4 . Support sheets are also attached to the ring frame. As a support sheet, the above-mentioned adhesive sheet can be illustrated. That is, when attaching the adhesive sheet to the wafer with protective film and the ring frame, the adhesive layer 5 for jigs can be omitted from the configuration shown in FIG.

Next, as shown in FIG. 8 , the first modified region A1 is formed by focusing the laser from the laser irradiation device L on the region corresponding to the planned dividing line inside the wafer 6 (step 3). Furthermore, before and after the formation of the first modified region, the laser is focused from the laser irradiation device L on the region corresponding to the planned dividing line inside the protective film 1 to form the second modified region A2 (step 4).

The first modified region and the second modified region are regions whose intensity is lower than that of other regions due to laser irradiation, and cracks are generated along the thickness direction of the wafer or the protective film in these regions. As the laser, for example, a laser in the infrared region can be used.

The formation position of the first modified region is not limited as long as the crack extends when it propagates and the protective film-attached wafer is properly divided. In addition, a plurality of first modified regions may also be formed in the depth direction of the wafer.

By forming the second modified region in the protective film, a portion having lower strength than other portions can be formed in a specific area of the protective film. Therefore, at the time of expansion, the protective film is surely and sufficiently divided from the second modified region as a starting point.

Such a state where a portion having lower strength than other portions is formed in a specific region of the protective film corresponds to a right-angle tear test in which tensile force tends to concentrate on a specific position of the test piece. Therefore, in the present embodiment, by making the right-angle tear strength of the cured protective film-forming film (protective film) in the right-angle tear test within a predetermined range, the division of the workpiece with the protective film at the time of expansion can be made Sex becomes good.

On the contrary, a general tensile test does not correspond to a state where a portion having lower strength than other portions is formed in a specific region of the protective film. Therefore, the tensile strength calculated from the usual tensile test is not directly related to the right-angle tear strength.

In this embodiment, in order to reliably divide the protective film, it is preferable to form the second modified region near the interface between the protective film and the wafer.

As shown in FIG. 9 , the protective film-attached wafer 100 formed with the first modified region and the second modified region is singulated by expanding E (step 5 ). Singulation of the wafer with a protective film can be performed by stretching the base material 41 of the adhesive sheet 4 so that a tensile force acts on the wafer with a protective film. The tensile stress inside the wafer with a protective film 100 is generated by this tensile force, so that the cracks formed in the first modified region and the second modified region extend to both sides of the wafer with a protective film 100 . main face. Finally, the protective film-attached wafer is divided into a plurality of small pieces (singulated) along the planned dividing line, and the protective film-attached wafer 100a as a workpiece can be obtained.

Stretching may be cold stretching performed at a temperature lower than normal temperature (23° C.). In this embodiment, even if stretching is performed at normal temperature, the splittability of the workpiece with a protective film can be improved.

In addition, in this embodiment, by setting the right-angle tear strength of the cured protective film-forming film (protective film) in the right-angle tear test within a predetermined range, it is possible to suppress the expansion due to impact on the protective film or the like. before accidentally splitting the protective film. As a result, the outer peripheral line of the divided protective film becomes a straight line, and defects in the shape of the protective film can be suppressed.

After the expansion, in order to shrink the stretched and loosened area due to the expansion, the area of the adhesive sheet may be subjected to heat treatment (heat shrinkage). Then, as shown in FIG. 10 , the wafer with the protective film is picked up from the adhesive sheet by a vacuum nozzle or the like to recover it.

The picked-up wafer with protective film can be transported to the next step, or temporarily stored in a tray, tape, etc., and transported to the next step after a predetermined period of time.

The wafer with protective film 100a transported to the next step is mounted on a substrate to manufacture a semiconductor device.

(7. Variations) In addition, a release film may be laminated on the surface of the protective film-forming composite sheet 61 on the protective-film-forming film 10 side to protect the protective-film-forming film before use.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment at all, It can change in various forms within the range of this invention. Example

Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited to these Examples.

(Production of sheet for protective film formation) Using the following coating agent containing the composition for protective film formation, the sheet|seat for protective film formation was produced as follows.

(Coating agent containing protective film-forming film composition) The following components were mixed according to the composition ratio (solid content conversion) shown in Table 1, and diluted with methyl ethyl ketone so that the solid content concentration was 50% by mass to prepare a coating containing the composition for forming a protective film. Cloth agent. (A) Polymer composition (A-1): (meth)acrylic acid copolymerized by 55 parts by mass of n-butyl acrylate, 10 parts by mass of ethyl acrylate, 20 parts by mass of glycidyl methacrylate and 15 parts by mass of 2-hydroxyethyl acrylate Ester copolymer (weight average molecular weight: 800,000, glass transition temperature: -31°C) (A-2): (meth)acrylate copolymerized by 10 parts by mass of ethyl acrylate, 70 parts by mass of methyl acrylate, 5 parts by mass of glycidyl methacrylate and 15 parts by mass of 2-hydroxyethyl acrylate Copolymer (weight average molecular weight: 400,000, glass transition temperature: 4°C) (B) Curable component (thermosetting component) (B-1) Mixture of liquid bisphenol A epoxy resin and acrylic rubber particles (manufactured by NIPPON SHOKUBAI CO., LTD., BPA328, epoxy equivalent 235g/eq) (B-2) bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER1055, epoxy equivalent is 800~900g/eq) (B-3) Dicyclopentadiene-type epoxy resin (manufactured by DIC CORPORATION, EPICLON HP-7200HH, softening point: 88-98° C., epoxy equivalent: 274-286 g/eq) (C) Curing agent: Dicyandiamide (manufactured by ADEKA CORPORATION, ADEKA HARDENER EH-3636AS, thermoactive latent epoxy resin curing agent, active hydrogen content is 21g/eq) (D) Curing accelerator: 2-phenyl-4,5-dimethylimidazole (manufactured by SHIKOKU CHEMICALS CORPORATION, CUREZOL 2PHZ-PW) (E) Filling material (E-1) Epoxy-modified spherical silica filler (manufactured by Admatechs, SC2050MA, with an average particle diameter of 0.5 μm) (E-2) Amorphous silica filler (manufactured by TATSUMORI LTD., SV-10, with an average particle diameter of 8 μm) (F) Coupling agent: epoxy group-containing oligomer type silane coupling agent (manufactured by Mitsubishi Chemical Corporation, MKC Silicate MSEP2) (G) Coloring agent: carbon black (manufactured by Mitsubishi Chemical Corporation, MA-600B, average particle diameter of 20 nm)

A first release film (manufactured by LINTEC Corporation, SP-PET502150) in which a silicone-based release agent layer was formed on one side of a polyethylene terephthalate (PET) film having a thickness of 50 μm was prepared. In addition, a second release film (manufactured by LINTEC Corporation, SP-PET381031) in which a silicone-based release agent layer was formed on one side of a polyethylene terephthalate (PET) film having a thickness of 38 μm was prepared.

The prepared coating agent containing the protective film-forming film composition was applied to the release-treated surface of the first release film, and dried at 100° C. for 2 minutes to form a protective film-forming film with a thickness of 25 μm. Next, the second release film was attached to the protective film forming film to obtain a three-layer sheet for protective film formation in which the release film was laminated on both surfaces of the protective film forming film. The sticking conditions of the second peeling film were: temperature 60° C., pressure 0.4 MPa, speed 1 m/min.

The following measurement and evaluation were performed using the obtained sheet|seat for protective film formation.

(Right-angle tear strength and elongation at break of protective film forming film after curing) The respective second release films of the obtained two protective film-forming sheets were peeled off, and the exposed surfaces of the protective film-forming films (surfaces on which the first release film was not formed) were attached to each other, and one of the first release films was peeled off to obtain A laminate in which two protective films are laminated on the other first release film forms a film. Further, the exposed surface of the protective film-forming film from which the second peeling film was peeled off from another protective film-forming sheet is formed with the protective film of the laminate in which two protective film-forming films are laminated on the first peeling film. The exposed surface of the film is attached, and the first release film of the other protective film forming sheet is peeled off. This operation was repeated twice, and a total of four protective film forming films were laminated to produce a laminate in which the first release film, the protective film forming film having a thickness of 100 μm, and the first release film were sequentially laminated.

In addition, when the protective film forming film is 25 μm, the thickness of the laminated protective film forming film is preferably 100 μm. The thickness of the formed film was set at 95 to 120 μm.

This laminate was heated and cured at 130° C. for 2 hours in an air atmosphere to obtain a laminate in which the first release film was laminated on both surfaces of the cured protective film forming film laminated thereon.

Using a dumbbell-shaped cutter (Super Dumbbell Cutter) (manufactured by DUMBBELL CO., LTD, SDBK-1000), according to the dimensions of the rectangular tear test piece recorded in JIS K 7128-3:1998, the obtained laminated The laminate in which the first release film was laminated on both surfaces of the cured protective film forming film was die-cut. The shape of the rectangular tear test piece is the shape shown in FIG. 2 in JIS K 7128-3:1998.

The first peeling films on both surfaces were removed from the obtained right-angle tear test piece, and a right-angle tear test was implemented at a test temperature of 23° C. using a universal tensile tester (manufactured by Shimadzu Corporation, AG-IS). In the right-angle tear test, the test length (clamp distance) of the right-angle tear test piece before the test was set to 60 mm, the tensile speed was set to 10 mm/min, and the sampling time was set to 10 ms.

The right-angle tear strength (TS1: N/mm) at 23°C is obtained by dividing the maximum tensile force (N) until the test piece breaks by the thickness of the right-angle tear test piece before the test (0.1mm (=100μm) )) and calculated. In addition, the elongation (%) at break at 23° C. was calculated by the following formula when the elongation of the test piece at break was ΔL based on the start of stretching. The results are shown in Table 1. Elongation at break=(ΔL/test length (60mm) of the rectangular tear test piece before the test)×100

(manufacturing of support sheet) As a support sheet, the adhesive sheet (dicing tape for stealth dicing) which has a base material and an adhesive layer was produced as follows. In this embodiment, two types of support sheets, the support sheet A and the support sheet B, are produced.

(Production of Support Sheet A) The following components (h) and (i) were mixed, diluted with methyl ethyl ketone so that the solid content concentration became 25 mass %, and the coating agent containing the composition for adhesive layer was prepared. (h) Adhesive main agent: (meth)acrylate copolymer obtained by copolymerizing 80 parts by mass of 2-ethylhexyl acrylate, 10 parts by mass of methyl methacrylate and 10 parts by mass of 2-hydroxyethyl acrylate (Weight average molecular weight: 600,000, glass transition temperature: -55°C) 100 parts by mass (i) Crosslinking agent: 15 parts by mass of xylylene diisocyanate adduct of trimethylolpropane (manufactured by MITSUI TAKEDA CHEMICALS, INC, TAKENATE D110N)

As a base material, a polypropylene film (thickness: 80 μm) having a no-load stretch rate of 99% in the MD direction/99% in the CD direction, a tensile modulus of 290 MPa in the MD direction/270 MPa in the CD direction, and a melting point of 138° C. was prepared.

The prepared coating agent containing the adhesive layer composition was coated on a release film (SP-PET381031 manufactured by LINTEC Corporation) with a thickness of 38 μm, and dried at 100° C. for 2 minutes to form an adhesive layer with a thickness of 5 μm. agent layer. Then, the support sheet A is obtained by attaching the adhesive layer and the base material.

(Production of support sheet B) The following components (j) to (l) were mixed and diluted with methyl ethyl ketone so that the solid content concentration became 25% by mass to prepare a coating agent containing the composition for an adhesive layer. (j) Adhesive main agent: (meth)acrylate obtained by copolymerizing 22 parts by mass of 2-ethylhexyl acrylate, 73 parts by mass of vinyl acetate, 1 part by mass of acrylic acid and 4 parts by mass of methyl methacrylate Copolymer (weight average molecular weight: 600,000, glass transition temperature: 6°C) 100 parts by mass (k) urthane acrylate (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., SEIKABEAM14-29B) 110 parts by mass (l) Crosslinking agent: 5 parts by mass of trimethylolpropane toluene diisocyanate adduct (manufactured by TOSOH CORPORATION, Coronate L)

As a base material, a vinyl chloride resin film (manufactured by ACHILLES CORPORATION, PVC80, thickness 80 μm) was prepared.

The prepared coating agent containing the adhesive layer composition was coated on a release film (manufactured by LINTEC Corporation, SP-PET381031) with a thickness of 38 μm, and dried at 100° C. for 2 minutes to form a 5 μm-thick release film. Adhesive layer. Then, the support sheet B is obtained by pasting the adhesive layer and the base material.

(right-angle tear strength of support sheet) In the same manner as in the right-angle tear test of the cured protective film-forming film, the obtained support sheet was punched into the shape of a right-angle tear test piece to prepare a test piece. However, the lamination|stacking of several support sheets was not performed. The peeling film was removed from the prepared test piece in the same manner as the right-angle tear test of the cured protective film-forming film, and the right-angle tear strength (TS2) of the support sheet was measured. The results are shown in Table 1.

(extended test) Using an attachment device (manufactured by LINTEC Corporation, RAD-3600F/12), set the temperature of the adsorption table of the workpiece to 70°C, and cut the protective film of the sheet for forming a protective film that has the same shape as the silicon wafer The exposed surface formed by peeling off the second release film forming the film was attached to a workpiece made of a silicon wafer having a thickness of 100 μm and an outer diameter of 8 inches. After the first release film was peeled off, it was heated in an oven (in the atmosphere) at 130° C. for 2 hours to be cured to produce a wafer with a protective film.

Then, the dicing tape for stealth dicing (support sheet A or support sheet B) prepared above was attached to the protective film surface of the wafer with protective film using an attaching device (manufactured by LINTEC Corporation, RAD-2700F/12). At this time, the dicing tape was also attached to the ring frame for the 8-inch wafer. A laser irradiation device (manufactured by DISCO CORPORATION, DFL7361) was used to irradiate laser light (wavelength: 1064 nm) through a dicing tape so as to focus on the inside of the wafer and the interface between the protective film and the wafer. At this time, irradiation was performed while scanning along planned dividing lines set so as to form a wafer body of 5 mm×5 mm, to form modified regions (first modified region and second modified region).

Then, using a spreading device (manufactured by DISCO CORPORATION, DDS2300), in an environment at a temperature of 23°C, at a speed of 100mm/sec, and under the conditions of the spreading amount shown in Table 1, close contact with the wafer with a protective film was carried out. Fitting extensions for dicing tape.

The case of using a support sheet without scratches and the case of using a support sheet with a scratch of 5 mm in length and 10 μm in depth on the surface of the substrate assuming that scratches may occur during transportation are used. , to implement the extended test.

In the extension test, the case where the protective film and the wafer were 100% divided into wafers with a protective film was judged to be good in divisibility, and the case where the protective film and wafer were not 100% divided was judged to be unacceptable in divisibility. The results are shown in Table 1.

In addition, when the outer peripheral line of the divided protective film is straight, it is judged that the outer peripheral shape is good, and when a wafer with a protective film in which the outer peripheral line of the divided protective film is not straight is generated, it is judged that the outer peripheral shape is unacceptable. . The results are shown in Table 1.

In addition, evaluation was performed on whether or not the supporting sheet was cracked during expansion. The results are shown in Table 1.

[Table 1] Example 1A Example 2A Example 2B Example 2C Example 3A Example 3B Example 3C Comparative Example 1A Comparative Example 1B Comparative Example 1C Comparative Example 2A Comparative Example 3A Proportion of protective film forming film polymer composition A-1 19 19 - 19.8 19.9 8 A-2 - - 26 - - - epoxy resin B-1 11.2 11.2 10.4 11.2 11.2 6.2 B-2 2 2 1.7 2 2 1 B-3 5.6 5.6 5.2 5.6 5.6 2.6 Hardener C 0.5 0.5 0.47 0.05 - 0.45 curing accelerator D. 0.4 0.4 0.37 0.05 - 0.45 Filler E-1 6 6 55.4 6 6 26 E-2 54.8 54.8 - 54.8 54.8 54.8 Coupler f 0.4 0.4 0.36 0.4 0.4 0.4 Colorant G 0.1 0.1 0.1 0.1 0.1 0.1 Cured protective film forms a film (protective film) Tear strength (N/mm): TS1 15.28 15.28 19.45 18.65 19.73 8.41 Elongation at break (%) 0.46 0.46 6.59 58.34 61.21 0.39 support sheet type Support piece A Support piece B Support piece A Support piece B Support piece A Support piece A Tear strength (N/mm): TS2 169 118 169 118 169 169 Tear strength ratio: TS1/TS2 0.090 0.129 0.115 0.158 0.117 0.050 Characteristic evaluation Expansion 10mm 10mm 15mm 20mm 10mm 15mm 20mm 10mm 15mm 20mm 10mm 10mm Separation good good good good good good good unqualified unqualified unqualified unqualified good Peripheral shape after division good good good good good good good good good good good unqualified Cracking of support sheet (with scars) none none none have none none none none none have none none Cracking of support sheet (without scars) none none none none none none none none none none none none

As can be seen from Table 1, when the right-angle tear strength and elongation at break of the cured protective film forming film are within the above ranges, the splittability of the workpiece with the protective film and the outer peripheral shape of the protective film at the time of expansion in stealth dicing can be seen. for good. On the other hand, it was also confirmed that when the right-angle tear strength and the elongation at break of the cured protective film-forming film are outside the above-mentioned ranges, the splittability and the outer peripheral shape of the protective film are poor.

1: Protective film 5: Adhesive layer for fixture 51: Sheet for protective film formation 6: Workpiece 6a: Wafer 6b: Convex electrode 10: Protective film forming film 10a, 10b: main surface 21: The first release film 22: Second release film 61: Composite sheet for protective film formation 4: Adhesive sheet 41: Substrate 42: Adhesive layer 7: Ring frame 100: Work piece with protective film 100a: wafer with protective film 101a: undivided wafer with protective film 102a: wafer with protective film 200: split schedule line A1: The first modified area A2: The second modified area E: extension L: Laser irradiation device III: Direction

1 is a schematic cross-sectional view of an example of a work with a protective film in which a protective film obtained by curing the protective film-forming film of this embodiment is formed on the back surface of the work. FIG. 2 is a schematic cross-sectional view of an assembly of wafers with a protective film obtained by singulating workpieces with a protective film. 3 is a schematic partial plan view of an aggregate of singulated protective film-attached wafers viewed from the III direction shown in FIG. 2 . Fig. 4 is a schematic cross-sectional view of an example of the sheet for forming a protective film according to the present embodiment. Fig. 5 is a schematic cross-sectional view of an example of the composite sheet for forming a protective film according to the present embodiment. 6A is a schematic cross-sectional view for explaining the step of attaching the sheet for forming a protective film according to the present embodiment to the back surface of a workpiece. 6B is a schematic cross-sectional view for explaining the step of attaching the composite sheet for forming a protective film according to the present embodiment to the back surface of a workpiece. 7 is a schematic cross-sectional view illustrating a step of forming a protective film by curing the protective film-forming film attached to the back surface of the workpiece. 8 is a schematic cross-sectional view for explaining the step of forming a modified region inside the workpiece and inside the protective film. FIG. 9 is a schematic cross-sectional view for explaining a step of expanding a workpiece with a protective film on which a modified region is formed. 10 is a schematic cross-sectional view for explaining a step of picking up a wafer with a protective film from an aggregate of wafers with a protective film that have been singulated.

1: Protective film

5: Adhesive layer for fixture

6: Workpiece

6b: Convex electrode

61: Composite sheet for protective film formation

4: Adhesive sheet

41: Substrate

42: Adhesive layer

7: Ring frame

100: Work piece with protective film

A1: The first modified area

A2: The second modified area

L: Laser irradiation device

Claims (9)

A protective film-forming film that becomes a protective film after curing, wherein the right-angle tear strength is 10 N/mm when the cured protective film-forming film is subjected to a right-angle tear test at 23° C. The above, and in this right-angle tear test, the elongation at the time of rupture of the cured protective film-forming film is 10% or less. The protective film forming film according to claim 1, wherein the protective film is a thermally cured or energy ray cured product. The protective film forming film according to claim 1 or 2, wherein the right-angle tear strength is 25 N/mm or less. The protective film forming film according to any one of claims 1 to 3, which is used to form a modified region by focusing laser light on the protective film. A sheet for forming a protective film comprising the protective film forming film according to any one of claims 1 to 4, and a release film disposed on at least one main surface of the protective film forming film so as to be peelable. A composite sheet for forming a protective film, comprising the protective film forming film according to any one of claims 1 to 4, and a support sheet supporting the protective film forming film. The composite sheet for forming a protective film according to claim 6, wherein the right-angle tear strength of the protective film-forming film after curing at 23°C is set to TS1, and the support sheet is subjected to a right-angle tearing strength at 23°C. When the right-angle tear strength of the said support sheet at the time of a tear test is made into TS2, TS1/TS2 is 0.15 or less. A method of manufacturing a device, comprising: a step of attaching a protective film forming film to the back surface of the workpiece; The attached protective film forming film is solidified to form a protective film on the back side of the workpiece to obtain a workpiece with a protective film; Focusing the laser on a pre-set area inside the aforementioned workpiece, thereby forming a step of the first modified area; Focusing the laser on a predetermined area inside the protective film to form a second modified area; and A tensile force is applied to the workpiece with a protective film on which the first modified region and the second modified region are formed, thereby singulating the workpiece with a protective film to obtain a plurality of processed workpieces with a protective film A step of. The method for manufacturing a device according to claim 8, wherein the protective film forming film is the protective film forming film included in the protective film forming sheet according to claim 5, or the protective film according to claim 6 or 7. A protective film forming film included in the composite sheet is formed.

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